991 resultados para external R
Resumo:
Although the sympathetic nervous system (SNS) plays a major role in mediating the peripheral stress response, due consideration is not usually given to the effects of prolonged stress on the SNS. The present study examined changes in neurotransmission in the SNS after exposure of mice (BALB/c) to stressful housing conditions. Focal extracellular recording of excitatory junction currents (EJCs) was used as a relative measure of neurotransmitter release from different regions of large surface areas of the mouse vas deferens. Mice were either group housed (control), isolation housed (social deprivation), group housed in a room containing rats (rat odor stress), or isolation housed in a room containing rats (concurrent stress). Social deprivation and concurrent stressors induced an increase of 30 and 335% in EJC amplitude, respectively. The success rate of recording EJCs from sets of varicosities in the concurrent stressor group was greater compared with all other groups. The present study has shown that some common animal housing conditions act as stressors and induce significant changes in sympathetic neurotransmission.
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The distributions of the Eph-class receptors EphA4 and EphB 1, and their ligands ephrin-A2, ephrin-B1, and ephrin-B2, were analysed by immunostaining in the mouse inner ear. Complementary patterns of EphA4 and its potential ligand ephrin-A2 were found, with ephrin-A2 in many of the structures lining the cochlear duct and within the cochlear nerve cells, and EphA4 in the deeper structures underlying the cochlear duct and in the cells lining the nerve pathway. EphB1 and its potential ligands ephrin-B1 and ephrin-B2 showed a segregated layered expression in the lateral wall of the cochlear duct (the external sulcus), which together with EphA4 expressed in the area, form a four-layered structure with an alternating pattern of receptors and ligands in the different layers. This arrangement gives the potential for different bidirectional Eph-mediated interactions between each of the layers. The results suggest that the Eph system in the cochlea may have a role in maintaining cell segregation during phases of cochlear development. (C) 2002 Wiley-Liss, Inc.
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We have performed immunocytochemistry on rat brains using a highly specific antiserum directed against the originally described form of the glutamate transporter GLT-1 (referred to hereafter as GLT-1alpha), and another against a C-terminal splice variant of this protein, GLT-1B. Both forms of GLT-1 were abundant in rat brain, especially in regions such as the hippocampus and cerebral cortex, and macroscopic examination of sections suggested that both forms were generally regionally coexistent. However, disparities were evident; GLT-1alpha was present in the intermediate lobe of the pituitary gland, whereas GLT-1B was absent. Similar marked disparities were also noted in the external capsule, where GLT1A labeling was abundant but GLT-1B was only occasionally encountered. Conversely, GLT-1B was more extensively distributed, relative to GLT-1alpha, in areas such as the deep cerebellar nuclei. In most regions, such as the olfactory bulbs, both splice variants were present but differences were evident in their distribution. In cerebral cortex, patches were evident where GLT-1B was absent, whereas no such patches were evident for GLT-1alpha. At high resolution, other discrepancies were evident; double-labeling of areas such as hippocampus indicated that the. two splice variants may either be differentially expressed by closely apposed glial elements or that the two splice variants may be differentially targeted to distinct membrane domains of individual glial cells. (C) 2002 Wiley-Liss, Inc.
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Toxic (Gobiodon spp.) and non-toxic (Paragobiodon xanthosomus) gobies became infected with external parasites (gnathiid isopods) at equal rates in a laboratory experiment. Parasites were evenly distributed over the body of P. xanthosomus but were mostly confined to the fins of Gobiodon spp., where toxin glands are less abundant. Skin toxins were not associated with the rate of infection but their distribution did appear to influence the site of parasite attachment. (C) 2003 The Fisheries Society of the British Isles.
Resumo:
The small GTPases R-Ras and H-Ras are highly homologous proteins with contrasting biological properties, for example, they differentially modulate integrin affinity: H-Ras suppresses integrin activation in fibroblasts whereas R-Ras can reverse this effect of H-Ras. To gain insight into the sequences directing this divergent phenotype, we investigated a panel of H-Ras/R-Ras chimeras and found that sequences in the R-Ras hypervariable C-terminal region including amino acids 175-203 are required for the R-Ras ability to increase integrin activation in CHO cells; however, the proline-rich site in this region, previously reported to bind the adaptor protein Nck, was not essential for this effect. In addition, we found that the GTPase TC21 behaved similarly to R-Ras. Because the C-termini of Ras proteins can control their subcellular localization, we compared the localization of H-Ras and R-Ras. In contrast to H-Ras, which migrates out of lipid rafts upon activation, we found that activated R-Ras remained localized to lipid rafts. However, functionally distinct H-Ras/R-Ras chimeras containing different C-terminal R-Ras segments localized to lipid rafts irrespective of their integrin phenotype. (C) 2003 Elsevier Inc. All rights reserved.
