Dr. Andrew Phillips, assistant professor of medicine at Harvard Brigham and Women’s Hospital, will present “Modeling sleep and wake regulation in mammals” at 3 p.m. Thursday, April 14, in Room 103 Engineering Management Building. The seminar will discuss why different individuals have different preferred sleep timing, and why the loss of orexin neurons in the sleep disorder narcolepsy leads to instability of both sleep and wake states. Phillips is a Center for Statistical and Computational Modeling of Biological Complexity visiting scholar.