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<p>These molecules, designed to block immune cells from reacting to peanuts, could someday protect patients from the dangers of accidental exposure.</p>

Peanut Allergies are on the Rise. This Chemical Compound Could Prevent Life-Threatening Reactions.

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<p>Seven teeth, five hand and foot bones, and a partial femur point to a previously unknown population of early humans. Time will tell if it was truly a distinct lineage.</p>

50,000-Year-Old Fossils in the Philippines Hint at a New Species of Early Human

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<p>There’s water locked in lunar soil—and meteor showers have been knocking it out into space for billions of years.</p>

Meteoroids Pelting the Moon Reveal Water Trapped in Its Soil

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<p>NOVA Next is NOVA’s award-winning digital publication that provides answers from the cutting edge of science and technology. Launched in 2012, we feature in-depth articles and commentaries from some of the most respected journalists, scientists, and engineers. NOVA Next explores the ideas that are changing the future, from the frontiers of synthetic biology to the politics of personalized medicine.</p><p>Let us know what you think. We’re listening on <a href="http://www.facebook.com/NOVAonline">Facebook</a>, <a href="http://twitter.com/novapbs">Twitter</a>, and email.</p><p>If you’re a journalist and have an idea for a story, send it our way.</p>

NOVA Next is NOVA’s award-winning digital publication that provides answers from the cutting edge of science and technology.

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<p>NOVA Next is NOVA’s award-winning digital publication that provides answers from the cutting edge of science and technology.</p>

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      <div class="rich-text"><p>The <a href="https://www.pbs.org/wgbh/nova/video/saving-the-dead-sea/">Dead Sea</a> isn’t as dead as you might think. But in a lake where a few gulps of water can <a href="https://www.annemergmed.com/article/S0196-0644(89)80112-X/pdf">poison</a> a human body, what little life there is has to go to some pretty gnarly extremes to get by.</p><p>Microbes, however, have no trouble getting creative—and maybe a little macabre, according to a recent <a href="https://pubs.geoscienceworld.org/gsa/geology/article/569566/Recycling-of-archaeal-biomass-as-a-new-strategy">study</a> published in the journal <i>Geology</i>. Starved of proper sustenance, ancient single-celled residents of the Dead Sea might have consumed the corpses of other types of microbes to survive.</p><p>And munching on the bodies of fallen brethren might have served up a double dose of success in this inhospitably salty lake: In addition to supplying convenient food, the dead might have also indirectly gifted grave-robbing microbes with water.</p><p>The findings, which catalog the habits of bacteria that lived more than 100,000 years ago, don’t necessarily hold true in modern times. But they showcase the remarkable resilience of creatures weathering conditions possibly even more unforgiving than those of today’s Dead Sea—and might even inform the ongoing search for extraterrestrial life.</p><p>“This is yet another example of how extraordinarily innovative microbes are,” says <a href="https://nai.nasa.gov/directory/voytek-mary/">Mary Voytek</a>, an astrobiologist and microbial ecologist at NASA who was not involved in the study. “It’s a unique, clever solution to what organisms typically do, which is come up with ways to access the things they need.”</p></div>
  

  
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      <div class="rich-text"><p>By weight, ocean water is about 3.5 percent salt. Multiply that by 10, and you’ve got the suffocating salinity of the Dead Sea. “In this environment, the high salinity and lack of food are pretty extreme,” says <a href="https://www.usgs.gov/staff-profiles/joann-holloway?qt-staff_profile_science_products=0#qt-staff_profile_science_products">JoAnn Holloway</a>, a biogeochemist at the United States Geological Survey who was not involved in the study. “That’s going to limit who can live here.”</p><p>If any critters were up to the challenge, though, it would be archaea—a group of single-celled organisms distinct from bacteria with an impressive set of survival skills. These stalwart microbes have been found lounging in many harsh environments that host little, if any, other life, from volcanic hot springs to frigid subterranean Antarctic lakes.</p><p>Salt-tolerant archaea have long been known to reside in the Dead Sea, but the details of their day-to-day dealings aren’t fully understood—especially in the lake’s turbulent past. To search for clues of ancient life in the Dead Sea, a team of scientists led by <a href="https://www.unige.ch/sciences/terre/index.php?cID=1451">Camille Thomas</a>, a geomicrobiologist at the University of Geneva, drilled more than 1,000 feet into the sediments below.</p></div>
  

  
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      <div class="rich-text"><p>Entombed in these deep layers are the remains of some of “most extreme periods of Dead Sea history,” Thomas says. At several points in the past, lake levels likely plunged below even where they are today due to the arid climate, boosting the water’s salinity and likely pushing even its most adaptable tenants to the brink.</p><p>So the researchers were thrilled when they hit pay dirt at one of these low points, enshrined at 800 feet below the current lake bed (120,000 years ago). Here, there was clear evidence of life—in the form of <a href="https://link.springer.com/referenceworkentry/10.1007%2F978-3-540-77587-4_34">wax esters</a>, a type of fatty energy-storage molecule that some cells manufacture when food gets scarce.</p><p>There was just one problem: Archaea, the Dead Sea’s dominant denizens, don’t make wax esters. But the fatty molecules the team identified still carried traces of archaeal chemicals, as if bits of these cells had been repurposed by another life form.</p><p>Thomas and his colleagues found themselves in the middle of a geological whodunnit. Only certain kinds of bacteria and eukaryotes have the ability to synthesize wax esters—but Dead Sea eukaryotes are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5635157/">very rare</a>. This left one probable, and perhaps surprising, culprit: bacteria lurking in the ancient lake’s salty sediment.</p><p>Unlike their distant archaeal cousins, which are wrapped in an impermeable sleeve of body armor, bacteria are pretty porous. This sensitivity to their surroundings has made bacteria <a href="https://www.nature.com/articles/nrmicro2939">less common</a> in the Dead Sea, especially on its hostile, dimly lit floor. But by slurping up bits of dead archaea (and likely other cell types as well) and storing them as fuel, ancient bacteria might have found a way to hack it in the lake’s briny, resource-poor brew.</p><p>This might actually be a pretty sensible way to ride out the storm, says <a href="https://www.geosc.psu.edu/academic-faculty/macalady-jennifer">Jennifer Macalady</a>, a geomicrobiologist at Pennsylvania State University who was not involved in the study. “If you put it on the menu, you would expect some of our microbial biosphere to come and get it.”</p><p>What’s more, recycling these remains might have come with a bonus benefit. The same chemical reaction that transforms fragments of deceased archaea into wax esters produces water as a byproduct—something that likely came in handy in a body of water that’s 34 percent salt. This probably would have made for an efficient way to keep from shriveling up, Thomas says.</p><p>“These findings are fascinating,” says <a href="https://www.niagara.edu/biology-faculty/faculty/607">Cassandra Marnocha</a>, an environmental microbiologist at Niagara University who was not involved in the study. “We’re finding more and more that where it’s physically plausible to find life, life finds a way.”</p>
            <figure class="richtext-image full-width"><img alt="iStock-134523912.jpg" class="richtext-image full-width" height="533" width="800"
            src="/wgbh/nova/media/images/iStock-134523912.width-800.jpg"/><figcaption><p>What is dead may never die. But it sure as heck can be recycled. Image Credit: NickolayV, iStock</p><div class="credit"><p></p></div></figcaption>
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            <p>The work is still preliminary. Though it’s definitely possible that this evolutionary fork in the road yielded a set of salt-tolerant scavengers, more research is needed to solidify the theory, Macalady says.</p><p>Part of the challenge going forward, Thomas says, is that there’s not yet evidence this scavenging behavior is still happening today. At the time, this bacterial adaptation probably arose as a last resort, when cells were out of other options, he says. When more favorable conditions came along, scavengers might have been among those that were outcompeted by better-equipped species. And because the researchers weren’t able to recover any DNA in the sediment, it remains unclear what kinds of archaea and bacteria were engaging in this recycling rendezvous.</p><p>But as the Dead Sea continues to retreat due to human activity and the changing climate, microbes might once again be forced to take drastic measures. “Today, the Dead Sea is still not at its lowest level or highest salinity,” says <a href="https://www.gfz-potsdam.de/en/staff/ina-neugebauer/">Ina Neugebauer</a>, a geologist and climatologist at the GFZ German Research Centre for Geosciences who was not involved in the study. “If the lake level goes further down...then I think this is a strategy that will also happen in the future.”</p><p>Beyond the Dead Sea, though, research like this could have implications that are quite literally out of this world. As the search for extraterrestrial life continues, studying Earth’s strangest species could continue to redefine the boundaries of existence—and the extremes to which some will go to survive.</p><p>“It’s amazing what these microbes can do, and the types of environments they can live in,” Thomas says. “They can grow over thousands of years, and eat whatever they find. It’s really another way of thinking about life.”</p><p><i>To learn more about the Dead Sea and the ongoing effort to revive and desalinate its waters, watch &quot;</i><a href="https://www.pbs.org/wgbh/nova/video/saving-the-dead-sea/"><i>Saving the Dead Sea</i></a><i>,&quot; premiering at 9 p.m. EDT/8 p.m. CDT on Wednesday, April 24 on PBS.</i></p></div>
  

