877 research outputs found

    25th International Workshop on Qualitative Reasoning

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    Abstract Knowledge about the natural dynamics of wind resources and the advantages of its exploration as energy source has a high value for implementing sustainable and integrated environmental management. The present work aims to explain the mechanism of wind formation in coastal zone, its capacity to produce energy, and the conversion of wind power in to energy for domestic use by human activities. The model shows changes of the wind direction in the coast zone due to changes of the air temperature caused by differences of water and land specific heat, leading to variations of air pressure. The result is a sea-land breezes that creates an adequate scenario to place wind farms for energy production. The model was built using Qualitative Reasoning techniques, and implemented in the DynaLearn workbench (www.dynalearn.eu), software which is being tested and evaluated. Introduction Wind is an indirect form of solar power and has emerged as a preeminent option of energy sources, in part because it is considered for many experts to be ecologically sustainable Worldwide energy supply insecurity, high oil prices and increasing levels of greenhouse gases (GHG) emission have prompted researchers to look for alternative energy sources to replace existing non-renewable energy sources such as fossil fuels Based on that, the knowledge about the natural dynamics of this resource and the advantages of its exploration as energy source has a high value for making decisions in sustainable and integrate environmental management. In that way, Qualitative Reasoning (QR) offers a modelling paradigm which allows the explicit representation of the main process operating in atmosphere that causes the Wind dynamics providing a renewable supply of energy. Furthermore, the ontology provided by QR facilitates education about these processes, which will be useful for explanation to decision makers and stakeholders-those people who have a vested interest in the outcome of sustainable decisions For this modeling effort, we chose the Qualitative Process Theory (QPT) approach proposed by Once we are dealing with a conceptual representation of an applicable alternative of power production, this qualitative modeling approach should provide an easy and friendly way for learning about the atmospheric dynamics in order to promote a better understanding of how wind power systems works. This approach will facilitate a whole view of the system, its structure and behaviour by stakeholders (mainly who is responsible for public administration) in order to make better decisions about energy and resources management. These features are offered by DynaLearn, an interactive learning system that integrates techniques developed in three areas: qualitative conceptual modeling, semantic technology and virtual pedagogical agents Model system The use of qualitative modeling to the evaluation of the functioning conditions of a system becomes a valuable tool, which allows real conditions simulations, from the knowledge of the behavior of the processes involved that can happen in an uncertainty line, bound to the technicalscientific knowledge [Tucci, 1998]

    Prevalence of transfusion-transmitted Chagas disease among multitransfused patients in Brazil

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    <p>Abstract</p> <p>Background</p> <p>Blood transfusion has always been an important route for Chagas Disease (CD) transmission. The high prevalence of CD in Latin America and its lifelong asymptomatic clinical picture pose a threat for the safety of the blood supply. The outcome of measures designed to improve transfusion safety can be assessed by evaluating the prevalence of CD among multitransfused patients</p> <p>Methods</p> <p>In order to assess the impact of CD control measures on the safety of the blood supply, an observational cross-sectional study was designed to determine the prevalence of CD in 351 highly transfused patients, in which vectorial transmission was excluded. This study compared patients that received transfusion products before (n = 230) and after (n = 121) 1997, when measures to control transfusion-transmitted CD were fully implemented in Brazil.</p> <p>Results</p> <p>The study group consisted of 351 patients exposed to high numbers of blood products during their lifetime (median number of units transfused = 51, range 10–2086). A higher prevalence of transfusion-transmitted CD (1.30%) was observed among multitransfused patients that received their first transfusion before 1997, compared with no cases of transfusion-transmitted CD among multitransfused patients transfused after that year. The magnitude of the exposure to blood products was similar among both groups (mean number of units transfused per year of exposure = 25.00 ± 26.46 and 23.99 ± 30.58 respectively; P = 0.75, Mann-Whitney test).</p> <p>Conclusion</p> <p>Multiple initiatives aimed to control vector and parental transmission of CD can significantly decrease transfusion-transmitted CD in Brazil. Our data suggest that mandatory donor screening for CD represents the most important measure to interrupt transmission of CD by blood transfusions.</p

    Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV

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    The production of b jets in association with a Z/gamma* boson is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV and recorded by the CMS detector. The inclusive cross section for Z/gamma* + b-jet production is measured in a sample corresponding to an integrated luminosity of 2.2 inverse femtobarns. The Z/gamma* + b-jet cross section with Z/gamma* to ll (where ll = ee or mu mu) for events with the invariant mass 60 < M(ll) < 120 GeV, at least one b jet at the hadron level with pT > 25 GeV and abs(eta) < 2.1, and a separation between the leptons and the jets of Delta R > 0.5 is found to be 5.84 +/- 0.08 (stat.) +/- 0.72 (syst.) +(0.25)/-(0.55) (theory) pb. The kinematic properties of the events are also studied and found to be in agreement with the predictions made by the MadGraph event generator with the parton shower and the hadronisation performed by PYTHIA.Comment: Submitted to the Journal of High Energy Physic

    On the genetic involvement of apoptosis-related genes in Crohn's disease as revealed by an extended association screen using 245 markers: no evidence for new predisposing factors

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    Crohn's disease (CD) presents as an inflammatory barrier disease with characteristic destructive processes in the intestinal wall. Although the pathomechanisms of CD are still not exactly understood, there is evidence that, in addition to e.g. bacterial colonisation, genetic predisposition contributes to the development of CD. In order to search for predisposing genetic factors we scrutinised 245 microsatellite markers in a population-based linkage mapping study. These microsatellites cover gene loci the encoded protein of which take part in the regulation of apoptosis and (innate) immune processes. Respective loci contribute to the activation/suppression of apoptosis, are involved in signal transduction and cell cycle regulators or they belong to the tumor necrosis factor superfamily, caspase related genes or the BCL2 family. Furthermore, several cytokines as well as chemokines were included. The approach is based on three steps: analyzing pooled DNAs of patients and controls, verification of significantly differing microsatellite markers by genotyping individual DNA samples and, finally, additional reinvestigation of the respective gene in the region covered by the associated microsatellite by analysing single-nucleotide polymorphisms (SNPs). Using this step-wise process we were unable to demonstrate evidence for genetic predisposition of the chosen apoptosis- and immunity-related genes with respect to susceptibility for CD

    Airway Microbiota and Pathogen Abundance in Age-Stratified Cystic Fibrosis Patients

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    Bacterial communities in the airways of cystic fibrosis (CF) patients are, as in other ecological niches, influenced by autogenic and allogenic factors. However, our understanding of microbial colonization in younger versus older CF airways and the association with pulmonary function is rudimentary at best. Using a phylogenetic microarray, we examine the airway microbiota in age stratified CF patients ranging from neonates (9 months) to adults (72 years). From a cohort of clinically stable patients, we demonstrate that older CF patients who exhibit poorer pulmonary function possess more uneven, phylogenetically-clustered airway communities, compared to younger patients. Using longitudinal samples collected form a subset of these patients a pattern of initial bacterial community diversification was observed in younger patients compared with a progressive loss of diversity over time in older patients. We describe in detail the distinct bacterial community profiles associated with young and old CF patients with a particular focus on the differences between respective “early” and “late” colonizing organisms. Finally we assess the influence of Cystic Fibrosis Transmembrane Regulator (CFTR) mutation on bacterial abundance and identify genotype-specific communities involving members of the Pseudomonadaceae, Xanthomonadaceae, Moraxellaceae and Enterobacteriaceae amongst others. Data presented here provides insights into the CF airway microbiota, including initial diversification events in younger patients and establishment of specialized communities of pathogens associated with poor pulmonary function in older patient populations
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