904 resultados para complex communication needs
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A copper(II) chiral aza-bis(oxazoline) homogeneous catalyst (CuazaBox) was anchored onto the external surface of MCM-22 and ITQ-2 structures, as well as encapsulated into hierarchical MCM-22. The transition metal complex loading onto the porous solids was determined by ICP-AES and the materials were also characterized by elemental analysis (C, N, H, S), FTIR, XPS, TG and low temperature N-2 adsorption isotherms. The materials were tested as heterogeneous catalysts in the benchmark reaction of cyclopropanation of styrene to check the effect of the immobilization procedure on the catalytic parameters, as well as on their reutilization in several catalytic cycles. Catalyst CuazaBox anchored onto the external surface of MCM-22 and ITQ-2 materials were more active and enantioselective in the cyclopropanation of styrene than the corresponding homogeneous phase reaction run under similar experimental conditions. This is due to the propylation of the acidic aza-Box nitrogen. HMCM-22 was nevertheless the best heterogeneous catalyst. Encapsulation of CuazaBox on post-synthesis modified MCM-22 materials led to low activities and enantioselectivities. But reversal on the stereochemical course of the reaction was observed, probably due to confinement effect. (C) 2013 Elsevier Inc. All rights reserved.
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The hydrotris(pyrazol-1-yl)methane iron(II) complex [FeCl2{eta(3)-HC(pz)(3)}] (Fe, pz = pyrazol-1-yl) immobilized on commercial (MOR) or desilicated (MOR-D) zeolite, catalyses the oxidation of cyclohexane with hydrogen peroxide to cyclohexanol and cyclohexanone, under mild conditions. MOR-D/Fe (desilicated zeolite supported [FeCl2{eta(3)-HC(pz)(3)}] complex) provides an outstanding catalytic activity (TON up to 2.90 x 10(3)) with the concomitant overall yield of 38%, and can be easy recovered and reused. The MOR or MOR-D supported hydrotris(pyrazol-1-yl)methane iron(II) complex (MOR/Fe and MOR-D/Fe, respectively) was characterized by X-ray powder diffraction, ICP-AES, and TEM studies as well as by IR spectroscopy and N-2 adsorption at -196 degrees C. The catalytic operational conditions (e.g., reaction time, type and amount of oxidant, presence of acid and type of solvent) were optimized. (C) 2013 Elsevier B.V. All rights reserved.
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Video coding technologies have played a major role in the explosion of large market digital video applications and services. In this context, the very popular MPEG-x and H-26x video coding standards adopted a predictive coding paradigm, where complex encoders exploit the data redundancy and irrelevancy to 'control' much simpler decoders. This codec paradigm fits well applications and services such as digital television and video storage where the decoder complexity is critical, but does not match well the requirements of emerging applications such as visual sensor networks where the encoder complexity is more critical. The Slepian Wolf and Wyner-Ziv theorems brought the possibility to develop the so-called Wyner-Ziv video codecs, following a different coding paradigm where it is the task of the decoder, and not anymore of the encoder, to (fully or partly) exploit the video redundancy. Theoretically, Wyner-Ziv video coding does not incur in any compression performance penalty regarding the more traditional predictive coding paradigm (at least for certain conditions). In the context of Wyner-Ziv video codecs, the so-called side information, which is a decoder estimate of the original frame to code, plays a critical role in the overall compression performance. For this reason, much research effort has been invested in the past decade to develop increasingly more efficient side information creation methods. This paper has the main objective to review and evaluate the available side information methods after proposing a classification taxonomy to guide this review, allowing to achieve more solid conclusions and better identify the next relevant research challenges. After classifying the side information creation methods into four classes, notably guess, try, hint and learn, the review of the most important techniques in each class and the evaluation of some of them leads to the important conclusion that the side information creation methods provide better rate-distortion (RD) performance depending on the amount of temporal correlation in each video sequence. It became also clear that the best available Wyner-Ziv video coding solutions are almost systematically based on the learn approach. The best solutions are already able to systematically outperform the H.264/AVC Intra, and also the H.264/AVC zero-motion standard solutions for specific types of content. (C) 2013 Elsevier B.V. All rights reserved.
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10th International Phycological Congress, Orlando, Florida, USA, 4-10 de agosto 2013.
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10th International Phycological Congress, Orlando, Florida, USA, 4-10 de agosto 2013.
