tag:theconversation.com,2011:/us/topics/x-ray-9721/articles
X-ray – The Conversation
2024-02-06T22:11:32Z
tag:theconversation.com,2011:article/222058
2024-02-06T22:11:32Z
2024-02-06T22:11:32Z
Proton beam therapy: A modern treatment for cancer, but not in Canada (yet)
<p>Radiation is a targeted form of cancer treatment used for up to <a href="https://doi.org/10.1200/jco.2014.32.30_suppl.48">half of all patients with cancer</a>. Most radiation treatments are delivered using focused X-rays. Because X-rays travel through tissues, this can lead to extra exposure to radiation for healthy organs and tissue. </p>
<p>Proton beam therapy is a more precise treatment that can better focus radiation on a cancer, <a href="https://doi.org/10.1503/cmaj.190008">reducing the side-effects</a> of treatment. However, proton therapy is not available in Canada. Currently, Canadians do not have easy access to this key cancer treatment.</p>
<p>The benefits of proton therapy are especially important for <a href="https://doi.org/10.1016/j.ctrv.2021.102209">children, teenagers and young adults</a> with cancer, as they can live a long time when cured of their cancer. For example, medulloblastoma is an aggressive brain cancer seen in young people. This type of cancer is usually treated with radiation to the brain and spine, which has risks for cognitive impairment. </p>
<p>For these patients, proton therapy reduces radiation exposure to other organs, including <a href="https://doi.org/10.1016/j.ijrobp.2023.11.035">the brain</a>, as well as to <a href="https://doi.org/10.1093/neuonc/nov302">the thyroid</a>, chest, abdomen and pelvis. This leads to <a href="https://doi.org/10.1200/jco.19.01706">better cognitive function</a> and <a href="https://doi.org/10.1016/j.adro.2023.101189">fewer long-term side-effects</a> among patients who receive proton therapy compared to X-ray (photon) treatment.</p>
<p>Although proton therapy is more expensive to deliver than photon radiation, studies have shown <a href="https://doi.org/10.1002/cncr.28322">long-term cost-effectiveness</a> of proton beam therapy for medulloblastoma. <a href="https://doi.org/10.1001/jamaoncol.2019.4889">In a study</a> of more than 1,000 adults with other types of locally advanced cancer, proton therapy led to fewer unplanned hospitalizations.</p>
<p>Canadian guidelines suggest <a href="https://doi.org/10.1016/j.radonc.2022.10.004">many other cancers</a> would benefit from proton therapy, including some types of brain, head-and-neck and soft-tissue tumours. In addition, <a href="https://doi.org/10.3389/fonc.2023.1133909">ongoing studies</a> are evaluating proton therapy for other body sites, such as prostate and breast cancer.</p>
<p>At present, Canada is the <a href="https://www.ptcog.site/index.php/facilities-in-operation-public">only G7 nation</a> without a medical proton therapy facility. In contrast, many facilities are available across the continental <a href="https://doi.org/10.1016/j.ijrobp.2023.12.041">United States</a>. </p>
<p>Patients in the United Kingdom <a href="https://doi.org/10.1016/j.ijrobp.2023.06.688">gained public access</a> to proton therapy in 2018. <a href="https://doi.org/10.1111/1754-9485.13614">Australia is building</a> a facility that is expected to open in 2025. Other regions and countries with access to proton therapy include 13 countries <a href="https://doi.org/10.1016/j.radonc.2021.12.004">in Europe</a>, <a href="https://doi.org/10.3389/fonc.2022.819905">China</a>, <a href="https://doi.org/10.1093/jjco/hyw102">Japan</a>, <a href="https://doi.org/10.4143/crt.2021.409">South Korea</a>, <a href="https://doi.org/10.1111/iwj.13897">Taiwan</a>, <a href="https://doi.org/10.1200/GO.20.00319">India</a>, <a href="https://doi.org/10.15537%2Fsmj.2019.9.24496">Saudi Arabia</a>, <a href="https://doi.org/10.1007/978-981-10-9035-6_108">Singapore</a> and <a href="https://doi.org/10.1186/s13063-022-06822-8">Thailand</a>.</p>
<h2>Canadian patients need to travel for treatment</h2>
<p>As cancer doctors, we routinely recommend proton beam therapy for many of our young patients who have curable cancers. Researchers in the U.K. estimate that up to <a href="https://doi.org/10.1259/bjr.20211175">15 per cent</a> of all patients with curable cancers may benefit from proton therapy. However, without a domestic facility, Canadians who need proton beam therapy must travel <a href="https://doi.org/10.1016/j.ijrobp.2022.12.021">out-of-country</a> to receive this medically necessary treatment for their cancer.</p>
<p>Although many provinces will cover the costs of treatment with special application, treatment outside of Canada introduces many <a href="https://doi.org/10.1186/s12913-021-06701-z">barriers to care</a>. These include: </p>
<ul>
<li>Delays in review and approval by provincial insurance; </li>
<li>Lack of funding for travel, hotels or meals in some provinces; </li>
<li>Not having a Canadian passport or foreign visa; </li>
<li>Illness after cancer surgery preventing one from leaving the country; and</li>
<li>Inability to take time away from work due to financial hardship. </li>
</ul>
<p>Patients who are able to travel out-of-country <a href="https://onlinelibrary.wiley.com/doi/10.1002/jmrs.721">report high levels of stress and feelings of isolation</a>. Many of these concerns would be reduced with a domestic, Canadian proton therapy facility.</p>
<h2>Progress toward Canadian facilities</h2>
<p>In 2016, <a href="https://www.newswire.ca/news-releases/quebec-based-cdl-laboratories-to-build-70-m-state-of-the-art-proton-therapy-cancer-centre-in-montreal-the-first-of-its-kind-in-canada-691462591.html">Québec announced</a> a partnership with a private health-care company to build a standalone proton therapy facility in Montréal. </p>
<figure class="align-center ">
<img alt="A person with lying on a table with a net-like structure over their head" src="https://images.theconversation.com/files/573846/original/file-20240206-26-k3dis6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/573846/original/file-20240206-26-k3dis6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/573846/original/file-20240206-26-k3dis6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/573846/original/file-20240206-26-k3dis6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/573846/original/file-20240206-26-k3dis6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/573846/original/file-20240206-26-k3dis6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/573846/original/file-20240206-26-k3dis6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The benefits of proton therapy — such as lower risk of cognitive impairment — are especially important for children, teenagers and young adults with cancer, as they can live a long time when cured of their cancer.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>However, <a href="https://doi.org/10.1503/cmaj.73445">there were concerns</a> about the costs of a private-public partnership, as well as the ability of such a facility to care for complex patients, such as sick children with cancer. The favourable financial impact of a provincial proton unit within the public system has been <a href="https://muhc.ca/sites/default/files/annual_reports/2019/trauma/Report_number_85_2019-05-muhc-trauma.pdf">evaluated</a> at the McGill University Health Centre, and the Québec Ministry of Health has shown renewed interest in such an initiative.</p>
<p>It is recognized that the per-patient cost to deliver proton therapy <a href="https://www.hqontario.ca/Portals/0/Documents/evidence/reports/hta-proton-beam-therapy-for-cancer-in-children-and-adults.pdf">would be less</a> if a Canadian facility were available. In 2022, the <a href="https://news.ontario.ca/en/release/1001920/ontario-building-a-stronger-more-resilient-university-health-network">Ontario government announced</a> public funding to plan and design a proton therapy facility in Toronto; planning work is ongoing. </p>
<p>Cancer Care Alberta recently released <a href="https://www.albertahealthservices.ca/assets/info/hp/cancer/if-hp-cancer-guide-rt002-proton-beam-RT.pdf">provincial guidelines</a> outlining patients suitable for proton therapy. Concurrently, a charitable group has <a href="https://edmonton.ctvnews.ca/mike-stelter-back-from-u-s-cancer-treatment-with-goal-to-bring-therapy-to-canada-1.6689620">expressed interest in fundraising</a> for a proton facility in Edmonton.</p>
<p><a href="https://doi.org/10.1016/j.ijrobp.2022.12.021">Canadian doctors</a> <a href="https://www.thestar.com/politics/experts-national-parents-group-call-for-specialized-proton-therapy-clinic-in-canada/article_0f66ad2c-8c6b-5783-9a7e-ad304deb1246.html">and patients</a> eagerly await the day when a cancer patient can receive this advanced treatment without travelling out of country. </p>
<p>Having access to proton therapy would also allow Canadian researchers to collaborate globally in scientific studies. It would prevent Canada from falling behind with state-of-the-art treatments, and allow us to join other nations around the world in being able to offer this key treatment against cancer.</p>
<p><em>This article was co-authored by Dr. Carol Oliveira. She is a radiation oncologist working at the Cedars Cancer Centre, McGill University Health Centre, in Montréal, Québec.</em></p><img src="https://counter.theconversation.com/content/222058/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Derek Tsang receives research grant funding from ACCESS (<a href="https://accessforkidscancer.ca">https://accessforkidscancer.ca</a>), the Brain Tumour Foundation of Canada, and the US National Cancer Institute. Tsang also received travel funding from Mevion Medical Systems in 2022.</span></em></p>
Proton beam therapy is a precise form of radiation that can reduce the side-effects of cancer treatment. It is available around the world, but not in Canada.
Derek Tsang, Associate Professor, Department of Radiation Oncology, University of Toronto
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/209041
2023-07-16T20:00:42Z
2023-07-16T20:00:42Z
Why do I have to take my laptop out of the bag at airport security?
<figure><img src="https://images.theconversation.com/files/537438/original/file-20230714-15-diyhpf.jpeg?ixlib=rb-1.1.0&rect=69%2C688%2C5742%2C2884&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"></span> </figcaption></figure><p>Anyone who has travelled by air in the past ten years will know how stressful airports can be.</p>
<p>You didn’t leave home as early as you should have. In the mad rush to get to your gate, the security screening seems to slow everything down. And to add insult to injury, you’re met with the finicky request: “laptops out of bags, please”.</p>
<p>But what does your laptop have to do with security?</p>
<h2>The day that changed air travel forever</h2>
<p>Airport security changed dramatically after the terrorist attacks in the US on September 11 2001. Before 9/11, you could pass through security with a carry-on bag full of everything you might need for your holiday, <a href="https://www.npr.org/2021/09/10/1035131619/911-travel-timeline-tsa">including a knife</a> with a four-inch blade. Indeed, that’s how the 9/11 attackers brought their <a href="https://www.npr.org/2021/09/10/1035131619/911-travel-timeline-tsa">weapons on board</a>.</p>
<p>After 9/11, screening processes around the world changed overnight. In the US, private security contractors being paid a minimum wage were swapped out for a federalised program with highly trained security personnel. Anything that could be <a href="https://www.frontiersin.org/articles/10.3389/fnhum.2013.00654/full">considered a weapon</a> was confiscated.</p>
<p>Around the world, travellers were suddenly required to <a href="https://books.google.com.au/books?hl=en&lr=&id=6hBnJ-1hRp0C&oi=fnd&pg=PA86&dq=why+do+I+have+to+take+my+shoes+off+at+airport+security&ots=o6JIFHJzF1&sig=B6azb6xqN2uxM9CP-VZdfyt3Ag0#v=onepage&q=why%20do%20I%20have%20to%20take%20my%20shoes%20off%20at%20airport%20security&f=false">remove their shoes</a>, belts and outerwear, and take out their phones, laptops, liquids and anything else that could be used as part of an improvised explosive device.</p>
<p>This lasted for several years. Eventually, <a href="https://www.sciencedirect.com/science/article/pii/S2212478013000944">more advanced</a> screening methods were developed to effectively identify certain threats. Today, some countries don’t require you to remove your shoes when passing through security.</p>
<p>So why must you still take your laptop out? </p>
<h2>Airport scanners have come a long way</h2>
<p>The machine your bags and devices pass through is an X-ray machine. </p>
<p>The main reason you have to remove your laptop from your bag is because its <a href="https://www.smh.com.au/traveller/reviews-and-advice/why-do-i-have-to-remove-my-laptop-from-my-bag-at-the-airport-xray-machine-20170320-gv1vqs.html">battery</a> and other mechanical components are too dense for X-rays to penetrate effectively – especially if the scanning system is old. The same goes for power cords and other devices such as tablets and cameras.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/537439/original/file-20230714-21-x0ojbc.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/537439/original/file-20230714-21-x0ojbc.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/537439/original/file-20230714-21-x0ojbc.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/537439/original/file-20230714-21-x0ojbc.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/537439/original/file-20230714-21-x0ojbc.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/537439/original/file-20230714-21-x0ojbc.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/537439/original/file-20230714-21-x0ojbc.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/537439/original/file-20230714-21-x0ojbc.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Due to the size and construction of components in your laptop, X-rays can’t penetrate them as well as other materials.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>With these items in your bag, security officials can’t use the screened image to determine whether a risk is present. They’ll have to flag the bag for a physical search, which slows everything down. It’s easier if all devices are removed in the first place.</p>
<p>A laptop inside a bag can also shield other items from view that may be dangerous. Scanning it separately reveals its internal components on the screen. In some cases you might be asked to turn it on to prove it’s an actual working computer.</p>
<p>With newer multi-view scanning technology, security officials can view the bag from multiple angles to discern whether something is being covered up, or made to look like something else. For instance, people have tried to <a href="https://www.sciencedirect.com/science/article/pii/S2212478013000944">mix gun parts</a> with other components in an effort to pass checked baggage screening. </p>
<p>Some airports have upgraded <a href="https://www.smh.com.au/traveller/inspiration/no-more-removing-liquids-and-gels-laptops-at-melbourne-airport-as-new-scanners-installed-20191002-h1ijdf.html">3D scanning</a> that allows travellers to pass their bags through security without having to remove their laptops. If you’re not asked to take out your laptop, it’s probably because one of these more expensive systems is being used.</p>
<p>Nonetheless, amping up the technology won’t remove the lag caused by airport screenings. Ultimately, the reason these are a major choke point is because of the speed at which staff scan the imagery (which dictates the <a href="https://www.sciencedirect.com/science/article/pii/S2212478013000944">speed of the conveyor belt</a>).</p>
<p>Unless we find a way to automate the entire process and run it with minimal human supervision, you can expect delays.</p>
<h2>What about body scanners?</h2>
<p>But your bags aren’t the only thing getting scanned at airport security. You are too! </p>
<p>The tall frame you walk through is a <a href="https://science.howstuffworks.com/transport/flight/modern/airport-security3.htm">metal detector</a>. Its purpose is to uncover any weapons or other illegal objects that may be concealed under your clothes. Airport metal detectors use non-ionising radiation, which means they don’t emit X-rays. </p>
<p>The larger body scanners, on the other hand, are a type of X-ray machine. These can be <a href="https://www.sciencedirect.com/science/article/pii/S2212478013000944">active or passive</a>, or a combination of both.</p>
<p>Passive scanners simply detect the natural radiation emitted by your body and any objects that might be concealed. Active scanners emit low-energy radiation to create a scan of your body, which can then be analysed. </p>
<p>The kind of machine you walk through will depend on where in the world you are. For instance, one type of active body scanner that emits X-rays in what’s called “backscatter technology” was once <a href="https://electronics.howstuffworks.com/gadgets/high-tech-gadgets/backscatter-x-ray.htm">used widely</a> in the US, but is no longer used. It’s also banned in <a href="https://www.homeaffairs.gov.au/about-us/what-we-do/travelsecure/passenger-screening">Australia</a> and <a href="https://www.forbes.com/sites/daviddisalvo/2011/11/15/europe-bans-airport-body-scanners-over-health-and-safety-concerns/">the European Union</a>, where only non-ionising technology can be used.</p>
<p>Another type of scanner emits lower-energy <a href="https://science.howstuffworks.com/backscatter-machines-vs-millimeter-wave-scanners.htm">millimetre waves</a>, instead of X-rays, to image the passenger. Millimetre wave frequencies are considered to be non-ionising radiation.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/537440/original/file-20230714-27-gwwiup.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/537440/original/file-20230714-27-gwwiup.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/537440/original/file-20230714-27-gwwiup.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/537440/original/file-20230714-27-gwwiup.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/537440/original/file-20230714-27-gwwiup.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/537440/original/file-20230714-27-gwwiup.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/537440/original/file-20230714-27-gwwiup.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/537440/original/file-20230714-27-gwwiup.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Millimetre wave scanners usually produce a 3D scan of a person.</span>
<span class="attribution"><span class="source">Wikimedia</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/air-travel-exposes-you-to-radiation-how-much-health-risk-comes-with-it-78790">Air travel exposes you to radiation – how much health risk comes with it?</a>
</strong>
</em>
</p>
<hr>
<h2>AI in our airports</h2>
<p>AI seems to be all around us lately, and our airports are no exception. Advancements in AI systems stand to transform the future of airport security.</p>
<p>For now, human reviewers are required to identify potential threats in scanned images. However, what if an advanced <a href="https://thinkspace.csu.edu.au/artiificialintelligenceinsecuritycheck/article/">AI was trained</a> to do this using a database of images? It would do so in a fraction of the time.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/whats-the-safest-seat-on-a-plane-we-asked-an-aviation-expert-198672">What's the safest seat on a plane? We asked an aviation expert</a>
</strong>
</em>
</p>
<hr>
<p>Some airports are already using advanced <a href="https://www.in-security.eu/index.php/editorial/the-future-of-airport-security-faster-smarter-safer">computed tomography</a> (CT) <a href="https://www.theguardian.com/australia-news/2022/jun/21/3d-body-scanners-at-australian-airports-what-are-they-and-how-do-they-work">scanners</a> to produce high-definition 3D imagery. In the future, this technology could be further enhanced by AI to detect threats at a much faster rate. </p>
<p>Hypothetically, CT scans could also be used for both humans and their baggage. Could this allow travellers to walk through a body scanner while carrying their bags? Possibly.</p>
<p>Until then, you should probably try your best to leave the house on time.</p>
<hr>
<p><em>Correction: this article previously said X-ray backscatter technology is widely used in US airports, when in fact it is no longer used.</em></p><img src="https://counter.theconversation.com/content/209041/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Doug Drury does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Some countries no longer require you to remove your shoes when passing through security – but taking out your laptop is still mostly required.
Doug Drury, Professor/Head of Aviation, CQUniversity Australia
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/184892
2022-07-11T12:30:22Z
2022-07-11T12:30:22Z
What do molecules look like?
<figure><img src="https://images.theconversation.com/files/471251/original/file-20220627-20-ydsy5i.jpg?ixlib=rb-1.1.0&rect=2%2C1%2C782%2C774&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A nanographene molecule imaged by noncontact atomic force microscopy.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Hexabenzocoronene_AFM_2.jpg">Patrik Tschudin/gross3HR/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/us/topics/curious-kids-us-74795">Curious Kids</a> is a series for children of all ages. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskidsus@theconversation.com">curiouskidsus@theconversation.com</a>.</em></p>
<hr>
<blockquote>
<p><strong>What do molecules look like? – Justice B., age 6, Wimberley, Texas</strong></p>
</blockquote>
<hr>
<p>A molecule is a group of atoms bonded together. Molecules make up nearly everything around you – your skin, your chair, even your food. </p>
<p>They vary in size, but are extremely small. You can’t see an individual molecule with your eyes or even a microscope. They are 100,000 times smaller than the <a href="https://hypertextbook.com/facts/1999/BrianLey.shtml">width of a hair</a>.</p>
<p>The smallest molecule is made of two atoms stuck together, while a <a href="https://doi.org/10.1126/science.270.5244.1905-a">large molecule</a> can be a combination of 100,000 atoms or more. A molecule can be a repeat of the same atom, such as the oxygen molecules we breathe, or can be made up of a variety of atoms, such as a sugar molecule made of carbon, oxygen and hydrogen. </p>
<p>But what do molecules look like? It all begins with their building blocks: atoms. </p>
<h2>Opposites attract</h2>
<p>The <a href="https://education.jlab.org/atomtour/">particles of matter that make up an atom</a> are not all the same. They can have a positive charge, a negative charge or no charge. Scientists call them protons, electrons and neutrons. </p>
<figure>
<img src="https://cdn.theconversation.com/static_files/files/2147/A%CC%81tomo_de_Oro.gif?1656372844">
<figcaption> <span class="caption">A gold atom has a dense center made of 79 protons and 118 neutrons, with a more-spread-out cloud of 79 electrons around it. Illustration created by Galarza Creador.</span></figcaption>
</figure>
<p>Neutrons with no charge and protons with a positive charge form the heavy center of the atom. The negatively charged electrons surround this small center.</p>
<p>As atoms approach each other to potentially join and make molecules, the negative electrons in one atom are attracted to the positive protons in the other, and vice versa. Both atoms adjust themselves accordingly.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/471509/original/file-20220629-17-tyb14b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A diagram showing a round single atom, top. Below are two atoms stretched into oval shapes, with the positive part of one drawn to the negative part of the other." src="https://images.theconversation.com/files/471509/original/file-20220629-17-tyb14b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/471509/original/file-20220629-17-tyb14b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=270&fit=crop&dpr=1 600w, https://images.theconversation.com/files/471509/original/file-20220629-17-tyb14b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=270&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/471509/original/file-20220629-17-tyb14b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=270&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/471509/original/file-20220629-17-tyb14b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=340&fit=crop&dpr=1 754w, https://images.theconversation.com/files/471509/original/file-20220629-17-tyb14b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=340&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/471509/original/file-20220629-17-tyb14b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=340&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">When an atom is alone, the negative electrons surrounding its center are symmetric. As two atoms approach, the negative electrons of one atom move toward the positive center of the other atom.</span>
<span class="attribution"><span class="source">Christine Helms</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>You can compare it to trying to choose a seat in a classroom. There are some rules. For example, you have to stay in the classroom and you cannot sit on top of someone. Following those rules, you might try to sit next to your friends and far from your enemies. Finding the perfect position so everyone in the class is happy is similar to finding the perfect position for the atoms in a molecule. Sometimes, atoms cannot find a happy arrangement and no molecule is formed.</p>
<h2>Seeing the unseeable</h2>
<p>If molecules are too small to see with your eyes or even a powerful microscope, how do scientists see them? The answer is they have developed special tools to do it.</p>
<p>One tool uses X-rays, which you might know about since doctors use them to see bones in the body. <a href="https://theconversation.com/curious-kids-how-do-x-rays-see-inside-you-85895">X-rays are a type of light that human eyes can’t see</a>, <a href="https://www.amnh.org/research/natural-science-collections-conservation/general-conservation/preventive-conservation/light-ultraviolet-and-infrared">like ultraviolet or infrared light</a>. </p>
<p>When scientists <a href="https://www.sciencemuseum.org.uk/objects-and-stories/chemistry/x-ray-crystallography-revealing-our-molecular-world">shoot X-rays at molecules</a>, some bounce off. Scientists can record these rebounding X-rays and use their patterns to figure out what individual molecules look like. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/471249/original/file-20220627-22-lv4r5v.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A scattering of black dots on a white background." src="https://images.theconversation.com/files/471249/original/file-20220627-22-lv4r5v.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/471249/original/file-20220627-22-lv4r5v.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/471249/original/file-20220627-22-lv4r5v.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/471249/original/file-20220627-22-lv4r5v.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/471249/original/file-20220627-22-lv4r5v.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/471249/original/file-20220627-22-lv4r5v.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/471249/original/file-20220627-22-lv4r5v.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">X-rays that bounce off the atoms in a protein molecule form the black dots in the above image. The location of these dots tells scientists how the atoms are arranged in the molecule.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Lysozym_diffraction.png">Del45/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>In 1912, one of the <a href="https://doi.org/10.1038/491186a">first molecules seen this way was salt</a> (NaCl) – the molecule that makes up the ingredient we all know and love on french fries.</p>
<p>Scientists have invented other methods to see molecules, too. Similar to how the electrons change their behavior as two atoms come close together, the center of the atom can also change its behavior. A technique called <a href="https://www.jeol.co.jp/en/products/nmr/basics.html">nuclear magnetic resonance</a> detects those changes to the center of the atom and uses them as clues to determine what atoms are close by. </p>
<p>An <a href="https://www.parksystems.com/medias/nano-academy/how-afm-works">atomic force microscope</a> works like a flimsy diving board that shakes when you walk and jump on it. But this diving board is extremely small, so small that a negative charge on the end of it will bend it toward the positive center of an atom. Moving this diving board around and watching how it bends can show the location of atoms in a molecule.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/8gCf1sEn0UU?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">An animation showing how an atomic force microscope works.</span></figcaption>
</figure>
<p>One more technique scientists have developed to see molecules is called <a href="https://cryoem.slac.stanford.edu/what-is-cryo-em">cyro-electron microscopy</a>. First, scientists freeze molecules to a temperature much colder than snow or ice. Then they shoot electrons at the molecule and collect those that pass through to make an image. <a href="https://theconversation.com/chilled-proteins-and-3-d-images-the-cryo-electron-microscopy-technology-that-just-won-a-nobel-prize-85229">This technique won</a> the <a href="https://www.nobelprize.org/prizes/chemistry/2017/press-release/">Nobel Prize in Chemistry in 2017</a>. </p>
<h2>All shapes and sizes</h2>
<p>So what do molecules look like? They are a grouping of atoms, with the center containing most of the material, while the rest is largely empty space. Each atom has a specific position where it is happy, much like the students in that classroom. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/471674/original/file-20220629-21-45b5zt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Side by side diagram of a flat molecule and a round molecule." src="https://images.theconversation.com/files/471674/original/file-20220629-21-45b5zt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/471674/original/file-20220629-21-45b5zt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=315&fit=crop&dpr=1 600w, https://images.theconversation.com/files/471674/original/file-20220629-21-45b5zt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=315&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/471674/original/file-20220629-21-45b5zt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=315&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/471674/original/file-20220629-21-45b5zt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=396&fit=crop&dpr=1 754w, https://images.theconversation.com/files/471674/original/file-20220629-21-45b5zt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=396&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/471674/original/file-20220629-21-45b5zt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=396&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Diagrams of the atoms making up the molecules benzene, left, and fullerene, right.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Buckminsterfullerene-perspective-3D-balls.png">Jynto (left) Benjah-bmm27 (right)/Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>Every molecule is different – some are really different. For example, benzene is flat like a pancake, while fullerene is round like a ball. <a href="http://www.chemspider.com/Chemical-Structure.10338857.html">Penguinone</a> can be drawn to look like a penguin, while other molecules appear to look completely random. But the positions of atoms in a molecule are never random. </p>
<p>While scientists know what a lot of molecules look like, there are some we’re still trying to figure out. Knowing these answers can lead to inventions of new materials and <a href="https://www.mdpi.com/1422-0067/20/11/2783/htm">medicines</a>. </p>
<hr>
<p><em>Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskidsus@theconversation.com">CuriousKidsUS@theconversation.com</a>. Please tell us your name, age and the city where you live.</em></p>
<p><em>And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.</em></p><img src="https://counter.theconversation.com/content/184892/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christine Helms does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
A physicist explains how atoms arrange themselves into molecules – and how scientists are able to image these tiny bits of matter that make up everything around you.
