1,597 research outputs found

    Influence of Apolipoprotein E Plasma Levels and Tobacco Smoking on the Induction of Neutralising Antibodies to Interferon-Beta

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    Interferon-beta (IFN-beta) therapy for multiple sclerosis (MS) is associated with a potential for induction of neutralizing antibodies (NAbs). Because immune reactivity depends on changes in lipoprotein metabolism, we investigated whether plasma lipoprotein profiles could be associated with the development of NAbs. Thirty-one female MS patients treated with subcutaneously administered IFN-beta were included. Demographic and clinical characteristics were compared between NAbs response groups using t tests for continuous and logistic regression analysis and Fisher's exact tests for categorical data, respectively. Multivariate logistic regression was used to evaluate the effect of potential confounders. Patients who developed NAbs had lower apoE levels before treatment, 67 (47-74) mg/L median (interquartile range), and at the moment of NAb analysis, 53 (50-84) mg/L, in comparison to those who remained NAb-negative, 83 (68-107) mg/L, P = 0.03, and 76 (66-87) mg/L, P = 0.04, respectively. When adjusting for age and smoking for a one-standard deviation decrease in apoE levels, a 5.6-fold increase in the odds of becoming NAb-positive was detected: odds ratios (OR) 0.18 (95% CI 0.04-0.77), P = 0.04. When adjusting for apoE, smoking habit became associated with NAb induction: OR 5.6 (95% CI 1.3-87), P = 0.03. These results suggest that apoE-containing lipoprotein metabolism and, possibly, tobacco smoking may be associated with risk of NAb production in female MS patients treated with IFN-beta

    Probing the two-scale-factor universality hypothesis by exact rotation symmetry-breaking mechanism

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    We probe the two-scale factor universality hypothesis by evaluating, firstly explicitly and analytically at the one-loop order, the loop quantum corrections to the amplitude ratios for O(NN) λϕ4\lambda\phi^{4} scalar field theories with rotation symmetry-breaking in three distinct and independent methods in which the rotation symmetry-breaking mechanism is treated exactly. We show that the rotation symmetry-breaking amplitude ratios turn out to be identical in the three methods and equal to their respective rotation symmetry-breaking ones, although the amplitudes themselves, in general, depend on the method employed and on the rotation symmetry-breaking parameter. At the end, we show that all these results can be generalized, through an inductive process based on a general theorem emerging from the exact calculation, to any loop level and physically interpreted based on symmetry ideas.Comment: 17 pages, 3 figure

    Fibrous model for the simulation of the cyclic behaviour of 3D reinforced concrete frames

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    Relatório 07-DEC/E-04Non-linear finite element analysis has attracted a lot of attention in last few decades, as real life problems dealing with analysis of concrete beams and columns are generally non-linear in nature. This project deals with non-linear analysis of beam and columns, using Timoshenko beam theory. The Timoshenko beam theory is applied to every element, but before applying the theory the element is divided into fibers. The fibers as a whole will govern the behavior of element. The section of each element is divided in “finite elements”. Each finite element is a fiber along the length of element. Each fiber element is independent in terms of the material constitutive laws, which govern the behavior, while at the same time they are associated to each other by the relation of displacements. The material laws of each fiber deals with the stress-strain relation The numerical results are compared with the experimental results, which show a reasonable correlation, and in turn demonstrate the capability of the proposed model to depict the cyclic behavior of concrete elements

    Numerical model for CFRP confined concrete elements subject to monotonic and cyclic loadings

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    Uniaxial cyclic and monotonic compression tests were carried out on partially and fully wrapped concrete cylinders with Carbon Fibre Reinforced Polymer (CFRP) wet lay-up sheets. The influence of the concrete compressive strength, CFRP stiffness, geometric confinement arrangement and loading type on the compressive behaviour of reinforced concrete column elements of circular cross section up to their failure was assessed. A uniaxial stress-strain constitutive model is proposed, and the results obtained from the experimental tests were used to calibrate some of the parameters of this model, and to appraise the model performance. This model allows the simulation of reinforced concrete members by using Timoshenko one-dimensional elements, in the context of the finite element method (fibre model). Good agreement was obtained between numerical simulations and experimental results for both monotonic and cyclic loading tests.The first author acknowledges the support provided by the grant within the ambit of the research program PABERPRO supported by Program POCI 2010 - IDEIA, Project No. 13-05-04-FDR-00007, contract reference ADI/2007/V4.1/0049. The present work was also supported by Program PIDDAC, Project No. PTDC/ECM/74337/2006 by FCT. The authors acknowledge the materials generously supplied by S&P and Degussa Portugal

    Design-curves of strain softening and strain hardening fibre reinforced concrete elements subjected to axial load and bending moments

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    Several structural components made by fibre reinforced concrete (FRC) are submitted to axial load and bending moments. In some cases fibres cannot replace completely the conventional reinforcement, even if strain hardening FRC is used; therefore the optimization of the reinforcement solution for these elements depends on the post-cracking behaviour of the FRC, as well as the percentage of conventional reinforcement to replace. To fully exploit the FRC capabilities, the development of a suitable, comprehensive and design-oriented model of its tensile response is of the utmost importance. To provide a practical tool for the pre-design of FRC-structural-elements subjected to axial load and bending moments, design curves were generated using a computational program capable of simulating the main features of the tensile and compressive behaviour of strain softening and strain hardening FRC’s, and steel bars. The post-cracking tensile behaviour of the FRC is characterized by two parameters that define its residual strength ratio (α) and its corresponding tensile strain ratio (β). To generate these curves, a parametric study is carried out based on the tensile parameters α and β and considering distinct mechanical reinforcement ratios, from 0 to 1 with a step of 0.2. For every reinforcement ratio, four distinct cases in terms of β are considered; additionally, for every case of β, α is divided from strain hardening to strain softening in five distinct residual strength classes. By sequentially varying α and β, the bending capacity of a section is evaluated to provide a design perspective of the effect of ductility and strength. The model used in this study is described, the design curves are presented and analyzed and some practical design examples are provided

    Prediction of fatigue crack propagation in a cracked beam specimen

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    In day to day our life, Various types of loads are acting on beams, columns, studs etc. These forces may be tension, compression, internal pressure, bending or any combination of all. These different types of loading situation may initiate and propagate a crack. This becomes more significant if the beams carry are used in large construction works. In this project Aluminium alloy beam is considered for study of propagation of an existing crack. A finite element based two dimensional crack propagation simulator software FRANC2D and a pre-processor software for this simulator CASCA developed by Cornell Fracture Group of Cornell University was used for simulation of crack propagation in two dimensional beam. Four point bending test experiment is carried out on aluminium beam and crack growth propagation behaviour is observed. These two observations i.e. from FRANC2D and experiment are compared

    Viabilidade econômica do manejo de açaizais no estuário amazônico: estudo de caso na região do Rio Tauerá-açu, Abaetetuba - estado do Pará.

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    O objetivo deste estudo foi avaliar comparativamente o desempenho socioeconômico e a viabilidade econômica de sistemas produtivos de açaí manejado adotado pelos produtores e recomendado pela pesquisa agropecuária, em áreas de várzeas do estuário do rio Amazonas, no Estado do Pará. A coleta de dados para a análise do sistema de produção ocorreu por meio de entrevistas individuais com produtores e técnicos e pela realização de painéis técnicos reunindo produtores com experiência no desenvolvimento da atividade de manejo de açaizais. Foram estimados indicadores de rentabilidade e de viabilidade econômico-financeira para determinação do desempenho dos sistemas e realizadas análises de sensibilidade a variações de preços. Os resultados mostraram que tanto o sistema adotado pelo produtor quanto o sistema recomendado pela pesquisa apresentaram eficiência e viabilidade econômica, nas condições de produção e de mercado predominantes, com melhor desempenho e estabilidade para o sistema recomendado. A atividade de colheita é a etapa que representa maior custo no processo produtivo

    Female genital mutilation/cutting in Sierra Leone: are educated women intending to circumcise their daughters?

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    BACKGROUND:Female genital mutilation/cutting (FGM/C) has been recognized as a gross violation of human rights of girls and women. This is well established in numerous international legal instruments. It forms part of the initiation ceremony that confers womanhood in Sierra Leone. Girls and women who are subjected to this practice are considered to be ready for marriage by their parents and communities and are rewarded with celebrations, gifts, and public recognition. Following this, we examined the relationship between education and women's FGM/C intention for their daughters in Sierra Leone. METHODS:We used cross-sectional data from the women's file of the 2013 Sierra Leone Demographic and Health Survey (SLDHS) to explore the influence of education on FGM/C intention among women in the reproductive age (15-49). A sample of 6543 women were included in the study. Our analysis involved descriptive computation of education and FGM/C intention. This was followed by a two-level multilevel analysis. Fixed effect results were reported as Odds Ratios and Adjusted Odds Ratios with their respective credible intervals (CrIs) whilst results of the random effects were presented as variance partition coefficients and median odds ratios. RESULTS:Our findings showed that women who had no formal education were more likely to intend to circumcise their daughters [aOR = 4.3, CrI = 2.4-8.0]. Among the covariates, women aged 20-24 [aOR = 2.3, CrI = 1.5-3.4] were more likely to intend to circumcise their daughters compared to women between 45 and 49 years old. Poorest women were more likely to report intention of circumcising their daughters in the future compared with the richest [aOR = 2.1, CrI = 1.3-3.2]. We noted that, 63.3% of FGM/C intention in Sierra Leone is attributable to contextual factors. CONCLUSION:FGM/C intention is more common among women with no education, younger women as well as women in the lowest wealth category. We recommend segmented female-child educational and pro-poor policies that target uneducated women in Sierra Leone. The study further suggests that interventions to end FGM/C need to focus on broader contextual and social norms in Sierra Leone
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