  
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<p>Thousands of years ago, bacteria were faced with a Donner-Party-esque dilemma: consume the dead, or join them.</p>

Ancient Dead Sea Microbes Consumed Each Other’s Corpses to Survive





  
      <div class="rich-text"><p>With rogue asteroids and comets on the move, space can sometimes be a bit of a warzone.</p><p>Serious impacts with Earth are few and far between. But these collisions can be catastrophic (just ask a few disgruntled dinosaurs circa 66 million years ago)—and Earthlings are often caught unaware.</p></div>
  

  
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      <div class="rich-text"><p>That’s why a team of NASA astronomers has spent the past five years scouring the skies for near-Earth objects (NEOs)—asteroids and comets that orbit the Sun in our vicinity—in the hopes of potentially staving off impending doom.</p><p>“If we find an object only a few days from impact, it greatly limits our choices,” NASA astronomer Amy Mainzer <a href="https://www.eurekalert.org/pub_releases/2019-04/aps-htd041119.php">said in a statement</a>. “We&#x27;ve focused on finding NEOs when they are further away from Earth, providing the maximum amount of time and opening up a wider range of mitigation possibilities.”</p><p>The endeavor is a part of NASA’s <a href="http://wise2.ipac.caltech.edu/docs/release/neowise/">Near-Earth Object Wide-field Infrared Survey Explorer</a> (NEOWISE) mission, an <a href="https://www.nasa.gov/feature/jpl/neowise-celebrates-five-years-of-asteroid-data">Earth-orbiting satellite</a> equipped with cameras and an infrared-sensitive telescope. And the spacecraft, which isn’t limited to tracking the trajectories of asteroids, has kept itself busy: In the past half decade, it has recorded more than 95 billion measurements of asteroids, comets, stars, and galaxies, with data collection ongoing.</p></div>
  

  
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      <div class="rich-text"><p>These measurements have revealed <a href="https://www.jpl.nasa.gov/news/news.php?release=2019-069">more than 1,000 wayfaring asteroids</a> near our planet in the past half decade. None of these NEOs currently pose any threat to us here on Earth. But according to <a href="https://cneos.jpl.nasa.gov/stats/totals.html">NASA estimates</a>, about 20,000 near-Earth objects have flitted in and out of our neighborhood in recent decades—almost 900 of which were more than 3,200 feet across. And it was only six years ago that a meteor just 66 feet in diameter injured over 1,500 people when it exploded over the Russian region of Chelyabinsk.</p><p>Detecting rocky interlopers, however, is no easy task. Because NEOs are often so small and far away, they’re frustratingly hard to spot under even the best of circumstances. What’s more, under visible light, these objects can look as dark as coal or printer toner, making them hard to pick out against the black backdrop of space.</p><p>But the NEOWISE telescope has found a clever workaround—one that essentially involves it donning a set of cosmic night vision goggles. Heated by the warmth of the Sun, rocky bodies near Earth emit an infrared glow. By working in infrared, the telescope can pick up on any objects that are comin’ in hot, providing Mainzer’s team with images that reveal properties like a NEO’s size, mass, and composition. These measurements could someday help engineers calculate the <a href="https://www.space.com/stopping-earth-bound-asteroid-op-ed.html">amount of energy needed</a> for a spacecraft to “nudge” (or <a href="https://www.space.com/stopping-earth-bound-asteroid-op-ed.html">detonate</a>) a looming asteroid off an Earthbound path.</p><p>The NEOWISE spacecraft, which was initially launched for a separate mission in 2009, will eventually reach the end of its tenure when its changing orbit prevents it from acquiring high-quality data. But a plan is already in the works to succeed it with another telescope called NEOCam—a new and improved addition to the NEO suite that will purposefully be designed to peer into space for asteroids.</p><p>If funded, NEOCam will “do a much more comprehensive job of mapping asteroid locations and measuring their sizes,” Mainzer <a href="https://www.eurekalert.org/pub_releases/2019-04/aps-htd041119.php">said in the statement</a>.</p><p>NEOCam’s fate hasn’t yet been decided. For now, its predecessor remains on the frontlines of defense, and will still be actively collecting data. So for any asteroids, comets, or meteors headed our way, the message is clear: Earth has plans to take the heat—and it starts with taking note of it.</p></div>
  

  
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<p>The infrared-sensitive telescope, aboard an Earth-orbiting spacecraft, can detect near-Earth objects by sensing the heat they absorb from the Sun.</p>

How This NASA Telescope is Defending the Earth From Asteroids





  
      <div class="rich-text"><p>The ground beneath our feet is always rumbling. Even in the world’s most seismically active regions, however, most earthly shudders tend to pass unnoticed.</p><p>But now, with the help of a new computer algorithm that finds patterns in existing data, a team of researchers has expanded the number of Southern California earthquakes archived in the past decade by a factor of 10. Their final tally, <a href="https://science.sciencemag.org/cgi/doi/10.1126/science.aaw6888">published today</a> in the journal <i>Science,</i> tabulates 1.81 million events in the past decade alone, averaging out to an earthquake every 174 seconds.</p><p>Many of the new additions are seismic pipsqueaks, shaking with all the might of a quivering coffee table. But bolstering the geologic record could give scientists fresh perspectives on how earthquakes behave and interact.</p><p>“This research helps us see all the texture and details in the Earth’s crust that we weren’t able to see before,” says <a href="https://www.usgs.gov/staff-profiles/katherine-kate-scharer">Katherine Scharer</a>, a paleoseismologist at the United States Geological Survey who was not involved in the study. “We’ve just been handed a new set of tools to find out what causes big earthquakes, and how the crust responds to these changes.”</p></div>
  

