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
Europa Mission Begins With Selection Of Science Instruments
NASA has selected nine science instruments for a mission to Jupiter’s moon Europa to investigate whether the mysterious icy moon could harbor conditions suitable for life. NASA’s Galileo mission yielded strong evidence that Europa, about the size of Earth’s Moon, has an ocean beneath a frozen crust of unknown thickness. If proven to exist, this global ocean could have more than twice as much water as Earth. With abundant salt water, a rocky seafloor, and the energy and chemistry provided by tidal heating, Europa could be the best place in the solar system to look for present-day life beyond our home planet. [...] The payload of selected science instruments includes cameras and spectrometers to produce high-resolution images of Europa’s surface and determine its composition. An ice-penetrating radar will determine the thickness of the moon’s icy shell and search for subsurface lakes similar to those beneath Antarctica. The mission also will carry a magnetometer to measure strength and direction of the moon’s magnetic field, which will allow scientists to determine the depth and salinity of its ocean. A thermal instrument will scour Europa’s frozen surface in search of recent eruptions of warmer water, while additional instruments will search for evidence of water and tiny particles in the moon’s thin atmosphere. NASA’s Hubble Space Telescope observed water vapor above the south polar region of Europa in 2012, providing the first strong evidence of water plumes. If the plumes’ existence is confirmed — and they’re linked to a subsurface ocean — it will help scientists investigate the chemical makeup of Europa’s potentially habitable environment while minimizing the need to drill through layers of ice. astronomy.com
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LightSail Solar Sail Test Flight Stalled By Software Glitch
A tiny solar-sailing spacecraft has gone silent in Earth orbit, apparently victimized by a software glitch. LightSail, a CubeSat designed and built by the nonprofit Planetary Society, stopped beaming data home on Friday (May 22), just two days after it blasted off along with the United States Air Force's robotic X-37B space plane.
"LightSail is likley now frozen, not unlike the way a desktop computer suddenly stops responding," The Planetary Society's Jason Davis wrote in a mission update Tuesday (May 26).
The cause of the problem seems to lie with LightSail's flight software, Davis added. The spacecraft, which is about the size of a loaf of bread, was designed to beam telemetry data home in a "beacon packet" every 15 seconds. As this happens, the software writes corresponding information to an onboard file.
"As more beacons are transmitted, the file grows in size," Davis wrote in the update. "When it reaches 32 megabytes — roughly the size of 10 compressed music files — it can crash the flight system. The manufacturer of the avionics board corrected this glitch in later software revisions. But alas, LightSail's software version doesn't include the update."
space.com
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Cassini Prepares For Last Up-Close Look At Hyperion
NASA's Cassini spacecraft will make its final close approach to Saturn's large, irregularly shaped moon Hyperion on Sunday, May 31. The Saturn-orbiting spacecraft will pass Hyperion at a distance of about 21,000 miles (34,000 kilometers) at approximately 6:36 a.m. PDT (9:36 a.m. EDT). Mission controllers expect images from the encounter to arrive on Earth within 24 to 48 hours. Mission scientists have hopes of seeing different terrain on Hyperion than the mission has previously explored in detail during the encounter, but this is not guaranteed. Hyperion (168 miles, 270 kilometers across) rotates chaotically, essentially tumbling unpredictably through space as it orbits Saturn. Because of this, it’s challenging to target a specific region of the moon's surface, and most of Cassini's previous close approaches have encountered more or less the same familiar side of the craggy moon. [...] Cassini's next notable flyby after May 31 is slated for June 16, when the spacecraft will pass 321 miles (516 kilometers) above icy Dione. That flyby will represent the mission's penultimate close approach to that moon. In October, Cassini will make two close flybys of the active moon Enceladus, with its jets of icy spray, coming as close as 30 miles (48 kilometers) in the final pass. In late 2015, the spacecraft will again depart Saturn's equatorial plane -- where moon flybys occur most frequently -- to begin a year-long setup of the mission's daring final year. For its grand finale, Cassini will repeatedly dive through the space between Saturn and its rings. nasa.gov
Biology
Long-Term Study On Ticks Reveals Shifting Migration Patterns, Disease Risks
Over nearly 15 years spent studying ticks, Indiana University's Keith Clay has found southern Indiana to be an oasis free from Lyme disease, the condition most associated with these arachnids that are the second most common parasitic disease vector on Earth. [...]
