1. Division of Periodontics, Section of Oral, Diagnostic and Rehabilitation Sciences, College of Dental Medicine Columbia University New York New York USA
2. Department of Biostatistics, Mailman School of Public Health Columbia University New York New York USA
3. Taub Institute for Research on Alzheimer's Disease and the Aging Brain, GH Sergievsky Center and Department of Neurology, Vagelos College of Physicians and Surgeons Columbia University New York New York USA