751 resultados para lytic activity and cooperativity


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Vast montado areas are threatened by degradation, as the result of a long history of land use changes. Since improved pastures have been installed aiming soil quality improvement and system sustainability, it is crucial to evaluate the effects of these management changes on soil organic matter status and soil biological activity, as soil quality indicators. Therefore, a 35-yr old improved pasture and a natural pasture were studied, considering areas beneath tree canopy and in the open. Total organic C, total N, hot water soluble (HWS) and particulate (POM) C, microbial biomass C (MBC) and N (MBN), C mineralization rate (CMR) and net N mineralization rate (NMR) were determined. In addition, for a 1-yr period, soil β-glucosidase, urease, proteases and acid phosphomonoesterase were periodically determined. Improved pasture promoted the increase of soil C and N through POM-C increment, particularly beneath the trees canopies. The two study pastures did not show differences regarding soil microbial biomass, but variations in CMR, HWS-C and N availability (proteases and urease activities) suggest divergent soil microbial communities. Tree regulator role on C, N and P transformation processes in soil was confirmed

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Dissertação de Mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologias, Universidade do Algarve, 2014

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Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL

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Background: Vaspin is a newly-identified adipocytokine associated with insulin resistance (IR). Objective: The aim of this study was to investigate the correlation between plasma vaspin concentrations and IR and determine whether this association is affected by body composition, physical activity and pubertal stage in adolescents. Methods: Were studied 484 Brazilian adolescents aged 10-14 years whose anthropometric, clinical, biochemical, and lifestyle measurements were analized. We evaluated the correlation between vaspin and risk factors for IR in adolescents with normal and high body fat percentage (%BF) and did a logistic regression to calculate the odds ratio for IR according to vaspin quartiles sex specific for the sample. Results: Vaspin was positively correlated with IR in adolescents with high %BF (r = 0.23, p = 0.003). The logistic regression analysis adjusted for sex, age, BMI, and pubertal stage showed that adolescents in the 2nd (OR = 0.43, 95% CI = 0.23-0.80, p = 0.008) and 3rd (OR = 0.46, 95% CI = 0.25-0.85, p = 0.014) quartile of vaspin concentration had a lower risk for IR. When the model was adjusted for %BF and physical activity, the association remained statically significant only for adolescents in the 2nd quartile. Conclusion: Vaspin was correlated positively with risk factors associated with insulin metabolism in adolescents with high %BF. Vaspin was associated with a reduced risk of IR independently of BMI and pubertal stage and the association was influenced by body fat and physical activity in these adolescents.

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Purpose: To investigate the activity and mechanism of action of arbidol against Hantaan virus (HTNV) activity by modulating inflammation via TLR-4 pathway. Methods: HUVEC cells infected with HTNV 76-118 were treated with serially diluted arbidol solutions at -2h (2 h before viral infection, pre-treatment mode), 0 h (at the same time as viral infection, simultaneous treatment mode) or 2 h (2 h after viral infection, post-treatment mode). The transcript levels of TLR4 were detected by semi-quantitative reverse transcription-PCR (RT-PCR) at 6, 12, 18, and 24 h later. The levels of iNOS and TNF-α were examined using enzyme-linked immunosorbent assay (ELISA). Results: Pre-treatment with arbidol, rather than simultaneous treatment or post-treatment, effectively inhibited up-regulation of cellular TLR4 expression (up to 40 ± 6.1 % inhibition) and activity of supernatant iNOS induced by HTNV infection(up to 44.1 ± 9.4 % inhibition), as well as in a LPSstimulated inflammatory endothelial cell. Arbidol decreased the elevated TNF-α levels induced by LPS stimulation. Conclusion: These results are the first evidence that arbidol modulates viral PRRs signaling and its consequential inflammatory cytokine/chemokine response during hantavirus infection.

