1,412 research outputs found

    Leaf death in Araucaria araucana (Mol.) K. Koch seedlings due to freezing temperatures : preliminary results

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    En este trabajo se comunica la respuesta fenológica que experimenta el follaje de plantines de Araucaria araucana sometidos a cuatro niveles de temperaturas de congelamiento (-2°C, -6°C, -10°C y -15°C), inducidas durante la temporada de activo crecimiento vegetal. Para ello se utilizaron plantines de vivero y los distintos niveles de congelamiento fueron producidos en freezer mediante control por computador. Los resultados mostraron que, a tres semanas del tratamiento térmico, el 90% de los plantines de A. araucana mantuvieron vivas todas sus hojas hasta -6°C, mientras que al descender la temperatura del aire a -10°C o menos, los plantines presentaron porcentajes variables de hojas necrosadas hasta muerte total del follaje. En condiciones naturales, heladas tardías en el norte de Patagonia expondrían los plantines de A. araucana a consecuencias potencialmente letales. Por ello, un mayor conocimiento de la respuesta de A. araucana a extremos de frío resulta de particular utilidad para interpretar procesos de dinámica forestal y establecer pautas de manejo y conservación frente a escenarios de cambio climático.In this work we report the phenological response experienced by the foliage of A. araucana seedlings to four levels of freezing temperatures (-2 °C, -6 °C, -10 °C and -15°C) induced during the active plant growth season. Nursery seedlings were exposed to different frost levels in a freezer under computer control. The results showed that after three weeks of the thermal treatments, 90% of the A. araucana seedlings remained with living leaves at temperatures up to -6°C, whereas when the temperature decreased to -10°C or lower, the seedlings showed a variable percentage of dead leaves and even total death of the foliage. Under natural conditions, late frosts in northern Patagonia may expose seedlings of A. araucana to potentially lethal consequences. Therefore, a better understanding of the response of A. araucana to extreme low temperatures is particularly useful for interpreting forest dynamics processes and for management and conservation guidelines in relation to future climate change scenarios.Fil: Arco Molina, Julieta Gabriela. Universidad Nacional de CuyoFil: Hadad, Martín Ariel. Universidad Nacional de San JuanFil: Gonzalez Antivilo, Francisco. Universidad Nacional de CuyoFil: Roig, Fidel Alejandro. Universidad Nacional de Cuy

    Diseño de un itinerario para el desarrollo de competencias transversales en un grado de ingeniería electrónica: primeros pasos

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    Este trabajo recoge la motivación, metodología y primeros resultados de un proyecto de innovación educativa a dos años (2015-2017) que se está llevando a cabo en la Escuela Técnica Superior de Ingeniería de Telecomunicación de la Universidad de Málaga. El objetivo fundamental del proyecto es diseñar y poner en marcha un itinerario para abordar el desarrollo de las competencias transversales a lo largo de los grados. Hasta la fecha, se han cruzado las competencias generales que la legislación vigente impone con otros marcos competenciales de especial interés, como ABET o Eur-Ace. Este cruce ha permitido seleccionar un conjunto de competencias con las que comen-zar a trabajar. El estudio de los marcos nos ha ayudado también a profundizar en la caracterización docente de cada una de ellas (resultados de aprendizaje, actividades formativas y actividades de evaluación), paso previo a establecer el orden temporal para su desarrollo. Las dificultades encontra-das en esta tarea nos han llevado a proponer un modelo de desarrollo de competencias transversales que, en fases futuras del proyecto, el profesorado usará para, coordinadamente, incorporar nuevas competencias transversales a su docencia o formalizar las que ya desarrollaUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    EMTP model of a bidirectional cascaded multilevel solid state transformer for distribution system studies

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    This paper presents a time-domain model of a MV/LV bidirectional solid state transformer (SST). A multilevel converter configuration of the SST MV side is obtained by cascading a single-phase cell made of the series connection of an H bridge and a dual active bridge (dc-dc converter); the aim is to configure a realistic SST design suitable for MV levels. A three-phase four-wire converter has been used for the LV side, allowing the connection of both load/generation. The SST model, including the corresponding controllers, has been built and encapsulated as a custom-made model in the ATP version of the EMTP for application in distribution system studies. Several case studies have been carried out in order to evaluate the behavior of the proposed SST design under different operating conditions and check its impact on power qualityPostprint (published version

