1 Departments of Community Health Sciences and History, Hotchkiss Brain Institute and O'Brien Institute for Public Health, University of Calgary, 3280 Hospital Drive N.W., Calgary, AB, T2N 4Z6, Canada.
2 Departments of Community Health Sciences and History, Hotchkiss Brain Institute and O'Brien Institute for Public Health, University of Calgary, 3280 Hospital Drive N.W., Calgary, AB, T2N 4Z6, Canada. fwstahni@ucalgary.ca.