785 research outputs found

    Cyclic Elastoplastic Large Displacement Analysis of Cold-formed Steel Box Columns under Combined Action of Axial and Bidirectional Lateral Loading

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    This paper deals with the cyclic elastoplastic large displacement analysis of cold-formed steel box columns under combined action of axial and bidirectional lateral loading. Cold-formed steel box columns are very useful in highway bridge pier construction as they offer flexible space requirement and provide speedy construction. Behavior of cold-formed steel box columns under earthquake-induced loads is rather complicated as earthquakes occur in an oblique direction. However, modern seismic design philosophies have been based on the behavior of structures under independent actions of uni-directional loading in orthogonal directions. In this study, inelastic cyclic behavior of steel columns subjected to constant axial force together with simultaneous bi-directional cyclic lateral loads is investigated using an advanced finite element analyses procedure. Several types of linear and non-linear idealized loading patte rns are employed to check the strength and ductility. The effects of important structural parameters and loading history on the behavior of cold-formed thin-walled steel box columns are examined using the proposed procedure

    A test for normality based on the empirical distribution function

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    In this paper, a goodness-of-fit test for normality based on the comparison of the theoretical and empirical distributions is proposed. Critical values are obtained via Monte Carlo for several sample sizes and different significance levels. We study and compare the power of forty selected normality tests for a wide collection of alternative distributions. The new proposal is compared to some traditionaltest statistics, such as Kolmogorov-Smirnov, Kuiper, Cramér-von Mises, Anderson-Darling, Pearson Chi-square, Shapiro-Wilk, Shapiro-Francia, Jarque-Bera, SJ, Robust Jarque-Bera, and also to entropy-based test statistics. From the simulation study results it is concluded that the best performance against asymmetric alternatives with support on the whole real line and alternative distributions with support on the positive real line is achieved by the new test. Other findings derivedfrom the simulation study are that SJ and Robust Jarque-Bera tests are the most powerful ones for symmetric alternatives with support on the whole real line, whereas entropy-based tests are preferable for alternatives with support on the unit interval

    Combined population dynamics and entropy modelling supports patient stratification in chronic myeloid leukemia

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    Modelling the parameters of multistep carcinogenesis is key for a better understanding of cancer progression, biomarker identification and the design of individualized therapies. Using chronic myeloid leukemia (CML) as a paradigm for hierarchical disease evolution we show that combined population dynamic modelling and CML patient biopsy genomic analysis enables patient stratification at unprecedented resolution. Linking CD34+ similarity as a disease progression marker to patientderived gene expression entropy separated established CML progression stages and uncovered additional heterogeneity within disease stages. Importantly, our patient data informed model enables quantitative approximation of individual patients’ disease history within chronic phase (CP) and significantly separates “early” from “late” CP. Our findings provide a novel rationale for personalized and genome-informed disease progression risk assessment that is independent and complementary to conventional measures of CML disease burden and prognosis

    Wall-resolved versus wall-modeled LES of the flow field and surface forced convective heat transfer for a low-rise building

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    Large eddy simulation (LES) is widely used to investigate the aerodynamics and convective heat transfer (CHT) at the surfaces of sharp-edged bluff bodies for a wide range of Reynolds (Re) numbers. Due to the heavy computational costs associated with implicit filtering in LES at high Reynolds number flows (Re ≥ 105), wall-modeled (WM) rather than wall-resolved (WR) LES is often adopted. However, the performance of LES-WM for such applications has not yet been systematically investigated. Therefore, this study evaluates the performance of LES-WM and LES-WR for the flow and thermal field at the facades of a low-rise building immersed in an atmospheric boundary layer. Four grids are constructed for LES-WM, each employing different resolution at the building surfaces reaching maximum non-dimensional wall distance y+ = 43, 57, 70, and 95. In addition, the performance of two wall functions, namely the Werner and Wengle and the enhanced wall function is investigated. The results show that the use of LES-WM can result in significant deviations in the predicted near-facade flow pattern and the surface convective heat transfer coefficient (CHTC). Grid resolution significantly impacts the CHTC results and deviations go up to 88% (at the base of the windward facade). Considerable deviations among the employed wall functions are apparent only on the finest grid. In this case, the implementation of the enhanced wall function indicates better performance compared to the non-blended law of the wall (combined with the Werner and Wengle) for CHTC in the regions of the leeward facade where the flow remains attached to the wall. The deviation of the enhanced wall function for surface-averaged CHTC is found to be 10.8% against the wall-resolved LES results, while for the non-blended law of the wall this is 19.2%.</p

    Does knowledge of cancer diagnosis affect quality of life? A methodological challenge

