1,354 research outputs found

    Uncertainty in epidemiology and health risk assessment

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    Experimentalist governance

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    Spatial clustering of mental disorders and associated characteristics of the neighbourhood context in Malmö, Sweden, in 2001

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    Study objective: Previous research provides preliminary evidence of spatial variations of mental disorders and associations between neighbourhood social context and mental health. This study expands past literature by (1) using spatial techniques, rather than multilevel models, to compare the spatial distributions of two groups of mental disorders (that is, disorders due to psychoactive substance use, and neurotic, stress related, and somatoform disorders); and (2) investigating the independent impact of contextual deprivation and neighbourhood social disorganisation on mental health, while assessing both the magnitude and the spatial scale of these effects. Design: Using different spatial techniques, the study investigated mental disorders due to psychoactive substance use, and neurotic disorders. Participants: All 89 285 persons aged 40–69 years residing in Malmö, Sweden, in 2001, geolocated to their place of residence. Main results: The spatial scan statistic identified a large cluster of increased prevalence in a similar location for the two mental disorders in the northern part of Malmö. However, hierarchical geostatistical models showed that the two groups of disorders exhibited a different spatial distribution, in terms of both magnitude and spatial scale. Mental disorders due to substance consumption showed larger neighbourhood variations, and varied in space on a larger scale, than neurotic disorders. After adjustment for individual factors, the risk of substance related disorders increased with neighbourhood deprivation and neighbourhood social disorganisation. The risk of neurotic disorders only increased with contextual deprivation. Measuring contextual factors across continuous space, it was found that these associations operated on a local scale. Conclusions: Taking space into account in the analyses permitted deeper insight into the contextual determinants of mental disorders

    Italian small business development lessons for U.S. industrial policy

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    Formula for success: Multilevel modelling of Formula One Driver and Constructor performance, 1950-2014

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    This paper uses random-coefficient models and (a) finds rankings of who are the best formula 1 (F1) drivers of all time, conditional on team performance; (b) quantifies how much teams and drivers matter; and (c) quantifies how team and driver effects vary over time and under different racing conditions. The points scored by drivers in a race (standardised across seasons and Normalised) is used as the response variable in a cross-classified multilevel model that partitions variance into team, team-year and driver levels. These effects are then allowed to vary by year, track type and weather conditions using complex variance functions. Juan Manuel Fangio is found to be the greatest driver of all time. Team effects are shown to be more important than driver effects (and increasingly so over time), although their importance may be reduced in wet weather and on street tracks. A sensitivity analysis was undertaken with various forms of the dependent variable; this did not lead to substantively different conclusions. We argue that the approach can be applied more widely across the social sciences, to examine individual and team performance under changing conditions

    Contracting for innovation : vertical disintegration and interfirm collaboration

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    Rapidly innovating industries are not behaving the way theory expects. Conventional industrial organization theory predicts that, when parties in a supply chain have to make transaction-specific investments, the risk of opportunism will drive them away from contracts and toward vertical integration. Despite the conventional theory, however, contemporary practice is moving in the other direction. Instead of vertical integration, we observe vertical disintegration in a significant number of industries, as producers recognize that they cannot themselves maintain cutting-edge technology in every field required for the success of their products. In doing this, the parties are developing forms of contracting beyond the reach of contract theory models. In this Article, we connect the emerging contract practice to theory, learning from what has happened in the real world to frame a theoretical explanation of this cross-organizational innovation and to reconceptualize the boundaries of the firm accordingly. We argue that the vertical disintegration of the supply chain in many industries is mediated neither by fully specified technical interfaces that allow suppliers to produce a modular piece of the ultimate product, nor by entirely implicit relational contracts supported only by norms of reciprocity and the expectation of future dealings. Rather, we suggest that the change in the boundary of the firm has given rise to a new form of contracting between firms -- what we call "contracting for innovation." This pattern braids explicit and implicit contracting to support iterative collaborative innovation by raising switching costs. These costs, represented by the parties' parallel transaction-specific investments in knowledge about their collaborators' capacities, deter opportunism under circumstances where explicit contracting, renegotiation, and the anticipation of future dealings cannot

    Contract and Innovation: The Limited Role of Generalist Courts in the Evolution of Novel Contractual Forms

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    In developing a contractual response to changes in the economic environment, parties choose the method by which their innovation will be adapted to the particulars of their context. These choices are driven centrally by the thickness of the relevant market – the number of actors who see themselves as facing similar circumstances – and the uncertainty related to that market. In turn, the parties\u27 choice of method will shape how generalist courts can best support the parties\u27 innovation and the novel regimes they envision. In this Article, we argue that contractual innovation does not come to courts incrementally, but instead reaches courts later in the innovation\u27s evolution and more fully developed than the standard picture contemplates. Highly stylized, the trajectory of innovation in contract we find is this: Private actors respond to exogenous shocks in their economic environments by changing existing structures or procedures to make them efficient under the new circumstances. The innovating parties stabilize their newly emergent practices through a variety of regimes – both bilateral and multilateral – with the goal of establishing the context through which the innovation is implemented. It is only at this point, and when a dispute is presented to them, that courts step in. If contract innovation does indeed reach generalist courts through the mediating institution of these contextualizing regimes, then our argument follows directly: Because a central goal of contract adjudication is to enforce the agreement in the context the parties intended, the courts\u27 willingness to defer to the context provided by the parties will put the law more directly in the service of innovation

    Demineralization of Enamel in Primary Second Molars Related to Properties of the Enamel

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    Enamel structure is of importance in demineralization. Differences in porosity in enamel effect the rate of demineralization, seen between permanent and deciduous teeth. Individual differences have been shown in the mean mineral concentration values in enamel, the role of this in demineralization is not thoroughly investigated. The aim of this study was to study variations of depths of artificial lesions of demineralization and to analyze the depth in relation to variations in the chemical and mineral composition of the enamel. A demineralized lesion was created in second primary molars from 18 individuals. Depths of lesions were then related to individual chemical content of the enamel. Enamel responded to demineralization with different lesion depths and this was correlated to the chemical composition. The carbon content in sound enamel was shown to be higher where lesions developed deeper. The lesion was deeper when the degree of porosity of the enamel was higher
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