65 resultados para Physiological variables
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The effects of shading and water sprinkling on physiological responses and milk production were studied in Holstein cows managed in an equatorial semi-arid region. Five cows were observed for 36 days during May and June 2009. We studied the effects of sun, shade, shade plus single sprinkling, shade plus sprinkling every 2. h and shade plus sprinkling every hour on physiological responses, i.e., rectal temperature, coat surface temperature and respiratory rate, and on milk production. Environmental variables, i.e., air temperature, black globe temperature, mean radiant temperature, relative humidity and wind speed, were recorded every 30. min throughout the observation period. The statistical analysis utilized a 5×5 replicated latin square, and the results showed reduced values in physiological variables in cows that were protected from short wave radiation and that received water sprinkling; milk yield increased by approximately 3.5. kg in such animals relative to those not receiving such treatment. However, the milk yield for the morning milking presented similar mean values regardless of whether the animals received shading and sprinkling benefits, which indicates that frequency of sprinkling and amount of time (permanence) in the shade were critical for the effect on milk yield. © 2013 Elsevier B.V.
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Purpose. - The purposes of this study were: i) to compare the physiological responses measured during a specific table tennis incremental test with the physiological responses measured during cycling, arm cranking, and treadmill running tests; and ii) to verify the accuracy of table tennis performance prediction based on the physiological responses from these tests.Methods. - Eleven national level male table tennis players participated in the study and undertook incremental tests using ergometers. Table tennis performance was defined as the ranking obtained during a simulated tournament between the participants.Results. - In general, peak values for physiological variables (e.g., (V) over dotO(2PEAK) and [La]PEAK) were significantly lower (P < 0.05) in the specific test (e.g., (V) over dotO(2PEAK) = 39.9 +/- 1.5 ml.kg(-1) per minute and [La]PEAK = 6.4 +/- 0.5 mmol.L-1) than during cycling (e.g., (V) over dotO(2PEAK) = 41.3 +/- 1.4 ml.kg(-1) per minute and [La]PEAK = 10.2 +/- 0.7 mmol.L-1) or running (e.g., (V) over dotO(2PEAK) = 43.9 +/- 1.5 ml.kg(-1) per minute and [La]PEAK = 10.0 +/- 0.7 mmol.L-1), but higher than during arm cranking (e.g., (V) over dotO(2PEAK) = 26.6 +/- 1.6 ml.kg(-1) per minute and [La]PEAK = 8.9 +/- 0.6 mmol.L-1). At respiratory compensation point intensity (RCP), only the variables measured on arm cranking were lower (P < 0.05) than on the other ergometers. Stepwise multiple regression analysis showed significant correlation between table tennis performance and lactate concentration ([La]) and also rate of perceived effort (RPE) at RCP during cycling (r = 0.89; P < 0.05).Conclusion. - In conclusion, the significant differences obtained between the specific and laboratory ergometers demonstrate the need to use a specific test to measure physiological parameters in table tennis and the physiological parameters measured, independent of the ergometer used, are unable to predict table tennis performance. (C) 2013 Elsevier Masson SAS. All rights reserved.
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The relationships between physiological variables and sugarcane productivity under water deficit conditions were investigated in field studies during 2005 and 2006 in Weslaco, Texas, USA. A total of 78 genotypes and two commercial varieties were studied, one of which was drought-tolerant (TCP93-4245) and the other drought-sensitive (TCP87-3388). All genotypes were subjected to two irrigation regimes: a control well-watered treatment (wet) and a moderate water-deficit stress (dry) treatment for a period of 90 days. Maximum quantum efficiency of photosystem II (F (v)/F (m)), estimated chlorophyll content (SPAD index), leaf temperature (LT), leaf relative water content (RWC) and productivity were measured. The productivity of all genotypes was, on average, affected negatively; however, certain genotypes did not suffer significant reduction. Under water deficit, the productivity of the genotypes was positively and significantly correlated with F (v)/F (m), SPAD index and RWC, while LT had a negative correlation. These findings suggest that genotypes exhibiting traits of high RWC values, high chlorophyll contents and high photosynthetic radiation use efficiency under low moisture availability should be targeted for selection and variety development in programmes aimed at improving sugarcane for drought prone environments.
