Current+Events+In+Science

= Welcome to the Current Events in Science Page! =

Monday, April 4, 2011 The information in this article, has been obtained from the following site:

http://www.sciencenews.org/view/generic/id/72187/title/Worries_grow_over_monarch_butterflies

= Worries Grow Over Monarch Butterflies = North America’s beloved monarch butterfly may be sliding into a long-term decline. While monarch numbers have fluttered up and down over recent decades, one research group now says that there’s enough data to spot a downward trend. During the past 17 years, the area of Mexican forest patches covered by overwintering butterflies has been shrinking overall, says conservation biologist Ernest Williams of Hamilton College in Clinton, N.Y. He and his colleagues use the area occupied, which has averaged 7.24 hectares since the end of 1994, as a rough index of winter monarch population size. Several menaces, including habitat loss, confront monarchs but the researchers focused on assessing trends in the populations instead of confirming the causes. Within the overall downward trend, seven of the 10 below-average years in the study followed one another in a worrisome streak through the winter of 2010–11, the researchers say. The downward trend did not appear to be a fluke based on a couple of good or bad years; it still showed up when researchers removed the largest area (20.97 hectares in 1996–97) or the smallest (1.92 hectares in 2009–10) from the data, Williams and his colleagues report online March 21 in //Insect Conservation and Diversity//. “We have enough data now to say that we are seeing a long-term decline,” Williams says. That trend in winter populations may be statistically significant, says monarch researcher Karen Oberhauser of the University of Minnesota in St. Paul, but she and other researchers are now working on a broader analysis of monarchs and the challenges the insects face throughout the year to get a better handle on whether the population is declining and, if so, why. “I am not arguing that monarch populations are not facing threats, nor am I saying I’m not concerned,” she says. “I don’t think the [wintering] trend data clarify the situation.” That situation concerns the long-term health of what Williams calls the best-known butterfly in the world. Orange-and-black monarchs dart and waver over North American summer landscapes coast to coast and as far north as Canada, seeking milkweed plants as sites for laying eggs. The species’ annual migration is perhaps its most dramatic feat, though. Butterflies that hatch during summer and in fall — without ever having been to Mexico — find their way to the same patches of forest their predecessors did. In those spots, monarchs blanket the forest. “It’s stunning,” Williams says. “Sometimes you look at a tree trunk and you can’t see the bark.” When a burst of sunlight stirs the monarchs to flight, “you hear a whishing sound of their wings.” For butterflies in Mexico and in their summer range, “we see a confluence of threats,” Williams says. Winter monarch retreats are officially protected, but illegal logging chews away at Mexico’s forests. Plus, looming climate changes may bring more episodes of severe weather, which can hammer the butterflies. And monarchs across North America are finding less breeding habitat than they used to. Open land for milkweeds is falling to development, and researchers warn that a boom in genetically engineered crops is changing herbicide use patterns and thinning the ranks of milkweeds. Sparser milkweeds for breeding could in theory have a major effect on monarch abundance, says insect ecologist Myron Zalucki of the University of Queensland in Brisbane, Australia, “The big problem,” he says, “is disentangling the effects of all the threatening processes.”

Monday, April 11, 2011 The information in this article, has been obtained from the following site:

[]

