1. Department of Epidemiology and
2. Department of Environmental Health Sciences, Center for Occupational and Environmental Health, UCLA School of Public Health, University of California at Los Angeles, Los Angeles, California, USA
3. Department of Neurology, UCLA School of Medicine, University of California at Los Angeles, Los Angeles, California, USA
4. Department of Environmental Health Sciences, School of Public Health, University of California at Berkeley, Berkeley, California, USA
5. Division of Neurogenetics, Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
6. Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA