A fast exact algorithm for the problem of optimum cooperation and the structure of its solutions

Given a graph G=(V,E) with edge weights w _e ∈ℝ, the optimum cooperation problem consists in determining a partition of the graph that maximizes the sum of weights of the edges with nodes in the same class plus the number of the classes of the partition. The problem is also known in the literature as the optimum attack problem in networks. Furthermore, a relevant physics application exists.     

Sibling Facilitation Mediates the Association Between Older and Younger Sibling Alcohol Use in Late Adolescence

Previous research has shown adolescent siblings are similar in their alcohol use and that this similarity is largely due to their shared environment. Using a genetically informed sibling sample (196 full‐biological pairs, 384 genetically unrelated pairs), we confirmed that the extent to which older siblings facilitate younger siblings' alcohol use (i.e., help them get alcohol) was one factor contributing to this shared environmental association. All analyses controlled for parent and peer influences. Findings were not moderated by sibling differences in genetic relatedness, gender, or ethnicity. Proximity in sibling age strengthened these associations, somewhat. Results were especially strong for sibling pairs where the older sibling was of legal drinking age. Implications for prevention and intervention are discussed.     

Becoming a (Pan)ethnic Attorney: How Asian American and Latino Law Students Manage Dual Identities

Managing professional and personal identities often belabor upwardly mobile racialized individuals. I examine in this article how Asian American and Latino law students negotiate (pan)ethnic identities while learning to become lawyers. I contend that managing dual identities creates (pan)ethnic duty among Asian American and Latino law students. I focus on those planning to work in law firms, at least initially. While there are many career options for law students, most, irrespective of race, pursue initial careers at law firms. What leads them there? How do racialization and expectations play a role in this career aspiration? And how do students negotiate the pressure to give back, or manage the internally/externally imposed duty they feel to serve respective communities? I find that Asian American and Latino law students draw on a repertoire of strategies (marginal panethnicity, tempered altruism, and instrumental ethnicity) that encompass different accounts, identities, and roles enabling creativity and elasticity for professional and personal identities. The findings suggest that panethnicity remains salient for upwardly mobile individuals of color, even those who do not ostensibly appear to be concerned with panethnic communities and causes.     

A marginalized diffusion model for estimating age at first lower endoscopy use from current status data

Summary.  We propose an approach for estimating the age at first lower endoscopy examination from current status data that were collected via two series of cross-sectional surveys. To model the national probability of ever having a lower endoscopy examination, we incorporate birth cohort effects into a mixed influence diffusion model. We link a state-specific model to the national level diffusion model by using a marginalized modelling approach. In future research, results from our model will be used as microsimulation model inputs to estimate the contribution of endoscopy examinations to observed changes in colorectal cancer incidence and mortality.     

An improved class of estimators for the population mean

Starting from the Rao (Commun Stat Theory Methods 20:3325–3340, 1991) regression estimator, we propose a class of estimators for the unknown mean of a survey variable when auxiliary information is available. The bias and the mean square error of the estimators belonging to the class are obtained and the expressions for the optimum parameters minimizing the asymptotic mean square error are given in closed form. A simple condition allowing us to improve the classical regression estimator is worked out. Finally, in order to compare the performance of some estimators with the regression one, a simulation study is carried out when some population parameters are supposed to be unknown.     

Testing the Comparability of Different Types of Social Indicators Across Groups

The social indicator movement has realized a considerable increase in importance during the last 50 years. This happened not the least by the publications in the journal Social Indicators Research. Social indicators have been developed for many aspects of life. The scores on these indicators often are compared through time and across groups. An essential requirement for such research is that the measures used are comparable through time and across groups. The comparability through time is not such a big problem but the comparability of measures across groups is not so obvious. This requires harmonization of indicators based on objective variables and invariance testing for indicators based on subjective and objective variables. In this paper we discuss how the comparability of different types of social indicators based on subjective and objective variables can be tested using invariance testing. This is a relevant issue because the existing testing procedure is designed for only one type of social indicators and this test is not directly applicable on the other types of social indicators.     

Measurement Invariance in Multilingual Survey Research: The Role of the Language of the Questionnaire

This paper examines whether or not survey measures asked to two linguistic groups exhibit invariance within a country. It tests configural, metric and scalar invariance in a model that distinguishes the response component and the cognitive component of the measurement process using survey items. Our findings show that when differences in the response process are allowed, concepts are (partially) invariant across groups. The analysis is conducted for items measuring some aspects of political trust and satisfaction with politics for six linguistic groups including French, Dutch, Estonian, German, Ukrainian and Russian in four countries. Data comes from the European Social Survey.     

‘Widening cross-disciplinary research for mental health’: what is missing from the Research Councils UK mental health agenda?

This current issues article is a brief critical examination of the recent Research Councils UK agenda and call for cross-disciplinary research in mental health. Our argument is based on the fact that patient and public involvement (PPI) is the only involvement and influencing strategy for service users and survivors in the agenda. Service user and survivor research as a discipline in itself remains unacknowledged. We conclude that service user and survivor research is distinct and is different to PPI, and should be recognised in any mental health research agenda.     

Maternal struggles and the politics of childlessness under pronatalist Caribbean slavery

ABSTRACT

This article considers the relationship of enslaved and apprenticed women in the Anglophone Caribbean to the embodied experience of childbearing, motherhood, and childlessness. It places this analysis in the context of a discussion of the development and implementation of pronatalist policies in the Anglophone Caribbean during the late period of slavery. It examines the experience of pronatalist policies by enslaved women, using as a case study a microhistory from Jamaica during the apprenticeship period (1834–1848). Although the existence of pronatalist policies gave some women (mothers with large numbers of children) a position from which to claim reduced workloads and other ‘rights’, they made the situation of childless women more difficult. In historians' attention to the struggles of mothers, we have sometimes paid insufficient attention to the perspective of childless and bereaved women.     

Silent privatisation of customary land in Zambia: opportunities for a few,challenges for many

The conversion of customary land into leasehold tenure has sparked intense debates in Zambia and beyond. Growing interest in land in the last decade and half has led to a spike in demand for land across Africa, especially land adjacent to major cities, towns and developed infrastructure. This growing demand for land is gradually being directed at customary land, which well-resourced urban and local elites, as well as foreign investors, are converting from customary to private tenure, raising serious questions about the future of customary land in Africa. This paper discusses the emerging dynamics around customary land conversion drawing from a case study conducted in Chongwe and Chibombo districts in Zambia. Evidence gathered in this study suggest that while the conversion of customary land to leasehold tenure is generating opportunities for the urban elite, a few traditional leaders and international investors, it is, at the same time, creating serious challenges for the majority of the people in the local communities.