= Sugar Fuels Growth of Insulin-Making Cells = A spoonful of sugar may be a remedy for diabetes. The more glucose that insulin-producing cells in the pancreas use, the faster those cells reproduce, a new study in mice shows.The findings, published in the April 6 //Cell Metabolism//, may help researchers devise new treatments for both type 1 and type 2 diabetes by harnessing the mechanism that leads to sugar-fueled cell growth. Such a strategy could help restore function to the cells in the pancreas damaged in diabetes while avoiding the toxic effects of high blood sugar. Giving animals more food to eat or bathing cells with glucose — the type of sugar that cells burn for energy — can increase the amount of insulin-producing pancreatic cells known as beta cells. But exactly how the sugar increases the number of beta cells has not been clear. “It was not a simple question to unravel,” says Patricia Kilian, director for regeneration at the Juvenile Diabetes Research Foundation. “There are just so many moving parts.” In fact, many researchers doubted glucose was the factor responsible for beta cell growth because the sugar can kill cells (that’s why high blood sugar is so bad for diabetics). The new study “uncovers the black box” and is an important contribution toward learning how to restore the function of the pancreas, she says.In the new study, researchers led by Yuval Dor and Benjamin Glaser of the Hebrew University of Jerusalem used genetic techniques to wipe out about 80 percent of the beta cells in the pancreases of mice. The mice became unable to produce enough insulin and thus diabetic, but between a month and six weeks later, the mice’s blood sugar levels dropped to normal. The researchers discovered that some of the beta cells had grown back. “Beta cells, contrary to expectations, do have a regenerative capacity. It’s slow. It’s weak. It may be defective in diabetics, but it’s there,” says Dor, a developmental biologist.He and his colleagues wanted to know whether that slow growth was fueled by the mice’s high blood sugar or by other factors. To find out, the researchers again killed about 80 percent of beta cells in another group of mice, but this time transplanted insulin-producing cells elsewhere in the mice to keep their blood sugar at normal levels. That meant the surviving beta cells in the pancreas didn’t have to work as hard. The cells’ regeneration rate dropped along with their work load, the team found. The result convinced researchers that glucose really was involved in the cells’ regrowth.To confirm the finding the team removed an enzyme called glucokinase from the mice’s beta cells. Glucokinase is a key enzyme in the conversion of glucose to energy. Without glucokinase “the beta cell replication dropped nearly to zero,” Dor says. That told the researchers that the cells’ ability to process glucose was important. The result also suggested that drugs that boost activity of glucokinase might increase beta cell growth. The researchers tested an experimental glucokinase-stimulating drug and found that the drug could boost beta cell production in mice. People with mutations that increase glucokinase activity also have more beta cells in their pancreases. Similar drugs might help diabetics, who have few functional beta cells, heal their pancreases, an important step to curing the disease. Such drugs might boost beta cell growth while still lowering circulating blood sugar levels. The next step is to figure out the entire biological process involved in glucose spurring beta cell regeneration, Dor says. Drugs that boost beta cell growth might also help diabetics who get transplants of pancreatic islet cells, Kilian says.

Monday, April 18, 2011 The information in this article, has been obtained from the following site:

http://www.sciencenews.org/view/generic/id/73067/title/NASA_pulls_out_of_astrophysics_missions = NASA Pulls Out of Astrophysics Missions = Two proposed space missions to study supermassive black holes and other high-energy phenomena have fallen into NASA’s gaping budget hole. Both missions were collaborations between NASA and the European Space Agency. When NASA recently determined that it could not come up with its share of funding for astrophysics research over the next few years, ESA decided it would have to scrap the projects as now envisioned. A third mission, planned by NASA alone, also appears to be in jeopardy. One of the missions, known as LISA, short for Laser Interferometer Space Antenna, would have been the first dedicated space mission to search for gravitational waves, ripples in spacetime predicted by Einstein’s theory of general relativity. LISA’s design called for three identical spacecraft that would use lasers to detect minute movements of a 2-kilogram gold-platinum alloy cube inside each craft. The tiny motions would be evidence of the passage of a gravitational wave generated by sources such as merging supermassive black holes. Total cost of the mission is estimated at about $2.4 billion, of which NASA’s share would have been $1.5 billion. The other disbanded mission, the roughly $5 billion International X-ray Observatory, would have cost NASA about $3.1 billion and was slated to use a large X-ray mirror to peer through dust and gas clouds to discover and examine some of the universe’s earliest supermassive black holes. The X-ray mission would have been a successor to two spacecraft now in orbit, NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton Observatory. Jon Morse, head of NASA’s astrophysics division, announced the decision to cut funding for both missions during an April 7 teleconference with a NASA astrophysics advisory board. ESA is considering scaled-down versions of these and other missions, and NASA may play a minor role if such a plan goes forward. Although the U.S. president’s proposed budget for fiscal year 2012 provides money to continue studying the designs of LISA and IXO, the projects weren’t the top priorities in last year’s National Research Council report on recommended astrophysics missions for the coming decade. “This is the most exciting time ever in astrophysics, but it coincides with a very challenging time for funding,” says Michael Turner of the University of Chicago, a coauthor of the council report. He notes that while ESA was eager to collaborate with NASA on IXO, LISA and Laplace — a mission to Jupiter and its moons — it became clear that NASA’s budget wouldn’t allow the mission’s to be ready to fly in the 2020 timeframe that ESA had in mind. “They have money now and need to produce good science with it or face the loss of contributions from member states,” says Turner. “Thus, they are forced into a position of going it alone on less capable versions of these missions.” James Ira Thorpe of NASA’s Goddard Space Flight Center in Greenbelt, Md., predicts that overall, any design that ESA might propose for a revamped gravitational wave mission “will look a lot like LISA.” He adds that if such a mission is not selected for continued study by ESA, “I would expect the communities in the U.S. and Europe to regroup and propose a LISA-like mission to their respective communities for a future opportunity.” NASA’s woes stem from a low budget for new astrophysics research, exacerbated by a $1.4 billion projected overrun for the James Webb Space Telescope. “The JWST overrun — if taken all from astrophysics — would eat up almost all of this money for new things,” Turner says. NASA Administrator Charles Bolden has suggested that the Webb telescope won’t launch before 2018, two years later than recently estimated. To meet that target, NASA would have to postpone the National Research Council’s highest-priority space mission, the proposed Wide-Field Infrared Survey Telescope, from a recommended 2020 launch to 2025, notes Alan Boss of the Carnegie Institution for Science in Washington, D.C. At that point, he says, the scientific timeliness of the mission to examine dark energy and exoplanets would have waned and support for the mission would have weakened.

