284 research outputs found

    Dietary magnesium intake can affect mechanical properties of rat carotid artery

    Get PDF
    The purpose of the present study was to determine the effects of Mg deficiency and supplementation on the mechanical properties of the rat common carotid artery. The internal diameter and intra-arterial pressure of carotid artery were measured continuously using an echo-tracking device. Systolic, diastolic and mean intra-arterial pressures were not significantly different in Mg-deficient, -supplemented or control rats. Histological examination showed a larger cross-sectional area, increased intima-media thickness and a greater media:lumen value in carotid artery of Mg-deficient rats, indicating that Mg deficiency may directly stimulate growth and/or proliferation of arterial wall components. In addition, we observed a negative linear relationship between intima-media thickness and plasma Mg concentration, suggesting that increased Mg intake may counteract arterial wall hypertrophy. Neither Mg deficiency nor supplementation modified the arterial distensibility v. intra-arterial pressure curve or the Einc v. wall stress curve, indicating that dietary Mg intake did not modify wall stiffness in young rats. At mean intra-arterial pressure, the stress and Einc values were, however, significantly lower in Mg-deficient rats (P<0·05 in both cases); this finding could be related to the alteration in the geometry of the carotid artery. In conclusion, these findings suggest that Mg deficiency modifies the mechanical properties of the common carotid artery in young rats. Since Mg deficiency is considered a risk factor, these mechanical alterations could contribute to the development of atherosclerosis, hypertension and cardiovascular disease

    Poster Gérer de manière intégrée

    Get PDF

    THE IMPACT OF STORAGE CONDITIONS ON THE FOREST BIOMASS QUALITY FOR BIOFUELS PRODUCTION

    Get PDF
    Biomass quality is an essential parameter for the production of biofuels both by thermal ways (gasification, pyrolysis, torrefaction, etc) or biochemical ways (enzymatic hydrolysis and yeast saccharification). Storage is one of the most important parameters to be taken in account in the logistics chains of biomass supply for biofuel conversion sites. Morever, some benefits in terms of biomass quality can be obtained by storing biomass prior transportation or usage. In this case, storage can be considered as a pre-treatment of biomass for biofuel production. In this project, we have studied the evolution of biomass quality of different wooden resources (softwoods and hardwoods; short/very-short rotation coppices and residues of forest exploitation) stored under different conditions : seasons (spring/summer or autumn/winter), sites (forest roadside and storage platforms; uncovered and covered; under water sprinkling). Two locations were also tested, one in Bordeaux area (southwest of France) and the second in Dijon area (northeast of France). Different piles of approximately 10 m3 (2.5 to 3.5 tons of wood chips) were constituted for each modality. Samples were taken from two different levels of the piles at different intervals of storage (0 to 6 months). The following biomass quality parameters were followed : moisture content, elemental (C, H, O, N, S, Cl) and chemical (extractives, lignin, polysaccharides – cellulose and hemicelluloses, C5 and C6 sugars contents) composition; heating value; ash content, fusibility behaviour and composition. The results obtained indicated that the conditions of storage strongly influence the biomass quality, especially for the thermal conversion. The type of initial raw material (softwoods or hardwoods / short/very-short rotation coppices and residues of forest exploitation) are also of major importance, especially if the biomass material is stored with or without leaves. In that way, the season aspect becomes very important. Water sprinkling is an interesting way to remove certain compounds, such ash constituents or extractives, partially responsible for tar formation. On the other way, in this case a compulsory drying step is needed and a careful energy balance is needed in order to evaluate the pertinence or not of this technology. Concerning the biochemical conversion, no major differences were observed for the mono/polysaccharides contents. However, the removal of certain elements/substances could impact the enzymatic hydrolysis and fermentation for bioethanol production

    Myths and lessons of liberal intervention: The British campaign for the abolition of the Atlantic slave trade to Brazil

    Get PDF
    This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 Martinus NijhoffThis article takes issue with recent references to the British nineteenth century campaign for the abolition of the trans-Atlantic slave trade to Brazil that serve to bolster interventionist or imperialist agendas. In particular, such accounts reproduce two and a half myths about the campaign: that it can serve as a model for the present age; that the success of the campaign can be explained through the actions of the intervening party alone (with a corresponding neglect of those of the ‘target’ state); and the half-myth that the campaign’s success was due to military action (at the expense of institutional (legal) and normative factors and the capacity of the target state). I argue instead that this case – and interventions more generally – would benefit from an analysis that considers the role of force in relation to a series of residual institutional and cultural constraints within the liberal state and to political conditions in the target state. In light of the complexities and contingencies that these factors present the underlying lesson is that military force should be used sparingly, if at all

    Influence of the consumption pattern of magnesium from magnesium-rich mineral water on magnesium bioavailability

    Get PDF
    It is generally considered that the absorption of Mg is inversely related to the ingested dose. The objective of the present study was to determine if the mode of administration (bolus v. consumption throughout the day) could influence Mg bioavailability from Mg-rich natural mineral water comparing the same nutritional Mg amount (126mg). Using a 2d cross-over design, twelve healthy men were asked to drink 1·5 litres Mg-rich mineral water either as 2×750ml or 7×212ml throughout the day. Two stable isotopes (25Mg and 26Mg) were used to label the water in order to distinguish both regimens. Fractional apparent Mg absorption was determined by faecal monitoring and Mg retention was determined by measuring urinary excretion of Mg isotopes. Higher Mg absorption (50·7 (sd 12·7) v. 32·4 (sd 8·1) %; P=0·0007) and retention (47·5 (sd 12·9) v. 29·0 (sd 7·5) %; P=0·0008) from Mg-rich mineral water were observed when it was consumed in seven servings compared with larger servings. Thus, regular water consumption throughout the day is an effective way to increase Mg bioavailability from Mg-rich mineral wate

    SUITABILITY OF WOOD CHIPS FROM FORESTRY AND DIFFERENT BIOMASS FEEDSTOCKS FOR USE IN A SEMI-INDUSTRIAL PLANT OF BTL PRODUCTION BY GASIFICATION

    Get PDF
    A semi-industrial plant of BtL production by biomass gasification is planned to be operating in 2011 in the Northern-East of France by a French Energy Research Centre, called Commissariat à l’Energie Atomique (CEA), and several partners. This demonstration plant will be a 50 MW plant, based on an entrained flow reactor, followed by different stages of syngas cleaning and a final stage of Fischer-Tropsch synthesis. One study has been launched on the biomass regional resources that may be used as feedstock in the plant. The first task of this study deals with the availability of the resources and their feasibility and cost of supply. This paper is focused on the second task, whose aim is to check the suitability of the potential resources with the process, in order to define which one should be chosen. A sampling based on several tens samples from the region was first used, both from wood chips from forestry, wood chips from Short Rotation Coppice (SRC) and agricultural raw materials including straw and energy crops. Measurements were done on the main influential properties of biomass, either physical (granulometry, density, moisture), thermal (LHV) or physico-chemical (proximate analysis, elemental composition, particularly in minor elements, ash composition and fusibility). Results show that there is not much variability in the biomass properties inside the different families (wood chips, agricultural raw materials). The values of most properties fall in the range of the required specifications. However, some properties may be questionable: (i) wood chips granulometry, with too many fine particles (ii) density, which is too low in agricultural products (0.05), (iii) sulphur, fluorine and chlorine contents, which are too high, especially chlorine in agricultural residues (1000-8000 ppm) (iv) other impurities amounts, such as Cr, Cu, Zn, Ni, that are above specifications in some samples (v) ash content, which is slightly too high in SRC (3 wmf%) and too high in most agricultural raw materials (5 wmf%) (vi) ash melting point - whose measurement still needs to be confirmed - but which is apparently too low in most agricultural samples and in some SRC. Based on these statements, wood chips from forestry appear as the most suitable resource for the process. SRC also seem quite suitable for the process and may be seen as a short-term alternative. Agricultural raw materials are more problematical and may be seen as a short to mid-term option. Therefore, wood chips will be the first resource to be used in the demonstration plant and a complimentary sampling has been recently performed on this kind of feedstock, leading to the adjunction of 60 new samples. These measurements should enable to define more precisely the range of variation of the problematic properties

    Cardiovascular effects of arginase inhibition in spontaneously hypertensive rats with fully developed hypertension

