Genome-wide association and linkage identify modifier loci of lung disease severity in cystic fibrosis at 11p13 and 20q13.2

A combined genome-wide association and linkage study was used to identify loci causing variation in cystic fibrosis lung disease severity. We identified a significant association (P = 3.34 × 10(-8)) near EHF and APIP (chr11p13) in p.Phe508del homozygotes (n = 1,978). The association replicated in p.Phe508del homozygotes (P = 0.006) from a separate family based study (n = 557), with P = 1.49 × 10(-9) for the three-study joint meta-analysis. Linkage analysis of 486 sibling pairs from the family based study identified a significant quantitative trait locus on chromosome 20q13.2 (log(10) odds = 5.03). Our findings provide insight into the causes of variation in lung disease severity in cystic fibrosis and suggest new therapeutic targets for this life-limiting disorder.     

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.     

Genome-wide association study of leaf architecture in the maize nested association mapping population

US maize yield has increased eight-fold in the past 80 years, with half of the gain attributed to selection by breeders. During this time, changes in maize leaf angle and size have altered plant architecture, allowing more efficient light capture as planting density has increased. Through a genome-wide association study (GWAS) of the maize nested association mapping panel, we determined the genetic basis of important leaf architecture traits and identified some of the key genes. Overall, we demonstrate that the genetic architecture of the leaf traits is dominated by small effects, with little epistasis, environmental interaction or pleiotropy. In particular, GWAS results show that variations at the liguleless genes have contributed to more upright leaves. These results demonstrate that the use of GWAS with specially designed mapping populations is effective in uncovering the basis of key agronomic traits.     

制造信息系统的有序性测度理论研究

为了测度制造信息系统的有序性,研究了制造信息系统的有序程度与制造信息之间的关系.首先将制造信息分为车间设备信息、制造执行信息、流程管理信息、业务决策信息和战略决策信息5个层次,并根据制造信息所在的层次定义了制造信息绝对信息量的评分标准及同一层次内部信息重要性的评分标准;然后采用Shannon的信息论计算制造信息的信息量,并结合前述的两个评分标准计算每个信息的绝对信息量;再结合制造信息量之间的相关性系数,确定各个制造信息的独立信息量.制造信息系统中所有独立信息的总量就是制造信息系统的信息总量;另外,当制造信息系统处于极端条件下时,其信息总量会出现最大值与最小值,根据这三个值,文中找到了评价制造信息系统有序性的参数并称之为系统有序度Θ(t).使用系统有序度Θ(t)来测度制造信息系统的有序性时,系统有序度越大,制造信息系统的有序性越高.     

离子强度对牛磺酸离子交换平衡的影响

采用静态吸附法研究离子强度对牛磺酸/OH-体系在阴离子树脂D290上离子交换平衡的影响,测定了不同离子强度下牛磺酸在碱式阴离子交换树脂上的交换平衡等温线.研究结果表明:(1)随着溶液离子强度的升高,阴离子树脂对牛磺酸的平衡交换吸附容量逐渐降低,牛磺酸在树脂上的分配系数λTau逐渐下降;(2)随着溶液离子强度增大,达到平衡时液相的pH值升高,溶液中牛磺酸阴离子Tau±含量迅速增加,而牛磺酸两性离子Tau±含量迅速降低;(3)在一定的牛磺酸浓度范围内,溶液离子强度增大,有利于提高离子交换树脂对牛磺酸的选择性.     

基于遗传算法的制造网络服务质量优化

服务质量的合成是面向服务架构系统面临的重要挑战,评价面向服务架构制造网络最优化的典型标准是加工时间成本和系统响应时间.文中提出了一种应用遗传算法解决制造网络服务质量优化问题的新方法.首先用着色Petri网和排队论分别对制造网络的物流和信息流进行建模,然后应用遗传算法对该模型进行调度并获取服务质量的近似最优解.在该算法中,染色体采用分段基因编码,它们分别是制造网络物流和信息流调度方案的规则与加权系数的组合;遗传操作包括选择、交叉、变异3种类型.在每一代种群中,通过仿真得到与每个染色体相对应的各项性能指标值,以模糊综合评判方法求取制造网络服务质量适应度的函数值.实验结果表明,该方法能有效优化制造网络的服务质量.     

