1. Department of Physiology, University of Medicine and Dentistry-New Jersey Medical School, Newark, NJ 07103
2. Department of Ophthalmology, University of Medicine and Dentistry-New Jersey Medical School, Newark, NJ 07103
3. Macromolecular and Cell Structure, Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 600 East Mermaid Lane, Philadelphia, PA 19118