Welcome to the Saturday Science Edition of Overnight News Digest
Overnight News Digest is a regular daily feature which provides noteworthy news items and commentary from around the world. The editorial staff includes side pocket, maggiejean, wader, Doctor RJ, rfall, and JML9999.
Neon Vincent is our editor-in-chief.
Special thanks go to Magnifico for starting this venerable series.
Astronomy
Dawn Glimpses Ceres’ North Pole
After spending more than a month in orbit on the dark side of dwarf planet Ceres, NASA's Dawn spacecraft has captured several views of the sunlit north pole of this intriguing world. [The] images were taken April 10 from a distance of 21,000 miles (33,000 kilometers), and they represent the highest-resolution views of Ceres to date. Subsequent images of Ceres will show surface features at increasingly better resolution. Dawn arrived at Ceres on March 6, marking the first time a spacecraft has orbited a dwarf planet. Previously, the spacecraft explored giant asteroid Vesta for 14 months from 2011 to 2012. Dawn has the distinction of being the only spacecraft to orbit two extraterrestrial targets. Ceres, with an average diameter of about 590 miles (950km), is the largest body in the main asteroid belt between Mars and Jupiter. Dawn has been using its ion propulsion system to maneuver to its first science orbit at Ceres, which it will reach April 23. The spacecraft will remain at a distance of 8,400 miles (13,500km) from the dwarf planet until May 9. Afterward, it will make its way to lower orbits. astronomy
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Ancient Galaxies Seen Dying Inside-Out
The most massive galaxies in today’s universe are bulbous ellipticals easily 100 times the mass of our spiral Milky Way. These galaxies are essentially “red and dead” — they built up about 80% of their stars more than 6 billion years ago, so any stars shining today are old and rust-colored. They generally have no star formation today. But 10 billion years ago, at the peak of star formation across the cosmos, these galaxies were ablaze with new, young stars. Between then and now, those stars fizzled out. Last year, two teams found compact, star-forming galaxies in this early cosmic period. Stars in these galaxies are packed as densely as those in so-called compact cores, galaxies in the early universe 10 times the mass of the Milky Way and where star formation has already ceased. That correlation suggests the star-forming compact galaxies became the compact cores. They in turn likely grew into today’s most massive ellipticals by usurping stars from much smaller galaxies, accreting stars onto their outskirts as they tore up and ate their smaller siblings. [...] In the April 17th Science, Sandro Tacchella (ETH Zurich, Switzerland) and colleagues report their analysis of 22 star-forming galaxies 10 to 11 billion years ago (average redshift 2.2). These galaxies are not as dense as the compact cores, but the most massive rival them in number of stars. Using images from the Hubble Space Telescope and spectra from the SINFONI instrument on the ESO’s Very Large Telescope in Chile, the team tracked star formation inside the galaxies and found that, in the most massive ones, star formation is shutting down — and from the inside out. Essentially, these massive galaxies contain dead centers surrounded by star-forming envelopes. These galaxies, unlike the compact ones, churn out stars for longer, retaining a youthful glow for another 2 or 3 billion years. So instead of beefing up their edges by merging with punier galaxies, they grew by forming their own stars. By about 7 billion years ago (redshift of 1), they’ll also be red and dead. skyandtelescope
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Scientists Map the Dark Matter Around Millions of Galaxies
This week, scientists with the Dark Energy Survey (DES) collaboration released the first in a series of detailed maps charting the distribution of dark matter inferred from its gravitational effects. The new maps confirm current theories that suggest galaxies will form where large concentrations of dark matter exist. The new data show large filaments of dark matter where visible galaxies and galaxy clusters lie and cosmic voids where very few galaxies reside. “Our analysis so far is in line with what the current picture of the universe predicts,” said Chihway Chang from the Swiss Federal Institute of Technology (ETH) in Zurich, a co-leader of the analysis. “Zooming into the maps, we have measured how dark matter envelops galaxies of different types and how together they evolve over cosmic time.” The research and maps, which span a large area of the sky, are the product of a massive effort of an international team from the US, UK, Spain, Germany, Switzerland, and Brazil. They announced their new results at the American Physical Society (APS) meeting in Baltimore, Maryland. According to cosmologists, dark matter particles stream and clump together over time in particular regions of the cosmos, often in the same places where galaxies form and cluster. Over time, a “cosmic web” develops across the universe. Though dark matter is invisible, it expands with the universe and feels the pull of gravity. Astrophysicists then can reconstruct maps of it by surveying millions of galaxies, much like one might infer the shifting orientation of a flock of birds from its shadow moving along the ground. universetoday
Biology
Diversity Is Key To Stability, Grassland Study Finds