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    BACKGROUND: As part of an assessment of quality of life in lung cancer patients an investigation was carried out to examine whether the knowledge of their diagnosis affected their quality of life. METHODS: Every patient in a defined geographical area with a potential diagnosis of lung cancer was interviewed at first consultation and after a definitive treatment has been given. Quality of life was assessed using three standard measures: the Nottingham Health Profile (NHP), the EORTC quality of life questionnaire (QLQ-C30) and its lung cancer supplementary questionnaire (QLQ-LC13). Comparison was made in quality of life scores between patients who knew their cancer diagnosis and those who did not. RESULTS: In all, 129 lung cancer patients were interviewed. Of these, 30 patients (23%) knew and 99 (78%) did not know their cancer diagnosis at the time of baseline assessment. The patient groups were similar in their characteristics except for age (P = 0.04) and cell type (P < 0.0001). Overall, there were no significant differences between these two groups with regard to their scores on the three instruments used. A major finding was that both group scored almost the same on emotional reactions (P = 0.8) and social isolation (P = 1.0) as measured by the NHP, and emotional (P = 0.7) and social functioning (P = 1.0) as measured by the EORTC QLQ-C30. In addition there were no significant differences in patients' symptom scores between those who knew their diagnosis and those who did not, nor did any consistent pattern emerge. The only significant difference was for sleep difficulties (P = 0.02). CONCLUSION: The findings suggest that the knowledge of cancer diagnosis does not affect the way in which patients respond to quality of life questionnaires

    Determinants of Early Marriage from Married Girls' Perspectives in Iranian Setting: A Qualitative Study

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    Early marriage is a worldwide problem associated with a range of health and social consequences for teenage girls. Designing effective health interventions for managing early marriage needs to apply the community-based approaches. However, it has received less attention from policymakers and health researchers in Iran. Therefore, the current study aimed to explore determinants of early marriage from married girls' perspectives. The study was conducted from May 2013 to January 2015 in Ahvaz, Iran. A purposeful sampling method was used to select fifteen eligible participants. Data were collected through face-to-face, semistructured interviews and were analyzed using the conventional content analysis approach. Three categories emerged from the qualitative data including "family structure," "Low autonomy in decision-making," and "response to needs." According to the results, although the participants were not ready to get married and intended to postpone their marriage, multiple factors such as individual and contextual factors propelled them to early marriage. Given that early marriage is a multifactorial problem, health care providers should consider a multidimensional approach to support and empower these vulnerable girls. � 2016 Simin Montazeri et al

    The Effect of Trifluralin on Rhizoctonia solani (isolate AG4), Causal Agent of Soybean Damping off

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    Damping off caused by Rhizoctonia solani (isolate AG4) constrains growing soybean in the north Iranian province of Golestan. The pathogen was grown on malt agar containing 0, 50, 100 or 200 ppm trifluralin then its vegetative growth and virulence were evaluated. The response of soybean cv. Williams seedlings grown in soil containing 0, 0.5, 1 and 2 ?g ai g-1 trifluralin was investigated. On malt agar containing trifluralin, the radial growth of the fungal colonies was slower than that on untreated medium. There was no significant difference between these two types of colony in their abaility to cause disease symptoms on soybean seedlings. The incidence of soybean damping off in autoclaved soil treated with trifluralin was significantly higher than that in untreated soil. The results indicate that trifluralin enhanced the susceptibility of soybean radicles to the pathogen

    A seismic-driven 3D model of rock mechanical facies: An example from the Asmari reservoir, SW Iran

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    Asmari Formation is one of the most prolific and important hydrocarbon reservoirs in Iran. This formation in the Cheshmeh-Khosh oilfield shows mixed carbonate-siliciclastic lithology and its elastic modulus changes are correlatable with facies changes. To address these changes, we investigated the relation between sedimentary environment (facies) and texture with various elastic moduli. The Young's modulus shows higher correlation with the facies changes. Data from three wells are analyzed and used for the construction of rock mechanical facies. Based on elastic properties, facies and texture changes as well as petrophysical characteristics seven rock mechanical facies (RMFs) are recognized in the studied formation. To predict RMFs at inter-well spaces more efficiently and capturing the lateral formation property variationsa 3D rock mechanical facies model is constructed based on seismic attributes. In this method, RMFs are correlatable between the studied wells and mappable by seismic attribute in the field scale. Finally, the distribution of RMFs and their related properties is investigated in the studied field

    Influence of B cells in liver fibrosis associated with hepatitis B virus harboring basal core promoter mutations

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    The development of the liver disease in chronic hepatitis B with common viral variants can be determined through the interaction between the virus and the host immune response. B cells constitute half of the intrahepatic lymphocyte population with an impact on fibrosis. A proliferation-inducing ligand (APRIL) has been shown to have a co-stimulatory activity on B cells. For this study HBV DNA was amplified and then sequenced to show the presence of the basal core promoter (BCP) mutations in the serum from 57 patients with chronic hepatitis B. The range of IgD-positive B cells was detected by immunohistochemistry in liver biopsies; and patients serum was assayed for APRIL levels by enzyme immunoassay. Twenty-seven patients (47.4) harbored the A1762T-G1764A BCP mutations. Coefficients of logistic regression showed that the effect of increasing IgD-positive B cells in rising odds of the liver disease is the same in the patients with BCP mutation A1762T-G1764A and in the patients without mutation, nevertheless the effect of APRIL is not similar in these two groups of patients. Logistic regression in patients with BCP A1762T-G1764A mutations demonstrated that increasing one score of APRIL decreased the odds of fibrosis stage about 8. These results suggest that in infection with viral variants of hepatitis B virus, the population of IgD-positive B cells may play a decisive role in later stages of the liver disease which is reduced by APRIL in chronic hepatitis patients with BCP mutations. J. Med. Virol. 84:18891896, 2012. (c) 2012 Wiley Periodicals, Inc
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