1Institute of Environmental Health Sciences, Wayne State University, Detroit, MI, United States
2Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL, United States
3Department of Biological Sciences, University at Albany, SUNY, Albany, NY, United States
4Department of Biology, Skidmore College, Saratoga Springs, NY, United States
5Department of Environmental Health Sciences, University of Alabama at Birmingham, Birmingham, AL, United States
6Statistics and Epidemiology Unit, RTI International, Atlanta, GA, United States