1. Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
2. Mailman School of Public Health, Columbia University, New York, New York, USA
3. School of Public Health, University of Michigan, Ann Arbor, Michigan, USA
4. Sonoma Technology, Inc., Petaluma, California, USA
5. Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA