344 research outputs found

    Study of Zγ events and limits on anomalous ZZγ and Zγγ couplings in pp̄ collisions at s=1.96TeV

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    We present a measurement of the Zγ production cross section and limits on anomalous ZZγ and Zγγ couplings for form-factor scales of Λ=750 and 1000 GeV. The measurement is based on 138 (152) candidates in the eeγ (μμγ) final state using 320(290)pb-1 of pp̄ collisions at s=1.96TeV. The 95% C.L. limits on real and imaginary parts of individual anomalous couplings are |h10,30Z|<0.23, |h20,40Z|<0.020, |h10,30γ|<0.23, and |h20,40γ|<0.019 for Λ=1000GeV. © 2005 The American Physical Society

    Intervals of Intense Energetic Electron Beams Over Jupiter's Poles

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    Juno's Jupiter Energetic particle Detector Instrument often detects energetic electron beams over Jupiter's polar regions. In this paper, we document a subset of intense magnetic field‐aligned beams of energetic electrons moving away from Jupiter at high magnetic latitudes both north and south of the planet. The number fluxes of these beams are often dominated by electrons with energies above about 1 MeV. These very narrow beams can create broad angular responses in the Jupiter Energetic particle Detector Instrument with unique signatures in the detector count rates, probably because of >10 MeV electrons. We use these signatures to identify the most intense beams. These beams occur primarily above the swirl region of the polar cap aurora. This polar region is described as being of low brightness and high absorption and the most magnetically “open” at Jupiter

    12-month mortality and loss-to-program in antiretroviral-treated children: The IeDEA pediatric West African Database to evaluate AIDS (pWADA), 2000-2008

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    <p>Abstract</p> <p>Background</p> <p>The IeDEA West Africa Pediatric Working Group (pWADA) was established in January 2007 to study the care and treatment of HIV-infected children in this region. We describe here the characteristics at antiretroviral treatment (ART) initiation and study the 12-month mortality and loss-to-program of HIV-infected children followed in ART programs in West Africa.</p> <p>Methods</p> <p>Standardized data from HIV-infected children followed-up in ART programs were included. Nine clinical centers from six countries contributed to the dataset (Benin, Côte d'Ivoire, Gambia, Ghana, Mali and Senegal). Inclusion criteria were the followings: age 0-15 years and initiated triple antiretroviral drug regimens. Baseline time was the date of ART initiation. WHO criteria was used to define severe immunosuppression based on CD4 count by age or CD4 percent < 15%. We estimated the 12-month Kaplan-Meier probabilities of mortality and loss-to-program (death or loss to follow-up > 6 months) after ART initiation and factors associated with these two outcomes.</p> <p>Results</p> <p>Between June 2000 and December 2007, 2170 children were included. Characteristics at ART initiation were the following: median age of 5 years (Interquartile range (IQR: 2-9) and median CD4 percentage of 13% (IQR: 7-19). The most frequent drug regimen consisted of two nucleoside reverse transcriptase inhibitors and one non-nucleoside reverse transcriptase inhibitors (62%). During the first 12 months, 169 (7.8%) children died and 461(21.2%) were lost-to-program. Overall, in HIV-infected children on ART, the 12-month probability of death was 8.3% (95% Confidence Interval (CI): 7.2-9.6%), and of loss-to-program was 23.1% (95% CI: 21.3-25.0%). Both mortality and loss-to program were associated with advanced clinical stage, CD4 percentage < 15% at ART initiation and year (> 2005) of ART initiation.</p> <p>Conclusion</p> <p>Innovative and sustainable approaches are needed to better document causes of death and increase retention in HIV pediatric clinics in West Africa.</p

    Potassium Dependent Regulation of Astrocyte Water Permeability Is Mediated by cAMP Signaling

