898 resultados para Patterns of conduct


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Grinding is a parts finishing process for advanced products and surfaces. However, continuous friction between the workpiece and the grinding wheel causes the latter to lose its sharpness, thus impairing the grinding results. This is when the dressing process is required, which consists of sharpening the worn grains of the grinding wheel. The dressing conditions strongly affect the performance of the grinding operation; hence, monitoring them throughout the process can increase its efficiency. The objective of this study was to estimate the wear of a single-point dresser using intelligent systems whose inputs were obtained by the digital processing of acoustic emission signals. Two intelligent systems, the multilayer perceptron and the Kohonen neural network, were compared in terms of their classifying ability. The harmonic content of the acoustic emission signal was found to be influenced by the condition of dresser, and when used to feed the neural networks it is possible to classify the condition of the tool under study.

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Specimens (n= 41) of the amphisbaenid Amphisbaena wuchereri taken from a population in Minas Gerais state, south-eastern Brazil, were examined for gastrointestinal parasites. A single nematode species was found, Paradollfusnema amphisbaenia. This was a new host record for this nematode species. This parasite was encountered in the large intestine (prevalence of 100%), in the stomach (prevalence of 2%) and in the small intestine (prevalence of 7.3%). The intensity of infection ranged from 1 to 457 individual parasites per host and was positively correlated with body size of both male and female amphisbaenians. The discrepancy index (D) indicated that P. amphisbaenia tended to an even distribution in this host population. The nematode, which did not affect fat body mass, induced inflammatory infiltrations in the small intestine, indicating that the parasites might injure the host's organs. Copyright © Cambridge University Press 2012.

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Distemper leukoencephalitis is a disease caused by the canine distemper virus (CDV) infection. It is a demyelinating disease affecting mainly the white matter of the cerebellum and areas adjacent to the fourth ventricle; the enzymes of the matrix metalloproteinases (MMPs) group, especially MMP-2 and MMP-9 have a key role in the myelin basic protein fragmentation and in demyelination, as well as in leukocyte traffic into the nervous milieu. To evaluate the involvement of MMPs during subacute distemper leukoencephalitis, we measured the levels of MMP-2 and MMP-9 by zymography in the cerebrospinal fluid (CSF) and in the cerebellum of 14 dogs naturally infected with CDV and 10 uninfected dogs. The infected dogs presented high levels of pro-MMP-2 in the CSF and elevated levels of pro-MMP-2 and pro-MMP-9 in the cerebellar tissue. Active MMP-2 was detected in the CSF of some infected dogs. As active MMP-2 and MMP-9 are required for cellular migration across the blood-brain barrier and any interference between MMPs and their inhibitors may result in an amplification of demyelination, this study gives additional support to the involvement of MMPs during subacute distemper leukoencephalitis and suggests that MMP-2 and MMP-9 may take part in the brain inflammatory changes of this disease. © 2013 Elsevier B.V.

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The aim of the present study was to detect progesterone receptors (A and B isoforms), α and β estrogen receptors, luteinizing hormone receptors and aromatase cytochrome P450 enzymes in the corpus luteum of Nelore (Bos taurus indicus) cows using immunohistochemistry. The estrous cycles of 16 Nelore cows were synchronized, and luteal samples were collected via an incision into the vaginal vault. Samples were collected during specific days of the estrous cycle (days 6, 10, 15 and 18) and 24. h after circulating progesterone dropped, after luteolysis had occurred. After each biopsy was taken, all animals were resynchronized so that each biopsy was performed during a different estrous cycle. Our results showed that the concentration of studied proteins vary throughout the bovine estrous cycle. The highest concentration of α and β estrogen receptors and the highest concentration of plasma progesterone were both observed on days 10 and 15 of the estrous cycle. The highest concentration of progesterone receptors was observed on days 6 and 10 of the estrous cycle, and the most intense immunostaining for cytochrome P450 aromatase enzymes was observed on day 10 of the estrous cycle. The highest score of cells with plasma membrane immunostaining for LH receptors was observed on day 15 of the estrous cycle. In conclusion, this study demonstrates the varying concentrations of specific proteins within the corpus luteum of Nelore cows during the estrous cycle. This finding suggests that these receptors and enzymes, and their interactions, are important in regulating luteal viability. © 2013 Elsevier B.V.

