小麦-簇毛麦端体附加系中6V端体的细胞遗传学行为及其在Moisson 6MV/6B中的传递

簇毛麦6V染色体上携有抗白粉病基因Pm21.本研究利用抗白粉病小麦-簇毛麦单端体和双端体附加系(2n=42+1t和2n=42+2t)为材料,通过自交,观察后代植株6V端体出现频率,以评价外源染色体在小麦背景中的遗传平衡程度及稳定性,为利用培育小麦-簇毛麦导入系提供理论依据.通过对自交群体植株根尖细胞染色体数观察,发现在双端体附加系(2n=42+2t)自交群体(F2)中,2n=42+2t,2n=42+1t,2n=42的出现频率分别为51.92%,40.38%和7.7%;在单端体附加系(2n=42+1t)的F2群体中,2n=42+2t,2n=42+1t,2n=42的出现频率分别为1.85%,17.59%和80.56%.χ2检验表明(χ20.01=0.000),两自交群体问6V端体传递能力存在显著差异,6V端体的传递能力与亲本携带的端体数密切相关,双端体附加系在减数分裂时主要形成n+t配子,而单端体附加系则形成n和n+t两种配子,n+t配子参与受精的竞争能力主要取决于6V端体的遗传平衡程度,单端体附加系自交群体中的6V端体出现频率较低.这表明6V端体可能携有较多的不利基因导致n+t配子竞争能力较差.小麦-簇毛麦6V双端体附加系Pana(2n=42+2t)6VS在Moisaon 6MV/6B中通过雌雄配子传递频率研究发现,6VS通过雌配子的传递频率(33.33%)远高于通过雄配子的传递频率(4.87%).这也与其抗病性鉴定结果一致.此外,还发现以Pana(2n=42+21)为母本获得了小麦-偏凸山羊草-簇毛麦三属杂种,而以Pana(2n=42+2t)为父本却未能获得小麦-偏凸山羊草-簇毛麦三属杂种,暗示Pana(2n=42+2t)附加端体可能对花粉育性有一定不利影响.     

On the enumeration of some D-optimal designs

Two matrices with elements taken from the set {-1,1}$\{-1,1\}$ are Hadamard equivalent if one can be converted into the other by a sequence of permutations of rows and columns, and negations of rows and columns. In this paper we summarize what is known about the number of equivalence classes of matrices having maximal determinant. We establish that there are 7 equivalence classes for matrices of order 21 and that there are at least 9884 equivalence classes for matrices of order 26. The latter result is obtained primarily using a switching technique for producing new designs from old.     

A note on the queue with a random set-up time under a restricted admissibility policy with a Bernoulli vacation schedule

This paper deals with the queue size distribution of an M^x/G/1 queue with a random set-up time and with a Bernoulli vacation schedule under a restricted admissibility policy. This generalizes the model studied by Madan and Choudhury [Sankhyá 66 (2004) 175–193].     

PREDICT-1 (CNA106030): the first powered, prospective trial of pharmacogenetic screening to reduce drug adverse events

Pharmacogenetics (PGx) – the study of DNA variation in the human genome and the way this impacts the efficacy and safety of medicines – is becoming an increasingly important research tool as physicians, patients, regulatory authorities and payers look for innovative ways to improve the risk:benefit ratio of medicines. While scientific knowledge about PGx is rapidly increasing, implementation of PGx findings to patient care has yet to be fully achieved. One area where significant progress has been made is in the identification of PGx markers associated with variable response to antiretroviral medicines. For example, the major histocompatibility complex HLA‐B*5701 allele has been associated with hypersensitivity to abacavir (ABC) by several independent researchers. While PGx associations have been identified largely through retrospective examination, the clinical utility of these PGx markers in patient care has not been prospectively determined in a randomized study. This paper outlines the design of a study to evaluate the utility of prospective screening for HLA‐B*5701 to reduce the incidence of ABC hypersensitivity in an ABC‐naïve population of HIV‐infected subjects. This represents the first fully powered, randomized, blinded, prospective study to determine the clinical utility of PGx screening to reduce drug‐associated adverse events in any patient population. This type of trial design may have utility for other important medicines which have treatment‐limiting side effects. Copyright © 2007 John Wiley & Sons, Ltd.     

Single cycle policies for the one-warehouse N-retailer inventory/distribution system

We address a multi-echelon inventory system with one-warehouse and N  -retailers. The demand at each retailer is assumed to be known and satisfied by the warehouse. Shortages are not allowed and lead times are negligible. Costs at each facility consist of a fixed charge per order and a holding cost. The goal is to determine single-cycle policies which minimize the average cost per unit time, that is, the sum of the average holding and setup costs per unit time at the retailers and at the warehouse. We propose a O(NlogN)$\mathrm{O}(N\log N)$ heuristic procedure to compute efficient single-cycle policies. This heuristic is compared with other approaches proposed by Schwarz, Graves and Schwarz and Muckstadt and Roundy. We carry out a computational study to test the effectiveness of the heuristic and to compare the performance of the different procedures. From the computational results, it is shown that the new heuristic provides, on average, better single-cycle policies than those given by the Muckstadt and Roundy method.     

中国古代分封制与郡县制之争

由于中国古代社会君主专制的中央集权政权不断巩固与发展,自秦汉以来郡县制一直占主导地位,而分封制也以与西周不同的形式长期延续存在.分封制与郡县制都是君主专制政体下中央和地方关系的体现形式,二者的长期争论反映了中央集权与地方分权的斗争.     

A two phases queueing system with Bernoulli vacation schedule under multiple vacation policy

This paper deals with a single server Poisson arrival queue with two phases of heterogeneous service along with a Bernoulli schedule vacation model, where after two successive phases service the server either goes for a vacation with probability p (0≤p≤1) or may continue to serve the next unit, if any, with probability q(=1−p). Further the concept of multiple vacation policy is also introduced here. We obtained the queue size distributions at a departure epoch and at a random epoch, Laplace Stieltjes Transform of the waiting time distribution and busy period distribution along with some mean performance measures. Finally we discuss some statistical inference related issues.     

现代世界起源的非欧洲中心论阐释

罗伯特.B.马克斯在《现代世界的起源》中从全球的、生态的角度对现代世界的起源进行了非欧洲中心论的阐释。在罗伯特看来,1800年以前,世界的经济中心在亚洲,亚洲与欧洲地位的变化发生于19世纪始自英国的工业革命。英国的工业革命纯粹由于便利的煤炭开采和殖民地,而在其他国家,政府起到了核心作用。走上工业化道路的西方国家把先进的技术应用于武器装备,对中国和非洲等地区进行疯狂掠夺,是这些国家工业资本主义得以顺利发展的重要条件。     

B2C电子商务顾客满意度测评研究

文章在参考已有研究成果的基础上,构建了B2C电子商务顾客满意度测评模型及其评价指标体系,并运用模糊综合评判法对某电子商务公司进行实证测评,最后对测评结果进行分析,并提出相应的对策以提升顾客满意度.     

基于B/S的机房动力和环境监控模拟实验系统

探讨基于B/S结构的网络化模拟实验室的构建,并以机房动力和环境监控系统为实验对象,用网际组态软件W ebAccess实现集数据采集、视频监控、安防消防等综合模拟实验平台的开发。