1. Geoinformatics Laboratory, School of Computing and Information, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
2. Department of Health and Community Systems, School of Nursing, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
3. Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, Georgia, USA
4. Division of General Internal Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
5. Department of Behavioral and Community Health Sciences, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
6. Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA