Two Nobel laureates are associated with the university, including faculty member Arthur B. McDonald, who received the Nobel Prize in Physics for fundamental research elucidating neutrino change identities and mass, and former National Research Council postdoctoral fellow at Queen's Sir Fraser Stoddart, awarded the Nobel Prize in Chemistry "for the design and synthesis of molecular machines". Another notable individual associated with University is Sandford Fleming, an engineer who first proposed the use of a universal time standard and the former Chancellor of Queen's. Notable alumni in the field of science include Adolfo de Bold, who won the Gairdner Foundation Award for the discovery and isolation of atrial natriuretic peptide, and Shirley Tilghman, a microbiologist and former President of Princeton University.