基于同义词词林的中文文本主题词提取

中文文本主题词的提取可以浓缩一篇文章,可以提炼一个中文网页,还可以帮助实现网上广告与网页的精确匹配。提出了一种基于同义词词林的中文文本主题词提取方法,不仅考虑了传统的影响主题词语权重的因素,还考虑到了同义词、相关词以及下位词的出现对于词语权重的影响。实验表明,用该方法对中文文本     

Mutations in genes encoding melanosomal proteins cause pigmentary glaucoma in DBA/2J mice.

Pigmentary glaucoma is a significant cause of human blindness. Abnormally liberated iris pigment and cell debris enter the ocular drainage structures, leading to increased intraocular pressure (IOP) and glaucoma. DBA/2J (D2) mice develop a form of pigmentary glaucoma involving iris pigment dispersion (IPD) and iris stromal atrophy (ISA). Using high-resolution mapping techniques, sequencing and functional genetic tests, we show that IPD and ISA result from mutations in related genes encoding melanosomal proteins. IPD is caused by a premature stop codon mutation in the Gpnmb (GpnmbR150X) gene, as proved by the occurrence of IPD only in D2 mice that are homozygous with respect to GpnmbR150X; otherwise, similar D2 mice that are not homozygous for GpnmbR150X do not develop IPD. ISA is caused by the recessive Tyrp1b mutant allele and rescued by the transgenic introduction of wildtype Tyrp1. We hypothesize that IPD and ISA alter melanosomes, allowing toxic intermediates of pigment production to leak from melanosomes, causing iris disease and subsequent pigmentary glaucoma. This is supported by the rescue of IPD and ISA in D2 eyes with substantially decreased pigment production. These data indicate that pigment production and mutant melanosomal protein genes may contribute to human pigmentary glaucoma. The fact that hypopigmentation profoundly alleviates the D2 disease indicates that therapeutic strategies designed to decrease pigment production may be beneficial in human pigmentary glaucoma.     

变量有上界的线性规划的对偶单纯形方法

给出变量有上界的线性规划问题的对偶单纯形算法, 该算法包含了一般线性规划问题的对偶单纯形算法, 为解变量有上界的线性规划问题提供了又一种方法.     

黄酮类化合物清除对苯半醌负离子自由基研究(Ⅰ)

以对苯半醌负离子自由基为模型 ,利用ESR技术研究黄酮类化合物清除自由基的作用 ,初步获得一些构效关系。     

UML在多层分布式系统建模中的应用

UML统一建模语言已受到工程界广泛的关注，但采用UML对多层分布式应用系统进行建模没有统一的标准，本文介绍在工程实践中采用的建模方法，并采用UML为多层分布式系统建模，该方法已在工程应用中取得较好的效果。     

Altruistic punishment in humans.

Human cooperation is an evolutionary puzzle. Unlike other creatures, people frequently cooperate with genetically unrelated strangers, often in large groups, with people they will never meet again, and when reputation gains are small or absent. These patterns of cooperation cannot be explained by the nepotistic motives associated with the evolutionary theory of kin selection and the selfish motives associated with signalling theory or the theory of reciprocal altruism. Here we show experimentally that the altruistic punishment of defectors is a key motive for the explanation of cooperation. Altruistic punishment means that individuals punish, although the punishment is costly for them and yields no material gain. We show that cooperation flourishes if altruistic punishment is possible, and breaks down if it is ruled out. The evidence indicates that negative emotions towards defectors are the proximate mechanism behind altruistic punishment. These results suggest that future study of the evolution of human cooperation should include a strong focus on explaining altruistic punishment.     

宇宙生命化:一个真实的人类未来图景

近几年来，人类在所有科学领域取得成果的速率在惊人地加快。当我们拓展对地球的控制时，同时也在准备重塑和改造地球上的景观，为自己到地球外居住作准备。几个世纪以来，我们已经花大力改造了地球，现在，我们正准备把宇宙转变成一个充满生命的有生气的实体。我们将通过把我们的意识、技能、智力以及我们自身扩展到其他行星上来实现这个目标。我们把人类改变和改善地球环境（最终是宇宙本身）的努力总称为“生命化”。生命化是调节人类行为的一种力量，赋予地球并最终赋予整个宇宙以意识和智慧，是全部人类生产活动背后的原动力。然而，为…     

关于局部分次Morita对偶

证明了一些gr－线性紧模的性质，刻划了gr－内射，gr－线性紧和gr－反射之间的关系。同时给出了局部分次Morrita对偶的刻划， 推广了C.Menini和A.D.Rio 的一个主要结果。     

随机多址访问协议中最优帧模式的混合遗传算法

在随机接入协议中 ,竞争时隙与预约时隙在一帧中的相对位置 (帧模式 )对系统的吞吐量有很大的影响 .利用混合遗传算法搜索出不同业务量下的最优帧模式 ,提高了系统的吞吐量 .     

Sox9 induces testis development in XX transgenic mice.

Mutations in SOX9 are associated with male-to-female sex reversal in humans. To analyze Sox9 function during sex determination, we ectopically expressed this gene in XX gonads. Here, we show that Sox9 is sufficient to induce testis formation in mice, indicating that it can substitute for the sex-determining gene Sry.