1,025 research outputs found
Knowledge management in small companies in Tepic, México.
La administración del conocimiento ha tenido un considerable avance en años recientes, lo cual ha incidido en la aparición de estudios sobre cómo una organización puede adquirir, almacenar, desarrollar y compartir el conocimiento generado por sus miembros. Este estudio explora y analiza 40 pequeñas empresas de menudeo en Nayarit, mediante la metodología propuesta por el eKnowledge Center (2000), cuya encuesta se utiliza como modelo de administración del conocimiento en las empresas estudiadas
Concordancia y confiabilidad de una prueba neuromuscular y cognitiva basada en estímulos de luz para evaluar el tiempo de reacción integrativo en el deporte
La reacción en los deportes de equipo implica una serie de procesos sistémicos que integran funciones para desarrollar una respuesta considerando la situación, el tiempo y el espacio. El objetivo de este estudio fue analizar la concordancia y la confiabilidad de una prueba neuromuscular y cognitiva basada en estímulos de luz para evaluar el tiempo de reacción integrativo en los deportes. Catorce participantes activos realizaron dos sesiones con 10 repeticiones de la Prueba de Reacción Deportiva NeuroPhys (NPSRT). La prueba mostró confiabilidad moderada a casi perfecta (coeficiente de correlación intraclase = 0.53-0.81) y buena concordancia (Método Bland-Altman, BIAS = -0.0004-0.029) entre sesiones; no hubo diferencias medias absolutas entre sesiones (prueba t de medidas repetidas = p≤0.050) y presentaron correlaciones lineales moderadas a altas (Pearson r = 0.53-0.83, p≤0.05). El NPSRT podría considerarse como una prueba confiable para evaluar el tiempo de reacción en los deportes de equipo.Reaction in team sports involves a series of systemic processes integrating functions to develop a response considering situation, time and space. The aim of this study was to analyze the agreement and reliability of a neuromuscular and cognitive test based on light stimuli to assess integrative reaction time in sports. Fourteen active participants performed two sessions with 10 repetitions of the NeuroPhys Sport Reaction Test (NPSRT). The test showed moderate to almost perfect reliability (intraclass correlation coefficient = 0.53-0.81) and good agreement (Bland-Altman Method, BIAS = -0.0004-0.029) between sessions; there were no absolute mean differences between sessions (repeated measures t-test = p≤0.050) and presented moderate to high lineal correlations (Pearson r = 0.53-0.83, p≤0.05). The NPSRT could be considered as a reliable test to assess reaction time in team sports.peerReviewe
The Urban Biography of a Mauritanian City: Microstratigraphic Analysis of the Eastern Quarter of Tamuda (Morocco)
The lack of vertical stratigraphic sondages and open area excavations constitutes a challenge to understanding Mauritanian urbanism. This makes the characterization of the spatio-temporal evolution of Mauritanian towns a difficult task. Systematic excavations carried out in Tamuda by several research teams in the twentieth century provided vertical and horizontal views of Mauritanian urbanism. Our study offers, for the first time, a high-resolution geoarchaeological analysis of Tamuda’s urban sequence (third through first century BC). The microfacies analysis, by means of micromorphology and µ-XRF of Spaces E18 and E20 of the Eastern Quarter revealed a complex interaction of deposits and site formation processes that resulted from changes in everyday urban life. In this respect, the overlap of different construction phases and the alternation of episodes of active use and abandonment is highly significant. This study examines the functional characterization of urban spaces, including the identification of midden activities, a roasting pit, and a milling site (possibly) linked to fish flour production. These activities leave traces on beaten floors and occupation surfaces, and several features indicate abandonment periods between short-term occupations. The result is a complex urban biography of this Mauritanian town, in which human occupation was not constant over time.37 página
Co-manejo de una especie de alto valor con derechos de uso territorial para la pesca: un enfoque bioeconómico espacial con variabilidad ambiental
Abalone is a high-value resource that is an important export market fishery of Mexico that is managed through territorial use rights for fisheries allocated to a coastal community. A specific age-structured spatial bioeconomic model was applied to this fishery to undertake stock recovery to target levels. The model incorporates uncertainty in the parameter k of a von Bertalanffy growth function with environmental variability. The risk of falling below and exceeding the target and bioeconomic limit reference points of the population with alternative fisheries management strategies was studied using a Monte Carlo analysis. The management strategy evaluation showed that Emin (minimum effort) and EmaxNPV (resource rent maximization effort) generated higher biomass levels and higher present value of resource rent than Emsy (effort in maximum sustainable yield) at the end of the simulation period, regardless of the bioeconomic reference points and assuming a reduction in fishing effort. Emin and EmaxNPV increased and maximized the present value of resource rent generated by the species while avoiding its overexploitation. The social consequences of the management strategies were considered with the participation of fishers of this co-managed fishery.El abulón es un recurso de alto valor que constituye un importante mercado de exportación pesquera en México, gestionado a través de derechos de uso territorial para la pesca (TURF) asignados a una comunidad costera. Se aplicó un modelo bioeconómico espacial específico estructurado por edades a esta pesquería para llevar a cabo la recuperación de las poblaciones hasta niveles objetivos. El modelo incorpora la incertidumbre en el parámetro k de la Función de Crecimiento de von Bertalanffy con variabilidad ambiental. Se realizó un análisis de Monte Carlo para evaluar el riesgo de caer