Modeling cooperation among self-interested agents: a critique

This paper reviews recent attempts to model cooperation in groups of self-interested unrelated individuals. It concludes that no empirically plausible model has been developed, and the economist's quest for an explanation of human prosociality in terms of self-interested agents has not been successful. We show that the equilibrium criteria employed in standard game-theoretic models have no attractive dynamic properties, and the mechanisms deployed in these models are not generally seen in empirical examples of cooperative groups. We also show that these models are not robust to plausible rates of signaling error and mutation. We present an alternative, involving strongly reciprocal agents, that satisfies all the requirements for a dynamically stable model of cooperation.     

Robustness of a Class of Partial Diallel Cross Designs to the Unavailability of a Complete Block of Observations

Complete and partial diallel cross designs are examined as to their construction and robustness against the loss of a block of observations. A simple generalized inverse is found for the information matrix of the line effects, which allows evaluation of expressions for the variances of the line-effect differences with and without the missing block. A-efficiencies, based on average variances of the elementary contrasts of the line-effects, suggest that these designs are fairly robust. The loss of efficiency is generally less than 10%, but it is shown that specific comparisons might suffer a loss of efficiency of as much as 40%.     

传统科技视野下的恐怖主义及其应对

科学技术的发展及其被恶意运用,使当代的恐怖主义活动变得更加复杂多样和令人恐慌.掌握和使用高科技的超级恐怖主义组织的确存在,但对于一般恐怖分子而言,高科技的运用还不大现实.多数情况下,都是传统通用科技引导着普通的恐怖主义活动.恐怖活动与传统通用科技相伴发展的历史事实,表明传统通用科技对恐怖主义与反击恐怖主义双重力量扩张所起的作用,具体体现在武器技术、交通运输和通信技术的应用等方面.科学技术既是恐怖主义盛行的因素,也是恐怖主义的克星,运用高科技手段反击恐怖主义也是我们的必然选择.     

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.     

Person Perception through Gait Information and Target Choice for Sexual Advances: Comparison of likely Targets in Experiments and Real Life

Point-light and full-view short video clips of female walkers were displayed on a CRT monitor and male students rated the likelihood of selecting a walker for various advances. Relationships between the ratings, the walkers’ self-reported frequencies of being approached, gait cues, and self-rated personality traits were examined. In the point-light condition, raters selected slow walkers with a short stride length and personality traits implying vulnerability as targets for inappropriate touching. In the full-view condition, the raters selected fashionably groomed or physically attractive walkers as sexual advance targets. These criteria corresponded partially with reported occurrences of advances. Awkward movement impression was suggested as a kinematic gait quality influencing sexual advance target choice.     

Marginal and association regression models for longitudinal binary data with drop‐outs: A likelihood‐based approach

Longitudinal data often contain missing observations, and it is in general difficult to justify particular missing data mechanisms, whether random or not, that may be hard to distinguish. The authors describe a likelihood‐based approach to estimating both the mean response and association parameters for longitudinal binary data with drop‐outs. They specify marginal and dependence structures as regression models which link the responses to the covariates. They illustrate their approach using a data set from the Waterloo Smoking Prevention Project They also report the results of simulation studies carried out to assess the performance of their technique under various circumstances.     

信息时代下高校图书馆员综合素质的研究

分析了目前高校图书馆员的素质状况，并结合现实从思想、职业道德和专业素质3个方面论述了高校图书馆员应具备的素质以及提高高校图书馆员素质的途径和方法。     

图书馆在加强大学生信息素质教育中作用初探

信息素质是大学生整体素质的重要组成部分,高校图书馆在加强大学生信息素质教育方面拥有很多优势,承担着重要责任,要充分发挥高校图书馆在信息资源提供、信息检索查询、信息网络保障、信息人才支持等方面的独特作用,做好大学生的信息素质教育工作。     

基于互信息的功能磁共振图像配准

互信息作为衡量两幅图像配准的相似性测度函数,当两幅图像配准时,互信息达到最大值。该文提出了基于互信息脑功能磁共振图像配准新方法,采用了无需计算梯度的Powell直接搜索算法,并通过多分辨的方式加快了图像配准速度。磁共振的配准实验证明,互信息法能准确地实现多模态医学图像的配准,并且能达到亚像素的精度。     

Potential exposures and risks from beryllium-containing products.

Beryllium is the strongest of the lightweight metals. Used primarily in military applications prior to the end of the Cold War, beryllium is finding new applications in many commercial products, including computers, telecommunication equipment, and consumer and automotive electronics. The use of beryllium in nondefense consumer applications is of concern because beryllium is toxic. Inhalation of beryllium dust or vapor causes a chronic lung disease in some individuals at concentrations as low as 0.01 microg/m3 in air. As beryllium enters wider commerce, it is prudent to ask what risks this might present to the general public and to workers downstream of the beryllium materials industry. We address this question by evaluating the potential for beryllium exposure from the manufacturing, use, recycle, and disposal of beryllium-containing products. Combining a market study with a qualitative exposure analysis, we determine which beryllium applications and life cycle phases have the largest exposure potential. Our analysis suggests that use and maintenance of the most common types of beryllium-containing products do not result in any obvious exposures of concern, and that maintenance activities result in greater exposures than product use. Product disposal has potential to present significant individual risks, but uncertainties concerning current and future routes of product disposal make it difficult to be definitive. Overall, additional exposure and dose-response data are needed to evaluate both the health significance of many exposure scenarios, and the adequacy of existing regulations to protect workers and the public. Although public exposures to beryllium and public awareness and concern regarding beryllium risks are currently low, beryllium risks have psychometric qualities that may lead to rapidly heightened public concern.