1. Department of Health Promotion, Social and Behavioral Health, College of Public Health, University of Nebraska Medical Center, Omaha, NE, USA;
2. Department of Environmental, Agricultural and Occupational Health, College of Public Health, University of Nebraska Medical Center, Omaha, NE, USA;
3. Department of Epidemiology, College of Public Health, University of Nebraska Medical Center, Omaha, NE, USA;
4. McGoogan Library of Medicine, University of Nebraska Medical Center, Omaha, NE, USA;
5. Department of Biochemistry and Molecular Biology, University of Nebraska Epigenomics Core Facility, Omaha, NE, USA