Biological diversity brings beauty and variety to our lives and to the world around us. It also could be the key to keeping ecosystems strong, according to a new University of Minnesota study published April 17 in the journal Science. The study, led by Yann Hautier a Marie Curie Fellow associated with the College of Biological Sciences at the University of Minnesota and with the University of Oxford, U.K., looked at 28 years' worth of data on plant growth, number of species, ecosystem stability and exposure to changes in nitrogen, carbon dioxide, fire, grazing and water collected from experimental grassland plots at Cedar Creek Ecosystem Science Reserve near East Bethel as part of other studies. It found that all of the human-induced changes affected the productivity of the grassland plots, but only those that reduced biodiversity reduced ecosystem stability. "Basically, we found that any driver of environmental change that will cause a loss of plant diversity will in turn reduce the stable production of plant biomass through time," Hautier said. "Biodiversity is somehow a special case, because it's not only a cause of changes in ecosystems but also a response to other changes." The study is unusual because it looks at several factors that affect ecosystem stability at the same time over a long period in a setting that kept other potential variables constant. It is important because understanding the cause-and-effect cascade of changes to ecosystems is key to anticipating impacts of human actions and minimizing damage to natural systems that undergird our planet's ability to support human life. sciencedaily
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Unprecedented Microbial Diversity Reported In Remote Amazonian Tribe
A multicenter team of U.S. and Venezuelan scientists, led by researchers from NYU Langone Medical Center, have discovered the most diverse collection of bodily bacteria yet in humans among an isolated tribe of Yanomami Indians in the remote Amazonian jungles of southern Venezuela. By comparison, the microbiome of people living in industrialized countries is about 40 percent less diverse, the scientists estimate. The team reports its findings today in the journal Science Advances. The results, the researchers say, suggest a link between modern antibiotics and industrialized diets, and greatly reduced diversity of the human microbiome--the trillions of bacteria that live in and on the body and are increasingly seen as vital to our health. The Yanomami villagers of this study, who have subsisted by hunting and gathering for hundreds of generations, are believed to have lived in total seclusion from the outside world until 2009 when they were first contacted by a medical expedition. Among a rare population of people unexposed to modern antibiotics, the villagers offer a unique window onto the human microbiome.
"We have found unprecedented diversity in fecal, skin, and oral samples collected from the Yanomami villagers," says Maria Dominguez-Bello, PhD, associate professor of medicine at NYU Langone Medical Center and the senior author of the study. "Our results bolster a growing body of data suggesting a link between, on the one hand, decreased bacterial diversity, industrialized diets, and modern antibiotics, and on the other, immunological and metabolic diseases--such as obesity, asthma, allergies, and diabetes, which have dramatically increased since the 1970s," notes Dr. Dominguez-Bello. "We believe there is something environmental occurring in the past 30 years that is driving these diseases. We think the microbiome could be involved."
biologynews
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Arm Coordination in Octopus Crawling Involves Unique Motor Control Strategies
Highlights •Octopuses use unique strategies to coordinate their arms in crawling •They can crawl in any direction relative to the facing (body) direction •Arms create pushing thrust by simple shortening and then elongating movements •Arm coordination in octopus crawling lacks any obvious rhythmical pattern Summary To cope with the exceptional computational complexity that is involved in the control of its hyper-redundant arms, the octopus has adopted unique motor control strategies in which the central brain activates rather autonomous motor programs in the elaborated peripheral nervous system of the arms. How octopuses coordinate their eight long and flexible arms in locomotion is still unknown. Here, we present the first detailed kinematic analysis of octopus arm coordination in crawling. The results are surprising in several respects: despite its bilaterally symmetrical body, the octopus can crawl in any direction relative to its body orientation; body and crawling orientation are monotonically and independently controlled; and contrasting known animal locomotion, octopus crawling lacks any apparent rhythmical patterns in limb coordination, suggesting a unique non-rhythmical output of the octopus central controller. We show that this uncommon maneuverability is derived from the radial symmetry of the arms around the body and the simple pushing-by-elongation mechanism by which the arms create the crawling thrust. These two together enable a mechanism whereby the central controller chooses in a moment-to-moment fashion which arms to recruit for pushing the body in an instantaneous direction. Our findings suggest that the soft molluscan body has affected in an embodied way the emergence of the adaptive motor behavior of the octopus. cell.com
Chemistry
Major Advance In Artificial Photosynthesis Poses Win/Win For The Environment
A potentially game-changing breakthrough in artificial photosynthesis has been achieved with the development of a system that can capture carbon dioxide emissions before they are vented into the atmosphere and then, powered by solar energy, convert that carbon dioxide into valuable chemical products, including biodegradable plastics, pharmaceutical drugs and even liquid fuels. Scientists with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley have created a hybrid system of semiconducting nanowires and bacteria that mimics the natural photosynthetic process by which plants use the energy in sunlight to synthesize carbohydrates from carbon dioxide and water. However, this new artificial photosynthetic system synthesizes the combination of carbon dioxide and water into acetate, the most common building block today for biosynthesis.
"We believe our system is a revolutionary leap forward in the field of artificial photosynthesis," says Peidong Yang, a chemist with Berkeley Lab's Materials Sciences Division and one of the leaders of this study. "Our system has the potential to fundamentally change the chemical and oil industry in that we can produce chemicals and fuels in a totally renewable way, rather than extracting them from deep below the ground."
Yang, who also holds appointments with UC Berkeley and the Kavli Energy NanoSciences Institute (Kavli-ENSI) at Berkeley, is one of three corresponding authors of a paper describing this research in the journal Nano Letters. The paper is titled "Nanowire-bacteria hybrids for unassisted solar carbon dioxide fixation to value-added chemicals." The other corresponding authors and leaders of this research are chemists Christopher Chang and Michelle Chang. Both also hold joint appointments with Berkeley Lab and UC Berkeley. In addition, Chris Chang is a Howard Hughes Medical Institute (HHMI) investigator. (See below for a full list of the paper's authors.) The more carbon dioxide that is released into the atmosphere the warmer the atmosphere becomes. Atmospheric carbon dioxide is now at its highest level in at least three million years, primarily as a result of the burning of fossil fuels. Yet fossil fuels, especially coal, will remain a significant source of energy to meet human needs for the foreseeable future. Technologies for sequestering carbon before it escapes into the atmosphere are being pursued but all require the captured carbon to be stored, a requirement that comes with its own environmental challenges. phys.org
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Making Fracking Greener
Researchers in the US have created a chemically-responsive fluid to efficiently fracture rocks that could decrease the amount of energy required for fracking. Current hydraulic fracturing methods are energy-intensive due to the need to pump, on average, 4 million gallons of water per reservoir, at very high pressures and flow rates deep into the ground. This water also contains additives including biocides, corrosion inhibitors and friction reducers. The fluid, developed by Carlos Fernandez of Pacific Northwest National Laboratory and coworkers, expands by up to 2.5 times its original volume in response to carbon dioxide. It is made from poly(allylamine) and could reduce the volume of water required for fracking, as well as being non-toxic, a biocide, and a corrosion inhibitor, circumventing the addition of extra chemicals. On stimulation with carbon dioxide, Fernandez’s fluid transitions from an aqueous solution to a hydrogel, exerting pressure and stress in the rock as it swells, which initiates fractures. This reduces the requirement for external pressure, and since the transition is reversible via carbon dioxide depressurisation or addition of acid, the fluid can be removed from the rock and recycled, further limiting its environmental impact. chemistryworld
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Liquor-Store Spirits Provide Green Alternative To HPLC Solvents
Long considered a lab workhorse, high-performance liquid chromatography (HPLC) typically requires expensive chemicals that need to be disposed of as hazardous waste. A new study shows that rum, vodka, and other distilled alcohols combined with household products can serve as low-cost and sustainable alternative eluents for HPLC, and in many cases produce excellent analytical results. Chemists most often use the solvent acetonitrile in HPLC separations to elute the components of mixtures from the instrument’s chromatographic column. During a worldwide shortage of acetonitrile in 2009, which caused the price to skyrocket, researchers found that ethanol was a good substitute. Still, the cost of HPLC-grade absolute ethanol is high, typically about $120/L. Recent innovations have reduced the size and cost of HPLC-based instruments, raising the possibility that HPLC could someday be used in doctors’ offices and in labs in developing countries. So Erik L. Regalado, Christopher J. Welch, and colleagues of Merck Research Laboratories, in Rahway, N.J., wanted to see if cheaper and more readily available solvents could perform as well as HPLC-grade ethanol. The researchers combined distilled spirits purchased from a local liquor store with ammonia and white vinegar from a supermarket and used the eluents to separate a mixture of five compounds—uracil, caffeine, 1-phenylethanol, butylparaben, and anthracene—in a conventional HPLC instrument. In HPLC, compounds separate based on how quickly they move through the instrument’s column. The team found that grain alcohol, which cost $22/L, was a good substitute for HPLC-grade ethanol, especially when analyzing more hydrophilic compounds that move slowly through the column. Rum and the lower-proof alcohols were less effective at eluting the strongly retained components, but they cleanly separated compounds that came off the column in a shorter time. The liquor-store alcohol-based eluents also performed as well as HPLC-grade ethanol in HPLC combined with mass spectrometry (HPLC/MS) when measuring caffeine and theanine in brewed black teas and vitamin C from oranges and supplement pills. chemical&engineeringnews