  
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      <div class="rich-text"><p>Today, more than 500 different seismic monitoring stations speckle the arid landscape of Southern California, listening for shakes and trembles in the earth below. Between 2008 and 2017, this vast network detected a whopping 180,000 earthquakes rippling through the southern half of the state—some 50 events per day.</p><p>But scientists have long known that these are just the tip of the seismic iceberg.</p><p>Though high-magnitude earthquakes tend to hog the limelight, these catastrophic events are pretty uncommon compared to milder temblors. And trying to understand what’s going on in the Earth’s crust with just rare, cataclysmic events is as futile as recreating a symphony with only the clash and clang of the orchestra’s loudest cymbals.</p><p>But lower-magnitude tremors are, by nature, trickier to detect. Earthquakes operate on a logarithmic scale: Each single-digit decrease in magnitude (for instance, going from 4.0 to 3.0) corresponds to a 10-fold drop in amplitude, or ground motion, as well as a 31-fold dip in energy released. This means quakes can even run at magnitudes of 0 and below.</p><p>Seismic monitors are pretty good at picking up geologic grumbles that run above a magnitude of about 2.0 (barely enough to wobble a creaky building). Below this level, however, movements in the Earth’s crust get jumbled up with vibrations from other sources, like construction, air traffic, trains, and even the ocean. In a sense, the orchestra’s more modest melodies are still being recorded—they’re just getting drowned out by the din of a chatty crowd.</p><p>“You might think that since you don’t feel small earthquakes, they’re not very useful,” says study author <a href="https://www.lanl.gov/expertise/profiles/view/daniel-trugman">Daniel Trugman</a>, a seismologist at the Los Alamos National Laboratory. “But they really tell us a lot about the physical processes that are hidden beneath our feet.”</p>
            <figure class="richtext-image full-width"><img alt="Aerial-SanAndreas-CarrizoPlain.jpg" class="richtext-image full-width" height="741" width="800"
            src="/wgbh/nova/media/images/Aerial-SanAndreas-CarrizoPlain.width-800.jpg"/><figcaption><p>An aerial photo of California&#x27;s San Andreas Fault. Image Credit: John Wiley, Wikimedia Commons</p><div class="credit"><p></p></div></figcaption>
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            <p>To identify earthquakes masked by the cacophony, a team of seismologists led by <a href="http://www.seismolab.caltech.edu/ross_z.html">Zachary Ross</a> of Caltech decided to take a computational approach. Even minor earthquakes tend to look and behave in similar ways. And when seismic waves are picked up by monitors, they tend to leave the same telltale traces of their passing. This means earthquakes have something of a seismic fingerprint—one that could be used to tease similarly-shaped events out of noisy data.</p><p>And so the researchers trained a computer program to do just that. Using templates based on nearly 284,000 past earthquakes, their algorithm scoured 10 years of data banked by the <a href="http://www.scsn.org/">Southern California Seismic Network (SCSN)</a> for pint-sized versions of the same patterns.</p><p>Scharer compares the technique to a seismic Shazam app—one that can test a musical snippet against a database of songs, hunting for a perfect match.</p><p>With such a vast repository of seismic waves in the archives, the researchers had to wrangle about 100 terabytes of data. Even backed by the computational firepower of a giant computer cluster with 200 processing units, each iteration of the program still took weeks to run its course. “If you make one little mistake, it sets you back a month,” Trugman says.</p><p>But the effort paid off: In went the data, and out came more than 1.6 million previously undocumented earthquakes. While the original catalog was rife with gaps below magnitude 2.0, the team’s calculations show their new-and-improved version is nearly complete down to 0.3. Several quakes even registered at values close to -1—that’s “like dropping a bag of groceries on the floor,” Scharer says. “It’s amazing they were able to pull that kind of detail out.”</p></div>
  

  
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      <div class="rich-text"><p><a href="https://eileenrmartin.github.io/">Eileen Martin</a>, a computational scientist specializing in geophysics at Virginia Tech who was not involved in the study, also praises the more comprehensive catalog as impressive. “This really has a big payoff in our ability to observe the world,” she says.</p><p>And revising the overall numbers of events was just the beginning. With the subtleties of Southern California’s seismic symphony fleshed out, the team was also able to reassess the nature of past seismic events.</p><p>Earthquakes often occur in rapid succession without warning or a clear source—but in one case, the revamped archives unveiled over 30 tiny quakes preceding a recorded swarm. Seismic “breadcrumb trails” like this could someday help researchers figure out how these tectonic collusions are triggered, Scharer says.</p><p>And just as earthquakes can be preceded by subdued shaking, they can also be followed by a series of seismic waves—and these echoes can reverberate far and wide. In 2010, a magnitude 7.2 earthquake rocked Baja California, sending ripples through the landscape that were detected more than 100 miles away. But the new algorithm shows that even this was an underestimation: The initial shock’s true reach was actually closer to 200 miles.</p><p>Finally, because more seismically active spots tend to match up with fault lines, the more complete catalog also yielded clearer maps of areas like the San Jacinto Fault Zone—one of the most volatile regions in the San Andreas Fault. Delineating these types of geological boundaries could help with everything from city planning to simulating the reach of future earthquakes.</p>
            <figure class="richtext-image full-width"><img alt="Fig2.jpg" class="richtext-image full-width" height="1050" width="800"
            src="/wgbh/nova/media/images/Fig2.width-800.jpg"/><figcaption><p>The old (top) and new (bottom) catalogs of seismic events in the San Jacinto fault zone. The geology of the area is marked more clearly with updated archives. Image Credit: Courtesy of Ross et al., Science, 2019</p><div class="credit"><p></p></div></figcaption>
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            <p>Though the researchers have so far only focused their work on Southern California, there’s no reason the algorithm can’t be applied to other high-stakes places like Japan and Italy. Because of region- and instrument-specific quirks, templates generated in California probably won’t translate over to other locations. But anywhere with a good network of monitors can probably fine-tune the approach to match its own unique seismic soundtrack, Ross says.</p><p>At the same time, because the crux of the method rests on a reliable seismic fingerprint, places that lack thorough earthquake archives and instrument coverage probably can’t benefit as much from this technology, says <a href="https://www.uprm.edu/geology/faculty/">Elizabeth Vanacore</a>, a geophysicist at the University of Puerto Rico at Mayagüez who was not involved in the study.</p><p>But those newer to the seismometer scene can potentially use other computational techniques to identify earthquakes concealed in what data they have. For instance, some methods can hunt for aberrations, or unexpected jumps, in instrument readouts—which could even generate the kinds of templates necessary for the new algorithm to run, Martin says.</p><p>“We’d like to know the conditions that lead to big earthquakes and fatalities and injuries,” Scharer says. “If we can see in greater detail what’s happening in the days or months prior to a large event, maybe we can find signals that help us clue in to what’s important.”</p><p>Some of the Earth’s grandest compositions might be quiet. But that doesn’t mean they’re not worth a listen.</p></div>
  

  
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<p>A new computer algorithm adds over 1.5 million earthquakes to California’s seismic archives, giving a clear picture of past quakes.</p>

Tiny Earthquakes Rattle Southern California Every Three Minutes. Now, Scientists Have the Tools to Track Them.





  
      <div class="rich-text"><p>Someday, in the not-so-distant future, new parents might have the option of having their children’s fates forecast at birth. These prophecies, which might reveal everything from an individual’s height to their risk of developing a certain disease, will arise not through readings of tea leaves or tarot cards, but of DNA.</p><p>Although there are many ethical and scientific hurdles to overcome, the toolkit of genetic prediction continues to grow. The latest addition? A <a href="https://www.cell.com/cell/fulltext/S0092-8674(19)30290-9">score</a> that tabulates an individual’s inborn risk for obesity, published today in the journal <i>Cell.</i></p><p>The metric, which compiles information from more than two million spots in the genome that affect a person’s weight, isn’t a perfect predictor of physique. But adults that score in the top 10 percent are, on average, almost 29 pounds heavier than those in the bottom 10 percent—and it appears that genetically driven differences in weight can materialize as early as age three.</p><p>“This work is, overall, an important contribution,” says <a href="https://irp.nih.gov/pi/charles-rotimi">Charles Rotimi</a>, a human geneticist at the National Institutes of Health who was not involved in the study. “It takes advantage of all the genetic resources we’re getting out of [studies of human genetics]...and takes into account a lot of the variation we’ve found with obesity.”</p><p>Regardless of its performance, however, Rotimi and other experts advise caution in interpreting the results. Weight is certainly <i>affected</i> by genes, but “a genetic score can never fully predict obesity,” says <a href="https://icahn.mssm.edu/profiles/ruth-loos">Ruth Loos</a>, a human geneticist at the Icahn School of Medicine at Mt. Sinai who was not involved in the study. “Lifestyle and environmental factors remain equally, if not more, important.”</p></div>
  