"Just in the past 10 years, we're seeing things shift considerably," Clay said. "You used to never see lone star ticks in Indiana; now they're very common. In 10 years, we’re likely to see the Gulf Coast tick here, too. There are several theories for why this is happening, but the big one is climate change."
[...] The conclusions are drawn from years of work spent mapping tick boundaries and disease risks, but the exact cause of the shifting borders is not clear. In addition to changing temperatures, Clay references changes in animal populations, including deer, which provide large, mobile hosts for the parasites. Defining these boundaries is critical due to ticks' status as the most important vector for infectious disease in the U.S. In addition to Lyme disease, ticks are responsible for Rocky Mountain spotted fever, southern tick-associated rash illness and a number of other serious diseases. Other conditions, such as mammalian meat allergy, caused by lone star tick bites, are caused by an immune response to proteins in tick saliva. Mammalian meat allergy sufferers experience serious allergic reaction to consuming meat and sometimes other products from mammals. indiana.edu
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Biodiversity: 11 New Species Come To Light In Madagascar
Madagascar is home to extraordinary biodiversity, but in the past few decades, the island's forests and associated biodiversity have been under greater attack than ever. Rapid deforestation is affecting the biotopes of hundreds of species, including the panther chameleon, a species with spectacular intra-specific colour variation. A new study by Michel Milinkovitch, professor of genetics, evolution, and biophysics at the University of Geneva (UNIGE), led in close collaboration with colleagues in Madagascar, reveals that this charismatic reptilian species, which is only found in Madagascar, is actually composed of eleven different species. [...] A Talkative Drop of Blood It took two expeditions led from East to West for the scientists to collect a drop of blood from each of 324 individuals and document them through colour photographs. The DNA (mitochondrial and nuclear) of each of the specimens were sequenced and analysed in the laboratory according to the hypothesis that a chameleon's dominant colour might be related to the geographic zone where it is found. Most importantly, the genetic material indicated strong genetic structure among geographically-restricted lineages, revealing very low interbreeding among populations. A Key for Turning Genetics into Color The mathematical analyses of the 324 colour photographs demonstrated that subtle colour patterns could efficiently predict assignment of chameleon individuals to their corresponding genetic lineage, confirming that many of the geographical populations might need to be considered separated species. The scientists then simplified their analyses of the colour diversity into a classification key, which allows to link most chameleons to their corresponding species using only the naked eye. This case of hidden speciation confirms a major characteristic of Madagascar: it is amongst the most diverse places for life on Earth; a biodiversity hotspot. biologynews.net
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Mexican Jays Can Detect Nut Properties, Ornithologists Say
Using slow-motion video-recording and experiments, an international team of ornithologists has found that the Mexican Jays are able to ‘weigh’ peanuts while handling them in their beaks.
“When we presented the jays with ten empty and ten full identically looking pods (pods without or with three nuts inside), we noticed that after picking them up the birds rejected the empty ones and accepted the full peanuts, without opening them,” said Dr Lee [...]
A series of similar experiments with identically looking normal nuts and nuts that were 1g heavier (pods with some clay added) confirmed that jays always were able to distinguish and preferred the heavier nuts. [...] In another experiment the team prepared one type of peanut pods by opening the shell, removing two out of the three nuts and closing the shell again. The second type of pod was prepared by opening a small pod, which normally contains only one nut, and closing it. Thus, the birds were to choose between nuts of similar content and mass but of different size.
“The jays figured out that the larger pods did not weigh as much as they should and the birds preferred the smaller pods, which weighed as expected for their size. They behaved as if they knew that something is wrong with the larger nuts,” said co-author Dr Maciej Fuszara of Cardinal Stefan Wyszynski University in Warsaw, Poland.
sci-news.com
Chemistry
Major Milestone Reached As 90% Of Global Chemical Weapon Stocks Destroyed
Director-General, Ambassador Ahmet Üzümcü, today announced that 90% of declared chemical weapons had been verified by the [Organisation for the Prohibition of Chemical Weapons] as destroyed. This includes stocks of unitary weapons, such as sulfur mustard, and primary precursor chemicals for producing deadly nerve agents, like sarin. All destruction activities have been completed in a safe manner.
“This is a major milestone that shows we are well on the way to ridding the world of chemical weapons,” said Ambassador Üzümcü.
The process to complete the elimination of Cold War-era stockpiles in Russia and the United States is well under way and is scheduled to be completed before the end of 2020 and 2023, respectively. [...] The Chemical Weapons Convention has 190 States Parties, with six States – Angola, Egypt, Israel, Myanmar, North Korea and South Sudan – still outside the Convention. Angola’s and Myanmar’s parliaments recently approved joining the Convention, and both countries are expected to soon become States Parties opcw.org
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Coffin Remains Tell Life Story Of Ancient Sun-Worshiping Priestess
Once upon a time in the Bronze Age, a girl was born to a family of sun worshipers living in the Black Forest of what is today Germany. When she was young she became a priestess in the local sun cult, and soon attracted the eye of a tribal chief who lived far to the north. The girl’s family married her off, and she went to live with the chief in what is now Denmark. She often traveled back and forth between Denmark and her ancestral home and eventually gave birth to a child while she was away. Sometime before her 18th birthday, she and the child died. They were buried together in an oak coffin, the young woman wearing a bronze belt buckle in the shape of the sun. How do we know? A new study of the 3400-year-old girl’s chemical isotopes, along with more conventional archaeological evidence, tells us so. At least, these are the conclusions of scientists who recently analyzed the teeth, fingernails, hair, and clothes of the Egtved Girl, so named for the Danish village where archaeologists first discovered her in 1921. The study is “state-of-the-art,” says Joachim Burger, an archaeologist at the Johannes Gutenberg University Mainz in Germany, who was not involved in the research. Alex Bentley, an archaeologist at the University of Bristol in the United Kingdom, calls the work “impressive and meticulous.” The study is highly unusual, researchers say, in the way that it brings together chemical tracers from a number of tissue types to reconstruct the life history of a single individual. sciencemag.org
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Patent Picks: Hydrogels
Contact Lenses As Health Monitors People normally wear contact lenses to correct their eyesight. But one day, the polymer lenses might be harnessed for other medical applications such as health monitoring. In a 2015 patent, Randall Braxton Pugh of Johnson & Johnson Vision Care reports contact lenses made from either silicone hydrogels or fluorohydrogels that can wirelessly communicate with devices such as PCs, tablets, and cell phones to report health data (US 20150063605). Hydrogels help contact lenses stay moist and allow oxygen to reach the eye, preventing damage to the cornea. Braxton Pugh’s proposed contact lens sports a clear “optic zone” in the center and an embedded microacoustic element and microfluidic biosensor around the edge, out of a person’s line of sight. The biosensing lens could be designed to sample a wearer’s tears for biomarkers of high blood pressure, for example. If the biomarker level breaches a certain threshold, the sensor would transmit a signal to a wireless device, which would then induce the microacoustic element to send a warning sound to a person’s inner ear via bone conduction. Better Insulin Delivery For Diabetics For patients with diabetes, regular insulin injections and finger pricks to monitor blood glucose are a necessary burden. Implantable devices that deliver insulin and measure glucose levels are in clinical trials and could make life easier for these patients, but the systems have their limitations. For example, devices that detect glucose using glucose oxidase need more dissolved oxygen to function efficiently than may be available in blood. Other devices damage surrounding cells. Recently, injectable systems based on phenylboronic acid (PBA), a glucose-binding moiety, have attracted attention from researchers. Robert S. Langer and colleagues at MIT have now designed an improved PBA-based hydrogel that, when injected under the skin, reacts to changing blood glucose levels to avoid hyperglycemia (too much blood sugar) and hypoglycemia (too little blood sugar) (US 20150025005). Their glucose-binding hydrogel is made of peptides that have hydrophobic regions linked to PBA. It also traps insulin within its gel matrix. When glucose binds to the PBA groups, the hydrogel’s structure changes and the system releases insulin. After the insulin reduces a patient’s blood sugar levels, glucose vacates the hydrogel, and the material reverts to its original shape, once again entrapping insulin. The technology has already been licensed. Injectable Hydrogels Reconstruct Tissue During cosmetic reconstructive surgery, doctors often implant polymeric scaffolds to aid tissue regeneration. Injectable scaffolds, which would cause less trauma, could be an improvement over implants. Antonios G. Mikos and coworkers at Rice University have now developed injectable thermogelling hydrogels capable of serving as tissue scaffolds (US 20150079020). Poly(N-isopropylacrylamide)-based hydrogels have shown promise, but they have a tendency to shrink once inside the body. To stabilize their hydrogel, the Rice University inventors add polyamidoamines as temperature-responsive cross-linkers. When injected into the bodies of animals during preclinical testing, the new scaffolds transform from liquid to gel in response to the animals’ higher internal temperature, and they fill voids left behind by injuries. acs.org
Earth Science
Why Heat Is Accelerating The California Drought
Although record low precipitation has been the main driver of one of the worst droughts in California history, abnormally high temperatures have also played an important role in amplifying its adverse effects, according to a recent study by the U.S. Geological Survey and university partners. Experiments with a hydrologic model for the period Oct. 2013-Sept. 2014 showed that if the air temperatures had been cooler, similar to the 1916-2012 average, there would have been an 86% chance that the winter snowpack would have been greater, the spring-summer runoff higher, and the spring-summer soil moisture deficits smaller. To gauge the effect of high temperatures on drought, lead author Shraddhanand Shukla (University of California – Santa Barbara, UCSB) devised two sets of modeling experiments that compared climate data from water year 2014 (Oct. 2013-Sept. 2014) to similar intervals during 1916-2012. In the first simulation set, Shukla substituted 2014 temperature values with the historical temperatures for each of the study’s 97 years, while keeping the 2014 precipitation values. In the second simulation set, he combined the observed 2014 temperatures with historical precipitation values for each of the preceding years, 1916-2012.
“This experimental approach allows us to model past situations and tease out the influence of temperature in preceding drought conditions,” said Chris Funk, a USGS scientist and a co-author of the investigation. “By crunching enough data over many, many simulations, the effect of temperature becomes more detectable. We can’t do the same in reality, the here and now, because then we only have a single sample.”
enn.com
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Environmental Group Collects Tar Balls In Effort To Identify Source
Reynolds, a staffer, pulled on latex gloves and opened a small glass jar to collect the sample. She leaned over the edge of the boat and scooped up the hamburger slider-sized tar patty, then brought it to eye level and shook it gently. It was a few inches long and a quarter of an inch thick, shedding little black specks that floated inside the jar. Dozens of tar balls washed ashore in the South Bay on Wednesday, causing beaches to close along nearly nine miles of coastline from El Segundo to Redondo Beach. Scientists with the U.S. Coast Guard and the National Oceanic and Atmospheric Administration are investigating the cause, including whether the gunk is related to last week's oil spill in Santa Barbara County. The beaches are closed indefinitely while scientists study the substances and cleanup crews remove the last 10% of tar balls, which were baseball- to football-sized, officials said. Test results to determine the source and composition of the petroleum product could take a few days to several weeks. [...]
"No one's identified the source of the spill, so it's good to keep an eye on it either way so we can say, 'OK, we saw these pieces of tar in these places,' and we can track them over time and see if it's spreading or if it's just a one-time event," Reynolds said.
latimes.com
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Rain Is A Good Thing, But Here Come The Insects
The recent deluge that hit several Southern states has brought a reprieve from years of drought, which will be a blessing for many farmers. But it also might pack its own curse: the wet conditions are a boon to certain invasive insect species that could threaten crops. Scientists are warning it could be a buggy summer across newly wet regions. Fields are soaked, and the weather is still relatively cool. As the weather starts to warm, the bugs will come out, and farmers in the region will see a "superabundance" of insect pests that could carry over into 2016, said Micky Eubanks, an entomologist at Texas A&M University. Farmers in the region have struggled to keep their crops and livestock watered during a multiyear drought. But the newly verdant land will be "heaven" for insect species, Eubanks said.
"This is the greenest I have ever seen the state of Texas," Eubanks said. "The fields are green, and all of the wildflowers and herbaceous plants are just going crazy."
Insects are already gorging themselves on those wild plants and will likely move over to domestic crops by the end of the summer, Eubanks said. Many of the species can feed on several types of plants, so all crops stand to be affected. nbcnews.com
Physics
Memory Shape Alloy Can Be Bent 10 Million Times And Still Snaps Back
A combined team of researchers from the University of Kiel in Germany and the University of Maryland in the U.S. has created a shape memory alloy that is able to be bent and snap back to its original form up to ten million times. In their paper published in the journal Science, the team describes how they came up with the alloy and why they believe it could have a wide variety of uses. Richard James of the University of Minnesota offers a Perspective piece on the work done by the team in the same journal issue. Memory shape alloys got their name by the unique property of being able to be bent and returning to their original shape automatically. Such metals can have their shape altered by subjecting them to physical bending, or by heating them. Up till now, no such alloy was able to snap back after being subjected to bending more than a few thousand times—scientists would like to bump that number up significantly because it would allow for creating devices that are more durable—artificial aortic valves, for example, or as a replacement for liquids in refrigerating devices. But despite a lot of effort, no one had been able to find a way to make that happen. The researchers with the team readily acknowledge that their find was largely luck, they were tinkering with different mixtures, in this case, adding a little bit of cobalt to an already existing alloy made of nickel, copper and titanium. The resulting alloy surprised them during initial testing. Because such an alloy had never been created, neither had a means for testing its durability—they had to come up with two types of testing devices, one to repeatedly bend and allow for release, very quickly and another for heating and cooling. Both types of tests wound up having to run for weeks to reach the ten million mark. It is not yet clear why the new alloy has such super bending properties, but the researchers suspect that it has to do with its ability to switch from one crystalline form to another, and then of course, back again without suffering from molecular knots, which for most alloys introduce imperfections, which lead to failure. phys.org
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New Maze-Like Beamsplitter Is World's Smallest
An ultracompact beamsplitter – the smallest one in the world – has been designed and fabricated by researchers in the US. Using a newly developed algorithm, the team built the smallest integrated polarization beamsplitter to date, which could allow computers and mobile devices of the future to function millions of times faster than current machines. Beamsplitters divide light waves into two separate channels of information, and will be crucial for the development of so-called silicon photonic chips that compute and shuttle data using light instead of electrons. "Light is the fastest thing you can use to transmit information," says Rajesh Menon, an electrical and computer engineer at the University of Utah. "But that information has to be converted to electrons when it comes into your laptop. In that conversion, you're slowing things down. The vision is to do everything in light." Light maze Silicon photonics could significantly increase the power and speed of machines such as supercomputers and data-centre servers. In theory, devices employing such chips should not only be faster, but also consume far less power as well. Measuring only 2.4 × 2.4 μm2, the new beamsplitter is nearly 50 times smaller than any beamsplitter created to date. It also has an unorthodox maze-like shape. "Most polarizing beamsplitters do not look like this today," says Menon. "We wanted our device to be as easy as possible to fabricate using existing techniques, and to be as efficient as possible." To do this, Menon and his team created an algorithm that tried various geometries, until it found the smallest and most efficient design. Menon described this process as a "smart" search, explaining that "the 'smartness' is important because there are too many possibilities to try and the alternatives would take a very long time." As the design takes existing manufacturing techniques into account, the team says its beamsplitter could be produced on an industrial scale almost as inexpensively as electronic transistors are today. physicsworld.com
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Self-Folding Robot Walks, Swims, Climbs, Dissolves
A demo sparking interest at the ICRA 2015 conference in Seattle was all about an origami robot that was worked on by researchers. More specifically, the team members are from the computer science and artificial intelligence lab at MIT and the department of informatics, Technische Universitat in Germany. "An untethered miniature origami robot that self-folds, walks, swims, and degrades" was the name of the paper, co-authored by Shuhei Miyashita, Steven Guitron, Marvin Ludersdorfer, Cynthia R. Sung and Daniela Rus. They focused on an origami robot that does just what the paper's title suggests. A video showing the robot in action showcases each move. One can watch the robot walking on a trajectory, walking on human skin, delivering a block; swimming (the robot has a boat-shaped body so that it can float on water with roll and pitch stability); carrying a load (0.3 g robot); climbing a slope; and digging through a stack. It also shows how a polystyrene model robot dissolves in acetone.
YouTube Video
Even Ackerman in IEEE Spectrum reported on the Seattle demo. Unfolded, the robot has a magnet and PVC sandwiched between laser-cut structural layers (polystyrene or paper). How it folds: when placed on a heating element, the PVC contracts, and where the structural layers have been cut, it creates folds, said Ackerman. The self-folding exercise takes place on a flat sheet; the robot folded itself in a few seconds. Kelsey Atherton in Popular Science, said, "Underneath it all, hidden like the Wizard of Oz behind his curtain, sit four electromagnetic coils, which turn on and off and makes the robot move forward in a direction set by its shape." When placed in the tank of acetone, the robot dissolves, except for the magnet. The authors noted "minimal body materials" in their design enabled the robot to completely dissolve in a liquid environment, "a difficult challenge to accomplish if the robot had a more complex architecture." Possible future directions: self-folding sensors into the body of the robot, which could lead to autonomous operation, and eventually, even inside the human body. The authors wrote, "Such autonomous '4D-printed' robots could be used at unreachable sites, including those encountered in both in vivo and bionic biological treatment." phys.org