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Sugarcane is a very important economic crop in Brazil. The effects of abiotic stresses cause negative reduction of the productivity in the sugarcane industry. In order to identify indicators of stresses tolerance, two physiological variables were evaluated, nitrate reductase activity and chlorophyll contents in young plants of sugarcane, cv. IAC91-5155. The simultaneous effect of abiotic stresses of high occurrence in Brazilian soils are, water deficiency and aluminum toxicity. The plants were submitted to three treatments of water availability (% field capacity, FC): no stress (70% FC), moderate stress (55% FC), and extreme stress (40% FC); and three acidity treatments in the soil (base saturation, V%): no acidity (V=55%), average acidity (V=33%), and high acidity (V=23%). The experiment was carried out in greenhouse, with 29.7 +/- 4.3 degrees C and 75 +/- 10% RH. The experimental design was in randomized blocks, in 3x3 factorial arrangement, with four replicates. After 60 days, nitrate reductase activity and chlorophyll contents were evaluated in the diagnostic leaf. The results demonstrate that the response of plants to a combination of drought and aluminum toxicity, similar to the conditions in many natural environments, is different from the response of plants to each of these stresses applied individually, as typically tested in the laboratory. The nitrate reductase activity can be used as a biochemical-physiological marker of water deficiency while chlorophyll contents can be used as a biochemical-physiological marker of both of them, water deficiency or aluminum toxicity in soil. Both parameters can not be as a biochemical-physiological marker for acclimation of young plants of sugarcane cv. IAC91-5155, under the combined stresses.
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A study was conducted on the effects of acute administration of aminophylline on physiological variables in purebred Arabian horses submitted to incremental exercise test. Twelve horses were submitted to two physical tests separated by a 10-day interval in a crossover study. These horses were divided into two groups: control (C, n = 12) and aminophylline (AM, n = 12). The drug at 10 mg/kg body weight or saline was given intravenously, 30 minutes before the incremental exercise test. The treadmill exercise test consisted of an initial warmup followed by gradually increasing physical exigency. Blood samples were assayed for lactic acid, glucose, and insulin. Maximal lactic acidemia was greater (P = .0238) in the AM group. Both V-2 and V-4 (velocities at which lactate concentrations were 2 and 4 mmol/ L, respectively) were reduced in the AM group by 15.85% (P = .0402) and 17.76% (P = .0 109), respectively. At rest as well as at 4 minutes, insulinemia was greater in the AM group (P = .0417 and .0393), Glycemia group at times 8 was statistically lower in the Al (P = .0138) and 10 minutes (P = .0432). Use of ammophylline in horses during incremental exercise does not seem to be beneficial, because this drug has a tendency to cause hypoglycemia and to increase dependence on anaerobic glucose metabolism.
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This study evaluated the effect of dietary supplementation with -tryptophan (L-TRP), a serotonin precursor, on the aggressiveness of juvenile matrinx . Fish were kept in individual aquaria for 7 days receiving the diets: D1 (control: 0.47% of TRP), D2 (0.94% of TRP), D3 (1.88% of TRP), and D4 (3.76% of TRP). After this, they were grouped with an intruder fish to establish a resident-intruder relationship during periods of 20 min. Blood cortisol, glucose, chloride, sodium and calcium; hemoglobin, hematocrit, red blood cell count and volume; liver glycogen and lipids were measured. Territoriality had significant effect on the aggressiveness of matrinx (the residents were more aggressive than intruders, < 0.001) and tryptophan significantly affected their behavior. Fish fed with the D2 diet presented a longer latency until the first attack ( = 0.0069) and bit the intruder fewer times ( = 0.0136) during the period of observation, compared to the control group. The frequency of bites and chases after the first attack was not affected by the dietary supplementation of TRP. Physiological variables were not significantly affected by the diet, except for a moderate increase in cortisol level in fish fed with D2 diet after the fight, indicating slight activation of the hypothalamus-pituitary-interrenal axis. The results show that juvenile matrinx have aggressive and territorial behavior and that a diet containing 9.4 g TRP kg(-1) alter their aggressiveness, without affecting the stress-related physiological parameters.
