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61.
A Note on K-modes Clustering 总被引:2,自引:0,他引:2
Recently, Chaturvedi, Green and Carroll (2001) presented a nonparametric approach
to deriving clusters from categorical data using a new clustering procedure called
K-modes. Huang (1998) proposed the K-modes clustering algorithm. In this note, we
demonstrate the equivalence of the two K-modes procedures. 相似文献
62.
Cho YS Chen CH Hu C Long J Ong RT Sim X Takeuchi F Wu Y Go MJ Yamauchi T Chang YC Kwak SH Ma RC Yamamoto K Adair LS Aung T Cai Q Chang LC Chen YT Gao Y Hu FB Kim HL Kim S Kim YJ Lee JJ Lee NR Li Y Liu JJ Lu W Nakamura J Nakashima E Ng DP Tay WT Tsai FJ Wong TY Yokota M Zheng W Zhang R Wang C So WY Ohnaka K Ikegami H Hara K Cho YM Cho NH Chang TJ Bao Y Hedman ÅK Morris AP McCarthy MI;DIAGRAM Consortium;MuTHER Consortium Takayanagi R Park KS Jia W Chuang LM Chan JC Maeda S Kadowaki T Lee JY Wu JY 《Nature genetics》2012,44(1):67-72
We conducted a three-stage genetic study to identify susceptibility loci for type 2 diabetes (T2D) in east Asian populations. We followed our stage 1 meta-analysis of eight T2D genome-wide association studies (6,952 cases with T2D and 11,865 controls) with a stage 2 in silico replication analysis (5,843 cases and 4,574 controls) and a stage 3 de novo replication analysis (12,284 cases and 13,172 controls). The combined analysis identified eight new T2D loci reaching genome-wide significance, which mapped in or near GLIS3, PEPD, FITM2-R3HDML-HNF4A, KCNK16, MAEA, GCC1-PAX4, PSMD6 and ZFAND3. GLIS3, which is involved in pancreatic beta cell development and insulin gene expression, is known for its association with fasting glucose levels. The evidence of an association with T2D for PEPD and HNF4A has been shown in previous studies. KCNK16 may regulate glucose-dependent insulin secretion in the pancreas. These findings, derived from an east Asian population, provide new perspectives on the etiology of T2D. 相似文献
63.
Zang ZJ Cutcutache I Poon SL Zhang SL McPherson JR Tao J Rajasegaran V Heng HL Deng N Gan A Lim KH Ong CK Huang D Chin SY Tan IB Ng CC Yu W Wu Y Lee M Wu J Poh D Wan WK Rha SY So J Salto-Tellez M Yeoh KG Wong WK Zhu YJ Futreal PA Pang B Ruan Y Hillmer AM Bertrand D Nagarajan N Rozen S Teh BT Tan P 《Nature genetics》2012,44(5):570-574
Gastric cancer is a major cause of global cancer mortality. We surveyed the spectrum of somatic alterations in gastric cancer by sequencing the exomes of 15 gastric adenocarcinomas and their matched normal DNAs. Frequently mutated genes in the adenocarcinomas included TP53 (11/15 tumors), PIK3CA (3/15) and ARID1A (3/15). Cell adhesion was the most enriched biological pathway among the frequently mutated genes. A prevalence screening confirmed mutations in FAT4, a cadherin family gene, in 5% of gastric cancers (6/110) and FAT4 genomic deletions in 4% (3/83) of gastric tumors. Frequent mutations in chromatin remodeling genes (ARID1A, MLL3 and MLL) also occurred in 47% of the gastric cancers. We detected ARID1A mutations in 8% of tumors (9/110), which were associated with concurrent PIK3CA mutations and microsatellite instability. In functional assays, we observed both FAT4 and ARID1A to exert tumor-suppressor activity. Somatic inactivation of FAT4 and ARID1A may thus be key tumorigenic events in a subset of gastric cancers. 相似文献
64.
The major hanging gardens and associated water seeps in Zion National Park were surveyed for the presence of the Zion Snail ( Physa zionis ). Environmental parameters, including water depth, water velocity, substrate slope, and algal cover, were measured to determine their effect on the local distribution of the snail. Large populations (densities 125 to 250/m 2 ) were found in the Virgin River Narrows area of the park and at a hanging garden and seep located 1.0 km north of Scout Lookout. Densities in other localities were low in comparison. Snails were not found in all hanging gardens or seeps. The major factor controlling within seep distribution was determined to be water velocity. Experiments were conducted to test the ability of the snail to remain attached during differing water flows. The snail showed an ability to remain attached during high flows, but few snails were found in areas of high flow. 相似文献
65.
Chronic high-fat diet in fathers programs β-cell dysfunction in female rat offspring 总被引:1,自引:0,他引:1
The global prevalence of obesity is increasing across most ages in both sexes. This is contributing to the early emergence of type 2 diabetes and its related epidemic. Having either parent obese is an independent risk factor for childhood obesity. Although the detrimental impacts of diet-induced maternal obesity on adiposity and metabolism in offspring are well established, the extent of any contribution of obese fathers is unclear, particularly the role of non-genetic factors in the causal pathway. Here we show that paternal high-fat-diet (HFD) exposure programs β-cell 'dysfunction' in rat F(1) female offspring. Chronic HFD consumption in Sprague-Dawley fathers induced increased body weight, adiposity, impaired glucose tolerance and insulin sensitivity. Relative to controls, their female offspring had an early onset of impaired insulin secretion and glucose tolerance that worsened with time, and normal adiposity. Paternal HFD altered the expression of 642 pancreatic islet genes in adult female offspring (P?0.01); genes belonged to 13 functional clusters, including cation and ATP binding, cytoskeleton and intracellular transport. Broader pathway analysis of 2,492 genes differentially expressed (P?0.05) demonstrated involvement of calcium-, MAPK- and Wnt-signalling pathways, apoptosis and the cell cycle. Hypomethylation of the Il13ra2 gene, which showed the highest fold difference in expression (1.76-fold increase), was demonstrated. This is the first report in mammals of non-genetic, intergenerational transmission of metabolic sequelae of a HFD from father to offspring. 相似文献
66.
67.
Some decompositions of modules over a ring can be discussed in special categories Here we study the decomposition of quasi-injective objects over a Grothendieck category and generalize some propositions on quasi-injective modules over a ring in [1] and [3]. 相似文献
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