Christine Helms, Associate Professor of Physics, University of Richmond
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/175947
2022-03-02T11:54:09Z
2022-03-02T11:54:09Z
No PCR, no problem: how COVID can be diagnosed with X-rays
<figure><img src="https://images.theconversation.com/files/449491/original/file-20220302-23-gpznxv.jpg?ixlib=rb-1.1.0&rect=8%2C0%2C892%2C525&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/xray-person-s-lungs-disease-coronavirus-1687773055">Bal Iryna/Shutterstock</a></span></figcaption></figure><p>It sounds simple, but to treat someone you suspect has COVID, you need to confirm they are actually infected with the coronavirus. In the UK, it is easy to take this for granted – we’ve had a reliable detection method for diagnosing infected patients widely available since early on in the pandemic. This allowed for people to be treated and cared for promptly, saving lives.</p>
<p>The main technique for identifying whether someone has COVID is called reverse transcription polymerase chain reaction testing – or RT-PCR. This process can tell whether the coronavirus’s genetic material is present in a sample taken from a person, usually gathered my swabbing inside the nose or throat. </p>
<p>This testing is normally done in a lab, and the resources needed mean that doing it at scale is a major challenge. High-income countries have been able to scale up their COVID testing at great cost, but in some low- and middle-income countries – such as Pakistan, Sri Lanka, India and many African countries – health staff haven’t been able to carry out large numbers of COVID tests due to a lack of resources. This is a particular problem in remote locations. </p>
<p>On top of this, PCR testing isn’t very quick. It typically takes around two hours, and longer if extra time is needed to get the test sample to a suitable lab for testing. In many cases, confirming whether someone has the virus needs to happen much more rapidly. When someone has severe COVID, treatment really needs to start immediately. Quickly diagnosing the disease is potentially life saving.</p>
<figure class="align-center ">
<img alt="A scientist preparing samples for PCR testing in a lab" src="https://images.theconversation.com/files/449492/original/file-20220302-25-17rfh9l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/449492/original/file-20220302-25-17rfh9l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/449492/original/file-20220302-25-17rfh9l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/449492/original/file-20220302-25-17rfh9l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/449492/original/file-20220302-25-17rfh9l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/449492/original/file-20220302-25-17rfh9l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/449492/original/file-20220302-25-17rfh9l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Because it’s lab-based, PCR testing takes time and isn’t widely available all around the world.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/epidemiologist-protective-suit-mask-glasses-works-1656056080">tilialucida/Shutterstock</a></span>
</figcaption>
</figure>
<p>So, <a href="https://www.mdpi.com/1424-8220/21/17/5702">our team investigated</a> whether a quick and reliable alternative to PCR testing could be provided by using commonly available hospital equipment – namely, the machines available in the radiography department.</p>
<h2>COVID shows up in chest scans</h2>
<p>Chest-imaging techniques – such as computed tomography (CT) or X-ray – can be analysed by radiologists to search for visual markers of a COVID infection. <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30183-5/fulltext">Investigations</a> early on in the pandemic found that abnormalities showed up in the chest radiography images of patients with the virus, leading the World Health Organization to <a href="https://www.who.int/publications/i/item/use-of-chest-imaging-in-covid-19">recommend</a> using radiography for diagnosing COVID when PCR testing isn’t available, especially for severe patients.</p>
<p>But there’s a resource bottleneck here, too. Using X-rays and CT scans for diagnosis requires radiologists to carefully decipher the chest images, since COVID’s visual pointers can be hard to spot. So, we created an artificial intelligence program to do this instead, to speed up diagnosis and allow radiologists to get on with their jobs. </p>
<p>The program is based on something called a deep convolutional neural network, a type of algorithm typically used to analyse images. Such algorithms can pick out the key features of images and classify those that have similarities and differences.</p>
<p>We began by training and testing a number of different algorithms – some already existing, some that we had created – using a database of around 3,000 chest X-rays. These were a mix of scans from patients with COVID, healthy individuals and people with viral pneumonia. As we worked, we tweaked the algorithms to make them better at spotting the differences between the X-rays. Over time, we found that one clearly performed better than the others. </p>
<p>We then evaluated this top performer by giving it a completely new set of X-rays that it hadn’t seen before, and asked it to determine whether each came from a COVID patient or not. The program got the answer right 98.04% of the time.</p>
<h2>How could this be used?</h2>
<p>Following these results, we developed an app that could run the program outside of our lab, so that it could be used in places where it could make a difference. The app doesn’t require lots of computer memory or power to run and so can be installed on normal PCs and laptops. </p>
<figure class="align-center ">
<img alt="A doctor using a laptop" src="https://images.theconversation.com/files/449497/original/file-20220302-25-1rtohmz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/449497/original/file-20220302-25-1rtohmz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/449497/original/file-20220302-25-1rtohmz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/449497/original/file-20220302-25-1rtohmz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/449497/original/file-20220302-25-1rtohmz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/449497/original/file-20220302-25-1rtohmz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/449497/original/file-20220302-25-1rtohmz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The diagnosis app doesn’t require any complex equipment to run – just a standard computer.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/african-businessman-typing-on-laptop-close-2039980232">wavebreakmedia/Shutterstock</a></span>
</figcaption>
</figure>
<p>It has been designed in such a way that no additional equipment is needed. Patient X-rays just have to be uploaded to the app via USB or the web, and then the algorithm analyses the image and gives back a result indicating if it is COVID positive or not. </p>
<p>This app will not replace PCR. But it could be very effective in A&E departments where patients come in with severe illness. It would allow for a chest X-ray to be quickly taken and analysed, and if the patient is positive, for treatment to start straightaway rather then waiting for lab results. As well as being beneficial for patients, this could also speed up their passage onto suitable wards elsewhere in the hospital, and so relieve the strain on hard-pressed A&E departments.</p>
<p>The app could also be very effective at diagnosing COVID cases in low-income countries and remote areas where PCR is not readily available. So, as a next step, we’re planning to test it out in Pakistan, as part of the EU-funded <a href="https://safe-rh.eu/Home/About">SAFE RH</a> project, to see what impact it can have in the real world.</p><img src="https://counter.theconversation.com/content/175947/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
X-ray scans are taken in hospitals worldwide – and an AI program has been taught to scan them for coronavirus.
Naeem Ramzan, Professor of Computing Engineering, University of the West of Scotland
Gabriel Okolo, PhD Candidate, School of Computing, Engineering & Physical Sciences, University of the West of Scotland
Stamos Katsigiannis, Assistant Professor in Computer Science, Durham University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/168925
2021-11-23T13:30:15Z
2021-11-23T13:30:15Z
Art illuminates the beauty of science – and could inspire the next generation of scientists young and old
<figure><img src="https://images.theconversation.com/files/432929/original/file-20211119-17-ptux52.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4962%2C5816&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The annual BioArt competition highlights the hidden parts of biology revealed under a microscope.</span> <span class="attribution"><a class="source" href="https://faseb.org/FASEB/media/Page-Images/Partnerships%20and%20Outreach/BioArt/2021BioArtWinners/green.png">Todd Green/BioArt</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>Scientists have often invited the public to see what they see, using everything from <a href="https://www.latimes.com/science/sciencenow/la-sci-sn-cell-printing-chinese-woodblock-inkjet-20140210-story.html">engraved woodblocks</a> to <a href="https://www.smithsonianmag.com/science-nature/science-images-that-border-on-art-50661407/">electron microscopes</a> to explore the complexity of the scientific enterprise and the beauty of life. <a href="https://doi.org/10.1038/d41586-019-03306-9">Sharing these visions</a> through illustrations, photography and videos has allowed laypeople to explore a range of discoveries, from new bird species to the inner workings of the human cell.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Micrograph of mouse intestinal villi." src="https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1352&fit=crop&dpr=1 600w, https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1352&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1352&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1699&fit=crop&dpr=1 754w, https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1699&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/432930/original/file-20211119-25-1hsisp8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1699&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A winner of the 2018 BioArt contest, this image shows the intestinal villi of a mouse.</span>
<span class="attribution"><a class="source" href="https://faseb.org/FASEB/media/Page-Images/Partnerships%20and%20Outreach/BioArt/2018BioArtWinners/2018BioArtWinners-09.jpg">Amy Engevik/BioArt</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>As a <a href="https://www.researchgate.net/profile/Christine-Curran">neuroscience and bioscience researcher</a>, I know that scientists are sometimes pigeonholed as white lab coats obsessed with charts and graphs. What that stereotype misses is their passion for science as a mode of discovery. That’s why scientists frequently turn to <a href="https://www.cnn.com/style/article/bio-art-microbes-and-machines/index.html">awe-inducing visualizations</a> as a way to explain the unexplainable.</p>
<p>The <a href="https://faseb.org/partnerships-and-outreach/bioart">BioArt Scientific Image and Video Competition</a>, administered by the <a href="https://www.faseb.org/">Federation of American Societies for Experimental Biology</a>, shares images rarely seen outside the laboratory with the public in order to introduce and educate laypeople about the wonder often associated with biological research. BioArt and similar contests reflect the lengthy history of using imagery to elucidate science. </p>
<h2>A historical and intellectual moment</h2>
<p>The <a href="https://www.livescience.com/55230-renaissance.html">Renaissance</a>, a period in European history between the 14th and 17th centuries, breathed new life into both science and art. It brought together the fledgling discipline of <a href="https://www.encyclopedia.com/history/modern-europe/ancient-history-middle-ages-and-feudalism/natural-history">natural history</a> – a field of inquiry observing animals, plants and fungi in their ordinary environments – with artistic illustration. This allowed for wider study and classification of the natural world.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Peter Paul Ruben's 'Anatomical Studies: a left forearm in two positions and a right forearm'" src="https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=865&fit=crop&dpr=1 600w, https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=865&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=865&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1086&fit=crop&dpr=1 754w, https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1086&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/429597/original/file-20211101-15-95l3wv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1086&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Art played a role in advancing the natural sciences in the Renaissance period, such as Rubens’ human anatomical studies.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Anatomical_Studies-_a_left_forearm_in_two_positions_and_a_right_forearm_MET_DT3993.jpg">Peter Paul Rubens/The Metropolitan Museum of Art via Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>Artists and artistic naturalists were also able to advance approaches to the study of nature by illustrating discoveries of early botanists and anatomists. Flemish artist Peter Paul Rubens, for example, offered remarkable insight into human anatomy in his <a href="https://www.illustrationhistory.org/essays/the-drawing-methods-and-techniques-of-peter-paul-rubens">famous anatomical drawings</a>.</p>
<p>This art-science formula was further democratized in the 17th and 18th centuries as the <a href="https://www.metmuseum.org/toah/hd/prnt/hd_prnt.htm">printing process became more sophisticated</a> and allowed early ornithologists and anatomists to publish and disseminate their elegant drawings. Initial popular entries included John James Audubon’s
“<a href="https://www.outsideonline.com/outdoor-adventure/environment/plaid-and-canvas-audubons-birds-america/">Birds of America</a>” and Charles Darwin’s “<a href="https://www.smithsonianmag.com/science-nature/beautiful-drawings-darwins-artist-residence-180954953/">The Origin of the Species</a>” – groundbreaking at the time for the clarity of their illustrations.</p>
<p>Publishers soon followed with well-received field guides and encyclopedias detailing observations of what were seen through early microscopes. For example, a Scottish encyclopedia published in 1859, “<a href="https://www.nms.ac.uk/collections-research/our-research/highlights-of-previous-projects/chambers-collection/">Chambers’s Encyclopaedia: A Dictionary of Universal Knowledge for the People</a>,” sought to broadly explain the natural world through woodblock illustrations of mammals, microorganisms, birds and reptiles.</p>
<p>These publications responded to the public’s demand for more news and views of the natural world. People formed amateur naturalist societies, hunted for fossils, and enjoyed trips to local zoos or menageries. By the 19th century, <a href="https://digpodcast.org/2018/04/29/natural-history-museums/">natural history museums</a> were being constructed around the world to share scientific knowledge through illustrations, models and real-life examples. Exhibits ranged from taxidermied animals to human organs preserved in liquid.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Wilhelm Roentgen's X-ray photograph of his wife's hand" src="https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=872&fit=crop&dpr=1 600w, https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=872&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=872&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1095&fit=crop&dpr=1 754w, https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1095&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/429604/original/file-20211101-13-1gmx9g8.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1095&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The first X-ray image was the hand of X-ray discoverer Wilhelm Roentgen’s wife.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Wilhelm-Roentgen's-X-ray-photograph-of-his-wife's-hand.png">Wilhelm Conrad Röntgen/Brockhaus Multimedial via Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>What began as hand drawings has morphed over the past 150 years with the help of new technologies. The advent of sophisticated imaging techniques such as <a href="https://www.nde-ed.org/NDETechniques/Radiography/Introduction/history.xhtml">X-rays</a> in 1895, <a href="https://www.thermofisher.com/blog/microscopy/the-history-of-the-electron-microscope/">electron microscopes</a> in 1931, <a href="https://doi.org/10.1016/j.tcb.2011.09.007">3D modeling</a> in the 1960s and <a href="https://pubs.rsna.org/doi/10.1148/radiol.14140706">magnetic resonance imaging, or MRI</a> in 1973 made it easier for scientists to share what they were seeing in the lab. In fact, Wilhelm Roentgen, a physics professor who first discovered the X-ray, made the first human X-ray image with his wife’s hand.</p>
<p>Today, scientific publications including <a href="https://doi.org/10.1038/s41594-021-00587-5">Nature</a> and <a href="https://www.the-scientist.com/profession/bioscience-moves-into-galleries-as-bioart-52533">The Scientist</a> have taken to sharing their favorites with readers. Visualizations, whether through photography or video, are one more method for scientists to document, test and affirm their research.</p>
<h2>Science, art and K-12 education</h2>
<p>These science visualizations have found their way into classrooms, as K-12 schools add scientific photographs and videos to lesson plans. </p>
<p>Art museums, for example, have developed <a href="https://www.getty.edu/education/teachers/classroom_resources/curricula/art_science2/">science curricula based on art</a> to give students a glimpse of what science looks like. This can help promote <a href="https://doi.org/10.1073/pnas.1912436117">scientific literacy</a>, increasing both their understanding of basic scientific principles and their critical thinking skills.</p>
<p>Scientific literacy is especially important now. During a pandemic in which misinformation about COVID-19 and vaccines has been rampant, a better understanding of natural phenomena could help students learn how to make informed decisions about disease risk and transmission. Teaching scientific literacy gives students the skills to <a href="https://techonomy.com/2020/07/science-literacy-and-americas-covid-crisis/">evaluate the claims</a> of both scientists and public figures, whether they’re about COVID-19, the common cold or climate change.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Hindlimbs from chick embryos." src="https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=352&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=352&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=352&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=442&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=442&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430336/original/file-20211104-21148-1049jhf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=442&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A winner of the 2020 BioArt contest, this image shows hind limbs from chick embryos. The left limb is normal, while the right is a mutant. The yellow staining indicates the presence of a protein that marks progenitors of bone and cartilage development.</span>
<span class="attribution"><a class="source" href="https://faseb.org/FASEB/media/Page-Images/Partnerships%20and%20Outreach/BioArt/2020BioArtWinners/hindlimbs_1.jpg">Christian Bonatto/BioArt</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>However, science knowledge appears to be stagnating. The <a href="https://www.nationsreportcard.gov/science/?grade=4">2019 National Assessment of Education Progress</a> measures the science knowledge and scientific inquiry capabilities of U.S. public school students in grades 4, 8 and 12 from a scale of zero to 300. Scores stagnated for all grades from 2009 to 2019, hovering between 150 to 154.</p>
<p>[<em>Too busy to read another daily email?</em> <a href="https://memberservices.theconversation.com/newsletters/?source=inline-toobusy">Get one of The Conversation’s curated weekly newsletters</a>.]</p>
<p>A survey of K-12 teachers shows that 77% of elementary teachers spend <a href="https://www.nationsreportcard.gov/science/student-experiences/?grade=4">under four hours a week on science</a>. And the 2018 National Survey of Science and Mathematics Education found that K-3 students receive an average of only <a href="http://horizon-research.com/NSSME/2018-nssme/research-products/reports/highlights-2018-nssme">18 minutes of science instruction per day</a>, compared to 57 minutes in math.</p>
<p>Making science more visual may make <a href="https://www.firstdiscoverers.co.uk/science-education-early-childhood/">learning science at an early age</a> easier. It could also help students both understand scientific models and develop skills like teamwork and how to communicate complex concepts.</p>
<h2>Deepening scientific knowledge</h2>
<p>The <a href="https://faseb.org/partnerships-and-outreach/bioart">BioArt Scientific Image and Video Competition</a> was established 10 years ago to both give scientists an outlet to share their latest research and allow a wider audience to view bioscience from the researcher’s point of view.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Electron microscope image of HeLa cells infected with Listeria monocytogenes." src="https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=840&fit=crop&dpr=1 600w, https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=840&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=840&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1056&fit=crop&dpr=1 754w, https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1056&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/432932/original/file-20211119-22-aruydm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1056&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A winner of the 2020 BioArt contest, this image shows HeLa cells infected with the common but fatal foodborne pathogen Listeria monocytogenes.</span>
<span class="attribution"><a class="source" href="https://faseb.org/FASEB/media/Page-Images/Partnerships%20and%20Outreach/BioArt/2021BioArtWinners/dhanda.png">Arandeep Dhanda/BioArt</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>What’s unique about the BioArt competition is the diversity of submissions over the past decade. After all, bioscience encompasses the wide range of disciplines within the life sciences. The 2021 BioArt contest winners range from a <a href="https://faseb.org/FASEB/media/Page-Images/Partnerships%20and%20Outreach/BioArt/2021BioArtWinners/nacke.png">zebra fish embryo’s developing eye</a> to the shell of a species of <a href="https://faseb.org/FASEB/media/Page-Images/Partnerships%20and%20Outreach/BioArt/2021BioArtWinners/smith.png">96 million-year-old helochelydrid fossil turtle</a>.</p>
<p>I have served as a judge for the BioArt competition over the past five years. My appreciation for the science behind the images is often exceeded by my enjoyment of their beauty and technical skill. For instance, photography using <a href="https://www.popphoto.com/tips-pro-microscopic-photography/">polarized light</a>, which filters light waves so they oscillate in one direction instead of many directions, allows scientists to reveal what the otherwise hidden insides of samples look like.</p>
<p>Whether today or in the past, science elucidates the foundation of our world, both in miniature and at scale. It’s my hope that visually illuminating scientific processes and concepts can advance scientific literacy and give both students and the general public access to a deeper understanding of the natural world that they need to be informed citizens. That those images and videos are often beautiful is an added benefit.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/1Q9j9QvHO4U?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">This video by 2021 BioArt winner Thomas Gebert shows a human intestinal organoid infected with rotavirus.</span></figcaption>
</figure><img src="https://counter.theconversation.com/content/168925/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Curran receives funding from the National Institutes of Health and the National Science Foundation. She is a member of the FASEB Board of Directors. </span></em></p>
Scientists have been using art to illuminate and share their research with the public for centuries. And art could be one way to bolster K-12 science education and scientific literacy in the public.
Chris Curran, Professor and Director Neuroscience Program, Northern Kentucky University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/149907
2021-09-30T12:29:56Z
2021-09-30T12:29:56Z
50 years ago, the first CT scan let doctors see inside a living skull – thanks to an eccentric engineer at the Beatles’ record company
<figure><img src="https://images.theconversation.com/files/423940/original/file-20210929-26-mhu7qn.jpg?ixlib=rb-1.1.0&rect=55%2C0%2C4034%2C2996&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Godfrey Hounsfield stands beside the EMI-Scanner in 1972.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/the-25-000-macrobert-award-and-gold-medal-were-presented-by-news-photo/828266748"> PA Images via Getty Images</a></span></figcaption></figure><p>The possibility of precious objects hidden in secret chambers can really ignite the imagination. In the mid-1960s, <a href="https://doi.org/10.4103/0972-2327.194414">British engineer Godfrey Hounsfield</a> pondered whether one could detect hidden areas in Egyptian pyramids by capturing cosmic rays that passed through unseen voids.</p>
<p>He held onto this idea over the years, which can be paraphrased as “<a href="https://birorgukportal.force.com/CPBase__item?id=a0j20000006wvWqAAI">looking inside a box without opening it</a>.” Ultimately he did figure how to use high-energy rays to reveal what’s invisible to the naked eye. He invented a way to see inside the hard skull and get a picture of the soft brain inside.</p>
<p>The first computed tomography image – a CT scan – of the human brain was made 50 years ago, on Oct. 1, 1971. Hounsfield never made it to Egypt, but his invention did take him to Stockholm and Buckingham Palace.</p>
<h2>An engineer’s innovation</h2>
<p>Godfrey Hounsfield’s early life did not suggest that he would accomplish much at all. He was not a particularly good student. As a young boy his teachers <a href="https://www.worldcat.org/title/godfrey-hounsfield-intuitive-genius-of-ct/oclc/823708300&referer=brief_results">described him as “thick</a>.”</p>
<p>He joined the British Royal Air Force at the start of the Second World War, but he wasn’t much of a soldier. He was, however, a wizard with electrical machinery – especially the <a href="https://www.iwm.org.uk/history/how-radar-changed-the-second-world-war">newly invented radar</a> that he would jury-rig to help pilots better find their way home on dark, cloudy nights.</p>
<p>After the war, Hounsfield followed his commander’s advice and got a degree in engineering. He practiced his trade at EMI – the company would become <a href="https://doi.org/10.1097/RCT.0b013e318249416f">better known for selling Beatles albums</a>, but started out as Electric and Music Industries, with a focus on electronics and electrical engineering.</p>
<p>Hounsfield’s natural talents propelled him to lead the team building the most advanced mainframe computer available in Britain. But by the ‘60s, EMI wanted out of the competitive computer market and wasn’t sure what to do with the brilliant, eccentric engineer.</p>
<p>While on a forced holiday to ponder his future and what he might do for the company, Hounsfield met a physician who complained about the poor quality of X-rays of the brain. <a href="https://www.medmuseum.siemens-healthineers.com/en/stories-from-the-museum/our-brain?">Plain X-rays show marvelous details of bones</a>, but the brain is an amorphous blob of tissue – on an X-ray it all looks like fog. This got Hounsfield thinking about his old idea of finding hidden structures without opening the box.</p>
<h2>A new approach reveals the previously unseen</h2>
<p>Hounsfield formulated a new way to approach the problem of imaging what’s inside the skull.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/423821/original/file-20210929-18-8ywyce.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="schematic of three X-ray beams through one 'slice' of brain" src="https://images.theconversation.com/files/423821/original/file-20210929-18-8ywyce.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/423821/original/file-20210929-18-8ywyce.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=567&fit=crop&dpr=1 600w, https://images.theconversation.com/files/423821/original/file-20210929-18-8ywyce.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=567&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/423821/original/file-20210929-18-8ywyce.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=567&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/423821/original/file-20210929-18-8ywyce.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=712&fit=crop&dpr=1 754w, https://images.theconversation.com/files/423821/original/file-20210929-18-8ywyce.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=712&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/423821/original/file-20210929-18-8ywyce.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=712&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">X-rays beam through each ‘slice’ of brain, oriented at each degree from 1 to 180 in a semicircle.</span>
<span class="attribution"><span class="source">Edmund S. Higgins</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>First, he would conceptually <a href="https://doi.org/10.1259/0007-1285-46-552-1016">divide the brain into consecutive slices</a> – like a loaf of bread. Then he planned to beam a series of X-rays through each layer, repeating this for each degree of a half-circle. The strength of each beam would be captured on the opposite side of the brain – with stronger beams indicating they’d traveled through less dense material.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/423822/original/file-20210929-24-lb50bz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="simplified illustration of more X-rays making it through softer material" src="https://images.theconversation.com/files/423822/original/file-20210929-24-lb50bz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/423822/original/file-20210929-24-lb50bz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=365&fit=crop&dpr=1 600w, https://images.theconversation.com/files/423822/original/file-20210929-24-lb50bz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=365&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/423822/original/file-20210929-24-lb50bz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=365&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/423822/original/file-20210929-24-lb50bz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=458&fit=crop&dpr=1 754w, https://images.theconversation.com/files/423822/original/file-20210929-24-lb50bz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=458&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/423822/original/file-20210929-24-lb50bz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=458&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Calculating the strength of each X-ray once it’s passed through the object, and working backward with an impressive algorithm, it is possible to construct an image.</span>
<span class="attribution"><span class="source">Edmund S. Higgins</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Finally, in possibly his most ingenious invention, Hounsfield created an algorithm to reconstruct an image of the brain based on all these layers. By working backward and using one of the era’s fastest new computers, he could calculate the value for each little box of each brain layer. Eureka!</p>
<p>But there was a problem: EMI wasn’t involved in the medical market and had no desire to jump in. The company allowed Hounsfield to work on his product, but with scant funding. He was forced to scrounge through the scrap bin of the research facilities and cobbled together a primitive scanning machine - small enough to rest atop a dining table.</p>
<p>Even with <a href="https://doi.org/10.1259/0007-1285-49-583-604">successful scans of inanimate objects</a> and, later, <a href="https://www.jweekly.com/1997/04/25/kosher-cow-brains-help-pioneer-ct-scan-technology/">kosher cow brains</a>, the powers that be at EMI remained underwhelmed. Hounsfield needed to find outside funding if he wanted to proceed with a human scanner. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/423636/original/file-20210928-14-96ensy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="line drawing of CT scanner" src="https://images.theconversation.com/files/423636/original/file-20210928-14-96ensy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/423636/original/file-20210928-14-96ensy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=786&fit=crop&dpr=1 600w, https://images.theconversation.com/files/423636/original/file-20210928-14-96ensy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=786&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/423636/original/file-20210928-14-96ensy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=786&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/423636/original/file-20210928-14-96ensy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=988&fit=crop&dpr=1 754w, https://images.theconversation.com/files/423636/original/file-20210928-14-96ensy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=988&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/423636/original/file-20210928-14-96ensy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=988&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Schematic diagram of the CT scanner included in Hounsfield’s U.S. patent.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:CT_US4115698_Fig1.jpg">Godfrey Newbold Hounsfield</a></span>
</figcaption>
</figure>
<p>Hounsfield was a brilliant, intuitive inventor, but not an effective communicator. Luckily he had a sympathetic boss, Bill Ingham, who saw the value in Hounsfield’s proposal and struggled with EMI to keep the project afloat. </p>
<p>He knew there were no grants they could obtain quickly, but reasoned the U.K. Department of Health and Social Security could purchase equipment for hospitals. Miraculously, Ingham sold them four scanners before they were even built. So, Hounsfield organized a team, and they raced to build a safe and effective human scanner. </p>
<p>Meanwhile, Hounsfield needed patients to try out his machine on. He found a somewhat reluctant neurologist who agreed to help. The team installed a full-sized scanner at the <a href="http://www.impactscan.org/CThistory.htm?">Atkinson Morley Hospital in London</a>, and on Oct. 1, 1971, they scanned their first patient: a middle-aged woman who showed signs of a brain tumor.</p>
<p><a href="https://doi.org/10.1259/bjr/29444122">It was not a fast process</a> – 30 minutes for the scan, a drive across town with the magnetic tapes, 2.5 hours processing the data on an EMI mainframe computer and capturing the image with a Polaroid camera before racing back to the hospital.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/423942/original/file-20210929-64926-b3svf8.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="pixelated image of a brain" src="https://images.theconversation.com/files/423942/original/file-20210929-64926-b3svf8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/423942/original/file-20210929-64926-b3svf8.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=530&fit=crop&dpr=1 600w, https://images.theconversation.com/files/423942/original/file-20210929-64926-b3svf8.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=530&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/423942/original/file-20210929-64926-b3svf8.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=530&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/423942/original/file-20210929-64926-b3svf8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=665&fit=crop&dpr=1 754w, https://images.theconversation.com/files/423942/original/file-20210929-64926-b3svf8.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=665&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/423942/original/file-20210929-64926-b3svf8.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=665&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The first clinical CT scan, with brain tumor visible as darker blob.</span>
<span class="attribution"><a class="source" href="https://www.ncbi.nlm.nih.gov/books/NBK546157/figure/ch8.fig2/">'Medical Imaging Systems: An Introductory Guide,' Maier A, Steidl S, Christlein V, et al., editors.</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>And there it was – in her left frontal lobe – a cystic mass about the size of a plum. With that, every other method of imaging the brain was obsolete.</p>
<h2>Millions of CT scans every year</h2>
<p>EMI, with no experience in the medical market, suddenly held a monopoly for a machine in high demand. It jumped into production and was initially very successful at selling the scanners. But within five years, bigger, more experienced companies with more research capacity such as GE and Siemens were producing better scanners and gobbling up sales. EMI eventually exited the medical market – and <a href="https://www.blackwellpublishing.com/content/GrantContemporaryStrategyAnalysis/docs/Grant_Cases_Guide_Chapter_10.pdf">became a case study</a> in why it can be better to partner with one of the big guys instead of trying to go it alone.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/423941/original/file-20210929-66198-1pskqvw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Hounsfield in tuxedo shaking hands with King facing away from camera" src="https://images.theconversation.com/files/423941/original/file-20210929-66198-1pskqvw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/423941/original/file-20210929-66198-1pskqvw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=641&fit=crop&dpr=1 600w, https://images.theconversation.com/files/423941/original/file-20210929-66198-1pskqvw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=641&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/423941/original/file-20210929-66198-1pskqvw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=641&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/423941/original/file-20210929-66198-1pskqvw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=805&fit=crop&dpr=1 754w, https://images.theconversation.com/files/423941/original/file-20210929-66198-1pskqvw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=805&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/423941/original/file-20210929-66198-1pskqvw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=805&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">King Carl Gustaf awards the Nobel Prize to Hounsfield in Stockholm on Dec. 11, 1979.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/british-scientist-sir-godfrey-hounsfield-joint-nobel-news-photo/51867039">Keystone/Hulton Archive via Getty Images</a></span>
</figcaption>
</figure>
<p>Hounsfield’s innovation transformed medicine. He <a href="https://www.nobelprize.org/prizes/medicine/1979/press-release/">shared the Nobel Prize</a> for Physiology or Medicine in 1979 and was knighted by the Queen in 1981. He continued to putter around with inventions until his final days in 2004, when he died at 84. </p>
<p>In 1973, American <a href="https://doi.org/10.1197/jamia.M2127">Robert Ledley</a> developed <a href="https://doi.org/10.1126/science.186.4160.207">a whole-body scanner</a> that could image other organs, blood vessels and, of course, bones. Modern scanners are faster, provide better resolution, and most important, do it with less radiation exposure. There are even mobile scanners.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/423640/original/file-20210928-26-3rul6h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/423640/original/file-20210928-26-3rul6h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/423640/original/file-20210928-26-3rul6h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/423640/original/file-20210928-26-3rul6h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/423640/original/file-20210928-26-3rul6h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/423640/original/file-20210928-26-3rul6h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/423640/original/file-20210928-26-3rul6h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/423640/original/file-20210928-26-3rul6h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Modern CT scans provide much higher resolution images of the ‘slices’ of the brain than Hounsfield’s original scan did in 1971.</span>
</figcaption>
</figure>
<p>By 2020, technicians were performing <a href="https://www.sciencedaily.com/releases/2020/07/200723115909.htm">more than 80 million scans annually in the U.S.</a>. Some physicians argue that number is excessive and maybe a third are unnecessary. While that may be true, the CT scan has <a href="https://www.fda.gov/radiation-emitting-products/medical-x-ray-imaging/computed-tomography-ct">benefited the health</a> of many patients around the world, helping identify tumors and determine if surgery is needed. They’re particularly useful for a quick search for internal injuries after accidents in the ER.</p>
<p>And remember Hounsfield’s idea about the pyramids? In 1970 scientists placed <a href="https://en.wikipedia.org/wiki/Cosmic-ray_observatory">cosmic ray detectors</a> in the lowest chamber in the Pyramid of Khafre. They concluded that <a href="https://doi.org/10.1126/science.167.3919.832">no hidden chamber was present within the pyramid</a>. In 2017, another team placed cosmic ray detectors in the Great Pyramid of Giza and <a href="https://doi.org/10.1038/nature.2017.22939">found a hidden, but inaccessible, chamber</a>. It’s unlikely it will be explored anytime soon. </p>
<p><em>This article has been updated to correct the spelling of the name of Hounsfield’s boss at EMI, Bill Ingham.</em></p>
<p>[<em>You’re smart and curious about the world. So are The Conversation’s authors and editors.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=youresmart">You can read us daily by subscribing to our newsletter</a>.]</p><img src="https://counter.theconversation.com/content/149907/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Edmund S. Higgins does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
On Oct. 1, 1971, Godfrey Hounsfield’s invention took its first pictures of a human brain, using X-rays and an ingenious algorithm to identify a woman’s tumor from outside of her skull.
