Domain: nature.com
Stories and comments across the archive that link to nature.com.
Stories · 1,757
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New Blood Test Offers Early Warning for Alzheimer's Onset
Georgetown researcher (and executive dean of Georgetown's medical school) Howard Federoff has taken a "systems" approach to diagnostics for certain chronic diseases. By comparing blood samples taken from patients who subsequently developed Alzheimer's to blood samples after the disease has manifested, Federoff has identified markers and created a blood test that is described as "90 percent accurate" (the BBC article does not delve into the ratio of false positives to false negatives) in predicting whether a currently healthy patient is likely to develop Alzheimer's in the following three years. Understandably, this raises some ethical and practical questions. What would you do differently if this test came back positive for yourself? Or for a parent? Here's the (paywalled) paper, at Nature Medicine. -
Dinosaurs Done In By... Dark Matter?
bmahersciwriter writes "Theoretical physicists propose that the Sun periodically crosses into a dense layer of dark matter sandwiching the Milky Way. The gravitational push and pull that this creates disturbs debris in the Oort cloud sending deadly comets and asteroids ricocheting around the solar system. This passage happens, their admittedly speculative model suggests, every 35 million years, which jibes somewhat with evidence on impact craters. Take it with a dino-sized grain of salt." -
Scientists Revive a Giant 30,000 Year Old Virus From Ice
bmahersciwriter writes "It might be terrifying if we were amoebae. Instead, it's just fascinating. The virus, found in a hunk of Siberian ice, is huge, but also loosely packaged, which is strange says evolutionary biologist Jean-Michel Claverie: 'We thought it was a property of viruses that they pack DNA extremely tightly into the smallest particle possible, but this guy is 150 times less compacted than any bacteriophage [viruses that infect bacteria]. We don't understand anything anymore!'" -
Pine Forest Vapor Particles Can Limit Climate Change
Solo-Malee writes "New research suggests a strong link between the powerful smell of pine trees and climate change. Scientists say they've found a mechanism by which these scented vapors turn into aerosols above boreal forests. These particles promote cooling by reflecting sunlight back into space and helping clouds to form." -
Publishers Withdraw More Than 120 Fake Papers
bmahersciwriter writes "Over the past two years, computer scientist Cyril Labbé of Joseph Fourier University in Grenoble, France, has cataloged computer-generated papers that made it into more than 30 published conference proceedings between 2008 and 2013. Sixteen appeared in publications by Springer, which is headquartered in Heidelberg, Germany, and more than 100 were published by the Institute of Electrical and Electronic Engineers (IEEE), based in New York. Both publishers, which were privately informed by Labbé, say that they are now removing the papers." Looks like journal trolling is really easy. -
1870s Horse Flu Epidemic Brought US Economy To Its Knees
Nemo the Magnificent writes with this excerpt from the University of Arizona: "A new study (paywalled) published in the journal Nature provides the most comprehensive analysis to date of the evolutionary relationships of influenza virus across different host species over time... In the 1870s, an immense horse flu outbreak swept across North America. City by city and town by town, horses got sick and perhaps five percent of them died. Half of Boston burned down during the outbreak, because there were no horses to pull the pump wagons. In the West, the U.S. Cavalry was fighting the Apaches on foot because all the horses were sick... The horse flu outbreak pulled the rug out from under the economy."" -
Why P-values Cannot Tell You If a Hypothesis Is Correct
ananyo writes "P values, the 'gold standard' of statistical validity, are not as reliable as many scientists assume. Critically, they cannot tell you the odds that a hypothesis is correct. A feature in Nature looks at why, if a result looks too good to be true, it probably is, despite an impressive-seeming P value." -
National Ignition Facility Takes First Steps Towards Fusion Energy
sciencehabit writes "As it approaches its fifth birthday, the National Ignition Facility (NIF), a troubled laser fusion facility in California, has finally produced some results that fusion scientists can get enthusiastic about. In a series of experiments late last year (abstract 1, abstract 2), NIF researchers managed to produce energy yields 10 times greater than produced before and to demonstrate the phenomenon of self-heating that will be crucial if fusion is to reach its ultimate goal of 'ignition'—a self-sustaining burning reaction that produces more energy than it consumes." -
Iconic Predator-Prey Study In Peril
An anonymous reader writes "Scientists have charted the ebb and flow of moose and wolf populations on Isle Royale in Lake Superior for nearly 50 years. Ice bridges to Canada regularly supplied the genetic stocks for much of that time, but have been rare in recent years leading to inbreeding, dwindling populations and developmental deformity for the wolves that inhabit the island. Now, with the first solid freeze in six years, new wolves could join the mix ... or the remaining island dwellers could leave." If new wolves do not appear, or all of the current wolves leave, the moose would end up destroying the native Fir population. The wildlife service is considering introducing new wolves as part of a genetic rescue, or reintroducing wolves should the population reach zero on its own. -
Oldest Known Star In the Universe Discovered
