1. Research Participation Program at the Centers for Disease Control and Prevention, Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA.
2. Division of Violence Prevention, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
3. Division of Adolescent and School Health, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.