Most living things -- including humans, plants and fruit flies -- follow 24-hour cycles known as circadian rhythms, which influence sleep and other physiologic processes. Neuroscientist Amita Sehgal, PhD, talks about her research on fruit flies and what it tells us about human sleep. Sehgal, a professor at the University of Pennsylvania's Perelman School of Medicine, was in Syracuse as the keynote speaker for student research day at Upstate.