964 resultados para Parton energy loss
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The present study examined the effects of aerobic training and energy restriction on adipokines levels in mesenteric (MEAT) and retroperitoneal (RPAT) white adipose tissue from obese rats. Male Wistar rats were fed with standard laboratory diet (Control group) or high fat diet (HFD). After 15 weeks, HFD rats were randomly assigned to the following groups: rats submitted to HFD, which were sedentary (sedentary HFD, n = 8) or trained (trained HFD, n = 8); or submitted to energy-restriction (ER), which were sedentary (sedentary ER, n = 8) or trained (trained ER, n = 8). Trained rats ran on a treadmill at 55% VO(2max) for 60 min/day, 5 days/week, for 10 weeks. ER rats were submitted to a reduction of 20% daily caloric ingestion compared to the Control group. ER and aerobic training decreased body weight, MEAT and RPAT absolute weight, and fat mass. IL-6, IL-10 and TNF-alpha levels were decreased and adiponectin did not change in RPAT in response to ER protocol. On the other hand, ER and the aerobic training protocol decreased IL-6, TNF-alpha and adiponectin levels in MEAT. Absolute MEAT weight showed a positive correlation with IL-6 (r = 0.464), INF-alpha (r = 0.508); and adiponectin (r = 0.342). These results suggest a tissue-specific heterogeneous response in adipokines level. The combination of the protocols (aerobic training and energy restriction) did not induce an enhanced effect. Published by Elsevier Ltd.
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O sucesso de um programa de perda de peso para animais de estimação depende da colaboração do proprietário. A adesão deste é fundamental para a correta instituição do manejo alimentar do paciente. Este trabalho teve por objetivo comparar a efetividade de um programa de perda de peso em dois grupos de cães, um mantido sob condições experimentais e outro com seus proprietários. Empregou-se a mesma ração hipocalórica para todos os animais. A quantidade fornecida foi restrita a 60% da necessidade energética de manutenção estimada para o peso corporal meta, definido como o peso autal reduzido em 15%. Os animais foram acompanhados durante 90 dias. Por meio de um questionário padronizado, estudou-se a percepção dos proprietários quanto à obesidade e seu tratamento. Verificou-se que o protocolo e a dieta empregados foram eficazes. Os animais controle apresentaram uma perda de peso média de 1,39% por semana. Os cães de proprietário perderam, em média, 0,75% do peso vivo por semana, resultado estatisticamente menor (P<0,05), o que sugere uma indisponibilidade dos mesmos em cumprir rigorosamente o tratamento. Mesmo com esta perda de peso modesta, foi perceptível a satisfação dos proprietários com os resultados obtidos. O uso de questionários demonstrou ser uma ferramenta importante na investigação das causas e no acompanhamento do tratamento da obesidade canina.
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Nove vacas Holandesas lactantes com 526 ± 5 kg de peso corporal (cinco predominantemente pretas e quatro predominantemente brancas), criadas em região tropical e manejadas em pastagens, foram observadas com os objetivos de determinar simultaneamente as taxas de evaporação cutânea e respiratória em ambiente tropical e desenvolver modelos de predição. Para a medição da perda de calor latente pela superfície corporal, utilizou-se uma cápsula ventilada e, para a perda por respiração, utilizou-se uma máscara facial. Os resultados mostraram que as vacas que tinham maior peso corporal (classe 2 e 3) apresentaram maiores taxas evaporativas. Quando a temperatura do ar aumentou de 10 para 36ºC e a umidade relativa do ar caiu de 90 para 30%, a eliminação de calor por evaporação respiratória aumentou de aproximadamente 5 para 57 W m-2 e a evaporação na superfície corporal passou de 30 para 350 W m-2. Esses resultados confirmam que a eliminação de calor latente é o principal mecanismo de perda de energia térmica sob altas temperaturas (>30ºC); a evaporação cutânea é a maior via e corresponde a aproximadamente 85% da perda total de calor, enquanto o restante é eliminado pelo sistema respiratório. O modelo para predizer o fluxo de perda de calor latente baseado em variáveis fisiológicas e ambientais pode ser utilizado para estimar a contribuição da evaporação na termorregulação, enquanto o modelo baseado somente na temperatura do ar deve ser usado apenas para a simples caracterização do processo evaporativo.