Edmund S. Higgins, Affiliate Associate Professor of Psychiatry & Family Medicine, Medical University of South Carolina
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/148022
2020-10-13T12:29:11Z
2020-10-13T12:29:11Z
Fossilised teeth reveal first mammals were far from warm blooded
<figure><img src="https://images.theconversation.com/files/363168/original/file-20201013-17-e5bmqi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Artist's impression of early mammals.</span> <span class="attribution"><span class="source">John Sibbick/University of Bristol</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Warm blood is one of the key traits that led to the success of mammals as they evolved from scurrying beneath the feet of dinosaurs to spreading into the wild and wonderful collection of animals we know today. But our <a href="https://www.nature.com/articles/s41467-020-18898-4">new research</a>, which involved X-ray scanning hundreds of fossilised teeth, suggests the first mammals were more like cold blooded reptiles, and that warm blood evolved much later.</p>
<p>Warm blood helps us maintain our body temperature regardless of our environment, allowing us to gather food at night and in cold climates, and helps us stay active for longer than our cold blooded relatives. However, exactly when, why, and how this evolved is still poorly understood. </p>
<p>We know from tiny <a href="https://theconversation.com/fossil-teeth-reveal-the-secret-rise-of-mammals-millions-of-years-before-dinosaurs-became-extinct-60711">fossils of bones and teeth</a> that mammals first evolved over 200 million years ago, and had many of the traits we associate with mammals, such as specialised chewing teeth and bigger brains. But the physiologies (how an animal’s body works day-to-day) of these animals is difficult to estimate using traditional methods, as this relates to soft organs that aren’t usually fossilised. </p>
<p>Our new research, published in <a href="https://www.nature.com/articles/s41467-020-18898-4">Nature Communications</a>, now offers a glimpse into the physiologies of the first mammals, by pioneering X-ray imaging to count growth rings in their teeth and measure blood flow through their bones. Although it had previously been assumed that even the earliest mammals were warm blooded, this research suggests that they still had some way to go before developing warm blood and its benefits that we enjoy today.</p>
<h2>Long lifespans and slow metabolism</h2>
<p>Working with a 20-strong international team of scientists, we have estimated the lifespans of the earliest mammals for the first time. This was done by X-ray scanning hundreds of fossilised teeth <a href="http://www.bristol.ac.uk/news/2014/august/jurassic-mammals.html">found in south Wales</a> of two tiny mammals, <em>Morganucodon</em> and <em>Kuehneotherium</em>, from the Early Jurassic epoch. </p>
<p>High-resolution scans performed at powerful “synchrotron” X-ray sources in Switzerland <a href="https://natureecoevocommunity.nature.com/posts/shedding-light-on-early-mammal-physiology?channel_id=521-behind-the-paper">and France</a> allowed us to count annual growth lines preserved in the fossilised cementum of these teeth. Cementum is the little-known tissue that anchors mammal tooth roots to the jaw, recording every year of an animal’s life by growth lines that can be counted like tree rings to estimate lifespan. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/363170/original/file-20201013-23-165ssi9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="X-ray image of round shape containing concentric rings." src="https://images.theconversation.com/files/363170/original/file-20201013-23-165ssi9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/363170/original/file-20201013-23-165ssi9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=603&fit=crop&dpr=1 600w, https://images.theconversation.com/files/363170/original/file-20201013-23-165ssi9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=603&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/363170/original/file-20201013-23-165ssi9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=603&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/363170/original/file-20201013-23-165ssi9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=758&fit=crop&dpr=1 754w, https://images.theconversation.com/files/363170/original/file-20201013-23-165ssi9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=758&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/363170/original/file-20201013-23-165ssi9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=758&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">X-ray image of tooth cementum from <em>Morganucodon</em> revealing growth rings.</span>
<span class="attribution"><span class="source">University of Bristol</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>These lines are counted in living mammals by grinding teeth down into thin sections that can be studied using microscopes. As this destroys the tooth, we could not do this with precious museum fossils, and so we used X-ray imaging. Counting rings in our fossil mammal teeth gave a lifespan of 14 years for <em>Morganucodon</em>, and nine years for <em>Kuehneotherium</em>. </p>
<p>These are significantly, and surprisingly, longer lifespans than those of similar, shrew-sized mammals living today whose wild lifespans rarely exceed two to three years. This suggests a dramatically slower metabolism, or pace of life, than living mammals, and instead more closely resembles that of living reptiles.</p>
<h2>Low activity levels</h2>
<p>The size of the openings for the major blood vessels running through an animal’s limb bones is known to be proportionate to the levels of sustained activity (such as hunting and foraging) that they are capable of: smaller size suggests lower activity levels. </p>
<p>When we measured this in the femur of <em>Morganucodon</em>, we found that, while smaller than living mammals, they were also higher than those of living reptiles. This suggests that early mammals had an intermediate ability for sustained activity, between warm blooded mammals and cold blooded reptiles.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/363171/original/file-20201013-23-1xn6e2h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/363171/original/file-20201013-23-1xn6e2h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/363171/original/file-20201013-23-1xn6e2h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=300&fit=crop&dpr=1 600w, https://images.theconversation.com/files/363171/original/file-20201013-23-1xn6e2h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=300&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/363171/original/file-20201013-23-1xn6e2h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=300&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/363171/original/file-20201013-23-1xn6e2h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=377&fit=crop&dpr=1 754w, https://images.theconversation.com/files/363171/original/file-20201013-23-1xn6e2h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=377&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/363171/original/file-20201013-23-1xn6e2h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=377&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">University of Bristol</span></span>
</figcaption>
</figure>
<p>This combined approach of studying the lifespans and activity levels of early mammals provides the first direct window onto several aspects of how they lived. We can see that our earliest relatives kept a much slower pace of life, but had definitely started on the road to the active lifestyles of living mammals today. </p>
<p>We shall continue these studies through the early mammal fossil record, to shed light on the first steps towards the modern mammalian lifestyle, and when we truly became warm blooded.</p><img src="https://counter.theconversation.com/content/148022/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elis Newham received funding from the NERC and EPSRC as part of his PhD project at the University of Southampton. He is now funded by a Knowledge Transfer Secondment from the EPSRC. </span></em></p><p class="fine-print"><em><span>Pam Gill received funding from NERC, for earlier research.</span></em></p>
New study used X-rays of the teeth of early mammals’ to show they were more like cold blooded reptiles.
Elis Newham, Research Associate in Palaeontology, University of Bristol
Pam Gill, Senior Research Associate in Palaeontology, University of Bristol
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/124367
2019-11-08T10:02:26Z
2019-11-08T10:02:26Z
Helena Gleichen: pioneer radiographer, suffragist and forgotten hero of World War I
<figure><img src="https://images.theconversation.com/files/298927/original/file-20191028-114005-mjekz5.jpg?ixlib=rb-1.1.0&rect=51%2C8%2C5725%2C3797&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Gleichen sacrificed her own well-being to help save the lives of injured soldiers on the Italian Front. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/mature-man-xray-showing-right-pulmonary-1504168982?src=1mKvAmvXoKR80N5doKk9Hw-1-24">Douglas Olivares/ Shutterstock</a></span></figcaption></figure><p>“Women, your country needs you,” Millicent Fawcett, the campaigner for women’s suffrage, proclaimed when war was declared in August 1914. One enthusiastic respondent to the call was Helena Gleichen, a rich aristocrat and a cousin of George V who had dined with Queen Victoria, danced at debutante balls and spent much of her life riding or painting animals. But when the war started, she renounced her Germanic family titles and committed herself to war work. More than 100 years after the armistice was signed, Gleichen has become a forgotten hero of the World War I – despite her brave contributions having saved thousand of lives on the Italian Front.</p>
<p>Although the British Army scornfully refused offers from women willing to travel overseas, that failed to stop many brave volunteers from getting involved. Although now forgotten, Gleichen was Britain’s war-time Marie Curie – the Polish scientist who invented mobile X-ray units that she took to the French front. While Curie was saving French lives, this English landscape artist was rescuing Italian soldiers. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/299242/original/file-20191029-183136-eyc7aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/299242/original/file-20191029-183136-eyc7aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=873&fit=crop&dpr=1 600w, https://images.theconversation.com/files/299242/original/file-20191029-183136-eyc7aq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=873&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/299242/original/file-20191029-183136-eyc7aq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=873&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/299242/original/file-20191029-183136-eyc7aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1097&fit=crop&dpr=1 754w, https://images.theconversation.com/files/299242/original/file-20191029-183136-eyc7aq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1097&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/299242/original/file-20191029-183136-eyc7aq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1097&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Lady Helena Gleichen.</span>
<span class="attribution"><a class="source" href="https://www.iwm.org.uk/collections/item/object/205380422">© IWM</a></span>
</figcaption>
</figure>
<p>Medical radiography was still in its infancy. The German physicist Wilhelm Conrad Röntgen had <a href="https://www.bl.uk/learning/cult/bodies/xray/roentgen.html">discovered X-rays in 1895</a>, and the following year created the first X-ray photograph, memorably revealing the bones of his wife’s hand. Two decades later, suitable machines were available in major hospitals, but they were located too far away to help soldiers injured on the battle field.</p>
<p>Curie <a href="https://www.nobelprize.org/prizes/physics/1903/marie-curie/biographical/">won two Nobel Prizes</a> for her pioneering research into radioactivity, but during the war she abandoned her laboratory to support her adopted country. Her Curie cars brought radiography equipment – including miniature dark rooms for developing prints – right to the scene of battle, so that <a href="https://theconversation.com/marie-curie-and-her-x-ray-vehicles-contribution-to-world-war-i-battlefield-medicine-83941">soldiers could be examined and treated immediately</a>.</p>
<p>In 1915, Gleichen and her friend Nina Hollings converted a French chateau into a military hospital before travelling to Paris and training with X-rays. But the War Office informed them with unassailable illogic that because no women were radiographers it was impossible to employ them. Undeterred, they came back to London and organised their own relief operation.</p>
<p>To get advice, Gleichen contacted the distinguished Scottish pioneer of <a href="https://specialcollectionslearning.wordpress.com/2017/10/17/sir-james-mackenzie-davidson-a-founding-father-of-british-radiology/">medical radiography, James Mackenzie Davidson</a>. She raised enough money from her wealthy family to buy one of the new portable machines he was developing, as well as a specially adapted Austin car to drive it in.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/298930/original/file-20191028-114005-ph3z7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/298930/original/file-20191028-114005-ph3z7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=391&fit=crop&dpr=1 600w, https://images.theconversation.com/files/298930/original/file-20191028-114005-ph3z7t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=391&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/298930/original/file-20191028-114005-ph3z7t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=391&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/298930/original/file-20191028-114005-ph3z7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=492&fit=crop&dpr=1 754w, https://images.theconversation.com/files/298930/original/file-20191028-114005-ph3z7t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=492&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/298930/original/file-20191028-114005-ph3z7t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=492&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Gleichen would have used a mobile X-ray unit similar to this one that Marie Curie designed.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Marie_Curie_-_Mobile_X-Ray-Unit.jpg">Eve Curie/Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>Gleichen and Hollings set off for Italy, where they settled just behind the frontline in a country villa near the border town of Gorizia. Their home became a busy X-ray department, its machinery powered by a cable snaking along the hallway from the car parked outside. Alone in the middle of a battle zone, the pair learnt how to service their electrical equipment and fix their car. On one occasion, Gleichen enterprisingly melted two large altar candles to replace some cracked insulation.</p>
<p>Although photos show two demure women in heavy uniform, hats firmly in place even when working inside, Gleichen recounts adventures as hair-raising as those of any frontline soldier. Often at risk from enemy bullets, they took many thousands of X-rays, eventually damaging their hands and their eyes. </p>
<p>In a letter to Davidson, Gleichen explained that they needed to work quickly. With more and more wounded soldiers arriving daily, many of them already close to death, there was often no time for the luxury of standard procedures. Weighing down their un-anaesthetised patients with sandbags, they explored precisely yet rapidly to locate bullets lodged in a soldier’s body by a rough-and-ready technique of aiming along two perpendicular lines to see where they intersected.</p>
<p>Gleichen was particularly jubilant about managing to pinpoint a bullet deep inside a soldier’s skull. She sent Davidson a small sketch, telling him that she was “cocka hoopy”. Despite this experimental success, she faced up to wartime realities: “Anyway it has been deeply interesting + I expect they will kill him by operating + equally kill him by leaving it. I am sorry as he was such a nice boy in tremendous spirits + health.”</p>
<p>Gleichen was forced to leave rapidly when Gorizia fell in 1916, but after the war she was awarded medals by both Britain and Italy for her distinguished contributions. <a href="https://archive.org/details/in.ernet.dli.2015.211199/page/n7">In her memoir</a>, she wrote: “And after the War? What then? As with many other people, we were incapable of sitting still, or of resuming a normal existence.”</p>
<p>Gleichen was one of the women who were able to experience the freedom and independence which are normally deserved for men. Although she later returned to her apparently contented rural life as an artist, she had – <a href="https://global.oup.com/academic/product/a-lab-of-ones-own-9780198794998?q=A%20Lab%20of%20One%27s%20Own&lang=en&cc=gb">like so many other women</a> – become a different person.</p><img src="https://counter.theconversation.com/content/124367/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Patricia Fara does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The landscape artist bravely left her aristocratic life behind to help save lives on the Italian front.
Patricia Fara, Fellow of Clare College, Cambridge, University of Cambridge
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/104297
2018-12-03T11:45:17Z
2018-12-03T11:45:17Z
Scientist at work: To take atomic-scale pictures of tiny crystals, use a huge, kilometer-long synchrotron
<figure><img src="https://images.theconversation.com/files/247512/original/file-20181127-76752-130m1ub.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4200%2C3444&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">It takes a giant piece of equipment to look deep inside a tiny atom.</span> <span class="attribution"><a class="source" href="https://www.aps.anl.gov/About/Welcome">Advanced Photon Source at Argonne National Lab</a></span></figcaption></figure><p>It’s 4 a.m., and I’ve been up for about 20 hours straight. A loud alarm is blaring, accompanied by red strobe lights flashing. A stern voice announces, “Searching station B. Exit immediately.” It feels like an emergency, but it’s not. In fact, the alarm has already gone off 60 or 70 times today. It is a warning, letting everyone in the vicinity know I’m about to blast a high-powered X-ray beam into a small room full of electronic equipment and plumes of vaporizing liquid nitrogen.</p>
<p>In the center of this room, which is called station B, I have placed a crystal no thicker than a human hair on the tip of a tiny glass fiber. I have prepared dozens of these crystals, and am attempting to analyze all of them. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/240005/original/file-20181010-72110-13t1boh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/240005/original/file-20181010-72110-13t1boh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/240005/original/file-20181010-72110-13t1boh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=311&fit=crop&dpr=1 600w, https://images.theconversation.com/files/240005/original/file-20181010-72110-13t1boh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=311&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/240005/original/file-20181010-72110-13t1boh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=311&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/240005/original/file-20181010-72110-13t1boh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=391&fit=crop&dpr=1 754w, https://images.theconversation.com/files/240005/original/file-20181010-72110-13t1boh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=391&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/240005/original/file-20181010-72110-13t1boh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=391&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The author and her colleagues preparing crystalline samples to take to the synchrotron, in hopes of determining their atomic-level structures.</span>
<span class="attribution"><span class="source">Courtesy of Kerry Rippy</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>These crystals are made of <a href="https://theconversation.com/smart-windows-could-combine-solar-panels-and-tvs-too-95352">organic semiconducting materials</a>, which are used to make computer chips, LED lights, smartphone screens and solar panels. I want to find out precisely where each atom inside the crystals is located, how densely packed they are and how they interact with each other. This information will help me predict how well electricity will flow through them.</p>
<p>To see these atoms and determine their structure, I need the help of a synchrotron, which is a massive scientific instrument containing a kilometer-long loop of electrons zooming around at near the speed of light. I also need a microscope, a gyroscope, liquid nitrogen, a bit of luck, a gifted colleague and a tricycle.</p>
<h2>Getting the crystal in place</h2>
<p>The first step of this experiment involves placing the super-tiny crystals on the tip of the glass fiber. I use a needle to scrape a pile of them together onto a glass slide and put them under a microscope. The crystals are beautiful – colorful and faceted like little gemstones. I often find myself transfixed, staring with sleep-deprived eyes into the microscope, and refocusing my gaze before painstakingly coaxing one onto the tip of a glass fiber. </p>
<p>Once I’ve gotten the crystal attached to the fiber, I begin the often frustrating task of centering the crystal on the tip of a gyroscope inside station B. This device will spin the crystal around, slowly and continuously, allowing me to get X-ray images of it from all sides. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/240002/original/file-20181010-72113-1aubjn9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/240002/original/file-20181010-72113-1aubjn9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/240002/original/file-20181010-72113-1aubjn9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=211&fit=crop&dpr=1 600w, https://images.theconversation.com/files/240002/original/file-20181010-72113-1aubjn9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=211&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/240002/original/file-20181010-72113-1aubjn9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=211&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/240002/original/file-20181010-72113-1aubjn9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=265&fit=crop&dpr=1 754w, https://images.theconversation.com/files/240002/original/file-20181010-72113-1aubjn9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=265&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/240002/original/file-20181010-72113-1aubjn9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=265&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">On the left is the gyroscope, designed to rotate the crystal through a series of different angles as the X-ray beam hits it. Behind it is the detector panel which records the diffraction spots. On the right is a zoomed in picture of a single crystal, mounted on a glass fiber attached to the tip of the gyroscope.</span>
<span class="attribution"><span class="source">Kerry Rippy</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>As it spins, liquid nitrogen vapor is used to cool it down: Even at room temperature, atoms vibrate back and forth, making it hard to get clear images of them. Cooling the crystal to minus 196 degrees Celsius, the temperature of liquid nitrogen, makes the atoms stop moving so much.</p>
<h2>X-ray photography</h2>
<p>Once I have the crystal centered and cooled, I close off station B, and from a computer control hub outside of it, blast the sample with X-rays. The resulting image, called a diffraction pattern, is displayed as bright spots on an orange background. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/247144/original/file-20181125-149332-prb8n6.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/247144/original/file-20181125-149332-prb8n6.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/247144/original/file-20181125-149332-prb8n6.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=608&fit=crop&dpr=1 600w, https://images.theconversation.com/files/247144/original/file-20181125-149332-prb8n6.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=608&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/247144/original/file-20181125-149332-prb8n6.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=608&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/247144/original/file-20181125-149332-prb8n6.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=764&fit=crop&dpr=1 754w, https://images.theconversation.com/files/247144/original/file-20181125-149332-prb8n6.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=764&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/247144/original/file-20181125-149332-prb8n6.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=764&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This is a diffraction pattern that results when you shoot an X-ray beam at a single crystal.</span>
<span class="attribution"><span class="source">Kerry Rippy</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>What I am doing is not very different from taking photographs with a camera and a flash. I’m about to send light rays at an object and record how the light bounces off it. But I can’t use visible light to photograph atoms – they’re too small, and the wavelengths of light in the visible part of the spectrum are too big. X-rays have shorter wavelengths, so they will diffract, or bounce off atoms. </p>
<p>However, unlike with a camera, diffracted X-rays can’t be focused with a simple lens. Instead of a photograph-like image, the data I collect are an unfocused pattern of where the X-rays went after they bounced off the atoms in my crystal. A full set of data about one crystal is made up of these images taken from every angle all around the crystal as the gyroscope spins it. </p>
<h2>Advanced math</h2>
<p>My colleague, <a href="https://www.linkedin.com/in/nicholasjohndeweerd/">Nicholas DeWeerd</a>, sits nearby, analyzing data sets I’ve already collected. He has managed to ignore the blaring alarms and flashing lights for hours, staring at diffraction images on his screen to, in effect, turn the X-ray images from all sides of the crystal into a picture of the atoms inside the crystal itself.</p>
<p>In years past, this process might have taken years of careful calculations done by hand, but now he uses computer modeling to put all the pieces together. He is our research group’s unofficial expert at this part of the puzzle, and he loves it. “It’s like Christmas!” I hear him mutter, as he flips through twinkling images of diffraction patterns.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/247152/original/file-20181126-149338-1sjgkjx.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/247152/original/file-20181126-149338-1sjgkjx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/247152/original/file-20181126-149338-1sjgkjx.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=332&fit=crop&dpr=1 600w, https://images.theconversation.com/files/247152/original/file-20181126-149338-1sjgkjx.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=332&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/247152/original/file-20181126-149338-1sjgkjx.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=332&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/247152/original/file-20181126-149338-1sjgkjx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=418&fit=crop&dpr=1 754w, https://images.theconversation.com/files/247152/original/file-20181126-149338-1sjgkjx.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=418&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/247152/original/file-20181126-149338-1sjgkjx.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=418&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Solving a set of diffraction patterns produces an atomic-level picture of a crystal, showing individual molecules (left) and how they pack together to form a crystalline structure.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1002/cplu.201800451">Kerry Rippy</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>I smile at the enthusiasm he’s managed to maintain so late into the night, as I fire up the synchotron to get my pictures of the crystal perched in station B. I hold my breath as diffraction patterns from the first few angles pop up on the screen. Not all crystals diffract, even if I’ve set everything up perfectly. Often that’s because each crystal is made up of lots of even smaller crystals stuck together, or crystals containing too many impurities to form a repeating crystalline pattern that we can mathematically solve. </p>
<p>If this one doesn’t deliver clear images, I’ll have to start over and set up another. Luckily, in this case, the first few images that pop up show bright, clear diffraction spots. I smile and sit back to collect the rest of the data set. Now as the gyroscope whirls and the X-ray beam blasts the sample, I have a few minutes to relax.</p>
<p>I would drink some coffee to stay alert, but my hands are already shaking from caffeine overload. Instead, I call over to Nick: “I’m gonna take a lap.” I walk over to a group of tricycles sitting nearby. Normally used just to get around the large building containing the synchrotron, I find them equally helpful for a desperate attempt to wake up with some exercise. </p>
<p>As I ride, I think about the crystal mounted on the gyroscope. I’ve spent months synthesizing it, and soon I’ll have a picture of it. With the picture, I’ll gain understanding of whether the modifications that I have made to it, which make it slightly different than other materials I have made in the past, have improved it at all. If I see evidence of better packing or increased intermolecular interactions, that could mean the molecule is a good candidate for testing in electronic devices. </p>
<p>Exhausted, but happy because I’m collecting useful data, I slowly pedal around the loop, noting that the synchrotron is in high demand. When the beamline is running, it is used 24/7, which is why I’m working through the night. I was lucky to get a time slot at all. At other stations, other researchers like me are working late into the night. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/zfhJgY2Begk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Taking a tricycle for a ride at the Advanced Photon Source.</span></figcaption>
</figure><img src="https://counter.theconversation.com/content/104297/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kerry Rippy does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
It turns out to be fairly complicated to figure out how electricity will flow through materials – a crucial question for designing new electronics and semiconductor materials.
