tag:theconversation.com,2011:/uk/topics/science-journal-8398/articlesScience (journal) – The Conversation2016-07-04T15:54:36Ztag:theconversation.com,2011:article/620072016-07-04T15:54:36Z2016-07-04T15:54:36ZShrinking hole in the ozone layer shows what collective action can achieve<figure><img src="https://images.theconversation.com/files/129618/original/image-20160706-12717-1eeovek.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Ban on CFCs in aerosol sprays and refrigerants has led to a steady shrinking of the ozone hole.</span> <span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:Aerosol.png">PiccoloNamek</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>The hole in the ozone layer was <a href="http://www.nature.com/nature/journal/v315/n6016/abs/315207a0.html">first discovered in 1985</a> by scientists from the British Antarctic Survey, who described how ozone levels above the Antarctic were steadily dropping compared to the previous decade. This was quickly recognised as a severe environmental problem – and the culprit was identified as the unchecked use of chlorofluorocarbons, or CFCs.</p>
<p>Soon after, the Montreal Protocol banning the use of CFCs was signed and came into effect in 1989. Now, 27 years later, we have published evidence that shows the <a href="http://science.sciencemag.org/content/early/2016/06/29/science.aae0061">ozone hole is beginning to close</a>. </p>
<p>CFCs are a family of non-toxic, non-flammable chemical compounds developed in the 1930s as a safe alternative to dangerous substances such as ammonia for refrigeration and spray can propellants. As CFCs were thought to be risk-free, their use grew enormously. </p>
<p>The chlorine atom is the component of CFCs that is responsible for ozone destruction. Very little chlorine exists naturally in the upper atmosphere as it generally emerges near Earth’s surface – for example from salt (sodium chloride, or NaCl) in sea spray – in water-soluble forms that are “washed out” of the atmosphere by snow and rain. CFCs on the other hand are not water soluble, so are extremely efficient at carrying chlorine high into the stratosphere at the level of the ozone layer. Once in the stratosphere, ultraviolet radiation breaks free the chlorine atom to destroy ozone and react with other substances. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/129218/original/image-20160704-19103-rvyokw.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/129218/original/image-20160704-19103-rvyokw.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/129218/original/image-20160704-19103-rvyokw.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/129218/original/image-20160704-19103-rvyokw.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/129218/original/image-20160704-19103-rvyokw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/129218/original/image-20160704-19103-rvyokw.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/129218/original/image-20160704-19103-rvyokw.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The ozone hole over Antarctica in September 2006.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>The reason there is an ozone hole in the Antarctic is that it is the coldest place on Earth – it is so cold that clouds form in the Antarctic stratosphere. Those clouds provide surfaces on which the man-made chlorine from the CFC may go on to destroy ozone much more efficiently. Together with sunlight, this special chemistry is what makes springtime (late August to October) ozone depletion worse in the Antarctic.</p>
<h2>Ozone layer on the mend</h2>
<p>Our study, led by Professor Susan Solomon of the Massachusetts Institute of Technology alongside colleagues from the National Centre for Atmospheric Research in Boulder, Colorado, shows that the rapid worldwide agreement to sign and implement the Montreal Protocol has paid off. Signed by all the countries in the world, it was the first universally ratified treaty in United Nations history. </p>
<p>We show that the average size of the ozone hole above Antarctica each September has shrunk from about 20m square kilometres to 16m square kilometres since 2000. There are other metrics that indicate the ozone layer is on the mend – such as observations that the ozone hole is opening about 10 days later than in 2000. These observations became even more meaningful through our study’s computer model simulations which meant we were able to attribute more than half of the hole’s shrinking to the reduction in CFCs. </p>
<p>While a trend showing the hole is shrinking is evident, the size has varied from year to year. This is in part due to the effects of volcanic eruptions. For example, the fourth-largest ozone hole occurred in October 2015 following the eruption of <a href="http://www.bbc.co.uk/news/world-latin-america-32544075">Calbuco volcano in Chile</a>. The mechanism by which volcanic eruptions affect ozone levels is well-known: eruptions emit sulphur dioxide, which is converted into tiny airborne particles (aerosols) that enhance chemical conditions for chlorine to destroy ozone. </p>
<p>What is surprising here is that Calbuco was a relatively modest eruption – this underscores the need to monitor and describe such volcanic events carefully in order to account for natural variability in documenting the recovery of the ozone layer.</p>
<p>Regardless of the annual ups and downs of the size of the ozone hole, it’s now clear that banning CFCs through the Montreal Protocol almost 30 years ago was the right decision. Because of swift international action, that decision is now bearing fruit and the Antarctic ozone hole is starting to heal – perhaps to close completely by as early as the 2050s.</p>
<p>But even while we are on the way to resolving one environmental issue, the next is already upon us: man-made climate change. While the ozone hole is a relatively contained problem and involved only a single CFC-producing industry, the factors contributing to climate change involve many huge, established worldwide industries worth many trillions of dollars. The task ahead of us is great, nonetheless, tackling the ozone hole problem shows what can be achieved if we collectively set our minds to solving a problem.</p><img src="https://counter.theconversation.com/content/62007/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Anja Schmidt receives funding from NERC, the Royal Society, and the NSF. </span></em></p><p class="fine-print"><em><span>Ryan Neely receives funding from NERC and the NSF. </span></em></p>What the Montreal Protocol has done for the ozone hole threat other international accords could do for climate change – if we all agree.Anja Schmidt, Academic Research Fellow in Volcanic Impacts and Hazards, University of LeedsRyan Neely, Lecturer in Observational Atmospheric Science, University of LeedsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/500272015-11-02T13:26:28Z2015-11-02T13:26:28ZLithium-air: a battery breakthrough explained<p>In the quest for smaller, longer-lasting, more powerful batteries, scientists have tried many alternative approaches to battery chemistry. One may have just produced the breakthrough we’re waiting for.</p>
<p>The urban legend is that there was a small leak in a battery cell that chemist K M Abraham was testing in his laboratory in 1995, which provided the cell with a far higher energy content than expected. Rather than try to fix the leak, Abraham investigated and discovered the first <a href="http://jes.ecsdl.org/content/143/1/1.abstract">rechargeable lithium-air (Li-air) battery</a>. So far this discovery hasn’t led to any technically viable products, but <a href="http://www.sciencemag.org/content/350/6260/530.abstract">a paper</a> published in Science from a University of Cambridge research group may be about to change that.</p>
<p>In 2008, Tesla amazed industry watchers with its bold, <a href="http://my.teslamotors.com/en_GB/roadster/specs">electric Roadster</a> car that ran on off-the-shelf lithium-ion (Li-ion) batteries, the sort that power everything from smartphones to laptops to cameras and toys. Since then, not only has the market for electric vehicles quickly grown, but so has the average range of the batteries that power them. However that growth needs to accelerate: from 1994 it took 20 years to <a href="http://electronicdesign.com/power/here-comes-electric-propulsion">triple the energy content</a> of a typical Li-ion battery. </p>
<p>The new research, led by professors Gunwoo Kim and Clare Grey, experimented with Li-air cells that use only an electron conductor, such as lightweight, porous carbon, instead of a metal-oxide typically used in a Li-ion battery. Practically speaking, this saves a lot of weight, but brings its own difficulties. </p>
<h2>How Lithium-air batteries work</h2>
<p>A Li-air cell creates voltage from the availability of oxygen molecules (O<sub>2</sub>) at the positive electrode. O<sub>2</sub> reacts with the positively charged lithium ions to form lithium peroxide (Li<sub>2</sub>O<sub>2</sub>) and generate electric energy. Electrons are drawn out of the electrode and such a battery is empty (discharged) if no more Li<sub>2</sub>O<sub>2</sub> can be formed.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/100388/original/image-20151030-16532-1rvhzl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/100388/original/image-20151030-16532-1rvhzl.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=598&fit=crop&dpr=1 600w, https://images.theconversation.com/files/100388/original/image-20151030-16532-1rvhzl.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=598&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/100388/original/image-20151030-16532-1rvhzl.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=598&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/100388/original/image-20151030-16532-1rvhzl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=751&fit=crop&dpr=1 754w, https://images.theconversation.com/files/100388/original/image-20151030-16532-1rvhzl.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=751&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/100388/original/image-20151030-16532-1rvhzl.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=751&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Theoretically, a Li-air battery is empty (discharged) when all pores of the positive electrode (right-hand side) are filled with lithium peroxide, shown here filling from top to bottom.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>However, Li<sub>2</sub>O<sub>2</sub> is a very bad electron conductor. If deposits of Li<sub>2</sub>O<sub>2</sub> grow on the electrode surface that supplies the electrons for the reaction, it dampens and eventually kills off the reaction, and therefore the battery’s power. This problem can be overcome if the reaction product (lithium peroxide in this case) is stored close to the electrode but does not coat it.</p>
<p>The Cambridge researchers found a recipe that does exactly that – using a standard electrolyte mixture and adding lithium iodide (LI) as an additive. The team’s experiment also include a rather spongy, fluffy electrode made of many thin layers of graphene filled with large pores. The last important ingredient is a small amount of water. </p>
<p>With this combination of chemicals, the reaction as the battery discharges does not form the Li<sub>2</sub>O<sub>2</sub> that would gunge up the electrode’s conducting surface (see image below, left hand side). Instead it incorporates hydrogen stripped from the water (H<sub>2</sub>O) to form lithium hydroxide (LiOH) crystals. These crystals fill the size of the pores in the fluffy carbon electrode, but crucially they don’t coat and block the vital carbon surface that is generating the supply of voltage (right hand side). So the presence of lithium iodide as “facilitator” (though its exact role is not yet clear) and water as co-reactant in the process boosts the Li-air battery’s capacity.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/100383/original/image-20151030-16519-17wdvk2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/100383/original/image-20151030-16519-17wdvk2.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=280&fit=crop&dpr=1 600w, https://images.theconversation.com/files/100383/original/image-20151030-16519-17wdvk2.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=280&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/100383/original/image-20151030-16519-17wdvk2.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=280&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/100383/original/image-20151030-16519-17wdvk2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=352&fit=crop&dpr=1 754w, https://images.theconversation.com/files/100383/original/image-20151030-16519-17wdvk2.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=352&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/100383/original/image-20151030-16519-17wdvk2.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=352&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Li-air batteries with lithium peroxide (left, blocking the carbon electrode) and lithium hydroxide (right, with electrode unblocked) as discharge products. Note that the electrode pore structure is not drawn for simplicity.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>How will Li-air change things?</h2>
<p>This process which ensures the electrode surface is kept clear is essential to boost battery capacity. However, the drawback is that the same lack of electrical contact between the electrode and the discharge product that boosts its capacity should in principle make it difficult to recharge. </p>
<p>Again, it turns out the lithium iodide additive is the missing ingredient needed: at the electrode, negatively charged iodide ions are converted into I<sub>3</sub> (triiodide) ions (see picture, right-hand side). These combine with the LiOH crystals and dissolve, allowing for a complete recharge by clearing the pores. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/100384/original/image-20151030-16502-o0ctue.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/100384/original/image-20151030-16502-o0ctue.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=280&fit=crop&dpr=1 600w, https://images.theconversation.com/files/100384/original/image-20151030-16502-o0ctue.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=280&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/100384/original/image-20151030-16502-o0ctue.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=280&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/100384/original/image-20151030-16502-o0ctue.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=352&fit=crop&dpr=1 754w, https://images.theconversation.com/files/100384/original/image-20151030-16502-o0ctue.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=352&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/100384/original/image-20151030-16502-o0ctue.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=352&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Recharging Li-air batteries. Left: lithium peroxide has to be removed from the carbon surface. Right: cycle of iodide and triiodide, where triiodide chemically dissolves lithium hydroxide, freeing the elements so they can be re-combined again to produce electricity.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In fact this mechanism is even more effective than the recharge of Li<sub>2</sub>O<sub>2</sub> attached to the electrode surface. Since the electrons do not need to travel through a Li<sub>2</sub>O<sub>2</sub> layer, less voltage is required to recharge a Li-air battery with the iodine additive than without it. So less energy is needed to recharge the battery, which would make an electric car running on such a Li-air battery more energy efficient. The study’s authors present data that are approaching an energy efficiency of around 90% – which brings this new battery technology close to that of conventional Li-ion batteries.</p>
<p>Their findings reveal a promising way forward for Li-air technology, at a time when many other research groups have given up. As more researchers return to the subject following this breakthrough, perhaps a commercial Li-air battery will finally become reality.</p><img src="https://counter.theconversation.com/content/50027/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Harry Hoster 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>Lithium-air batteries demonstrate 90% efficiency in the lab, enough for commercial use. Perhaps the battery breakthrough we’ve been waiting for is here.Harry Hoster, Director of Energy Lancaster and Professor of Physical Chemistry, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/460902015-08-14T10:50:02Z2015-08-14T10:50:02Z‘Teenage’ Jupiter may hold the secret of how planets form<figure><img src="https://images.theconversation.com/files/91758/original/image-20150813-21425-18e4ni9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Artist's conception of the young exoplanet 51 Eridani b. </span> <span class="attribution"><span class="source"> Danielle Futselaar & Franck Marchis, SETI Institute</span></span></figcaption></figure><p>In the past 20 years, thousands of planets have been discovered orbiting other stars. Far from resembling families of planets like Earth and its companions, most of these discoveries have made our solar system look like the odd one out. </p>
<p>But now astronomers have announced <a href="http://www.sciencemag.org/lookup/doi/10.1126/science.aac5891">a new exoplanet</a> that looks surprisingly familiar. The exoplanet, 51 Eridani b, looks a lot like Jupiter – or at least the way we think Jupiter looked when it was much younger. Studying this juvenile version of our familiar neighbour will help us to unlock Jupiter’s past and find out more about the circumstances of its birth. </p>
<h2>Bright young thing</h2>
<p>The newly discovered exoplanet is a gas giant in orbit around a star 96 light years away. The star and its planetary system are estimated to be just 20m years old, less than a hundredth of the age of our solar system. This means that while Jupiter is a fully-grown planet, 51 Eridani b is still a teenager.</p>
<p>The youthfulness of 51 Eridani b was the key to its discovery. The planet has barely had time to cool down from its formation, which means that it is still bright enough to be directly imaged. Using the <a href="http://planetimager.org/">Gemini Planet Imager</a>, a new instrument on the 8-meter Gemini South Telescope in Chile, an international team of astronomers was able to carefully block out the light from the parent star and spot the planet. The results have been published in the current issue of the journal <em>Science</em>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/91738/original/image-20150813-21421-lk323m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/91738/original/image-20150813-21421-lk323m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=353&fit=crop&dpr=1 600w, https://images.theconversation.com/files/91738/original/image-20150813-21421-lk323m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=353&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/91738/original/image-20150813-21421-lk323m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=353&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/91738/original/image-20150813-21421-lk323m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=444&fit=crop&dpr=1 754w, https://images.theconversation.com/files/91738/original/image-20150813-21421-lk323m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=444&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/91738/original/image-20150813-21421-lk323m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=444&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Discovery image of the planet 51 Eridani b, taken in the near-infrared with the Gemini Planet Imager on December 18 2014. The bright central star has been mostly removed to enable the detection of the exoplanet.</span>
