1,502 research outputs found

    Diseño y desarrollo de un sistema basado en Learning Analytics para evaluar la competencia de trabajo en equipo.Design and development of a Learning Analytics System to evaluate group work competence

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    La adquisición de la competencia grupal es algo básico en la docencia universitaria. Esta tarea va a suponer evaluar diferentes factores en un número elevado de alumnos, lo que puede supone gran complejidad y un esfuerzo elevado. De cara a evitar este esfuerzo se puede pensar en emplear los registros de la interacción de los usuarios almacenados en las plataformas de aprendizaje. Para ello el presente trabajo se basa en el desarrollo de un sistema de Learning Analytics que es utilizado como herramienta para analizar las evidencias individuales de los distintos miembros de un equipo de trabajo. El trabajo desarrolla un modelo teórico apoyado en la herramienta, que permite relacionar las evidencias observadas de forma empírica para cada alumno, con indicadores obtenidos tanto de la acción individual como cooperativo de los miembros de un equipo realizadas a través de los foros de trabajo. Abstract — The development of the group work competence is something basic in university teaching. It should be evaluated, but this means to analyze different issues about the participation of a high number of students which is very complex and implies a lot of effort. In order to facilitate this evaluation it is possible to analyze the logs of students’ interaction in Learning Management Systems. The present work describes the development of a Learning Analytics system that analyzes the interaction of each of the members of working group. This tool is supported by a theoretical model, which allows establishing links between the empirical evidences of each student and the indicators of their action in working forums

    Fine-grained high-performance Ba0.85Ca0.15 Zr0.1Ti0.9O3 piezoceramics obtained by current-controlled flash sintering of nanopowders

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    Due to environmental concerns, extensive research has been carried out to develop high-performance lead-free piezoceramics capable of replacing commercial lead-based materials. The lead-free (Ba0.7Ca0.3)TiO3 -Ba(Zr0.2Ti0.8)O3 system has emerged as a candidate for room temperature transducer applications because a high piezoelectric charge coefficient is achieved in this system for compositions at the morphotropic phase boundary. However, conventional ceramic processing of these eco-friendly piezoceramics demands high energy consumption because long-lasting, high-temperature heat treatments are needed, which often lead to microstructural degradation that compromises the material reliability. Field-assisted flash sintering has started to be explored since the application of an adequate electric field was shown to significantly reduce the sintering time and temperature, thereby controlling grain growth. In this work, Ba0.85Ca0.15Zr0.1Ti0.9O3 ceramics are obtained by current-controlled flash sintering of mechanosynthesized nanopowders. Exhaustive control of the sintering parameters allows tailoring of the microstructure, which allows dense fine-grained flash-sintered ceramics exhibiting a high electric field-induced strain response to be obtained.This work was supported by the Agencia Estatal de Investigación (AEI), Spain, projects PGC2018-099158-B-I00 and PID2021–122708OB-C33. S. L-B. thanks Agència de Gestió d′Ajuts Universitaris i de Recerca (AGAUR), Catalonia, Spain, for the FI-SDUR contract (2020 FISDU 00489). The authors acknowledge the ESRF (The European Synchrotron) for provision of synchrotron radiation facilities, and we would like to thank the BM25 (SpLine) staff for assistance in using the beamline.Peer ReviewedPostprint (published version

