2,103 research outputs found

    Efecto de factores contextuales en la composición corporal de jugadores profesionales de fútbol. Un estudio retrospectivo

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    La exigencia de las demandas físicas en el fútbol ha evolucionado en los últimos años, poniendo de manifiesto la necesidad de investigar sobre aquellos aspectos que condicionan el rendimiento deportivo. Es por esto que el objetivo de este estudio fue describir la incidencia del entrenamiento individualizado, la compañía en las comidas, la raza y la demarcación sobre las variables antropométricas en jugadores de fútbol profesional. Para ello se desarrolló un estudio retrospectivo sobre 51 jugadores profesionales de la Segunda División B española durante las temporadas de 2015/2016, 2016/2017 y 2017/2018. La valoración antropométrica se realizó bajo las normas técnicas de medición recomendadas por el International Working Group of Kinanthropometry, adoptadas por la International Society for the Advancement of Kinanthropometry (ISAK). Los resultados revelaron que el entrenamiento individualizado y la compañía en las comidas fueron los factores que más influyeron sobre las variables antropométricas. Los valores de masa grasa y de masa muscular, y el sumatorio de pliegues son sensibles al efecto de la intervención sobre dichos factores. Los mayores niveles de interacción se producen entre la compañía en las comidas y el entrenamiento individualizado, y entre la demarcación y la compañía en las comidas. Considerando la composición corporal como un aspecto a tener en cuenta en el desarrollo del rendimiento, se concluye que la aplicación de ciertos contenidos del entrenamiento según las características individuales y el estilo de vida de los jugadores es un factor que posee una influencia significativa sobre los futbolistas profesionales

    Awareness, treatment and control of hypertension: Trend from population-based surveys conducted in a low-middle income country

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    Aim: To estimate and determine temporal trends for awareness, treatment and control of hypertension in adults from the urban area in Colombia. Methods: We conducted two population-based surveys (years 2010 and 2015) in the Metropolitan Area of Bucaramanga-Santander, Colombia, using the WHO STEPwise approach. Participants were asked to provide demographic, socioeconomic and cardiovascular risk factors data. Blood pressure (BP) was measured twice using an automated device. Hypertension was defined as a systolic BP≥140 mmHg, a diastolic BP≥90 mmHg or self-reported antihypertensive treatment. We estimated age, sex, and socioeconomic status (SES) adjusted prevalence ratios (PR), with 2010 as the reference survey, using poisson regression and correcting standard errors by clustering. Results: We evaluated 1,136 (mean age: 35.7 years; 43% male) and 872 (mean age:37.7 years; 41% male) adults from the 2010 and 2015 surveys, respectively. There were a larger proportion of individuals sampled from low SES in the 2015 as compared to the 2010 survey (93.6% vs. 70.9%). Overall, prevalence of hypertension was 16.4% (95%CI: 14.8 – 17.9): It increased significantly with age (from 2.4% among individuals 15-19 years old to 41.1% among individuals 50 years and older; p-trend<0.001) but did not differed by sex (17.8% in men vs. 15.4% in women) or year (16.1% vs. 16.6% in 2010 and 2015, respectively). Overall, prevalence of awareness, treatment and control of hypertension were 65.0%, 84.1%, and 62.2%, respectively. Although awareness and control increased from 2010 to 2015 (PR=1.05 and PR=1.12, respectively), only the prevalence of treatment showed a statistically significant increment of 11% (PR=1.11; 95%IC: 1.01 – 1.24). Implication: The STEPwise is a suitable surveillance strategy to estimate the burden of cardiovascular risk factors in low-middle income countries. Our results are consistent with national data from urban areas and show for the first time a short-time improvement in antihypertensive coverage

    Updating known distribution models for forecasting climate change impact on endangered species

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    To plan endangered species conservation and to design adequate management programmes, it is necessary to predict their distributional response to climate change, especially under the current situation of rapid change. However, these predictions are customarily done by relating de novo the distribution of the species with climatic conditions with no regard of previously available knowledge about the factors affecting the species distribution. We propose to take advantage of known species distribution models, but proceeding to update them with the variables yielded by climatic models before projecting them to the future. To exemplify our proposal, the availability of suitable habitat across Spain for the endangered Bonelli’s Eagle (Aquila fasciata) was modelled by updating a pre-existing model based on current climate and topography to a combination of different general circulation models and Special Report on Emissions Scenarios. Our results suggested that the main threat for this endangered species would not be climate change, since all forecasting models show that its distribution will be maintained and increased in mainland Spain for all the XXI century. We remark on the importance of linking conservation biology with distribution modelling by updating existing models, frequently available for endangered species, considering all the known factors conditioning the species’ distribution, instead of building new models that are based on climate change variables only.Ministerio de Ciencia e Innovación and FEDER (project CGL2009-11316/BOS

    Macro-Climatic Distribution Limits Show Both Niche Expansion and Niche Specialization among C4 Panicoids

