Hummingbirds arent known for their power-lifting prowess. But researchers nevertheless put nearly 1,000 Peruvian hummers through lifting trials and flight tests over a two-year stretch in order to find out how their flying abilities are affected by the lower oxygen and thin air of higher elevations.
The results, which appeared this week in the Proceedings of the National Academy of Sciences (PNAS) Online Early Edition, show a clear decline in hummingbirds lifting ability with altitude, not unlike that seen in athletes competing at high elevations.
What this means for hummingbirds is less reserve power for the bursts of flight needed to chase off competitors or escape from predators, said researchers from the University of California, Berkeley, and the California Institute of Technology. "The costs of hovering flight are the same across elevations because hummingbirds compensate by having larger wings and by having a larger stroke amplitude," said study leader Douglas Altshuler, a postdoctoral fellow at Caltech. "However, that compensation doesnt come for free. They dont have as much excess power at high elevations as they do at low elevations."
Robert Sanders | EurekAlert!
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Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
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An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
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In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
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