Affiliation: | Virginia Tech, Blacksburg, Virginia, USA (R.A. Silverman, A. Cohen, M.J. Friedlander, C.V. Finkielstein);Fralin Biomedical Research Institute, Roanoke, Virginia, USA (A. Ceci, M.J. Friedlander, C.V. Finkielstein);Virginia Department of Health, Richmond, Virginia, USA (M. Helmick, E. Short, P. Bordwine). |