Physics Today Daily Edition
Science: When the ground becomes saturated with water, the risk for flooding increases. Now researchers have shown that the strength of Earth’s gravity in the area also increases. They studied data collected by NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites in the months preceding the catastrophic 2011 flooding on the Missouri River and found that the gravity signal improved model forecasts more than measures of snowmelt and soil wetness. However, GRACE’s resolution is too low and the time it takes to retrieve and process the data is too long to make such measurements useful in current flood prediction efforts. The researchers hope to improve on that capability when a GRACE follow-on mission is launched in 2017.
New Scientist: Launched in December 2013, the European Space Agency’s Gaia is on a mission to compile the most accurate and extensive catalog of our galaxy's stars. But fulfilling that mission has been delayed because of several problems. Most important, excessive stray light has been entering the telescope. In addition, water that was trapped in the spacecraft before launch has been outgassing and freezing on the telescope’s mirrors. Although researchers tried to deal with both potential problems before launch by installing a sunshield to keep out stray light and heaters to melt the ice, the spacecraft has taken in more light and accumulated more ice than had been anticipated. Researchers are looking into modified observing strategies and computer software to optimize the data that are collected. However, mission managers say that even if the problems can’t be fixed, only the quality of the data collected for the faintest stars will be affected.
New York Times: Despite lengthy negotiations, no agreement has yet been reached between Iran and the P5 + 1 nations (the US, the UK, France, Russia, China, and Germany) concerning Iran’s nuclear program. For the past decade Iran’s nuclear activity has been a source of international contention, and as a result, economic sanctions have been imposed against the country. Iranian officials maintain that the nuclear facilities are for purely peaceful purposes but have balked at allowing inspections or other forms of monitoring. In recent months all parties have been working to resolve the problem and lift the sanctions. However, with less than three weeks left to reach a final agreement, two of the principal negotiators, US secretary of state John Kerry and Iranian foreign minister Javad Zarif, are already blaming each other if the talks collapse. Because of the substantial differences that must be overcome, the talks could be extended.
MIT Technology Review: Inspired by the Nepenthes pitcher plant, whose insect-trapping mouth is surrounded by a slippery lip created by a thin film of water, a team of researchers led by Joanna Aizenberg of Harvard University has developed a lubricating film that repels liquids and solids from almost any surface. Called SLIPS, for slippery liquid-infused porous surfaces, the novel material is composed of a textured solid infused with a chemically inert liquid that forms a superthin, supersmooth film to which nothing can stick, including water, blood, oil, ice, dust, and bacteria. Among SLIPS’s numerous properties are that it works under extreme conditions, it is self-healing and self-cleaning, and it can be made from low-cost materials. The research team is now working to commercialize the material for use in such applications as self-defrosting freezers and as an anti-icing material for planes and wind turbines.
BBC: The teams behind the ground-based BICEP2 experiment and the Planck satellite have announced that they are negotiating to share data. The groups have only just begun talking, but hope that the data sharing could result in the publication of a joint paper. In March, BICEP2 announced that the project appeared to have detected evidence of gravitational waves in the cosmic microwave background (CMB) radiation. One of the immediate responses was that the project didn't accurately account for interstellar dust in the area that was observed. An updated map of cosmic dust from the Planck satellite, which has been mapping the CMB, is expected this fall.
New Scientist: When the cosmic microwave background (CMB) radiation was mapped, a large cold spot was revealed. The current theory of inflation doesn't predict the existence of such an area, so many exotic theories have been proposed to explain it. István Szapudi at the University of Hawaii in Honolulu and his colleagues have found evidence that suggests a much simpler solution. They examined the all-sky survey data from the Wide-field Infrared Survey Explorer and found a large void that is 1.8 billion light-years across and located 2.8 billion light-years from Earth. As the CMB passed through this huge area of space that is devoid of matter, it could have lost enough energy to create the cold spot. The void they found is the largest so far and is twice as large as the previous largest known void.
Nature: The US National Institutes of Health (NIH) will be announcing a $248 million project to map the body's electrical system and to develop medical implants that can be used to stimulate nerves as a treatment for diseases. A similar project is already underway at pharmacological research company GlaxoSmithKline. The Food and Drug Administration (FDA) recently approved a sleep apnea device that stimulates the muscles that control breathing. And another device awaits FDA approval: Designed for weight control, it stimulates the vagus nerve to make a person feel full. The benefit of such devices is that, unlike pharmaceuticals, they can target specific problems. However, the understanding of why those devices work is still limited. The goal of the NIH project is to provide a much clearer understanding of the nervous system to allow for improvements in and faster development of stimulus implants.
BBC: Devil rays had been thought to be a tropical fish because they dwell in relatively warm surface waters. So the presence in the animals’ skull of a mesh of large and small arteries, called the rete mirabile, had puzzled researchers for some 30 years. The rete mirabile help keep the brains of cold-water-dwelling fish warm and functioning. Recently, Simon Thorrold of the Woods Hole Oceanographic Institution and colleagues tagged and tracked 15 Chilean devil rays (Mobula tarapacana) in the North Atlantic Ocean over several months. They were surprised to find that the rays could dive at speeds up to 22 km/h to depths of almost 2 km—faster and deeper than most other sea-dwelling creatures, including sharks and whales. In between dives, the rays floated near the surface, presumably to warm themselves back up. The fish could provide an important link between surface ecosystems and those of the deep ocean.
Science: A kangaroo’s tail works as hard to propel the animal forward as all four of its legs combined, according to a recent study published in Biology Letters. Max Donelan of Simon Fraser University in Burnaby, British Columbia, Canada, and colleagues studied five red kangaroos (Macropus rufus) as they walked. The movement of kangaroos has been called pentapedal, or five-footed, because of the way they place their tail on the ground in time with their front legs as they bring their hind legs forward. Through the use of video recordings and force measurements taken from a special plate installed in the laboratory floor, the researchers were able to determine that a kangaroo’s tail not only acts as a support, which had been believed to be its chief function, but also propels and powers the animal forward much like a human leg does. That is because the tail actually has larger muscles than the forelimbs. The researchers propose that it may be this unique combination of shortened forelimbs and more muscular tail that allows the animals to reach speeds of up to 60 km/hour.
BBC: Erin Lavik of Case Western Reserve University and his colleagues have created nanoscopic spheres covered in thin protein chains to increase blood's natural clotting ability. The protein chains bind with platelets, the cells responsible for clotting, and accelerate the speed at which clots form. Lavik's team found that the particles increased the survival rate of injured mice from 60% to 90%. Although products exist for treating injuries that produce major bleeding, they require refrigeration and have shelf lives of just a few days. The new nanoparticles can be stored for weeks as a powder and are turned into a solution simply by mixing with saltwater or sugar water. The particles will be tested on larger animals before they are tried in humans.
Nature: Women earn more than 50% of the PhDs in the life sciences every year, but only 18% of full professors in the field are women. The discrepancy may be because most assistant professors are chosen from elite labs and those labs hire significantly more men than women. The finding was made by Jason Sheltzer of MIT and Joan Smith of Twitter who analyzed demographics data from labs in 39 departments at 24 of the top US research institutions. In labs led by men, 36% of postdocs and 47% of grad students were women, compared with 46% and 53% respectively in labs led by women. In male-led "elite" labs—those led by men who are members of the National Academies of Science or receiving Howard Hughes Medical Institute funding—the proportion of female postdocs dropped to just 31%. In elite labs led by women, there was no significant change in gender distribution in postdocs and grad students.
Science: An NSF study found that the annual number of graduates in science, technology, engineering, and mathematics (STEM) fields increased steadily from 241 000 in 2000 to 355 000 in 2012. Even if the increase doesn't continue through 2015, the number of STEM graduates in the workforce will likely exceed 1 million and and will meet the goal of the President’s Council of Advisers on Science and Technology (PCAST) . However, it will be reached without any of the STEM education funding that has been requested from Congress. The number of graduates considered by NSF and PCAST includes both bachelors and associates degrees.
New Scientist: A limestone quarry in Sweden has produced around 100 iron-poor L chondrite meteorites that all date to 470 million years ago. But a newly discovered meteorite in the quarry that dates to the same period is not an L chondrite, nor is it like any other known meteorites. L chondrite meteorites from that period have been found all around Earth, and the bombardment is believed to have been caused by the collision of two asteroids. Because the new meteorite has been found in the same rock layer, it may be a remnant of the other asteroid, which is believed to have been much smaller than the one that produced the L chondrites. The meteorite bombardment could be connected to a burst of new species appearing in the fossil record in the same time period, though whether the impacts sparked the population explosion is uncertain.