Kaare Christensen, professor of epidemiology at the University of Southern Denmark, will present talks on aging on the University of Iowa campus. Both events, which are part of the Ida Beam Distinguished Professor program, are free and open to the public. Christensen directs the Danish Aging Research Center and the Danish Twin Registry. His research team leads a longitudinal study of people who are at least 100 years old to determine whether they have common social, physical, mental or genetic characteristics. "Why Do We Age So Differently" will be presented at 7 p.m. Thursday, April 15, in room 401W of the Pappajohn Business Building. The talk is sponsored by the UI Department of Pediatrics.