<span class="attribution"><span class="source">J. Rameau (UdeM) and C. Marois (NRC Herzberg)</span></span>
</figcaption>
</figure>
<p>The authors of the study estimate that 51 Eridani b is 2.5 times further from its star than Jupiter is from the Sun, meaning that if it was located in our solar system, it would sit between Saturn and Uranus. The planet is roughly the same size as Jupiter but being much denser has at least twice the mass. </p>
<h2>Show us what you’re made of</h2>
<p>By studying how the amount of light emitted by the planet varies with colour (or wavelength), scientists are starting to learn about the planet’s composition. “We already know that the atmosphere is rich in methane,” said Mark Marley, a co-author on the paper and an astronomer at NASA Ames Research Centre. “This planet has an atmospheric composition that is the most similar to our own Jupiter of any directly imaged planet.” </p>
<p>The biggest difference between the two planets is the temperature: 51 Eridani b is a sweltering 450°C, while Jupiter is much more frosty, at -150°C. But as time passes and 51 Eridani b gradually cools down, it will start to look more and more like our gas giant neighbour.</p>
<p>The exoplanet provides a glimpse back in time to how Jupiter might have looked when it was just a few million years old. Studying planets like this could be the key to unlocking the secrets of our own solar system. </p>
<p>“In the solar system we have been trying to understand the formation and evolution of giant planets just by studying them as they are today,” said Marley. “By studying young Jupiters, we are catching them closer to their birth and thus we hope to be able to see more clues about the details of their formation.”</p>
<h2>How do planets form?</h2>
<p>We know that planets are formed in the circular cloud of dust and gas that surrounds a newborn star, but the precise way in which this happens isn’t well understood. There are two main theories for the formation of gas giant planets: core-accretion, where material gradually clumps together into bigger and bigger pieces, and disc-instability, where there is rapid fragmentation into planet-size chunks as the circular cloud cools.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/91752/original/image-20150813-21425-xswh8k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/91752/original/image-20150813-21425-xswh8k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/91752/original/image-20150813-21425-xswh8k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/91752/original/image-20150813-21425-xswh8k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/91752/original/image-20150813-21425-xswh8k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/91752/original/image-20150813-21425-xswh8k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/91752/original/image-20150813-21425-xswh8k.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">
<figcaption>
<span class="caption">Artist’s impression of a planet forming within a gap in the dusty disc surrounding a young star.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Planet_formation.jpg">NASA/JPL-Caltech</a></span>
</figcaption>
</figure>
<p>Astronomers think that Jupiter formed through core-accretion, but until now, it had seemed like the odd one out. All of the young Jupiter-like exoplanets that had previously been discovered were too hot and bright for the core-accretion model to fit, suggesting that they formed via disc instability instead – 51 Eridani b is the first one that seems like it could have formed in the same way as Jupiter.</p>
<h2>The first of many?</h2>
<p>This is just the start, according to Marley. “Once we have more data we can begin to piece together the formation scenario for this planet and hopefully more planets that are yet to be discovered. Once we have a systematic view of many young giant planets we hope to understand planet formation much better than we do now.” </p>
<p>This is just the beginning for the GPI instrument, too, which is expected to make many more discoveries during its operational life. The young planets we hope it will find may hold the key to the history of our solar system. It may be only a teenager, but 51 Eridani b certainly has a lot to tell us.</p><img src="https://counter.theconversation.com/content/46090/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rohini Giles receives funding from the Royal Society.</span></em></p>Studying the young, Jupiter-sized planet 51 Eridani b opens a window into our solar system’s past.Rohini Giles, DPhil Candidate in Planetary Physics, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/355092014-12-19T06:16:33Z2014-12-19T06:16:33ZAfter Rosetta, Japanese mission aims for an asteroid in search of origins of Earth’s water<p>The <a href="http://www.esa.int/ESA">European Space Agency</a>’s <a href="http://www.esa.int/Our_Activities/Space_Science/Rosetta">Rosetta mission</a> to land on comet 67P was one of the most audacious in space history. The idea of landing on a small chunk of icy rock 300m kilometres away from Earth and hurtling towards the sun at speeds approaching 135,000km/hour is incredible – made more so by the fact they <a href="http://www.bbc.co.uk/news/live/science-environment-29985988">actually achieved it</a>.</p>
<p>What scientists have learned from the data returned by Rosetta supports the need for another ambitious space mission that has just begun: the Japanese Aerospace Exploration Agency (JAXA) <a href="http://www.jspec.jaxa.jp/e/activity/hayabusa2.html">Hayabusa2</a> mission will intercept not a comet, but an asteroid, landing on its surface no fewer than three times.</p>
<p>Data returned by the Rosetta mission has already provided us with many surprises, including <a href="http://www.sciencemag.org/content/early/2014/12/09/science.1261952">the results now published</a> in the journal Science, which reveal that the nature of the water found on comet 67P does not match that found on Earth. </p>
<p>Examining the vaporous cloud that encloses the comet nucleus, Rosetta measured the ratio of hydrogen to its heavier form, <a href="http://www.britannica.com/EBchecked/topic/159684/deuterium">deuterium</a>, and found it was <a href="http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_fuels_debate_on_origin_of_Earth_s_oceans">three times higher</a> than that found on Earth. This is an important discovery, since while water is vital to our existence on Earth, it is not at all obvious where it came from.</p>
<h2>In the beginning</h2>
<p>The Earth was formed from small rocky <a href="http://www.britannica.com/EBchecked/topic/463084/planetesimal">planetesimals</a> that circled the young sun, coalescing into a planet that was most likely born a dry world. Ices are not found in the planetary formation process until we reach lower temperatures much further out into the solar system. This means that the Earth must have had a water delivery at a later time.</p>
<p>One hypothesis is that water came via <a href="https://solarsystem.nasa.gov/faq/index.cfm?Category=Comets#q3">comet impacts</a>. Comets are formed in the chilly reaches around the giant planets of Jupiter, Saturn, Uranus and Neptune and are heavy in ice. During the end of our solar system’s formation, a large number of these were scattered towards the inner planets via gravitational kicks from their mammoth planetary neighbours. Striking our dry world, their icy contents could have begun the formation of our oceans. </p>
<p>But Rosetta’s analysis of comet 67P suggests that our oceans are not filled with fresh comet water. What we need is an alternative source, which leads us to Hayabusa2’s mission to the asteroids. </p>
<h2>Answers from asteroids</h2>
<p>The <a href="http://spaceflightnow.com/2014/12/03/hayabusa-2-launches-on-audacious-asteroid-adventure/">JAXA Hayabusa2</a> mission, which launched in early December, aims to intercept <a href="http://iopscience.iop.org/1538-3881/146/2/26">asteroid 1999 JU3</a>, touch down on its surface three times, deploy a lander with a trio of rovers and return to Earth with the asteroid samples in 2020. In short, it is a worthy successor to Rosetta. </p>
<p>Both comets and asteroids are left-over rocky parts from the planet formation process, but asteroids sit much closer to the Earth. The majority form a band orbiting the sun beyond Mars, known as the <a href="http://space-facts.com/asteroid-belt/">asteroid belt</a>, but Hayabusa2’s target is far closer, currently orbiting the sun between the Earth and Mars. </p>
<p>Asteroids come in <a href="http://www.astronomysource.com/tag/s-type-asteroids/">different flavours</a>. The S-type group have been heated during their lifetime in processes that alter their original composition, while C-type asteroids – the target of Hayabusa2 – are thought to have changed very little since their original formation. </p>
<p>As its name implies, Hayabusa2 has a predecessor that visited the S-type asteroid, <a href="http://global.jaxa.jp/article/special/hayabusa_sp3/index_e.html">Itokawa</a>, which showed evidence of experiencing heating up to 800°C. While its exploration illuminated much about the evolution of such space rocks, it held no answers as to the arrival of water on Earth.</p>
<h2>Answers in clay</h2>
<p>At only around 1km across, 1999 JU3 has insufficient gravity to hold liquid water, but observations suggest it contains clays, which require water to form. This, and its current unstable orbit, implies that it was once part of a larger object that broke apart.</p>
<p>After completing an initial analysis, Hayabusa2’s first touchdown will be at the site of the discovered clays. While Rosetta deployed a lander to reach the comet surface, Hayabusa2 will itself make contact with the asteroid, firing a bullet as it descends to break up surface material that it can gather. It will do this twice more at different locations; the third descent will preceded by the firing of a larger missile to bring up rocky debris from beneath the surface of the asteroid. While making a direct landing is risky, the advantage is that these samples can be brought back to Earth for thorough analysis. </p>
<p>Despite touching down itself, Hayabusa2 will also deploy a lander. Developed by the same German and French teams that built the Rosetta lander, Philae, Hayabusa2’s MASCOT (<a href="http://www.dlr.de/irs/en/desktopdefault.aspx/tabid-5960/10970_read-34316/">Mobile Asteroid Surface SCout</a>) will run on a 15-hour battery and dispatch three small rovers to explore the surface. </p>
<h2>Life’s building blocks in space</h2>
<p>However, water may be only one part of the secrets to be discovered on 1999 JU3. Previous <a href="http://www.newscientist.com/article/dn22127-meteorites-lefthanded-molecules-a-blow-to-et-search.html">research has suggested</a> that reactions with water on asteroids are linked to the production of amino acids: the organic building blocks for life. Not only this, but these amino acids seem to be predominantly <a href="http://www.nasa.gov/topics/solarsystem/features/life-turned-left.html">left-handed</a>; a distinctive feature of those in life on Earth.</p>
<p>While amino acids created in the laboratory appear equally as both left- and right-handed mirror images, biology strongly favours the left-handed version. We don’t know the reason for this preference, making the suggestion that such selectivity could have begun in space extremely exciting. If this turns out to be true, then scientists opening Hayabusa2’s sample jar in six years time may not only find the source of our water, but perhaps also the very beginnings of life.</p><img src="https://counter.theconversation.com/content/35509/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elizabeth Tasker does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The European Space Agency’s Rosetta mission to land on comet 67P was one of the most audacious in space history. The idea of landing on a small chunk of icy rock 300m kilometres away from Earth and hurtling…Elizabeth Tasker, Assistant Professor, Hokkaido UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/355952014-12-16T21:34:10Z2014-12-16T21:34:10ZCuriosity catches a whiff of methane on Mars – and a possibility of past life<figure><img src="https://images.theconversation.com/files/67395/original/image-20141216-14147-1bjt15o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Curiosity Rover has used its onboard lab to detect methane on the Martian atmosphere</span> <span class="attribution"><span class="source">NASA</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>NASA has revealed that a whiff of methane has been detected twice in the last couple of years at the Martian surface by the <a href="https://theconversation.com/pakistan-school-attack-years-of-inaction-on-terror-threat-led-to-this-atrocity-35586">Curiosity Rover</a>. </p>
<p>The source of the methane is uncertain. It is not even clear if the methane originated on Mars or arrived there by way of a meteorite that landed on the surface of the red planet, but this is the strongest evidence yet of possible life in its ancient past.</p>
<p>“We have full confidence that there is methane in the atmosphere of Mars,” announced John Grotzinger of CalTech, a Curiosity project scientist, on December 16. “Life is one of the few hypotheses for the formation of methane on Mars”.</p>
<p>The data that the Curiosity Rover is collecting about what Mars is like today provides strong clues about its history. The first in situ detection shows methane in the Martian atmosphere at a low background level as well as in episodic spikes at ten times the background concentration.</p>
<p>These latest results were announced at the American Geophysical Union’s meeting in San Francisco, a gathering of more than 25,000 Earth and planetary scientists. The findings, published in the journal Science, were obtained through separate periods of daytime sampling in late 2013 and early 2014. </p>
<p>The results were described as “An unexpected episodic increase in the Mars methane” by members of the project. Sushil Atreva, of the University of Michigan said: “A sudden spike and just as suddenly a disappearance of methane tells us that the Mars surface is communicating with the atmosphere.”</p>
<h2>How did it get there?</h2>
<p>There are three likely scenarios for the origin of the methane. The first is alteration of surface organics formed from past life on Mars that have since been broken down by the Sun’s ultraviolet rays.</p>
<p>Another is a reaction of water with minerals in the Martian subsurface that created methane from olivine in a process called serpentinisation. Or it could have been delivered from elsewhere in the Solar System as cosmic dust or micrometeorites.</p>
<p>Once produced, it seems most likely that the methane was stored as gas ice-like crystals, called clathrate hydrates, in the subsurface.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/67398/original/image-20141216-14132-hbf4if.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/67398/original/image-20141216-14132-hbf4if.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/67398/original/image-20141216-14132-hbf4if.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=386&fit=crop&dpr=1 600w, https://images.theconversation.com/files/67398/original/image-20141216-14132-hbf4if.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=386&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/67398/original/image-20141216-14132-hbf4if.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=386&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/67398/original/image-20141216-14132-hbf4if.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=485&fit=crop&dpr=1 754w, https://images.theconversation.com/files/67398/original/image-20141216-14132-hbf4if.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=485&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/67398/original/image-20141216-14132-hbf4if.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=485&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Possible pathways for methane on Mars.</span>
<span class="attribution"><span class="source">NASA</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>It seems that the methane is periodically destabilised and escapes into the atmosphere. It is distributed across the surface of the planet by winds over the course of a few months, and then oxidised by photochemistry, eventually breaking down to CO2 in the atmosphere. The methane source was described by NASA scientists as localised and small, and they claim that this strongly suggests Mars is currently active.</p>
<h2>Now what?</h2>
<p>Grotzinger said that NASA doesn’t know when methane will next appear but will monitor the surface continuously in a bid to determine how it got there.</p>
<p>The NASA scientists suggest that the methane originates from organic compounds accumulated in the Martian sediment, possibly early in the planet’s history, maybe billions of years ago. Loose sediment accumulates organics, they explained, which are degraded by cosmic radiation. Fluids containing oxidising compounds then move through the rock, and the rock undergoes chemical change. Then cosmic radiation destroys the organics.</p>
<p>Instruments on board Curiosity identified a compound called chlorobenzine from samples of dust drilled at the <a href="http://mars.jpl.nasa.gov/msl/mission/timeline/prelaunch/landingsiteselection/galecrater2/">Gale crater</a>. For Roger Summons of the Massachusetts Institute of Technology, this chlorobenzine is indicative of “more complex organic matter in the sample”.</p>
<p>“The stability of the clathrates depends on where they are in the surface. Small impacts or thermal stresses may have destabilised the clathrates, which may represent ancient methane. They can be stored for billions of years,” said Syshil Atreya, from the University of Michigan.</p>
<p>The background levels measured in the Martian gas samples correspond to a total of around five thousand tonnes of methane in the entire atmosphere. At their peak, the methane “burps” reached concentrations ten times this amount. This compares with the much higher amount of methane in Earth’s air, which stands at around five hundred million tonnes.</p>
<p>The team is planning further drilling samples to try to characterise the nature of the source of the methane in the trapped sediments.</p><img src="https://counter.theconversation.com/content/35595/count.gif" alt="The Conversation" width="1" height="1" />
