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Wysłany: Wto 20:10, 26 Lis 2013 Temat postu: scientists say.With climate change |
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UPI NewsTrack Science and Technology News
Climate change affecting growing seasonsGREENBELT, Md., March 11 () -- Growing seasons in Earth's northern latitudes are shifting and vegetation increasingly resembles lusher latitudes to the south, scientists say.With climate change, temperatures and vegetation in northern latitudes resemble those found 4 degrees to 6 degrees of latitude farther south as recently as 1982, they said.NASA scientists along with U.S. and international researchers analyzed the relationship between changes in surface temperature and vegetation growth from 45 degrees north latitude to the Arctic Ocean."Higher northern latitudes are getting warmer, arctic sea ice and the duration of snow cover are diminishing, the growing season is getting longer and plants are growing more," Ranga Myneni of Boston University's Department of Earth and Environment said in a NASA release Monday."In the north's arctic and boreal areas, the characteristics of the seasons are changing, leading to great disruptions for plants and related ecosystems."The researchers analyzed satellite data to quantify vegetation changes at different latitudes from 1982 to 2011.Increased temperatures and a longer growing season have created large patches of vigorously productive vegetation spanning a third of the northern landscape, or more than 3.5 million square miles, an area about equal to the contiguous United States.This landscape resembles what was found 250-430 miles to the south in 1982, researchers said."It's like Winnipeg, Manitoba, moving to Minneapolis-St. Paul in only 30 years," Compton Tucker of NASA's Goddard Space Flight Center in Greenbelt, Md., said.Increased concentrations of heat-trapping greenhouse gasses cause Earth's surface, ocean and lower atmosphere to warm, driving the changes, Myneni said."This sets in motion a cycle of positive reinforcement between warming and loss of sea ice and snow cover, which we call the amplified greenhouse effect," Myneni said. "The greenhouse effect could be further amplified in the future as soils in the north thaw, releasing potentially significant amounts of carbon dioxide and methane."Climate models suggest increased temperatures in arctic and boreal regions would be the equivalent of a 20-degree latitude shift by the end of the 21st century, the researchers said. Close neighbor of sun discoveredUNIVERSITY PARK, Pa., March 11 () -- A U.S. astronomer says a pair of newly discovered stars makes up the third-closest star system to the sun and is the closest discovered since 1916.Penn State astronomy and astrophysics Professor Kevin Luhman, who made the discovery in star surveys conducted by the NASA-funded WISE satellite that was confirmed by ground telescopes, said the stars are "brown dwarfs," stars too small in mass to become hot enough to ignite hydrogen fusion.Such stars are very cool and dim, resembling a giant planet like Jupiter more than a bright star like the sun."The distance to this brown dwarf pair is 6.5 light-years -- so close that Earth's television transmissions from 2006 are now arriving there," Luhman said in a Penn State release Monday.The new star system, dubbed WISE 1049-5319 is only slightly farther away than the second-closest star, Barnard's star, discovered 6.0 light-years from the sun in 1916. The closest star system consists of Alpha Centauri, found in 1839 at 4.4 light-years and the fainter Proxima Centauri, discovered in 1917 at 4.2 light-years.The close proximity of the system makes it an ideal candidate for the search for planets outside the solar system, Luhman said."It will be an excellent hunting ground for planets because it is very close to Earth, which makes it a lot easier to see any planets orbiting either of the brown dwarfs," he said. Dispute over Antarctic 'unidentified' lifeST. PETERSBURG, Russia, March 11 () -- Russian scientists still say an "unclassified" species of bacteria was found in water samples beneath Antarctic ice, although some colleagues are disputing it.The Arctic and Antarctic Research Institute in St. Petersburg officially confirmed on Monday probes from Lake Vostok,[url=http://www.ksacinc.com/christianlouboutindiscount]christian louboutin discount[/url], 2 miles beneath the frozen ice cover of Antarctica, contained a bacterium that did not match DNA sequences of any of the main subdivisions of the biological domain of bacteria."After excluding all known contaminants ... we discovered bacterial DNA that does not match any known species listed in global data banks. We call it unidentified and 'unclassified' life," Sergei Bulat, a researcher at the Laboratory of Eukaryote Genetics at the St. Petersburg institute told RIA Novosti.But a colleague of Bulat's has disputed that claim."We found certain specimens, although not many, but all of them belonged to contaminants [microorganisms from the bore-hole kerosene, human bodies or the lab]," Eukaryote lab head Vladimir Korolyov said Saturday. "There was one strain of bacteria which we did not find in drilling liquid, but the bacteria could in principal use kerosene as an energy source," Korolyov said."That is why we can't say that a previously unknown bacteria was found," he said.But Bulat is maintaining the bacterium has no relation to any existing types.He acknowledged the small size of the initial sample and its heavy contamination made it difficult to conduct more extensive research.New samples of clean frozen water from the sub-glacial lake due to arrive in St. Petersburg this spring will make it possible to "confirm the find and, perhaps, discover new previously unknown forms of microbial life," he said. 'Internet for robots' createdZURICH, Switzerland, March 11 () -- European computer scientists say they have created an "Internet for robots," a cloud-computing system to aid in robotics tasks and robot learning.Researchers at five European universities said the system will allow robots connected to the Internet to directly access the powerful computational, storage and communications infrastructure of modern data centers like the giant server farms that power companies like Google, Facebook and Amazon.The RoboEarth Cloud Engine will allow robots to share knowledge with other robots via a Web-style database, greatly speeding up robot learning and adaptation in complex tasks, a release from the ETH Zurich technical research center said Monday.The cloud will enable robots to perform complex functions like mapping, navigation or processing of human voice commands in a fraction of the time required by robots' on-board computers, researchers said."The RoboEarth Cloud Engine is particularly useful for mobile robots, such as drones or autonomous cars,[url=http://www.tymarc.com/]christian louboutin sale[/url], which require lots of computation for navigation," ETH Zurich researcher Mohanarajah Gajamohan said.The new computing platform could help in developing lighter, cheaper, more intelligent robots, the researchers said."On-board computation reduces mobility and increases cost," said Heico Sandee, RoboEarth's Program Manager at Eindhoven University of Technology in the Netherlands. "With the rapid increase in wireless data rates caused by the booming demand of mobile communications devices, more and more of a robot's computational tasks can be moved into the cloud."
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