动物中microRNA及其生物发生相关蛋白的研究

microRNA(简称miRNA)是一类长度为21~25nt内源性的非编码小RNA。研究发现,miRNA广泛参与生命过程中一系列重要的进程,在控制细胞分化、生长发育以及肿瘤发生等过程中都起着重要的作用。miRNA的产生及功能行使的过程中,需要多种蛋白或者蛋白复合体的参与。本文对动物中miRNA及其生物发生相关蛋白研究进展进行了综述。     

浅析H.264标准中的CAVLC编码

本文是在阅读了讲解H.264/AVC中熵编码相关内容的书籍后的感想,主要介绍了熵编码的基本原理,H.264/AVC中熵编码的方法,重点介绍了基于上下文自适应的可变长编码(CAVLC),并将它和基于上下文二进制算术编码(CABAC)进行了比较。     

自适应Huffman编码算法分析及研究

Huffman编码作为一种高效而简单的可变长编码常用于信源编码。但现有的Huffman编码算法存在效率不高,同时应用受到一些限制,因此,提出一种自适应Huffman编码算法,该算法与其他的Huffman编码相比效率更高,应用范围更广。     

生物所在植物信使RNA监控系统研究中取得新进展

<正>近日,中国农业科学院生物技术研究所植物分子生物学研究室与沙特国王科技大学科研人员合作,在植物信使RNA(mRNA)监控系统研究中取得新进展。该研究成果于2月17日在线发表在国际植物学著名刊物《植物细胞(The Plant Cell)》上。无义介导的mRNA降解(nonsensemediated mRNA decay,NMD)是真核细胞中重要mRNA监控机制,识别     

基于扎根理论的猎头顾问胜任特征模型构建

近年来猎头行业在中国迅速发展,猎头顾问作为猎头公司的核心资源,其胜任特征的研究越来越受到各组织的关注。扎根理论研究方法是一种科学有效的定性研究方法,采用开放性编码、关联性编码和选择性编码析出猎头顾问的胜任特征,建立猎头顾问胜任特征模型,包括两个维度:个人素质和专业技能,对猎头顾问的选拔和任用具有一定的指导作用。     

产业集群下的区域旅游合作开发模式研究

区域旅游合作是化解旅游客体(旅游资源)的不可移动性与旅游主体(游客)的选择性之间的矛盾的关键,也是实现旅游业可持续发展的必由之路。文章指出,以产业集群模式进行合作,力图打造武陵山区旅游产业集群品牌,提升区域竞争力是武陵山区旅游业发展的客观要求。     

中国农科院创新团队发现副猪嗜血杆菌氟苯尼考耐药株

<正>近日,中国农业科学院上海兽医研究所猪呼吸综合症研究团队首次发现副猪嗜血杆菌氟苯尼考耐药株,并阐明外排泵基因floR(细菌编码一种像排水泵一样的可以主动将抗生素药物排出菌体外致使药物疗效降低或治疗失败的耐药基因)是介导该耐药表型的分子机制。相关研究成果发表在该领域国际顶级杂志《抗菌化疗法杂志(Journal of     

基于JPEG2000的感兴趣区域编码方法研究

JPEG2000是由联合图像专家组为静态图像编码所制定的一个新的国际标准,通过感兴趣区域编码算法实现JPEG2000编码的高压缩率。本文通过对JPEG2000标准的ROI编码的两种位移编码算法分析和对比,引出一种新的ROI编码方法-GPBShift,并介绍了其编码原理及性能。     

赤拟谷盗基因组中microRNA的生物信息学预测与进化分析

本文通过计算机编程技术以及预测miRNA的RNAfold和Triplet-SVM软件在赤拟谷盗基因组中预测了43个miRNA。进一步对预测的miRNA进行长度统计以及保守性分析。     

收入准则解释——分摊交易价格(二)

三、分摊可变对价 企业与客户签订的合同中的交易价格如为可变的,企业应根据合同的具体条款、相关事实和情况估计其预期收取的对价金额.企业在分摊交易价格时,应考虑该可变对价是与整个合同相关,还是仅与合同中某一特定组成部分相关.     

Determinants of variable pay for top managers of foreign subsidiaries in Finland

There is a large body of research dealing with top management compensation from an agency theory perspective. Difficulties in monitoring top management (the agent) are exacerbated in the multinational corporation, where there are significant information asymmetries between headquarters and foreign subsidiaries. Headquarters may use variable pay for subsidiary top managers to reduce the agency problems. By studying 110 foreign-owned subsidiaries located in Finland, this paper attempts to identify determinants of variable pay to the subsidiary general manager. In line with agency theory, the results suggest that the roles played by the subsidiary influence the compensation strategy used for the subsidiary general manager. However, while agency theory predicts that the cultural distance beween the home country of the multinational corporation and the location of the foreign subsidiary would have an effect on the compensation system, no such effect was found. Instead, in accordance with the institutionalization perspective, we found a significant 'nationality effect' on the use of variable pay.     

Discovering Statistically Significant Periodic Gene Expression

One frequent application of microarray experiments is in the study of monitoring gene activities in a cell during cell cycle or cell division. High throughput gene expression time series data are produced from such microarray experiments. A new computational and statistical challenge for analyzing such gene expression time course data, resulting from cell cycle microarray experiments, is to discover genes that are statistically significantly periodically expressed during the cell cycle. Such a challenge occurs due to the large number of genes that are simultaneously measured, a moderate to small number of measurements per gene taken at different time points and high levels of non-normal random noises inherited in the data. Computational and statistical approaches to discovery and validation of periodic patterns of gene expression are, however, very limited. A good method of analysis should be able to search for significant periodic genes with a controlled family-wise error (FWE) rate or controlled false discovery rate (FDR) and any other variations of FDR, when all gene expression profiles are compared simultaneously. In this review paper, a brief summary of currently used methods in searching for periodic genes will be given. In particular, two methods will be surveyed in details. The first one is a novel statistical inference approach, the C & G Procedure that can be used to effectively detect statistically significantly periodically expressed genes when the gene expression is measured on evenly spaced time points. The second one is the Lomb–Scargle periodogram analysis, which can be used to discover periodic genes when the gene profiles are not measured on evenly spaced time points or when there are missing values in the profiles. The ultimate goal of this review paper is to give an expository of the two surveyed methods to researchers in related fields.     

A Multiregional Impact Assessment Model for disaster analysis

This paper presents a recursive dynamic multiregional supply-use model, combining linear programming and input–output (I–O) modeling to assess the economy-wide consequences of a natural disaster on a pan-European scale. It is a supply-use model which considers production technologies and allows for supply side constraints. The model has been illustrated for three floods in Rotterdam, The Netherlands. Results show that most of the neighboring regions gain from the flood due to increased demand for reconstruction and production capacity constraints in the affected region. Regions located further away or neighboring regions without a direct export link to the affected region mostly suffered small losses. These losses are due to the costs of increased inefficiencies in the production process that have to be paid for by all (indirectly) consuming regions. In the end, the floods cause regionally differentiated welfare effects.     

THE RELATIVE IMPORTANCE OF EXPORTS IN DETERMINING LEVELS OF REGIONAL OUTPUT AND INCOME: A Model and Empirical Evidence from Kenya

Exports have long been assumed by many to be the most important variable in driving regional growth, although factors such as government expenditure, investment demand, and remittances, among others, have also been recognized as significant. In addition, supply-side constraints to the promotion of regional growth and development have recently received increased attention in the literature. This paper evaluates the relative importance of exports, investment demand, and remittances, as well as supply-constrained agricultural production, in determining levels of regional output, value added, and household income in a single region in Kenya. The analysis is based on a mixed endogenous/ exogenous model derived from a social accounting matrix (SAM) which allows for incorporation of both demand and supply-side considerations. The paper finds that exports are, in fact, the most important factor in explaining regional output and wage income in the region studied, although not overwhelmingly so. In addition, the analysis demonstrates the importance of supply-constrained agricultural production as a determinant of income at the household level.     