NASA has revealed that a whiff of methane has been detected twice in the last couple of years at the Martian surface by the Curiosity Rover. The source of the methane is uncertain. It is not even clear…Simon Redfern, Professor in Earth Sciences, University of CambridgeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/324152014-10-14T11:04:19Z2014-10-14T11:04:19ZWe can restore cognition by manipulating where the body meets the mind<figure><img src="https://images.theconversation.com/files/61673/original/qns3sdxq-1413279289.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Targeting cognition through the body.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/s/think/search.html?page=1&inline=178355147">Cognition by Shutterstock</a></span></figcaption></figure><p>When we age our whole body gradually deteriorates. This includes our brains, where our personality, memories and personal values reside. It is therefore understandable that <a href="https://theconversation.com/uk/topics/dementia">dementia</a> and memory loss are some of the most devastating hallmarks of <a href="https://theconversation.com/why-do-humans-deteriorate-with-age-its-a-biological-puzzle-21824">ageing</a>, for the elderly, their families, and the healthcare system. This is why researchers want to find ways to rejuvenate the brain and therefore maintain the young mind and cognition in old age.</p>
<p>Throughout our life, immune cells that circulate in the blood help maintain our bodies, yet the brain, structurally secluded from the circulation by an impermeable blood-brain barrier, was for years considered to be an organ which ideally operates autonomously. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/61257/original/96zb2dkx-1412836772.gif?ixlib=rb-1.1.0&rect=172%2C160%2C2246%2C1405&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/61257/original/96zb2dkx-1412836772.gif?ixlib=rb-1.1.0&rect=172%2C160%2C2246%2C1405&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/61257/original/96zb2dkx-1412836772.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=605&fit=crop&dpr=1 600w, https://images.theconversation.com/files/61257/original/96zb2dkx-1412836772.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=605&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/61257/original/96zb2dkx-1412836772.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=605&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/61257/original/96zb2dkx-1412836772.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=760&fit=crop&dpr=1 754w, https://images.theconversation.com/files/61257/original/96zb2dkx-1412836772.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=760&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/61257/original/96zb2dkx-1412836772.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=760&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 brain’s choroid plexus under immunofluorescence microscopy.</span>
<span class="attribution"><span class="source">Kuti Baruch and Aleksandra Deczkowska</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>However, work by our group has focused on a part of the brain called the choroid plexus. This tissue is found in the ventricles of the brain, where cerebrospinal fluid is produced, and acts as a unique interface between the blood and the brain: on one side it is exposed to signals from the brain and on its other side to the rest of the body and the circulation.</p>
<p>From previous work <a href="http://www.pnas.org/content/110/6/2264">we know that</a> the choroid plexus enables communication between the brain and immune cells present in the blood. This means that it could also reflect the status of the brain throughout life, and serve as a mediator from which immune cells support brain function. But as brain function declines with age, we hypothesised that a possible reason might be dysregulation of choroid plexus activity.</p>
<h2>The ageing brain signature</h2>
<p>In a <a href="http://www.sciencemag.org/content/346/6205/89.short">study</a>, published in Science, our group examined the activity of the choroid plexus in ageing compared to other body tissues, including the brain and immune organs such as the lymph nodes and the spleen. We found that when aged, the choroid plexus was the only organ that produced a high level of Interferon-β, a protein generally associated with an anti-viral response – even though there was no viral infection.</p>
<p>To determine which set of signals – from the brain or the blood – causes the ageing choroid plexus to produce Interferon-β, we surgically connected old and young mice so they shared blood circulation. We found that the infusion of aged mouse blood to a young mouse did not induce Interferon-β at the choroid plexus, but when we exposed choroid plexus cells to the cerebrospinal fluid of aged mice in a culture in the lab, they showed signs of the anti-viral response. This indicates that signals from the brain are involved in this phenomenon in ageing.</p>
<h2>Memory testing</h2>
<p>On average, 70% of aged mice suffer from cognitive impairments. So the next step in our investigation was to determine whether the ageing-associated changes at the choroid plexus could affect brain function, including spatial learning and memory skills which can be easily tested in the lab by <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3332351/">Novel Location Recognition</a> (NLR) test. In this task mice are placed in a defined environment with two distinct objects, which they explore for a certain time. The next day, one of the objects is placed in a different location; mice with good memory will recognise this change of location, and will spend more time exploring the relocated object, not the object that was not moved.</p>
<p>Using NLR, we first tested a large cohort of aged mice and selected only the ones that exhibited defective memory; we injected half of these mice, directly into the brain, with a treatment that interferes with Interferon-β activity. After two weeks, we retested the mice for their cognitive performance and observed that the old mice in which Interferon-β was blocked at the choroid plexus showed improved spatial memory. Also, the number of newborn neurons in the brain, which significantly drops in old age, was elevated.</p>
<p>Given these recent findings, one can view the choroid plexus as a display window of brain’s status; when something goes wrong inside, it relays this signal to the immune system. We have learnt that targeting the brain itself is not the only way to treat its disorders, and the choroid plexus may serve as a new emerging target for restoring brain function. We hope that further research will allow us to learn more about the relationship between the brain and the choroid plexus, paving the way towards safe and effective therapies against brain disorders.</p><img src="https://counter.theconversation.com/content/32415/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michal Schwartz receives funding from the European Research Council (ERC), the European Union Seventh Framework Program (FP7), and the Marie Curie Actions Initial Training Networks (ITN)</span></em></p><p class="fine-print"><em><span>Aleksandra Deczkowska and Kuti Baruch 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>When we age our whole body gradually deteriorates. This includes our brains, where our personality, memories and personal values reside. It is therefore understandable that dementia and memory loss are…Michal Schwartz, Maurice and Ilse Katz Professorial Chair in Neuroimmunology , Weizmann Institute of ScienceAleksandra Deczkowska, PhD Student, Weizmann Institute of ScienceKuti Baruch, Postdoctoral research fellow, Weizmann Institute of ScienceLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/312482014-09-03T15:26:24Z2014-09-03T15:26:24ZTop scientific publisher chooses not to advance open access<figure><img src="https://images.theconversation.com/files/58141/original/pxshkrxt-1409741712.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Most science remains sealed.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/biblioteekje/6325328112">biblioteekje</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>Access to research is limited worldwide by the high cost of subscription journals, which force readers to pay for their content. The use of scientific research in new studies, educational material and news is often restricted by these publishers, who require authors to sign over their rights and then control what is done with the published work. In response, a movement that would allow free access to information and no restrictions on reuse – termed <a href="https://theconversation.com/uk/topics/open-access">open access</a> – is growing.</p>
<p>Some universities and funding organisations, including those administered by governments, now mandate open access, recognising its potential to increase the impact of research paid for by public money. The United Nations is considering the importance of open access to ensure the “<a href="http://www.scidev.net/global/human-rights/feature/q-a-farida-shaheed-on-the-human-right-to-science.html">right to enjoy the benefits of scientific progress and its applications</a>”.</p>
<p>The <a href="http://www.aaas.org/">American Association for the Advancement of Science</a> (AAAS), which is the largest scholarly society in the world, has recently launched a new open-access journal. But its approach is at odds with that of other <a href="http://www.plos.org/open-access/">major open-access publishers</a> and could impair the goals of the movement.</p>
<p>The journal <a href="http://scienceadvances.org/">Science Advances</a>, to be launched in February by the AAAS, plans to publish articles under a license that would <a href="http://creativecommons.org/licenses/by-nc/4.0/">prevent commercial reuses</a> by default. This includes publication on some educational blogs and incorporation into educational material, as well as reuse by small-medium enterprises. <a href="http://www.budapestopenaccessinitiative.org/">By definition</a>, this is not open access. AAAS will give authors the option to publish their work under a fully open license, but will levy a US$1,000 surcharge on top of the US$3,000 base publication fee. A reason for this surcharge was not given.</p>
<p>Science Advances is going to be an online-only journal, but AAAS will also charge authors US$1,500 more to publish articles that are more than ten pages long. They believe editorial services are enough justification for this charge, but there is no calculation to support this claim. They reason this limit is also necessary due to concerns about brevity and writing quality. However, these issues can be addressed during peer review – a process by which scientists judge other scientists’ work as objectively as possible and which is done at little to no cost to the journal. </p>
<p>Some scientists worry that a page-limit surcharge could lead to the omission of details necessary for replicating experiments, a core tenet of scientific research. Leading open-access journals from publishers such as PLOS and BioMedCentral offer unlimited page lengths at no additional cost.</p>
<p>A comparison shows that <a href="http://scienceadvances.org/apc/">fees to be charged</a> by Science Advances are among the highest in the publishing industry.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/58139/original/2qq2dzgr-1409741382.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/58139/original/2qq2dzgr-1409741382.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=367&fit=crop&dpr=1 600w, https://images.theconversation.com/files/58139/original/2qq2dzgr-1409741382.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=367&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/58139/original/2qq2dzgr-1409741382.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=367&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/58139/original/2qq2dzgr-1409741382.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=461&fit=crop&dpr=1 754w, https://images.theconversation.com/files/58139/original/2qq2dzgr-1409741382.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=461&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/58139/original/2qq2dzgr-1409741382.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=461&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="http://neurodojo.blogspot.mx/2014/08/the-sticker-price-on-aaass-zune-journal.html">Zen Faulkes</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>AAAS says it is fully committed to open-access publishing, but an examination of its recent actions are cause for concern. </p>
<p>In October, AAAS’s journal Science published a “<a href="http://www.sciencemag.org/content/342/6154/60.full">study</a>”, claiming systemic problems with peer review at open-access journals. But it was <a href="https://theconversation.com/flawed-sting-operation-singles-out-open-access-journals-18846">severely criticised for its flaws</a>.</p>
<p>In June, AAAS wrote a <a href="http://www.aaas.org/sites/default/files/leshner-letter-061314-openaccess.pdf">letter to Farina Shaheed</a>, Special Rapporteur in the field of cultural rights at the United Nations. Shaheed is preparing a report on open access for the UN Human Rights Council. AAAS expressed reservations about open access, calling the movement “young”, the approaches “experimental”, and encouraging Shaheed not to ignore the potential benefits of the reader-pays publishing model.</p>
<p>In August, AAAS announced that Kent Anderson has been appointed as <a href="http://www.aaas.org/news/aaas-names-new-science-publisher">publisher</a> of the Science journals and will oversee the launch of Science Advances. The choice of Anderson, a <a href="https://docs.google.com/document/d/136Jr5hgDv7vz3x_UT3Y8kEwk99R0viq9VL5-iubV8Ro/pub">vocal sceptic of open-access publishing</a>, was <a href="http://www.michaeleisen.org/blog/?p=1621">criticised</a> by academics.</p>
<p>Concerns about AAAS’s approach to open-access publishing recently led more than 100 scientists, including us, to sign an <a href="https://thewinnower.com/papers/open-letter-to-the-american-association-for-the-advancement-of-science">open letter</a> to them providing recommendations to improve Science Advances. AAAS have not responded formally to the open letter, choosing instead to <a href="http://scienceadvances.org/faq/">publish a FAQ</a> which makes no changes to their policies. </p>
<p>Some of Science Advances’s potential competitors have unfortunately taken a similar approach to open access. Nature Publishing Group (NPG) levies a <a href="http://www.nature.com/ncomms/open_access/index.html">US$400 surcharge for publishing under a fully open license</a> in its journal, Nature Communications. The Society for Neuroscience will do the same, with a <a href="http://eneuro.sfn.org/fees.html">US$500 surcharge for open licensing</a> in its new journal, eNeuro. The American Chemical Society charges <a href="http://acsopenaccess.org/acs-authorchoice/">US$1000 for upgrading to an open license</a>. In contrast, leading open-access publishers such as PLOS and BioMedCentral offer open licensing as standard for no additional cost.</p>
<p>It is unfortunate that AAAS and others have chosen not to fully embrace open access and maximise the impact of publicly funded research. These are missed opportunities for the world’s largest general scientific society to lead the way in increasing worldwide access to information.</p><img src="https://counter.theconversation.com/content/31248/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jon Tennant receives funding from The National Environmental Research Council.</span></em></p><p class="fine-print"><em><span>Erin McKiernan 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>Access to research is limited worldwide by the high cost of subscription journals, which force readers to pay for their content. The use of scientific research in new studies, educational material and…Erin McKiernan, Researcher in Medical Sciences, Wilfrid Laurier UniversityJon Tennant, PhD student, Imperial College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/303922014-08-15T15:39:04Z2014-08-15T15:39:04ZThe way the wind blows may not be enough to prevent ocean ‘dead zones’ growing<figure><img src="https://images.theconversation.com/files/56609/original/rjgvxz7b-1408105600.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Enormous algal blooms off Cornwall, which can lead to low oxygen waters.</span> <span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Cwall99_lg.jpg">NASA</a></span></figcaption></figure><p>The world’s oceans are plagued with the problem of “dead zones”, areas of high nutrients (such as nitrogen and phosphorus) in which plankton blooms cause a major reduction of oxygen levels in the water. Sea creatures need oxygen to breathe just as we do, and if oxygen levels fall low enough <a href="http://www.newscientist.com/article/dn14835-marine-dead-zones-leave-crabs-gasping.html">marine animals can suffocate</a>. This commonly happens around coastlines where fertilisers are washed from fields into rivers and the sea, but also mid-ocean, where currents trap waters in gyres (large systems of rotating ocean currents).</p>
<p>To date most studies have shown that these dead zones have been growing with global warming. But a <a href="http://www.sciencemag.org/content/345/6197/665">recent study</a> published in Science by Curtis Deutsch and colleagues suggests that the ocean’s largest anoxic zone – where there has been a total depletion of oxygen – in the eastern tropical North Pacific, may in fact shrink due to weakening trade winds caused by global warming. </p>
<p>The <a href="http://oceanservice.noaa.gov/education/kits/currents/05currents2.html">trade winds</a> drive water away from the coast, and the gap is filled by new cold and nutrient-rich waters that come up from the deep. These nutrients trigger algae and plankton blooms upon which larger animals feed, which builds up an accumulation of organic matter. As bacteria decompose this organic matter the oxygen in the water is depleted. This causes low oxygen areas, such as the <a href="http://depts.washington.edu/aog/oxygen-minimum-zones/">oxygen minimum zones</a> (OMZs) with very low oxygen content found at intermediate ocean depths.</p>
<p>Weaker trade winds would mean less upwelling of these deep nutrient-rich waters, and consequently less plankton and less oxygen depletion. Deutsch and colleagues affirm that although initial oxygen content will be lower due to higher temperatures, oxygen demand will decrease as trade winds do. So, the result would be that low oxygen areas in the tropical north Pacific would shrink.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/56547/original/2ktvn4dh-1408028153.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/56547/original/2ktvn4dh-1408028153.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=354&fit=crop&dpr=1 600w, https://images.theconversation.com/files/56547/original/2ktvn4dh-1408028153.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=354&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/56547/original/2ktvn4dh-1408028153.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=354&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/56547/original/2ktvn4dh-1408028153.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=445&fit=crop&dpr=1 754w, https://images.theconversation.com/files/56547/original/2ktvn4dh-1408028153.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=445&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/56547/original/2ktvn4dh-1408028153.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=445&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Map showing low oxygen areas (in blue).</span>
<span class="attribution"><a class="source" href="http://www.washington.edu/news/2014/08/07/oceans-most-oxygen-deprived-zones-to-shrink-under-climate-change/">C. Deutsch/University of Washington</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>A natural problem exacerbated by man</h2>
<p>Natural dead zones can be found worldwide, particularly near regions where strong upwelling occurs. These natural dead zones have typically had low oxygen levels over huge lengths of time, due to ocean circulation patterns that prevent mixing. Although these OMZs are natural, they can become larger and more intense due to human activities, such as prolonged and intensive use of fertilisers, changes in land use, deforestation, soil erosion, global warming, and waste waters from cities or industry. All these are well known to cause algal blooms and so drive the expansion of oxygen-depleted areas. In fact, dead zones caused by these human factors have <a href="https://theconversation.com/coastal-dead-zones-on-the-rise-15496">increased over time</a>. Naturally occurring OMZs have also been expanding <a href="http://www.newscientist.com/article/dn16477-global-warming-could-suffocate-the-sea.html">as temperature rises</a>, so the paper’s prediction that such oxygen minimum zones would shrink flies in the face of previous studies.</p>
<h2>Rising temperatures pose problems</h2>
<p>Animals increase their respiration rates as temperature rises, so they need more oxygen to breathe at higher temperatures. Warmer water also dissolves less oxygen, so as climate change warms the oceans the amount of oxygen decreases, making the effects on marine life even more acute.</p>
<p>Warming also encourages <a href="http://centerforoceansolutions.org/climate/impacts/ocean-warming/water-column-stratafi/">water stratification</a>, where the water separates into layers based on temperature or salinity, creating a physical barrier that prevents oxygen reaching deeper waters.</p>
<p><a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2009.02094.x/abstract">Previous studies</a> have predicted a weakening of trade winds in tropical areas, but have also forecasted changes to low-pressure weather fronts over coastlines that would lead to stronger winds, sufficient to replace any upwelling effect lost by weaker trade winds. </p>
<p>It seems likely that, in the same way, greater water stratification will lead to a worsening and expansion of dead zones, counteracting any effect the weakening trade winds might have to halt the process of de-oxygenation, and the paper’s authors acknowledge that this is possible.</p>
<p>Taking everything into account, it seems that the process of warming oceans under climate change will inexorably lead to larger areas of oxygen-poor ocean, with all the knock-on effects for marine life that entails.</p><img src="https://counter.theconversation.com/content/30392/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Raquel Vaquer-Sunyer 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 world’s oceans are plagued with the problem of “dead zones”, areas of high nutrients (such as nitrogen and phosphorus) in which plankton blooms cause a major reduction of oxygen levels in the water…Raquel Vaquer-Sunyer, Marie Curie post-doctoral researcher, Lund UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/300842014-08-08T04:42:45Z2014-08-08T04:42:45ZDating the sun’s prenatal history can help find life on other planets<figure><img src="https://images.theconversation.com/files/55839/original/6wwwsbkd-1407302030.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A new approach to dating the birth of our solar system could help find other similar systems.</span> <span class="attribution"><a class="source" href="http://www.flickr.com/photos/boyarrin/6341552347">Flickr/Dmitry Boyarin</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Without the sun, there would be no Earth – but amazingly, we don’t know the finer details about the prenatal history of our sun, where it was born and if other stars in our galaxy share a similar history.</p>
<p>In a study published today in <a href="http://www.sciencemag.org/lookup/doi/10.1126/science.1253338">Science</a>, we add a couple of pieces to the solar jigsaw and show that two stellar events – a supernova or neutron star merger, plus a dying giant – flung heavy elements into the nursery in which our sun was born, roughly 100 million and 30 million years before the sun’s formation.</p>
<p>Research in the prehistory of the sun helps us compare the circumstances of the birth of the sun with those of other stars in our galaxy, setting the existence of the sun, the Earth and humans more firmly within the broader context of the billions of stars and planets (and possibly other lifeforms) that exist in the Milky Way. </p>
<h2>It’s a matter of time</h2>
<p>Recent historical events have been recorded by the writings of historians. Going back further in time, though, we have to rely on other methods to date events.</p>
<p>One of the main tools to achieve this is radioactivity. Radioactive nuclei, by definition, decay as time passes by emitting energetic particles that can be very dangerous to living organisms.</p>
<p>The rate at which they decay is defined by their half-life, which is the time it takes for half of the original nuclei to disappear.</p>
<p>A famous example is <a href="http://science.howstuffworks.com/environmental/earth/geology/carbon-14.htm">carbon-14</a>, which has a half-life of 5,730 years. If the recovered bones of a human contain roughly half the amount of carbon-14 present in the biosphere, that individual must have died 5,730 years ago.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/55901/original/tkddb5fg-1407373417.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/55901/original/tkddb5fg-1407373417.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/55901/original/tkddb5fg-1407373417.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/55901/original/tkddb5fg-1407373417.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/55901/original/tkddb5fg-1407373417.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/55901/original/tkddb5fg-1407373417.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/55901/original/tkddb5fg-1407373417.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/55901/original/tkddb5fg-1407373417.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">We know the age of the Earth from radioactive dating.</span>
<span class="attribution"><a class="source" href="http://www.flickr.com/photos/gsfc/4392965590">Flickr/NASA Goddard Space Flight Center</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Radioactivity has also allowed us to date the age of the Earth at 4.54 billion years and, via analysis of extra-terrestrial rock samples carried to us via meteoritic falls or space missions, to derive a detailed timing of the events that led to the formation of planets in the solar system.</p>
<p>Using the same techniques, we can also learn something about the major events in the prehistory of the matter in the solar system, such as the period prior to the formation of the sun.</p>
<h2>Ingredients for a solar system</h2>
<p>Elements in our solar system, except for hydrogen and helium (which were created in the <a href="https://theconversation.com/topics/big-bang">Big Bang</a>), were produced by nuclear reactions in stars. </p>
<p>The material that makes up the solar system was slowly added to by hundreds to thousands of stars as they exploded into supernovas, a process we call “stellar addition”.</p>
<p>At some point, this heavier material became isolated inside a star-forming region of the galaxy, where the gas was cooler and denser than the usual galactic gas. </p>
<p>Within this stellar nursery, gas collapsed to form a number of stars, including our sun. By timing the life span of this stellar nursery we can start deducing how massive it was and how many stars were born alongside our sun.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/55700/original/ng6t59tq-1407162216.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/55700/original/ng6t59tq-1407162216.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/55700/original/ng6t59tq-1407162216.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/55700/original/ng6t59tq-1407162216.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/55700/original/ng6t59tq-1407162216.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/55700/original/ng6t59tq-1407162216.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/55700/original/ng6t59tq-1407162216.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/55700/original/ng6t59tq-1407162216.png?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">How to make a solar system.</span>
</figcaption>
</figure>
<p>To be able to time the interval that elapsed between the last of the stellar additions and the formation of the sun, we needed to know the how much radioactive nuclei was present at the time of the two events.</p>
<p>Meteoritic analysis provides us these abundances at the formation of the sun. But the abundances in the final stellar addition - and the beginning of the stellar nursery – can only be predicted theoretically by models of nuclear processes in stars, which aren’t well understood.</p>
<p>A long-standing, frustrating problem has been related to the abundances of the radioactive nuclei <a href="http://periodictable.com/Isotopes/053.129/index3.p.full.html">iodine-129</a> and <a href="http://periodictable.com/Isotopes/072.182/index.p.full.html">hafnium-182</a>. </p>
<p>Until today, these two nuclei were believed to be produced by the same stellar event, such as a supernova or a neutron star merger, in a process that produces heavy elements including gold and lead.</p>
<p>Trying to date this last stellar addition, though, produced two completely inconsistent timings: roughly 45 or 90 million years using hafnium-182 or iodine-129, respectively.</p>
<p>The main result of our study published today is that these two nuclei were instead produced by two different types of events: iodine-129 was still produced with gold by a supernova or a neutron star merger, but hafnium-182 was instead produced with lead by a dying giant star.</p>
<p>The stellar addition from this last giant star happened at most 30 million years before the formation of the sun. </p>
<p>This dating provides us with an upper limit for the life span of the stellar nursery where the sun was born, which will allow us to know more intimately the parent stellar nursery of our sun – and the sun’s “siblings” which may harbour solar systems similar to ours.</p><img src="https://counter.theconversation.com/content/30084/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Maria Lugaro has received funding from the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Alexander Heger is supported by an ARC Future Fellowship (FT120100363).</span></em></p>Without the sun, there would be no Earth – but amazingly, we don’t know the finer details about the prenatal history of our sun, where it was born and if other stars in our galaxy share a similar history…Maria Lugaro, Senior Lecturer, Monash UniversityAlexander Heger, Professor, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/301602014-08-07T20:30:21Z2014-08-07T20:30:21ZTrueNorth: a ‘brain-like’ chip to turn computing on its head<figure><img src="https://images.theconversation.com/files/55904/original/pjgqx4yb-1407374337.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Neurons provided inspiration for a new type of computer chip.</span> <span class="attribution"><a class="source" href="http://www.flickr.com/photos/wellcomeimages/5814816180">Wellcome Images/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>Computers and brains work in virtually opposite ways. Computers are laboriously programmed for specific tasks. Brains learn from experience and can perform a wide variety of complicated tasks that are currently impossible for a computer. </p>
<p>But in the journal <a href="http://www.sciencemag.org/lookup/doi/10.1126/science.1254642">Science</a> today, scientists from IBM and Cornell University published details of a computer chip called TrueNorth that mimics much of what we know about how the brain works – and the possibilities for such technology are mind-boggling. </p>
<p>Normal computers contain a handful of extremely complicated, extremely fast and extremely powerful chips (central processing units or CPUs). </p>
<p>Brains, on the other hand, work with a huge number of much simpler and slower neurons (brain cells). A bee brain contains about <a href="https://faculty.washington.edu/chudler/facts.html">a million neurons</a> and a human brain around <a href="http://www.nature.com/scitable/blog/brain-metrics/are_there_really_as_many">86 billion</a>. But it’s the way these neurons work together that makes brains so clever.</p>
<h2>How does TrueNorth work?</h2>
<p>In a brain, each neuron is connected to thousands of others. Neurons send signals to each other using tiny electrical discharges called spikes. When a neuron receives the right number of spikes from other neurons at the right time, those incoming spikes make a pattern (such as dots on a page). </p>
<p>If the pattern matches one that the neuron has learnt through experience (such as a certain pattern of dots that it has seen many times before), it will send out a spike of its own to the thousands of other neurons that it connects to. That spike will add to the patterns being seen by all those other neurons.</p>
<p>TrueNorth works exactly the same way as the brain. Instead of a small number of big CPUs, it has a huge number of small artificial neurons, all connected. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/55899/original/w8zxqwr4-1407371574.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/55899/original/w8zxqwr4-1407371574.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/55899/original/w8zxqwr4-1407371574.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=375&fit=crop&dpr=1 600w, https://images.theconversation.com/files/55899/original/w8zxqwr4-1407371574.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=375&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/55899/original/w8zxqwr4-1407371574.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=375&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/55899/original/w8zxqwr4-1407371574.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=471&fit=crop&dpr=1 754w, https://images.theconversation.com/files/55899/original/w8zxqwr4-1407371574.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=471&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/55899/original/w8zxqwr4-1407371574.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=471&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 chip’s layout (left) shows its architecture of 64x64 ‘neurosynaptic cores’. Each core (right) has 256 neurons and 65,536 synapses.</span>
<span class="attribution"><span class="source">IBM Research</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Normal computers can perform precision calculations with blinding speed, but brains can deal with imprecision and vague decisions in a constantly changing world. Exactly how brains do this we don’t fully understand, but we hope to learn more by building brain-like computers and studying what they’re capable of. </p>
<p>One of the clues seems to be that the patterns a neuron sees don’t need to be exact. They can be out of time, or have missing dots, but the neuron will still respond. This helps give the brain the ability to deal with the vagueness and unpredictability of the real world.</p>
<h2>What can TrueNorth do?</h2>
<p>The short answer is: plenty. Normal computers are dumb. Sure, there have been many attempts to make them appear smarter than they are, such as Apple’s personal assistant Siri (and does anyone remember the paperclip from Microsoft Word?), but even though they are starting to access brain-like technology in the cloud, they are still at the gimmicky stage. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/55914/original/37nmxbhj-1407376403.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/55914/original/37nmxbhj-1407376403.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/55914/original/37nmxbhj-1407376403.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=383&fit=crop&dpr=1 600w, https://images.theconversation.com/files/55914/original/37nmxbhj-1407376403.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=383&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/55914/original/37nmxbhj-1407376403.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=383&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/55914/original/37nmxbhj-1407376403.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=481&fit=crop&dpr=1 754w, https://images.theconversation.com/files/55914/original/37nmxbhj-1407376403.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=481&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/55914/original/37nmxbhj-1407376403.gif?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"></a>
<figcaption>
<span class="caption">And annoying at times.</span>
<span class="attribution"><a class="source" href="http://www.flickr.com/photos/ross/6349695">Ross Mayfield/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>For working on spreadsheets and word processing, for complex engineering calculations, secure financial transactions, fast information retrieval and computer games, normal computers work well. </p>
<p>But all these activities happen mostly <em>inside</em> the computer (or inside a computer network) and are controlled by us through relatively simple interfaces such as keyboards, mice and touchscreens. We use these simple interfaces because they are easy for the computer to understand.</p>
<p>Put a normal computer in the real world – to understand speech in a noisy office, to recognise you in sunglasses or after a radical haircut, to read text and actually understand it well enough to answer questions, to notice what we are doing and offer genuinely helpful advice – and it will fail. </p>
