1. Assistant Professor in the Department of Biostatistics and Epidemiology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73126-0901, USA
2. Professor in the Département de mathématiques et de statistique, Université de Montréal, Montréal, Québec H3C 3J7, Canada
3. Assistant Professor in the Department of Mathematics and Statistics, University of Winnipeg, Winnipeg, Manitoba R3B 2E9, Canada