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Tradicionalmente, los biomarcadores han sido de interés en las ciencias del deporte para medir el rendimiento, el progreso en el entrenamiento y para identificar el sobreentrenamiento. Durante los últimos años, cada vez hay mayor interés en evaluar los efectos relacionados con la salud que se producen en el organismo debidos a una actividad física regular y al deporte. El valor o la concentración de un biomarcador depende de muchos factores, como el grado de entrenamiento, el grado de fatiga y del tipo, la intensidad y la duración del ejercicio, aparte de la edad y del sexo. La mayor parte de los biomarcadores se miden en sangre, orina y saliva. Una de las principales limitaciones que presentan los biomarcadores bioquímicos es la falta de valores de referencia adaptados específicamente para deportistas y personas físicamente activas. Las concentraciones pueden variar considerablemente de los valores de referencia normales. Por lo tanto, es importante adaptar los valores de referencia siempre y cuando sea posible y controlar a cada sujeto regularmente, con el fin de establecer su propia escala de referencia. Otros biomarcadores útiles son la composición corporal (específicamente masa muscular, masa grasa, peso), la condición física (capacidad cardiorrespiratoria, fuerza, agilidad, flexibilidad), frecuencia cardíaca y presión arterial. Dependiendo de la finalidad, será conveniente analizar uno o varios biomarcadores. Para esta revisión, profundizaremos en los biomarcadores que se emplean para evaluar condición física, fatiga crónica, sobreentrenamiento, riesgo cardiovascular, estrés oxidativo e inflamación.

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Purpose: To investigate the analgesic properties of fruit extracts of Vitis vinifera (grape) and Punica granatum (pomegranate) in Albino mal mice. Methods: The analgesic activity of fruit extracts of V. vinifera and P. granatum were examined in vivo using thermal stimulus assays (i.e., tail immersion and hot plate) and acetic acid-induced writhing test using acetylsalicylic acid (0.1 g/kg, per os) as standard. The extracts were administered orally in doses of 1.0, 2.0 and 3.0 g/kg. Results: In acetic acid writhes test, both fruit extract pretreatments (1.0, 2.0 and 3.0 g/kg, per os) significantly decreased the number of writhes (p < 0.0001) in a dose-dependent manner compared to control. The Index of Pain Inhibition (IPI) values following V. vinifera extract treatments were 36.52 % (1.0 g/kg), 66.67 % (2.0 g/kg) and 89.71 % (3.0 g/kg) which were significantly different from those for P. granatum extracts (45.39 %, 1.0 g/kg), 70.93 %, 2.0 g/kg) and 86.88 %, 3.0 g/kg) at equivalent doses of 2.0 and 3.0 g/kg of the extracts The fruit extracts of both species increased the reaction latency time. In tail-immersion assay, only the fruit extract of P. granatum significantly increased the response to heat stimulus at doses of 2.0 g/kg (p < 0.05). Conclusion: The hydroalcohol fruit extracts of P. granatum and V. vinifera have potential analgesic effects. Further studies are needed to determine the active component responsible for this effect.

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Within a country social conditions change over time and these conditions vary from country to country. The associations between these conditions, somatic growth, physical activity and fitness reflect these changes. Aim: The study documented variation in somatic growth, physical activity and fitness associated with socio-economic status (SES). Subjects and methods: The study involved 507 subjects (256 boys and 251 girls) from the Madeira Growth Study, a mixed longitudinal study of five cohorts (8, 10, 12, 14 and 16 years of age) followed at yearly intervals over 3 years (1996–1998). A total of 1493 observations were made. Anthropometric measurements included lengths, body mass, skeletal breadths, girths and skinfolds. Physical activity and SES were collected via questionnaire and interview. Physical fitness was assessed using the Eurofit test battery. Variation in somatic growth, physical activity and physical fitness by SES (high, average and low) was tested with analysis of variance. Results: Significant differences between SES groups were observed for height, body mass and skinfolds. Boys and girls from high SES groups were taller, heavier and fatter (subscapular and triceps skinfolds) than their peers from average and low SES groups. At some age intervals, the high SES group had larger skeletal breadths (girls) and girths (boys and girls) than low SES. Small SES differences were observed for physical activity (sport and leisure-time indices). SES was significantly associated with physical fitness. At some age levels, boys from the low SES group performed better for muscular and aerobic endurance whereas girls from the high SES group performed better for power. Conclusion: Considerable variation in somatic growth and physical fitness in association with SES has been demonstrated, but little association was found for physical activity.

