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
New Exoplanet Too Big For Its Star
The Australian discovery of a strange exoplanet orbiting a small cool star 500 light-years away is challenging ideas about how planets form.
“We have found a small star, with a giant planet the size of Jupiter, orbiting very closely,” said George Zhou from the Research School of Astrophysics and Astronomy at the Australian National University. “It must have formed further out and migrated in, but our theories can’t explain how this happened.”
[...] The host star of the latest exoplanet, HATS-6, is classed as an M dwarf, which is one of the most numerous types of stars in the galaxy. Although they are common, M-dwarf stars are not well understood. Because they are cool, they are also dim, making them difficult to study. [...] HATS-6 emits only one-twentieth of the light of our Sun. The giveaway that the faint star had a planet circling it was a dip in its brightness caused as the planet passed in front of the star, which was observed by small robotic telescopes, including telescopes at the ANU Siding Spring Observatory. [...]
“The planet has a similar mass to Saturn, but its radius is similar to Jupiter, so it’s quite a puffed-up planet. Because its host star is so cool, it’s not heating the planet up so much; it’s very different from the planets we have observed so far,” Zhou said. “The atmosphere of this planet will be an interesting target for future study.”
astronomy.com
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Messenger Crashes, Its Results Endure
We've known for months that NASA's Messenger spacecraft was operating on borrowed time. Its fuel tanks nearly empty after a decade of interplanetary maneuvering, the spacecraft could only fire its engine so many times before the pull of Mercury's gravity — coupled with the Sun's perturbing pull — forced it to crash into the planet. The end came yesterday at 19:26 Universal Time (3:26 p.m. Eastern Daylight Time). Actually, missions engineers can only assume that the spacecraft crashed as predicted because the impact occurred on the planet's unseen side. Presumably it skimmed over the large crater Shakespeare before striking an unnamed ridge located at 54.5° north, 210.1° east. A few minutes later, when the spacecraft would have emerged from behind the planet and been in view from Earth, no radio signal was received. The mood in the mission control center at Johns Hopkins University's Applied Physics Laboratory was "both celebratory and somber" as team members watched the final transmissions arrive after 4,105 orbits around Mercury. [...] One of the mission's most unexpected results is that the rocks and dust on Mercury's surface contain very little iron. It's baffling, actually, because this planet has a huge, iron-dominated core that takes up three-fourths of the planet's diameter and half its volume. So geochemists expected that the planet's surface would contain an abundance of iron-rich minerals. This finding, curious in itself, has a bearing on another Mercurian mystery. The planet's surface is very dark, reflecting only about 7% of the sunlight striking it. That's even darker than the Moon. Researchers have long known that the lunar surface becomes less reflective over time because tiny meteorites pepper the lunar dust, momentarily flash-melting its iron-bearing silicate minerals and creating submicroscopic bits of metallic iron. These iron particles are what make the Moon appear dark. But given Mercury's iron-poor surface, some other process must be involved. skyandtelescope
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Buster the Dummy Strapped In For Mile High SpaceX Dragon Flight Test
SpaceX and NASA are just days away from a crucial test of a crew capsule escape system that will save astronauts lives in the unlikely event of a launch failure with the Falcon 9 rocket. Buster the Dummy is already strapped into his seat aboard the SpaceX Crew Dragon test vehicle for what is called the Pad Abort Test, that is currently slated for Wednesday, May 6. The test is critical for the timely development of the human rated Dragon that NASA is counting on to restore the US capability to launch astronauts from US soil abroad US rockets to the International Space Station (ISS) as early as 2017. [...] The SpaceX Dragon and trunk together stand about 20 feet tall and are positioned atop the launch mount at SLC-40 for what is clearly labeled as a development test to learn how the Dragon, engines and abort system perform. Buster will soar along inside the Dragon that will be rapidly propelled to nearly a mile high height solely under the power of eight SpaceX SuperDraco engines. The trunk will then separate, parachutes will be deployed and the capsule will splashdown about a mile offshore from Florida in the Atlantic Ocean, said Hans Koenigsmann, vice president of Mission Assurance at SpaceX during a May 1, 2015 press briefing on the pad abort test at the Kennedy Space Center, Florida. universetoday
Biology
Out-Of-Body Experience Triggered By Researchers In A Lab
