Scientists Take Global Warming's Temperature

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  By how many degrees would the average temperature of the Earth rise if carbon dioxide levels doubled? Scientists have been pursuing an accurate estimate of this figure since the late 19th century—it’s the “holy grail of climate science,” writes Justin Gillis in
  <em>
   The New York Times.
  </em>
  Most experts believe that this “climate sensitivity” figure lies somewhere just above five degrees Fahrenheit.
 </p>
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   That may not sound like a particularly scary number to many people — after all, we experience temperature variations of 20 or 30 degrees in a single day. But as an average for the entire planet, five degrees is a huge number.
  </p>
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   The ocean, covering 70 percent of the surface, helps bring down the average, but the warming is expected to be higher over land, causing weather extremes like heat waves and torrential rains. And the poles will warm even more, so that the increase in the Arctic could exceed 10 or 15 degrees Fahrenheit. That could cause substantial melting of the polar ice sheets, ultimately flooding the world’s major coastal cities.
  </p>
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  Some recent studies, though, have proposed estimates below four degrees, stirring climate change skeptics and making some wonder if the future might look better than expected. But the well-regarded climate scientist James Annan warns against dismissing the threat of global warming. Gillis concludes:
 </p>
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   Even if climate sensitivity turns out to be on the low end of the range, total emissions may wind up being so excessive as to drive the earth toward dangerous temperature increases.
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   So if the recent science stands up to critical examination, it could indeed turn into a ray of hope — but only if it is then followed by a broad new push to get the combustion of fossil fuels under control.
  </p>
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  Alternatively, we might be able to put excessive carbon dioxide
  <a href="http://www.pbs.org/wgbh/nova/tech/carbon-sink.html" title="into storage.">
   into storage
  </a>
  .
 </p>
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Electric Shocks to Brain Could Improve Math Skills

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  Oxford University researchers found that students were better number-crunchers after a five-day course of brain stimulation. Here’s Ian Sample writing for Guardian Science:
 </p>
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<p>
   If future studies prove that it works – and is safe – the cheap and non-invasive procedure might be used routinely to boost the cognitive power of those who fall behind in maths, the scientists said. Researchers led by Roi Cohen Kadosh zapped students’ brains with a technique called transcranial random noise stimulation (TRNS) while they performed simple calculations, or tried to remember mathematical facts by rote learning.
  </p>
<p>
   In the study published in
   <a href="http://dx.doi.org/10.1016/j.cub.2013.04.045" title="">
    Current Biology
   </a>
   , 25 students had electrical pulses fired across their brains, while 26 others had a sham treatment, in which they thought they had brain stimulation, but the equipment was turned off.
  </p>
<p>
   In tests afterwards, the students who had their brains stimulated solved maths puzzles 27% faster than the control group, suggesting that their brains were working more efficiently.
  </p>
</blockquote>
<p>
  Some scientists doubt the claim’s validity, primarily because the study’s sample size was so small. Widespread implementation of this practice could also have ethical ramifications. Listen to this NOVA
  <a href="http://www.pbs.org/wgbh/nova/body/boost-kids-brainpower.html" title="radio story">
   radio story
  </a>
  (co-produced with PRI’s The World) to learn more.
 </p>
</section>

