253 research outputs found

    Limit analysis of reinforced masonry vaults

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    Reinforced brick masonry has experienced only scarce use as a fully structural material due to, among other reasons, the lack of design criteria and calculation tools allowing a scientific, but also practical, engineering approach to design and assessment. Aiming at contributing to a more widespread use of this material, a simplified method for the ultimate analysis of reinforced masonry arches and cylindrical vaults, based on the lower-bound theorem (or static approach) of plasticity, has been developed. This approach has been satisfactorily validated by comparison with experimental and numerical results obtained by more accurate numerical models

    Deep Learning for Vanishing Point Detection Using an Inverse Gnomonic Projection

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    We present a novel approach for vanishing point detection from uncalibrated monocular images. In contrast to state-of-the-art, we make no a priori assumptions about the observed scene. Our method is based on a convolutional neural network (CNN) which does not use natural images, but a Gaussian sphere representation arising from an inverse gnomonic projection of lines detected in an image. This allows us to rely on synthetic data for training, eliminating the need for labelled images. Our method achieves competitive performance on three horizon estimation benchmark datasets. We further highlight some additional use cases for which our vanishing point detection algorithm can be used.Comment: Accepted for publication at German Conference on Pattern Recognition (GCPR) 2017. This research was supported by German Research Foundation DFG within Priority Research Programme 1894 "Volunteered Geographic Information: Interpretation, Visualisation and Social Computing

    Surface hydrolysis of polyamide with a new polyamidase from Beauveria brongniartii

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    Twelve fungi were screened for the potential of their extracellular enzymes to increase the hydrophilicity of polyamide (PA) materials. The most pronounced increase in hydrophilicity was found for enzymes from Beauveria brongniartii and B. bassiana. The 55 kDa polyamidase from B. brongniartii was purified using ultrafiltration, anion exchange chromatography and size exclusion chromatography. This polyamidase was able to hydrolyse adipic acid bishexylamide and various typical amidase substrates, but did not show protease activity. In contrast, the 27 kDa protease from B. brongniartii did not show activity on PA. The improvement of hydrophilicity due to hydrolysis with the 55 kDa polyamidase from B. brongniartii based on rising height was 11 cm for PA 6 Perlon fibres and 5 cm for PA 6.6 Nylon. The drop dissipation measurement corroborated the improvement of the hydrophilicity giving 7 s and less than 1 s for the two enzyme treated materials, respectively. The surface tension s of Perlon increased from 46.1 to 67.4 mNm after enzyme treatment.The research was financed by the SFG, the FFG, the city of Graz and the province of Styria and by European Commission within the project GRD 2000-30110 Biosynte

    Socioeconomic Health Inequalities in Adolescent Metabolic Syndrome and Depression:No Mediation by Parental Depression and Parenting Style

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    We assessed to what extent parental depression and parenting style mediate the relationships between different measures of parental socioeconomic status (SES) and both depression and metabolic syndrome (MetS) in adolescents, and whether sex moderates these mechanisms. Data were from the prospective multigenerational Dutch Lifelines Cohort Study. Our sample consisted of 1217 adolescents with an average follow-up of 33.3 (SD = 7.33) months and a median baseline age of 13 (IQR:13–14) years. We used structural equation models to assess the direct and indirect effects of SES on baseline and changes at follow-up in both depression and MetS, and to assess moderation by sex. For each additional year of education, continuous MetS scores were 0.098 (95%CI: 0.020; 0.184) units lower at baseline and decreased 0.079 (95%CI: 0.004; 0.158) units at follow-up. No other direct or indirect effects of SES were found, and there was no moderation by sex. Additionally, warmer parenting style was generally associated with more favorable outcome scores. Therefore, improving parenting style may improve health for all adolescents. However, in this study parental depression and parenting style did not account for adolescent socioeconomic health inequalities. This may be partly due to good access to social services within the Netherlands

    An anti-interleukin-2 receptor drug attenuates thelper 1 lymphocytes-mediated inflammation in an acute model of endotoxin-induced uveitis

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    The aim of the present study was to evaluate the anti-inflammatory efficacy of Daclizumab, an anti-interleukin-2 receptor drug, in an experimental uveitis model upon a subcutaneous injection of lipopolysaccharide into Lewis rats, a valuable model for ocular acute inflammatory processes. The integrity of the blood-aqueous barrier was assessed 24 h after endotoxin-induced uveitis by evaluating two parameters: cell count and protein concentration in aqueous humors. The histopathology of all the ocular structures (cornea, lens, sclera, choroid, retina, uvea, and anterior and posterior chambers) was also considered. Enzyme-linked immunosorbent assays of the aqueous humor samples were performed to quantify the levels of the different chemokine and cytokine proteins. Similarly, a biochemical analysis of oxidative stress-related markers was also assessed. The inflammation observed in the anterior chamber of the eyes when Daclizumab was administered with endotoxin was largely prevented since the aqueous humor protein concentration substantially lowered concomitantly with a significant reduction in the uveal and vitreous histopathological grading. Th1 lymphocytes-related cytokines, such as Interleukin-2 and Interferon-c, also significantly reduced with related anti-oxidant systems recovery. Daclizumab treatment in endotoxin-induced uveitis reduced Th1 lymphocytes-related cytokines, such as Interleukin-2 and Interferon gamma, by about 60–70% and presented a preventive role in endotoxin-induced oxidative stress. This antioxidant protective effect of Daclizumab may be related to several of the observed Daclizumab effects in our study, including IL-6 cytokine regulatory properties and a substantial concomitant drop in INFc. Concurrently, Daclizumab treatment triggered a significant reduction in both the uveal histopathological grading and protein concentration in aqueous humors, but not in cellular infiltration

    Do Uncontrolled Hypertension, Diabetes, Dyslipidemia, and Obesity Mediate the Relationship Between Health Literacy and Chronic Kidney Disease Complications?

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    Health literacy is the ability to deal with information related to one's health. Patients with low health literacy and chronic diseases, such as chronic kidney disease (CKD), have poor disease-management skills, which could lead to complications. We used logistic regressions and structural equational modeling to assess whether low health literacy is associated with the development of cardiovascular disease and mortality in patients with CKD, and whether this association is mediated by the presence of uncontrolled hypertension, diabetes, dyslipidemia, obesity, or albuminuria. Data from 2742 adult participants with CKD from the Lifelines study were analyzed at baseline and after approximately four years. Low health literacy was associated with cardiovascular disease and mortality in the crude models, with OR and 95%CI of 1.93 (1.46 to 2.55) and 1.59 (1.08 to 2.36), respectively. After adjustment for age and sex, low health literacy was only associated with cardiovascular disease (OR 1.76 (1.31 to 2.23)). This association was mediated by uncontrolled diabetes (27.1%) and obesity (8.0%). Low health literacy is associated with the development of cardiovascular disease after adjustment for age and sex, and this association is mediated by uncontrolled diabetes and obesity

    Viviendas de auto-construcciĂłn en MĂ©rida, Venezuela. Comportamiento sĂ­smico y propuestas de rehabilitaciĂłn y de nueva construcciĂłn

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    The seismic risk for an informal settlement in Mérida (“La Milagrosa”) is qualitatively assessed and retrofit strategies are proposed. The buildings in the settlement are thoroughly examined and four prototype buildings are chosen to represent the vast majority of houses in “La Milagrosa”. The structural behavior of these buildings under gravity loads and seismic actions is deeply analyzed; this study shows that the prototype buildings are unsafe for gravity loads, and that the seismic demands largely exceed their capacity. Based on these conclusions, feasible retrofit strategies are proposed, together with draft recommendations for new similar constructions. Earlier quantitative estimative appraisals show that the proposed seismic strengthening measures can be very effective in reducing fatalities and economical losses, and are significantly more cost-efficient than reconstruction-based approaches. These conclusions might be generalized to many non-engineered urban areas in earthquake-prone regions of the developing world.Se evalúa cualitativamente el riesgo sísmico para un asentamiento informal en Mérida («La Milagrosa») y se proponen estrategias de rehabilitación sísmica. Se eligen cuatro edificios prototipo que representan a la gran mayoría de los de «La Milagrosa». El comportamiento estructural de estos edificios se analiza en profundidad y se concluye que los edificios no son seguros para cargas gravitatorias, y que las solicitaciones sísmicas son muy superiores a su capacidad. A partir de estas conclusiones, se proponen estrategias de rehabilitación sísmica, junto con recomendaciones de proyecto para nuevas construcciones de características similares. Evaluaciones cuantitativas estimativas previas muestran que las medidas propuestas de fortalecimiento sísmico pueden ser muy eficaces en la reducción de muertes y de pérdidas económicas; siendo significativamente más rentables que los planteamientos basados en la reconstrucción. Estas conclusiones pueden generalizarse a otros muchos asentamientos informales en zonas urbanas situadas en regiones de sismicidad alta en países en desarrollo

    Capacidad lĂ­mite Ăşltima de disipaciĂłn de energĂ­a de estructuras de hormigĂłn armado sometidas a acciones sĂ­smicas

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    El principal objetivo de esta monografía es la evaluación de la capacidad límite de disipación de energía de las estructuras sometidas a terremotos. En ella se expone, a través de su aplicación a varias estructuras tipo, una de las metodologías posibles para llevarla a cabo

    Reinforced brick-masonry light vaults : semi-prefabrication, construction, testing and numerical modeling

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    This work deals with short to mid span-length light vaults made of reinforced brick-masonry. The research is oriented at proposing semi-prefabrication and construction techniques. Numerical models for predicting the structural behavior of this type of structures are developed. Experimental research is performed with the following three main objectives: (i) validating the proposed construction techniques, (ii) investigating the structural performance, and (iii) calibrating the numerical models. The obtained results show that the proposed techniques are feasible, and that the structural behavior is adequate in terms of ductility and of strength. The structural system can be modeled with the developed numerical tools.This work has received financial support from the Catalonian Government (CIDEM, "CERARMAT" IT - Technological Innovation - project 605) the Spanish Government (Ministry of Industry and Energy, "PRECERAM" ATYCA project M172/1999) and the European Commission ("ISO-BRICK" CRAFT - Cooperative Research - Project G5ST-CT-2001-50095). All these supports are gratefully acknowledged
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