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    Grasses are ancestrally tropical understory species whose current dominance in warm open habitats is linked to the evolution of C4 photosynthesis. C4 grasses maintain high rates of photosynthesis in warm and water stressed environments, and the syndrome is considered to induce niche shifts into these habitats while adaptation to cold ones may be compromised. Global biogeographic analyses of C4 grasses have, however, concentrated on diversity patterns, while paying little attention to distributional limits. Using phylogenetic contrast analyses, we compared macro-climatic distribution limits among ~1300 grasses from the subfamily Panicoideae, which includes 4/5 of the known photosynthetic transitions in grasses. We explored whether evolution of C4 photosynthesis correlates with niche expansions, niche changes, or stasis at subfamily level and within the two tribes Paniceae and Paspaleae. We compared the climatic extremes of growing season temperatures, aridity, and mean temperatures of the coldest months. We found support for all the known biogeographic distribution patterns of C4 species, these patterns were, however, formed both by niche expansion and niche changes. The only ubiquitous response to a change in the photosynthetic pathway within Panicoideae was a niche expansion of the C4 species into regions with higher growing season temperatures, but without a withdrawal from the inherited climate niche. Other patterns varied among the tribes, as macro-climatic niche evolution in the American tribe Paspaleae differed from the pattern supported in the globally distributed tribe Paniceae and at family level.Fil: Aagesen, Lone. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Biganzoli, Fernando. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bena, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Godoy Bürki, Ana Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Reinheimer, Renata. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Zuloaga, Fernando Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentin

    Feeding spectra and activity of the freshwater crab Trichodactylus kensleyi (Decapoda: Brachyura: Trichodactylidae) at La Plata basin

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    Background: In inland water systems, it is important to characterize the trophic links in order to identify the ‘trophic species’ and, from the studies of functional diversity, understand the dynamics of matter and energy in these environments. The aim of this study is to analyze the natural diet of Trichodactylus kensleyi of subtropical rainforest streams and corroborate the temporal variation in the trophic activity during day hours. Results: A total of 15 major taxonomic groups were recognized in gut contents. The index of relative importance identified the following main prey items in decreasing order of importance: vegetal remains, oligochaetes, chironomid larvae, and algae. A significant difference was found in the amount of full stomachs during day hours showing a less trophic activity at midday and afternoon. The index of relative importance values evidenced the consumption of different prey according to day moments. Results of the gut content indicate that T. kensleyi is an omnivorous crab like other trichodactylid species. Opportunistic behavior is revealed by the ingestion of organisms abundant in streams such as oligochaetes and chironomid larvae. The consumption of allochthonous plant debris shows the importance of this crab as shredder in subtropical streams. However, the effective assimilation of plant matter is yet unknown in trichodactylid crabs. Conclusions: This research provides knowledge that complements previous studies about trophic relationships of trichodactylid crabs and supported the importance of T. kensleyi in the transference of energy and matter from benthic community and riparian sources to superior trophic levels using both macro- and microfauna.Fil: Williner, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; ArgentinaFil: de Azevedo Carvalho, Debora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Collins, Pablo Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentin

    The Digital Elevation Model Intercomparison eXperiment DEMIX, a community-based approach at global DEM benchmarking

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    This paper presents an initiative recently launched under the auspices of the Committee on Earth Observation Satellites (CEOS) aiming at providing harmonised terminology and methods, as well as practical guidelines and results allowing the intercomparison of continental or global Digital Elevation Models (DEM). As the work is still ongoing the main purpose of this article is not the dissemination of the outcome but rather to inform the wider community about the initiative, communicate the chosen approach to raise awareness, and attract possible further participants. Nevertheless, some preliminary results are included and an outlook on planned next steps is provided

    Simulation of impulse response for indoor visible light communications using 3D CAD models

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    n this article, a tool for simulating the channel impulse response for indoor visible light communications using 3D computer-aided design (CAD) models is presented. The simulation tool is based on a previous Monte Carlo ray-tracing algorithm for indoor infrared channel estimation, but including wavelength response evaluation. The 3D scene, or the simulation environment, can be defined using any CAD software in which the user specifies, in addition to the setting geometry, the reflection characteristics of the surface materials as well as the structures of the emitters and receivers involved in the simulation. Also, in an effort to improve the computational efficiency, two optimizations are proposed. The first one consists of dividing the setting into cubic regions of equal size, which offers a calculation improvement of approximately 50% compared to not dividing the 3D scene into sub-regions. The second one involves the parallelization of the simulation algorithm, which provides a computational speed-up proportional to the number of processors used

    Engineering transketolase to accept both unnatural donor and acceptor substrates and produce α‐hydroxyketones

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    A narrow substrate range is a major limitation in exploiting enzymes more widely as catalysts in synthetic organic chemistry. For enzymes using two substrates, the simultaneous optimisation of both substrate specificities is also required for the rapid expansion of accepted substrates. Transketolase (TK) catalyses the reversible transfer of a C2‐ketol unit from a donor substrate to an aldehyde acceptor and suffers the limitation of narrow substrate scope for industrial applications. Herein, TK from Escherichia coli was engineered to accept both pyruvate, as a novel donor substrate, and unnatural acceptor aldehydes, including propanal, pentanal, hexanal and 3‐formylbenzoic acid (FBA). Twenty single‐mutant variants were first designed and characterised experimentally. Beneficial mutations were then recombined to construct a small library. Screening of this library identified the best variant with a 9.2‐fold improvement in the yield towards pyruvate and propionaldehyde, relative to wild‐type (WT). Pentanal and hexanal were used as acceptors to determine stereoselectivities of the reactions, which were found to be higher than 98% enantiomeric excess (ee) for the S configuration. Three variants were identified to be active for the reaction between pyruvate and 3‐FBA. The best variant was able to convert 47% of substrate into product within 24 h, whereas no conversion was observed for WT. Docking experiments suggested a cooperation between the mutations responsible for donor and acceptor recognition, which would promote the activity towards both the acceptor and donor. The variants obtained have the potential to be used for developing catalytic pathways to a diverse range of high‐value products
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