Zothecula writes "A team of astronomers at The Australian National University working on a five-year project to produce the first comprehensive digital survey of the southern sky has discovered the oldest known star in the Universe. The star dates back 13.7 billion years, only shortly after the Big Bang itself. It's also nearby (at least, from a cosmological perspective) — about 6,000 light-years away. The star is notable for the very small amount of iron it contains (abstract). The lead researcher, Stefan Keller, said, 'To make a star like our Sun, you take the basic ingredients of hydrogen and helium from the Big Bang and add an enormous amount of iron – the equivalent of about 1,000 times the Earth's mass. To make this ancient star, you need no more than an Australia-sized asteroid of iron and lots of carbon. It's a very different recipe that tells us a lot about the nature of the first stars and how they died.'" -
Massive New Cambrian-Era Fossil Bed Found
jfbilodeau sends word of a massive new trove of fossils located in Canada, which scientists say will rival the acclaimed Burgess Shale fossil bed. The rock formation inside which both fossil sites were found is roughly 505 million years old (abstract). The fossils provide insight into the Cambrian explosion, a time that brought the rapid appearance and diversification of many animal forms. "In just two weeks, the research team collected more than 3,000 fossils representing 55 species. Fifteen of these species are new to science." Paleontologist Jean-Bernard Caron said, "The rate at which we are finding animals — many of which are new — is astonishing, and there is a high possibility that we'll eventually find more species here than at the original Yoho National Park site, and potentially more than from anywhere else in the world." The fossils at the new site are about 100,000 years younger and are better preserved than those at the renowned Burgess shale site. -
Graphene Conducts Electricity Ten Times Better Than Expected
ananyo writes "Physicists have produced nanoribbons of graphene — the single-atom-thick carbon — that conduct electrons better than theory predicted even for the most idealized form of the material (abstract). The finding could help graphene realize its promise in high-end electronics, where researchers have long hoped it could outperform traditional materials such as silicon. In graphene, electrons can move faster than in any other material at room temperature. But techniques that cut sheets of graphene into the narrow ribbons needed to form wires of a nano-scale circuit leave ragged edges, which disrupt the electron flow. Now a team led by physicist Walt de Heer at the Georgia Institute of Technology in Atlanta has made ribbons that conduct electric charges for more than 10 micrometres without meeting resistance — 1,000 times farther than in typical graphene nanoribbons. The ribbons made by de Heer's team in fact conduct electrons ten times better than standard theories of electron transport they should, say the authors." -
Graphene Conducts Electricity Ten Times Better Than Expected
ananyo writes "Physicists have produced nanoribbons of graphene — the single-atom-thick carbon — that conduct electrons better than theory predicted even for the most idealized form of the material (abstract). The finding could help graphene realize its promise in high-end electronics, where researchers have long hoped it could outperform traditional materials such as silicon. In graphene, electrons can move faster than in any other material at room temperature. But techniques that cut sheets of graphene into the narrow ribbons needed to form wires of a nano-scale circuit leave ragged edges, which disrupt the electron flow. Now a team led by physicist Walt de Heer at the Georgia Institute of Technology in Atlanta has made ribbons that conduct electric charges for more than 10 micrometres without meeting resistance — 1,000 times farther than in typical graphene nanoribbons. The ribbons made by de Heer's team in fact conduct electrons ten times better than standard theories of electron transport they should, say the authors." -
Graphene Conducts Electricity Ten Times Better Than Expected
ananyo writes "Physicists have produced nanoribbons of graphene — the single-atom-thick carbon — that conduct electrons better than theory predicted even for the most idealized form of the material (abstract). The finding could help graphene realize its promise in high-end electronics, where researchers have long hoped it could outperform traditional materials such as silicon. In graphene, electrons can move faster than in any other material at room temperature. But techniques that cut sheets of graphene into the narrow ribbons needed to form wires of a nano-scale circuit leave ragged edges, which disrupt the electron flow. Now a team led by physicist Walt de Heer at the Georgia Institute of Technology in Atlanta has made ribbons that conduct electric charges for more than 10 micrometres without meeting resistance — 1,000 times farther than in typical graphene nanoribbons. The ribbons made by de Heer's team in fact conduct electrons ten times better than standard theories of electron transport they should, say the authors." -
India To Build World's Largest Solar Plant
ananyo writes "India has pledged to build the world's most powerful solar plant. With a nominal capacity of 4,000 megawatts, comparable to that of four full-size nuclear reactors, the 'ultra mega' project will be more than ten times larger than any other solar project built so far, and it will spread over 77 square kilometres of land — greater than the island of Manhattan. Six state-owned companies have formed a joint venture to execute the project, which they say can be completed in seven years at a projected cost of US$4.4 billion. The proposed location is near Sambhar Salt Lake in the northern state of Rajasthan." -
Elsevier Opens Its Papers To Text-Mining
ananyo writes "Publishing giant Elsevier says that it has now made it easy for scientists to extract facts and data computationally from its more than 11 million online research papers. Other publishers are likely to follow suit this year, lowering barriers to the computer-based research technique. But some scientists object that even as publishers roll out improved technical infrastructure and allow greater access, they are exerting tight legal controls over the way text-mining is done. Under the arrangements, announced on 26 January at the American Library Association conference in Las Vegas, Nevada, researchers at academic institutions can use Elsevier's online interface (API) to batch-download documents in computer-readable XML format. Elsevier has chosen to provisionally limit researchers to 10,000 articles per week. These can be freely mined — so long as the researchers, or their institutions, sign a legal agreement. The deal includes conditions: for instance, that researchers may publish the products of their text-mining work only under a license that restricts use to non-commercial purposes, can include only snippets (of up to 200 characters) of the original text, and must include links to original content." -
Astronomers Investigating Unknown Object That Hit the Earth In 773 AD
KentuckyFC writes "In November 2012, a group of Japanese scientists discovered that the concentration of carbon-14 in Japanese cedar trees suddenly rose between 774 AD and 775 AD. Others have since found similar evidence and narrowed the date to 773 AD. Astronomers think this stuff must have come from space so now the quest is on to find the extraterrestrial culprit. Carbon-14 is continually generated in the atmosphere by cosmic rays hitting nitrogen atoms. But because carbon-14 is radioactive, it naturally decays back into nitrogen with a half-life of about 5700 years. This constant process of production and decay leaves the amount of carbon-14 in the atmosphere relatively constant at about one part in a trillion will be carbon-14. One possible reason for the increase is that the Sun belched a superflare our way, engulfing the planet in huge cloud of high energy protons. Recent calculations suggest this could happen once every 3000 years and so seems unlikely. Another possibility is a nearby supernova, which bathed the entire Solar System in additional cosmic rays. However, astronomers cannot see any likely candidates nearby and there are no historical observations of a supernova from that time. Yet another possibility is that a comet may have hit the Earth, dumping the extra carbon-14 in the atmosphere. But astronomers have ruled that out on the basis that a comet carrying enough carbon-14 must have been over 100 km in diameter and would surely have left other evidence such as an impact crater. So for the moment, astronomers are stumped." -
Amherst Researchers Create Magnetic Monopoles
An anonymous reader writes "Nearly 85 years after pioneering theoretical physicist Paul Dirac predicted the possibility of their existence, an international collaboration led by Amherst College Physics Professor David S. Hall '91 and Aalto University (Finland) Academy Research Fellow Mikko Möttönen has created, identified and photographed synthetic magnetic monopoles in Hall's laboratory on the Amherst campus. The groundbreaking accomplishment paves the way for the detection of the particles in nature, which would be a revolutionary development comparable to the discovery of the electron." That's quite a step beyond detecting monopoles; the Nature abstract is online, but the full paper is paywalled. -
20% of Neanderthal Genome Survives In Humans
vinces99 writes "A substantial fraction of the Neanderthal genome persists in modern human populations. A new analysis (abstract) of 665 people from Europe and East Asia shows that more than 20 percent of the Neanderthal genome survives in the DNA of this contemporary group, whose genetic information is part of the 1,000 Genomes Project." Another study published today (abstract) finds that Neanderthal genes are present in some parts of our genome that we've found to be important. Some of the genes influence fertility and skin pigment, and others actually increase our susceptibility to diseases like diabetes and lupus. The researchers are now taking these known genetic markers and seeing if they correlate with any other health conditions. -
Acid Bath Offers Easy Path To Stem Cells
ananyo writes "In 2006, Japanese researchers reported a technique for creating cells that have the embryonic ability to turn into almost any cell type in the mammalian body — the now-famous induced pluripotent stem (iPS) cells. In papers published this week in Nature, another Japanese team says that it has come up with a surprisingly simple method — exposure to stress, including a low pH — that can make cells that are even more malleable than iPS cells, and do it faster and more efficiently. The work so far has focused on mouse white blood cells but the group are now trying to make the method work with cells from adult humans. If they're successful, that would dramatically speed up the process of creating stem cells for potential clinical applications." -
Acid Bath Offers Easy Path To Stem Cells
ananyo writes "In 2006, Japanese researchers reported a technique for creating cells that have the embryonic ability to turn into almost any cell type in the mammalian body — the now-famous induced pluripotent stem (iPS) cells. In papers published this week in Nature, another Japanese team says that it has come up with a surprisingly simple method — exposure to stress, including a low pH — that can make cells that are even more malleable than iPS cells, and do it faster and more efficiently. The work so far has focused on mouse white blood cells but the group are now trying to make the method work with cells from adult humans. If they're successful, that would dramatically speed up the process of creating stem cells for potential clinical applications." -
How Farming Reshaped Our Genomes
sciencehabit writes "The earliest farmers may not have been built for the profession. They may have been unable to digest starch and milk, according to a new ancient DNA study of a nearly 8000-year-old human skeleton from Spain (a hunter-gatherer who had dark skin and blue eyes). But these pioneers did already possess immune defenses against some of the diseases that would later become the scourge of civilization. The findings are helping researchers understand what genetic and biological changes humans went through as they made the transition from hunting and gathering to farming." -