  
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      <div class="rich-text"><p>It’s long been clear that lifestyle changes like a healthy diet and regular exercise can help stave off weight gain. But the genetic side of this equation has always been far murkier. Like most traits, weight isn’t controlled by the flip of a single molecular switch. Dozens, possibly hundreds, of genes can affect a person’s risk of becoming obese—and scientists are nowhere close to finding and characterizing them all.</p><p>The score detailed in the study, however, has a workaround. In recent years, researchers have found over 2.1 million genetic alterations—equivalent to single-letter typos—that are more prevalent in obese individuals.</p><p>Even without knowing what the underlying genes actually do, scientists can still tally up the tweaks in any given individual. The result integrates information scattered across the genome into a single, interpretable number, “almost like a cholesterol score,” says study author <a href="http://www.kathiresanlab.org/about-sek/">Sekar Kathiresan</a>, a cardiologist and human geneticist at Massachusetts General Hospital.</p><p>When Kathiresan and his team put their score to the test in a population of 300,000 adults, it accurately stratified groups of individuals by weight, body mass index (BMI), and prevalence of obesity. For instance, when arrayed by score, people in the top 10 percent were 25 times more likely to be severely obese, with a BMI of at least 40 kilograms per square meter, than those in the bottom 10 percent.</p><p>“How striking these differences are...is what got us so excited,” Kathiresan says. “The tremendous differences between the two ends of the spectrum are remarkable.”</p>
            <figure class="richtext-image full-width"><img alt="iStock-910049866.jpg" class="richtext-image full-width" height="533" width="800"
            src="/wgbh/nova/media/images/iStock-910049866.width-800.jpg"/><figcaption><p>Environmental factors and genetics both play into weight. But while a lot is known about the lifestyle choices that can influence obesity, the genetic side is far murkier. Image Credit: Rostislav_Sedlacek, iStock</p><div class="credit"><p></p></div></figcaption>
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            <p>The technology isn’t ready for use in the clinic. But the researchers are hoping to create a low-cost test—maybe around $50 per patient—that could use an easy-to-take sample like blood to scour the genome for obesity-related variants.</p><p>Making this kind of information widely available could be an important step toward reducing cultural stigma around obesity, which can both cause undue emotional hardship and dissuade people from seeking effective treatment. “Obesity is viewed as a problem of willpower,” Kathiresan says. “We blame the patient. What this [score] says is, ‘There’s a big biological underpinning that’s not necessarily within their control.’”</p><p>Such stigma is frustrating, given that obesity isn’t always disease-related, Rotimi says. “Not all of these people have diseases like diabetes,” he says. “There are people who are very heavy, but are doing fine.”</p><p>But those individuals are the exception, rather than the norm. High-scoring adults in the study were also more likely to suffer from several heart-related conditions—including coronary artery disease, diabetes, heart failure, and stroke—and had higher rates of overall mortality.</p></div>
  

  
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      <div class="rich-text"><p>Of course, most adults don’t need a genetic test to tell them whether or not they’re overweight, Kathiresan says. Genetic tests remain far more costly than stepping on a scale. These types of scores could still be explanatory, however—by offering someone perspective on why they’ve struggled to shed excess weight, for instance.</p><p>And there’s still a large contingent of people who might be able to use these scores to guide weight-based interventions—in themselves, or perhaps even their kids, says study author <a href="http://www.kathiresanlab.org/our-people/amit-khera/">Amit Khera</a>, a cardiologist and geneticist at Massachusetts General Hospital. The scores didn’t perform quite as well in children, but differences in body mass were discernible in individuals as young as three years old. “There’s no question that the impact takes effect very early in life,” Khera says. “A major goal is to use this info to empower people to offset inherited risk.”</p><p>Before any of that can happen, though, it’s important to acknowledge how much of obesity <i>can’t</i> be captured by this score, Loos says. In its current iteration, the test makes predictions that are often incorrect: About 40 percent of the highest-scoring adults were obese—but that leaves 60 percent that weren’t (and the accuracy drops further in younger populations). This could tread into tricky territory, especially if parents end up making lifestyle decisions on behalf of their children before the kids themselves can have a say, Rotimi says.</p><p>In the end, there are limits to what even the most rigorous genetic scans can tell us. A perfect, diversity-conscious genetic test would still capture only a fraction of what’s feeding the obesity epidemic, Loos says.</p><p>Altogether, these considerations could limit such a score’s utility in the clinic. “If we introduce a test into health care that is not predictive enough to be useful, then we are basically making health care more inefficient,” says <a href="http://www.cecilejanssens.org/">Cecile Janssens</a>, an epidemiologist and genomics researcher at Emory University who was not involved in the study. Even if the test is free, any interventions will require substantial public health investment, putting the onus on researchers to make these scores as accurate as possible, she says.</p>
            <figure class="richtext-image full-width"><img alt="iStock-1042024608.jpg" class="richtext-image full-width" height="533" width="800"
            src="/wgbh/nova/media/images/iStock-1042024608.width-800.jpg"/><figcaption><p>Human genetics research is accelerating at an unprecedented pace. But most studies are still done in populations of European ancestry. Image Credit: undefined, iStock</p><div class="credit"><p></p></div></figcaption>
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            <p>How this sort of information is doled out also needs to be carefully handled. The nature of the research reflects good intentions, Rotimi says, but “if we don’t carefully weigh the overall implications of these recommendations, we may indeed do more harm than good.”</p><p>While some individuals might be able to use a high score as motivation to be extra-conscious about their weight, others might feel like their fates are sealed by these genetic report cards, Loos says. Researchers have conducted similar risk assessments in the past with mixed results. In one study, disclosure actually backfired: People informed that they had a high genetic risk for obesity <a href="https://www.nejm.org/doi/full/10.1056/nejmoa1011893"><i>increased</i> their fat intake</a> in the months after receiving the news. The uptick was <a href="https://jmg.bmj.com/content/50/6/393.long">temporary</a>, but this kind of behavior, wherein people effectively resign themselves to what they see as genetic destiny, is definitely cause for concern, Loos says.</p><p>The converse could cause problems as well, Rotimi says. Just as there are individuals who might carry a higher risk for obesity, so, too, exist those who are a little more protected from it. Getting an ultra-low score might make some people think they can eat and do whatever they want, he says. And no one is immune to the repercussions of persistently unhealthy behavior.</p><p>There’s another big caveat. One of the largest limitations of the study is the fact that it was conducted exclusively with data from individuals of European ancestry. Based on previous research, these scores will apply to everyone, but will work best in those of European descent, Khera says. Leveling the playing field will require <a href="https://www.pbs.org/wgbh/nova/article/lack-diversity-genetic-research-could-be-costing-us-our-health/">expanding research to include other groups</a>.</p><p>With these issues in mind, the ultimate message is about striking a balance between nature and nurture. “This speaks to the fact that the endpoint of obesity is the result of genetics as well as lifestyle,” Kathiresan says.</p><p>And for many, that could actually be a silver lining: Genes are powerful—but we still have a lot of control over our own bodies. “People who are susceptible may have to work harder to keep weight off,” Kathiresan says. “But it’s important to know that they <i>can,</i> with great success.”</p></div>
  

  
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<p>There can be a 30-pound weight difference between people with low and high genetic risk. But genes aren’t everything.</p>

This Score Can Tell You Your Genetic Risk for Obesity. Is It Worth Knowing?





