Many herbs have shown positive results in-vitro, animal model or small-scale clinical tests, while studies on some herbal treatments have found negative results. In 2002, the U.S. National Center for Complementary and Alternative Medicine of the National Institutes of Health began funding clinical trials into the effectiveness of herbal medicine. In a 2010 survey of 1000 plants, 356 had clinical trials published evaluating their "pharmacological activities and therapeutic applications" while 12% of the plants, although available in the Western market, had "no substantial studies" of their properties. Herbalists criticize the manner in which many scientific studies make insufficient use of historical knowledge, which has been shown useful in drug discovery and development in the past and present. They maintain that this traditional knowledge can guide the selection of factors such as optimal dose, species, time of harvesting and target population. The National Center for Complementary and Alternative Medicine (NCCAM), formerly the Office of Alternative Medicine (OAM), is a United States government agency that investigates complementary and alternative medicine (CAM) healing practices in the context of rigorous science, in training complementary and alternative medicine researchers, and in disseminating authoritative information to the public and professionals. The NCCAM is one of the 27 institutes and centers that make up the National Institutes of Health (NIH) within the Department of Health and Human Services of the federal government of the United States. The NIH is one of eight agencies under the Public Health Service (PHS) in the Department of Health and Human Services (DHHS). The National Institutes of Health (NIH) is an agency of the United States Department of Health and Human Services and is the primary agency of the United States government responsible for biomedical and health-related re earch. Its science and engineering counterpart is the National Science Foundation. It comprises 27 separate institutes, centers, and offices which includes the Office of the Director. Francis S. Collins is the current Director. As of 2003, the NIH was responsible for 28%Чabout US$26.4 billionЧof the total biomedical research funding spent annually in the U.S., with most of the rest coming from industry. The NIH's research is divided into two parts: the NIH Extramural Research Program is responsible for the funding of biomedical research outside the NIH, while the NIH Intramural Research Program (IRP) is the internal research program of the NIH, known for its synergistic approach to biomedical science. With 1,200 principal investigators and more than 4,000 postdoctoral fellows in basic, translational, and clinical research, the IRP is the largest biomedical research institution on earth. The unique funding environment of the IRP facilitates opportunities to conduct both long-term and high-impact science that would otherwise be difficult to undertake. With rigorous external reviews ensuring that only the most innovative research secures funding, the IRP is responsible for many scientific accomplishments, including the discovery of fluoride to prevent tooth decay, the use of lithium to manage bipolar disorder, and the creation of vaccines against hepatitis, Haemophilus influenzae (HIB), and human papillomavirus. Intramural research is primarily conducted at the main campus in Bethesda, Maryland, and the surrounding communities. The National Institute on Aging and the National Institute on Drug Abuse are located in Baltimore, Maryland, and the National Institute of Environmental Health Sciences is located in the Research Triangle region of North Carolina. The National Institute of Allergy and Infectious Diseases (NIAID) maintains its Rocky Mountain Labs in Hamilton, Montana, with an emphasis on virology.