Most of us have heard of an out-of-body experience - the idea that a person's consciousness can travel and exist outside the physical body. Some of you may have even had such an experience. Now, researchers from the Karolinska Institutet in Sweden reveal how they induced an out-of-body illusion in healthy study participants. What is more, the researchers were able to use this illusion to perceptually "teleport" these participants to various locations in a room, indicating that the location of where we believe our physical body to be can be interpreted from specific brain patterns. [...] [Lead author Arvid Guterstam and colleagues] explain that in order for a person to determine the exact location of their body within a certain environment, the brain must constantly draw information from the different senses. [...] For their study, 15 healthy participants were placed inside a brain scanner while wearing a head-mounted display, on which the participants were able to view themselves inside the brain scanner from another area in the room. The head-mounted display then showed each participant the body of a stranger standing in front of their body in the brain scanner. To trigger an out-of-body illusion, a researcher touched the participant's actual body with an object, while the display showed the stranger receiving identical touches in synchrony. "In a matter of seconds, the brain merges the sensation of touch and visual input from the new perspective, resulting in the illusion of owning the stranger's body and being located in that body's position in the room, outside the participant's physical body," explains Guterstam. The researchers then used this out-of-body illusion to "teleport" the participants to different locations in the room while monitoring their brain activity via pattern recognition techniques. medicalnewstoday
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Unique Fish Fossils Identified
A team of Ludwig-Maximilians-Universitaet (LMU) in Munich has identified the first fossil specimens of a major group of killifishes that is widely distributed in freshwater habitats today. The 6-million-year-old material sheds new light on the evolution of the bony fishes. Killifish are true survivors. These colorful little fish are perfectly adapted to the demands of their ephemeral habitats. They spend their short lives in temporary freshwater pools that form during the rainy season, and owe their long-term survival to the fact that their eggs are resistant to desiccation. Although they are a species-rich group, and are widely distributed in the tropics and subtropics, their fossil record is sparse. But now LMU palaeontologists Professor Bettina Reichenbacher and Melanie Altner have identified the first fossil representatives of one of the two extant suborders of killifish. "The specimens are exceptionally well preserved, date from about 6 million years ago, and were discovered in Kenya by French palaeoanthropologists," says Reichenbacher. "Our studies have now shown that they are members of a previously unknown genus that is now extinct, which we have named Kenyaichthys - the fish from Kenya." A cache that includes 77 complete specimens The fossils originate from a site located in the Tugen Hills, which lie in the Eastern arm of the East African Rift Valley. During the Late Miocene - about six million years ago - the site formed part of a lake, and the newly described specimens, each 2 to 4 cm long, were preserved in the sediment beds that accumulated on the lake bottom. "The sample comprises a total of 169 individuals, and 77 of these are complete," says Altner. The anatomical details discernible in the impressions left in the sediments enabled the two researchers to conclusively identify all of these individuals as killifishes. "Analysis of the structures of the tailfin, the pelvic fins and the bones in the skull, in particular, yielded crucial information that convinced us that this material constituted the first fossils attributable to the killifish Suborder Aplocheiloidei. This group also encompasses modern African killifishes, such as Pachypanchax from Madagascar, the striped panchaxes of Southeast Asia and the rivulids of South America," Altner explains. In addition to the fossil aplocheiloids, only a few other freshwater forms were found at the site. Reichenbacher and Altner assume that the prevailing environmental conditions were too extreme for less specialized species. During the Late Miocene, the climate got drier and extensive areas of savannah developed. "We believe that, like modern killifish species, Kenyaichthys was well equipped to survive long periods of drought, and could cope better with such conditions than other species of fish," says Reichenbacher. biologynews.net
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Biodiversity Promotes Multitasking In Ecosystems
A new study of the complex interplay between organisms and their environment shows that biodiversity—the variety of organisms living on Earth—is even more important to the healthy functioning of ecosystems than previously thought. The findings bolster the view that conservation of biodiversity benefits the plants and animals directly involved, and by extension the human populations that rely on these organisms and ecosystems for food, water, and other basic services. [...]
“Many recent studies support the idea that greater biodiversity helps maintain more stable and productive ecosystems,” says [Jonathan Lefcheck, a post-doctoral research associate and recent Ph.D. graduate at the College of William & Mary’s Virginia Institute of Marine Science], “but this conclusion rests mostly on experiments that tested how losing species affects only a single ecosystem process, such as plant growth. “Our study,” he says, “is the first systematic look at how biodiversity affects the suite of interconnected processes that keep ecosystems healthy and functioning.”
