Domain: sciencemag.org
Stories and comments across the archive that link to sciencemag.org.
Stories · 1,414
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Earth's Oxygen History Could Explain "Darwin's Dilemma" In Evolution
TaleSlinger (3080869) writes Scientists following two different lines of evidence have just published research [Here's the abstract to the paywalled Science paper] that may help resolve "Darwin's dilemma," a mystery that plagued the father of evolution until his death more than a century ago. Life appeared when the earth was tens of millions of years old, but evolution didn't go into high gear until the "Cambrian Explosion", nearly a billion years later. The two papers propose complementary theories that help explain this. The first suggests that scientists have long overestimated the amount of oxygen in the earth's atmosphere in the pre-Cambrian era just before the "explosion." The second suggests suggests that very dramatic changes driven by the tectonic breakup of the so-called "supercontinents" of the pre-Cambrian era could have caused an extraordinary leap in oxygen levels of both the ancient oceans and the earth's atmosphere. These two studies fit neatly together, suggesting that a world deprived of oxygen could have changed relatively quickly into an incubator for new life in shallow ponds spread across the continents and fed by waters rich in nutrients. Perhaps that set the stage for the explosion, which may have been five times the evolutionary rate seen today. -
Why Scientists Think Completely Unclassifiable and Undiscovered Life Forms Exist
An anonymous reader writes: In a new paper published in Science, researchers at the Department of Energy's Joint Genome Institute note that "there are reasons to believe that current approaches [to discovering life] may indeed miss taxa, particularly if they are very different from those that have so far been characterized." They believe life forms exist that don't fall into the established eukaryota, archaea, or bacteria kingdoms. They argue that there may be life out there that doesn't use the four DNA and RNA bases that we're used to; there may be life out there that has evolved completely separately from everything that we have ever known to exist; there may be life that lives in places we haven't even looked. -
Robot Makes People Feel Like a Ghost Is Nearby
sciencehabit writes: In 2006, cognitive neuroscientist Olaf Blanke of the University of Geneva in Switzerland was testing a patient's brain functions before her epilepsy surgery when he noticed something strange. Every time he electrically stimulated the region of her brain responsible for integrating different sensory signals from the body, the patient would look behind her back as if a person was there, even when she knew full well that no one was actually present. Now, with the help of robots, Blanke and colleagues have not only found a neurological explanation for this illusion, but also tricked healthy people into sensing "ghosts," they report online in Current Biology (abstract). The study could help explain why schizophrenia patients sometimes hallucinate that aliens control their movements. -
Bats Can Jam Each Other's Ultrasonic Signals
sciencehabit writes Just before nabbing an insect, a bat emits a rapid series of ultrasonic calls whose echoes back pinpoint the prey's exact location. Scientists call these sounds 'the feeding buzz,' and they're known to attract other bats presumably in search of a meal. When another bat arrives, it can jam the hunter's buzz, according to a new study, much like someone blocking a radio signal. That causes the original bat to miss its meal, allowing its competitor to swoop in to grab the insect instead. This is the first time that this type of competitive interference among individuals of the same species has been discovered in animals, the scientists say. -
Satellites Spot Hidden Villages In Amazon
sciencehabit writes The Amazon is home to perhaps dozens of isolated tribes who make their living far off the grid from the wider society, growing crops and hunting and gathering in the forest. These reclusive peoples are threatened by drug running, illegal logging, and highway construction, even if they dwell in 'protected' reserves in Peru or Brazil; one group, apparently pushed out of its lands, made contact this summer. Now, researchers have a new way of examining their fate without disruptive and frightening flyovers by aircraft. Researchers use high-resolution WorldView or GeoEye satellite images to monitor demographic changes in isolated Amazon tribes. The scientists got location and population estimates for five isolated villages along the Brazil-Peru border from Brazilian government reports and other sources. Then they examined 50-centimeter resolution satellite images taken in 2006, 2012, and 2013 and could spot the peoples' horticultural fields and characteristic pattern of either longhouses or clusters of small houses; these villages could be clearly differentiated from the transient camps of illegal loggers or drug runners. -
Crowdsourcing Project Predicts Progression of ALS
sciencehabit writes Using data from old clinical trials, two groups of researchers have found a better way to predict how amyotrophic lateral sclerosis (ALS) progresses in different patients. The winning algorithms—designed by non-ALS experts—outperformed the judgments of a group of ALS clinicians given the same data. The advances could make it easier to test whether new drugs can slow the fatal neurodegenerative disease. For the competition, participants were given just a slice of this data set, collected over 3 months, and asked to design an algorithm to predict how patients would fare in the subsequent 9 months, according to a standard functional scale that measures their ability to move and care for themselves. When predictions from the two winning algorithms were combined, they outperformed estimates solicited from a dozen ALS clinicians who pored over the same data, the authors report. They estimate that using these algorithms to predict outcomes could allow a drug sponsor to reduce the size of the trial by at least 20% and save as much as $6 million in a large phase III trial. -
Birds Found Using Human Musical Scales For the First Time
sciencehabit writes The flutelike songs of the male hermit thrush are some of the most beautiful in the animal kingdom. Now, researchers have found that these melodies employ the same mathematical principles that underlie many Western and non-Western musical scales—the first time this has been seen in any animal outside humans. It's doubtful that the similarity is due to the physics of the birds' vocal tract, the team reports. Rather, it seems male hermit thrushes choose to sing notes from these harmonic series. It may be that such notes are easier for the males to remember, or provide a ready yardstick for their chief critics—female hermit thrushes. The study adds to other research indicating that human music is not solely governed by cultural practices, but is also at least partially determined by biology. -
Dance Your Ph.D. Winner Announced
sciencehabit writes When she isn't out in the forest gathering data for her Ph.D. in plant biology at the University of Georgia, Athens, Uma Nagendra spends a good deal of her time hanging upside down from a trapeze doing circus aerials. "It turns out that there are a lot of scientists doing it," she says. To combine the two halves of her life, she teamed up with her fellow aerialists to create the midair dance based on her scientific research. Nagendra's circus extravaganza is the overall winner of this year's "Dance Your Ph.D." contest. -
Physicists Identify Possible New Particle Behind Dark Matter
sciencehabit writes: Like cops tracking the wrong person, physicists seeking to identify dark matter — the mysterious stuff whose gravity appears to bind the galaxies — may have been stalking the wrong particle. In fact, a particle with some properties opposite to those of physicists' current favorite dark matter candidate — the weakly interacting massive particle, or WIMP — would do just as good a job at explaining the stuff, a quartet of theorists says. Hypothetical strongly interacting massive particles — or SIMPs — would also better account for some astrophysical observations, they argue. -
Ebola Forecast: Scientists Release Updated Projections and Tracking Maps
An anonymous reader writes Scientists of the Northeastern University, in collaboration with European scientists, developed a modeling approach aimed at assessing the progression of the Ebola epidemic in West Africa and its international spread under the assumption that the outbreak continues to evolve at the current pace. They also considered the impact of travel restrictions, and concluded that such restrictions may delay by only a few weeks the risk that the outbreak extends to new countries. Instead, travel bans could hamper the delivery of medical supplies and the deployment of specialized personnel to manage the epidemic. In the group's page, there's also an updated assessment of the probability of Ebola virus disease case importation in countries across the world, which was also invoked during the Congressional Ebola debate. The group also released a map with real-time tracking of conversations about Ebola on Twitter. Policy makers and first responders are the main target audience of the tool, which is able to show a series of potential warnings and events (mostly unconfirmed) related to Ebola spreading and case importation. -
Drones Could 3D-Map Scores of Hectares of Land In Just a Few Hours
sciencehabit writes: Unmanned drones aren't just for warfare. In recent years, they've been used to map wildlife and monitor crop growth. But current software can't always handle the vast volume of images they gather. Now, researchers have developed an algorithm that will allow drones to 3D-map scores of hectares of land in less than a day — an advance that is important for cost-effective farming, disaster relief, and surveillance operations.
Their computer program directly projects the points from each photo onto a 3D space without knowing the exact shape of the land or the camera positions. As a result, the tie points don't necessarily match up, which means the same corn plant can have two projections on the model. When that happens, the algorithm automatically takes the middle point between the two projections as the more accurate location and adjusts the camera position accordingly, one image at a time. Because the algorithm tweaks far fewer things at each step, the shortcut drastically speeds up calculations. Once the software has adjusted the camera positions for all the photos, the software repeats the entire process — starting from projecting the points to the 3D space — to correct for any errors. -
Taking the Census, With Cellphones
sciencehabit writes: If you want to figure out how many people live in a particular part of your country, you could spend years conducting home visits and mailing out questionnaires. But a new study describes a quicker way. Scientists have figured out how to map populations using cellphone records — an approach that doesn't just reveal who lives where, but also where they go every day. The researchers also compared their results to population density data gathered through remote sensing technologies, a widely-used method that relies on satellite imaging to gather detailed information on population settlement patterns and estimate population counts. They found that the two methods are comparable in accuracy when checked against actual survey-based census data, but estimates from mobile phone data can provide more timely information, down to the hours. -
"Dance Your Ph.D." Finalists Announced
sciencehabit writes "Science has announced the 12 finalists for its annual "Dance Your PhD" contest. Among the finalists are dances about nanofibers and explosions, fusion implosions at the National Ignition Facility, and the science of tornadoes. A panel of esteemed scientists, artists, and educators are judging the finalists now to choose the winners. The winners and audience favorite will be announced on 3 November. -
Creationism Conference at Michigan State University Stirs Unease
sciencehabit writes "A creationist conference set for a major research campus — Michigan State University (MSU) in East Lansing — is creating unease among some of the school's students and faculty, which includes several prominent evolutionary biologists. The event, called the Origins Summit, is sponsored by Creation Summit, an Oklahoma-based nonprofit Christian group that believes in a literal interpretation of the Bible and was founded to "challenge evolution and all such theories predicated on chance." The one-day conference will include eight workshops, according the event's website, including discussion of how evolutionary theory influenced Adolf Hitler's worldview, why "the Big Bang is fake," and why "natural selection is NOT evolution." News of the event caught MSU's scientific community largely by surprise. Creation Summit secured a room at the university's business school through a student religious group, but the student group did not learn about the details of the program—or the sometimes provocative talk titles — until later. -
Study: Past Climate Change Was Caused by Ocean, Not Just the Atmosphere
Chipmunk100 writes Most of the concerns about climate change have focused on the amount of greenhouse gases that have been released into the atmosphere. Researchers have found that circulation of the ocean plays an equally important role in regulating the earth's climate. The study results were published the journal Science (abstract. "Our study suggests that changes in the storage of heat in the deep ocean could be as important to climate change as other hypotheses – tectonic activity or a drop in the carbon dioxide level – and likely led to one of the major climate transitions of the past 30 million years," said one of the authors." -
High Speed Evolution
Taco Cowboy writes: Normally, the term "evolution" implicitly refers to super-long time frames. However, in the case of lizards on Florida islands, evolution seems to have shifted into a higher gear. Researchers have documented noticeable changes in a native species over a period of just 15 years, after an invading species altered their behavior (abstract). "After contact with the invasive species, the native lizards began perching higher in trees, and, generation after generation, their feet evolved to become better at gripping the thinner, smoother branches found higher up. The change occurred at an astonishing pace: Within a few months, native lizards had begun shifting to higher perches, and over the course of 15 years and 20 generations, their toe pads had become larger, with more sticky scales on their feet.
'We did predict that we'd see a change, but the degree and quickness with which they evolved was surprising,' said Yoel Stuart, a postdoctoral researcher in the Department of Integrative Biology at The University of Texas at Austin and lead author of the study... 'To put this shift in perspective, if human height were evolving as fast as these lizards' toes, the height of an average American man would increase from about 5 foot 9 inches today to about 6 foot 4 inches within 20 generations — an increase that would make the average U.S. male the height of an NBA shooting guard,' said Stuart." -
Recent Nobel Prize Winner Revolutionizes Microscopy Again
An anonymous reader writes: Eric Betzig recently shared in the Nobel Prize for Chemistry for his work on high-resolution microscopy. Just yesterday, Betzig and a team of researchers published a new microscopy technique (abstract) that "allows them to observe living cellular processes at groundbreaking resolution and speed." According to the article, "Until now, the best microscope for viewing living systems as they moved were confocal microscopes. They beam light down onto a sample of cells. The light penetrates the whole sample and bounces back. ... The light is toxic, and degrades the living system over time. Betzig's new microscope solves this by generating a sheet of light that comes in from the side of the sample, made up of a series of beams that harm the sample less than one solid cone of light. Scientists can now snap a high-res image of the entire section they're illuminating, without exposing the rest of the sample to any light at all." -
Decades-old Scientific Paper May Hold Clues To Dark Matter
sciencehabit writes: Here's one reason libraries hang on to old science journals: A paper from an experiment conducted 32 years ago may shed light on the nature of dark matter, the mysterious stuff whose gravity appears to keep the galaxies from flying apart. The old data put a crimp in the newfangled concept of a 'dark photon' and suggest that a simple bargain-basement experiment could put the idea to the test. The data come from E137, a "beam dump" experiment that ran from 1980 to 1982 at SLAC National Accelerator Laboratory in Menlo Park, California. In the experiment, physicists slammed a beam of high-energy electrons, left over from other experiments, into an aluminum target to see what would come out. Researchers placed a detector 383 meters behind the target, on the other side of a sandstone hill 179 meters thick that blocked any ordinary particles. -
Leaked Documents Reveal Behind-the-Scenes Ebola Vaccine Issues
sciencehabit writes Extensive background documents from a meeting that took place today at the World Health Organization (WHO) have provided new details about exactly what it will take to test, produce, and bankroll Ebola vaccines, which could be a potential game changer in the epidemic. ScienceInsider obtained materials that vaccinemakers, governments, and WHO provided to the 100 or so participants at a meeting on 'access and financing' of Ebola vaccines. The documents put hard numbers on what until now have been somewhat fuzzy academic discussions. And they make clear to the attendees—who include representatives from governments, industry, philanthropies, and nongovernmental organizations—that although testing and production are moving forward at record speed, knotty issues remain. -
Oldest Human Genome Reveals When Our Ancestors Mixed With Neanderthals
sciencehabit writes DNA recovered from a femur bone in Siberia belongs to a man who lived 45,000 years ago, according to a new study. His DNA was so well preserved that scientists were able to sequence his entire genome, making his the oldest complete modern human genome on record. Like present-day Europeans and Asians, the man has about 2% Neanderthal DNA. But his Neanderthal genes are clumped together in long strings, as opposed to chopped up into fragments, indicating that he lived not long after the two groups swapped genetic material. The man likely lived 7000 to 13,000 years after modern humans and Neanderthals mated, dating the mixing to 52,000 to 58,000 years ago, the researchers conclude. That's a much smaller window than the previous best estimate of 37,000 to 86,000 years ago. -
Fiber Optics In Antarctica Will Monitor Ice Sheet Melting
sciencehabit writes: Earth is rapidly being wired with fiber-optic cables — inexpensive, flexible strands of silicon dioxide that have revolutionized telecommunications. They've already crisscrossed the planet's oceans, linking every continent but one: Antarctica. Now, fiber optics has arrived at the continent, but to measure ice sheet temperatures rather than carry telecommunication signals. A team of scientists using an innovative fiber-optic cable–based technology has measured temperature changes within and below the ice over 14 months. This technology, they say, offers a powerful new tool to observe and quantify melting at the base of the West Antarctic Ice Sheet. -
Smart Battery Tells You When It's About To Explode
sciencehabit writes Material scientists have found a clever way to alert users of damaged batteries before any hazard occurs. A typical lithium-ion cell consists of a lithium oxide cathode and a graphite anode, separated by a thin, porous polymer sheet that allows ions to travel between the electrodes. When the cell is overcharged, microscopic chains of lithium, called "dendrites," sprout from the anode and pierce through the polymer separator until they touch the cathode. An electrical current passing through the dendrites to the cathode can short-circuit the cell, which causes overheating and, in some cases, fire. Attempts to stop dendrite formation have met with limited success, so the researchers tried something different. They built a "smart" separator by sandwiching a 50-nanometer thin copper layer between two polymer sheets and connecting the copper layer to a third electrode for voltage measurement. When the dendrites reach the separator, the voltage between the anode and the copper layer drops to zero, alerting users that they should change the damaged battery while it is still operating safely—disaster averted. -
Feces-Filled Capsules Treat Bacterial Infection
sciencehabit writes Clostridium difficile infections kill approximately 14,000 Americans every year, often because the diarrhea-causing bacteria are highly resistant to standard antibiotics. Now, scientists have found an unusual way to combat the bugs: human feces in pill form. In the new study, researchers show that frozen fecal matter encapsulated in clear, 1.6 g synthetic pills was just as safe and effective as traditional fecal transplant techniques at treating C. difficile. Within 8 weeks or less, 18 out of 20 participants saw a complete resolution of diarrhea after consuming 30 or 60 of the feces-filled capsules. "It's probably not the best experience of your life," says team leader Ilan Youngster, a pediatric infectious disease doctor at Harvard University. "But it beats getting a tube stuck down your throat or a colonoscopy or having C. diff." -
Z Machine Makes Progress Toward Nuclear Fusion
sciencehabit writes Scientists are reporting a significant advance in the quest to develop an alternative approach to nuclear fusion. Researchers at Sandia National Laboratories in Albuquerque, New Mexico, using the lab's Z machine, a colossal electric pulse generator capable of producing currents of tens of millions of amperes, say they have detected significant numbers of neutrons — byproducts of fusion reactions — coming from the experiment. This, they say, demonstrates the viability of their approach and marks progress toward the ultimate goal of producing more energy than the fusion device takes in. -
