977 resultados para Pavimentazione stradale,prova dinamica,geogriglia,aggregato,box test, materiali granulari


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In recent years. studies in behavioral pharmacology have shown the involvement of dopaminergic mechanisms in avoidance behavior as assessed by the two-way active avoidance test (CAR). Changes in dopaminergic transmission also occur in response to particularly threatening challenges. However, studies on the effects of benzodiazepine (BZD) drugs ill this test are still unclear. Given the interplay of dopamine and other neurotransmitters in the neurobiology of anxiety and schizophrenia the aim of this work was to evaluate the effects of systemic administration of midazolam, the dopaminergic agonist apomorphine, and the D(2) receptor antagonist sulpiride using the CAR, a test that shows good sensitivity to typical neuroleptic drugs. Whereas midazolam did not alter the avoidance response. apomorphine increased and sulpiride reduced them in this test. Escape was not affected by any drug treatments. Heightened avoidance was not associated with the increased motor activity caused by apomorphine. In contrast with the benzodiazepine midazolam, activation of post-synaptic D(2) receptors with apomorphine facilitates, whereas the D(2) receptor antagonism with sulpiride inhibited the acquisition of the avoidance behavior. Together, these results bring additional evidence for a role of D(2) mechanisms in the acquisition of the active avoidance. (C) 2009 Elsevier Inc. All rights reserved.

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Increasing efforts exist in integrating different levels of detail in models of the cardiovascular system. For instance, one-dimensional representations are employed to model the systemic circulation. In this context, effective and black-box-type decomposition strategies for one-dimensional networks are needed, so as to: (i) employ domain decomposition strategies for large systemic models (1D-1D coupling) and (ii) provide the conceptual basis for dimensionally-heterogeneous representations (1D-3D coupling, among various possibilities). The strategy proposed in this article works for both of these two scenarios, though the several applications shown to illustrate its performance focus on the 1D-1D coupling case. A one-dimensional network is decomposed in such a way that each coupling point connects two (and not more) of the sub-networks. At each of the M connection points two unknowns are defined: the flow rate and pressure. These 2M unknowns are determined by 2M equations, since each sub-network provides one (non-linear) equation per coupling point. It is shown how to build the 2M x 2M non-linear system with arbitrary and independent choice of boundary conditions for each of the sub-networks. The idea is then to solve this non-linear system until convergence, which guarantees strong coupling of the complete network. In other words, if the non-linear solver converges at each time step, the solution coincides with what would be obtained by monolithically modeling the whole network. The decomposition thus imposes no stability restriction on the choice of the time step size. Effective iterative strategies for the non-linear system that preserve the black-box character of the decomposition are then explored. Several variants of matrix-free Broyden`s and Newton-GMRES algorithms are assessed as numerical solvers by comparing their performance on sub-critical wave propagation problems which range from academic test cases to realistic cardiovascular applications. A specific variant of Broyden`s algorithm is identified and recommended on the basis of its computer cost and reliability. (C) 2010 Elsevier B.V. All rights reserved.

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The context of this report and the IRIDIA laboratory are described in the preface. Evolutionary Robotics and the box-pushing task are presented in the introduction.The building of a test system supporting Evolutionary Robotics experiments is then detailed. This system is made of a robot simulator and a Genetic Algorithm. It is used to explore the possibility of evolving box-pushing behaviours. The bootstrapping problem is explained, and a novel approach for dealing with it is proposed, with results presented.Finally, ideas for extending this approach are presented in the conclusion.

