1. Department of Population Health Sciences, School of Public Health, Georgia State University , Atlanta, GA , USA
2. Division of Laboratory Sciences, National Center for Environmental Health, U.S. Centers for Disease Control and Prevention , Atlanta, GA , USA
3. Office of Science, Center for Tobacco Products, U.S. Food and Drug Administration , Silver Spring, MD , USA
4. Division of Epidemiology, Services and Prevention Research, National Institute for Drug Abuse, National Institutes of Health , Bethesda, MD , USA
5. Kelly Government Solutions , Rockville, MD , USA