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Anticancer activity of the new [Ru(eta(5)-C5H5)(PPh3)(Me(2)bpy)][CF3SO3] (Me(2)bpy = 4,4'-dimethyl-2,2'-bipyridine) complex was evaluated in vitro against several human cancer cell lines, namely A2780, A2780CisR, HT29, MCF7, MDAMB231 and PC3. Remarkably, the IC50 values, placed in the nanomolar and sub-micromolar range, largely exceeded the activity of cisplatin. Binding to human serum albumin, either HSA (human serum albumin) or HSA(faf) (fatty acid-free human serum albumin) does not affect the complex activity. Fluorescence studies revealed that the present ruthenium complex strongly quench the intrinsic fluorescence of albumin. Cell death by the [Ru(eta(5)-C5H5)(PPh3)(Me(2)bpy)][CF3SO3] complex was reduced in the presence of endocytosis modulators and at low temperature, suggesting an energy-dependent mechanism consistent with endocytosis. On the whole, the biological activity evaluated herein suggests that the complex could be a promising anticancer agent. (C) 2013 Elsevier Inc. All rights reserved.
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We present the first version of a new tool to scan the parameter space of generic scalar potentials, SCANNERS (Coimbra et al., SCANNERS project., 2013). The main goal of SCANNERS is to help distinguish between different patterns of symmetry breaking for each scalar potential. In this work we use it to investigate the possibility of excluding regions of the phase diagram of several versions of a complex singlet extension of the Standard Model, with future LHC results. We find that if another scalar is found, one can exclude a phase with a dark matter candidate in definite regions of the parameter space, while predicting whether a third scalar to be found must be lighter or heavier. The first version of the code is publicly available and contains various generic core routines for tree level vacuum stability analysis, as well as implementations of collider bounds, dark matter constraints, electroweak precision constraints and tree level unitarity.
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Esta comunicação tem como objetivo analisar como as políticas respeitantes à segurança escolar são reinterpretadas e reorientadas em resultado das estratégias e filosofias de intervenção das direções das escolas e outros agentes educativos. Tendo como premissa que o contexto social não determina linearmente a violência escolar, o estudo centrou-se na análise das relações entre o contexto social local e organizacional das escolas, procurando identificar os factores relevantes para o processo de regulação da violência. Foram selecionados três clusters de escolas na Área Metropolitana de Lisboa, tendo em conta contrastes intra e inter clusters assim como a sua posição relativa face aos níveis de violência registadas a nível nacional. Foi identificada uma diversidade significativa de respostas à violência, concretizadas na mobilização de diferentes recursos pelos responsáveis das escolas com o duplo objetivo de atingir as metas políticas definidas e os seus próprios interesses estratégicos. Esta apropriação e reorientação das políticas realiza-se através da estruturação de redes locais de poder, hierarquizando competências e responsabilidades, e no processo, redefinindo os objetivos do processo de prevenção e intervenção. A ocultação das situações de violência, o recrutamento preferencial de estudantes de classe média ou com sucesso educativo elevado, ou ainda as sanções desproporcionais para alunos agressores ou indisciplinados, foram algumas das estratégias identificadas. Isto mostra que os atores têm diferentes possibilidades e capacidades de ação num sistema complexo de regras sociais que, dentro de certos limites, lhes permite reinterpretar e reconstruir regras e, em última instância, contribuir para a alteração do próprio sistema (Mouzelis, 2000;; Burns e Flam, 2000;; Lipsky, 1980).
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Mestrado (PES II), Educação Pré-Escolar e Ensino do 1.º Ciclo do Ensino Básico, 1 de Julho de 2014, Universidade dos Açores.
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Os Hospitais são organizações extraordinariamente complicadas, representando uma das formas mais complexas de organização humana. Desempenham, igualmente, um papel inquestionável e essencial para a sociedade – a prestação dos cuidados de saúde, mas também a promoção, prevenção e protecção da mesma. Ao contrário do que se pensa, a compreensão da necessidade de desenvolvimento de departamentos de comunicação organizacional no seio das instituições de saúde públicas não é só uma realidade nos países anglo-saxónicos. Na realidade um pouco por toda a Europa a consciencialização sobre o valor intrínseco da comunicação organizacional e institucional para o melhor desempenho das unidades de saúde é já uma questão de facto ao contrário do que parece continuar a acontecer em Portugal. Esta investigação tem como objectivo por um lado a caracterização das estruturas de comunicação existentes nos hospitais públicos portugueses e por outro lado, evidenciar as áreas que são mais privilegiadas por estas estruturas. É importante num momento de mudança em termos de políticas públicas de saúde, a clarificação do papel dos departamentos de comunicação no seio das unidades hospitalares colocando-os enquanto órgãos estratégicos no desenvolvimento e na prossecução dos objectivos das instituições.