<p>Brain-like computers will be able to do all these things and much, much more.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/55898/original/fww95fht-1407371566.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/55898/original/fww95fht-1407371566.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/55898/original/fww95fht-1407371566.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=349&fit=crop&dpr=1 600w, https://images.theconversation.com/files/55898/original/fww95fht-1407371566.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=349&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/55898/original/fww95fht-1407371566.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=349&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/55898/original/fww95fht-1407371566.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=439&fit=crop&dpr=1 754w, https://images.theconversation.com/files/55898/original/fww95fht-1407371566.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=439&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/55898/original/fww95fht-1407371566.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=439&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">… while keeping cool. The chip is designed for low power consumption, which can be seen in this thermal image. The TrueNorth chip (left) runs cool alongside a hot field-programmable gate array (FPGA) chip (right).</span>
<span class="attribution"><span class="source">IBM Research</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>The future</h2>
<p>Once computers can recognise and understand things in the real world, they can get out of the boxes and screens they are currently inside, and start actually doing things for us. </p>
<p>Once a computer knows what a floor is, put it in a small robot and it can vacuum (simple examples of this <a href="https://www.youtube.com/watch?v=Of2HU3LGdbo">already exist</a>). Once a computer knows what shelves and cereal boxes are, it can restock the aisles at the supermarket. Other computers can undertake difficult and dangerous construction and industrial jobs and perform hazardous rescues on mountaintops or in burning buildings.</p>
<p>The possibilities are nearly endless. Brain-like computers promise to change the world in ways we can’t yet even imagine.</p><img src="https://counter.theconversation.com/content/30160/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Stratton 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>Computers and brains work in virtually opposite ways. Computers are laboriously programmed for specific tasks. Brains learn from experience and can perform a wide variety of complicated tasks that are…Peter Stratton, Postdoctoral Research Fellow, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/285402014-07-31T20:49:16Z2014-07-31T20:49:16ZHow small birds evolved from giant meat eating dinosaurs<figure><img src="https://images.theconversation.com/files/54730/original/ffznsqk9-1406169015.jpg?ixlib=rb-1.1.0&rect=0%2C109%2C1203%2C810&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A flock of early birds (Longirostravis) preen one of their large dinosaurian relatives (Yutyrannus). </span> <span class="attribution"><span class="source">Brian Choo</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Spectacular transitional fossils, many from northern China, provide overwhelming evidence that dinosaurs <a href="http://evolution.berkeley.edu/evolibrary/article/evograms_06">evolved into birds</a> and thus didn’t all perish when the deadly meteorite struck at the end of the Cretaceous period.</p>
<p>We now know that many bipedal, meat-eating dinosaurs (theropods) – including relatives of T. rex and Velociraptor – were adorned with a <a href="http://www.nature.com/news/rise-of-the-feathered-dinosaurs-1.10933">variety of feathers</a>. They were preserved in such detail in fine volcanic ash that often even their colours can be reconstructed. Plumage might have even been present in <a href="http://news.nationalgeographic.com/news/2014/07/140724-feathered-siberia-dinosaur-scales-science/">all dinosaurs</a></p>
<p>A study by our team published today in the journal <a href="http://www.sciencemag.org/">Science</a> sheds new light on the evolutionary journey from bulky ground-dwelling dinosaurs to agile flying birds.</p>
<p>Our research shows that the ancestors of birds were the only lineage of dinosaurs to continually shrink in size for an extended period of time (at least 50 million years, and perhaps twice as long). They were also the fastest-evolving lineage of dinosaurs. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/54643/original/fhkmz642-1406102487.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/54643/original/fhkmz642-1406102487.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/54643/original/fhkmz642-1406102487.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=147&fit=crop&dpr=1 600w, https://images.theconversation.com/files/54643/original/fhkmz642-1406102487.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=147&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/54643/original/fhkmz642-1406102487.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=147&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/54643/original/fhkmz642-1406102487.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=185&fit=crop&dpr=1 754w, https://images.theconversation.com/files/54643/original/fhkmz642-1406102487.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=185&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/54643/original/fhkmz642-1406102487.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=185&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Five successive ancestors leading from dinosaurs to modern birds. From left to right: the ancestral neotheropod (~220 million years old), the ancestral tetanuran (~200 myo), the ancestral coelurosaur (~175 myo), the ancestral paravian (~165 myo), and the ancestral avialan (150 myo). See movie below for animated explanation.</span>
<span class="attribution"><span class="source">Davide Bonadonna</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/FQd9TXW5SXw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>These results also relate – unexpectedly – to human health and an implausible 1980s TV show.</p>
<h2>The incredible shrinking dinosaur</h2>
<p>We constructed a detailed family tree for theropod dinosaurs including birds, and nutted out the evolutionary events that happened on each branch – that is, did body size increase or decrease and did any novel adaptations evolve? </p>
<p>For instance, if all the dinosaurs above a branch possessed a unique adaptation (such a shoulder blades fused into a bird-like <a href="http://www.smithsonianmag.com/science-nature/this-thanksgiving-make-a-wish-on-a-dinosaur-87598064/">wishbone</a>), then we can infer that the wishbone evolved on that branch.</p>
<p>We then identified the series of successive branches leading from the very base of the dinosaur tree all the way to living birds: this is the “bird stem lineage”. </p>
<p>A close analogy would be taking a real tree and tracing the single path that leads from the trunk all the way to a “special” little bunch of leaves somewhere high in the crown. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/54655/original/w248x7sx-1406108813.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/54655/original/w248x7sx-1406108813.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/54655/original/w248x7sx-1406108813.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=720&fit=crop&dpr=1 600w, https://images.theconversation.com/files/54655/original/w248x7sx-1406108813.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=720&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/54655/original/w248x7sx-1406108813.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=720&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/54655/original/w248x7sx-1406108813.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=905&fit=crop&dpr=1 754w, https://images.theconversation.com/files/54655/original/w248x7sx-1406108813.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=905&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/54655/original/w248x7sx-1406108813.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=905&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 Broad-billed Hummingbird (<em>Cynanthus latirostris</em>) in front of a tooth of a massive dinosaurian predecessor (the six-tonne <em>Carcharodontosaurus</em>).</span>
<span class="attribution"><span class="source">Terry Sohl/Christophe Hendrickx</span></span>
</figcaption>
</figure>
<p>It turns out that the bird stem lineage – the dinosaurs on the road to becoming birds – were evolving in a noticeably different manner to other theropod lineages around at the time.</p>
<p>This lineage kept shrinking in size, with each successive descendant smaller than its predecessor. In contrast, in other dinosaur lineages, body size was alternately increasing and decreasing, with no sustained trend in one direction. </p>
<p><a href="http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001853">Another recent study</a> further shows that body size along the bird stem lineage often changed unusually rapidly (in addition to in a coherent direction).</p>
<h2>Taking the evolutionary lead</h2>
<p>Evolutionary novelties were appearing on the bird stem lineage at a faster rate than across the rest of the tree. Many were major innovations such as complex feathers, bigger brains, wings and wishbones. Stem-birds were out-evolving their contemporaries by changing approximately four times as fast.</p>
<p>This continual and often rapid shrinking was probably directly related to the accelerated evolution of anatomical novelties. </p>
<p>Reduced body size, for instance, allowed bird-stem dinosaurs to explore new postures (<a href="http://www.livescience.com/29001-bird-crouch-evolved-before-flight.html">bird-like walking</a> where the thigh bone is held horizontal) and habitats (such as arboreal and, later, aerial habitats). This in turn would have created pressure to evolve radical new adaptations such as reshaping fluffy feathers into wings. </p>
<p>Perhaps the movement of small dinosaurs into trees was one reason for the appearance of gliding flight, using aerodynamic feathers? </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/52404/original/x4hjst8f-1403830888.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/52404/original/x4hjst8f-1403830888.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/52404/original/x4hjst8f-1403830888.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=647&fit=crop&dpr=1 600w, https://images.theconversation.com/files/52404/original/x4hjst8f-1403830888.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=647&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/52404/original/x4hjst8f-1403830888.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=647&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/52404/original/x4hjst8f-1403830888.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=813&fit=crop&dpr=1 754w, https://images.theconversation.com/files/52404/original/x4hjst8f-1403830888.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=813&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/52404/original/x4hjst8f-1403830888.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=813&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 feathered dinosaur <em>Microraptor</em> preyed on a group of primitive birds (<em>Sinornis</em>) in Jurassic-era China.</span>
<span class="attribution"><span class="source">Brian Choo</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>Small theropods with feathered arms, legs and tails – such as <a href="http://blogs.scientificamerican.com/tetrapod-zoology/2013/11/18/flight-of-the-microraptor/"><em>Microraptor</em></a> and the recently-described <a href="http://www.nature.com/ncomms/2014/140715/ncomms5382/full/ncomms5382.html"><em>Changyuraptor</em></a> – were very likely excellent climbers, as fossils have been found with small birds in their stomachs.</p>
<h2>Survival of the ‘MacGyver dinosaurs’</h2>
<p>Ultimately, the dinosaurian lineage that was the most evolvable during the Mesozoic also proved to be the most long-lived (there are 10,000 species of birds still alive today).</p>
<p>It is not surprising that the ability to adapt rapidly is a key to long-term survival. </p>
<p>A timely example concerns the influenza virus in the (southern) winter. Of the many and varied flu strains circulating now, the <a href="http://evolution.berkeley.edu/evolibrary/news/130201_flu">fastest-evolving strains</a> are more likely to outwit our immune systems and to persist and cause problems next winter.</p>
<p>A certain resourceful 1980s TV character fits into this picture in two ways: secret agent <a href="http://www.imdb.com/title/tt0088559/">Angus MacGyver</a> epitomised the ability to adapt quickly to any novel situation – just like the avian stem lineage. </p>
<p>But there is a more profound point of relevance. The methods we used to infer dinosaur evolutionary trees and patterns of size evolution were actually originally developed to better understand the molecular evolution and <a href="http://mbe.oxfordjournals.org/content/27/8/1877.full">geographic spreading</a> of viruses (such as influenza and HIV) in real time. </p>
<p>The intricate theory and mathematics required are virtually identical for both situations. So rather than re-invent a very complex wheel, we “MacGyvered it” by transferring the analytic tools from molecular biology over to palaeontology.</p><img src="https://counter.theconversation.com/content/28540/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mike Lee receives research funding from the Australian Research Council, the South Australian Museum, and the Environment Institute (University of Adelaide).</span></em></p><p class="fine-print"><em><span>Gareth Dyke does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.</span></em></p>Spectacular transitional fossils, many from northern China, provide overwhelming evidence that dinosaurs evolved into birds and thus didn’t all perish when the deadly meteorite struck at the end of the…Mike Lee, Senior Research Scientist (joint appointment with South Australian Museum), University of AdelaideGareth Dyke, Palaeontologist, University of SouthamptonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/277622014-06-12T04:55:31Z2014-06-12T04:55:31ZThe ‘greening’ of Europe’s farms has been a failure<figure><img src="https://images.theconversation.com/files/50852/original/ksgrktv6-1402496526.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Not all that which is greening is green.</span> <span class="attribution"><span class="source">André Künzelmann/UFZ</span></span></figcaption></figure><p>The European policies designed to encourage a more biodiverse environment that is better able to support wildlife and plants are failing. In fact, our analysis of the <a href="http://www.bbc.co.uk/news/world-europe-11216061">reforms</a> designed to “green” the EU Common Agricultural Policy (CAP) suggests they neither encourage greater wildlife abundance nor provide adequate protection for vulnerable habitats such as grasslands. </p>
<p>Finally adopted in March, the long process of reforming the CAP was supposed to require farmers to “observe practices beneficial to the climate and environment” in order to qualify for some of their direct payment subsidies, as well as offering pro-environmental farm stewardship as a voluntary step.</p>
<p>While we depend upon the food grown in agricultural fields we also benefit from the environment to which they are a part, from the wildlife such as the iconic <a href="https://www.youtube.com/watch?v=ZR2JlDnT2l8">skylarks</a> lauded by Vaughan Williams, or the “green and pleasant land” of a traditional, diverse rural landscape. Land given over to agriculture should produce more than just food and profits, but things of a wider worth to society. </p>
<p>The reformed CAP is an effort to recognise that we should pay farmers to produce both. Much of Northwest Europe’s farmland is now monotonous, monocrop farmland, degraded and denuded of its wildlife. Eastern Europe’s more traditional landscapes remain wildlife rich, and the policies’ green measures should help protect them, while encouraging farm modernisation. This is the aim but not, we discovered, the reality.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/50868/original/ghzx37z2-1402529637.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/50868/original/ghzx37z2-1402529637.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/50868/original/ghzx37z2-1402529637.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/50868/original/ghzx37z2-1402529637.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/50868/original/ghzx37z2-1402529637.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/50868/original/ghzx37z2-1402529637.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/50868/original/ghzx37z2-1402529637.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">
<figcaption>
<span class="caption">Hedgerows aren’t enough; the right hedges in the right place, managed the right way.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Rotbuchenhecke_in_der_Eifel.jpg">Steffen Heinz</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Shades of green</h2>
<p>In the UK, the Advertising Standards Agency (ASA)’s <a href="http://www.asa.org.uk/Rulings/Adjudications/Display-Code.aspx?CodeId=%7b34DFD3FF-9D88-4A14-842A-819A26E864CC%7d&amp;ItemId=%7b9A4A0858-4A97-4ADA-8420-28016CA9B97C%7d">code</a> on environmental claims says words such as “greener” can be justified if the advertised product provides a total environmental benefit over that of the marketer’s previous product, and the basis of the comparison is clear. Let’s apply this logic to the CAP reform.</p>
<p>As part of a team of environmental and farming experts from across the EU, we analysed the “greening” credentials of the new CAP relative to the old one. Our results, <a href="http://www.sciencemag.org/content/344/6188/1090.summary">published</a> in the journal Science, reveal that, alarmingly, the reformed CAP fails the ASA test: there is no basis for claiming that it is greener.</p>
<p>While many farmers across Europe have in the past volunteered to receive payments for the so-called “agri-environment schemes”, some of which have provided environmental benefits, this budget has shrunk by almost 20%. For the reformed CAP to increase its environmental benefit overall, any benefits lost as a result would have to first be replaced. </p>
<p>The reformed CAP introduces three measures: <a href="http://www.fwi.co.uk/articles/21/03/2014/143828/ecological-focus-areas-how-do-they-work.htm">Ecological Focus Areas</a>, in which 5% of agricultural land is managed to provide habitat for wildlife. Maintaining 95% of permanent grasslands, home to many wildflowers and the insects and birds they support, from being ploughed into fields. And the requirement to grow at least three crops on arable farms over 30 hectares in order to generate a more diverse landscape.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/50696/original/zzzhhy8z-1402398532.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/50696/original/zzzhhy8z-1402398532.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/50696/original/zzzhhy8z-1402398532.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/50696/original/zzzhhy8z-1402398532.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/50696/original/zzzhhy8z-1402398532.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/50696/original/zzzhhy8z-1402398532.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/50696/original/zzzhhy8z-1402398532.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Grass meadows should look more like this.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/anguskirk/7285224676">Angus Kirk</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Not living up to expectations</h2>
