I am an associate professor in the Department of Applied Science at the College of William and Mary with research interests in computational cell biology and computational neuroscience. While I have worked at William and Mary since 2001, the previous two years I was an assistant professor in the Department of Mathematics at Arizona State University. My post-doctoral training includes an NRSA Fellowship at Center for Neural Science at New York University (1998-1999) as well as an IRTA Fellow at the Mathematical Research Branch, NIDDK, NIH (1996-1998), both under the direction of John Rinzel. My Ph.D. (1996) in (theoretical cellular) biophysics was awarded by the Biophysics Graduate Group at UC Davis. I studied under Joel Keizer, who at that time was director of the Institute for Theoretical Dynamics. My undergraduate work was in biology at MIT (B.S., 1982).

As a theoretical biologist, I often collaborate closely with physiologists and neuroscientists to develop mathematical models of an experimental preparation of interest.  Once such a model is developed to  reproduce the significant features of experimental observation, explicit predictions about cellular responses are made and subsequently confirmed or invalidated by future experiment.

Indeed, our understanding of dynamic phenomena in cell biology and neuroscience is largely based on such mathematical models.  Some examples are: 1) whole cell models of intracellular calcium handling, 2) reaction-diffusion models for subcellular phenomena that have a spatial component, e.g., the buffered diffusion of intracellular calcium near open calcium channels, and 3) biophysically realistic neuronal networks based on Hodgkin-Huxley-style modeling of plasma membrane excitability.

My current research funding includes an NSF  early career development (CAREER) award from the Division of Molecular and Cellular Biosciences  that supports integrated research and educational activities in the interdisciplinary area of  computational cell biology at the College of William and Mary.   Under my guidance, graduate and undergraduate students in my group are using computational and mathematical approaches to investigate the dynamics of calcium (Ca²⁺) release at inositol (1,4,5)-trisphosphate (IP₃)-senstive Ca²⁺ release sites.  Our work is attempting to account for the stochastic activation and inactivation of IP₃ receptors consistent with current knowledge of IP₃ diversity as well as a realistic account of the buffered diffusion of intracellular Ca²⁺ leading to cooperative IP₃ receptor activity.

The educational activities supported by the NSF  MCB  CAREER award are intended to increase the exposure of graduate and undergraduate students at William and Mary  to quantitative approaches in cell and molecular biology.  To this end I have developed and introduced a new course entitled Cellular Biophysics and Modeling that emphasizes diffusion, membrane transport, mass action kinetics, single channel recording of voltage- and ligand-gated ion channels, whole cell currents, compartmental modeling, plasma membrane electrical excitability, and dynamics in cell signal transduction. A second course, Introductory Bioinformatics exposes biology majors (with minimal background in computer programming) to the basic algorithms of computational molecular biology including sequence comparison, fragment assembly, phylogenetic tree construction, and secondary structure prediction.

In collaboration with Saleet Jafri (School of Computational Sciences, George Mason University) and Eric Sobie (New York University and University of Maryland Biotechnology Institute), I am developing a probability density approach to modeling important stochastic aspects of local Ca²⁺ signaling in cardiac myocytes. The resulting models of interacting plasma membrane and intracellular Ca²⁺ channels (the so-called couplons or stochastic functional units) are then integrated into detailed models of cardiac excitation-contraction (EC) coupling and used to address questions related to graded release during EC coupling, defects in EC coupling that occur during congestive heart failure, and whether Ca²⁺ sparks can account for the leak of Ca²⁺ from internal stores. This research is supported by the Joint DMS/BIO/NIGMS Initiative to Support Research in the Area of Mathematical Biology.

Prior funding includes an NSF grant from the Division of Integrative Biology and Neuroscience that is supporting the development of biophysically realistic neuronal network models of the lateral geniculate nucleus, a visually responsive region of the thalamus.  The goal of this computational neuroscience  research is to understand the function of inhibitory neurons associated with the lateral geniculate nucleus.

I often serve as a referee for scientific journals such as the American Journal of Physiology, Biophysical Journal, Bulletin of Mathematical Biology, Journal of Computational Neuroscience, and Journal of Theoretical Biology.