1. Division of Thoracic and Cardiovascular Surgery, University of Florida, Gainesville, FL USA
2. Department of Neurology, University of Florida, Gainesville, FL USA
3. Division of Cardiology, Department of Medicine, University of Florida, Gainesville, FL USA
4. Department of Clinical and Health Psychology, University of Florida, Gainesville, FL USA
5. Department of Radiology, NF/SG Veterans Administration and University of Florida, Gainesville, FL USA.