289 research outputs found

    Caracterización del medio físico y biótico de la escombrera de Las Minas de Alquife (Granada)

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    La actividad minera, siempre que se produzca con una cierta intensidad, provoca alteraciones en el medio natural, desde las más imperceptibles hasta las que representan claros impactos sobre el medio en que se desarrollan. Este es el caso de la formación de escombreras por el acopio de materiales procedentes de las actividades extractivas sobre la superficie del suelo. La tendencia actual en materia medioambiental promueve la integración de estos espacios en el paisaje, al mismo tiempo que su reutilización con fines socio-económicos. Una de las actuaciones primordiales para conseguir estos fines es la recuperación del suelo y la implantación de cubierta vegetal. Previamente al plan de actuación, se lleva a cabo la caracterización de la situación actual en la que se encuentra el ecosistema. En este emplazamiento, los suelos, de textura arenosa, presentan un pH alcalino, una baja capacidad de intercambio catiónico y bajo contenido en materia orgánica. La vegetación es escasa, dispersa y dominan las especies herbáceas seguidas de las arbustivas. Dentro de las especies herbáceas los representantes más abundantes pertenecen a las familias de Gramíneas, Compuestas y Labiadas. Adicionalmente, se ha evaluado la presencia de micorrizas en las raíces de las especies dominantes, como indicador del equilibrio microbiológico y potencial bioestabilizador del suelo, detectándose colonización micorrícica en la mayoría de ellas, si bien su promedio es muy bajo (5%)

    Eficacia y seguridad del adhesivo tisular Tisuacryl en el cierre de la piel de la episiotomía

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    Se realizó un ensayo clínico fase III, en el Hospital Docente Materno Infantil 10 de Octubre, de Ciudad de La Habana, Cuba, entre julio de 1999 y marzo del 2000, con el objetivo de evaluar la eficacia y seguridad del adhesivo tisular Tisuacryl en el cierre de la piel de la episiotomía. Cada grupo constó de 300 pacientes, de acuerdo a los criterios de inclusión establecidos para el ensayo. En el grupo estudio se presentaron menos molestias en la episiorrafia (95.6 %) que en el grupo control (56.3 %) a los 30 minutos post parto, así como al tercer día posterior al nacimiento (97.6 % vs. 61.3 %). Al séptimo día, los resultados en el afrontamiento, estética y molestias en la herida fueron significativamente mejores con el adhesivo tisular evaluado. Los riesgos relativos de resultados adversos al séptimo día posterior al parto fueron 3.2 veces mayores en relación con afrontamiento y 2.9 veces con la estética no satisfactorias cuando se utilizó catgut cromado al comparar con el Tisuacryl. Para las molestias en la episiorrafia, el riesgo relativo se elevó a 24.2, todos con diferencias estadísticas significativas. Se concluye que el uso del adhesivo tisular Tisuacryl para el cierre de la piel en la episiotomía tiene menor probabilidad de afrontamiento y estética de la herida no satisfactoria y de menor sensación dolorosa en la herida quirúrgica que el catgut cromado.Peer Reviewe

    Multiwavelength optical observations of chromospherically active binary systems V. FF UMa (2RE J0933+624): a system with orbital period variation

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    This is the fifth paper in a series aimed at studying the chromospheres of active binary systems using several optical spectroscopic indicators to obtain or improve orbital solution and fundamental stellar parameters. We present here the study of FF UMa (2RE J0933+624), a recently discovered, X-ray/EUV selected, active binary with strong H_alpha emission. The objectives of this work are, to find orbital solutions and define stellar parameters from precise radial velocities and carry out an extensive study of the optical indicators of chromospheric activity. We obtained high resolution echelle spectroscopic observations during five observing runs from 1998 to 2004. We found radial velocities by cross correlation with radial velocity standard stars to achieve the best orbital solution. We also measured rotational velocity by cross-correlation techniques and have studied the kinematic by galactic space- velocity components (U, V, W) and Eggen criteria. Finally, we have determined the chromospheric contribution in optical spectroscopic indicators, from Ca II H & K to Ca II IRT lines, using the spectral subtraction technique. We have found that this system presents an orbital period variation, higher than previously detected in other RS CVn systems. We determined an improved orbital solution, finding a circular orbit with a period of 3.274 days. We derived the stellar parameters, confirming the subgiant nature of the primary component and obtained rotational velocities (vsini), of 33.57 km/s and 32.38 km/s for the primary and secondary components respectively. From our kinematic study, we can deduce its membership to the Castor moving group. Finally, the activity study has given us a better understanding of the possible mechanisms that produce the orbital period variation.Comment: Latex file with 16 pages, 18 figures. Available at http://www.ucm.es/info/Astrof/invest/actividad/actividad_pub.html Accepted for publication in: Astronomy & Astrophysics (A&A

