9,558 research outputs found

    Perfil de compra de produtos básicos em assentamentos rurais: evidências empíricas [Profile of purchase of basic products in rural resettlement in Brazil: empirical evidences]

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    The habit of purchase of agricultural populations is one of the gaps of the Brazilian national statistics. This paper addresses a reference of the consumption guideline of families in rural re settlements from a survey research in rural settlements in the region of the Northwest of Minas Gerais. The data point the establishment of a standard of consumption next to the urban standards and with relevant importance to urban equipment of supplying as supermarkets. It also evidences the low degree of commercialization of the production of the seated ones in the proper settlements, placing as important question for quarrel the creation of ways of commercialization in the rural settlements.rural resettlement; food consumption; household income

    Um novo enredo para uma velha história? Uma análise da aplicação do conceito de redes para o sistema agroalimentar [A new plot for an old history? An analysis of the application of the concept of network for the agrifood system]

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    This paper has as objective the analysis of the organization characteristics in network and its utilization to the agri-food system as useful instrument to identify and to explain important aspects in the valorization of the agri-food capital starting from your interactions and organizations. Several network concepts developed in the economical literature are analyzed as the concepts of information networks, technological network and commercial network, as well as the concepts of social network To the light of this literature, the interpretations of the application of the concept of companies are analyzed in net for the system. The analysis developed about the adherence of the concept of network to the agri food system, it tried to evidence that this concept cannot be taken as a new theoretical paradigm and either it should be taken as representative of a historical stage of the capitalist development in the agriculture, succedaneous of the conformation of agroindustrial complex. The network concept can be taken as an analytic tool, that has specific prescriptions in terms of the phenomena that it is capable to express with advantages on the analysis of chains, starting from the analytic framework of the one of transaction.network; agrifood system; industrial organization

    A semiquantitative approach to the impurity-band-related transport properties of GaMnAs nanolayers

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    We investigate the spin-polarized transport of GaMnAs nanolayers in which a ferromagnetic order exists below a certain transition temperature. Our calculation for the self-averaged resistivity takes into account the existence of an impurity band determining the extended ("metallic" transport) or localized (hopping by thermal excitation) nature of the states at and near the Fermi level. Magnetic order and resistivity are inter-related due to the influence of the spin polarization of the impurity band and the effect of the Zeeman splitting on the mobility edge. We obtain, for a given range of Mn concentration and carrier density, a "metallic" behavior in which the transport by extended carriers dominates at low temperature, and is dominated by the thermally excited localized carriers near and above the transition temperature. This gives rise to a conspicuous hump of the resistivity which has been experimentally observed and brings light onto the relationship between transport and magnetic properties of this material

    e-Sispaf: Sistema de Informação e Promoção de Produtos e Serviços da Agricultura Familiar - guia de instalação e configuração do sistema. Versão 0,1.

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    O e-Sispaf é um sistema de informação que promove a consolidação e a disseminação de conhecimentos relativos ao mapeamento da produção e informações da comercialização e do mercado de produtos convencionais, orgânicos e artesanais para agricultura familiar. O objetivo do sistema é facilitar as transações entre produtores e consumidores, promovendo, assim a execução de ações efetivas para o crescimento da renda do segmento. Através do sistema, produtor e consumidor podem trocar informações e negociar suas produções diretamente, sem nenhum intermediário. O sistema é importante porque auxilia na tomada de decisões de todos os seus possíveis usuários (produtores, comerciantes e governos), que passam a contar com instrumentos decisivos para o planejamento das políticas agrícolas. O e-Sispaf foi Implementado utilizando-se software livre (osCommerce) para o ambiente web, eliminando assim custos para operacionalização. Baseia-se nos pressupostos do comércio eletrônico (e-commerce) e oferece aos usuários - que podem ser produtores rurais, cooperativas, associações ou organizações públicas ou privadas - a oportunidade de expor seus produtos e trocar dados, obtidos junto aos produtores, às cooperativas, às associações, aos órgãos do governo e/ou órgãos privados localizados na região de abrangência do e-Sispaf. Este guia contém um conjunto de informações, distribuídas em sessões, com o objetivo de facilitar a instalação e configuração do e-Sispaf. Algumas das opções de configuração disponibilizadas não foram utilizadas na atual versão do e-Sispaf. Elas fazem parte do software osCommerce e são configuradas para aquisição de produtos de forma on-line, o que não ocorre no e-Sispaf.bitstream/item/17881/1/docmeionorte191.pd

    Purinergic P2 receptors trigger adenosine release leading to adenosine A2A receptor activation and facilitation of long-term potentiation in rat hippocampal slices

