Professor, biochemist, biophysicist, and fourth president of Israel. Born in Kiev, Russia, he was brought to Palestine by his parents at age nine. A graduate of the Hebrew University, in 1949 he was appointed Acting Head of Department of Biophysics in the Weizmann Institute of Science at Rehovot, and later its substantive director. From 1966 to 1968, he was Chief Scientist to the Ministry of Defense. He has written extensively on proteins and such natural products as nucleic acids and is a member of a number of national and international societies. In 1966, he was the first Israeli to be elected to the U.S. National Academy of Sciences. He was president of the State of Israel from 1973 to 1978.