A Hybrid Geometric Phase II/III Clinical Trial Design based on Treatment Failure Time and Toxicity

The problem of comparing several experimental treatments to a standard arises frequently in medical research. Various multi-stage randomized phase II/III designs have been proposed that select one or more promising experimental treatments and compare them to the standard while controlling overall Type I and Type II error rates. This paper addresses phase II/III settings where the joint goals are to increase the average time to treatment failure and control the probability of toxicity while accounting for patient heterogeneity. We are motivated by the desire to construct a feasible design for a trial of four chemotherapy combinations for treating a family of rare pediatric brain tumors. We present a hybrid two-stage design based on two-dimensional treatment effect parameters. A targeted parameter set is constructed from elicited parameter pairs considered to be equally desirable. Bayesian regression models for failure time and the probability of toxicity as functions of treatment and prognostic covariates are used to define two-dimensional covariate-adjusted treatment effect parameter sets. Decisions at each stage of the trial are based on the ratio of posterior probabilities of the alternative and null covariate-adjusted parameter sets. Design parameters are chosen to minimize expected sample size subject to frequentist error constraints. The design is illustrated by application to the brain tumor trial.     

成员企业权力结构对联盟中控制权不对称分布影响的研究

以我国电器制造企业间联盟为样本,考察了成员企业权力结构对联盟控制权不对称分布的影响.结果表明,成员企业的权力结构各因素显著影响着联盟控制权的不对称分布:内部联合权力水平会弱化这种不对称,而其冲突水平则会强化这一不对称;外部联合权力水平会显著强化这种不对称,内外部联合权力间的冲突水平也会强化这种不对称.同时,成员企业的权力结构相似性与联盟中控制权分布的不对称之间存在负相关关系,但这种关系并非线性关系,仅在成员权力结构具有高度相似性时,才会倾向于降低联盟控制权分布的不对称.     

Just for fun? Alcohol and drugs in youth lifestyles: a survey

The article presents an analysis of the relationship between young people and alcohol and drug use, examining both their attitudes and behaviors. The analysis is based on statistics collected through a structured-questionnaire survey of 1071 students from the secondary schools of Rome and the Province. The first part of the article examines patterns and levels of alcohol and drug use and typical places of use. The central part is dedicated to the perceptions and opinions on alcohol and drugs, with particular regard to the dimensions of risk and sociality, and to the different roles of school and family in raising risk awareness. Sociality appears as a crucial element in young people's tendency to associate alcohol and drugs with an effect of relaxation and disinhibition that makes social relations easier. The article finally examines the relationship between young people and social norms, identifying transgressive models and habits. On the whole, the study highlights a connection between alcohol and drug use and desire of sociality, which is experienced more as a situational and ever-changing practice than as a search for close friendships.     

Ask and you shall receive: Social network contacts’ provision of help during the job search

Social network contacts—the people who are asked to help with others’ job searches—are key players in the job networking process. Before job seekers can become employed with the help social networks, contacts must first be able and willing to share the social resources job seekers need for their search. Little is known about the factors that affect contacts’ ability and willingness to do this. Analyses of a unique dataset of contacts show that they typically have access to resources and help job seekers by sharing them. Still, contacts are better able to help when they are male, employed, and better educated than job seekers. They are more willing to help when they perceive job seekers to be “good” workers. In identifying the conditions in which contacts provide social resources, this study illustrates how social networks are a productive job search strategy for some, but not all, job seekers.     

Motivations for self-assembling into project teams

This study investigates the self-assembly mechanisms of ad hoc project teams using a bipartite network perspective. Individuals and projects are modeled as two types of nodes and team membership as relations between them. This approach enables us to investigate factors that impact voluntary team assembly at the individual, dyadic, and team levels simultaneously. Using Exponential Random Graph Models (ERGM/p*), we study players’ combat teams in a Massively Multiplayer Online Role-Playing Game (MMORPG) as a case of self-assembled project teams. Empirical results show that individuals are motivated to join ad hoc teams to complete difficult projects but not projects with long durations. We also found that individuals tend to collaborate with specific teammates who have complementary skills, those who have similar age or skill level, and those who are affiliated with the same organizational entity.     

