David Ruderman is director of the Center for Advanced Judaic Studies at the University of Pennsylvania, where he is also a professor of modern Jewish history. Contact 215-238-1290.

Jonathan Helfand was a professor of modern Jewish history at Brooklyn College in New York until his retirement in 2012. He specialized in French Jewry.

The Arab American Institute (AAI) is a nonprofit organization committed to the civic and political empowerment of Americans of Arab descent through campaigns and elections as well as policy formulation and research.

Gershon Greenberg is a professor in philosophy and religion at American University in Washington, D.C., where he specializes in Jewish philosophy and thought, especially in America.

Sharon Flatto is an assistant professor in Judaic studies at Brooklyn College in New York, where she specializes in modern Jewish thought and the Kabbalah. She teaches courses in modern Jewish history and thought and in Hasidism.

Jeremy Dauber is the acting director of the Columbia University Institute for Israel and Jewish Studies, where he specializes in Yiddish and Yiddish literature.

Annelise Orleck is a history professor at Dartmouth College in Hanover, N.H. She is an expert on Jewish-American immigrants, especially Soviet immigrants.

Jon Levisohn is an assistant professor of Jewish education at Brandeis University in Waltham, Mass., and assistant academic director of the Mandel Center for Studies in Jewish Education.

Roger Brooks is a professor of Judaic studies at Connecticut College in New London, Conn. He teaches courses in rabbinic law, the Talmud and the Mishnah and has worked with the Holocaust Educational Foundation.