478 research outputs found

    Dominance of the planktonic diatom Thalassiosira minima in recent summers in the Bahia Blanca Estuary, Argentina

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    The diatom Thalassiosira minima was first recorded in the Baha Blanca Estuary in 1992. In 19921993 it exhibited a broad seasonal occurrence. A recent survey (20062007) showed a seasonal appearance restricted mainly to summer together with a greater relative abundance within the phytoplankton. A close connection was found with warmer, more saline and highly turbid conditions experienced in recent summers in the estuary. Whether these changes will impact the estuary trophic dynamics remains an open question

    Smartphone-interrogated test supports for the enzymatic determination of putrescine and cadaverine in food

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    Diamino-oxidase (DAO), horseradish peroxidase (HRP), and tetramethylbenzidine (TMB) have been immobilized into cellulose to obtain circular cellulose test supports (CCTSs) for the determination of cadaverine (Cad) and putrescine (Put). During the enzymatic reaction, TMB is oxidized and a blue spot is obtained. This color (RGB coordinates) is measured with a smartphone and a commercial application. The highest sensitivity is provided by the component R and a linear response is observed for low biogenic amine (BA) concentrations, but a second-order polynomial response better fits the experimental results for a wider concentration range. This has been successfully explained with a model developed to explain the RGB values obtained in this type of analytical system. Optimization studies enable CCTSs to be obtained for Put and Cad determination, which could be used (kept at 4 °C) for at least 45 days if a stabilizer (StabilCoatℱ or StabilGuardℱ) is added during its synthesis. In these conditions, the R coordinate follows the model up to at least 4 × 10-4 M Put and/or Cad (both analytes give the same response). The method permits the Put and Cad determination from 5 × 10-5 M up to 4 × 10-4 M (RSD = 3%, n = 3). The CCTSs have been applied to Put + Cad determination in a tuna sample without any interference by other biogenic amines. The concentration found statistically agrees with that obtained using a HPLC-MS-validated method

    Physical and mathematical modeling of wave propagation in the Ariane 5 VEB structure

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    The separation of the lower stage of the ARIANE 5 Vehicle Equipment Bay (VEB) Structure is to be done using a pyrotechnic device. The wave propagation effects produced by the explosion can affect the electronic equipment, so it was decided to analyze, using both physical and numerical modeling, a small piece of the structure to determine the distribution of the accelerations and the relative importance of damping, stiffness, connections, etc. on the response of the equipment

    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: Guzmån, 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

    Conduite du changement et management par la qualitĂ© pour une meilleure dynamique de recherche finalisĂ©e : Retour d’expĂ©rience dans un laboratoire de recherche en horticulture et production de semences

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    Cet article issu d'un regard pluridisciplinaire (ingĂ©nierie des systĂšmes, sciences physiques, biologie, psychologie du travail, sciences de gestion et ergonomie), porte sur la conduite du changement Ă  travers un SystĂšme de management de la qualitĂ© (SMQ) au sein d'un laboratoire de recherche en biologie, avec comme focus principal les rĂ©sistances et les leviers. L'autre angle choisi concerne l'intĂ©rĂȘt d'un SMQ pour un laboratoire dans le but de fiabiliser les rĂ©sultats de recherche, anticiper et maĂźtriser les risques liĂ©s aux activitĂ©s de recherche et l'impact sur la cohĂ©sion et la motivation des personnes. Il est assorti d'exemples pratiques montrant les bĂ©nĂ©fices et les amĂ©liorations induites

    Accident causation and pre-accidental driving situations. Part 3. Summary report

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    This report aims to present the final results of the descriptive statistical, in-depth and risk analysis performed within TRACE Work Package ‘WP2-Type of situations’, in order to identify the main problems and the magnitude of these problems related to accident causation and risk factors for the following four types of situations: the stabilized situations, the specific manoeuvres, the intersection situations and the degraded situations. The different analysis (descriptive, in-depth and risk) of each of these five tasks has been performed using the available European accident databases within TRACE (national, in-depth and exposure databases). The objectives achieved in this WP are: ‱ Identify and quantify accident causation factors associated to particular types of driving and pre-accidental situations, at a statistical level, by analyzing various available databases in Europe. ‱ Obtain a focused understanding of accident causation issues related to these types of situations at an in-depth level by analyzing data from available in-depth databases. ‱ Identify the level of risk associated to these selected types of situation in causing accidents

    Accident causation and pre-accidental driving situations. Part 2. In-depth accident causation analysis

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    WP2 of the European Project TRACE is concerned with “Types of Situations” to analyse the causation of road traffic accidents from the pre-accidental driving situation point of view. Four complementary situations were defined: stabilized situations, intersection, specific manoeuvre and degradation scenario. To reach this objective, the analysis is based on a common methodology composed on 3 steps: the “descriptive analysis” which from general statistics will allow to identify among the studied situations those them relevant and to give their characteristics, the “in-depth analysis” allowing to obtain accident causes from the generic description of the problems identified in the previous step and the risk analysis identifying the risk of being involved in an accident taking into account the results obtained from the ‘in–depth’ level. This report is dedicated to the identification of the accident causes analysed for the pre-accidental driving situation point of view, i.e. the circumstances in which the driver is involved just prior the accident. This analysis has been conducted from the scenarios identified for each type of situation during the descriptive analysis realized in a first part (Report D2.1: Accident causation and pre-accidental driving situations. Part 1. Overview and general statistics). These results are based on the study of disaggregated data (in-depth accidents collection databases) available via WP8 in TRACE. With the identification of the main causes and contributing factor, the aspect related to the human functional failure has been taken into account. This innovative concept studied in TRACE WP5, has been used here in order to have a more complete overview of the problems in working on each road users involved in the accident and not only on the whole accident
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