283 research outputs found

    First report of Tomato torrado virus on weed hosts in Spain

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    Alfaro Fernández, AO.; Córdoba-Sellés, C.; Cebrián, M.; Herrera-Vásquez, J.; Sanchez Navarro, JA.; Juárez, M.; Espino, A.... (2088). First report of Tomato torrado virus on weed hosts in Spain. Plant Disease. 92(5):831-831. https://doi.org/10.1094/pdis-92-5-0831b83183192

    Crowding of Polymer Coils and Demixing in Nanoparticle-Polymer Mixtures

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    The Asakura-Oosawa-Vrij (AOV) model of colloid-polymer mixtures idealizes nonadsorbing polymers as effective spheres that are fixed in size and impenetrable to hard particles. Real polymer coils, however, are intrinsically polydisperse in size (radius of gyration) and may be penetrated by smaller particles. Crowding by nanoparticles can affect the size distribution of polymer coils, thereby modifying effective depletion interactions and thermodynamic stability. To analyse the influence of crowding on polymer conformations and demixing phase behaviour, we adapt the AOV model to mixtures of nanoparticles and ideal, penetrable polymer coils that can vary in size. We perform Gibbs ensemble Monte Carlo simulations, including trial nanoparticle-polymer overlaps and variations in radius of gyration. Results are compared with predictions of free-volume theory. Simulation and theory consistently predict that ideal polymers are compressed by nanoparticles and that compressibility and penetrability stabilise nanoparticle-polymer mixtures.Comment: 18 pages, 4 figure

    NUEVAS APORTACIONES AL CATÁLOGO FAUNÍSTICO DE LOS QUIRONOMIDOS (DIPTERA: CHIRONOMIDAE) DEL PARQUE NACIONAL DE DOÑANA (SW DE ESPAÑA)

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    Twenty one species of chironomids have been recorded from Doñana National Park. Amongst these, 12 records are new for the area and 4 for the Iberian península. Total number of chironomid species known in the area rises to 35. A complete list of species including comments on their ecology and biogeography is includedEn los muestreos realizados para la ejecución del presente trabajo se han capturado ejemplares de 21 especies, de ellas 12 son nuevas citas para el Parque Nacional de Doñana y 4 para la Península Ibérica. Con la mencionada aportación, el número de especies de Quironómidos citados para el Parque asciende a 35. Se presenta una relación de las 21 especies capturadas con consideraciones de tipo ecológico y comentarios sobre las implicaciones biogeográficas de las especies más interesantes

    The Lamé Class of Lorenz Curves.

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    In this paper, the class of Lamé Lorenz curves is studied. This family has the advantage of modeling inequality with a single parameter. The family has a double motivation: it can be obtain from an economic model and from simple transformations of classical Lorenz curves. The underlying cumulative distribution functions have a simple closed form, and correspond to the Singh-Maddala and Dagum distributions, which are well known in the economic literature. The Lorenz order is studied and several inequality and polarization measures are obtained, including Gini, Donaldson-Weymark-Kakwani, Pietra and Wolfson indices. Some extensions of the Lamé family are obtained. Fitting and estimation methods under two different data configuration are proposed. Empirical applications with real data are given. Finally, some relationships with other curves are included.The authors thank to Ministerio de Econom a y Competitividad, project ECO2010-15455, for partial support. The second author thanks to the Ministerio de Educaci on (FPU AP-2010-4907) for partial support. We are grateful for the constructive suggestions provided by the reviewers, which improved the paper

    Estudio de la valoración del dolor articular y del grado de satisfacción,tras infiltración con plasma rico en fibrina en pacientes con artrosis de rodilla.

