AMHERST, Mass. — A memorial service for Holocaust scholar and former University of Massachusetts professor David Wyman is scheduled for this weekend.Wyman died March 14 at his home in Amherst at age 89.He was best known for the 1984 book "The Abandonment of the Jews: America and the Holocaust 1941-45," a look at the widespread indifference and hostility to the Jews in Europe, despite conclusive documentation of their systematic extermination by the Nazis.