Kerry Rippy, Ph.D. Candidate in Chemistry, Colorado State University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/107360
2018-11-29T19:08:21Z
2018-11-29T19:08:21Z
X-rays of rocks show their super-fluid past, and reveal mineral deposits vital for batteries
<figure><img src="https://images.theconversation.com/files/247454/original/file-20181127-130878-5vud0d.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The green blob is metal-rich molten sulfide in an ore from the Norilsk area in Siberia, the most valuable accumulation of metals of any kind on the planet. </span> <span class="attribution"><span class="source">Steve Barnes </span>, <span class="license">Author provided</span></span></figcaption></figure><p>New X-ray technologies reveal some of the incredible processes that took place in Earth’s geological history – and should help us <a href="https://pubs.geoscienceworld.org/msa/ammin/article-abstract/102/3/473/277863/sulfide-silicate-textures-in-magmatic-ni-cu-pge?redirectedFrom=fulltext">identify new high value ores</a>.</p>
<p>We see that some of the most valuable accumulations of metals ever mined by humans formed from molten rocks, and particularly from molten sulfide minerals (those that feature sulfur as a major compenent).</p>
<p>These metal accumulations, called ore deposits, contain nickel, copper and cobalt – metals that are critical components of lithium-ion batteries. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-to-make-batteries-that-last-almost-forever-79750">How to make batteries that last (almost) forever</a>
</strong>
</em>
</p>
<hr>
<p>Even at present prices, large examples of such once-molten orebodies contain hundreds of billions of dollars worth of nickel, usually with valuable by-products copper, cobalt, platinum and palladium.</p>
<p>We need to keep finding new, high-grade deposits – like the recently discovered <a href="http://www.igo.com.au/irm/content/nova-project.aspx?RID=503">Nova-Bollinger orebody</a> east of Kalgoorlie in Western Australia – to keep up with the inevitable increase in demand. On current projections, a new one of these is needed every year to keep up with <a href="https://www.visualcapitalist.com/nickel-secret-driver-battery-revolution/">demand for nickel</a> in lithium-ion batteries.</p>
<p>A better understanding of how these deposits formed, deep in the Earth’s crust millions of year ago, will help us improve our exploration success rate.</p>
<h2>Plumbing system in ancient volcanoes</h2>
<p>The geological process that formed ores from molten sulfides have a lot in common with smelting (the procedure used by people for millennia to extract pure metals from sulfur-bearing minerals). </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/247626/original/file-20181127-32236-11w1irw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/247626/original/file-20181127-32236-11w1irw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/247626/original/file-20181127-32236-11w1irw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/247626/original/file-20181127-32236-11w1irw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/247626/original/file-20181127-32236-11w1irw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/247626/original/file-20181127-32236-11w1irw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/247626/original/file-20181127-32236-11w1irw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Smelting iron ore to produce steel.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/hard-work-foundry-liquid-metal-melting-792262471?src=mAgzc3ytKA0r_nN1yj10uw-1-7">from www.shutterstock.com</a></span>
</figcaption>
</figure>
<p>Millions of years ago, molten iron sulfide minerals reacted with magma in the plumbing system of ancient volcanoes – in effect scavenging the essential metals nickel, copper, cobalt and platinum. These minerals accumulated in sufficient concentrations such that they could be mined once erosion had exposed the ore at the surface.</p>
<p>Over the past few years, we have greatly improved our understanding of how these remarkable ore deposits formed. This understanding has been built up using new techniques in imaging the ores in two and three dimensions, using <a href="https://www.csiro.au/en/Research/MRF/Areas/Orebody-knowledge/Maia">X-ray technologies at CSIRO</a> and the <a href="http://archive.synchrotron.org.au/">Australian Synchrotron</a> .</p>
<p>We have been using a technique called microbeam X-ray element mapping to make detailed 2D images of the ores and the rocks they sit in. </p>
<p>Some of these images – such as the one at the top of this story – are created on the X-ray fluorescence microscopy beamline at the Australian Synchrotron, applying the <a href="https://publications.csiro.au/rpr/pub?pid=csiro:EP1311783">Maia detector system</a>. This enables gigapixel images to be collected in a matter of minutes.</p>
<h2>Like turning on the light</h2>
<p>Complementing this technique, we’ve also applied high-resolution 3D X-ray tomography – the equivalent of a hospital CT scan – to reveal in 3D details on the shape and size of the droplets of sulfide liquid that formed the ores. </p>
<p>The effect has been to turn on a light in a dark room: we have seen features inside solid rocks that have not previously been revealed.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/247456/original/file-20181127-130884-sebjs6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/247456/original/file-20181127-130884-sebjs6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=413&fit=crop&dpr=1 600w, https://images.theconversation.com/files/247456/original/file-20181127-130884-sebjs6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=413&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/247456/original/file-20181127-130884-sebjs6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=413&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/247456/original/file-20181127-130884-sebjs6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=519&fit=crop&dpr=1 754w, https://images.theconversation.com/files/247456/original/file-20181127-130884-sebjs6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=519&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/247456/original/file-20181127-130884-sebjs6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=519&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An X-ray tomography image (CT scan) of an ore sample showing frozen droplets of sulfide liquid as red blobs.</span>
<span class="attribution"><span class="source">Steve Barnes</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Sulfide liquids, it turns out, have remarkable physical properties. They behave like a hot knife through butter: so corrosive that they can melt their way through solid rocks, ending up in some cases tens of metres away from their original host rocks.</p>
<p>We now know that orebodies form in very particular parts of the ancient “plumbing systems” that fed magmas to the volcanoes above. The ores formed where the flowing magma was so hot that it melted the rocks around it. </p>
<p>The “hot knife” sulfide liquid then continued to melt its way into the floor, such that the ores are now found injected into the underlying non-igneous rocks.</p>
<p>In the case of the supergiant nickel ores of the Norilsk region in Siberia, the rocks that melted also supplied the sulfur to form the orebodies. </p>
<p>In fact, so much sulfur was released by this process that much of it, along with vast amounts of nickel, was actually erupted into the atmosphere, contributing to the <a href="https://theconversation.com/death-metal-how-nickel-played-a-role-in-the-worlds-worst-mass-extinction-74754">greatest mass extinction in Earth history</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/death-metal-how-nickel-played-a-role-in-the-worlds-worst-mass-extinction-74754">Death metal: how nickel played a role in the world's worst mass extinction</a>
</strong>
</em>
</p>
<hr>
<h2>Needle in haystack targets</h2>
<p>This type of work helps us improve geological models the exploration industry uses to explore for new deposits. </p>
<p>Nickel sulfide ores are notoriously difficult “needle in haystack” targets, and we need to bring our best combination of geophysical detection techniques and predictive geological models.</p>
<p>So where next? </p>
<p>Research is ongoing: both into the fundamental processes of ore formation and into the implications of this understanding for where and how to look for new deposits. </p>
<p>Some of the minerals that form along with the sulfide ores can be dispersed by erosion, and rivers transport them long distances from the deposits themselves. </p>
<p>We are learning how to recognise these chemically distinctive grains, in the same way diamond explorers use “indicator minerals” to find fertile kimberlites (the source rock for diamonds). </p>
<p>We’re also doing more fundamental research, such as using analogue material (salt water and olive oil work very well, it turns out) and computational fluid dynamic models on supercomputers to look into the physics of how magmatic ores come to look the way they do.</p><img src="https://counter.theconversation.com/content/107360/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Steve Barnes receives funding from the CSIRO Research Office Science Leader fund. The synchrotron XRF mapping was carried out on the XFM beamline of the Australian Synchrotron, Clayton, Victoria, operated by ANSTO.</span></em></p>
Liquid minerals containing sulfur behave like a hot knife through butter – they’re so corrosive they can melt their way through solid rock.
Steve Barnes, Geologist, CSIRO
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/101344
2018-08-16T11:26:15Z
2018-08-16T11:26:15Z
Why X-rays could be about to get a lot more personal
<figure><img src="https://images.theconversation.com/files/231873/original/file-20180814-2894-5gdxj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Finger mounted flexible detector</span> </figcaption></figure><p>X-rays could be about to change. Since its discovery at the end of the 19th century, the radiation has provided a window into the inner workings of the body, and later gave us the power to “see” inside everything from buildings to suitcases. But the technology has remained in principle the same: the rays are fired through whatever object is being inspected onto a fixed, rigid and usually small detector that can produce the desired image.</p>
<p>But X-rays could be much more flexible in future. New technology means that X-ray detectors could one day effectively be printed onto any suitable surface. So they could be made curved to wrap around the part of the patient’s body being scanned to produce a much more accurate image. They could be large enough to scan an entire truck in one go. And they could be portable enough to quickly carry through a crowd to inspect a suspicious package. And this future is now a step closer thanks to a recent advance that my colleagues and I have made.</p>
<p>Today, many X-ray images are created by firing the rays onto a <a href="http://iopscience.iop.org/article/10.1088/0031-9155/42/1/001/pdf">digital detector</a> rather than photographic film. These detectors convert the X-rays into electrical charges and a computer converts these into a digital image. Many industries have benefitted from this massive leap from X-ray film because it has enabled the creation of more detailed images that can be viewed in real time. But the solid detectors are also rigid and flat and so limited.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/13J16FqWeXg?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>By contrast, the human body naturally consists of curved surfaces. And firing X-rays through a curved object onto a flat detector can cause <a href="https://www.holstcentre.com/news---press/2017/curvedxray/">errors</a>. This can lead to a cancer misdiagnosis or a patient being given the wrong dose of radiotherapy. Overexposing someone to X-rays can also cause tissue damage and even the growth of <a href="http://stopcancerfund.org/pz-environmental-exposures/everything-you-ever-wanted-to-know-about-radiation-and-cancer-but-were-afraid-to-ask-2/">secondary tumours</a>.</p>
<p>Because current X-ray detectors are mostly made from thick slabs of inorganic material, they are expensive to make in large sizes for scanning large objects such as vehicles. Some detectors also require very high voltages to operate and so would’t be suitable for <a href="https://www.or-technology.com/en/products/mobile/leonardo-dr-mini.html">portable applications</a>.</p>
<p>For inspecting manufactured parts and products for defects (known as non-destrutive testing), traditional X-ray films are still commonly used to capture images because they are cheaper than digital detectors. But these films need to be processed in a special lab so they can’t provide the real-time images that digital detectors can.</p>
<h2>Flexible detectors</h2>
<p>All these applications would benefit from the creation of more flexible digital X-ray detectors. And it looks as if there might finally be a solution. In 2017, researchers demonstrated the <a href="http://www.osadirect.com/news/article/2053/holst-centre-imec-and-philips-demo-worlds-first-curved-plastic-photodetector/">world’s first</a> curved plastic X-ray imager. And now, my colleagues and I have developed a way to create detectors using a <a href="https://www.nature.com/articles/s41467-018-05301-6">special ink</a> that can be deposited on a surface to create an X-ray sensitive film.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/eeVovEfLFe8?wmode=transparent&start=1" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>The ink contains nanoparticles that can stop the incoming X-rays and generate an electrical charge, and organic material that carries the charge to a set of electrodes. It can be coated or printed onto any suitable surface of any size and only needs to be several micrometers thick, less than a sheet of paper.</p>
<p>As a result, it is now possible to create large, flexible X-ray detectors powered using only a couple of coin cell batteries. Alternatively, we could create portable X-ray detectors that, coupled with portable X-ray sources, could fit into ambulances and be used to make diagnoses on the road and not just in hospitals. And improving the resolution of the images could allow the technology to be used for detecting cancer.</p>
<p>Researchers are also <a href="https://healthcare-in-europe.com/en/news/high-resolution-detectors-to-create-safer-x-ray-diagnosis.html">working</a> to create detectors that can work with lower X-ray doses, to minimise the amount of radiation that patients and operators are exposed to. This will require identifying materials that are more sensitive to X-rays so that a better response can be achieved with a lower dose. This technology has such exciting potential to revolutionise current imaging techniques and where this would take us is only limited by our imagination.</p><img src="https://counter.theconversation.com/content/101344/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hashini Thirimanne receives funding from the Leverhulme Trust. </span></em></p>
An X-ray sensitive ink means future detectors could be printable, portable and flexible.
Hashini Thirimanne, PhD Candidate in Electronic Engineering, University of Surrey
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/99017
2018-07-05T20:03:07Z
2018-07-05T20:03:07Z
Having a scan? Here’s how the different types work and what they can find
<figure><img src="https://images.theconversation.com/files/225444/original/file-20180629-117422-1q85uik.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Medical imaging such as MRI can seem daunting, and perhaps even a little sci-fi.</span> <span class="attribution"><span class="source">from www.shutterstock.com</span></span></figcaption></figure><p>Our first introduction to medical imaging occurs when a doctor asks us to have an x-ray or scan to investigate an injury, pain or symptom that cannot otherwise be explained. We can be overwhelmed when we see how complicated, large and noisy some of the equipment is.</p>
<p>Many different types of examinations can be performed to investigate conditions and injuries. Sometimes more than one of the following medical imaging techniques is required to enable doctors to offer the best advice on treatment options. </p>
<h2>‘X-rays’ or planar radiography</h2>
<p>This is still the most common, widely-available and simplest form of medical imaging, often used to see a broken bone. X-rays are actually photons, or tiny packets of energy (referred to as ionizing radiation) and form part of the electromagnetic spectrum (as does visible light, microwaves and radio waves).</p>
<p>As an x-ray beam passes through human tissue, these x-ray photons can be absorbed and deflected by dense tissue structures such as bone and may not exit the body. Other x-ray photons may encounter tissue that is less dense (such as muscle) and are able to pass through this quite easily and exit the body.</p>
<p>The exiting x-ray photons then reach a digital imaging receptor or detector where they provide a tissue density pattern for the digital receptor to convert into the x-ray image (or radiograph) that we are familiar with.</p>
<p>Dense tissue such as bone that has attenuated the x-ray beam appears dense or white; less dense tissue such as lungs that are filled with air appear less dense or dark, which we observe with a “chest x-ray”. Other tissues in the human body have densities between these two extremes and appear on an x-ray image as different shades of grey.</p>
<p>Patients should be reassured this form medical imaging is straight-forward, and there should be no risk or danger from the radiation when used correctly.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/225433/original/file-20180629-117374-fk5vwz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225433/original/file-20180629-117374-fk5vwz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/225433/original/file-20180629-117374-fk5vwz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=444&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225433/original/file-20180629-117374-fk5vwz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=444&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225433/original/file-20180629-117374-fk5vwz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=444&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225433/original/file-20180629-117374-fk5vwz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=558&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225433/original/file-20180629-117374-fk5vwz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=558&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225433/original/file-20180629-117374-fk5vwz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=558&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The x-ray beam can easily pass through less-dense material such as muscular or soft tissues. It requires higher energy to pass through denser materials such as bone.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<h2>Computed tomography (CT)</h2>
<p>This technique uses an x-ray beam to produce cross-sectional images of the human body. When the imaging process is taking place, the x-ray tube continuously emits an x-ray beam and is rotating in a 360 degree circle in a device called a gantry. </p>
<p>While this is happening, the patient is lying on a special CT imaging table that is allowing the x-ray beam through. The x-ray beam is shaped similar to a hand-held fan and is often described as a fan beam. There are multiple digital detectors located within this circular gantry that continually identify the energy of the x-ray photons that exit the patient.</p>
<p>The motion of the table and patient moving through the gantry allows images to be reconstructed as slices (or tomographs) of human tissue. The most common CT exam is to scan a patient’s chest, abdomen and pelvis, and the most common reason for this is to identify the spread of cancer. “X-ray dyes” are injected into patients to identify cancer when using CT imaging, as the cancer tissue will absorb the “x-ray dye” and be more obvious on the image. </p>
<p>With routine CT imaging techniques, there should not be any risks or danger to patients from the levels of radiation used.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/225617/original/file-20180702-116139-nq8z7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225617/original/file-20180702-116139-nq8z7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/225617/original/file-20180702-116139-nq8z7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225617/original/file-20180702-116139-nq8z7f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225617/original/file-20180702-116139-nq8z7f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225617/original/file-20180702-116139-nq8z7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225617/original/file-20180702-116139-nq8z7f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225617/original/file-20180702-116139-nq8z7f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The rotating x-ray beam in CT scans creates images in the form of slices (or tomographs) of the body and can also be reconstructed using computer software to produce the above images.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<h2>Magnetic resonance imaging (MRI)</h2>
<p>MRI uses a combination of a powerful cylindrical magnet and radiofrequency waves to generate an image of the body. It’s quite loud and patients must be wearing suitable hearing protection devices such as earplugs or headphones (where relaxing music can be listened to).</p>
<p>Patients normally lie within the magnet cylinder, and a frame (which works like an antennae) is placed around the body area needing to be imaged, as close as possible, so the maximum possible signal can be detected in order to reconstruct highly detailed images. </p>
<p>Our body contains hydrogen, so a radiofrequency is transmitted into the body at the frequency that will cause hydrogen atoms to oscillate. When the radiofrequency is switched off, the hydrogen atoms continue to oscillate and the frequency of this oscillation is detected by the frame or antennae.</p>
<p>The radiofrequency causes a voltage signal in the antennae, which is <a href="https://en.wikipedia.org/wiki/Faraday%27s_law_of_induction">identified as an electrical signal</a>. This is then digitised and an image is reconstructed using complex mathematical calculations. </p>
<p>Safety is paramount for patients having an MRI scan, and all patients must complete a safety questionnaire first to ensure they’re compatible with the imaging environment. The safety questionnaire asks if patients have any implanted metal objects such as pacemakers or infusion pumps or similar medical devices. This is because certain metal objects can cause harm to patients or staff if they enter the MRI environment because of the powerful magnet.</p>
<p>The most common application of MRI is imaging the brain with conditions that relate to neurology or neurosurgery.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/225618/original/file-20180702-116126-1tgyo8r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225618/original/file-20180702-116126-1tgyo8r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/225618/original/file-20180702-116126-1tgyo8r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=428&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225618/original/file-20180702-116126-1tgyo8r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=428&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225618/original/file-20180702-116126-1tgyo8r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=428&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225618/original/file-20180702-116126-1tgyo8r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=538&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225618/original/file-20180702-116126-1tgyo8r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=538&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225618/original/file-20180702-116126-1tgyo8r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=538&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">MRI can produce highly detailed images of the brain.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<h2>Positron emission tomography (PET)</h2>
<p>The imaging techniques used with x-rays, CT and MRI, are mostly designed to observe structural information – this includes the arrangement of anatomy and the location of disease or injuries. PET imaging is a unique imaging process, as it can identify and image functional information such as metabolic (the converting of energy) or chemical processes of internal body organs.</p>
<p>To do this, radioactive substances need to be injected into patients and these are chemically bonded to compounds used by our organs (such as glucose) or molecules that bind to specific receptors or specific types of cells (such as proteins).</p>
<p>These radioactive substances emit gamma rays (another form of ionizing radiation). From their location within the body, the gamma rays pass through tissue and exit the body where they are detected by a PET scanner containing a gamma camera while the patient is lying still.</p>
<p>The PET scanner detects the gamma rays, converts their intensity or strength into an electrical signal and then reconstructs an image based on this intensity. The detectors are arranged around a patient’s body so the originating location of the gamma rays within the patient can be calculated using mathematical processes.</p>
<p>PET imaging is excellent for identifying the activity of tumours within organs that cannot be structurally identified with other imaging techniques.</p>
<p>Even though the thought of being injected with radioactive material may sound dangerous, it actually isn’t. Imaging techniques similar to this have been around for many decades and PET imaging techniques are performed nearly everyday in major hospitals across Australia. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/225438/original/file-20180629-117425-6dyb0p.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225438/original/file-20180629-117425-6dyb0p.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/225438/original/file-20180629-117425-6dyb0p.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=316&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225438/original/file-20180629-117425-6dyb0p.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=316&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225438/original/file-20180629-117425-6dyb0p.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=316&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225438/original/file-20180629-117425-6dyb0p.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=398&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225438/original/file-20180629-117425-6dyb0p.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=398&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225438/original/file-20180629-117425-6dyb0p.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=398&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In PET scans patients are injected with radioactive substances that move through the body and emit gamma rays. This means the images can show the functioning of cells and tumours.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<h2>Ultrasound</h2>
<p>Ultrasound uses sound waves to generate a medical image of human anatomy, and has no known detrimental effects. The frequency of ultrasound is higher than the sound wave frequencies that can be detected by human hearing. Sound waves can only travel through a medium, so a water-based gel needs to be applied to the skin, which allows the ultrasound to be transmitted from the transducer (or probe - the thing that’s moved over the area being scanned) into the body. </p>
<p>Ultrasound reflects sound waves differently from all the different tissues within the body, the more dense a tissue is, the more sound waves are reflected and returned to the transducer. Where tissue is less dense, part of the sound waves will be returned to the transducer and part of the ultrasound will be transmitted through this tissue until it reaches a different type of tissue and the process continues (partly reflected and partly transmitted).</p>
<p>When ultrasound waves return to the transducer, the sound waves are converted into an electrical signal, which is then digitised and reconstructed as an image. The image is formed by calculating the distance from where the reflected sound waves interacted with tissue and the transducer, and is calculated by knowing that in human tissue, ultrasound travels at approximately 1,540 metres per second.</p>
<p>For many ultrasound imaging examinations, patients are asked to hold their breath so internal organs remain still while imaging is taking place. They may also be asked to move into certain positions.</p>
<p>In addition to providing structural information on how anatomy is arranged, ultrasound has the added benefit of providing biomechanical and functional information, as it can also image in real time and observe muscles and tendons moving.</p>
<p>Ultrasound imaging has two important applications. The first is in pregnancy and the second is to see if muscles and tendons are in some way damaged.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/225441/original/file-20180629-117436-1gbzl1g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225441/original/file-20180629-117436-1gbzl1g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/225441/original/file-20180629-117436-1gbzl1g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=435&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225441/original/file-20180629-117436-1gbzl1g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=435&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225441/original/file-20180629-117436-1gbzl1g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=435&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225441/original/file-20180629-117436-1gbzl1g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=547&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225441/original/file-20180629-117436-1gbzl1g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=547&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225441/original/file-20180629-117436-1gbzl1g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=547&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Everyone would be familiar with this sight. Ultrasound is used extensively to image during pregnancy.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure><img src="https://counter.theconversation.com/content/99017/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Giovanni Mandarano is member of the Australian Society of Medical Imaging and Radiation Therapy and is also registered with the Medical Radiations Practice Board of Australia. </span></em></p>
There are many different types of medical imaging and they all pick up different things.
