1. Department of Statistics; University of Connecticut; 215 Glenbrook Road, U-4120, Storrs, Connecticut 06269 U.S.A.
2. Department of Biostatistics; University of North Carolina; McGavran Greenberg Hall, CB#7420, Chapel Hill, North Carolina 27599 U.S.A.
3. Global Biostatistical Science; Amgen Inc.; One Amgen Center Drive, Thousand Oaks, California 91320 U.S.A.