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O presente estudo avaliou a digestibilidade aparente da proteína e da energia de ingredientes (farelo de soja, farinha de peixe, farelo de trigo e milho) por juvenis de apaiari (Astronotus ocellatus) usando dois diferentes intervalos de coleta (30 min. e 12h). Os 160 juvenis de apaiari utilizados (22,37 ± 3,06 g de peso corporal) foram divididos em quatro tanques rede plásticos e cilíndricos, cada um colocado em um tanque de alimentação de 1.000 L. O experimento foi inteiramente casualizado em esquema fatorial 2 x 4 (2 intervalos de coleta de fezes e 4 ingredientes foram) com quatro repetições. Os testes estatísticos não detectaram efeito da interação entre o intervalo de coleta e tipo de ingrediente nos coeficientes de digestibilidade. O intervalo de coleta não afetou a digestibilidade da proteína e da energia. As características físicas das fezes dos juvenis de apaiari aparentemente as tornam menos sensíveis à perda de nutrientes por lixiviação, permitindo intervalos de coleta maiores. A digestibilidade da proteína dos ingredientes avaliados foi semelhante, mostrando que a digestibilidade aparente de ingredientes animais e vegetais por juvenis de apaiari é eficiente. Os coeficientes de digestibilidade da energia foram maiores para a farinha de peixe e o farelo de soja comparado a farelo de trigo e milho. Ingredientes ricos em carboidratos (farelo de trigo e milho) apresentaram os piores coeficientes de digestibilidade da energia e, portanto, não são usados eficientemente pelos juvenis de apaiari.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Background: Changes in mineral density in the mandibular and femoral bones (BMD) after estrogen deficiency caused by ovariectomy (OVX) and the influence of these changes on induced periodontal disease were evaluated in female rats.Methods: Forty-eight female Holtzman rats (90 days old) were randomly divided into five groups: 0: control (N = 9); 1: SHAM without induced periodontal disease (N = 11); 2: SHAM with induced disease (N = 10); 3: OVX without induced disease (N = 9); and 4: OVX with induced disease (N = 9). In groups 2 and 4, the first lower molars were tied with ligatures for 30 days 120 days after surgery. After 5 months the animals were sacrificed to measure global mineral density (BMD) and that of the sub-regions of the mandible and femur by dual energy x-ray absorptiometry (DXA). The extent of vertical bone loss was evaluated with digital radiography by measuring the distance from the bone crest to the cemento-enamel junction at the mesial of the first lower molar.Results: Results of the femur (Kruskal-Wallis test) showed a significant difference (P < 0.001) between the groups SHAM and OVX in bone density values for all regions. Comparison between the groups in relation to the BMD of the mandible, both in the sub-regions and global revealed no differences (P < 0.05). The vertical bone loss measured for the groups with induced disease was similar (P= 0.713).Conclusions: Differences between the groups were found in the bone mineral density BMD of the femur but not of the mandible. OVX had no influence on induced periodontal disease.
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This paper studies energy localization conditions in lattices of the type proposed by Peyrard and Bishop. Homogeneous and inhomogeneous lattices are analyzed and the role of interfaces in the latter is emphasized. Simulations allowed us to identify critical energy values for the existence of localization. After a certain energy value, it is possible to observe the loss of energy localization along the chain.
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The energy flow, dE/d eta, is studied at large pseudorapidities in proton-proton collisions at the LHC, for centre-of-mass energies of 0.9 and 7 TeV. The measurements are made using the CMS detector in the pseudorapidity range 3:15 < vertical bar eta vertical bar < 4.9, for both minimum-bias events and events with at least two high-momentum jets. The data are compared to various pp Monte Carlo event generators whose theoretical models and input parameter values are sensitive to the energy-flow measurements. Inclusion of multiple-parton interactions in the Monte Carlo event generators is found to improve the description of the energy-flow measurements.
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Protein-energy malnutrition is a syndrome in which anaemia together with multivitamin and mineral deficiency may be present. The pathophysiological mechanisms involved have not, however, yet been completely elucidated. The aim of the present study was to evaluate the pathophysiological processes that occur in this anaemia in animals that were submitted to protein-energy malnutrition, in particular with respect to Fe concentration and the proliferative activity of haemopoietic cells. For this, histological, histochemical, cell culture and immunophenotyping techniques were used. Two-month-old male Swiss mice were submitted to protein-energy malnutrition with a low-protein diet (20g/kg) compared with control diet (400 g/kg). When the experimental group had attained a 20% loss of their original body weight, the animals from both groups received, intravenously, 20IU erythropoietin every other day for 14 d. Malnourished animals showed a decrease in red blood cells, Hb concentration and reticulocytopenia, as well as severe bone marrow and splenic atrophy. The results for serum Fe, total Fe-binding capacity, transferrin and erythropoietin in malnourished animals were no different from those of the control animals. Fe reserves in the spleen, liver and bone marrow were found to be greater in the malnourished animals. The mixed colony-forming unit assays revealed a smaller production of granulocyte-macrophage colony-forming units, erythroid burst-forming units, erythroid colony-forming units and CD45, CD117, CD119 and CD71 expression in the bone marrow and spleen cells of malnourished animals. These findings suggest that, in this protein-energy malnutrition model, anaemia is not caused by Fe deficiency or erythropoietin deficiency, but is a result of ineffective erythropoiesis.