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The capacitor test process at ABB Capacitors in Ludvika must be improved to meet future demands for high voltage products. To find a solution to how to improve the test process, an investigation was performed to establish which parts of the process are used and how they operate. Several parts which can improves the process were identified. One of them was selected to be improved in correlation with the subject, mechanical engineering. Four concepts were generated and decision matrixes were used to systematically select the best concept. By improving the process several benefits has been added to the process. More units are able to be tested and lead time is reduced. As the lead time is reduced the cost for each unit is reduced, workers will work less hours for the same amount of tested units, future work to further improve the process is also identified. The selected concept was concept 1, the sway stop concept. This concept is used to reduce the sway of the capacitors as they have entered the test facility, the box. By improving this part of the test process a time saving of 20 seconds per unit can be achieved, equivalent to 7% time reduction. This can be compared to an additional 1400 units each year.

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Purpose. The purposes of the study were to investigate the test-retest reliability and the validity of new versions of the Melbourne Edge Test (MET) and the High/Low Contrast Visual Acuity (H/LCVA) chart and to investigate the agreement between the original and new versions.

Methods. The MET original photographic version, MET new light box version, H/LCVA Chart original photographic version, H/LCVA Chart new printed version, and the Pelli-Robson chart were administered twice to one eye of 22 subjects with low vision and 20 soft contact lenses wearers.

Results. For the low vision group, the test-retest 95% limits of agreement were ±5.2 dB for the MET new light box version and ±0.39 logarithm of the minimum angle of resolution (logMAR) for the LCVA component of the H/LCVA new printed version. For the soft contact lens group, the test-retest 95% limits of agreement were ±2.1 dB for the MET new light box version and ± 0.26 logMAR for the LCVA component of the H/LCVA new printed version. Moderate to high correlations were obtained between contrast sensitivity tests, thus providing evidence of validity. Scores obtained for the new test versions were significantly higher than the original versions (p < 0.01).

Conclusions. Of all the tests administered, the MET original photographic version and the Pelli-Robson Chart had the highest test-retest reliability for the low vision group. For the soft contact lens group, the H/LCVA original version (low contrast letters, 18% Weber) and the Pelli-Robson Chart had the highest reliability.

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O presente trabalho tem por objetivo estudar a governança das águas brasileiras, especialmente seu funcionamento em situações de escassez hídrica. Com este propósito, após a apresentação da crise hídrica da região Sudeste do Brasil, que colocou à prova o aparato institucional e regulatório das águas nacionais, examina-se o regime de competências constitucionais em matéria de meio ambiente e de águas e as peculiaridades afetas ao Sistema Nacional de Gerenciamento de Recursos Hídricos. Por fim, de forma propositiva, são elencadas medidas que buscam auxiliar no aperfeiçoamento da governança das águas e do enfrentamento da crise hídrica.

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The accelerated ageing (AA) test is widely used to evaluate seed vigor in various species including vegetable crops. The objective of this work was to study procedures for conducting AA to evaluate seed vigor of pumpkin and zucchini seed lots. Five seed lots of commercially acceptable quality (germination) standards were selected from both cv. `Menina Brasileira' (zucchini) and `Barbara' Hybrid (pumpkin). The following tests were conducted: standard germination, the first count of germination, and AA with and without saline solution (periods of 48, 72 and 96 hours). For each combination of temperature and ageing period, seeds were placed in a single layer on a screen in a germination plastic box with either 40 mL deionized water or 40g NaCl/100mL of water. Both AA methods identified lots 2 and 5 of `Menina Brasileira' and lot 10 of `Barbara' hybrid as having the lowest physiological quality. The temperature 41 C promoted a more drastic reduction in germination than did 38 C. This observation was more marked after 96 hours. Based on the results obtained, it can be concluded that the combination 41 degrees C/96 hours should be used to evaluate the physiological potential of pumpkin and zucchini seeds; however, additional studies are necessary to evaluate other combinations and confirm this indication.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Introdução: The scales of cognitive screening are important tools for early detection of dementia, creating the possibility of developing measures to slow this process and assist in the management of the disease. Objective: To validate the Leganés Cognitive Test (Prueba Cognitive de Leganés) (PCL) for cognitive screening in low educated elderly Brazilians. Methods: The study sample was composed of 59 elderly residents from the city of Santa Cruz, Brazil with low schooling levels. Reliability was analyzed with a 2-day interval between assessments, and concurrent validity was assessed using the Mini Mental State Examination (MMSE). Results: According to the PCL, the prevalence of dementia was 11.8%. The scale items showed a moderate to strong correlation between domains (p <0.01), and inter-rater reliability exhibited ICC = 0.81, 95% CI (0.72-0.88). Factor analysis resulted in two factors: memory and orientation. Interscale agreement was considered poor (k = - 0.02), supporting the hypothesis of an educational impact on final MMSE scores. Conclusion: The results suggest that PCL has acceptable levels of reliability for use in low educated elderly Brazilians

