Claudio Stampi. Portrait of Dr Claudio Stampi, Associate Director of the Institute for Circadian Physiology in Cambridge, Massachusetts, USA. Dr Stampi conducts research on human circadian rhythms. These rhythms are governed by an internal biological clock which controls human awake and sleep periods, daily changes in body temperature, and metabolic activity. This clock is linked to daily exposure to bright light. By understanding the mechanisms of this clock, human circadian rhythms may be shifted or delayed. This research may assist night shift workers to stay more alert in the early morning hours. It may also be used to treat people suffering from sleep disorders.