    The role of heart rate on the associations between body composition and heart rate variability in children with overweight/obesity : the ActiveBrains project

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    Background: Heart rate variability (HRV) is negatively associated with body mass index and adiposity in several populations. However, less information is available about this association in children with overweight and obesity, especially severe/morbid obesity, taking into consideration the dependence of HRV on heart rate (HR). Objectives: (1) to examine associations between body composition measures and HRV, (2) to study differences in HRV between children with overweight and severe/morbid obesity; and (3) to test whether relationships and differences tested in objectives 1 and 2, respectively are explained by the dependency of HRV on HR. Methods: A total of 107 children with overweight/obesity (58% boys, 10.03 +/- 1.13 years) participated in this study. Body composition measures were evaluated by Dual-energy X-ray absorptiometry (DXA). HRV parameters were measured with Polar RS800CXR (R). Results: Body composition measures were negatively associated with HRV indicators of parasympathetic activity (beta values ranging from -0.207 to -0.307, all p 0.05). Conclusion: All associations between adiposity/obesity and HRV could be explained by HR, suggesting a key confounding role of HR in HRV studies in children with weight disturbances

    Exposure of Developing Male Rats to One or Multiple Noise Sessions and Different Housing Conditions: Hippocampal Thioredoxin Changes and Behavioral Alterations

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    Exposure of developing rats to noise has shown to induce hippocampal-related behavioral alterations that were prevented after a week of housing in an enriched environment. However, neither the effect of repeated exposures nor its impact on key endogenous antioxidants had been studied yet. Thus, the aim of the present work was to reveal novel data about hippocampal oxidative state through the measurement of possible age-related differences in the levels of hippocampal thioredoxins in rats exposed to noise at different developmental ages and subjected to different schemes and housing conditions. In addition, the possibility that oxidative changes could underlie hippocampal-related behavioral changes was also analyzed. Developing male Wistar rats were exposed to noise for 2 h, either once or for 5 days. Upon weaning, some animals were transferred to an enriched cage for 1 week, whereas others were kept in standard cages. One week later, auditory and behavioral assessments, as well as measurement of hippocampal thioredoxin, were performed. Whereas no changes in the auditory function were observed, significant behavioral differences were found, that varied according to the age, scheme of exposure and housing condition. In addition, a significant increase in Trx-1 levels was found in all noise-exposed groups housed in standard cages. Housing animals in an enriched environment for 1 week was effective in preventing most of these changes. These findings suggest that animals become less susceptible to undergo behavioral alterations after repeated exposure to an environmental challenge, probably due to the ability of adaptation to an unfavorable condition. Moreover, it could be hypothesized that damage to younger individuals could be more easily prevented by a housing manipulation.Fil: Molina, Sonia Jazmín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Buján, Gustavo Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Cátedra de Farmacología; ArgentinaFil: Rodriguez Gonzalez, Monserrat. Universidad de Buenos Aires. Facultad de Medicina. Cátedra de Farmacología; ArgentinaFil: Capani, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Gomez Casati, Maria Eugenia. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia; ArgentinaFil: Guelman, Laura Ruth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentin

    Influence of plasma-generated negative oxygen ion impingement on magnetron sputtered amorphous SiO2 thin films during growth at low temperatures

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    Growth of amorphous SiO2 thin films deposited by reactive magnetron sputtering at low temperatures has been studied under different oxygen partial pressure conditions. Film microstructures varied from coalescent vertical column-like to homogeneous compact microstructures, possessing all similar refractive indexes. A discussion on the process responsible for the different microstructures is carried out focusing on the influence of (i) the surface shadowing mechanism, (ii) the positive ion impingement on the film, and (iii) the negative ion impingement. We conclude that only the trend followed by the latter and, in particular, the impingement of O- ions with kinetic energies between 20 and 200 eV, agrees with the resulting microstructural changes. Overall, it is also demonstrated that there are two main microstructuring regimes in the growth of amorphous SiO2 thin films by magnetron sputtering at low temperatures, controlled by the amount of O2 in the deposition reactor, which stem from the competition between surface shadowing and ion-induced adatom surface mobilityMinisterio de Innovación español-MAT 2007-65764Ministerio de Innovación español (CONSOLIDER INGENIO 2010)-CSD2008-00023Junta de Andalucía-TEP2275, TEP5283, P07-FQM-03298 y P10-FQM-690

    Muerte foliar en plantines de Araucaria araucana (Mol.) K. Koch por efecto de temperaturas de congelamiento. Resultados preliminares

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    In this work we report the phenological response experienced by the foliage of A. araucana seedlings to four levels of freezing temperatures (-2 ºC, -6 ºC, -10 ºC and -15ºC) induced during the active plant growth season. Nursery seedlings were exposed to different frost levels in a freezer under computer control. The results showed that after three weeks of the thermal treatments, 90% of the A. araucana seedlings remained with living leaves at temperatures up to -6ºC, whereas when the temperature decreased to -10ºC or lower, the seedlings showed a variable percentage of dead leaves and even total death of the foliage. Under natural conditions, late frosts in northern Patagonia may expose seedlings of A. araucana to potentially lethal consequences. Therefore, a better understanding of the response of A. araucana to extreme low temperatures is particularly useful for interpreting forest dynamics processes and for management and conservation guidelines in relation to future climate change scenarios.En este trabajo se comunica la respuesta fenológica que experimenta el follaje de plantines de Araucaria araucana sometidos a cuatro niveles de temperaturas de congelamiento (-2ºC, -6ºC, -10ºC y -15ºC), inducidas durante la temporada de activo crecimiento vegetal. Para ello se utilizaron plantines de vivero y los distintos niveles de congelamiento fueron producidos en freezer mediante control por computador. Los resultados mostraron que, a tres semanas del tratamiento térmico, el 90% de los plantines de A. araucana mantuvieron vivas todas sus hojas hasta -6ºC, mientras que al descender la temperatura del aire a -10ºC o menos, los plantines presentaron porcentajes variables de hojas necrosadas hasta muerte total del follaje. En condiciones naturales, heladas tardías en el norte de Patagonia expondrían los plantines de A. araucana a consecuencias potencialmente letales. Por ello, un mayor conocimiento de la respuesta de A. araucana a extremos de frío resulta de particular utilidad para interpretar procesos de dinámica forestal y establecer pautas de manejo y conservación frente a escenarios de cambio climático

    Impact of operatoŕs experience on peri-procedural outcomes with Watchman FLX: Insights from the FLX-SPA registry 2

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    Left atrial appendage; Occlusion; OutcomesApéndice auricular izquierdo; Oclusión; ResultadosApèndix auricular esquerre; Oclusió; ResultatsBackground The Watchman FLX is a device upgrade of the Watchman 2.5 that incorporates several design enhancements intended to simplify left atrial appendage occlusion (LAAO) and improve procedural outcomes. This study compares peri-procedural results of LAAO with Watchman FLX (Boston Scientific, Marlborough, Massachusetts) in centers with varying degrees of experience with the Watchman 2.5 and Watchman FLX. Methods Prospective, multicenter, “real-world” registry including consecutive patients undergoing LAAO with the Watchman FLX at 26 Spanish sites (FLX-SPA registry). Implanting centers were classified according to the center’s prior experience with the Watchman 2.5. A further division of centers according to whether or not they had performed ≤ 10 or > 10Watchman FLX implants was prespecified at the beginning of the study. Procedural outcomes of institutions stratified according to their experience with the Watchman 2.5 and FLX devices were compared. Results 359 patients [mean age 75.5 (SD8.1), CHA2DS2-VASc 4.4 (SD1.4), HAS-BLED 3.8(SD0.9)] were included. Global success rate was 98.6%, successful LAAO with the first selected device size was achieved in 95.5% patients and the device was implanted at first attempt in 78.6% cases. There were only 9(2.5%) major peri-procedural complications. No differences in efficacy or safety results according to the centeŕs previous experience with Watchman 2.5 and procedural volume with Watchman FLX existed. Conclusions The Watchman FLX attains high procedural success rates with complete LAA sealing in unselected, real-world patients, along with a low incidence of peri-procedural complications, regardless of operatoŕs experience with its previous device iteration or the number of Watchman FLX devices implanted

