1986-87 - Staff Physician, Himalayan Rescue Association, Pheriche, Nepal 1990-96 - Assistant Professor of Medicine; 1997-02- Associate Professor of Medicine; 2002-Present- Professor of Medicine, Cardiology, UTSWMC 1992-Present - Director, Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas and UTSWMC 1993-98 - Unit Director, Cardiovascular, NASA Specialized Center of Research and Training (Director C. Gunnar Blomqvist, M.D., PH.D. 1996- Present - Human Research Facility (Space Station) Scientific Working Group 1998-01- National Space Biomedical Research Institute Board of Scientific Counselors 2001-2004 - Center for Scientific Review - NIH/NHLBI Clinical Cardiovascular Sciences Special Emphasis Panel; 2004-Present, Clinical Integrative Cardiovascular Sciences (CICS) Study Section 2003 - 2006 American Heart Association - Physical Activity Committee, Council on Nutrition, Physical Activity and Metabolism 2005 - Board of Directors of the American Autonomic Society 2006 - Board of Trustees of the American College of Sports Medicine 2007 - Cardiovascular Team Leader, National Space Biomedical Research Institute