Indonesian Cave Art May Be World's Oldest
sciencehabit writes The world's oldest cave art may not lie in Europe but rather halfway around the globe in Indonesia, according to a new study. The images date to around 40,000 years ago, making them a similar age to cave paintings from Western Europe that represent the world's oldest known cave art. The findings suggest that humans were producing figurative art by around 40,000 years ago at opposite ends of the Pleistocene Eurasian world. Further research is needed to investigate whether rock art was an integral part of the cultural repertoire of the first modern human populations to reach Southeast Asia from Africa, or whether these practices developed independently in different regions. -
Chimpanzee "Personhood" Is Back In Court
sciencehabit writes Chimpanzees are back in court. Judges in New York State heard the first in a series of appeals attempting to grant "legal personhood" to the animals. The case is part of a larger effort by an animal rights group known as the Nonhuman Rights Project (NhRP) to free a variety of creatures—from research chimps to aquarium dolphins—from captivity. If the case is successful, it could grant personhood to chimps throughout the state. -
Killer Whales Caught On Tape Speaking Dolphin
sciencehabit writes Two years ago, scientists showed that dolphins imitate the sounds of whales. Now, it seems, whales have returned the favor. Researchers analyzed the vocal repertoires of 10 captive orcas, three of which lived with bottlenose dolphins and the rest with their own kind. Of the 1551 vocalizations these seven latter orcas made, more than 95% were the typical pulsed calls of killer whales. In contrast, the three orcas that had only dolphins as pals busily whistled and emitted dolphinlike click trains and terminal buzzes, the scientists report in the October issue of The Journal of the Acoustical Society of America. The findings make orcas one of the few species of animals that, like humans, is capable of vocal learning (video)—a talent considered a key underpinning of language." -
Ebola Vaccine Trials Forcing Tough Choices
An anonymous reader writes: Medical researchers hope an experimental vaccine for Ebola can help protect against infection and slow the spread of the disease. Efficacy trials for the vaccine begin in a few months, and it's forcing some difficult decisions for health care officials. The first test will involve front line health care workers, who, as a group, are at the gravest risk of infection. But every trial needs a control group, and scientists are bitterly divided over whether the vaccine should be withheld from a portion of those putting their lives on the line to protect the rest of us. Development of the vaccine has been vastly accelerated already, due to the virus's spread and its mortality rate.
"The leading alternative is a design known as step-wedge, which essentially uses time to create a control group. In this design, researchers take advantage of the inescapable reality that large-scale trials can't give everyone the vaccine on the exact same date; they compare the rates of infection in people already vaccinated with those who have yet to receive the shots. Barney Graham, a virologist ... says "people are more comfortable" with the step-wedge design, because everyone in such a study would get the Ebola vaccine. But statistically speaking, this design makes it more difficult to determine the vaccine's worth, and it takes longer." NY Mag has a related story summarizing the treatments currently being used to fight Ebola. -
Genes Don't Just Predict Intelligence, But Also How Well You Do In School
sciencehabit writes: If you sailed through school with high grades and perfect test scores, you probably did it with traits beyond sheer smarts. A new study of more than 6000 pairs of twins finds that academic achievement is influenced by genes affecting motivation, personality, confidence, and dozens of other traits, in addition to those that shape intelligence (abstract). The results may lead to new ways to improve childhood education. -
Study Weighs In On the Reliability of Eyewitness Testimony
sciencehabit writes The victim peers across the courtroom, points at a man sitting next to a defense lawyer, and confidently says, "That's him!" Such moments have a powerful sway on jurors who decide the fate of thousands of people every day in criminal cases. But how reliable is eyewitness testimony? A new report concludes that the use of eyewitness accounts need tighter control, and among its recommendations is a call for a more scientific approach to how eyewitnesses identify suspects during the classic police lineup. -
Past Measurements May Have Missed Massive Ocean Warming
An anonymous reader writes "Previous estimates of global ocean warming have been significantly underestimated due to historically sparse temperature data from the Southern Ocean, new research has found. From the article: "Earth's oceans have absorbed more than 90% of the warming caused by greenhouse gases, researchers estimate, with the stored heat showing up as warmer seawater. But a new analysis suggests scientists may have underestimated the size of the heat sink in the upper ocean—which could have implications for researchers trying to understand the pace and scale of past warming." -
AIDS Origin Traced To 1920s Kinshasa
An anonymous reader writes: A new study published in Science (abstract) has traced the origin of HIV/AIDS back to Kinshasa in the 1920s. The authors say Kinshasa, now in the Democratic Republic of Congo, was then undergoing explosive population growth while supporting an abundant sex trade. These factors, combined with the use of unsterilized needles at health clinics and the railways moving a million people in and out of the city each year, conspired to start the pandemic. "HIV is a mutated version of a chimpanzee virus, known as simian immunodeficiency virus, which probably made the species-jump through contact with infected blood while handling bush meat. The virus made the jump on multiple occasions. One event led to HIV-1 subgroup O which affects tens of thousands in Cameroon. Yet only one cross-species jump, HIV-1 subgroup M, went on to infect millions of people across every country in the world." -
