Probability and statistics, stochastic processes, quantitative and mathematical biology.

• Professor, University of Arizona, Tucson, Arizona (2007 - Ongoing)
• Associate Professor, University of Arizona, Tucson, Arizona (1996 - 2007)
• Visiting Assistant Professor, University of Arizona, Tucson, Arizona (1992 - 1996)
• Senior Research fellow, Northwestern University, Evanston, Illinois (1987)
• Assistant Professor, University of Southern California, Los Angeles, California (1986 - 1992)
• Postdoctoral Fellow, Institute for Mathematics and its Applications, University of Minnesota (1985)
• Postdoctoral Fellow, University of British Columbia, Vancouver, British Columbia (1982 - 1985)
• Wissenschaflicher Mitarbeiter, Freie Universität Berlin (1980)