981 resultados para Energy restriction
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An important role in protein-energy metabolism has been attributed to leucine because of its long-term effects on body fat reduction and on the improvement of some indicators of protein status in rodents. The present study investigated the influence of leucine supplementation on the body composition and protein status of rats during the early phase of weight loss, which is characterized by a rapid loss of body weight. Thirty adult male Wistar rats were divided into 2 groups, a control and a leucine group (diet supplemented with 0.59% L-leucine), and were submitted to 1 week of 50% food restriction. The following parameters were evaluated: chemical carcass composition, protein and RNA content in liver and gastrocnemius muscle, and serum concentrations of insulin-like growth factor-1 and corticosterone. A higher liver weight and liver protein content were observed in the supplemented group (p < 0.05). However, no difference in body fat was found between groups (p > 0.05). The results indicate that low-dose leucine supplementation favors liver protein status but does not reduce body fat in rats during the early phase of rapid weight loss.
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Caloric restriction is the most effective non-genetic intervention to enhance lifespan known to date. A major research interest has been the development of therapeutic strategies capable of promoting the beneficial results of this dietary regimen. In this sense, we propose that compounds that decrease the efficiency of energy conversion, such as mitochondrial uncouplers, can be caloric restriction mimetics. Treatment of mice with low doses of the protonophore 2,4-dinitrophenol promotes enhanced tissue respiratory rates, improved serological glucose, triglyceride and insulin levels, decrease of reactive oxygen species levels and tissue DNA and protein oxidation, as well as reduced body weight. Importantly, 2,4-dinitrophenol-treated animals also presented enhanced longevity. Our results demonstrate that mild mitochondrial uncoupling is a highly effective in vivo antioxidant strategy, and describe the first therapeutic intervention capable of effectively reproducing the physiological, metabolic and lifespan effects of caloric restriction in healthy mammals.
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The effect of feed restriction on water balance and nutrient utilization was investigated in individually penned Boer x Saanen kids. Twenty-two male Boer x Saanen kids with an initial average live weight (LW) of 15 kg were used. Seven kids were slaughtered at the beginning of the experiment (reference animals) and the remainders were allocated to one of the three treatments (0, 30 and 60% restriction) and therefore there were five kids per treatment. The feed intake for the 0% restriction treatment animals determined the intake for the animals in the 30 and 60% restriction treatment. When the animals in the 0% restriction treatment group reached 25 kg LW, the animals in the 30 and 60% restriction treatment groups were also slaughtered. There was a negative relationship between DMI and water intake. The digestibility coefficients for DM, OM, carbohydrates, ash, ether extract, energy, NDF, ADF and lignin did not differ between treatments, whereas the digestibility coefficient for CP was different between treatment groups. The highest metabolic water production was in animals in the 0% restriction treatment group. No significant differences were observed in the composition of gastro-intestinal tract contents of the goats in the different treatments. Lower water retention was found in the animals in the 60% restriction treatment group. The study showed that feed restriction affected water intake, CP digestibility and water retention in the body of the kid goats. This experiment demonstrated that DM:water intake ratio changed when severe feed restriction was applied (60% restriction) and water was freely available. It shows a different pattern of behaviour of penned goats, particularly if feed intake is restricted and perhaps caution is needed to extrapolate results from nutritional and physiological trials in pens to goats at pasture. (c) 2005 Elsevier BX All rights reserved.
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One hundred sixty-two commercial 70-wk-old ISA Brown laying hens, previously subjected to induced molting by feed restriction, were distributed in a completely randomized design with 3 x 3 factorial arrangement (i.e., 3 metabolizable energy levels: 2,850; 2,950, and 3,050 kcal of ME/kg) and 3 protein levels (16, 18, and 20% CP), which totaled 9 treatments with 3 replicates of 6 birds each. Experimental diets were offered to birds after the feed restriction period. Performance and egg quality parameters were evaluated in 14-d intervals from the 4th to 12th weeks after forced molting for a total of 4 evaluation periods. Increases in dietary energy and protein levels did not improve performance or egg quality. The levels of 2,850 kcal of ME and 16% protein were sufficient for laying hens starting the second production cycle without decreasing their performance or egg quality.