Physicists Observe the Majorana Fermion, Which Is Its Own Antiparticle
Charliemopps writes: "For the first time Princeton University scientists have observed a Majorana fermion, a long-predicted but never observed exotic particle that acts as both matter and anti-matter (abstract). "The setup they created starts with an ultrapure crystal of lead, whose atoms naturally line up in alternating rows that leave atomically thin ridges on the crystal's surface. The researchers then deposited pure iron into one of these ridges to create a wire that is just one atom wide and about three atoms thick. ...[Next, they] placed the lead and the embedded iron wire under the scanning-tunneling microscope and cooled the system to -272 degrees Celsius, just a degree above absolute zero. After about two years of painstaking work, they confirmed that superconductivity in the iron wire matched the conditions required for Majorana fermion to be created in their material." The particle is surprisingly stable. Being in both states at once seems to make it interact very weakly with its surrounding material. This could also be a major step towards quantum computing. -
Satellites Reveal Hidden Features At the Bottom of Earth's Seas
sciencehabit writes Oceanographers have a saying: Scientists know more about the surface of Mars than they do about the landscape at the bottom of our oceans. But that may soon change. Using data from satellites that measure variations in Earth's gravitational field, researchers have found a new and more accurate way to map the sea floor. The improved resolution has already allowed them to identify previously hidden features—including thousands of extinct volcanoes more than 1000 meters tall—as well as piece together some lingering uncertainties in Earth's ancient history. -
Underwater Landslide May Have Doubled 2011 Japanese Tsunami
sciencehabit writes An underwater landslide the size of the Paris may have triggered the worst of the tsunami that struck Japan on 11 March 2011, a new study claims. In the new study, researchers worked back from details of the ocean surface motion recorded by gauges along the Japanese shore on the day of the earthquake. Much as sound waves can help the ear pinpoint the source of a gunshot and whether a small pistol or a large cannon fired it, tsunami waves carry the imprint of the ocean floor disturbance that created them. The team concludes that during the earthquake a slab of sediment 20 km by 40 km and up to 2 km thick slid about 300 meters down the steep slope of Japan Trench, 'acting like a piston.' -
How Did the 'Berlin Patient' Rid Himself of HIV?
sciencehabit writes: Researchers are closer to unraveling the mystery of how Timothy Ray Brown, the only human cured of HIV, defeated the virus, according to a new study. Although the work doesn't provide a definitive answer, it rules out one possible explanation. [R]esearchers point to three different factors that could independently or in combination have rid Brown’s body of HIV. The first is the process of conditioning, in which doctors destroyed Brown’s own immune system with chemotherapy and whole body irradiation to prepare him for his bone marrow transplant. His oncologist, Gero Hütter, who was then with the Free University of Berlin, also took an extra step that he thought might not only cure the leukemia but also help rid Brown’s body of HIV. He found a bone marrow donor who had a rare mutation in a gene that cripples a key receptor on white blood cells the virus uses to establish an infection. (For years, researchers referred to Brown as "the Berlin patient.") The third possibility is his new immune system attacked remnants of his old one that held HIV-infected cells, a process known as graft versus host disease. -
Device Allows Paralyzed Rats To Walk, Human Trials Scheduled Next Summer
An anonymous reader writes "A new technique pioneered by scientists working on project NEUWalk at the Swiss Federal Institute for Technology (EPFL) have figured out a way to reactivate the severed spinal cords of fully paralyzed rats, allowing them to walk again via remote control. Human trials are scheduled for next summer. "We have complete control of the rat's hind legs," EPFL neuroscientist Grégoire Courtine said. "The rat has no voluntary control of its limbs, but the severed spinal cord can be reactivated and stimulated to perform natural walking. We can control in real-time how the rat moves forward and how high it lifts its legs." -
US Asks Universities To Flag Risky Pathogen Experiments
sciencehabit writes 'Academic scientists with federal funding who work with any of 15 dangerous microbes or toxins will soon have to flag specific studies that could potentially be used to cause harm and work with their institutions to reduce risks, according to new U.S. government rules released today. The long-awaited final rule is similar to a February 2013 draft and is "about what we expected," says Carrie Wolinetz, a deputy director of federal relations at the Association of American Universities (AAU) in Washington, D.C., which represents more than 60 major research universities. Those schools see the rules as replicating other federal security and safety rules, Wolinetz says, but will adjust to them. But some observers have concerns, such as that the rules do not apply to other risky biological agents. In a conference call with reporters today, a White House official said the government is open to a "broader discussion" about whether it should expand the list of 15 regulated agents. -
Fukushima Radiation Still Poisoning Insects