谈谈字母词

全球几千种语言,“很少是自给自足的”(萨丕尔),时刻都在进行着跨语言文化的词语代码转化,并生成民族化的外来词。在200个国家中有120个国家,在民族化的同时兼顾国际化：拉丁文语种以借形为主,非拉丁文语种(俄语、日语)以借音为主(兼顾借形),而汉语以借意为主(约占75%)。20世纪初,在新文化浪潮的冲击下,中国开始出现了借形的新奇现象。数学和文学里分别出现了x+y=a,阿Q。紧接着自然科学和社会科学纷纷出现了诸如此类的现象。到了改革开放新时期,借形已成了新潮。所谓的“字母词”,就是借形词的一种。对于汉语借形词,有人坚决反对。较早的时候,有人把x+y=a改为“天+地=甲”,上演一出国粹闹剧。可是怎么也演不下去,因为罗马和希腊字母作为数学符号,常见的至少有60来个,而我们的天干地支总共才22个,不可能对译,而且用起来很别扭。后来,有人看阿Q很刺眼,可是阿Q站起来了,而且堂而皇之地走进了汉语词汇家族。鲁迅在20世纪30年代,还用过ABC、OK等许多字母词。时至今日,字母词已成百上千地出现在书报上,迫使严肃的辞书也不得不逐渐承认它们。一向有开明意识的《辞海》,1979年版附录了63条,1989年版附录了97条,1999年版附录了126条。一贯以规范著称的《现代汉语词典》第三版附录了39条,第四版附录了142条,第五版附录了182条。2001年上海辞书出版社出版了资深语言学家刘涌泉的《字母词词典》,内收2000多条。这也只是一般书报上多见的,如果再稍微扩大到专业书报,再加上近几年产生的,编一本《字母词大词典》,估计收词至少有5000条。字母词不仅频率不断增加,而且分布不断扩大。从自然科学技术领域,渐渐扩大到社会科学及生活领域。如WTO(世界贸易组织)、GNP(国民生产总值)、DVD(数字影碟)、VCD(影碟)、MTV(音乐电视)、IC(集成电路)卡、IP电话、IP卡电话、B超等等。刘涌泉先生给字母词概括了四个优点：快,简,明,广。此外,似乎还可以增加一个优点：补——填补词汇空缺(lexical gap),如A股、B股、A型血、B型血、A调、C调、OK等等。集“快,简,明,广,补”于一身的,有两个更典型的词：GMDSS,这是国际通用的求救信号,是汉语所无,而且换任何一个符号都不如它“快,简,明,广”;DNA,是脱氧核糖核酸,即遗传基因成分,是国际通用的测量公众科学素养的三个概念之一(另两个概念是“分子molecule”,“计算机软件computer software”)。与此相连带的,还有利用字母形状,借形表意,填补表形空缺的,如：U型管、S钩、T型台、A字裙、V字领、T型人才(横杠表示知识广,竖杠表示专业深)、X型人才(X表示交叉,指掌握两门交叉专业的人)。此外,字母词还有多种语用价值。有价值的,就是优变;无价值的,就是畸变。优存畸亡,适者生存。这就是历史的选择。这种选择总是以价值为尺度的。在生物界,名人达尔文有一句名言：“The Nature Selects the Fittest Survives.”被名家严复巧译成名句：“物竞天择,适者生存。”这是英汉翻译史上令人拍案叫绝的“绝译”。不仅词句绝佳,而且道理绝真。即使应用于词汇现象,类推也是成立的：词竞众择,适者生存。所谓“词竞”,是词语以其词形、语音、结构(含理据或内部形式)、语义、语用(含频率)等价值条件,跟并行词语、对应词语或相关词语竞争。例如：email/e-mail/Email,其中e-mail使用频率高,是多数人的选择,《现代汉语词典》便以它为规范词形。所谓“众择”,是语言的广大使用者的选择。广大使用者包括一般使用者和专家。选择,就是根据词语的各种价值和交际需要确定词语的取舍。选择的过程是：个体→群体→社团→全民。在这个过程中就形成一个或一些词语的使用趋势和习惯。而语言中的最高权威,就是众人的习惯。专家不要过早地表态或下结论。专家的任务,就是观察并描写习惯,发现趋势(趋势代表着方向,预示着规律),总结并完善规范标准,选择约定俗成的流行形式,引导言语活动,优化交际效能。例如：对BP机、PP机、呼机、寻呼机、无线传呼机等,要允许它们有一个被选择的过程,不要过早地定于一尊。对书写形式,特别是字母大小写表示不同意义的,要强调规范形式。如pH表示氢离子浓度指数,ph表示光照度单位“辐射”(非法定的)。对字母加汉字的混合词,不要采取过激的态度。有人讽刺这类词是“马褂加领带”。其实,这类中西合璧从阿Q时代就开始了,在国外早已有之,通称“混合词”,英语叫hybrid word,法、德、俄语分别叫mots hybrids,hybrids word,гибрид(或意译为полукалька),都是指语源不同的成分构成的词,可见混合词是许多语言共有的现象。这一现象刚出现时,人们难免看不惯,说三道四。最后,混合词终于以其准确性、科学性冲破习惯势力的森然门禁。总之,字母词从阿Q到T型人才,在中国形成了队伍,占领的地盘越来越大,其势不可阻挡。但是,不能滥用,更不能乱用。必须考虑交际对象、环境、语体等等因素。使用的指导思想只能是“科学实用,便于推行和普及,促进汉语健康发展”。     

