There have been many advances in statistical methodology for the analysis of recurrent event data in recent years. Multiplicative semiparametric rate-based models are widely used in clinical trials, as are more general partially conditional rate-based models involving event-based stratification. The partially conditional model provides protection against extra-Poisson variation as well as event-dependent censoring, but conditioning on outcomes post-randomization can induce confounding and compromise causal inference. The purpose of this article is to examine the consequences of model misspecification in semiparametric marginal and partially conditional rate-based analysis through omission of prognostic variables. We do so using estimating function theory and empirical studies.
Assessment of analytical similarity of tier 1 quality attributes is based on a set of hypotheses that tests the mean difference of reference and test products against a margin adjusted for standard deviation of the reference product. Thus, proper assessment of the biosimilarity hypothesis requires statistical tests that account for the uncertainty associated with the estimations of the mean differences and the standard deviation of the reference product. Recently, a linear reformulation of the biosimilarity hypothesis has been proposed, which facilitates development and implementation of statistical tests. These statistical tests account for the uncertainty in the estimation process of all the unknown parameters. In this paper, we survey methods for constructing confidence intervals for testing the linearized reformulation of the biosimilarity hypothesis and also compare the performance of the methods. We discuss test procedures using confidence intervals to make possible comparison among recently developed methods as well as other previously developed methods that have not been applied for demonstrating analytical similarity. A computer simulation study was conducted to compare the performance of the methods based on the ability to maintain the test size and power, as well as computational complexity. We demonstrate the methods using two example applications. At the end, we make recommendations concerning the use of the methods. 相似文献
Discrimination reduces the matching probability and output in the skill‐intensive differentiated‐product sector so that discrimination‐induced comparative advantage may overshadow technological comparative advantage in determining the pattern of trade. Trade liberalization generates a decrease in the skilled‐worker wage gap in the country that is an exporter of goods from the simple sector but increases it in the country that is a net exporter of differentiated products. Trade liberalization has an opposite effect on firms. In the country that is an exporter of simple goods, trade liberalization reduces the profits of the nondiscriminatory firms by more than those of the discriminatory firms. (JEL F16, F66, J71) 相似文献
Viral videos offer contemporary activists a nimble, provocative tool with which to disseminate humanitarian messages. This article historicizes anti-trafficking video media that imagine a new potential with which to alter behavioral norms around cocoa and chocolate. The article engages theories and approaches to historical and contemporary modalities of naming and shaming, spanning three centuries to the present day. Videos are examined for style, format, and content, with the view to describing a ‘blood chocolate’ visual and textual metonymy. Recurring themes include transnational power, corporate responsibility, and the horrific scale of exploitation. But viral videos also appear deeply influenced by neoliberal economics that celebrate lawful enterprise and promote consumer-driven solutions to exploitative child labor. 相似文献
Intercollegiate athletics represent an industry prone to challenges of work addiction and life balance. Work addiction and life balance domains in male and female intercollegiate athletic coaches and administrators (N = 245) were examined using multiple regression analysis. Higher levels of stress/anxiety, sleep disturbance, and career satisfaction and lower levels of quality of relationships and friendships were the strongest predictors of work addiction. Counseling focused on reducing the negative aspects of work addiction, while maintaining job performance, may benefit this population. 相似文献
This paper examines the construction of prisoners’ identity through rap in England’s high security prisons. While hip hop studies has often addressed rap’s connection to the social practices of criminalized youths, prison rap cultures have received scant attention. This paper draws on a series of rap workshops and interviews with prisoners to investigate the experiences of black prisoners in high security prisons and how identities are produced and negotiated through rap. Rap is associated with the production of a range of identities and identifications, enabling prisoners to accommodate themselves to the conditions of their incarceration and to challenge aspects of the criminal justice system that they experience as unfair or illegitimate. 相似文献
The increasing prevalence of obesity in sub-Saharan African women is not well understood, and black South African women in the region are particularly vulnerable. This study aimed to examine whether the relationship of socioeconomic status (SES) with changes in body mass index (BMI) and waist circumference (WC) is mediated by physical activity in ageing African women.
