Evolutionary dynamics of collective action in spatially structured populations.

Many models proposed to study the evolution of collective action rely on a formalism that represents social interactions as n-player games between individuals adopting discrete actions such as cooperate and defect. Despite the importance of spatial structure in biological collective action, the analysis of n-player games games in spatially structured populations has so far proved elusive. We address this problem by considering mixed strategies and by integrating discrete-action n-player games into the direct fitness approach of social evolution theory. This allows to conveniently identify convergence stable strategies and to capture the effect of population structure by a single structure coefficient, namely, the pairwise (scaled) relatedness among interacting individuals. As an application, we use our mathematical framework to investigate collective action problems associated with the provision of three different kinds of collective goods, paradigmatic of a vast array of helping traits in nature: "public goods" (both providers and shirkers can use the good, e.g., alarm calls), "club goods" (only providers can use the good, e.g., participation in collective hunting), and "charity goods" (only shirkers can use the good, e.g., altruistic sacrifice). We show that relatedness promotes the evolution of collective action in different ways depending on the kind of collective good and its economies of scale. Our findings highlight the importance of explicitly accounting for relatedness, the kind of collective good, and the economies of scale in theoretical and empirical studies of the evolution of collective action.

Analyse rétrospective et création d'un modèle prédictif des réadmissions précoces dans le Service de Médecine Interne du CHUV

Le taux de réadmission à 30 jours de la sortie de l'hôpital est un indicateur de la qualité de prise en charge hospitalière pouvant refléter des soins suboptimaux ou une coordination insuffisante avec les intervenants ambulatoires. Il existe un algorithme informatisé validé dénommé SQLape® qui, basé sur des données administratives suisses, les codes diagnostiques et les codes d'interventions, permet d'identifier rétrospectivement les réadmissions potentiellement évitables (REAPE), avec une haute sensibilité (96%) et spécificité (96%). Sont considérées REAPE, les réadmissions précoces (< 30 jours), non planifiées à la sortie du séjour index et dues à un diagnostic déjà actif lors du précédent séjour ou dues à une complication d'un traitement. Le but de notre étude a été d'analyser rétrospectivement tous les séjours des patients admis dans le service de Médecine Interne du CHUV entre le 1 janvier 2009 et le 31 décembre 2011, afin de quantifier la proportion de REAPE, puis d'identifier des facteurs de risques afin d'en dériver un modèle prédictif. Nous avons analysé 11'074 séjours. L'âge moyen était de 72 +/- 16,8 ans et 50,3 % étaient des femmes. Nous avons comptabilisé 8,4 % décès durant les séjours et 14,2 % réadmissions à 30 jours de la sortie, dont la moitié (7,0 %) considérées potentiellement évitables selon SQLape®. Les facteurs de risques de REAPE que nous avons mis en évidence étaient les suivants : au moins une hospitalisation antérieure à l'admission index, un score de comorbidité de Charlson > 1, la présence d'un cancer actif, une hyponatrémie, une durée de séjour > 11 jours ou encore la prescription d'au moins 15 médicaments différents durant le séjour. Ces variables ont été utilisées pour en dériver un modèle prédictif de REAPE de bonne qualité (aire sous la courbe ROC de 0,70), plus performant pour notre population qu'un autre modèle prédictif développé et validé au Canada, dénommé score de LACE. Dans une perspective d'amélioration de la qualité des soins et d'une réduction des coûts, la capacité à identifier précocement les patients à risque élevé de REAPE permettrait d'implémenter rapidement des mesures préventives ciblées (par exemple un plan de sortie détaillé impliquant le patient, son entourage et son médecin traitant) en plus des mesures préventives générales (par exemple la réconciliation médicamenteuse)

Transnational private authority, regulatory space and workers' collective competences: Bringing local contexts and worker agency back in

The impact of transnational private regulation on labour standards remains in dispute. While studies have provided some limited evidence of positive effects on 'outcome standards' such as wages or occupational health and safety, the literature gives little reason to believe that there has been any significant effect on 'process rights' relating primarily to collective workers' voice and social dialogue. This paper probes this assumption by bringing local contexts and worker agency more fully into the picture. It outlines an analytical framework that emphasizes workers' potential to act collectively for change in the regulatory space surrounding the employment relationship. It argues that while transnational private regulation on labour standards may marginally improve workers access to regulatory spaces and their capacity to require the inclusion of enterprises in them, it does little to increase union leverage. The findings are based on empirical research work conducted in Sub-Saharan Africa.

Respiratory health effects of fifteen years of improved collective protection in a wheat-processing worker population.

INTRODUCTION: Occupational exposure to grain dust causes respiratory symptoms and pathologies. To decrease these effects, major changes have occurred in the grain processing industry in the last twenty years. However, there are no data on the effects of these changes on workers' respiratory health. OBJECTIVES: The aim of this study was to evaluate the respiratory health of grain workers and farmers involved in different steps of the processing industry of wheat, the most frequently used cereal in Europe, fifteen years after major improvements in collective protective equipment due to mechanisation. MATERIALS AND METHOD: Information on estimated personal exposure to wheat dust was collected from 87 workers exposed to wheat dust and from 62 controls. Lung function (FEV1, FVC, and PEF), exhaled nitrogen monoxide (FENO) and respiratory symptoms were assessed after the period of highest exposure to wheat during the year. Linear regression models were used to explore the associations between exposure indices and respiratory effects. RESULTS: Acute symptoms - cough, sneezing, runny nose, scratchy throat - were significantly more frequent in exposed workers than in controls. Increased mean exposure level, increased cumulative exposure and chronic exposure to more than 6 mg.m (-3) of inhaled wheat dust were significantly associated with decreased spirometric parameters, including FEV1 and PEF (40 ml and 123 ml.s (-1) ), FEV1 and FVC (0.4 ml and 0.5 ml per 100 h.mg.m (-3) ), FEV1 and FVC (20 ml and 20 ml per 100 h at >6 mg.m (-3) ). However, no increase in FENO was associated with increased exposure indices. CONCLUSIONS: The lung functions of wheat-related workers are still affected by their cumulative exposure to wheat dust, despite improvements in the use of collective protective equipment.

Is Transnational Private Regulation Potentially an Effective Means of Promoting Collective Industrial Relations?

This paper asks whether collective industrial relations can be promoted by means other than seeking change in public policy. Recent research points to the increasing significance of transnational private regulation (TPR) in developing economies. There is an emerging consensus that market incentives to improve wages and conditions of work can have a modest positive effect on measurable outcomes like hours of work, and health and safety. However, it appears that TPR has little impact on the capacity of workers to pursue such improvements for themselves via collective action. The paper takes a closer look at the potential of TPR to enhance worker voice and participation. It argues that this potential cannot be properly evaluated without understanding how local actors mobilise the social and political resources that TPR provides. The case studies presented show how different TPR schemes have been used by unions in Africa as a means to pursue the interests of members. The authors found that the scale of the impact of TPR in all of the contexts studied depended almost entirely on the existing capacities and resources of the unions involved. TPR led to the creation of collective industrial relations processes, or helped unions to ensure that certain enterprises participated in existing industrial relations processes, but did virtually nothing to enhance the political and organisational capacity of the unions to influence the outcomes of those processes in terms of wages and conditions of employment. The paper concludes that the potential of TPR to promote the emergence of collective industrial relations systems is very low.