174 research outputs found

    Los niveles glauconíticos de la Formación Salamanca, Chubut : su efectividad agronómica como fuente alternativa de fertilizante potásico

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    391-398The Maastrichtian-Early Palaeocene Salamanca Formation and equivalent marine sequences show several glaucony levels, which could be used as a source of potassium and could partially replace current fertilizer requirements met from import. First agronomic assays are shown comparing the efficiency of greensands (GL) with a traditional potassium fertilizer (KCl). Prospection and sampling took place in the heads of Rio Chico to east of Lago Colhué Huapi, Chubut, where glauconitic levels thickness reach to 20m. This research was separated in phases: phase 1, prospection, sampling, and sedimentological and chemical routine analyses, phase 2a, concentration and ore treatment assays, and phase 2b, agronomic assays. This last phase, was done in culture chamber, with 125 um and 250 um fractions (2,85 and 2,82 percent K 2O respectively) and KCl. Varying the dose, seven treatments were completed. In successive harvests (four in total) was observed that GL1 and GL2 (125), did not present a significantly differential behavior with the control. Both treatments of GL 250 um showed major accumulated biomass, overcoming the control in 44 and 60 percent respectively. As conclusion, better results were obtained by 250 um overcoming even to the KCl fertilization. Probably the major participation of K feldspars in the 125 um and fast leaching of K in this fraction during successive irrigations of soil would originate the minor observed yield. The great areal extension of the Salamanca Formation and the continuity of the glauconitic levels encourage continuing the evaluation as fertilizer or amendment

    Los niveles glauconíticos de la Formación Salamanca, Chubut : su efectividad agronómica como fuente alternativa de fertilizante potásico

    Get PDF
    391-398The Maastrichtian-Early Palaeocene Salamanca Formation and equivalent marine sequences show several glaucony levels, which could be used as a source of potassium and could partially replace current fertilizer requirements met from import. First agronomic assays are shown comparing the efficiency of greensands (GL) with a traditional potassium fertilizer (KCl). Prospection and sampling took place in the heads of Rio Chico to east of Lago Colhué Huapi, Chubut, where glauconitic levels thickness reach to 20m. This research was separated in phases: phase 1, prospection, sampling, and sedimentological and chemical routine analyses, phase 2a, concentration and ore treatment assays, and phase 2b, agronomic assays. This last phase, was done in culture chamber, with 125 um and 250 um fractions (2,85 and 2,82 percent K 2O respectively) and KCl. Varying the dose, seven treatments were completed. In successive harvests (four in total) was observed that GL1 and GL2 (125), did not present a significantly differential behavior with the control. Both treatments of GL 250 um showed major accumulated biomass, overcoming the control in 44 and 60 percent respectively. As conclusion, better results were obtained by 250 um overcoming even to the KCl fertilization. Probably the major participation of K feldspars in the 125 um and fast leaching of K in this fraction during successive irrigations of soil would originate the minor observed yield. The great areal extension of the Salamanca Formation and the continuity of the glauconitic levels encourage continuing the evaluation as fertilizer or amendment

    Elaboración de una Unidad Didáctica de apoyo a la enseñanza presencial de programas y guías de aprendizaje a través de las TIC

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    Una de las muchas competencias que un docente debe desarrollar para realizar una docencia de calidad es la planificación de sus asignaturas, lo cual en la Universidad de Deusto se verifica a través del programa y de la guía de aprendizaje. La elaboración de estos dos instrumentos requiere contar, no solo con cursos presenciales, sino con documentación de apoyo actualizada y fácilmente accesible. A través de un proyecto de innovación y gracias a la utilización de las TIC se ha diseñado, implementado y validado una “asignatura para docentes”, que acompaña a dichos cursos presenciales, en la plataforma institucional. La novedad no es el uso de la plataforma en sí, sino la forma en que se ha diseñado la Unidad Didáctica: siguiendo el ciclo de aprendizaje establecido en la Universidad, y utilizando metodologías activas, recursos variados y un proceso de evaluación formativa y feedback. De este modo, no solo se forma en contenidos, sino que se ofrece al profesorado una Unidad que le sirve como ejemplo de lo que se le pide desarrollar en sus propias asignaturas. Los resultados en cuanto a seguimiento de fases, cumplimiento de objetivos e indicadores de impacto han sido muy satisfactorios

