1. Rutgers Institute for Nicotine and Tobacco Studies , New Brunswick, NJ , USA
2. Arnold School of Public Health, University of South Carolina , Columbia, SC , USA
3. Center for Interdisciplinary Research on Nicotine Addiction, Department of Psychiatry, University of Pennsylvania Perelman School of Medicine , Philadelphia, PA , USA
4. Annenberg School of Communication, University of Pennsylvania , Philadelphia, PA , USA