1. University of Minnesota, Minneapolis, MN, USA
2. University of California San Diego, La Jolla, CA, USA
3. University of Alabama at Birmingham, Birmingham, AL, USA
4. Yale School of Public Health, New Haven, CT, USA
5. Washington University in St. Louis School of Medicine, St. Louis, MO, USA
6. University of Washington, Seattle, WA, USA
7. University of North Carolina at Chapel Hill, Chapel Hill, NC, USA