The team examined the relationship between biodiversity and these various processes, termed “multifunctionality,” by compiling and analyzing the results from 94 experiments conducted around the world. Each experiment involved manipulation of at least 3 different species and the monitoring of at least 2 and up to 12 distinct ecosystem functions—from the accumulation of soil nitrogen to the control of aquatic algae. The experiments were evenly divided between terrestrial and aquatic habitats. The results of the team’s synthesis were clear. “We found that biodiversity generally enhances multiple functions in experimental ecosystems,” says Lefcheck. “In other words, as you consider more aspects of an ecosystem, biodiversity becomes more important: one species cannot do it all.” vims.edu
Chemistry
Does Artificial Food Coloring Contribute To ADHD In Children?
Kraft Macaroni & Cheese—that favorite food of kids, packaged in the nostalgic blue box—will soon be free of yellow dye. Kraft announced Monday that it will remove artificial food coloring, notably Yellow No. 5 and Yellow No. 6 dyes, from its iconic product by January 2016. Instead, the pasta will maintain its bright yellow color by using natural ingredients: paprika, turmeric and annatto (the latter of which is derived from achiote tree seeds). The company said it decided to pull the dyes in response to growing consumer pressure for more natural foods. But claims that the dyes may be linked to attention-deficit hyperactivity disorder (ADHD) in children have also risen recently, as they did years ago, putting food dyes under sharp focus once again. On its Web site Kraft says synthetic colors are not harmful, and that their motivation to remove them is because consumers want more foods with no artificial colors. [...] After a 2007 study in the U.K. showed that artificial colors and/or the common preservative sodium benzoate increased hyperactivity in children, the European Union started requiring food labels indicating that a product contains any one of six dyes that had been investigated. The label states the product "may have an adverse effect on activity and attention in children." The FDA convened a Food Advisory Committee meeting in 2011 to review the existing research, and concluded that there was not sufficient evidence proving that foods with artificial colors caused hyperactivity in the general population. The FDA also decided that further research was needed, and that a label disclosing a possible link between dyes and hyperactivity was unnecessary. But Joel Nigg, professor of psychiatry, pediatrics and behavioral neuroscience at Oregon Health & Science University, says the studies support the link between dyes and hyperactivity. "The literature here is so sparse that on the one hand you can sympathize with those who want to take a wait-and-see attitude. But on the other hand, when we do look at the literature we have, it's surprising that we do see effects that seem to be real," he says. "Do you want to take a chance that these initial studies are wrong and put kids at risk or do you want to take a chance that they're right? We have to work on the data we have." scientificamerican
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Salt And Flavour Reach A Compromise
Scientists in the UK have developed a water-in-oil-in-water (wow) emulsion that could cut salt levels in emulsion-based food by more than a fifth but maintain the same flavour. Excess dietary salt can increase blood pressure – a risk factor for cardiovascular diseases. Processed foods, such as ready-made soups, often contain salt as a preservative and flavour enhancer. However, most of the salt in these emulsion-based foods is swallowed without us actually tasting it, and we often find ourselves adding even more. Bettina Wolf and coworkers at the University of Nottingham, UK, have taken a microstructure approach to solve this problem. They trapped sodium chloride in the internal aqueous phase of an emulsion made from quinoa starch that had been modified with octenyl succinic anhydride. Salivary enzyme amylase will hydrolyse the starch. This means the salt is released immediately into the mouth, maximising its delivery to taste receptors.
‘Wolf has successfully demonstrated how the interfacial layers of emulsion droplets can be engineered for the targeted release of salt or other tastants, over realistic timescales’, comments food scientist Peter Wilde, from the Institute of Food Research in the UK. ‘This could lead to rationally designed, lower salt foods requiring no artificial taste enhancers or salt replacers.’
chemistryworld
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Silver Turns Bacteria Into Deadly Zombies
The zombie apocalypse may be more than just a horror story for some bacteria. New research shows that when exposed to a microbe-slaying silver solution, the germs can “go zombie,” wiping out their living compatriots even after death. The results may explain silver's long-lasting antibacterial power and could improve the performance of medical products that keep us safe from harmful pathogens. The use of silver in medicine dates back thousands of years, and scientists have long known that the metal is a potent antibacterial agent. Silver ions perform their deadly work by punching holes in bacterial membranes and wreaking havoc once inside. They bind to essential cell components like DNA, preventing the bacteria from performing even their most basic functions. But silver's "zombie effect" has gone unrecognized—until now. To uncover this grisly mechanism, scientists first killed a sample of the bacterium Pseudomonas aeruginosa using a solution of silver nitrate. Then, they carefully separated the dead bacteria from the silver solution. When they exposed living bacteria to the dead, they witnessed a microscopic massacre: Up to 99.99% of the living bacteria met their doom. Using electron microscopy, the researchers imaged the dead bacteria and discovered what caused them to go on their killing spree. Reservoirs of silver nanoparticles had built up in their corpses, indicating that the dead bacteria act like sponges, soaking up silver as they die. The stored silver can leach out to the environment, "especially if the environment contains other sponges for that silver," says chemist David Avnir of the Hebrew University of Jerusalem, the senior author of the new study. "In our case, the other sponge is a living bacterium." sciencemag
Earth Science
Rivers Recover After Dam Removal
More than 1,000 dams have been removed across the United States because of safety concerns, sediment buildup, inefficiency or having otherwise outlived usefulness. A paper published today in Science finds that rivers are resilient and respond relatively quickly after a dam is removed.
