379 research outputs found

    Association entre l'Ă©lastographie vasculaire non invasive et l'indice de masse corporelle chez les enfants

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    Sachant que l’AthĂ©rosclĂ©rose commence durant l’enfance par des marqueurs subcliniques, cette Ă©tude explore l’association entre l’indice de masse corporelle (IMC) et l’élastographie vasculaire non-invasive (NIVE) des artĂšres carotides communes chez les enfants. On compare aussi les techniques de mesure de l’intima-mĂ©dia (IMT) des artĂšres carotides en se basant sur le mode-B et la radiofrĂ©quence (RF) chez les enfants avec IMC normal et Ă©levĂ©. Il s’agit d’une Ă©tude prospective effectuĂ©e entre 2005 et 2011. Les paramĂštres de « NIVE » ont Ă©tĂ© comparĂ©s pour deux groupes d’IMC (normal et Ă©levĂ©) de 60 enfants respectivement, faisant tous partie de la cohorte de l’étude QUebec Adipose and Lifestyle Investigation in Youth (QUALITY). Les paramĂštres de NIVE incluent la contrainte axiale cumulative (CAS) en %, la translation axiale cumulative (CAT) en mm. L’épaisseur de l’intima-mĂ©dia est calculĂ©e selon trois mĂ©thodes : logiciel «M’ath-Std» (mode-B), « echotracking » des signaux de RF et probabilitĂ© de distribution des signaux de RF sur la plateforme NIVE. Une analyse ANOVA et corrĂ©lation Pearson ont Ă©tĂ© effectuĂ©es sur le logiciel SAS version 9.3. Une corrĂ©lation intra-class (ICC) a Ă©tĂ© effectuĂ©e sur un logiciel MedCalc version 17.2. L’ñge moyen Ă©tait 11,4 ans pour le groupe IMC normal et 12 pour le groupe IMC Ă©levĂ©. Cinquante-huit pourcent Ă©taient des garçons dans le groupe IMC normal et 63% dans le groupe IMC Ă©levĂ©. Les deux groupes Ă©taient diffĂ©rents selon l’ñge, stade de Tanner, tension artĂ©rielle (systolique et diastolique), et LDL mais similaire pour le sexe. En contrĂŽlant pour les variables confondantes, la CAS n’est pas diffĂ©rente entre les deux groupes. La CAT est plus basse chez les enfants avec IMC normal (CAT=0.51 +/-0.17 mm pour le groupe « IMC normal » et 0.67+/-0.24 mm pour le groupe « IMC Ă©levĂ© » (p<0.001)). Il y a une trĂšs faible corrĂ©lation entre les trois techniques de mesure d’IMT ICC=0,34 (95% intervalle de confiance 0,27-0,39). L’IMT est significativement plus Ă©levĂ© dans le groupe d’enfants « IMC Ă©levĂ© ». Mode-B (0.55 mm « IMC normal » vs. 0.57 mm « IMC Ă©levĂ© »; p=0.02); IMT RF (0.45 mm « IMC normal » vs. 0.48 mm « IMC Ă©levĂ© »; p=0.03) et IMT probabilitĂ© de distribution des signaux RF (0.32 mm « IMC normal » vs. 0.35 mm « IMC Ă©levĂ© »; p=0.010). La NIVE montre une diffĂ©rence significative dans la CAT de l'artĂšre carotide commune des enfants avec un IMC normal par rapport Ă  l'IMC Ă©levĂ©. Des variations significatives de la mesure des IMT ont Ă©tĂ© observĂ©es entre les diffĂ©rentes techniques. Cependant, les enfants avec IMC Ă©levĂ© ont des valeurs IMT plus Ă©levĂ©es, indĂ©pendamment de la mĂ©thode utilisĂ©e. Les deux marqueurs subcliniques peuvent ĂȘtre utilisĂ©s pour la stratification des enfants Ă  risque de maladies cardiovasculaires. La mĂȘme mĂ©thode devrait toujours ĂȘtre utilisĂ©e.Knowing that cardiovascular disease risk factors are present in asymptomatic children, this study explores the association between non-invasive vascular elastography (NIVE) as a subclinical marker of atherosclerosis and obesity in children. In the absence of a gold standard, we also compare B-mode and Radiofrequency (RF) based ultrasound measurements of intima-media thickness (IMT) in children with normal and increased body mass index (BMI). This is a prospective study between 2005 and 2011. NIVE parameters and IMT of the common carotid artery were compared between 60 children with normal BMI and 60 children with increased BMI enrolled in the QUebec Adipose and Lifestyle Investigation in Youth cohort (QUALITY). NIVE parameters included cumulated axial strain (CAS) (%) and cumulated axial translation (CAT) in mm. The three methods of IMT measurements included M’ath Std (B-mode), RF echotracking system and RF probability distribution using NIVE platform. ANOVA analysis and Pearson correlation were calculated using SAS version 9.3. Intra-class correlation coefficient (ICC) and regression analysis was done on MedCalc software version 17.2. The mean age was 11.4 years for the normal BMI group and 12 years for the increased BMI group. Fifty-eight percent were boys in the normal BMI group and 63% in the increased BMI group. The two groups were significantly different with respect to age, Tanner stage, systolic and diastolic blood pressure and were similar with respect to sex. After controlling for confounders, the results show no difference in CAS between the two groups and a significantly lower CAT in the normal BMI group (CAT=0.51+/-0.17 mm for the normal BMI group and 0.67+/-0.24 mm for the increased BMI group (p<0.001)). There is a weak correlation among the three techniques. ICC=0.34 (95% confidence interval (CI): 0.27-0.39). There is however significantly increased IMT in children with increased BMI according to all three techniques. The results were as follow: for B-mode IMT (0.55 mm (normal BMI group) vs. 0.57 mm (increased BMI group); p=0.02); for RF echotracking IMT (0.45 mm (normal BMI group) vs. 0.48 mm (increased BMI group); p=0.03) and for RF probability distribution IMT (0.32 mm (normal BMI group) vs. 0.35 mm (increased BMI group); p=0.010).NIVE is a one-step technique for IMT and CAT measurement in children at risk. Significant IMT measurement variation is observed between the three techniques. However, children with increased BMI tend to have higher IMT values regardless of the technique. Both subclinical markers can be used for optimal stratification of children with cardiovascular disease risk factors. The same technique should be used throughout

    Key Tensions in Refugee Education

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    Globally, education is in crisis, with steep inequities, low learning outcomes, irrelevant content, and ineffective learning and teaching strategies in many settings. The global education crisis is also a global refugee education crisis, as far too many refugee students must contend with barriers to access, low quality, and limited relevance in their learning opportunities. Refugee education continues to be under-supported in policy dialogue and funding. As advocacy efforts push for global and national commitments to equitable, high-quality education for all, this paper is intended to help ensure refugee education is part of the education transformation agenda.This paper is intended for refugee education donors, policymakers, and implementers and aims to inform policy dialogue by answering the following three questions:Why is refugee education more urgent than ever?What are the key tensions in refugee education and how might they be addressed?How does centering refugee voices and engagement in education policy and programming advance the sector

    Monte Carlo Simulation on the Indirect Exchange Interactions of Co-doped ZnO Film

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    Monte Carlo simulations using a three-dimensional lattice model studied the Ruderman–Kittel–Kasuya–Yosida (RKKY) indirect exchange interaction of doped magnetic Co ions in ZnOfilms. The results of the calculations show that the RKKY interaction in Co-doped ZnO is long ranged and its magnitude is proportional to (inverse of the distance from a central ion). The sign oscillates with a frequency that depends on the concentration of the carrier. The long-distance sum of the RKKY indirect exchange energies is positive indicating that these materials are ferromagnetic, in direct correlation with previously reported results

    Clean and efficient extraction of copper ions and deposition as metal

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    AbstractA simple, clean and efficient one-pot process is offered as an alternative to the conventional complex processing presently used to extract copper ions from copper containing materials, like copper concentrate or slag, and to form copper metal. The alternative process uses a eutectic molten salt of potassium chloride, sodium chloride and zinc chloride as the reaction fluid which is recyclable, low in cost, environmentally benign, low melting (melting point 204°), high boiling (vapor pressure is only a few psi at 800°) and chemically, thermally and physically stable. The metal completely dissolves out of copper concentrate or slag in the aerobic eutectic molten chloride salt in a graphite or glassy carbon pot, which serves as a cathode, with a graphite anode, to reduce the metal ions to metal which sinks to the bottom of the graphite pot. The total efficiency for extraction and deposition is virtually 100% as determined by elemental and gravimetric analyses
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