In order to reduce the stress and boredom of the 34-day hospitalization, it is anticipated that the subjects will be studied in pairs so that they will always have someone in a similar situation to interact with. They will have free access to television, the internet and local phone service while in the clinical research unit. The subjects must eat breakfast and dinner in the research unit and sleep there. Otherwise, they may go out on pass during the day and after dinner in the evenings for shopping, entertainment, etc. We will pack their lunch if they choose to go out for the day as they will not be allowed to consume any food or drink other than what is provided in their agreed upon diet. Visitors will be allowed during normal hospital visiting hours.