1,887 research outputs found

    Challenges of a College Tutor

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    AbstractThis paper explains the changes that have emerged in recent years in Europe and Latin America about the universities, and therefore the challenges teachers are faced with, in order to become good tutors. The tutor's challenges are divided into pedagogical, social, administrative, and technical. The conclusion from reviewing the literature is that there are five main challenges for the tutors, which have to do with the mastery of his subject, creating a learning atmosphere, knowing the administrative processes, having the knowledge for instructional design, and the most complex of all, the efficient use of Information and Communications Technology (ICT)

    The use of public support on internationalization activities, firms competencies and internationalization requirements

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    In particularly in times of budget constraints governments should analyze in detail all aspects related to the implementation of their public support to enterprises. With an Heckman selection model and data collected through a survey to Portuguese firms, we test which variables may affect awareness and use of the public support to internationalization. The results show that firms’ competencies positively affect awareness and negatively affect use of public support. Otherwise, the requirements of internationalization positively affect both the awareness and the use of public support

    Linefish resources annual report for the year 2000. Part 1: fisheries assessment

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    This work reflects the activities of line and trap fishing in Southern Mozambique in 2000. The catch in line fishing has been estimated at 441 mt, according to the DNAP records. The same sources indicated that 1767 days were spent at sea and the estimated catch rate was 250 Kg per boaticlay. Most of the line fishing effort shifted away from Maputo and moved to Inhambane region. The monthly analysis of fishing vessels, stricter controls over catch and effort data submission, development of long-term research programme and the continuation of the on board sampling to improve the data collection are the recommendation for line fishing. The catch of trap vessels increases from 30mt in 1997 to 172 mt in 2000, during which the total number of traps increased from 25 to 300. During this time the number of fishing days has remained relatively constant, as well the soak time. These data sets are thus not compatible with each other, reflecting an increase in daily catch from 243 Kg to 791 kg. The species composition is mainly dominated by P. coeruleopunctatus, C. puniceus, C. nufar and E. andersoni

    Automatic learning for the system identification. A case study in the prediction of power generation in a wind farm

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    [EN] One of the greatest technical challenges of today is obtaining predictive models for complex systems. In this paper we propose using data collected during a process to identify said process by means of automatic learning algorithms. Specifically, we describe the development of a project to determine the predictive model of a system based on supervised automatic learning algorithms. As an example, we use the problem of determining the energy generated in a wind farm. We do so by studying how the data collected are transformed, the search for the best algorithm, how to determine its goodness, and finally, the training and adjustment of the selected model. This study relies on the Python programming language, which has libraries that facilitate this type of project, and the Jupyter Notebook environment to carry out the project and disseminate the results.[ES] Uno de los mayores desafíos tecnológicos de la actualidad es la obtención de modelos predictivos de sistemas complejos. En este artículo se propone darle valor a los datos recogidos sobre un proceso utilizándolos para la identificación del mismo mediante el empleo de algoritmos de aprendizaje automático. En concreto, se describe el desarrollo de un proyecto de determinación del modelo predictivo de un sistema, a partir de algoritmos de aprendizaje automático supervisado, usando como ejemplo el problema de determinar la generación de energía de un campo eólico. Para ello se estudian las transformaciones a realizar a los datos recogidos, la búsqueda del mejor algoritmo, cómo determinar la bondad del mismo y, finalmente, el entrenamiento y a juste del modelo seleccionado. Todo ello usando el lenguaje de programación Python, que dispone de librerías que facilitan este tipo de proyectos, y en el entorno de Jupyter Notebook para realiza el proyecto y divulgar los resultados.Este trabajo ha sido financiado por el Ministerio de Ciencia,Innovación y Universidades a través del proyecto titulado “Gestión de Redes Eléctricas Inteligentes con estimación De producción de Energías Renovables basado en modelos mesoescalaresde alta resolución - GRIDER”, RTC-2017-6409-3Aguilar, R.; Torres, J.; Martín, C. (2018). Aprendizaje Automático en la Identificación de Sistemas. Un Caso de Estudio en la Predicción de la Generación Eléctrica de un Parque Eólico. Revista Iberoamericana de Automática e Informática. 16(1):114-127. https://doi.org/10.4995/riai.2018.9421SWORD11412716

    Modeling and behavior of the simulation of electric propagation during deep brain stimulation

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    Deep brain stimulation (DBS) is an effective treatment for Parkinson's disease. In the literature, there are a wide variety of mathematical and computational models to describe electric propagation during DBS; however unfortunately, there is no clarity about the reasons that justify the use of a specific model. In this work, we present a detailed mathematical formulation of the DBS electric propagation that supports the use of a model based on the Laplace Equation. Moreover, we performed DBS simulations for several geometrical models of the brain in order to determine whether geometry size, shape and ground location influence electric stimulation prediction by using the Finite Element Method (FEM). Theoretical and experimental analysis show, firstly, that under the correct assumptions, the Laplace equation is a suitable alternative to describe the electric propagation, and secondly, that geometrical structure, size and grounding of the head volume affect the magnitude of the electric potential, particularly for monopolar stimulation. Results show that, for monopolar stimulation, basic and more realistic models can differ more than 2900%