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Foram utilizados 50 suínos machos castrados para avaliar o efeito da restrição alimentar qualitativa sobre a digestibilidade dos componentes dietéticos, os órgãos do trato digestório, a composição e a produção fecal. Foram utilizadas cinco dietas experimentais, com níveis de restrição qualitativa de 0, 5, 10, 15 e 20%. Houve redução linear (P<0,001) para todos os coeficientes de digestibilidade, com exceção da fibra em detergente ácido, que apresentou resposta quadrática (P<0,05). Os teores de sólidos totais (P<0,01) e voláteis (P<0,05), e minerais totais (P<0,001) nas fezes aumentaram com os níveis de restrição alimentar, enquanto os níveis de K (P<0,05), Cu (P<0,01) e de N, P, Na, Ca, Mg, Fe e Zn (P<0,001), apresentaram resposta quadrática. A excreção diária de fezes, sólidos totais e voláteis, minerais totais, N, P, K, Mn e Cu (P<0,001), Ca, Na, Mg e Fe (P<0,05) apresentaram aumento em função do nível da restrição alimentar qualitativa. A restrição qualitativa pode ser alternativa para destinação de resíduos da agroindústria, conferindo boas propriedades às fezes suínas, no que diz respeito à utilização para adubação de culturas.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This investigation was carried out to study the influence of early qualitative feed restriction and environmental rearing temperature on long bone development in broiler. Energy and protein restriction reduced femur width and humerus weight, but did not affect tibia parameters. Broilers kept at cold environmental temperature showed reduced femur, tibia and humerus length and tibia weight, but the calculated density was not affected by rearing temperature. These findings suggest that qualitative feed restriction and environmental temperature influenced the normal long bone growth; however, bone weight/bone length index (calculated density) was not affected by rearing temperature. (c) 2007 Elsevier Ltd. All rights reserved.
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Purpose: To determine the effect of dietary restriction on metabolic pathways and the relationship of the metabolic shifting on antioxidant enzymes in cardiac tissue. Design: Randomized, controlled study. Male rats at 60 days old were randomly divided into four groups. Materials and Methods: The rats of control groups C30 and C60 were given free access to the diet over 30 and 60 days. The rats of the DR30 group were fed 60% of the chow consumed by the control groups over 30 days. The animals of the DR60 group ate 60% of the amount consumed by the C60 group over 60 days. Serum was used for total protein, lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Protein, glycogen, total lipids, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), LDH, AST and ALT were determined in cardiac tissue. Results: Dietary restriction induced diminished serum and cardiac LDH activities. AST activities were lower in the serum and cardiac muscle of the DR60 animals. Dietary restriction induced elevated total lipid concentrations in cardiac muscle. No significant differences were observed in total protein and glycogen content among the groups. Antioxidant enzyme determinations demonstrated increased cardiac GSH-Px activities in the DR60 animals and increased SOD activities in the cardiac tissue of both feed-restricted groups. Conclusions: Dietary restriction was protective against oxidative stress in the heart by improving cardiac endogenous antioxidant defences and shifting the metabolic pathway for energy production.
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In the context of the hamiltonian formulation of the teleparallel equivalent of general relativity we compute the gravitational energy of Kerr and Kerr Anti-de Sitter (Kerr-AdS) space-times. The present calculation is carried out by means of an expression for the energy of the gravitational field that naturally arises from the integral form of the constraint equations of the formalism. In each case, the energy is exactly computed for finite and arbitrary spacelike two-spheres, without any restriction on the metric parameters. In particular, we evaluate the energy at the outer event horizon of the black holes. © SISSA/ISAS 2003.
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Dietary modification ought to be the first line of strategy in prevention of the development of cardiac disease. The purpose of this study was to investigate whether dietary restriction, dietary-fibre-enriched diet, and their interactions might affect antioxidant capacity and oxidative stress in cardiac tissue. Male Wistar rats (180-200 g; n = 10) were divided into four groups: control ad libitum diet (C), 50% restricted diet (DR), fed with fibre-enriched diet (F), and 50% restricted fibre-enriched diet (DR-F). After 35 days of the treatments, F, DR, and DR-F rats showed low cholesterol, LDL-cholesterol, and triacylglycerol, and high HDL-cholesterol in serum. The DR, DR-F, and F groups had decreased myocardial lipoperoxide and lipid hydroperoxide. The DR-F and F treatments increased superoxide dismutase and glutatione peroxidase (GSH-Px). The DR treatment increased GSH-Px and catalase activities. Dietary fibre beneficial effects were related to metabolic alterations. The F and DR-F groups showed high cardiac glycogen and low lactate dehydrogenase/citrate synthase ratios, indicating diminished anaerobic and elevated aerobic myocardial metabolism in these animals. There was no synergistic effect between dietary restriction and dietary fibre addition, since no differences were observed in markers of oxidative stress in the F and DR-F groups. Dietary fibre supplementation, rather than energy intake and dietary restriction, appears to be the main process retarding oxidative stress in cardiac tissue.
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The main objective this article is describe a methodology for the calculation of the profile of the electric field in the level soil and proximities originated by electric energy transmission systems real and in operation in the country. It also is commented the equation used and your computational implementation in order to agile and to optimize the studies. The results of simulations were just presented for the transmission system in the voltage class 500 kV for simplify the understanding and space restriction in the article, very although five others types of configurations have also been used in the complete study with very voltages and respective classes. The results were animating and very nearby of values well-known of electric field of other and publications traditional in the area. The graphic exits of program for better visual comprehension and understanding went in accomplished in the plan and in the space © 2010 IEEE.
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Includes bibliography
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)