Bayesian analysis of directed graphs data with applications to social networks

Summary.  A fully Bayesian analysis of directed graphs, with particular emphasis on applica- tions in social networks, is explored. The model is capable of incorporating the effects of covariates, within and between block ties and multiple responses. Inference is straightforward by using software that is based on Markov chain Monte Carlo methods. Examples are provided which highlight the variety of data sets that can be entertained and the ease with which they can be analysed.     

当代中东伊斯兰激进组织的暴力行为研究

中东伊斯兰激进组织行动无论与"基地"是否有关,也无论具体的行动是否由本·拉登策划和指挥,绝大部分都打着"本·拉登"的旗号,对外宣称是"基地"组织的一部分.它们选择各种暴力方式,将主要目标指向以美国为首的西方大国、以色列和中东地区的亲美世俗政府,通过威胁性的政治报复性爆炸、恐吓性的经济破坏性屠杀和胁迫性谈判的劫机绑架等途径,追求轰动效应和恐怖后果,从而满足某种政治诉求.     

Stripping in the New Millennium: Thinking about Trends in Exotic Dance and Dancers' Lives

With the increasing presence of sex and sexuality in American popular culture, the stripping industry is undoubtedly undergoing important subcultural and organizational transition. What are the implications of these changes for the individuals involved? The current paper reviews much of the literature on exotic dance to consider the potential transformations in the organization of the sex industry and how these changes may impact the lives of those involved. Specifically, I note some key differences in the literature that suggest how exotic dance has shifted. I then pose some questions for empirical inquiry. I argue that transformations in the exotic industry are creating new opportunities and challenges for women, and may be particularly deleterious for poor and minority women. I call for sociologists to investigate the consequences of organizational transferal in sexual labor, reevaluate the dynamics of agency and exploitation, and consider the potential differential impact of these trends on poor women and women of color.     

盆景风格因子初探

盆景艺术风格是盆景艺术家的创作个性在作品中的外在表现 ,它对盆景艺术的发展起着很重要的作用 ,人们对盆景的感性认识直接来源于盆景的风格。大部分盆景方面的书和文章都会涉及到盆景艺术风格的问题 ,但是 ,迄今为止对盆景艺术风格的形成和发展进行过系统研究的人还不是很多。基于对艺术发展规律和中国各种艺术风格盆景发展历史的研究 ,该文详细论述了影响盆景艺术风格形成和发展的内在、外在因素及它们之间的关系 ,并对怎样给我国盆景艺术注入新的活力提出了一些建议 ,对我国盆景艺术的发展和创新起到一定的指导作用     

畜产品质量安全监管研究综述

随着经济的发展和社会的进步，畜产品在人们的日常生活中占有越来越重要的地位，目前我国对畜产品质量安全的监管还很不到位。文章总结了我国畜产品安全监管的现状，并介绍了国外畜产品安全监管的现状，通过比较找出我国监管的不足，从而进一步加强我国对畜产品质量安全的监管。     

Sampling Returns for Realized Variance Calculations: Tick Time or Transaction Time?

This article introduces a new model for transaction prices in the presence of market microstructure noise in order to study the properties of the price process on two different time scales, namely, transaction time where prices are sampled with every transaction and tick time where prices are sampled with every price change. Both sampling schemes have been used in the literature on realized variance, but a formal investigation into their properties has been lacking. Our empirical and theoretical results indicate that the return dynamics in transaction time are very different from those in tick time and the choice of sampling scheme can therefore have an important impact on the properties of realized variance. For RV we find that tick time sampling is superior to transaction time sampling in terms of mean-squared-error, especially when the level of noise, number of ticks, or the arrival frequency of efficient price moves is low. Importantly, we show that while the microstructure noise may appear close to IID in transaction time, in tick time it is highly dependent. As a result, bias correction procedures that rely on the noise being independent, can fail in tick time and are better implemented in transaction time.     

The Impact of Taking Parental Leave on Fathers’ Participation In Childcare And Relationships With Children: Lessons from Sweden

In Sweden, government-mandated paid parental leave has been available to both mothers and fathers since 1974. By 2006, each parent had two non-transferable leave months and nine additional months to share. From the beginning, parental leave was presented as a policy designed to promote gender equality, with women and men having equal opportunities and responsibilities to contribute economically to the family and care for children. Sweden thus provides a unique setting to explore whether social policy can be an important instrument for changing the gender contract. Analysing survey data from 356 fathers working in large private companies, we found that the amount of parental leave days taken had positive effects on several aspects of fathers’ participation in childcare and on their satisfaction with contact with children, controlling for other factors contributing to fathers’ participation in childcare. Our findings suggest that the full potential of Sweden's parental leave policy for degendering the division of labour for childcare will not likely be met until fathers are strongly encouraged by social policy to take a more equal portion of parental leave.     

Optimal sampling for repeated binary measurements

The authors consider the optimal design of sampling schedules for binary sequence data. They propose an approach which allows a variety of goals to be reflected in the utility function by including deterministic sampling cost, a term related to prediction, and if relevant, a term related to learning about a treatment effect To this end, they use a nonparametric probability model relying on a minimal number of assumptions. They show how their assumption of partial exchangeability for the binary sequence of data allows the sampling distribution to be written as a mixture of homogeneous Markov chains of order k. The implementation follows the approach of Quintana & Müller (2004), which uses a Dirichlet process prior for the mixture.     

Classifying At‐Risk High School Youth: The Influence of Exposure to Community Violence and Protective Factors on Academic and Health Outcomes

Using cluster analysis, 789 predominately Latino and African American high school youth were classified into varying academic at‐risk profiles using self‐reported levels of academic confidence, motivation to attend school, perceived family support, connections with teachers and peers, and exposure to violence. Six clusters emerged, 5 of which were identified as “at‐risk.” The clusters were examined in relation to academic stress, health status, grades, and school retention. Exposure to violence was one distinguishing feature of youth identified as most vulnerable, vulnerable, and resilient; however, youth identified as resilient recorded better academic outcomes.