1. Epidemiology Program, University of Delaware, Newark, DE, USA
2. Department Landscape Architecture and Urban Planning, Texas A&M University, College Station, TX, USA
3. Public Policy, University of Redlands, CA, USA
4. Department of Epidemiology, University of North Carolina at Chapel Hill, NC, USA
5. Department of Epidemiology and Biostatistics, Texas A&M University, College Station, TX, USA