Earth Science
Study Shows How Climate Affects Biodiversity
A key question in the climate debate is how the occurrence and distribution of species is affected by climate change. But without information about natural variation in species abundance it is hard to answer. In a major study, published today in the leading scientific journal Current Biology, researchers can now for the first time give us a detailed picture of natural variation. The impact of climate change on species occurrence and distribution is a central issue in the climate debate, since human influence on the climate risks posing threats to biodiversity. But until now methods for investigating how natural climate variation in the past has affected the abundance of species have been lacking. Now, for the first time, Krystyna Nadachowska-Brzyska and Hans Ellegren of Uppsala University’s Evolutionary Biology Centre in collaboration with researchers at the Beijing Genomics Institute, have managed to clarify the issue in detail by analysing the whole genome of some 40 bird species. By studying the genetic variation of DNA molecules, they have succeeded in estimating how common these species were at various points in time, from several million years ago to historical times. [...] ‘The last Ice Age (110,000–12,000 years ago) had a particularly heavy impact on birds. Many species suffered their most dramatic falls in numbers then.’ Accordingly, there is a risk of the relatively recent influence exerted by human beings on environments and habitats, and of course the climate, having a particularly adverse effect on species that have already ‘declined’. Anthropogenic impact may therefore be what irrevocably pushes their decline beyond the ‘tipping point’ to eventual extinction. enn
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Why Did ‘Shocking' Amounts Of BP Oil Fall To The Seafloor?
In April 2010, as the biggest oil spill in U.S. history stained beaches and plastered birds with thick goo, something totally unexpected was happening under the surface of the Gulf of Mexico (map). Out of the public eye, a mass of ocean plants, creatures, and other detritus bigger than the state of Connecticut was speeding oil to the seafloor in "shockingly large" amounts—likely millions of gallons, according to David Hollander, a chemical oceanographer at the University of South Florida in St. Petersburg. (See pictures from the oil spill in National Geographic magazine.) The phenomenon known as marine snow usually works like this: Phytoplankton that is stressed by oil or chemicals pump out a sticky mucus nicknamed sea snot. This substance glues together algae, feces, and other random bits into clumps that resemble falling snowflakes. (Related: "'Sea Snot' Explosion Caused by Gulf Oil Spill?") But scientists say something different happened in 2010 after the blowout of BP’s Macondo well. Clay particles from the Mississippi River and dispersants used in cleanup efforts joined the mix, forming a big "dirty blizzard," Hollander says. Then heavy, oil-rich particles plummeted to the bottom of the Gulf like stones—"a perfect storm of events." This mechanism for how oil reaches the seafloor, dubbed MOSSFA or marine oil snow sedimentation and flocculent accumulation, is new to science. But it's apparently not new to history. Scientists now think it may be commonplace. nationalgeographic
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Solar Power Battle Puts Hawaii At Forefront Of Worldwide Changes
Allan Akamine has looked all around the winding, palm tree-lined cul-de-sacs of his suburban neighborhood in Mililani here on Oahu and, with an equal mix of frustration and bemusement, seen roof after roof bearing solar panels. Mr. Akamine, 61, a manager for a cable company, has wanted nothing more than to lower his $600 to $700 monthly electric bill with a solar system of his own. But for 18 months or so, the state’s biggest utility barred him and thousands of other customers from getting one, citing concerns that power generated by rooftop systems was overwhelming its ability to handle it. Only under strict orders from state energy officials did the utility, the Hawaiian Electric Company, recently rush to approve the lengthy backlog of solar applications, including Mr. Akamine’s. It is the latest chapter in a closely watched battle that has put this state at the forefront of a global upheaval in the power business. Rooftop systems now sit atop roughly 12 percent of Hawaii’s homes, according to the federal Energy Information Administration, by far the highest proportion in the nation. [...] Other states and countries, including California, Arizona, Japan and Germany, are struggling to adapt to the growing popularity of making electricity at home, which puts new pressures on old infrastructure like circuits and power lines and cuts into electric company revenue. As a result, many utilities are trying desperately to stem the rise of solar, either by reducing incentives, adding steep fees or effectively pushing home solar companies out of the market. In response, those solar companies are fighting back through regulators, lawmakers and the courts. nyt
Physics
Physicists Tune Large Hadron Collider To Find 'Sweet Spot' In High-Energy Proton Smasher
Start up of the world's largest science experiment is underway—with protons traveling in opposite directions at almost the speed of light in the deep underground tunnel called the Large Hadron Collider near Geneva. As protons collide, physicists will peer into the resulting particle showers for new discoveries about the universe, said Ryszard Stroynowski, a collaborator on one of the collider's key experiments and a professor in the Department of Physics at Southern Methodist University, Dallas. "The hoopla and enthusiastic articles generated by discovery of the Higgs boson two years ago left an impression among many people that we have succeeded, we are done, we understand everything," said Stroynowski, who is the senior member of SMU's Large Hadron Collider team. "The reality is far from this. The only thing that we have found is that Higgs exist and therefore the Higgs mechanism of generating the mass of fundamental particles is possible." There is much more to be learned during Run 2 of the world's most powerful particle accelerator. "In a way we kicked a can down the road because we still do not have sufficient precision to know where to look for the really, really new physics that is suggested by astronomical observations," he said. "The observed facts that are not explained by current theory are many." phys.org
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XENON1T Will Join The Hunt For Dark Matter This Autumn
The hunt for dark matter will gain a more-than-an-order-of-magnitude boost in detection sensitivity when the next-generation XENON1T detector achieves first light this autumn. The challenges of constructing the world's largest direct-detection dark-matter experiment and the scientific prospects for the future were presented by project spokesperson Elena Aprile of Columbia University, US, at the April Meeting of the American Physical Society in Maryland last weekend. The XENON experiment began 10 years ago with XENON10, a 25 kg tank of liquid xenon deep under a mountain at the Gran Sasso National Laboratory in Italy. XENON100 followed in 2008 with 161 kg of liquid xenon and more than a hundred times the sensitivity of its predecessor. As the latest iteration, XENON1T is far more than a "second generation" detector – it contains 3300 kg of xenon and another hundred times the sensitivity of XENON100. The world's current limit on the dark-matter interaction rate was set in 2013 by the Large Underground Xenon (LUX) detector in South Dakota – a limit that XENON1T is expected to surpass by about a factor of 40. The goal of most direct-detection dark-matter experiments is to observe a weakly interacting massive dark-matter particle (WIMP) as it scatters off the nucleus of an atom. If dark matter is a particle at all, then WIMPs are our current best candidate. XENON1T has been designed to be particularly good at detecting heavy WIMPs with masses of 50 GeV and above. physicsworld
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Harvesting Energy From Electromagnetic Waves
or our modern, technologically-advanced society, in which technology has become the solution to a myriad of challenges, energy is critical not only for growth but also, more importantly, survival. The sun is an abundant and practically infinite source of energy, so researchers around the world are racing to create novel approaches to "harvest" clean energy from the sun or transfer that energy to other sources. This week in the journal Applied Physics Letters, from AIP Publishing, researchers from the University of Waterloo in Canada report a novel design for electromagnetic energy harvesting based on the "full absorption concept." This involves the use of metamaterials that can be tailored to produce media that neither reflects nor transmits any power -- enabling full absorption of incident waves at a specific range of frequencies and polarizations. "The growing demand for electrical energy around the globe is the main factor driving our research," said Thamer Almoneef, a Ph.D. student. "More than 80 percent of our energy today comes from burning fossil fuels, which is both harmful to our environment and unsustainable as well. In our group, we're trying to help solve the energy crisis by improving the efficiency of electromagnetic energy-harvesting systems." Since the inception of collecting and harvesting electromagnetic energy, classical dipole patch antennas have been used. "Now, our technology introduces 'metasurfaces' that are much better energy collectors than classical antennas," explained Omar M. Ramahi, professor of electrical and computer engineering. Metasurfaces are formed by etching the surface of a material with an elegant pattern of periodic shapes. The particular dimensions of these patterns and their proximity to each other can be tuned to provide "near-unity" energy absorption. This energy is then channeled to a load through a conducting path that connects the metasurface to a ground plane. sciencedaily