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    Astrocytes express potassium and water channels to support dynamic regulation of potassium homeostasis. Potassium kinetics can be modulated by aquaporin-4 (AQP4), the essential water channel for astrocyte water permeability regulation. We investigated whether extracellular potassium ([K+]o) can regulate astrocyte water permeability and the mechanisms of such an effect. Studies were performed on rat primary astrocytes and a rat astrocyte cell line transfected with AQP4. We found that 10mM [K+]o caused an immediate, more than 40%, increase in astrocyte water permeability which was sustained in 5min. The water channel AQP4 was a target for this regulation. Potassium induced a significant increase in intracellular cAMP as measured with a FRET based method and with enzyme immunoassay. We found that protein kinase A (PKA) could phosphorylate AQP4 in vitro. Further elevation of [K+]o to 35mM induced a global intracellular calcium response and a transient water permeability increase that was abolished in 5min. When inwardly rectifying potassium (Kir)-channels were blocked, 10mM [K+]o also induced a calcium increase and the water permeability increase no longer persisted. In conclusion, we find that elevation of extracellular potassium regulates AQP4 and astrocyte water permeability via intracellular signaling involving cAMP. A prolonged increase of astrocyte water permeability is Kir-channel dependent and this response can be impeded by intracellular calcium signaling. Our results support the concept of coupling between AQP4 and potassium handling in astrocytes

    Prenatal and Perinatal Risk Factors for Autism in China

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    We conducted a case–control study using 190 Han children with and without autism to investigate prenatal and perinatal risk factors for autism in China. Cases were recruited through public special education schools and controls from regular public schools in the same region (Tianjin), with frequency matching on sex and birth year. Unadjusted analyses identified seven prenatal and seven perinatal risk factors significantly associated with autism. In the adjusted analysis, nine risk factors showed significant association with autism: maternal second-hand smoke exposure, maternal chronic or acute medical conditions unrelated to pregnancy, maternal unhappy emotional state, gestational complications, edema, abnormal gestational age (<35 or >42 weeks), nuchal cord, gravidity >1, and advanced paternal age at delivery (>30 year-old)

    Structure-based classification and ontology in chemistry

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    <p>Abstract</p> <p>Background</p> <p>Recent years have seen an explosion in the availability of data in the chemistry domain. With this information explosion, however, retrieving <it>relevant </it>results from the available information, and <it>organising </it>those results, become even harder problems. Computational processing is essential to filter and organise the available resources so as to better facilitate the work of scientists. Ontologies encode expert domain knowledge in a hierarchically organised machine-processable format. One such ontology for the chemical domain is ChEBI. ChEBI provides a classification of chemicals based on their structural features and a role or activity-based classification. An example of a structure-based class is 'pentacyclic compound' (compounds containing five-ring structures), while an example of a role-based class is 'analgesic', since many different chemicals can act as analgesics without sharing structural features. Structure-based classification in chemistry exploits elegant regularities and symmetries in the underlying chemical domain. As yet, there has been neither a systematic analysis of the types of structural classification in use in chemistry nor a comparison to the capabilities of available technologies.</p> <p>Results</p> <p>We analyze the different categories of structural classes in chemistry, presenting a list of patterns for features found in class definitions. We compare these patterns of class definition to tools which allow for automation of hierarchy construction within cheminformatics and within logic-based ontology technology, going into detail in the latter case with respect to the expressive capabilities of the Web Ontology Language and recent extensions for modelling structured objects. Finally we discuss the relationships and interactions between cheminformatics approaches and logic-based approaches.</p> <p>Conclusion</p> <p>Systems that perform intelligent reasoning tasks on chemistry data require a diverse set of underlying computational utilities including algorithmic, statistical and logic-based tools. For the task of automatic structure-based classification of chemical entities, essential to managing the vast swathes of chemical data being brought online, systems which are capable of hybrid reasoning combining several different approaches are crucial. We provide a thorough review of the available tools and methodologies, and identify areas of open research.</p

    Dietary and other lifestyle characteristics of Cypriot school children: results from the nationwide CYKIDS study

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    Dietary and lifestyle behaviors at young ages have been associated with the development of various chronic diseases. Schools are regarded as an excellent setting for lifestyle modification; there is a lack, however, of published dietary data in Cypriot school children. Thus, the objective of this work was to describe lifestyle characteristics of a representative segment of Cypriot school children and provide implications for school health education. Methods. The CYKIDS (Cyprus Kids Study) is a national, cross-sectional study conducted among 1140 school children (10.7 0.98 years). Sampling was stratified and multistage in 24 primary schools of Cyprus. Dietary assessment was based on a 154-item semi-quantitative food-frequency questionnaire and three supplementary questionnaires, assessing dietary patterns and behaviors. Adherence to the Mediterranean diet was evaluated by the KIDMED index (Mediterranean Diet Quality Index for children and adolescents). Physical activity was assessed by a 32-item, semi-quantitative questionnaire. Results. Analysis revealed that 6.7% of the children were classified as high adherers, whereas 37% as low adherers to the Mediterranean diet. About 20% of boys and 25% of girls reported "not having breakfast on most days of the week", while more than 80% of the children reported having meals with the family at least 5 times/week. Some food-related behaviors, such as intake of breakfast, were associated with socio-demographic factors, mostly with gender and the geomorphological characteristics of the living milieu. With respect to physical activity, boys reported higher levels compared to girls, however, one fourth of children did not report any kind of physical activity. Conclusion. A large percentage of Cypriot school children have a diet of low quality and inadequate physical activity. Public health policy makers should urgently focus their attention to primary school children and design school health education programs that target the areas that need attention in order to reduce the future burden of metabolic disorders and chronic diseases

    Transcriptional Regulation of Human Dual Specificity Protein Phosphatase 1 (DUSP1) Gene by Glucocorticoids

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    Background: Glucocorticoids are potent anti-inflammatory agents commonly used to treat inflammatory diseases. They convey signals through the intracellular glucocorticoid receptor (GR), which upon binding to ligands, associates with genomic glucocorticoid response elements (GREs) to regulate transcription of associated genes. One mechanism by which glucocorticoids inhibit inflammation is through induction of the dual specificity phosphatase-1 (DUSP1, a.k.a. mitogen-activated protein kinase phosphatase-1, MKP-1) gene. Methodology/Principal Findings: We found that glucocorticoids rapidly increased transcription of DUSP1 within 10 minutes in A549 human lung adenocarcinoma cells. Using chromatin immunoprecipitation (ChIP) scanning, we located a GR binding region between 21421 and 21118 upstream of the DUSP1 transcription start site. This region is active in a reporter system, and mutagenesis analyses identified a functional GRE located between 21337 and 21323. We found that glucocorticoids increased DNase I hypersensitivity, reduced nucleosome density, and increased histone H3 and H4 acetylation within genomic regions surrounding the GRE. ChIP experiments showed that p300 was recruited to the DUSP1 GRE, and RNA interference experiments demonstrated that reduction of p300 decreased glucocorticoid-stimulated DUSP1 gene expression and histone H3 hyperacetylation. Furthermore, overexpression of p300 potentiated glucocorticoid-stimulated activity of a reporter gene containing the DUSP1 GRE, and this coactivation effect was compromised when the histone acetyltransferase domain was mutated. ChIP-reChIP experiments using GR followed by p300 antibodies showed significant enrichment of the DUSP1 GRE upon glucocorticoid treatment, suggesting that GR and p300 are in the same protein complex recruited to the DUSP1 GRE. Conclusions/Significance: Our studies identified a functional GRE for the DUSP1 gene. Moreover, the transcriptional activation of DUSP1 by glucocorticoids requires p300 and a rapid modification of the chromatin structure surrounding the GRE. Overall, understanding the mechanism of glucocorticoid-induced DUSP1 gene transcription could provide insights into therapeutic approaches against inflammatory diseases. © 2010 Shipp et al
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