University of Michigan, Ann Arbor, Mathematics Department

--Professor, 1989-present

University of Missouri, Columbia, Mathematics Department --Professor, 1988-1990 --Associate Professor, 1984-1988

--Assistant Professor, 1978-1984

Courant Institute of Mathematical Sciences, New York University, NATO postdoctoral fellow, 1976 - 1978

University of Oxford, Center for Industrial and Applied Mathematics, visiting scientist, 1996-97

University of Vienna, Institute for theoretical physics, visiting scientist, 1983-84

University of Oxford, Mathematical Institute

--D.Phil. in Mathematics, 1976, thesis adviser: Bryce McLeod

Cambridge University, Mathematics Department,

-- B.A. in Mathematics, 1973