189 research outputs found

    Gestão de serviços dos ecossistemas em bacias hidrográficas

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    Os serviços de ecossistemas referem-se a uma dimensão normalmente menosprezada das actividades agrícolas e florestais. Com efeito, estas actividades, para além dos produtos transaccionáveis, produzem, ou contribuem para a produção de serviços não transaccionáveis que importa reconhecer, avaliar e, progressivamente, remunerar. Esta remuneração é da maior importância no actual contexto de desvalorização dos rendimentos associados a essas actividades na maior parte dos espaços anteriormente a elas dedicados, desvalorização que vem pondo progressivamente em risco esses espaços multifuncionais e, particularmente, as suas contribuições para as funções económicas e sociais dos restantes espaços de uso, com relevo para os espaços de produção, urbanização e de serviços. Com efeito, estes últimos, não poderão ser viáveis sem as funções de produção e regulação que são garantidas pelos espaços hoje classificados como marginais e pelas actividades agrícolas e florestais de rentabilidade insuficiente, mas que garantem funções de produção e regulação dos sistemas hidrológicos (através, por exemplo, da infiltração ou da regularização do escoamento) ou de protecção contra os fenómenos erosivos e a perda de solo. Estas funções são hoje reconhecidas por inúmeros instrumentos legais e acordos internacionais (caso da Directiva Quadro da Água, da proposta de Directiva Quadro para a Protecção do Solo (COM(2006) 232 e a recente declaração do Conselho da União Europeia sobre a Protecção dos recursos hídricos e a gestão integrada sustentável da água na União Europeia (Junho de 2011). Interessa agora desenvolver os mecanismos quer para a sua gestão integrada, quer para a sua efectiva e adequada remuneração

    Is erucin a promising bioactive against renal cell carcinoma?

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    A large number of epidemiological studies have linked cruciferous vegetable consumption to a reduced risk of various types of cancer, including renal cell carcinoma. Organosulfur compounds from cruciferous vegetables, glucosinolates and their metabolic breakdown derivatives, isothiocyanates and indole-3-carbinol, rise scientific interest by exerting unique anticancer properties. Erucin (ER) is an isothiocyanate that is generated by enzymatic hydrolyzes of glucoerucin, a glucosinolate predominant found in rocket species, or by in vivo reduction of sulforaphane, its structural oxidized analog. In the present study, the inhibitory effects of ER on renal cancer cell viability, migration and invasion were investigated. The 786- O human renal cancer cell line and the Vero normal-like cells were treated with different concentrations of ER (10-100 μM). Cell viability was determined using the MTT and PI assays. The intracellular level of reactive oxygen species was evaluated using dichlorodihydrofluorescein diacetate. The collective cell migration and chemotaxis/chemoinvasion were studied by a wound healing and transwell assay, respectively. ER induced a concentration-dependent decrease in cell viability, with more cytotoxicity for 786-O cells than against Vero cells. Non-cytotoxic concentration of ER significantly reduced cell migration rate, chemotaxis and invasiveness potential of 786-O cells. The observed favorable anticancer potential of ER against human renal carcinoma in vitro requires further investigation.Nutraceuticals in balancing redox status in ageing and age-related diseases WGs Meeting of the NutRedOx COST Action CA16112 Belgrade, March 2-3, 202

    Aerobic exercise prevents cardiomyocyte damage caused by oxidative stress in early cardiovascular disease by increasing vascularity while L-arginine supplementation prevents it by increasing activation of the enzyme nitric oxide synthase

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    L-Arginine and chronic exercise reduce oxidative stress. However, it is unclear how they affect cardiomyocytes during cardiovascular disease (CVD) development. The aim of this research was to investigate the possible effects of L-arginine supplementation and aerobic training on systemic oxidative stress and their consequences on cardiomyocytes during cardiometabolic disease onset caused by excess fructose. Wistar rats were allocated into four groups: control (C), fructose (F, 10% fructose in water), fructose training (FT; moderate running, 50-70% of the maximal velocity), and fructose arginine (FA; 880 mg/kg/day). Fructose was given for two weeks and fructose plus treatments for the subsequent eight weeks. Body composition, blood glucose, insulin, lipid profile, lipid peroxidation, nitrite, metalloproteinase-2 (MMP-2) activity, left ventricle histological changes, microRNA-126, -195, and -146, eNOS, p-eNOS, and TNF-α expressions were analyzed. Higher abdominal fat mass, triacylglycerol level, and insulin level were observed in the F group, and both treatments reversed these alterations. Myocardial vascularization was impaired in fructose-fed groups, except in FT. Cardiomyocyte hypertrophy was observed in all fructose-fed groups. TNF-α levels were higher in fructose-fed groups than in the C group, and p-eNOS levels were higher in the FA than in the C and F groups. Lipid peroxidation was higher in the F group than in the FT and C groups. During CVD onset, moderate aerobic exercise reduced lipid peroxidation, and both training and L-arginine prevented metabolic changes caused by excessive fructose. Myocardial vascularization was impaired by fructose, and cardiomyocyte hypertrophy appeared to be influenced by pro-inflammatory and oxidative environments

    CVD diamond coated silicon nitride self-mated systems : tribological behaviour under high loads

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    Friction and wear behaviour of self-mated chemical vapour deposited (CVD) diamond films coating silicon nitride ceramics (Si3N4) were investigated in ambient atmosphere. The tribological tests were conducted in a reciprocal motion ball-on-flat type tribometer under applied normal loads up to 80 N (~10 GPa). Several characterisation techniques - including scanning electron microscopy (SEM), atomic force microscopy (AFM) and micro-Raman studies - were used in order to assess the quality, stress state and wear resistance of the coatings. In addition, a novel method is presented to estimate the wear coefficient of the diamond coated flat specimens from AFM and optical microscopy (OM) observations of the wear tracks
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