Affiliation: | 1. Department of Bioinformatics and Biostatistics, University of Louisville, Louisville, Kentucky 40202, U.S.A.;2. Department of Preventive and Community Dentistry Department of Epidemiology, University of Iowa, Iowa City, Iowa 52242, U.S.A.;3. Department of Biostatistics, University of Florida, Gainesville, Florida 32610, U.S.A. |