Amy Greer, University of Guelph (IMAGE) University of Guelph Caption Population medicine professor Amy Greer, Canada Research Chair in Population Disease Modelling, and University of Toronto researchers used a mathematical model for this study that they developed in early spring. Credit University of Guelph Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.