Response Modification Factors for Concrete Bridges in Europe

The paper presents a methodology for evaluating the actual response modification factors (q or R) of bridges and applies it to seven concrete bridges typical of the stock found in southern Europe. The usual procedure for analytically estimating the q-factor is through pushover curves derived for the bridge in (at least) its longitudinal and transverse directions. The shape of such curves depends on the seismic energy dissipation mechanism of the bridge; hence, bridges are assigned to two categories, those with inelastically responding piers and those whose deck is supported through bearings on strong, elastically responding piers. For bridges with yielding piers, the final value of the q-factor is found as the product of the overstrength-dependent component (qs) and the ductility-dependent component (qμ), both estimated from the pertinent pushover curve. For bridges with bearings and nonyielding piers of the wall type, an equivalent q-factor is proposed, based on spectral accelerations at failure and at design level. In this paper, pushover curves are also derived for an arbitrary angle of incidence of seismic action using a procedure recently developed by the authors, to investigate the influence of the shape of the pushover curve on the estimation of q-factors. It is found that in all cases the available force reduction factors are higher than those used for design to either Eurocode 8 or AASHTO specifications

Arabic spam tweets classification using deep learning

With the increased use of social network sites, such as Twitter, attackers exploit these platforms to spread counterfeit content. Such content can be fake advertisements or illegal content. Classifying such content is a challenging task, especially in Arabic. The Arabic language has a complex structure and makes classification tasks more difficult. This paper presents an approach to classifying Arabic tweets using classical machine learning (non-deep machine learning) and deep learning techniques. Tweets corpus were collected through Twitter API and labelled manually to get a reliable dataset. For an efficient classifier, feature extraction is applied to the corpus dataset. Then, two learning techniques are used for each feature extraction technique on the created dataset using N-gram models (uni-gram, bi-gram, and char-gram). The applied classical machine learning algorithms are support vector machines, neural networks, logistics regression, and naïve Bayes. Global vector (GloVe) and fastText learning models are utilised for the deep learning approaches. The Precision, Recall, and F1-score are the suggested performance measures calculated in this paper. Afterwards, the dataset is increased using the synthetic minority oversampling technique class to create a balanced dataset. After applying the classical machine learning models, the experimental results show that the neural network algorithm outperforms the other algorithms. Moreover, the GloVe outperforms the fastText model for the deep learning approach

Hypertension Programmed in Adult Hens by Isolated Effects of Developmental Hypoxia In Ovo.

In mammals, pregnancy complicated by chronic hypoxia can program hypertension in the adult offspring. However, mechanisms remain uncertain because the partial contributions of the challenge on the placenta, mother, and fetus are difficult to disentangle. Here, we used chronic hypoxia in the chicken embryo-an established model system that permits isolation of the direct effects of developmental hypoxia on the cardiovascular system of the offspring, independent of additional effects on the mother or the placenta. Fertilized chicken eggs were exposed to normoxia (N; 21% O2) or hypoxia (H; 13.5%-14% O2) from the start of incubation (day 0) until day 19 (hatching, ≈day 21). Following hatching, all birds were maintained under normoxic conditions until ≈6 months of adulthood. Hypoxic incubation increased hematocrit (+27%) in the chicken embryo and induced asymmetrical growth restriction (body weight, -8.6%; biparietal diameter/body weight ratio, +7.5%) in the hatchlings (all P<0.05). At adulthood (181±4 days), chickens from hypoxic incubations remained smaller (body weight, -7.5%) and showed reduced basal and stimulated in vivo NO bioavailability (pressor response to NG-nitro-L-arginine methyl ester, -43%; phenylephrine pressor response during NO blockade, -61%) with significant hypertension (mean arterial blood pressure, +18%), increased cardiac work (ejection fraction, +12%; fractional shortening, +25%; enhanced baroreflex gain, +456%), and left ventricular wall thickening (left ventricular wall volume, +36%; all P<0.05). Therefore, we show that chronic hypoxia can act directly on a developing embryo to program hypertension, cardiovascular dysfunction, and cardiac wall remodeling in adulthood in the absence of any maternal or placental effects.The British Heart Foundation The Wellcome Trus

Sports celebrity personality and purchase intention: the role of endorser-brand congruence, brand credibility and brand image transfer

Purpose: This study aims to examine the influence of five sports celebrity personality (SCP) attributes - attractiveness, expertise level, credibility, trustworthiness, and character - on consumers’ purchase intentions (CPI). It identifies celebrity brand congruence (CBC), endorsed brand celebrity (EBC), and transfer of brand image (TBI) as antecedents of CPI. Methodology: The purposive sampling technique was used to collect the data from 838 respondents. This study developed a multidimensional construct for SCP. The covariance-based structural equation modeling (SEM) technique was used to examine the relationship between SCP and the endorsed brand. The study used celebrity brand congruence (CBC) as a mediator and endorsed brand credibility (EBC) and transfer of brand image (TBI) as partial mediators. The direct and indirect effect of SCP on CPI was investigated using CBC, EBC, and TBI as mediators. Findings: This study supports the importance of three antecedents (i.e. CBC, EBC, and TBI) on CPI. It finds congruence across SCP and CBC variables, and a positive impact of SCP on EBC and TBI variables. Also, it exhibits a significant direct effect of CBC on EBC and TBI, whereas the direct effect of CBC on CPI is not substantial. The indirect effect of CBC through mediating variables EBC and TBI found to be significant. Research Limitation/Implication: This study concludes that sports celebrity endorsement is essential to transfer the positive celebrity image to the endorsed brand image. However, it is not merely sufficient to influence the buyers’ purchase conduct; the brand credibility additionally assumes to take a role in changing their behavioral intentions. Originality/Value: This study contributes to the sports marketing literature by its novelty in analyzing the sports celebrity personality at a multidimensional level. It uses SCP’s different attributes as one construct and studies its impact on CPI by taking CBC, EBC, and TBI as mediators. The results of this study equip sports management professionals with the knowledge to build better long-term relationships with consumers

Induction of controlled hypoxic pregnancy in large mammalian species.

Progress in the study of pregnancy complicated by chronic hypoxia in large mammals has been held back by the inability to measure long-term significant reductions in fetal oxygenation at values similar to those measured in human pregnancy complicated by fetal growth restriction. Here, we introduce a technique for physiological research able to maintain chronically instrumented maternal and fetal sheep for prolonged periods of gestation under significant and controlled isolated chronic hypoxia beyond levels that can be achieved by habitable high altitude. This model of chronic hypoxia permits measurement of materno-fetal blood gases as the challenge is actually occurring. Chronic hypoxia of this magnitude and duration using this model recapitulates the significant asymmetric growth restriction, the pronounced cardiomyopathy, and the loss of endothelial function measured in offspring of high-risk pregnancy in humans, opening a new window of therapeutic research.This work was supported by The British Heart Foundation and The Royal Society. DG is Professor of Cardiovascular Physiology & Medicine at the Department of Physiology Development & Neuroscience at the University of Cambridge, Professorial Fellow and Director of Studies in Medicine at Gonville & Caius College, a Lister Institute Fellow and a Royal Society Wolfson Research Merit Award Holder.This is the final version of the article. It was first available from the American Physiological Society via http://dx.doi.org/10.14814/phy2.1261

Altered Skeletal Muscle Lipase Expression and Activity Contribute to Insulin Resistance in Humans

International audienceOBJECTIVE: Insulin resistance is associated with elevated content of skeletal muscle lipids, including triacylglycerols (TAGs) and diacylglycerols (DAGs). DAGs are by-products of lipolysis consecutive to TAG hydrolysis by adipose triglyceride lipase (ATGL) and are subsequently hydrolyzed by hormone-sensitive lipase (HSL). We hypothesized that an imbalance of ATGL relative to HSL (expression or activity) may contribute to DAG accumulation and insulin resistance. RESEARCH DESIGN AND METHODS: We first measured lipase expression in vastus lateralis biopsies of young lean (n = 9), young obese (n = 9), and obese-matched type 2 diabetic (n = 8) subjects. We next investigated in vitro in human primary myotubes the impact of altered lipase expression/activity on lipid content and insulin signaling. RESULTS: Muscle ATGL protein was negatively associated with whole-body insulin sensitivity in our population (r = -0.55, P = 0.005), whereas muscle HSL protein was reduced in obese subjects. We next showed that adenovirus-mediated ATGL overexpression in human primary myotubes induced DAG and ceramide accumulation. ATGL overexpression reduced insulin-stimulated glycogen synthesis (-30%, P < 0.05) and disrupted insulin signaling at Ser1101 of the insulin receptor substrate-1 and downstream Akt activation at Ser473. These defects were fully rescued by nonselective protein kinase C inhibition or concomitant HSL overexpression to restore a proper lipolytic balance. We show that selective HSL inhibition induces DAG accumulation and insulin resistance. CONCLUSIONS: Altogether, the data indicate that altered ATGL and HSL expression in skeletal muscle could promote DAG accumulation and disrupt insulin signaling and action. Targeting skeletal muscle lipases may constitute an interesting strategy to improve insulin sensitivity in obesity and type 2 diabetes

Intervention against hypertension in the next generation programmed by developmental hypoxia.

Evidence derived from human clinical studies and experimental animal models shows a causal relationship between adverse pregnancy and increased cardiovascular disease in the adult offspring. However, translational studies isolating mechanisms to design intervention are lacking. Sheep and humans share similar precocial developmental milestones in cardiovascular anatomy and physiology. We tested the hypothesis in sheep that maternal treatment with antioxidants protects against fetal growth restriction and programmed hypertension in adulthood in gestation complicated by chronic fetal hypoxia, the most common adverse consequence in human pregnancy. Using bespoke isobaric chambers, chronically catheterized sheep carrying singletons underwent normoxia or hypoxia (10% oxygen [O2]) ± vitamin C treatment (maternal 200 mg.kg-1 IV daily) for the last third of gestation. In one cohort, the maternal arterial blood gas status, the value at which 50% of the maternal hemoglobin is saturated with oxygen (P50), nitric oxide (NO) bioavailability, oxidative stress, and antioxidant capacity were determined. In another, naturally delivered offspring were raised under normoxia until early adulthood (9 months). Lambs were chronically instrumented and cardiovascular function tested in vivo. Following euthanasia, femoral arterial segments were isolated and endothelial function determined by wire myography. Hypoxic pregnancy induced fetal growth restriction and fetal oxidative stress. At adulthood, it programmed hypertension by enhancing vasoconstrictor reactivity and impairing NO-independent endothelial function. Maternal vitamin C in hypoxic pregnancy improved transplacental oxygenation and enhanced fetal antioxidant capacity while increasing NO bioavailability, offsetting constrictor hyper-reactivity and replenishing endothelial function in the adult offspring. These discoveries provide novel insight into mechanisms and interventions against fetal growth restriction and adult-onset programmed hypertension in an animal model of complicated pregnancy in a species of similar temporal developmental milestones to humans.British Heart Foundatio