por debajo o superar los puntos de referencia bioeconómicos objetivo y límite de la población con estrategias alternativas de manejo pesquero. La evaluación de las estrategias de manejo mostró que Emin (esfuerzo mínimo) y EmaxNPV (maximización de la renta que genera el recurso) en comparación con Emsy (esfuerzo en el rendimiento máximo sostenible) son estrategias que generan niveles de biomasa más altos y un mayor valor presente de la renta que genera el recurso al final del período de simulación. Independientemente de los puntos de referencia bioeconómicos, las estrategias que presentaron las mejores condiciones fueron Emin y EmaxNPV, asumiendo una reducción en el esfuerzo pesquero, aumentando y maximizando el valor presente de la renta del recurso generado por la especie al evitar su sobreexplotación. Se consideraron las consecuencias sociales de las estrategias de manejo con la participación de los pescadores de esta pesquería co-gestionada
Radon transport events associated with the impact of a NORM repository in the SW of Europe
Two radon measurement stations located to the north and south of a NORM (Naturally Occurring Radioactive Materials) repository of phosphogypsum (southwest of Europe) were used to monitor radon behavior during 2018. The stations are located at opposing sides of the repository, one in Huelva City to the north and other one in a rural area to the south. This setup aimed to identify the influence of the NORM repository on each station and use radon levels as a marker of atmospheric transport in the local area. To achieve this, a comparison was carried out with other coastal stations in the south of Spain, finding higher average concentrations in Huelva City, ~3.3 Bq m− 3
. Hierarchical clustering was applied to identify days with different radon patterns at each
Huelva station, detecting possible local radon transport events from the repository. Three events were investigated with WRF (Weather Research and Forecasting) and FLEXPART-WRF (FLEXible PARTicle dispersion model). It was found that both sampling sites required atmospheric stagnant conditions to reach high radon concentration. However, under these conditions the urban station showed high radon regardless of wind direction while the rural station also required radon transport from the repository, either directly or indirect.This research was supported by the Spanish Ministry of Science,
Innovation and Universities, by the project ‘Fluxes of radionuclides
emitted by the PG piles located at Huelva; assessment of the dispersion,
radiological risks and remediation proposals’ (Ref.: CTM2015-68628-
R). It is important to reiterate the significant contribution of CSN to
this research providing radon measurements from the REA network.
Special thanks are given to Antonio Padilla for his invaluable technical
support and know-how. Resources supporting this work were provided
by the CEAFMC and Universidad de Huelva High Performance Computer
(HPC@UHU) funded by ERDF/MINECO project UNHU-15CE-2848.Funding for open access charge: Universidad de Huelva / CBU
Radon behavior investigation based on cluster analysis and atmospheric modelling
Radon measurements were performed in Huelva, a city located near a phosphogypsum repository in the SW of the Iberian Peninsula, between March 2015 and March 2016. The mean values of this gas oscillate between 5.6 and 10.9 Bq m-3 and maximum ranges between 36.4 and 53.4 Bq m-3. Radon shows the expected monthly variation with higher levels in November and December. Typical daily evolutions were also observed, with maximum between 06:00 and 08:00 UTC (Coordinated Universal Time) and minimum around noon. To extract daily radon patterns, the cluster technique of K-means was applied. Based on this classification, four different case study periods were analyzed in detail, describing two events with high radon levels and two with low radon. Local meteorology, back-trajectories computed with the HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) model and meteorological fields from the WRF (Weather Research and Forecasting) model, were used to analyze the four case study periods selected. Low radon periods are characterized by the occurrence of non-pure breezes and maritime air masses from the Atlantic Ocean, whereas high radon periods occur under pure sea-land breezes affected by Mediterranean air masses. Factors such as meteorology or local emission sources alone may not be enough to explain the high radon events in the area. Other factors could be playing a major role in the radon levels. The obtained results indicate the contribution of radon transported from medium-long range, suggesting that, under specific weather conditions, the Gulf of Cadiz could act as a radon trap and the continental areas around the Western Mediterranean Basin could act as a radon source.Postprint (author's final draft
Líder o gerente, ¿qué los hace diferentes? (Leader or manager, What makes them different?)
A través del tiempo, el concepto de liderazgo ha sido analizado desde diversas perspectivas y aplicado a infinidad de áreas temáticas. Algunos lo analizan desde la visión humana, otros desde la eficiencia y productividad, algunos más definen estilos y perfiles de liderazgo. El presente artículo es un análisis teórico del origen, evolución y tipos de liderazgo, así como la diferenciación entre este término y el de gestión, que permita establecer las bases de posteriores estudios no sólo teóricos sino también empíricos respecto al tema.Palabras clave: líder, liderazgo, gerente, gestiónAbstract.Over time, the concept of leadership has been analyzed from various perspectives and applied to many areas. Some analyze it from the human perspective, others from efficiency and productivity, some more define leadership styles and profiles. The present article is a theoretical analysis of the origin and evolution of leadership, types of leadership, as well as the differentiation between this term and that of management, that allows to establish the bases of later studies not only theoretical but also empirical with respect to the subject.Key words: leader, leadership, management, manager.
La termografía infrarroja como herramienta efectiva para detectar áreas músculares dañadas después de correr una maratón
Introducción. La termografía infrarroja (TI) es un equipo de imagen que capta las radiaciones de calor emitidas por los cuerpos y las recoge en valores de temperatura. En el ámbito deportivo se utiliza para identificar daños en estructuras músculo-esqueléticas a partir de la variación de la temperatura corporal en zonas anatómicas afectadas.Objetivo. Valorar la efectividad de la TI como herramienta para detectar músculos dañados después de correr una maratón.Materiales y métodos. Se evaluaron 17 corredores antes y después de correr una maratón (42.196 km) utilizando un equipo termográfíco.Resultados. Se encontraron diferencias estadísticamente significativas entre la temperatura previa y posterior a correr una maratón. Se presentó una diferencia entre la medición previa y posterior 1°C en el vasto lateral, vasto medial, recto femoral y aductor de la pierna dominante, lo que, basados en parámetros clínicos, representa un daño en estos músculos. Los aumentos de temperatura se mostraron de manera heterogénea entre las zonas anatómicas.Conclusiones. La TI es una herramienta efectiva para detectar zonas musculares dañadas en corredores después de participar en una maratón.Introduction: Infrared thermography (IT) is an imaging technique that detects heat radiation emitted by an object and collects it to convert it into temperature values. In sports, it is used to identify damage to musculoskeletal structures based on the variation of body temperature in affected anatomical areas.Objective: To assess the effectiveness of IT as a tool to detect damaged muscles after running a marathon.Materials and methods: 17 runners were assessed before and after running a marathon (42.196 km) using thermographic equipment.Results: Statistically significant temperature differences were found before and after running a marathon. There was a difference between previous and posterior measurement 1°C in the vastus lateralis, vastus medialis, rectus femoris and adductor of the dominant leg, which, based on clinical parameters, indicates damage in these muscles. Increases in temperature were heterogeneous among anatomical areas.Conclusions: IT is an effective tool for detecting damaged muscle areas in runners after participating in a marathon
Fructose metabolism in Chromohalobacter salexigens: interplay between the Embden–Meyerhof–Parnas and Entner–Doudoroff pathways
Background
The halophilic bacterium Chromohalobacter salexigens metabolizes glucose exclusively through the Entner–Doudoroff (ED) pathway, an adaptation which results in inefficient growth, with significant carbon overflow, especially at low salinity. Preliminary analysis of C. salexigens genome suggests that fructose metabolism could proceed through the Entner–Doudoroff and Embden–Meyerhof–Parnas (EMP) pathways. In order to thrive at high salinity, this bacterium relies on the biosynthesis and accumulation of ectoines as major compatible solutes. This metabolic pathway imposes a high metabolic burden due to the consumption of a relevant proportion of cellular resources, including both energy molecules (NADPH and ATP) and carbon building blocks. Therefore, the existence of more than one glycolytic pathway with different stoichiometries may be an advantage for C. salexigens. The aim of this work is to experimentally characterize the metabolism of fructose in C. salexigens.
Results
Fructose metabolism was analyzed using in silico genome analysis, RT-PCR, isotopic labeling, and genetic approaches. During growth on fructose as the sole carbon source, carbon overflow was not observed in a wide range of salt concentrations, and higher biomass yields were reached. We unveiled the initial steps of the two pathways for fructose incorporation and their links to central metabolism. While glucose is metabolized exclusively through the Entner–Doudoroff (ED) pathway, fructose is also partially metabolized by the Embden–Meyerhof–Parnas (EMP) route. Tracking isotopic label from [1-13C] fructose to ectoines revealed that 81% and 19% of the fructose were metabolized through ED and EMP-like routes, respectively. Activities of enzymes from both routes were demonstrated in vitro by 31P-NMR. Genes encoding predicted fructokinase and 1-phosphofructokinase were cloned and the activities of their protein products were confirmed. Importantly, the protein encoded by csal1534 gene functions as fructose bisphosphatase, although it had been annotated previously as pyrophosphate-dependent phosphofructokinase. The gluconeogenic rather than glycolytic role of this enzyme in vivo is in agreement with the lack of 6-phosphofructokinase activity previously described.
Conclusions
Overall, this study shows that C. salexigens possesses a greater metabolic flexibility for fructose catabolism, the ED and EMP pathways contributing to a fine balancing of energy and biosynthetic demands and, subsequently, to a more efficient metabolism.University of Murcia and University of Seville was supported by projects: BIO2015-63949-R, BIO2014-54411-C2-1-REuropa MINECO/FEDER RTI2018-094393-B-C21Fundación Séneca (Grant no. 19236/PI/14
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