The potential of integrated modelling in conservation biology: A case study of the black‐footed albatross (Phoebastria nigripes)

Conservation biology aims at assessing the status of a population, based on information which is often incomplete. Integrated population modelling based on state‐space models appears to be a powerful and relevant way of combining into a single likelihood several types of information such as capture‐recapture data and population surveys. In this paper, the authors describe the principles of integrated population modelling and they evaluate its performance for conservation biology based on a case study, that of the black‐footed albatross, a northern Pacific albatross species suspected to be impacted by longline fishing     

英语写作中有效反馈信息的探讨

文章简要阐述了反馈信息,论述了作文工作研究的意义及在作文写作中有效的信息反馈形式,提出了增强写作能力的可行措施。     

提高网络环境下的检索效率

围绕查全率、查准率这两个重要指标对网络环境下影响检索效率的因素进行了分析,提出提高网络环境下检索效率的一些方法,以便更好地服务于用户.     

批发、零售行业的宏观营销效率研究

我国批发、零售行业宏观营销效率与发达国家相比还有很大的差距。造成这种差距既有经济方面的原因,又由非经济方面的因素。提高我国批发、零售行业宏观营销效率,政府、行业协会、企业三方必须采取相应的对策和方法。     

Parent‐Adolescent Communication About Sex: Retrospective Reports by Latino College Students

Latina female (n= 97) and Latino male (n= 69) college students (M age = 21.4 years) completed self‐report surveys regarding family of origin experiences, including sexual communication with parents while growing up. Latino parents of this comparatively highly educated sample tended to use direct rather than indirect strategies for communicating about sexuality with their children. Young women reported higher levels of sexual communication with mothers while growing up than did young men, and respondents reported less communication with fathers than mothers. Among young women, sexual communication with mother was positively associated with non‐Mexican origin and negatively associated with having older brothers living at home. In contrast, maternal education was positively associated with mother‐son communication about sex. Paternal education and the absence of older brothers positively predicted communication with both sons and daughters. The analyses provide novel information regarding sexual communication in Latino families and suggest directions for future research.     

Choice of the primary analysis in longitudinal clinical trials

Missing data, and the bias they can cause, are an almost ever‐present concern in clinical trials. The last observation carried forward (LOCF) approach has been frequently utilized to handle missing data in clinical trials, and is often specified in conjunction with analysis of variance (LOCF ANOVA) for the primary analysis. Considerable advances in statistical methodology, and in our ability to implement these methods, have been made in recent years. Likelihood‐based, mixed‐effects model approaches implemented under the missing at random (MAR) framework are now easy to implement, and are commonly used to analyse clinical trial data. Furthermore, such approaches are more robust to the biases from missing data, and provide better control of Type I and Type II errors than LOCF ANOVA. Empirical research and analytic proof have demonstrated that the behaviour of LOCF is uncertain, and in many situations it has not been conservative. Using LOCF as a composite measure of safety, tolerability and efficacy can lead to erroneous conclusions regarding the effectiveness of a drug. This approach also violates the fundamental basis of statistics as it involves testing an outcome that is not a physical parameter of the population, but rather a quantity that can be influenced by investigator behaviour, trial design, etc. Practice should shift away from using LOCF ANOVA as the primary analysis and focus on likelihood‐based, mixed‐effects model approaches developed under the MAR framework, with missing not at random methods used to assess robustness of the primary analysis. Copyright © 2004 John Wiley & Sons, Ltd.     

武汉制造业人力资本利用效率低下的原因

人力资本对经济增长或发展的实际作用，不仅取决于其存量的高低，还取决于其实际利用效率的大小。而人力资源利用效率低下是我国当前人力资本发展的突出矛盾和问题。以武汉制造业为对象，分析了导致其人力资本利用效率低下的两大关键因素：产权制度缺陷和人力资本投资与配置不当。     

对欠发达地区农村信用社运行效率的分析

农村信用社改革及其运行效率是当前中国金融界的一个重要课题,农村信用社运行效率的高低依赖于改革的主导力量及其模式的具体选择。中国农村信用社已经历了多次在政府主导下进行的反反复复的体制性变迁,产权制度及治理结构问题未能得到有效解决,其运行效率较低。结合在江西若干县(区)的调查,对欠发达地区农村信用社运行效率进行了分析,并提出了提升农村信用社运行效率的对策建议。     

对“资本限量决策”方法的改进

企业面临的一类投资决策是所谓的资本限量决策,文献1给出两种解法:获利指数法和净现值法。究其实质,净现值法是一种枚举法或互斥化法,该方法可以获得最优解,但当项目个数较多时,互斥化的组合方案数很大,难以实用;计算加权获利指数工作量又很大。本文提出用差量效率指标排序法予以改进。     

史料引用致误原因分析

史料是史学研究的基础.但自古以来,由于种种原因,错误的或者事实模糊不清的史料很多,如果不作必要的考证鉴别,很难获得科学的研究成果.造成史料引用致误的原因是多方面的,归结起来主要有:(1)史料本身无误,由于没有正确理解原意或者标点不正确而致误;(2)史料本身无误,由于引用者推断不确而致误;(3)史料内容比较含蓄,由于引用者缺乏深入辨析而致误;(4)没有直接引用原书而致误;(5)因版本不善而造成史料的错误或脱漏;(6)史料本身就有错误.