    Promiscuous mismatch extension by human DNA polymerase lambda

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    DNA polymerase lambda (Pol λ) is one of several DNA polymerases suggested to participate in base excision repair (BER), in repair of broken DNA ends and in translesion synthesis. It has been proposed that the nature of the DNA intermediates partly determines which polymerase is used for a particular repair reaction. To test this hypothesis, here we examine the ability of human Pol λ to extend mismatched primer-termini, either on ‘open’ template-primer substrates, or on its preferred substrate, a 1 nt gapped-DNA molecule having a 5′-phosphate. Interestingly, Pol λ extended mismatches with an average efficiency of ≈10−2 relative to matched base pairs. The match and mismatch extension catalytic efficiencies obtained on gapped molecules were ≈260-fold higher than on template-primer molecules. A crystal structure of Pol λ in complex with a single-nucleotide gap containing a dG·dGMP mismatch at the primer-terminus (2.40 Å) suggests that, at least for certain mispairs, Pol λ is unable to differentiate between matched and mismatched termini during the DNA binding step, thus accounting for the relatively high efficiency of mismatch extension. This property of Pol λ suggests a potential role as a ‘mismatch extender’ during non-homologous end joining (NHEJ), and possibly during translesion synthesis

    Influencia del riego deficitario controlado precosecha sobre la calidad de la cereza ´Prime Giant`

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    El uso de redes de sensores para el manejo del riego deficitario controlado (RDC) en cerezo puede incidir en la mejora de la productividad del agua, calidad de la fruta y en su comportamiento poscosecha, al permitir el conocimiento y control del estado hídrico del suelo y árbol en todo momento. En el primer año de ensayo, el riego deficitario aplicado en precosecha para satisfacer el 85% de las necesidades máximas del cultivo (ETcg) permitió un ahorro de agua del 17% (380 m3 ha-1) respecto al tratamiento control, que se regó al 110% de la ETcg. Este déficit hídrico ligero no afectó a la producción (16,13 t ha-1) e incluso mejoró la calidad del fruto. Así, en el momento de la cosecha (t0) los frutos bajo déficit ligero presentaron matices más rojos y mayor acidez que los de riego completo. Esta mayor acidez no afectó al índice de madurez debido a la compensación por sólidos solubles totales (SST). El carácter de mayor acidez perduró tras 30 días de conservación en frio (t1) y 5 días de simulación de las condiciones de comercialización (t2). Igualmente, los frutos bajo déficit hídrico presentaron una tendencia a menores pérdidas de peso por deshidratación a finales de los periodos de conservación en frio y de simulación de la comercialización.Ministerio de Economía y Competitividad AGL2013-49047-C2-1

    Efecto del silenciamiento de genes que codifican poligalacturonasas sobre el reblandecimiento del fruto de fresa asociado a la maduración

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    La degradación de las pectinas de la pared celular mediada por poligalacturonasas juega un papel clave en el reblandecimiento de la fresa. Así, el silenciamiento del gen FaPG1 incrementa la firmeza del fruto maduro y alarga su vida postcosecha. Además de FaPG1, en fresa se ha descrito otro gen que codifica una poligalacturonasa específica de maduración, FaPG2. Con el fin de profundizar en el papel de estos genes, se han obtenido plantas transgénicas con el gen FaPG2 silenciado (líneas BPG), así como plantas con FaPG1 y FaPG2 silenciados (líneas ABPG), obtenidas mediante retransformación de una línea antiFaPG1 (APG29) que mostraba un fuerte silenciamiento del gen y un incremento en la firmeza de fruto. Se obtuvieron 24 líneas BPG y 15 ABPG. Estas plantas, junto con la línea APG29 y controles sin transformar, fueron analizadas durante 3 años consecutivos. El 50% de las líneas BPG mostraron mayor firmeza de fruto rojo que el control sin transformar, aunque el incremento en firmeza fue similar al obtenido en la línea APG29. Todas las líneas dobles transformantes dieron frutos de mayor firmeza que el control, siendo los valores ligeramente superiores a los de la línea APG29 en alguna de ellas. A nivel de expresión, las líneas BPG seleccionadas mostraron un silenciamiento del gen FaPG2 que varió entre el 60-70%, e inesperadamente, un silenciamiento significativo de FaPG1, a pesar de la baja homología entre ambos genes. El silenciamiento de FaPG1 en las líneas ABPG fue superior al 95%; sin embargo, el silenciamiento de FaPG2 fue similar al obtenido en las plantas BPG. Estos resultados confirman el papel clave de las poligalacturonasas en el reblandecimiento de la fresa y sugieren la existencia de una regulación compleja en la expresión de ambos genes. Este trabajo ha sido financiado por el proyecto AGL2011-24814 y Fondos FEDERUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    One-year, efficacy and safety open label study, with a single injection of a new hyaluronan for knee OA: the SOYA trial

