Investigation of control region sequences of mtDNA in Naqu Tibetan population from Northwestern China.

BACKGROUND: The sequence polymorphisms of mitochondrial DNA (mtDNA) are valuable in forensic medicine and anthropological genetics. AIM: We analysed the sequences of the mtDNA control region in 207 unrelated Tibetan individuals from the Naqu region, Tibet Autonomous Region in the People's Republic of China, and investigated the population structure of the region by population comparison with other groups. SUBJECTS AND METHODS: Genomic DNA was extracted and hypervariable regions (HVS-I and HVS-II) were amplified and sequenced. Subsequently, sequences were aligned and compared with the revised Cambridge sequence. Moreover, population comparison was performed between the Naqu Tibetan group and the other groups. CONCLUSION: Our study provided available data for exploring the mtDNA haplotype of the Tibetan population in the Naqu region, and population comparisons found that the Naqu Tibetan population has its own unique structure.

Foreign-Trained Physicians in the United States: A Descriptive Profile.

More than a quarter of physicians in the United States are international medical graduates (IMGs). This statistic, although large, does not fully capture the importance of IMGs in certain specialties and locations. We provide a comprehensive profile of IMGs documenting where and in what specialties they work and how these distributions have changed over time. Estimates show that IMGs disproportionately work in densely populated, low-income communities with sicker residents and low physician density. IMGs are overrepresented in primary care and the lowest paying specialties, and their concentration in these specialties is growing. Calculations show that U.S. medical graduates exit the workforce at 2.5 times the exit rate of IMGs suggesting that in the near future IMGs will likely provide care for an increasingly larger share of Americans.