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Objetivo: estudar a validade da prova de trabalho de parto (PTP) em gestantes com uma cesárea anterior. Métodos: estudo retrospectivo, tipo coorte, incluindo 438 gestantes com uma cesárea anterior ao parto em estudo e seus 450 recém-nascidos (RN), divididas em dois grupos - com e sem PTP. O tamanho amostral mínimo foi de 121 gestantes/grupo. Considerou-se variável independente a PTP e as dependentes relacionaram-se à ocorrência de parto vaginal e à freqüência de complicações maternas e perinatais. Foram efetuadas análises uni e multivariada, respectivamente. A comparação entre as freqüências (%) foi analisada pelo teste do qui-quadrado (chi²) com significância de 5% e regressão logística com cálculo do odds ratio (OR) e do intervalo de confiança a 95% (IC95%). Resultados: a PTP associou-se a 59,2% de partos vaginais. Foi menos indicada nas gestantes com mais de 40 anos (2,7% vs 6,5%) e nas portadoras de doenças associadas e complicações da gravidez: síndromes hipertensivas (7,0%) e hemorragias de 3º trimestre (0,3%). A PTP não se relacionou às complicações maternas e perinatais. As gestantes que tiveram o parto por cesárea, independente da PTP, apresentaram maior risco de complicações puerperais (OR = 3,53; IC95% = 1,57-7,93). A taxa de mortalidade perinatal foi dependente do peso do RN e das malformações fetais e não se relacionou à PTP. Ao contrário, as complicações respiratórias foram mais freqüentes nos RN de mães não testadas quanto à PTP (OR = 1,92; IC95% = 1,20-3,07). Conclusões: os resultados comprovaram que a PTP em gestantes com uma cesárea anterior é estratégia segura - favoreceu o parto vaginal em 59,2% dos casos e não interferiu com a morbimortalidade materna e perinatal. Portanto, é recurso que deve ser estimulado.

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In this paper we conducted several analysis of the simulated dynamic behavior of two passive suspension types of the trailed sprayer booms. The suspension analysis was conducted under conditions of a bump track test ISO 5008, with two levels of speed (5 km h(-1) and 15 km h(-1)) and two track profiles proposed in these standards (bumpy and smooth). It was used the simulations software MATLAB (R), SIMULINK (R) and Visual Nastran (R). The results obtained showed that suspensions of trapezoidal type have good performance at low frequencies input (omega < 0,2 Hz) while suspensions of simple pendulum type have good performance in others conditions.