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Within a country social conditions change over time and these conditions vary from country to country. The associations between these conditions, somatic growth, physical activity and fitness reflect these changes. Aim: The study documented variation in somatic growth, physical activity and fitness associated with socio-economic status (SES). Subjects and methods: The study involved 507 subjects (256 boys and 251 girls) from the Madeira Growth Study, a mixed longitudinal study of five cohorts (8, 10, 12, 14 and 16 years of age) followed at yearly intervals over 3 years (1996–1998). A total of 1493 observations were made. Anthropometric measurements included lengths, body mass, skeletal breadths, girths and skinfolds. Physical activity and SES were collected via questionnaire and interview. Physical fitness was assessed using the Eurofit test battery. Variation in somatic growth, physical activity and physical fitness by SES (high, average and low) was tested with analysis of variance. Results: Significant differences between SES groups were observed for height, body mass and skinfolds. Boys and girls from high SES groups were taller, heavier and fatter (subscapular and triceps skinfolds) than their peers from average and low SES groups. At some age intervals, the high SES group had larger skeletal breadths (girls) and girths (boys and girls) than low SES. Small SES differences were observed for physical activity (sport and leisure-time indices). SES was significantly associated with physical fitness. At some age levels, boys from the low SES group performed better for muscular and aerobic endurance whereas girls from the high SES group performed better for power. Conclusion: Considerable variation in somatic growth and physical fitness in association with SES has been demonstrated, but little association was found for physical activity.

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We recorded the number of terrestrial mammal species in each Argentinian province, and the number of species belonging to particular groups (Marsupialia, Placentaria, and among the latter, Xenarthra, Carnivora, Ungulates and Rodentia). We performed multiple regressions of each group’s SR on environmental, human and spatial variables, to determine the amounts of variation explained by these factors. We then used a variance partitioning procedure to specify which proportion of the variation in SR is explained by each of the three factors exclusively and which proportions are attributable to interactions between factors.

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In Alzheimer’s disease, the most common form of dementia, the loss of cholinergic neurons leads to the progressive reduction of acetylcholine in the brain, resulting cognitive impairment. Inhibition of the hydrolysis of acetylcholine by blocking acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) has been considered as a potential target in the treatment of Alzheimer’s disease. Essential oils and extracts of aromatic plants may have an important role in the oxidative stress protection. Traditionally, in Alentejo (Portugal), aromatic herbs Calamintha nepeta, Foeniculum vulgare, Mentha spicata and Thymus mastichina are often used by local population as condiments in food preparations. In this study, essential oils (EOs) and aqueous extracts (decoction waters) of these flavouring herbs were selected in order to evaluate its antioxidant potential and ability to inhibit AChE and BChE activities. Results suggest the potential use of EOs and extracts as nutraceutical or pharmaceutical preparations in the prevention of the oxidative stress and degenerative diseases.

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Lignocelulose é o componente mais abundante do meio ambiente e recurso orgânico renovável no solo. Alguns fungos filamentosos têm desenvolvido a habilidade de degradar e utilizar celulose, hemicelulose e lignina como fonte de energia. O objetivo deste trabalho foi analisar o efeito de três fontes de nitrogênio (sulfato de amônio, nitrato de potássio e farelo de soja) na atividade enzimática de Lentinula edodes EF 50 utilizando como substrato serragem de E. benthamii. Foi aplicado um planejamento experimental de mistura com três repetições no ponto central constituído de sete tratamentos (T) de iguais concentrações em nitrogênio de sulfato de amônia, nitrato de potássio e farinha de soja cozida. Foram determinadas a atividade enzimática da avicelase, carboximetilcelulase, β-glicosidase, xilanases e manganês peroxidase. Foram avaliados o teor de umidade, pH, atividade de água (aw) e análise qualitativa do crescimento micelial em 8 tempos de cultivo. Os resultados mostraram efeito negativo na produção das enzimas nos tratamentos com máxima concentração de sulfato de amônia e nitrato de potássio. Os tratamentos com farinha de soja cozida expressaram maiores atividades enzimáticas, nos tempos de 3, 6 e 9 dias de cultivo exceto na atividade do manganês peroxidase. A maior produção foi observada no tratamento com sulfato de amônia e farinha de soja cozida (83.86 UI.L?1) em 20 dias de cultivo.