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    Electrophysiological recordings were used to investigate the effects of ATP analogues on [theta]-burst-induced long-term potentiation (LTP) in rat hippocampal slices. [alpha],[beta]-Methylene ATP ([alpha],[beta]-MeATP; 20 [mu]M) decreased LTP from 36±9% to 17±5%, an effect prevented by adenosine A1 receptor blockade in accordance with the localised catabolism of ATP analogues into adenosine, leading to adenosine A1 receptor activation. Thus, to probe the role of extracellular ATP, all experiments were performed with the A1 receptor selective antagonist, 1,3-dipropyl-8-cyclopentylxanthine (50 nM). In these conditions, [alpha],[beta]-MeATP or 5'-adenylylimido-diphosphate ([beta],[gamma]-ImATP; 20 [mu]M) facilitated LTP by 120%, an effect prevented by the P2 receptor antagonists, pyridoxalphosphate-6-azophenyl-2'-4'-disulphonic acid (PPADS; 20 [mu]M) or suramin (75 [mu]M), as well as by the P2X1/3-selective antagonist 8-(benzamido)naphthalene-1,3,5-trisulfonate (10 [mu]M). The facilitations of LTP by either [alpha],[beta]-MeATP or [beta],[gamma]-ImATP (20 [mu]M) were also prevented by both 4-(2-[7-amino-2-(2-furyl(1,2,4)-triazolo(2,3a)-(1,3,5)triazin-5-yl-amino]ethyl)phenol (50 nM) or 7-2(-phenylethyl)-5-amino-2-(2-furyl)-pyrazolo-[4,3-e]-1,2,4-triazolo[1,5-c] pyrimidine (50 nM), antagonists of facilitatory adenosine A2A receptors, were occluded by the A2A receptor agonist, CGS 21680 (10 nM) and were prevented by the protein kinase C inhibitor, chelerythrine (6 [mu]M) and unaffected by the protein kinase A inhibitor, H89 (1 [mu]M). Furthermore, [beta],[gamma]-ImATP (20 [mu]M) enhanced [3H]adenosine outflow from rat hippocampal slices by nearly 150%, an effect prevented by PPADS (20 [mu]M) or suramin (75 [mu]M). The adenosine transport inhibitors, nitrobenzylthioinosine (5 [mu]M) and dipyridamole (10 [mu]M) also prevented [beta],[gamma]-ImATP (20 [mu]M)-induced [3H]adenosine outflow and facilitation of LTP. These results suggest that ATP analogues facilitate LTP through P2 receptor activation that mainly triggers adenosine release leading to the activation of adenosine A2A receptors.http://www.sciencedirect.com/science/article/B6T0F-49SFDNY-1/1/bd15c287ddd50f5af9c1be35dcb9227

    Avaliação de fontes de magnésio em porta-enxertos de seringueira.

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    Bioactive peptides produced from the mussel mytilus galloprovincialis by enzymatic hydrolysis with corolase

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    Bioactive peptides have been produced from several marine sources since they can exhibit positive effects for humans and animals. Mytilus galloprovincialis is highly consumed in several countries and has a meat rich in proteins, which has been described as a source of bioactive peptides with relevant properties such as antioxidant, anti-hypertensive and antimicrobial activities. Mussel commercialization generates waste, since the small or broken mussels are discarded. Thus, in this work discarded mussels were used with the goal of producing water soluble extracts rich in proteins and bioactive peptides. The mussel meat was firstly minced, and then submitted to different conditions of enzymatic hydrolysis, using the protease corolase to generate peptides. The variable factors evaluated were temperature, incubation time and enzyme concentration. To achieve the optimal extraction conditions, a Box-Behnken experimental design was performed using statgraphic centurion software. Factorial design allowed the evaluation of the effects of the three factors on protein release, antioxidant and anti-hypertensive properties of the extracts. The protein content of each extract was determined by Kjeldahl, the antioxidant activity was determined by oxygen-radical absorbance-capacity (ORAC) assay and anti-hypertensive property was determined by the inhibition method of Angiotensin-I converting enzyme (ACE). The incubation of the minced mussel meat with 3% of enzyme, at 40 ºC for 3 hours, appears to be the best conditions to obtain the best results of protein extraction, and antioxidant and anti-hypertensive properties. With these conditions, the obtained extracts showed 48% of protein content, an antioxidant activity of 821 μmol TE / g of extract, and an ability of inhibiting the activity of ACE in 61% (using a concentration of 10 mg / mL). Thus, the factorial design allowed to confirm the combination of experimental factors that leads to the most efficient extraction of antioxidant and anti-hypertensive peptides of the mussel Mytilus galloprovincialis. In conclusion, the use of discarded mussels to produce functional ingredients for food, cosmetic and pharmaceutic industries contribute to valorise world waste in a circular economy context.info:eu-repo/semantics/publishedVersio
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