DASA 2019-2 Wright H. langham Departmert of Biological and Medical Research Los Alamos Scienific Laboratory Los Alamos, New Mexico William J. Schull Department of Human Genetics University of Michigan Medical school Ann Arbor, Michigan Robere W, Ralph E. Spear Public Administration Service Washington, D.C, Epidemiology Branch National Cancer Institute National Institutes of Health Bethesda, Maryland John ALP. Millet Psychoanalytic Clinic for Training and Research Columbia University College of Physicians and Surgeons New York, New York Lin Root 44 West 44th Strect New York, New York Theodore 8, Taylor International Research and Technology Corporation Vienna, Austria Stafford L. Warren Department of Biophysics Univeraity of California Los Angeles, California John N. Wolfe Division of Biology and Medicine U.S. Atomic Energy Commission Washington, D.C, Harold O. Wyckoff Armed Forces Radiobiology Research Inatitute Defense Atomic Support Agency Bethesda, Maryland