Modeling association between DNA copy number and gene expression with constrained piecewise linear regression splines

DNA copy number and mRNA expression are widely used data types in cancer studies, which combined provide more insight than separately. Whereas in existing literature the form of the relationship between these two types of markers is fixed a priori, in this paper we model their association. We employ piecewise linear regression splines (PLRS), which combine good interpretation with sufficient flexibility to identify any plausible type of relationship. The specification of the model leads to estimation and model selection in a constrained, nonstandard setting. We provide methodology for testing the effect of DNA on mRNA and choosing the appropriate model. Furthermore, we present a novel approach to obtain reliable confidence bands for constrained PLRS, which incorporates model uncertainty. The procedures are applied to colorectal and breast cancer data. Common assumptions are found to be potentially misleading for biologically relevant genes. More flexible models may bring more insight in the interaction between the two markers.Comment: Published in at http://dx.doi.org/10.1214/12-AOAS605 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Engaged but exhausted: Work-related wellbeing profiles of South African employees

Organizations and colleagues alike benefit from dedicated employees who are immersed in their work and energetically pursue their tasks. Unfortunately, this may come at a price for employees who may burn out. Organizations are, therefore, confronted with a responsibility to assist employees in striking a balance between eagerly engaging in their tasks and taking care of their wellbeing. Before designing and implementing interventions, it is valuable to identify how engagement and burnout components cluster within individuals and whether these different combinations have different implications for employees. The study aimed to explore whether burnout and work engagement combine within individuals to form different burnout-engagement profiles. The study also aimed to examine the implications of different profiles for employees’ psychological distress, affective commitment, and turnover intention. Among 1048 South African employees, latent profile analysis highlighted five distinct burnout-engagement profiles: Burned-out, Risky, Moderately balanced, Stars, and Workaholics. The Burned-out reported higher levels of psychological distress than the Risky. Still, both reported higher levels than the Moderately balanced, who also reported higher levels of psychological distress than the Stars. The Burned out and the Workaholics reported equal levels of psychological distress. The Stars reported the highest levels of affective commitment, followed by the Workaholics, the Moderately balanced, and the Risky, with the lowest levels reported by the Burned-out. The Burned-out reported the highest levels of turnover intention, followed by the Risky, the Workaholics, and the Moderately balanced, with the lowest levels reported by the Stars. Limitations, recommendations for future research and practical implications are discussed

Social value orientation, organizational goal concerns and interdepartmental problem-solving behavior

In a study in 11 organizations among 120 manufacturing, planning and sales employees, support was found for the hypothesis that a prosocial value orientation – as a personality trait -increases the likelihood that employees show a high concern for the goals of other departments. This concern, combined with a high concern for own goals, furthermore appeared to increase the likelihood of problem-solving behavior during interdepartmental negotiations. Measures of goal concerns were attained, firstly, by asking employees how important they found six specific organizational goals and, secondly, by assessing which goals were found most important by members of which department. The results of this study suggest that problem solving can be induced by selecting or developing prosocial employees, because a prosocial value orientation increases the likelihood of having broad role orientations, in which employees not only care for goals characteristic of their own department, but also for goals of other departments

Geography in The Netherlands

Geographical thought in Dutch society In May 1999, after years of preparation, the EU Council of Ministers approved the European Spatial Development Perspective (ESDP), a non-binding framework for spatial and regional policies at a European scale. The Netherlands had been one of the pioneers of this project. The ESDP had been given a substantial stimulus at the June 1997 conference of EU Ministers in the Dutch seaside resort of Noordwijk, a meeting about the (un)desirability and feasibility o..

Growth references for height, weight and body mass index of twins aged 0–2.5 years.

Aim: To determine the size of the growth deficit in Dutch monozygotic and dizygotic twins aged 0-2.5 years as compared to singletons and to construct reference growth charts for twins. Methods: Growth of twins was studied using longitudinal data on over 4000 twins aged 0-2.5 years of the Netherlands Twin Register. The LMS method was used to obtain growth references for length/height, weight, and body mass index (BMI) for twins. Results: During the first 2.5 years of age, differences in length/height and weight between twins and singletons decrease but do not disappear. BMI of twins deviates less than that of singletons. Approximately half of the growth retardation from birth until 1.5 years of age was attributable to gestational age. Between 1.5 years and 2.5 years of age, this difference was reduced to one-third. Thus, a substantial part of the growth difference could not be explained by gestational age. © 2008 Foundation Acta Pædiatrica

What Does It Mean for an Organisation to Be Intelligent? Measuring intellectual bandwidth for value creation

The importance of electronic collaboration has risen as successful organisations recognize that they need to convert their intellectual resources into goods and services their customers will value. The shift from personal computing to interpersonal or collaborative computing has given rise to ways of working that may bring about better and more effective use of intellectual resources. Current efforts in managing knowledge have concentrated on producing, sharing and storing knowledge while business problems require the use of these intellectual resources to create value. This paper draws upon Nunamaker et. al.'s (2001) Intellectual Bandwidth Model to measure an organization's potential to create value. Following an analysis of initial data collected at the Netherlands branch of Cap-Gemini Ernst & Young, conclusions are drawn with respect to what it means for an organisation to be intelligent and how such organisations can create value through the use of information and collaboration technologies to increase its intellectual bandwidth