1. Department of Family Medicine and Public Health Sciences, Wayne State University School of Medicine, Detroit, Michigan, USA
2. Department of Educational Psychology and Learning Systems, Florida State University, Tallahassee, Florida, USA
3. Department of Epidemiology, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
4. School of Psychology, Northeast Normal University, Changchun, Jilin, China
5. Center for Public Health Initiatives, University of Pennsylvania, Philadelphia, Pennsylvania, USA