A comparison of statistical methods for combining relative bioactivities from parallel line bioassays

This paper compares the ordinary unweighted average, weighted average, and maximum likelihood methods for estimating a common bioactivity from multiple parallel line bioassays. Some of these or similar methods are also used in meta‐analysis. Based on a simulation study, these methods are assessed by comparing coverage probabilities of the true relative bioactivity and the length of the confidence intervals computed for these methods. The ordinary unweighted average method outperforms all statistical methods by consistently giving the best coverage probability but with somewhat wider confidence intervals. The weighted average methods give good coverage and smaller confidence intervals when combining homogeneous bioactivities. For heterogeneous bioactivities, these methods work well when a liberal significance level for testing homogeneity of bioactivities is used. The maximum likelihood methods gave good coverage when homogeneous bioactivities were considered. Overall, the preferred methods are the ordinary unweighted average and two weighted average methods that were specifically developed for bioassays. Copyright © 2013 John Wiley & Sons, Ltd.     

Errors in variables: consistent adjusted least squares (cals) estimation

A single equation errors-in-variables model is considered. Exact restrictions on the parameters in the model are assumed to be available such that the model is just-identified. A Consistent Adjusted Least Squares (CALS) estimator for this model is proposed and its asymptotic distribution is given. Special cases are given as illustrations. CALS is identical to the Method of Moments (MM), and to Maximum Likelihood (ML) under the structural interpretation. Under the functional interpretation it is identical to ML in cases where the latter method is consistent.     

Combining two classical approaches for statistical selection

This paper presents a selection procedure that combines Bechhofer's indifference zone selection and Gupta's subset selection approaches, by using a preference threshold. For normal populations with common known variance, a subset is selected of all populations that have sample sums within the distance of this threshold from the largest sample sum. We derive the minimal necessary sample size and the value for the preference threshold, in order to satisfy two probability requirements for correct selection, one related to indifference zone selection, the other to subset selection. Simulation studies are used to illustrate the method.     

Loneliness Literacy Scale: Development and Evaluation of an Early Indicator for Loneliness Prevention

To develop and evaluate the Loneliness Literacy Scale for the assessment of short-term outcomes of a loneliness prevention programme among Dutch elderly persons. Scale development was based on evidence from literature and experiences from local stakeholders and representatives of the target group. The scale was pre-tested among 303 elderly persons aged 65 years and over. Principal component analysis and internal consistency analysis were used to affirm the scale structure, reduce the number of items and assess the reliability of the constructs. Linear regression analysis was conducted to evaluate the association between the literacy constructs and loneliness. The four constructs “motivation”, “self-efficacy”, “perceived social support” and “subjective norm” derived from principal component analysis captured 56 % of the original variance. Cronbach’s coefficient α was above 0.7 for each construct. The constructs “self-efficacy” and “perceived social support” were positively and “subjective norm” was negatively associated with loneliness. To our knowledge this is the first study developing a short-term indicator for loneliness prevention. The indicator contributes to the need of evaluating public health interventions more close to the intervention activities.     

The Evolution of Food Safety Policy–making Institutions in the UK, EU and Codex Alimentarius

After the British government announced in March 1996 that a novel fatal human disease (now called variant Creutzfeldt–Jakob disease) had emerged and was almost certainly caused by consuming BSE–contaminated food, national and international authorities have been struggling to deal with the consequences of a serious loss of public confidence in the safety of foods and in food safety policy–making institutions. One of the main ways in which governments and officials have responded to those challenges has been by initiating a broad range of structural and procedural reforms to the ways in which public policies are decided, legitimated and communicated. This paper outlines some of the more important respects in which national and international authorities have changed the ways in which they assess and manage the risks to human consumers of food–borne hazards. The focus is on developments in the UK, the EU and, at the global level, the Codex Alimentarius Commission; the period covered runs from the late 1960s until summer 2002. The discussion focuses on the case for separating the responsibilities for regulating and sponsoring the agricultural and food industries, for conducting risk appraisals and decision–making in open and democratically accountable ways and for drawing on experts representing a wide range of interests and expertise rather than on a narrow industry–based group. The paper concludes by indicating some key structural and procedural conditions for effectively differentiating the scientific from the political aspects of risk appraisal and decision–making, and then for coupling them together in ways that would provide both scientific and democratic legitimacy.     

Caring for Troubled Children in Flanders, The Netherlands, and the United Kingdom

Correspondence to Dr Matthew Colton, Lecturer in Applied Social Studies, Centre for Applied Social Studies, University College of Swansea, Singleton Park, Swansea SA2 8PP. Summary This article reviews research on residential care and otherservices for troubled children in Flanders, the Netherlands,and the United Kingdom. We begin by looking at Flanders andthe Netherlands. This includes an account of the organizationof services and a critical evaluation of initiatives resultingfrom the growing dissatisfaction with residential care overrecent years. We then compare the evidence from these two countrieswith the situation in the United Kingdom. Notwithstanding importantdifferences, there are clear similarities in the issues surroundingthe residential care of children in the three countries. Weconclude by outlining likely future developments in residentialchild care.     

The Beneficial Effects of Social Identity Protection on the Performance Motivation of Members of Devalued Groups

For members of socially devalued or stigmatized groups, work and educational settings can threaten social identity, inducing the use of coping strategies that lower their motivation (e.g., self-segregation, domain disengagement) rather than improving their position in the social hierarchy. We review a recent research program on women and ethnic minorities to show that members of these stigmatized groups can maintain their motivation in threatening work and educational contexts when they are offered ways to protect their social identity. For example, organizations that communicate value for the social identities of women and ethnic minorities allow members of these groups to focus on success and motivate them to improve their performance on dimensions that increase their social status. Furthermore, social identity protection has important benefits over more individualistic forms of identity protection because it maintains group members' concern for their group's plight, increasing opportunities for successful collective action. The practical implications of this work are discussed.     

Measuring power and satisfaction in societies with opinion leaders: an axiomatization

Opinion leaders are actors who have some power over their followers as they are able to influence their followers’ choice of action in certain instances. In van den Brink et al. (Homo Oeconomicus 28:161–185, 2011) we proposed a two-action model for societies with opinion leaders. We introduced a power and a satisfaction score and studied some common properties. In this paper we strengthen two of these properties and present two further properties, which allows us to axiomatize both scores for the case that followers require unanimous action inclinations of their opinion leaders to follow them independently from their own action inclinations.