958 resultados para Group Key Exchange
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OBJECTIVE: To assess the feasibility of HIV rapid testing for pregnant women at maternity hospital admission and of subsequent interventions to reduce perinatal HIV transmission. METHODS: Study based on a convenience sample of women unaware of their HIV serostatus when they were admitted to delivery in public maternity hospitals in Rio de Janeiro and Porto Alegre, Brazil, between March 2000 and April 2002. Women were counseled and tested using the Determine HIV1/2 Rapid Test. HIV infection was confirmed using the Brazilian algorithm for HIV infection diagnosis. In utero transmission of HIV was determined using HIV-DNA-PCR. There were performed descriptive analyses of sociodemographic data, number of previous pregnancies and abortions, number of prenatal care visits, timing of HIV testing, HIV rapid test result, neonatal and mother-to-child transmission interventions, by city studied. RESULTS: HIV prevalence in women was 6.5% (N=1,439) in Porto Alegre and 1.3% (N=3.778) in Rio de Janeiro. In Porto Alegre most of women were tested during labor (88.7%), while in Rio de Janeiro most were tested in the postpartum (67.5%). One hundred and forty-four infants were born to 143 HIV-infected women. All newborns but one in each city received at least prophylaxis with oral zidovudine. It was possible to completely avoid newborn exposure to breast milk in 96.8% and 51.1% of the cases in Porto Alegre and Rio de Janeiro, respectively. Injectable intravenous zidovudine was administered during labor to 68.8% and 27.7% newborns in Porto Alegre and Rio de Janeiro, respectively. Among those from whom blood samples were collected within 48 hours of birth, in utero transmission of HIV was confirmed in 4 cases in Rio de Janeiro (4/47) and 6 cases in Porto Alegre (6/79). CONCLUSIONS: The strategy proved feasible in maternity hospitals in Rio de Janeiro and Porto Alegre. Efforts must be taken to maximize HIV testing during labor. There is a need of strong social support to provide this population access to health care services after hospital discharge.
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Relatório apresentado à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Ensino do 1º e do 2º Ciclos do Ensino Básico
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Relatório de Estágio apresentado à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Ensino do 1.º e 2.º ciclo do Ensino Básico
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In recent years several countries have set up policies that allow exchange of kidneys between two or more incompatible patient–donor pairs. These policies lead to what is commonly known as kidney exchange programs. The underlying optimization problems can be formulated as integer programming models. Previously proposed models for kidney exchange programs have exponential numbers of constraints or variables, which makes them fairly difficult to solve when the problem size is large. In this work we propose two compact formulations for the problem, explain how these formulations can be adapted to address some problem variants, and provide results on the dominance of some models over others. Finally we present a systematic comparison between our models and two previously proposed ones via thorough computational analysis. Results show that compact formulations have advantages over non-compact ones when the problem size is large.
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Low-rate low-power consumption and low-cost communication are the key points that lead to the specification of the IEEE 802.15.4 standard. This paper overviews the technical features of the physical layer and the medium access control sublayer mechanisms of the IEEE 802.15.4 protocol that are most relevant for wireless sensor network applications. We also discuss the ability of IEEE 802.15.4 to fulfil the requirements of wireless sensor network applications.
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OBJETIVO: To assess factors associated with a low risk perception of zoonoses and to identify the gaps in knowledge about transmission and prevention of zoonoses in immigrant and Italian workers. MÉTODOS: A cross-sectional study with 175 workers in the agro-livestock and agro-food industry in Piemonte, Italy, was carried out. Data were collected with a semi-structured questionnaire based on knowledge, attitudes and practices (KAP) survey. We calculated proportions and used chi-square tests and odds ratios to assess associations. Eight individual interviews with key informants on immigration and public health in Piemonte were carried out. RESULTADOS: Participants were 82 (47%) Italians and 93 (53%) immigrants. Immigrants were from Romania, Morocco, Albania, India, China, Argentina, Peru, Macedonia, Ivory Coast, Ukraine and Colombia. The study revealed significant differences in risk perception at work (p = 0.001). We found associations between "not having correct knowledge about zoonoses" and the following variables: i. "being immigrant" OR = 4.1 (95%CI 1.7;9.8 p ≤ 0.01); ii. "working in the livestock industry" OR = 2.9 (95%CI 1.2;15.4 p = 0.01); and iii. "being an unqualified worker" OR = 4.4 (95%CI 2.9;15.4 p ≤ 0.01). Another strong association was found between being immigrant and having a low job qualification OR = 6.7 (IC95% 2.9 - 15.4 p ≤ 0.01). Asian immigrants were the group with the highest frequency of risky behaviours and the lowest level of knowledge about zoonoses. CONCLUSÕES: Our results indicate that there were differences in risk perception of zoonoses between the groups participating in our study. These results suggest that immigrant status can be considered a risk factor for having lower risk perception and lower level of knowledge of zoonoses at work. There is a relationship between this specific knowledge of zoonoses and lack of training and instruction among migrant populations. Our results stress the need for developing education programs on zoonoses prevention among the immigrant population in Piemonte, Italy.
