970 resultados para 54301-019
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The nearly ubiquitous consumption of cereals all over the world renders them an important position in international nutrition, but concurrently allocates exposure to possible contained contaminants. Mycotoxins are natural food contaminants, difficult to predict, evade, and reduce, so it is important to establish the real contribution of each contaminated food product, with the aim to evaluate mycotoxin exposure. This was the key objective of this survey and analysis for ochratoxin A content on 274 samples of commercialized bread in the Portuguese market, during the winter 2007. Different bread products were analyzed through an HPLC-FD method, including traditional types, novel segments, and different grain based bread products. A wide-ranging low level contamination was observed in all regions and types of bread products analyzed, especially in the Porto and Coimbra regions, and in the maize and whole-grain or fiber-enriched bread. Nevertheless, the exposure through contaminated wheat bread continues to be the most significant, given its high consumption and dominance in relation to the other types of bread.
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OBJETIVO: Analisar a percepção de profissionais da Estratégia de Saúde da Família sobre práticas integrativas e complementares. MÉTODOS: Estudo com 177 médicos e enfermeiros a partir de um questionário auto-aplicado em 2008. As variáveis desfecho foram "interesse pelas práticas integrativas e complementares" e "concordância com a Política Nacional de Práticas Integrativas e Complementares". Sexo, idade, graduação, pós-graduação, tempo de formado e de trabalho, possuir filhos, oferta de práticas integrativas e complementares no local de trabalho e uso de homeopatia ou acupuntura compuseram as variáveis independentes. Os dados foram analisados pelo teste do qui-quadrado e teste exato de Fisher. RESULTADOS: Dezessete centros de saúde ofereciam práticas integrativas e complementares; 12,4% dos profissionais possuíam especialização em homeopatia ou acupuntura; 43,5% dos médicos eram especialistas em medicina de família e comunidade/saúde da família. Dos participantes, 88,7% desconheciam as diretrizes nacionais para a área, embora 81,4% concordassem com sua inclusão no Sistema Único de Saúde. A maioria (59,9%) mostrou interesse em capacitações e todos concordaram que essas práticas deveriam ser abordadas na graduação. A concordância com a inclusão dessas práticas mostrou-se associada significativamente com o fato de ser enfermeiro (p = 0,027) e com o uso de homeopatia para si (p = 0,019). Interesse pelas práticas complementares esteve associado a usar homeopatia para si (p = 0,02) e acupuntura para familiares (p = 0,013). CONCLUSÕES: Existe aceitação das práticas integrativas e complementares pelos profissionais estudados, associada ao contato prévio com elas e possivelmente relacionada à residência/especialização em medicina de família e comunidade/saúde da família.
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OBJETIVO: Analisar a mortalidade feminina por agressão segundo indicadores sociodemográficos e de saúde. MÉTODOS: Estudo ecológico sobre a mortalidade feminina por agressão ocorrida no Brasil de 2003 a 2007. Os dados de 19.459 óbitos foram obtidos do Sistema de Informações sobre Mortalidade. Os coeficientes padronizados de mortalidade feminina por agressão foram relacionados (teste de correlação de Pearson) com 28 indicadores socioeconômicos, demográficos e de saúde. Foi realizada regressão linear múltipla com variáveis que apresentaram p < 0,20 e excluídas as variáveis que apresentaram multicolinearidade. RESULTADOS: O coeficiente padronizado de mortalidade foi de 4,1 óbitos/100.000 mulheres no período. Após o ajuste, três variáveis permaneceram significativas e associadas à mortalidade feminina por agressão: taxa de natalidade (p = 0,072), percentual de evangélicos (p = 0,019) e coeficiente de mortalidade por agressão no sexo masculino (p < 0,001). O modelo possui uma capacidade de predição do desfecho de 69% (r² = 0,699). Espírito Santo, Pernambuco, Mato Grosso, Rio de Janeiro, Rondônia, Alagoas, Mato Grosso do Sul, Roraima e Amapá apresentaram os maiores coeficientes no período. CONCLUSÕES: A mortalidade feminina por agressão no Brasil foi elevada e não homogênea entre as regiões. Entre as variáveis associadas ao evento, destaca-se a mortalidade masculina por agressão, indicando a importância da redução da violência estrutural como proteção das mulheres contra a violência.
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Celiac disease (CD) is a gluten-induced autoimmune enteropathy characterized by the presence of antibodies against gliadin (AGA) and anti-tissue transglutaminase (anti-tTG) antibodies. A disposable electrochemical dual immunosensor for the simultaneous detection of IgA and IgG type AGA and antitTG antibodies in real patient’s samples is presented. The proposed immunosensor is based on a dual screen-printed carbon electrode, with two working electrodes, nanostructured with a carbon–metal hybrid system that worked as the transducer surface. The immunosensing strategy consisted of the immobilization of gliadin and tTG (i.e. CD specific antigens) on the nanostructured electrode surface. The electrochemical detection of the human antibodies present in the assayed serum samples was carried out through the antigen–antibody interaction and recorded using alkaline phosphatase labelled anti-human antibodies and a mixture of 3-indoxyl phosphate with silver ions was used as the substrate. The analytical signal was based on the anodic redissolution of enzymatically generated silver by cyclic voltammetry. The results obtained were corroborated with commercial ELISA kits indicating that the developed sensor can be a good alternative to the traditional methods allowing a decentralization of the analyses towards a point-of-care strategy.
