Nonlinear Racking Analysis of Nailed Walls

An energy formation of nonlinear analysis of racking resistance of nailed walls is presented. The analysis is dependent on the nonlinear load-slip relationship of nailed connections. The method permits the calculation of the racking force associated with a given horizontal displacement and uses as input data panel geometry, number and spacing of nails, and load distortion relationship of a single connection.Two 4 ft x 8 ft panels with two thicknesses of 1/2 in. and 5/8 in. plywood are analyzed using linear and nonlinear methods, and results of horizontal displacement versus racking force are displayed graphically. It is shown that while the two methods converge at ultimate loads, true representation of wall behavior at low levels of displacement is best described through nonlinear analysis. Good comparison is obtained with a finite element approach

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

A case study with breast cancer and brain metastasis encompassing acute onset of amnesia and altered mental status due to limbic encephalitis - biochemical and proteomic aspects

A biochemical case study is reported on a 50-year old lady known to have breast cancer. The woman was treated by mastectomy and this was followed by unraveling brain metastases three years post-diagnosis of the cancer, which was treated by radiation and chemotherapy. Two months after ending her treatment, she exhibited acute changes in her mental status manifested by severe amnesia and fever. A generalized analytical and biochemical assessment revealed the presence of paraneoplastic limbic encephalitis

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

Sildenafil therapy for fetal cardiovascular dysfunction during hypoxic development: studies in the chick embryo.

KEY POINTS: Common complications of pregnancy, such as chronic fetal hypoxia, trigger a fetal origin of cardiovascular dysfunction and programme cardiovascular disease in later life. Sildenafil treatment protects placental perfusion and fetal growth, but whether the effects of sildenafil transcend the placenta to affect the fetus is unknown. Using the chick embryo model, here we show that sildenafil treatment directly protects the fetal cardiovascular system in hypoxic development, and that the mechanisms of sildenafil protection include reduced oxidative stress and increased nitric oxide bioavailability; Sildenafil does not protect against fetal growth restriction in the chick embryo, supporting the idea that the protective effect of sildenafil on fetal growth reported in mammalian studies, including humans, is secondary to improved placental perfusion. Therefore, sildenafil may be a good candidate for human translational antioxidant therapy to protect the chronically hypoxic fetus in adverse pregnancy. ABSTRACT: There is a need for developing clinically translatable therapy for preventing fetal origins of cardiovascular disease in pregnancy complicated by chronic fetal hypoxia. Evidence shows that sildenafil protects placental perfusion and fetal growth. However, whether beneficial effects of sildenafil transcend onto the fetal heart and circulation in complicated development is unknown. We isolated the direct effects of sildenafil on the fetus using the chick embryo and hypothesised that sildenafil also protects fetal cardiovascular function in hypoxic development. Chick embryos (n = 11 per group) were incubated in normoxia or hypoxia (14% O2 ) from day 1 and treated with sildenafil (4 mg kg-1  day-1 ) from day 13 of the 21-day incubation. Hypoxic incubation increased oxidative stress (4-hydroxynonenal, 141.1 ± 17.6% of normoxic control), reduced superoxide dismutase (60.7 ± 6.3%), increased phosphodiesterase type 5 expression (167 ± 13.7%) and decreased nitric oxide bioavailability (54.7 ± 6.1%) in the fetal heart, and promoted peripheral endothelial dysfunction (70.9 ± 5.6% AUC of normoxic control; all P < 0.05). Sildenafil treatment after onset of chronic hypoxia prevented the increase in phosphodiesterase expression (72.5 ± 22.4%), protected against oxidative stress (94.7 ± 6.2%) and normalised nitric oxide bioavailability (115.6 ± 22.3%) in the fetal heart, and restored endothelial function in the peripheral circulation (89.8 ± 2.9%). Sildenafil protects the fetal heart and circulation directly in hypoxic development via mechanisms including decreased oxidative stress and enhanced nitric oxide bioavailability. Sildenafil may be a good translational candidate for human antioxidant therapy to prevent fetal origins of cardiovascular dysfunction in adverse pregnancy.British Heart Foundation