1 Division of Thoracic Surgery, Department of Surgery, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY 14642. Electronic address: paul_feingold@urmc.rochester.edu.
2 Department of Mathematics and Statistics, Vassar College, Poughkeepsie, New York.
3 Division of Thoracic Surgery, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts.