122 research outputs found

    Mecanismos de participação cívica em Portugal: o caso dos teferendos locais

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    O presente trabalho procura dar o seu humilde contributo para a dignificação e qualificação do Poder Local em Portugal, analisando um dos mecanismos que a lei coloca ao serviço dos órgãos autárquicos e da iniciativa popular: o referendo local. Pretende-se verificar até que ponto a teoria da escolha pública e dos custos de transação políticos poderão explicar o comportamento dos políticos locais relativamente ao seu posicionamento em relação ao recurso a mecanismos de participação cívica, em concreto, aos referendos locais. O escasso recurso a estes últimos estará relacionado com critérios de racionalidade política ou de oportunismo político, para lá do mero interesse público que juram defender? Não terão os eleitos locais receio das suas consequências políticas no caso de aprovação (ou não), sobretudo se a votação for no sentido oposto ao que defendem? Poderão os resultados colocar em causa a sua reeleição? A opção por essa temática prende-se com o facto de serem escassos os estudos e obras dedicadas ao referendo local, embora abundem no que concerne à participação cívica e ao divórcio entre eleitos e eleitores. Por outro lado, pretendemos dignificar este instrumento e tentar colocá-lo na agenda política atual por lhe reconhecermos virtualidades inegáveis no aprofundamento e na qualidade da democracia local. A pergunta de investigação a que procuraremos responder de forma adequada é a seguinte: Quais os fatores que explicam ou motivam a apresentação de propostas de referendos locais em Portugal?info:eu-repo/semantics/publishedVersio

    Setting the Stage : introduction

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    Higher education systems have changed significantly in recent years in response to rising global challenges and various national policy initiatives. One of the major forces fostering change in higher education over recent decades has been its persistent expansion. As higher education has continued to expand, governments’ responses have been to seek structural changes at system level (Taylor et al., 2008).info:eu-repo/semantics/publishedVersio

    Bionomy and Nesting Behavior of the Bee Epanthidium tigrinum (Schrottky, 1905) (Hymenoptera: Megachilidae) in Trap-Nests

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    About 85% of pollinating bees are solitary, but few are used for agricultural pollination. The Anthidiini tribe looks very promising in Brazil, in the light of ecosystem utility, but  it is still a species with poorly scientific research[EdM1] . To fill this gap studies on the bionomics of this species may collaborate on future studies on use of Epanthidium tigrinum as pollinator. Presented research results aims to describe the bionomy and the biological cycle of the bee E. tigrinum (SCHROTTKY, 1905) in pre-existing cavities. Conventional trap-nests inserted in wooden blocks were placed in covered spaces and daily observations of spontaneous nesting as well as individually tagged bees and nests incubated in B.O.D. were carried out during 11 months in Fortaleza-CE. The results showed that the competition with other species of bees for the pre-existing cavities and the lack of food resources or nest building materials are limiting factors for the establishment of E. tigrinum populations. However, once these problems were remedied, the bees showed multivoltine behavior, nesting throughout the experimental period. Data from 16 nests studied showed that bee foraging began on average at 7:50 a.m., foragers collected pollen in the morning and resin in the afternoon, took on average 15 days to complete a nest and there was a negative correlation with the temperature for the number of nests and for the number of cells constructed. The offspring took 43 days for the emergency, presented sexual ratio of 1.2: 1 (n = 66 emerged bees) and a mortality rate of 18.5%. The number of nests constructed per female ranged from 1 to 4 with an average size of 7.97 mm. It is concluded that E. tigrinum shows potential to rational rearing in trap nests aiming crop pollination. [EdM1

    Rat olfactory mucosa mesenchymal stem/stromal cells (om-mscs): a characterization study

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    Stem/stromal cell-based therapies are a branch of regenerative medicine and stand as an attractive option to promote the repair of damaged or dysfunctional tissues and organs. Olfactory mucosa mesenchymal stem/stromal cells have been regarded as a promising tool in regenerative therapies because of their several favorable properties such as multipotency, high proliferation rate, helpful location, and few associated ethical issues. These cells are easily accessible in the nasal cavity of most mammals, including the rat, can be easily applied in autologous treatments, and do not cope with most of the obstacles associated with the use of other stem cells. Despite this, its application in preclinical trials and in both human and animal patients is still limited because of the small number of studies performed so far and to the nonexistence of a standard and unambiguous protocol for collection, isolation, and therapeutic application. In the present work a validation of a protocol for isolation, culture, expansion, freezing, and thawing of olfactory mucosa mesenchymal stem/stromal cells was performed, applied to the rat model, as well as a biological characterization of these cells. To investigate the therapeutic potential of OM-MSCs and their eventual safe application in preclinical trials, the main characteristics of OMSC stemness were addressed.info:eu-repo/semantics/publishedVersio

    A "masculinização" da produção de leite.

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    O fortalecimento de organizações sociais que possibilitaram fazer da produção de leite uma atividade destinada ao mercado provocou profundas mudanças na divisão sexual do trabalho. A análise sociológica das trocas intradomiciliares nos estabelecimentos rurais familiares mostra que tradições culturais, diferenças de poder entre os gêneros e contextos sociais que ampliam diferenças de acesso aos mercados entre homens e mulheres são as bases sociais e culturais de uma hierarquia estruturada segundo sexo e geração, no qual as mulheres, especialmente as mais jovens, ocupam posições de grande desvantagem. Com o fortalecimento de cooperativas, a produção de leite passou a ocupar um lugar de destaque no provimento de recursos da família, mas o domínio da atividade foi deslocado para o controle masculino. Esse foi um dos resultados não esperados da forma como as organizações conduziram o processo de modernização da produção e de reestruturação dos mercados, que reforçaram ainda mais o domínio masculino sobre a produção familiar e um aumento das desigualdades de gênero no acesso aos recursos

    Ordered mesoporous silica materials for protein adsorption

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    Lysozyme and BSA were used, as model proteins of considerably different dimensions, in order to evaluate the influence of the distinct pore structural characteristics of three types of ordered mesoporous silica materials (MCF, SBA-15 and MCM-41) on protein adsorption. Characterisation by X ray diffraction and nitrogen adsorption at 77K revealed the typical pore structural features of each type of material. The maximum of the pore size distributions indicated that the width of the windows of MCF (2) (mesitylene/P123 of 2) was larger than the pore diameter of the unidirectional tubular pores of SBA-15. All the materials presented similar small external surface areas but high pore volumes, with that of MCF (2) being the highest. The adsorption of lysozyme at pH=8 increased in the order MCM-41<< SBA-15< MCF (2), and the uptakes were well above those of BSA at pH=5. Although BSA is not completely excluded from the mesopores of SBA-15 and MCF (2), as happens with MCM-41, the adsorption occurs to a very limited extent. The overall behaviour of these SBA-15 and MCF (2) samples was not significantly different and both revealed potential for the separation of these proteins

    Host-defense peptides AC12, DK16 and RC11 with immunomodulatory activity isolated from Hypsiboas raniceps skin secretion

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    Inflammation is a natural defense mechanism of the immune system; however, when unregulated, it can lead to chronic illness. Glucocorticoids are the most commonly used agents to effectively treat inflammatory conditions, including autoimmune diseases, however these substances can trigger a number of side effects. Thus, viable alternatives to the use of these drugs would be advantageous. In this study, we have analyzed the anti-inflammatory profile of three synthetic peptides first identified in skin secretion of the tree frog Hypsiboas raniceps. Structural characterization was performed using NMR spectroscopy and Mass Spectrometry, and the peptides were tested in vitro in RAW 264.7 cells and in vivo in Balb/c mice for their functional properties. The samples did not show a significant antimicrobial profile. NMR spectroscopy indicated that AC12 (ACFLTRLGTYVC) has a disulfide bond between C2 and C11 and a β-sheet-turn-β-sheet conformation in aqueous solution. This peptide showed no cytotoxic effect in mammalian cells and it was the most effective in reducing anti-inflammatory markers, such as NO, TNF-α and IL-12. Peptide DK16 (DKERPICSNTFRGRKC) demonstrated anti-inflammatory properties in vitro, while RC11 (RCFRRRGKLTC) significantly altered the cell viability in RAW 264.7 but was shown to be safe in Balb/c erythrocytes. Our results indicate that, of the three peptides studied, AC12 is the most efficient in reducing anti-inflammatory markers, and it could be a potential agent for the treatment of inflammatory diseases.publishe

    The sphingosine 1‐phosphate analogue, FTY720, modulates the lipidomic signature of the mouse hippocampus

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    The small‐molecule drug, FTY720 (fingolimod), is a synthetic sphingosine 1‐phosphate (S1P) analogue currently used to treat relapsing–remitting multiple sclerosis in both adults and children. FTY720 can cross the blood–brain barrier (BBB) and, over time, accumulate in lipid‐rich areas of the central nervous system (CNS) by incorporating into phospholipid membranes. FTY720 has been shown to enhance cell membrane fluidity, which can modulate the functions of glial cells and neuronal populations involved in regulating behaviour. Moreover, direct modulation of S1P receptor‐mediated lipid signalling by FTY720 can impact homeostatic CNS physiology, including neurotransmitter release probability, the biophysical properties of synaptic membranes, ion channel and transmembrane receptor kinetics, and synaptic plasticity mechanisms. The aim of this study was to investigate how chronic FTY720 treatment alters the lipid composition of CNS tissue in adolescent mice at a key stage of brain maturation. We focused on the hippocampus, a brain region known to be important for learning, memory, and the processing of sensory and emotional stimuli. Using mass spectrometry‐based lipidomics, we discovered that FTY720 increases the fatty acid chain length of hydroxy‐phosphatidylcholine (PCOH) lipids in the mouse hippocampus. It also decreases PCOH monounsaturated fatty acids (MUFAs) and increases PCOH polyunsaturated fatty acids (PUFAs). A total of 99 lipid species were up‐regulated in the mouse hippocampus following 3 weeks of oral FTY720 exposure, whereas only 3 lipid species were down‐regulated. FTY720 also modulated anxiety‐like behaviours in young mice but did not affect spatial learning or memory formation. Our study presents a comprehensive overview of the lipid classes and lipid species that are altered in the hippocampus following chronic FTY720 exposure and provides novel insight into cellular and molecular mechanisms that may underlie the therapeutic or adverse effects of FTY720 in the central nervous system

    Spatial Evaluation and Modeling of Dengue Seroprevalence and Vector Density in Rio de Janeiro, Brazil

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    Dengue is a major public health problem in many tropical regions of the world, including Brazil, where Aedes aegypti is the main vector. We present a household study that combines data on dengue fever seroprevalence, recent dengue infection, and vector density, in three neighborhoods of Rio de Janeiro, Brazil, during its most devastating dengue epidemic to date. This integrated entomological–serological survey showed evidence of silent transmission even during a severe epidemic. Also, past exposure to dengue virus was highly associated with age and living in areas of high movement of individuals and social/commercial activity. No association was observed between household infestation index and risk of dengue infection in these areas. Our findings are discussed in the light of current theories regarding transmission thresholds and relative role of mosquitoes and humans as vectors of dengue viruses
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