1. Postdoctoral Research Fellow, Department of Anesthesiology, Baylor College of Medicine, Houston, Texas.
2. Research Fellow, Department of Anesthesiology, University of Texas Medical School at Houston, Houston, Texas.
3. Research Assistant Professor, Department of Anesthesiology, Baylor College of Medicine, Houston, Texas.
4. Assistant Professor, Department of Anesthesiology, University of Texas Medical School at Houston, Houston, Texas.
5. Professor, Department of Anesthesiology and Pharmacology, and Division of Clinical Pharmacology, University of Texas Medical School at Houston, Houston, Texas.
6. Professor, Department of Anesthesiology, University of Texas Medical School at Houston, Houston, Texas.