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Short-term cold exposure of homeothermic animals leads to higher thermogenesis and food consumption accompanied by weight loss. An analysis of cDNA-macroarray was employed to identify candidate mRNA species that encode proteins involved in thermogenic adaptation to cold. A cDNA-macroarray analysis, confirmed by RT-PCR, immunoblot, and RIA, revealed that the hypothalamic expression of melanin-concentrating hormone (MCH) is enhanced by exposure of rats to cold environment. The blockade of hypothalamic MCH expression by antisense MCH oligonucleotide in cold-exposed rats promoted no changes in feeding behavior and body temperature. However, MCH blockade led to a significant drop in body weight, which was accompanied by decreased liver glycogen, increased relative body fat, increased absolute and relative interscapular brown adipose tissue mass, increased uncoupling protein 1 expression in brown adipose tissue, and increased consumption of lean body mass. Thus, increased hypothalamic MCH expression in rats exposed to cold may participate in the process that allows for efficient use of energy for heat production during thermogenic adaptation to cold.
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This work describes the influence of the ion bombardment on the electrical, optical and mechanical properties of polymer films deposited from radio-frequency plasmas of benzene. Irradiations were conducted using N+ at 5 x 10(19) ions/m(2), varying the ion energy, E-0, from 0 to 150 keV. Film elemental composition was determined by Rutherford backscattering spectroscopy. Electrical resistivity and hardness were obtained by the two-point probe and nanoindentation technique, respectively. Ultraviolet-visible spectroscopy was employed to investigate the optical constants of the samples. Etching rate was determined by exposure of the films to reactive oxygen plasmas. Ion bombardment induced gradual loss of H and increase in C and O concentrations with Eo. As a consequence the electrical, optical and mechanical properties were drastically affected. Interpretation of these results is proposed in terms of chain cross-linking and unsaturation. (C) 2001 Elsevier B.V. B.V. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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In order to estimate the deforestation consequences on the actual solar energy budget of the Central Amazon Region, two ecosystems of different characteristics were compared. The present conditions of the region were represented by a typical 'terra firme' forest cover located at INPA's Ducke Forest Reserve, where the measurements necessary to evaluate its solar energy balance were carried out. The second ecosystem, simulating a deforested area, was represented by an area about 1.0 ha without natural vegetation and situated in the same Reserve. In this area lysimeters were placed, two of them filled with yellow latosol and two others with quartzose sand soil. Both soils are representative soils in the region. Their water balances were taken into account as well as the other parameters necessary to compute the solar energy balances. The results showed that water loss by evaporation was about 41.8% of the total precipitation in the yellow latosol lysimeters and about 26.4% for the quartzose sand ones. For the forest cover it was estimated an evapotranspiration of 67.9% of the rainfall amount. In relation to solar energy balance calculated for the forest cover, it was found that 83.1% of the total energy incoming to this ecosystem was used by the evapotranspiration process, while the remaining of 16.9% can be taken as sensible heat. For bare soils, 55.1% and 31.8% of the total energy were used as latent heat by yellow latosol and quartzose sand soils, respectively. So, the remaining amounts of 44.9% and 68.2% were related to sensible heat and available to atmospheric air heating of these ecosystems. Such results suggest that a large deforestation of the Amazon Region would have direct consequences on their water and solar radiation balances, with an expected change on the actual climatic conditions of the region. © 1993.
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The high parton density effects are strongly dependent of the spatial gluon distribution within the proton, with radius R, which cannot be derived from perturbative QCD. In this paper we assume that the unitarity corrections are present in the HERA kinematical region and constrain the value of R using the data for the proton structure function and its slope. We obtain that the gluons are not distributed uniformly in the whole proton disc, but behave as concentrated in smaller regions. (C) 2000 Elsevier Science B.V.
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We develop a relativistic quark model for pion structure, which incorporates the nontrivial structure of the vacuum of quantum chromodynamics as modelled by instantons. Pions are bound states of quarks and the strong quark-pion vertex is determined from an instanton induced effective Lagrangian. The interaction of the constituents of the pion with the external electromagnetic field is introduced in gauge invariant form. The parameters of the model, i.e., effective instanton radius and constituent quark mass, are obtained from the vacuum expectation values of the lowest dimensional quark and gluon operators and the low-energy observables of the pion. We apply the formalism to the calculation of the pion form factor by means of the isovector nonforward parton distributions and find agreement with the experimental data. © 2000 Elsevier Science B.V.