    Patient reported outcome measure in atopic dermatitis patients treated with dupilumab: 52-weeks results

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    Dupilumab is used to treat atopic dermatitis (AD) patients who have proven to be refractory to previous treatments. The aim of this study was to assess evolution and patient reported outcome measures in adult patients with moderate-to-severe AD treated with dupilumab in routine clinical practice. The outcomes were evaluated and registered at baseline and weeks 16, 40 and 52. The variables evaluated were: disease severity, pruritus, stressful life events, difficulty to sleep, anxiety and depression, quality of life, satisfaction, adherence to the treatment, efficacy and safety. Eleven patients were recruited between 14 Nov 2017 and 16 Jan 2018. Demographic variables: 90% Caucasian, 82% women. Clinical variables: Mean duration of AD = 17.7 (±12.8), 91% had severe disease severity. At baseline, SCORAD median (range) score = 69.2 (34.8–89.2); itch was reported by 100% of patients; itch visual analogue scale median (range) was 9 (6–10); HADS median (range) total score = 13 (5–21); DLQI mean score = 16 (2–27); EQ-5D-3L median (range) = 57 (30–99). At week- 52 there was a significant reduction of SCORAD scores median (range) = 4.3 (0–17.1), HADS total score median (range) = 2 (0–10) and improved quality of life EQ-5D-3L median (range) = 89 (92–60). This study confirms that dupilumab, used for 52-weeks under routine clinical practice, maintains the improved atopic dermatitis signs and symptoms obtained at week 16, with a good safety profile. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    A wavelet analysis of the Rosenblatt process: chaos expansion and estimation of the self-similarity parameter

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    By using chaos expansion into multiple stochastic integrals, we make a wavelet analysis of two self-similar stochastic processes: the fractional Brownian motion and the Rosenblatt process. We study the asymptotic behavior of the statistic based on the wavelet coefficients of these processes. Basically, when applied to a non-Gaussian process (such as the Rosenblatt process) this statistic satisfies a non-central limit theorem even when we increase the number of vanishing moments of the wavelet function. We apply our limit theorems to construct estimators for the self-similarity index and we illustrate our results by simulations

    Application of mineralogical, petrological and geochemical tools for evaluating the palaeohdrogeological evolution of the PADAMOT study sites

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    The role of Work Package (WP) 2 of the PADAMOT project – ‘Palaeohydrogeological Data Measurements’ - has been to study late-stage fracture mineral and water samples from groundwater systems in Spain, Sweden, United Kingdom and the Czech Republic, with the aim of understanding the recent palaeohydrogeological evolution of these groundwater systems. In particular, the project sought to develop and evaluate methods for obtaining information about past groundwater evolution during the Quaternary (about the last 2 million years) by examining how the late-stage mineralization might record mineralogical, petrographical and geochemical evidence of how the groundwater system may have responded to past geological and climatological changes. Fracture-flow groundwater systems at six European sites were studied: • Melechov Hill, in the Bohemian Massif of the Czech Republic: a shallow (0-100 m) dilute groundwater flow system within the near-surface weathering zone in fractured granitic rocks; • Cloud Hill, in the English Midlands: a (~100 m) shallow dilute groundwater flow system in fractured and dolomitized Carboniferous limestone; • Los Ratones, in southwest Spain: an intermediate depth (0-500 m) dilute groundwater flow system in fractured granitic rocks; • Laxemar, in southeast Sweden: a deep (0-1000 m) groundwater flow system in fractured granitic rocks. This is a complex groundwater system with potential recharge and flushing by glacial, marine, lacustrine and freshwater during the Quaternary; • Sellafield, northwest England: a deep (0-2000 m) groundwater flow system in fractured Ordovician low-grade metamorphosed volcaniclastic rocks and discontinuous Carboniferous Limestone, overlain by a Permo-Triassic sedimentary sequence with fracture and matrix porosity. This is a complex coastal groundwater system with deep hypersaline sedimentary basinal brines, and deep saline groundwaters in crystalline basement rocks, overlain by a shallow freshwater aquifer system. The site was glaciated several times during the Quaternary and may have been affected by recharge from glacial meltwater; • Dounreay, northeast Scotland: a deep (0-1400 m) groundwater flow system in fractured Precambrian crystalline basement overlain by fractured Devonian sedimentary rocks. This is within the coastal discharge area of a complex groundwater system, comprising deep saline groundwater hosted in crystalline basement, overlain by a fracture-controlled freshwater sedimentary aquifer system. Like Sellafield, this area experienced glaciation and may potentially record the impact of glacial meltwater recharge. In addition, a study has been made of two Quaternary sedimentary sequences in Andalusia in southeastern Spain to provide a basis of estimating the palaeoclimatic history of the region that could be used in any reconstruction of the palaeoclimatic history at the Los Ratones site: • The Cúllar-Baza lacustrine sequence records information about precipitation and palaeotemperature regimes, derived largely from the analysis of the stable isotope (δ18O and δ13C) signatures from biogenic calcite (ostracod shells). • The Padul Peat Bog sequence provided information on past vegetation cover and palaeogroundwater inputs based on the study of fossil pollen and biomarkers as proxies for past climate change. Following on from the earlier EC 4th Framework EQUIP project, the focus of the PADAMOT studies has been on calcite mineralization. Calcite has been identified as a late stage mineral, closely associated with hydraulically-conductive fractures in the present-day groundwater systems at the Äspö-Laxemar, Sellafield, Dounreay and Cloud Hill sites. At Los Ratones and Melechov sites late-stage mineralization is either absent or extremely scarce, and both the quantity and fine crystal size of any late-stage fracture mineralization relevant to Quaternary palaeohydrogeological investigations is difficult to work with. The results from the material investigated during the PADAMOT studies indicate that the fracture fillings at these sites are related to hydrothermal activity, and so do not have direct relevance as Quaternary indicators. Neoformed calcite has not been found at these two sites at the present depth of the investigations. Furthermore, the HCO3 - concentration in all the Los Ratones groundwaters is mainly controlled by complex carbonate dissolution. The carbonate mineral saturation indices do not indicate precipitation conditions, and this is consistent with the fact that neoformed calcite, ankerite or dolomite have not been observed petrographically

