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Two new faculty members at the University of California, Davis, neuroscientist Marie Burns and mathematician Alexander Soshnikov, have won prestigious Alfred P. Sloan Research Fellowships worth $40,000 over two years.

Burns studies how light-sensitive cells generate signals. For vision to work properly, the thousands of light-sensitive cells in the retina -- rods and cones -- have to switch on and off very quickly in response to light and darkness. The "on" switch is a biochemical pathway called the G-protein cascade, which stays on as long as the cell is exposed to light. Burn's laboratory studies how the G-protein cascade is extinguished when the lights go out.

G-protein cascades are also found in all kinds of other cells, Burns said. They amplify signals from the cell surface and transmit them to other parts of the cell. G-protein cascades in photoreceptors and other neurones are especially interesting because they have to switch on and off very quickly compared to other cells. Elsewhere in the brain, they are involved in processes such as learning and memory, she said. G-proteins in photoreceptors are a good model system for signaling in other cells in the nervous system and elsewhere, Burns said.

Soshnikov studies pure statistics and mathematical physics. One area of his research is random matrix theory, originally proposed in the 1950's by physicist Eugene Wigner as a way of predicting the energy levels of atomic nuclei. Wigner's matrices are large tables of values, with each value being randomly set, for example at 1 or minus 1. Wigner hoped that although the values in the tables were random, the properties shown by typical tables would give insight on quantum mechanics, Soshnikov said.

Mathematicians have made notable progress with random matrix theory in the last ten years. Soshnikov's own work has shown that some rules, previously found by Craig Tracy from °ÄÃÅÁùºÏ²Ê×ÊÁÏ¿â Davis and Harold Widom from °ÄÃÅÁùºÏ²Ê×ÊÁÏ¿â Santa Cruz to be true for some types of matrices, do in fact apply to apply to all random matrices. Random matrix theory also turns out to have unexpected links to combinatorial theory, an area of mathematics that deals with sorting and ordering values.

Burns was awarded her bachelor's degree by Susquehanna University, Pa., in 1992 and her Ph.D. from Duke University in 1996. She carried out postdoctoral research at Stanford University before joining the faculty of the °ÄÃÅÁùºÏ²Ê×ÊÁÏ¿â Davis psychiatry department and the Center for Neuroscience in early 2001.

Soshnikov received his bachelor's degree from Moscow State University in 1991 and his Ph.D. from Princeton University in 1997. After a semester at the Institute for Advanced Study at Princeton, he spent two years at the California Institute of Technology as a Tausky-Todd Fellow. He joined °ÄÃÅÁùºÏ²Ê×ÊÁÏ¿â Davis as an assistant professor in 1999.

The Sloan Foundation awards approximately 100 fellowships a year to outstanding young scientists in the fields of physics, chemistry, pure or applied mathematics, neuroscience, economics or computer science. Since the program began in 1955, 26 Sloan fellows have gone on to win Nobel prizes.

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