Powering Phones, PCs Using Sugar
Nerval's Lobster writes "A team of researchers at Virginia Tech University have developed a battery with energy density an order of magnitude higher than lithium-ion batteries, while being almost endlessly rechargeable and biodegradable as well – because it's made of sugar. The battery is an enzymatic biofuel fuel cell – a type of fuel cell that uses a catalyst to strip molecules from molecules of a fuel material. Instead of using platinum or nickel for catalysts, however, biofuel cells use the catalysts made from enzymes similar to those used to break down and digest food in the body. Sugar is a good fuel material because it is energy dense, easy to obtain and transport, and so simple to biodegrade that almost anything biological can eat it. Sugar-based fuel cells aren't new, but existing designs use only a small number of enzymes that don't oxidize the sugar completely, meaning the resulting battery can hold only small amounts of energy that it releases slowly. A new design that uses 13 enzymes that can circulate freely to get better access to sugar molecules, however, is able to store energy at a density of 596 amp-hours per kilogram – an order of magnitude higher than lithium-ion batteries, according to Y.H. Percival Zhang, who studies biological systems engineering at the College of Agriculture and Life Sciences and College of Engineering at Virginia Tech. "Sugar is a perfect energy storage compound in nature," Zhang said in a statement announcing publication in Nature Communications of his paper describing the battery. "So it's only logical that we try to harness this natural power in an environmentally friendly way to produce a battery."" -
Stephen Hawking: 'There Are No Black Holes'
ananyo writes "Stephen Hawking has proposed a new solution to the black-hole firewall paradox, which has been vexing physicists for almost two years. The paradox troubles physicists because if the firewall scenario is correct, Einstein's general theory of relativity is flouted. But the classical theory black hole cannot be reconciled to the quantum mechanical prediction that energy and information can escape from a black hole. Now Hawking has proposed a tantalizingly simple solution to the paradox which allows both quantum mechanics and general relativity to remain intact — black holes simply do not have an event horizon to catch fire. The key to his claim is that quantum effects around the black hole cause spacetime to fluctuate too wildly for a sharp boundary surface to exist. As Hawking writes in his paper, 'The absence of event horizons mean that there are no black holes — in the sense of regimes from which light can't escape to infinity.'" -
Water Plume Detected At Dwarf Planet Ceres
astroengine writes "Astronomers analyzing data from the now defunct Herschel infrared space observatory have made a huge discovery deep inside the asteroid belt. Dwarf planet Ceres, the largest body in the region, is generating plumes of water vapor. 'This is the first time water vapor has been unequivocally detected on Ceres or any other object in the asteroid belt and provides proof that Ceres has an icy surface and an atmosphere,' said Michael Küppers of the European Space Agency in Spain and lead author of a paper published today (Jan. 22) in the journal Nature." -
MIT Develops Inexpensive Transparent Display Using Nanoparticles
rtoz writes "Researchers at MIT have come up with an innovative approach to creating transparent displays inexpensively, while providing wide viewing angles and scalability to large sizes. To create the transparent display, silver nanoparticles are embedded in plastic, tuned to scatter only certain wavelengths of light and to allow all other wavelengths through. In this example (video), it is tuned to scatter only blue color using 60nm silver particles. The researchers believe that it can be easily enhanced to a multicolor display by creating nanoparticles that can scatter other primary colors. The ability to display graphics and texts on an inexpensive transparent screen could enable many useful applications. For example, they could bring navigation data to windshields of cars and aircraft, and advertisements to the sides of skyscrapers. Cheap 'stick-on screens' could be developed using this technology. The messages broadcast on nanoparticle screens are accessible from virtually every angle. Transparent screens themselves are not new; for example, Google is working on Google glass. But they are expensive. This MIT invention will help to produce transparent displays easily and inexpensively." -
CERN Antimatter Experiment Produces First Beam of Antihydrogen
An anonymous reader writes "Matter and antimatter annihilate immediately when they meet, so aside from creating antihydrogen, one of the key challenges for physicists is to keep antiatoms away from ordinary matter. To do so, experiments take advantage of antihydrogen's magnetic properties (which are similar to hydrogen's) and use very strong non-uniform magnetic fields to trap antiatoms long enough to study them. However, the strong magnetic field gradients degrade the spectroscopic properties of the (anti)atoms. To allow for clean high-resolution spectroscopy, the ASACUSA collaboration developed an innovative set-up to transfer antihydrogen atoms to a region where they can be studied in flight, far from the strong magnetic field (scientific paper)." -
Why Transitivity Violations Can Be Rational
ananyo writes "Organisms, including humans, are often assumed to be hard-wired by evolution to try to make optimal decisions, to the best of their knowledge. Ranking choices consistently — for example, in selecting food sources — would seem to be one aspect of such rationality. If A is preferred over B, and B over C, then surely A should be selected when the options are just A and C? This seemingly logical ordering of preferences is called transitivity. Furthermore, if A is preferred when both B and C are available, then A should 'rationally' remain the first choice when only A and B are at hand ... But sometimes animals do not display such logic. For example, honeybees and gray jays have been seen to violate the Independence of Irrational Alternatives, and so have hummingbirds ... Researchers have now used a theoretical model to show that, in fact, violations of transitivity can sometimes be the best choice (original paper) for the given situation, and therefore rational. The key is that the various choices might appear or disappear in the future. Then the decision becomes more complicated than a simple, fixed ranking of preferences. So while these choices look irrational, they aren't necessarily." -