Giovanni Mandarano, Associate Professor in Medical Imaging, Deakin University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/96771
2018-05-31T10:45:00Z
2018-05-31T10:45:00Z
Immigration agents X-raying migrants to determine age isn’t just illegal, it’s a misuse of science
<figure><img src="https://images.theconversation.com/files/221038/original/file-20180530-120518-d8e1xv.jpg?ixlib=rb-1.1.0&rect=3%2C2%2C772%2C542&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Teeth and bones can tell something about age – but not someone's birthday.</span> <span class="attribution"><a class="source" href="https://openi.nlm.nih.gov/detailedresult.php?img=PMC3190433_JFDS-3-14-g005&query=&req=4&npos=-1">Journal of Forensic Dental Sciences</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>A teenager’s father is murdered in Somalia, and the boy travels to the United States seeking asylum. Another teen’s father and brother are murdered by extremist groups in Afghanistan and he too makes his way to the U.S. to seek asylum. Since both are minors, <a href="https://www.gpo.gov/fdsys/pkg/PLAW-107publ296/html/PLAW-107publ296.htm">federal law decrees</a> that they must be held separately from adults under the oversight of the Office of Refugee Resettlement (<a href="https://www.acf.hhs.gov/orr">ORR</a>).</p>
<p>However, <a href="https://www.revealnews.org/blog/heres-how-ice-sent-children-seeking-asylum-to-adult-detention-centers/">in these two cases</a>, and an unknown number of others, these minors were taken in handcuffs by Immigration and Customs Enforcement and held in adult detention facilities. The reason? In the absence of other information that could corroborate the teens’ self-reported ages, analysis of their dental X-rays revealed that both could be adults.</p>
<p>Lawyers for these two teens <a href="https://www.nwirp.org/wp-content/uploads/2016/05/050516-Pechman-Order.pdf">sued on</a> <a href="https://www.documentcloud.org/documents/4451390-H-S-order.html">the grounds</a> that sole reliance on X-rays for age determination is illegal, and several federal judges agreed.</p>
<p>As a forensic anthropologist, I support these judicial decisions. My work can include estimating the ages of deceased persons using X-rays of bones and teeth, and I’m intimately familiar with the limitations of how specific these techniques can be. In my field, we generate an age range alongside several caveats; it’s irresponsible for ICE to rely solely on X-rays to provide a definitive answer in determining if a person is a minor or an adult.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/220866/original/file-20180529-80637-1e77wee.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/220866/original/file-20180529-80637-1e77wee.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/220866/original/file-20180529-80637-1e77wee.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=266&fit=crop&dpr=1 600w, https://images.theconversation.com/files/220866/original/file-20180529-80637-1e77wee.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=266&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/220866/original/file-20180529-80637-1e77wee.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=266&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/220866/original/file-20180529-80637-1e77wee.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=334&fit=crop&dpr=1 754w, https://images.theconversation.com/files/220866/original/file-20180529-80637-1e77wee.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=334&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/220866/original/file-20180529-80637-1e77wee.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=334&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">X-ray of a mouth with wisdom teeth emerging on the outside.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.4103/0975-1475.137068">Journal of Forensic Dental Sciences</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<h2>What can bones and teeth tell us?</h2>
<p><a href="https://www.crcpress.com/Forensic-Anthropology-An-Introduction/Langley-Tersigni-Tarrant/p/book/9781439898253">Forensic anthropologists study</a> the hard tissues of the human body, which includes bones and teeth. I’m typically charged with <a href="https://www.elsevier.com/books/research-methods-in-human-skeletal-biology/digangi/978-0-12-385189-5">estimating biological characteristics</a> of deceased persons, including how old a person was when they died.</p>
<p>For children and teenagers, such an analysis can be carried out by examining X-rays. Growth and development are predictable processes, and milestones occur in a particular order. This is the reason that a tooth such as the first adult molar is also known as the “six-year molar,” because it generally erupts in everyone around age 6, give or take.</p>
<p>The analysis proceeds the same way whether we’re examining the X-rays of a living or deceased person. Essentially, we compare the stage of growth shown in the X-ray to <a href="https://www.atlas.dentistry.qmul.ac.uk">existing growth charts</a> from children and teenagers of known ages.</p>
<p>The crucial point is that it’s not possible to make a definitive, single age determination from X-rays or examination of bones or teeth. A variety of factors affect how well chronological age corresponds with biological age; that is, the amount of time since birth doesn’t necessarily correlate to the exact same stage of growth in every child or teenager. </p>
<p><a href="http://admin.cambridge.org/academic/subjects/life-sciences/biological-anthropology-and-primatology/paleodemography-age-distributions-skeletal-samples#jmjs2GKsG24UOjZ3.97">Lots of things</a> can influence how well <a href="https://global.oup.com/academic/product/biological-anthropology-and-aging-9780195068290?lang=en&cc=be">biological and chronological age line up</a>, including nutrition, environmental exposure to disease-causing germs and viruses (and their level of virulence), whether the person has been vaccinated against preventable diseases, body weight, hormones and genetics, among many others.</p>
<p>While these factors differ between individuals, they also differ broadly between populations of people – for instance, as a group, Americans likely develop at a different rate than sub-Saharan Africans. </p>
<p>Many of the studies relied upon to make age estimations are based on populations not representative of the individuals to whom they’re being applied. Therefore, a <a href="https://www.wiley.com/en-us/A+Companion+to+Forensic+Anthropology-p-9781118959794">certain amount of error</a> can be expected in the final age estimation. What’s more, this error is immeasureable. Without scientific studies on growth that are specific to each population, we don’t know if on average, Population A ages six months, one year or two years faster or slower than Population B. And while many methods are bolstered by a statistical likelihood, this is not the same thing as being certain. We can never be 100 percent sure.</p>
<h2>Estimation ranges versus exact ages</h2>
<p>Of course, the amount of time since birth is the legally important age. But because a disparity exists, forensic anthropologists refer to the results of the scientific methods we use as “age estimation.” The estimation will never be a pinpointed exact age, because of the variation that exists between individuals and between populations of people.</p>
<p>Therefore, forensic anthropologists report age estimations as a range. For example, rather than saying someone is 17 years and 8 months old, our estimation may be that she is between 17 and 20 years old.</p>
<p><iframe id="dqTSx" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/dqTSx/4/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>Sometimes, the estimated age range might include ages below and above 18. Take the development of the wisdom tooth, something we often look at when estimating age of older teenagers and young adults. But the development of this tooth is extremely variable, ranging from never developing at all to erupting anywhere from the mid-teens to early 20s. In such cases, how would a final decision of adult or minor status be made?</p>
<p><a href="https://www.state.gov/j/tip/laws/113178.htm">Federal law</a> dictates that X-rays in cases where adult age is not obvious be used only in concert with other methods, such as verification of documentation and interviews. This makes sense because X-rays only provide orienting information rather than a definitive answer. </p>
<p>The recent court cases demonstrate that ICE has broken the law by exclusively relying on X-rays for age determination, ruling that the teens be released back into ORR’s custody as minors. Are these cases isolated or illustrative of a bigger problem? <a href="https://www.documentcloud.org/documents/4450510-DHS-OIG-Report-on-ICE.html">A 2008 report</a> by the Office of Homeland Security found that it was not only unclear how often ICE needed to resort to X-rays to assist with age determination, but unknown how common it was for them to rely solely on X-ray results. Without accurate numbers, there is no way to know how widespread the practice is or how to improve the process.</p>
<p>The stakes are high. Children – especially unaccompanied ones – are especially vulnerable. For this reason, the <a href="https://www.aclu.org/sites/default/files/assets/flores_settlement_final_plus_extension_of_settlement011797.pdf">1997 Flores Settlement Agreement</a>, which ICE is bound by, stipulates that migrant minors be kept separate from unrelated adults. </p>
<p>Given recent news that ORR doesn’t know the <a href="https://www.nytimes.com/2018/04/26/us/politics/migrant-children-missing.html">whereabouts of almost 1,500 children</a> it placed, many people have lost confidence in these agencies to do the right or moral thing regarding migrants. If ORR can’t keep track of children under its care, can ICE be trusted to lawfully treat people whose ages are uncertain?</p>
<p>In this situation, the law is consistent with the science. And as a scientist, I am obligated to ensure my interpretations are not used irresponsibly in a way that could cause harm. Citizens, scientists and government officials alike should ensure that refugees and migrants are treated fairly, with the dignity and respect they deserve, and in a way consistent with how we would expect to be treated. Making age determinations based on X-rays alone is not in line with that goal and can have serious punitive consequences for young migrants.</p><img src="https://counter.theconversation.com/content/96771/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elizabeth A. DiGangi is affiliated with the ACLU. </span></em></p>
If an undocumented migrant is a minor or an adult can have far-reaching implications. A forensic anthropologist explains why relying solely on dental X-rays to determine age doesn’t work.
Elizabeth A. DiGangi, Assistant Professor of Anthropology, Binghamton University, State University of New York
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/93628
2018-03-22T10:36:04Z
2018-03-22T10:36:04Z
The dinosaur that got away: how we diagnosed a 200-million-year-old infected predator bite
<figure><img src="https://images.theconversation.com/files/211201/original/file-20180320-31602-nc28x0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Reconstruction of the bite wound affecting the shoulder of our herbivorous dinosaur.</span> <span class="attribution"><span class="source">Zongda Zhang/Lida Xing</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><blockquote>
<p>Nature, red in tooth and claw. </p>
</blockquote>
<p>When Tennyson published his poem <a href="http://www.online-literature.com/tennyson/718/">In Memoriam</a>, little did he know that this phrase from it would become so intimately associated with the process of Darwinian natural selection. Five little words which evoke the harsh evolutionary realities of competition for food, resources and life itself between predator and prey, the hunter and the hunted. </p>
<p>Now my colleagues and I, led by Lida Xing from the China University of Geosciences (Beijing), have <a href="http://www.nature.com/articles/s41598-018-23451-x">published evidence</a> of one lucky animal that got away – in this case, a herbivorous dinosaur from China. Our work highlights how the use of X-ray tomography – a rapidly developing technique in digital imaging – is revolutionising the study of the fossil record.</p>
<p>Our dinosaur is <em>Lufengosaurus huenei</em>, a Lower Jurassic sauropod, who would have lived 200-170m years ago in what is now Yunnan Province, China. <a href="http://www.prehistoric-wildlife.com/species/l/lufengosaurus.html"><em>Lufengosaurus</em></a> was a herbivore, around six metres in length and weighing a little under two tonnes. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/211351/original/file-20180321-165568-1tywk1n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/211351/original/file-20180321-165568-1tywk1n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=342&fit=crop&dpr=1 600w, https://images.theconversation.com/files/211351/original/file-20180321-165568-1tywk1n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=342&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/211351/original/file-20180321-165568-1tywk1n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=342&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/211351/original/file-20180321-165568-1tywk1n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=430&fit=crop&dpr=1 754w, https://images.theconversation.com/files/211351/original/file-20180321-165568-1tywk1n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=430&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/211351/original/file-20180321-165568-1tywk1n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=430&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Map showing the location of the dinosaur fossil discovery.</span>
<span class="attribution"><span class="source">Lida Xing</span></span>
</figcaption>
</figure>
<p>When the dinosaur was excavated in 1997, there was a pathological abnormality on one of the right ribs of the animal. Viewed from the side, there is a concave section of missing bone which cuts almost halfway through the rib. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/211346/original/file-20180321-165568-m5eei6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/211346/original/file-20180321-165568-m5eei6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/211346/original/file-20180321-165568-m5eei6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1138&fit=crop&dpr=1 600w, https://images.theconversation.com/files/211346/original/file-20180321-165568-m5eei6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1138&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/211346/original/file-20180321-165568-m5eei6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1138&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/211346/original/file-20180321-165568-m5eei6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1430&fit=crop&dpr=1 754w, https://images.theconversation.com/files/211346/original/file-20180321-165568-m5eei6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1430&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/211346/original/file-20180321-165568-m5eei6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1430&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The pathological rib of Lufengosaurus, showing the removal of a large area of bone.</span>
<span class="attribution"><span class="source">Lida Xing</span></span>
</figcaption>
</figure>
<p>The traditional approach in studying bone pathology is what is termed “morphoscopic evaluation”. This usually involves low powered magnification of the bone, but this would only image the external surface of the fossil. In the case of our rib, the lesion penetrated deep into the bone, so seeing the internal structure was needed for a diagnosis. </p>
<p>Now, 20 years after its initial discovery, we have used <a href="https://www.microphotonics.com/how-does-a-microct-scanner-work/">X-ray micro-computed tomography</a>, or micro-CT for short, to image the deep structures of our dinosaur.</p>
<h2>Seeing inside fossils</h2>
<p>Tomography (from the Greek <em>tomos</em> to slice, and <em>graphos</em> to write) is a non-invasive technique that has significant diagnostic advantages over conventional methods, allowing high-resolution slices and 3D images to be built up of internal structures without damaging the fossil.</p>
<p>Following micro-CT scanning, we reconstructed the cellular structure of the rib. In cross-section, there was clear evidence of both destructive changes and new bone formation which could not be observed from the outside. The pattern of these bone-destroying and bone-forming processes tells us that the disease process was both chronic (long-term) and active at the time of the animal’s death.</p>
<p>We diagnosed a process called osteomyelitis, which in this case had produced an abscess inside the bone. Osteomyelitis is a severe infection originating in the bone marrow, usually resulting from the introduction of pyogenic (pus-producing) bacteria into the bone. Pathogens enter the bone via the bloodstream, or through open wounds or fractures.</p>
<p>This is only the second case of osteomyelitis to be found in a sauropod dinosaur in the fossil record. The only other case comes from a <a href="https://www.researchgate.net/publication/308797156_The_first_evidence_of_osteomyelitis_in_a_sauropod_dinosaur">giant titanosaur from Argentina</a> who had a bacterial infection of the spine. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/211352/original/file-20180321-165577-1dduk9t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/211352/original/file-20180321-165577-1dduk9t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=610&fit=crop&dpr=1 600w, https://images.theconversation.com/files/211352/original/file-20180321-165577-1dduk9t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=610&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/211352/original/file-20180321-165577-1dduk9t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=610&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/211352/original/file-20180321-165577-1dduk9t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=766&fit=crop&dpr=1 754w, https://images.theconversation.com/files/211352/original/file-20180321-165577-1dduk9t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=766&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/211352/original/file-20180321-165577-1dduk9t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=766&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Micro-computed tomography allowed us to produce surface renderings of the fossil in 3D (top row) and 2D X-ray slices through the rib (bottom row). These show areas of cellular reorganisation, bone destruction and bone formation indicative of ostemyelitis.</span>
<span class="attribution"><span class="source">Patrick Randolph-Quinney, UCLan</span></span>
</figcaption>
</figure>
<h2>Tooth and claw</h2>
<p>In this <em>Lufengosaurus</em> we also have the earliest recorded case of a bony abscess caused by osteomyelitis in the fossil record. </p>
<p>Given the shape of the lesion, and its position on the ribcage, we think that the infection may have been caused by a puncture wound from a bite. The teardrop shape suggests that the damage was produced by a tooth or claw, and is in keeping with evidence for predator bite trauma found elsewhere in the dinosaur fossil record.</p>
<p>The bacterial infection would have had a big impact on the life of the Yunnan dinosaur. Osteomyelitis is known to produce fever, fatigue, nausea and discomfort, and may send tracts of bacteria into the brain, accelerating death. We know that the dinosaur survived for some time with this infection, but this may have made it vulnerable to other diseases or unable to fend for itself in the long term.</p>
<p>What is exciting is that this case gives us evidence of interaction between a large plant-eating dinosaur (a sauropod) and one of the aggressive predators living at that time. We don’t just have evidence of disease but of behaviour between animals – between predator and prey at this deep period in prehistory. </p>
<p>We do not know which species of predator caused the bite, but the wound from the failed attack is a smoking gun. It is possible that <a href="http://www.prehistoric-wildlife.com/species/s/sinosaurus.html"><em>Sinosaurus</em></a>, a well-known predator found in Jurassic Yunnan, would have been able to attack <em>Lufengosaurus</em>.</p>
<h2>Virtual palaeontology</h2>
<p>This discovery was only made possible by the application of X-ray tomography (micro-CT). The first commercially available micro-CT scanner appeared in 1994, but it is only in the last decade that it has begun to be used in palaeontology, partly because of the cost of the equipment. Tomography is increasingly allowing us to understand processes such as trauma and infection in the fossil record at the cellular level. </p>
<p>This technology has opened up the fossil record, allowing palaeontologists to image and analyse the deep structure of fossils. This has enabled spectacular discoveries such as the <a href="https://www.sajs.co.za/article/view/3566">earliest hominin cancer</a> and the <a href="https://www.sajs.co.za/article/view/3562">earliest tumour</a>, the <a href="https://www.nature.com/articles/s41467-018-03296-8.pdf">flight pattern of Archaeoptryx</a>, or to <a href="https://www.sciencedirect.com/science/article/pii/S2095927318300331">rebuild an early bird trapped in amber</a>. It has also allowed us to <a href="https://www.sajs.co.za/article/view/3580">correct historical cases of pathological misdiagnosis</a> in fossils. </p>
<p>The resulting scans can be shared across the world, visualised and studied without the need to access the fossils directly. They can also be <a href="http://johnhawks.net/weblog/topics/metascience/open-access/benefits-data-brouwers-q-and-a-2015.html">3D printed</a>, both in their actual size or at any other scale that we require. </p>
<p>Who knows what spectacular discoveries await us using this technology, but it is clear that the future of <a href="https://www.theguardian.com/science/2016/mar/30/getting-under-a-fossils-skin-how-ct-scans-have-changed-palaeontology-dinosaur-lizard">palaeontological research is virtual</a>.</p><img src="https://counter.theconversation.com/content/93628/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Patrick Randolph-Quinney does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
New research uses pathology in dinosaur bones to look at predator-prey interactions in the fossil record.
Patrick Randolph-Quinney, Reader/Associate Professor in Biological and Forensic Anthropology, University of Central Lancashire
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/86068
2018-01-21T19:14:40Z
2018-01-21T19:14:40Z
Looking at the universe through very different ‘eyes’
<figure><img src="https://images.theconversation.com/files/199349/original/file-20171215-26009-n5x6px.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Small Magellanic Cloud galaxy here seen in infrared light, but it looks different when viewed at other wavelengths.</span> <span class="attribution"><a class="source" href="https://www.nasa.gov/multimedia/imagegallery/image_feature_2323.html">ESA/NASA/JPL-Caltech/STScI</a></span></figcaption></figure><p>We are bathed in starlight. During the day we see the Sun, light reflected off the surface of the Earth and blue sunlight <a href="https://theconversation.com/curious-kids-why-is-the-sky-blue-and-where-does-it-start-81165">scattered by the air</a>. At night we see the stars, as well as sunlight reflected off the Moon and the planets.</p>
<p>But there are more ways of seeing the universe. <a href="https://theconversation.com/explainer-what-is-the-electromagnetic-spectrum-8046">Beyond visible light</a> there are gamma rays, X-rays, ultraviolet light, infrared light, and radio waves. They provide us with new ways of appreciating the universe.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-to-look-for-when-buying-a-telescope-51466">What to look for when buying a telescope</a>
</strong>
</em>
</p>
<hr>
<h2>X-ray Moon</h2>
<p>Have you looked at the Moon during the daytime? You will see part of the Moon bathed in sunlight and the Earth’s blue sky in front of the Moon.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/196867/original/file-20171129-28849-10ab0ib.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/196867/original/file-20171129-28849-10ab0ib.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/196867/original/file-20171129-28849-10ab0ib.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/196867/original/file-20171129-28849-10ab0ib.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/196867/original/file-20171129-28849-10ab0ib.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/196867/original/file-20171129-28849-10ab0ib.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/196867/original/file-20171129-28849-10ab0ib.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/196867/original/file-20171129-28849-10ab0ib.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Moon behind a blue sky.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/blachswan/14990521817/">Flickr/Ed Dunens</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Now put on your X-ray specs, courtesy of the <a href="http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10424/">ROSAT satellite</a>, and you will see something intriguing. </p>
<p>The Sun emits X-rays, so you can see the daytime side of the Moon easily enough. But the night time side of the Moon is silhouetted against the X-ray sky. The X-ray sky is <em>behind</em> the Moon!</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/196868/original/file-20171129-28899-t5t4hp.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/196868/original/file-20171129-28899-t5t4hp.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/196868/original/file-20171129-28899-t5t4hp.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=627&fit=crop&dpr=1 600w, https://images.theconversation.com/files/196868/original/file-20171129-28899-t5t4hp.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=627&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/196868/original/file-20171129-28899-t5t4hp.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=627&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/196868/original/file-20171129-28899-t5t4hp.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=788&fit=crop&dpr=1 754w, https://images.theconversation.com/files/196868/original/file-20171129-28899-t5t4hp.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=788&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/196868/original/file-20171129-28899-t5t4hp.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=788&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Moon seen in X-rays by ROSAT. The night side of the Moon is silhouetted against the X-ray background.</span>
<span class="attribution"><a class="source" href="https://apod.nasa.gov/apod/ap960929.html">DARA, ESA, MPE, NASA, J.H.M.M. Schmitt</a></span>
</figcaption>
</figure>
<p>Just what is the <a href="https://ned.ipac.caltech.edu/level5/Fabian/Fabian1.html">X-ray sky</a>? Well, X-rays are more energetic than visible light photons, so X-rays often come from the hottest and most violent celestial objects. Much of the X-ray sky is produced by active galactic nuclei, which are powered by matter falling towards black holes.</p>
<p>In X-rays, the Moon is silhouetted against many millions of celestial sources, powered by black holes, scattered across billions of <a href="https://theconversation.com/explainer-light-years-and-units-for-the-stars-16995">light years</a> of space. </p>
<h2>Radio skies</h2>
<p>If you’re in the southern sky and away from light pollution (including the Moon), then you can see the <a href="http://www.messier.seds.org/xtra/ngc/smc.html">Small Magellanic Cloud</a>. This is a companion galaxy to our own Milky Way. With the unaided eye it looks like a diffuse cloud, but what we are actually seeing is the combined light of millions of distant stars.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/196904/original/file-20171129-29143-1sctcud.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/196904/original/file-20171129-29143-1sctcud.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/196904/original/file-20171129-29143-1sctcud.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=423&fit=crop&dpr=1 600w, https://images.theconversation.com/files/196904/original/file-20171129-29143-1sctcud.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=423&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/196904/original/file-20171129-29143-1sctcud.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=423&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/196904/original/file-20171129-29143-1sctcud.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=531&fit=crop&dpr=1 754w, https://images.theconversation.com/files/196904/original/file-20171129-29143-1sctcud.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=531&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/196904/original/file-20171129-29143-1sctcud.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=531&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Visible light images of the Small Magellanic Cloud are dominated by starlight.</span>
<span class="attribution"><span class="source">ESA/Hubble and Digitized Sky Survey/Davide De Martin</span></span>
</figcaption>
</figure>
<p>Radio waves provide <a href="http://www.anu.edu.au/news/all-news/astronomers-create-most-detailed-radio-image-of-nearby-dwarf-galaxy">a very different view of the Small Magellanic Cloud</a>. Using the <a href="https://www.csiro.au/en/Research/Facilities/ATNF/ASKAP">Australian Square Kilometre Array Pathfinder</a>, tuned to <a href="http://www.cv.nrao.edu/course/astr534/HILine.html">1,420.4MHz</a>, we no longer see stars but instead see atomic hydrogen gas.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/196905/original/file-20171129-29114-mwy2rw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/196905/original/file-20171129-29114-mwy2rw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/196905/original/file-20171129-29114-mwy2rw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/196905/original/file-20171129-29114-mwy2rw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/196905/original/file-20171129-29114-mwy2rw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/196905/original/file-20171129-29114-mwy2rw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/196905/original/file-20171129-29114-mwy2rw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/196905/original/file-20171129-29114-mwy2rw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Radio waves can trace the hydrogen gas in the Small Magellanic Cloud.</span>
<span class="attribution"><a class="source" href="http://www.anu.edu.au/news/all-news/astronomers-create-most-detailed-radio-image-of-nearby-dwarf-galaxy">ANU and CSIRO</a></span>
</figcaption>
</figure>
<p>The hydrogen gas is cold enough that the atoms hang onto their electrons (unlike ionised hydrogen). It can also cool further and collapse (under the force of gravity) to produce <a href="http://coolcosmos.ipac.caltech.edu/cosmic_classroom/cosmic_reference/molecular_clouds.html">clouds of molecular hydrogen gas</a> and eventually new stars. </p>
<p>Radio waves thus allow us to see the fuel for star formation, and the Small Magellanic Cloud is indeed producing <a href="https://arxiv.org/abs/astro-ph/0312100">new stars right now</a>.</p>
<h2>Feeling the heat in the microwave</h2>
<p>If the universe were infinitely large and infinitely old, then presumably every direction would eventually lead the surface of a star. This would lead to a rather bright night sky. The German astronomer <a href="https://www.britannica.com/biography/Wilhelm-Olbers">Heinrich Olbers</a>, <a href="http://www.hup.harvard.edu/catalog.php?isbn=9780674192713">among others,</a> recognised this “paradox” centuries ago. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/196917/original/file-20171129-29101-d1jh91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/196917/original/file-20171129-29101-d1jh91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/196917/original/file-20171129-29101-d1jh91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=300&fit=crop&dpr=1 600w, https://images.theconversation.com/files/196917/original/file-20171129-29101-d1jh91.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=300&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/196917/original/file-20171129-29101-d1jh91.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=300&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/196917/original/file-20171129-29101-d1jh91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=377&fit=crop&dpr=1 754w, https://images.theconversation.com/files/196917/original/file-20171129-29101-d1jh91.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=377&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/196917/original/file-20171129-29101-d1jh91.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=377&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A visible light image of the entire night sky is dominated by starlight from the Milky Way.</span>
<span class="attribution"><a class="source" href="https://www.eso.org/public/netherlands/images/eso0932a/">ESO/S. Brunier</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>When we look up at the night sky, we can see the stars, planets and Milky Way. But most of the night sky is black, and this tells us something important. </p>
<p>But lets take a look at the universe in microwave light. The <a href="http://sci.esa.int/planck/">Planck satellite</a> reveals glowing gas and dust in the Milky Way. Beyond that, in every direction, there is light! Where does it come from?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/196919/original/file-20171129-29114-1av7ju3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/196919/original/file-20171129-29114-1av7ju3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/196919/original/file-20171129-29114-1av7ju3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=323&fit=crop&dpr=1 600w, https://images.theconversation.com/files/196919/original/file-20171129-29114-1av7ju3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=323&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/196919/original/file-20171129-29114-1av7ju3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=323&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/196919/original/file-20171129-29114-1av7ju3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=406&fit=crop&dpr=1 754w, https://images.theconversation.com/files/196919/original/file-20171129-29114-1av7ju3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=406&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/196919/original/file-20171129-29114-1av7ju3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=406&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The microwave sky is glowing in every direction.</span>
<span class="attribution"><a class="source" href="https://jpl.jpl.nasa.gov/spaceimages/details.php?id=PIA13239">ESA, HFI & LFI consortia</a></span>
</figcaption>
</figure>
<p>At microwave wavelengths we can observe the <a href="http://www.esa.int/Our_Activities/Space_Science/Planck/Planck_and_the_cosmic_microwave_background">afterglow of the Big Bang</a>. This afterglow was produced 380,000 years after the Big Bang, when the universe had a temperature of roughly 2,700°C. </p>
<p>But the afterglow we see now doesn’t look like a 2,700°C ball of gas. Instead, we see a glow equivalent to -270°C. Why? Because we live in an <a href="https://theconversation.com/au/topics/universe-expansion-6052">expanding universe</a>. The light we observe now from the Big Bang’s afterglow has been stretched from visible light into lower-energy microwave light, resulting in the colder observed temperature.</p>
<h2>Planetary radio</h2>
<p>Jupiter is one of the most rewarding planets to observe with a <a href="http://www.skyandtelescope.com/observing/jupiter-big-bright-andbeautiful/">small telescope</a> – you can see the cloud bands stretching across the giant planet. Even binoculars can reveal the <a href="https://solarsystem.nasa.gov/news/2009/10/15/the-discovery-of-the-galilean-satellites">four moons discovered by Galileo</a> centuries ago.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/197242/original/file-20171201-30916-bv8l14.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/197242/original/file-20171201-30916-bv8l14.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/197242/original/file-20171201-30916-bv8l14.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=750&fit=crop&dpr=1 600w, https://images.theconversation.com/files/197242/original/file-20171201-30916-bv8l14.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=750&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/197242/original/file-20171201-30916-bv8l14.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=750&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/197242/original/file-20171201-30916-bv8l14.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=943&fit=crop&dpr=1 754w, https://images.theconversation.com/files/197242/original/file-20171201-30916-bv8l14.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=943&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/197242/original/file-20171201-30916-bv8l14.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=943&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A visible light image of Jupiter, taken by the Cassini spacecraft.</span>
<span class="attribution"><a class="source" href="https://photojournal.jpl.nasa.gov/catalog/PIA04866">NASA/JPL/Space Science Institute</a></span>
</figcaption>
</figure>
<p>But you get a less familiar view of Jupiter when you switch to radio waves. A radio telescope reveals the dull warm glow of the planet itself. But what really stands out are radio waves coming from <em>above</em> the planet. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/197243/original/file-20171201-30912-ul361c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/197243/original/file-20171201-30912-ul361c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/197243/original/file-20171201-30912-ul361c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/197243/original/file-20171201-30912-ul361c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/197243/original/file-20171201-30912-ul361c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/197243/original/file-20171201-30912-ul361c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=423&fit=crop&dpr=1 754w, https://images.theconversation.com/files/197243/original/file-20171201-30912-ul361c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=423&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/197243/original/file-20171201-30912-ul361c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=423&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Jupiter is a copious emitter of radio waves.</span>
<span class="attribution"><a class="source" href="https://www.atnf.csiro.au/research/solarsys/jupiter/images/index.html">CSIRO</a></span>
</figcaption>
</figure>
<p>Much of the radio emission from Jupiter is produced by <a href="http://www.synchrotron.org.au/synchrotron-science/what-is-synchrotron-light">synchrotron and cyclotron radiation</a>, which results from speeding electrons spiralling in a magnetic field.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fifty-years-ago-jocelyn-bell-discovered-pulsars-and-changed-our-view-of-the-universe-88083">Fifty years ago Jocelyn Bell discovered pulsars and changed our view of the universe</a>
</strong>
</em>
</p>
<hr>
<p>On Earth we use particle accelerators to produce such radiation. But in Jupiter’s powerful magnetic field it occurs naturally (and copiously).</p>
<p>The synchrotron produced by Jupiter is so powerful that you can detect it on Earth – not just with multimillion-dollar radio telescopes, but with equipment that can be bought for <a href="https://radiojove.gsfc.nasa.gov/">several hundred dollars</a>. You don’t need to be a professional astronomer to expand your view of the universe beyond visible light.</p><img src="https://counter.theconversation.com/content/86068/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael J. I. Brown receives research funding from the Australian Research Council and Monash University.</span></em></p>
The galaxies, stars and planets in our universe can look very different when you view them through equipment that sees beyond the visible light our eyes can see.
