could conduct long-term ecosystem research without having to worry about outside disturbances like tourists. Today, the NRS manages 39 reserves that total more than . UC Agriculture and Natural Resources (UCANR, Division of Agriculture and Natural Resources) plays an important role in the state's agriculture industry, as mandated by UC's legacy as a land-grant institution. In addition to conducting agriculture and Youth development research, every county in the state has a cooperative extension office with county farm advisors. The county offices also support 4-H programs and have nutrition, family, and consumer sciences advisors who assist local government. Currently, the division's University of California 4-H Youth Development Program is a national leader in studying thriving in the field of youth development. Other national research centers From September 2003 to July 2016, UC managed a contract valued at more than $330 million to establish and operate a University Affiliated Research Center (UARC) at the NASA Ames Research Center at Moffett Federal Airfield —the largest grant ever awarded the university. UC Santa Cruz managed the UARC for the University of California, with the goal of increasing the science output, safety, and effectiveness of NASA's missions through new technologies and scientific techniques. Since 2002, the NSF-funded San Diego Supercomputer Center at UC San Diego has been managed by the University of California, which took over from the previous manager, General Atomics. Medical centers and schools The University of California operates five medical centers throughout the state: UC Davis Medical Center, in Sacramento; UC Irvine Medical Center, in Orange; UCLA Medical Center, comprising two distinct hospitals: Ronald Reagan UCLA Medical Center, in Los Angeles; UCLA Santa Monica Medical Center, in Santa Monica; UC San Diego Medical Center, comprising two distinct hospitals: UC San Diego Medical Center, Hillcrest, in San Diego; Jacobs Medical Center, in La Jolla; and UCSF Medical Center, operating as a single medical center across three physically distinct campuses around San Francisco. There are two medical centers that bear the UCLA name, but are not operated by UCLA: Harbor–UCLA Medical Center and Olive View–UCLA Medical Center. They are actually Los Angeles County-operated facilities that UCLA uses as teaching hospitals. Each medical center serves as the primary teaching site for that campus's medical school. UCSF is perennially among the top five programs in both research and primary care, and both UCLA and UC San Diego consistently rank among the top fifteen research schools, according