  
      <div class="rich-text"><p>As planes take off at an Army National Guard airfield in Concord, New Hampshire, Elizabeth Crone and Nick Dorian carefully tiptoe through the greenery surrounding the runways. Heads down and decked out in the bright orange vests required of civilians who visit the airfield, Dorian and Crone focus on what no one else seems to notice: a tiny, delicate life form that’s arguably more reliant on the U.S. military than the soldiers are themselves.</p><p>Crone, a population ecologist at Tufts University, and Dorian, her graduate student, are searching for small green caterpillars barely distinguishable from the leaves they feed on. These critters are the next generation of the Karner Blue butterfly, an insect that landed on the Endangered Species List in <a href="https://www.fws.gov/midwest/endangered/insects/kbb/kbb_fact.html">1992</a>. While Karner Blue populations have been completely wiped out across much of the species’ former habitat, many of the healthiest populations of these butterflies still thrive on military bases—the more explosive, the better.</p><p></p>
            <figure class="richtext-image full-width"><img alt="Crone_cropped.jpg" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/Crone_cropped.width-800.jpg"/><figcaption><p>Elizabeth Crone at an Army National Guard airfield in Concord, New Hampshire | Photo credit: Christina Couch </p><div class="credit"><p></p></div></figcaption>
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            <p>Crone has spent the last 20 years bouncing between military installations, including artillery ranges and weapons testing facilities, to study why some of the world’s most fragile and imperiled butterflies flourish in these simulated war zones. Cracking that question means working hand-in-hand with the Department of Defense (DoD), an agency that’s polarizing amongst environmental groups. While many major environmental voices have <a href="https://www.nrdc.org/onearth/military-takes-climate-change-seriously-why-wont-commander-chief">praised</a> the agency for being a leader in <a href="https://www.documentcloud.org/documents/5689153-DoD-Final-Climate-Report.html">climate change mitigation</a> and <a href="https://www.politico.com/story/2016/12/james-mattis-climate-change-trump-defense-232833">clean energy</a> solutions, the department has also been called &quot;<a href="https://www.newsweek.com/2014/07/25/us-department-defence-one-worlds-biggest-polluters-259456.html">one of the world’s worst polluters</a>&quot; due to widespread instances of <a href="https://www.propublica.org/nerds/data-get-an-inside-look-at-the-department-of-defense-struggle-to-fix-pollution">soil</a> and <a href="https://partner-mco-archive.s3.amazonaws.com/client_files/1524589484.pdf">water contamination</a> in present and former military locations.</p><p>For scientists like Crone who are racing the clock to pull endangered populations back from the brink of extinction, military partnerships and DoD research funding are crucial. Some of the most robust populations of Karner Blues are found close to areas where bullets fly and bombs detonate. To preserve this and more than 400 other federally listed species that reside on DoD properties, Crone and environmental researchers across the country have formed unlikely, and sometimes complicated, alliances with military agencies.</p><p></p>
            <figure class="richtext-image full-width"><img alt="Dorian_cropped.jpg" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/Dorian_cropped.width-800.jpg"/><figcaption><p>Crone’s graduate student, Nick Dorian, searches for Karner Blues amid the lupines at the airfield. | Photo credit: Christina Couch </p><div class="credit"><p></p></div></figcaption>
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            <p>“In general, people who study ecology are not big fans of the military,” Crone says. “Just accepting money from the military is not where you first think of looking as an ecologist.”</p><h2><b>Bullets and Butterfly Wings</b></h2><p>Crone avoided applying for funding from the Department of Defense for the first decade of her career as a university professor. But a mounting pile of scientific evidence on the unique biology of some endangered butterflies eventually persuaded her. Twenty-five years ago, Crone partnered with Cheryl Schultz—now a conservation biologist at Washington State University, Vancouver—to study the Fender’s Blue butterfly, a relative of the Karner Blue that was <a href="https://www.fws.gov/oregonfwo/articles.cfm?id=149489429">believed to be extinct</a> until small populations were rediscovered in 1989.</p></div>
  

  
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      <div class="rich-text"><p>Like Karner Blues, Fender’s Blue larvae dine solely on lupine plants—a genus that sprouts on open grasslands. Maintaining these habitats is challenging. If left alone, grasslands grow into shrub lands or forests that choke out low-growing lupines. And even though nature has its own system for preserving grasslands—roaming mammals feed on accumulating brush while periodic wildfires burn off overgrowth, eliminate weeds, and send lupine-loving nutrients into the soil—modern day humans have essentially wrecked that system by either taking over prairie lands entirely or corralling the animals and small fires that keep these areas intact. Controlled burns could help maintain grasslands, but they also introduce a conundrum: Use fire and some endangered larvae also go up in flames. But avoid fire and grasslands collapse—taking the butterflies, too.</p><p></p>
            <figure class="richtext-image full-width"><img alt="lupines_cropped.jpg" class="richtext-image full-width" height="460" width="800"
            src="/wgbh/nova/media/images/lupines_cropped.width-800.jpg"/><figcaption><p>Both Fender’s Blue and Karner Blue butterflies rely on lupine plants to survive. | Photo credit: <a href="https://pixabay.com/es/photos/flores-lupinos-lupino-verano-3934519/">Pixabay</a> </p><div class="credit"><p></p></div></figcaption>
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            <p>In the early 90s, Oregon State University botanists Mark Wilson and Deborah Clark were studying post-fire lupine regrowth at the Baskett Slough National Wildlife Refuge. Schultz and Crone joined to observe how the Fender’s Blue might be affected, and in 1994, the team conducted high-intensity burns on three patches of dry land containing Fender’s Blue eggs and larvae. Flames ignited. Larvae died. And still, the butterflies multiplied. Following a repeat burn in 1996, the researchers found that Fender’s Blue females laid roughly four times more eggs in burned areas than they did in untouched control patches.</p><p>Fire helps jumpstart Fender’s Blue fertility because it clears out young forest growth that hinders lupine plants and it quickly converts organic material into ash, which releases nutrients and enriches soil much faster than natural decomposition. This newly-enriched soil not only stimulates growth of larger, healthier populations of lupine plants that can support bigger Fender’s Blue colonies—it also attracts ants that act like six-legged butterfly bodyguards. In exchange for feeding on sugars and amino acids secreted through glands on the Fender’s Blue caterpillar’s back, ants protect these caterpillars from predators, significantly increasing the caterpillars’ chance of survival.</p></div>
  

  
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      <div class="rich-text"><p>Since those first fires, Schultz and Crone have done extensive work building models to determine how and when fire can be used to revive butterfly populations. They’ve found that hot, high-intensity burns—the kind that tend to ignite where guns and explosives go off—completely wipe out larvae, but over time, boost butterfly reproduction much more than lower-temperature burns done in cooler months or after rainfall.</p><p>“It’s kind of like a really hard fifth grade algebra word problem. If a fire kills half of the over-wintering larvae and if it increases the fecundity on the site by 10 percent, does that balance?” Crone says. “You can see why it’s controversial.”</p><p>For the Fender’s Blue, this controversial approach is working, which is why Crone has partnered with the DoD to collect preliminary data to determine whether the same methods will work for the Karner Blue. Since those early test fires at Baskett Slough, Fender’s Blue populations have increased at least nine-fold, possibly more. There are currently an estimated 14,000 to 28,000 Fender’s Blues flitting between lupine plants, Schultz says—a population size that’s large enough to give conservationists hope that the species will survive.</p><p>“Here’s a story where we’ve turned it around, but that’s not the usual story,” she says. “Many of our butterflies are sharply in decline, and not just the rare ones.”</p><h2><b>Soldiers and Scientists</b></h2><p>For environmental researchers, studying species that live on the <a href="https://www.fws.gov/endangered/what-we-do/fws-dod.html">25 million acres</a> of land managed by the DoD means dealing with military rules and restrictions. At Fort Bragg in North Carolina, Michigan State University ecologist Nick Haddad works alongside Brian Ball, one of nine wildlife biologists (plus one botanist) in the installation’s <a href="https://home.army.mil/bragg/index.php/about/garrison/directorate-public-works/environmental-division/endangered-species-branch">Endangered Species Branch</a>, a division dedicated to managing and monitoring the five endangered species of flora and fauna found on base. Haddad and Ball have partnered up to save the St. Francis Satyr, a species of butterfly so rare it was thought to be extinct until a small population was discovered on base in the mid-90s. The tan and black species isn’t found anywhere else in the world besides Fort Bragg, and the healthiest colonies live on just 25 precious acres of land within the Fort’s borders.</p></div>
  

  
      

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      <div class="rich-text"><p>The St. Francis Satyr relies on sedge plants, which grow in a specific type of murky wetland that quickly morphs into forestland if not maintained. In the wild, beavers build dams that remove trees and flood sedge plant habitat while brushfires burn off overgrowth. But North Carolina beavers are still recovering after being trapped to near-extinction in the early 1900s; humans, too, have eliminated natural, small-scale brushfires to protect infrastructure. So with beavers and brushfires in short supply, the largest and healthiest remaining populations of these butterflies now live inside Fort Bragg’s artillery impact zones, along creeks and drainage areas that catch fire from nearby munitions. Some smaller, less stable populations live outside of these fire-prone zones, but still within Bragg&#x27;s borders.</p></div>
  

  
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      <div class="rich-text"><p>More than 50,000 active duty soldiers work on base, meaning that conservation efforts must work in tandem with training programs that restrict civilians from certain areas for safety reasons. Haddad and Ball are only allowed into artillery ranges once or twice a year, always with a military escort and for just a few hours. While the pair spends entire days working alongside Haddad’s graduate students and other researchers to meticulously track changes in Satyr population health outside of impact zones, they generally only get about 30 minutes per site inside impact zones and must leave their research partners behind. These limitations make it impossible to get exact population counts or to conduct intensive monitoring.</p><p></p>
            <figure class="richtext-image full-width"><img alt="FortBragg_cropped.jpg" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/FortBragg_cropped_1fGi16x.width-800.jpg"/><figcaption><p>Paratroopers paddle across Mott Lake on Fort Bragg during a training in 2015. | Photo credit: <a href="http://archive.defense.gov/photoessays/photoessayss.aspx?id=6877">U.S. Army, Staff Sgt. Mary S. Katzenberger</a> </p><div class="credit"><p></p></div></figcaption>
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            <p>“I wish I had more access, but on other hand, I understand why I don’t and I’m comfortable with that because frankly, when I do go in [to impact zones], the butterflies are doing well there,” Haddad says. “My highest concern is outside those areas.”</p><p>Haddad and Ball are currently lobbying to artificially replicate spontaneous fires found within impact zones in Satyr habitat located outside of artillery areas. Fort Bragg already operates an extensive controlled burning program as part of larger conservation and ecosystem management efforts, but the St. Francis Satyr lives in wetlands and it’s &quot;difficult to get fire into these areas consistently while being safe,” Ball says.</p><p>In the meantime, Haddad and Ball are replicating a different kind of natural disturbance: floods.</p><p>After years of watching local St. Francis Satyr populations go extinct, the pair adopted a new strategy in 2011: save the butterflies by acting like beavers. To prevent wetlands from transforming into dense forests, they began removing trees and flooding Satyr habitats, creating more hospitable conditions for sedge growth and for butterfly reproduction.</p></div>
  

  
      

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      <div class="rich-text"><p>Satyr populations are also boosted by an on-site captive rearing program wherein butterflies are raised from eggs to adults in greenhouses, then released into wild colonies or onto restoration sites within Fort Bragg to reproduce.</p><p>Flooding combined with captive restoration have collectively transformed sites where Satyrs were once extinct into areas that boast populations of 800 or more. Haddad says that these new butterflies represent about 25 percent of the total St. Francis Satyr population.</p><p>“If it weren’t for the military and especially if it weren’t for these artillery ranges, the St. Francis Satyr would now be extinct,” he says.</p><h2><b>Warriors and Woodpeckers</b></h2><p>Haddad and Crone both enthusiastically praise their colleagues at the Department of Defense, but it’s only relatively recently that many within the research community and the general public began thinking of the department as an agency that prioritizes species preservation.</p><p>In the ’80s and ’90s, “there really was this perception that the DoD didn’t care about the bugs and bunny issues,” says Alison Dalsimer, manager of the department’s Natural Resources Program.</p><p>That perception slowly began to change thanks to the red-cockaded woodpecker, or RCW (as it would come to be known). The RCW thrives on longleaf pine, a tree that once occupied more than <a href="https://www.fws.gov/natures-good-neighbors/stories/a-harmonious-future-for-profits-pine-and-at-risk-species-along-the-florida-alabama-line/">90</a> <a href="https://www.nfwf.org/whoweare/mediacenter/pr/Pages/3-Million-in-Funding-for-Longleaf-Pine-Forests.aspx">million</a> acres across the United States, but was logged down to less than <a href="https://www.fws.gov/endangered/map/ESA_success_stories/NC/NC_story1/index.html">3.4 million</a> by the early 21st century, taking woodpecker populations down with it. In 1988, a federal judge ruled that clear-cut logging violated the Endangered Species Act and banned the practice from happening within the woodpecker’s habitat. In the wake of the suit, the U.S. Fish and Wildlife Service issued a mandate requiring RCW protection at Fort Bragg and nearby Camp Mackall, thus launching the rocky start to a now crucial partnership between the military and conservationists and directly leading to the creation of new conservation management programs within military installations including Fort Bragg&#x27;s Endangered Species Branch.</p><p></p>
            <figure class="richtext-image full-width"><img alt="Woodpecker_cropped.jpg" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/Woodpecker_cropped.width-800.jpg"/><figcaption><p>Public opinion of the DoD’s conservation efforts began to change for the better after a federal judge ruled that clear-cut logging within the red-cockaded woodpecker’s habitat violated the Endangered Species Act. | Photo credit: <a href="https://commons.wikimedia.org/wiki/File:Red-cockaded_woodpecker,_Fred_Babcock_%E2%80%93_Cecil_Webb_state_wildlife_management_area_(32804240314).jpg">Russ / Flickr (CC BY 2.0)</a> </p><div class="credit"><p></p></div></figcaption>
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            <p>Dalsimer calls the RCW ruling a “turning point” for engaging the DoD in conservation efforts and helping conservation partners see that, “‘Oh wow, the DoD actually does care.’”</p><p>Dalsimer counts herself among the converted. In the mid-’90s, just a few years following the RCW lawsuit, Dalsimer worked on behalf of the National Fish and Wildlife Foundation on a few joint projects with the DoD, including a review of research on natural resources located on military-owned lands that were scheduled to be transferred to the government of Panama. While working on these projects, she says she saw first-hand the department’s commitment to land stewardship. Dalsimer joined the department in 1997, where she currently oversees, among other initiatives, the <a href="https://www.partnersinflight.org/working_groups/dod-pif/">DoD Partners in Flight program</a>—one piece of a massive bird conservation collaboration that currently includes 150 partner organizations, the DoD being just one.</p><p>“The fact is the DoD is a premier steward of its resources and puts a lot of time and effort and money into managing those resources at a very high level,” she says. “I don’t know that people are really aware of that.”</p><p>For rare butterflies like the Karner Blue and the St. Francis Satyr, effective partnerships between ecologists and the military are the last remaining hope. Nick Haddad is cautiously optimistic. Buoyed by stories like that of the red-cockaded woodpecker—which has <a href="https://www.fws.gov/endangered/map/ESA_success_stories/NC/NC_story1/index.html">fully recovered</a> on Fort Bragg—Haddad keeps a close vigil on his St. Francis Satyr colonies. He’s worried, but not discouraged. If he can replicate the success he&#x27;s had with Satyr colonies in places within military borders and beyond, “then there’s a realistic hope of calling this species recovered,” he says. “There is a path forward.”</p><p></p></div>
  



<p>To save endangered butterflies, an unlikely team of ecologists and the Department of Defense are setting some of them on fire.</p>

These Super Rare Butterflies Thrive on Army Bases. The U.S. Military is Helping Them.





