360 research outputs found

    Torsion and its interaction with other internal forces in EN 1993-1-1: a new approach

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    This is the accepted version of the following article: [Real, E., Bordallo, J. and Real, E. (2016), Torsion and its interaction with other internal forces in EN 1993-1-1 – a new approach. Steel Construction, 9: 240–248. doi:10.1002/stco.201500005], which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/stco.201500005/abstractThis paper presents and clarifies the treatments included in EN 1993-1-1, relating to checking the resistance of the steel cross-sections under torsion and its interaction with other internal forces. Specifically, the origin of the formulations for shear-torsion interaction, which was not found in the literature, is presented. Furthermore, a very simple formulation based on the expressions used for shear-torsion interaction is developed, in order to take into account bending-warping torsion interaction for symmetrical double T cross-sections (IP and HE steel profiles). Such formulation overcomes the overly conservative approach stated in EN 1993-1-1, for Class 1 and Class 2 cross-sections (plastic and compact cross-sections). Finally, a rigorous method for the determination of the bending resistance of cross-sections is proposed, considering the interaction with shear and torsion. The proposal is well suited to the concept of cross-sectional class and it is perfectly consistent with the approaches set out to consider the bending-shear and bending-warping torsion interactions.Peer ReviewedPostprint (author's final draft

    On a family of rational perturbations of the doubling map

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    The goal of this paper is to investigate the parameter plane of a rational family of perturbations of the doubling map given by the Blaschke products Ba(z)=z3z−a1−aˉzB_a(z)=z^3\frac{z-a}{1-\bar{a}z}. First we study the basic properties of these maps such as the connectivity of the Julia set as a function of the parameter aa. We use techniques of quasiconformal surgery to explore the relation between certain members of the family and the degree 4 polynomials (z‾2+c‾)2+c\left(\overline{\overline{z}^2+c}\right)^2+c. In parameter space, we classify the different hyperbolic components according to the critical orbits and we show how to parametrize those of disjoint type

    M81 Extragalactic nova explosions

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    Using data from the Joan Oró telescope (located in Montsec, Catalonia) and the reference catalogue from Max Planck Institute, we will observe the evolution of different novae in the M81 galaxy. This article explains the data analysis that has been performed and comments the obtained results2020/202

    An effective algorithm to compute Mandelbrot sets in parameter planes.

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    McMullen in 2000 proved that copies of generalized Mandelbrot set are dense in the bifurcation locus for generic families of rational maps. We develop an algorithm to an effective computation of the location and size of these generalized Mandelbrot sets in parameter space. We illustrate the effectiveness of the algorithm by applying it to concrete families of rational and entire maps

    Glycaemic control and antidiabetic treatment trends in primary care centres in patients with type 2 diabetes mellitus during 2007-2013 in Catalonia: a population-based study.

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    OBJECTIVES: To assess trends in prescribing practices of antidiabetic agents and glycaemic control in patients with type 2 diabetes mellitus (T2DM). DESIGN: Cross-sectional analysis using yearly clinical data and antidiabetic treatments prescribed obtained from an electronic population database. SETTING: Primary healthcare centres, including the entire population attended by the Institut Català de la Salut in Catalonia, Spain, from 2007 to 2013. PARTICIPANTS: Patients aged 31-90 years with a diagnosis of T2DM. RESULTS: The number of registered patients with T2DM in the database was 257 072 in 2007, increasing up to 343 969 in 2013. The proportion of patients not pharmacologically treated decreased by 9.7% (95% CI -9.48% to -9.92%), while there was an increase in the percentage of patients on monotherapy (4.4% increase; 95% CI 4.16% to 4.64%), combination therapy (2.8% increase; 95% CI 2.58% to 3.02%), and insulin alone or in combination (increasing 2.5%; 95% CI 2.2% to 2.8%). The use of metformin and dipeptidyl peptidase-IV inhibitors increased gradually, while sulfonylureas, glitazones and α-glucosidase inhibitors decreased. The use of glinides remained stable, and the use of glucagon-like peptide-1 receptor agonists was still marginal. Regarding glycaemic control, there were no relevant differences across years: mean glycated haemoglobin (HbA1c) value was around 7.2%; the percentage of patients reaching an HbA1c≤7% target ranged between 52.2% and 55.6%; and those attaining their individualised target from 72.8% to 75.7%. CONCLUSIONS: Although the proportion of patients under pharmacological treatment increased substantially over time and there was an increase in the use of combination therapies, there have not been relevant changes in glycaemic control during the 2007-2013 period in Catalonia

    Assessment of the length of sick leave in patients with ischemic heart disease

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    Background The prevalence of ischemic heart disease is high. Few recent studies have investigated the periods of sick leave of these patients. Our aim is to determine the length of sick leave after an acute coronary syndrome, its costs, associated factors and to assess the use of antidepressants and/or anxiolytics. Methods An observational study of a retrospective cohort of patients on sick leave due to ischemic heart disease in a health region between 2008-2011, with follow-up until the first return to work, death, or end of the study (31/12/2012). Measurements: length of sick leave, sociodemographic variables and medical prescriptions. Results Four hundred and ninety-seven patients (mean age 53 years, 90.7% male), diagnosed with acute myocardial infarction (60%), angina pectoris (20.7%) or chronic form of ischemic heart disease (19.1%). Thirty-seven per cent of patients took anxiolytics the year after diagnosis and 15% took antidepressants. The average duration of sick leave was 177 days (95% CI: 163-191 days). Patients diagnosed with acute myocardial infarction returned to work after a mean of 192 days, compared to 128 days in cases with angina pectoris. Patients who took antidepressants during the year after diagnosis returned to work after a mean of 240 days. The mean work productivity loss was estimated to be 9,673 euros/person. Conclusions The mean duration of sick leave due to ischemic heart disease was almost six months. Consumption of psychotropic medication doubled after the event. Older age, suffering an acute myocardial infarction and taking antidepressants were associated with a longer sick leave period

    Previous antibiotic exposure and antibiotic resistance of commensal Staphylococcus aureus in Spanish primary care

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    Introduction: Commensal flora of healthy people is becoming an important reservoir of resistant bacteria. Objectives: To evaluate the relationship of previous antibiotic-dispensed and resistance pattern of strains of Staphylococcus aureus in primary care patients. Methods: A cross-sectional study was carried out in seven primary care centres in Catalonia, Spain, from October 2010 to May 2011, as part of the APRES (The appropriateness of prescribing antibiotics in primary care in Europe concerning antibiotic resistance) study. Outpatients aged 4 or more who did not present an infectious disease and had not taken antibiotic or had not been hospitalised in the previous 3 months were invited to participate. Nasal swabs were collected for S. aureus culture, and antimicrobial susceptibility testing was carried out. Antibiotics dispensed boxes in the previous 4 years were extracted from Information System for Research in Primary Care. Results: A total of 4,001 nasal swabs were collected, and 3,969 were tested for identification, 765 S. aureus were tested for resistance. Resistance rates to penicillin, azithromycin and methicillin were 87.1%, 11.6% and 1.3%, respectively, and a total of 10 MRSA strains were isolated (1.3%). Penicillin-resistant staphylococci were statistically significantly associated with the previous number of packages of penicillin dispensed (OR, 1.18; 95% CI, 1.04-1.35). Conclusion: Although no causal inference is possible, an association was observed between previous antibiotic dispensation and isolation of resistant organisms in community-dwelling individuals, mainly between packages of penicillin and penicillin-resistant staphylococci
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