How to Grow a Green Roof

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  Green rooftops aren’t just verdant escapes for urban dwellers. For the past two years, New York City
  <a href="http://www.nyc.gov/html/planyc2030/html/home/home.shtml" target="_blank">
   Mayor Michael Bloomberg’s PlaNYC initiative
  </a>
  has offered tax abatements for green roof construction projects, which help stabilize building temperatures and manage stormwater runoff. Many of these rooftops are populated with sedum, a plant that’s resilient to wind and UV rays, but, unfortunately, can sometimes make buildings hotter by absorbing heat rather than reflecting it. So what’s a good alternative? The answer might lie in the soil—not the plants themselves. Here’s Amy Kraft writing for Scientific American:
 </p>
<blockquote>
<p>
   Krista McGuire has taken sedum’s inadequacy as a challenge. The assistant professor of biological sciences at Barnard College wanted to see if a variety of native plants could survive on green roofs and how well they would deliver the desired benefits. Since 2010, the year Bloomberg announced his green roof initiative, McGuire has been comparing soil samples from 10 roofs planted with native vegetation with soil from five city parks spanning New York’s five boroughs, seeking to identify the microbial communities that thrive on green roofs to better to understand how healthy rooftop ecosystems sustain themselves.
  </p>
<p>
   Her study,
   <a href="http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0058020" target="_blank">
    published in
    <em>
     PLoS ONE
    </em>
</a>
   last April,
   <strong>
</strong>
   found that green roofs have distinct fungal communities that help plants to thrive in harsh, polluted environments and filter heavy metals. On average, 109 different types of fungi were present on each roof including
   <em>
    Pseudallescheria fimeti
   </em>
   , a fungus that grows in polluted soils and human-dominated environments. Rooftop soil also contained fungi from the genus
   <em>
    Peyronellaea,
   </em>
   which live in the tissues of plants to help them take in nutrients.
  </p>
</blockquote>
<p>
  Her study might be a step in right direction:
 </p>
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<p>
   “In the long term, this information may help individuals decide which types of soil microbes to amend on their green roofs, so that they can maximize plant survival and minimize management,” she says.
  </p>
</blockquote>
<p>
  This discovery is a variation on
  <a href="http://www.pbs.org/wgbh/nova/next/nature/fungal-network-helps-plants-communicate/" title="last week's">
   last week’s
  </a>
  ; a study published in Ecology Letters found that subterranean fungal networks help plants warn each other against impending aphid attacks.
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Some astrophysicists propose that the universe was formed by a collapsing 4D star.

Collapsing 4D Star Could Have Spawned Universe

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</p>
<p>
 There could be a gaping hole in the Big Bang theory. Or rather, a giant, colossal black-hole caused by the collapse of a four-dimensional star.
</p>
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<p>
 One of the main problems with the Big Bang is that the temperature of the universe is nearly uniform. If a “big bang” event
 <i>
  had
 </i>
 created the universe, then according to some explanations, there hasn’t been enough time between then and now for it to have reached that temperature equilibrium. Here’s Zeeya Merali writing for Nature News:
</p>
<p>
 To most cosmologists, the most plausible explanation for that uniformity is that, soon after the beginning of time, some unknown form of energy made the young Universe inflate at a rate that was faster than the speed of light. That way, a small patch with roughly uniform temperature would have stretched into the vast cosmos we see today.
</p>
</blockquote>
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<p>
 But the Big Bang, as it’s envisioned, was so chaotic that few people had any idea what or from where that initial homogenous patch could have come from.
</p>
<p>
 So Canadian astrophysicist Niayesh Afshordi and his colleagues have turned to an idea first proposed 13 years ago. In that model, our 3D universe is merely a membrane—also known as a brane—floating through a 4D “bulk universe":
</p>
<blockquote>
<p>
 Ashfordi’s team realized that if the bulk universe contained its own four-dimensional (4D) stars, some of them could collapse, forming 4D black holes in the same way that massive stars in our Universe do: they explode as supernovae, violently ejecting their outer layers, while their inner layers collapse into a black hole.
</p>
<p>
 In our Universe, a black hole is bounded by a spherical surface called an event horizon. Whereas in ordinary three-dimensional space it takes a two-dimensional object (a surface) to create a boundary inside a black hole, in the bulk universe the event horizon of a 4D black hole would be a 3D object — a shape called a hypersphere. When Afshordi’s team modelled the death of a 4D star, they found that the ejected material would form a 3D brane surrounding that 3D event horizon, and slowly expand.
</p>
</blockquote>
<p>
 Afshordi’s team believes that the universe—its stars, nebulae, planets, even us—might be that very membrane, and that its inflation might be triggered by motion through a “higher-dimensional reality.” In other words, we might be living in a brane around the event horizon of a collapsed hyperdimensional star that gave birth to the universe.
</p>
<p>
 It’s a bold claim—but one that solves a handful of problems in fundamental physics. Read Merali’s article for more details, and watch NOVA’s “Origins: Back to the Beginning” to learn more about other theories behind the creation of the universe:
</p>
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<p>
 Illustration by NASA
</p>

<p>We might be living in a brane around an event horizon of a collapsed hyperdimensional star that gave birth to the universe.</p>

