tag:theconversation.com,2011:/us/topics/human-body-46400/articles
Human body – The Conversation
2023-05-10T16:20:16Z
tag:theconversation.com,2011:article/203452
2023-05-10T16:20:16Z
2023-05-10T16:20:16Z
Cold water therapy: what are the benefits and dangers of ice baths, wild swimming and freezing showers?
<p><a href="https://bjsm.bmj.com/content/44/6/461">Immersion in cold water</a>
is definitely an activity that divides people – some love it others hate it. But many now practice it weekly or even daily in the belief that it’s good for their mental and physical health. </p>
<p>Cold water therapy, as it has come to be known, can take the form of outdoor swimming – in lakes, rivers or the ocean – cold showers or even ice baths. It has been used for a while by <a href="https://theconversation.com/ice-bath-after-exercise-the-benefits-might-be-in-your-head-33597">sportspeople</a> <a href="https://www.today.com/health/ice-bath-benefits-why-do-athletes-take-ice-baths-do-t191381">as a way to</a> <a href="https://www.tandfonline.com/doi/abs/10.1080/17461391.2011.570380">reduce muscle soreness</a> and speed up <a href="https://link.springer.com/content/pdf/10.1007/s40279-015-0431-7.pdf">recovery</a> time – with people typically spending about ten minutes after exercise in cold water that’s about <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5350472/">10-15°C</a>.</p>
<p>Cold water has also been used to help treat <a href="https://casereports.bmj.com/content/2018/bcr-2018-225007">symptoms of depression</a>, <a href="https://pubmed.ncbi.nlm.nih.gov/35021915/#:%7E:text=Conclusions%3A%20Cold%2Dwater%20immersion%20decreased,increase%20the%20quality%20of%20life.">pain</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1697736/">migraine</a>. Indeed, there are many accounts of how <a href="https://www.ft.com/content/52a91abf-7b2d-4026-8944-4028333e1aa7">cold water therapy</a> has changed lives, <a href="https://www.theguardian.com/news/2021/mar/23/how-cold-water-swimming-cured-my-broken-heart">cured broken hearts</a> and helped people during <a href="https://www.walesonline.co.uk/news/health/ice-bath-cold-water-swimming-26539194">difficult times</a>. </p>
<p>While <a href="https://theconversation.com/ice-bath-after-exercise-the-benefits-might-be-in-your-head-33597">many studies</a> have shown benefits linked to ice baths and post-exercise recovery, research from 2014 found there could be a placebo effect going on here.</p>
<p>Indeed, research into the potential benefits of cold water therapy or outdoor swimming is in its early stages, but what is clear is that cold water immersion can have potentially <a href="https://journals.lww.com/acsm-csmr/Fulltext/2021/11000/ACSM_Expert_Consensus_Statement__Injury_Prevention.11.aspx">harmful effects</a> on the human body. </p>
<h2>Cold water risks</h2>
<p>With any activity that’s intended for therapeutic effect, the minimum requirement is that it “does no harm”. But we can’t say that about cold water – as it comes with a lot of <a href="https://bjsm.bmj.com/content/56/23/1332">risks</a>. </p>
<p>At the moment, the science to <a href="https://www.scottishdailyexpress.co.uk/lifestyle/health/study-suggests-cold-water-swimming-28060941">fully support cold water as a therapy</a> is not available and it’s not yet known if there is a certain duration or temperature that works best. But what we do know is that <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7730683/">less is definitely more</a> when it comes to cold water immersion. In other words, going in colder water or staying in for longer is not better for you. In fact, it can have just the opposite effect. </p>
<p>In the UK, the water temperatures in natural environments are roughly between 10-28°C in the summer, falling to between 0-7°C in the winter. And it’s important to point out that open water temperatures lag behind air temperatures, so in April when the air temperature can be warm the sea temperature, even on the south coast, is likely to be below 10°C.</p>
<p>It might seem that when it comes to cold water therapy, showers and baths are a less hazardous option because you have greater control in terms of temperature and exposure time compared with open water. But due to the colder temperatures showers and ice baths can achieve and the solitary nature of the immersion they still pose significant risks. </p>
<p>One of the little-known problems associated with cold water immersion is what’s known as <a href="https://physoc.onlinelibrary.wiley.com/doi/10.1113/EP091139">non-freezing cold injury</a>. When we are exposed to the cold, it’s normal for the hands and feet to feel very cold or numb and they may tingle or be painful on rewarming. For most people, these symptoms are transient, with normal sensations returning within a few minutes. But for those with non-freezing cold injury, these symptoms (pain, altered sensation and cold sensitivity) can persist in the affected areas for many years due to <a href="https://pubmed.ncbi.nlm.nih.gov/28969380/">nerve</a> and <a href="https://physoc.onlinelibrary.wiley.com/doi/10.1113/EP090721">blood vessel</a> damage. </p>
<p>It’s caused by prolonged exposure to cold and wet conditions such as those seen in the trenches during wars – hence its nickname “trench foot”. It’s not just the military who are susceptible though, cases have been <a href="https://www.sciencedirect.com/science/article/pii/S1080603220300089?via%3Dihub">recently reported</a> in rough sleepers and those undertaking <a href="https://www.sciencedirect.com/science/article/abs/pii/S1080603222000497?via%3Dihub">water sports</a>. </p>
<p>Another issue is that it’s not known how cold is too cold when it comes to cold water immersion and non-freezing cold injury. There are also a lot of differences in the way our individual bodies <a href="https://www.tandfonline.com/doi/full/10.1080/23328940.2022.2044740">respond to cooling</a>. For example, those from African and Caribbean backgrounds seem to be more <a href="https://militaryhealth.bmj.com/content/165/6/400.long">susceptible to non-freezing cold injury</a> – so the risks from cold exposure will vary between different people.</p>
<p>Encouragingly though, one study from 2020 with cold water swimmers indicates that although they may have cold sensitivity, this was not associated with damage to the <a href="https://physoc.onlinelibrary.wiley.com/doi/10.1113/EP088555">blood vessels in the skin</a>. </p>
<h2>Cold water tips</h2>
<p>So if you are wanting to give cold water therapy a go, here are some things to consider:</p>
<p>• Check with your GP beforehand to make sure it’s safe for you to do.</p>
<p>• Make sure you’re not alone and the water is safe – if outdoors consider tides, currents, waves, underwater obstacles, pollution and jelly fish. </p>
<figure class="align-center ">
<img alt="Boy or man with closed eyes bathing in the cold water among ice cubes" src="https://images.theconversation.com/files/525149/original/file-20230509-16-v7ddvj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/525149/original/file-20230509-16-v7ddvj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/525149/original/file-20230509-16-v7ddvj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/525149/original/file-20230509-16-v7ddvj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/525149/original/file-20230509-16-v7ddvj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/525149/original/file-20230509-16-v7ddvj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/525149/original/file-20230509-16-v7ddvj.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">Always make sure you’re careful when immersing yourself in cold water, don’t stay too long and look after yourself afterwards.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/vilnius-lithuania-april-30-2022-boy-2151783209"> Michele Ursi/Shutterstock</a></span>
</figcaption>
</figure>
<p>• Plan how you’re going to get in and out of the water safely (remember that your muscles won’t work as well when you’re cold and you may not be able to feel with your hands and feet).</p>
<p>• Know how you’re going to get warm afterwards - make sure you have towels, dry clothes, windproofs, a hot drink and somewhere to shelter. Don’t drive or cycle until you have completely warmed up.</p>
<p>• Only stay in cold water for a short period of time, get out before you experience numbness, pain or shivering.</p><img src="https://counter.theconversation.com/content/203452/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>
From depression to muscle soreness: what are the potential benefits of cold water therapy?
Heather Massey, Senior Lecturer, Faculty of Science & Health, School of Sport, Health & Exercise Science, University of Portsmouth
Clare Eglin, Principal Lecturer in the School of Sport, Health, and Exercise Science, University of Portsmouth
Mike Tipton, Professor of Human and Applied Physiology, University of Portsmouth
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/204439
2023-04-26T16:37:40Z
2023-04-26T16:37:40Z
Here’s what happened when we endowed volunteers with a sixth finger
<figure><img src="https://images.theconversation.com/files/522997/original/file-20230426-489-97um5.png?ixlib=rb-1.1.0&rect=5%2C14%2C1911%2C997&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">This is not a _deepfake_ but a genuine sixth robotic finger.</span> <span class="attribution"><a class="source" href="https://www.youtube.com/watch?v=232jn-Vu6Rk">Yoichi Miyawaki Laboratory</a>, <span class="license">Author provided</span></span></figcaption></figure><p>Have you spotted what distinguishes this hand from those you see usually? Count the number of fingers…</p>
<p>The hand has a robotic “sixth finger” which we developed with <a href="https://www.lirmm.fr/ganesh-gowrishankar/">our collaborator</a>, Prof Yoichi Miyawaki of the University of Electro-Communications in Tokyo.</p>
<p>Users can control this sixth digit independently of the others. In fact, we can pinpoint, with an algorithm, muscle activity in the forearm which doesn’t contribute to normal finger movement, and use this signal to control the robot finger.</p>
<p>It’s also equipped with a haptic sensor (ie, concerned with the sense of touching): this feels what a real finger would feel, and offers “haptic feedback” – that is, light pressures applied on the palm of the hand, giving a tactile sensation.</p>
<p>The user can move around this extra digit with a minimum of training – for many people within less than an hour. One could put it to use by playing the piano!</p>
<p>What we have been studying is how, confronted with new digits, the body reacts. This is also what happens when the body is challenged to accept a prosthesis, for example.</p>
<h2>When the representation of the body changes</h2>
<p>Drawing on behavioural experiments and brain imagery, <a href="https://www.nature.com/articles/s41598-022-06040-x">our research</a> is focused on the way in which the user’s brain gels with the sixth finger. Changes in users’ bodily perceptions come very quickly.</p>
<p>More specifically, we’ve asked participants to touch a drawn line with their own little finger, without looking at their fingers. This experiment showed that people became uncertain about the positioning of their own little finger in space.</p>
<p>We’re pursuing these studies at the moment to directly observe using magnetic resonance imaging the extent of change to users’ brain activity, as this relates to representation of the robot sixth finger. For example, one could look to find out which zones of the brain are activated when the user moves their finger.</p>
<p>In neuroscience, the term <a href="https://www.sciencedirect.com/science/article/abs/pii/S0010027708000061">“embodiment”</a> of a limb refers to the human brain’s capacity to accept a prosthesis and believe it is part of one’s body. In French the expression is “incarnation”.</p>
<p>Another striking example is that of the <a href="https://www.youtube.com/watch?v=sxwn1w7MJvk">“rubber hand” illusion</a>, where the user thinks someone is tapping their hand, when their real arm is somewhere else.</p>
<h2>The human brain can accept foreign body parts</h2>
<p>This example and <a href="https://www.sciencedirect.com/science/article/pii/S2589004220309299">other scientific studies</a> over <a href="https://www.nature.com/articles/35784">recent decades</a>, including <a href="https://www.sciencedirect.com/science/article/abs/pii/S1053810016303038">our own</a>, have shown that it’s actually quite easy to deceive our brain into thinking that artificial limbs are part of our bodies. The brain is very adaptable and flexible about what it defines and accepts as our body.</p>
<p>This flexibility is very useful, because the human body changes as we grow up and get old. Physical changes can also be caused by accidents or through paralysis, which people are potentially capable of adapting to as well.</p>
<p>This notion of “incarnation” is also what allows us to accept prostheses to replace or complete lost bodily functions.</p>
<h2>The limits of acceptance for a new limb</h2>
<p>In our study of extra body parts, like the sixth finger, we have been interested in the limits of this acceptance. Is it possible to add new integral body parts? And can we feel added elements as if they are part of our body?</p>
<p>A number of previous studies have tried to address these questions by attaching artificial limbs to their subjects, including <a href="https://www.mrc-cbu.cam.ac.uk/blog/2022/06/the-third-thumb-project-at-the-royal-society-summer-science-exhibition/">robot fingers</a>, <a href="https://ieeexplore.ieee.org/document/8612275">arms</a>, and a <a href="https://pubmed.ncbi.nlm.nih.gov/23428442/">virtual tail</a> for humans.</p>
<p>However, all these investigations are on the basis of a limb replacement, where the added part is animated by movements and haptic feedback of existing body parts – effectively substituting a new artificial limb for a flesh and bones one.</p>
<p>In our study, we’re trying to find out if our brains can accept a truly autonomous extra body part, which can be moved around independently of any other part and from which we can obtain haptic feedback, on which the flesh and bones body has no bearing. It seems that they can.</p>
<p>Thinking of the applications, our finding that additional limbs can be accepted by the brain is encouraging for the future development of wearable artificial limbs.</p>
<hr>
<p><em>This article was translated from French by <a href="https://twitter.com/JoshNeicho">Joshua Neicho</a></em>.</p><img src="https://counter.theconversation.com/content/204439/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>This research was supported by JST ERATO Grant Number JPMJER1701, in Japan.</span></em></p>
Our body can adopt a sixth robotic finger, which we can move independently of the other fingers and with tactile sensations.
Ganesh Gowrishankar, Chercheur au Laboratoire d'Informatique, de Robotique et de Microelectronique de Montpellier, Université de Montpellier
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/202644
2023-04-03T15:38:49Z
2023-04-03T15:38:49Z
A professor is going to live in an underwater hotel for 100 days – here’s what it might do to his body
<p>As nightmares go, being trapped in a small box deep underwater is probably high on many peoples’ lists. But one US professor is <a href="https://www.usf.edu/news/2023/usf-researcher-attempts-to-set-world-record-by-living-underwater-for-100-days-hopes-to-emerge-super-human.aspx">doing this on purpose</a>. Joe Dituri, a former US navy diver and expert in biomedical engineering has been living in a 55 square meter space 30 feet below the surface of the Florida Keys since March 1, and plans to stay for 100 days. If he manages this, he will break a record for most time spent in a habitat beneath the surface of the ocean. </p>
<p>Dituri conducts research into the effects of hyperbaric pressure – when air pressure is greater than it would be at sea level – on the human body. He is hoping to use his time spent below the surface to examine what impact living in this high-pressure environment has on his health.</p>
<p>Interestingly, Dituri’s endeavour will be very different from living on a submarine. Submarines are sealed when submerged and maintained at sea level pressure. This means there’s no significant difference in pressure, even when a submarine is at depths of hundreds of meters.</p>
<p>But Dituri’s underwater habitat won’t have any solid hatches or air locks between the ocean and the dry living space, as a submarine does. Think of it like when a glass of water is turned upside down and pushed into a sink full of water. A pocket of air will still exist at the top of Dituri’s living space, with a pool of water in the floor of one room that comes from the ocean outside. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/u5GhJKBB5P8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A tour of the underwater habitat Dituri will be using.</span></figcaption>
</figure>
<p>This means that the air inside his habitat is squeezed by the ocean’s weight, increasing the air pressure around him. At a depth of 30 feet, the air pressure inside this habitat is about twice as much as what he’d be used to on land. </p>
<h2>Under pressure</h2>
<p>Little research has investigated what effect long-term exposure to hyperbaric pressure has on the body.</p>
<p>As every certified diver is well aware, though, hyperbaric pressure can pose a very real threat to us. Our bodies have been adapted by generations of evolution for sea level conditions, where the two major gases involved in breathing (oxygen and carbon dioxide) are the only two that freely cross between our lungs and our blood. </p>
<p>But as pressure increases, nitrogen in the air is forced across the delicate walls of our lungs and into our blood. This can cause a range of adverse effects. At depths of ten to 30 meters, this <a href="https://pubmed.ncbi.nlm.nih.gov/33510647/">may cause mild euphoria</a> and positive moods. After about 30 meters below sea level and beyond, it can lead to intoxicated-like behaviour – hence the name “narcosis”. </p>
<p>Scientists don’t fully understand <a href="https://pubmed.ncbi.nlm.nih.gov/27347903/">why this happens</a>, but it could be due to changes in the way neurotransmitters signal between neurons in our brain. Fortunately, this won’t be a risk to Dituri, as he’s only at a depth of ten meters.</p>
<h2>Health changes</h2>
<p>But Dituri can expect to experience other physical changes while living in his underwater habitat.</p>
<p>Although the habitat has large windows, Dituri will still only be exposed to half the amount of sunlight as on land. This could cause issues with his circadian rhythm – the internal “clock” that controls many body functions, including our sleep-wake cycle – which relies on daylight. This may mean disrupted sleeping.</p>
<p>Another challenge for Dituri will be getting enough vitamin D. The skin must receive UV exposure to make this vitamin, and this typically comes from the sun. It’s likely that Dituri will not be exposed to enough vitamin D while living in his underwater environment.</p>
<p>Vitamin D plays key roles in maintaining <a href="https://efsa.onlinelibrary.wiley.com/doi/abs/10.2903/j.efsa.2010.1468">bone density, muscle function and immunity</a>. Research on people who lived at an underwater habitat run by NASA as a spaceflight analogue found they had <a href="https://pubmed.ncbi.nlm.nih.gov/26116982/">reduced immune function</a> after only a 14-day stay. </p>
<p>Dituri will need to get vitamin D from other sources – such as foods high in vitamin D, supplements or from <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2846322/">UV lamps</a> – to minimise reductions in his immune function. Even though Dituri will be living alone, astronauts living in similar environments <a href="https://humanresearchroadmap.nasa.gov/Evidence/reports/IMMUNE%20EB%20Update%202021%20v02%20FINAL_6-15-22.pdf">report latent infections occuring</a>. These are viruses that many of us carry which our immune system normally keeps under control. This could also cause Dituri to fall ill if his immune function wavers.</p>
<p>Besides a minimal amount of walking around a very small habitat, the only exercise Dituri will get is from swimming. As swimming is non-weight bearing, losses in bone and muscle mass are likely – and may be similar to what astronauts see during <a href="https://pubmed.ncbi.nlm.nih.gov/27779600/">long missions on the International Space Station</a> (but not as exteme). Adding some resistance exercises such as squats and lunges may help Dituri offset muscle and bone mass losses. </p>
<h2>Long-term effects</h2>
<p>While Dituri’s underwater habitat will be different from a submarine, the amount of time he’s spending there is not altogether different from what many submarine crews endure. We know from research on submariners that even just a few months below the surface can have long-term effects, despite measures to prevent this from happening. </p>
<p>For instance, even after two months below the sea, submariners still had disturbed sleep patterns and problems with the levels of <a href="https://pubmed.ncbi.nlm.nih.gov/35142558/">certain hormones</a> linked to sleep. Crew also showed <a href="https://pubmed.ncbi.nlm.nih.gov/19882096/">losses in bone and muscle mass</a>. This reinforces how important it will be for Dituri to get enough vitamin D exposure and exercise.</p>
<p>Of course, the biggest question that remains is what effect long-term hyperbaric pressure will have on Dituri. What studies we do have on the effects of hyperbaric pressure have only looked at <a href="https://pubmed.ncbi.nlm.nih.gov/27984436/">short-term exposures</a>, which may have shown <a href="https://pubmed.ncbi.nlm.nih.gov/34376365/">positive effects on wound healing</a>. This will be both a physiologically and possibly psychologically challenging feat so, although Dituri is only one person, data from his experiment will still be useful to the field.</p><img src="https://counter.theconversation.com/content/202644/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bradley Elliott receives funding from The Endocrine Society, The Physiological Society, the Quintin Hogg Charitable Trust and private philanthropic donors. He has consulted with industry partners on atmospheric physiology. He is affiliated with The Physiological Society, and is a Trustee of the British Society for Research on Ageing.</span></em></p>
Dr Joe Dituri is hoping to set a world record during his experiment.