Ampere Could Be Redefined After Experiments Track Single Electrons Crossing Chip
ananyo writes "Physicists have tracked electrons crossing a semiconductor chip one at a time — an experiment that should at last enable a rational definition of the ampere, the unit of electrical current. At present, an ampere is defined as the amount of charge flowing per second through two infinitely long wires one meter apart, such that the wires attract each other with a force of 2×10^-7 newtons per meter of length. That definition, adopted in 1948 and based on a thought experiment that can at best be approximated in the laboratory, is clumsy — almost as much of an embarrassment as the definition of the kilogram, which relies on the fluctuating mass of a 125-year-old platinum-and-iridium cylinder stored at the International Bureau of Weights and Measures in Paris. The new approach, described in a paper posted onto the arXiv server on 19 December, would redefine the amp on the basis of e, a physical constant representing the charge of an electron." -
First Recorded Observation of Freshwater Fish Preying On Birds In Flight
ananyo writes "The waters of the African lake seem calm and peaceful. A few migrant swallows flit near the surface. Suddenly, leaping from the water, a fish grabs one of the famously speedy birds straight out of the air. 'The whole action of jumping and catching the swallow in flight happens so incredibly quickly that after we first saw it, it took all of us a while to really fully comprehend what we had just seen,' says Nico Smit, director of the Unit for Environmental Sciences and Management at North-West University in Potchefstroom, South Africa. After the images did sink in, he adds, 'the first reaction was one of pure joy, because we realized that we were spectators to something really incredible and unique.' Rumours of such behaviour by the African tigerfish (Hydrocynus vittatus), which has been reported as reaching one metre in length, have circulated since the 1940s. But this is the first confirmed record of a freshwater fish preying on birds in flight, the team reports in the Journal of Fish Biology (PDF)." -
Metal-Free 'Rhubarb' Battery Could Store Renewable Grid Energy
sciencehabit writes "A molecule nearly identical to one in rhubarb may hold the key to the future of renewable energy. Researchers have used the compound to create a high-performance 'flow' battery, a leading contender for storing renewable power in the electric utility grid. If the battery prototype can be scaled up, it could help utilities deliver renewable energy when the wind is calm and the sun isn't shining." Abstract. -
Swarms of Small Satellites Set To Deliver Close To Real-Time Imagery of Earth
ananyo writes "A swarm of small satellites set to deliver close to real-time imagery of swathes of the planet is launching today. San Francisco-based Planet Labs, founded in 2010 by three former NASA scientists, is scheduled to launch 28 of its 'Doves' on 9 January. Each toaster-sized device weighs about 5 kilograms and can take images at a resolution of 3–5 metres. Meanwhile Skybox Imaging plans to launch a swarm of 24 satellites, each weighing about 100 kilograms, which will take images of 1 meter resolution or better. Skybox launched its first satellite on 21 November (and captured the first HD video of the world from space) and plans to launch another this year, followed by the remainder between 2015 and 2017. In a first — at least for civilian satellites — Skybox's devices will also stream short segments of near-live high-resolution video footage of the planet. So, too, will UrtheCast, a start-up based in Vancouver, Canada, whose cameras will hitch a ride on the International Space Station. Because the swarms are still to be launched, scientists have yet to fully assess the quality of the imagery. But the satellites' spatial resolutions of 1–5 metres are much higher than those of most scientific satellites. Landsat, NASA's Earth-observation workhorse, for example, has a resolution of 15–100 metres depending on the spectral frequency, with 30 metres in the visible-light range." -
Bizarre Star Could Host a Neutron Star In Its Core
ananyo writes "Astronomers say that they have discovered the first example of a long-sought cosmic oddity: a bloated, dying star with a surprise in its core — an ultradense neutron star. Such entities, known as Thorne-Zytkow objects, are theoretically possible but would alter scientists' understanding of how stars can be powered. Since Thorne-Zytkow objects were first proposed in 1975, researchers have occasionally offered up candidates, but none have been confirmed." -
China Tops Europe In R&D Intensity
ananyo writes "By pouring cash into science and technology faster than its economy has expanded, China has for the first time overtaken Europe on a key measure of innovation: the share of its economy devoted to research and development. In 2012, China invested 1.98% of its gross domestic product (GDP) into R&D — just edging out the 28 member states of the European Union, which together managed 1.96%, according to the latest estimates of research intensity, to be released this month by the OECD. The figures show that China's research intensity has tripled since 1998, whereas Europe's has barely increased (see graph). The numbers are dominated by business spending, reflecting China's push in the manufacturing and information- and communication-technology industries." -
China Tops Europe In R&D Intensity