Lipids of sulfate-reducing bacteria and sulfur-oxidizing bacteria found in the Dongsheng uranium deposit

U-bearing sandstones from the Dongsheng deposit in Ordos Basin contain abundant C15-C18 fatty acids. The fatty acids may have been derived from modern and ancient organisms including organisms from the intervals of U mineralization. A certain amount of i15:0, a15:0, a17:0 fatty acids coexist with small amounts of i17:1ω7c and 10me16:0, characteristic biomarkers of Desulfovibrio and Desulfobacter sp., respectively. This indicates the existence of sulfate-reducing bacteria (SRB) in the sandstones. The presence of sulfur-oxidizing bacteria (SOB), such as Beggiatoa and Thioploca, is indicated by significant amounts of 16:1ω7c and 18:1ω7c fatty acids. The existence of the SRB in the deposit, as inferred from the fatty acids, is consistent with results from fossilized microorganisms and isotopic compositions of ore-stage pyrite. This suggests that the environment may have been favorable for the SRB to grow since ore formation (9.8-22 Ma). The bacteria may have degraded hydrocarbons directly, or indirectly utilized hydrocarbons degraded by oxic microbes in the deposits. This process may have produced 12C-rich calcite and prominent baseline humps of unresolved complex mixtures (UCM), and 25-demethylated hopanes and tricyclic terpanes. The existence of sulfur-oxidizing bacteria and sulfate-reducing bacteria in the deposit may have resulted in bacterial sulfate reduction to sulfide, re-oxidization of the sulfide to sulfate and subsequent reduction of the sulfate to sulfide. This assertion is supported by ore-stage pyrite with δ34S values as low as-39.2‰, and the lightest sulfate (about 11‰) measured during the Phanerozoic, a difference of more than 46‰.     

动力学在交通事故处理中的应用

公安院校基础教学中公安知识的渗透,有力地驱动学生创造力的培养。在现场勘查中,针对事故现场的实况,可运用动力学的知识,对肇事车辆行驶速度作出科学的鉴定。     

Gas-liquid phase coexistence and finite-size effects in a two-dimensional Lennard-Jones system

The gas-liquid phase coexistence in a two-dimensional Lennard-Jones system is investigated using Maxwell construction method together with molecular dynamics simulations.The results of phase coexistence in different truncations of the potential are compared with data obtained from the literature,and the corresponding critical properties calculated.The crossover from Ising-like to mean field behavior is observed and confirmed as the temperature approaches the critical point from below.Performing simulations on systems with different sizes,we find that a finite size effect is more significant than those shown in most of the previous results,and a lower critical temperature is obtained when the full extent of this finite size effect is considered.