This grant permits Dr. Beall to conduct human biological research in Phala, Tibet Autonomous Region, Peoples Republic of China. The approximately 170 male and female nomads (between the ages of 15 .85) to be studied reside at high altitudes of between 4900 . 5450 m above sea level and the goal of this project is to understand how people adapt to year round habitation at such heights. Dr. Beall will measure the distribution of hemoglobin concentration, percent arterial oxygen saturation and ventilation. Study participants will provide fingerstick blood samples for hematological analysis and undergo noninvasive oximetry. Resting ventilation volumes will also be measured. This will yield basic epidemiologic data on age and sex differences in these parameters and allow Dr. beall to test the hypothesis that an inverse association exists between hemoglobin concentration and percent arterial oxygen saturation. Dr. Beall also hypothesiszes that there is a positive association between the percent of arterial oxygen saturation and ventilation. This is an extremely interesting study population because it resides year round at such a high altitude. It is also interesting because it appears that Tibetians adapt to the oxygen stress imposed by high altitude differently from South Americans who live in the Andes. This latter group exhibit barrel chests and higher levels of hemoglobin concentration. These features appear to be abscent in Tibetans. This research is important because it will increase our understanding of how humans adapt to physical stress. It may aid in the management of altitude sickness and will help to open this extremely interesting part of the world to U.S. reseachers. I