Bayesian updating of atmospheric dispersion after a nuclear accident

Summary.  We consider a Bayesian forecasting system to predict the dispersal of contamination on a large scale grid in the event of an accidental release of radioactivity. The statistical model is built on a physical model for atmospheric dispersion and transport called MATCH. Our spatiotemporal model is a dynamic linear model where the state parameters are the (essentially, deterministic) predictions of MATCH; the distributions of these are updated sequentially in the light of monitoring data. One of the distinguishing features of the model is that the number of these parameters is very large (typically several hundreds of thousands) and we discuss practical issues arising in its implementation as a realtime model. Our procedures have been checked against a variational approach which is used widely in the atmospheric sciences. The results of the model are applied to test data from a tracer experiment.     

Leaving Home Early: Passing from Girlhood to Womanhood

This paper presents a case study of a young woman’s narrative of leaving home and her transition to adulthood. The case study is part of a larger research project about young women with an experience of an early break-up from home, through running away or being thrown out. Empirical material underlying this paper consists of a qualitative study of 12 young women that have been interviewed. The aim of the study is to understand how events like running away/being thrown out of home influences their transition to adulthood. The particular narrative demonstrates how a young woman presents and accounts for such a dramatic event as running away or being thrown out from home, and how that is understood in relation to her adulthood. A further aim is to illustrate how social services efforts are reflected in her narrative.     

A new nonlinear asymmetric cointegration approach using error correction models

In this article, two new powerful tests for cointegration are proposed. The general idea is based on an intuitively appealing extension of the traditional, rather restrictive cointegration concept. In this article, we allow for a nonlinear, but most importantly a different, asymmetric convergence process to account for negative and positive changes in our cointegration approach. Using Monte Carlo simulations we verify, that the estimated size of the first test depends on the unknown value of a signal-to-noise ratio q. However, our second test—which is based on the original ideas of Kanioura and Turner—is more successful and robust in the sense that it works in all of the different evaluated situations. Furthermore it is shown to be more powerful than the traditional residual based Enders and Siklos method. The new optimal test is also applied in an empirical example in order to test for potential nonlinear asymmetric price transmission effects on the Swedish power market. We find that there is a higher propensity for power retailers to rapidly and systematically increase their retail electricity prices subsequent to increases in Nordpool's wholesale prices, than there is for them to reduce their prices subsequent to a drop in wholesale spot prices.     

Participatory Spaces of Mental Health Service User Organizations in the Post-deinstitutional Era: Mapping Roles and Challenges

By applying the concept of participatory spaces, this article maps and analyzes current research on mental health service user organizations (MHSUOs). We have analyzed research literature from 2006 to 2016 to examine how the role of and challenges facing MHSUOs are formulated in the post-deinstitutional era. The current situation is marked by MHSUOs parallel presence in invited, claimed and popular spaces for participation. The post-deinstitutional era is characterized by a shift in focus from gaining access to such participatory spaces, to critically examining the political opportunities available in these. We further argue that the dominance of psychiatry-specific spaces could prevent MHSUOs from fully exploring their potential for participation in broader social issues.     

How union mergers affect membership participation

Using data from a survey of union members, we explore how an amalgamation of two Swedish unions affects membership participation. The research literature on the topic is mostly anecdotal and speculative, suggesting that mergers might have detrimental effects on membership participation because they create large unions with centralized governance and administration. But in this study, we do not find a broad-based decline in membership participation measured before and after merger as well as in relation to a comparison union that did not merge. These results are discussed in terms of the national context of union mergers in Sweden and the ways that mergers are negotiated, presented, and implemented to preserve membership participation. An earlier version of this paper was presented at the Third International Conference on Emerging Union Structures: Reshaping Labour Market Institutions, Canberra, Australia in December 1997. The data collection for this project was supported by funds from the National Institute for Working Life in Stockholm.     

Childcare costs and the demand for children—evidence from a nationwide reform

Exploiting the exogenous variation in user fees caused by a Swedish childcare reform, we are able to identify the causal effect of childcare costs on fertility in a context in which childcare enrollment is almost universal, user fees are low, and labor force participation of mothers is very high. Anticipation of a reduction in childcare costs increased the number of first and higher-order births, but only seemed to affect the timing of second births. For families with many children we also find a marginally significant negative income effect on fertility.     

Improving confidence in tree species selection for challenging urban sites: a role for leaf turgor loss

High species diversity is argued to be the most important requisite for a resilient urban forest. In spite of this, there are many cities in the northern hemisphere that have very limited species diversity within their tree population. Consequently, there is an immense risk to urban canopy cover, if these over-used species succumb to serious pests or pathogens. Recognition of this should motivate the use of less commonly used species. Analysis of plant traits, such as the leaf water potential at turgor loss (Ψ_P0), can provide useful insights into a species’ capacity to grow in warm and dry urban environments. Therefore, the aim of this study was to evaluate Ψ_P0 of 45 tree species, the majority of which are rare in urban environments. To help evaluate the potential for using Ψ_P0 data to support future decision-making, a survey of professionals engaged with establishing trees in urban environments was also used to assess the relationship between the measured Ψ_P0 and the perceived drought tolerance of selected species. This study demonstrates that Ψ_P0 gives strong evidence for a species’ capacity to tolerate dry growing conditions and is a trait that varies substantially across species. Furthermore, Ψ_P0 was shown to closely relate to the experience of professionals involved in establishing trees in urban environments, thus providing evidence of its practical significance. Use of plant traits, such as Ψ_P0, should, therefore, give those specifying trees confidence to recommend non-traditional species for challenging urban environments.