    Prevalence of Helicobacter pylori infection and associated factors among adults in Southern Brazil: a population-based cross-sectional study

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    BACKGROUND: Helicobacter pylori (Hp) infection is associated with several upper gastrointestinal disorders. Local data on the epidemiology of the infection are scarce in Brazil. The purpose of this study is to measure the prevalence rate and to explore the associated factors among the adult population living in Pelotas, a southern Brazilin city. METHODS: This was a population-based cross-sectional study. Through a multi-stage sampling method all individuals 20 years and over living at the selected households at the urban area of the city were interviewed regarding past and current socio-economic indicators; demographic characteristics; nutritional and behavioural habits; and history of upper gastrointestinal symptoms.Hp infection was ascertained through the (13)C-UBT. Due to the high prevalence, data were analysed through robust Poisson regression. All analyses took into account the family clustering of the data. RESULTS: Among 563 eligible individuals, 363 agreed to perform the (13)C-UBT (refusal rate of 35.5%). Refusals were associated with female sex, consumption of mate drinking, and presence of upper gastrointestinal symptoms. The prevalence rate of H. pylori infection was 63.4% (95%CI 59.3%–69.3%). In crude analyses, prevalence was associated with increasing age, non-white skin colour, lower current family income, lower education level, higher size of the family, low socio-economic conditions in childhood, higher number of siblings and attendance to day-care centres in childhood, and presence of dyspeptic symptoms. In adjusted analysis the level of education of the father was inversely associated with the infection, whereas number of siblings and attendance to day-care centre in childhood were directly associated with it. Non-white skin colour remained significantly associated with increased prevalence even after allowing for past and current socio-economic characteristics, age and sex. Compared to non-symptomatic individuals, those reporting dyspeptic symptoms presented a higher prevalence of the infection even after allowing for current and past socio-economic conditions, ethnicity, age, and sex. CONCLUSION: Hp infection is as common among adults in southern Brazil as it is in other developing countries. Socio-economic conditions in childhood besides ethnicity and presence of dyspeptic symptoms were the factors significantly associated with the infection

    Changes of solar cell parameters during damp-heat exposure

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    The degradation of PV modules during damp-heat exposure is investigated. Power degradation is analysed in dependence of temperature and humidity during exposure. The module’s equivalent circuit parameters are calculated from I-V characteristics measured during ageing. A dose function is developed and degradations of power as well as equivalent circuit parameters can be analysed against the dose, which provides a better understanding of the module ageing behaviour. EL images of modules before and after ageing support the changes of solar cell parameters

    Evaluating Patterns of a White-Band Disease (WBD) Outbreak in Acropora palmata Using Spatial Analysis: A Comparison of Transect and Colony Clustering

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    . Likewise, there is little known about the spatiality of outbreaks. We examined the spatial patterns of WBD during a 2004 outbreak at Buck Island Reef National Monument in the US Virgin Islands. colonies with and without WBD.As the search for causation continues, surveillance and proper documentation of the spatial patterns may inform etiology, and at the same time assist reef managers in allocating resources to tracking the disease. Our results indicate that the spatial scale of data collected can drastically affect the calculation of prevalence and spatial distribution of WBD outbreaks. Specifically, we illustrate that higher resolution sampling resulted in more realistic disease estimates. This should assist in selecting appropriate sampling designs for future outbreak investigations. The spatial techniques used here can be used to facilitate other coral disease studies, as well as, improve reef conservation and management
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