CAUTION: The Sender of this email is not from within Dalhousie. With great sadness, I learned today that my dissertation advisor Barry Mitchell passed away in late January in a nursing home in Kingston, New York. As part of the group at Columbia University in the sixties, Barry was involved in the development of category theory and wrote one of the earliest books on the subject. He was active through the seventies and early eighties writing papers on abelian categories and homological algebra. He was a great supervisor and mentor, and will be remembered for his insightful and interesting approach to mathematics. [Note from moderator: There is an obituary at: https://www.legacy.com/obituaries/dailyfreeman/obituary.aspx?n=barry-m-mitchell&pid=197672237&fhid=3910 ] [For admin and other information see: http://www.mta.ca/~cat-dist/ ]