1. R. F. Costantino, Department of Biological Sciences, University of Rhode Island, Kingston, RI 02881, USA.
2. R. A. Desharnais, Department of Biology and Microbiology, California State University, Los Angeles, CA 90032, USA.
3. J. M. Cushing, Department of Mathematics, University of Arizona, Tucson, AZ 85721, USA.
4. B. Dennis, Department of Fish and Wildlife Resources and Division of Statistics, University of Idaho, Moscow, ID 83844, USA.