    Influence of the calibration on experimental UV index at a midlatitude site, Granada (Spain)

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    The ultraviolet index (UVI) is the most commonly used variable to inform about the level and potential harmful effect of ultraviolet (UV) radiation reaching the Earth's surface. This variable is derived from the output signal of UV radiometers applying conversion factors from calibration methods. This paper focused on the influence of the use of two of these methods (called one-step and two-steps methods) on the experimental UVI measured by a YES UVB-1 radiometer located in a midlatitude station, Granada (Spain) for the period 2006–2009. In addition, it also analyzes the deviation from the UVI values obtained when the manufacturer's calibration factors are applied. For this goal, a detailed characterization of the UVB-1 radiometer from the first Spanish calibration campaign of broadband UV radiometers at the "El Arenosillo" INTA station in 2007 was used. In addition, modeled UVI data derived from the LibRadtran/UVSPEC radiative transfer code are compared with the experimental values recorded at Granada for cloud-free conditions. Absolute mean differences between measured and modeled UVI data at Granada were around 5% using the one-step and two-steps calibration methods, indicating an excellent performance of these two techniques for obtaining UVI data from the UVB-1 radiometer. Conversely, the application of the manufacture's calibration factor produced a large overestimation (~14%) of the UVI values, generating unreliable alarming high UVI data in summer. Thus, the number of days with an extreme erythemal risk (UVI higher than 10) increased up to 46% between May and September at Granada. This percentage reduced to a more reliable value of 3% when the conversion factors obtained with the two-steps calibration method are used. These results evidence the need for a sound calibration of the broadband UV instruments in order to obtain reliable measurements.This work was partially supported by the Andalusian Regional Government through projects P08-RNM-3568 and P10-RNM-6299, the Spanish Ministry of Science and Technology through projects CGL2010-18782 and CSD2007-00067

    El gasto económico en centros de fitness low-cost: Diferencias según fidelidad y características del cliente

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    Thegrowth in thenumber of fitness centers and theirclients, thestudysoughtto examine and understandthebehavior of consumers of these sport organizations. Therefore, theobjective of thisstudywastoanalyzefordifferences in economicexpendituresbasedoncustomerloyalty and customerprofile in low-cost fitness centers. Thesamplewascomposed of 8462 clients of which50.9% (n=4303) werewomen and 49.1% (n=4159) men. A descriptiveanalysiswasconductedwiththevariancetoaddresstheobjective of thestudy. Theprincipleresultsindicatesignificantdifferences in regardstotheeconomicexpendituresaccordingtogender, age, longevitywiththeorganization and behaviorintentions as measuredwith Net Promoter Score. Thesefindings are of importantrelevanceoffering a detailedunderstanding of clients and variables whichshould be appropriatelymanagedtoincreasetheclients' expenditure.Debido al incremento en el número de instalaciones y clientes, los centros de fitness están siendo examinados para comprender el comportamiento del consumidor que asiste a estas organizaciones deportivas. Por ello, el objetivo de esta investigación fue analizar si existían diferencias de gasto económico en base al perfil y a la fidelidad de clientes en centros de fitness low-cost. La muestra se compuso de 8462 clientes de los que el 50.9% (n=4303) fueron mujeresy el 49.1% (n=4159) hombres. Se realizaron análisis descriptivos y de la varianza para dar respuesta al objetivo. Los principales resultados indican que existen diferencias significativas en cuanto al gasto económico según el género, la edad, la permanencia en la organización y las intenciones de comportamiento medidas con el Net Promoter Score. Estos hallazgos son de especial relevancia ya que favorecen el conocimiento detallado de los clientes, y de cuáles son las variables que se deberían gestionar adecuadamente para aumentar el gasto

    Aplicación de la teoría de la generalizabilidad en la evaluación de servicios en gestión deportiva

