1. Assistant Professor, Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine.
2. Assistant Professor and Director Neurosurgical Anesthesia, Department of Anesthesiology, Hospital of the University of Pennsylvania.
3. Professor and Director of Research, Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine.
4. Robert Dunning Dripps Professor and Chairman, Department of Anesthesiology, Hospital of the University of Pennsylvania.