Frequent mutations of chromatin remodeling genes in transitional cell carcinoma of the bladder

Transitional cell carcinoma (TCC) is the most common type of bladder cancer. Here we sequenced the exomes of nine individuals with TCC and screened all the somatically mutated genes in a prevalence set of 88 additional individuals with TCC with different tumor stages and grades. In our study, we discovered a variety of genes previously unknown to be mutated in TCC. Notably, we identified genetic aberrations of the chromatin remodeling genes (UTX, MLL-MLL3, CREBBP-EP300, NCOR1, ARID1A and CHD6) in 59% of our 97 subjects with TCC. Of these genes, we showed UTX to be altered substantially more frequently in tumors of low stages and grades, highlighting its potential role in the classification and diagnosis of bladder cancer. Our results provide an overview of the genetic basis of TCC and suggest that aberration of chromatin regulation might be a hallmark of bladder cancer.     

Drosophila Piwi functions in Hsp90-mediated suppression of phenotypic variation

Canalization, also known as developmental robustness, describes an organism's ability to produce the same phenotype despite genotypic variations and environmental influences. In Drosophila, Hsp90, the trithorax-group proteins and transposon silencing have been previously implicated in canalization. Despite this, the molecular mechanism underlying canalization remains elusive. Here using a Drosophila eye-outgrowth assay sensitized by the dominant Kr(irregular facets-1)(Kr(If-1)) allele, we show that the Piwi-interacting RNA (piRNA) pathway, but not the short interfering RNA or micro RNA pathway, is involved in canalization. Furthermore, we isolated a protein complex composed of Hsp90, Piwi and Hop, the Hsp70/Hsp90 organizing protein homolog, and we demonstrated the function of this complex in canalization. Our data indicate that Hsp90 and Hop regulate the piRNA pathway through Piwi to mediate canalization. Moreover, they point to epigenetic silencing of the expression of existing genetic variants and the suppression of transposon-induced new genetic variation as two major mechanisms underlying piRNA pathway-mediated canalization.     

集聚效应对中国风电产业发展差异影响的实证研究

风电产业的发展是清洁能源发展的热点之一。本文从产业集聚效应的角度出发,深入研究了我国风电产业链的发展情况,利用地区集中度LQ指标对2009~2012年华北、东北、西北和江苏沿海风电产业集聚情况进行了实证研究,得出我国四大区域确实存在风电产业集聚现象。同时利用产业地区集中度cR指标测度各地的市场集中度,深入分析了我国典型地区的风电产业集聚特征,得出受集聚效应和各地经济资源禀赋不同的影响,我国风电产业发展存在差异且缺少地区间的产业联动发展,并提出相应的对策建议。     

Interaction model of artificial fish in virtual environment

Conventional artificial fish has some shortages on the interaction with environment, other fish, and the animator. This article proposes a multi-tier interaction control model of artificial fish, realizes the interaction model through integration of virtual reality technology and Markov sequence, and provides a virtual marine world to describe the interaction between artificial fish and the virtual environment and the interaction between the artificial fish and the animator. Simulation results show that the interaction model owns not only the basic characteristics of virtual biology, but also has high trueness interaction function.     

基于L-M算法的EV71传播预测模型

本文基于神经网络L-M优化算法,提出一种时EV71病毒的有效预测模型,利用matlab进行仿真模拟,结果和阜阳病毒感染情况非常符合.神经网络L-M优化算法克服了神经网络BP算法收敛速度慢的缺点,同时通过学习训练,本模型的神经系统具有有效性和通用性的特点.     

Heritable germline epimutation of MSH2 in a family with hereditary nonpolyposis colorectal cancer

Epimutations in the germline, such as methylation of the MLH1 gene, may contribute to hereditary cancer syndrome in human, but their transmission to offspring has never been documented. Here we report a family with inheritance, in three successive generations, of germline allele-specific and mosaic hypermethylation of the MSH2 gene, without evidence of DNA mismatch repair gene mutation. Three siblings carrying the germline methylation developed early-onset colorectal or endometrial cancers, all with microsatellite instability and MSH2 protein loss. Clonal bisulfite sequencing and pyrosequencing showed different methylation levels in different somatic tissues, with the highest level recorded in rectal mucosa and colon cancer tissue, and the lowest in blood leukocytes. This mosaic state of germline methylation with different tissue distribution could act as the first hit and provide a mechanism for genetic disease inheritance that may deviate from the mendelian pattern and be overlooked in conventional leukocyte-based genetic diagnosis strategy.     

关于牛顿“碑文”翻译的一个争论

诗人蒲柏曾给牛顿拟过一个碑文，后来虽未予采用，但该诗却流传甚广，很多关于牛顿的文章都引用过它。其后，另一个英国诗人J．C．斯奎尔，按同样的形式又续了一首诗。对于后一首诗准确的理解和翻译，曾经引起了一场很热烈的争论。