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Future distribution systems will have to deal with an intensive penetration of distributed energy resources ensuring reliable and secure operation according to the smart grid paradigm. SCADA (Supervisory Control and Data Acquisition) is an essential infrastructure for this evolution. This paper proposes a new conceptual design of an intelligent SCADA with a decentralized, flexible, and intelligent approach, adaptive to the context (context awareness). This SCADA model is used to support the energy resource management undertaken by a distribution network operator (DNO). Resource management considers all the involved costs, power flows, and electricity prices, allowing the use of network reconfiguration and load curtailment. Locational Marginal Prices (LMP) are evaluated and used in specific situations to apply Demand Response (DR) programs on a global or a local basis. The paper includes a case study using a 114 bus distribution network and load demand based on real data.
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In the last few years, the number of systems and devices that use voice based interaction has grown significantly. For a continued use of these systems, the interface must be reliable and pleasant in order to provide an optimal user experience. However there are currently very few studies that try to evaluate how pleasant is a voice from a perceptual point of view when the final application is a speech based interface. In this paper we present an objective definition for voice pleasantness based on the composition of a representative feature subset and a new automatic voice pleasantness classification and intensity estimation system. Our study is based on a database composed by European Portuguese female voices but the methodology can be extended to male voices or to other languages. In the objective performance evaluation the system achieved a 9.1% error rate for voice pleasantness classification and a 15.7% error rate for voice pleasantness intensity estimation.
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Mestrado em Gestão e Avaliação de Tecnologias em Saúde
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OBJETIVO: Descrever a tendência dos casos de aids por sexo e faixa etária de 1986 a 2008. MÉTODOS: Foi analisada a tendência da aids por faixa etária e por sexo, em Londrina, PR, em dois períodos: 1986-1995 e 1996-2008. Dentre os modelos polinomiais, o de primeiro grau explicou melhor a tendência da epidemia da aids nos dois períodos. Foram calculadas as taxas de incidência para homens que fazem sexo com homens (HSH), usuários de drogas injetáveis (UDI), homens heterossexuais e mulheres. RESULTADOS: No primeiro período, de 1986 a 1995, houve incremento das taxas de incidência em quase todas as faixas etárias e crescimento da epidemia em ambos os sexos (p < 0,001), mais acentuado em homens de 14 a 39 anos. O segundo período (1996-2008) não apresentou incremento estatístico positivo ou negativo, indicando estabilização da epidemia. Verificou-se que ocorreu queda significativa na faixa de 14 a 29 anos no sexo masculino, com incremento de 0,88 no primeiro período e 0,87 no segundo. Mulheres de 50 anos e mais apresentaram aumento significativo (p = 0,019). Os grupos UDI e HSH predominaram como categorias de exposição e HSH ultrapassou UDI no último triênio do estudo. A partir de 2000, a taxa de incidência entre mulheres de 15 a 49 anos superou a de homens heterossexuais. CONCLUSÕES: Houve queda nas taxas de incidência nas faixas etárias mais jovens e estabilização nas demais idades. O aumento da proporção de mulheres e do predomínio de HSH entre as categorias de exposição aponta para necessidade de estratégias diferenciadas para atingir grupos com características diversas.
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Secure group communication is a paradigm that primarily designates one-to-many communication security. The proposed works relevant to secure group communication have predominantly considered the whole network as being a single group managed by a central powerful node capable of supporting heavy communication, computation and storage cost. However, a typical Wireless Sensor Network (WSN) may contain several groups, and each one is maintained by a sensor node (the group controller) with constrained resources. Moreover, the previously proposed schemes require a multicast routing support to deliver the rekeying messages. Nevertheless, multicast routing can incur heavy storage and communication overheads in the case of a wireless sensor network. Due to these two major limitations, we have reckoned it necessary to propose a new secure group communication with a lightweight rekeying process. Our proposal overcomes the two limitations mentioned above, and can be applied to a homogeneous WSN with resource-constrained nodes with no need for a multicast routing support. Actually, the analysis and simulation results have clearly demonstrated that our scheme outperforms the previous well-known solutions.
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Historical buildings are important fingerprints of the history and culture of a region and its communities. Climatic and environmental conditions are often very severe for construction materials, namely in presence of high humidity or in direct contact with water and salts. However, some historical buildings have in our days a very good condition, probably due to careful construction and/or accurate materials selection and to a specific technology. The knowledge of old mortars composition has a fundamental role on the preservation of cultural heritage, allowing information about the used materials, their performance in their specific environment, conducting to adequate and compatible materials to conservation purposes. This article presents two case studies of historical buildings with important defence functions in Lisbon coast, in which ancient lime mortars where used under severe seaside environmental actions. Mortar samples from these two case studies are characterized and the relationship of their composition with the good performance and high durability observed is discussed.