Bradley Elliott, Senior Lecturer in Physiology, University of Westminster
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/198537
2023-02-08T14:28:15Z
2023-02-08T14:28:15Z
How do I improve my immunity? Expert shares tips on what to do - and what to avoid
<figure><img src="https://images.theconversation.com/files/507107/original/file-20230130-7241-9z07f6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Exercising regularly, and spending time outdoors can improve your health. </span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>The human immune system is arguably the most complex system in the human body. But scientists have made a lot of progress in understanding how it functions.</p>
<p>That’s important for understanding illnesses and how to manage them. For instance, it’s important to understand that an immune response takes several days to fully develop. This knowledge would hopefully prevent people from getting impatient and seeking inappropriate care. </p>
<p>The immune system is made up of an intricate network of cells, tissues and molecules. These control the delicate balance between eliminating cancerous or infected cells, and not harming the body in the process. </p>
<p>A poorly functioning immune system can cause a variety of health problems. </p>
<p>It could lead to a person getting recurrent infections. Depending on the nature of the immune deficiency, the infections can range from viral (such as colds, flu, shingles and fever blisters) to bacterial (such as tuberculosis) or fungal (such as thrush). </p>
<p>Immune system dysfunction can also present as excessive inflammation or even auto-immunity. In this case the body starts seeing its own tissues as foreign and attacks them. Some examples of these conditions are rheumatoid arthritis, lupus and psoriasis.</p>
<p>The factors that affect our immune system range from things we can’t change, such as our genetic make-up and exposure to past pathogens, to things we may be able to control or modify.</p>
<p>I am an immunologist, and in this article I unpack the changes you can make today to help your immune system function better. They include diet, managing stress levels, and limiting exposure to environmental factors, such as germs, pollution and toxins. </p>
<p>Optimal immune function plays an important role in maintaining health. Given the immense complexity of the immune system, simplistic solutions are not effective. It’s important to understand some of the things you should – and shouldn’t – do. </p>
<h2>What not to do</h2>
<p>Many products claim to “boost” the immune system. But given the complex interplay between the cells in our bodies, it’s not really possible to “boost” just one part of the immune system. </p>
<p>And even if it was possible, “boosting” one aspect of your immune system can set off bad reactions by upsetting the delicate balance that makes up our bodies. For instance, “boosting” the immune system’s ability to fight infection could also “boost” other aspects, such as inflammation, that could harm normal tissue. </p>
<p>It is true that the immune system relies on vitamins and minerals to perform its tasks. But there is no solid evidence that taking vitamins and mineral supplements will improve its functioning. </p>
<p>The exception is when a person has a known deficiency, such as vitamin D deficiency. Most people with vitamin D deficiency do not have any symptoms or only have vague, non-specific symptoms, such as tiredness or lower back ache. People living with osteoporosis, diabetes, kidney disease, obesity, or depression, or those with limited sun exposure, especially the elderly, are at increased risk of having a deficiency. It’s important to address the problem because it can increase the risk of fractures, as well as infection from various pathogens, especially those affecting the lungs, such as flu and SARS-CoV-2. </p>
<p>If you think you’ve got a nutrient deficiency you should consult a healthcare practitioner for an accurate diagnosis. They can set out an evidence-based management strategy for you. </p>
<p>The reason for seeking professional help is that dosing up on supplements can be bad for you. </p>
<p>Firstly, some vitamins, such as vitamin A, D, E and K, are fat-soluble and are stored in the body. It is therefore possible to have levels that are too high, which can cause its own problems. For instance, too-high levels of vitamin D can cause kidney stones, constipation and high blood pressure. Too much vitamin A or iron can cause damage to the liver and other organs. </p>
<p>Secondly, nutrients should not be seen as independent components. Rather they should be seen as parts of a whole. Many supplements can interact negatively with other supplements and even with medication. For instance, vitamin K can reduce the ability of the blood thinner warfarin to prevent blood clots.</p>
<p>Combining different supplements can also lead to excessive or inadequate amounts of certain nutrients, with potentially detrimental effects. For example, prolonged zinc supplementation can cause copper deficiency, which has been linked to anaemia and impaired brain function. </p>
<h2>What to do</h2>
<p>The best way to ensure that your immune system gets what it needs is through a healthy and balanced lifestyle. </p>
<p>Diet is critical. Eat food that is unprocessed, preservative-free, and rich in a variety of vitamins, minerals and antioxidants. Your diet should include green and yellow vegetables, fruit and berries, whole grains, seeds and nuts. </p>
<p>And it’s not just the individual components of food that are important. The interplay between them matters too. This is something that cannot be reproduced in a tablet. </p>
<p>Lifestyle factors are also key. Stress is a normal and essential part of life, but it must be switched off to protect the body. Finding effective ways to control stress, such as breathing exercises, yoga and meditation, is important. </p>
<p>Activities that have been shown to improve health include getting enough rest, exercising regularly, spending time outdoors, and staying connected socially. Smoking and excessive alcohol use are clearly harmful. </p>
<p>Finally, we often forget to be kind to ourselves. When you are ill, take time to recover. When you are going through an especially stressful time, make an extra effort to de-stress. </p>
<p>Most importantly, don’t regard these as emergency measures. Make them part of your lifestyle. As tempting as it may be, it is not possible to “supplement” yourself out of a bad lifestyle.</p><img src="https://counter.theconversation.com/content/198537/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Theresa Rossouw 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>
As tempting as it is, it is not possible to “supplement” oneself out of a bad lifestyle.
Theresa Rossouw, Professor, University of Pretoria
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/164655
2021-09-13T12:14:14Z
2021-09-13T12:14:14Z
What happens when your foot falls asleep?
<figure><img src="https://images.theconversation.com/files/417576/original/file-20210824-17-1ma6ikr.jpg?ixlib=rb-1.1.0&rect=494%2C1005%2C4994%2C2982&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">That pins-and-needles feeling can come from sitting in the same position for a while.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/legs-of-a-girl-wearing-dotted-socks-royalty-free-image/1195442823">Westend61 via Getty Images</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 happens when your foot falls asleep? – Helen E., age 8, Somerville, Massachusetts</strong></p>
</blockquote>
<hr>
<p>Imagine you’ve just sat down to watch your favorite TV show. You decide to snuggle in with your legs crisscrossed because you find it more comfortable that way.</p>
<p>When the episode ends, you try to stand up and suddenly your right foot isn’t working. At first you just can’t move it, then it feels like it has pins and needles all over it. For a minute or two it feels uncomfortable and weird, but soon enough you are able to stand up and walk around normally.</p>
<p>What just happened?</p>
<p><a href="https://scholar.google.com/citations?user=gn8ZiLMAAAAJ&hl=en&oi=ao">I’m an exercise physiologist</a> – a scientist who studies what happens to our bodies when we move and exercise. The goal of much of my research has been to understand how the brain talks to and controls the different parts of our bodies. When your foot falls asleep, there is something wrong with the communication between your brain and the muscles in that area.</p>
<p>Every time you decide to move your body, whether it’s standing up, walking around or playing sports, your brain sends signals to your muscles to make sure they move correctly. When the brain is unable to talk with a muscle or groups of muscles, some weird things can happen – including that part of your body getting that weird falling-asleep sensation.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/L6w0_j6mWbo?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">An animation explains how the nervous system works.</span></figcaption>
</figure>
<p>It usually starts with a sense of numbness or tingling in that area. This sensation, which people often also call “pins and needles,” is technically known as <a href="https://www.racgp.org.au/afp/2015/march/paraesthesia-and-peripheral-neuropathy/">paresthesia</a>.</p>
<p>Some people mistakenly think a lack of blood flow causes this feeling. They imagine the “asleep” feeling happens when your blood, which carries nutrients all over your body, is unable to get to your foot. But that’s not right.</p>
<p>When your foot falls asleep, it’s actually because the <a href="https://doi.org/10.2165/00007256-200232060-00003">nerves that connect the brain to the foot</a> are getting squished thanks to the position you’re sitting in. Remember, it’s these nerves that carry messages back and forth to let your brain and your foot communicate with each other. If the nerves have been compressed for a little while, you won’t have much feeling in your foot because it can’t get its normal messages through to your brain about how it feels or if it’s moving.</p>
<p>Once you start to move around again, the pressure on the nerves is released. They “wake up” and you’ll start to notice a “pins and needles” feeling. Don’t worry, that feeling will only last for a few minutes and then everything will feel normal again.</p>
<p>Now comes the important question: Is this dangerous? Most of the time, when your foot, or any other body part, falls asleep, it is temporary and nothing to worry about. In fact, since it lasts for only a minute or two, you may not even remember it happened by the end of the day.</p>
<p>Even though it’s not causing any permanent damage, you might still want to avoid the uncomfortable feeling that comes when your foot falls asleep. Here are a couple of tips that may help:</p>
<ul>
<li>Switch your position often.</li>
<li>Don’t cross your legs for very long.</li>
<li>When you are sitting for a long time, try standing up every so often.</li>
</ul>
<p>You probably can’t 100% prevent your foot from ever falling asleep. So don’t worry when it happens every once in a while. It’ll go away pretty quickly – and maybe it can remind you of all the important brain messages your nerves are usually transmitting without your even noticing.</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/164655/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Zachary Gillen 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>
An exercise physiologist explains how it’s a problem of communication between your brain and your body.
Zachary Gillen, Assistant Professor of Exercise Physiology, Mississippi State University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/143313
2020-11-17T13:22:58Z
2020-11-17T13:22:58Z
Racial discrimination ages Black Americans faster, according to a 25-year-long study of families
<figure><img src="https://images.theconversation.com/files/366512/original/file-20201029-21-aenhdo.jpg?ixlib=rb-1.1.0&rect=0%2C11%2C4000%2C2646&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Anti-racism protest, 2020.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/woman-wearing-a-protective-face-mask-reading-i-cant-breathe-news-photo/1218209395">Fabrice Coffrini/AFP via Getty Images</a></span></figcaption></figure><p><em>The <a href="https://theconversation.com/us/topics/research-brief-83231">Research Brief</a> is a short take about interesting academic work.</em></p>
<h2>The big idea</h2>
<p>I’m part of a <a href="https://cfr.uga.edu/fachs/">research team</a> that has been following more than 800 Black American families for almost 25 years. We found that people who had reported experiencing high levels of racial discrimination when they were young teenagers <a href="https://doi.org/10.1037/hea0000788">had significantly higher levels of depression in their 20s</a> than those who hadn’t. This elevated depression, in turn, showed up in their blood samples, which revealed accelerated aging on a cellular level. </p>
<p>Our research is not the first to show <a href="https://doi.org/10.1146/annurev-publhealth-040218-043750">Black Americans live sicker lives and die younger</a> than other racial or ethnic groups. The experience of constant and accumulating stress due to racism throughout an individual’s lifetime can wear and tear down the body – literally “getting under the skin” to affect health.</p>
<p>These findings highlight how stress from racism, particularly experienced early in life, can affect the mental and physical health disparities seen among Black Americans. </p>
<h2>Why it matters</h2>
<p>As news stories of Black American women, men and children being killed due to racial injustice persist, our research on the effects of racism continue to have significant implications.</p>
<p>COVID-19 has been <a href="https://www.washingtonpost.com/opinions/2020/05/13/stress-was-already-killing-black-americans-covid-19-is-making-it-worse/">labeled a “stress pandemic” for Black populations</a> that are <a href="https://theconversation.com/covid-19-is-hitting-black-and-poor-communities-the-hardest-underscoring-fault-lines-in-access-and-care-for-those-on-margins-135615">disproportionately affected</a> due to factors like poverty, unemployment and lack of access to health care. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/365258/original/file-20201023-19-1eyt63q.jpg?ixlib=rb-1.1.0&rect=30%2C20%2C6679%2C4446&q=45&auto=format&w=1000&fit=clip"><img alt="Young black mother comforting sad school age daughter at home." src="https://images.theconversation.com/files/365258/original/file-20201023-19-1eyt63q.jpg?ixlib=rb-1.1.0&rect=30%2C20%2C6679%2C4446&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/365258/original/file-20201023-19-1eyt63q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/365258/original/file-20201023-19-1eyt63q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/365258/original/file-20201023-19-1eyt63q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/365258/original/file-20201023-19-1eyt63q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/365258/original/file-20201023-19-1eyt63q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/365258/original/file-20201023-19-1eyt63q.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">Racism has a far-reaching impact on children’s health.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/young-black-mother-taking-care-of-her-sad-little-royalty-free-image/1143896999">skynesher/E+ via Getty Images</a></span>
</figcaption>
</figure>
<p>In 2019, the <a href="https://doi.org/10.1542/peds.2019-1765">American Academy of Pediatrics identified racism</a> as having a profound impact on the health of children, adolescents, emerging adults and their families. Our findings support this conclusion – and show the need for society to truly reflect on the lifelong impact racism can have on a Black child’s ability to prosper in the U.S.</p>
<h2>How we do the work</h2>
<p>The <a href="https://cfr.uga.edu/fachs/">Family and Community Health Study</a>, established in 1996 at Iowa State University and the University of Georgia, is looking at how stress, neighborhood characteristics and other factors affect Black American parents and their children over a lifetime. Participants were recruited from rural, suburban and metropolitan communities. Funded by the National Institutes of Health, this research is the largest study of African American families in the U.S., with <a href="https://cfr.uga.edu/fachs/">800 families participating</a>.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/365260/original/file-20201023-18-1mcm3we.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Black man concentrates while completing a form." src="https://images.theconversation.com/files/365260/original/file-20201023-18-1mcm3we.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/365260/original/file-20201023-18-1mcm3we.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=903&fit=crop&dpr=1 600w, https://images.theconversation.com/files/365260/original/file-20201023-18-1mcm3we.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=903&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/365260/original/file-20201023-18-1mcm3we.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=903&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/365260/original/file-20201023-18-1mcm3we.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1135&fit=crop&dpr=1 754w, https://images.theconversation.com/files/365260/original/file-20201023-18-1mcm3we.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1135&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/365260/original/file-20201023-18-1mcm3we.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1135&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Early experiences of racism can have long-term physical effects.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/attractive-young-african-american-man-writing-royalty-free-image/181864094">PamelaJoeMcFarlane/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<p>Researchers collected data – including self-reported questionnaires on experiences of racial discrimination and depressive symptoms – every two to three years. In 2015, the team started taking blood samples, too, to assess participants’ risks for heart disease and diabetes, as well as test for biomarkers that predict the early onset of these diseases. </p>
<p>We utilized a <a href="https://doi.org/10.1038/ncomms9570">technique that examines how old a person is at a cellular level</a> compared with their chronological age. We found that some young people were older at a cellular level than would have been expected based on their chronological age. Racial discrimination accounted for much of this variation, suggesting that <a href="https://doi.org/10.1037/hea0000788">such experiences were accelerating aging</a>. </p>
<p>Our study shows how vital it is to think about how mental and physical health difficulties are interconnected. </p>
<h2>What’s next</h2>
<p>Some of the next steps for our work include focusing more closely on the accelerated aging process. We also will look at resiliency and early life interventions that could possibly offset and prevent health decline among Black Americans.</p>
<p>Due to COVID-19, the next scheduled blood sample collection has been delayed until at least spring 2021. The original children from this study will be in their mid- to late 30s and might possibly be experiencing chronic illnesses at this age due, in part, to accelerated aging. </p>
<p>With continued research, my colleagues and I hope to identify ways to interrupt the harmful effects of racism so that Black lives matter and are able to thrive.</p><img src="https://counter.theconversation.com/content/143313/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>This research was supported by the National Institute of Child Health and Human Development
(R01HD080749), the National Heart, Lung, Blood Institute (R01HL118045), the National
Institute of Drug Abuse (R01DA021898). In addition, support for this study was provided by the
Center for Translational and Prevention Science (P30DA02782) funded by the National Institute
on Drug Abuse. The content is solely the responsibility of the authors and does not necessarily
represent the official views of the National Institutes of Health.</span></em></p>
A study of 800 Black American families shows early experiences of racism have long-term consequences for physical and mental health.
Sierra Carter, Assistant Professor of Psychology, Georgia State University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/142728
2020-09-16T04:42:00Z
2020-09-16T04:42:00Z
Curious Kids: what are cells made out of?
<figure><img src="https://images.theconversation.com/files/348502/original/file-20200720-23-1spd472.png?ixlib=rb-1.1.0&rect=0%2C0%2C771%2C384&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fluorescent human cells seen through a microscope.</span> <span class="attribution"><span class="license">Author provided</span></span></figcaption></figure><blockquote>
<p><strong><em>I know veins are made out of cells but what are cells made out of? It’s very tricky to answer that — Bea, 4 years old</em></strong></p>
</blockquote>
<p><a href="https://theconversation.com/au/topics/curious-kids-36782"><img src="https://images.theconversation.com/files/291898/original/file-20190911-190031-enlxbk.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=90&fit=crop&dpr=1" width="100%"></a></p>
<p>That is a great question, Bea!</p>
<p>The human body is just like a big puzzle, but with billions of tiny pieces called cells. Our cells come in many different shapes and sizes. Together, they make up all of the parts of our body, from our veins to our brain.</p>
<p>Our cells are really, really small. For example, look at how thin a single strand of your hair is. Although it’s so thin, nearly 20 cells could fit across it. That’s how small they are.</p>
<p>Scientists have discovered cells are made from different building blocks we call molecules, such as water, plus other types like proteins, fats and DNA.</p>
<p>Just like our body, which has different parts that all work together, our cells also have different parts too. Let’s take a closer look.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/358115/original/file-20200915-24-zbja94.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/358115/original/file-20200915-24-zbja94.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/358115/original/file-20200915-24-zbja94.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=890&fit=crop&dpr=1 600w, https://images.theconversation.com/files/358115/original/file-20200915-24-zbja94.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=890&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/358115/original/file-20200915-24-zbja94.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=890&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/358115/original/file-20200915-24-zbja94.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1118&fit=crop&dpr=1 754w, https://images.theconversation.com/files/358115/original/file-20200915-24-zbja94.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1118&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/358115/original/file-20200915-24-zbja94.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1118&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Artistic representation of a human cell.</span>
<span class="attribution"><span class="source">Ivan Poon</span></span>
</figcaption>
</figure>
<h2>Cells have skin</h2>
<p>The outside skin of a cell is called the <em>plasma membrane</em>. It is made mainly of molecules called fats. This skin forms a bubble around the outside of the whole cell and holds it together.</p>
<p>Plants also have cells. But plant cells have an extra layer of skin called the <em>cell wall</em> which is strong and tough, not soft like a bubble, which explains why plants like trees can grow so tall.</p>
<h2>Cells have skeletons</h2>
<p>Like the bones inside our body, cells also have a kind of skeleton called the <em>cytoskeleton</em> (which means “cell skeleton”). It is made from molecules called proteins. The cell’s skeleton makes it strong, and also helps our cells move around the body.</p>
<h2>Cells have brains (sort of)</h2>
<p>One of the most important molecules in a cell is its DNA, made from a type of building block called nucleotides. DNA is like an instruction book for everything our cells have to do (including making more cells, moving, and fighting germs). As the <em>nucleus</em> stores most of our DNA, it’s just like the brain of the cell.</p>
<p>You might have heard of genes (not the ones you wear, but the ones inside you). They are just like a recipe your cells use to make you! They decide how tall you will grow, what colour your eyes or hair are, and more.</p>
<p>Our genes are made of DNA and we get this DNA from our mum and dad. For example, if a dad has brown eyes, he can pass on the recipe in his DNA to his child which tells their cells how to make brown eyes. This explains why we can look similar to our parents.</p>
<figure class="align-center ">
<img alt="A close up of a person's eye" src="https://images.theconversation.com/files/349506/original/file-20200727-23-pg60pb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/349506/original/file-20200727-23-pg60pb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/349506/original/file-20200727-23-pg60pb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/349506/original/file-20200727-23-pg60pb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/349506/original/file-20200727-23-pg60pb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/349506/original/file-20200727-23-pg60pb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/349506/original/file-20200727-23-pg60pb.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 billions of cells within our bodies make up who we are.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Cells have stomachs</h2>
<p>When you’re hungry, you eat! Your stomach then breaks down your food, in a process called digestion. Just like this, your cells also have their own mini stomachs which are important to digest the food and waste from the cell and keep them happy.</p>
<h2>Cells make energy</h2>
<p>If you turn on a light switch, the room quickly lights up. This is because of electricity which is a type of energy, made in big powerhouses. We use electricity for so many things like lights but also TVs, phones, heating and cooling.</p>
<p>Nearly everything that happens inside a cell needs energy too. Therefore, cells have special sections in them called <em>mitochondria</em>, which are the powerhouses of the cell and make all the energy the cell needs to work.</p>
<h2>Cells can talk to each other!</h2>
<p>If our cells are so tiny and our body is so big, how can all of our cells work together? The answer is they can talk … well, kind of.</p>
<p>Instead of picking up the phone to talk to each other, our cells have to send messages. These messages are made of molecules that help cells communicate.</p>
<p>Here is a cool example. If you get stung by a bee (ouch!) your skin will start to go red and puffy. This may look scary but actually, it is your body helping you. The cells in this area are quickly sending out messages for help. Cells in other areas get these messages and then go in for the rescue.</p>
<p>As scientists, we know a lot about cells. But we still don’t know everything. That’s why we need young kids to stay curious and ask questions, like Bea!</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskids@theconversation.edu.au">curiouskids@theconversation.edu.au</a></em></p><img src="https://counter.theconversation.com/content/142728/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Georgia Atkin-Smith receives funding from The CASS Foundation. </span></em></p><p class="fine-print"><em><span>Ivan Poon receives funding from the NHMRC, ARC, CASS Foundation, and Ramaciotti Foundation. </span></em></p>
Our cells may be small, but they are mighty. And they are made of lots of amazing stuff, from the DNA that tells your body how to grow, to mini skeletons that let cells move around.
