3,366 research outputs found

    Social Trust in Emerging Technologies: The Challenge to Incorporate Fundamentally Different Perspectives in Public Engagement

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    128-146The social construction of emerging science and technology systems requires extensive dialogue between diverse stakeholders, each with historically-diverse scientific, political and historical points of view. Public-engagement in debates about novel technologies has received substantial coverage within science communication studies but the origin of opposing positions regarding controversial science and technology developments has received little coverage. This work uses the juxtaposition between scientific and historical origins as a tool to explain the roots of different perceptions of emerging technologies in various sectors, with nanotechnologies as an empirical example

    Correlation between different PBL assessment components and the final mark for MB ChB III at a rural South African university

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    Background. Problem-based learning (PBL) is now an accepted component of many medical school programmes worldwide. Our university also follows the PBL ‘SPICES’ model for MB ChB III. The assessment modalities used are the modified essay questions (MEQ), objective structured practical examination (OSPE), individualised process assessment (IPA) and tutorial continuous assessment (TUT). This study was done to compare the students’ performances in individual assessment components with the final mark to determine the correlation between these parameters. Materials and methods. The study was retrospective, descriptive and analytical, based on the integrated marks of all the MB ChB III students at Walter Sisulu University (WSU) in 2007. Assessment marks were stratified according to blocks and different types of assessment (MEQ, TUT, OSPE, IPA). Regression analysis was used to compute and scrutinise these vis-à-vis their correspondence with the final marks for each block. Results. Three hundred and seventy-nine block assessment marks of 96 students from 4 blocks of MB ChB III were analysed and the correlation between the assessment components and final mark were compared. Regression analysis showed good correlation when analysing the assessment modality versus the final mark for the MEQs (r=0.93, 0.93, 0.94, 0.96), followed by OSPEs (r=0.71, 0.70, 0.76, 0.77) and IPAs (r=0.62, 0.51, 0.68, 0.77). However, correlation was not significant with the TUT. Conclusion. There was good correlation between the students’ performance in the majority of assessment modalities and the final mark in the different blocks of the MB ChB III examination. There may be a need to make tutorial assessment methods more objective, partly by additional tutor training

    Clientelismo en democracia : una propuesta para el análisis de las relaciones clientelares a nivel local

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    El presente artículo presenta una crítica de la división analítica entre clientelismo moderno y tradicional defendida por diferentes autores. Basándose en el estudio en un municipio del sudoeste gallego llevado a cabo entre los años 2002 y 2004 se elabora una propuesta centrada en tres elementos principales: 1) la diferenciación entre recursos expresivos e instrumentales; 2) la subdivisión de la clientela de un mismo patrón en varios tipos en base a los recursos intercambiados; 3) plantear el estudio de las relaciones clientelares a través de la definición de sus prácticas. La combinación de estos tres elementos permite englobar las relaciones clientelares existentes en el caso de estudio del cual se parte

    Low fruitfulness in local almond orchards could be due to the inbreeding depression effect

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    Fruitfulness of 26 promising local almond genotypes in four Moroccan localities under two different agro-ecological systems, mountains and oasis ecosystem, was assessed by physiological means including pollen tube growth and fruit set after self- and cross-pollination and open-pollination. All studied genotypes are self-incompatible. The analysis of variance showed significant effects of the genotype, the year and the origin on fruit set in open-pollinated branches. Over two years, fruit set ranged from 5.3 % to 25.7 %,which is lower than the 30% threshold for a commercial crop in almond. The reciprocal cross-pollination test carried out in 6 genotypes from Agdez oasis locality showed that the genotypes Km-3 and Km-4 are cross-incompatible. Fruit set after cross-pollination among genotypes was low, with low to medium number of pollen tube at the style base after the reciprocal crosses, probably due to the inbreeding effect. In some crosses, the number of pollen tubes at the style base was high, whereas the fruit set was low. These results indicate that in traditional almond orchards, based on local cultivars propagated locally by seed, potential yield of the tree is limited by the effect of inbreeding depression. Keywords: Almond, Cross pollination, Fruit set, Self-incompatibility, Inbreeding depressio

    Does grade retention affect achievement? Some evidence from PISA

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    Grade retention practices are at the forefront of the educational debate. In this paper, we use PISA 2009 data for Spain to measure the effect of grade retention on students' achievement. One important problem when analyzing this question is that school outcomes and the propensity to repeat a grade are likely to be determined simultaneously. We address this problem by estimating a Switching Regression Model. We find that grade retention has a negative impact on educational outcomes, but we confirm the importance of endogenous selection, which makes observed differences between repeaters and non-repeaters appear 14.6% lower than they actually are. The effect on PISA scores of repeating is much smaller (-10% of non-repeaters' average) than the counterfactual reduction that non-repeaters would suffer had they been retained as repeaters (-24% of their average). Furthermore, those who repeated a grade during primary education suffered more than those who repeated a grade of secondary school, although the effect of repeating at both times is, as expected, much larger

    "Optical conductance fluctuations: diagrammatic analysis in Landauer approach and non-universal effects"