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    The definition of platelet rich plasma (PRP) is still controversial, though it can be described in general terms as ?a volumeof autologous plasma that contains a higher platelet concentration than the physiological basal concentration?. A retrospective observational analytical study was carried out in our hospital in order to assess the results and satisfaction of patients that had undergone PRF injection in knee. Between January and December of 2017, 80 gonoarthrosis patients treated with PRF injection were selected by the Orthopaedic Surgery and Rehabilitation Department, all of whom attended several medical appointments to check their recovery. Those cases that did not follow an appropriate clinical follow-up were dismissed from the study.Pain before treatment was assessed by the Numeric Rating Scale, with a mean of 8.48. A statistically significant decrease was observed after treatment (p<0.001), with a 4.87 mean and a 5.00 post-injection median. Regarding walking perimeter, most patients walked a median of 30 minutes and 55.3 minute mean, and their walking autonomy increased after treatment, doubling the median to 60 minutes, with an average of 93.15 minutes of pain-free walking. This 37.8 minute increase in the walking ability impliesa statistically significant improvement (p<0.001). A significant decrease in analgesics intake after treatment was also observed, being 81.3% patients who needed analgesia prior to treatment (n=61), and just 49.3% (n=37) after the procedure.Consequently,there is a significative improvement of pain, walking perimeter and absolute intake of analgesics that cannot be explained by any variable prior to PRF injection

    Climate-driven impacts of exotic species on marine ecosystems

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    Aim Temperature is fundamental to the physiological and ecological performance of marine organisms, but its role in modulating the magnitude of ecological impacts by exotic species remains unresolved. Here, we examine the relationship between thermal regimes in the range of origin of marine exotic species and sites of measured impact, after human-induced introduction. We compare this relationship with the magnitude of impact exerted by exotic species on native ecosystems. Location Global. Time period 1977–2017 (meta-analysis). Major taxa studied Marine exotic species. Methods Quantitative impacts of exotic species in marine ecosystems were obtained from a global database. The native range of origin of exotic species was used to estimate the realized thermal niche for each species and compared with the latitude and climatic conditions in recipient sites of recorded impact of exotic species. The difference in median temperatures between recipient sites and the thermal range of origin (i.e., thermal midpoint anomaly) was compared with the magnitude of effect sizes by exotic species on native species, communities and ecosystems. Results Recorded impacts occurred predominantly within the thermal niche of origin of exotic species, albeit with a tendency toward higher latitudes and slightly cooler conditions. The severity of impacts by exotic species on abundance of native taxa displayed a hump-shaped relationship with temperature. Peak impacts were recorded in recipient sites that were 2.2°C cooler than the thermal midpoint of the range of origin of exotic species, and impacts decreased in magnitude toward higher and lower thermal anomalies. Main conclusions Our findings highlight how temperature and climatic context influence ecological impacts by exotic species in marine ecosystems and the implications for existing and novel species interactions under climate change.En prensa5,14

    Progress in Detection and Projection of Climate Change in Spain since the 2010 CLIVAR-Spain regional climate change assessment report

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    The Iberian Peninsula region offers a challenging benchmark for climate variability studies for several reasons. It exhibits a wide variety of climatic regimes, ranging from wet Atlantic climates with annual precipitation around 2000 mm, to extensive semiarid regions with severe hydrological stress, to even cold alpine environments in some isolated areas

    A first-principles approach to electrical transport in atomic-scale nanostructures

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    We present a first-principles numerical implementation of Landauer formalism for electrical transport in nanostructures characterized down to the atomic level. The novelty and interest of our method lies essentially on two facts. First of all, it makes use of the versatile Gaussian98 code, which is widely used within the quantum chemistry community. Secondly, it incorporates the semi-infinite electrodes in a very generic and efficient way by means of Bethe lattices. We name this method the Gaussian Embedded Cluster Method (GECM). In order to make contact with other proposed implementations, we illustrate our technique by calculating the conductance in some well-studied systems such as metallic (Al and Au) nanocontacts and C-atom chains connected to metallic (Al and Au) electrodes. In the case of Al nanocontacts the conductance turns out to be quite dependent on the detailed atomic arrangement. On the contrary, the conductance in Au nanocontacts presents quite universal features. In the case of C chains, where the self-consistency guarantees the local charge transfer and the correct alignment of the molecular and electrode levels, we find that the conductance oscillates with the number of atoms in the chain regardless of the type of electrode. However, for short chains and Al electrodes the even-odd periodicity is reversed at equilibrium bond distances.Comment: 14 pages, two-column format, submitted to PR
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