Physical Activity,Exercise, and Sedentary Behavior in College Students

Abstract

Objective: This article examines students’ perceptions of individual and institutional responsibility for sexual health so that institutions can better provide for the needs of their students to increase academic success and healthy relationship outcomes. Participants: Students from 2- and 4-year colleges in 1 state (N = 78). Methods: From May through November 2010, the authors used go-along interviews to examine students’ perceptions of resources for sexual health on their campuses. Results: Participants believed that it is the college's responsibility to provide resources and the responsibility of students to access resources. Participants at 2-year schools wanted referrals to resources, whereas participants at 4-year schools expected resources to be available and emphasized the importance of a supportive community. Conclusions: Students at 2- and 4-year colleges have different expectations of their institutions; by making resources and referrals for sexual health available, colleges can better serve their students, which will result in improved health outcomes.     

THE POPULAR IN THE POLITICAL SYSTEM

This paper suggests a systems theoretical re-reading of popular communication and the Popular in the political system. Luhmann' anti-humanist notion of communication helps to reframe the discussion of the Popular: it is not defined by an en- or decoding instance, but by a particular mode of ‘connectivity'. Drawing from heterogeneous material (Mars Attacks!, crowd psychology, theory of democracy), it is argued that the problem of the Popular arises when a functional system has to represent something that transgresses the system' universality. That which the system has to exclude to become a system re-emerges as ‘grotesque hybrid’, thus pointing at a universality that is, on the one hand, an opportunity for a further universalization and, on the other, a threat to the very universality of the system. The ‘Popular’ thus acquires a hybrid position by articulating these two dimensions.     

Migration and Aging

Abstract

This paper is based on a study in Zimbabwe of older people over age 60 living in Harare, Mutare, and villages up to 50 km from these two cities. The major areas studied were the types of migrants, preferred residence, and their overall life satisfaction. Interviews were carried out by unemployed school dropouts from the two cities, especially trained for the job. The results showed that the rural-urban migrants constituted the largest group, while returnee migrants were the smallest. Among the respondents were also foreign, rural-rural, and non-migrants. There were significant differences by location and gender. Three-quarters of the respondents preferred to live in a village than in a city. Returnee migrants were consistently the most satisfied, and those who had not migrated, the least. Policy implications are discussed.     

Pulping the Black Atlantic: Chester Himes’ A Case of Rape and the Limits of Expatriation

Abstract

This article examines the early expatriate career of Chester Himes, and his overlooked Paris-set novella A Case of Rape (1956). Scholars have identified postwar Paris as the locus of a ‘Black Atlantic’ cosmopolitanism that allowed African American writers to transcend American racial and literary regimes, and in particular the stigma of black ‘protest’ fiction. By contrast, this article argues that Himes’ exile was paradoxical; defined by an exchange, rather than an ‘exceeding’ of American racial and literary stigmas. First, I explore the fetishistic racial politics that energized the Left Bank’s construction of black expatriates as symbols of individualist, masculine, and specifically western transgression. Second, I examine the way in which A Case of Rape, and its narrative of the false conviction of four African American expatriates for rape, dramatizes this paradox. With supreme irony, the novella sees the expatriate celebrity merge with a central symbol of the African American ‘protest’ novel: the black male rapist of white women. Finally, I argue that A Case of Rape is of particular importance for the ways in which it anticipates Himes’ move into pulp fiction. Like his later detective series, A Case of Rape captures Himes’ own disillusionment with conventional notions of authorial autonomy, and literary instrumentality. I conclude that expatriation worked to galvanize, rather than displace, Himes’ interest in the overdetermination of African American literature within dominant western racial discourses.     

桌面式PPCNC在《CAD/CAM》教学实践中的应用

随着数字化技术的迅速发展及其与制造业的紧密融合,CAD/CAM技术已成为机械工程师不可或缺的一项专业技能。很多工科院校已将《CAD/CAM》课程纳入本科教学的专业主干课群中。在课堂教学中引入桌面式PPCNC,实时展示数控加工过程,并建设开放式CAD/CAM技术平台和组建CAD/CAM技术实践小组,对凸显CAD/CAM技术的实践性、适应应用型人才的培养目标、提升课程教学质量、调动学生积极性、激发学生的自主能动性都是有益的探索和尝试。