ananyo writes "By pouring cash into science and technology faster than its economy has expanded, China has for the first time overtaken Europe on a key measure of innovation: the share of its economy devoted to research and development. In 2012, China invested 1.98% of its gross domestic product (GDP) into R&D — just edging out the 28 member states of the European Union, which together managed 1.96%, according to the latest estimates of research intensity, to be released this month by the OECD. The figures show that China's research intensity has tripled since 1998, whereas Europe's has barely increased (see graph). The numbers are dominated by business spending, reflecting China's push in the manufacturing and information- and communication-technology industries." -
World's Oldest Decimal Multiplication Table Discovered
ananyo writes "From a few fragments out of a collection of 23-century-old Chinese bamboo strips, historians have pieced together what they say is the world's oldest example of a multiplication table in base 10. Each strip is about 7 to 12 millimeters wide and half a meter long, and has a vertical line of ancient Chinese calligraphy painted on it in black ink. The bamboo pieces constitute 65 ancient texts and are thought to be among the most important artifacts from the Warring States period before the unification of China. But 21 bamboo strips contained only numbers and, on closer inspection, turned out to be a multiplication table. As in a modern multiplication table, the entries at the intersection of each row and column in the matrix provide the results of multiplying the corresponding numbers. The table can also help users to multiply any whole or half integer between 0.5 and 99.5. The researchers suspect that officials used the multiplication table to calculate surface area of land, yields of crops and the amounts of taxes owed." -
Reducing Climate Change Uncertainty By Figuring Out Clouds
Most climate scientists agree that the Earth's climate is getting warmer, but models predicting the severity of the temperature rise span a (relatively) broad range. One big reason for this is the difficulty in modeling things like cloud cover and how different air masses mix and move around each other. "Specifically, they have differences in how water-rich air at the bottom of the atmosphere gets mixed with the layers immediately above it. In some cases, this mixing increases rapidly as the temperature rises, effectively drying out the lower atmosphere and suppressing cloud formation there. This in turn would enhance the warming effect. In others, the increase in mixing is more gradual, limiting the impact of warming on clouds. The former produces a higher climate sensitivity; the latter a lower one. ... So, the authors turned to the atmosphere, using data to determine the relative importance of these processes (abstract). In the end, they find that the models that dry out the lower atmosphere more quickly are likely to get the process right. And, in these models, the mixing increases the drying rate in the lower atmosphere by about five to seven percent for each Kelvin the Earth's temperature increases. In contrast, the rate of evaporation, which adds moisture to the lower atmosphere, only increases by two percent for each Kelvin. Thus, the lower atmosphere dries out, cloud formation there is suppressed, and the planet warms even further. How much more will it warm? Quite a bit." -
Researchers Confirm Exoplanet Has Clouds Using Hubble Telescope
Exoplanet GJ 1214 b was discovered in 2009 by the MEarth project. Researchers now have strong evidence that it has an atmosphere. "[A] team of astronomers led by UChicago's Laura Kreidberg and Jacob Bean have detected clear evidence of clouds in the atmosphere of GJ 1214b from data collected with the Hubble Space Telescope. The Hubble observations used 96 hours of telescope time spread over 11 months. This was the largest Hubble program ever devoted to studying a single exoplanet. ... The first spectra, which were obtained by Bean in 2010 using a ground-based telescope, suggested that the planet's atmosphere either was predominantly water vapor or hydrogen-dominated with high-altitude clouds. ... More precise Hubble observations made in 2012 and 2013 allowed the team to distinguish between these two scenarios. ... The best explanation for the new data is that there are high-altitude clouds in the atmosphere of the planet, though their composition is unknown. Models of super-Earth atmospheres predict clouds could be made out of potassium chloride or zinc sulfide at the scorching temperatures of 450 degrees Fahrenheit found on GJ 1214b." -
Scientists Predict Earthquake's Location and Strength
A new study has been published in Nature Geoscience (abstract) detailing how scientists correctly anticipated the location and strength of an earthquake earlier this year. On September 5th, a 7.6 earthquake rocked Costa Rica's Nicoya Peninsula. That region had seen earthquakes of (roughly) magnitude 7 in 1853, 1900, and 1950, so "geoscientists had forecast that a magnitude 7.7 to 7.8 quake should occur around the year 2000, plus or minus 20 years." "The Nicoya Peninsula is prone to earthquakes because it's an area of subduction, where the Cocos Plate is pushing underneath the Caribbean Plate, moving at a rate of about 8.5 centimeters per year. When regions such as this suddenly slip, they produce a megathrust earthquake. Most of the world's largest earthquakes — including the magnitude 9.0 Tohoku-Oki quake in Japan in 2011 and the magnitude 9.15 Sumatra-Andaman earthquake in 2004, both of which produced devastating tsunamis — fall into this category. .. The close study of this region allowed scientists to calculate how much strain was building in the fault and in May 2012 they published a study in which they identified two locked spots capable of producing an earthquake similar to the one in 1950. In September of that year, the landward patch ruptured and produced the earthquake. The offshore one is still locked and capable of producing a substantial but smaller earthquake, an aftershock with a magnitude as high as 6.9, the researchers say." -
2013: an Ominous Year For Warnings and Predictions
