Rabbi Peter J. Haas is a Jewish studies professor and director of the Rosenthal Center for Judaic Studies at Case Western Reserve University in Cleveland. He wrote Human Rights and the World’s Major Religions: The Jewish Tradition (Greenwood Press, 2005).

Robert Melson is political professor at Purdue University in West Lafayette, Ind., and current president of the International Association of Genocide Scholars, which he co-founded in 1995. His primary area of research is ethnic conflict and genocide, and he has written widely on the topic.

Alan Kuperman is associate professor of public affairs at the University of Texas at Austin. He is author of The Limits of Humanitarian Intervention: Genocide in Rwanda (Brookings Institution Press, 2001) and co-editor of Gambling on Humanitarian Intervention: Moral Hazard, Rebellion, and Civil War (Routledge, 2006).

Helmut Walser Smith is Martha Rivers Ingram Chair of History at Vanderbilt University and Director of the Max Kade Center for European and German. He is author of The Holocaust and Other Genocides: History, Representation, Ethics (Vanderbilt University Press, 2002).

Randolph L. Braham is director of the Rosenthal Institute for Holocaust Studies at the City University of New York. He is author of The Politics of Genocide: The Holocaust in Hungary (Wayne State University Press, 2000) and The Vatican and the Holocaust (East European Monographs, 2000).

Timothy Longman is director of the African Studies Centre at Boston University and author of Commanded by the Devil: Christianity and Genocide in Rwanda (Cambridge University Press).

Richard J. Foster, who lives in the Denver area, is the author of Freedom of Simplicity: Finding Harmony in a Complex World (HarperSanFrancisco, 25th anniversary edition, 2005). He is a Quaker and the founder of Renovaré, a movement committed to church renewal.

Congregation Or Atid, a Conservative synagogue in Richmond, Va. conducts a “Switch Day,” when members take the shifts of Christian volunteers at nearby Beth Sholom Nursing Home.

Since 1990, Cedar Village, a retirement and nursing home in Mason, Ohio, has held a “Mitzvah Day” every Dec. 25, in which Jewish staff members volunteer to work for Christian staffers. Contact Rachel Festenstein, director of marketing and community outreach.