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The performance of the Weather Research and Forecast (WRF) model in wind simulation was evaluated under different numerical and physical options for an area of Portugal, located in complex terrain and characterized by its significant wind energy resource. The grid nudging and integration time of the simulations were the tested numerical options. Since the goal is to simulate the near-surface wind, the physical parameterization schemes regarding the boundary layer were the ones under evaluation. Also, the influences of the local terrain complexity and simulation domain resolution on the model results were also studied. Data from three wind measuring stations located within the chosen area were compared with the model results, in terms of Root Mean Square Error, Standard Deviation Error and Bias. Wind speed histograms, occurrences and energy wind roses were also used for model evaluation. Globally, the model accurately reproduced the local wind regime, despite a significant underestimation of the wind speed. The wind direction is reasonably simulated by the model especially in wind regimes where there is a clear dominant sector, but in the presence of low wind speeds the characterization of the wind direction (observed and simulated) is very subjective and led to higher deviations between simulations and observations. Within the tested options, results show that the use of grid nudging in simulations that should not exceed an integration time of 2 days is the best numerical configuration, and the parameterization set composed by the physical schemes MM5–Yonsei University–Noah are the most suitable for this site. Results were poorer in sites with higher terrain complexity, mainly due to limitations of the terrain data supplied to the model. The increase of the simulation domain resolution alone is not enough to significantly improve the model performance. Results suggest that error minimization in the wind simulation can be achieved by testing and choosing a suitable numerical and physical configuration for the region of interest together with the use of high resolution terrain data, if available.
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Mestrado em Segurança e Higiene no Trabalho
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This paper studies the dynamics of a system composed of a collection of particles that exhibit collisions between them. Several entropy measures and different impact conditions of the particles are tested. The results reveal a Power Law evolution both of the system energy and the entropy measures, typical in systems having fractional dynamics.
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The three-dimensional (3D) exact solutions developed in the early 1970s by Pagano for simply supported multilayered orthotropic composite plates and later in the 1990s extended to piezoelectric plates by Heyliger have been extremely useful in the assessment and development of advanced laminated plate theories and related finite element models. In fact, the well-known test cases provided by Pagano and by Heyliger in those earlier works are still used today as benchmark solutions. However, the limited number of test cases whose 3D exact solutions have been published has somewhat restricted the assessment of recent advanced models to the same few test cases. This work aims to provide additional test cases to serve as benchmark exact solutions for the static analysis of multilayered piezoelectric composite plates. The method introduced by Heyliger to derive the 3D exact solutions has been successfully implemented using symbolic computing and a number of new test cases are here presented thoroughly. Specifically, two multilayered plates using PVDF piezoelectric material are selected as test cases under two different loading conditions and considering three plate aspect ratios for thick, moderately thick and thin plate, in a total of 12 distinct test cases. (C) 2013 Elsevier Ltd. All rights reserved.
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The morpho-structural evolution of oceanic islands results from competition between volcano growth and partial destruction by mass-wasting processes. We present here a multi-disciplinary study of the successive stages of development of Faial (Azores) during the last 1 Myr. Using high-resolution digital elevation model (DEM), and new K/Ar, tectonic, and magnetic data, we reconstruct the rapidly evolving topography at successive stages, in response to complex interactions between volcanic construction and mass wasting, including the development of a graben. We show that: (1) sub-aerial evolution of the island first involved the rapid growth of a large elongated volcano at ca. 0.85 Ma, followed by its partial destruction over half a million years; (2) beginning about 360 ka a new small edifice grew on the NE of the island, and was subsequently cut by normal faults responsible for initiation of the graben; (3) after an apparent pause of ca. 250 kyr, the large Central Volcano (CV) developed on the western side of the island at ca 120 ka, accumulating a thick pile of lava flows in less than 20 kyr, which were partly channelized within the graben; (4) the period between 120 ka and 40 ka is marked by widespread deformation at the island scale, including westward propagation of faulting and associated erosion of the graben walls, which produced sedimentary deposits; subsequent growth of the CV at 40 ka was then constrained within the graben, with lava flowing onto the sediments up to the eastern shore; (5) the island evolution during the Holocene involves basaltic volcanic activity along the main southern faults and pyroclastic eruptions associated with the formation of a caldera volcano-tectonic depression. We conclude that the whole evolution of Faial Island has been characterized by successive short volcanic pulses probably controlled by brief episodes of regional deformation. Each pulse has been separated by considerable periods of volcanic inactivity during which the Faial graben gradually developed. We propose that the volume loss associated with sudden magma extraction from a shallow reservoir in different episodes triggered incremental downward graben movement, as observed historically, when immediate vertical collapse of up to 2 m was observed along the western segments of the graben at the end of the Capelinhos eruptive crises (1957-58).