1. S. F. Arnold, Department of Environmental Health Sciences, Tulane University of Public Health and Tropical Medicine, 1501 Canal Street, New Orleans, LA 70112, USA and Tulane-Xavier Center for Bioenvironmental Research, 1430 Tulane Avenue, New Orleans, LA 70112, USA.
2. D. M. Klotz, B. M. Collins, P. M. Vonier, Program in Molecular and Cellular Biology, Tulane University Medical Center, 1430 Tulane Avenue, New Orleans, LA 70112 USA and Tulane-Xavier Center for Bioenvironmental Research, 1430 Tulane Avenue, New Orleans, LA 70112, USA.
3. L. J. Guillette Jr., Department of Zoology, University of Florida, 223 Bartam Hall, Gainesville, FL 32611, USA and Tulane-Xavier Center for Bioenvironmental Research, 1430 Tulane Avenue, New Orleans, LA 70112, USA.
4. J. A. McLachlan, Department of Environmental Health Sciences, Tulane University of Public Health and Tropical Medicine, 1501 Canal Street, New Orleans, LA 70112, USA; Department of Pharmacology, Tulane University Medical Center, 1430 Tulane Avenue, New Orleans, LA 70112, USA; and Tulane-Xavier Center for Bioenvironmental Research, 1430 Tulane Avenue, New Orleans, LA 70112, USA.