Extradyadic Activity in a Random Sample of Norwegian Couples

The purpose of this study was to explore extradyadic sexual activity (ESA) in Norwegian heterosexual couples and to identify factors connected to each of the parties that may predict ESA. The study comprised a representative sample of 399 couples (798 individuals) between 22 to 67 years of age. The data were collected by means of self-administered postal questionnaires. In 6% of couples the female partner had had a concurrent sex partner, in 13% of couples the male partner had had a parallel sex partner and in 4% of couples both had engaged in ESA. A man with experience of ESA experienced negative work-to-home interference, was preoccupied with sex, and frequently thought of others during sex with his wife. The male partner of a woman with experience of ESA was reported being self-confident and she perceived him as easy to talk to about sex. Furthermore, his attitude was that two persons who love each other should not have secrets from each other. The woman with experience of ESA, on the other hand, reported having secrets from her partner and to think of others during intercourse.     

Death Clustering,Mothers' Education and the Determinants of Child Mortality in Rural Punjab,India

In this paper the behavioural factors which make for continuing high levels of child mortality in rural Punjab, despite favourable conditions in terms of nutrition, income, women's literacy and health care facilities are examined. A major factor is that inadequate attention has been paid to improved health care practices within the home. Women's autonomy, social class, and mothers' education significantly influence child survival. One of the pathways by which mothers' education affects child survival is through improved child care. In this society, a woman's autonomy is lowest during that part of her life-cycle which also contains her peak childbearing years: this perverse overlap raises child mortality. The risk of dying is distributed very unevenly amongst children, as the majority of child deaths are clustered amongst a small proportion of the families. The death-clustering variable remained significant even after several possible biological and socio-economic reasons for clustering had been controlled. It is argued that this clustering of deaths is partly due to the poor basic abilities of some mothers and other carers.     

Patterns of abuse in male same-sex relationships

Previous studies of abuse in male same-sex relationships have been limited by convenience samples and/or by incomplete assessments of partner abuse. We examined patterns of same-sex partner abuse in a random sample of 284 gay and bisexual men. Respondents reported on perpetration and receipt of physical, psychological, and sexual abuse over multiple time frames, as well as injuries resulting from abuse. Almost all respondents reported psychological abuse, more than one-third reported physical abuse, and 10% reported having engaged in unwanted sexual activity because of partner force or threats of force. More than half of recipients of partner violence reported sustaining injury. We found strong associations between different forms of abuse, and between severity of abuse receipt and perpetration.     

Estimation of spatial processes using local scoring rules

We display pseudo-likelihood as a special case of a general estimation technique based on proper scoring rules. Such a rule supplies an unbiased estimating equation for any statistical model, and this can be extended to allow for missing data. When the scoring rule has a simple local structure, as in many spatial models, the need to compute problematic normalising constants is avoided. We illustrate the approach through an analysis of data on disease in bell pepper plants.     

Effectiveness of combinations of Gaussian graphical models for model building

Combining statistical models is an useful approach in all the research area where a global picture of the problem needs to be constructed by binding together evidence from different sources [M.S. Massa and S.L. Lauritzen Combining Statistical Models, M. Viana and H. Wynn, eds., American Mathematical Society, Providence, RI, 2010, pp. 239–259]. In this paper, we investigate the effectiveness of combining a fixed number of Gaussian graphical models respecting some consistency assumptions in problems of model building. In particular, we use the meta-Markov combination of Gaussian graphical models as detailed in Massa and Lauritzen and compare model selection results obtained by combining selections over smaller sets of variables with selection results over all variables of interest. In order to do so, we carry out some simulation studies in which different criteria are considered for the selection procedures. We conclude that the combination performs, generally, better than global estimation, is computationally simpler by virtue of having fewer and simpler models to work on, and has an intuitive appeal to a wide variety of contexts.     

An agent-based approach to modelling virtual enterprises

This paper describes how virtual enterprises (VEs) can be modelled using the AGORA multi-agent architecture, designed for modelling and supporting cooperative work among distributed entities. The model consists of a structure of AGORAs and agents, where AGORAs are facilitators of cooperative work for agents and the agents represent the partners of the VE, the cooperative mechanisms and the service providers. The distributed and goal-oriented nature of the VE provides a strong motivation for the use of agents to model VEs. The main advantages of this approach are that the structure of AGORAs provides a homogeneous modelling environment throughout the life cycle of the VE, traceability of the VE activities and a history of the VE. In addition to these, it is important to point out that, agents being computational entities, the resulting model provides an easy and efficient passage from the model to the computational support that is required by the VE.