Application of the Yale Technology Concordance to the Construction of International Spillover Variables for India

Although there is increased interest in the role of international technology spillovers, empirical studies have been hampered by a host of measurement problems. This paper reviews recent attempts to address two of these problems. First, there are differing degrees of transferability of technology from one region to another. Second, both embodied and disembodied technology are transferred, and these different modes of transfer have distinct implications for both behavior and policy. To deal with the first measurement problem, the Yale Technology Concordance (YTC)—a matrix that maps patents into industries of manufacture and sectors of use—was used to construct indices of relevance of foreign technology to India. To deal with the second measurement problem, the YTC was again used to construct pools of embodied and disembodied international technology. After describing the variable construction, the paper highlights the performance of these variables in equations that predict Indian firms' R&D, technology purchases and output.     

Estimating the economic impacts of public spending in a sub-region: an econometric approach.

Expenditures on a public institution represent not only a cost to the taxpayer but an economic benefit to the region in which it is located. The economic impact on a region's income is here calculated through an econometric model and associated multipliers. The impact on government income tax recepits is similarly calculated. The tax revenues are also used in determining the net cost of operation of the institution. These calculations are performed for the expenditures associated with the new State University Hospital at Stony Brook, N.Y. located in the region formed by Nassau and Suffolk Countries. The regional income multiplier is found to be 1.64.     

External labor market strategy and career success: CEO careers in Europe and the United States

In this paper, we examine the career histories of the chief executive officers (CEOs) affiliated with the 500 largest organizations in Europe and the 500 largest in the United States. Our purpose is to determine whether frequent career moves across employers, a phenomenon we label an “external labor market strategy,” brings greater career rewards than moves inside the same organization. The results reveal that an external labor market strategy is negatively related to career success. On both continents, CEOs who have spent a smaller fraction of their career in their current organization or have changed employers more often have taken a longer time from the start of their career to be promoted to the most influential corporate positions. The labor market institutions in the 22 countries sampled do not influence the relationship between an external labor market strategy and career success, while the specific geographic region in which the employers are located has a limited impact on this relationship. © 2009 Wiley Periodicals, Inc.     

Nonlinear pricing in spatial oligopoly

A model of duopoly competition in nonlinear pricing when firms are imperfectly informed about consumer locations is analyzed. A continuum of consumers purchase a variable amount of a product from one of two firms located at the endpoints of the market. At the Nash equilibrium in quantity-outlay schedules, consumers buy the same quantities as they would from the same firm if it were a monopolist facing the same informational asymmetries, but they receive greater surplus. Hence, no efficiency gains result from competition. If consumers have the option to reveal their locations and have the firms deliver the goods, all consumers choose to reveal their locations in equilibrium. Thus, the inefficiencies from information asymmetries may not arise because firms can deliver the good to consumers. In contrast, with a monopoly seller, consumers have no incentives to reveal their locations.     

糖脂消对胰岛素抵抗高血压大鼠基因表达谱的影响

目的:利用基因芯片技术探讨糖脂消对胰岛素抵抗高血压大鼠基因表达谱的变化,研究糖脂消治疗胰岛素抵抗高血压的作用机制。方法:用高果糖饲料诱发SD大鼠胰岛素抵抗模型,给予糖脂消口服后,用基因芯片分别检测高果糖组、治疗组,计算机软件分析后,观察基因表达的变化。结果:治疗组表达差异的基因有95条,新基因有23条,已知基因34条。结论:糖脂消可以改变其基因表达谱,为进一步探讨糖脂消治疗作用创造了条件。