Description of Study Phases Screening: Participants will be recruited from a variety of advertisements, and pre-screened using a telephone IRB-approved questionnaire. If participants are interested and pass the initial screening, a screening study visit in the research center will be scheduled. This visit should take approximately 90 minutes, during which full physical examination and medical history will be obtained, as well as physical diagnostics to assess for eligibility. This visit must be completed within the 28 days prior to enrollment.