811 resultados para play-fighting
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Increased fighting is an effect of desynchronized sleep deprivation (DSD) in rats, and recently this behavior has been suggested to be spontaneous panic and equivalent to panic disorder. In the present study we tested this hypothesis by evaluating the effect of sodium lactate on this aggressiveness, because this substance is recognized to induce spontaneous panic attacks in patients. A total of 186 male albino Wistar rats, 250-350 g, 90-120 days of age, were submitted to DSD (multiple platform method) for 0, 4, or 5 days. At the end of the deprivation period the rats were divided into subgroups respectively injected intraperitoneally with 1.86, 2.98 and 3.72 g/kg of 1 M sodium lactate, or 1.86 and 3.72 g/kg of 2 M sodium lactate. The control animals were submitted to the same procedures but received equivalent injections of sodium chloride. Regardless of DSD time, sleep-deprived animals that received sodium lactate presented a significantly higher mean number of fights (0.13 ± 0.02 fights/min) and a longer mean time spent in confrontation (2.43 ± 0.66 s/min) than the controls (0.01 ± 0.006 fights/min and 0.12 ± 0.07 s/min, respectively; P<0.01, Student t-test). For the sodium lactate group, concentration of the solution and time of deprivation increased the number of fights, with the mean number of fights and mean duration of fighting episodes being greater with the 2.98 g/kg dose using 1 M lactate concentration. These results support the hypothesis that fighting induced by DSD is probably a spontaneous panic manifestation. However, additional investigations are necessary in order to accept this as a promising animal model for studies on panic disorder.
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In previous studies using bilateral carotid occlusion in conscious freely moving rats we suggested that aortic baroreceptors may play a more important role in the regulation of hindlimb than in renal and mesenteric vascular resistances. In the present study we performed electrical stimulation of the aortic baroreceptor nerve and analyzed the changes in mean arterial pressure and in hindlimb, renal, and mesenteric vascular resistances. All the experiments were performed under urethan anesthesia. Unilateral electrical stimulation (3 V, 2 ms, 50 Hz) of the aortic baroreceptor nerve produced a fall in arterial pressure (-27 +/- 3 mmHg) and an important reduction in hindlimb vascular resistance (-43 +/- 5%), with an increase in renal (+3 +/- 14%) and mesenteric (+48 +/- 12%) vascular resistances. Similar changes in arterial pressure as well as in the resistance of the three vascular beds studied were also observed during electrical stimulation of the aortic baroreceptor nerve in rats with bilateral carotid baroreceptor denervation or in rats treated with methylatropine. The data obtained with electrical stimulation indicated that aortic baroreceptors play a more important role in the regulation of blood flow in hindlimb than in renal and mesenteric vascular beds.
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The aggressive display in Betta splendens is particularly prominent, and vital to its adaptation to the environment. Methylmercury is an organic variation of Hg that presents particularly pronounced neuro-behavioral effects. The present experiments aim to test the effect of acute and chronic poisoning with methylmercury on the display in Bettas. The animals were poisoned by trophic means in both experiments (16 ug/kg in acute poisoning; 16 ug/kg/day for chronic poisoning), and tested in agonistic pairs. The total frequency of the display was recorded, analyzing the topography of the agonistic response. The methylmercury seems to present a dose- and detoxification-dependent effect on these responses, with a more pronounced effect on motivity in acute poisoning and on emotionality in the chronic poisoning. It is possible that this effect could be mediated by alteration in the mono-amino-oxidase systems.
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Includes bibliography
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Includes bibliography
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The fungus Rhizoctonia solani AG-1 IA causes sheath blight, one of the most important rice diseases worldwide. The first objective of this study was to analyse the genetic structure of R. solani AG-1 IA populations from three locations in the Iranian Caspian Sea rice agroecosystem. Three population samples of R. solani AG-1 IA isolates were obtained in 2006 from infected rice fields separated by 126-263km. Each field was sampled twice during the season: at the early booting stage and 45days later at the early mature grain stage. The genetic structure of these three populations was analysed using nine microsatellite loci. While the population genetic structure from Tonekabon and Amol indicated high gene flow, they were both differentiated from Rasht. The high gene flow between Tonekabon and Amol was probably due mainly to human-mediated movement of infested seeds. The second objective was to determine the importance of recombination. All three populations exhibited a mixed reproductive mode, including both sexual and asexual reproduction. No inbreeding was detected, suggesting that the pathogen is random mating. The third objective was to determine if genetic structure within a field changes over the course of a growing season. A decrease in the proportion of admixed genotypes from the early to the late season was detected. There was also a significant (P=0·002) increase in the proportion of loci under Hardy-Weinberg equilibrium. These two lines of evidence support the hypothesis that basidiospores can be a source of secondary inoculum. © 2012 BSPP.
