1. Research Assistant Professor, Department of Anethesiology, Baylor Colloge of Medicine.
2. Research Fellow, Department of Anesthesiology, University of Texes Medical School at Houston; current address: Department of Anesthesiology, St. Michael's Hospital, Toronto, Canada.
3. Visiting Research Assistant Professor, Department of Anesthesiology, University of Texas Medical School at Houston; Current address: Department of Anesthesiology, University of Oslo, Oslo, Norway.
4. Associate Professor, Department of Medicine, Baylor College of Medicine.
5. Associate Research Professor, Department of Medicine, Baylor College of Medicine.
6. Professor, Department of Anesthesiology, University of Texas Medical School at Houston.