1,590 research outputs found

    Enhancing the top signal at Tevatron using Neural Nets

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    We show that Neural Nets can be useful for top analysis at Tevatron. The main features of ttˉt\bar t and background events on a mixed sample are projected in a single output, which controls the efficiency and purity of the ttˉt\bar t signal.Comment: 11 pages, 6 figures (not included and available from the authors), Latex, UB-ECM-PF 94/1

    Neural network analysis for gamma gamma -> 3pi at Daphne

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    We consider the possibility of using neural networks in experimental data analysis in Daphne. We analyze the process γγπ+ππ0\gamma\gamma\to \pi^+ \pi^- \pi^0 and its backgrounds using neural networks and we compare their performances with traditional methods of applying cuts on several kinematical variables. We find that the neural networks are more efficient and can be of great help for processes with small number of produced events.Comment: 11 pages, latex, 2 figures

    Discriminating signal from background using neural networks. Application to top-quark search at the Fermilab Tevatron

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    The application of Neural Networks in High Energy Physics to the separation of signal from background events is studied. A variety of problems usually encountered in this sort of analyses, from variable selection to systematic errors, are presented. The top--quark search is used as an example to illustrate the problems and proposed solutions.Comment: 11 pages, 3 figures, psfi

    Interoperabilidad del Servicio de Nomenclátor del Instituto de Cartografía de Andalucía

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    Programa de las jornadas en: http://www.sigte.udg.edu/jornadassiglibre2009/index.php?page=jornadasAndalucía (ICA) basa sus servicios en una base de datos que sigue el estándar del Modelo de Nomenclátor de España y que actualmente contiene unos 149.500 topónimos e identificadores geográficos clasificados temáticamente en áreas administrativas, entidades de población, hidrografía, orografía, patrimonio, infraestructuras, actividades industriales, extractivas, servicios y equipamientos. Este servicio OGC basado en el software libre Deegree 2.2. trata de dar servicio a otros proyectos del ICA como la IDEAndalucia, el catálogo de productos on-line LINE@ y en un futuro al buscador de cartografía histórica; por otro lado dispone de un visor propio de búsqueda de nombres geográficos con utilidades de descarga, rectificación y localización de topónimos cercanos.The Gazetteer WFS-G service of the Institute of Cartography of Andalusia is based on a database following standard Spanish Gazetteer model. Nowadays it contains 149.500 placed-names and geographical records sorted by administrative areas, towns, rivers, mountains, culture and heritage constructions, infrastructures, industrial activities, public administration services and public buildings. This freeware OGC service is developed in Deegree software and give service to another ICA projects such as IDEAndalucia, ICA on-line product catalogue named LINE@ and, in the future to historical cartography searcher. On the other hand, it offers an own viewer to place-names search with download, ratification and search neighbours place-names utilities

    Using detergent to enhance detection sensitivity of African trypanosomes in human CSF and blood by Loop-Mediated Isothermal Amplification (LAMP)

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    <p><b>Background:</b> The loop-mediated isothermal amplification (LAMP) assay, with its advantages of simplicity, rapidity and cost effectiveness, has evolved as one of the most sensitive and specific methods for the detection of a broad range of pathogenic microorganisms including African trypanosomes. While many LAMP-based assays are sufficiently sensitive to detect DNA well below the amount present in a single parasite, the detection limit of the assay is restricted by the number of parasites present in the volume of sample assayed; i.e. 1 per µL or 103 per mL. We hypothesized that clinical sensitivities that mimic analytical limits based on parasite DNA could be approached or even obtained by simply adding detergent to the samples prior to LAMP assay.</p> <p><b>Methodology/Principal Findings:</b> For proof of principle we used two different LAMP assays capable of detecting 0.1 fg genomic DNA (0.001 parasite). The assay was tested on dilution series of intact bloodstream form Trypanosoma brucei rhodesiense in human cerebrospinal fluid (CSF) or blood with or without the addition of the detergent Triton X-100 and 60 min incubation at ambient temperature. With human CSF and in the absence of detergent, the LAMP detection limit for live intact parasites using 1 µL of CSF as the source of template was at best 103 parasites/mL. Remarkably, detergent enhanced LAMP assay reaches sensitivity about 100 to 1000-fold lower; i.e. 10 to 1 parasite/mL. Similar detergent-mediated increases in LAMP assay analytical sensitivity were also found using DNA extracted from filter paper cards containing blood pretreated with detergent before card spotting or blood samples spotted on detergent pretreated cards.</p> <p><b>Conclusions/Significance:</b> This simple procedure for the enhanced detection of live African trypanosomes in biological fluids by LAMP paves the way for the adaptation of LAMP for the economical and sensitive diagnosis of other protozoan parasites and microorganisms that cause diseases that plague the developing world.</p&gt

    The use of internal audits as a tool to analyze skills and competences

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    [EN] The degrees of the faculty of Chemistry of the University of Barcelona have implemented a quality management system (QMS) (Real Decreto 1393/2007; Real Decreto 861/2010). One of the common subjects taught in formative period of the students is Quality and Prevention. The competences that the students must acquire are knowing the QMS and the basis of certification and accreditation. They must also have skills to plan and propose actions to ensure quality and to prepare documentation of a quality management system, among others. The aim of the work is the execution of internal audits carried out by students to analyze the degree of skills and competences obtained by the auditors throughout the course Quality and Prevention.Fernandez, J.; Cruells, M.; Escaja, N.; Garrido, JA.; Giménez, J.; Llauradó, M.; Roca, A.... (2016). The use of internal audits as a tool to analyze skills and competences. En 2nd. International conference on higher education advances (HEAD'16). Editorial Universitat Politècnica de València. 196-202. https://doi.org/10.4995/HEAD16.2015.2647OCS19620

    Environmental variables, habitat discontinuity and life history shaping the genetic structure of Pomatoschistus marmoratus

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    Coastal lagoons are semi-isolated ecosystems exposed to wide fluctuations of environmental conditions and showing habitat fragmentation. These features may play an important role in separating species into different populations, even at small spatial scales. In this study, we evaluate the concordance between mitochondrial (previous published data) and nuclear data analyzing the genetic variability of Pomatoschistus marmoratus in five localities, inside and outside the Mar Menor coastal lagoon (SE Spain) using eight microsatellites. High genetic diversity and similar levels of allele richness were observed across all loci and localities, although significant genic and genotypic differentiation was found between populations inside and outside the lagoon. In contrast to the FST values obtained from previous mitochondrial DNA analyses (control region), the microsatellite data exhibited significant differentiation among samples inside the Mar Menor and between lagoonal and marine samples. This pattern was corroborated using Cavalli-Sforza genetic distances. The habitat fragmentation inside the coastal lagoon and among lagoon and marine localities could be acting as a barrier to gene flow and contributing to the observed genetic structure. Our results from generalized additive models point a significant link between extreme lagoonal environmental conditions (mainly maximum salinity) and P. marmoratus genetic composition. Thereby, these environmental features could be also acting on genetic structure of coastal lagoon populations of P. marmoratus favoring their genetic divergence. The mating strategy of P. marmoratus could be also influencing our results obtained from mitochondrial and nuclear DNA. Therefore, a special consideration must be done in the selection of the DNA markers depending on the reproductive strategy of the species
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