262 research outputs found

    Prediction of each road deterioration considering traffic and the interaction with other surface deteriorations, using automated learningmachine technics

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    For road user, the pavement is a surface that must allow the circulation of mixed traffic, in conditions of safety and comfort, under any climatic condition, for a long time. Once the pavement is in service, it begins to have deteriorations that can cause that the user modifies their behavior and start driving at a slower speed in order to maintain traffic safety conditions; this circumstance causes travel times increasing and therefore circulation costs increase. There are different deteriorations to consider, roughness, road surface adherence, rutting, cracking and potholes. Periodic deterioration evaluation and prediction modelling allows that corrective actions can be anticipated, so that road quality does not fall below acceptability limits. To prioritize improvements and routine maintenance, it is necessary to develop adequate tools to predict the deterioration evolution, which can be incorporated into the pavement management systems used to prepare multi-year works and maintenance plans. Periodic observations of surface deteriorations of sections in service located on routes of Littoral region of Argentina were usedin the paper. It was possible to develop predictive models using Support Vector Machine Regression SVR and Random Forest Regression RFR; these are learning machine tools, which can be used to solve estimation problems of multidimensional functions. First a model to predict cracking was developed. When it was optimized, the model to predict rutting was realized. And at the end, the model to predict roughness was adjusted, using cracking and rutting models developed previously. Results indicate that SVR and RFR regression models have the capacity to perform training and prediction that help to develop road surface deterioration models

    Desarrollo y empleo de juegos educativos on-line destinados al auto-entrenamiento y auto-evaluación

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    La implantación del EEES, está originando cambios en el modelo docente, cada vez más orientado al trabajo autónomo del alumno. Los contenidos electrónicos que apoyan el proceso de aprendizaje también deben, por tanto, orientarse a facilitar el aprendizaje autónomo, como por ejemplo los procesos de autoevaluación y auto-entrenamiento por parte del estudiante. Por ello, parece adecuado desarrollar contenidos electrónicos que motiven y a la vez entretengan de forma amena al alumnado durante su aprendizaje autónomo. En esta contribución, proponemos una serie de juegos educativos electrónicos como herramienta que haga de la auto-evaluación y del autoentrenamiento un proceso ameno y entretenido.Peer Reviewe

    Neuroimagen estructural y funcional en las enfermedades priónicas humanas

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    INTRODUCTION: Prion diseases are neurodegenerative disorders resulting from the accumulation of a misfolded isoform of the cellular prion protein (PrPc). They can occur as acquired, sporadic or hereditary forms. Although prion diseases show a wide range of phenotypic variations, pathological features and clinical evolution, they are all characterised by a common unfavourable course and a fatal outcome. REVIEW SUMMARY: Some variants, such as kuru, have practically disappeared, while others, for example the variant Creutzfeldt-Jakob (vCJD) or those attributable to iatrogenic causes, are still in force and pose a challenge to current medicine. There are no definitive pre-mortem diagnostic tests, except for vCJD, where a tonsil biopsy detects 100% of the cases. For this reason, diagnostic criteria dependent on statistical probability have had to be created. These require complementary examinations, such as an electroencephalogram (EEG) or the detection of 14-3-3 protein in cerebrospinal fluid (CSF). Only the "pulvinar sign" in magnetic resonance imaging (MRI) has been included as a vCJD diagnostic criterion. The present review discusses neuroimaging findings for each type of prion disease in patients with a definitive histopathological diagnosis. CONCLUSIONS: The aim is to define the usefulness of these complementary examinations as a tool for the diagnosis of this family of neurodegenerative diseases

    Solar active envelope module with an adjustable transmittance/absorptance

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    A solar active envelope module with a high flexibility degree is proposed in this paper. The transparent module controls the day-lighting of the room, improving the indoor environment, while absorbing the superfluous solar energy inside. That energy is used to increase the efficiency of heating, ventilation, and the air-conditioning (HVAC) system of the building. This is carried out through a fine control of the absorptance of the envelope module. The active envelope module consists of three glazed chambers with advanced coatings and frames to assure a minimum thermal transmittance while allowing transparency. A fluid containing heat-absorbing nanoparticles flows inside the central chamber and is heated up due to the impinging solar energy. Unlike other systems proposed in the past, which included transparency control systems based on complex filters and chemical processes, the absorption of the module is controlled by the variation of the thickness of the central chamber with a mechanical device. That is, varying the thickness of the central chamber, it allows controlling the absorptance of the whole system and, as a result, indoor day-lighting and thermal loads. Therefore, a new system is proposed that enables to

    Comparing heat flow models for interpretation of precast quadratic pile heat exchanger thermal response tests

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    This paper investigates the applicability of currently available analytical, empirical and numerical heat flow models for interpreting thermal response tests (TRT) of quadratic cross section precast pile heat exchangers. A 3D finite element model (FEM) is utilised for interpreting five TRTs by inverse modelling. The calibrated estimates of soil and concrete thermal conductivity are consistent with independent laboratory measurements. Due to the computational cost of inverting the 3D model, simpler models are utilised in additional calibrations. Interpretations based on semi-empirical pile G-functions yield soil thermal conductivity estimates statistically similar to those obtained from the 3D FEM inverse modelling, given minimum testing times of 60 hours. Reliable estimates of pile thermal resistance can only be obtained from type curves computed with 3D FEM models. This study highlights the potential of applying TRTs for sizing quadratic, precast pile heat exchanger foundations

    Theoretical estimates of the anapole magnetizabilities of C4H4X2 cyclic molecules for X=O, S, Se, and Te

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    Calculations have been carried out for C4H4X2 cyclic molecules, with X=O, S, Se, and Te, characterized by the presence of magnetic-field induced toroidal electron currents and associated orbital anapole moments. The orbital anapole induced by a static nonuniform magnetic field B, with uniform curl C =∇× B, is rationalized via a second-rank anapole magnetizability tensor aαβ , defined as minus the second derivative of the second-order interaction energy with respect to the components Cα and Bβ. The average anapole magnetizability a equals −χ, the pseudoscalar obtained by spatial averaging of the dipole-quadrupole magnetizability χα,βγ . It has different sign for D and L enantiomeric systems and can therefore be used for chiral discrimination. Therefore, in an isotropic chiral medium, a homogeneous magnetic field induces an electronic anapole Aα, having the same magnitude, but opposite sign, for two enantiomorphs.Fil: Pagola, Gabriel Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Ferraro, Marta Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Provasi, Patricio Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnologica; ArgentinaFil: Pelloni, Stefano. Universidad de Modena y Reggio Emilia. Departamento de Química; ItaliaFil: Lazzeretti, Paolo. Universidad de Modena y Reggio Emilia. Departamento de Química; Italia; Itali

    Multiphase CT Angiography Improves Prediction of Intracerebral Hemorrhage Expansion

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    Angiography; Intracerebral hemorrhage; PredictionAngiografía; Hemorragia intracerebral; PredicciónAngiografia; Hemorràgia intracerebral; PrediccióPurpose To determine the prevalence of the spot sign and the accuracy of using the spot sign to predict intracerebral hemorrhage (ICH) expansion with standardized multiphase computed tomographic (CT) angiography. Materials and Methods This prospective observational cohort study included 123 consecutive patients with acute ICH (onset 33% or >6 mL) at 24 hours. Associations between the presence of the spot sign and substantial hematoma expansion were assessed by using the Pearson χ2 test. Results The later the phase of CT angiography, the higher the frequency of the spot sign. The spot sign was seen in 29.3% of patients in phase 1, 43.1% of patients in phase 2, and 46.3% of patients in phase 3 (P B > C > D > no spot sign (P = .002). Conclusion Multiphase CT angiography can help differentiate among different forms of spot sign presentation and can help stratify patients at risk for hematoma expansion. The more arterial the spot sign pattern, the greater the frequency and extent of expansion

    Broad MICA/B expression in the small bowel mucosa: a link between cellular stress and celiac disease

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    The MICA/B genes (MHC class I chain related genes A and B) encode for non conventional class I HLA molecules which have no role in antigen presentation. MICA/B are up-regulated by different stress conditions such as heat-shock, oxidative stress, neoplasic transformation and viral infection. Particularly, MICA/B are expressed in enterocytes where they can mediate enterocyte apoptosis when recognised by the activating NKG2D receptor present on intraepithelial lymphocytes. This mechanism was suggested to play a major pathogenic role in active celiac disease (CD). Due to the importance of MICA/B in CD pathogenesis we studied their expression in duodenal tissue from CD patients. By immunofluorescence confocal microscopy and flow cytometry we established that MICA/B was mainly intracellularly located in enterocytes. In addition, we identified MICA/B+ T cells in both the intraepithelial and lamina propria compartments. We also found MICA/B+ B cells, plasma cells and some macrophages in the lamina propria. The pattern of MICA/B staining in mucosal tissue in severe enteropathy was similar to that found in in vitro models of cellular stress. In such models, MICA/B were located in stress granules that are associated to the oxidative and ER stress response observed in active CD enteropathy. Our results suggest that expression of MICA/B in the intestinal mucosa of CD patients is linked to disregulation of mucosa homeostasis in which the stress response plays an active role.Fil: Allegretti, Yessica Lorena. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biologicas. Laboratorio de Investigaciones del Sistema Inmune; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bondar, Constanza María. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biologicas. Laboratorio de Investigaciones del Sistema Inmune; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Guzmán, Luciana. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de la Plata; ArgentinaFil: Cueto Rua, Eduardo. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de la Plata; ArgentinaFil: Chopita, Nestor. Provincia de Buenos Aires. Hospital Interzonal General de Agudos Gral. San Martin; ArgentinaFil: Fuertes, Mercedes Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Zwirner, Norberto Walter. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología; ArgentinaFil: Chirdo, Fernando Gabriel. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biologicas. Laboratorio de Investigaciones del Sistema Inmune; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
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