A former U.S. ambassador now heading a world food security body is a special guest of Mississippi State University this week. Kenneth M. Quinn, leader of the Iowa-based World Food Prize organization, spoke on campus Tuesday and will be featured speaker Wednesday for the Executive Lecture Forum in Jackson. “Challenges of International Food Security and How They Relate to Political and Economic Instability” is the topic of his program. American ambassador to Cambodia from 1996-99, Quinn comes at the invitation of MSU’s Janos Radvanyi Chair in International Security Studies and the campus’ International Institute.