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O objetivo deste estudo foi analisar a validade do consumo máximo de oxigênio (VO2max), velocidade associada ao VO2max (vVO2max), tempo de exaustão na vVO2max (Tlim), limiar anaeróbio (LAn), economia de corrida (EC) e força explosiva (FE) para predizer a performance aeróbia de corredores de endurance nas distâncias de 1.500m, 5.000m e 10.000m. Participaram deste estudo 11 corredores de endurance moderadamente treinados (28,36 ± 6,47 anos) que realizaram os seguintes testes: provas simuladas em uma pista de 400m em diferentes dias, nas distâncias de 10.000m, 5.000m e 1.500m; teste incremental máximo para determinar os índices VO2max, vVO2max, e LAn; um teste submáximo de carga constante para determinar a EC, seguido por um teste máximo também de carga constante a 100% da vVO2max para determinar o Tlim; e um teste de salto vertical para determinar a FE. de acordo com a análise de regressão múltipla, a vVO2max utilizada de forma isolada explicou 57% da variação de performance na prova de 1.500m. No entanto, quando o Tlim, a FE e a vVO2max foram analisados em conjunto, a explicação para a performance nessa prova foi de 88%. Nos 5.000m, o Tlim, a vVO2max e o LAn responderam por 88% da variação de performance (p < 0,05). Diferentemente, na prova de 10.000m, o LAn foi a única variável que apresentou capacidade de predição de performance. em conclusão, a predição da performance aeróbia de corredores moderadamente treinados por meio de variáveis fisiológicas e neuromusculares é dependente da distância da prova (1.500m, 5.000m e 10.000m)

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Uma prova de imunoadsorção enzimática (ELISA) para detecção de anticorpos contra Babesia bovis foi desenvolvida e avaliada em comparação à imunofluorescência indireta (IFI). A sensibilidade e especificidade do ELISA, determinadas pela análise de 100 soros positivos de bovinos infectados experimentalmente com B. bovis e 108 soros negativos colhidos de bovinos livres de infecção por este hemoparasito, foram de 98,0% e 98,1%, respectivamente. Os valores preditivos positivo e negativo foram, respectivamente, 98,0% e 98,1% e a precisão do teste foi de 98,1%. Não foram detectadas reações cruzadas com 80 soros de bezerros experimentalmente inoculados com Babesia bigemina. O ELISA foi comparado à IFI usando 110 soros de rebanhos de área de estabilidade endêmica e 168 soros de rebanhos de áreas de instabilidade endêmica. em ambos os casos, houve concordância significativa (P=0,631 e 0,4725, respectivamente) entre os resultados demonstrados pelos dois testes. em um estudo epidemiológico realizado com o ELISA na região do Pantanal de Mato Grosso do Sul, com 1.365 soros de bovinos, 83,9% foram positivos para anticorpos contra B. bovis, caracterizando a região estudada como endemicamente estável.

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Com o objetivo de verificar o efeito da adição de níveis crescentes de óleo no concentrado sobre a atividade plasmática das enzimas creatina quinase (CK), aspartato aminotransferase (AST) e lactato desidrogenase (LDH) como indicativo de metabolismo energético, foram fornecidas dietas experimentais compostas de cinco níveis de óleo (controle, 6, 12, 18 e 24% do concentrado). Utilizaram-se 20 equinos da raça Árabe, peso médio de 400 kg, submetidos a prova de enduro de 80 km em esteira rolante. O enduro foi dividido em quatro anéis de 20 km, com duração média de 1 hora e dez minutos. A adição de óleo e a distância percorrida tiveram efeitos sobre as variáveis AST, CK e LDH, que apresentaram as respectivas expressões: AST (7,045-0,2292x+0,007991x2+0,008517z- 0,0003282xz), CK (8,06-,07020x+0,05546x2-0,001262x3+0,01204z+0,0006207xz) e LDH (6,624-0,3522x+0,03448x2-0,0008382x3+0,02401z-0,0007489xz) . O óleo é uma importante e bem aproveitada fonte de energia para equinos em exercício, pois sua adição na dieta de animais submetidos a prova de enduro promoveu alteração metabólica que favorece a produção de energia. O metabolismo animal poupou suas reservas energéticas oriundas da glicose, favorecendo a utilização do óleo. A menor atividade plasmática das enzimas AST, CK e LDH com a adição de óleo nas dietas indica direcionamento do metabolismo energético para a β-oxidação. Como apresentam várias isoenzimas, as enzimas estudadas atuam amplamente no metabolismo energético, favorecendo a constante reposição de ATP ao longo do exercício.