-
1986 Centre for Mathematical Biology, Oxford (Nov.)
- 1989 Department of Applied Mathematics, University of Washington, Seattle (Feb.)
- 1989 Department of Biology, University of Iowa, Iowa City (June, Nov.)
- 1991 Department of Mathematics, University of Bonn (Jan.)
- 1991 Department of Mathematics, University of Utah, Salt Lake City (Sept.)
- 1992 Sonderforschungsbereich 123, University of Heidelberg (Jan.)
- 1992 Department of Mathematics, University of Utah, Salt Lake City (March; Dec.)
- 1992 Department of Mathematics, University of Bath (April)
- 1993 Department of Mathematics, University of Utah, Salt Lake City (Aug; Dec.)
- 1995 Departamento de Fisica Quimica, UNAM, Mexico (May-June)
- 1996 Department of Mathematics, University of Utah, Salt Lake City, NSF-funded Special Year in Mathematical Biology Visitor (Jan.)
- 1997 Department of Mathematics and Computer Science, University of Dundee (Sept.)
- 1999 Nonlinear Systems and Applications, Lorentz Center, University of Leiden (Aug.-Sept.)
- 2000 Laboratoire de Mathematiques, Universite de Paris-Sud, Orsay (March)
- 2000 Institute of Mathematics and Informatics of the Bulgarian Academy of Sciences (16-21 Aug.)
- 2001 MPI for Mathematics in the Sciences, Leipzig (8-12 Mar.)
- 2003 Researcher (Pattern Formation in Physics and Biology Program) Kavli Institute for Theoretical Physics (KITP), UCSB (1-27 Sept)
- 2003 Stowers Institute for Medical Research, Kansis City, Missouri (17-21 Sept)
- 2003 Institut fur Biologie, Theoretische Biophysik, Humboldt-Universitat zu Berlin (9-13 Dec)
- 2004 MPI for Mathematics in the Sciences, Leipzig (28 Mar -
2 April)
- 2007 Univ Fed de Pernambuco, Recife (16 Oct - 2 Nov)
- 2007 Dept of Electronic and Telecommunications, Univ of Florence (24-28 Nov)
- 2008 Institute of Industrial Science, Univ of Tokyo (26-30 March)
- 2012 Instituto Matematica Aplicada a la Ciencia y la ingenieria, Universidad De Castilla-La Mancha, Spain (25-28 March)
- 2022 NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, (11 July - 19 Aug)