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Bioaerosols are mainly composed of fungal particles, bacteria and plant spores, being fungi responsible for the release of VOCs and micotoxins into indoor environments. Aspergillus flavus is a common opportunistic pathogen causing human infections and is involved in the production of aflatoxin and other secondary metabolites associated with toxic and allergic reactions. Poultry workers are exposed to high concentrations of fungi and are therefore more prone to develop associated pathologies. To evaluate occupational exposure of the workers to Aspergillus flavus and aflatoxins, six animal production facilities were selected, including 10 buildings, from which indoor air samples and outdoor reference samples were obtained. Twenty-five duplicate samples were collected by two methodologies: impactation onto malt extract agar of 25L air samples using a Millipore Air Tester were used to evaluate quantitative (CFU/m3) and qualitative (species identification, whenever possible) sample composition; 300 L air samples collected with the Coriolis Air Sampler into phosphate–saline buffer were used to isolate DNA, following molecular identification of Aspergillus section flavi using nor-1 specific primers by real-time PCR.
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Mestrado em Engenharia Informática. Sistemas Gráficos e Multimédia
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The evolution of hybrid polyploid vertebrates, their viability and their perpetuation over evolutionary time have always been questions of great interest. However, little is known about the impact of hybridization and polyploidization on the regulatory networks that guarantee the appropriate quantitative and qualitative gene expression programme. The Squalius alburnoides complex of hybrid fish is an attractive system to address these questions, as it includes a wide variety of diploid and polyploid forms, and intricate systems of genetic exchange. Through the study of genome-specific allele expression of seven housekeeping and tissue-specific genes, we found that a gene copy silencing mechanism of dosage compensation exists throughout the distribution range of the complex. Here we show that the allele-specific patterns of silencing vary within the complex, according to the geographical origin and the type of genome involved in the hybridization process. In southern populations, triploids of S. alburnoides show an overall tendency for silencing the allele from the minority genome, while northern population polyploids exhibit preferential biallelic gene expression patterns, irrespective of genomic composition. The present findings further suggest that gene copy silencing and variable expression of specific allele combinations may be important processes in vertebrate polyploid evolution.
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Este artigo é uma introdução à teoria do paradigma desconstrutivo de aprendizagem cooperativa. Centenas de estudos provam com evidências o facto de que as estruturas e os processos de aprendizagem cooperativa aumentam o desempenho académico, reforçam as competências de aprendizagem ao longo da vida e desenvolvem competências sociais, pessoais de cada aluno de uma forma mais eficaz e usta, comparativamente às estruturas tradicionais de aprendizagem nas escolas. Enfrentando os desafios dos nossos sistemas educativos, seria interessante elaborar o quadro teórico do discurso da aprendizagem cooperativa, dos últimos 40 anos, a partir de um aspeto prático dentro do contexto teórico e metodológico. Nas últimas décadas, o discurso cooperativo elaborou os elementos práticos e teóricos de estruturas e processos de aprendizagem cooperativa. Gostaríamos de fazer um resumo desses elementos com o objetivo de compreender que tipo de mudanças estruturais podem fazer diferenças reais na prática de ensino e aprendizagem. Os princípios básicos de estruturas cooperativas, os papéis de cooperação e as atitudes cooperativas são os principais elementos que podemos brevemente descrever aqui, de modo a criar um quadro para a compreensão teórica e prática de como podemos sugerir os elementos de aprendizagem cooperativa na nossa prática em sala de aula. Na minha perspetiva, esta complexa teoria da aprendizagem cooperativa pode ser entendida como um paradigma desconstrutivo que fornece algumas respostas pragmáticas para as questões da nossa prática educativa quotidiana, a partir do nível da sala de aula para o nível de sistema educativo, com foco na destruição de estruturas hierárquicas e antidemocráticas de aprendizagem e, criando, ao mesmo tempo, as estruturas cooperativas.
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Dissertação apresentada à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Ciências da Educação, especialidade Educação Especial – Problemas Cognitivos e Multideficiência