990 resultados para energy profile
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Some observations of galaxies, and in particular dwarf galaxies, indicate a presence of cored density profiles in apparent contradiction with cusp profiles predicted by dark matter N-body simulations. We constructed an analytical model, using particle distribution functions (DFs), to show how a supernova (SN) explosion can transform a cusp density profile in a small-mass dark matter halo into a cored one. Considering the fact that an SN efficiently removes matter from the centre of the first haloes, we study the effect of mass removal through an SN perturbation in the DFs. We find that the transformation from a cusp into a cored profile occurs even for changes as small as 0.5 per cent of the total energy of the halo, which can be produced by the expulsion of matter caused by a single SN explosion.
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2,4-Dinitrophenol (DNP) is classically known as a mitochondrial uncoupler and, at high concentrations, is toxic to a variety of cells. However, it has recently been shown that, at subtoxic concentrations, DNP protects neurons against a variety of insults and promotes neuronal differentiation and neuritogenesis. The molecular and cellular mechanisms underlying the beneficial neuroactive properties of DNP are still largely unknown. We have now used DNA microarray analysis to investigate changes in gene expression in rat hippocampal neurons in culture treated with low micromolar concentrations of DNP. Under conditions that did not affect neuronal viability, high-energy phosphate levels or mitochondrial oxygen consumption, DNP induced up-regulation of 275 genes and down-regulation of 231 genes. Significantly, several up-regulated genes were linked to intracellular cAMP signaling, known to be involved in neurite outgrowth, synaptic plasticity, and neuronal survival. Differential expression of specific genes was validated by quantitative RT-PCR using independent samples. Results shed light on molecular mechanisms underlying neuroprotection by DNP and point to possible targets for development of novel therapeutics for neurodegenerative disorders.
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This study aimed: 1) to classify ingredients according to the digestible amino acid (AA) profile; 2) to determine ingredients with AA profile closer to the ideal for broiler chickens; and 3) to compare digestible AA profiles from simulated diets with the ideal protein profile. The digestible AA levels of 30 ingredients were compiled from the literature and presented as percentages of lysine according to the ideal protein concept. Cluster and principal component analyses (exploratory analyses) were used to compose and describe groups of ingredients according to AA profiles. Four ingredient groups were identified by cluster analysis, and the classification of the ingredients within each of these groups was obtained from a principal component analysis, showing 11 classes of ingredients with similar digestible AA profiles. The ingredients with AA profiles closer to the ideal protein were meat and bone meal 45, fish meal 60 and wheat germ meal, all of them constituting Class 1; the ingredients from the other classes gradually diverged from the ideal protein. Soybean meal, which is the main protein source for poultry, showed good AA balance since it was included in Class 3. on the contrary, corn, which is the main energy source in poultry diets, was classified in Class 8. Dietary AA profiles were improved when corn and/or soybean meal were partially or totally replaced in the simulations by ingredients with better AA balance.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Recent lines of evidence suggest that the beneficial effects of olive oil are not only related to its high content of oleic acid, but also to the antioxidant potential of its polyphenols. The aim of this work was determine the effects of olive oil and its components, oleic acid and the polyphenol dihydroxyphenylethanol (DPE), on serum lipids, oxidative stress, and energy metabolism on cardiac tissue. Twenty four male Wistar rats, 200 g, were divided into the following 4 groups (n = 6): control (C), OO group that received extra-virgin olive oil (7.5 mL/kg), OA group was treated with oleic acid (3.45 mL/kg), and the DPE group that received the polyphenol DPE (7.5 mg/kg). These components were administered by gavage over 30 days, twice a week. All animals were provided with food and water ad libitum The results show that olive oil was more effective than its isolated components in improving lipid profile, elevating high-density lipoprotein, and diminishing low-density lipoprotein cholesterol concentrations. Olive oil induced decreased antioxidant Mn-superoxide dismutase activity and diminished protein carbonyl concentration, indicating that olive oil may exert direct antioxidant effect on myocardium. DPE, considered as potential antioxidant, induced elevated aerobic metabolism, triacylglycerols, and lipid hydroperoxides concentrations in cardiac muscle, indicating that long-term intake of this polyphenol may induce its undesirable pro-oxidant activity on myocardium. © 2006 NRC Canada.
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The simultaneous existence of alternative oxidases and uncoupling proteins in plants has raised the question as to why plants need two energy-dissipating systems with apparently similar physiological functions. A probably complete plant uncoupling protein gene family is described and the expression profiles of this family compared with the multigene family of alternative oxidases in Arabidopsis thaliana and sugarcane (Saccharum sp.) employed as dicot and monocot models, respectively. In total, six uncoupling protein genes, AtPUMP1-6, were recognized within the Arabidopsis genome and five (SsPUMP1-5) in a sugarcane EST database. The recombinant AtPUMP5 protein displayed similar biochemical properties as AtPUMP1. Sugarcane possessed four Arabidopsis AOx1-type orthologues (SsAOx1a-1d); no sugarcane orthologue corresponding to Arabidopsis AOx2-type genes was identified. Phylogenetic and expression analyses suggested that AtAOx1d does not belong to the AOx1-type family but forms a new (AOx3-type) family. Tissue-enriched expression profiling revealed that uncoupling protein genes were expressed more ubiquitously than the alternative oxidase genes. Distinct expression patterns among gene family members were observed between monocots and dicots and during chilling stress. These findings suggest that the members of each energy-dissipating system are subject to different cell or tissue/organ transcriptional regulation. As a result, plants may respond more flexibly to adverse biotic and abiotic conditions, in which oxidative stress is involved. © The Author [2006]. Published by Oxford University Press [on behalf of the Society for Experimental Biology]. All rights reserved.
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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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An important alteration of the equivalent loads profile has been observed in the electrical energy distribution systems, for the last years. Such fact is due to the significant increment of the electronic processors of electric energy that, in general, behave as nonlinear loads, generating harmonic distortions in the currents and voltages along the electric network. The effects of these nonlinear loads, even if they are concentrated in specific sections of the network, are present along the branch circuits, affecting the behavior of the entire electric network. For the evaluation of this phenomenon it is necessary the analysis of the harmonic currents flow and the understanding of the causes and effects of the consequent voltage harmonic distortions. The usual tools for calculation the harmonic flow consider one-line equivalent networks, balanced and symmetrical systems. Therefore, they are not tools appropriate for analysis of the operation and the influence/interaction of mitigation elements. In this context, this work proposes the development of a computational tool for the analysis of the three-phase harmonic propagation using Norton modified models and considering the real nature of unbalanced electric systems operation. © 2011 IEEE.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The urbanization of modern societies has imposed to the planners and decision-makers a more precise attention to facts not considered before. Several aspects, such as the energy availability and the deleterious effect of pollution on the populations, must be considered in the policy decisions of cities urbanization. The current paradigm presents centralized power stations supplying a city, and a combination of technologies may compose the energy mix of a country, such as thermal power plants, hydroelectric plants, wind systems and solar-based systems, with their corresponding emission pattern. A goal programming multi-objective optimization model is presented for the electric expansion analysis of a tropical city, and also a case study for the city of Guaratinguetá, Brazil, considering a particular wind and solar radiation patterns established according to actual data and modeled via the time series analysis method. Scenarios are proposed and the results of single environmental objective, single economic objective and goal programming multi-objective modeling are discussed. The consequences of each dispatch decision, which considers pollutant emission exportation to the neighborhood or the need of supplementing electricity by purchasing it from the public electric power grid, are discussed. The results revealed energetic dispatch for the alternatives studied and the optimum environmental and economic solution was obtained. © 2012 Elsevier Ltd.
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The polysaccharide β-glucan has biological properties that stimulate the immune system and can prevent chronic pathologies, including cancer. It has been shown to prevent damage to DNA caused by the chemical and physical agents to which humans are exposed. However, the mechanism of β-glucan remains poorly understood. The objective of the present study was to verify the protective effect of β-glucan on the expression of the genes ERCC5 (involved in excision repair of DNA damage), CASP9 (involved in apoptosis), and CYP1A1 (involved in the metabolism of xenobiotics) using real-time polymerase chain reaction and perform metabolic profile measurements on the HepG2 cells. Cells were exposed to only benzo[a]pyrene (B[a]P), β-glucan, or a combination of B[a]P with β-glucan. The results demonstrated that 50 μg/mL β-glucan significantly repressed the expression of the ERCC5 gene when compared with the untreated control cells in these conditions. No change was found in the CASP9 transcript level. However, the CYP1A1 gene expression was also induced by HepG2 cells exposed to B[a]P only or in association with β-glucan, showing its effective protector against damage caused by B[a]P, while HepG2 cells exposed to only β-glucan did not show CYP1A1 modulation. The metabolic profiles showed moderate bioenergetic metabolism with an increase in the metabolites involved in bioenergetic metabolism (alanine, glutamate, creatine and phosphocholine) in cells treated with β-glucan and to a lesser extent treated with B[a]P. Thus, these results demonstrate that the chemopreventive activity of β-glucan may modulate bioenergetic metabolism and gene expression. © 2013 The Author(s).
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The objective was to evaluate the effect of unsaturated fatty acid sources supplementation on nutrients balances and milk fatty acid profile of mid lactation dairy cows. Twelve Brazilian Holstein cows in the mid lactation (mean of 128 days) and (580 ± 20kg of weight; mean ± SD) with milk yield of 25kg/d were assigned randomly into three 4 × 4 Latin square, fed the following diets: control (C); refined soybean oil; (SO); whole soybean raw (WS) and; calcium salts of unsaturated fatty acids (CSFA). Milk yield was 26.6; 26.4; 24.1 and 25.7 to the diets CO, SO, WS and CSFA respectively. Cows fed the WS treatment produced less milk (1.95kg/d of milk), fat and lactose than did cows fed the SO and CSFA. Cows fed the CSFA treatment showed less blood, urine (g/d) concentrations of N more energetic efficiency and intake of energy than did cows fed the SO treatment. Cows fed the unsaturated fatty acids sources showed more C18:2 cis-9, trans-11 CLA and trans-C18:1 FA concentration in milk than did cows fed the CO treatment. Diets with whole soybeans and soybeans oil provide more efficient digestive processes, and increase milk composition of unsaturated fatty acids.
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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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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)