“The apparent success of dam removal as a means of river restoration is reflected in the increasing number of dams coming down, more than 1,000 in the last 40 years,” said lead author of the study Jim O’Connor, geologist with the U.S. Geological Survey. “Rivers quickly erode sediment accumulated in former reservoirs and redistribute it downstream, commonly returning the river to conditions similar to those prior to impoundment.”
Dam removal and the resulting river ecosystem restoration is being studied by scientists from several universities and government agencies, including the USGS and U.S. Forest Service, as part of a national effort to document the effects of removing dams. Studies show that most river channels stabilize within months or years, not decades, particularly when dams are removed rapidly.
“In many cases, fish and other biological aspects of river ecosystems also respond quickly to dam removal,” said co-author of the study Jeff Duda, an ecologist with USGS. “When given the chance, salmon and other migratory fish will move upstream and utilize newly opened habitat.”
enn.com
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Nepal quake: Why Are Some Tremors So Deadly?
On 1 April, 2014, a Magnitude 8.2 earthquake rocked northern Chile. Six people died, 2,500 homes were damaged and 80,000 people were displaced. Just over one year later, a M7.8 earthquake strikes Nepal. Over 6,200 people (and counting) have been killed, entire towns and villages flattened and millions of people left homeless. Chile's earthquake barely made the news, whilst Nepal's has brought complete and utter devastation. How did two such similar earthquakes have such disparate effects? A huge part of the answer is, of course, building standards and wealth. Since Chile's terrible M9.5 earthquake in 1960, where over 5,500 people died, the country has taken big steps in modernising its buildings, designing them to withstand the shaking produced by great earthquakes. Meanwhile, in Nepal, few buildings were up to code, and many toppled when the earthquake struck. But wealth and building codes don't tell the entire story: the geology is different, too. Nepal sits on a continental collision zone (India is smashing into Asia) and its earthquake fault is well disguised: most of the fault is buried deep underground and surface ruptures are quickly covered by muds washed down by monsoon rains and the dense jungle. Furthermore, the speed of this continental collision (around 4.5cm every year) means that major quakes only hit Nepal every few decades. Chile's fault meanwhile is obvious - a whopping great trench where the Pacific Ocean floor dives underneath South America at a rate of nearly 10cm per year - with major earthquakes occurring every year, making earthquake-resilience a priority. bbc
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Declining 'Large Herbivore' Populations May Lead To An 'Empty Landscape'
The decline of the world's large herbivores, especially in Africa and of Asia, is raising the specter of an "empty landscape" in some of the most diverse ecosystems on the planet, according to a newly published study. Many populations of animals such as rhinoceroses, zebras, camels, elephants and tapirs are diminishing or threatened with extinction in grasslands, savannahs, deserts and forests, scientists say. An international team of wildlife ecologists led by William Ripple, Oregon State University distinguished professor in the College of Forestry, conducted a comprehensive analysis of data on the world's largest herbivores (more than 100 kilograms, or 220 pounds, on average), including endangerment status, key threats and ecological consequences of population decline. They published their observations today in Science Advances, the open-access online journal of Science magazine. The authors focused on 74 large herbivore species - animals that subsist on vegetation - and concluded that "without radical intervention, large herbivores (and many smaller ones) will continue to disappear from numerous regions with enormous ecological, social, and economic costs." Ripple initiated the study after conducting a global analysis of large-carnivore decline, which goes hand-in-hand, he said, with the loss of their herbivore prey.