sciencehabit writes: Eating food contaminated with radioactive particles may be more perilous than previously thought — at least for insects. Butterfly larvae fed even slightly tainted leaves collected near the Fukushima Daiichi Nuclear Power Station were more likely to suffer physical abnormalities and low survival rates than those fed uncontaminated foliage, a new study finds. The research suggests that the environment in the Fukushima region, particularly in areas off-limits to humans because of safety concerns, will remain dangerous for wildlife for some time. In other lingering radiation news, reader Rambo Tribble writes: Forest detritus, contaminated in the aftermath of the 1986 Chernobyl disaster (abstract), is decaying at a much slower rate than normal, building up and creating a significant fire risk. This, in turn, is creating a real potential for the residual radioactive material to be distributed, through smoke, over a broad area of Europe and Russia. Looking at different possible fire intensities, researchers speculate, "20 to 240 people would likely develop cancer, of which 10 to 170 cases may be fatal." These figures are similar to those hypothesized for Fukushima. -
Anonymous Peer-review Comments May Spark Legal Battle
sciencehabit writes: The power of anonymous comments — and the liability of those who make them — is at the heart of a possible legal battle embroiling PubPeer, an online forum launched in October 2012 for anonymous, postpublication peer review. A researcher who claims that comments on PubPeer caused him to lose a tenured faculty job offer now intends to press legal charges against the person or people behind these posts — provided he can uncover their identities, his lawyer says. -
Ancient Campfires Led To the Rise of Storytelling
sciencehabit writes A study of evening campfire conversations by the Ju/'hoan people of Namibia and Botswana suggests that by extending the day, fire allowed people to unleash their imaginations and tell stories, rather than merely focus on mundane topics. As scientists report, whereas daytime talk was focused almost entirely on economic issues, land rights, and complaints about other people, 81% of the firelight conversation was devoted to telling stories, including tales about people from other Ju/'hoan communities. The team suggests that campfires allowed human ancestors to expand their minds in a similar way and also solidified social networks. -
Study: Chimpanzees Have Evolved To Kill Each Other
sciencehabit writes A major new study of warfare in chimpanzees finds that lethal aggression can be evolutionarily beneficial in that species, rewarding the winners with food, mates, and the opportunity to pass along their genes. The findings run contrary to recent claims that chimps fight only if they are stressed by the impact of nearby human activity—and could help explain the origins of human conflict as well. -
Scientists Capture the Sound Made By a Single Atom
Jason Koebler writes Researchers at Columbia University and Sweden's Chalmers University of Technology say that they have, for the first time, "captured" the sound a single atom makes when it is excited—a single "phonon," as it were. So, why do this? For one, the team wanted to simply see if it could capture the softest sound ever made, which is certainly a noble goal. But, secondly, the researchers wanted to explore the quantum nature of sound. Photons have always been used in quantum experiments, but they're pretty hard to manipulate because they're so fast. Phonons move 10^5 slower and thus could make quantum communication easier. -
Journal Published Flawed Stem Cell Papers Despite Serious Misgivings About Work
sciencehabit writes: As two discredited, and now retracted, stem cell papers have produced an almost unimaginable fallout — a national hero accused of scientific fraud, the revamping of one of Japan's major research institutes, and the suicide of a respected cell biologist — researchers have privately and publicly asked how Nature could have published work that, in retrospect, seems so obviously flawed. Another piece of the puzzle has now come to light. The Science news team received a copy of email correspondence between a Nature editor and Haruko Obokata, the lead author of the papers, which indicates the work initially received as rocky a reception there as at two other journals, Cell and Science, that had rejected the work previously. The email, dated 4 April 2013, includes detailed separate criticisms of the two papers and suggestions for new data to support the authors' claims of a simple and novel way to make stem cells that could form the myriad cell types within a body. The Nature editor rejected the papers, but left open a window, writing, "Should further experimental data allow you to address these criticisms, we would be happy to look at a revised manuscript." The two papers were published 10 months later. -
Researcher Fired At NSF After Government Questions Her Role As 1980s Activist
sciencehabit writes Valerie Barr was a tenured professor of computer science at Union College in Schenectady, New York, with a national reputation for her work improving computing education and attracting more women and minorities into the field. But federal investigators say that Barr lied during a routine background check about her affiliations with a domestic terrorist group that had ties to the two organizations to which she had belonged in the early 1980s. On 27 August, NSF said that her 'dishonest conduct' compelled them to cancel her temporary assignment immediately, at the end of the first of what was expected to be a 2-year stint. Colleagues who decry Barr's fate worry that the incident could make other scientists think twice about coming to work for NSF. In addition, Barr's case offers a rare glimpse into the practices of the Office of Personnel Management (OPM), an obscure agency within the White House that wields vast power over the entire federal bureaucracy through its authority to vet recently hired workers. -
Reanalysis of Clinical Trials Finds Misleading Results
sciencehabit writes: Clinical trials rarely get a second look — and when they do, their findings are not always what the authors originally reported. That's the conclusion of a new study (abstract), which compared how 37 studies that had been reanalyzed measured up to the original. In 13 cases, the reanalysis came to a different outcome — a finding that suggests many clinical trials may not be accurately reporting the effect of a new drug or intervention. Moreover, only five of the reanalyses were by an entirely different set of authors, which means they did not get a neutral relook.
