Y-Chromosome Evidence for Common Ancestry of Three Chinese Populations with a High Risk of Esophageal Cancer

High rates of esophageal cancer (EC) are found in people of the Henan Taihang Mountain, Fujian Minnan, and Chaoshan regions of China. Historical records describe great waves of populations migrating from north-central China (the Henan and Shanxi Hans) through coastal Fujian Province to the Chaoshan plain. Although these regions are geographically distant, we hypothesized that EC high-risk populations in these three areas could share a common ancestry. Accordingly, we used 16 East Asian-specific Y-chromosome biallelic markers (single nucleotide polymorphisms; Y-SNPs) and six Y-chromosome short tandem repeat (Y-STR) loci to infer the origin of the EC high-risk Chaoshan population (CSP) and the genetic relationship between the CSP and the EC high-risk Henan Taihang Mountain population (HTMP) and Fujian population (FJP). The predominant haplogroups in these three populations are O3*, O3e*, and O3e1, with no significant difference between the populations in the frequency of these genotypes. Frequency distribution and principal component analysis revealed that the CSP is closely related to the HTMP and FJP, even though the former is geographically nearer to other populations (Guangfu and Hakka clans). The FJP is between the CSP and HTMP in the principal component plot. The CSP, FJP and HTMP are more closely related to Chinese Hans than to minorities, except Manchu Chinese, and are descendants of Sino-Tibetans, not Baiyues. Correlation analysis, hierarchical clustering analysis, and phylogenetic analysis (neighbor-joining tree) all support close genetic relatedness among the CSP, FJP and HTMP. The network for haplogroup O3 (including O3*, O3e* and O3e1) showed that the HTMP have highest STR haplotype diversity, suggesting that the HTMP may be a progenitor population for the CSP and FJP. These findings support the potentially important role of shared ancestry in understanding more about the genetic susceptibility in EC etiology in high-risk populations and have implications for determining the molecular basis of this disease

hermal-Aware Microchannel Cooling of Multicore Processors: A Three-Stage Design Approach

<p>This study goes beyond the common microchannel cooling system composed of uniform parallel straight microchannels and proposed a three-stage design approach for spatially thermal-aware microchannel cooling of 2D multicore processors. By applying effective strategies and arranging key design parameters, stronger cooling is provided under the high power core area, and less cooling is provided under the low power cache area to effectively save the precious pumping power, lower the hot spot temperature and lower temperature gradients on chip. Two microchannel cooling systems are specifically designed for a 2 core 150 W Intel Tulsa processor and an 8 core 260 W (doubled power) Intel Nehalem processor with single phase HFE7100 as coolant. For the Tulsa processor, a strategy named strip-and-zone is used. The final design leads to 30 kPa pressure drop and 0.094 W pumping power while maintains the hot spot temperature to be 75 °C. For the Nehalem processor, a split flow microchannel system and a widen-inflow strategy are applied. A design is achieved to cost 15 kPa pressure drop and 0.0845 W pumping power while maintains the hot spot temperature to be 82.9°C. The design approach in this study provides the basic guide for the industrial applications of effective multicore processor cooling using microchannels.</p

Optical properties of Er, Yb co-doped YAG transparent ceramics

The transparent polycrystalline erbium and ytterbium co-doped yttrium aluminum garnet (Er, Yb:YAG) ceramics with various Yb contents from 5% to 25% were prepared by the solid-state reaction and the vacuum-sintering technique. The in-line transmittances of the mirror-polished ceramics exceed 80% from the visible band to the infrared band. The samples are very compact with few pores. The average grain size of the Er,Yb:YAG ceramic is about 15 mu m. The upconversion luminescence spectra, infrared luminescence spectra and luminescence decay curves of the ceramics were observed and discussed. For 1%Er doped YAG ceramic, the best ion ratio of Yb(3+) and Er(3+) is around 15:1. (C) 2010 Elsevier Ltd and Techna Group S.r.l. All rights reserved