Methods
In a longitudinal analysis of the 518 caregivers associated with the Birth to Twenty Plus study, the role of SES associated with 10-year changes in BMI and WC was tested using structural equation modelling (SEM). The degree of mediation of moderate-vigorous physical activity (MVPA) and sitting time in this association was also assessed.
Results
The prevalence of obesity increased significantly from baseline to follow-up (p?<?0.0001). In the SEM models, baseline SES had a direct positive effect on changes in BMI (β, 95% CI, 0.02 (0.005 to 0.04), and a direct negative effect on changes in MVPA (β, 95% CI, ??3.81 (??6.92 to ??0.70). Baseline MVPA had a direct negative effect (β, 95% CI, ??0.002 (??0.003 to ??0.0003) and indirect positive effect via change in MVPA (β, 95% CI, 0.01 (0.0001 to 0.001) on change in WC.
Conclusions
Our study demonstrates the role and interaction of sociodemographic and behavioural predictors of obesity, and suggests a multifaceted approach to management of the crisis in communities of ageing urban African women.
Globally, social enterprise is used increasingly by nonprofit organizations to create new funding streams in the face of dwindling public funds. In light of evidence that institutions of higher education are making similar adaptations, this study explores the extent to which academic centers in US schools of social work are using social enterprise strategies to fund mission efforts. Interviews with the directors of 16 social work research centers in 14 states reveal incentives and barriers that exist at multiple levels and considerably impact the potential viability of social enterprise in the social work academic setting. Implications for institutions of higher education and social work scholars are discussed. 相似文献
In recent years, nonprofit scholars have increasingly studied the phenomenon of social enterprises which has become a generic term describing a wider reorientation among third sector organizations. The emergence of social enterprises has also led to a dynamic of hybridization and broadening in the cooperative sector, similar to an earlier dynamic of “economization”, but this time on the other end of the organizational spectrum. This paper aims at developing a fine-grained conceptual understanding of how this organizational dynamic is shaped in terms of member coordination, thus contributing to a more comprehensive theoretical understanding of different organizational forms of cooperatives. Specifically, to highlight the difference to traditional member-focused cooperatives, the paper introduces the term third-party-focused cooperatives for those social enterprises which emphasize economic goals as well as control and ownership by a particular community (typically place-based). The key result of the paper is that with the shift from member- to community-focus in cooperatives, the main coordination mechanism becomes one of norm-based trust on the basis of generalized reciprocity. In contrast to traditional maxim-based trust member coordination on the basis of relation-specific reciprocity, this enables third-party-focused cooperatives to mobilize bridging and linking social capital, facilitating collective action aimed towards the community interest. The findings suggest that this identity shift requires a mutual re-positioning between the cooperative and the nonprofit sector, in terms of umbrellas as well as regulatory and legislative bodies. 相似文献
In both adolescents and adults, gambling problems and depressive symptoms co-occur and share some common risk factors (e.g., impulsivity and socio-family risk). However, little is known about (1) the developmental course of the co-morbidity of these problems; (2) variables that may moderate the effect of these common risk factors on gambling problems and depressive symptoms. Of specific interest could be individuals’ social relationships with significant others such as parents and friends, because research shows that they moderate the effect of other risk factors on gambling problems and depressive symptoms. The goals of this study were to: (a) identify developmental pathways for gambling problems and depressive symptoms, with a focus on co-morbidity; (b) assess the moderating effect of relationship quality with parents and friends on the link between common risk factors and the trajectories of gambling problems and depressive symptoms. Study participants were 878 males. Predictors were assessed during childhood and adolescence and gambling problems and depressive symptoms were assessed in late adolescence and young adulthood. Latent class analysis revealed four distinct joint trajectories of gambling problems and depressive symptoms. Subsequent logistic regression revealed that impulsivity predicted membership in all pathogenic trajectories, and quality of the relationship with parents predicted membership in depressogenic trajectories. In addition, we found that the membership in the comorbid trajectory can be predicted by an interaction between friendship quality and socio-family risk. 相似文献