The head of the theater program at private Mississippi College and a former United Nations World Food Program official, Judith Lewis, starts work Aug 1. as executive director of Mississippi Public Broadcasting, the Jackson Clarion-Ledger reported yesterday. She succeeds Marie Antoon, who announced her retirement earlier this year and will continue to work with MPB for a transition month. Lewis is an associate professor of communications at the college in Clinton, near the state capital, Jackson. She retired about three yeares ago from the U.N. program; she was a regional director in eastern and southern Africa and has lived in Angola, Ethiopia, Uganda and South Africa, the newspaper said. The board chair said there were 60 applicants.