<p>Ecological Focus Areas will only work if they provide the right habitat for wildlife in the right place. But the scheme doesn’t include those interventions known to help wildlife, such as <a href="https://theconversation.com/bees-declared-extinct-30-years-ago-take-to-uk-skies-again-thanks-to-farmers-26987">flowers planted for pollinators</a>, or plots for ground-nesting birds. </p>
<p>And in any case, the payment rests on simply having them, rather than managing them in the right way or in the right place to make a difference. Management is critical to making any real difference – hedgerows, for example, are not much good for birds and insects if they are cut short every year and hardly allowed to flower. Fallow land is poor for wildlife if it is sprayed with herbicide in late spring to prevent weeds colonising crops.</p>
<p>The measure designed to protect permanent grassland, doesn’t. A farmer can continue to collect the subsidy if they convert a patch of flower-rich meadow into an intensively-managed improved pasture field, because it is technically still “grassland”. If taken up, the 5% reduction allowable under the scheme will over the six-year lifespan of the current CAP represent more than double the rate of loss of permanent grassland that occurred between 1993 and 2011, when just over 6% of Europe’s grasslands were lost.</p>
<p>As for the three crop rule, there is no evidence that having three crops, rather than two or one, provides any environmental or diversity benefit. It entirely depends on which crops are planted, and how they are managed – for example, what pesticides are used and when. Even now in half of EU member states the average arable farm already has four or five crops, so requiring three will not provide any additional environmental benefits.</p>
<p>On top of it all, most European farmers and about half the farmed area are in any case exempt from Ecological Focus Areas and minimum crop diversity, because they don’t apply to livestock farms or small arable farms.</p>
<p>The message that, after hard-won reform, the CAP is now greener is really appealing to society, so it’s particularly unfortunate that our analysis indicates that it is nothing of the sort. It’s important that national governments recognise that our evidence-based analysis indicates a shortfall between rhetoric and reality, and do what they can in their own power to improve matters. </p>
<p>It is also up to us, as citizens and consumers, to recognise that relying on food to be cheap and plentiful implies that sustainable farming will take second place. If we don’t like this choice, it’s up to us to voice it.</p><img src="https://counter.theconversation.com/content/27762/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lynn Dicks receives funding from NERC (grant NE/K015419/1).</span></em></p><p class="fine-print"><em><span>Tim Benton receives funding from the NERC, BBSRC and European Union for research into agricultural-environment interactions.</span></em></p>The European policies designed to encourage a more biodiverse environment that is better able to support wildlife and plants are failing. In fact, our analysis of the reforms designed to “green” the EU…Lynn Dicks, NERC Research Fellow, University of CambridgeTim Benton, Professor of Population Ecology, University of LeedsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/261922014-05-01T18:39:01Z2014-05-01T18:39:01ZCunning drongo cries wolf in the ‘language’ of other species<figure><img src="https://images.theconversation.com/files/47583/original/r5g29f6d-1398968825.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The drongo and babbler look different, but one can masterfully impersonate the other.</span> <span class="attribution"><span class="source">Tom Flowers</span></span></figcaption></figure><p>In Aesop’s fable of <a href="http://www.vam.ac.uk/content/articles/a/aesops-fables-the-boy-who-cried-wolf/">the boy who cried wolf</a>, the boy warns farmers of imaginary wolves threatening their flocks just to laugh at the sight of them running to the rescue for no reason. Of course, when the real wolf comes no one believes his cries – the moral of the story being that nobody believes a liar, even when he tells the truth.</p>
<p>There are some species in nature that also cry wolf, but they are much more clever about it than the boy in the fable. A <a href="http://www.sciencemag.org/lookup/doi/10.1126/science.1249723">new study</a> published in the journal Science has shown how a species of African birds called <a href="http://www.birdlife.org/datazone/speciesfactsheet.php?id=31347">fork-tailed drongos</a> will cry wolf in a bid to steal a free lunch from those they alarm. They wait for an unsuspecting <a href="http://www.birdlife.org.uk/datazone/speciesfactsheet.php?id=7970">pied babbler</a> or <a href="http://www.theguardian.com/environment/gallery/2014/apr/08/baby-meerkats-in-botswana-in-pictures">meerkat</a> to find an especially tasty morsel such as a lizard or cricket. Then the drongo screams blue murder and, as the terrified animal runs for cover, swoops in and nabs the abandoned meal.</p>
<p>This system relies on the fact that drongos also sound the alarm when predators actually are present. In fact they act as sentinels, perching high up in the trees and scanning for danger – predators such as foxes, mongooses, and especially raptors such as goshawks – and will quickly call an alarm before diving for cover themselves. Meerkats and other birds, such as babblers and starlings, also produce alarm calls, and since they share many predators each pays attention to the warnings given by the other.</p>
<p>Cross-species alarm calls use is actually quite common in the avian world because a bird that eavesdrops on others’ alarm calls could gain critical, potentially life saving information about predators. For example, members of a species I’ve worked on in North America, called <a href="http://animals.nationalgeographic.com/animals/birding/black-capped-chickadee/">chickadees</a>, are adept at spotting danger and more than 50 different species of birds are known to <a href="http://www.telegraph.co.uk/science/science-news/3352376/Nuthatches-can-speak-chickadee.html">respond to their alarms</a>. Australian <a href="http://birdlife.org.au/bird-profile/superb-fairy-wren">fairy-wrens</a> and <a href="http://birdlife.org.au/bird-profile/White-browed-Scrubwren">scrub-wrens</a> also respond to each other’s alarm calls, and <a href="https://theconversation.com/pitch-perfect-how-fairy-wrens-identify-other-species-alarm-calls-11894">recent work</a> has demonstrated that this interspecies understanding is learned.</p>
<p>This type of cross-species, or heterospecific, eavesdropping is not restricted to birds either. Several types of monkeys eavesdrop on each other’s alarm calls and birds called <a href="http://creagrus.home.montereybay.com/hornbills.html">hornbills</a> can also <a href="http://news.nationalgeographic.com/news/2004/03/0318_040313_hornbills.html">distinguish between primate alarm calls</a>. Even some species of lizard – which don’t vocalize at all – can <a href="http://www.newscientist.com/article/dn12735-eavesdropping-iguanas-heed-hawk-alarms.html">understand</a> alarm calls relevant to them.</p>
<p>Predators have, naturally, dramatic impacts on their prey, and it should not be a surprise that animals will use whatever means possible to avoid becoming something else’s lunch.</p>
<p>So, while alarm calling is common, the deceptive use of alarm calls to trick eavesdroppers is much rarer. This type of behaviour was originally proposed for mixed species bird flocks in the <a href="http://www.nytimes.com/1986/01/14/science/deceit-found-pervasive-in-the-natural-world.html">Amazon</a>, but fork-tailed drongos are probably the best example. But how do they avoid the fate of the boy who cried wolf in the fable, with other species becoming wise to their false alarms? Drongos have another trick up their sleeves: they pretend to be those other species. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/47557/original/h3ttvzb5-1398945118.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/47557/original/h3ttvzb5-1398945118.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/47557/original/h3ttvzb5-1398945118.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=896&fit=crop&dpr=1 600w, https://images.theconversation.com/files/47557/original/h3ttvzb5-1398945118.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=896&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/47557/original/h3ttvzb5-1398945118.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=896&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/47557/original/h3ttvzb5-1398945118.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1126&fit=crop&dpr=1 754w, https://images.theconversation.com/files/47557/original/h3ttvzb5-1398945118.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1126&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/47557/original/h3ttvzb5-1398945118.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">Best of friends until there’s food up for grabs.</span>
<span class="attribution"><span class="source">Tom Flowers</span></span>
</figcaption>
</figure>
<p>Watching how humans or animals react to repeated stimuli is a commonly used psychological test to ascertain whether a response is habitual or whether the response is connected in some way to the context or source of the stimuli. The boy in the fable crying wolf is eventually ignored, but a cry from someone other than the boy would generate a response, because it is the source of the cry (the boy) that is relevant, rather than the cry itself. The same principle appears in groups of animals; a drongo giving repeated false alarms might soon be ignored were it not for the fact that, as a look-out, the drongo also provides warning of real threats. By mimicking the alarm calls of other species the drongo appears even more reliable. </p>
<p>What <a href="http://www.babbler-research.com/research-projects.html">the researchers behind this study</a> observed is that drongos adjust their calling behaviour depending on their audience. They are more likely to mimic the species they are targeting – if it’s a babbler they wish to steal from they produce an imitation of the babbler’s alarm, if it is a starling, they imitate the starling.</p>
<p></p>
<p></p>
<p></p>
<p></p>
<p> </p>
<p>Drongos were more than twice as likely to mimic a target species’ alarm call during attempts to steal a free meal than that of other species, and when the researchers played back these mimiced calls they found babblers responded more strongly to a drongo mimicking them than to the drongo’s own alarm calls. This suggests that drongos associate each of the mimicked calls with a particular species, rather than simply treating their entire repertoire of alarm calls as the same and interchangeable. </p>
<p>The cunning drongo even goes one step further in this charade, keeping track of whether they have previously fooled certain individual babblers, and varying their alarm calls when attempting to fool and steal from the same individual. The researchers played back alarm calls to babblers and demonstrated that birds become habituated to false alarms, but will respond again if the type of alarm call is changed. Drongos that change their call were much more successful at getting a meal: the likelihood of stealing food from an unsuspecting babbler increased by nearly 50% compared with individuals that did not change their alarm call. </p>
<p>Taken together, this suggests these birds might understand the experience of babblers, indicative of sophisticated cognitive abilities; a very clever bird indeed.</p><img src="https://counter.theconversation.com/content/26192/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christopher N. Templeton receives funding from the Natural Environment Research Council (NERC) and the Royal Society.
</span></em></p>In Aesop’s fable of the boy who cried wolf, the boy warns farmers of imaginary wolves threatening their flocks just to laugh at the sight of them running to the rescue for no reason. Of course, when the…Christopher N Templeton, NERC Research Fellow, University of St AndrewsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/254552014-04-11T09:34:25Z2014-04-11T09:34:25ZPlant powerhouses are more than just energy producers<figure><img src="https://images.theconversation.com/files/46132/original/gcqdv5wm-1397145472.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Powerhouse and secret communicator.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/arwing3/6946034795">arwing3</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>For more than a billion years, plants have had an internal dialogue, and we are just beginning to learn the words. The unusual dialogue occurs between two compartments within plant cells – the nucleus and the chloroplast. It is a dialogue that continues today, and, according to research just published in <a href="http://dx.doi.org/10.1126/science.1250322">Science</a>, it shapes the productivity of plants.</p>
<p>All living organisms are made of cells. These cells contain many compartments, a bit like organs in an animal body. Each plant cell contains many chloroplasts, which are responsible for producing energy.</p>
<p>A billion years ago, the ancestors of chloroplasts existed as free-living individual cells, able to convert energy from light into sugar. But in a spectacular evolutionary event, these early chloroplasts were consumed by larger cells, where they eventually took up residence, supplying them with sugar. The legacy of that merger is evident around us every day in the green tissues of plants.</p>
<p>The fate of every plant cell is inextricably tied to the interaction between chloroplasts and other compartments of the plant cell. The most important of these interactions is with the nucleus.</p>
<p>The nucleus is the home of the genetic material for the plant – its genome. The genome contains all of the plant’s genes, written in DNA code. Like human beings, plants have tens of thousands of genes in the nucleus.</p>
<p>Each gene encodes a specific set of instructions – a recipe of sorts – for a particular cell component. The nucleus is like a non-circulating library for all of the plant’s genetic recipes. All the information is there, but it can’t leave the nucleus to be used elsewhere in the cell. In order to use the information in the recipe library, it has to be transcribed into a different kind of information molecule – an <a href="http://en.wikipedia.org/wiki/Messenger_RNA">RNA transcript</a>. The transcript is then transported out of the nucleus, where it is used as instructions to create a particular piece of cellular machinery.</p>
<p>Some of the genes in the nucleus are recipes for cellular machinery needed for the chloroplast to do its job – to undertake photosynthesis. It is important that the nucleus transcribes these genes in response to appropriate cues, especially daylight.</p>
<p>Light effects the transcription of one in every five plant genes. Intriguingly, some genes are transcribed based on a signal that comes from the chloroplast. The chloroplast informs the nucleus that certain genes need to be transcribed. Signalling from the chloroplast to the nucleus is called <a href="http://en.wikipedia.org/wiki/Retrograde_signaling">retrograde signalling</a>. It has <a href="http://journal.frontiersin.org/Journal/10.3389/fpls.2012.00135/full">fascinated scientists for decades</a> because the nature of the signal from the chloroplast is unknown.</p>
<p>Now this story has become even more intriguing. According to the Science paper, authored by Ezequiel Petrillo at the University of Buenos Aires and colleagues, it seems that this form of signalling from chloroplasts can do more than direct the transcription of genes – it can also direct modifications of the RNA transcribed from the genes. These transcripts are modified by <a href="http://www.dnalc.org/resources/animations/rna-splicing.html">splicing the RNA</a>, which removes bits of superfluous information from them. Without splicing, most RNAs wouldn’t be able to encode proteins.</p>
<p>Petrillo and colleagues found a transcript that is spliced in different ways depending on whether light is present or not, and showed that the switch depended on the chloroplast’s signalling. The transcript in question encodes part of the cell’s splicing machinery, so the splicing process itself is regulated by a retrograde signal. That means that the effects can be broader than simply this one protein.</p>
<p>Whatever signal the chloroplast is producing, it must be able to move not just within the cell but also throughout the plant. If they shone light on the leaves, cells in the roots contained the spliced transcript. If they shone light on roots that do not contain active chloroplasts, the root cells did not contain the spliced transcript. This implies that the signal must travel from other tissues to the roots – so that the entire plant body is informed that the leaves have perceived light.</p>
<p>Finding out what this signal is would help researchers understand more about the process and perhaps exploit it for applications such as engineering plants that work in low light. One hypothesis was that the signal could be the sugars produced by chloroplasts, but that idea was shot down. Sugar-starved plants growing in the dark failed to produce any spliced transcript, as expected. But supplying them with sugars didn’t restore the splicing.</p>
<p>The signal has to be something new. Some have suggested candidate retrograde signals involved in other aspects of <a href="http://journal.frontiersin.org/Journal/10.3389/fpls.2012.00135/full">chloroplast communication with the nucleus</a>, but we will have to wait for further studies to see if those are involved in the regulation of transcript splicing too.</p>
<p>Chloroplasts have resided in cells with a nucleus for about a billion years now. That the chloroplasts have discovered ways of communicating to the nucleus is not entirely surprising. That they communicate using a mechanism that remains a mystery is fascinating. Learning the “words” of their language, such as the retrograde signal for splicing, will provide illuminating discoveries for the coming years.</p><img src="https://counter.theconversation.com/content/25455/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Malcolm Campbell receives funding from the Natural Science and Engineering Research Council (NSERC) of Canada, and Genome Canada.</span></em></p>For more than a billion years, plants have had an internal dialogue, and we are just beginning to learn the words. The unusual dialogue occurs between two compartments within plant cells – the nucleus…Malcolm Campbell, Professor & Vice-Principal Research, University of TorontoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/252482014-04-07T05:11:01Z2014-04-07T05:11:01ZThe grizzly outlook for hunted bears in Canada<figure><img src="https://images.theconversation.com/files/45654/original/7gb46pb3-1396621631.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Had his chips?
