Institution: | (1) Experimental Station, E.I. DuPont de Nemours & Co., Central Research and Development Department E173/118, P.O. Box 80173, 19880-0173 Wilmington, DE, USA;(2) Present address: Department of Biology, Indiana University, 47405 Bloomington, IN, USA;(3) Present address: Department of Physics, University of California, 92093 San Diego, LaJolla, CA, USA |