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Dissertação de Natureza Científica para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Edificações
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Aims: Obesity and asthma are widely prevalent and associated disorders. Recent studies of our group revealed that Substance P (SP) is involved in pathophysiology of obese-asthma phenotype in mice through its selective NK1 receptor (NK1-R). Lymphangiogenesis is impaired in asthma and obesity, and SP activates contractile and inflammatory pathways in lymphatics. Our aim was to study whether NK1-R expression was involved in lymphangiogenesis on visceral (VAT) and subcutaneous (SAT) adipose tissues and in the lungs, in obeseallergen sensitized mice. Main methods: Diet-induced obese and ovalbumin (OVA)-sensitized Balb/c mice were treated with a selective NK1-R antagonist (CJ 12,255, Pfizer Inc., USA) or placebo. Lymphatic structures (LYVE-1+) and NK1-R expression were analyzed by immunohistochemistry. A semi-quantitative score methodology was used for NK1-R expression. Key findings: Obesity and allergen-sensitization together increased the number of LYVE-1+ lymphatics in VAT and decreased it in SAT and lungs. NK1-R was mainly expressed on adipocyte membranes of VAT, blood vessel areas of SAT, and in lung epithelium. Obesity and allergen-sensitization combined increased the expression of NK1-R in VAT, SAT and lungs. NK1-R antagonist treatment reversed the effects observed in lymphangiogenesis in those tissues. Significance: The obese-asthma phenotype in mice is accompanied by increased expression of NK1-R on adipose tissues and lung epithelium, reflecting that SP released during inflammation may act directly on these tissues. Blocking NK1-R affects lymphangiogenesis, implying a role of SP, with opposite physiological consequences in VAT, and in SAT and lungs. Our results provide a clue for a novel SP role in the obese-asthma phenotype.
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Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil
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A recent and comprehensive review of the use of race and ethnicity in research that address health disparities in epidemiology and public health is provided. First it is described the theoretical basis upon which race and ethnicity differ drawing from previous work in anthropology, social science and public health. Second, it is presented a review of 280 articles published in high impacts factor journals in regards to public health and epidemiology from 2009-2011. An analytical grid enabled the examination of conceptual, theoretical and methodological questions related to the use of both concepts. The majority of articles reviewed were grounded in a theoretical framework and provided interpretations from various models. However, key problems identified include a) a failure from researchers to differentiate between the concepts of race and ethnicity; b) an inappropriate use of racial categories to ascribe ethnicity; c) a lack of transparency in the methods used to assess both concepts; and d) failure to address limits associated with the construction of racial or ethnic taxonomies and their use. In conclusion, future studies examining health disparities should clearly establish the distinction between race and ethnicity, develop theoretically driven research and address specific questions about the relationships between race, ethnicity and health. One argue that one way to think about ethnicity, race and health is to dichotomize research into two sets of questions about the relationship between human diversity and health.
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I (Prática Pedagógica) - Neste relatório de estágio apresenta-se uma caracterização do Conservatório de Música de Santarém (CMS). Dá-se a conhecer um pouco da sua história, o seu funcionamento e os seus objetivos pedagógicos. Caracterizam-se também os alunos que participam no estágio e faz-se uma pequena descrição dos seus percursos académicos; suas influências, motivações e expectativas. Nas práticas desenvolvidas apresentam-se os princípios pedagógicos – A Motivação, como condição fundamental para o sucesso escolar dos alunos; e ainda a importância da aquisição de competências metacognitivas, ao permitirem a reflexão sobre os processos de aprendizagem. É feita uma descrição sobre as estratégias que o professor deve adotar com o objetivo de obter a motivação dos alunos; e apresentam-se os objetivos pedagógicos propostos para este estágio. Por último é feita uma análise do trabalho desenvolvido com os alunos e uma análise crítica da atividade docente, onde a criatividade, a autoavaliação e a reflexão devem estar sempre presentes no íntimo do professor. Ainda no encerramento da secção pedagógica dá-se conta do novo paradigma do ensino vocacional de música, após a Portaria nº 691/2009 de 25 de junho, e a necessidade do professor se adaptar a esta nova realidade.
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Reliability of communications is key to expand application domains for sensor networks. SinceWireless Sensor Networks (WSN) operate in the license-free Industrial Scientific and Medical (ISM) bands and hence share the spectrum with other wireless technologies, addressing interference is an important challenge. In order to minimize its effect, nodes can dynamically adapt radio resources provided information about current spectrum usage is available. We present a new channel quality metric, based on availability of the channel over time, which meaningfully quantifies spectrum usage. We discuss the optimum scanning time for capturing the channel condition while maintaining energy-efficiency. Using data collected from a number of Wi-Fi networks operating in a library building, we show that our metric has strong correlation with the Packet Reception Rate (PRR). This suggests that quantifying interference in the channel can help in adapting resources for better reliability. We present a discussion of the usage of our metric for various resource allocation and adaptation strategies.
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Graphics processor units (GPUs) today can be used for computations that go beyond graphics and such use can attain a performance that is orders of magnitude greater than a normal processor. The software executing on a graphics processor is composed of a set of (often thousands of) threads which operate on different parts of the data and thereby jointly compute a result which is delivered to another thread executing on the main processor. Hence the response time of a thread executing on the main processor is dependent on the finishing time of the execution of threads executing on the GPU. Therefore, we present a simple method for calculating an upper bound on the finishing time of threads executing on a GPU, in particular NVIDIA Fermi. Developing such a method is nontrivial because threads executing on a GPU share hardware resources at very fine granularity.
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There is an increasing demand for highly dynamic realtime systems where several independently developed applications with different timing requirements can coexist. This paper proposes a protocol to integrate shared resources and precedence constraints among tasks in such systems assuming no precise information on critical sections and computation times is available. The concept of bandwidth inheritance is combined with a capacity sharing and stealing mechanism to efficiently exchange bandwidth among needed tasks, minimising the cost of blocking.
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During the recent years human society evolved from the “industrial society age” and transitioned into the “knowledge society age”. This means that knowledge media support migrated from “pen and paper” to computer-based Information Systems. Due to this fact Ergonomics has assumed an increasing importance, as a science/technology that deals with the problem of adapting the work to the man, namely in terms of Usability. This paper presents some relevant Ergonomics, Usability and User-centred design concepts regarding Information Systems.