Michael J. I. Brown, Associate professor, Monash University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/83941
2017-10-11T00:37:18Z
2017-10-11T00:37:18Z
Marie Curie and her X-ray vehicles’ contribution to World War I battlefield medicine
<figure><img src="https://images.theconversation.com/files/189262/original/file-20171006-25752-pat0e4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Marie Curie in one of her mobile X-ray units in October 1917.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Marie_Curie_-_Mobile_X-Ray-Unit.jpg">Eve Curie</a></span></figcaption></figure><p>Ask people to name the most famous historical woman of science and their answer will likely be: Madame Marie Curie. Push further and ask what she did, and they might say it was something related to <a href="http://www.physics.org/article-questions.asp?id=71">radioactivity</a>. (She actually discovered the radioisotopes <a href="https://www.iupac.org/publications/ci/2011/3301/5_adloff.html">radium and polonium</a>.) Some might also know that she was the first woman to win a <a href="https://www.nobelprize.org/nobel_prizes/chemistry/laureates/1911/marie-curie-facts.html">Nobel Prize</a>. (She actually won two.)</p>
<p>But few will know she was also a major hero of World War I. In fact, a visitor to her Paris laboratory 100 years ago would not have found either her or her radium on the premises. Her radium was in hiding and she was at war. </p>
<p>For Curie, the war started in early 1914, as German troops headed toward her hometown of Paris. She knew her scientific research needed to be put on hold. So she gathered her entire stock of radium, put it in a lead-lined container, transported it by train to Bordeaux – 375 miles away from Paris – and left it in a safety deposit box at a local bank. She then returned to Paris, confident that she would reclaim her radium after France had won the war.</p>
<p>With the subject of her life’s work hidden far away, she now needed something else to do. Rather than flee the turmoil, she decided to join in the fight. But just how could a middle-aged woman do that? She decided to redirect her scientific skills toward the war effort; not to make weapons, but to save lives.</p>
<h2>X-rays enlisted in the war effort</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/189249/original/file-20171006-25752-16upvo5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/189249/original/file-20171006-25752-16upvo5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/189249/original/file-20171006-25752-16upvo5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=674&fit=crop&dpr=1 600w, https://images.theconversation.com/files/189249/original/file-20171006-25752-16upvo5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=674&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/189249/original/file-20171006-25752-16upvo5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=674&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/189249/original/file-20171006-25752-16upvo5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=847&fit=crop&dpr=1 754w, https://images.theconversation.com/files/189249/original/file-20171006-25752-16upvo5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=847&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/189249/original/file-20171006-25752-16upvo5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=847&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">X-ray of a bullet in the heart.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Bullet_in_heart.jpg">U.S. Army</a></span>
</figcaption>
</figure>
<p><a href="https://www.livescience.com/32344-what-are-x-rays.html">X-rays</a>, a type of <a href="https://www.livescience.com/38169-electromagnetism.html">electromagnetic radiation</a>, had been discovered in 1895 by Curie’s fellow Nobel laureate, <a href="https://www.nobelprize.org/nobel_prizes/physics/laureates/1901/rontgen-bio.html">Wilhelm Roentgen</a>. As I describe in my book <a href="https://press.princeton.edu/titles/10691.html">“Strange Glow: The Story of Radiation</a>,” almost immediately after their discovery, physicians began using X-rays to image patients’ bones and find foreign objects – like <a href="http://www.bmj.com/content/1/1950/1252">bullets</a>.</p>
<p>But at the start of the war, <a href="http://science.howstuffworks.com/x-ray2.htm">X-ray machines</a> were still found only in city hospitals, far from the battlefields where wounded troops were being treated. Curie’s solution was to invent the first “radiological car” – a vehicle containing an X-ray machine and photographic darkroom equipment – which could be driven right up to the battlefield where army surgeons could use X-rays to guide their surgeries.</p>
<p>One major obstacle was the need for electrical power to produce the X-rays. Curie solved that problem by incorporating a <a href="http://www.edisontechcenter.org/generators.html">dynamo</a> – a type of electrical generator – into the car’s design. The petroleum-powered car engine could thus provide the required electricity.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/189295/original/file-20171008-25775-tb6ded.JPEG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/189295/original/file-20171008-25775-tb6ded.JPEG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/189295/original/file-20171008-25775-tb6ded.JPEG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=448&fit=crop&dpr=1 600w, https://images.theconversation.com/files/189295/original/file-20171008-25775-tb6ded.JPEG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=448&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/189295/original/file-20171008-25775-tb6ded.JPEG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=448&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/189295/original/file-20171008-25775-tb6ded.JPEG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=563&fit=crop&dpr=1 754w, https://images.theconversation.com/files/189295/original/file-20171008-25775-tb6ded.JPEG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=563&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/189295/original/file-20171008-25775-tb6ded.JPEG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=563&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">One of Curie’s mobile units used by the French Army.</span>
<span class="attribution"><a class="source" href="http://catalogue.bnf.fr/ark:/12148/cb40504352c">Bibliothèque nationale de France, département Estampes et photographie</a></span>
</figcaption>
</figure>
<p>Frustrated by delays in getting funding from the French military, Curie approached the Union of Women of France. This philanthropic organization gave her the money needed to produce the first car, which ended up playing an important role in treating the wounded at the <a href="http://www.history.com/news/the-first-battle-of-the-marne-100-years-ago">Battle of Marne</a> in 1914 – a major Allied victory that kept the Germans from entering Paris.</p>
<p>More radiological cars were needed. So Curie exploited her scientific clout to ask wealthy Parisian women to donate vehicles. Soon she had 20, which she outfitted with X-ray equipment. But the cars were useless without trained X-ray operators, so Curie started to train women volunteers. She recruited 20 women for the first training course, which she taught along with her daughter <a href="https://www.nobelprize.org/nobel_prizes/chemistry/laureates/1935/joliot-curie-facts.html">Irene</a>, a future Nobel Prize winner herself.</p>
<p>The curriculum included theoretical instruction about the physics of electricity and X-rays as well as practical lessons in anatomy and photographic processing. When that group had finished its training, it left for the front, and Curie then trained more women. In the end, a total of 150 women received X-ray training from Curie.</p>
<p>Not content just to send out her trainees to the battlefront, Curie herself had her own <a href="http://sierrawyllie.weebly.com/little-curies.html">“little Curie”</a> – as the radiological cars were nicknamed – that she took to the front. This required her to learn to drive, change flat tires and even master some rudimentary auto mechanics, like cleaning carburetors. And she also had to deal with car accidents. When her driver careened into a ditch and overturned the vehicle, they righted the car, fixed the damaged equipment as best they could and got back to work.</p>
<p>In addition to the mobile little Curies that traveled around the battlefront, Curie also oversaw the construction of 200 radiological rooms at various fixed field hospitals behind the battle lines. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/189259/original/file-20171006-25775-dltyvr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/189259/original/file-20171006-25775-dltyvr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/189259/original/file-20171006-25775-dltyvr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=541&fit=crop&dpr=1 600w, https://images.theconversation.com/files/189259/original/file-20171006-25775-dltyvr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=541&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/189259/original/file-20171006-25775-dltyvr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=541&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/189259/original/file-20171006-25775-dltyvr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=680&fit=crop&dpr=1 754w, https://images.theconversation.com/files/189259/original/file-20171006-25775-dltyvr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=680&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/189259/original/file-20171006-25775-dltyvr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=680&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Medics at a French WWI field hospital locating a bullet with X-ray machine.</span>
<span class="attribution"><a class="source" href="http://hdl.loc.gov/loc.pnp/stereo.1s04120">Library of Congress Prints and Photographs Division</a></span>
</figcaption>
</figure>
<h2>X-rays’ long shadow for Marie Curie</h2>
<p>Although few, if any, of the women X-ray workers were injured as a consequence of combat, they were not without their casualties. Many <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3520298/">suffered burns from overexposure to X-rays</a>. Curie knew that such high exposures posed future health risks, such as cancer in later life. But there had been no time to perfect X-ray safety practices for the field, so many X-ray workers were overexposed. She worried much about this, and later wrote a <a href="https://www.amazon.com/Radiologie-Guerre-French-Marie-Curie-ebook/dp/B00WZVQBDM">book about X-ray safety</a> drawn from her war experiences. </p>
<p>Curie survived the war but was concerned that her intense X-ray work would ultimately cause her demise. Years later, she did contract <a href="http://www.mayoclinic.org/diseases-conditions/aplastic-anemia/symptoms-causes/dxc-20266535">aplastic anemia</a>, a blood disorder sometimes produced by high radiation exposure.</p>
<p>Many assumed that her illness was the result of her decades of radium work – it’s well-established that <a href="https://www.osti.gov/accomplishments/documents/fullText/ACC0029.pdf">internalized radium is lethal</a>. But Curie was dismissive of that idea. She had always protected herself from ingesting any radium. Rather, she attributed her illness to the high X-ray exposures she had received during the war. (We will likely never know whether the wartime X-rays contributed to her death in 1934, but a sampling of her remains in 1995 showed her <a href="https://search.proquest.com/docview/204463756?pq-origsite=gscholar">body was indeed free of radium</a>.)</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/189253/original/file-20171006-25775-126uwsy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/189253/original/file-20171006-25775-126uwsy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/189253/original/file-20171006-25775-126uwsy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=842&fit=crop&dpr=1 600w, https://images.theconversation.com/files/189253/original/file-20171006-25775-126uwsy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=842&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/189253/original/file-20171006-25775-126uwsy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=842&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/189253/original/file-20171006-25775-126uwsy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1058&fit=crop&dpr=1 754w, https://images.theconversation.com/files/189253/original/file-20171006-25775-126uwsy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1058&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/189253/original/file-20171006-25775-126uwsy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1058&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Marie Curie and her daughter Irène in the laboratory after WWI.</span>
<span class="attribution"><a class="source" href="https://www.nobelprize.org/nobel_prizes/physics/laureates/1903/marie-curie-photo.html">© Association Curie Joliot-Curie</a></span>
</figcaption>
</figure>
<p>As science’s first woman celebrity, Marie Curie can hardly be called an unsung hero. But the common depiction of her as a one-dimensional person, slaving away in her laboratory with the single-minded purpose of advancing science for science’s sake, is far from the truth.</p>
<p>Marie Curie was a multidimensional person, who worked doggedly as both a scientist and a humanitarian. She was a strong patriot of her adopted homeland, having immigrated to France from Poland. And she leveraged her scientific fame for the benefit of her country’s war effort – using the winnings from her second Nobel Prize to buy war bonds and even trying to melt down her Nobel medals to convert them to cash to buy more.</p>
<p>She didn’t allow her gender to hamper her in a male-dominated world. Instead, she mobilized a small army of women in an effort to reduce human suffering and win World War I. Through her efforts, it is estimated that the total number of wounded soldiers receiving X-ray exams during the war exceeded <a href="http://theinstitute.ieee.org/tech-history/technology-history/how-marie-curie-helped-save-a-million-soldiers-during-world-war-i">one million</a>.</p><img src="https://counter.theconversation.com/content/83941/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Timothy J. Jorgensen does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
During World War I, Marie Curie left her lab behind, inventing a mobile X-ray unit that could travel to the battlefront and training 150 women to operate these ‘Little Curies.’
Timothy J. Jorgensen, Director of the Health Physics and Radiation Protection Graduate Program and Associate Professor of Radiation Medicine, Georgetown University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/80033
2017-06-30T09:47:04Z
2017-06-30T09:47:04Z
Neutron stars could be our GPS for deep space travel
<figure><img src="https://images.theconversation.com/files/175660/original/file-20170626-29064-1mkqu96.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.nasa.gov/mission_pages/GLAST/multimedia/pulsar_stills.html">NASA</a></span></figcaption></figure><p>NASA’s Neutron Star Interior Composition Explorer, or <a href="https://www.nasa.gov/nicer">NICER</a>, is an X-ray telescope <a href="https://twitter.com/NASA/status/871114366837432321/video/1">launched</a> on a SpaceX Falcon 9 rocket in early June 2017. <a href="https://www.youtube.com/watch?v=sDd2PjbXEg8">Installed on the International Space Station</a>, by mid-July it will commence its scientific work – to study the exotic astrophysical objects known as neutron stars and examine whether they could be used as deep-space navigation beacons for future generations of spacecraft.</p>
<p>What are <a href="https://imagine.gsfc.nasa.gov/science/objects/neutron_stars1.html">neutron stars</a>? When stars at least eight times more massive than the Sun exhaust all the fuel in their core through thermonuclear fusion reactions, the pressure of gravity causes them to collapse. The supernova explosion that results ejects most of the star’s material into the far reaches of space. What remains forms either a neutron star or a black hole.</p>
<p>I study neutron stars because of their rich range of astrophysical phenomena and the many areas of physics to which they are connected. What makes neutron stars extremely interesting is that each star is about 1.5 times the mass of the Sun, but only about 25km in diameter – the size of a single city. When you cram that much mass into such a small volume, the matter is more densely packed than that of an atomic nucleus. So, for example, while the nucleus of a helium atom has just two neutrons and two protons, a neutron star is essentially a single nucleus made up of 10<sup>57</sup> neutrons and 10<sup>56</sup> protons.</p>
<h2>Exotic physics impossible on Earth</h2>
<p>We can use neutron stars to probe properties of nuclear physics that cannot be investigated in laboratories on Earth. For example, some current theories predict that exotic particles of matter, such as <a href="https://www.britannica.com/science/hyperon">hyperons</a> and <a href="https://www.britannica.com/science/quark">deconfined quarks</a>, can appear at the high densities that are present in neutron stars. Theories also indicate that at temperatures of a billion degrees Celsius, protons in the neutron star become <a href="https://www.britannica.com/science/superconductivity">superconducting</a> and neutrons, without charge, become <a href="https://www.scientificamerican.com/article/superfluid-can-climb-walls/">superfluid</a>. </p>
<p>The magnetic field of neutron stars is extreme as well, possibly the strongest in the universe, and billions of times stronger than anything created in laboratories. While the gravity at the surface of a neutron star may not be as strong as that near a black hole, neutron stars still create major distortions in spacetime and can be sources of gravitational waves, which were <a href="https://www.nobelprize.org/nobel_prizes/physics/laureates/1993/press.html">inferred from research into neutron stars in the 1970s</a>, and <a href="https://theconversation.com/explainer-gravitational-waves-and-why-their-discovery-is-such-a-big-deal-53239?sr=3">confirmed from black holes by the LIGO experiments</a> recently.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/IOEPDf2DYNM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>The main focus of NICER is to accurately measure the mass and radius of several neutron stars – and, although the telescope will observe other types of astronomical objects, those of us studying neutron stars hope NICER will provide us with unique insights into these fascinating objects and their physics. NICER will measure how the brightness of a neutron star changes according to its energy, and how it changes as the star rotates, revealing different parts of the surface. These observations will be compared to theoretical models based on properties of the star such as mass and radius. Accurate determinations of mass and radius will provide a vital test of nuclear theory.</p>
<h2>A GPS for deep space</h2>
<p>Another aspect of neutron stars that could prove important for future space travel is their rotation– and this will also be tested by NICER. Rotating neutron stars, known as pulsars, emit beams of radiation like a lighthouse and are seen to spin as fast as 716 times per second. This rotation rate in some neutron stars is more stable than the best atomic clocks we have on Earth. In fact, it is this characteristic of neutron stars that led to the discovery of the first planets outside our solar system in 1992 – <a href="http://dx.doi.org/10.1038/355145a0">three Earth-sized planets revolving around a neutron star</a>. </p>
<p>The NICER mission, using a part of the telescope called <a href="https://gameon.nasa.gov/projects/deep-space-x-ray-navigation-and-communication/">SEXTANT</a>, will test whether the extraordinary regularity and stability of neutron star rotation could be <a href="https://arxiv.org/abs/1305.4842">used as a network of navigation beacons in deep space</a>. Neutron stars could thus serve as natural satellites contributing to a Galactic (rather than Global) Positioning System and could be relied upon by future manned and unmanned spacecraft to navigate among the stars.</p>
<p>NICER will operate for 18 months, but it is hoped that NASA will continue to support its operation afterwards, especially if it can deliver on its ambitious scientific goals. I hope so too, because NICER combines and greatly improves upon the invaluable capabilities of previous X-ray spacecraft – <a href="https://heasarc.gsfc.nasa.gov/docs/xte/xtegof.html">RXTE</a>, <a href="http://chandra.harvard.edu/">Chandra</a>, and <a href="https://www.cosmos.esa.int/web/xmm-newton">XMM-Newton</a> – that are used to uncover neutron stars’ mysteries and reveal properties of fundamental physics. </p>
<p>The first neutron star, a pulsar, was <a href="http://www.bbc.co.uk/science/space/universe/scientists/jocelyn_bell_burnell">discovered in 1967 by Jocelyn Bell Burnell</a>. It would be fitting to obtain a breakthrough on neutron stars in this 50th anniversary year.</p><img src="https://counter.theconversation.com/content/80033/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Wynn Ho receives funding from the Science and Technology Facilities Council in the UK.</span></em></p>
Studying mysterious neutron stars could uncover the secrets of exotic physics – and a way to navigate the stars.
Wynn Ho, Associate professor, University of Southampton
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/70636
2016-12-20T20:15:26Z
2016-12-20T20:15:26Z
Why you can’t fry eggs (or testicles) with a cellphone
<figure><img src="https://images.theconversation.com/files/151083/original/image-20161220-26741-nmhzbw.jpg?ixlib=rb-1.1.0&rect=721%2C0%2C3197%2C1982&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Pocket your phone without worry.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic.mhtml?id=533966416">Phone image via www.shutterstock.com.</a></span></figcaption></figure><p>A minor craze in men’s underwear fashions these days seems to be <a href="http://www.nbcnews.com/news/world/boxer-shorts-claim-protect-testicles-cellphone-radiation-n538576">briefs that shield the genitals</a> from cellphone radiation. The sales claim is that these products protect the testicles from the harmful effects of the radio waves emitted by cellphones, and therefore help maintain a robust sperm count and high fertility. These undergarments may shield the testicles from radiation, but do <a href="http://www.newsweek.com/boxer-rebellion-pocketed-cellphone-may-be-behind-your-infertility-287075">male cellphone users really risk infertility</a>?</p>
<p>The notion that electromagnetic radiation in the radio frequency range can cause male sterility, either temporary or permanent, has been around for a long time. As I describe in my book <a href="http://press.princeton.edu/titles/10691.html">“Strange Glow: The Story of Radiation</a>,” during World War II some enlisted men would consistently and inexplicably volunteer for radar duty just prior to their scheduled leave days. It turned out that a rumor had been circulating that exposure to radio waves from the radar equipment produced temporary sterility, which the soldiers saw as an employment benefit.</p>
<p>The military wanted to know whether there was any substance to the sterility rumor. So they asked <a href="https://www.nobelprize.org/nobel_prizes/medicine/laureates/1946/muller-bio.html">Hermann Muller</a> – a geneticist who <a href="https://www.nobelprize.org/nobel_prizes/medicine/laureates/1946/muller-lecture.html">won the Nobel Prize</a> for showing that x-rays could cause sterility and genetic mutations – to evaluate the effects of radio waves in the same fruit fly experimental model he had used to show that x-rays impaired reproduction. </p>
<p>Muller could find no dose of radio waves that produced either sterility or genetic mutations, and concluded that radio waves did not present the same threat to fertility that x-rays did. Radio waves were different. But why? Aren’t both x-rays and radio waves <a href="http://www.livescience.com/38169-electromagnetism.html">electromagnetic radiation</a>?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=326&fit=crop&dpr=1 600w, https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=326&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=326&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=410&fit=crop&dpr=1 754w, https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=410&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=410&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The electromagnetic spectrum, tiny wavelengths on the left, longer wavelengths on the right.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:EM_Spectrum_Properties_reflected.svg">Inductiveload</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Yes, they are – but they differ in one key factor: They have very different wavelengths. All electromagnetic radiation travels through space as invisible waves of energy. And it’s the specific wavelength of the radiation that determines all of its effects, both physical and biological. The shorter wavelengths carry higher amounts of energy than the longer wavelengths.</p>
<p>X-rays are able to damage cells and tissues precisely because their wavelengths are extremely short – one-millionth the width of a human hair – and thus are highly energetic and very harmful to cells. Radio waves, in contrast, carry little energy because their wavelengths are very long – about the length of a football field. Such long-wavelength radiations have really low energies – too low to damage cells. And it’s this big difference between the wavelengths of x-rays and radio waves that the infertility theorists fail to recognize.</p>
<p>X-rays, and other high-energy waves, produce sterility by killing off the testicular cells that make sperm – the “<a href="https://www.repropedia.org/spermatogonium">spermatogonia</a>.” And x-ray doses must be extremely high to kill enough cells to produce sterility. Still, even when the doses are high, the sterility effect is usually temporary because the surviving spermatogonia are able to <a href="http://doi.org/10.1002/aja.1001180211">spawn replacements</a> for their dead comrades, and sperm counts typically return to their normal levels within a few months.</p>
<p>So, if high doses of highly energetic x-rays are needed to kill enough cells to produce sterility, how can low doses of radio waves with energies too low to kill cells do it? Good question.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/axUBeF-W7II?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Don’t fall for the phone-cooking-egg hoax.</span></figcaption>
</figure>
<p>At this point you may be thinking that you’ve seen videos of <a href="https://www.youtube.com/watch?v=axUBeF-W7II">cellphones cooking eggs</a>. And you’ve even experienced your cellphone getting pretty warm when it’s used heavily. But this doesn’t show that cellphones put out a lot of radiation energy. The cooked egg video is a prank, and the phone gets hot because of the heat generated by the chemical reactions going on within the battery, not from radio waves.</p>
<p>Still you protest: What about those sporadic reports claiming that cellphones suppress sperm counts? For the moment, that’s all they are – sporadic reports, unconfirmed by other investigators. You can find all kinds of random assertions about the effects of radiation on health, both <a href="http://www.orau.org/ptp/collection/quackcures/quackcures.htm">good</a> and <a href="https://www.scribd.com/document/59721111/TOP10-Myths-About-Radiation">bad</a>, most of which imply that there is some type of validated scientific evidence to support the claim. Why not believe all of them?</p>
<p>If we’ve learned anything over the years about scientific evidence, it’s that isolated findings from individual labs, reporting limited experimental data, do not a strong case make. Most of the very limited “scientific” reports of infertility caused by cellphones, often <a href="http://www.ewg.org/cell-phone-radiation-damages-sperm-studies-find">cited by anti-cellphone activists</a>, come from outside the radiation biology community, and are published in lower-tier journals of questionable quality. Few, if any, of these reports make any attempt at actually measuring the radiation doses received from the cellphones (probably because they lack either the expertise or the equipment required to do it).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=384&fit=crop&dpr=1 600w, https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=384&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=384&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=483&fit=crop&dpr=1 754w, https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=483&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=483&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Human sperm, unconcerned by what’s in your pocket.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Sperm_(265_33)_human.jpg">Doc. RNDr. Josef Reischig, CSc.</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>And none actually measure fertility rates – the health endpoint of concern – but rather measure sperm counts and other sperm quality parameters and then infer that there will be an impact on fertility. In fact, sperm counts can vary widely between normally fertile individuals and even within the same individual from day to day. For example, men who frequently ejaculate have lower sperm counts, as you might expect, because they are regularly jettisoning sperm. (Men who ejaculate daily can have <a href="http://doi.org/10.1186/s12958-015-0045-9">sperm counts 50 percent lower</a> than men who don’t.) Perhaps the allegedly lower sperm counts of cellphone users just means that they are having more sex!</p>
<p>But seriously, the point is this: There are so many things that can affect sperm counts in big ways that minor fluctuations in sperm counts have no practical impact on whether a man will produce babies, even if it were true that cellphones can modestly suppress sperm counts.</p>
<p>It is clear that these infertility claims are not the consensus of the mainstream scientific community – a community that demands more rigorous evidence. There are many excellent laboratories around the world that study radiation effects, and it isn’t difficult to study infertility in fruit flies, mice and even people. (It’s fairly easy to find men willing to <a href="https://verdict.justia.com/2012/01/24/men-who-give-it-away">donate sperm samples</a>.) If the sterility story were true, there would be a chorus of well-respected laboratories from around the world singing the cellphone infertility song, not just a few.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=666&fit=crop&dpr=1 600w, https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=666&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=666&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=837&fit=crop&dpr=1 754w, https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=837&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=837&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Guglielmo Marconi, inventor of the radio.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/smithsonian/2551824648">Smithsonian Institution</a></span>
</figcaption>
</figure>
<p>The fact is, the current data suggesting that cellphones cause infertility are too weak to challenge the dogma of over 100 years of commercial experience with radio waves. Radio waves are not unique to cellphones. They have been used for telecommunication ever since <a href="http://www.history.com/this-day-in-history/marconi-sends-first-atlantic-wireless-transmission">Marconi first demonstrated in 1901</a> that they could carry messages across the entire Atlantic Ocean. Early radio workers received massive doses of radio waves, yet there is no indication they had any problems with their fertility. If they didn’t experience fertility problems with their high doses, how can the relatively low doses from cellphones have such an effect? Hard to understand.</p>
<p>Nevertheless, people can spend their money as they please and wear any underwear they want. But if you are still concerned about radio waves affecting your fertility, why not just carry your cellphone in your shirt pocket rather than your pants, and let your testicles be?</p><img src="https://counter.theconversation.com/content/70636/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Timothy J. Jorgensen does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Did your holiday gift list include radiation-shielding undies to protect your privates from cellphone radio waves? A radiation expert explains they’re unnecessary – your phone won’t affect your fertility.