"I expected that habitat change would be the main factor causing the endangerment of large herbivores," Ripple said. "But surprisingly, the results show that the two main factors in herbivore declines are hunting by humans and habitat change. They are twin threats."
enn.com
Physics
Portable 'Battlefield MRI' Comes Out Of The Lab
A practical, portable ultralow-field magnetic resonance imaging (MRI) system has been unveiled by researchers from the Los Alamos National Laboratory in the US. With its low power requirements and lightweight construction, the researchers hope that their prototype design can soon be deployed for use in medical centres in developing countries as well as in military field hospitals. MRI is a powerful medical diagnostic tool, which can be applied to the detailed imaging of a variety of soft tissues, in particular the brain. MRI scanners work by using large, powerful magnets to align the protons (hydrogen atoms) in water molecules. Short bursts of radio waves are then used to excite the protons, which as they relax give off weak radio waves the scanner can detect. Image contrast is provided by the varying relaxation times between different tissue types. Despite their usefulness, however, conventional MRI systems require both a considerable source of power and a supply of cryogens, such as helium or liquid nitrogen, to keep the magnets cool and functioning. On top of that, they are expensive to build and bulky to house. Scaling down "Standard MRI machines just can't go everywhere," explains project leader Michelle Espy, a physicist at Los Alamos. "Soldiers wounded in battle usually have to be flown in to a large hospital – and people in emerging nations just don't have access to MRI at all." To scale down the scanners, Espy and her team have made use of ultralow magnetic fields, which have intensities comparable to that of the Earth's magnetic field, to develop what they call "battlefield MRI" (bMRI). To detect the much weaker signals, their machine uses a superconducting quantum interference device (SQUID), which acts as an extremely sensitive magnetometer. While previous research has demonstrated the potential of ultralow-field MRI scanners, it has been limited by poor image qualities, long imaging times and – most critically – an impractical need to operate in an environment almost entirely isolated from ambient electromagnetic noise. "SQUIDs are so sensitive they'll respond to a truck driving by outside, or a radio signal from 50 miles away," explains Al Urbaitis, an engineer at Los Alamos. physicsworld
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Giant Electromagnet Arrives At Brookhaven Lab To Map Melted Matter
Why did the 40,000-pound superconducting magnet cross the country? The full answer to this twist on the old joke is complicated, but here's the short version: to unlock the secrets of the atom Pristine, particle-tracking magnets are rare enough to count on two hands. Most of these one-of-a-kind engineering feats sit at the heart of some of the most ambitious physics experiments in history and were built specifically to discover new facets of matter. One such singular instrument recently arrived at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory. The massive electromagnet is central to proposed upgrades at Brookhaven's Relativistic Heavy Ion Collider (RHIC), which smashes particles together at nearly the speed of light to recreate the ultra-hot conditions of the early universe. [...]
"After 14 years of discovery, RHIC remains the world's most versatile collider and our best tool for exploring the atomic nucleus," said Berndt Mueller, who leads Brookhaven's Nuclear and Particle Physics Directorate. "We have much more to learn about the foundations of matter, and RHIC is running more productively than ever. We are grateful to our colleagues and collaborators at SLAC for the opportunity to give this remarkable magnet a second life at RHIC."
The massive solenoid—a cylindrical electromagnet that generates a precise and uniform magnetic field—already spent nearly a decade driving discoveries at SLAC National Accelerator Laboratory in California. From 1999 to 2008, it sat inside a particle detector in SLAC's BaBar experiment, probing the puzzling asymmetry between matter and antimatter. When BaBar finished its run, SLAC stored the 20-ton solenoid for use in future experiments. phys.org
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Pacquiao, Mayweather, And The Physics Of Getting Punched In The Head
A prize fight might be thrilling but it's murder on the brain In a perfect world, a highly trained, heavily muscled man would not punch you in the head. Fortunately for most of us, the world is indeed perfect in that one small way. But most of us aren’t boxers. For those who are–say, Floyd Mayweather Jr. and Manny Pacquiao, who square off this weekend in a matchup dubbed “the fight of the century“—getting punched in the head by highly trained men is an occupational hazard. The payday can be huge, but the price—in terms of traumatic brain injury—can be very high. [...]
“[Boxing] is not really tracked the way school sports are tracked,” says Robert Cantu, clinical professor of neurology and neurosurgery at the Boston University school of medicine. “Concussions in boxing are a poorly reported sample, but at B.U. we’ve had a 100% incidence of CTE in the boxers we’ve studied.”
With good reason. Various studies have put the force delivered by a blow from a trained boxer at anywhere from 450 lbs. (204 kg) to over 1,400 lbs. (635 kg), enough to accelerate the head to 53 g’s. Those forces hit in one of two ways—linear and rotational—and neither of them is good. “Acceleration from a straight-on punch is linear, while a roundhouse is more rotational,” says Dr. Christopher Giza, professor of pediatric neurology and neurosurgery at UCLA’s Mattel Children’s Hospital, and a former commissioner of the California State Athletic Association. “We think rotational forces are more important in getting knocked out, but most punches have components of both.” time.com