“Circus Acrobats,” a 1981 sculpture by George Segal, has been installed above the entrance to the University Art Museum in McCormick Hall. A recent gift from the George and Helen Segal Foundation, the work exemplifies Segal’s plaster sculptures and installations depicting scenes from everyday life. The summer also saw the departure of Magdalena Abakanowicz’s “Big Figures,” the grouping of 20 headless bronze figures outside the building’s front entrance that had been on loan for five years from an anonymous donor.