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The synthesis and characterization of ruthenium compounds of the type [RuCl2(P)2(N-N)] [(P)2 = (PPh3) 2, dppb = 1,4-bis(diphenylphosphino)butano; dppp = 1,3-bis(diphenylphosphino)propane; N-N = 5,5′-dimethyl-2,2′dipyridyl (5,5′-mebipy) or 4,4′-dimethyl-2,2′dipyridyl (4,4′-mebipy)] are described. The complexes were characterized using elemental analysis, UV-Vis and infrared spectroscopies, cyclic voltammetry, and X-ray crystallography. In vitro evaluation of the complexes, using the MTT methodology, revealed their cytotoxic activities in a range of 5.4-15.7 μM against the MDA-MB-231 breast tumor cells and showed that, in this case, they are more active than the reference metallodrug cisplatin. The in vitro antimycobacterial activities of the complexes had their Minimum Inhibitory Concentration (MIC) for MTB cell growth measured, by the REMA method. The MICs for these complexes were found to be between 12.5 and 25.0 μg/mL. The results are comparable with the second line drug cycloserine (MIC = 12.5-50.0 μg/mL), commonly used in the treatment of TB. © 2013 Elsevier Ltd. All rights reserved.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Este trabalho faz uma análise de desempenho de aplicações triple play através da tecnologia Power Line Communication, fazendo uma abordagem direcionada para qualidade de serviço e qualidade de experiência. Apresenta resultados obtidos em cenários residenciais onde o uso desta tecnologia como última milha mostra-se uma solução passível de implementação diante dos testes realizados com transmissões de chamadas VoIP, transmissões de vídeo em alta definição e dados. O conceito de rede doméstica, interligando todos os pontos de uma casa, vem representando um novo rumo na definição de um padrão global, no qual a transmissão de dados por meio da fiação elétrica será uma das tecnologias empregadas e de maior destaque. Também será mostrado o desempenho das métricas avaliadas como jitter, largura de banda, perda de pacotes, PSNR, MOS, VQM, SSIM e suas correlações.
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A maior proporção de fumantes entre negros no Brasil tem sido atribuída a desigualdades socioeconômicas, mas fatores genéticos também poderiam contribuir para esse achado. Este estudo visou investigar associações entre status tabágico com ancestralidade definida geneticamente e características socioeconômicas em brasileiros. Amostras de sangue foram colhidas de 448 voluntários (66,7% homens; idade: 37,1±11,4 anos) classificados como fumantes atuais (FA: 60,9%), ex-fumantes (EF:8,9%) e não fumantes (NF:30,1%).Misturas éticas individuais foram determinadas empregando-se um painel informativo de ancestralidade composto por 48 polimorfismos de deleções e inserções. FA mostraram menor proporção de ancestralidade europeia do que NF (0,837±0,243 X 0,883±0,194; p≤0,05) e EF (0,837±0,243 X 0,864±0,230; p≤0,05), e maior proporção de ancestralidade africana sub-saárica do que EF (0,128±0,222 X 0,07±0,174, p≤0,05) e NF (0,128±0,222 X 0,085±0,178, p≤0,05). NF informaram maior número de anos de escola do que FA (11,2±3,7 X 8,9±3,8; p≤0,001). FA foram menos comuns na Classe econômica A (30%) e mais comuns na Classe B (56,8%). Em análise multivariada, apenas menor número de anos escolares e menor classe econômica estiveram associados com chances maiores para FA. O uso de marcadores de genética molecular para caracterizar o background étnico confirmou que diferenças socioeconômicas são os principais determinantes de maiores taxas de tabagismo entre negros no Brasil.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)