Stories of modern science ... from UPI

July 11, 2002 at 8:57 AM
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Shining near-infrared radiation on damaged retinal cells can keep them alive and prevent permanent blindness, U.S. military researchers have discovered. A report in New Scientist describes studies of military personnel who have suffered laser eye injuries. If the infrared technique works on people, it could be used to treat a wide range of eye injuries and diseases. It even could help heal all sorts of injuries and sores, researchers said, and it is already being used to treat severe mouth ulcers in children undergoing chemotherapy. In the late 1990s, lab studies on cells showed that near-infrared light boosted the activity of the mitochondria, the crucial powerhouses in all living cells. The treatment requires high-intensity light, but instead of lasers, researchers have developed powerful light-emitting diodes for the job. Lasers tend to damage cells, whereas LEDs can deliver light in a way that is less harmful to tissue.


Researchers at Stanford and Yale universities report certain bacteria play their own version of the age-old game, "Rock-paper-scissors." Working with three populations of the world's best-studied bacterium, E. coli, researchers observed the microbes "chasing" each other around the petri dish in a series of attacks and defenses and counter-defenses. The skirmishes did not produce a clear victor but preserved the biodiversity of the overall ecosystem. Eventually, the biodiversity broke down, however, leading researchers to conclude that separation may be necessary for different populations to coexist. "The scale at which organisms interact and disperse can have profound effects on the maintenance of biodiversity," researchers said. "Organisms exist in neighborhoods in nature, and historically that's been overlooked by many ecologists. And the fact that they exist in neighborhoods has profound implications for the maintenance of biodiversity."


U.S. military researchers are testing a new kind of engine called a scramjet that is intended to power the next generation of high-speed aircraft and cruise missiles. The scramjet -- a nickname for supersonic ramjet -- differs from other types of jet engines because instead of spinning turbine blades, its combustion chamber essentially has no moving parts. It provides thrust by compressing rapidly incoming air and mixing it with fuel. The advantage of a scramjet is it does not need to carry its own oxygen like rocket engines. The disadvantage is it cannot operate slower than the speed of sound, so a conventional engine must provide a craft's initial speed. Researchers said the scramjet has performed well in early tests. In simulated conditions, the engine reached MACH 6.5 -- or 6.5 times the speed of sound -- and operated at 90,000 feet altitude.


University of Cincinnati researchers have discovered a tropical snake that feasts on soft-shelled crabs by tearing them apart and swallowing one bite at a time. "The snake literally rips the crab's body apart," researchers said. "They'll tug and pull on it to tear it apart." The researchers were trying to understand the diets of two snakes found in Singapore -- Fordonia leucobalia and Gerarda prevostiana. Both eat crabs, which is unusual for snakes, but while examining stomach contents, it became obvious that crabs eaten by Gerarda were in pieces. Because crabs can drop their limbs and because their joints can break as they are captured and eaten, it was important to verify how the crabs actually were pulled apart. So, researchers brought the snake into the laboratory and recorded Gerarda's feeding behavior. The snake forms itself into a loop and uses the loop to hold and tear apart its prey. The ability to rip the crabs apart was a surprise, because snake teeth are not adapted for slicing and cutting. Instead, they curve back into the mouth, an adaptation for holding prey.

(Editors: For more information on LIGHT TREATMENT, contact Claire Bowles in the U.K. at +44-207-331-2751 or For BACTERIA WARS, Dawn Levy at 650-725-1944 or For SCRAMJET, Gail Cleere at 703-696-4987 or For SNAKE BITE, Chris Curran at 513-556-1806 or

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