Timothy J. Jorgensen, Director of the Health Physics and Radiation Protection Graduate Program and Associate Professor of Radiation Medicine, Georgetown University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/65663
2016-09-21T18:59:51Z
2016-09-21T18:59:51Z
You can thank our pre-mammalian ancestors for your sexy teeth
<figure><img src="https://images.theconversation.com/files/138412/original/image-20160920-11127-lx5rs3.jpg?ixlib=rb-1.1.0&rect=0%2C49%2C650%2C406&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">This skull belongs to the carnivorous gorgonopsian therapsid Smilesaurus ferox which lived 255 million years ago</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Smilesaurus_skull.jpg">Cradle of Humankind/Flickr/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Next time you’re getting ready for a hot date and pause to flash a toothy grin at yourself in the mirror, thank your ancestors.</p>
<p>Mammals have a dentition divided into three distinct types of teeth.</p>
<p>There are large, sharp canines and next to them incisors. Behind them, in our cheeks, are teeth known as post-canine dentition. This separation has been traced back more than 300 million years when our ancestors still looked like huge reptiles. </p>
<p>These were the pre-mammalian <a href="http://www.newworldencyclopedia.org/entry/Therapsid">therapsids</a>. They had long, sometimes sabre-like canines. Scientists long thought that these sharp teeth were deadly hunting devices. But there was a problem: even herbivorous species of therapsid had sabre-like canines. Their chompers clearly weren’t for hunting prey. Some speculated that the canines in question might be for defence from predators.</p>
<p>Or were they actually used for sexual display? </p>
<p>Today, sabre-tooth mammals such as the walrus or the deer-like <a href="http://www.iucnredlist.org/details/42190/0">muntiac</a>, have their canines constantly on display. This allows them to seduce mates or intimidate their kin. That’s the modern situation. My colleagues and I <a href="http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0161457">wanted to know</a> whether sexual selection was also an important phenomenon among our pre-mammalian ancestors.</p>
<p>The answer, <a href="http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0161457">uncovered</a> by cutting edge technology and careful study, is “yes”.</p>
<h2>Putting therapsids under the microscope</h2>
<p>Our research involved a team of palaeontologists from the University of the Witwatersrand’s <a href="https://www.wits.ac.za/esi/">Evolutionary Studies Unit</a>; a group from the university’s <a href="https://www.wits.ac.za/anatomicalsciences/">School of Anatomical Sciences</a> and scientists from the <a href="http://www.esrf.eu/">European Synchrotron Radiation Facility</a> in Grenoble, France.</p>
<p>Our subject was a mysterious fossil therapsid, Choerosaurus dejageri. It is part of the Eutheriodontia family. Little is known about this mammal-like reptile that lived 259 million years ago and belonged to the lineage that gave birth to mammals. Choerosaurus is unique, as it’s the only Eutheriodont to have two symmetrical bosses: horn-like structures on its upper and lower jaws, the maxilla and mandible.</p>
<p>We wanted to figure out what these cranial bosses were for: combat or sexual display.</p>
<p>Only one Choerosaurus fossil has been found, on a farm near Beaufort West in South Africa: a delicate skull. We used X-ray computerised micro-tomographic, or microCT, on this fossil. We compared the scans with those from another therapsid, the monstruous dinocephalian Moschops. The Moschops is known to have head butted its enemies, so its skull and cranial bosses were obviously developed for high energy combat. </p>
<p>But the Choereosaurus’ skull and cranial bosses were found to be too weak for such combat. In addition, the Choereosaurus’ maxillary boss was packed full of nerves and veins. This isn’t ideal for fighting, since any combat would cause a lot of pain and bleeding.</p>
<p>The maxillary boss is far more suited to supporting a colourful, sensitive cornified pad – a keratinous covering, like a horn. This suggests a bias towards display behaviour, and away from combat.</p>
<h2>Sexual selection</h2>
<p>This is the first evidence of structures dedicated solely to competition between males for mates and territory. These structures would have been used either for low energy fighting and/or sexual display in Eutheriodontia. Since this group was the direct ancestors of modern mammals, revealing their toothy secrets gives us a better understanding of our own mouths and those of other mammals.</p>
<p>The Choereosaurus fossil shows that sexual competition and the associated complex, ritualised behaviour like sexual display and ceremonies of intimidation were an important component of therapsid evolution. This finding suggests that sexual selection may have played a more important role in the origin of mammals than originally thought. </p>
<p>It’s a vital step to reshaping our understanding of humans’ deep evolutionary roots – right down to our canine teeth.</p><img src="https://counter.theconversation.com/content/65663/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julien Benoit receives funding from PAST and its Scatterlings projects; the National Research Foundation of South Africa; and the DST-NRF Centre of Excellence in Palaeosciences (CoE in Palaeosciences). </span></em></p>
Modern sabre-tooth mammals have their canines constantly on display. This allows them to seduce mates. But was sexual selection also an important phenomenon among our pre-mammalian ancestors?
Julien Benoit, Postdoc in Vertebrate Palaeontology, University of the Witwatersrand
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/63500
2016-08-04T20:10:16Z
2016-08-04T20:10:16Z
How we used a particle accelerator to find the hidden face in Degas’s Portrait of a woman
<figure><img src="https://images.theconversation.com/files/133102/original/image-20160804-478-ojcyy3.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The X-rays of the Australian Synchrotron reveal a remarkably clear picture of the woman's face.</span> <span class="attribution"><span class="source">David Thurrowgood</span></span></figcaption></figure><figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/133104/original/image-20160804-505-1w2tpsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/133104/original/image-20160804-505-1w2tpsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/133104/original/image-20160804-505-1w2tpsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=729&fit=crop&dpr=1 600w, https://images.theconversation.com/files/133104/original/image-20160804-505-1w2tpsa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=729&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/133104/original/image-20160804-505-1w2tpsa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=729&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/133104/original/image-20160804-505-1w2tpsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=917&fit=crop&dpr=1 754w, https://images.theconversation.com/files/133104/original/image-20160804-505-1w2tpsa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=917&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/133104/original/image-20160804-505-1w2tpsa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=917&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The painting as it appears in the gallery. The hidden face is upside down and obscured by the portrait on top.</span>
<span class="attribution"><span class="source">National Gallery of Victoria</span></span>
</figcaption>
</figure>
<p>Edgar Degas’s painting <a href="http://www.ngv.vic.gov.au/essay/edgar-degass-portrait-of-a-woman/">Portrait of a woman</a> is an enigmatic piece. When it was first acquired by the National Gallery of Victoria in 1937, it was unveiled to mixed reviews.</p>
<p>Some commented that it showed the hallmarks of the French painter’s style around the 1870s. Others criticised its brown hues and the apparent discolouration across the woman’s face.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/133105/original/image-20160804-496-870o6d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/133105/original/image-20160804-496-870o6d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/133105/original/image-20160804-496-870o6d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=710&fit=crop&dpr=1 600w, https://images.theconversation.com/files/133105/original/image-20160804-496-870o6d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=710&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/133105/original/image-20160804-496-870o6d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=710&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/133105/original/image-20160804-496-870o6d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=892&fit=crop&dpr=1 754w, https://images.theconversation.com/files/133105/original/image-20160804-496-870o6d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=892&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/133105/original/image-20160804-496-870o6d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=892&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Earlier attempts at revealing the portrait underneath didn’t show much detail.</span>
<span class="attribution"><span class="source">National Gallery of Victoria</span></span>
</figcaption>
</figure>
<p>Little did they know at the time that the painting held a secret: there was another portrait of a woman, inverted, lying just under the surface. Some of the discolouration was due to this other ghostly figure bleeding through.</p>
<p>It appears that Degas abandoned this earlier work and repurposed the canvas for the newer portrait. But when did he paint the first woman? Who was the model?</p>
<p>Thus began a quest to reveal the hidden woman without disturbing the portrait on top. X-ray imagery showed a little more detail, revealing the faint outline of a young woman, painted perhaps only shortly before the canvas was re-used.</p>
<p>Subsequent infra-red photography suggested the original figure was painted as early as 1860, while other barely visible features hinted at an earlier creation.</p>
<p>And this is where the Australian Synchrotron comes into the picture. </p>
<h2>Brighter than the sun</h2>
<p>As is often the case in cutting-edge science, a recurring challenge is to devise technology that facilitates what researchers want to achieve. For every leap forward in power or speed, supporting equipment and infrastructure is needed to make the most of the new innovation.</p>
<p>Such was the situation at the Australian Synchrotron. Just after beginning operations in 2008, we formed a strong collaboration with the CSIRO and Brookhaven National Laboratory in the United States. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/133107/original/image-20160804-513-6blq95.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/133107/original/image-20160804-513-6blq95.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/133107/original/image-20160804-513-6blq95.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=893&fit=crop&dpr=1 600w, https://images.theconversation.com/files/133107/original/image-20160804-513-6blq95.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=893&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/133107/original/image-20160804-513-6blq95.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=893&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/133107/original/image-20160804-513-6blq95.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1122&fit=crop&dpr=1 754w, https://images.theconversation.com/files/133107/original/image-20160804-513-6blq95.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1122&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/133107/original/image-20160804-513-6blq95.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1122&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Maia detector is carefully positioned less than 2mm from the painting’s surface in order to achieve the highest quality data.</span>
<span class="attribution"><span class="source">David Thurrowgood</span></span>
</figcaption>
</figure>
<p>At the time, we were receiving vast reams from the synchrotron’s <a href="http://www.synchrotron.org.au/aussyncbeamlines/x-ray-fluorescence-microscopy/techniques-available">X-ray fluorescence microscopy beamline</a> as it delivered light a million times brighter than the sun into a variety of scientific samples.</p>
<p>This collaboration helped us to develop an X-ray fluorescence detector capable of operating significantly faster than the current technology available at the time to make the most of this data. </p>
<p>We have also had an exciting and long-lasting collaboration with the National Gallery of Victoria (NGV). </p>
<p>The NGV has a fantastic collection of Australian and international art. Some items in the collection have unanswered questions that conventional analytical techniques are not able to resolve, such as Degas’s Portrait of a woman.</p>
<p>This collaboration has proved highly successful, and the new technology developed by CSIRO and Brookhaven National Laboratory in the United States, dubbed the Maia detector, opened up innovative research that was previously not possible.</p>
<p>Before the Maia detector, we were restricted to acquiring small images of a sample – such as a leaf containing traces of metals, electrodes used in medical implants or the hidden layers in a painting – which contained a rather limited number of pixels, preventing us from seeing the whole picture. </p>
<p>With the new Maia detector, this hindrance was overcome. We are now able to routinely acquire elemental images composed of millions of pixels over large areas in only an hour or so. </p>
<h2>The reveal</h2>
<p>With the technology available at the Australian Synchrotron, we believed there was a good chance we could reveal the hidden portrait by subjecting small areas to radiation for only a fraction of a second. And, importantly, we could do this without damaging the artwork. </p>
<p>After several months of planning, the painting arrived from the NGV early in the morning and we secured it in a custom mount, with the detector only 2mm above the painting’s surface. We set up the coordinates of the area to scan so we could capture as much of the hidden portrait as possible. </p>
<p>After some fine-tuning of the X-ray beam, we launched a scan that would take approximately 33 hours to complete, giving individual images in excess of 31 megapixels, which is beyond the resolution of most of today’s best digital cameras. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/133108/original/image-20160804-513-356y1p.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/133108/original/image-20160804-513-356y1p.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/133108/original/image-20160804-513-356y1p.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=415&fit=crop&dpr=1 600w, https://images.theconversation.com/files/133108/original/image-20160804-513-356y1p.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=415&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/133108/original/image-20160804-513-356y1p.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=415&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/133108/original/image-20160804-513-356y1p.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=522&fit=crop&dpr=1 754w, https://images.theconversation.com/files/133108/original/image-20160804-513-356y1p.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=522&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/133108/original/image-20160804-513-356y1p.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=522&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">By intentionally applying incorrect colours to elements it was possible to highlight areas of the painting and study artistic technique.</span>
<span class="attribution"><span class="source">David Thurrowgood</span></span>
</figcaption>
</figure>
<p>We were able to do an initial analysis of the elements present and load this into the computer to give a real-time image of the painting as the data was collected. </p>
<p>It was incredibly exciting to see the image build up on the computer monitor and reveal, pixel by pixel, the hidden portrait beneath. </p>
<p>Based on our analysis and comparison to other works by Degas, we suggest the hidden portrait is of the model Emma Dobigny.</p>
<p>We know Degas painted Emma other times, such as the famous portrait from 1869 <a href="http://www.wikiart.org/en/edgar-degas/emma-dobigny-1869">named after her</a>.</p>
<p>We hope this data can provide art historians with more information about Degas and the evolution of his work. And we hope that the fruitful collaboration with the NGV and CSIRO continues for many more years to come.</p><img src="https://counter.theconversation.com/content/63500/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daryl Howard does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
It took cutting edge technology and a collaboration between the Australian Synchrotron and the CSIRO to reveal the mysterious hidden lady in Degas’s famous painting.
Daryl Howard, Scientist - X-ray Fluorescence Microscopy, Australian Synchrotron
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/57406
2016-05-31T01:04:47Z
2016-05-31T01:04:47Z
How computing power can help us look deep within our bodies, and even the Earth
<figure><img src="https://images.theconversation.com/files/122911/original/image-20160517-9476-w78fh8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The computer does more of the work than you might think.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-401715220/stock-photo-thessaloniki-greece-february-official-opening-of-the-first-ct-imaging-pet-ct-scanner.html?src=wcSemSkkJRQbjbDYm9SbKA-2-59">CT computer and scan room image via shutterstock.com</a></span></figcaption></figure><p>CAT scans, MRI, ultrasound. We are all pretty used to having machines – and doctors – peering into our bodies for a whole range of reasons. This equipment can help diagnose diseases, pinpoint injuries, or give expectant parents the first glimpse of their child.</p>
<p>As computational power has exploded in the past half-century, it has enabled a parallel expansion in the capabilities of these computer-aided imaging systems. What used to be pictures of two-dimensional “slices” have been assembled into high-resolution three-dimensional reconstructions. Stationary pictures of yesteryear are today’s real-time video of a beating heart. The advances have been truly revolutionary.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/EN5qgpVxrcU?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A cardiac MRI scan shows a heart beating.</span></figcaption>
</figure>
<p>Though different in their details, X-ray computed tomography, ultrasound and even MRI have a lot in common. The images produced by each of these systems derive from an elegant interplay of sensors, physics and computation. They do not operate like a digital camera, where the data captured by the sensor are basically identical to the image produced. Rather, a lot of processing must be applied to the the raw data collected by a CAT scanner, MRI machine or ultrasound system to produce before it the images needed for a doctor to make a diagnosis. Sophisticated algorithms based on the underlying physics of the sensing process are required to put Humpty Dumpty back together again.</p>
<h2>Early scanning methods</h2>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/122907/original/image-20160517-9491-18otosr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/122907/original/image-20160517-9491-18otosr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=360&fit=crop&dpr=1 600w, https://images.theconversation.com/files/122907/original/image-20160517-9491-18otosr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=360&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/122907/original/image-20160517-9491-18otosr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=360&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/122907/original/image-20160517-9491-18otosr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=453&fit=crop&dpr=1 754w, https://images.theconversation.com/files/122907/original/image-20160517-9491-18otosr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=453&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/122907/original/image-20160517-9491-18otosr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=453&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">One of the first published X-rays (at right, with normal view of the hand at left), from 1896.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File%3AX-ray_1896_nouvelle_iconographie_de_salpetriere.jpg">Albert Londe</a></span>
</figcaption>
</figure>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/122908/original/image-20160517-9464-1m98rqs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/122908/original/image-20160517-9464-1m98rqs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=367&fit=crop&dpr=1 600w, https://images.theconversation.com/files/122908/original/image-20160517-9464-1m98rqs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=367&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/122908/original/image-20160517-9464-1m98rqs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=367&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/122908/original/image-20160517-9464-1m98rqs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=461&fit=crop&dpr=1 754w, https://images.theconversation.com/files/122908/original/image-20160517-9464-1m98rqs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=461&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/122908/original/image-20160517-9464-1m98rqs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=461&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A modern hand X-ray.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/golanlevin/19300737031/">golanlevin/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Though we use X-rays in some cutting-edge imaging techniques, X-ray imaging actually <a href="https://www.nde-ed.org/EducationResources/CommunityCollege/Radiography/Introduction/history.htm">dates back to the late 1800s</a>. The shadowlike contrast in X-ray images, or projections, shows the density of the material between the X-ray source and the data sensor. (In the past this was a piece of X-ray film, but today is usually a digital detector.) Dense objects, such as bones, absorb and scatter many more X-ray photons than skin, muscle or other soft tissue, which appear darker in the projections.</p>
<p>But then in the early 1970s, X-ray CAT (which stands for Computerized Axial Tomography) scans were developed. Rather than taking just a single X-ray image from one angle, a CAT system rotates the X-ray sources and detectors to collect many images from different angles – a process known as tomography. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/yTDgFW2UZFI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Computerized tomography imagery of a hand.</span></figcaption>
</figure>
<p>The difficulty is how to take all the data, from all those X-rays from so many different angles, and get a computer to properly assemble them into 3D images of, say, a person’s hand, as in the video above. That problem had a mathematical solution that had been studied by the <a href="https://thatsmaths.com/2013/03/07/ct-scans-and-the-radon-transform/">Austrian mathematician Johann Radon</a> in 1917 and rediscovered by the American physicist (and Tufts professor) <a href="http://www.nytimes.com/1998/05/09/us/allan-cormack-74-nobelist-who-helped-invent-cat-scan.html">Allan Cormack</a> in the 1960s. Using Cormack’s work, <a href="http://dx.doi.org/10.1148/radiol.2343042584">Godfrey Hounsfield</a>, an English electrical engineer, was the first to demonstrate a working CAT scanner in 1971. For their work on CAT, Cormack and Hounsfield received the <a href="http://www.nobelprize.org/nobel_prizes/medicine/laureates/1979/">1979 Nobel Prize in Medicine</a>. </p>
<h2>Extending the role of computers</h2>
<p>Until quite recently, these processing methods had more or less been constant since the 1970s and 1980s. Today, additional medical needs – and more powerful computers – are driving big changes. There is increased interest in CT systems that <a href="http://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/MedicalImaging/MedicalX-Rays/ucm115329.htm">minimize X-ray exposure</a>, yielding high-quality images from fewer images. In addition, certain uses, such as breast imaging, encounter physical constraints on how much access the imager can have to the body part. This requires scanning from only a very limited set of angles around the subject. These situations have led to research into <a href="http://www.massgeneral.org/imaging/services/3D_mammography_tomosynthesis.aspx">what are called “tomosynthesis” systems</a> – in which limited data are interpreted by computers to form fuller images. </p>
<p>Similar problems arise, for example, in the context of imaging the ground to see what objects – such as pollutants, land mines or oil deposits – are hidden beneath our feet. In many cases, all we can do is <a href="http://physicsworld.com/cws/article/news/2016/feb/16/ground-penetrating-radar-boosts-asparagus-production">send signals from the surface</a>, or drill a few holes to take sampling measurements. <a href="https://www.ncjrs.gov/school/ch3c_5.html">Security scanning in airports</a> is constrained by cost and time, so those X-ray systems can take only a few images.</p>
<p>In these and a host of other fields, we are faced with less overall data, which means the Cormack-Hounsfield mathematics can’t work properly to form images. The effort to solve these problems has led to the rise of a new area of research, “computational sensing,” in which sensors, physics and computers are being brought together in new ways. </p>
<p>Sometimes this involves applying more computer processing power to the same data. In other cases, hardware engineers designing the equipment <a href="https://www.ecse.rpi.edu/homepages/saulnier/eit/eit.html">work closely with the mathematicians</a> figuring out how best to analyze the data provided. Together these systems can provide new capabilities that hold the promise of major changes in many research areas.</p>
<h2>New scanning capabilities</h2>
<p>One example of this potential is in bio-optics, the use of light to look deep within the human body. While visible light does not penetrate far into tissue, anyone who has shone a red laser pointer into their finger knows that red light does in fact make it through at least a couple of centimeters. Infrared light penetrates even farther into human tissue. This capability opens up entirely new ways to image the body than X-ray, MRI or ultrasound.</p>
<p>Again, it takes computing power to move from those images into a unified 3D portrayal of the body part being scanned. But the calculations are much more difficult because the way in which light interacts with tissue is far more complex than X-rays.</p>
<p>As a result we need to use a different method from that pioneered by Cormack in which X-ray data are, more or less, directly turned into images of the body’s density. Now we construct an algorithm that follows a process over and over, feeding the result from one iteration back as input of the next. </p>
<p>The process starts by having the computer guess an image of the optical properties of the body area being scanned. Then it uses a computer model to calculate what data from the scanner would yield that image. Perhaps unsurprisingly, the initial guess is generally not so good: the calculated data don’t match the actual scans. </p>
<p>When that happens, the computer goes back and refines its guess of the image, recalculates the data associated with this guess and again compares with the actual scan results. While the algorithm guarantees that the match will be better, it is still likely that there will be room for improvement. So the process continues, and the computer generates a new and more improved guess. </p>
<p>Over time, its guesses get better and better: it creates output that looks more and more like the data collected by the actual scanner. Once this match is close enough, the algorithm provides the final image as a result for examination by the doctor or other professional.</p>
<p>The new frontiers of this type of research are still being explored. In the last 15 years or so, researchers – including my Tufts colleague <a href="https://ase.tufts.edu/biomedical/research/Fantini/">Professor Sergio Fantini</a> – have explored many potential uses of infrared light, such as <a href="http://dx.doi.org/10.1007/s10549-013-2802-9">detecting breast cancer</a>, functional brain imaging and <a href="http://dx.doi.org/10.1016/j.bbapap.2013.01.025">drug discovery</a>. Combining “big data” and “big physics” requires a close collaboration among electrical and biomedical engineers as well as mathematicians and doctors. As we’re able to develop these techniques – both mathematical and technological – we’re hoping to make major advances in the coming years, improving how we all live.</p><img src="https://counter.theconversation.com/content/57406/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eric Miller receives funding from NSF, NIH, DHS. </span></em></p>
Pairing more powerful computers with increasingly sensitive scanners can yield many benefits in medicine and other fields.
Eric Miller, Professor and Chair of Electrical and Computer Engineering, Adjunct Professor of Computer Science, Adjunct Professor of Biomedical Engineering, Tufts University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/59504
2016-05-24T09:49:25Z
2016-05-24T09:49:25Z
The flower breeders who sold X-ray lilies and atomic marigolds
<p>The <a href="https://www.rhs.org.uk/shows-events/rhs-chelsea-flower-show">Chelsea Flower Show</a>, one of the biggest and best known horticultural shows in the world, is now open. In the coming days, some <a href="http://www.standard.co.uk/goingout/attractions/chelsea-flower-show-2016-tickets-times-highlights-and-travel-info-a3252546.html">150,000</a> visitors will make their way to the Royal Hospital Chelsea, expecting to be wowed by innovative garden designs and especially by gorgeous flowers. Among other things, show-goers will have a chance to learn the winner of the Royal Horticultural Society’s <a href="https://www.rhs.org.uk/shows-events/rhs-chelsea-flower-show/2015/articles/Plant-of-the-Year">Plant of the Year</a> award. This annual prize goes to the “most inspiring new plant” on display at the show – a high honour indeed given the number and range of varieties introduced each year.</p>
<p>The relentless pursuit of showy flowers for garden display extends back significantly further than the 104 years of the Chelsea show. One need only recall the <a href="https://www.rijksmuseum.nl/en/explore-the-collection/timeline-dutch-history/1637-tulipmania">infamous Dutch tulip craze</a> of the 17th century to be reminded that fascination with floral novelties has a long and storied history. </p>
<p>Over the centuries, entrepreneurial cultivators have endeavoured to create unique plant varieties, either by bringing together the genetic material from established lines through <a href="http://www.biologyreference.com/Ho-La/Hybridization-Plant.html">hybridisation</a> or through the discovery of new genetic variation such as a chance mutation in a field. Today, flower breeding is pursued with a far better understanding of plant biology than ever before, in some cases with the aid of technologies such as tissue culture and genetic transformation. Yet the goal remains the same: the creation of tantalising tulips, ravishing roses, show-stopping snapdragons and myriad other plants that will ideally prove irresistible to gardeners and turn a handsome profit.</p>
<p>The quest to produce profitable new varieties – and to do so as fast as possible – at times led to breeders to embrace <a href="http://press.uchicago.edu/ucp/books/book/chicago/E/bo24313051.html">methods that today seem strange</a>. There is no better illustration of this than the mid-century output of one of America’s largest flower-and-vegetable-seed companies, <a href="http://www.burpee.com/">W Atlee Burpee & Co</a>. </p>
<h2>Gardening with X-rays</h2>
<p>In 1941, Burpee Seed introduced a pair of calendula flowers called the “X-Ray Twins”. The company president, <a href="https://flic.kr/p/gaYqK">David Burpee</a>, claimed that these had their origins in a batch of seeds exposed to X-rays in 1933 and that the radiation had generated mutant types, from which the “X-Ray Twins” were eventually developed.</p>
<p>At the time, Burpee was not alone in exploring whether X-rays might facilitate flower breeding. Geneticists had only recently come to agree that radiation could lead to genetic mutation: the possibilities for creating variation “on demand” now seemed boundless. Some breeders even hoped that X-ray technologies would help them press beyond existing biological limits. </p>
<p>The Czech-born horticulturist Frank Reinelt thought that subjecting bulbs to radiation might help him produce an elusive red delphinium. Unfortunately, the experiment did not produce the hoped-for hue. Greater success was achieved by two engineers at the General Electric Research Laboratory, who produced – <a href="https://patents.google.com/patent/USPP165P">and patented</a> – a new variety of lily as a result of their experiments in X-ray breeding.</p>
<p>Though Reinelt’s and other breeders’ tangles with X-ray technology resulted in woefully few marketable plant varieties, David Burpee remained keen on testing new techniques as they appeared on the horizon. He was especially excited about methods that, like X-ray irradiation, promised to generate manifold genetic mutations. He thought these would transform plant breeding by making new inheritable traits – the essential foundation of a novel flower variety – available on demand. He estimated that “in his father’s time” a breeder chanced on a mutation “once in every 900,000 plants”. He and his breeders, by comparison, equipped with X-rays, UV-radiation, chemicals, and other mutation-inducing methods, could “turn them out once in every 900 plants. Or oftener”.</p>
<h2>Scientific sales pitches</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/123630/original/image-20160523-11025-1sr1nq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/123630/original/image-20160523-11025-1sr1nq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=930&fit=crop&dpr=1 600w, https://images.theconversation.com/files/123630/original/image-20160523-11025-1sr1nq4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=930&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/123630/original/image-20160523-11025-1sr1nq4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=930&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/123630/original/image-20160523-11025-1sr1nq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1169&fit=crop&dpr=1 754w, https://images.theconversation.com/files/123630/original/image-20160523-11025-1sr1nq4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1169&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/123630/original/image-20160523-11025-1sr1nq4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1169&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A 1973 Burpee cover.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/burpee/167768850/in/album-72157594166703655/">Burpee</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Burpee’s numbers were hot air, but in a few cases plant varieties produced through such methods did prove hot sellers. In the late 1930s Burpee breeders began experimentation with a plant alkaloid called <a href="https://archive.org/details/useofcolchicinei3424derm">colchicine</a>, a compound that sometimes has the effect of doubling the number of chromosomes in a plant’s cells. They exploited the technique to create new varieties of popular garden flowers such as marigold, phlox, zinnia, and snapdragons. </p>
<p>All were advertised as larger and hardier as a result of their chromosome reconfiguration – and celebrated by the company as the products of “chemically accelerated evolution”. The technique proved particularly successful with snapdragons, giving rise to a line of “Tetra Snaps” that were by the mid-1950s the best-selling varieties of that flower in the United States.</p>
<p>Burpee’s fascination with (in his words) “<a href="https://books.google.co.uk/books?id=IEEEAAAAMBAJ&pg=PA15">shocking mother nature</a>” to create novel flowers for American gardeners eventually led him to explore still more potent techniques for generating inheritable variation. He even had some of the company’s flower beds seeded with radioactive phosphorus in the 1950s. These efforts do not appear to have led to any new varieties – Burpee Seed never hawked an “atomic-bred” flower – but the firm’s experimentation with radiation did result in a new Burpee product. Beginning in 1962, they offered for sale packages of “atomic-treated” marigold seeds, from which home growers might expect to grow a rare white marigold among other oddities.</p>
<p>Burpee was, above all, a consummate showman and a master salesman. His enthusiasm for the use of X-rays, chemicals, and radioisotopes in flower breeding emerged as much from his knowledge that these methods could be effectively incorporated into sales pitches as from his interest in more efficient and effective breeding. Many of his mid-century consumers wanted to see the latest science and technology <a href="http://dx.doi.org/10.1017/S0007087412001057">at work in their gardens</a>, whether in the form of plant hormones, chemical treatments, or varieties produced through startling new techniques. </p>
<p>Times have changed, 60-odd years later. Chemicals and radiation are as more often cast as threatening than benign, and it is likely that many of today’s visitors to the Chelsea Flower Show hold a different view about the kinds of breeding methods they’d like to see employed on their garden flowers. But as the continued popularity of the show attests, their celebration of flower innovations and the human ingenuity behind these continues, unabated.</p><img src="https://counter.theconversation.com/content/59504/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Helen Anne Curry does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The relentless pursuit of showy flowers for garden display – as seen at Chelsea Flower Show – has seen some odd uses of radiation and chemicals .
Helen Anne Curry, Peter Lipton Lecturer in History of Modern Science and Technology, University of Cambridge
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/54963
2016-02-25T04:27:12Z
2016-02-25T04:27:12Z
See the cosmos with X-ray vision: Japan’s new Hitomi space telescope
<figure><img src="https://images.theconversation.com/files/112287/original/image-20160222-25876-fnnjy7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An artist's impression of the ASTRO-H telescope.</span> <span class="attribution"><a class="source" href="http://astro-h.isas.jaxa.jp/en/gallery-en/">JAXA/Akihiro Ikeshita</a></span></figcaption></figure><p>In June 1962, an <a href="http://airandspace.si.edu/collections/artifact.cfm?object=nasm_A19760034000">Aerobee 150</a> sounding-rocket blasted above the Earth’s atmosphere from the White Sands Missile Range in the United States of America. During its five-minute flight, the small research craft aimed to detect X-rays fluorescing from the moon. What it found instead would take a decade to explain.</p>
<p>X-rays are an extremely high-energy form of <a href="https://theconversation.com/let-there-be-light-celebrating-the-theory-of-electromagnetism-35723">electromagnetic radiation</a>. While visible light, from violet to red, has a wavelength of between 400 and 700 nanometers, X-ray wavelengths stretch from only 0.1 to 10 nanometers.</p>
<p>Radiation from the sun extends over both spectrums, but the energy in X-rays is a millionth of that emitted in visible light. The X-rays that reach the Earth are unable to penetrate through our atmosphere, so exploration of cosmic sources needs to be done from space.</p>
<p>Despite being a hundred times more sensitive than previous attempts, no one expected the X-ray detector on board the Aerobee 150 to see many cosmic X-ray sources. Even if our nearest star, Sirius, emitted X-rays as luminous as its visible light (unlikely given the sun’s 1:1,000,000 ratio), it was still far too dim to be seen. </p>
<p>Instead, the rocket was hoping to see the moon’s fluorescence due to the incident X-rays from the sun. But the data rolled in to reveal another source in the sky.</p>
<h2>A mysterious source</h2>
<p>Named <a href="http://www.britannica.com/topic/Scorpius-X-1">Scorpius X-1</a>, this X-ray source was so strong that if its ratio to visible light had matched that of the sun, its brightness would have rivalled the moon from its position 9,000 light years away. This was a whole new type of cosmic engine and marked the birth of X-ray astronomy.</p>
<p>Scorpius X-1 would eventually reveal itself to be a binary of two stars in close orbit. One member of the pair had reached the end of its life and collapsed to form an immensely dense object known as a <a href="http://astronomy.swin.edu.au/cosmos/N/Neutron+Star">neutron star</a>.</p>
<p>Its strong gravity was pulling gas off its stellar twin, which gained energy as it descended towards the neutron star, like a stone speeding up as it drops from a tall building. The energy was heating the gas to millions of degrees, causing it to radiate X-rays.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/111991/original/image-20160218-1276-1irw3k7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/111991/original/image-20160218-1276-1irw3k7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/111991/original/image-20160218-1276-1irw3k7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/111991/original/image-20160218-1276-1irw3k7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/111991/original/image-20160218-1276-1irw3k7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=423&fit=crop&dpr=1 754w, https://images.theconversation.com/files/111991/original/image-20160218-1276-1irw3k7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=423&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/111991/original/image-20160218-1276-1irw3k7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=423&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Galaxy cluster 3C295 in x-ray (left) and optical (right).</span>
<span class="attribution"><span class="source">NASA/CXC/SAO and NASA/HST/A.Dressier</span></span>
</figcaption>
</figure>
<p>X-ray astronomy moved from short-lived rockets to satellite observatories over the two decades following the Aerobee launch. NASA launched its <a href="http://heasarc.gsfc.nasa.gov/docs/einstein/heao2.html">Einstein observatory</a> in 1978, and in 1979, Japan launched the first of its X-ray telescopes, <a href="http://heasarc.gsfc.nasa.gov/docs/hakucho/hakucho.html">Hakucho</a>.</p>
<p>These satellites revealed that the darkest regions in the universe were bursting with high-energy activity. The space between clusters of galaxies turned out to be filled with incredibly hot gas that contained more mass than all the cooler optically-visible matter combined.</p>
<p>Gas was seen spiralling into neutron stars like Scorpius X-1 and swirling around their even more mysterious cousins, black holes.</p>
<h2>Launch of a new telescope</h2>
<p>The intrigue of this high-energy side of our universe continues and on the evening of February 17 this year, the Japanese Aerospace Exploration Agency (<a href="http://global.jaxa.jp/">JAXA</a>) launched its sixth X-ray observatory, <a href="http://astro-h.isas.jaxa.jp/en/">Hitomi</a>. The telescope is part of an international collaboration with NASA, the European Space Agency (ESA) and a number of other countries.</p>
<p>The satellite will orbit at an altitude of 575 kilometres, taking roughly an hour and a half to circle the Earth. On board are four telescopes of two different types.</p>
<p>Two telescopes focus the soft lower energy X-rays, while the second pair focus the higher energy hard X-rays. There is also a detector for the presence of the even higher energy gamma rays. In total, this allows Hitomi to be sensitive to an impressively broad range of wavelengths between 4 nanometres to 0.002 nanometres.</p>
<p>In addition to forming images, the soft X-ray telescope can measure the strength of the received X-rays at different wavelengths. This process is known as spectrometry and is equivalent to measuring the different strength of colours in the spectrum of visible light.</p>
<p>The spectrometer on-board Hitomi is about 50 times more sensitive for spread-out sources than previous missions, making it the first satellite able to measure the spectra from objects, such as galaxy clusters, in addition to bright point sources like Scorpius X-1.</p>
<p>Such measurements will allow far more accurate values to be placed on the energy in the hot gas, revealing the dynamics of cluster interactions and star formation.</p>
<h2>A name change for Hitomi</h2>
<p>Prior to launch, the satellite telescope was designated ASTRO-H, where the “H” recognises it as JAXA’s eighth planned space observatory, six of which have been X-ray satellites.</p>
<p>On the launch day, the Japanese space agency announced the <a href="http://astro-h.isas.jaxa.jp/en/info-en/2600/">telescope’s new name was Hitomi</a>, which is Japanese for the pupil of the eye, as it will be the aperture used to explore the X-ray universe.</p>
<p>When announcing Hitomi’s new name, the agency related an ancient folktale about a painter who drew four dragons, but did not include their pupils.</p>
<blockquote>
<p>People who looked at the painting said “why don’t you paint Hitomi, it is not complete!” The painter hesitated, but people pressured him. The painter then drew Hitomi on two of the four dragons. Immediately, these dragons came to life and flew up into the sky. The two dragons without Hitomi remained still.</p>
</blockquote>
<p>Clearly, the hitomi represented the key part of the painting, as the new Hitomi telescope will surely be on understanding the high-energy universe.</p><img src="https://counter.theconversation.com/content/54963/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elizabeth Tasker does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The universe looks very different with X-ray vision, revealing some of the most energetic interactions in our galaxy. Japan’s new Hitomi telescope will help us see these wonders.
Elizabeth Tasker, Assistant Professor, Hokkaido University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/43165
2015-06-16T18:09:49Z
2015-06-16T18:09:49Z
When science gets ugly – the story of Philipp Lenard and Albert Einstein
<figure><img src="https://images.theconversation.com/files/84791/original/image-20150612-11430-g85m2w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The dispute between Philipp Lenard and Albert Einstein sheds considerable light on the power of nonscientific concerns to sway scientists. </span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Einstein_gyro_gravity_probe_b.jpg">NASA via Wikimedia Commons </a></span></figcaption></figure><p>Scientists are not always as scientific as many suppose. Recent well-publicized cases of scientific fraud prove that scientists can be as susceptible to the allures of wealth, power and fame as politicians, the group that enjoys the lowest public trust. Glaring recent cases have included falsified results in the development of an <a href="http://www.nbcnews.com/news/us-news/researcher-charged-hiv-vaccine-fraud-case-n140041">HIV vaccine</a> and new techniques for <a href="http://www.nature.com/news/stem-cell-scientist-found-guilty-of-misconduct-1.14974">producing stem cells</a>.</p>
<p>Such breaches prove that scientists do not always base their work strictly on rigorous experimentation, data collection and analysis, and hypothesis testing. In fact, scientists frequently disagree with one another, both as individuals and as representatives of competing schools of thought. Some of these debates rage on for years. Superstring theory, sometimes called the “theory of everything,” has been a topic of vigorous contention for over 30 years.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/84768/original/image-20150611-11430-1k8v6il.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/84768/original/image-20150611-11430-1k8v6il.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/84768/original/image-20150611-11430-1k8v6il.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=799&fit=crop&dpr=1 600w, https://images.theconversation.com/files/84768/original/image-20150611-11430-1k8v6il.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=799&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/84768/original/image-20150611-11430-1k8v6il.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=799&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/84768/original/image-20150611-11430-1k8v6il.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1004&fit=crop&dpr=1 754w, https://images.theconversation.com/files/84768/original/image-20150611-11430-1k8v6il.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1004&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/84768/original/image-20150611-11430-1k8v6il.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1004&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Phillipp Lenard in 1900.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File%3APhillipp_Lenard_in_1900.jpg">Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>In some cases, personalities, prejudices and petty jealousies enter the picture. Consider, for example, one of the great disputes of 20th-century physics, the long-running feud between two world-renowned physicists. The antagonism between Philipp Lenard and Albert Einstein sheds considerable light on the power of nonscientific concerns to sway scientists. </p>
<p>Philipp Lenard (1862-1947) was a German experimental physicist who advanced the study of X-ray tubes, the photoelectric effect and atomic theory. His results led him to propose (correctly) that most of the atom is composed of empty space. Lenard was a genius, operating with a deep conviction that only careful experimentation could advance the understanding of the structure of the universe. Lenard received the Nobel Prize in physics in 1905 for his work on <a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1905/">cathode rays</a>.</p>
<p>Albert Einstein (1879-1955), who needs little introduction, was a Swiss theoretical physicist who developed the theories of special relativity, general relativity, mass-energy equivalence (E = mc2), and the photoelectric effect – the latter relying on key experimental results furnished by the work of Lenard. Amazingly, Einstein made many of his seminal contributions not like Lenard, while running a laboratory at a prestigious university, but while working as a low-level Swiss patent clerk. Einstein won the Nobel prize in physics in 1921 <a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1921/">for his discovery</a> of the law of the photoelectric effect. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/84769/original/image-20150611-11424-q6186h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/84769/original/image-20150611-11424-q6186h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/84769/original/image-20150611-11424-q6186h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=749&fit=crop&dpr=1 600w, https://images.theconversation.com/files/84769/original/image-20150611-11424-q6186h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=749&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/84769/original/image-20150611-11424-q6186h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=749&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/84769/original/image-20150611-11424-q6186h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=941&fit=crop&dpr=1 754w, https://images.theconversation.com/files/84769/original/image-20150611-11424-q6186h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=941&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/84769/original/image-20150611-11424-q6186h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=941&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Albert Einstein in 1921.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File%3AEinstein1921_by_F_Schmutzer_2.jpg">Ferdinand Schmutzer via Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>Initially, the relationship between Lenard and Einstein seems to have been cordial. Their correspondence suggests that each held the other in high admiration. When Einstein published his quantum theory explaining the photoelectric effect, Lenard wrote to him, “Nothing can make me happier than a thinker of great depth and scope deriving some pleasure from my work.” Einstein, in turn, referred to Lenard as “a great master and genius.” </p>
<p>But as detailed in a recent book, <a href="http://www.brucejhillman.com/">The Man Who Stalked Einstein</a>, their relationship soon deteriorated. In a letter to a friend a few years later, Einstein expressed a quite different view of Lenard, who was then regarded by many as the most celebrated physicist in Germany:</p>
<blockquote>
<p>His theories on the ether seem to me almost infantile, and some of his investigations border on the ludicrous. I am very sorry that you must waste your time with such stupidities.</p>
</blockquote>
<p>Lenard, meanwhile, was soon swept along in a wave of German nationalism that accompanied World War I. He became increasingly convinced of the existence of a distinctively German physics that needed to be defended against the plagiarized or frankly fabricated work emanating from other countries. Lenard also became more and more mired in anti-Semitism, accusing the “Jewish press” of, among other things, promoting Einstein’s dangerous work on relativity.</p>
<p>In 1920, just a year before Einstein won the Nobel Prize, the debate between Lenard and Einstein erupted into a duel of words at a major German research conference. </p>
<p>Lenard argued that Einstein’s hyper-theoretical and hyper-mathematical approach to physics was exerting a pernicious influence in the field. The time had come, he argued, to restore experimentalism to its proper place. He also launched a malicious attack on Einstein, making little attempt to conceal his antipathy toward Jews. </p>
<p>Lenard’s attacks on Einstein became increasingly vitriolic. He compared theoretical physicists to Cubist painters, who in his view were “unable to paint decently.” He lamented the fact that a “Jewish spirit” had come to rule over physics. Of Einstein himself, whose ideas had been accepted by many of the most prominent physicists around the world, Lenard opined, “Just because a goat is born in a stable does not make him a noble thoroughbred.” </p>
<p>Einstein initially attempted to respond to Lenard’s attacks on his theory of relativity with humor:</p>
<blockquote>
<p>“When you are courting a nice girl, an hour seems like a second, but when you sit on a red-hot cinder, a second seems like an hour. That’s relativity.” </p>
</blockquote>
<p>Later, he abandoned all pretense of patience and tolerance, labeling Lenard “a really twisted fellow” who must continue “to do business with the monster until he bites the dust.”</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/84793/original/image-20150612-11433-q9aulr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/84793/original/image-20150612-11433-q9aulr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=860&fit=crop&dpr=1 600w, https://images.theconversation.com/files/84793/original/image-20150612-11433-q9aulr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=860&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/84793/original/image-20150612-11433-q9aulr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=860&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/84793/original/image-20150612-11433-q9aulr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1080&fit=crop&dpr=1 754w, https://images.theconversation.com/files/84793/original/image-20150612-11433-q9aulr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1080&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/84793/original/image-20150612-11433-q9aulr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1080&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">WC Roentgen, 1906.</span>
<span class="attribution"><span class="source">Wellcome Images</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Lenard’s conviction that science, “like everything else man produces,” was somehow grounded in bloodlines led him to become one of the early adherents of National Socialism. Unlike many German scientists who regarded Adolf Hitler with disdain, Lenard was one of his most fervent supporters, and became the regime’s number one physics authority. Ironically, the National Socialists’ disdain for “Jewish physics” was one of the main reasons they did not develop nuclear weapons. </p>
<p>Lenard directed his invective at other scientists. He grew extremely resentful of the credit accorded to Wilhelm Roentgen, who received <a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1901/">the first Nobel Prize in physics</a> for the discovery of the X-ray, despite the fact that Roentgen was German and a non-Jew. Lenard wrote that he, not Roentgen, was the “mother of the X-rays,” since he had invented the apparatus used to produce them. He likened Roentgen’s role to that of a “midwife” who merely assists with the birth.</p>
<p>Lenard eventually became “Chief of Aryan Physics” under the Nazi regime. In 1933 he published a book called Great Men in Science, which omitted all mention of Einstein, Roentgen and such other notable 20th-century scientists as Marie Curie. When World War II ended, Lenard’s prominent role in the Nazi regime led to his arrest, but he was quite advanced in years. Instead of being sentenced to prison, he was sent to live in a small German village, where he died at age 83. </p>
<p>The story of Philipp Lenard reminds us that even scientists of the very highest caliber sometimes think, speak and act in utterly unscientific ways, swayed by prejudices that have no scientific basis. They are human beings too, and members of the general public need to be careful to distinguish between a scientist whose arguments are based in evidence and one whose pronouncements stem from other, less reliable sources of conviction.</p><img src="https://counter.theconversation.com/content/43165/count.gif" alt="The Conversation" width="1" height="1" />
Scientists are not always as scientific as many suppose. Recent well-publicized cases of scientific fraud prove that scientists can be as susceptible to the allures of wealth, power and fame as politicians…
Richard Gunderman, Chancellor's Professor of Medicine, Liberal Arts, and Philanthropy, IUPUI
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/28905
2014-07-10T04:36:02Z
2014-07-10T04:36:02Z
From the sweet taste of urine to MRI: how doctors lost their senses
<figure><img src="https://images.theconversation.com/files/53502/original/ykkhvnvx-1404965798.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">While doctors still use their senses for diagnoses, they have technologies to back them up.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/proimos/6869336880">Alex Proimos/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>“Diabetic urine”, the surgeon <a href="http://livesonline.rcseng.ac.uk/biogs/E002700b.htm">Herbert Mayo</a> wrote in 1832, “is almost always of a pale straw or greenish colour. Its smell is commonly faint and peculiar, sometimes resembling sweet whey or milk.” </p>
<p>The use of a culinary metaphor for describing a disease symptom would come as no surprise to Ritu Lakhtakia whose “<a href="http://mh.bmj.com/content/early/2014/05/28/medhum-2014-010522">Twist of taste: gastronomic allusions in medicine</a>”, is published today in the BMJ’s Medical Humanities.</p>
<h2>From food metaphors</h2>
<p>Lakhtakia draws our attention to the fact that medical educators have often relied upon culinary metaphors to describe the look of particular medical conditions. </p>
<p>“Creamy pus”, she tells us, “is the unwholesome attribute of an inflammatory exudate composed of necrotic tissues, white blood cells and bacteria.” To you and me that means pus with the texture of the stuff we put on strawberries – a striking, if somewhat alarming, metaphor.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/53501/original/29gsh9sf-1404965597.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/53501/original/29gsh9sf-1404965597.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53501/original/29gsh9sf-1404965597.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53501/original/29gsh9sf-1404965597.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53501/original/29gsh9sf-1404965597.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53501/original/29gsh9sf-1404965597.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53501/original/29gsh9sf-1404965597.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">It’s enough to put you off dessert.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/36933654@N00/5682350294">Andy /Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>She might, however, be surprised that Mayo’s description was far from metaphorical. The taste of diabetic urine, he maintained, was “always decidedly saccharine”. In other words, Mayo had used three of his senses to diagnose diabetes, sight, smell and taste.</p>
<p>That most famous of British surgeons, <a href="http://www.surgical-tutor.org.uk/default-home.htm?surgeons/hunter.htm%7Eright">John Hunter (1726-1793)</a> took the use of taste even further. </p>
<p>“The semen,” he said, “would appear from the smell and the taste, to be a mawkish kind of substance; but when held some time in the mouth, it produces a warmth similar to spices, which lasts some time.” </p>
<p>One assumes, at least, that he was tasting his own.</p>
<h2>To sensory medicine</h2>
<p>What all this reminds us is how sense-laden the history of medicine is. For millennia, healers, in their encounters with patients, used all their senses most of the time. </p>
<p>Sense use was not restricted to the emblematic activity of the medieval and early modern physician of looking at, smelling, and tasting flasks of urine. It was gazing, touching, palpitating, listening and smelling the patient for the slightest sign of disease. </p>
<p>The history of diagnosis has been the history of doctors’ use of the five senses.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/53504/original/k2h93n86-1404966148.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/53504/original/k2h93n86-1404966148.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=758&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53504/original/k2h93n86-1404966148.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=758&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53504/original/k2h93n86-1404966148.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=758&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53504/original/k2h93n86-1404966148.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=953&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53504/original/k2h93n86-1404966148.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=953&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53504/original/k2h93n86-1404966148.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=953&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">British surgeon John Hunter tasted more than others.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:John_Hunter_by_John_Jackson_detail.jpg">National Portrait Gallery, London</a></span>
</figcaption>
</figure>
<p>And as time passed, doctors developed ways of enhancing their senses. Most celebrated of all was probably the invention of the stethoscope in 1816 by French physician <a href="http://en.wikipedia.org/wiki/Ren%C3%A9_Laennec">Rene Laennec (1781-1826)</a> as a means of detecting lung or heart problems through the amplification of the body’s sounds. </p>
<p>But whereas the stethoscope enhanced the doctor’s senses, a battery of machines was developed in the 19th century to replace them. These included the <a href="http://en.wikipedia.org/wiki/Sphygmomanometer">sphygmomanometer</a> (Von Basch 1881), which measured blood pressure and, towards the end of the century, <a href="http://www.bl.uk/learning/cult/bodies/xray/roentgen.html">Röntgen rays</a> (X-rays), which became the first means of seeing what was going on inside a living human body.</p>
<h2>Technological leaps</h2>
<p>One of the most striking technological replacements of the senses was developed by <a href="http://www.dundee.ac.uk/museum/exhibitions/medical/cardiology/cardiology1/">James Mackenzie (1853-1925)</a> while he was still a humble GP in Burnley during the late 19th century. </p>
<p>His clinical experience combined with the use of his senses told him that a young woman whose labour he was attending was safe, despite an audible heart murmur. Her sudden death through a heart attack shocked him. </p>
<p>Clearly the senses were not enough; he decided to dedicate his life to studying heart murmurs. But how?</p>
<p>Murmurs were usually detected through the stethoscope. But they were incredibly hard to classify. No one could work out which were harmless and which fatal. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/53500/original/nx9rydfx-1404965182.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53500/original/nx9rydfx-1404965182.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=412&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53500/original/nx9rydfx-1404965182.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=412&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53500/original/nx9rydfx-1404965182.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=412&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53500/original/nx9rydfx-1404965182.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=518&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53500/original/nx9rydfx-1404965182.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=518&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53500/original/nx9rydfx-1404965182.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=518&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">These days doctors are unlikely to sip the urine for a sugar-like taste; much easier – and safer – to test for insulin levels in the blood.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-175399784/stock-photo-man-leaning-on-sink-with-urine-collection-container.html?src=RZzI5YwI6teWDsxeTspYTg-1-94">Shutterstock</a></span>
</figcaption>
</figure>
<p>So Mackenzie created a small portable “clinical polygraph”, which he would clip to the wrist of any patient in whom he had detected a murmur. He collected thousands of printouts from his polygraph, which over the years he correlated with the fate of each patient. </p>
<p>In the process, not only was he able to diagnose a wide variety of cardiac arrhythmias, but he also transformed his career from a humble practitioner treating the poor working classes of Burnley, to a Harley Street specialist with wealthy celebrity patients which included the ornate novelist Henry James.</p>
<h2>Towards better diagnoses</h2>
<p>Because of the success of enterprising doctors such as Mackenzie, during the 20th century the clinical use of the senses has been further eroded. Now there is a battery of technology dedicated to detecting what the senses cannot. </p>
<p>Ultrasound maps foetal development and detects physical irregularities. <a href="https://theconversation.com/the-science-of-medical-imaging-x-rays-and-ct-scans-15029">CT</a> and <a href="https://theconversation.com/the-science-of-medical-imaging-magnetic-resonance-imaging-mri-15030">MRI scans</a> enable the realistic (and sometimes real-time) visualisation of what is going on in the body. </p>
<p>So while doctors still use their senses, and are trained to do so, it is a brave one who diagnoses a potentially serious condition by the human senses alone.</p>
<p>Lakhtakia shows that the senses remain vitally important to the practice of medicine and medical education. She draws our attention to the look and smell of food, and the analogies that can be drawn between them and disease. </p>
<p>She rightly understands that the process is old and effective, and helps reinforce the ability of practitioners to diagnose. For like all sciences, medicine must not only observe but describe, and in shifting from observation to description, metaphor becomes crucial.</p>
<p>But metaphor will only get you so far. Today, while a medical practitioner might possibly agree with Mayo that a diabetic’s urine smelled like “sweet whey or milk”, she’s unlikely to sip the urine for a sugar-like taste; much easier – and safer – to test for glucose levels in the blood. And more reliable too.</p><img src="https://counter.theconversation.com/content/28905/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James Bradley does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
“Diabetic urine”, the surgeon Herbert Mayo wrote in 1832, “is almost always of a pale straw or greenish colour. Its smell is commonly faint and peculiar, sometimes resembling sweet whey or milk.” The use…
James Bradley, Lecturer in History of Medicine/Life Science, The University of Melbourne
Licensed as Creative Commons – attribution, no derivatives.