</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-126888161/stock-photo-brown-bear-on-alaska.html?src=QAr-zv948Bdz2_q6GjZMjw-1-7">Galyna Andrushko/shutterstock</a></span></figcaption></figure><p>This month marks the <a href="http://www.ctvnews.ca/canada/british-columbia-s-controversial-spring-grizzly-bear-hunt-opens-1.1756119">re-opening</a> of the controversial trophy hunt for at-risk grizzly bears in the province of British Columbia, Canada. </p>
<p>Scrutiny of this hunt was ramped up last year with new evidence that its economic benefits are small when <a href="http://www.responsibletravel.org/projects/documents/Economic_Impact_of_Bear_Viewing_and_Bear_Hunting_in_GBR_of_BC.pdf">compared with ecotourism</a>. Add to this further research that suggests hunting management strategies <a href="http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0078041">impose considerable risks</a> to bear populations and it’s not surprising that concerns are being raised.</p>
<p>There is strong opposition from many indigenous groups, which have renewed calls for the government to respect tribal laws that ban the hunt on their <a href="http://www.theecologist.org/News/news_analysis/2271852/overkill_trophy_hunting_slams_bcs_grizzly_bears.html">traditional territories</a>. They are not alone – recent poll data suggests that 80-90% of citizens in the province, including hunters who target other species, <a href="http://d3n8a8pro7vhmx.cloudfront.net/bearsforever/pages/42/attachments/original/1378071208/V1.0_BC_Bear_Survey_-_Final_Results_-_July_28_2013_-_Backgrounder.pdf?1378071208">oppose the trophy hunt</a>. </p>
<p>Nevertheless, despite this opposition the hunt was not only re-opened but <em>expanded</em> on April 1st – what might have passed for an April Fools’ joke was instead presented as “science-based” management.</p>
<h2>Protecting against over-kill</h2>
<p>But our recent study <a href="http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0078041">casts doubt</a> on this “science-based” management. We found that between 2001-2011, human kills of grizzly bears (of which four out of every five were from trophy hunting) exceeded government limits in half of all hunted populations.</p>
<p>We also found that hunt targets were not conservative because they did not properly take into account uncertainty in bear numbers, population growth rates, or poaching rates. This uncertainty is not surprising: counting bears accurately in their remote wilderness habitats is difficult, let alone studying how quickly they reproduce and replace lost individuals.</p>
<p>To address this we described a management approach that explicitly takes uncertainty into account. To keep the probability of over-kill below 5%, targets would need to be reduced by 80%, and one third of hunted bear populations would need to be closed to hunting.</p>
<h2>Contradictions</h2>
<p>Surprisingly, shortly after this study was released, the government instead announced plans to increase the number of bears to be hunted, and to re-open the hunt in two populations that had previously been closed because of over-kills.</p>
<p>Managers <a href="http://www.thefreepress.ca/news/237171991.html">stated</a> that “because we recognise inherent uncertainty in our population and harvest rate estimates, conservative mortality targets are used”. While the government used language reminiscent of the recent study, they decided to expand the hunt, contrary to its conclusions.</p>
<p>The minister in British Columbia responsible for managing the hunt <a href="http://www.leg.bc.ca/hansard/40th2nd/20140306pm-CommitteeA-Blues.htm">came under fire</a> repeatedly in the provincial legislature for this, and also for <a href="http://www.leg.bc.ca/hansard/40th2nd/20140310pm-CommitteeA-Blues.htm">claiming in a press release</a> that sustainability of the hunt was confirmed by <a href="http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0082757">another study</a>, which was not the case. This raises the question – are “science-based” management decisions actually guided by science? </p>
<h2>Science-based management?</h2>
<p>Scientific research and enquiry is held up for external scrutiny through the peer review process. This ensures key scientific values: transparency, rationality, and reliance on rigorous evidence. Scientists have no choice about this; if they want to publish their work in a credible journal, it needs to be peer-reviewed. Work that does not stand up to scrutiny gets rejected. But there is no such requirement for most wildlife management decisions, even those claiming to be “science-based”.</p>
<p>Although scientists might spend years gathering and analysing data, packaging it into a manuscript, and revising their work in light of reviews by independent experts, politicians can make “science-based” claims without any such checks. Not surprisingly this can and does lead to decisions guided more by politics than by science. The infamous <a href="http://www.canadahistory.com/sections/eras/pcsinpower/cod_collapse.htm">collapse of the cod fishery</a> in eastern Canada in the 1980s comes to mind. And more recently, the science behind efforts to <a href="http://www.theguardian.com/environment/2014/feb/07/review-gray-wolf-endangered-species-list">remove gray wolves</a> from the US Endangered Species Act, and in the decision to <a href="http://www.bbc.co.uk/news/science-environment-26868650">cull badgers in the UK</a>, has also been questioned. </p>
<p>A <a href="http://johnreynolds.org/wp-content/uploads/2012/07/Artelle-et-al.-Science-2014.pdf">recent letter</a> in the journal Science has pointed this shortcoming in “science-based” wildlife management, and following the letters’ release, more stories of questionable science emerged. It seems examples of scientific shortcomings might be the rule, not the exception. </p>
<p>Fortunately, the well-established scientific publishing process can provide ways to improve management decisions: subjecting management decisions to the same outside scrutiny expected of scientists would be an important first step. As well as making science management more rigorous and transparent, external peer review would have the added bonus of helping to bridge the long bemoaned science-policy gap.</p><img src="https://counter.theconversation.com/content/25248/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kyle Artelle works with Raincoast Conservation Foundation and the Earth 2 Oceans department at Simon Fraser University. He receives funding from the Natural Sciences and Engineering Research Council of Canada through a Vanier Fellowship, and the Tula Foundation through the Hakai Network for Coastal Peoples and Ecosystems. He has previously received funding from the Anne Vallee Ecological Fund, the David Suzuki Foundation, the C.D. Nelson Memorial Foundation, and through an Alexander Graham Bell Canada Graduate Scholarship.</span></em></p>This month marks the re-opening of the controversial trophy hunt for at-risk grizzly bears in the province of British Columbia, Canada. Scrutiny of this hunt was ramped up last year with new evidence that…Kyle A. Artelle, Biologist with Raincoast Conservation Foundation and Researcher in Conservation Ecology, Simon Fraser UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/237472014-02-28T11:21:45Z2014-02-28T11:21:45ZFirst Americans lived on land bridge for thousands of years, genetics study suggests<figure><img src="https://images.theconversation.com/files/42754/original/m98mxmzc-1393585747.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An Inupiat Eskimo family from Alaska in 1929, whose ancestors would have crossed Beringia thousands of years previously.</span> <span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Inupiat_Family_from_Noatak,_Alaska,_1929,_Edward_S._Curtis_(restored).jpg">Edward Curtis</a></span></figcaption></figure><p>The theory that the Americas were populated by humans crossing from Siberia to Alaska across a land bridge was first proposed as far back as 1590, and has been generally accepted since the 1930s.</p>
<p>But genetic evidence shows there is no direct ancestral link between the people of ancient East Asia and modern Native Americans. A comparison of DNA from 600 modern Native Americans with ancient DNA recovered from a late Stone Age <a href="http://www.pasthorizonspr.com/index.php/archives/11/2013/siberia-america-connected-24000-year-old-malta-boy">human skeleton from Mal'ta</a> near Lake Baikal in southern Siberia shows that Native Americans diverged genetically from their Asian ancestors around 25,000 years ago, just as the last ice age was reaching its peak.</p>
<p>Based on archaeological evidence, humans did not survive the last ice age’s peak in northeastern Siberia, and yet there is no evidence they had reached Alaska or the rest of the New World either. While there is evidence to suggest northeast Siberia was inhabited during a warm period about 30,000 years ago before the last ice age peaked, after this the archaeological record goes silent, and only returns 15,000 years ago, after the last ice age ended.</p>
<p>So where did the ancestors of the Native Americans go for 15,000 years, after they split from the rest of their Asian relatives?</p>
<h2>Surviving in Beringia</h2>
<p>As <a href="http://instaar.colorado.edu/people/john-f-hoffecker/">John Hoffecker</a>, <a href="http://faculty.utah.edu/u0030839-DENNIS_H_O'ROURKE/research/index.hml">Dennis O'Rourke</a> and I argue in an article for <a href="http://www.sciencemag.org/content/343/6174/979.summary">Science</a>, the answer seems to be that they lived on the <a href="http://ows.edb.utexas.edu/site/hight-kreitman/land-bridge-theory">Bering Land Bridge</a>, the region between Siberia and Alaska that was dry land when sea levels were lower, as much of the world’s freshwater was locked up in ice, but which now lies underneath the waters of the Bering and Chukchi Seas. This <a href="http://news.illinois.edu/news/07/1025genetics.html">theory</a> has become increasingly <a href="http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0000829">supported by genetic evidence</a>.</p>
<figure> <img src="http://upload.wikimedia.org/wikipedia/commons/5/52/Beringia_land_bridge-noaagov.gif"><figcaption>Disappearing Beringia, from 21,000 years before present (BP) to today. <i>NOAA</i></figcaption></figure>
<p>The Bering Land Bridge, also known as central part of Beringia, is thought to have been up to 600 miles wide. Based on evidence from sediment cores drilled into the now submerged landscape, it seems that here and in some adjacent regions of Alaska and Siberia the landscape at the height of the last glaciation 21,000 years ago was shrub tundra – as found in Arctic Alaska today.</p>
<p>This is dominated by dwarf shrubs such as <a href="http://www.iceland-nh.net/plants/data/Salix-herbacea/salix_herbacea.html">willow</a> and birch, only a few centimetres tall. There is evidence that there may have been some stands of spruce trees in these regions too in some protected microhabitats, where temperatures were milder than the regions around. The presence of a particular group of beetle species that live in shrub tundra habitats today in Alaska, and are associated with a specific range of temperatures, also supports the idea that the area was a refuge for both flora and fauna.</p>
<p>This kind of vegetation would not have supported the large, grazing animals – woolly mammoth, woolly rhino, Pleistocene horses, camels, and bison. These animals lived on the vegetation of the steppe-tundra which dominated the interior of Alaska and the Yukon, as well as interior regions of northeast Siberia. This shrub tundra would have supported elk, perhaps some bighorn sheep, and small mammals. But it had the one resource people needed most to keep warm: wood.</p>
<p>The wood and bark of dwarf shrubs would have been used to start fires that burned large mammal bones. The fats inside these bones won’t ignite unless they are heated to high temperatures, and for that you need a woody fire. And there is evidence from archaeological sites that people burned bones as fuel – the charred remains of leg bones have been found in many ancient hearths. It is the heat from these fires that kept these intrepid hunter-gatherers alive through the bitter cold of Arctic winter nights.</p>
<h2>Escape to America</h2>
<p>The last ice age ended and the land bridge began to disappear beneath the sea, some 13,000 years ago. Global sea levels rose as the vast continental ice sheets melted, liberating billions of gallons of fresh water. As the land bridge flooded, the entire Beringian region grew more warm and moist, and the shrub tundra vegetation spread rapidly, out-competing the steppe-tundra plants that had dominated the interior lowlands of Beringia.</p>
<p>While this spelled the end of the woolly mammoths and other large grazing animals, it probably also provided the impetus for human migration. As retreating glaciers opened new routes into the continent, humans travelled first into the Alaskan interior and the Yukon, and ultimately south out of the Arctic region and toward the temperate regions of the Americas. The first definitive archaeological evidence we have for the presence of people beyond Beringia and interior Alaska comes from this time, about 13,000 years ago.</p>
<p>These people are called <a href="http://www.nichbelize.org/ia-archaeology/paleo-indian-period.html">Paleoindians</a> by archaeologists. The <a href="http://www.nature.com/nature/journal/v505/n7481/full/nature12736.html">genetic evidence</a> records mutations in mitochondrial DNA passed from mother to offspring that are present in today’s Native Americans but not in the Mal'ta remains. This indicates a population isolated from the Siberian mainland for thousands of years, who are the direct ancestors of nearly all of the Native American tribes in both North and South America – the original “first peoples”.</p>
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<p><em>For more commentaries written by academic experts, like The Conversation’s <a href="http://bit.ly/TCUKfacebook">Facebook page</a>. Or follow us on <a href="http://bit.ly/TCUKtwitter">Twitter</a> for updates throughout the day.</em></p><img src="https://counter.theconversation.com/content/23747/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Scott Armstrong Elias has received funding from the National Science Foundation of the USA to conduct research on the Bering Land Bridge,</span></em></p>The theory that the Americas were populated by humans crossing from Siberia to Alaska across a land bridge was first proposed as far back as 1590, and has been generally accepted since the 1930s. But genetic…Scott Armstrong Elias, Professor of Quaternary Science, Royal Holloway University of LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/221022014-01-28T06:33:54Z2014-01-28T06:33:54ZGreen combination helps turn wood into biofuels<figure><img src="https://images.theconversation.com/files/39912/original/64fmj7ms-1390833116.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">From tree to biofuel in few steps.</span> <span class="attribution"><span class="source">University of Wisconsin-Madison</span></span></figcaption></figure><p>Turning wood and agricultural waste into biofuels is one step closer to being a truly green process, according to a recently published study in the journal <a href="https://www.sciencemag.org/content/343/6168/277.abstract">Science</a>. James Dumesic of the University of Wisconsin-Madison and colleagues report a new method of extracting energy from any type of organic material, and they achieve this without using large amounts of acid or costly chemicals. </p>
<p><a href="https://theconversation.com/explainer-what-are-biofuels-12907">Biofuels</a> are obtained from the carbon present in plants. In contrast to fossil fuels, which take millions of years to form, plants are can be replenished quickly. They are also seen to be carbon neutral, because the carbon they release when burnt has been offset by the amount they absorbed whilst growing. </p>
<p>First-generation bioethanol, a common type of biofuel, is made from the starch and sugars present in corn or sugarcane. These two components can be readily transformed into fuel by microbes. But given that these crops can be used for food too, the United Nations <a href="https://theconversation.com/food-first-fuel-second-is-the-uns-message-on-biofuels-15705">found</a> that using them for making fuel is having a negative effect on the world’s food supply.</p>
<p>To avoid this problem, <a href="https://theconversation.com/explainer-the-evolution-of-biofuels-3180">second-generation biofuels</a> are being sought from plants that can be grown on land not suited for food production. But the problem with these crops is that most of their carbon is trapped in cellulose, a polymer which is resistant to fermentation and that has to be broken down into smaller sugar units that are soluble in water.</p>
<p>Producing biofuels is a four-step process: acquiring the biomass, breaking it down to individual sugars, fermenting the sugars using microbes into desired biofuel and separating all the components to make the fuel usable. Each step can be improved to make the process more effective. Dumesic’s method targets the second step, which has so far proved to be harder to optimise.</p>
<p>So far the process of deconstructing cellulose has required toxic chemicals and a lot of energy. Dumesic’s team make that process easier by using the chemical gamma-valerolactone (GVL), which can be easily recovered at the end, making the process a lot greener.</p>
<p>GVL loosens the cellulose, but it doesn’t completely break it down into the component sugars. That is achieved with small quantities of acid. The second critical part in the new method is to use liquid carbon dioxide at the end of the process to separate and recycle the GVL for the precious syrup. Sugars can then be used for the microbial fermentation that converts the biomass to biofuel.</p>
