Government of the United States of America - Los Alamos National Laboratory, Government of the United States of America - Los Alamos National Laboratory, University of Leeds, Hong Kong Polytechnic University - Department of Applied Mathematics, affiliation not provided to SSRN, University of Leeds, University of Leeds, Government of the United States of America - Los Alamos National Laboratory, Los Alamos National Laboratory - Theoretical Biology and Biophysics and Government of the United States of America - Los Alamos National Laboratory