Georgia Atkin-Smith, Research scientist, La Trobe University
Ivan Poon, Associate Professor, Biochemistry, La Trobe University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/129200
2020-05-13T11:29:23Z
2020-05-13T11:29:23Z
Seven things you might not know about blood
<figure><img src="https://images.theconversation.com/files/334639/original/file-20200513-156625-1nybj1k.jpg?ixlib=rb-1.1.0&rect=0%2C855%2C6709%2C3611&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Here's some facts you ought to know.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/top-view-hands-gloves-holding-blood-787103713">LightField Studios/ Shutterstock</a></span></figcaption></figure><p>Blood is fascinating. Many people learn at school that its function is to transport oxygen and nutrients around the body and remove waste products. But blood has <a href="https://www.ncbi.nlm.nih.gov/books/NBK279392/">many more functions</a>, including defence against pathogens, regulating our temperature, and keeping important internal chemicals and nutrients balanced.</p>
<p>Here are some other things you might not know about blood.</p>
<h2>1. Blood is both liquid and solid</h2>
<p>Blood is a connective tissue in the body. It has a multi-cellular component (made of red blood cells, white blood cells and platelets) and a liquid <a href="https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=90&ContentID=P02316">extracellular matrix</a>. </p>
<p>Unlike the other connective tissues in the body, blood is a liquid. The extracellular matrix, plasma, is liquid and suspends the cells in blood. But when tissues are damaged, by a cut for example, blood becomes a solid like other connective tissues. This is known as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4826570/">clotting</a>.</p>
<p>Clotting is activated by exposure to anything other than the smooth inner surface of a blood vessel, where a cascade commences to plug the wound. Platelets stick to the open wound, then soluble fibrinogen, a type of plasma protein, is converted to insoluble fibrin, which forms a “mesh” around the plug and prevents further blood loss. Over time, as this heals, the mesh and plug are broken down (or pulled off, if you pick scabs). </p>
<p>In most people, the blood is made up of about 45% cells – mainly red blood cells, only 1% are white blood cells – and 55% plasma. Too much or too little of any of these can cause disease, such as anaemia.</p>
<p>Blood cells are constantly produced and recycled. The body produces about <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4717490/">2 million</a> red blood cells a second, but this can be vastly increased in times of stress, such as at high altitudes, where less oxygen is available.</p>
<p><a href="https://www.nhs.uk/conditions/red-blood-count">On average</a>, men have between 4.7 to 6.1 million cells per microlitre, and women between 4.2 to 5.4 million cells per microlitre. There are 1,000 microlitres per millilitre.</p>
<h2>2. Volume is always changing</h2>
<p>The volume of blood in a person’s body changes over a <a href="https://www.jstage.jst.go.jp/article/jjphysiol1950/20/5/20_5_550/_pdf">24-hour</a> period. The body has its highest volume before lunch, as liquid is taken into the body. </p>
<p>A pregnant woman’s blood volume can <a href="https://www.ahajournals.org/doi/full/10.1161/circulationaha.114.009029">increase by up to 50%</a> during pregnancy. This is to support the uterus, which has the placenta and developing foetus in it. </p>
<p>But on average, men normally have between five to six litres of blood, and women have between <a href="https://www.ncbi.nlm.nih.gov/books/NBK526077/">four to five litres</a>. </p>
<h2>3. There are more than four blood types</h2>
<p>We inherit our blood type from our parents. We either have <a href="http://www.annclinlabsci.org/content/33/4/471.short">blood type</a> A, B, AB, or O. These groups determines what antigens you have, which means that depending on your blood type, blood from a person with an incompatible group cannot be transfused into another person. </p>
<p>But the other main blood group typing is Rhesus (Rh). People are either Rh+ or Rh- – meaning a person who is Rh+ has additional antigens, and cannot donate blood to someone who is Rh-, as this can cause an immune response. </p>
<h2>4. We’re always making more blood cells</h2>
<p>We constantly recycle blood cells and can make more blood cells when blood is lost. This means we can donate approximately 470 millilitres of blood at one time. The body takes about 12 weeks for men and 16 weeks for women to <a href="https://www.blood.co.uk/the-donation-process/after-your-donation/how-your-body-replaces-blood/">fully replenish</a> all the blood cells donated.</p>
<p>However, if we lose more than 40% of blood volume (a process known as <a href="https://www.ncbi.nlm.nih.gov/pubmed/29785654">exsanguination</a>), we die. If we lose around 10-20% of blood, the body goes into shock. While in shock, the body will try to fix the situation by increasing heart rate and breathing, and the body sweats and skin loses colour. </p>
<h2>5. Blood has a ‘use-by’ date</h2>
<p>It used to be that “whole” blood donations had to be used all at once. But now, the blood is separated into <a href="https://www.blood.co.uk/why-give-blood/how-blood-is-used/">its different components</a> – red blood cells, white blood cells, platelets and plasma – to make sure it is used as efficiently as possible, since a patient may only need one blood component. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/334641/original/file-20200513-156645-1nr28p8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334641/original/file-20200513-156645-1nr28p8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334641/original/file-20200513-156645-1nr28p8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334641/original/file-20200513-156645-1nr28p8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334641/original/file-20200513-156645-1nr28p8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334641/original/file-20200513-156645-1nr28p8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334641/original/file-20200513-156645-1nr28p8.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">After separation. Blood plasma is yellow in colour.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/preparing-plasmolifting-blood-tubes-two-layers-241407193">Iryna Kalamurza/ Shutterstock</a></span>
</figcaption>
</figure>
<p>Blood, like all things, has a <a href="https://www.redcrossblood.org/donate-blood/blood-donation-process/what-happens-to-donated-blood.html">use-by date</a>. How quickly it must be used depends on the part of blood. Red blood cells can be stored for about six weeks. But platelets only last a few days so are constantly needed. Other parts, such as plasma, can be frozen for up to a year. White cells are usually filtered out of donations.</p>
<h2>6. Blood loss was medicine</h2>
<p>“Bloodletting,” which dates back at least <a href="https://www.bcmj.org/premise/history-bloodletting">3000 years</a>, used to be a popular treatment for many common ailments. Many cases of bloodletting used leeches, which can consume five to ten millilitres of blood at a time – about ten times its body weight.</p>
<p>Bloodletting is behind the <a href="https://www.history.com/news/why-are-barber-poles-red-white-and-blue">red-and-white poles</a> you see outside a barber’s shop. The red represents the blood, and the white represents bandages. Barbers used to perform common medical procedures, including bloodletting.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-we-learned-to-keep-organs-alive-outside-the-body-a-horrible-history-132997">How we learned to keep organs alive outside the body: a horrible history</a>
</strong>
</em>
</p>
<hr>
<p>Bloodletting is still used, even with <a href="https://www.ouh.nhs.uk/patient-guide/leaflets/files/32855Pleech.pdf">leeches</a> that are specially farmed, in cases of plastic or reconstructive surgery. They help to remove clotted blood in an area of tissue that requires healing or attachment. </p>
<p>Another form of bloodletting uses a needle to remove blood and reduce the amount of iron in the body to treat <a href="https://www.nhs.uk/conditions/haemochromatosis/treatment/">haemochromatosis</a> – where there’s too much iron in the body.</p>
<h2>7. Not all blood is red</h2>
<p>Human blood is red because of the <a href="https://www.ncbi.nlm.nih.gov/books/NBK310577/">presence of haemoglobin</a>. But not all animals bleed red.</p>
<p>Icefish have clear blood, and one species of skink (a type of lizard) has <a href="https://www.nationalgeographic.com/news/2015/03/150312-blood-antarctica-octopus-animals-science-colors/">green blood</a>. Peanut worms have purple blood, and many bugs and beetles have yellow blood. </p>
<p>The colour of blood is usually because of specific proteins in the blood. These proteins may also have some survival advantage depending on the environment in which the species lives. </p>
<p>Despite medical advances, one challenge scientists still face is being able to <a href="https://www.scientificamerican.com/article/how-do-scientists-make-ar/">produce artificial blood</a> that is as high quality and efficient at all the jobs human blood does.</p><img src="https://counter.theconversation.com/content/129200/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Taylor is affiliated with the Anatomical Society. </span></em></p>
We’re full of blood – around five litres, on average.
Adam Taylor, Professor and Director of the Clinical Anatomy Learning Centre, Lancaster University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/127280
2019-11-18T21:20:47Z
2019-11-18T21:20:47Z
Anhidrosis: why some people – apparently like Prince Andrew – just can’t sweat
<figure><img src="https://images.theconversation.com/files/302295/original/file-20191118-66973-137v649.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Prince Andrew during the recent BBC interview.</span> <span class="attribution"><span class="source">BBC/Mark Harrison</span></span></figcaption></figure><p>Sweating is a controversial topic at the moment. In his <a href="https://www.independent.co.uk/news/uk/home-news/prince-andrew-interview-latest-jeffrey-epstein-bbc-paedophile-a9206661.html">extraordinary</a> recent <a href="https://www.bbc.co.uk/iplayer/episode/m000c1j4/newsnight-prince-andrew-the-epstein-scandal-the-newsnight-interview">BBC interview</a>, Prince Andrew <a href="https://www.youtube.com/watch?v=sE9iJPEuYHE">dismissed</a> some of the <a href="https://www.bbc.co.uk/news/uk-50446065">allegations</a> made against him by Virginia Giuffre (known previously as Virginia Roberts) on the grounds that he couldn’t sweat at the time – she had claimed he had been <a href="https://www.bbc.co.uk/news/uk-50451953">“profusely sweating”</a>. During the interview, Prince Andrew, who has <a href="https://www.bbc.co.uk/news/uk-50446065">categorically denied</a> all of the claims against him, said:</p>
<blockquote>
<p>I didn’t sweat at the time because I had suffered what I would describe as an overdose of adrenaline in the Falklands War, when I was shot at … it was almost impossible for me to sweat.</p>
</blockquote>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/sE9iJPEuYHE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>But what makes us sweat, why do we do it – and can some conditions prevent us from doing it at all?</p>
<p>The human body is an amazing entity and responds to thousands of internal and external signals every day. These responses enable us to survive in rapidly changing conditions.</p>
<p>The skin is the largest and heaviest organ of the human body. It is calculated to <a href="https://www.sciencedirect.com/science/article/pii/S0022202X15503679">weigh</a> approximately three to 4.5kg and, over the course of your life, you will lose about <a href="https://pubs.acs.org/doi/full/10.1021/es103894r">35kg</a> of skin. Skin constantly repairs and replaces itself and performs many functions. It protects the body against pathogens, provides insulation, synthesises vitamin D, provides sensation and most importantly regulates temperature.</p>
<p>The regulation of temperature is complex. Nerve fibres detect the temperature of whatever is in contact with the skin and relay this information to the brain, which makes a decision about what to do next – take off a jumper or put on a coat. But there are also more primitive and uncontrollable responses.</p>
<p>The skin is covered in most places by hair. When cold, the brain causes these hairs to stand on end, trapping a layer of insulating air next to the skin. Conversely, when it’s too hot, the body sweats, producing fluid from the approximately 4m sweat glands in the skin to help heat evaporate away from the body – cooling us down.</p>
<h2>What is sweating?</h2>
<p>Sweating is the release of a water-like fluid from special glands in the skin to help regulate body temperature. The fluid is approximately 99% water but also <a href="https://academic.oup.com/chemse/article/35/2/101/483325">contains</a> electrolytes, fatty acids, urea (as found in urine) and lactic acid. Many of these chemicals are now being <a href="https://journals.humankinetics.com/view/journals/ijsnem/18/5/article-p457.xml">analysed</a> to detect health and <a href="http://pdfs.semanticscholar.org/3c33/33413c4cb5674f56e3783a9105a6c7a2d773.pdf">hydration</a> levels, and assist in diagnosing diseases such as <a href="https://www.sciencedirect.com/science/article/pii/S0022347608003983">cystic fibrosis</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/from-perspiration-to-world-domination-the-extraordinary-science-of-sweat-62753">From perspiration to world domination – the extraordinary science of sweat</a>
</strong>
</em>
</p>
<hr>
<p>The body is composed of up to 75% water and the loss of as little as 1% of this can cause dehydration. A 10% loss, meanwhile, can lead to life-threatening changes to the body.</p>
<p>A sedentary adult loses approximately <a href="https://www.nature.com/articles/ejcn2009111">450ml</a> of water through invisible perspiration a day, while athletes in hot, dry environments can produce <a href="https://www.ncbi.nlm.nih.gov/books/NBK236237/">1,200ml</a> of sweat per hour. Total water loss can often be between two and three litres a day through sweating, breathing and other routes in a sedentary adult. But in warmer climates and with activity, these rates can increase hugely.</p>
<h2>How does sweating work?</h2>
<p>Sweating is usually initiated by an increase in body temperature from the normal 37C. When the body senses it is getting too hot, an area of the brain called the <a href="https://www.ncbi.nlm.nih.gov/books/NBK507838/">hypothalamus</a> controls the response. It does this through the sympathetic nervous system – also known as the “fight or flight” mechanism, because it also helps us fight for our lives or run away when we’re in danger. In this case, it triggers nervous impulses to release neurotransmitters (chemicals) that activate the sweat glands.</p>
<p>The main neurotransmitter involved in controlling sweating is called acetylcholine and its presence causes sweat glands to produce sweat – although a few also respond to a different neurotransmitter called adrenaline. The reason some respond to different neurotransmitters is to do with the receptors they have on their surface. Think of this as a lock and key – only the correct neurotransmitter (key) can fit in the receptor (lock) to cause the sweat gland to function.</p>
<p>In stressful situations, cold sweats are usually mediated by adrenaline. This is because the adrenaline causes the blood vessels to narrow and a few sweat glands to become active – producing a drop in skin temperature and a cold sweat. Most temperature-related sweating, however, is controlled by acetylcholine and the presence of adrenaline would not have any consequence on the function of these sweat glands.</p>
<h2>Does everyone sweat?</h2>
<p>Sweating is normal and just about everyone does it. Some people, however, do it more or less than others.</p>
<p>A complete absence of sweating is called anhidrosis. It can occur in particular areas of the body or be global – where more than 80% of the body has no ability to sweat. The causes are usually damage or pathology of the nervous system, or they may be inherited, such as in the case of <a href="https://www.nhs.uk/conditions/sjogrens-syndrome/">Sjogrens Syndrome</a>. Some individuals suffer from hypohidrosis which is a reduction in sweating and can be indicative of dehydration.</p>
<p>Regarding Prince Andrew’s claim, an excess or continual exposure to adrenaline is not widely recognised as causing a lack of sweating in humans. However, there is some data in <a href="https://www.ncbi.nlm.nih.gov/pubmed/6359664">horses</a> that has suggested that exposure to extreme temperatures may result in damage to the type of sweat glands that respond to adrenaline.</p>
<p>Similarly, the fact that the central nervous system, and parts of it that are linked to controlling the “fight or flight” response system, can also be involved or damaged in psychological trauma, means it is impossible to rule out this possibility without more information. There are a number of reports of individuals who have developed an idiopathic (unexplained) inability to sweat during <a href="https://pdfs.semanticscholar.org/f593/bab5d37b0f21754a17eb9ab28e29b8c231a9.pdf">military</a> and extreme training. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/302252/original/file-20191118-66957-1vnk0km.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/302252/original/file-20191118-66957-1vnk0km.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/302252/original/file-20191118-66957-1vnk0km.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/302252/original/file-20191118-66957-1vnk0km.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/302252/original/file-20191118-66957-1vnk0km.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/302252/original/file-20191118-66957-1vnk0km.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/302252/original/file-20191118-66957-1vnk0km.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">Hypohidrosis?</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sweaty-spot-on-shirt-because-heat-447385741">Shutterstock</a></span>
</figcaption>
</figure>
<p>At the opposite end of the spectrum is hyperhidrosis, which is excessive sweating. This condition can be systemic (body-wide) or localised. It is known that axillary hyperhidrosis (excessive armpit sweating) affects approximately <a href="https://www.ncbi.nlm.nih.gov/pubmed/15280843">3%</a> of the US population. Interference of tumours and other <a href="https://casereports.bmj.com/content/2013/bcr-2013-009732">pathologies</a> with the central nervous system can result in this symptom.</p>
<p>While sweating is seen to have its primary role in reducing body temperature, it is becoming clear that what is contained in sweat is far more interesting. Sweat even appears to be able to convey a person’s emotional state.</p>
<p>Women who were exposed to <a href="https://academic.oup.com/chemse/article/31/5/415/395942">sweat samples</a> that were collected from donors who were exhibiting fear while watching videos, for example, performed better in word association tasks than those women who were exposed to sweat which was produced by people watching neutral videos or samples that had no sweat on them at all. The sweat appears to contain a “signal” that suggests the person was undertaking a task that produced a heightened emotional or fearful state.</p>
<p>We may never know the truth about Prince Andrew’s sweating, but it’s something we all do and rely on – and researchers will continue to unlock its secrets for years to come.</p><img src="https://counter.theconversation.com/content/127280/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Taylor is affiliated with the Anatomical Society. </span></em></p>
In his recent interview, Prince Andrew claimed that he had stopped sweating. Here’s what the research says about how and why our bodies do it.
Adam Taylor, Professor and Director of the Clinical Anatomy Learning Centre, Lancaster University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/125268
2019-10-16T13:50:35Z
2019-10-16T13:50:35Z
Want to donate your body to research? What you need to know
<figure><img src="https://images.theconversation.com/files/297287/original/file-20191016-98648-swlcel.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">After death, your body can contribute to medical research and knowledge.</span> <span class="attribution"><span class="source">Anatomy Insider/Shutterstock</span></span></figcaption></figure><p><em>As the old aphorism has it, only two things are certain in life: death, and taxes. But while death may be inevitable, it does throw up a number of uncertainties – like what should be done with your body. A number of university anatomy schools globally run body donation programmes, and the practice is becoming more common on the African continent.</em></p>
<p><em>The University of the Witwatersrand’s School of Anatomical Sciences in Johannesburg, South Africa is celebrating its centennial year. PhD student Kimberleigh Tommy sat down with lecturer Dr Brendon Billings to find out why people should consider leaving their body to science and the huge shifts in how body donation works.</em></p>
<p><strong>Why should I consider donating my body to an anatomy school? And what will be done with it?</strong></p>
<p>The study of anatomy has been the foundation for training medical and allied health sciences students for hundreds of years. Dentists, physiotherapists, occupational therapists, doctors, pharmacists, nurses and medical scientists all need to understand the structure of the human body so they have the necessary skills to do their jobs properly.</p>
<p>Dissection also plays an important role in introducing students to death. It provides moral and ethical training for students as well as a humanistic approach to patient care. Overall, cadaver-based teaching prepares students intellectually and emotionally to deal with the challenges they face in their future careers.</p>
<p>Donated bodies are strictly used for teaching and research. They first undergo a process called perfusion. Perfusion and embalming is the process of removing blood from the body and replacing the blood with a fixative (chemical cocktail) to preserve the remains and make them safe for students to dissect.</p>
<p><strong>What will the students be told about me? Will they know my name?</strong></p>
<p>There are ethical and legal implications involved in identifying donors, so a student or researcher will never be told your name.</p>
<p>When it comes to research, if more personal details are needed – like your demographics or your occupation – then the researcher signs a non-disclosure agreement which strictly prohibits the use of any personal details in the publication of the research manuscript, dissertation or thesis. </p>
<p><strong>You mentioned ethics. Which guidelines are followed at the University of Witwatersand’s School of Anatomical Sciences in terms of legal and ethical use of human remains for teaching and research?</strong></p>
<p>At our school, the use of human cadavers for training health professional students falls under the <a href="https://www.up.ac.za/media/shared/12/ZP_Files/health-act.zp122778.pdf">National Health Act of the Republic of South Africa</a> and follows the ethical guidelines of the <a href="http://www.ifaa.net/">International Federation of Associations of Anatomy</a>. </p>
<p><strong>When do I sign up and can someone donate on my behalf?</strong></p>
<p>At Wits, you can register to donate your remains at any point during your lifetime or your family may donate your remains as a next of kin donor. While self-donation is preferred, quite a few of the bodies are donated by families after death. The reasons associated with a next-of-kin donation include following the wishes of the family member to financial constraints (the school does not pay for donations, but does cover the costs of cremation once research and teaching is complete). </p>
<p><strong>Do I need to document my donation in a will?</strong></p>
<p>Adding a codicil to a will is encouraged. However, it is not required if you complete the specific school’s body donor registration form, which acts as a will or codicil indicating your wishes.</p>
<p><strong>Does my family receive money for the donation?</strong></p>
<p>All donations are an altruistic gift. Our school cannot pay the donor or the family any money for the donation.</p>
<p><strong>Can my family still have a funeral for me if I am donating my body?</strong></p>
<p>Yes. In certain instances, families have requested the embalmed remains for a memorial ceremony. After that the embalmed body is then returned to the school for teaching and research.</p>
<p><strong>And once that teaching and research is done, will my remains be given back to my family? If so, when?</strong></p>
<p>Return of remains to a family is optional. The donor may request for their remains to be returned to the family after dissection of the body has been completed and the remains cremated – the school pays for the cremation. Alternatively, donors could opt to donate their bodies to the school for an indefinite period of time.</p>
<p><strong>Can I donate if I am an organ donor?</strong></p>
<p>Yes, you can be both an organ donor and a body donor – but there are some provisos to take note of. If your organs turn out not to be suitable for donation, then we will accept the body donation. We need a full body for our particular programme; if certain organs have been removed leaving an open wound the perfusion process that’s necessary to embalm corpses is compromised.</p>
<p><strong>Do I need to get medical clearance or disclose any diseases like HIV?</strong></p>
<p>Our school has a list of communicable diseases that will exclude an individual from donating their remains. These exclusions are provided on the body donor information sheets. You are not required to disclose your HIV status if you plan to donate your body to our school’s body donor programme.</p>
<p><strong>Does my cause of death matter?</strong></p>
<p>Yes, it does. Motor vehicle accidents, homicides and suicides or any other case that requires an autopsy will be addressed by the state mortuary services and not the school. In such instances the donated body cannot be accepted by the school.</p>
<p><strong>Who processes my death certificate with South Africa’s Department of Home Affairs?</strong></p>
<p>We do, as the school.</p>
<p><strong>So if I decide that your school’s programme is the one I’d like to donate my body to, do I have to live in Johannesburg?</strong></p>
<p>The majority of donations are within 300km from Wits University, but individuals living in the broader Gauteng province may donate to the school. Exceptions can be made, if the family is willing to transport the body to an area within the distance indicated. It’s worth checking geographical exclusions and requirements for other schools if you’re looking to donate to another programme.</p><img src="https://counter.theconversation.com/content/125268/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brendon Kurt Billings has previously received funding from the National Research Foundation</span></em></p><p class="fine-print"><em><span>Kimberleigh Ashley Tommy receives funding from National Research Foundation, The University of the Witwatersrand and the DST-NRF Centre of Excellence in Palaeosciences
Affiliations: Black Women in Science (BWIS) </span></em></p>
Dissection also plays an important role in introducing students to death. It provides moral and ethical training for students as well as a humanistic approach to patient care.
Brendon Kurt Billings, Lecturer/Curator, University of the Witwatersrand
Kimberleigh Ashley Tommy, PhD Candidate (Biological Anthropology), University of the Witwatersrand
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/118603
2019-08-30T02:17:30Z
2019-08-30T02:17:30Z
Curious Kids: how do wounds heal?
<figure><img src="https://images.theconversation.com/files/278847/original/file-20190611-32373-17h8wdw.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5742%2C3837&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">When you have a wound, your body gets to work straight away to clean it out, kill germs and repair the skin. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/pleasant-nice-girl-holding-her-knee-628311236?studio=1">Shutterstock/Yakobchuk Viacheslav</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>If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au.</em> </p>
<hr>
<blockquote>
<p><strong>I would like to know how wounds heal. – Simon, age 7.</strong></p>
</blockquote>
<hr>
<p>Thank you for this excellent question, Simon. To explain how the body heals a break in the skin, I first need to explain a bit about how skin works. </p>
<p>Did you know the skin is the largest organ in the body? It has three layers that protect us from germs and help our body keep the right temperature. For example, when our body gets too hot, we have sweat glands in the skin that release salty water to cool us down (it’s like air conditioning in our bodies). Our skin also has a lot of sensors so we can touch and feel hot and cold.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-does-our-blood-fight-viruses-like-chicken-pox-and-colds-119394">Curious Kids: how does our blood fight viruses like chicken pox and colds?</a>
</strong>
</em>
</p>
<hr>
<h2>Plugging the wound</h2>
<p>Once we get a wound, the first thing the body tries to do is stop the bleeding. </p>
<p>Within minutes or even seconds, tiny things in your blood called “blood cells” start to group together, protecting and plugging up the wound to stop any more bleeding. A scab will start to form. </p>
<p>The body tries to plug up the wound as quick as it can. It wants to stop germs getting in through broken skin and making you really sick. But even as this happens, the wound may let out a bit of clear fluid that helps to clean the wound.</p>
<p>Your doctor may also decide to close your wound with stitches, special glue or staples to keep the skin together until the body has built new skin to heal.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/281076/original/file-20190625-81754-du1xsq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/281076/original/file-20190625-81754-du1xsq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281076/original/file-20190625-81754-du1xsq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281076/original/file-20190625-81754-du1xsq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281076/original/file-20190625-81754-du1xsq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281076/original/file-20190625-81754-du1xsq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281076/original/file-20190625-81754-du1xsq.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">Scabs help keep germs out.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/450987034?studio=1&size=huge_jpg">Shutterstock</a></span>
</figcaption>
</figure>
<h2>Behind the scenes</h2>
<p>Under the skin, your body is hard at work cleaning and fixing. </p>
<p>The wound may be swollen, red and painful. Doctors call this “inflammation”. Swelling like this means the body is sending more fluid, oxygen and blood cells to the wound to get to work fixing it. </p>
<p>In your blood there are special “soldier” cells in charge of fighting germs. They are called white blood cells, and as soon as you get a cut, your body will send a lot of white blood cells to the wound to get to work. They eat any germs that may have come in when your skin was broken and they also guide the healing process. </p>
<p>The blood cells in the body then work to start building new skin, layer by layer. One thing they do is tell the body to start producing more of a chemical called “collagen” which helps the skin form new layers.</p>
<p>It usually takes a few days for a wound to heal fully, but it sometimes takes much longer. If you get a really big wound, you might get a scar. A scar is also made out of collagen. It is a mark on your skin. Sometimes they stay there forever, and sometimes they disappear or get lighter over time. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/281069/original/file-20190625-81737-1f1zox7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/281069/original/file-20190625-81737-1f1zox7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=211&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281069/original/file-20190625-81737-1f1zox7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=211&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281069/original/file-20190625-81737-1f1zox7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=211&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281069/original/file-20190625-81737-1f1zox7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=265&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281069/original/file-20190625-81737-1f1zox7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=265&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281069/original/file-20190625-81737-1f1zox7.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">
<figcaption>
<span class="caption">White blood cells will eat any germs that may have come in when your skin was broken.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/search/blood+cells+wound+skin?search_source=base_landing_page">Shutterstock</a></span>
</figcaption>
</figure>
<h2>How to help your body fix a wound</h2>
<p>It is important to keep the wound clean, damp and covered to help it heal quicker. Wounds that are left uncovered are likely to dry out and are not protected from other injuries.</p>
<p>If your wound creates a scab, it might get really itchy. But try not to scratch! Your skin is busy healing underneath. Just let it fall off on its own. Band-aids are perfect to protect small wounds from further injury.</p>
<p>You should eat healthy food to help fuel your body while it fixes itself. Your body needs protein (like meat, milk and cheese), carbohydrates (like bread and pasta) and vitamins (like oranges, carrots and spinach). </p>
<p>These foods supply energy for healing your wound, and help your immune system fight germs.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-do-we-have-two-kidneys-when-we-can-live-with-only-one-113201">Curious Kids: why do we have two kidneys when we can live with only one?</a>
</strong>
</em>
</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au</em></p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em>Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/118603/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christina Parker is a member of Wounds Australia and is the secretary for the QLD committee. </span></em></p><p class="fine-print"><em><span>Helen Edwards receives funding from research grants, including government grants, philanthropic foundation grants and NHMRC grants for wound research. She is a member of Wounds Australia, Fellow, College of Nursing Australia, Fellow, Sigma Theta Tau International and has an Order of Australia Medal.</span></em></p><p class="fine-print"><em><span>Kathleen Finlayson receives funding from government grants, philanthropic foundation grants and NHMRC grants for wound research. She is a member and volunteer for Wounds Australia, the Australian Nursing Council, and Sigma Theta Tau International.
</span></em></p>
The body tries to plug a wound quickly to stop germs getting in through broken skin and making you sick. But behind the scenes, your blood is working hard to repair a wound.
Christina Parker, Senior Lecturer, Queensland University of Technology
Helen Edwards, Professor, Queensland University of Technology
Kathleen Finlayson, Lecturer, Queensland University of Technology
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/115890
2019-05-24T10:44:53Z
2019-05-24T10:44:53Z
Mathematics of scale: Big, small and everything in between
<figure><img src="https://images.theconversation.com/files/272592/original/file-20190503-103068-1dvf5rv.jpeg?ixlib=rb-1.1.0&rect=0%2C0%2C1359%2C1098&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">How many lakes are in Alaska? Thermokarst lakes on Alaska's North Slope are self-similar and fractal.</span> <span class="attribution"><a class="source" href="https://www.gaeacherissa.com/">Painting by Cherissa Dukelow</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Breathe. As your lungs expand, air fills 500 million tiny alveoli, each a fraction of a millimeter across. As you exhale, these millions of tiny breaths merge effortlessly through larger and larger airways into one ultimate breath.</p>
<p>These airways are fractal.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/273393/original/file-20190508-183096-1c8a0r2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/273393/original/file-20190508-183096-1c8a0r2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/273393/original/file-20190508-183096-1c8a0r2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=905&fit=crop&dpr=1 600w, https://images.theconversation.com/files/273393/original/file-20190508-183096-1c8a0r2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=905&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/273393/original/file-20190508-183096-1c8a0r2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=905&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/273393/original/file-20190508-183096-1c8a0r2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1138&fit=crop&dpr=1 754w, https://images.theconversation.com/files/273393/original/file-20190508-183096-1c8a0r2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1138&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/273393/original/file-20190508-183096-1c8a0r2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1138&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 branches within lungs are an example of self-similarity.</span>
<span class="attribution"><span class="source">Brockhaus and Efron Encyclopedic Dictionary/Wikimedia</span></span>
</figcaption>
</figure>
<p>Fractals are a mathematical tool for describing objects with detail
at every scale. Mathematicians and physicists <a href="https://lsa.umich.edu/cscs/people/post-docs-lecturers-visiting-scholars/mgnew.html">like
me</a> use fractals and related concepts to understand how things change going from small to big.</p>
<p>You and I translate between vastly different scales when we think about how our choices affect the world. Is this latte contributing to climate change? Should I vote in this election?</p>
<p>These conceptual tools apply to the body as well as landscapes, natural disasters and society.</p>
<h2>Fractals everywhere</h2>
<p>In 1967, mathematician Benoit Mandelbrot asked, <a href="https://users.math.yale.edu/%7Ebbm3/web_pdfs/howLongIsTheCoastOfBritain.pdf">“How long is the coast of Britain?”</a> </p>
<p>It’s a trick question. The answer depends on how you measure it. If you trace the outline on a map, you get one answer, but if you walk the coastline with a meter stick, the result is quite different. Anyone who has tried to estimate the length of a rugged hiking trail from a map knows the treachery of the large-scale picture.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/272800/original/file-20190506-103057-1idtjez.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/272800/original/file-20190506-103057-1idtjez.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/272800/original/file-20190506-103057-1idtjez.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=874&fit=crop&dpr=1 600w, https://images.theconversation.com/files/272800/original/file-20190506-103057-1idtjez.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=874&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/272800/original/file-20190506-103057-1idtjez.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=874&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/272800/original/file-20190506-103057-1idtjez.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1099&fit=crop&dpr=1 754w, https://images.theconversation.com/files/272800/original/file-20190506-103057-1idtjez.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1099&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/272800/original/file-20190506-103057-1idtjez.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1099&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Satellite image of Great Britain and Northern Ireland.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Satellite_image_of_Great_Britain_and_Northern_Ireland_in_April_2002.jpg">NASA</a></span>
</figcaption>
</figure>
<p>That’s because lungs, the British coastline and hiking trails all have <a href="https://www.worldcat.org/title/fractal-geometry-of-nature/oclc/7876824">fractality</a>: their length, number of branches or some other quantity depends on the scale or resolution you use to measure them.</p>
<p>The coastline is also <a href="https://en.wikipedia.org/wiki/Self-similarity">self-similar</a> – it’s made out of smaller copies of itself. Fern fronds, trees, snail shells, landscapes, the silhouettes of mountains and river networks all look like smaller versions of themselves. </p>
<p>That’s why, when you’re looking at an aerial photograph of a landscape, it’s often hard to tell whether the scale bar should be 50 km or 500 m. </p>
<p>Your lungs are self-similar, because the body finely calibrates each branch in exact proportions, making each branch a smaller replica of the previous. This modular design makes lungs efficient at any size. Think of a child and an adult, or a mouse, a whale. The only difference between small and large is in how many times the airways branch.</p>
<p>Self-similarity and fractality appear in art and architecture, in the arches within arches of Roman aqueducts and the spires of Gothic cathedrals that mirror the forest canopy. Even ancient Chinese calligraphers Huai Su and Yan Zhenqing <a href="https://arxiv.org/pdf/0810.1242.pdf">prized the fractality</a> of summer clouds, cracks in a wall and water stains in a leaking house in 722.</p>
<h2>Scale invariance</h2>
<p>Self-similar objects have a scale invariance. In other words, some property holds regardless of how big they get, such as the efficiency of lungs.</p>
<p>In effect, scale invariance describes what changes between scales by saying what doesn’t change.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/273383/original/file-20190508-183077-1ki11a5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/273383/original/file-20190508-183077-1ki11a5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/273383/original/file-20190508-183077-1ki11a5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=621&fit=crop&dpr=1 600w, https://images.theconversation.com/files/273383/original/file-20190508-183077-1ki11a5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=621&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/273383/original/file-20190508-183077-1ki11a5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=621&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/273383/original/file-20190508-183077-1ki11a5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=780&fit=crop&dpr=1 754w, https://images.theconversation.com/files/273383/original/file-20190508-183077-1ki11a5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=780&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/273383/original/file-20190508-183077-1ki11a5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=780&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 sketch from Leonardo da Vinci’s notes on tree branches.</span>
<span class="attribution"><span class="source">Fractal Foundation</span></span>
</figcaption>
</figure>
<p><a href="https://www.insidescience.org/news/uncovering-da-vincis-rule-trees">Leonardo da Vinci observed</a> that, as trees branch, the total cross-sectional area of all branches is preserved. In other words, going from trunk to twigs, the number of branches and their diameter change with each branching, but the total thickness of all branches bundled together stays the same.</p>
<p>Da Vinci’s observation implies a scale invariance: For every branch of a certain radius, there are four downstream branches with half that radius.</p>
<p>Earthquake frequency has a similar scale invariance, <a href="https://authors.library.caltech.edu/47734/1/185.full.pdf">which was observed in the 1940s</a>. The big ones come to mind – Lisbon 1755, San Francisco 1989 – but many small earthquakes occur in California every day. The Gutenberg-Richter law says that earthquake frequency depends on the size of the earthquake. The answer is surprisingly simple. A tenfold bigger earthquake occurs roughly one-tenth as often.</p>
<h2>Society and the power law</h2>
<p>A 19th-century economist Vilifredo Pareto – famous in business school for <a href="https://betterexplained.com/articles/understanding-the-pareto-principle-the-8020-rule/">the 80/20 rule</a> – observed that the number of families with a certain wealth is inversely proportional to their wealth, raised to some exponent. Pareto measured the exponent for different years and different countries and found that it was usually around 1.5. </p>
<p>Pareto’s wealth distribution came to be known as the power law, ostensibly because of the exponent or “power.”</p>
<p>Anything self-similar <a href="https://arxiv.org/abs/cond-mat/9707012">has a corresponding power law</a>. In <a href="https://doi.org/10.1103/PhysRevLett.122.158303">an April paper</a>, my colleague and I describe the corresponding power law for lungs, blood vessels and trees. It differs from Pareto’s power law only by taking into account specific ratios between branches.</p>
<p>The sizes of fortunes then are akin to the sizes of tree twigs or blood vessels – a few trunks or large branches and exponentially more tiny twigs.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/272801/original/file-20190506-103071-1emh5qv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/272801/original/file-20190506-103071-1emh5qv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/272801/original/file-20190506-103071-1emh5qv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/272801/original/file-20190506-103071-1emh5qv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/272801/original/file-20190506-103071-1emh5qv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/272801/original/file-20190506-103071-1emh5qv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/272801/original/file-20190506-103071-1emh5qv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/272801/original/file-20190506-103071-1emh5qv.jpg?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">Patterns in an oak’s branches.</span>
<span class="attribution"><span class="source">Schlegelfotos/shutterstock.com</span></span>
</figcaption>
</figure>
<p>Pareto thought of his distribution of wealth as a natural law, but <a href="https://doi.org/10.1126%2Fscience.286.5439.509">many different models of social organization</a> give rise to a Pareto distribution and societies do vary in <a href="https://en.wikipedia.org/wiki/List_of_countries_by_distribution_of_wealth">wealth inequality</a>. The higher Pareto’s exponent, the more egalitarian the society.</p>
<p>From understanding how humans are made up of tiny cells to how we affect the planet, self-similarity, fractality and scale invariance often help translate from one level of organization to another.</p><img src="https://counter.theconversation.com/content/115890/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mitchell Newberry receives funding from US National Science Foundation. </span></em></p>
What do earthquakes, wealthy Italian families and your circulatory system have in common? Scientists use fractals, self-similarity and power laws to translate from local to global scales.
Mitchell Newberry, Assistant Professor of Complex Systems, University of Michigan
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/115323
2019-04-23T08:25:34Z
2019-04-23T08:25:34Z
Curious Kids: why can’t we tickle ourselves?
<figure><img src="https://images.theconversation.com/files/269755/original/file-20190417-139101-p29sse.jpg?ixlib=rb-1.1.0&rect=7%2C7%2C5052%2C3360&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The good type of tickles. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/mother-tickling-her-daughter-sitting-garden-531868747?src=MToNrAen08bW-2uwTc-0eA-1-15">Shutterstock.</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a> is a series by <a href="https://theconversation.com/uk">The Conversation</a>, which gives children of all ages the chance to have their questions about the world answered by experts. All questions are welcome: send them – along with your name, age and the town or city where you live – to curiouskids@theconversation.com. We won’t be able to answer every question, but we’ll do our best.</em></p>
<hr>
<blockquote>
<p><strong><em>Why can’t we tickle ourselves? – Florence, aged 12, Cambridgeshire, UK.</em></strong></p>
</blockquote>
<p>Thanks for the question, Florence. The short answer is, we humans can’t tickle ourselves because we’ll already be expecting it. And a big part of what makes tickles ticklish is the element of surprise. </p>
<p>Tickling is an important sign that someone or something is touching you. In general, there are two types of tickles. There are good tickles, like when your family or friends tickle you and make you laugh. And there are bad tickles, like when you can feel a bug on you. </p>
<p>Both types of tickles help us in different ways. </p>
<h2>Bad tickles</h2>
<p>Over the hundreds of thousands of years that humans have been around, being ticklish has had its advantages. Tickling tells us when there is a bug or something else crawling on our skin. </p>
<p>The reason why we feel ticklish is because our body is covered in small hairs. These help us to feel danger that might be too small to see – like bugs. </p>
<p>People who are ticklish can feel bugs land on them, and flick them off before they bite. This helps to avoid getting bitten by poisonous insects. </p>
<p>Over the ages, ticklish people would have been less likely to be bitten by poisonous bugs, so they would have lived longer and had more babies, who were also ticklish. </p>
<p>In other words, humans <a href="https://www.bbc.com/bitesize/articles/z9qs4qt">have evolved</a> to be ticklish, because it can help us to sense danger, such as bugs. If we could tickle ourselves, then we might have more trouble telling when there’s a bug on us or when we are just touching ourselves. </p>
<p>So it makes sense that we cannot tickle ourselves, so that we can be sure when dangerous things, such as bugs, are on us.</p>
<h2>Good tickles</h2>
<p>Good tickles feel good and can make us laugh. It can be a fun way to play – and humans aren’t the only animals that can tickle. </p>
<p>Did you know that when chimpanzees chase and tickle each other they make panting sounds? These pants do not mean that the chimp is tired – they actually mean that it <a href="https://www.cell.com/current-biology/pdf/S0960-9822(15)00679-X.pdf?fbclid=IwAR34K8nGxl5l9PiHIMkbrYZSz-PSLZop8vTwExFQ2zIc-l8u8AGxIDGa8no">wants to play!</a> </p>
<p>Pets, such as rats, also make noises like laughter when people stroke them. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/78PfGQbL-g0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Laughter and play are good ways for animals (including us!) <a href="https://www.tandfonline.com/doi/full/10.4161/cib.3.2.10944">to make friends</a> . And if you could tickle yourself, you might be less likely to laugh and play with others. </p>
<p>So, there are good reasons why we can only be tickled by others, and not ourselves. But to understand how tickling really works, we’ll have to look inside the human body. </p>
<h2>The motor system</h2>
<p>The motor system is a thing that most animals – including humans – have in their body. It’s made up of our muscles and brain, and it’s what <a href="http://t.tutis.ca/NeuroMD/L9Touch/tickle.pdf">lets us move</a> </p>
<p>Every time that you move, your brain sends a plan to your muscles. It does this by sending the plan, in the form of electrical signals, along the nerves that run like wires through your body. </p>
<p>This plan tells the muscles when and how to move, and also what to expect when we have moved.</p>
<p>We have five senses: sight, smell, taste, touch and hearing. The plans sent to your muscles guess how each of these senses may change, after you have moved. </p>
<p>So, when you try to tickle yourself, your brain sends the plan through the nerves: it tells the muscles in one arm to move to do the tickling, and it also tells your other muscles that the tickle is coming. </p>
<p>When somebody else tickles you, your muscles haven’t got a plan from your brain, so the feeling is surprising – and ticklish! </p>
<p>But you can’t tickle yourself, because your brain is always one step ahead, telling your muscles and senses what to expect and stopping you from giving yourself a surprise. But then, maybe it’s better that way. </p>
<hr>
<p><em>More <a href="https://theconversation.com/topics/curious-kids-36782?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">Curious Kids</a> articles, written by academic experts:</em></p>
<ul>
<li><p><em><a href="https://theconversation.com/curious-kids-why-do-eggs-have-a-yolk-111605?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">Why do eggs have a yolk? – Rafael, age 7.</a></em></p></li>
<li><p><em><a href="https://theconversation.com/curious-kids-who-is-siri-114940?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">Who is Siri? – Miles, aged four, London, UK.</a></em></p></li>
<li><p><em><a href="https://theconversation.com/curious-kids-what-would-happen-if-the-sun-exploded-115329?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">What would happen if the sun exploded? – Lizey, aged 12, Australia.</a></em></p></li>
</ul><img src="https://counter.theconversation.com/content/115323/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Aysha Bellamy 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>
Tickling is an important sign that someone – or something – is touching you. An expert explains how it works.
Aysha Bellamy, PhD Candidate, Royal Holloway University of London
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/110989
2019-04-01T00:02:35Z
2019-04-01T00:02:35Z
Curious Kids: why do we have fingernails and toenails?
<figure><img src="https://images.theconversation.com/files/260940/original/file-20190226-150698-3fscmu.jpg?ixlib=rb-1.1.0&rect=0%2C396%2C7344%2C4503&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Nails help us scratch an itch, but also pick up tiny things. </span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p><em><a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a> is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also like the podcast <a href="http://www.abc.net.au/kidslisten/imagine-this/">Imagine This</a>, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.</em> </p>
<hr>
<blockquote>
<p><strong>Why do we have fingernails and toenails? - Jake (age 9) and Ben (age 7), Melbourne.</strong></p>
</blockquote>
<hr>
<p>The reason we have fingernails and toenails is not to pick our noses or to scratch our siblings.</p>
<p>The short answer is we have evolved to have nails because they help us pick things up (like food), pick things off (like bugs), and hold tightly onto things.</p>
<p>Early humans who had these type of nails (instead of claws) tended to live long enough to have babies and pass on the fingernails gene to their kids. So over time, the number of human ancestors with nails grew and the number with claws shrunk. That’s how evolution works. </p>
<p>But the story goes back further than that.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/261136/original/file-20190226-150721-opfm4y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/261136/original/file-20190226-150721-opfm4y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/261136/original/file-20190226-150721-opfm4y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/261136/original/file-20190226-150721-opfm4y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/261136/original/file-20190226-150721-opfm4y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/261136/original/file-20190226-150721-opfm4y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/261136/original/file-20190226-150721-opfm4y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/261136/original/file-20190226-150721-opfm4y.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">Flat nails are better than claws for grasping.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Our primate ancestors and cousins</h2>
<p>Humans are members of the primate family. The primates are the most intelligent group of mammals (mammals are animals who do not lay eggs). Primates have evolved to have nails. </p>
<p>That’s why you see primates like apes and monkeys also have nails on all their fingers and toes, as well as our closest primate “cousins”: gibbons, bonobos, chimpanzees, gorillas and orangutans. </p>
<p>While humans don’t usually use our toes these days to pick things up, our primate cousins do. So our toenails are a hangover from a time in our evolutionary past where we often used our feet to pick stuff up and pick stuff off. </p>
<p>All these primates – including us – evolved from a common ancestor that had claws.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/260619/original/file-20190225-26177-6k5hjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/260619/original/file-20190225-26177-6k5hjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/260619/original/file-20190225-26177-6k5hjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/260619/original/file-20190225-26177-6k5hjv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/260619/original/file-20190225-26177-6k5hjv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/260619/original/file-20190225-26177-6k5hjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/260619/original/file-20190225-26177-6k5hjv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/260619/original/file-20190225-26177-6k5hjv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Here you can see a chimpanzee’s fingernails and toenails.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/nilsrinaldi/5158418328/">Nils Rinaldi</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Nails vs claws</h2>
<p>So why did we evolve to have nails instead of claws? The answer is that nails let us do a lot of important things that you can’t do with claws.</p>
<p>Compare your nails to those of a dog or cat. Your nails are wide, flat and shield-shaped. They are also on the back of the tip of your fingers and toes. </p>
<p>A dog or cat has claws that are thin, curved and pointed. They wrap around the end of their “fingers” and “toes”. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/260943/original/file-20190226-150702-1viy395.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/260943/original/file-20190226-150702-1viy395.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/260943/original/file-20190226-150702-1viy395.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/260943/original/file-20190226-150702-1viy395.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/260943/original/file-20190226-150702-1viy395.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/260943/original/file-20190226-150702-1viy395.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/260943/original/file-20190226-150702-1viy395.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/260943/original/file-20190226-150702-1viy395.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Claws are great for scratching but would get in the way if you had to hold a tool or pick up something tiny.</span>
<span class="attribution"><span class="source">Shuttertock</span></span>
</figcaption>
</figure>
<p>By having nails, you can pick up tiny things like small LEGO bricks off the ground, pick off stickers, or pick a bug off you easily. You can make and use tools. Can a cat do that with its claws? No! In fact, having super-long, clawlike nails can <a href="https://www.instyle.com/news/i-wore-kylie-jenner-nails-week">make it really hard</a> to do a lot of things humans need to do – like eating, washing and holding things.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/260938/original/file-20190226-150712-k6hk7q.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4726%2C3127&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/260938/original/file-20190226-150712-k6hk7q.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4726%2C3127&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/260938/original/file-20190226-150712-k6hk7q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/260938/original/file-20190226-150712-k6hk7q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/260938/original/file-20190226-150712-k6hk7q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/260938/original/file-20190226-150712-k6hk7q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/260938/original/file-20190226-150712-k6hk7q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/260938/original/file-20190226-150712-k6hk7q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Without nails, it would be much harder to pick up small things.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>On the other hand, claws are useful for some things that cats and dogs often need to do.</p>
<p>By having claws, your cat can quickly run up a tree (even if it doesn’t have many lower branches) to catch a bird. Plus your dog can dig up your backyard in one afternoon (to find food, for example). </p>
<p>Primates also climb trees but we mostly do it by grasping onto branches, and long claws get in the way when you’re grasping. Nails provide a rigid backing to primates’ fingertips to improve grasping. We dig too, of course, but we use tools for that. You don’t have the same needs as a dog or a cat, so you don’t have the same type of nails or claws.</p>
<p>Each type of animal has evolved to have the type of finger-covering (either claws or nails) that best suits its needs.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-do-tongues-taste-food-103744">Curious Kids: how do tongues taste food?</a>
</strong>
</em>
</p>
<hr>
<h2>What if we didn’t have nails?</h2>
<p>Imagine for a moment that humans didn’t have nails. First, a lot of nail salons would go out of business, and we couldn’t enjoy painting our nails lots of different colours. </p>
<p>But more importantly, having a lump of soft skin at the end of our fingers would make it harder to hold things and control our grip on them. The ends of our fingers and toes have changed to match our changed lives.</p>
<p>So next time you’re at the zoo, look at the hands of gibbons, chimpanzees, gorillas and orangutans, and you’ll see they have nails just like yours. Think about all the amazing things we primates can do with nails.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/260944/original/file-20190226-150712-1drfkys.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/260944/original/file-20190226-150712-1drfkys.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/260944/original/file-20190226-150712-1drfkys.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=480&fit=crop&dpr=1 600w, https://images.theconversation.com/files/260944/original/file-20190226-150712-1drfkys.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=480&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/260944/original/file-20190226-150712-1drfkys.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=480&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/260944/original/file-20190226-150712-1drfkys.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=603&fit=crop&dpr=1 754w, https://images.theconversation.com/files/260944/original/file-20190226-150712-1drfkys.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=603&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/260944/original/file-20190226-150712-1drfkys.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=603&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Orangutan nails are not that different to ours.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-is-everything-really-made-of-molecules-109145">Curious Kids: is everything really made of molecules?</a>
</strong>
</em>
</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au</em></p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em>Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/110989/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amanda Meyer 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 short answer is we have evolved to have nails because they help us pick things up (like food) and pick things off (like bugs).
Amanda Meyer, Lecturer of Human Anatomy, The University of Western Australia
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/112399
2019-03-31T19:12:34Z
2019-03-31T19:12:34Z
Leonardo da Vinci revisited: how a 15th century artist dissected the human machine
<figure><img src="https://images.theconversation.com/files/263087/original/file-20190311-86696-hyvkk6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Leonardo da Vinci's anatomical drawings and mechanical designs reveal his fascination with engineering, motion, anatomy and ageing.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Leonardo_da_Vinci_-_Superficial_anatomy_of_the_shoulder_and_neck_(recto)_-_Google_Art_Project.jpg">Google Art Project, via Wikimedia Commons.</a></span></figcaption></figure><p><em>On the <a href="https://www.britannica.com/biography/Leonardo-da-Vinci">500th anniversary of his death</a>, this series brings together scholars from different disciplines to re-examine the work, legacy and myth of Leonardo da Vinci.</em></p>
<p>Leonardo da Vinci was fascinated by the human body. His disdain for painters who did not bother to learn anatomy was barely concealed in his criticisms of those who “draw their nude figures looking like wood, devoid of grace; so that you would think you were looking at a sack of walnuts rather than the human form”.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/263092/original/file-20190311-86678-gqor3j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/263092/original/file-20190311-86678-gqor3j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/263092/original/file-20190311-86678-gqor3j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=853&fit=crop&dpr=1 600w, https://images.theconversation.com/files/263092/original/file-20190311-86678-gqor3j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=853&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/263092/original/file-20190311-86678-gqor3j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=853&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/263092/original/file-20190311-86678-gqor3j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1072&fit=crop&dpr=1 754w, https://images.theconversation.com/files/263092/original/file-20190311-86678-gqor3j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1072&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/263092/original/file-20190311-86678-gqor3j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1072&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Leonardo da Vinci, Anatomical studies of the shoulder, c 1510.</span>
<span class="attribution"><span class="source">Wikiart.org</span></span>
</figcaption>
</figure>
<p>His bodies envisioned something very different – living mechanics – combining ideas that he explored across many fields of investigation, including animal and human dissections. </p>
<p>In doing so, he anticipated many questions that now preoccupy modern scientists, from the mechanics of the human body to the possibility of a mechanical body for humans.</p>
<p>Leonardo was born the illegitimate son of a notary and a peasant woman. He did not attend a university and had a rather haphazard and informal education. His knowledge of the human body was self-taught and largely experiential.</p>
<p>Leonardo’s notebooks are filled with an explosion of ideas, in treatises, sketches and jottings. One note mentioned the following: </p>
<blockquote>
<p>Have Avicenna’s work on useful inventions translated; spectacles with the case, steel and fork and…., charcoal, boards, and paper, and chalk and white, and wax;…. …. for glass, a saw for bones with fine teeth, a chisel, inkstand …….. three herbs, and Agnolo Benedetto. Get a skull, nut,— mustard.</p>
</blockquote>
<p>In this jumble of thoughts, we see Leonardo’s interest in the body, one he would explore through dissection. Perhaps his most famous dissection was that of a man who claimed to be over 100 years old, at the Santa Maria Nuova hospital in Florence in 1506. </p>
<p>Leonardo had chatted to this man on the night he passed away: “And this old man told me, a few hours before his death, that he was over a hundred years old and he was conscious of no bodily failure, apart from weakness.” After he had died, Leonardo proceeded to probe the man’s corpse.</p>
<h2>Anatomical mechanics</h2>
<p>Leonardo’s anatomical drawings show exploded and multiple views, unusual for his time but similar to modern mechanical drawings and descriptive geometry. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/260968/original/file-20190226-150702-1gg89mh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/260968/original/file-20190226-150702-1gg89mh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=861&fit=crop&dpr=1 600w, https://images.theconversation.com/files/260968/original/file-20190226-150702-1gg89mh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=861&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/260968/original/file-20190226-150702-1gg89mh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=861&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/260968/original/file-20190226-150702-1gg89mh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1082&fit=crop&dpr=1 754w, https://images.theconversation.com/files/260968/original/file-20190226-150702-1gg89mh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1082&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/260968/original/file-20190226-150702-1gg89mh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1082&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Superficial anatomy of the shoulder and neck, recto, c. 1510, Royal Collections, RCIN 919003, Google Art Project.</span>
<span class="attribution"><span class="source">Wikimedia Commons</span></span>
</figcaption>
</figure>
<p>As he wrote: “If you wish thoroughly to know the parts of man, anatomically, you – or your eye – require to see it from different aspects, considering it from below and from above and from its sides, turning it about and seeking the origin of each member.”</p>
<p>Leonardo was thinking outside the box. His approach connects anatomy to engineering. </p>
<p>His interest in machinery linked to his fascination with motion. His drawings vividly illustrate how components of machines, animals and humans are designed to move, and how motion and forces are transferred from one component to another. </p>
<p>Strong analogies are formed between mechanical and biological parts, such as the role of ropes and cords, and sinews and tendons. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/263089/original/file-20190311-86690-16nqcx9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/263089/original/file-20190311-86690-16nqcx9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/263089/original/file-20190311-86690-16nqcx9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=703&fit=crop&dpr=1 600w, https://images.theconversation.com/files/263089/original/file-20190311-86690-16nqcx9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=703&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/263089/original/file-20190311-86690-16nqcx9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=703&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/263089/original/file-20190311-86690-16nqcx9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=883&fit=crop&dpr=1 754w, https://images.theconversation.com/files/263089/original/file-20190311-86690-16nqcx9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=883&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/263089/original/file-20190311-86690-16nqcx9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=883&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Leonardo da Vinci, Anatomy of a Bear’s Foot, c. 1488-90.</span>
<span class="attribution"><span class="source">Wikiart.org</span></span>
</figcaption>
</figure>
<p>Leonardo was fascinated by the change of form over time, whether in the processes of nature or the gradual disintegration of the human body. He found the 100 year-old man’s artery, for instance: “to be dry, shrunk and withered.” </p>
<p>Alongside this autopsy, he recorded another dissection: “of a child two years old, in which I found everything the opposite that of the old man”.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/260964/original/file-20190226-150721-6lvy3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/260964/original/file-20190226-150721-6lvy3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/260964/original/file-20190226-150721-6lvy3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/260964/original/file-20190226-150721-6lvy3l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/260964/original/file-20190226-150721-6lvy3l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/260964/original/file-20190226-150721-6lvy3l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/260964/original/file-20190226-150721-6lvy3l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/260964/original/file-20190226-150721-6lvy3l.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">A re-construction of Leonardo’s mechanical knight.</span>
<span class="attribution"><span class="source">Photography by Erik Möller, Wikimedia Commons.</span></span>
</figcaption>
</figure>
<p>Leonardo also had a lifelong interest in depicting decrepitude and the grotesque in human form. In his work, we see the contrast between robust mechanical forms and ageing bodies.</p>
<p>With his designs for various forms of <a href="https://en.wikipedia.org/wiki/Automaton">automata</a> – machines that operate alone by following predetermined instructions for movement – some of which witnesses suggest he brought to life, Leonardo moves from the human body, which is subject to weakness and ageing, to the wholly mechanical body.</p>
<p>The mechanical knight, for example, that he sketched in the Forster notebooks appears to have been designed from clockwork and geared mechanisms. It could move its arms, hands and legs, and turn its head. </p>
<p>Leonardo’s interest in automata in a human form and replicating human bodily movement foreshadow ideas present in modern robotics.</p>
<p>Through Leonardo’s exploration of the human body, we see his fascination with engineering, motion, anatomy and ageing, topics that still preoccupy us scientifically today.</p><img src="https://counter.theconversation.com/content/112399/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Susan Broomhall receives funding from the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Ivan Marusic receives funding from the Australian Research Council.</span></em></p>
Leonardo’s interest in the human form and replicating human bodily movement foreshadow ideas present in modern robotics.
Susan Broomhall, Professor of History, The University of Western Australia
Ivan Marusic, Professor of Mechanical Engineering, The University of Melbourne
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/109481
2019-03-12T10:46:10Z
2019-03-12T10:46:10Z
Diets can do more than help you lose weight – they could also save the planet
<figure><img src="https://images.theconversation.com/files/262708/original/file-20190307-82656-18dhhab.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some diets have ambitions a lot weightier than helping you lose a few pounds.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Japan-PETA/022e67cb8e174374837d583a78f29bce/4/0">AP Photo/Shuji Kajiyama</a></span></figcaption></figure><p>Fad diets <a href="https://legionathletics.com/outrageous-fad-diets-what-they-do-to-your-body/">have long been brushed off</a> as <a href="https://www.acsh.org/news/2018/07/02/fad-diets-are-bad-diets-13134">selfish</a>, <a href="https://www.modernmom.com/5751c0f4-3b45-11e3-8407-bc764e04a41e.html">superficial</a> quests to lose weight. </p>
<p>But if you study the actual content of popular diet books, you will discover that most tell a different story. Many inspire dieters to improve the health of their bodies, society and the planet. </p>
<p>It’s a topic I explore in <a href="https://history.cornell.edu/adrienne-rose-bitar">my research</a>, as well as my 2018 book, “<a href="https://www.rutgersuniversitypress.org/diet-and-the-disease-of-civilization/9780813589640">Diet and the Disease of Civilization</a>.” More than merely guides for getting thin, diet books tell rich stories that urge people to change their lives to save the world. </p>
<h2>Grand ambitions</h2>
<p>Diets inspire change not because <a href="https://jamanetwork.com/journals/jama/fullarticle/2673150">one is more effective than another</a>, but because they tell stories worth believing in.</p>
<p>Peel away the nutrition advice and you’ll find that, while most popular diets ennoble seemingly selfish goals, they also insist that individual health is inextricably linked to the larger environment.</p>
<p>A quick review of diet books reveals their grand aspirations. Think of the Paleo diet. Hundreds of Paleo diets describe peaceful prehistoric communities rich with singing, dancing and storytelling. Today, leaders promise that “eating Paleo can save the world.”</p>
<p>Promoters of detox diets make similar claims. Detoxers
believe that environmental pollution and toxins cause <a href="https://www.penguinrandomhouse.com/books/11466/7-day-detox-miracle-by-peter-bennett-nd-and-stephen-barrie-nd-with-sara-faye-foreword-by-jeffrey-s-bland-phd/9780761530978/">stress, obesity and other modern ills</a>. </p>
<p>A <a href="https://books.google.com/books/about/Detox.html?id=JDQQAQAAMAAJ">detox book from 1984</a> argued that humans cannot “dissociate our fate from the fate of the earth” and insisted that “what we have learned about freeing our bodies from harmful substances must also apply to cleaning up the world.” </p>
<p>Today’s diets go a step further, intimating that if you’re not “eating clean” you could be eating “dirty” foods full of pesticides, toxins and carcinogens. One diet book explains that clean foods are “<a href="https://us.macmillan.com/books/9781250182074">not only good for one’s health, but equally important for the environment</a>.” “<a href="https://thekindlife.com/books/">The Kind Diet</a>,” a popular vegan book written by actor and animal rights activist Alicia Silverstone and Victoria Pearson, is subtitled “A Simple Guide to Feeling Great, Losing Weight and Saving the Planet.” </p>
<h2>Diet consequences</h2>
<p>Arguably, today’s food world could use some saving. </p>
<p>The health consequences of how Americans eat have long been cataloged. For example, <a href="https://www.cdc.gov/nchs/fastats/obesity-overweight.htm">2 in 3 Americans are overweight</a> or obese, costing the U.S. economy an <a href="https://www.hsph.harvard.edu/obesity-prevention-source/obesity-consequences/economic/">estimated US$190 billion</a> a year. </p>
<p>But the environmental consequences of these food choices are just as stark. <a href="https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions">Agriculture is responsible for about one-tenth</a> of greenhouse gas emissions in the U.S. Farming <a href="http://www.fao.org/docrep/003/t0800e/t0800e0a.htm">consumes more than two-thirds</a> of the planet’s fresh water. </p>
<p>And it’s specific dietary choices that are driving these environmental pressures. Animal products, for example, provide just <a href="http://science.sciencemag.org/content/360/6392/987">18 percent of the typical American’s calories</a> yet take up 83 percent of all farmland. Just cutting down on beef would be more effective at reducing your <a href="https://www.theguardian.com/environment/2014/jul/21/giving-up-beef-reduce-carbon-footprint-more-than-cars">carbon footprint</a> than giving up your car. </p>
<h2>The government’s role</h2>
<p>This is where the government could learn from popular diet plans and promote sustainable diets for public health and the environment. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/262711/original/file-20190307-82684-phouo3.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/262711/original/file-20190307-82684-phouo3.gif?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/262711/original/file-20190307-82684-phouo3.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=815&fit=crop&dpr=1 600w, https://images.theconversation.com/files/262711/original/file-20190307-82684-phouo3.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=815&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/262711/original/file-20190307-82684-phouo3.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=815&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/262711/original/file-20190307-82684-phouo3.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1024&fit=crop&dpr=1 754w, https://images.theconversation.com/files/262711/original/file-20190307-82684-phouo3.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1024&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/262711/original/file-20190307-82684-phouo3.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1024&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Preventing food waste was critical to U.S. government aid to Europe in World War I.</span>
<span class="attribution"><a class="source" href="https://catalog.archives.gov/id/512488">National Archives</a></span>
</figcaption>
</figure>
<p>In its dietary guidelines, the U.S. Department of Agriculture <a href="https://health.gov/dietaryguidelines/2015/guidelines/executive-summary/">encourages Americans to consume a healthy diet</a> that focuses on foods high in nutrients and low in sugars and saturated fats. But despite the <a href="https://hub.jhu.edu/2016/03/11/dietary-guidelines-sustainability-survey/">recommendation of an advisory committee</a>, it does not include language about food system sustainability or how such diets have a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6033153/">well-established link</a> to human health. </p>
<p>The government is also discouraging other steps toward an environmentally friendly diet. Consider the new technologies of culturing meat from living animal cells – a technology that could cut out 14.5 percent of global <a href="http://www.fao.org/news/story/en/item/197623/icode/">anthropogenic greenhouse gas emissions</a>. At the same time, the government is bending to industry concerns and enforcing <a href="https://themissouritimes.com/51224/general-assembly-missouri-meat-must-meet-meat-definition/">needlessly strict definitions of meat</a>, preventing soy- and lab-based products using the label. </p>
<p>History shows that today’s Department of Agriculture is missing a valuable opportunity. During World War I, the American government used diets to do more than improve individuals’ health. As the head of the Food Administration, Herbert Hoover <a href="https://www.archives.gov/publications/prologue/2017/summer/poh-wwi-posters">urged Americans</a> to stop wasting food so the U.S. could use it to prevent starvation in Europe. His efforts are now credited with saving the lives of about <a href="https://www.archives.gov/publications/prologue/1989/spring/hoover-belgium.html">7 million Belgians</a> and 2 million French people. </p>
<p>Popular diets <a href="http://www.gutenberg.org/ebooks/15069">also picked up</a> the humanitarian cause. One <a href="http://www.gutenberg.org/ebooks/15069">1918 diet</a> included a program dubbed “Watch Your Weight Anti-Kaiser.”</p>
<p>Today’s food authorities could do the same: urge Americans to eat better because the food system is actually a web. Our food choices have a profound impact on our health and the planet.</p>
<p><em>This article has been updated to correct the scale of greenhouse gas emission cuts as a result of culturing meat from living animal cells.</em></p><img src="https://counter.theconversation.com/content/109481/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adrienne Rose Bitar 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>
Many diets make the case that eating certain types of foods will improve your health while redeeming our society and saving the planet.
Adrienne Rose Bitar, Postdoctoral Associate, Cornell University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/110353
2019-02-25T00:51:08Z
2019-02-25T00:51:08Z
Curious Kids: how does my tummy turn food into poo?
<figure><img src="https://images.theconversation.com/files/258380/original/file-20190211-174883-1erkkjk.jpg?ixlib=rb-1.1.0&rect=0%2C5%2C3703%2C2165&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Your tummy is a juicy rollercoaster ride for food!</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/left-hand/1459699823/in/photolist-3dZkUk-nA4zJ6-dCFZ4f-5vcJF7-pk8yT1-bZUvus-5mEBMu-ekjAir-6mYkfw-71hZJ8-ev5rbY-oJHGmL-6bojKg-pBCxR4-pk7hYi-6bojKa-pk9fCF-pehNqR-ntPYce-7LhWfG-5ABxpw-dY925u-pk9fJH-enWtJ8-pBCzMi-etwZa9-pBmdwF-pk8Vmf-pzzHmL-dWgfrA-TaxFLS-bXJtXw-pzzNgq-pk8kK9-pripqq-pk7nKc-aYsGT-okAYSF-pk8Qg5-ooggYx-pzzHNN-dMDPHw-6g9xTZ-9RraXd-6KA436-pk8QmL-if7QSv-5RMojM-pBmoY2-93pSKx">Flickr/Stuart Richards</a></span></figcaption></figure><p><em><a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a> is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also like the podcast <a href="http://www.abc.net.au/kidslisten/imagine-this/">Imagine This</a>, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.</em> </p>
<hr>
<blockquote>
<p><strong>How does my tummy turn the food I eat into poo? – Luke, age 4.</strong></p>
</blockquote>
<hr>
<p>Hi Luke. What a terrific question! The story of how your food ends up as poo is an amazing one. </p>
<p>The food that you eat is broken into small pieces by chewing and mashing it in your mouth. You make a little food ball with the help of your tongue. </p>
<p>Your body has a cool trick to get the food ball down to your tummy and not into your lungs. Just behind the tongue is a little gate called the epiglottis. It closes to stop food going down the wrong way and accidentally getting into your breathing pipe. If you have ever accidentally had some food or water go down the wrong way, you’ll know it makes you cough a lot. </p>
<p>When you swallow, the food ball is pushed back down to the start of a food tunnel called the oesophagus that leads to your stomach. </p>
<h2>Getting food from your mouth to your stomach and beyond</h2>
<p>Starting in the oesophagus (that food tunnel in your neck) an amazing action called peristalsis takes place. Peristalsis happens with the help of walls inside your gut. It gives your body the strength to send the food ball from the food tunnel to the stomach and all the way down to your bum. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/258408/original/file-20190212-174890-1rk4pb4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/258408/original/file-20190212-174890-1rk4pb4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/258408/original/file-20190212-174890-1rk4pb4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/258408/original/file-20190212-174890-1rk4pb4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/258408/original/file-20190212-174890-1rk4pb4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/258408/original/file-20190212-174890-1rk4pb4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/258408/original/file-20190212-174890-1rk4pb4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/258408/original/file-20190212-174890-1rk4pb4.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">Peristalsis is where muscles in body squeeze and squeeze (the red arrows) to push the ball food along a tube.</span>
<span class="attribution"><span class="source">shutterstock</span></span>
</figcaption>
</figure>
<p>The stomach is a J-shaped moving box full of stomach juices. When you start eating, the lower part of your stomach starts moving and mixing. </p>
<p>Did you know your stomach gets bigger when the food ball arrives? Your stretched stomach makes juices that can help to break the food ball into even tinier pieces <a href="https://europepmc.org/articles/pmc2996823">no more than 3mm.</a> That’s even smaller than your pinky nail! </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-do-we-really-need-to-take-10-000-steps-a-day-109079">Health Check: do we really need to take 10,000 steps a day?</a>
</strong>
</em>
</p>
<hr>
<h2>A little help from your liver and pancreas</h2>
<p>This mish-mash of small food pieces and stomach juices will now enter the very long windy tube known as the small intestine, which is labelled on this picture:</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/258413/original/file-20190212-174870-x5epp6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/258413/original/file-20190212-174870-x5epp6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/258413/original/file-20190212-174870-x5epp6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=414&fit=crop&dpr=1 600w, https://images.theconversation.com/files/258413/original/file-20190212-174870-x5epp6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=414&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/258413/original/file-20190212-174870-x5epp6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=414&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/258413/original/file-20190212-174870-x5epp6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=521&fit=crop&dpr=1 754w, https://images.theconversation.com/files/258413/original/file-20190212-174870-x5epp6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=521&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/258413/original/file-20190212-174870-x5epp6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=521&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 small intestine is like a long sausage. Around it sits the large intestine (which is dark pink-coloured in this diagram).</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Now, two friends will start to help digest the food - a flat, pear-shaped thing called the pancreas and the liver. The pancreas makes juices of its own to break the food down and make it even smooshier. And the liver (among other things) makes bile. </p>
<p>Bile is a yellow-green, thick, sticky juice that acts like washing powder. It helps break big chunks of fat from oily foods into little pieces. The small intestine also has juices that help turn food such as bread into energy.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/258410/original/file-20190212-174894-v5c2tw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/258410/original/file-20190212-174894-v5c2tw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/258410/original/file-20190212-174894-v5c2tw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=692&fit=crop&dpr=1 600w, https://images.theconversation.com/files/258410/original/file-20190212-174894-v5c2tw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=692&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/258410/original/file-20190212-174894-v5c2tw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=692&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/258410/original/file-20190212-174894-v5c2tw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=869&fit=crop&dpr=1 754w, https://images.theconversation.com/files/258410/original/file-20190212-174894-v5c2tw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=869&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/258410/original/file-20190212-174894-v5c2tw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=869&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Lots of different body parts have to work together to get what you need from food and turn the waste into poo.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>This smooth mush mixed with little fat pieces and energy can move from the small intestine into your blood. This part is called absorption and means that healthy things can get to different parts of the body where they are needed. The small intestine absorbs important parts of the food, such as iron, that help your body stay healthy.</p>
<p>Any food that is not taken in by the small intestine enters the large intestine (which we call the colon). </p>
<p>In the colon, a lot of water is taken away from the food, which makes it dry and hard. Many tiny bugs and germs live in the colon (that is normal and healthy, by the way). These germs also eat some of the food, and when they do, they produce gas. This is the gas that comes out when you fart.</p>
<p>The dry and hard food that cannot be used by your body now becomes waste. It is kept in the last part of the colon (known as the rectum) and is ready to leave the body when you do a poo. </p>
<p>And don’t forget to wash your hands!</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-when-should-you-throw-away-leftovers-92256">Health Check: when should you throw away leftovers?</a>
</strong>
</em>
</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au</em></p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
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</figure>
<p><em>Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/110353/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vincent Ho 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>
Your stomach works very hard with some other body parts to break down food into small pieces. Your body takes in what it needs and the rest is turned into poo.
Vincent Ho, Senior Lecturer and clinical academic gastroenterologist, Western Sydney University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/108988
2019-02-06T02:58:20Z
2019-02-06T02:58:20Z
Curious Kids: why are burps so loud?
<figure><img src="https://images.theconversation.com/files/257347/original/file-20190206-86210-11j2g3m.jpg?ixlib=rb-1.1.0&rect=876%2C15%2C4299%2C3430&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Excuse me!</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/OTTRDB2oHNc">Photo by Natasha Kasim on Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p><em><a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a> is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also like the podcast <a href="http://www.abc.net.au/kidslisten/imagine-this/">Imagine This</a>, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.</em> </p>
<hr>
<blockquote>
<p><strong>Why are burps so loud? - Byron, age 6, Sydney.</strong></p>
</blockquote>
<hr>
<p>That’s a great question Byron. Some burps can be really loud, but they can be quiet too. How loud a burp is depends of a few factors, like how much gas is in your stomach to burp up and the structure of your food pipe that the burp travels along before it leaves your mouth. Let’s look at <a href="https://www.ncbi.nlm.nih.gov/pubmed/25001253">burps in a bit more detail</a>. </p>
<h2>What is a burp?</h2>
<p>“Burp” is the word that describes the release of gas that builds up in your stomach and food pipe after eating and drinking. The food pipe, also called the gullet, has the scientific name <a href="https://en.wikipedia.org/wiki/Esophagus">oesophagus</a>. The oesophagus is a muscular tube, about the length of a ruler, that joins the stomach to the back of your throat. </p>
<h2>Where does the ‘burp’ noise come from?</h2>
<p>If you open your mouth wide in front of a mirror, you can see a flap of tissue hanging down at the back of your throat. This is called the <a href="https://en.wikipedia.org/wiki/Epiglottis">epiglottis</a>. When you swallow, the epiglottis tips back to block off the windpipe that leads down to your lungs and that means the opening to your food pipe is now clear. (The epiglottis is a bit like a traffic controller.) </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/257357/original/file-20190206-86202-1qbj4m5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/257357/original/file-20190206-86202-1qbj4m5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/257357/original/file-20190206-86202-1qbj4m5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=519&fit=crop&dpr=1 600w, https://images.theconversation.com/files/257357/original/file-20190206-86202-1qbj4m5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=519&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/257357/original/file-20190206-86202-1qbj4m5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=519&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/257357/original/file-20190206-86202-1qbj4m5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=653&fit=crop&dpr=1 754w, https://images.theconversation.com/files/257357/original/file-20190206-86202-1qbj4m5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=653&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/257357/original/file-20190206-86202-1qbj4m5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=653&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It’s all about the epiglottis and the oesophagus.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>The noise made when you burp comes from gas that is trapped in your stomach and upper oesophagus when the food pipe is shut. This gas is under pressure, especially when there is a lot of it. As the pressurised gas flows up the food pipe, over the surface of the upper esophagus and past the epiglottis, it makes the surface of the upper part of your oesophagus rattle and vibrate. It is a bit like windows that rattle during a windy storm. The other factor is that because the oesophagus is long and round, the noise echoes as it travels up the food pipe. </p>
<h2>Can you make yourself burp more loudly or quietly?</h2>
<p>Take an empty cardboard tube from inside a roll of lunch wrap, or a toilet roll. Put your lips over the end and softly hum. This makes a louder noise compared to when you just hum without the tube, because of the echo. Now do it again, but put a lot of power into your hum. The noise is much louder. Forcing more air into the tube makes a louder echo. This is why bigger burps are noisier.</p>
<p>Whether you can make yourself burp more loudly or softly depends on how big your food pipe is and how much gas you have in there. Windows rattle more during a wild storm compared to when there is a gentle breeze blowing. </p>
<p>If you drink a small glass of soda water then you will only have a small amount of gas from the bubbles of carbon dioxide gas in the soda to burp up, <em>but</em> if you drink a whole can <em>and</em> take lots of gulps so you swallow more air <em>and</em> you can hold on so you burp all the gas out in one go, then you can produce a really loud burp. </p>
<p>Babies have small food pipes and small stomachs and produce burps that are more quiet than burps from children and adults.</p>
<h2>Where does the gas come from?</h2>
<p>The <a href="https://www.ncbi.nlm.nih.gov/pubmed/16574342">gas comes from a few different places</a>. It can be from air that you swallow when you eat and drink which ends up in your stomach. Some people swallow more air if they eat too fast or when they drink from a straw. The “fizz” in soft drinks is the gas <a href="https://en.wikipedia.org/wiki/Carbon_dioxide">carbon dioxide</a> and some other gasses are produced in your intestines during digestion.</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au</em></p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em>Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/108988/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Clare Collins is affiliated with the Priority Research Centre for Physical Activity and Nutrition, the University of Newcastle, NSW. She is an NHMRC Senior Research and Gladys M Brawn Research Fellow. She has received research grants from NHMRC, ARC, Hunter Medical Research Institute, Meat and Livestock Australia, Diabetes Australia, Heart Foundation, Bill and Melinda Gates Foundation, nib foundation, Rijk Zwaan Australia and Greater Charitable Foundation. She has consulted to SHINE Australia, Novo Nordisk, Quality Bakers, the Sax Institute and the ABC. She was a team member conducting systematic reviews to inform the Australian Dietary Guidelines update and 2017 evidence review on dietary patterns for the Heart Foundation.</span></em></p>
As gas from your stomach comes up your food pipe, it makes the surface of the upper part of your oesophagus rattle and vibrate. It is a bit like windows that rattle during a windy storm.
Clare Collins, Professor in Nutrition and Dietetics, University of Newcastle
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/104881
2018-10-16T15:06:20Z
2018-10-16T15:06:20Z
Curious Kids: if you have lots of the thing you’re allergic to, does your body get used to it?
<figure><img src="https://images.theconversation.com/files/240814/original/file-20181016-165918-1fshi24.jpg?ixlib=rb-1.1.0&rect=95%2C27%2C4432%2C2966&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/little-asian-boy-has-allergies-flower-397846021?src=1EuFgJwIEmV76yzFhQ55Bg-1-8">Shutterstock.</a></span></figcaption></figure><p><em>This is an article from <a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a>, a series for children of all ages. The Conversation is asking young people to send in questions they’d like an expert to answer. All questions are welcome: find out how to enter at the bottom.</em> </p>
<hr>
<blockquote>
<p><strong>If you have lots of the thing you’re allergic to, does your body eventually get used to it? – Karen and Dawn, age 14 and nine, Manchester, UK</strong></p>
</blockquote>
<p>Thanks for your brilliant question, Karen and Dawn! As usual with science, there is not a simple answer. But the first thing to say is that if you know you are allergic to something, you must not purposefully go near it or eat it to try and make your allergy better. It won’t work and might make you very unwell. </p>
<p>Some people are allergic to things in the air, such as pollen, dust and animal hair. Other people are allergic to certain foods, or things that we touch. </p>
<p>When you are allergic to something, your body mistakenly thinks that the thing you are allergic to is going to cause you harm. </p>
<p>This triggers your immune system (which normally fights infections) to start fighting whatever you’re allergic to. Then you get symptoms, which are the signs that something is wrong in your body. </p>
<p><a href="https://www.nhs.uk/conditions/allergies/symptoms/">The symptoms</a> could be anything from an itchy nose and sneezing to breathing problems or a skin rash. In the case of serious allergies, people may get a swollen tongue or throat, which can be very dangerous. </p>
<p>There are some very serious allergies that you must always be very careful with, because they can lead to a very serious medical problem called anaphylaxis. </p>
<p>The most common foods that cause anaphylaxis are nuts and eggs. People who have these allergies must carry a special injection with them all the time, in case they accidentally eat these things, and they always need to be extra careful around food. </p>
<p>Some less serious allergies, such as hay fever, might get better if you were stuck on an island for a long period of time with no medication. This is because our bodies can get used to the pollen that causes this allergy. </p>
<p>There are <a href="https://www.nhs.uk/conditions/allergies/treatment/">medical ways</a> of testing this, which experts call “desensitisation therapy” or “immunotherapy”. This means that you are given a certain amount of the thing you are allergic to every day, until you become less sensitive to it. This should always be done with the help of a doctor, and it doesn’t work for all allergies. </p>
<p>There are some things that you might be intolerant to, but not allergic to. This means that when you eat it, you might get some tummy trouble, but it would not cause you any serious harm.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/240816/original/file-20181016-165909-1je462h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/240816/original/file-20181016-165909-1je462h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=383&fit=crop&dpr=1 600w, https://images.theconversation.com/files/240816/original/file-20181016-165909-1je462h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=383&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/240816/original/file-20181016-165909-1je462h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=383&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/240816/original/file-20181016-165909-1je462h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=481&fit=crop&dpr=1 754w, https://images.theconversation.com/files/240816/original/file-20181016-165909-1je462h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=481&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/240816/original/file-20181016-165909-1je462h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=481&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Milk can give some people a sore tummy.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/cute-little-girl-drinking-milk-countryside-674878165?src=rSXm8E-p4NcNjfGpNy3D3g-1-4">Shutterstock.</a></span>
</figcaption>
</figure>
<p>Milk is a really good example of this. There is a type of sugar in milk called lactose. To digest lactose, humans need a special chemical called an enzyme, which is made in our intestines. </p>
<p>When we are babies, we all produce lots of this enzyme because we only have milk. Some people stop making the enzyme altogether when they are adults and some people might just make a bit less of it. And some people will produce more or less of it depending on how much milk they drink. </p>
<p>That means that sometimes, if you haven’t had much milk for a while, then you have a lot, you might have a sore tummy. But you might also find that the more milk you have, the more of the enzyme your gut produces and the more milk you can enjoy without a tummy ache. </p>
<p>Only milk from animals (including humans) has the sugar lactose in it, anything that is made from plants like coconut milk, soya milk and almond milk does not contain any lactose. </p>
<p>But whether you’ve got an allergy or an intolerance, it’s very important to always follow your doctor’s instructions.</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. You can:</em></p>
<p><em>* Email your question to curiouskids@theconversation.com
<br>
* Tell us on <a href="https://twitter.com/ConversationUK">Twitter</a> by tagging <a href="https://twitter.com/ConversationEDU">@ConversationUK</a> with the hashtag #curiouskids, or
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* Message us on <a href="https://www.facebook.com/ConversationUK/">Facebook</a>.</em></p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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</figure>
<p><em>Please tell us your name, age and which town or city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question, but we will do our best.</em></p>
<hr>
<p><em>More <a href="https://theconversation.com/topics/curious-kids-36782?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">Curious Kids</a> articles, written by academic experts:</em></p>
<ul>
<li><p><em><a href="https://theconversation.com/curious-kids-why-do-hens-still-lay-eggs-when-they-dont-have-a-mate-104077?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">Why do hens still lay eggs when they don’t have a mate? – Finley, age ten; Evie, age eight; and Jonah, age five, Cambridgeshire, UK</a></em></p></li>
<li><p><em><a href="https://theconversation.com/curious-kids-whats-the-history-of-aircraft-squawk-codes-and-how-do-they-work-103102?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">What’s the history of aircraft squawk codes and how do they work? – Daniel, age 12, Perth, Australia</a></em></p></li>
<li><p><em><a href="https://theconversation.com/curious-kids-how-can-chickens-run-around-after-their-heads-have-been-chopped-off-103701?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">How can chickens run around after their heads have been chopped off? – Gaelle, age four, Bristol, UK</a></em></p></li>
</ul><img src="https://counter.theconversation.com/content/104881/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sophie Medlin 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>
Don’t try this at home, kids.
Sophie Medlin, Lecturer in Nutrition and Dietetics, King's College London
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/95644
2018-04-29T20:12:59Z
2018-04-29T20:12:59Z
Real Bodies controversy: how Australian museums regulate the display of human remains
<p>Protesters are urging a boycott of <a href="http://www.realbodiesexhibition.com.au/">Real Bodies: The Exhibition</a>, which recently opened in Sydney, due to the possibility that the <a href="https://bodyworlds.com/plastination/plastination-technique//">plastinated</a> human bodies and organs on display were taken without consent from <a href="https://www.theguardian.com/australia-news/2018/apr/25/call-to-shut-real-bodies-exhibition-over-fears-it-uses-executed-prisoners">executed Chinese political prisoners</a>.</p>
<p>The chief executive of the company behind Real Bodies, Tom Zaller, has <a href="http://www.news.com.au/technology/science/human-body/real-bodies-the-exhibition-controversy-about-disturbing-origins-of-corpses/news-story/fb3e9d7702cfdbb1bba171b87df9ca32">defended the exhibition</a>. He claims that although the bodies come from China, they were legally sourced from people who died from natural causes and were unclaimed. The exhibition also cleared Australian bio-security checks. </p>
<p>The New South Wales Department of Health states that bodies or human tissues sourced from international institutions <a href="http://www.health.nsw.gov.au/humantissue/Pages/anatomy-laboratories.aspx#8">must meet</a> its ethical and legal standards, which includes donor <a href="http://www1.health.nsw.gov.au/pds/ActivePDSDocuments/PD2011_052.pdf">consent forms</a> to be publicly displayed. Zaller admitted that there is no proof of the bodies’ identities or donor consent forms, raising questions about whether NSW regulations have been met. A group of lawyers, academics, and human rights campaigners, from the International Coalition to End Organ Transplant Abuse in China, has called for the exhibition to be shut down in an <a href="https://endtransplantabuse.org/open-letter-urges-for-real-bodies-the-exhibtion-to-be-closed-down/">open letter</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/reconsidering-body-worlds-why-do-we-still-flock-to-exhibits-of-dead-human-beings-57024">Reconsidering Body Worlds: why do we still flock to exhibits of dead human beings?</a>
</strong>
</em>
</p>
<hr>
<p>This is not the first public anatomy exhibition to face claims of unethical body sourcing. German anatomist Gunther von Hagens, who invented the plastination technique, has toured his controversial yet popular <a href="https://theconversation.com/reconsidering-body-worlds-why-do-we-still-flock-to-exhibits-of-dead-human-beings-57024">Body Worlds</a> for two decades. In 2004, he denied seven corpses from an outside, non-affiliated collection in China after conceding they <a href="https://www.theguardian.com/world/2004/jan/23/arts.china">may have come from political prisoners</a>. The Body Worlds exhibition states that all displayed bodies have been sourced from a donation program in Germany with <a href="https://bodyworlds.com/plastination/bodydonation/">appropriate documentation</a>.*</p>
<p>We don’t know whether or not the bodies in Real Bodies were unethically obtained. But, we can look to the past to see how attitudes towards the collection and display of human remains have changed in recent decades. We can also consider how Australian museums negotiate these issues today.</p>
<p>Australian states and territories have their own regulations for the collection of human remains. Some also include directives for their display. It is then up to museums to develop policies for publicly displaying human remains. In short, museums should provide statements about the provenance of displayed bodies to avoid misleading the public.</p>
<h2>Chequered history</h2>
<p>Australia has a chequered history of collecting and displaying human remains. In the 19th century, Australian universities began to collect specimens of human anatomy and pathology. These formed an important part of medical education. However doctors and anatomists often took body parts from corpses without consent from the family or previously obtained from the person, and flouted regulation and convention to add interesting specimens to university collections.</p>
<p>In 1903, South Australia’s Inspector of Anatomy, Dr William Ramsay Smith, was <a href="https://www.tandfonline.com/doi/abs/10.2104/ha090040?journalCode=raha20">accused</a> of keeping parts of bodies that should have been buried in a proper coffin within church grounds. Prominent Sydney anatomist J.T. Wilson had also faced scrutiny a few years earlier for unlawfully <a href="http://press-files.anu.edu.au/downloads/press/p72251/pdf/article089.pdf">removing a man’s skeleton</a> from a hospital post-mortem room.</p>
<p>University collections were not open to the public. They were only for medical students and researchers to learn about the human body and the diseases that affect it. Although several <a href="https://theconversation.com/donating-your-body-to-science-dont-worry-its-not-what-it-used-to-be-5567">protests</a> took place in the 19th century about the practice, Australian medical schools continued to collect human remains throughout the 20th century for educational purposes, but now with some of these ethical considerations in mind.</p>
<p>There is also precedent for public debate over anatomy collections for public entertainment and amusement. In 1869, a <a href="http://nla.gov.au/nla.news-article188573338">letter</a> to The Age accused the owners of a public anatomical museum in Melbourne’s Bourke Street of “groping the gutters for a livelihood”. Similar criticisms are being levelled at Real Bodies - even though it may also have the power to educate the public.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/essays-on-air-can-art-really-make-a-difference-95138">Essays On Air: can art really make a difference?</a>
</strong>
</em>
</p>
<hr>
<p>Ethical concerns about collected human remains grew in the 1980s and 1990s. In response, Australian museums began to develop policies and practices for their display. Museums took a cautious approach, particularly for the collection and display of Indigenous Australian human remains. Such remains had been <a href="https://www.springer.com/gp/book/9783319518732">stolen from graves</a> throughout the 19th and 20th centuries for scientific and racial studies. This remains a source of immense distress for many Indigenous Australians today.</p>
<p>Australian universities began talks in the 1980s about the future of their collections. These discussions juggled the ongoing importance of anatomy museums in medical education with historical issues of consent. The National Museum of Australia ceased to collect Indigenous Australian remains in the mid-1990s. In 2009, it decided to stop seeking human remains altogether. There are also increasing moves to repatriate Indigenous remains. Although <a href="https://www.questia.com/library/journal/1P3-2851707381/material-legacies-indigenous-remains-and-contested">some museums</a> have not supported this, pressure is building for them to support the requests of Indigenous communities for remains to be returned.</p>
<p>Recently, Museums Victoria <a href="https://museumsvictoria.com.au/article/museums-victorias-position-on-displaying-human-remains/">decided not to display</a> human remains from the Vikings: Beyond the Legend exhibition to avoid possible distress to Indigenous Australian visitors, after consulting with Indigenous communities. Remains, the museum stated, could cause “distress and sadness” due to “past practices of museums who displayed Ancestors without permission” and the spiritual belief that Ancestors should be laid to rest rather than displayed. Human remains featured in the Vikings exhibition at other global destinations.</p>
<p>Museums should heed the lessons of past grievances. This will ensure that future displays are in tune with cultural sensitivities and avoid getting into possibly murky ethical territory.</p>
<hr>
<p><em><strong>Correction</strong>: This article was corrected on May 4 to remove claims that von Hagens had been accused of unethically importing corpses from Russia, and clarify the sourcing of bodies from China.</em></p><img src="https://counter.theconversation.com/content/95644/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eugenia Pacitti 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>
Protesters have urged a boycott of Sydney’s current Real Bodies exhibition, over claims that it could display remains of executed Chinese political prisoners.
Eugenia Pacitti, PhD Candidate in History, Monash University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/94454
2018-04-09T11:42:39Z
2018-04-09T11:42:39Z
Naked Utopia: how England’s first nudists imagined the future
<figure><img src="https://images.theconversation.com/files/213856/original/file-20180409-114128-rzlw77.jpg?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.shutterstock.com/image-photo/naked-men-beach-new-zealand-517287238?src=lw1OXlhQc6Bdu-husNhqwQ-1-2">Thomas Wong/Shutterstock.com</a></span></figcaption></figure><p>The naked body is as old as humanity. But nudism as a social form, organised into clubs and societies, only <a href="https://muse.jhu.edu/article/686648/pdf">came of age in England in the 1920s</a>. Its practitioners were from a range of backgrounds and included those with interests in “physical culture” (today we would refer to this as body building and beauty contests). Many were interested in natural health, including vegetarian and raw food diets, and new exercise regimes from hiking to yoga. </p>
<p>Nudism was particularly embraced by artists and intellectuals as part of a wider set of progressive practices associated with free thought. Many were internationalists inspired by longer standing German nudist traditions, which were far more popular and organised on a larger scale than English efforts. They understood disrobing to be part of a wider ideal of physical, mental and spiritual liberation.</p>
<p>For nudists in this mould, taking one’s clothes off in organised groups promised nothing less than heaven on earth. As one 1933 enthusiast claimed in the magazine Gymnos (“For Nudists Who Think”): </p>
<blockquote>
<p>It stands for all-round regeneration, in that it changes the false for the true; bondage for freedom; hypocrisy and cant for truth of purpose and resolve, and, above all, elevates the mind, and prompts the soul to strive for heights far above the petty and mean things which are attached to civilisation, as we know it today. </p>
</blockquote>
<p>Civilisation – here indicating the modern, mechanised and industrialised world – was seen as corrupt. Its manifold problems were made material in everything that was wrong with contemporary clothing.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/213807/original/file-20180409-114084-899kl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/213807/original/file-20180409-114084-899kl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/213807/original/file-20180409-114084-899kl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=413&fit=crop&dpr=1 600w, https://images.theconversation.com/files/213807/original/file-20180409-114084-899kl7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=413&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/213807/original/file-20180409-114084-899kl7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=413&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/213807/original/file-20180409-114084-899kl7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=519&fit=crop&dpr=1 754w, https://images.theconversation.com/files/213807/original/file-20180409-114084-899kl7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=519&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/213807/original/file-20180409-114084-899kl7.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"></a>
<figcaption>
<span class="caption">Advertisement for Spielplatz nudist camp, Health and Efficiency magazine, 1935.</span>
<span class="attribution"><span class="source">© H&E naturist magazine/Hawk Editorial Ltd.</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>The death of fashion</h2>
<p>If nudism was Utopian and escapist, dress was necessarily its inverse: dystopian and imprisoning. Garments were described by impassioned early nudists in their publications as “dirty cloth jails” and “the iron chains which civilisation and custom have riveted on suffering humanity”. Illness was seen as “largely an inevitable result of the enslavement of the body within the dark walls of its own clothing”. Rather than suffer this fate, interwar nudists proposed an alternative way of life, declaring in magazines from Sun Bathing Review to Health and Efficiency: “Clothes are dead.”</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/213808/original/file-20180409-114105-xk12oh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/213808/original/file-20180409-114105-xk12oh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=906&fit=crop&dpr=1 600w, https://images.theconversation.com/files/213808/original/file-20180409-114105-xk12oh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=906&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/213808/original/file-20180409-114105-xk12oh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=906&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/213808/original/file-20180409-114105-xk12oh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1138&fit=crop&dpr=1 754w, https://images.theconversation.com/files/213808/original/file-20180409-114105-xk12oh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1138&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/213808/original/file-20180409-114105-xk12oh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1138&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">‘Sun worship’. Health and Efficiency magazine, 1935.</span>
<span class="attribution"><span class="source">© H&E naturist magazine/Hawk Editorial Ltd.</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>For some of its most ardent supporters, nudity was proposed as a complete cure to modern ills. If its physical and mental benefits were to be felt, nothing at all should be worn at any time. These enthusiasts looked forward to a time when nudism would become the norm on the streets of London, when “all normal-minded civilised people … live as nudists” and “permanently discard clothes”. Some nudists predicted that bodies would evolve to have no need of garments for warmth or protection; the healthy and vigorous bodies produced by total exposure would be impervious to changes of climate. Some of nudism’s most ardent early practitioners climbed mountains and even skied in the buff. </p>
<p>But others saw these kinds of practices as a bridge too far from the conventional world. More moderate voices argued that “clothing has an important place to fill and no one but a crank would propose its total abolition”. </p>
<p>It is worth remembering that nudity in public was (<a href="https://en.wikipedia.org/wiki/Clothing_laws_by_country">and is</a>) a prosecutable offence. The establishment of private “sun clubs” and “sunbathing societies” in the interwar years, with strict membership procedures, ensured that nudists avoided arrest, and they also helped maintain respectability. Popular conceptions of nudism ranged from the amused to the frankly appalled; nudist magazines regularly summarised articles from the mainstream press that claimed nudism to be immoral, even “evil”. Even if viewed benignly, nudism was popularly seen as eccentric, so a “sane” or rational approach was promoted by those who wished to avoid accusations of cultishness.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/213809/original/file-20180409-114128-j1fyx4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/213809/original/file-20180409-114128-j1fyx4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=952&fit=crop&dpr=1 600w, https://images.theconversation.com/files/213809/original/file-20180409-114128-j1fyx4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=952&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/213809/original/file-20180409-114128-j1fyx4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=952&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/213809/original/file-20180409-114128-j1fyx4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1196&fit=crop&dpr=1 754w, https://images.theconversation.com/files/213809/original/file-20180409-114128-j1fyx4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1196&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/213809/original/file-20180409-114128-j1fyx4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1196&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">‘Sunbathing in Sussex.’ Health and Efficiency magazine, 1935.</span>
<span class="attribution"><span class="source">© H&E naturist magazine/Hawk Editorial Ltd.</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Those who followed a more moderate line of nudism acknowledged that shifting practices of dress and undress as circumstances allowed were needed. This more pragmatic approach promoted occasional sunbathing, under appropriate conditions, in the minimum of attire for the purposes of improved health and well-being. It also led some to invent clothing for nudists as a concession to the country’s many sunless days. Design ambitions ranged from the rational to the fantastic.</p>
<h2>The nudist’s wardrobe</h2>
<p>The most complete scheme was proposed in 1933 by Maurice Parmalee, author of <a href="https://books.google.co.uk/books/about/Nudism_in_Modern_Life.html?id=zRd-CgAAQBAJ&redir_esc=y">Nudism in Modern Life</a>. He proposed that articles of dress, to be worn when some form of protection was required, should be open, airy and cover no more of the body than was absolutely necessary.</p>
<p>In addition to these practical suggestions, he offered more visionary ideals, including the elimination of sartorial differences between the sexes. He promoted specific garments to resolve issues of warmth, protection for the feet, and the practicalities of menstruation at a time before internal sanitary products were widely used. Inspiration was freely drawn from across history and geography, with the net result forming an outlandish ensemble of doublet, cummerbund, Bavarian braces, Scottish kilt, socks and Japanese sandals, a hooded South American poncho, and a clutch bag for daily necessities. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/213810/original/file-20180409-114098-1q4f18l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/213810/original/file-20180409-114098-1q4f18l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=810&fit=crop&dpr=1 600w, https://images.theconversation.com/files/213810/original/file-20180409-114098-1q4f18l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=810&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/213810/original/file-20180409-114098-1q4f18l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=810&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/213810/original/file-20180409-114098-1q4f18l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1018&fit=crop&dpr=1 754w, https://images.theconversation.com/files/213810/original/file-20180409-114098-1q4f18l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1018&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/213810/original/file-20180409-114098-1q4f18l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1018&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Health and Efficiency magazine, 1933.</span>
<span class="attribution"><span class="source">© H&E naturist magazine/Hawk Editorial Ltd.</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The individual items were designed to address specific practical shortcomings of nudity, but they also reflected the changed nature of the coming nudist world. Parmalee argued that in his nudist future: “There will be less temptation to dishonesty, so that the lack of pockets will not be a serious drawback.”</p>
<h2>The nude future</h2>
<p>For all the claims of nudism’s inevitability, nearly 100 years on it’s no more common to find naked people on the high street than it ever was. The nudist Utopia of the 1920s remains an impossible dream. Even by the mid-1930s the fantasy had begun to tarnish; the dramatic political shifts in Germany showed that undressing alone could not bring a new democratic, pacifist, egalitarian world. Nonetheless, the visions of the English moderates, with their ambition for lightweight clothes and sunbathing in a minimum of attire, gained steady traction during the 1930s as part of a general relaxation of dress and manners. Post-war, it was only English social nudism, organised through clubs and societies, which waned. Nudism for leisure, especially on continental holidays, continued in the pink of health.</p>
<p>These days, contemporary practitioners of what is now more usually called naturism tend not to link their undressing to the socialism, vegetarianism or anti-materialism of nudism’s interwar pioneers; it is merely perceived as a pleasant pastime. As such, the campaigns of the first social nudists in England might seem to be a closed case. </p>
<p>Yet at their most radical, philosophers of nudism recommended the deconstruction of all social propriety in search of a new future. The world they foresaw would unite all in one brotherhood, re-establish a union with nature and make the world a safer, fairer, and more beautiful place. These ambitions remain today, although modern subscribers might differ in their approach to how they should be delivered. It may take centuries to come, as Parmalee expected, but the hope of a new world springs eternal.</p><img src="https://counter.theconversation.com/content/94454/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Annebella Pollen's research into historical dress reform has received funding from the Arts and Humanities Research Council UK.</span></em></p>
A century ago, utopian thinkers and practitioners predicted the coming of a nude world of liberated bodies.
Annebella Pollen, Principal Lecturer in the History of Art and Design, University of Brighton
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/91419
2018-02-25T07:34:53Z
2018-02-25T07:34:53Z
How we pinned down what attracts mosquitos that carry dengue fever
<figure><img src="https://images.theconversation.com/files/206221/original/file-20180213-44639-paf95e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Flickr/AFPMB</span></span></figcaption></figure><p>Kenya has seen a rapid <a href="http://www.who.int/csr/don/09-august-2016-chikungunya-kenya/en/">increase</a> in <a href="https://theconversation.com/delhi-has-been-hit-by-a-chikungunya-epidemic-what-is-this-disease-65592">chikungunya</a> and <a href="https://theconversation.com/explainer-what-is-dengue-fever-8571">dengue viruses</a> outbreaks since 2016. Both are mosquito-borne viral infections that lead to debilitating joint and muscle pain.</p>
<p>The two sister diseases are transmitted by the <a href="https://www.ncbi.nlm.nih.gov/pubmed/5301574">Aedes aegypti</a> – a black mosquito with white spots that only bites during the day. The viruses are <a href="http://www.who.int/mediacentre/factsheets/fs327/en/">spread</a> by the female mosquito when she searches for blood as a source of protein and iron which she needs to <a href="https://www.cabdirect.org/cabdirect/abstract/19900596879">form mosquito eggs</a>. </p>
<p>The outbreaks in Kenya have been in areas normally associated with the diseases, such as the coastal city of Mombasa, as well as new areas such as the North Eastern part of the country. </p>
<p>Compared with the large amount of research that’s been done on the vectors that carry malaria, not many studies have been done on those that spread dengue and chikungunya. The main reason for this is that malaria continues to kill one million people each year while dengue and chikungunya claim less than <a href="http://www.eliminatedengue.com/our-research/dengue-fever">25 000 lives a year</a>.</p>
<p>As a result only a limited number of methods have been developed to manage the Aedes aegypti.</p>
<p>We wanted to understand what attracts the black mosquito to its hosts. To do this, we compared commercially available bait traps that contained bait made from natural body odours to see which were more attractive to mosquitoes in their natural environments. Our <a href="https://www.ncbi.nlm.nih.gov/pubmed/25246030">study</a> found that body odour lured the mosquitoes better. We went further and narrowed the attraction down to <a href="https://parasitesandvectors.biomedcentral.com/articles/10.1186/s13071-015-0866-6">four groups of chemical compounds</a> in body odour. </p>
<p>Our findings provide the first evidence of how chemical compounds found in body odour can be used to develop effective bait traps to control dengue and chikungunya. </p>
<h2>Finding the perfect host</h2>
<p>Studies have shown that the <a href="https://www.ncbi.nlm.nih.gov/pubmed/1983456">lure of carbon dioxide</a> in the human breathe help mosquitoes detect a host. Several additional pieces of research have gone further, showing that mosquitoes are attracted to several different stimuli including physical, visual and olfactory. Physical cues include heat and moisture while visual stimuli include light, colour and form.</p>
<p>One study, for example showed that <a href="https://www.ncbi.nlm.nih.gov/pubmed/2230769">mosquitoes were attracted</a> to objects that had been heated and covered in body odour. In another, researchers established that a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3162918/">combination</a> of heat, moisture and body odour was even more <a href="https://www.nature.com/scientificamerican/journal/v233/n1/pdf/scientificamerican0775-104.pdf">potent</a>. </p>
<p>And in yet <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4983048/">another study</a>, where light traps were baited with carbon dioxide, researchers were able to establish that one of the three mosquitoes that spread malaria – the anopheles gambiae mosquito – bites their hosts at night.</p>
<h2>All about the smell</h2>
<p>Efforts to understand what attracts the Aedes aegypti mosquitoes has been researched in ernest over the past 12 years. </p>
<p>The challenge with many previous studies is that most were conducted on samples in laboratories and not in the field. We set about conducting our tests in the field. In addition, we wanted to test the entire body odour and not just the breathe. </p>
<p>We did two studies. In the first, we used samples of body odour from used socks and worn t-shirts in bait traps in the field. When we compared them to the commercial versions of the traps, we found that the mosquitoes were more attracted to the body odour traps. </p>
<p>Once we established this, we then analysed the body odour and identified most potent chemical compounds. These were from four major chemical groups: the aldehydes, fatty acids, ketones and alcohols. </p>
<p>Aldehydes and fatty acids dominate human odour profiles. But each person has a unique chemical compound profile, with different ratios of the four groups of compounds. This means that different people offer different levels of attractiveness to a mosquito. </p>
<p>The chemical compound profile also changes at different points of the body of an individual. This makes certain parts of the body more or less attractive to the mosquito. </p>
<p>Our second study took these compounds into baited traps. We found that when the compounds were combined with carbon dioxide, they sharpened the body odours that mosquitoes were able to pick up using their antennae.</p>
<p>Our results suggest that there are additional chemical compound candidates that could be commercialised to attract mosquitoes, particularly Aedes aegypti. </p>
<h2>Trap bait</h2>
<p>Ultimately, our findings could lead to a technology made from compounds that come from human body odours to lure and kill mosquitoes that spread the dengue and chikungunya viruses. </p>
<p>For now our next steps are to identify the other compounds in body odour that could also attract mosquitoes. Once these are identified they will need to be tested to see if they are also capable of being used as super bait for mosquitoes.</p><img src="https://counter.theconversation.com/content/91419/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eunice Anyango Owino is a medical entomologist and works as a lecturer at the University of Nairobi. Funding for the reported findings was from the Swedish International Development Cooperation Agency, SIDA and the research was based at the Behavioural and Chemical Ecology Unit, icipe. </span></em></p>
In the future, traps for mosquito that spread the dengue and chikungunya virus could be made from the carbon dioxide in human breathe as well as body odour.
