1. Department of Chemistry and Plant Sciences Institute, and Psychology in Education Research Lab, Iowa State University, Ames, Iowa 50011-3211, Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan 48109-2125, Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, Department of Microbiology, Montana State University, Bozeman, Montana 59717, and Department of Chemistry, University of Wisconsin, Eau Claire, Wisconsin 54702