The Cox Institute is hosting a WUGA Day at Grady in observance of the station’s 30th year (and the 50th year of public broadcasting.)  Included in the celebration is a session at 9:30 a.m. in which GPB will tape an episode of “On Second Thought.” At 11 a.m., Steve Inskeep from “Morning Edition” will lecture in class.  At 2 p.m., Marilyn Geewax from the NPR Business Desk in Washington, D.C. will lecture in class.