Eunice Anyango Owino, Medical Entomologist at the School of Biological Sciences, University of Nairobi
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/86270
2018-01-08T12:19:45Z
2018-01-08T12:19:45Z
How the Victorians help explain our obsession with the microbiome
<figure><img src="https://images.theconversation.com/files/198549/original/file-20171211-27693-kt6qxc.jpg?ixlib=rb-1.1.0&rect=40%2C40%2C1552%2C1110&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/nihgov/29872812646/in/photolist-22eoPNH-EnXnBR-dCgjey-WhcSWz-f8dwh1-WdHDgJ-dCaUk6-sxJ8Ky-V3HYBc-V3HYjt-WhcTyg-V3HYnK-NiWJ4K-UZSgAq-gWqook-UZSgLW-WhcTFF-UZSgS7-V3HXYZ-VG2Ccy-WdHDkG-V3HXcD-V3HYxp-V3HXiv-WhcSSr-WhcT1c-WhcTrH-V3HXGr-V3HY2p-UZSgJw-V3HXoR-V3HXVx-VG2CiA-WhcTtr-WhcSUk-V3HYfk-WhcTBx-Ft7HA1-nf3q5M-nwh1kk-UZSgWA-VG2CJA-HsgNK3-MvKYrU-He4Jbg-svAPTm-sgiRUL-WhcT6c-He4JLe-NqHyDL">nihgov/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>In recent years, the <a href="https://theconversation.com/uk/topics/microbiome-3734">microbiome</a> has made a transformation from “<a href="https://www.nature.com/news/microbiology-microbiome-science-needs-a-healthy-dose-of-scepticism-1.15730">obscure to ubiquitous</a>”. Numerous studies have tentatively associated the whole range of microorganisms that live inside us with our immune, bodily, and even mental health. From <a href="http://www.xtalks.com/Microbiome-Cancer-Immunotherapy-Drug-459.ashx">how well we respond</a> to cancer treatments (or indeed <a href="https://academic.oup.com/carcin/article/35/2/249/2463060/Emerging-roles-of-the-microbiome-in-cancer">how vulnerable we are</a> to cancer), from whether or not we suffer from <a href="https://kresserinstitute.com/ibs-gut-brain-microbiome-axis-disorder/">inflammatory bowel disorders</a> or <a href="https://kresserinstitute.com/ibs-gut-brain-microbiome-axis-disorder/">autistic spectrum disorders</a>, to how <a href="https://www.psychologytoday.com/blog/the-athletes-way/201710/study-links-gut-microbiome-ridiculously-healthy-aging">gracefully we age</a>, microbiome studies claims insider knowledge. </p>
<p>This vogue has not only caught the scientific imagination, but also the popular one. Books on the subject abound, from popular science, such as Ed Yong’s <a href="https://www.theguardian.com/science/occams-corner/2016/aug/25/lifes-little-surprises-i-contain-multitudes-ed-yong">I Contain Multitudes</a> and Rodney Dietert’s <a href="https://www.kirkusreviews.com/book-reviews/rodney-dietert/the-human-superorganism/">The Human Superorganism</a>, to diet books including Michael Mosley’s <a href="http://www.dailymail.co.uk/health/article-4501596/Dr-Michael-Mosley-unveils-life-changing-new-gut-diet.html">The Clever Guts Diet</a>. </p>
<p>The problem with the lure of the microbiome is that the correlations that underpin these studies are much more complicated than simple cause and effect. Such relationships can be very misleading. The number of people who drowned by falling into a pool in the US in period 1999-2009, for example, <a href="http://www.tylervigen.com/spurious-correlations">correlates bizarrely well</a> with the number of films that Nicholas Cage appeared in across the same ten year period. But we don’t tend to argue that one causes the other.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/198012/original/file-20171206-915-11cn4zl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/198012/original/file-20171206-915-11cn4zl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/198012/original/file-20171206-915-11cn4zl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/198012/original/file-20171206-915-11cn4zl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/198012/original/file-20171206-915-11cn4zl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/198012/original/file-20171206-915-11cn4zl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/198012/original/file-20171206-915-11cn4zl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=533&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Bacterial microbiome mapping – an artistic experiment.</span>
<span class="attribution"><a class="source" href="https://wellcomecollection.org/works/y4tykvg7">François-Joseph Lapointe, Université de Montréal</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>While microbiome studies promises genuine advances in many fields, it is, as Harvard professor of epidemiology William Hanage <a href="https://www.nature.com/news/microbiology-microbiome-science-needs-a-healthy-dose-of-scepticism-1.15730">notes</a>, in danger of “being drowned in a tsunami of its own hype”. Other promising emergent fields, like <a href="https://theconversation.com/uk/topics/epigenetics-250">epigenetics</a>, simply haven’t entered the popular sphere with anything like so much drama or success. So why does the microbiome hold so much cultural currency? I suggest that the answer might lay partly in our cultural indebtedness to the Victorians. </p>
<h2>What is health anyway?</h2>
<p>Microbiome studies advances a radically different model of the healthy body, challenging our sense of what it means to be human. The idea that humanity might find meaning in symbiosis (like lichen, <a href="http://www.britishlichensociety.org.uk/about-lichens/what-is-a-lichen">the very identity of which</a> is built on organic relationships) is appealing. This is not only for its political implications, but because it offers a reprieve from full responsibility. “Are the bacteria in your gut making you fat?” asks <a href="http://www.cyclingweekly.com/archive/are-the-bacteria-in-your-gut-making-you-fat-71327">Cycling Weekly</a>. But unlike genetic explanations for pathology, explanations based on gut bacteria offer people the chance to change their “predispositions”. </p>
<p><a href="https://realfoodforager.com/change-your-microbiome-change-your-health/">Changing your gut bacteria</a> has been billed as a panacea-like fix for all our health needs. This desire for a holistic solution brings to mind Victorian patent medicine with its many pills promising to be all-singing, all-dancing, and all-curing. Holloway’s 19th century pills and ointments, for example, were marketed as curing everything from pimples to gout. Such treatments claimed to restore general “health” (whatever that means), like recharging a battery. Despite our ridicule of this kind of Victorian quack-doctorism, we still share the Victorian fantasy of a “one pill cures all” kind of medicine. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/198547/original/file-20171211-27705-rehkw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/198547/original/file-20171211-27705-rehkw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=390&fit=crop&dpr=1 600w, https://images.theconversation.com/files/198547/original/file-20171211-27705-rehkw6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=390&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/198547/original/file-20171211-27705-rehkw6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=390&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/198547/original/file-20171211-27705-rehkw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=490&fit=crop&dpr=1 754w, https://images.theconversation.com/files/198547/original/file-20171211-27705-rehkw6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=490&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/198547/original/file-20171211-27705-rehkw6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=490&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Parker’s tonic.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Trade_card;_Parker%27s_tonic,_1880%27s_Wellcome_L0030706.jpg">Wellcome Images</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>It’s not just this desire for panaceas that connects the Victorians to our current cultural moment. We have witnessed a plethora of diets from no-carbs to ketones, and from clean-eating to the 5:2. This perhaps explains why microbiome studies is so popular – its chief therapeutic intervention being dietary. This obsession with diet is also a legacy of the 19th century, which witnessed a widespread pathologisation of fatness and London’s first vegetarian restaurants. </p>
<h2>The gastric body</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/197846/original/file-20171205-22967-9930ne.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/197846/original/file-20171205-22967-9930ne.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/197846/original/file-20171205-22967-9930ne.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1014&fit=crop&dpr=1 600w, https://images.theconversation.com/files/197846/original/file-20171205-22967-9930ne.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1014&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/197846/original/file-20171205-22967-9930ne.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1014&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/197846/original/file-20171205-22967-9930ne.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1274&fit=crop&dpr=1 754w, https://images.theconversation.com/files/197846/original/file-20171205-22967-9930ne.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1274&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/197846/original/file-20171205-22967-9930ne.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1274&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Memoirs of stomach (1853).</span>
<span class="attribution"><span class="source">Whiting</span></span>
</figcaption>
</figure>
<p>The idea that food and its impact on the gut might be the key to wider health and well-being was a fundamental tenet of 19th-century medicine. Ill-health was often articulated through the language of the gastrointestinal region, with terms like “<a href="http://medical-dictionary.thefreedictionary.com/dyspepsia/">dyspepsia</a>” signifying not only chronic indigestion, but a diverse range of disruptions to physical and mental harmony.</p>
<p>The dynamic relationship between stomach and mind underpinned health and featured in medical essays, but also in novels and poems. While doctors writing about dyspeptic hypochondriasis might argue that digestive health and emotional well-being were interconnected, novelists would acknowledge the same kinds of connections in their novels. </p>
<p>Camilla in Charles Dickens’s Great Expectations (1861), for example, says: “If I could be less affectionate and sensitive, I should have a better digestion and an iron set of nerves.” What is being articulated here is what modern scientists refer to as the <a href="https://en.wikipedia.org/wiki/Gut%E2%80%93brain_axis/">gut-brain axis</a>, a pathway that has been implicated in chronic depression and anxiety disorders. </p>
<h2>Allies and room-mates</h2>
<p>We often think of the late 19th century as ushering in the fear of germs. But we forget that the Victorians were also attune to the benefits of living symbiotically. In H.G. Wells’s The War of the Worlds (1898), mankind is ultimately saved by a hard-won symbiosis with bacteria, our “microscopic allies”. </p>
<p>Earlier in the century, M. Easter-Ross had referred to microorganisms as “joint tenants”, while The Saturday Review <a href="https://archive.org/stream/saturdayreviewof8318unse/saturdayreviewof8318unse_djvu.txt">argued</a> that man could be envisaged as a law firm, “Homo & Co.”, with “one large shareholder and numberless small ones”. Such metaphors, which dominate microbiome studies today, encourage us to see our bodies as semi-porous ecosystems underpinned by complex neurochemical relationships. </p>
<p>These kinds of metaphors, together with ideas about the “<a href="https://www.scientificamerican.com/article/gut-feelings-the-second-brain-in-our-gastrointestinal-systems-excerpt/">second brain</a>”, form a powerful cultural narrative in part because they are, in fact, familiar. The complex intertwinement of the emotional and the physical, of human and microbe, of self and other (or is it still self?) that we are becoming familiar with is also latent in Victorian models of the body.</p>
<p>Microbiome studies offers us a different way of thinking about identity that promises a shift in our approach to health and well-being. But we must recognise that its popularity is not based on scientific merit alone. By engaging critically with the medical and cultural ideas that historically inform this “new-found” model of health, we might more fully appreciate its potential and be more wary of its “hype”.</p><img src="https://counter.theconversation.com/content/86270/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>As part of the Diseases of Modern Life team at St Anne's College, Oxford, Emilie Taylor-Brown receives funding from the European Research Council under the European Union's Seventh Framework Programme ERC Grant Agreement number 340121. </span></em></p>
Our obsession with gut health, diet and well-being is far from new: the Victorians had very similar concerns.
Emilie Taylor-Pirie, Postdoctoral Reseach Fellow, University of Oxford
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/85631
2017-11-20T05:44:24Z
2017-11-20T05:44:24Z
From Ayurveda to biomedicine: understanding the human body
<figure><img src="https://images.theconversation.com/files/195214/original/file-20171117-7557-1a2ltpu.jpg?ixlib=rb-1.1.0&rect=1296%2C179%2C4030%2C2543&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Courtesy of Wellcome Collection</span></span></figcaption></figure><p>What is a human body? This may seem a facetious question, but the answer will be very different according to which medical tradition you consult. Take Ayurveda, a traditional system of medical knowledge from India which has enjoyed a renaissance of popularity in the West since the 1980s – and is the subject of a new <a href="https://wellcomecollection.org/exhibitions/WduTricAAN7Mt8yY">exhibition</a> at London’s Wellcome Collection. </p>
<p>Walking round the show, one is encouraged to explore different ways of understanding and visualising the human body. The Ayurvedic body differs significantly from that of European biomedicine, which is based on dissection. The Ayurvedic body is a body of systems. It is conceptualised as being composed of five constituent parts (<em>mahābūta</em>), seven body substances (<em>dhātu</em>) and three regulating qualities (<em>doṣa</em>). According to Ayurvedic theory, by attending to imbalances between these principles in a body, health might be promoted and illness avoided. The Ayurvedic concepts of the <em>doṣas</em> – <em>vata</em>, <em>pitta</em> and <em>kapha</em> can be seen in the West today promoting teas, soaps and massages.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/195188/original/file-20171117-7573-2tb4hv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/195188/original/file-20171117-7573-2tb4hv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/195188/original/file-20171117-7573-2tb4hv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=417&fit=crop&dpr=1 600w, https://images.theconversation.com/files/195188/original/file-20171117-7573-2tb4hv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=417&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/195188/original/file-20171117-7573-2tb4hv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=417&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/195188/original/file-20171117-7573-2tb4hv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=524&fit=crop&dpr=1 754w, https://images.theconversation.com/files/195188/original/file-20171117-7573-2tb4hv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=524&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/195188/original/file-20171117-7573-2tb4hv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=524&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Parallels between the yogic and the medical/anatomical view of the body.</span>
<span class="attribution"><a class="source" href="https://wellcomecollection.org/works/vkntf5pb?query=Hamsasvarupa">Wellcome Collection, Svami Hamsasvarupa, Sanskrit MS 391.</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>But of course, there are many other different conceptions of the human body. There is the tantric understanding, often conflated with that of Ayurveda. Tantra focuses on the concept of energy channels (<em>nāḍīs</em>) which have particular centres of concentration along a line in the centre of the body (<em>chakras</em>). The traditional Chinese model, on the other hand, emphasises the dynamic principles of <em>ying</em> and <em>yang</em> as being paramount for ensuring health. Meanwhile, indigenous healing in many traditional cultures identifies problems between the individual and the greater social and metaphysical context as the cause of illness.</p>
<h2>Competing medical systems</h2>
<p>So what, then, has determined the dominance of one medical system of thought over another? The answer is far more complex than the “correct” or “most accurate” one.</p>
<p>This complexity is epitomised by the central piece of the exhibition, one of very few illustrations of the classical Ayurvedic systemic descriptions of the human body. This 16th-century drawing, as Dominik Wujastyk’s <a href="https://www.academia.edu/172759/A_Body_of_Knowledge_The_Wellcome_Ayurvedic_Anatomical_Man_and_his_Sanskrit_Context">research</a> has shown, was probably produced at the request of a rich, Nepalese patron by a scholar-physician, a scribe and a painter, none of whom were fluent with the original Sanskrit source. The Nepalese artist was clearly influenced by Tibetan medical illustrations. </p>
<p>We don’t know how this image was originally used or how influential it was, but its creation was dependent upon patronage and intercultural exchange. It was out of this mix of cultures, then, that came one of the most iconic visual presentations of the “Indian” Ayurvedic body. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/195191/original/file-20171117-7579-fulr11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/195191/original/file-20171117-7579-fulr11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/195191/original/file-20171117-7579-fulr11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=896&fit=crop&dpr=1 600w, https://images.theconversation.com/files/195191/original/file-20171117-7579-fulr11.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=896&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/195191/original/file-20171117-7579-fulr11.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=896&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/195191/original/file-20171117-7579-fulr11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1126&fit=crop&dpr=1 754w, https://images.theconversation.com/files/195191/original/file-20171117-7579-fulr11.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1126&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/195191/original/file-20171117-7579-fulr11.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1126&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 Ayurvedic Man.</span>
<span class="attribution"><span class="source">Courtesy of the Wellcome Collection</span></span>
</figcaption>
</figure>
<p>Economic and political powers are strong influences on the shape and popularity of Indian concepts of the body today. Yoga is currently the most widespread Indian approach to promoting the health of the body. It is flourishing globally. Millions attest that yoga makes them feel better and Ayurvedic concepts are often presented as integral to yoga practices. </p>
<p>But it is not well known that the contemporary global interest in Ayurveda and yoga is partially a result of colonial mismanagement of India. This point is creatively illustrated in the Wellcome’s new show through an interactive commission by the artist Ranjit Kandalgaonkar. Millions of lives were lost throughout the colonial period due to forcible redistribution of food and other resources away from local Indian populations, to serve what were considered to be the greater needs of the British Empire. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/OS7CUd_jiCI?wmode=transparent&start=5" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>As I have argued <a href="http://religion.oxfordre.com/view/10.1093/acrefore/9780199340378.001.0001/acrefore-9780199340378-e-253?rskey=HVLVPC&result=4">elsewhere</a>, reactions to the tragic deaths of millions of Indians transformed yoga. Swami Vivekananda was inspired by the effects of famine and plague to redefine Karma Yoga as a social-service mission. Many leaders of the Indian independence movement, including Mahatmas Gandhi and Mohan Malaviya, promoted Indian approaches to medicine and health. </p>
<p>And so the establishment of the modern Indian nation was closely linked with the health of millions of individual Indian bodies through “Indian” systems of healing. This continues today as the prime minister Narendra Modi demonstrates through his association with Indian’s popular “yoga-televangelist” <a href="https://www.reuters.com/investigates/special-report/india-modi-ramdev/">Swami Ramdev</a> and the elevation of traditional medicine to that of an <a href="http://ayush.gov.in/">independent government department</a>. </p>
<p>The promotion and preservation of Indian medicinal knowledge is laudable. But it is important not to oversimplify complex and sophisticated descriptions rooted in different worldviews. Economic imperatives often flatten traditions into marketable exports – and intercultural exchanges both enrich and confuse our models of understanding. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/195216/original/file-20171117-19285-yjlaxw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/195216/original/file-20171117-19285-yjlaxw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=375&fit=crop&dpr=1 600w, https://images.theconversation.com/files/195216/original/file-20171117-19285-yjlaxw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=375&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/195216/original/file-20171117-19285-yjlaxw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=375&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/195216/original/file-20171117-19285-yjlaxw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/195216/original/file-20171117-19285-yjlaxw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/195216/original/file-20171117-19285-yjlaxw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">19th century painting depicting a yogic posture.</span>
<span class="attribution"><span class="source">Courtesy of Wellcome Collection</span></span>
</figcaption>
</figure>
<h2>Many understandings</h2>
<p>So should there be one answer, one dominant understanding of the body? I’m currently part of a team <a href="http://ayuryog.org">researching the overlaps</a> between yoga, Ayurvedic medicine and Indian longevity practices (<em>rasāyana</em>) over the past 1000 years. Our research emphasises a plurality of understandings through time. Both yoga and Ayurveda are characterised by a diversity of practices, as well as by internal conceptual coherency. Millennia of intercultural exchange has <a href="https://www.academia.edu/1754873/Making_Heritage_Legible_Who_Owns_Traditional_Medical_Knowledge">created problems</a> for asserting national ownership of traditional medical knowledge.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/195231/original/file-20171117-19269-5e6tg3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/195231/original/file-20171117-19269-5e6tg3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/195231/original/file-20171117-19269-5e6tg3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=816&fit=crop&dpr=1 600w, https://images.theconversation.com/files/195231/original/file-20171117-19269-5e6tg3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=816&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/195231/original/file-20171117-19269-5e6tg3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=816&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/195231/original/file-20171117-19269-5e6tg3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1025&fit=crop&dpr=1 754w, https://images.theconversation.com/files/195231/original/file-20171117-19269-5e6tg3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1025&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/195231/original/file-20171117-19269-5e6tg3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1025&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 Western conception of the body: Leonardo da Vinci’s Vitruvian Man.</span>
<span class="attribution"><span class="source">Wikimedia Commons</span></span>
</figcaption>
</figure>
<p>All medical systems have shared interests in promoting human health and longevity. But it is important to understand the differences as well as the similarities. As early as 1923, Indian commentators were expressing concern about the potential biomedical “mining” of traditional remedies for single active ingredients. One commentator in the <a href="https://youtu.be/P08DWHUWBdI?t=146">Usman Report</a>, a pan-Indian survey of over 200 indigenous medical practitioners, asks: “Does this amount to quackery” by biomedical physicians?</p>
<p>Today, our mental image of our bodies is largely picture built up from dissection and, more recently, x-rays and various other scans. Yet in practice, we understand our bodies as a changing system. We monitor our energy levels. We adjust how we feel with food, drink, sleep, exercise and drugs. The Ayurvedic, system-oriented body, then, is perhaps not that far from most people’s daily experience. So how might we better visualise our bodies based on our lived, somatic understandings? </p>
<p>Ayurveda is a rich and complex tradition that has always encompassed influences from a variety of cultures as well as retaining very specific, local applications. Ayurveda cannot be reduced to a simple definition, marketing slogan or quantifiable national export. The Wellcome’s <a href="https://wellcomecollection.org/exhibitions/WduTricAAN7Mt8yY">new show</a> explores these complicated relationships and raises important questions. If we are not to become “quacks” ourselves, we must continue to resist reductions of the human body into a single visual model.</p><img src="https://counter.theconversation.com/content/85631/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Suzanne Newcombe currently receives funding from The European Research Council (ERC) and has previously received funding from the Arts and Humanities Research Council (AHRC). </span></em></p>
A history of Ayurvedic medical concepts is being exhibited at London’s Wellcome Collection.
Suzanne Newcombe, Lecturer in Religious Studies, The Open University
Licensed as Creative Commons – attribution, no derivatives.