55,956 research outputs found

    Parametrization and penalties in spline models with an application to survival analysis

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    In this paper we show how a simple parametrization, built from the definition of cubic splines, can aid in the implementation and interpretation of penalized spline models, whatever configuration of knots we choose to use. We call this parametrization value-first derivative parametrization. We perform Bayesian inference by exploring the natural link between quadratic penalties and Gaussian priors. However, a full Bayesian analysis seems feasible only for some penalty functionals. Alternatives include empirical Bayes methods involving model selection type criteria. The proposed methodology is illustrated by an application to survival analysis where the usual Cox model is extended to allow for time-varying regression coefficients

    E-portfolio in education. Practices and reflections

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    The main activities of the digiFolio Project include: Building a common knowledge base supported by research work on the theory of portfolio usage; Paper and online publication of the results of the research work; Establishment of the pedagogical model for the training course; Analysis of the existing technological infrastructures for digital portfolio usage; Adjustment of the best tools and training course setup; Piloting and evidencing of the training course; Monitoring of the trainees' work by using a specific online teachers' support structure; International seminar. Website: http://digifolioseminar.org/?The present publication addresses the use of digital portfolios in educational context and it is one of the latest dissemination activities of the Digifolio project – Digital Portfolio as a strategy for teachers’ professional development, a COMENIUS 2.1 project which was carried out between 2005 and 2008. It involved several universities and teacher training institutions from five different European countries. The project, which main focus was the reflection on the potentialities of portfolios and digital technologies in the perspective of teachers’ professional development, came to its end with an international seminar which aimed at disseminating the work produced in the frame of a previous teachers training course, as well as allowing and welcoming the contribution of other education professionals with their practices and reflections on the above-mentioned thematic.Europeen Comissio

    Comparison of cloud height and depth from atmospheric modelling and ceilometer measurements

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    In the current study, the cloud base height obtained from the ceilometer measurements, in Evora (south of Portugal), are compared with the results obtained from atmospheric modelling. The atmospheric model adopted is the nonhydrostatic MesoNH model, initiated and forced by ECMWF (European Centre for Medium-Range weather Forecasts) analyses. Also the simulated cloud depth results are presented. The availability of mesoscale modelling for the region, as well as the cloud local vertical distributions obtained from the ceilometer, provide a good opportunity to compare cloud base height and estimate the errors associated. From the obtained results it is possible to observe that the simulated cloud base height values are in good agreement with the correspondent values obtained from the ceilometer measurements

    Risk perceptions, risk attitudes and the formation of consumer acceptance of Genetically Modified (GM) food

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    The influence of risk perception and risk attitudes in the process of accepting genetically modified (GM) food is often ignored, and particularly whether both constructs (latent variables) have a combined effect in explaining consumer acceptance. Similarly, the inclusion of organic product standards juxtaposed to GM food is unknown. This paper attempts to shed some light on this question by examining the decision making process through the use of structural equation modeling (SEM). We use survey data from Spain and a set of theoretical constructs that allow us to identify independent mechanisms underlying individuals’ risk decision making. Our results suggest that the conceptualized model captures the decision making process, and that both perceptions and attitudes toward risk have independent effects on consumer acceptance. However, the effect from risk perception is larger in intensity. Finally, attitudes towards organic production emerge as an informative determinant of attitudes towards GM food.risk perceptions, consumer acceptance, risk attitudes, and GM food., Agricultural and Food Policy,

    The role of cost accounting in the university performance measurement in Portugal

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    Cost accounting is aimed at emphasising those elements of costs and profits of original importance to the management board of an organizational unit. Therefore, cost accounting was initially understood as mere collector of costs and profits, using the traditional system of costing everything, a budget with a limited base. Originally, it was designed to calculate real costs with the aim to determine the results. In public organizations, the aim of cost accounting, costs or management, can be summarized as follows: o Obtain information of how costs are found, both the ones corresponding to the internal activities as well as those for external services rendered and the cost realized investments; o Obtain information for cost and control management, with efficiency indicators of how the planned objectives were achieved and the efficient use of available resources. This paper aims at knowing the role of cost accounting in the public sector of higher education, and checks its contribution for the establishment of the management indicators in public institutions of higher education.Cost Accounting, management, indicators, education

    An integrative assessment to determine the genotoxic hazard of estuarine sediments: combining cell and whole-organism responses

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    The application of the Comet assay in environmental monitoring remains challenging in face of the complexity of environmental stressors, e.g., when dealing with estuarine sediments, that hampers the drawing of cause-effect relationships. Although the in vitro Comet assay may circumvent confounding factors, its application in environmental risk assessment (ERA) still needs validation. As such, the present work aims at integrating genotoxicity and oxidative DNA damage induced by sediment-bound toxicants in HepG2 cells with oxidative stress-related effects observed in three species collected from an impacted estuary. Distinct patterns were observed in cells exposed to crude mixtures of sediment contaminants from the urban/industrial area comparatively to the ones from the rural/riverine area of the estuary, with respect to oxidative DNA damage and oxidative DNA damage. The extracts obtained with the most polar solvent and the crude extracts caused the most significant oxidative DNA damage in HepG2 cells, as measured by the formamidopyrimidine-DNA glycosylase (FPG)-modified Comet assay. This observation suggests that metals and unknown toxicants more hydrophilic than polycyclic aromatic hydrocarbons may be important causative agents, especially in samples from the rural part of the estuary, where oxidative DNA damage was the most significant. Clams, sole, and cuttlefish responded differentially to environmental agents triggering oxidative stress, albeit yielding results accordant with the oxidative DNA damage observed in HepG2 cells. Overall, the integration of in vivo biomarker responses and Comet assay data in HepG2 cells yielded a comparable pattern, indicating that the in vitro FPG-modified Comet assay may be an effective and complementary line-of-evidence in ERA even in particularly challenging, natural, scenarios such as estuarine environments

    THE USE of CONSORTIA for the INTERNATIONALIZATION of FIRMS – MOTA-ENGIL CASE STUDY

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    Internationalization has been widely studied throughout the years. Broadly, it has been predicted as irrevocable and having increasing impact on firm-related strategy. Within entry modes, consortium, has not received as much attention as others. Hence, it seems important to understand how this specific entry mode allows the entrance of firms in the international markets. This study intends to answer the question of “how” to internationalize, anticipating the consortium as the most feasible way for construction firms to enter certain markets. The reasons that determine its choice concern the specificness of the projects, markets and of the firm. In the first part of the study, we review the existent literature on consortia as an entry mode and as a tool of internationalization used by construction firms. Through this review we build a framework that reveals the motivations that lead to this choice. In the second part, we present the case study of Mota-Engil, as a potential source of valuable information which may contribute to the understanding of the phenomenon under study. This case study corroborates the motivations found to create consortia. The paper closes with its contributions, limitations and suggestions for future researches.consortia, internationalization, cooperation, construction
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