A Non-parametric Frailty Model for Temporally Clustered Multivariate Failure Times

Abstract A model is introduced here for multivariate failure time data arising from heterogenous populations. In particular, we consider a situation in which the failure times of individual subjects are often temporally clustered, so that many failures occur during a relatively short age interval. The clustering is modelled by assuming that the subjects can be divided into ‘internally homogenous’ latent classes, each such class being then described by a time‐dependent frailty profile function. As an example, we reanalysed the dental caries data presented earlier in Härkänen et al. [Scand. J. Statist. 27 (2000) 577], as it turned out that our earlier model could not adequately describe the observed clustering.     

Amazonian Native Youths and Notions of Indigeneity in Urban Areas

The indigenous presence in urban areas of Amazonia has become more visible as Indian populations have negotiated their own spaces and acted in new contexts previously reserved for the dominant society. This article looks at ways in which today's young Indians in an urban area define and interpret their new cultural and social situations, drawing from research conducted with Apurinã, Cashinahua and Manchineri youths in Rio Branco, a city in Acre state, Western Brazil. These young people occupy a variety of “native” and “non-native” habituses and develop their notions of indigeneity within complex social networks as part of their strategy for rupturing the otherness associated with indigeneity. The text contributes to the discussion on the theory of practice and identity politics, as well as embodiment. Young Indians in urban Amazonia constitute their agencies in multiple ways and use various embodiments based in the practices and knowledge of their native groups and those of urban national and global society. The young natives break with the image of Lowland South American Indians as peoples uncontaminated by urban influences and help promote new interactions between native populations in the reserve and the city.     

Values and Their Change During the Business Education – A Gender Perspective

Modern management and organization theory have been criticized for being based on masculine values and concepts. The theory and associated values influence not only managerial behavior in practice, but also business education's value system. In this study, we analyze the change in values during business education from a gender perspective. By values we mean feminine and masculine values. Our empirical study is based on the literature of cultural values and gender socialization theories. We surveyed 324 students. The result of our study lends support to earlier research: men are more masculine and women more feminine in their values. The change towards masculinity during business education is not supported statistically in this study. However, there may be a weak tendency towards masculinity, especially among female students. In addition, we propose that it is possible that business students have a tendency to try to fulfil masculine needs in their occupational choice. Further research is needed to investigate the empirical findings of our study. This revised version was published online in July 2006 with corrections to the Cover Date.     

Does shift work lead to poorer health habits? A comparison between women who had always done shift work with those who had never done shift work

Shift work has been reported to predict health problems, and a possible explanation is that shift work may lead to poorer health habits, thereby increasing a person's vulnerability to illness. This study examined the association between shift work and health habits, as indicated by smoking, alcohol intake, physical activity and by being overweight. A questionnaire was sent to all 2795 female nurses working in the 10 hospitals of two Finnish health care districts. From the 2299 respondents, we selected those 506 shift workers who reported having always done shift work and those 183 day workers who had never done shift work. Shift workers were found to smoke more and to be overweight more often than day workers. These differences gradually increased in each successive age group, being 1.94 pack-years in smoking and 0.9 kg m^-2 in body mass index among nurses over 45 years of age. Shift work was not associated with alcohol intake or sedentary lifestyle. This evidence is compatible with the possibility that shift work in nurses increases smoking and being overweight to a degree that contributes to health problems, including coronary heart disease.     

Editorial statement: Stress and work compensation

Shift work has been reported to predict health problems, and a possible explanation is that shift work may lead to poorer health habits, thereby increasing a person's vulnerability to illness. This study examined the association between shift work and health habits, as indicated by smoking, alcohol intake, physical activity and by being overweight. A questionnaire was sent to all 2795 female nurses working in the 10 hospitals of two Finnish health care districts. From the 2299 respondents, we selected those 506 shift workers who reported having always done shift work and those 183 day workers who had never done shift work. Shift workers were found to smoke more and to be overweight more often than day workers. These differences gradually increased in each successive age group, being 1.94 pack-years in smoking and 0.9 kg m^-2 in body mass index among nurses over 45 years of age. Shift work was not associated with alcohol intake or sedentary lifestyle. This evidence is compatible with the possibility that shift work in nurses increases smoking and being overweight to a degree that contributes to health problems, including coronary heart disease.     

Women on the boards of listed companies: Evidence from Finland

This paper investigates gender differences on the corporate boards of Finnish listed companies. The personal characteristics, careers, and boardroom roles of female and male directors on boards were analyzed on the basis of empirical data collected by questionnaire. An analysis of the findings revealed only minor differences between the women and men in personal characteristics such as their marital status, number of children and education, or in their careers. However, female board members were on average younger than their male counterparts and considered themselves to be more protean, took more active roles on the board, and enjoyed power more than men did. They also felt a need for more women on the board. The goal of this study is to contribute to the existing research in two ways. Firstly, it provides empirical evidence on women??s representation on boards from Finland, where women??s and men??s rights are regarded as more equal than in many other countries. Secondly, the study aims to increase our knowledge of gender differences, careers and roles of women in top positions in Finnish business.     

Anisotropy analysis of pressed point processes

This paper introduces methods for the detection of anisotropies which are caused by compression of regular 3D point patterns. Isotropy tests based on directional summary statistics and estimators for the compression factor are developed. Using simulated data, the dependence of the power of these methods on the intensity, the degree of regularity, and the compression strength is studied. Finally, our methods are applied to the point patterns of centers of air pores extracted from tomographic images of ice cores. This way the presence of anisotropies in the ice caused by the compression of the ice sheet and an increase of their strength with increasing depth are shown.     

Intelligent Public Organisations

The article explores the nature of the intelligence and organisational learning of public sector organisations with regard to both individual organisations and multiple organisational ecosystems. The main ideas behind modern systems theory (MST) and the logic developed by the MST theorists in the domain of organisational intelligence are pinpointed in the paper. The article presupposes that the basic structure of the organisational features of intelligence consists of leadership, strategy and foresight, people, partnerships and resources, and organisational processes, and the intelligence builds on these features. The article concludes with an explicit definition of the organisational activities that generate organisational intelligence, putting forward best practice examples with regard to these activities while also presenting scientific evidence to back up these claims.     

Caries on Permanent Teeth: A Non-parametric Bayesian Analysis

Most earlier epidemiological investigations of dental caries have been based on cross-sectional data. Subject-specific information of dental caries in the past, and the duration of exposure of each tooth to the oral environment, are obviously important factors also influencing the presence of dental caries in the future. This has led us to consider multivariate survival models in which the information about the tooth eruption and failure times are combined to assess caries risk. A non-parametric Bayesian intensity model is presented, reflecting, on the one hand, the within subject and between subject sources of variability, and a corresponding split of variability when considering the 28 permanent teeth. We analyse a data set consisting of the dental history of 240 boys, where the observations are based on predetermined dental examinations taking place approximately once every year. Markov chain Monte Carlo integration techniques are applied in the numerical work.