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Investigaram-se a temperatura retal, a freqüência respiratória e a taxa de evaporação total de ovinos Corriedale sob três temperaturas ambientes, visando uma melhor compreensão dos mecanismos de termorregulação desses animais. Inicialmente, 21 animais adultos foram alojados em câmara climática à temperatura de 45ºC, e pressão parcial de vapor (PV) variável, registrando-se a freqüência respiratória (FR) e a temperatura retal (TR). Baseando-se na FR e TR, foram selecionados 10 animais, cinco com os valores mais baixos, assumindo-os como mais adaptados ao calor (grupo 1) e cinco com valores mais altos, assumindo-os como menos adaptados (grupo 2). Os animais selecionados foram mantidos em câmara climática, onde mediram-se novamente TR, FR e taxa de evaporacão total (TET), sob 20, 30 e 40ºC de temperatura do ar e PV variável. Não houve diferença estatística entre os grupos classificados, para todas as variáveis medidas. Concluiu-se que a utilização das variáveis fisiológicas TR e FR como parâmetros únicos para a seleção destes animais não é suficiente para avaliar o grau de adaptação a temperaturas elevadas.
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OBJETIVO: Avaliar parâmetros bioquímicos e fisiológicos em adolescentes do sexo feminino com sobrepeso/obesidade ou com peso corporal normal e avaliar se fatores de risco cardiovascular, postulados como componentes da síndrome metabólica, já estão presentes nessa faixa etária. MÉTODOS: Estudo transversal, tendo-se comparado a totalidade de meninas com idades entre 12 e 18 anos de um colégio de Ribeirão Preto, divididas em dois grupos: sobrepeso/obesidade (n=30) e controle (n=39). de cada menina, foram avaliados parâmetros antropométricos (peso, estatura, dobras cutâneas, circunferências do abdome e do quadril) e bioquímicos (glicose, insulina, lipidograma, ureia, creatinina, fibrinogênio, PAI-1, ferritina, sódio e microalbuminúria). RESULTADOS: As adolescentes com sobrepeso/obesidade apresentaram níveis maiores de pressão arterial, glicose, triglicérides, ácido úrico, PAI-1, fibrinogênio e insulina e níveis menores de colesterol-HDL em relação ao grupo controle. A análise de alterações e formação de clusters de fatores de risco demonstrou que 76,7% das adolescentes do grupo sobrepeso apresentaram dois ou mais fatores de risco relacionados à síndrome metabólica, enquanto 79,5% das adolescentes do grupo controle apresentaram nenhuma ou apenas uma alteração. Os parâmetros microalbuminúria e ferritina sérica não apresentaram alterações e diferenças entre os grupos. CONCLUSÕES: Adolescentes do sexo feminino com sobrepeso/obesidade já apresentam hipertensão, dislipidemias, disfibrinólise, hiperinsulinemia e clusters de fatores de risco cardiovascular.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The oral administration is a common route in the drug therapy and the solid pharmaceutical forms are widely used. Although much about the performance of these formulations can be learned from in vitro studies using conventional methods, evaluation in vivo is essential in product development. The knowledge of the gastrointestinal transit and how the physiological variables can interfere with the disintegration and drug absorption is a prerequisite for development of dosage forms. The aim of this work was to employing the ac biosusceptometry (ACB) to monitoring magnetic tablets in the human gastrointestinal tract and to obtain the magnetic images of the disintegration process in the colonic region. The ac biosusceptometry showed accuracy in the quantification of the gastric residence time, the intestinal transit time and the disintegration time (DT) of the magnetic formulations in the human gastrointestinal tract. Moreover, ac biosusceptometry is a non-invasive technique, radiation-free and harmless to the volunteers, as well as an important research tool in the pharmaceutical, pharmacological and physiological investigations. (c) 2005 Elsevier B.V. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)