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    This paper addresses from the use of the Generalizability Theory (TG) the optimization of resources in sports management. We used a design structure composed of the facets users (U), activities (A), scales (E) and items (I), following not orthogonal design, partially nested and multifaceted, within the General Linear Model. 537 participants (32.11 ± 11.11 years) completed the Questionnaire of Evaluation of the Perceived Quality in Sports Services obtaining excellent results both indexes of reliability (ξρ²(δ) > 0.98) and generalizability (ξρ²(Δ) > 0.98). The optimization showed that half of participants and fewer activities, we obtain a high degree of generalization and at the same time, reduced the total number of observations, being important for future studies which will facilitate the evaluation of sport service more efficiently.Esta investigación aborda a partir de la Teoría de la Generalizabilidad (TG) la optimización de recursos en la gestión deportiva. Se utilizó una estructura de diseño compuesta por las facetas usuarios (U), actividades (A), escalas (E) e ítems (I), siguiendo un diseño no ortogonal, parcialmente anidado y multifaceta dentro del Modelo General Lineal (GLM). Los 537 participantes (32.11 ± 11.11 años) cumplimentaron el Cuestionario de Evaluación de la Calidad Percibida en Servicios Deportivos obteniendo resultados excelentes de fiabilidad (ξρ²(δ) > 0.98) y generalizabilidad (ξρ²(Δ) > 0.98). La optimización mostró que con una reducción del número de participantes a la mitad y con un menor número de actividades evaluadas, obtenemos un alto grado de generalización al mismo tiempo que se reduce el número total de observaciones de cara a futuros registros, lo que facilitará la evaluación del servicio deportivo de manera más eficiente

    A scaling procedure for straightforward computation of sorptivity

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    This research has been supported by the Agence Nationale de la Recherche (grant no. ANR-17-CE04-010).Sorptivity is a parameter of primary importance in the study of unsaturated flow in soils. This hydraulic parameter is required to model water infiltration into vertical soil profiles. Sorptivity can be directly estimated from the soil hydraulic functions (water retention and hydraulic conductivity curves), using the integral formulation of Parlange (1975). However, calculating sorptivity in this manner requires the prior determination of the soil hydraulic diffusivity and its numerical integration between initial and final saturation degrees, which may be difficult in some situations (e.g., coarse soil with diffusivity functions that are quasi-infinite close to saturation). In this paper, we present a procedure to compute sorptivity using a scaling parameter, cp, that corresponds to the sorptivity of a unit soil (i.e., unit values for all parameters and zero residual water content) that is utterly dry at the initial state and saturated at the final state. The cp parameter was computed numerically and analytically for five hydraulic models: delta (i.e., Green and Ampt), Brooks and Corey, van Genuchten–Mualem, van Genuchten–Burdine, and Kosugi. Based on the results, we proposed brand new analytical expressions for some of the models and validated previous formulations for the other models. We also tabulated the output values so that they can easily be used to determine the actual sorptivity value for any case. At the same time, our numerical results showed that the relation between cp and the hydraulic shape parameters strongly depends on the chosen model. These results highlight the need for careful selection of the proper model for the description of the water retention and hydraulic conductivity functions when estimating sorptivity.French National Research Agency (ANR) European Commission ANR-17-CE04-01

    In vitro-generated Tc17 cells present a memory phenotype and serve as a reservoir of Tc1 cells in vivo

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    Indexación: Scopus.Memory CD8+ T cells are ideal candidates for cancer immunotherapy because they can mediate long-term protection against tumors. However, the therapeutic potential of different in vitro-generated CD8+ T cell effector subsets to persist and become memory cells has not been fully characterized. Type 1 CD8+ T (Tc1) cells produce interferon-γ and are endowed with high cytotoxic capacity, whereas IL-17-producing CD8+ T (Tc17) cells are less cytotoxic but display enhanced self-renewal capacity. We sought to evaluate the functional properties of in vitro-generated Tc17 cells and elucidate their potential to become long lasting memory cells. Our results show that in vitro-generated Tc17 cells display a greater in vivo persistence and expansion in response to secondary antigen stimulation compared to Tc1 cells. When transferred into recipient mice, Tc17 cells persist in secondary lymphoid organs, present a recirculation behavior consistent with central memory T cells, and can shift to a Tc1 phenotype. Accordingly, Tc17 cells are endowed with a higher mitochondrial spare respiratory capacity than Tc1 cells and express higher levels of memory-related molecules than Tc1 cells. Together, these results demonstrate that in vitro-generated Tc17 cells acquire a central memory program and provide a lasting reservoir of Tc1 cells in vivo, thus supporting the use of Tc17 lymphocytes in the design of novel and more effective therapies.https://www.frontiersin.org/articles/10.3389/fimmu.2018.00209/ful
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