126 resultados para Dirac delta


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This study was conducted at University of Marília, São Paulo State, Brazil, aiming to determine the phase of intake transition between exclusively liquid diet (milk) and diet based on milk, grass and/or ration by lambs by δ13C technique. Six Suffolk crossbreeding lambs were distributed in a totally random design (3x2), with two experimental groups and three replications. At the first one, lambs were penned and sucked milk from dams fed with C4 diet. besides, they had access to C3 ration in creep feeding, since their birth. At the second group, lambs were kept on a paddock with Tifton – 85 grass (C4 photosynthetic way) as well as their dams and had access to C3 ration in creep feeding, since their birth. The C3 ration contained soybean meal, ground oat grains, lucerne hay and also mineral salt. The penned lambs’ ration consumption overcame the milk intake at 30-35 days after birth; however, grazing lambs ingested more milk and pasture than ration until 40 days after birth. The δ 13C technique was considered effective on studies of lambs feeding behavior.

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Pharmacological treatments currently used in ethanol addiction are inefficient, requiring new drugs for this purpose. The pro-drug N-Acetylcysteine (N-Ac) has shown efficacy in the treatment of addiction to cocaine and nicotine in preclinical research and clinical pilot studies. When administered, N-Ac is subsequently converted to cysteine, and cystine, which has an action on the central nervous system. However, there are few data about the possible application of N-Ac in the ethanol addiction. Behavioral sensitization is the gradual increase of the psychostimulant effects induced by repeated administration of drugs of abuse, including ethanol, and its development has been linked to important neuroadaptations in addiction. These neuroadaptations occur in neural circuits that mediate the reinforcing properties of these drugs and may involve several proteins. The ΔFosB protein accumulates in neurons after repeated activation and mediates long lasting changes in response to drugs of abuse. These changes are manifested mainly in the nucleus accumbens (Acb) and prefrontal cortex (PFC) neurons. The aim of the study was to evaluate the effects of N-Ac treatment in the development of ethanol behavioral sensitization and in alterations in the ΔFosB protein in mice. Swiss male mice were exposed to a standardized behavioral sensitization protocol to the experimental conditions of the laboratory and treated with N-Ac. At the end of behavioral sensitization procedure, animals were euthanized and their brains removed for ΔFosB quantification by Western blotting. Two experiments of behavioral sensitization were performed to the standardization of the protocol. The first, although effective in demonstrating the development of behavioral sensitization, was not effective in allowing the evaluation of the expression of the behavioral sensitization. The age of the animals and the conditions of luminosity and color of locomotion apparatus were changed and a new...