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Objective: Investigate the influence of apprehensive gait on activation and cocontraction of lower limb muscles of younger and older female adults. Methods: Data of 17 younger (21.47±2.06 yr) and 18 older women (65.33±3.14. yr) were considered for this study. Participants walked on the treadmill at two different conditions: normal gait and apprehensive gait. The surface electromyographic signals (EMG) were recorded during both conditions on: rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), tibialis anterior (TA), gastrocnemius lateralis (GL), and soleus (SO). Results: Apprehensive gait promoted greater activation of thigh muscles than normal gait (F=5.34 and p=0.007, for significant main effect of condition; RF, p=0.002; VM, p<0.001; VL, p=0.003; and BF, p=0.001). Older adults had greater cocontraction of knee and ankle stabilizer muscles than younger women (F=4.05 and p=0.019, for significant main effect of groups; VM/BF, p=0.010; TA/GL, p=0.007; and TA/SO, p=0.002). Conclusion: Apprehensive gait promoted greater activation of thigh muscles and older adults had greater cocontraction of knee and ankle stabilizer muscles. Thus, apprehensive gait may leads to increased percentage of neuromuscular capacity, which is associated with greater cocontraction and contribute to the onset of fatigue and increased risk of falling in older people. © 2013 Elsevier Ltd.

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Includes bibliography

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Includes bibliography

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Includes bibliography

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This article analyses the pattern of technical change in the Brazilian economy between 1952 and 2008. A Marx-biased pattern of labour-saving and capital-using change predominated in the period under study. Three phases in the dynamism of technical change can be distinguished, however. The first, from 1952 to 1973, was highly dynamic. In the second, from 1973 to 1991, this dynamism lessened. Lastly, between 1991 and 2008, the dynamism of technical change recovered slightly. The wage share held fairly steady throughout the period. The rate of profit dropped between 1952 and 1991 before rising slightly from 1991 to 2008. The net capital accumulation rate contracted after 1975 because of the decline in the rates of profit and investment. Between 2004 and 2008, the net capital accumulation rate increased.

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Identificamos padrões ecomorfológicos que refletem a ecologia de espécies encontradas em poças de maré na Zona Costeira Amazônica (ZCA). Indivíduos de 19 espécies foram coletados no estado do Pará durante duas expedições em 2011. Foram estabelecidas dominância, grau de residência, guildas tróficas e tomadas medidas morfométricas de até 10 indivíduos de cada espécie. Calculou-se 23 atributos ecomorfológicos relacionados à locomoção, posição e forrageio, utilizados para o cálculo da distância ecomorfológica. Foram utilizadas Análises de Componentes Principais (PCA) para avaliar que atributos ecomorfológicos explicaram a variação entre as espécies. O teste de Mantel foi utilizado para testar a correlação da distância taxonômica com a morfologia das espécies e um teste de Mantel parcial para avaliar a correlação das guildas tróficas com os padrões ecomorfológicos, controlando-se o efeito da distância taxonômica entre as espécies. Nas análises formaram-se dois eixos principais para variação em relação aos padrões de locomoção, correlacionados à largura do pedúnculo caudal e formato da nadadeira anal, ocorrendo influência da distância taxonômica entre as espécies nos padrões ecomorfológicos. Espécies dominantes e residentes apresentaram menor capacidade de natação contínua. Quanto à posição na coluna d'água, formaram-se dois eixos principais da variação, correlacionados à posição do olho, área da nadadeira pélvica e formato do corpo, ocorrendo influência da distância taxônomica entre as espécies nas dissimilaridades morfológicas. A PCA agrupou espécies de hábito pelágico com espécies de hábito bentônico. Em relação ao forrageio, formaram-se dois eixos principais da variação, correlacionados ao tamanho da boca, tamanho do olho e comprimento do trato digestório. Espécies de diferentes guildas permaneceram agrupadas, sugerindo fraca relação da morfologia com o forrageio e não houve influência da distância taxonômica nas dissimilaridades nas guildas tróficas. Espécies residentes e dominantes em poças de maré na ZCA apresentam hábito sedentário, ocorrendo pouca influência da distância taxonômica nos padrões ecomorfológicos que se referem à posição na coluna d'água e locomoção, demonstrando que espécies distantes filogeneticamente podem apresentar padrões ecomorfológicos similares, e a morfologia demonstrou-se como fraca preditora das táticas de forrageio.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)