Obituary of Frank Moss (1934-2011)

Frank Edward Moss, 1934-2011. Frank Moss, pioneer in the field of stochastic resonance and in the application of stochastic nonlinear dynamics to biological systems, died in St. Louis, Missouri on January 4, 2011 after a five-year battle with lung cancer and emphysema. He was Curators’ Professor Emeritus of Physics in the Department of Physics and Astronomy at the University of Missouri-St. Louis, and had served as director of the Center for Neurodynamics from 1996 until 2006. Born in 1934 in Paris, Illinois, Moss earned a B.S. in Electrical Engineering (1956), an M.S. in Nuclear Engineering (1961) and a Ph.D. in Physics (1964) from the University of Virginia. After postdoctoral work at the University of Rome and at the University of Virginia, Moss joined the Department of Physics and Astronomy at the University of Missouri-St. Louis in 1971 as an Associate Professor. He was promoted to Full Professor in 1976 and to Curators’ Professor in 2000. Moss began his physics research career as a low-temperature experimentalist, injecting both negative ions and alpha particles into superfluid 4He. His instinctive flair for extracting interesting physics from highly ambiguous data, and his earlier electrical engineering training, led him during the period 1965-1980 to a comprehensive study of turbulence in the superfluid phase. He was notably responsible for the characterization of the noise spectrum of the tangle of quantized vortex lines which underlie this turbulence, using negative ions, which are trapped by the vortices. This work helped greatly in cementing our early understanding of the dynamics of turbulence in superfluids, still a highly active research topic today. Around 1979-1980, when Moss was a Visiting Professor at the Universities of Exeter and Lancaster, he began to focus his work more specifically on dynamics of stochastic nonlinear systems, which was a natural result of his long interest and expertise in noise processes in superfluids and in electrical engineering. It was a decision that was to have immense impact on his research career. Moss pioneered analog simulations of nonlinear noisy systems which allowed verification of numerous theoretical results in the field. Soon, however, he began to shift his interest to the role of noise in biological systems, noticing remarkable similarities between the statistical properties of physical systems exhibiting the phenomenon of stochastic resonance and the statistics of neuronal firing. With Lon Wilkens and others, Moss demonstrated noise-enhancement of information transfer in the crayfish mechanoreceptor system. This pioneering work was the first demonstration of the phenomenon of stochastic resonance in a biological system. In 1996, Moss and Wilkens co-founded the Center for Neurodynamics. In the relaxed yet intense interdisciplinary and international atmosphere of the Center, supported by funding from the Office of Naval Research, Moss and his colleagues began to investigate the role of noise in animal behavior. For these studies, they turned to the paddlefish (Polyodon spathula), which has a sensitive network of electroreceptor cells on its rostrum and head. By adding a small amount of electrical noise to the water of a swim mill, in which a paddlefish was swimming, they showed that stochastic resonance can have a behavioral effect: the fish detected the weak periodic electrical signals of their Daphnia prey more efficiently in the presence of an intermediate amount of added noise. This was the first demonstration of significance of stochastic resonance in the behavioral responses of a living system. Moss followed these seminal studies with many other investigations of noise in neural systems, including studies of the effect of visual noise on human perception. He also turned his attention to other problems of noise and collective behavior in biological systems, investigating the behavior of the paddlefish’s prey, Daphnia. Most recently, he studied problems in the dynamics and evolution of animal foraging patterns. Moss was a tireless researcher, whose energy, even during his illness, was an immense inspiration to his colleagues. His co-authors recollect him coming into the lab to work on his last paper even when he had to bring a portable oxygen tank with him. He was tireless and unstoppable. Moss maintained an intense travel schedule, attending conferences throughout the world, often as organizer or as invited speaker. In 1996, he was elected as a Fellow of the American Physical Society, cited for ‘elucidating the structure of turbulent superfluid helium and for the discovery of stochastic resonance in sensory biology.’ Moss received numerous other recognitions and awards from the international scientific community. He was awarded two Senior Visiting Fellowships by the British Science Research Council (1979-80 and 1986-87), the Albert Leimer Visiting Professorship at the University of Augsburg (1990), a NATO Senior Visiting Fellowship from the Italian National Research Council at the Institute of Biophysics at the University of Pisa (1993), and a senior Alexander von Humboldt Prize for study and research in Germany (1999). He also received local recognition of his work, being honored with the President’s Award for Research and Creativity from the University of Missouri System (1994) and the Peter H. Raven Lifetime Achievement Award (1999), and was elected to Fellowship in the Academy of Science of St. Louis in the same year. Moss retired in 2008 but continued doing research as long as his health permitted. He is survived by his wife Eleni Koumparakis Moss, their son, Frank, and two grandchildren, as well as by an international community of scientists and friends who have been inspired as much by his intellectual achievements as by his lust for life. His work at the interface of physics and biology was truly transformative; to his friends, as one German colleague put it, he was a herzensguter Mensch. Sonya Bahar and Bernard J. Feldman University of Missouri-St. Louis Philip Stamp University of British Columbia Alexander Neiman Ohio University