1. Department of Medicine; Division of Pulmonary and Critical Care Medicine; The University of Maryland School of Medicine; Baltimore Maryland
2. Department of Pathology and Laboratory Medicine; Mayo Clinic Arizona; Scottsdale Arizona
3. Department of Medicine; Division of Pulmonary and Critical Care; The University of San Diego Health System; La Jolla California
4. Department of Medicine; Division of Occupational and Environmental Medicine; The University of Maryland School of Medicine; Baltimore Maryland