266 research outputs found

    Immune-Mediated Inflammation May Contribute to the Pathogenesis of Cardiovascular Disease in Mucopolysaccharidosis Type I.

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    BackgroundCardiovascular disease, a progressive manifestation of α-L-iduronidase deficiency or mucopolysaccharidosis type I, continues in patients both untreated and treated with hematopoietic stem cell transplantation or intravenous enzyme replacement. Few studies have examined the effects of α-L-iduronidase deficiency and subsequent glycosaminoglycan storage upon arterial gene expression to understand the pathogenesis of cardiovascular disease.MethodsGene expression in carotid artery, ascending, and descending aortas from four non-tolerized, non-enzyme treated 19 month-old mucopolysaccharidosis type I dogs was compared with expression in corresponding vascular segments from three normal, age-matched dogs. Data were analyzed using R and whole genome network correlation analysis, a bias-free method of categorizing expression level and significance into discrete modules. Genes were further categorized based on module-trait relationships. Expression of clusterin, a protein implicated in other etiologies of cardiovascular disease, was assessed in canine and murine mucopolysaccharidosis type I aortas via Western blot and in situ immunohistochemistry.ResultsGene families with more than two-fold, significant increased expression involved lysosomal function, proteasome function, and immune regulation. Significantly downregulated genes were related to cellular adhesion, cytoskeletal elements, and calcium regulation. Clusterin gene overexpression (9-fold) and protein overexpression (1.3 to 1.62-fold) was confirmed and located specifically in arterial plaques of mucopolysaccharidosis-affected dogs and mice.ConclusionsOverexpression of lysosomal and proteasomal-related genes are expected responses to cellular stress induced by lysosomal storage in mucopolysaccharidosis type I. Upregulation of immunity-related genes implicates the potential involvement of glycosaminoglycan-induced inflammation in the pathogenesis of mucopolysaccharidosis-related arterial disease, for which clusterin represents a potential biomarker

    Large-eddy simulation of spectral coherence in a wind turbine wake

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    This work is mainly dedicated to the study of the characteristics of spectral coherence of turbulence fluctuations in wind turbine wakes. A computational fluid dynamics (CFD) code has been implemented using a large-eddy simulation (LES) approach, which is thought to be conceptually more suitable for studying the turbulence evolution in a wind turbine wake. Comparisons with experimental data from the Nørrekær Enge II Windfarm, in Denmark, and with an analytical model proposed by Panofsky and Dutton have been performed, and the results are found to be in reasonable agreement with both

    Using LES to Study Reacting Flows and Instabilities in Annular Combustion Chambers

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    Great prominence is put on the design of aeronautical gas turbines due to increasingly stringent regulations and the need to tackle rising fuel prices. This drive towards innovation has resulted sometimes in new concepts being prone to combustion instabilities. In the particular field of annular combustion chambers, these instabilities often take the form of azimuthal modes. To predict these modes, one must compute the full combustion chamber, which remained out of reach until very recently and the development of massively parallel computers. Since one of the most limiting factors in performing Large Eddy Simulation (LES) of real combustors is estimating the adequate grid, the effects of mesh resolution are investigated by computing full annular LES of a realistic helicopter combustion chamber on three grids, respectively made of 38, 93 and 336 million elements. Results are compared in terms of mean and fluctuating fields. LES captures self-established azimuthal modes. The presence and structure of the modes is discussed. This study therefore highlights the potential of LES for studying combustion instabilities in annular gas turbine combustors

    On the reliability of computed chaotic solutions of nonlinear differential equations

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    In this paper a new concept, namely the critical predictable time TcT_c, is introduced to give a more precise description of computed chaotic solutions of nonlinear differential equations: it is suggested that computed chaotic solutions are unreliable and doubtable when t>Tc t > T_c. This provides us a strategy to detect reliable solution from a given computed result. In this way, the computational phenomena, such as computational chaos (CC), computational periodicity (CP) and computational prediction uncertainty, which are mainly based on long-term properties of computed time series, can be completely avoided. So, this concept also provides us a time-scale to determine whether or not a particular time is long enough for a given nonlinear dynamic system. Besides, the influence of data inaccuracy and various numerical schemes on the critical predictable time is investigated in details by using symbolic computation software as a tool. A reliable chaotic solution of Lorenz equation in a rather large interval 0≤t<12000 \leq t < 1200 non-dimensional Lorenz time units is obtained for the first time. It is found that the precision of initial condition and computed data at each time-step, which is mathematically necessary to get such a reliable chaotic solution in such a long time, is so high that it is physically impossible due to the Heisenberg uncertainty principle in quantum physics. This however provides us a so-called "precision paradox of chaos", which suggests that the prediction uncertainty of chaos is physically unavoidable, and that even the macroscopical phenomena might be essentially stochastic and thus could be described by probability more economically.Comment: 29 pages, 13 figures, 1 tabl

    Trust in financial services: the influence of demographics and dispositional characteristics

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    So far, very little attention has been paid to examining consumer perceptions of trust from an interdisciplinary perspective. The purpose of this study is to examine how consumer trusting belief and disposition to trust within the financial services sector vary on the basis of individual demographic differences in trust. The research provides new insights into how consumers with higher dispositional trust have higher institutional trust and higher trusting belief and how consumers’ trusting belief significantly differs according to their demographic background in terms of age, marital status, ethnicity and gross annual income. The findings offer useful insights for the managers in financial institutions to carefully consider the impact of the influence of these individual differences on consumer behaviour in order to serve the needs of consumers in their target market and be able to design financial products and develop trust building strategies to attract and retain them. They also call for the action of the regulators and the financial institutions to play their part in building strong institutional systems that contribute to engendering higher levels of consumer trust

    Pulmonary complications in primary hypogammaglobulinemia: a survey by high resolution CT scan

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    Background. Primary hypogammaglobulinemia disorders are a group of heterogeneous immunodeficiency syndromes with an increased susceptibility to pulmonary complications. Methods. The aim of this study was to evaluate the extent of lung abnormalities in primary hypogammaglobulinaemic patients by high resolution computed tomography (HRCT) scan and pulmonary function test (PFT). HRCT and PFT were performed in 22 Iranian patients with primary hypogammaglobulinemia. Results. Pathological bronchial findings were observed in thirteen patients: three patients showed only peribronchial thickening and the remaining ten patients suffered from both bronchiectasis and peribronchial wall thickening. Mild type of bronchiectasis and peribronchial wall thickening were the most common type, predominantly observed in the right middle and both right and left lower lobe segments of lungs. Although bullae were not found, emphysema, air-trapping, and collapse/consolidation were observed in two patients. Bronchial involvement was mostly limited to 1 up to 5 bronchopulmonary segments; only one HRCT indicated bronchial involvement in more than nine bronchopulmonary segments. Pathological bronchial findings mostly observed in the proximal bronchi; meanwhile the involvement of the distal bronchi was less common. Decreasing FEV1 and FVC were observed in 65% and 55% of patients, respectively. There was a significant correlation between the HRCT score and the predicted values by PFT. The delay of diagnosis in patients with bronchiectasis was significantly higher than those without bronchiectasis. Conclusions. It seems that the majority of hypogammaglobulinaemic patients suffer from the mild type of bronchiectasis, which is mostly observed in the proximal bronchi of the lower lobe segments. The delay of diagnosis plays an important role in the occurrence of this complication in these patients

    Cystatin C Deficiency Promotes Epidermal Dysplasia in K14-HPV16 Transgenic Mice

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    Cysteine protease cathepsins are important in extracellular matrix protein degradation, cell apoptosis, and angiogenesis. Mice lacking cathepsins are protected from tumor progression in several animal models, suggesting that the regulation of cathepsin activities controls the growth of various malignant tumors.We tested the role of cathepsins using a mouse model of multistage epithelial carcinogenesis, in which the human keratin-14 promoter/enhancer drove the expression of human papillomavirus type 16 (HPV16) early region E6/E7 transgenes. During the progression of premalignant dysplasia, we observed increased expression of cysteine protease cathepsin S, but concomitantly reduced expression of cathepsin endogenous inhibitor cystatin C in the skin tissue extract. Absence of cystatin C in these transgenic mice resulted in more progression of dysplasia to carcinoma in situ on the face, ear, chest, and tail. Chest and ear skin extract real time PCR and immunoblot analysis, mouse serum sample ELISA, tissue immunohistological analysis, and tissue extract-mediated in vitro elastinolysis and collagenolysis assays demonstrated that cystatin C deficiency significantly increased cathepsin expression and activity. In skin from both the chest and ear, we found that the absence of cystatin C reduced epithelial cell apoptosis but increased proliferation. From the same tissue preparations, we detected significantly higher levels of pro-angiogenic laminin 5-derived γ2 peptides and concurrently increased neovascularization in cystatin C-deficient mice, compared to those from wild-type control mice.Enhanced cathepsin expression and activity in cystatin C-deficient mice contributed to the progression of dysplasia by altering premalignant tissue epithelial proliferation, apoptosis, and neovascularization

    A Guide for Social Science Journal Editors on Easing into Open Science

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    Journal editors have a large amount of power to advance open science in their respective fields by incentivising and mandating open policies and practices at their journals. The Data PASS Journal Editors Discussion Interface (JEDI, an online community for social science journal editors: www.dpjedi.org) has collated several resources on embedding open science in journal editing (www.dpjedi.org/resources). However, it can be overwhelming as an editor new to open science practices to know where to start. For this reason, we created a guide for journal editors on how to get started with open science. The guide outlines steps that editors can take to implement open policies and practices within their journal, and goes through the what, why, how, and worries of each policy and practice. This manuscript introduces and summarizes the guide (full guide: https://osf.io/hstcx).<br/

    Novel conditionally immortalized human proximal tubule cell line expressing functional influx and efflux transporters

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    Reabsorption of filtered solutes from the glomerular filtrate and excretion of waste products and xenobiotics are the main functions of the renal proximal tubular (PT) epithelium. A human PT cell line expressing a range of functional transporters would help to augment current knowledge in renal physiology and pharmacology. We have established and characterized a conditionally immortalized PT epithelial cell line (ciPTEC) obtained by transfecting and subcloning cells exfoliated in the urine of a healthy volunteer. The PT origin of this line has been confirmed morphologically and by the expression of aminopeptidase N, zona occludens 1, aquaporin 1, dipeptidyl peptidase IV and multidrug resistance protein 4 together with alkaline phosphatase activity. ciPTEC assembles in a tight monolayer with limited diffusion of inulin-fluorescein-isothiocyanate. Concentration and time-dependent reabsorption of albumin via endocytosis has been demonstrated, together with sodium-dependent phosphate uptake. The expression and activity of apical efflux transporter p-glycoprotein and of baso-lateral influx transporter organic cation transporter 2 have been shown in ciPTEC. This established human ciPTEC expressing multiple endogenous organic ion transporters mimicking renal reabsorption and excretion represents a powerful tool for future in vitro transport studies in pharmacology and physiology
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