    Additive Manufacturing of Gold Nanostructures Using Nonlinear Photoreduction under Controlled Ionic Diffusion

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    Multiphoton photoreduction of photosensitive metallic precursors via direct laser writing (DLW) is a promising technique for the synthesis of metallic structures onto solid substrates at the sub-micron scale. DLW triggered by a two photon absorption process is done using a femtosecond NIR laser (lambda = 780 nm), tetrachloroauric acid (HAuCl4) as a gold precursor, and isinglass as a natural hydrogel matrix. The presence of a polymeric, transparent matrix avoids unwanted diffusive processes acting as a network for the metallic nanoparticles. After the writing process, a bath in deionized water removes the gold precursor ions and eliminates the polymer matrix. Different aspects underlying the growth of the gold nanostructures (AuNSs) are here investigated to achieve full control on the size and density of the AuNSs. Writing parameters (laser power, exposure time, and scanning speed) are optimized to control the patterns and the AuNSs size. The influence of a second bath containing Au3+ to further control the size and density of the AuNSs is also investigated, observing that these AuNSs are composed of individual gold nanoparticles (AuNPs) that grow individually. A fine-tuning of these parameters leads to an important improvement of the created structures' quality, with a fine control on size and density of AuNSs.W.D.C. and M.G. acknowledge the support of the CNR Facility Beyond-Nano-Polo di Cosenza. W.D.C. acknowledges MIUR (Ministero dell'Istruzione, dell'Universita e della Ricerca-Italy) for her industrial PhD grant (PONa3_00362). This work was also funded by Ministry of Science, Innovation and Universities (project TEC2017-86102-C2-2-R) and Junta de Andalucia (Research group INNANOMAT, ref. TEP-946). Co-funding from UE is also acknowledged. A.S.d.L. and M.d.l.M. acknowledge Ministry of Science, Innovation and Universities for their Juan de la Cierva Incorporacion postdoctoral fellowships (IJC2019-041128-I, IJCI-2017-31507). SEM and TEM measurements were carried out at the DME-SC-ICyT-ELECMI-UCA. Documen

    Osteoarticular Expression of Musashi-1 in an Experimental Model of Arthritis

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    Background. Collagen-induced arthritis (CIA), a murine experimental disease model induced by immunization with type II collagen (CII), is used to evaluate novel therapeutic strategies for rheumatoid arthritis. Adult stem cell marker Musashi-1 (Msi1) plays an important role in regulating the maintenance and differentiation of stem/precursor cells. The objectives of this investigation were to perform a morphological study of the experimental CIA model, evaluate the effect of TNFα-blocker (etanercept) treatment, and determine the immunohistochemical expression of Msi1 protein. Methods. CIA was induced in 50 male DBA1/J mice for analyses of tissue and serum cytokine; clinical and morphological lesions in limbs; and immunohistochemical expression of Msi1. Results. Clinically, TNFα-blocker treatment attenuated CIA on day 32 after immunization (). Msi1 protein expression was significantly higher in joints damaged by CIA than in those with no lesions () and was related to the severity of the lesions (Spearman’s rho = 0.775, ). Conclusions. Treatment with etanercept attenuates osteoarticular lesions in the murine CIA model. Osteoarticular expression of Msi1 protein is increased in joints with CIA-induced lesion and absent in nonlesioned joints, suggesting that this protein is expressed when the lesion is produced in order to favor tissue repair.This investigation was partially supported by Research Group #CTS-138 (Junta de Andalucía, Spain)
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