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We use a new molecular phylogeny, developed from small and large subunit ribosomal RNA genes, to explore evolution of the digenean life cycle. Our approach is to map character states on the phylogeny and then use parsimony to infer how the character evolved. We conclude that, plesiomorphically, digenean miracidia hatched from eggs and penetrated gastropod first intermediate hosts externally. Fork-tailed cercariae were produced in rediae and emerged from the snail to be eaten directly by the teleost definitive host. These plesiomorphic characters are seen in extant Bivesiculidae. We infer that external encystment and the use of second intermediate hosts are derived from this behaviour and that second intermediate hosts have been adopted repeatedly. Tetrapod definitive hosts have also been adopted repeatedly. The new phylogeny proposes a basal dichotomy between 'Diplostomida' (Diplostomoidea, Schistosomatoidea and Brachylaimoidea) and 'Plagiorchiida' (all other digeneans). There is no evidence for coevolution between these clades and groups of gastropods. The most primitive life cycles are seen in basal Plagiorchiida. Basal Diplostomida have three-host life cycles and are associated with tetrapods. The blood flukes (Schistosomatoidea) are inferred to have derived their two-host life cycles by abbreviating three-host cycles. Diplostomida have no adult stages in fishes except by life cycle abbreviation. We present and test a radical hypothesis that the blood-fluke cycle is plesiomorphic within the Diplostomida.
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We investigated how the relative direction of limb movements in external space (iso- and non-isodirectionality), muscular constraints (the relative timing of homologous muscle activation) and the egocentric frame of reference (moving simultaneously toward/away the longitudinal axis of the body) contribute to the stability of coordinated movements. In the first experiment, we attempted to determine the respective stability of isodirectional and non-isodirectional movements in between-persons coordination. In a second experiment, we determined the effect of the relative direction in external space, and of muscular constraints, on pattern stability during a within-person bimanual coordination task. In the third experiment we dissociated the effects on pattern stability of the muscular constraints, relative direction and egocentric frame of reference. The results showed that (1) simultaneous activation of homologous muscles resulted in more stable performance than simultaneous activation of non-homologous muscles during within-subject coordination, and that (2) isodirectional movements were more stable than non-isodirectional movements during between-persons coordination, confirming the role of the relative direction of the moving limbs in the stability of bimanual coordination. Moreover, the egocentric constraint was to some extent found distinguishable from the effect of the relative direction of the moving limbs in external space, and from the effect of the relative timing of muscle activation. In summary, the present study showed that relative direction of the moving limbs in external space and muscular constraints may interact either to stabilize or destabilize coordination patterns. (C) 2003 Published by Elsevier B.V.
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The integrated control of nitrate recirculation and external carbon addition in a predenitrification biological wastewater treatment system is studied. The proposed control structure consists of four feedback control loops, which manipulate the nitrate recirculation and the carbon dosage flows in a highly coordinated manner such that the consumption of external carbon is minimised while the nitrate discharge limits (based on both grab and composite samples) are met. The control system requires the measurement of the nitrate concentrations at the end of both the anoxic and the aerobic zones. Distinct from ordinary control systems, which typically minimise the variation in the controlled variables, the proposed control system essentially maximises the diurnal variation of the effluent nitrate concentration and through this maximises the use of influent COD for denitrification, thus minimising the requirement for external carbon source. Simulation studies using a commonly accepted simulation benchmark show that the controlled system consistently achieves the designated effluent quality with minimum costs.
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The origin of intracellular Ca2+ concentration ([Ca2+](i)) transients stimulated by nicotinic ( nAChR) and muscarinic ( mAChR) receptor activation was investigated in fura-2-loaded neonatal rat intracardiac neurons. ACh evoked [Ca2+](i) increases that were reduced to similar to 60% of control in the presence of either atropine ( 1 muM) or mecamylamine ( 3 muM) and to < 20% in the presence of both antagonists. Removal of external Ca2+ reduced ACh-induced responses to 58% of control, which was unchanged in the presence of mecamylamine but reduced to 5% of control by atropine. The nAChR-induced [Ca2+](i) response was reduced to 50% by 10 μM ryanodine, whereas the mAChR-induced response was unaffected by ryanodine, suggesting that Ca2+ release from ryanodine-sensitive Ca2+ stores may only contribute to the nAChR-induced [Ca2+](i) responses. Perforated-patch whole cell recording at - 60 mV shows that the rise in [Ca2+](i) is concomitant with slow outward currents on mAChR activation and with rapid inward currents after nAChR activation. In conclusion, different signaling pathways mediate the rise in [Ca2+](i) and membrane currents evoked by ACh binding to nicotinic and muscarinic receptors in rat intracardiac neurons.
