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Vascular smooth muscle tone is controlled by a balance between the cellular signaling pathways that mediate the generation of force (vasoconstriction) and release of force (vasodilation). The initiation of force is associated with increases in intracellular calcium concentrations, activation of myosin light-chain kinase, increases in the phosphorylation of the regulatory myosin light chains, and actin-myosin crossbridge cycling. There are, however, several signaling pathways modulating Ca 2+ mobilization and Ca 2+ sensitivity of the contractile machinery that secondarily regulate the contractile response of vascular smooth muscle to receptor agonists. Among these regulatory mechanisms involved in the physiological regulation of vascular tone are the cyclic nucleotides (cAMP and cGMP), which are considered the main messengers that mediate vasodilation under physiological conditions. At least four distinct mechanisms are currently thought to be involved in the vasodilator effect of cyclic nucleotides and their dependent protein kinases: (1) the decrease in cytosolic calcium concentration ([Ca 2+ ]c), (2) the hyperpolarization of the smooth muscle cell membrane potential, (3) the reduction in the sensitivity of the contractile machinery by decreasing the [Ca 2+ ]c sensitivity of myosin light-chain phosphorylation, and (4) the reduction in the sensitivity of the contractile machinery by uncoupling contraction from myosin light-chain phosphorylation. This review focuses on each of these mechanisms involved in cyclic nucleotide-dependent relaxation of vascular smooth muscle under physiological conditions.

Recent studies have shown that testosterone induces relaxation of different arteries, although the mechanism of this action is still under debate. We investigated the involvement of potassium channels in this mechanism. Using standard organ bath techniques, rings of human umbilical arteries (HUA) without endothelium were contracted by serotonin (5-HT, 1 μM), histamine (10 μM) and potassium chloride (KCl, 30 and 60 mM), and the vasorelaxant effect of testosterone was analysed. Testosterone (100 μM) relaxed human umbilical arteries contracted with 5-HT (30.1 ± 3.2%), histamine (55.1 ± 2.6%), KCl 30 mM (52.9 ± 8.3%) and KCl 60 mM (54.8 ± 6.3%). Flutamide (10 μM), an inhibitor of classical intracellular testosterone receptor, and glibenclamide, an ATP-sensitive potassium-channels (K ATP ) inhibitor, did not influence the testosterone relaxant effect. 4-aminopyridine, a voltage-sensitive potassium-channels (Kv) inhibitor, decreased the effect of testosterone on histamine- and 5-HT-contracted arteries. Tetraethylammonium (TEA), which inhibits Kv channels and large-conductance Ca 2+ -activated potassium channels (BK Ca ), decreased the effect of testosterone on KCl (60 mM)-contracted and 5-HT-contracted HUA. In conclusion, testosterone induces relaxation of HUA, and this effect does not appear to be mediated via a classic intracellular testosterone receptor-dependent mechanism. Our results suggest that this relaxation is partially mediated by activation of BK Ca and K V channels. The involvement of these two channels in testosterone-relaxant mechanism is dependent on the pathways activated by the contractile agent used.

Aim: The sex hormones 17β-estradiol (βES) and progesterone (PRG) induce rapid non-genomic vasodilator effects which could be protective for the cardiovascular system. The purpose of this study was to analyze the mechanisms underlying their vasodilator effect in rat aortic smooth muscle preparations. Methods: Endothelium-denuded aorta artery rings were prepared from male Wistar rats and incubated in an organ bath. The contractions of the preparation were recorded through isometric transducers. The effects of the hormones on K + current and L-type Ca 2+ current (LTCC) were analyzed by using the whole cell voltage-clamp technique in A7r5 cells. Results: Both βES and PRG (1–100 μmol/L) concentration-dependently relaxed the endothelium-denuded aortic rings contracted by (–)-Bay K8644 (0.1 μmol/L) or by KCl (60 mmol/L). The IC 50 values of the two hormones were not statistically different. The K V channel blocker 4-aminopyridine (2 mmol/L), BK Ca channel blocker tetraethylammonium (1mmol/L) and K ATP channel blocker glibenclamide (10 μmol/L) did not significantly modify the relaxant effect of the hormones. On the other hand, the blockage of the intracellular βES and PRG receptors with estradiol receptor antagonists ICI 182,780 (1 μmol/L) and PRG receptor antagonist mifepristone (30 μmol/L), respectively, did not significantly modify the relaxant action of the hormones. In A7r5 cells, both the hormones (1–100 μmol/L) rapidly and reversibly inhibited the basal and BAY-stimulated LTCC. However, these hormones had no effect on the basal K + current. Conclusion: The vasorelaxant effects of βES and PRG are due to the inhibition of LTCC. The K + channels are not involved in the effects.