  
      <div class="rich-text"><p>The brain doesn’t last long after death. Deprived of blood and oxygen, the organ rapidly deteriorates and eventually shuts down completely.</p><p>That process is quick. But <i>quick</i> isn’t the same as <i>immediate</i>. If someone were to jumpstart electrical activity in the hours after death, a brain could maybe—just maybe—be salvaged.</p></div>
  

  
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      <div class="rich-text"><p>In a <a href="https://www.nature.com/articles/s41586-019-1099-1">study</a> published today in the journal <i>Nature,</i> a team of scientists has taken advantage of that critical window to partially revive the brains of dead pigs after slaughter. The brains didn’t regain the organized connectivity that they’d need for “consciousness,” but some neurons exhibited electrical activity. When coaxed with oxygen and glucose, the organs appeared to gobble them up, and even responded to drugs—clear signs that they had retained some metabolic function.</p><p>“This is a real advance,” Andrea Beckel-Mitchener, a neuroscientist at the National Institutes of Health who was not involved in the study, <a href="https://www.nytimes.com/2019/04/17/science/brain-dead-pigs.html">told Gina Kolata at <i>The New York Times</i></a>. “This has never been done before in a large intact mammalian brain.”</p><p>The ethical implications of the research—which has been described as <a href="https://www.washingtonpost.com/science/2019/04/17/scientists-restore-some-brain-cell-functions-pigs-four-hours-after-death/?utm_term=.890e3a731dd9">blurring the line</a> between life and death—have already sparked controversy. But scientifically, it presents a strong case for the idea that brain cells aren’t as fragile as previously thought.</p><p>Herein lies an important distinction, though: After their owners died, at no point did the brains come back to <i>life.</i> Restoring a subset of brain activity is not enough to constitute full reanimation, or even anything close. “This is not a living brain,” study author Nenad Sestan, a neuroscientist at Yale University, told the press. “This is a cellularly active brain.”</p><p>Regardless, “this is a huge breakthrough,” Nita Farahany, an ethicist at Duke Law School who was not involved in the study, <a href="https://www.washingtonpost.com/science/2019/04/17/scientists-restore-some-brain-cell-functions-pigs-four-hours-after-death/?utm_term=.189291333475">told Joel Achenbach at <i>The Washington Post</i></a>. “Our belief was there’s a point of no return. Certainly we would have believed that four hours after being decapitated, that was a point of no return. It turns out it’s not.”</p></div>
  

  
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      <div class="rich-text"><p>After sourcing 32 freshly decapitated pig heads from a local pork processing center, a team of researchers led by Sestan extracted the brains. While some were left to deteriorate, others were rejuvenated with a cocktail of nutrients and protective chemicals for six hours. It had only been four hours since the pigs had been slaughtered for their meat, but brain tissue is notoriously fickle and fragile. The goal was to maximize preservation—and, to an extent, it worked.</p><p>While some neurons continued their march toward death, others didn’t. Some kept consuming energy; a few even began to fire. But the researchers were unable to detect hints of awareness in any of the brains.</p><p>Or, at least, that’s what they think. During the experiment, the brains were infused with the anti-seizure drug lamotrigine, which subdues cellular activity, in the hopes that this would aid the preservation process. The drug could have masked the organized activity that’s often linked to consciousness, but it’s pretty unlikely, the researchers say. Besides, it was never the team’s goal to restore this type of awareness, and, had they seen any signals associated with it, they would have immediately administered anesthesia.</p><p>Still, consciousness is hard to define and measure under the best of circumstances—much less in a disembodied pig brain.</p><p>As such, the findings raise numerous ethical quandaries, including what this could mean for model organisms used in laboratories, or protocols of human organ transplants, which often rely on donors who have been declared dead and beyond resuscitation.</p><p>Any applications of the findings in human patients are a very, very long way off—and this isn’t going to pave the way to human brain transplants, Emory University neuroethicist Karen Rommelfanger, who was not involved in the study, <a href="https://www.theatlantic.com/science/archive/2019/04/scientists-partly-restore-activity-dead-pig-brains/587329/">told Ed Yong at <i>The Atlantic</i></a>. But there are less wild implications, including the advancement of new treatments for conditions ranging from Alzheimer’s to traumatic brain injury.</p><p>That’s not to minimize the ethical hurdles that stand in the way. In the meantime, the results of the study “should inform the discussion surrounding brain death,” Kathleen Fenton, a bioethicist and pediatric heart surgeon who was not involved in the study, <a href="https://www.statnews.com/2019/04/17/pig-brain-cellular-function-restored-after-death/">told Sharon Begley at <i>STAT</i></a>. “[What] was irreversible appears to not be irreversible...that’s important.”</p></div>
  

  
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<p>In a groundbreaking and controversial study, scientists have partially revived the brains of slaughtered pigs.</p>

Scientists Partially Restore Function in Dead Pigs’ Brains





  
      <div class="rich-text"><p>Last fall, a person addicted to cocaine arrived at the Medical University of South Carolina in Charleston. There, he or she watched a video of people using cocaine and was shown a small bag of what appeared to be either crack or powder cocaine, along with other drug-related paraphernalia. These cues were specifically designed to evoke memories of previous cocaine use and trigger intense craving. Shortly afterward, the individual was given a powerful pharmaceutical called propranolol that interferes with the brain’s ability to form memories. All of this may sound like a bad idea, but it’s actually a new and promising experimental treatment for addiction.</p></div>
  

  
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      <div class="rich-text"><p>Outside the controlled environment of a hospital, such a procedure would be risky, but this person—the last participant in a trial to test a new approach for preventing relapse—was carefully monitored on site and for six weeks after going home. Recently, much attention has focused on addiction as a chronic disease, but Mike Saladin, the research and clinical psychologist who led the study, explains that addiction is, in part, a disorder of learning and memory. The goal of his study is to reactivate memories of drug use—and then weaken them so they lose their power. The trial is one of 10 or more over the past decade inspired by lab experiments with rodents showing that memory can be manipulated to lessen its influence on addictive behavior. Researchers like Saladin aren’t trying to change the content of people’s memories. Instead, he says, “we’re turning down the volume” so that particular cues “don’t excite drug use the way they used to.”</p><p>Although the approach sounds like science fiction, it’s based on an understanding of learning and memory that goes back to an accidental discovery at the beginning of the last century, when the physiologist Ivan Pavlov, who was studying digestion in dogs, found that by repeatedly pairing a cue such as the tick of a metronome with the provision of food, the dogs would “learn” to salivate when they heard the noise—even before the meal arrived.</p></div>
  

  
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      <div class="rich-text"><p>The same associative learning applies to addiction. When you learn that the pop of a wine cork predicts you will soon be enjoying a drink, you’ve created a memory. The more meaningful the experience and the more often you’ve paired those two events, the stronger the memory, even though it may be unconscious. Saladin points out that “people who have long substance use histories are responding to a myriad of cues, some of which they are not really aware of.”</p><p>Ravi Das, a psychologist at University College London, is also testing ways to modify memories in order to treat addiction. “Our brains are great at learning around rewards and what predicts them,” he says, noting that smells, sounds, and even people can serve as cues that promote relapse. This may help explain why 40 to 60 percent of people who have found a way to stop using drugs eventually relapse. Even if they’ve succeeded in staying off drugs for weeks or months or years, the paired association between cues and rewards can reactivate those drug memories, creating an overwhelming desire to use again.</p><p>Although we tend to think of longstanding memories as permanent, learning can be reversed, as Pavlov discovered with his dogs. When he repeatedly stopped providing food after starting the metronome, the dogs no longer salivated when they heard the cue.</p></div>
  

  
      <div class="rich-text"><h2>Trial by Exposure</h2><p>Targeting memories in order to treat addiction, as well as anxiety, is not entirely new. The concept is the basis for extinction learning (also called exposure therapy), in which patients in the safe environment of a therapist’s office are exposed to environmental cues that normally trigger maladaptive memories. Because they’re exposed repeatedly to the cues without the response, those cues should gradually lose their power.</p><p>But it’s not that straightforward. It can be hard to transfer that new learning from the lab, to the therapist’s office, to the unpredictable chaos of the real world. “This is the million-dollar question,” says R. Kathryn McHugh, a research and clinical psychologist at McLean Hospital in Belmont, Massachusetts, who treats anxiety and substance use disorders. “People have been looking at this for decades now. In the lab, you absolutely can extinguish these cues. You can decrease craving.” Yet studies to assess the efficacy of incorporating cue exposure with cognitive behavioral therapy to treat alcohol addiction in earlier decades didn’t show much of a benefit, says McHugh. “If the basic research can make that jump more effectively, that would be a tremendous tool for us to have.”</p><p>David Epstein, who heads up the Real-world Assessment, Prediction, and Treatment Unit at the National Institute on Drug Abuse, is at the forefront of trying to make that jump. “We can’t treat addiction just by using extinction, in which someone is repeatedly exposed to drug-related cues until the cues cease to induce craving,” he said via email, “because extinction doesn’t generalize outside the environment where it occurs.”</p><p>Researchers in this nascent field aim to solve that problem by tinkering with how patients are exposed to cues. They were inspired in part by recent advances in treating post-traumatic stress disorder, or PTSD, in which maladaptive memories are triggered by stimuli associated with the original event, like a news report of an assault, or a sudden loud noise.</p></div>
  