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    [Abstract] Purpose. To assess the efficacy and safety of a single injection of a new formulation of hyaluronic acid (MPS-HA2%) in patients with symptomatic knee osteoarthritis after 12 months’ follow-up. Patients and Methods. Prospective, single-arm, multicentre, open-label, 12-month follow-up study. Patients with Kellgren–Lawrence (KL) 2–3 and visual analogue scale (VAS) pain scores of ≥40–< 80 mm received a single injection of MPS-HA2%. The primary outcome was the reduction in VAS pain scores from baseline, and the secondary outcomes were the Western Ontario and McMaster (WOMAC) Universities Osteoarthritis Index, the minimum clinically important improvement (MCII), and patient and investigator global assessments (PGA, IGA) measured on 5-point Likert scale. Adverse events were recorded throughout the study for safety purposes. Results. A total of 101 patients (mean age: 68 years; 74% female; and 78% overweight) were included. The mean reduction in pain at 12 months was 37.7%; the total WOMAC score improved by 36.5% and the pain, stiffness and physical function subscores returned improvements of 32.1%, 34.1% and 32.7%, respectively (p=0.0001 with respect to baseline). At 12 months, a statistically significant 62.2% of patients obtained an improvement equal to or greater than the MCII. The mean PGA score at baseline was 2.44 and 1.46 at 12 months (p<0.05), and the mean IGA scores at equivalent timepoints were 2.29 and 1.48 (p<0.05). Fourteen patients received a second injection at the 6-month follow-up visit. Eight patients reported a total of 12 treatment-related adverse events that were local, non-serious and of mild-to-moderate intensity. Conclusion. With just a single intra-articular injection, this not controlled trial suggests that MPS-HA2% is effective 12 months after the procedure in most cases. Patient tolerability and safety were both optimal (NCT03852914)

    DNA polymerase λ, a novel DNA repair enzyme in human cells

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    DNA polymerase lambda (pol λ) is a novel family X DNA polymerase that has been suggested to play a role in meiotic recombination and DNA repair. The recent demonstration of an intrinsic 5′-deoxyribose-5-phosphate lyase activity in pol A supports a function of this enzyme in base excision repair. However, the biochemical properties of the polymerization activity of this enzyme are still largely unknown. We have cloned and purified human pol A to homogeneity in a soluble and active form, and we present here a biochemical description of its polymerization features. In support of a role in DNA repair, pol λ inserts nucleotides in a DNA template-dependent manner and is processive in small gaps containing a 5′-phosphate group. These properties, together with its nucleotide insertion fidelity parameters and lack of proofreading activity, indicate that pol A is a novel β-like DNA polymerase. However, the high affinity of pol λ for dNTPs (37-fold over pol β) is consistent with its possible involvement in DNA transactions occurring under low cellular levels of dNTPs. This suggests that, despite their similarities, pol β and pol λ have nonredundant in vivo function

    High consumption of ultra-processed foods is associated with increased risk of micronutrient inadequacy in children: The SENDO project

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    Due to its rising prevalence, which parallels that of ultraprocessed food (UPF) consumption, inadequate micronutrient intake in childhood is a public health concern. This study aimed to evaluate the association between UPF consumption and inadequate intake of 20 micronutrients in a sample of children from the Mediterranean area. Cross-sectional information from participants in the “Seguimiento del Niño para un Desarrollo Óptimo” (SENDO) project 2015–2021 was used. Dietary information was gathered with a previously validated 147-item semi-quantitative food frequency questionnaire and the NOVA system was used to classify food items. Children were classifed by tertiles of energy intake from UPF. Twenty micronutrients were evaluated, and inadequate intake was defned using the estimated average requirement as a cutof. Crude and multivariable adjusted OR (95% CI) for the inadequacy of≥3 micronutrients associated with UPF consumption were calculated ftting hierarchical models to take into account intra-cluster correlation between siblings. Analyses were adjusted for individual and family confounders. This study included 806 participants (51% boys) with a mean age of 5 years old (SD: 0.90) and an average energy intake from UPF of 37.64% (SD: 9.59). An inverse association between UPF consumption and the intake of 15 out of the 20 micronutrients evaluated was found (p<0.01). After the adjustment for individual and family confounders, compared with children in the frst tertile of UPF consumption, those in the third tertile showed higher odds of inadequate intake of≥3 micronutrients (OR 2.57; 95%CI [1.51–4.40]). Conclusion: High UPF consumption is associated with increased odds of inadequate intake of micronutrients in childhood

    Aggregation-induced emission of [3]cumulenes functionalized with heptagon-containing polyphenylenes

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    This is accepted manuscript, the final published article is available in "García Jiménez, V.; et al. Aggregation-induced emission of [3]cumulenes functionalized with heptagon-containing polyphenylenes. Chemical Communications, online (2018). DOI: http://dx.doi.org/10.1039/C8CC00386FWe report the luminiscence at room temperature by aggregate formation of [3]cumulenes functionalized with propeller-like heptagon-containing polyphenylenes. These endgroups turn on the emission of a [3]cumulene by steric protection and restriction of their intramolecular rotations in the aggregates.European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (ERC-2015 -677023).Ministerio de Economía y Competitividad (MINECO, Spain – FEDER) (CTQ2015-70283-P, CTQ2014-53598-R, RyC-2013-12943).Fundação para a Ciência e a tecnologia (Portugal, IF/00759/2013, SFRH/BPD/75782/2011,SFRH/BPD/96707/2013,UID/NAN/50024/2013)

    Remote analysis of an open-pit slope failure: Las Cruces case study, Spain

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    Slope failures occur in open-pit mining areas worldwide, producing considerable damage in addition to economic loss. Identifying the triggering factors and detecting unstable slopes and precursory displacements ¿which can be achieved by exploiting remote sensing data¿ are critical for reducing their impact. Here we present a methodology that combines digital photogrammetry, satellite radar interferometry, and geo-mechanical modeling, to perform remote analyses of slope instabilities in open-pit mining areas. We illustrate this approach through the back analysis of a massive landslide that occurred in an active open-pit mine in southwest Spain in January 2019. Based on pre- and post-event high-resolution digital elevation models derived from digital photogrammetry, we estimate an entire sliding mass volume of around 14 million m3. Radar interferometry reveals that during the year preceding the landslide, the line of sight accumulated displacement in the slope reached ¿ 5.7 and 4.6 cm in ascending and descending geometry, respectively, showing two acceleration events clearly correlated with rainfall in descending geometry. By means of 3D and 2D stability analyses we located the slope instability, and remote sensing monitoring led us to identify the likely triggers of failure. Las Cruces event can be attributed to delayed and progressive failure mechanisms triggered by two factors: (i) the loss of historical suction due to a pore-water pressure increase driven by rainfall and (ii) the strain-softening behavior of the sliding material. Finally, we discuss the potential of this methodological approach either to remotely perform post-event analyses of mining-related landslides and evaluate potential triggering factors or to remotely identify critical slopes in mining areas and provide pre-alert warning.his work was supported by the Regional Administration of Madrid (Comunidad de Madrid) in the framework of the Industrial PhD Project GEODRON (IND2017/AMB-7789). It was also partially funded by the U-GEOHAZ project, co-funded by the European Commission, Directorate-General for Humanitarian Aid and Civil Protection (ECHO), under the call UCPM-2017-PP-AG, and E-SHAPE project co-funded by the European Union’s Horizon 2020 research and innovation program under grant agreements 820852
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