    Get PDF
    Aims Growing evidence suggests that arginase misregulation plays a key role in the pathophysiology of essential hypertension. In the present study, we investigated the potential cardiovascular therapeutic effects of a long-term treatment with an arginase inhibitor in adult spontaneously hypertensive rats (SHR) with fully developed hypertension. Methods and results Treatment of 25-week-old SHR with the arginase inhibitor Nω-hydroxy-nor-l-arginine (nor-NOHA, 40 mg/day for 10 weeks) sustainably reduced systolic blood pressure (−30 mmHg, P < 0.05). The antihypertensive effect of nor-NOHA was associated with changes on mesenteric artery reactivity including the restoration of angiotensin-II-induced contraction and acetylcholine-induced vasodilation to the values of normotensive Wistar Kyoto rats. Both nitric oxide synthase and cyclooxygenase-dependent mechanisms account for the improvement of endothelial function afforded by the arginase inhibitor, which in addition blunted hypertension-induced endothelial arginase I overexpression in mesenteric arteries. Nor-NOHA also prevented the remodelling of aorta as measured by collagen content and media/lumen ratio, and improved the compliance of carotid artery in SHR. Cardiac fibrosis assessed by collagen content of left heart ventricle was reduced by nor-NOHA, with no significant effect on cardiac hypertrophy. Conclusion Our results report that a long-term treatment with an arginase inhibitor reduced blood pressure, improved vascular function, and reduced cardiac fibrosis in SHR with fully developed hypertension. These data suggest that arginase represents a promising novel target for pharmacological intervention in essential hypertensio

    Determining a low disease activity threshold for decision to maintain disease-modifying antirheumatic drug treatment unchanged in rheumatoid arthritis patients

    Get PDF
    International audienceINTRODUCTION: The aim of this study was to determine a low disease activity threshold--a 28-joint disease activity score (DAS28) value--for the decision to maintain unchanged disease-modifying antirheumatic drug (DMARD) treatment in rheumatoid arthritis patients, based on expert opinion. METHODS: Nine hundred and sixty-seven case scenarios with various levels for each component of the DAS28 (resulting in a disease activity score between 2 and 3.2) were presented to 44 panelists. For each scenario, panelists had to decide whether or not DMARD treatment (excluding steroids) could be maintained unchanged. In each scenario, for decision, the participants were given the DAS28 parameters, without knowledge of the resultant DAS28. The relationship between panelists' decision, DAS28 value, and components of the score were analysed by multiple logistic regression analysis. Each panelist analysed 160 randomised scenarios. Intra-rater and inter-rater reproducibility were assessed. RESULTS: Forty-four panelists participated in the study. Inter-panelist agreement was good (kappa = 0.63; 95% confidence interval = 0.61 to 0.65). Intra-panelist agreement was excellent (kappa = 0.87; 95% confidence interval = 0.82 to 0.92). Quasi-perfect agreement was observed for DAS28 3.0. For values below 2.5, panelists agreed to maintain unchanged DMARDs; for values above 2.5, discrepancies occurred more frequently as the DAS28 value increased. Multivariate analysis confirmed the relationship between panelist's decision, DAS28 value and components of the DAS28. Between DAS28 of 2.4 and 3.2, a major determinant for panelists' decision was swollen joint count. Female and public practice physicians decided more often to maintain treatment unchanged. CONCLUSIONS: As a conclusion, panelists suggested that in clinical practice there is no need to change DMARD treatment in rheumatoid arthritis patients with DAS28 < or = 2.4

    CoMMA Corporate Memory Management through Agents Corporate Memory Management through Agents: The CoMMA project final report

    Get PDF
    This document is the final report of the CoMMA project. It gives an overview of the different search activities that have been achieved through the project. First, a description of the general requirements is proposed through the definition of two scenarios. Then it shows the different technical aspects of the projects and the solution that has been proposed and implemented

    Cardiovascular effects of arginase inhibition in spontaneously hypertensive rats with fully developed hypertension

    Get PDF
    Growing evidence suggests that arginase misregulation plays a key role in the pathophysiology of essential hypertension. In the present study, we investigated the potential cardiovascular therapeutic effects of a long-term treatment with an arginase inhibitor in adult spontaneously hypertensive rats (SHR) with fully developed hypertension
    corecore