    UV spectrophotometry method for the monitoring of galacto-oligosaccharides production

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    Monitoring the industrial production of galacto-oligosaccharides (GOS) requires a fast and accurate methodology able to quantify, in real time, the substrate level and the product yield. In this work, a simple, fast and inexpensive UV spectrophotometric method, together with partial least squares regression (PLS) and artificial neural networks (ANN), was applied to simultaneously estimate the products (GOS) and the substrate (lactose) concentrations in fermentation samples. The selected multiple models were trained and their prediction abilities evaluated by cross-validation and external validation being the results obtained compared with HPLC measurements. ANN models, generated from absorbance spectra data of the fermentation samples, gave, in general, the best performance being able to accurately and precisely predict lactose and total GOS levels, with standard error of prediction lower than 13 g kg-1 and coefficient of determination for the external validation set of 0.93–0.94, showing residual predictive deviations higher than five, whereas lower precision was obtained with the multiple model generated with PLS. The results obtained show that UV spectrophotometry allowed an accurate and non-destructive determination of sugars in fermentation samples and could be used as a fast alternative method for monitoring GOS production

    Morphological and electrophysiological properties of pyramidal-like neurons in the stratum oriens of Cornu ammonis 1 and Cornu ammonis 2 area of Proechimys

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    AbstractProechimys (Rodentia: Echimyidae) is a neotropical rodent of the Amazon region that has been successfully colonized in the laboratory and used for experimental medicine. Preliminary studies indicated that Proechimys (casiragua) rodents express an atypical resistance to developing a chronic epileptic condition in common models of temporal lobe epilepsy. Moreover, previous investigation of our laboratory described a remarkably different Proechimy's cytoarchitecture organization of the hippocampal CA2 subfield. In the present study, we investigated the intrinsic neuronal properties and morphological characteristics of the Proechimys's hippocampal pyramidal neurons of the CA1 and CA2 areas. A comparative approach was performed using neurons recorded in Wistar rats. A striking finding in Proechimys rodents was the presence of large pyramidal-like neurons throughout the stratum oriens from CA2 to CA1 area. In order to confirm such distinctive feature of the Proechimys's hippocampus, we performed Nissl staining and immunohistochemistry for neurofilament protein SM311. CA2 pyramidal neurons in the stratum pyramidale of Proechimys exhibited a significantly higher input resistance and lower time constant when compared to corresponding cell groups in the same area of the Wistar rat's. This newly identified population of pyramidal-shaped neurons in stratum oriens of Proechimys exhibited distinct electrophysiological and morphological properties. This included larger capacitance, lower input resistance, larger rheobase, long latency to first action potential and slower firing frequency. In addition, the apical dendrites of these neurons were oriented in parallel to apical dendrites of regular pyramidal neurons in stratum pyramidale. Moreover, these neurons were immunoreactive to SM311 as the majority of the neurons of the pyramidal layer. The functional role of these hippocampal neurons of the rodent Proechimys deserves further investigation
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