1. Facultad de Medicina, Universidad San Sebastian, Concepcion, Chile
2. Division of Thoracic Surgery and Interventional Pulmonology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
3. Division of Pulmonary, Critical Care and Environmental Medicine, Tulane University, New Orleans, Louisiana
4. Division of Pulmonary and Critical Care, Massachusetts General Hospital, Boston, Massachusetts
5. Division of Pulmonary and Critical Care, University of Florida, Gainesville, Florida; and
6. Division of Pulmonary and Critical Care, Mayo Clinic, Jacksonville, Florida