1,623 research outputs found

    Shocked into Growth

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    Epigenetics and Breast Cancers

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    Several of the active compounds in foods, poisons, drugs, and industrial chemicals may, by epigenetic mechanisms, increase or decrease the risk of breast cancers. Enzymes that are involved in DNA methylation and histone modifications have been shown to be altered in several types of breast and other cancers resulting in abnormal patterns of methylation and/or acetylation. Hypermethylation at the CpG islands found in estrogen response element (ERE) promoters occurs in conjunction with ligand-bonded alpha subunit estrogen receptor (Erα) dimers wherein the ligand ERα dimer complex acts as a transcription factor and binds to the ERE promoter. Ligands could be 17-β-estradiol (E2), phytoestrogens, heterocyclic amines, and many other identified food additives and heavy metals. The dimer recruits DNA methyltransferases which catalyze the transfer of methyl groups from S-adenosyl-L-methionine (SAM) to 5′-cytosine on CpG islands. Other enzymes are recruited to the region by ligand-ERα dimers which activate DNA demethylases to act simultaneously to increase gene expression of protooncogenes and growth-promoting genes. Ligand-ERα dimers also recruit histone acetyltransferase to the ERE promoter region. Histone demethylases such as JMJD2B and histone methyltransferases are enzymes which demethylate lysine residues on histones H3 and/or H4. This makes the chromatin accessible for transcription factors and enzymes

    Array CGH data modeling and smoothing in Stationary Wavelet Packet Transform domain

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    Background: Array-based comparative genomic hybridization (array CGH) is a highly efficient technique, allowing the simultaneous measurement of genomic DNA copy number at hundreds or thousands of loci and the reliable detection of local one-copy-level variations. Characterization of these DNA copy number changes is important for both the basic understanding of cancer and its diagnosis. In order to develop effective methods to identify aberration regions from array CGH data, many recent research work focus on both smoothing-based and segmentation-based data processing. In this paper, we propose stationary packet wavelet transform based approach to smooth array CGH data. Our purpose is to remove CGH noise in whole frequency while keeping true signal by using bivariate model. Results: In both synthetic and real CGH data, Stationary Wavelet Packet Transform (SWPT) is the best wavelet transform to analyze CGH signal in whole frequency. We also introduce a new bivariate shrinkage model which shows the relationship of CGH noisy coefficients of two scales in SWPT. Before smoothing, the symmetric extension is considered as a preprocessing step to save information at the border. Conclusions: We have designed the SWTP and the SWPT-Bi which are using the stationary wavelet packet transform with the hard thresholding and the new bivariate shrinkage estimator respectively to smooth the array CGH data. We demonstrate the effectiveness of our approach through theoretical and experimental exploration of a set of array CGH data, including both synthetic data and real data. The comparison results show that our method outperforms the previous approaches

    Vietnam’s Accession to the World Trade Organization: Economic Projections to 2020

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    This study presents a set of assessments of the long term economic effects of Vietnam’s accession to the WTO. Generally speaking, our results indicate that Vietnam would benefit from accelerating its participation in more open multilateralism. However, it is also clear from our analysis that these benefits will remain modest in the absence of comprehensive and complementary domestic economic reforms. Passive external liberalization, even when coupled with determined domestic reform, is inferior to WTO participation combined with negotiated market access and other activist multilateral agreements. Finally, our analysis shows that capital insufficiency is a very serious constraint on Vietnamese economic growth and diversification. Capital market reform can play an essential role in dynamic and sustained economic development for the country.Vietnam, WTO, Trade

    Micro-simulation of Car Drivers’ Movements at Parking Lots

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    AbstractDrivers’ movements across or within parking facilities contribute to various problems, i.e., congestion, safety, and environmental effects. Micro-simulation can help to increase the understanding of drivers’ movements and their effects on parking management. This study aims to develop a multi agent-based simulation tool to demonstrate its capability of studying driver movements across parking lots. The program was constructed using the multi-agent modeling environment NetLogo. The developed simulation tool allows to adjust features of the parking facilities. Additionally, vehicle travel time and parking occupancy indicators were integrated to investigate the efficiency of the parking

    Imagerie multimodale en choriorétinopathie séreuse centrale aiguë et chronique

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    De nombreuses théories ont été proposées concernant la pathophysiologie de la choriorétinopathie séreuse centrale (CRSC), sans consensus sur son étiologie exacte. La recherche a mené à diverses possibilités de traitement qui ciblent des mécanismes précis. L’imagerie multimodale, y compris l’autofluorescence du fond de l’œil (FAF), la tomographie par cohérence optique (TCO), l’angiographie fluorescéinique et l’angiographie au vert d’indocyanine, identifie les altérations vasculaires et structurelles qui peuvent confirmer le diagnostic de CRSC et adapter efficacement le traitement pour aider à maximiser le pronostic visuel chez ces patients. Les caractéristiques d’imagerie de la CRSC et des exemples de cas seront explorés

    Numerical modelling of moisture motion in heterogeneous soils using 1D-MIRBF method

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    In the present paper, we develop an efficient and accurate numerical approach based on one-dimensional-moving integrated radial basis function (1D-MIRBF) and fully implicit modified Picard method for simulating fluid movement in heterogeneous soils governed by the highly non-linear Richards equation. The major advantages of the proposed 1D-MIRBF method include (i) a banded sparse system matrix that helps reduce the computational cost; (ii) the Kronecker Delta property of the constructed shape functions, which helps impose the essential boundary conditions in an exact manner; and (iii) high accuracy and fast convergence rate owing to the use of the IRBF approximation. The performance of the present method is demonstrated through several 1--D and 2--D soil infiltration problems. Numerical results obtained are in agreement with other published results in the literature. This solver for moisture motion in soils will be incorporated into a surface-water-flow solver to handle the surface irrigation problem
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