3D Printed Soft Robots Could Ease Pain of Surgery

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  Surgery is a risky and brutal business. Even today’s most advanced medical technology—surgical robots—involves the touch of cold, unyielding metal to soft, delicate flesh. With all of those complications, surgery today can still be a precarious procedure. But soft robots
  <a href="http://www.gizmag.com/camouflage-robot-harvard/23749/" title="first created">
   first created
  </a>
  by Harvard University scientists might provide some relief.
 </p>
<p>
  The robots’ ability to maneuver through small spaces and
  <a href="http://www.youtube.com/watch?v=LpOl_pEmRqs" title="camouflage themselves">
   camouflage themselves
  </a>
  like
  <a href="http://www.pbs.org/wgbh/nova/nature/kings-of-camouflage.html" title="cuttlefish">
   cuttlefish
  </a>
  do initially caught the attention of the military. But now these squishy creations are being re-imagined as biomedical tools. Here’s Larry Greenemeier writing for Scientific American:
 </p>
<blockquote>
<p>
   Hard robots require a sophisticated feedback mechanism to help them determine how much force to apply during surgery so they do not damage our delicate tissues and organs. Soft robots could take advantage of their rubbery appendages to reduce the likelihood of surgical damage, says Carl Vause, CEO of Soft Robotics. “Specifically, with medical devices, [you would be] allowing a robotic instrument to get into a small space, be reconfigurable in that space and do it in a way that’s tissue compliant.” Another advantage: Soft robots can be 3-D printed in a day or two from silicone and other materials that cost about $20.
  </p>
</blockquote>
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/soft-robot.width-990_wsY6yJA.jpg"/>
<figcaption>This glowing robot might also be the surgical tool of the future.
        
    </figcaption>
</figure>
<p>
  Robotic surgery has prompted
  <a href="http://well.blogs.nytimes.com/2013/09/09/new-concerns-on-robotic-surgeries/" title="some concern">
   some concern
  </a>
  in the recent past. The most well-known robot surgical system, known as da Vinci, is a $2 million endeavor that allows surgeons to manipulate laparoscopic instruments and an endoscopic camera attached to four robotic arms. But da Vinci significantly ups the cost of surgery and has also led to several lawsuits due to reports of sepsis, punctured blood vessels, and more.
 </p>
<blockquote>
<p>
   It will be some time before soft robots are capable of anything nearly as sophisticated as da Vinci, but there is a lot of interest in how this emerging technology could be used in the medical field—either on its own or combined with a surgical system like da Vinci.
  </p>
</blockquote>
<p>
  Experts are also interested in how soft robots could aid in prosthetics. Discover how scientists and engineers are
  <a href="http://www.pbs.org/wgbh/nova/next/tech/prospects-for-prostheses/">
   adding intelligence and flexibility into advanced prostheses
  </a>
  .
 </p>
<p>
  To learn more about one of the critters that inspired soft robots, watch “Kings of Camouflage” below and tune in to NOVA’s “
  <a href="http://www.pbs.org/wgbh/nova/tech/making-more-stuff.html#making-stuff-wilder" title="Making Stuff: Wilder">
   Making Stuff: Wilder
  </a>
  ,” airing October 23 at 9/8c on PBS.
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<p>
 Photo courtesy
 <a href="http://www.darpa.mil/NewsEvents/Releases/2012/08/16a.aspx">
  DARPA
 </a>
</p>