dcblogs writes "This year may be remembered for its striking number of reports and warning of calamitous events. The National Intelligence Council released its Global Trends 2030: Alternative Worlds report that included a number of dire possibilities ahead, including the prospect of a catastrophic solar storm, on par with the 1859 Carrington Event. Historical records suggest a return period of 50 years for a repeat of the Quebec-level storm that knocked out the power for 6 million in 1989, and 150 years for very extreme storms, such as the Carrington Event, according to Lloyd's, in a report this year. Scientists at the Idaho National Laboratory recently demonstrated in tests that 'geomagnetic disturbances have the power to disrupt and possibly destroy electrical transformers, the backbone of our nation's utility grid.' This was also the year the average daily level of CO2 reached a concentration above 400 parts per million. In a recent National Academies report this year, 'Abrupt Impacts of Climate Change: Anticipating Surprises,' scientists recommend creation of a global early warning system to alert mankind to abrupt climate changes. A recent paper in Nature, Abrupt rise of new machine ecology beyond human response time, said financial trading systems are driving transaction times down to the speed of light, and 'the quickest that someone can notice potential danger and physically react, is approximately 1 second.'" -
Sun Not a Significant Driver of Climate Change
damn_registrars writes "Scientists from Edinburgh, Scotland have recently published a study based on 1,000 years of climate data. They have compared the effects of differing factors including volcanic activity, solar activity, and greenhouse gases to find which has the most profound effect on climate. They have concluded that the driving factor since 1900 has been greenhouse gases." -
Researchers Use Electroconvulsive Therapy To Disrupt Recall of Nasty Events
ananyo writes "In the film Eternal Sunshine of the Spotless Mind, unhappy lovers undergo an experimental brain treatment to erase all memories of each other from their minds. No such fix exists for real-life couples, but researchers report in Nature Neuroscience that a targeted medical intervention helps to reduce specific negative memories in patients who are depressed. The technique, called electroconvulsive (ECT) or electroshock therapy, induces seizures by passing current into the brain through electrode pads placed on the scalp. Despite its sometimes negative reputation, ECT is an effective last-resort treatment for severe depression, and is used today in combination with anaesthesia and muscle relaxants. Marijn Kroes, a neuroscientist at Radboud University Nijmegen in the Netherlands, and his colleagues found that by strategically timing ECT bursts, they could target and disrupt patients' memory of a disturbing episode." -
Huge Pool of Ice-Free Water Discovered Under Greenland Ice
The BBC reports that researchers have discovered a huge pool of meltwater beneath Greenland's ice sheet, trapped "in the air space between particles of ice, similar to the way that fruit juice stays liquid in a slush drink." From the article, based on research published in Nature Geoscience (abstract): "The scientists say the water is prevented from freezing by the large amounts of snow that fall on the surface of the ice sheet late in the summer. This insulates the water from the air temperatures which are below freezing, allowing the water to persist as liquid all year long. Other researchers believe this discovery may help explain disparities between projections of mass loss by climate models and observations from satellites." -
Researchers Crack Major HIV Mystery
mrspoonsi sends this news from Scientific American: "The difference between HIV infection and full-blown AIDS is, in large part, the massive die-off of the immune system's CD4 T-cells. But researchers have only observed the virus killing a small portion of those cells, leading to a longstanding question: What makes the other cells disappear? New research shows that the body is killing its own cells in a little-known process. What's more, an existing, safe drug could interrupt that self-destruction, thereby offering a way to treat AIDS. The destructive process has caught scientists by surprise. 'We thought HIV infects a cell, sets up a virus production factory and then the cell dies as a consequence of being overwhelmed by virus. But there are not enough factories to explain the massive losses,' says Warner Greene, director of virology and immunology at the Gladstone Institutes, whose team published two papers today in Science and Nature describing the work. Greene estimates 95 percent of the cells that die in HIV infections are killed through pyroptosis, so the findings raise hope for a new type of treatment that could prevent HIV from progressing into AIDS. 'Inhibiting activation of the immune system is not a new concept, but this gives us a new pathway to target,' says Robert Gallo. And in fact, a drug already exists that can block pyroptosis." -
Academics Should Not Remain Silent On Government Hacking
ananyo writes "The Guardian's technology editor, Charles Arthur, asks why researchers have remained largely silent in the wake of the revelation that the U.S. National Institute of Standards and Technology's standard for random numbers used for cryptography had been weakened by the NSA: 'The nature of the subversions sounds abstruse: the random-number generator, the 'Dual EC DRBG' standard, had been hacked by the NSA and the UK's GCHQ so that its output would not be as random as it should have been. That might not sound like much, but if you are trying to break an encrypted message, the knowledge that it is hundreds or thousands of times weaker than advertised is a great encouragement.' Arthur attributes the silence of UK academics, at least, to pressure from GCHQ. He goes on to say: 'For those who do care, White and Matthew Green, who teaches cryptography at Johns Hopkins University in Baltimore, Maryland, have embarked on an ambitious effort to clean up the mess — one that needs help. They have created a non-profit organization called OpenAudit.org, which aims to recruit experts to provide technical assistance for security projects in the public interest, especially open-source security software.'" -
