About the Authors
Department of Biostatistics, University of Kentucky College of Public Health, Lexington, Kentucky, United States of America
Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts, United States of America
Channing Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: DWF CL. Performed the experiments: DWF IIL CL. Analyzed the data: DWF IIL CL. Contributed reagents/materials/analysis tools: DWF IIL CL. Wrote the paper: DWF CL.