Monday, April 25, 2011 The information in this article, has been obtained from the following site:

[]

= Development in Fog Harvesting Process May Make Water Available to the World’s Poor = In the arid Namib Desert on the west coast of Africa, one type of beetle has found a distinctive way of surviving. When the morning fog rolls in, the Stenocara gracilipes species, also known as the Namib Beetle, collects water droplets on its bumpy back, then lets the moisture roll down into its mouth, allowing it to drink in an area devoid of flowing water. What nature has developed, Shreerang Chhatre wants to refine, to help the world's poor. Chhatre is an engineer and aspiring entrepreneur at MIT who works on fog harvesting, the deployment of devices that, like the beetle, attract water droplets and corral the runoff. This way, poor villagers could collect clean water near their homes, instead of spending hours carrying water from distant wells or streams. In pursuing the technical and financial sides of his project, Chhatre is simultaneously a doctoral candidate in chemical engineering at MIT; an MBA student at the MIT Sloan School of Management; and a fellow at MIT's Legatum Center for Development and Entrepreneurship. Access to water is a pressing global issue: the World Health Organization and UNICEF estimate that nearly 900 million people worldwide live without safe drinking water. The burden of finding and transporting that water falls heavily on women and children. "As a middle-class person, I think it's terrible that the poor have to spend hours a day walking just to obtain a basic necessity," Chhatre says. A fog-harvesting device consists of a fence-like mesh panel, which attracts droplets, connected to receptacles into which water drips. Chhatre has co-authored published papers on the materials used in these devices, and believes he has improved their efficacy. "The technical component of my research is done," Chhatre says. He is pursuing his work at MIT Sloan and the Legatum Center in order to develop a workable business plan for implementing fog-harvesting devices. Interest in fog harvesting dates to the 1990s, and increased when new research on Stenocara gracilipes made a splash in 2001. A few technologists saw potential in the concept for people. One Canadian charitable organization, FogQuest, has tested projects in Chile and Guatemala. Chhatre's training as a chemical engineer has focused on the wettability of materials, their tendency to either absorb or repel liquids (think of a duck's feathers, which repel water). A number of MIT faculty have made advances in this area, including Robert Cohen of the Department of Chemical Engineering; Gareth McKinley of the Department of Mechanical Engineering; and Michael Rubner of the Department of Materials Science and Engineering. Chhatre, who also received his master's degree in chemical engineering from MIT in 2009, is co-author, with Cohen and McKinley among other researchers, of three published papers on the kinds of fabrics and coatings that affect wettability. One basic principle of a good fog-harvesting device is that it must have a combination of surfaces that attract and repel water. For instance, the shell of Stenocara gracilipes has bumps that attract water and troughs that repel it; this way, drops collects on the bumps, then run off through the troughs without being absorbed, so that the water reaches the beetle's mouth. To build fog-harvesting devices that work on a human scale, Chhatre says, "The idea is to use the design principles we developed and extend them to this problem." To build larger fog harvesters, researchers generally use mesh, rather than a solid surface like a beetle's shell, because a completely impermeable object creates wind currents that will drag water droplets away from it. In this sense, the beetle's physiology is an inspiration for human fog harvesting, not a template. "We tried to replicate what the beetle has, but found this kind of open permeable surface is better," Chhatre says. "The beetle only needs to drink a few micro-liters of water. We want to capture as large a quantity as possible." In some field tests, fog harvesters have captured one liter of water (roughly a quart) per one square meter of mesh, per day. Chhatre and his colleagues are conducting laboratory tests to improve the water collection ability of existing meshes. FogQuest workers say there is more to fog harvesting than technology, however. "You have to get the local community to participate from the beginning," says Melissa Rosato, who served as project manager for a FogQuest program that has installed 36 mesh nets in the mountaintop village of Tojquia, Guatemala, and supplies water for 150 people. "They're the ones who are going to be managing and maintaining the equipment." Because women usually collect water for households, Rosato adds, "If women are not involved, chances of a long-term sustainable project are slim." Whatever Chhatre's success in the laboratory, he agrees it will not be easy to turn fog-harvesting technology into a viable enterprise. "My consumer has little monetary power," he notes. As part of his Legatum fellowship and Sloan studies, Chhatre is analyzing which groups might use his potential product. Chhatre believes the technology could also work on the rural west coast of India, north of Mumbai, where he grew up. Another possibility is that environmentally aware communities, schools or businesses in developed countries might try fog harvesting to reduce the amount of energy needed to obtain water. "As the number of people and businesses in the world increases and rainfall stays the same, more people will be looking for alternatives," says Robert Schemenauer, the executive director of FogQuest. Indeed, the importance of water-supply issues globally is one reason Chhatre was selected for his Legatum fellowship. "We welcomed Shreerang as a Legatum fellow because it is an important problem to solve," notes Iqbal Z. Quadir, director of the Legatum Center. "About one-third of the planet's water that is not saline happens to be in the air. Collecting water from thin air solves several problems, including transportation. If people do not spend time fetching water, they can be productively employed in other things which gives rise to an ability to pay. Thus, if this technology is sufficiently advanced and a meaningful amount of water can be captured, it could be commercially viable some day." Quadir also feels that if Chhatre manages to sell a sufficient number of collection devices in the developed world, it could contribute to a reduction in price, making it more viable in poor countries. "The aviation industry in its infancy struggled with balloons, but eventually became a viable global industry," Quadir adds. "Shreerang's project addresses multiple problems at the same time and, after all, the water that fills our rivers and lakes comes from air." <span style="color: black; font-family: 'Arial','sans-serif'; line-height: normal; margin: 0in 0in 0pt;">That said, fog harvesting remains in its infancy, technologically and commercially, as Chhatre readily recognizes. "This is still a very open problem," he says. "It's a work in progress."

Monday, April 10, 2011 The information in this article, has been obtained from the following site:

[]

= Thinking Better With Depression = Depression may have an analytical upside. People hospitalized for this mood disorder display a flair for making good choices when many options must be considered one at a time, a new study finds. Depression may prompt an analytical thinking style suited to solving sequential problems, such as deciding when to stop a house hunt and purchase a property or when to stop playing the field and marry a suitor, say psychologist Bettina von Helversen of the University of Basel in Switzerland and her colleagues. It’s also possible that depressed people adopt a pessimistic outlook that encourages a thorough evaluation of available options, von Helversen's team suggests in an upcoming //Journal of Abnormal Psychology//. “Depression may improve sequential decision making, which includes some high-stakes choices,” she says. Von Helversen’s study is the first to demonstrate a thinking advantage for clinically depressed patients, possibly because — unlike previous studies of people with the ailment — the team used a quantitative measure to evaluate the accuracy of realistic social choices, remarks psychologist Paul Andrews of Virginia Commonwealth University in Richmond. Andrews hypothesizes that depression evolved as an emotional response that induces people to isolate themselves and single-mindedly resolve painful personal problems. “Depressive cognition is more complex than has been assumed by clinicians,” he says. Over the past 20 years, psychologists such as Paula Hertel of Trinity University in San Antonio have found that depressed volunteers who are not hospitalized do as well as or better than nondepressed peers on various tasks, some demanding careful analysis and others calling for quick or spontaneous answers. Contrasting studies find that depression, and the rumination it often entails, derail attention and thinking abilities, says Stanford University psychologist Ian Gotlib. People move and react slowly when severely depressed, which could have delayed depressed patients’ choices in the new study and misleadingly made them look analytical and patient, Gotlib suggests. Waiting too long to select an option undermines sequential decisions as much as jumping the gun, but depressed patients usually put off choices just long enough to make a good call, von Helversen responds. In her investigation, volunteers tried to choose the best job candidate from a computer-presented sequence of 40 applicants. In a series of trials, 15 depressed patients considered an average of a dozen applicants before selecting a first choice and around 16 before making a second choice. A mathematical model of the task devised by the researchers indicated that patients stopped their applicant searches at key points where there was a strong likelihood of choosing a highly qualified candidate. In this lab task, rejected applicants could not be chosen later in the selection process. Participants saw a numerical rating of a current applicant’s ranking relative to those already seen. Severely depressed patients chose higher-qualified job applicants than 27 non-depressed volunteers and 12 depressed patients whose symptoms had moderated with treatment. All depressed patients were recruited from a Berlin psychiatric hospital. About half of depressed participants, regardless of symptom severity, received antidepressant drugs. Medicated and drug-free patients with severe depression chose job applicants with comparable success, von Helversen says.