1,518 research outputs found

    Sulfur-enhanced thermoluminescence of γ-radiated zirconia

    No full text
    Sulfur-modified zirconia with various S contents have been characterized and analyzed for potential applications in dosimetry. The thermoluminescent signal induced by gamma radiation in pure zirconia and sulfated zirconia in the tetragonal phase has been considered. Experimental results show that the thermoluminescent glow peak depends on both the crystalline structure and sulfate concentration and that the response is linear for an ample range of irradiation.Зразки модифікованої сірого двоокису цирконію з різним вмістом сірки охарактеризовано і проаналізовано з точки зору потенційного застосування в дозиметрії. Розглянуто термолюмінісцентний сигнал, викликаний гамма-випромінюванням в чистому і сульфатованому двоокису цирконію в тетрагональної фазі. Експериментальні результати показують, що пік термолюмінісцентного світіння залежить як від кристалічної структури, так і від концентрації сульфату. Ця характеристика лінійна для великого діапазону опромінення.Образцы модифицированной серой двуокиси циркония с различным содержанием серы охарактеризованы и проанализированы с точки зрения потенциального применения в дозиметрии. Рассмотрен термолюминисцентный сигнал, вызванный гамма-излучением в чистой и сульфатированной двуокиси циркония в тетрагональной фазе. Экспериментальные результаты показывают, что пик термолюминисцентного свечения зависит как от кристаллической структуры, так и от концентрации сульфата. Эта характеристика линейна для большого диапазона облучения

    Study of teaching practices in assessment in English as a foreign language in secondary education

    Get PDF
    Se critica la enseñanza del inglés en España y los resultados de aprendizaje. En este artículo se advierte que en parte se debe a la ausencia de evaluación oral en la ESO, y para ello se han analizado las prácticas docentes de evaluación. Se recogieron instrumentos de evaluación utilizados, en nuestro caso exámenes, y se analizaron sus contenidos. Los resultados obtenidos indican que las destrezas orales apenas se evalúan, que los elementos comunicativos son casi inexistentes y que no se siguen algunos criterios de evaluación marcados por la leyThe teaching of English in Spain and its learning outcomes are criticized in Spain. This article argues that it is due to the absence of oral assessment in secondary education. To corroborate such assumption the teaching practices of evaluation were studied. In order to do so we first collected assessment instruments and analyzed their contents. Results indicate that oral skills were hardly assessed, that communicative elements did not appear in exams, and that the evaluation criteria set by the law are neglected.Grupo FORCE (HUM-386). Departamento de Didáctica y Organización Escolar de la Universidad de Granada

    Estudio sobre prácticas docentes en evaluación de la lengua inglesa en la E.S.O.

    Get PDF
    Se critica la enseñanza del inglés en España y los resultados de aprendizaje. En este artículo se advierte que en parte se debe a la ausencia de evaluación oral en la ESO, y para ello se han analizado las prácticas docentes de evaluación. Se recogieron instrumentos de evaluación utilizados, en nuestro caso exámenes, y se analizaron sus contenidos. Los resultados obtenidos indican que las destrezas orales apenas se evalúan, que los elementos comunicativos son casi inexistentes y que no se siguen algunos criterios de evaluación marcados por la ley

    Microrna-21 and colorectal cancer

    Full text link
    Introducción. Los microRNAs son estructuras moleculares con actividad post-transcripcional que están implicados en la regulación de la expresión genética. Diversos estudios ponen de manifiesto la participación de los microRNAs con distintas funciones fisiológicas, así como con el proceso de la oncogénesis. La expresión de los microRNAs puede verse alterada en las neoplasias por su interacción bien con los genes supresores de tumores, bien con los oncogenes. Discusión. Llevamos a cabo una revisión de la literatura sobre el microRNA-21, poniendo de manifiesto la evidencia existente entre el microRNA-21 y la enfermedad neoplásica, de forma especial con el cáncer colorrectal. Conclusiones. El estado actual de los microRNAs hace necesario continuar con la investigación existente entre la etiopatogenia de las neoplasias y los microRNAs. El conocimiento de la verdadera implicación de los microRNAs en la fisiopatología de la enfermedad neoplásica, permitirá ampliar las supuestas aplicaciones clínicas del miR-21 no sólo a la determinación del pronóstico del cáncer colorrectal, sino también desde el punto de vista diagnóstico al poder diferenciar las lesiones de la mucosa colónicaIntroduction. MicroRNAs are molecular structures with post-transcriptional activity, involved in the gene expression regulation. Several studies have demonstrated the involvement of microRNAs in different physiological functions, as well as in the oncogenesis process. The expression of microRNAs may be altered in the tumors by either interaction with tumor suppressor genes or oncogenes. Discussion. A review of the medical literature on microRNA-21 has been conducted, showing the evidence between microRNA-21 and neoplastic disease, specially with colorectal cancer. Conclusion. The current status of microRNAs makes necessary to continue the investigation of the pathogenesis of cancer and microRNAs. The knowledge of the involvement of microRNAs in the pathophysiology of neoplastic disease, will allow to extend the supposed clinical applications of miR-21 not only to the determination of the prognosis of colorectal cancer, but also for the differential diagnosis of processes of colonic mucosa

    The kinematics of the quadrupolar nebula M1-75 and the identification of its central star

    Full text link
    The link between the shaping of bipolar planetary nebulae and their central stars is still poorly understood. The kinematics and shaping of the multipolar nebula M 1-75 are hereby investigated, and the location and nature of its central star are briefly discussed. Fabry-Perot data from GHaFAS on the WHT sampling the Doppler shift of the [N II] 658.3 nm line are used to study the dynamics of the nebula, by means of a detailed 3-D spatio-kinematical model. Multi-wavelength images and spectra from the WFC and IDS on the INT, and from ACAM on the WHT, allowed us to constrain the parameters of the central star. The two pairs of lobes, angularly separated by ~22 degrees, were ejected simultaneously approx. ~3500-5000 years ago, at the adopted distance range from 3.5 to 5.0 kpc. The larger lobes show evidence of a slight degree of point symmetry. The shaping of the nebula could be explained by wind interaction in a system consisting of a post-AGB star surrounded by a disc warped by radiative instabilities. This requires the system to be a close binary or a single star which engulfed a planet as it died. On the other hand, we present broad- and narrow-band images and a low S/N optical spectrum of the highly-reddened, previously unnoticed star which is likely the nebular progenitor. Its estimated V-I colour allows us to derive a rough estimate of the parameters and nature of the central star.Comment: 8 pages, 6 figures, accepted for publication in Astronomy & