202 research outputs found

    Leak identification in saturated unsteady flow via a Cauchy problem

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    This work is an initial study of a numerical method for identifying multiple leak zones in saturated unsteady flow. Using the conventional saturated groundwater flow equation, the leak identification problem is modelled as a Cauchy problem for the heat equation and the aim is to find the regions on the boundary of the solution domain where the solution vanishes, since leak zones correspond to null pressure values. This problem is ill-posed and to reconstruct the solution in a stable way, we therefore modify and employ an iterative regularizing method proposed in [1] and [2]. In this method, mixed well-posed problems obtained by changing the boundary conditions are solved for the heat operator as well as for its adjoint, to get a sequence of approximations to the original Cauchy problem. The mixed problems are solved using a Finite element method (FEM), and the numerical results indicate that the leak zones can be identified with the proposed method

    An Unruly Classic: Kalīla and Dimna and Its Syriac, Arabic, and Early Persian Versions

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    In this collective volume, members of the AnonymClassic project will discuss, from different perspectives, a core aspect of their work with Kalīla and Dimna: the study of variation. The aim is to shed light on Kalīla and Dimna’s variance—or textual instability, in the framework of Bernard Cerquiglini—and typologies of textual mobility/mouvance across linguistic traditions and historical periods. How can these dynamics best be described, analyzed, and classified? What were the reasons for the remarkable mobility of this book; who were the agents that intervened; and how

    Machine learning for predicting fracture strain in sheet metal forming

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    Machine learning models are built to predict the strain values for which edge cracking occurs in hole expansion tests. The samples from this test play the role of sheet metal components to be manufactured, in which edge cracking often occurs associated with a uniaxial tension stress state at the critical edges of components. For the construction of the models, a dataset was obtained experimentally for rolled ferritic carbon steel sheets of different qualities and thicknesses. Two types of tests were performed: tensile and hole expansion tests. In the tensile test, the yield stress, the tensile strength, the strain at maximum load and the elongation after fracture were determined in the rolling and transverse directions. In the hole expansion test, the strain for which edge cracking occurs, was determined. It is intended that the models can predict the strain at fracture in this test, based on the knowledge of the tensile test data. The machine learning algorithms used were Multilayer Perceptron, Gaussian Processes, Support Vector Regression and Random Forest. The traditional polynomial regression that fits a 2nd order polynomial function was also used for comparison. It is shown that machine learning-based predictive models outperform the traditional polynomial regression method; in particular, Gaussian Processes and Support Vector Regression were found to be the best machine learning algorithms that enable the most robust predictive models.publishe

    An Interim Report on the Editorial and Analytical Work of the AnonymClassic Project

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    In this collective article, members of the AnonymClassic project discuss various aspects of their work on the textual tradition Kalīla and Dimna. Beatrice Gruendler provides a general introduction to the questions being considered. This is followed by a number of short essays in specific areas, organized into three categories: codicology, literary history and theory, and the digital infrastructure of the project. Jan J. van Ginkel summarizes the challenges involved in editing the Syriac versions of Kalīla and Dimna; Rima Redwan explains the AnonymClassic team’s approach vis-à-vis the transcription and textual segmentation of Arabic manuscripts; Khouloud Khalfallah follows this with an overview of the types of data that are recorded for each codex that is integrated into the project; Beatrice Gruendler, in a second contribution, shares some preliminary results from the analysis of interrelationships among manuscripts; and Rima Redwan, also in a second contribution, discusses the sets of illustrations, or »image cycles«, that are found in many copies of Kalīla wa-Dimna. Moving into the realm of literary history and theory, Isabel Toral poses a range of questions relating to the status of Kalīla and Dimna, as (arguably) anonymous in authorship and as a fundamentally translated book; Johannes Stephan explores the references to Kalīla wa-Dimna found in various medieval Arabic scholarly works; and Matthew L. Keegan confronts the problem of the genre(s) to which Kalīla wa-Dimna might be assigned and the exceptional »promiscuity« of the text. The last section of the article, on digital infrastructure, contains two contributions: Theodore S. Beers describes a web application that the team has created to facilitate the consultation of published versions of Kalīla and Dimna, and, finally, Mahmoud Kozae and Marwa M. Ahmed offer a more comprehensive discussion of the digital tools and methods – specialized and in some cases developed »in-house« – on which the AnonymClassic project relies