For Better Recovery from Surgery, Tap Into Music's Rhythms

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<p>
  What if you could improve the outcome of an open-heart surgery simply by pressing “play?”
 </p>
<p>
  Doctors, psychologists, and other scientists have been using music therapy for years, treating a number of diseases like dementia, schizophrenia, Alzheimer’s, Parkinson’s, and cerebral ischemia. Even for people without those diseases, music has positive psychological and emotional affects. A study last year even demonstrated that listening to
  <a href="http://www.psmag.com/culture-society/struggling-to-reconcile-conflicting-beliefs-listen-to-mozart-47766/" title="Mozart could help resolve cognitive dissonance">
   Mozart could help people resolve cognitive dissonance
  </a>
  .
 </p>
<p>
  Now, researchers in Tokyo might have evidence that music really can make us feel better physically, not just mentally or emotionally. They serenaded a group of mice which were undergoing organ transplants with varying types of music—from Verdi’s to Mozart and even “The Best of Enya.” The results were promising. Here’s Maria Konnikova writing for The New Yorker:
 </p>
<blockquote>
<p>
   At Teikyo University, Masanori Niimi and his colleagues began to notice differences between the groups as the mice recovered: the mice placed in the silent or the single-frequency rooms suffered from acute graft rejection, as their immune systems rejected the foreign cells from the transplants. Those who had been listening to either Verdi or Mozart showed significantly improved survival outcomes, living an average of twenty days longer.
  </p>
</blockquote>
<p>
  Unfortunately, the mice who listened to Enya didn’t do as well, living an average of just four days longer than mice exposed to the flat tone or nothing at all.
 </p>
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<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/baby-headphones-cropped2.width-990_cm1bp3j.jpg"/>
<figcaption>Listening to music could help patients recover from complex surgeries.
        
    </figcaption>
</figure>
<p>
  Of course, any study that involves mice is subject to further scrutiny, since what works in mice might not work well in humans. World cultures may be attuned to music differently, too. But the key point is that rhythm appears to have a physiological and biological basis. The human auditory cortex particularly adept in its ability to differentiate between frequencies of sound:
 </p>
<blockquote>
<p>
   In fact, single neurons
   <a href="http://www.ncbi.nlm.nih.gov/pubmed/18185589?dopt=Abstract">
    can adjust
   </a>
   to barely noticeable frequency shifts at a level that exceeds almost all other mammals (bats are the exception). Music with a four-four tempo, which corresponds closely to a normal heart rate,
   <a href="http://www.ncbi.nlm.nih.gov/pubmed/260788">
    can help
   </a>
   regulate heart rate, circulation, and breathing. Lyrical melodies and rhythms of about sixty to eighty beats a minute, which is common to much classical music and bird song,
   <a href="http://www.ncbi.nlm.nih.gov/pubmed/18298503">
    can stimulate
   </a>
   relaxation and alpha brain waves, a type of pattern associated with wakeful relaxation. Yet music that departs from either of those tempos confers none of the benefits.
  </p>
</blockquote>
<p>
  Presumably, then, implementation of the right kind of music could help patients recover from a variety of procedures. Other scientists have even studied the effect of music on our sympathetic nervous system, metabolism, and even immune system. Perhaps someday doctors may prescribe a soundtrack to our surgery specially tuned to our biorhythms, making a speedy recovery not just dependent on medicine and rest.
 </p>
</section>
<p>
 Photo Credit: Flickr/Patricil (CC BY-NC-SA 2.0)
</p>

Why Naked Mole Rats Don't Get Cancer

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  When a group of researchers at the University of Rochester in New York tried growing skin cells from naked mole rats in lab flasks, they noticed that the fluid the cells were growing in became thick and syrupy. After some investigation, they discovered that the cells, like other cells of mammalian connective tissue, were secreting a sugar called hyaluronan, except the naked mole version was five times bigger. Andrei Seluanov, who led the study, believes that larger hyaluronan can trap potential cancer cells and prevent them from growing into tumors. Writes Ed Yong for Not Exactly Rocket Science:
 </p>
<blockquote>
<p>
   But it also allows cells to stop each other from growing if they become too crowded. This is called ‘
   <a href="http://www.ncbi.nlm.nih.gov/pubmed/19858485">
    contact inhibition
   </a>
   ’—it’s why healthy cells form a flat layer if they’re grown in a dish but cancerous ones pile on top of each other.
  </p>
<p>
<a href="http://www.nature.com/news/blind-mole-rats-may-hold-key-to-cancer-1.11741">
    Based on an earlier study
   </a>
   , Seluanov’s team suspected that naked mole rat cells are protected against cancer because they’re especially sensitive to contact inhibition. Now, they’ve shown that large hyaluronan is responsible. The rodents’ cells are very receptive to the sugar; as they get close, hyaluronan sticks to their surface and triggers a genetic programme that stops them from growing.
  </p>
</blockquote>
<p>
  The team switched on cancer genes in naked mole rat cells and transplanted them into mice. No cancer. But when they reduced the amount of hyaluronan created by the naked mole rat cells in the mice, tumors formed.
 </p>
</section>

Allison Eck

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