1. Center for Health Promotion, Performance, and Rehabilitation Research, Department of Nutrition, Metabolism, and Rehabilitation Sciences, School of Health Professions, University of Texas Medical Branch, Galveston, Texas, USA.
2. Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA.
3. Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA.
4. Department of Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, Minnesota, USA.
5. Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
6. Department of Epidemiology and Prevention, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA.
7. Department of Quantitative Health Sciences, Mayo Clinic, Rochester, Minnesota, USA.