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For more information on these science news and feature story tips, please contact the public information officer at the end of each item at (703) 292-8070. Editor: Cheryl Dybus Contents of this News Tip:
RESEARCHERS FIND UNEXPECTED FEATURE IN ZOOPLANKTON NERVOUS SYSTEMThe world's most prevalent animal is one of the least observed, but scrutiny by a University of Hawaii researcher may change the way scientists look at little insectlike ocean-dwelling invertebrates known as calanoid copepods. Copepods are members of the zooplankton, drifting animals of the seas. Calanoid copepods are only three millimeters long and eat phytoplankton, or plant plankton. They constitute the biggest source of protein in the ocean and form a critical link in the marine food chain between the phytoplankton on which they feed and the krill, fish and whales that in turn feed upon them. NSF-funded researcher Petra Lenz has discovered that nerve cells of copepods are coated with myelin - a substance generally thought to be limited, with very few exceptions, to humans and other vertebrates. The researcher's work has implications for the study of evolution as well as the understanding of the biology of the oceans. Myelin is a white fatty sheath that coats parts of the vertebrate nervous system, including the long axons of nerve cells. Like insulation on an electric wire, myelin protects and speeds the electrical signal, providing a competitive advantage for organisms that must respond quickly to capture food or escape predators. Such an advantage is particularly important for large animals, in which nerve signals must travel long distances from sensory cells to brain and brain to muscles, and scientists had assumed myelin was a feature nearly exclusive to vertebrates. Lenz observed myelin in transmission electron microscope images of the calanoid copepods. She had previously observed that the copepods are unusually fast in sprinting from danger-responding to stimuli about a hundred times faster than humans. [Cheryl Dybas] NSF PROGRAM IS PATHWAY TO SUCCESS FOR YOUNG ECONOMISTSWhat's the surest pathway to success for a young economist? Receive a grant from the National Science Foundation [NSF] Economics Program. Harvard University economics professor Andrei Shleifer, 38, is the latest proof of such success. The American Economic Association has selected Shleifer, an NSF grantee and previous NSF Presidential Young Investigator, to receive the John Bates Clark Medal in January, 2000. The Clark Medal is considered the most prestigious award in economics after the Nobel Prize, and is awarded every two years to an outstanding economist under 40 years old. Shleifer's award is for empirical research into the workings of financial markets, commercial law and corporate securities in countries making the transition from a socialist to a market economy. NSF economics program director Daniel Newlon says that Shleifer is the 17th of 18 Clark Medal recipients named since 1965 to have received prior support from his program, in NSF's Directorate for Social, Behavioral, and Economic Sciences. "Shleifer is another outstanding example of the impact that NSFsupported 'basic research' can have on the national and world economy," says Newlon. He notes that six of the seven Clark Medal recipients who later received the Nobel Prize [Paul Samuelson, Milton Friedman, James Tobin, Kenneth Arrow, Lawrence Klein, Robert Solow and Gary Becker] also received NSF grants before receiving their Nobels. [Joel Blumenthal] SUPERPLASTICITY MAY WORK BETTER IN SMALLER PACKAGESA physical quality called superplasticity lets manufacturers fashion metal into strong, intricate shapes, such as turbine blades and aircraft components. But achieving superplasticity typically requires impractically long "cooking" times or high heats. Now researchers at the University of California at Davis report findings that could simplify that process. The scientists' work is funded by the National Science Foundation (NSF). Manufacturers presently are limited to using materials, such as aluminum alloys, that can reach superplasticity -- the ability to stretch a long way without breaking -- at temperatures no higher than 1,800 degrees. The new experiments brought that temperature down to 450 degrees for an aluminum alloy and to 660 to 1,200 degrees for other materials that are desirable but currently impractical, such as nickel and a nickel-aluminum alloy. The key to cooler superplasticity was switching from materials made of microcrystals to those made of nanocrystals, which are 1,000 times smaller. (Microcrystals range from one to about 20 microns in diameter; 20 microns is about one-fourth the width of a human hair.) The finished nanostructured materials were also much stronger than microstructured ones, says researcher Amiya Mukherjee. [Cheryl Dybas]
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