The UD community and the public are invited to sign up for summer offerings at the University of Delaware’s Osher Lifelong Learning Institute (OLLI), UD’s social and learning cooperative for adults age 50-plus. Registration is available until May 22 and reopens June 8. OLLI “Summer Selections” classes and activities take place June 22-July 25 in Dover, Lewes, Wilmington and online, covering a wide range of topics.