  
      

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  <div class="rich-text"><p>“We can’t treat addiction just by using extinction, in which someone is repeatedly exposed to drug-related cues until the cues cease to induce craving.”</p></div>
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      <div class="rich-text"><p>Nearly a decade ago, neuroscientists studying these so-called fear memories discovered what seemed to be a way around the weakness of extinction learning. Their method was based on the idea that when memories are reactivated, they are temporarily unstable. (It makes sense for memories to be fluid and dynamic, capable of incorporating new information, so they can help us make accurate predictions about the future.) “Normally the memory would subsequently re-stabilize,” says Das, who was not involved in these early studies. “But it would be slightly updated and that serves to keep your memories valid and up-to-date.” What if, researchers wondered, that instability provides a temporary window during which to intervene and add new information to the memory?</p><p>The trick was to make sure the behavioral therapy happened while the window of vulnerability was still open. Surprisingly, simply inserting a correctly timed pause between reactivating the memory and providing extinction learning was all that was needed to break the link between the cue and the fear memory, making the new approach more effective in both rodents and humans.</p></div>
  

  
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      <div class="rich-text"><p>Epstein helped analyze the results of a clinical trial published in 2012 that sought to reduce heroin craving by inserting these properly timed cues prior to therapy. The research team, based at Peking University in Beijing, worked with hospitalized patients who had detoxified. If the researchers activated the drug-reward memory by showing a video of heroin use, but waited 10 minutes before beginning an hour-long extinction session, they could reduce their patients’ craving. However, if they waited six hours or more, it was too late. The memory had already reconsolidated without the new learning, and the craving for heroin was as strong as before.</p><p>“This is so remarkable on its face that I wouldn’t believe it if it hadn’t been replicated,” says Epstein, who points to follow-up studies in rats and humans.</p></div>
  

  
      <div class="rich-text"><h2>Destabilizing Memories</h2><p>Six years later, Epstein is now enrolling patients in the first clinical trial in this country testing a similar approach to treat alcohol misuse, but he’s added a new maneuver to address another weakness of extinction learning. Normally exposure cues that are just images, sounds, smells, or words associated with the drug are only capable of making a subset of drug-reward memories unstable. In Epstein’s trial, the cue for some participants will consist of drinking the alcohol itself. The hope is that this technique will, as Epstein puts it, “get you to the hub of where all learned associations are stored, instead of having to weaken them one by one.” For safety reasons, any test subjects who drink alcohol will stay in the hospital until their blood alcohol levels are very low and will then be taken home. Over the course of the following month, everyone in the trial will use a smartphone to keep track of their drinking and craving.</p><p>At University College London, Das is also testing memory manipulation to prevent relapse, but instead of using extinction learning to modify the memory, he uses drugs to block its reconsolidation. Ninety college graduates who drank heavily at least four times a week participated in a recent trial. They were at risk of transitioning to alcohol addiction and wanted to cut back.</p></div>
  

  
      

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      <div class="rich-text"><p></p><p>As with the heroin users in the 2012 study, these so-called hazardous drinkers were exposed to visual cues such as pictures of beer and were asked to rate how appealing the images were. This procedure alone should reactivate drinking memories, making them temporarily unstable, but Das added a twist. “It’s harder with these reward memories because they’re really robust,” says Das. “So, you have to get the parameters right during the retrieval in order to destabilize.”</p><p>On the first day of the experiment, participants were allowed to drink a glass of beer at the end of the rating session. When they returned the following day, they began the session assuming that the procedure would be the same. But after rating the pictures and being instructed to pick up the glass and prepare to drink, the beer was withheld at the very last moment. Das’ hope is that this extra element of surprise, which neuroscientists call a prediction error, will destabilize the memory more than just a simple retrieval would. The theory is that if the function of memory is to make accurate predictions, any time your predictions are wrong memories require more updating than usual.</p><p>The coup de grace to the memory occurs five to 10 minutes later with the administration of a drug called ketamine, a safe and widely used anesthetic which, at the low dose used in this trial, causes a psychedelic dissociative experience. Ketamine blocks certain receptors on the surfaces of neurons called NMDA receptors, which Das says have been shown to be key to restabilizing memories once they’ve been destabilized. This blockade makes it difficult for the now-destabilized and weaker alcohol reward memory to reform.</p></div>
  

  
      

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  <div class="rich-text"><p>Das acknowledges that there is some stigma against using a psychedelic drug to treat drug addiction.</p></div>
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      <div class="rich-text"><p>In the trial, which concluded in September, one third of the hazardous drinkers went through this procedure, another third got saline solution instead of ketamine, and the final third received ketamine but only rated pictures of orange juice. All the subjects kept diaries and returned one week, one month, three months, six months, and nine months later to report on their drinking. Das called the preliminary results encouraging and presented a poster session on the trial at a recent conference in Barcelona.</p><p>Das acknowledges that there is some stigma against using a psychedelic drug to treat drug addiction. But he argues that if it proves effective, that concern should be put aside. “If it works, then it works, and you have to weigh up the cost-benefit of giving people a single dose of ketamine versus repeatedly drinking heavily on an almost nightly basis for many years.”</p><h2>The Big Picture</h2><p>In the cocaine cue exposure trial in Charleston, South Carolina, Saladin uses a beta-blocking drug called propranolol—commonly used to treat high blood pressure—which accumulating evidence suggests may be effective in treating anxiety disorders and modulating memory. The five-year study he is now concluding is the follow-up to an earlier trial to treat cravings and reduce relapse in cocaine users. In that first trial, session participants who received propranolol reported less craving the next day, but when they returned for evaluation one week later, there was no significant difference between them and participants who did not receive propranolol.</p><p>In the new trial, Saladin is using two retrieval sessions instead of just one, and testing double the original dose of propranolol to see if drug reward memories will be weakened enough to prevent craving — and cocaine use — for longer than a day. Participants will be evaluated 18 times over the course of six weeks so researchers can document their craving in response to cues both in and out of the hospital, and to find out whether they have used cocaine.</p></div>
  

  
      

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  <div class="rich-text"><p>“There’s no consensus on whether these reconsolidation-targeted treatments really weaken or erase memories at the neural level.”</p></div>
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      <div class="rich-text"><p>Theories about precisely what’s going on are just that—theories. It’s possible that memories are not reconsolidating. “There’s no consensus on whether these reconsolidation-targeted treatments really weaken or erase memories at the neural level. It’s possible that the memories are still physically present, but difficult to access. In practical terms, that might be fine—unless the memories return,” says Epstein.</p><p>And memory manipulation does not address the underlying and complex reasons that lead to substance use disorders in the first place. So it’s not yet clear how effective this approach will be for individuals who struggle with depression, anxiety, or a history of trauma. Finally, it’s often the case that people use multiple drugs and are vulnerable to relapsing on multiple drugs. That could mean having to use separate memory manipulation treatments for each substance.</p><p>For these and other reasons, researchers are treading cautiously while also recognizing the urgent need for better treatment of addiction. “These people are in desperate circumstances and help is necessary,” says Saladin, adding that “reducing suffering is critical.”</p></div>
  



<p>Environmental cues can trigger powerful memories of substance use. What happens when those memories are disrupted?</p>

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