    Nucleic Acids Res

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    Fragile X syndrome (FXS), the most common form of inherited intellectual disability, is caused by the silencing of the FMR1 gene encoding an RNA-binding protein (FMRP) mainly involved in translational control. We characterized the interaction between FMRP and the mRNA of GRK4, a member of the guanine nucleotide-binding protein (G protein)-coupled receptor kinase super-family, both in vitro and in vivo. While the mRNA level of GRK4 is unchanged in the absence or in the presence of FMRP in different regions of the brain, GRK4 protein level is increased in Fmr1-null cerebellum, suggesting that FMRP negatively modulates the expression of GRK4 at the translational level in this brain region. The C-terminal region of FMRP interacts with a domain of GRK4 mRNA, that we called G4RIF, that is folded in four stem loops. The SL1 stem loop of G4RIF is protected by FMRP and is part of the S1/S2 sub-domain that directs translation repression of a reporter mRNA by FMRP. These data confirm the role of the G4RIF/FMRP complex in translational regulation. Considering the role of GRK4 in GABAB receptors desensitization, our results suggest that an increased GRK4 levels in FXS might contribute to cerebellum-dependent phenotypes through a deregulated desensitization of GABAB receptors

    Expression of uncoupling proteins-1,-2 and-3 mRNA is induced by an adenocarcinoma-derived lipid-mobilizing factor

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    The abnormalities of lipid metabolism observed in cancer cachexia may be induced by a lipid-mobilizing factor produced by adenocarcinomas. The specific molecules and metabolic pathways that mediate the actions of lipid-mobilizing factor are not known. The mitochondrial uncoupling proteins-1, -2 and -3 are suggested to play essential roles in energy dissipation and disposal of excess lipid. Here, we studied the effects of lipid-mobilizing factor on the expression of uncoupling proteins-1, -2 and -3 in normal mice. Lipid-mobilizing factor isolated from the urine of cancer patients was injected intravenously into mice over a 52-h period, while vehicle was similarly given to controls. Lipid-mobilizing factor caused significant reductions in body weight (-10%, P=0.03) and fat mass (-20%, P<0.01) accompanied by a marked decrease in plasma leptin (-59%, P<0.01) and heavy lipid deposition in the liver. In brown adipose tissue, uncoupling protein-1 mRNA levels were elevated in lipid-mobilizing factor-treated mice (+96%, P<0.01), as were uncoupling proteins-2 and -3 (+57% and +37%, both P<0.05). Lipid-mobilizing factor increased uncoupling protein-2 mRNA in both skeletal muscle (+146%, P<0.05) and liver (+142%, P=0.03). The protein levels of uncoupling protein-1 in brown adipose tissue and uncoupling protein-2 in liver were also increased with lipid-mobilizing factor administration (+49% and +67%, both P=0.02). Upregulation by lipid-mobilizing factor of uncoupling proteins-1, -2 and -3 in brown adipose tissue, and of uncoupling protein-2 in skeletal muscle and liver, suggests that these uncoupling proteins may serve to utilize excess lipid mobilized during fat catabolism in cancer cachexia

    Direct targets of Klf5 transcription factor contribute to the maintenance of mouse embryonic stem cell undifferentiated state

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    <p>Abstract</p> <p>Background</p> <p>A growing body of evidence has shown that Krüppel-like transcription factors play a crucial role in maintaining embryonic stem cell (ESC) pluripotency and in governing ESC fate decisions. Krüppel-like factor 5 (Klf5) appears to play a critical role in these processes, but detailed knowledge of the molecular mechanisms of this function is still not completely addressed.</p> <p>Results</p> <p>By combining genome-wide chromatin immunoprecipitation and microarray analysis, we have identified 161 putative primary targets of Klf5 in ESCs. We address three main points: (1) the relevance of the pathways governed by Klf5, demonstrating that suppression or constitutive expression of single Klf5 targets robustly affect the ESC undifferentiated phenotype; (2) the specificity of Klf5 compared to factors belonging to the same family, demonstrating that many Klf5 targets are not regulated by Klf2 and Klf4; and (3) the specificity of Klf5 function in ESCs, demonstrated by the significant differences between Klf5 targets in ESCs compared to adult cells, such as keratinocytes.</p> <p>Conclusions</p> <p>Taken together, these results, through the definition of a detailed list of Klf5 transcriptional targets in mouse ESCs, support the important and specific functional role of Klf5 in the maintenance of the undifferentiated ESC phenotype.</p> <p>See: <url>http://www.biomedcental.com/1741-7007/8/125</url></p
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