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Para tornar p??blicos seus conhecimentos, tecnologias, metodologias desenvolvidas e/ou adaptados para toda a sociedade, em especial aos jovens e pequenos produtores rurais, a Empresa est?? utilizando, al??m da m??dia convencional, mais uma m??dia ??? o r??dio. Isso porque, al??m da sua facilidade de uso e de entendimento, esse ve??culo ?? capaz de levar informa????es aos lugares de mais dif??cil acesso do Pa??s, onde, muitas vezes, outros meios de comunica????o n??o t??m acesso. Hoje, conta-se com cerca de 504 emissoras cadastradas, que transmitem o programa semanalmente com capacidade de atingir 14 milh??es de ouvintes e, certamente, est??o contribuindo para fortalecer os pequenos produtores e a juventude do campo, para que tenham reais possibilidades de constru????o de um futuro melhor, no contexto da agricultura familiar, e de um novo projeto de desenvolvimento regional
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A popula????o da Amaz??nia, por causa do tamanho da regi??o, sofre por falta de atendimento m??dico e desinforma????o. Doen??as f??ceis de serem curadas tornam-se epidemias porque a popula????o n??o tem ou n??o sabe como trat??-las. Com a inten????o de diminuir esse problema a R??dio Nacional da Amaz??nia fez parceira com a Funda????o Nacional de Sa??de visando usar a informa????o, atrav??s do r??dio, como meio de preven????o. A parceria deu certo. Desde 1990, entrevistas e informa????es s??o passadas ?? popula????o amaz??nica com sucesso. Hoje as doen??as s??o mais conhecidas e a popula????o j?? sabe como se prevenir contra elas. As campanhas divulgadas atrav??s do r??dio s??o sempre um sucesso e pode-se dizer que esta parceria melhorou os servi??os da r??dio nacional da amaz??nia, facilitou o trabalho da funda????o nacional de sa??de e, especialmente, ajudou o povo da regi??o amaz??nica. Os problemas n??o acabaram, mas foram reduzidos consideravelmente
Resumo:
O presente trabalho apresenta conceitos e aspectos operacionais do Sistema de Avalia????o e Premia????o por Resultados da Embrapa/SAPRE, implantado em 1996, cujo objetivo ?? o de elevar o desempenho das unidades de pesquisa, equipes e empregados da Empresa, recompensando os mais produtivos. O Sistema ?? constitu??do por 6 componentes: a) avalia????o de unidades; b) premia????o de unidades; c) avalia????o de equipes e empregados; d) premia????o de equipes e empregados; e) premia????o nacional de projetos e f) premia????o por excel??ncia. As unidades s??o avaliadas em conformidade a: a) cumprimento de metas; b) efici??ncia relativa; c) avalia????o de qualidade t??cnica; d) impacto s??cio-econ??mico; e) avalia????o de imagem. A conjuga????o desses fatores constitui o ??ndice de Desempenho Institucional de uma unidade, base para o c??lculo financeiro de sua premia????o. A avalia????o de equipes e empregados de cada unidade compreende o respectivo desempenho em: a) cumprimento de metas individuais; b) capta????o de recursos; c) criatividade em pesquisa e desenvolvimento (P&D); d) qualidade t??cnica dos projetos de pesquisa. Os empregados com melhor desempenho, individualmente e por equipes de trabalho, s??o premiados com um b??nus financeiro. Al??m disso, o SAPRE inclui a premia????o de projetos, que, no ??mbito nacional, se destacam em termos de criatividade, parceria, capta????o de recursos, qualidade t??cnica e melhoria de processos. Tamb??m s??o premiados com trof??us e diplomas os dois melhores empregados (um pesquisador e um de suporte ?? pesquisa) de cada unidade descentralizada e da sede como um todo.
Resumo:
Apesar de todo investimento nos ??ltimos anos, do poder p??blico, em qualificar profissionais, criar cursos e institui????es para forma????o de gestores p??blicos, o que parece ainda vigorar s??o as indica????es, para os cargos de gestores de unidades de sa??de. A carreira do Gestor P??blico na ??rea de sa??de deve ser feita atrav??s da Escola Nacional de Administra????o P??blica (ENAP), criada para tal fim, nos moldes atuais da carreira de Especialistas em Pol??ticas P??blicas e Gest??o Governamental (EPPGG) ou por outras Escolas como a Escola Nacional de Sa??de P??blica (ENSP). A????es e press??es de atores internacionais interferem na gest??o governamental, levando os governantes a promoverem reformas em suas administra????es visando atender esses interesses. Reformas administrativas ocorreram, em sua maioria, n??o por vontade do governo vigente, mas sim por v??rios fatores, sejam internos ou externos ao pa??s. Devido ao processo de globaliza????o e ao ide??rio neoliberal, que defendiam menor participa????o de interven????o do Estado na economia, reformas administrativas ocorreram e vem ocorrendo. Nos anos recentes, visando responder ??s demandas de novos conhecimentos e tecnologias colocadas pelo sistema de sa??de brasileiro em r??pida transforma????o, foi criado o espa??o institucional na, Escola de Governo em Sa??de (EGS), implantada na ENSP em 1998, dedicada a mobilizar e potencializar os esfor??os institucionais especificamente dirigidos a colaborar com a amplia????o da capacidade de governo em sa??de. Faremos uma breve exposi????o da forma????o de profissionais para a carreira de gest??o p??blica em alguns pa??ses das Am??ricas, mostrando a diversidade dos modelos de Escolas de Governo.