<p>Other attempts to optimise the second step have involved the development of enzymes, which are proteins that do a specific task, in this case breaking down cellulose. This has been an efficient process too, and many industrial enzymes exist today. But the cost of production of enzymes can be high. In contrast, GVL is cheap.</p>
<p>“Our approach is complementary to existing methods for biomass conversion,” Jeremy Luterbacher, the study’s lead author, said. “We find that GVL acts as the ideal solvent to convert plants to sugars without the use of concentrated acids, enzymes or other expensive alternatives.” </p>
<p>Luterbacher and his colleagues predict that, because it can be recycled at low energy costs, the minimum selling price of a gallon of bioethanol can be brought down from US$3.40 to US$3.23, which may not seem like a lot but on an industrial scale 5% reduction is a significant saving.</p>
<p>“Apart from biofuels, the sugars can also be converted into other molecules usually obtained from fossil fuel sources” Luterbacher said. GVL itself can be made from the sugars too, making the whole process greener and an attractive alternative to currently used methods.</p>
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<p class="fine-print"><em><span>Luc Henry 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>Turning wood and agricultural waste into biofuels is one step closer to being a truly green process, according to a recently published study in the journal Science. James Dumesic of the University of Wisconsin-Madison…Luc Henry, Postdoctoral Fellow, EPFL – École Polytechnique Fédérale de Lausanne – Swiss Federal Institute of Technology in LausanneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/215562013-12-19T19:11:05Z2013-12-19T19:11:05ZHow birds cooperate to defeat cuckoos<figure><img src="https://images.theconversation.com/files/38233/original/vd2j76vn-1387412787.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A juvenile black-eared cuckoo being fed by an adult speckled warbler.</span> <span class="attribution"><span class="source">David Cook</span></span></figcaption></figure><p>Why help another when you can help yourself? Cooperation is very common in nearly all life, from genes and cells to humans and other animals. However understanding why can be difficult: being selfish seems more rewarding. In a new study published in <a href="http://dx.doi.org/10.1126/science.1240039">Science</a>, we investigated whether the evolution of cooperative breeding in birds could be linked to defending their nests.</p>
<p>Cooperative breeding is when three or more individuals contribute to the care of young. While this happens in many animals, it is the social system of <a href="http://rspb.royalsocietypublishing.org/content/273/1592/1375.short">approximately 9% of birds</a>, and is particularly prevalent in <a href="http://www.sciencedirect.com/science/article/pii/S0960982210015861">sub-Saharan Africa and Australasia</a>. </p>
<p>However, understanding why evolution drove such behaviour remains controversial. Some studies have linked its occurrence with <a href="http://www.sciencedirect.com/science/article/pii/S0960982210015861">variable and unpredictable</a> environmental conditions, while others have linked it to <a href="http://www.jstor.org/discover/10.2307/2460654?uid=3737536&uid=2129&uid=2&uid=70&uid=4&sid=21103132982391">stable and predictable conditions</a>. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/38006/original/6tzkrfhf-1387267152.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/38006/original/6tzkrfhf-1387267152.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/38006/original/6tzkrfhf-1387267152.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1485&fit=crop&dpr=1 600w, https://images.theconversation.com/files/38006/original/6tzkrfhf-1387267152.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1485&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/38006/original/6tzkrfhf-1387267152.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1485&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/38006/original/6tzkrfhf-1387267152.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1867&fit=crop&dpr=1 754w, https://images.theconversation.com/files/38006/original/6tzkrfhf-1387267152.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1867&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/38006/original/6tzkrfhf-1387267152.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1867&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Three cooperatively breeding superb fairy-wrens.</span>
<span class="attribution"><span class="source">Alecia Carter</span></span>
</figcaption>
</figure>
<p>We thought it might have something to do with defending their nests against brood parasitism, a behaviour where other birds to raise your babies. Brood parasitism is most easily recognisable among cuckoo birds, who never build their own nest or raise their own offspring. Instead they lay their eggs in the nests of birds from other species, and leave the substantial task of raising their chick to the unsuspecting host. </p>
<p>We suspected that if larger cooperative breeding groups are better able to defend their nests against brood parasitism, these breeding systems may be evolutionarily linked.</p>
<p>To investigate this question we first looked at the global distribution of cooperative breeding and brood parasitic bird species. If these breeding systems are linked, brood parasites and cooperative breeders should live in the same areas.</p>
<p>We found that brood parasites and cooperative breeders are found in the same places around the world, with particularly high concentrations in sub-Saharan Africa and Australasia. So next we looked at whether hosts of brood parasites are more likely to be cooperative breeders. We conducted analyses focusing on Australia and South Africa as the species in these areas are particularly well understood. Again, we found that hosts of brood parasites were more likely to be cooperative breeders than non-host species in both these areas. </p>
<p>However, these analyses do not tell us whether cooperative breeders are being chosen by brood parasites, or if brood parasitism is driving species to become cooperative. To gain insight into this question, we conducted a detailed study of the superb fairy-wren (<em>Malurus cyaneus</em>). This bird cooperatively breeds, and is also a host of the Horsfield’s bronze-cuckoo (<em>Chalcites basalis</em>) in South-Eastern Australia.</p>
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<a href="https://images.theconversation.com/files/38008/original/6h237x6t-1387267432.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/38008/original/6h237x6t-1387267432.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/38008/original/6h237x6t-1387267432.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=232&fit=crop&dpr=1 600w, https://images.theconversation.com/files/38008/original/6h237x6t-1387267432.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=232&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/38008/original/6h237x6t-1387267432.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=232&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/38008/original/6h237x6t-1387267432.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=292&fit=crop&dpr=1 754w, https://images.theconversation.com/files/38008/original/6h237x6t-1387267432.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=292&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/38008/original/6h237x6t-1387267432.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=292&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Two male superb fairy-wrens.</span>
<span class="attribution"><span class="source">William Feeney</span></span>
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<p>First, we used data from Naomi Langmore, Robert Heinsohn and Rebecca Kilner’s long term study in Canberra to investigate whether cuckoos gained an advantage by parasitising larger groups. We found that they did; cuckoos raised by larger groups suffered lower predation and grew faster than those raised by smaller groups.</p>
<p>Next, we used long term data from the site in Canberra, as well as Raoul Mulder and Michelle Hall’s site in Lara (near Melbourne) to investigate whether larger groups of fairy-wrens were parasitised less than smaller groups. We found that larger groups were in fact parasitised less than smaller groups.</p>
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<span class="caption">An unfortunate reed warbler feeding a cuckoo chick.</span>
<span class="attribution"><span class="source">Per Harald Olsen</span></span>
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<p>Despite benefits to cuckoos from exploiting larger groups, this exploitation was not occurring in nature. To investigate why this may be, we conducted a series of experiments. We presented fairy-wren groups with model cuckoos and a variety of other nest threats. We found that they have a cuckoo-specific alarm call that functions to rapidly attract other fairy-wrens to help attack the cuckoo. We also found that larger groups are more aggressive and more vigilant around their nest.</p>
<p>I have written previously about another study in which we found that this alarm call can be <a href="https://theconversation.com/superb-fairy-wrens-recognise-an-adult-cuckoo-with-some-help-15124">rapidly learned</a> by watching the response of more knowledgeable fairy-wrens. Interestingly, the few other studies (such as those of <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1474-919X.2006.00633.x/abstract;jsessionid=E10FFFA122C9B9CEDE39BE2ED345CC0E.f04t02?deniedAccessCustomisedMessage=&userIsAuthenticated=false">colonial breeding southern red bishops, <em>Euplectes orix</em></a> and <a href="http://www.sciencedirect.com/science/article/pii/S0003347209001055">cooperative breeding carrion crows, <em>Corvus corone corone</em></a>) that have investigated this behaviour have also found larger groups of birds are better able to defend their nests.</p>
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<figcaption><span class="caption">Our study shows brood parasitism and cooperative breeding in birds are evolutionarily linked breeding systems, through a two-way process; brood parasitism is driving birds to become cooperative, and cooperation makes them better parents for brood parasite chicks. We suggest that if a cooperative breeding species becomes a host of a brood parasite, it should stay cooperative.
It is very interesting to think that interactions between two species may have the evolutionary potential to influence broad ecological patterns such as the global distribution of cooperation.</span></figcaption>
</figure><img src="https://counter.theconversation.com/content/21556/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>William Feeney receives funding from Australian Geographic and the Canberra Bird Conservation Fund.</span></em></p><p class="fine-print"><em><span>Naomi Langmore 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>Why help another when you can help yourself? Cooperation is very common in nearly all life, from genes and cells to humans and other animals. However understanding why can be difficult: being selfish seems…William Feeney, Australian National UniversityNaomi Langmore, Research Fellow, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/215472013-12-18T14:11:38Z2013-12-18T14:11:38ZAll those likes and upvotes are bad news for democracy<figure><img src="https://images.theconversation.com/files/38176/original/qghvbbwt-1387367132.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Clint Eastwood and his empty chair don't let facts get in the way of a good narrative.</span> <span class="attribution"><span class="source">Lynne Sladky/AP/Press Association Images</span></span></figcaption></figure><p>Human beings have long been easily influenced by the opinions of others but the social media networks that have come to dominate our lives may be making this “social proof” a problem.</p>
<p>A recent study in the journal <a href="http://www.sciencemag.org/content/341/6146/647.abstract">Science</a>, describing a randomised experiment on a social news aggregator platform, is testament to this phenomenon. The platform was set up to be similar to crowd-based sites such as Reddit and Digg, where content is displayed according to whether users vote it “up” or “down”. The researchers found that earlier ratings strongly affected future rating behaviour.</p>
<p>The study involved monitoring 101,281 comments made by users over a five-month period. These were viewed more than 10 million times and rated 308,515 times. In collaboration with the service, the researchers had rigged the setup in such a way that whenever a user left a comment it was automatically rendered with either a positive upvote, a negative downvote or no vote at all, for control.</p>
<p>They found that if a comment was given just a single upvote before publication, the likelihood of it receiving another upvote when the first user saw it was 32% higher than for the control group.</p>
<p>Overall, the comments that received an initial upvote came out with an overall rating of 25% higher than the control group, showing popularity really does breed popularity.</p>
<p>The researchers suggest results like these should make us think about the potentially dramatic consequences of the collective judgement phenomenon if it has spread to markets, politics or our health.</p>
<h2>Upvoting the vote</h2>
<p>It’s hardly news that we are susceptible to social information phenomena like herding, the lemming effect, cascades, bystander-effects and group-thinking. But as technology permeates every aspect of our lives, it has amplified the way in which social information processes distort truth, making us more vulnerable to err than ever and on a much larger scale.</p>
<p>The abundance of information driven by the internet has allowed us to increasingly side-step old methods of gathering the information we need, which seem cumbersome and time consuming now we can get what we need at the click of a button. This also means, however, that we are offered tempting avenues for by-passing traditional gate-keepers of correct information. Honestly, how many of us don’t just rely on what the internet says about some government ruling rather than looking at the original document?</p>
<p>Relying more and more on social media, crowd-based opinion generators and other online “democratic” rating, comment or information acquisition systems not only makes such side-tracking possible and more likely to occur; it also increases the numerical reach of the spreading of false beliefs, be that intentional or not. This is known as an <a href="http://onlinelibrary.wiley.com/doi/10.1111/meta.12028/abstract">infostorm</a>.</p>
<h2>In the eye of the infostorm</h2>
<p>Infostorms may be generating a new type of politics: the post-factual democracy. Facts are replaced by opportune narratives and the definition of a good story is one that has gone viral. Politics is simply about maximising voter support.</p>
<p>The American presidential election of 2012 presented some striking examples of this new beast rearing its head. On August 29 2012, the Republican candidate for the vice presidency, Paul Ryan, made a speech that was later summed up by Fox News characterised in three words: “<a href="http://www.foxnews.com/opinion/2012/08/30/paul-ryans-speech-in-three-words/">dazzling, deceiving, distracting</a>”. According to the news outlet, Ryan’s address was “an apparent attempt to set the world record for the greatest number of blatant lies and misrepresentations slipped into a single political speech.”</p>
<p>These included trying to blame the Obama administration for the downgrading of the US credit rating instead of the Republicans, who had played their own part when they threatened not to raise the debt ceiling. He likewise tried to pin the closing of a <a href="http://blogs.detroitnews.com/politics/2012/08/23/payne-ryan-obama-and-the-promise-of-janesville/">General Motors factory plant in Janesville</a>, Wisconsin on Obama while the plant was actually shut down under George W Bush.</p>
<p>During the election, the Democrats also tried moves that were <a href="Obama%20video%20hits%20Romney%20on%20offshore%20accounts">perpendicular to the narrow track of truth</a>, when they hit out at Mitt Romney over off-shore accounts.</p>
<p>There are quite a few narratives like this out there and they can be very advantageous for a certain political agenda if they can be made to stick and become robust. The internet, and social media in particular, are excellent mediums for padding stories through “likes”, upvotes, comments, reads, threads and views. Over a relatively short period of time, this padding can turn into social proof and cause the narrative to go viral.</p>
<p>But what is viral is not necessarily true, and what is true is not necessarily viral. Maximising votes does not require facts, but then again voter maximisation does not add up to robust democracy. If democracy doesn’t have access to reliable sources of information and instead relies on narratives and social influence then there is no way of distinguishing between junk evidence and facts. Without the ability to make this distinction we may be welcoming the post-factual democracy. Not a pretty picture.</p><img src="https://counter.theconversation.com/content/21547/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vincent F Hendricks 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>Human beings have long been easily influenced by the opinions of others but the social media networks that have come to dominate our lives may be making this “social proof” a problem. A recent study in…Vincent F Hendricks, Professor of Formal Philosophy, University of CopenhagenLicensed as Creative Commons – attribution, no derivatives.