Aim: The sex hormones 17 beta -estradiol ( beta ES) and progesterone (PRG) induce rapid non-genomic vasodilator effects which could be protective for the cardiovascular system. The purpose of this study was to analyze the mechanisms underlying their vasodilator effect in rat aortic smooth muscle preparations. Methods: Endothelium-denuded aorta artery rings were prepared from male Wistar rats and incubated in an organ bath. The contractions of the preparation were recorded through isometric transducers. The effects of the hormones on K super(+) current and L-type Ca super(2+) current (LTCC) were analyzed by using the whole cell voltage-clamp technique in A7r5 cells. Results: Both beta ES and PRG (1-100 mu mol/L) concentration-dependently relaxed the endothelium-denuded aortic rings contracted by (-)-Bay K8644 (0.1 mu mol/L) or by KCl (60 mmol/L). The IC sub(50) values of the two hormones were not statistically different. The K sub(V) channel blocker 4-aminopyridine (2 mmol/L), BK sub(Ca) channel blocker tetraethylammonium (1mmol/L) and K sub(ATP) channel blocker glibenclamide (10 mu mol/L) did not significantly modify the relaxant effect of the hormones. On the other hand, the blockage of the intracellular beta ES and PRG receptors with estradiol receptor antagonists ICI 182,780 (1 mu mol/L) and PRG receptor antagonist mifepristone (30 mu mol/L), respectively, did not significantly modify the relaxant action of the hormones. In A7r5 cells, both the hormones (1-100 mu mol/L) rapidly and reversibly inhibited the basal and BAY-stimulated LTCC. However, these hormones had no effect on the basal K super(+) current. Conclusion: The vasorelaxant effects of beta ES and PRG are due to the inhibition of LTCC. The K super(+) channels are not involved in the effects.

The sex hormones 17[beta]-estradiol ([beta]ES) and progesterone (PRG) induce rapid non-genomic vasodilator effects which could be protective for the cardiovascular system. The purpose of this study was to analyze the mechanisms underlying their vasodilator effect in rat aortic smooth muscle preparations. Endothelium-denuded aorta artery rings were prepared from male Wistar rats and incubated in an organ bath. The contractions of the preparation were recorded through isometric transducers. The effects of the hormones on K(+) current and L-type Ca(2+) current (LTCC) were analyzed by using the whole cell voltage-clamp technique in A7r5 cells. Both [beta]ES and PRG (1-100 μmol/L) concentration-dependently relaxed the endothelium-denuded aortic rings contracted by (-)-Bay K8644 (0.1 μmol/L) or by KCl (60 mmol/L). The IC(50) values of the two hormones were not statistically different. The K(V) channel blocker 4-aminopyridine (2 mmol/L), BK(Ca) channel blocker tetraethylammonium (1 mmol/L) and K(ATP) channel blocker glibenclamide (10 μmol/L) did not significantly modify the relaxant effect of the hormones. On the other hand, the blockage of the intracellular [beta]ES and PRG receptors with estradiol receptor antagonists ICI 182,780 (1 μmol/L) and PRG receptor antagonist mifepristone (30 μmol/L), respectively, did not significantly modify the relaxant action of the hormones. In A7r5 cells, both the hormones (1-100 μmol/L) rapidly and reversibly inhibited the basal and BAY-stimulated LTCC. However, these hormones had no effect on the basal K(+) current. The vasorelaxant effects of [beta]ES and PRG are due to the inhibition of LTCC. The K(+) channels are not involved in the effects.

Aim： The sex hormones 17β-estradiol （13ES） and progesterone （PRG） induce rapid non-genomic vasodilator effects which could be protective for the cardiovascular system. The purpose of this study was to analyze the mechanisms underlying their vasodilator effect in rat aortic smooth muscle preparations. Methods： Endothelium-denuded aorta artery rings were prepared from male Wistar rats and incubated in an organ bath. The contractions of the preparation were recorded through isometric transducers. The effects of the hormones on K^＋ current and L-type Ca^2＋ current （LTCC） were analyzed by using the whole cell voltage-clamp technique in A7r5 cells. Results： Both βES and PRG （1-100 pmol/L） concentration-dependently relaxed the endothelium-denuded aortic rings contracted by （-）-Bay K8644 （0.1 IJmol/L） or by KCl （60 mmol/L）. The IC5o values of the two hormones were not statistically different. The Kvchannel blocker 4-aminopyridine （2 mmol/L）, BKca channel blocker tetraethylammonium （lmmol/L） and KATP channel blocker glibenclamide （10 pmol/L） did not significantly modify the relaxant effect of the hormones. On the other hand, the blockage of the intracellular 13ES and PRG receptors with estradiol receptor antagonists ICI 182,780 （1 pmol/L） and PRG receptor antagonist mifepristone （30 pmol/L）, respectively, did not significantly modify the relaxant action of the hormones. In A7r5 cells, both the hormones （1-100 pmol/L） rapidly and reversibly inhibited the basal and BAY-stimulated LTCC. However, these hormones had no effect on the basal K^＋ current. Conclusion： The vasorelaxant effects of 13ES and PRG are due to the inhibition of LTCC. The K^＋ channels are not involved in the effects.

Este trabalho pretende estudar um novo conceito de aproveitamento energético, através de um sistema de concentração eólico adaptado para turbinas de eixo vertical (VAWT). O sistema permite aumentar a velocidade do vento à entrada do rotor da turbina e assim a potência disponível.O aproveitamento energético de fonte eólica ainda não é comum no ambiente urbano pelo que esta é uma área de investigação relativamente nova.Este projecto deu continuidade ao trabalho de carácter exploratório efectuado em 2012 no âmbito do Projecto de Licenciatura, onde foi optimizada uma estrutura aerodinâmica para concentração eólica.Neste trabalho, foram construídas duas estruturas de concentração e uma turbina VAWT com o propósito de verificar que o efeito de concentração se manteria no sistema integrado e se contribuiria para a melhoria do desempenho da turbina. Foram realizados dezenas de ensaios em túnel de vento, para diferentes velocidades de vento, de forma a caracterizar a turbina e os sistemas de concentração. Os resultados obtidos para o sistema VAWT e concentrador, mostram que o efeito de concentração com a VAWT existe, contudo de forma reduzida quando comparada com as simulações computacionais para a estrutura de concentração. A diminuição do efeito de concentração poderá estar ligada às condições dos ensaios, ao regime de operação da turbina projectada, e ainda a falhas no protótipo. Desta forma, e como o efeito de concentração foi verificado, recomenda-se a construção de um novo protótipo de maiores dimensões de forma a mitigar o efeito prejudicial do regime de operação do protótipo usado neste projecto.

