599 research outputs found

    Análise crítica do programa da reforma educativa para o ensino do português LS na 7ª classe em Angola

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    Dissertação para a obtenção de grau de Mestre em Ensino de Português Como Língua Segunda/ Língua EstrangeiraA situação actual da língua portuguesa em Angola desperta interesse de estudo em várias áreas. A questão do seu ensino, enquanto língua segunda, é a vertente que se destaca neste Trabalho. Recentemente o Governo angolano promulgou a 2ª Reforma Educativa com o objectivo de melhorar o sistema de ensino – aprendizagem. A língua portuguesa está em destaque. Não só por assumir o papel de língua oficial e de escolaridade, mas também por ser o veículo de comunicação internacional e de confluência com as línguas locais maioritariamente Bantu. É neste contexto que se procura dar a melhor resposta à necessidade de formação de usuários proficientes de PLS, e isto requer a elaboração e aplicação de metodologias que respondam ao desafio. Nesta perspectiva, propusemo-nos realizar o estudo com o título: Análise Crítica do Programa da Reforma Educativa para o Ensino do Português LS na 7ª Classe em Angola, com os objectivos essenciais de analisar as propostas metodológicas e sugerir melhorias. Para tal, servimo-nos do método empírico consubstanciado na consulta da bibliografia especializada e na de documentos reitores da Reforma. O Trabalho organiza-se em cinco capítulos, conclusão, sugestões, bibliografia e anexos. Da análise feita concluímos que a 2ª Reforma Educativa de Angola é um projecto ambicioso, com resultados aceitáveis, mas ainda distantes do ideal preconizado. Urge que se melhorem as condições de trabalho, de investigação, de ensino e infra-estruturais. Para a língua portuguesa em especial, a aposta na (re)qualificação dos quadros e a implementação de mais e melhores condições é fulcral. Do Programa vê-se uma estrutura diversificada que, se bem aplicada, facilita a aquisição de conhecimentos científicos e heurísticos. Porém as metodologias e as estratégias tendem mais para a mecanização do processo de ensino – aprendizagem. Aqui o papel do professor é fundamental, não só no respeito e cumprimento do legislado, mas sobretudo com uma perspectiva crítica construtiva

    de Sitter vacua in O(d,d) invariant cosmology

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    We perform a thorough analysis of de Sitter solutions in O⁡(,) invariant cosmologies. Starting with a homogeneous and isotropic framework we examine conditions for the existence of such solutions to the vacuum field equations, nonperturbative in ′ in both the string frame and the Einstein frame. We elucidate the nature of the instability in the string frame vacuum. For the Einstein frame, we demonstrate that the de Sitter solutions cannot be eternal. We then extend our analysis to include Bianchi I universes where the O⁡(,) symmetry includes scale factor exchange as well as scale factor duality. We show how the theory can be extended to the anisotropic case so that it admits de Sitter solutions, noting the crucial role played by the O⁡(,) symmetry in satisfying any additional constraints

    A VSA search for the extended Sunyaev-Zel'dovich Effect in the Corona Borealis Supercluster

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    We present interferometric imaging at 33 GHz of the Corona Borealis supercluster, using the extended configuration of the Very Small Array. A total area of 24 deg^2 has been imaged, with an angular resolution of 11 arcmin and a sensitivity of 12 mJy/beam. The aim of these observations is to search for Sunyaev-Zel'dovich (SZ) detections from known clusters of galaxies in this supercluster and for a possible extended SZ decrement due to diffuse warm/hot gas in the intercluster medium. We measure negative flux values in the positions of the ten richest clusters in the region. Collectively, this implies a 3.0-sigma detection of the SZ effect. In the clusters A2061 and A2065 we find decrements of approximately 2-sigma. Our main result is the detection of two strong and resolved negative features at -70+-12 mJy/beam (-157+-27 microK) and -103+-10 mJy/beam (-230+-23 microK), respectively, located in a region with no known clusters, near the centre of the supercluster. We discuss their possible origins in terms of primordial CMB anisotropies and/or SZ signals related to either unknown clusters or to a diffuse extended warm/hot gas distribution. Our analyses have revealed that a primordial CMB fluctuation is a plausible explanation for the weaker feature (probability of 37.82%). For the stronger one, neither primordial CMB (probability of 0.33%) nor SZ can account alone for its size and total intensity. The most reasonable explanation, then, is a combination of both primordial CMB and SZ signal. Finally, we explore what characteristics would be required for a filamentary structure consisting of warm/hot diffuse gas in order to produce a significant contribution to such a spot taking into account the constraints set by X-ray data.Comment: 16 pages, 10 figures. Accepted in MNRA

    Fresolimumab Treatment Decreases Biomarkers and Improves Clinical Symptoms in Systemic Sclerosis Patients

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    BACKGROUND. TGF-β has potent profibrotic activity in vitro and has long been implicated in systemic sclerosis (SSc), as expression of TGF-β–regulated genes is increased in the skin and lungs of patients with SSc. Therefore, inhibition of TGF-β may benefit these patients. METHODS. Patients with early, diffuse cutaneous SSc were enrolled in an open-label trial of fresolimumab, a high-affinity neutralizing antibody that targets all 3 TGF-β isoforms. Seven patients received two 1 mg/kg doses of fresolimumab, and eight patients received one 5 mg/kg dose of fresolimumab. Serial mid-forearm skin biopsies, performed before and after treatment, were analyzed for expression of the TGF-β–regulated biomarker genes thrombospondin-1 (THBS1) and cartilage oligomeric protein (COMP) and stained for myofibroblasts. Clinical skin disease was assessed using the modified Rodnan skin score (MRSS). RESULTS. In patient skin, THBS1 expression rapidly declined after fresolimumab treatment in both groups (P = 0.0313 at 7 weeks and P = 0.0156 at 3 weeks), and skin expression of COMP exhibited a strong downward trend in both groups. Clinical skin disease dramatically and rapidly decreased (P \u3c 0.001 at all time points). Expression levels of other TGF-β–regulated genes, including SERPINE1 and CTGF, declined (P = 0.049 and P = 0.012, respectively), and a 2-gene, longitudinal pharmacodynamic biomarker of SSc skin disease decreased after fresolimumab treatment (P = 0.0067). Dermal myofibroblast infiltration also declined in patient skin after fresolimumab (P \u3c 0.05). Baseline levels of THBS1 were predictive of reduced THBS1 expression and improved MRSS after fresolimumab treatment. CONCLUSION. The rapid inhibition of TGF-β–regulated gene expression in response to fresolimumab strongly implicates TGF-β in the pathogenesis of fibrosis in SSc. Parallel improvement in the MRSS indicates that fresolimumab rapidly reverses markers of skin fibrosis

    The economic impact of machine perfusion technology in liver transplantation

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    Introduction: Several clinical studies have demonstrated the safety, feasibility, and efficacy of machine perfusion in liver transplantation, although its economic outcomes are still underexplored. This review aimed to examine the costs related to machine perfusion and its associated outcomes.Methods: Expert opinion of several groups representing different machine perfusion modalities. Critical analysis of the published literature reporting the economic outcomes of the most used techniques of machine perfusion in liver transplantation (normothermic and hypothermic ex situ machine perfusion and in situ normothermic regional perfusion).Results: Machine perfusion costs include disposable components of the perfusion device, perfusate components, personnel and facility fees, and depreciation of the perfusion device or device lease fee. The limited current literature suggests that although this upfront cost varies between perfusion modalities, its use is highly likely to be cost-effective. Optimization of the donor liver utilization rate, local conditions of transplant programs (long waiting list times and higher MELD scores), a decreased rate of complications, changes in logistics, and length of hospital stay are potential cost savings points that must highlight the expected benefits of this intervention. An additional unaccounted factor is that machine perfusion optimizing donor organ utilization allows patients to be transplanted earlier, avoiding clinical deterioration while on the waiting list and the costs associated with hospital admissions and other required procedures.Conclusion: So far, the clinical benefits have guided machine perfusion implementation in liver transplantation. Albeit there is data suggesting the economic benefit of the technique, further investigation of its costs to healthcare systems and society and associated outcomes is needed.</p