In one of the trials, which examined the efficacy of the drug methotrexate in treating systemic sclerosis—an autoimmune disease that causes scarring of the skin and internal organs—the original researchers found the drug to be not much more effective than the placebo, as they reported in a 2001 paper. However, in a 2009 reanalysis of the same trial, another group of researchers including one of the original authors used Bayesian analysis, a statistical technique to overcome the shortcomings of small data sets that plague clinical trials of rare diseases such as sclerosis. The reanalysis found that the drug was, as it turned out, more effective than the placebo and had a good chance of benefiting sclerosis patients. -
Surprise! More Than Twice As Much Mercury In Environment As Thought
sciencehabit writes The most comprehensive estimate of mercury released into the environment is putting a new spotlight on the potent neurotoxin. By accounting for mercury in consumer products, such as thermostats, and released by industrial processes, the calculations more than double previous tallies of the amount of mercury that has entered the environment since 1850. The analysis also reveals a previously unknown spike in mercury emissions during the 1970s, caused largely by the use of mercury in latex paint. -
Scientists Sequence Coffee Genome, Ponder Genetic Modification
nbauman sends word that researchers have completed a project to sequence the genome of Coffea canephora, a species of plant responsible for roughly 30% of the world's coffee production. In the course of their genetic mapping, the researchers "pinpointed genetic attributes that could help in the development of new coffee varieties better able to endure drought, disease and pests, with the added benefit of enhancing flavor and caffeine levels." They also discovered a broad range of genes that contribute to the production of flavor-related compounds and caffeine. Plant genomist Victor Albert said, "For any agricultural plant, having a genome is a prerequisite for any sort of high technology breeding or molecular modification. Without a genome, we couldn't do any real advanced research on coffee that would allow us to improve it — not in this day and age." -
Giant Dinosaur Unearthed In Argentina
sciencehabit writes Researchers working in Argentina have discovered the most complete skeleton of a titanosaur, a group of gigantic plant-eating dinosaurs that dominated the Southern Hemisphere beginning about 90 million years ago. The new dino, named Dreadnoughtus schrani, was 26 meters long and weighed about 59 metric tons—that is, twice as long as Tyrannosaurus rex and as heavy as a herd of elephants. That puts it on a par with other well-known giants such as Argentinosaurus (but it's four times as large as the perhaps better known Diplodocus). The researchers say that the beast was so big it would have had no fear of predators. And it was about to get bigger: A close examination of the fossils, especially its back and shoulder bones, indicates that the animal was still growing when it died. -
Out of the Warehouse: Climate Researchers Rescue Long-Lost Satellite Images
sciencehabit (1205606) writes "Once stashed in warehouses in Maryland and North Carolina, images and video captured from orbit by some of NASA's first environmental satellites in the mid-1960s are now yielding a trove of scientific data. The Nimbus satellites, originally intended to monitor Earth's clouds in visible and infrared wavelengths, also would have captured images of sea ice, researchers at the University of Colorado's National Snow and Ice Data Center realized when they heard about the long-lost film canisters in 2009. After acquiring the film—and then tracking down the proper equipment to read and digitize its 16-shades-of-gray images, which had been taken once every 90 seconds or so—the team set about scanning and then stitching the images together using sophisticated software. So far, more than 250,000 images have been made public, including the first image taken by Nimbus-1 on 31 August 1964, of an area near the tip of the Antarctic Peninsula. Besides yielding a wealth of sea ice data, the data recovery project, which will end early next year, could also be used to extend satellite records of deforestation and sea surface temperatures."