1. Department of Epidemiology, Mailman School of Public Health, Columbia University, 722 West 168th Street, New York, NY 10032, USA
2. Department of Epidemiology, University of North Carolina, 2101 McGavran-Greenberg Hall, CB No. 7435 Chapel Hill, NC 27599, USA
3. Department of Nutrition, Department of Epidemiology, University of North Carolina, 2200 McGavran-Greenberg Hall, CB No. 7461 Chapel Hill, NC 27599, USA
4. Department of Preventive Medicine, Mount Sinai School of Medicine, 17 E 102nd Street, New York, NY 10029, USA
5. Department of Medicine, College of Physicians and Surgeons, Columbia University, 722 West 168th Street, New York, NY 10032, USA