    Follow-up observations at 16 and 33 GHz of extragalactic sources from WMAP 3-year data: I - Spectral properties

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    We present follow-up observations of 97 point sources from the Wilkinson Microwave Anisotropy Probe (WMAP) 3-year data, contained within the New Extragalactic WMAP Point Source (NEWPS) catalogue between declinations of -4 and +60 degrees; the sources form a flux-density-limited sample complete to 1.1 Jy (approximately 5 sigma) at 33 GHz. Our observations were made at 16 GHz using the Arcminute Microkelvin Imager (AMI) and at 33 GHz with the Very Small Array (VSA). 94 of the sources have reliable, simultaneous -- typically a few minutes apart -- observations with both telescopes. The spectra between 13.9 and 33.75 GHz are very different from those of bright sources at low frequency: 44 per cent have rising spectra (alpha < 0.0), where flux density is proportional to frequency^-alpha, and 93 per cent have spectra with alpha < 0.5; the median spectral index is 0.04. For the brighter sources, the agreement between VSA and WMAP 33-GHz flux densities averaged over sources is very good. However, for the fainter sources, the VSA tends to measure lower values for the flux densities than WMAP. We suggest that the main cause of this effect is Eddington bias arising from variability.Comment: 12 pages, 13 figures, submitted to MNRA

    Parallel tracks towards a global treaty on carbon pricing

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    We argue that a global carbon price is the only way to effectively tackle free riding in international climate policy, required to substantially reduce greenhouse gas emissions. We briefly review the main reasons behind the essential role of carbon pricing, address common misunderstandings and scepticism, and identify key complementary policy instruments. Negotiating global carbon pricing is argued to be much easier than negotiating binding country-level targets, especially if it includes equitable revenue recycling. Moreover, a global carbon price can be more readily adapted to new data and insights of climate science. We propose a political strategy towards a global carbon price that consists of two tracks. The first entails assembly of a carbon-pricing club, a specific case of a climate club, to gradually move towards a full participatory agreement on carbon pricing. The second track involves putting time and energy into re-focusing UNFCCC negotiations on a carbon-pricing agreement. The two tracks reinforce one another, increasing the likelihood of a successful outcome

    MAGIC upper limits on the very high energy emission from GRBs

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    The fast repositioning system of the MAGIC Telescope has allowed during its first data cycle, between 2005 and the beginning of year 2006, observing nine different GRBs as possible sources of very high energy gammas. These observations were triggered by alerts from Swift, HETE-II, and Integral; they started as fast as possible after the alerts and lasted for several minutes, with an energy threshold varying between 80 and 200 GeV, depending upon the zenith angle of the burst. No evidence for gamma signals was found, and upper limits for the flux were derived for all events, using the standard analysis chain of MAGIC. For the bursts with measured redshift, the upper limits are compatible with a power law extrapolation, when the intrinsic fluxes are evaluated taking into account the attenuation due to the scattering in the Metagalactic Radiation Field (MRF).Comment: 25 pages, 9 figures, final version accepted by ApJ. Changet title to "MAGIC upped limits on the VERY high energy emission from GRBs", re-organized chapter with description of observation, removed non necessaries figures, added plot of effective area depending on zenith angle, added an appendix explaining the upper limit calculation, added some reference

    Bouncing Braneworlds Go Crunch!

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    Recently, interesting braneworld cosmologies in the Randall-Sundrum scenario have been constructed using a bulk spacetime which corresponds to a charged AdS black hole. In particular, these solutions appear to `bounce', making a smooth transition from a contracting to an expanding phase. By considering the spacetime geometry more carefully, we demonstrate that generically in these solutions the brane will encounter a singularity in the transition region.Comment: 17 pages, 4 figures, ref adde
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