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    The optical conductance of a multiple scattering medium is the total transmitted light of a diffuse incoming beam. This quantity, very analogous to the electronic conductance, exhibits universal conductance fluctuations. We perform a detailed diagrammatic analysis of these fluctuations. With a Kadanoff-Baym technique all the leading diagrams are systematically generated. A cancellation of the short distance divergencies occurs, that yields a well behaved theory. The analytical form of the fluctuations is calculated and applied to optical systems. Absorption and internal reflections reduce the fluctuations significantly.Comment: 25 pages Revtex 3.0, 18 seperate postscript figure

    Auto-Classifier: A Robust Defect Detector Based on an AutoML Head

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    The dominant approach for surface defect detection is the use of hand-crafted feature-based methods. However, this falls short when conditions vary that affect extracted images. So, in this paper, we sought to determine how well several state-of-the-art Convolutional Neural Networks perform in the task of surface defect detection. Moreover, we propose two methods: CNN-Fusion, that fuses the prediction of all the networks into a final one, and Auto-Classifier, which is a novel proposal that improves a Convolutional Neural Network by modifying its classification component using AutoML. We carried out experiments to evaluate the proposed methods in the task of surface defect detection using different datasets from DAGM2007. We show that the use of Convolutional Neural Networks achieves better results than traditional methods, and also, that Auto-Classifier out-performs all other methods, by achieving 100% accuracy and 100% AUC results throughout all the datasets.Comment: 12 pages, 2 figures. Published in ICONIP2020, proceedings published in the Springer's series of Lecture Notes in Computer Scienc

    Effect of air voids content on thermal properties of asphalt mixtures

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    Air voids content is considered as one of the factors that may affect heat transfer through asphalt mixture, although their specific role on the asphalt mixture temperature is still unclear. The objective of this research is to have a deep insight of the effect of air voids content on the temperature evolution, transport and storage of heat in asphalt mixture under dry conditions. With this objective, asphalt mixture slabs with different air voids content have been built and their thermal conductivity, specific heat capacity, light absorptivity and thermal diffusivity related to their temperature evolution have been measured when they are exposed to infrared light and during the cooling process. It was observed that asphalt mixture with high air voids content exhibited slightly higher steady state temperatures than denser asphalt mixture and that the heating and cooling rates are higher in porous asphalt mixture than in denser materials. The reason for the faster increase and decrease in temperature of porous mixture and for the higher temperature reached by porous asphalt is its lower specific heat capacity and thermal conductivity. Finally, it could be observed that the connectivity of air voids in asphalt mixture did not play an important role on the temperature reached by asphalt mixture

    Synergies for Improving Oil Palm Production and Forest Conservation in Floodplain Landscapes

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    Lowland tropical forests are increasingly threatened with conversion to oil palm as global demand and high profit drives crop expansion throughout the world’s tropical regions. Yet, landscapes are not homogeneous and regional constraints dictate land suitability for this crop. We conducted a regional study to investigate spatial and economic components of forest conversion to oil palm within a tropical floodplain in the Lower Kinabatangan, Sabah, Malaysian Borneo. The Kinabatangan ecosystem harbours significant biodiversity with globally threatened species but has suffered forest loss and fragmentation. We mapped the oil palm and forested landscapes (using object-based-image analysis, classification and regression tree analysis and on-screen digitising of high-resolution imagery) and undertook economic modelling. Within the study region (520,269 ha), 250,617 ha is cultivated with oil palm with 77% having high Net-Present-Value (NPV) estimates (413/ha?yr413/ha?yr–637/ha?yr); but 20.5% is under-producing. In fact 6.3% (15,810 ha) of oil palm is commercially redundant (with negative NPV of 299/ha?yr-299/ha?yr--65/ha?yr) due to palm mortality from flood inundation. These areas would have been important riparian or flooded forest types. Moreover, 30,173 ha of unprotected forest remain and despite its value for connectivity and biodiversity 64% is allocated for future oil palm. However, we estimate that at minimum 54% of these forests are unsuitable for this crop due to inundation events. If conversion to oil palm occurs, we predict a further 16,207 ha will become commercially redundant. This means that over 32,000 ha of forest within the floodplain would have been converted for little or no financial gain yet with significant cost to the ecosystem. Our findings have globally relevant implications for similar floodplain landscapes undergoing forest transformation to agriculture such as oil palm. Understanding landscape level constraints to this crop, and transferring these into policy and practice, may provide conservation and economic opportunities within these seemingly high opportunity cost landscapes

    An analysis of wage differentials between full- and part-time workers in Spain

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    This research examines wage differences between part-time and full-time workers using microdata from the Spanish Structure of Earnings Survey. The main contribution of the paper is related to the analysis of differences along the wage distribution using econometric decomposition methods and introducing a regional perspective. The evidence shows that part-time workers in Spain experience a significant wage disadvantage. This disadvantage is worse in the case of female workers and it is not homogenous along the wage distribution, being comparatively more relevant for the most qualified women and becoming positive for the most qualified men. However, the disadvantage is practically explained by the endowments of characteristics, with a leading role of segregation of part-time workers in low-wage firms. From a regional perspective, although in the majority of the regions wage differences tend to be explained by endowments of characteristics, there are several regions where the unexplained part of the differential is significant, particularly in the case of male workers. These regional differences seem to be related to differences in the market power of firms at the regional level
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