Crescente importância da informação geográfica no contexto organizacional e o desenvolvimento das tecnologias de informação, implicou mudanças sociais nos processos e nos métodos de utilização da informação geográfica pelo capital humano das organizações, numa lógica de maior integração no contexto económico local, regional, nacional e, global. Crescimento-desenvolvimento-gestão-previsão tecnológica possibilita às organizações proceder através de novos processos de aquisição, armazenamento, tratamento e, análise de dados-informação-conhecimento-sabedoria espacial, com recurso às Tecnologias de Informação Geográfica, como por exemplo: o Desenho Assistido por Computador; a Detecção Remota; os Sistemas de Informação Geográfica; os Sistemas de Posicionamento. Inovação tecnológica e, organizacional criam novos desafios às organizações que, maximizando a utilização dos recursos internos, procuram integração competitiva no mercado interno e, externo. Incrementar a economia digital inclusiva é, neste âmbito, importante aos níveis da produtividade e da rentabilidade organizacionais e, por conseguinte, ao nível da equidade inclusa da sociedadeXXI. Geografia ciência das relações espaciais dos fenómenos no espaço não ficou indiferente à inovação, inovando incessantemente nos métodos e nos instrumentos científicos para adquirir, manipular, tratar, analisar e, gerir informação georeferenciada. Tecnologias de informação, sistemas de informação e, mais especificamente, Tecnologias de Informação Geográfica, desempenham importância fundamental nos resultados decorrentes da inovação geográfica. Com efeito, a informação espacial é crescentemente utilizada pelas organizações, nomeadamente as empresariais e, pelo cidadão, através do recurso a dispositivos móveis de localização espacial.Hoje, a informação espacial é fortemente utilizada, incrementada e, divulgada, nomeadamente: por organizações governamentais, designadamente a nível nacional, regional e, local; por organizações institucionais de ensino técnico/profissional e, superior; e, por organizações empresariais de grande dimensão, regra geral, enquadradas em sectores de inovação, designadamente das telecomunicações e dos transportes. Pequena e média dimensão da generalidade das organizações, nomeadamente empresariais, limita hoje a implementação das TIGem detrimento de outras prioridades de crescimento- desenvolvimento-gestão-previsão organizacional. Por conseguinte, a pequena e média dimensão das organizações, nomeadamente empresariais, é contextualizada em função do contexto financeiro limitado e, do contexto geográfico, económico, social e, tecnológico em que ocorrem as actividades empresariais.Projecto/Portal Évora Distrito Digital, integrado no programa Cidades e Regiões Digitais, abrangendo catorze municípios do distrito de Évora, é um exemplo de boas práticas de mobilização das organizações nomeadamente do sector público; do sector público administrativo; do sector privado; e, do sector público-privado. Évora Distrito Digital requer maior integração na economia digital aberta possibilitada pela difusão das tecnologias de informação e comunicação, particularmente da internete, pela progressiva generalização de dispositivos móveis e das Tecnologias de Informação Geográfica.Inclusão digital é um imperativo económico-social de crescimento- desenvolvimento-gestão-previsão, para o qual as organizações têm a missão de mobilizar o capital humano/cidadãos, para a racional e a adequada utilização da técnica e da informação espacial em prol do bem-estar colectivo. Organizações do sector público, do sector público administrativo, do sector privado e, do sector público-privado, mas também a sociedadeXXI, têm a missão de participarem em conjunto na construção de um futuro melhor e mais inclusivo e, na integração plena de todos os cidadãos independentemente da residência, da condição/situação socioeconómica e do sistema de valores. Sustentabilizar é a acção de crescimento-desenvolvimento-gestão-previsão que a Geografia enquadra e que a técnica facilita na definição das estratégias e das potencialidades económico-sociais de intervenção no espaço/território. Gerir o território rumo ao futuro, é pensar global e, agir global, regional e local.

The levels of educational attainment have risen strongly over the last thirty years in Europe. In Portugal, the education system, particularly the higher education sector, expanded in late 80s. Parallel to this expansion have been growing up concerns about the incidence of overeducation in Portuguese labour market. This study presents an extensive review of literature about overeducation and ways of measuring the phenomenon, as well an evolutive description on higher education in Portugal and some recent developments at European and National level. The study was based on objective and empirical approach, focusing overeducation as a form of underutilization of educational skills and linking worker’s formal education with the skills required to perform a job. Using the 1998, 2004 and 2009 data from Labour Force Survey collected by Office of National Statistics (INE), the present study analysed overeducation in Portugal, aiming to identify and quantify the existence of the phenomenon during the considered period. The study results revealed the existence of overeducation over the period, along with an increase of incidence, which varies with gender and being more relevant on women.

Lipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary fatty acid composition, contributing to the lipid profile of ruminant products. A method for the detailed dimethylacetal and fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or concentrate based diets supplemented with soybean oil. The methodological approach developed consisted on a basic/ acid direct transesterification followed by thin-layer chromatography to isolate fatty acid methyl esters from dimethylacetal, oxo- fatty acid and fatty acid dimethylesters. The dimethylacetal composition was quite similar to the fatty acid composition, presenting even-, odd- and branched-chain structures. Total and individual odd- and branched-chain dimethylacetals were mostly affected by basal diet. The presence of 18:1 dimethylacetals indicates that biohydrogenation intermediates might be incorporated in structural microbial lipids. Moreover, medium-chain fatty acid dimethylesters were identified for the first time in the rumen content despite their concentration being relatively low. The fatty acids containing 18 carbon-chain lengths comprise the majority of the fatty acids present in the rumen content, most of them being biohydrogenation intermediates of 18:2n26 and 18:3n23. Additionally, three oxo- fatty acids were identified in rumen samples, and 16-O-18:0 might be produced during biohydrogenation of the 18:3n23.