Simulations Back Up Theory That Universe Is a Hologram
ananyo writes "A team of physicists has provided some of the clearest evidence yet that our Universe could be just one big projection. In 1997, theoretical physicist Juan Maldacena proposed that an audacious model of the Universe in which gravity arises from infinitesimally thin, vibrating strings could be reinterpreted in terms of well-established physics. The mathematically intricate world of strings, which exist in nine dimensions of space plus one of time, would be merely a hologram: the real action would play out in a simpler, flatter cosmos where there is no gravity. Maldacena's idea thrilled physicists because it offered a way to put the popular but still unproven theory of strings on solid footing — and because it solved apparent inconsistencies between quantum physics and Einstein's theory of gravity. It provided physicists with a mathematical Rosetta stone, a 'duality', that allowed them to translate back and forth between the two languages, and solve problems in one model that seemed intractable in the other and vice versa. But although the validity of Maldacena's ideas has pretty much been taken for granted ever since, a rigorous proof has been elusive. In two papers posted on the arXiv repository, Yoshifumi Hyakutake of Ibaraki University in Japan and his colleagues now provide, if not an actual proof, at least compelling evidence that Maldacena's conjecture is true." -
Killer Qualities of Japanese Fault Revealed
Lasrick sends this report from Nature News: "The devastating 2011 earthquake and tsunami in Japan shocked researchers who did not expect that the seismic fault involved could release so much energy. Now the world's deepest-drilling oceanographic ship has been able to pin down the odd geology that made this disaster so horrific. The fault turns out to be unusually thin and weak, the researchers report in Science this week1–3. The results will help to pin down whether other offshore faults around the world are capable of triggering the same scale of disaster. ... The coring revealed a very thin clay layer, about 5 meters thick, separating the two sliding tectonic plates (abstract). 'That’s just weird,' says Emily Brodsky of the University of California, Santa Cruz (UCSC), who is an author on all three Science papers this week. 'Usually it’s tens of meters or more.' Lab tests confirmed that this wet clay layer is extremely slippery, and gets even more so under stress (abstract). As sliding creates friction and heat, water in the clay gets pressurized and pushes up against the impermeable rock around it. That 'jacks open the fault” says Brodsky, allowing it to slip even more. The temperature sensors found that more than a year after the quake, the fault was still up to 0.31 C warmer than its surroundings (abstract). From this they could extrapolate how much heat was generated from friction during the sliding event. Their calculations confirmed the very low friction of the 5-meter-thick clay layer." -
Scientists Find Olfactory "Memory" Passed Between Generations In Mice
New submitter Raging Bool writes "The BBC is reporting that acquired phobias or aversions by mice can be passed on to subsequent generations. From the article: 'Experiments showed that a traumatic event could affect the DNA in sperm and alter the brains and behavior of subsequent generations. A Nature Neuroscience study shows mice trained to avoid a smell passed their aversion on to their 'grandchildren.''" -
Google Supercomputers Tackle Giant Drug-Interaction Data Crunch
ananyo writes "By analysing the chemical structure of a drug, researchers can see if it is likely to bind to, or 'dock' with, a biological target such as a protein. Researchers have now unveiled a computational effort that used Google's supercomputers to assesses billions of potential dockings on the basis of drug and protein information held in public databases. The effort will help researchers to find potentially toxic side effects and to predict how and where a compound might work in the body. 'It's the largest computational docking ever done by mankind,' says Timothy Cardozo, a pharmacologist at New York University's Langone Medical Center, who presented the project at the US National Institutes of Health's High Risk–High Reward Symposium in Bethesda, Maryland. The result, a website called Drugable, is still in testing, but it will eventually be available for free, allowing researchers to predict how and where a compound might work in the body, purely on the basis of chemical structure." -
Study Linking GM Maize To Rat Tumors Is Retracted
ananyo writes "Bowing to scientists' near-universal scorn, the journal Food and Chemical Toxicology has fulfilled its threat to retract a controversial paper which claimed that a genetically modified (GM) maize causes serious disease in rats after the authors refused to withdraw it. The paper, from a research group led by Gilles-Eric Séralini, a molecular biologist at the University of Caen, France, and published in 2012, showed 'no evidence of fraud or intentional misrepresentation of the data,' said a statement from Elsevier, which publishes the journal. But the small number and type of animals used in the study means that 'no definitive conclusions can be reached.' The known high incidence of tumors in the Sprague-Dawley rat 'cannot be excluded as the cause of the higher mortality and incidence observed in the treated groups,' it added. Today's move came as no surprise. Earlier this month, the journal's editor-in-chief, Wallace Hayes, threatened retraction if Séralini refused to withdraw the paper, which is exactly what he announced at a press conference in Brussels this morning. Séralini and his team remained unrepentant, and allege that the retraction derives from the journal's editorial appointment of biologist Richard Goodman, who previously worked for biotechnology giant Monsanto for seven years."