3,738 research outputs found

    A quasi-static nonlinear analysis for assessing the fire resistance of 3d frames exploiting time-dependent yield surface

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    In this work an automatic procedure for evaluating the axial force-biaxial bending yield surface of reinforced concrete sections in fire is proposed. It provides an accurate time-dependent expression of the yield condition by a section analysis carried out once and for all, accounting for the strength reduction of the materials, which is a function of the fire duration. The equilibrium state of 3D frames with such yield conditions, once discretized using beam finite elements, is formulated as a nonlinear vectorial equation defining a curve in the hyperspace of the discrete variables and the fire duration. A generalized path-following strategy is proposed for tracing this curve and evaluating, if it exists, the limit fire duration, that is the time of exposure which leads to structural collapse. Compared to the previous proposals on the topic, which are limited to local sectional checks, this work is the first to present a global analysis for assessing the fire resistance of 3D frames, providing a time history of the fire event and taking account of the stress redistribution. Numerical examples are given to illustrate and validate the proposal

    Separating the North and South Pacific Meridional Modes Contributions to ENSO and Tropical Decadal Variability

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    North and South Pacific Meridional Modes (NPMM and SPMM) are known precursors of El Niño–Southern Oscillation (ENSO) and Tropical Pacific decadal variability (TPDV). However, the relative importance of these precursors and the timescale on which they impact the tropics remain unclear. Using a 30-member ensemble of the Community Earth System Model as the control climate, we generate two additional members where the NPMM and SPMM are selectively suppressed. We find that both meridional modes energize the tropical variance independently on different timescales. The absence of NPMM leads to a significant reduction of the tropical interannual variability (~35%), while the absence of the SPMM has no appreciable impact on ENSO but significantly reduces the TPDV (~30%). While the relative importance of the NPMM and SPMM may be model dependent, the stochastic atmospheric variability in the extratropics that energizes the meridional modes emerges as a key source of TPDV

    Are health literacy and lifestyle of undergraduates related to the educational field? An italian survey

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    Background: Health literacy (HL) is a fundamental ability to successfully deal with health and illness issues. This study aimed to assess HL among undergraduates from healthcare and non-healthcare degree courses of two Italian universities and the association between their HL, lifestyles, and BMI assumed as health outcome. Methods: The Health Literacy Assessment Tool (HLAT-8) and the Newest Vital Sign (NVS) were used to assess health literacy dimensions. Demographic and anthropometric data, adherence to Mediterranean diet (MD), physical activity levels, and smoking habits were assessed in the enrolled sample to highlight possible associations. Results: A total sample of 806 undergraduates (46% males, mean age 21.01 ± 1.78 years) was recruited. Higher HL scores were found among healthcare rather than non-healthcare students (28.7 ± 4.5 vs. 26.7 ± 4.2 for HLAT-8 and 4.9 ± 1.5 vs. 3.9 ± 1.8 for NVS, p < 0.01). However, healthcare undergraduates were more likely to report unhealthy behaviors. Body Mass Index (BMI) was associated with literacy and numeracy skills only in non-healthcare undergraduates. Significant associations were found between HL scores and adherence to MD in both groups. In the regression analysis, educational field and MD were shown to be predictors of HL scores. Conclusions: Attending a healthcare related degree course was associated with higher HL scores but not with healthy behaviors. This issue should be addressed considering the role that healthcare professionals may have in educating patients towards a healthy lifestyle. Adherence to MD seems to be related to higher HL scores

    The mtDNA 15497 G/A polymorphism in cytochrome b in severe obese subjects from Southern Italy.

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    Background and aim: A large number of mitochondrial DNA (mtDNA) mutations have been implicated in degenerative diseases and aging. The aim of this study was to evaluate whether the 15497 G/A mtDNA polymorphism (G251S) in the cytochrome b subunit of respiratory complex III, which has been associated with obesity-related variables and lipid metabolism in a Japanese population, is associated with severe obesity also in adult Caucasians from southern Italy. Methods and results: Unrelated severely obese patients (n Z 317; BMI > 40 kg/m2) and controls (n Z 217; BMI < 25 kg/m2) from Southern Italy were genotyped by allelic discrimination TaqMan assay for the 15497 G/A mtDNA polymorphism. In obese patients fasting serum total cholesterol, triglycerides, HDL-cholesterol and glucose were measured enzymatically and sitting blood pressure and heart rate were also collected. Mean levels of total cholesterol, triglycerides and glucose were below the upper reference limit for healthy subjects. Female obese subjects showed lower levels of blood pressure and heart rate and higher levels of HDL cholesterol than male obese patients (P < 0.001). All the control subjects and 315/317 severely obese patients were homozygous for the G allele (wild type), whereas only 2/317, were females homozygous for the A allele. Conclusions: The mtDNA 15497 G/A polymorphism in cytochrome b was present in 0.6% obese subjects, two females whose lipid parameters and BMI were similar to those of the overall group. Therefore, this mutation may appear to contribute in rare instances to severe obesity but does not explain the majority of cases in our population. A more extensive genetic haplogroup characterization is required to identify associations to obesity in Caucasians

    Non Gaussian extrema counts for CMB maps

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    In the context of the geometrical analysis of weakly non Gaussian CMB maps, the 2D differential extrema counts as functions of the excursion set threshold is derived from the full moments expansion of the joint probability distribution of an isotropic random field, its gradient and invariants of the Hessian. Analytic expressions for these counts are given to second order in the non Gaussian correction, while a Monte Carlo method to compute them to arbitrary order is presented. Matching count statistics to these estimators is illustrated on fiducial non-Gaussian "Planck" data.Comment: 4 pages, 1 figur

    Vaccinations in patients with inflammatory bowel disease.

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    Treatment of inflammatory bowel disease (IBD) frequently requires administration of immunosuppressive therapies, which increases susceptibility to a number of infectious pathogens. However, many infections can be prevented by correct and appropriate utilization of vaccinations. While several guidelines have been published on vaccination schedules in patients with IBD, vaccination rates remain suboptimal and even lower than those in the general population. This is due to many factors including poor awareness of the importance of vaccines by gastroenterologists and general practitioners as well as potential prejudices of patients regarding the safety and benefits of vaccines. With the aim of increasing awareness about the key role of immunization in the management of patients with IBD, the present review examines the existing literature relating to the main vaccinations and their application in these patients. We also summarize current evidence in order to provide clinicians with an easy source of reference for the principal recommendations for prevention of infectious diseases in patients with IBD. In addition, the recommendations about traveling for IBD patients are briefly explored. Lastly, since it is important for gastroenterologists to be aware of recommendations on vaccination, we recommend implementing educational programs to ensure compliance with current guidelines
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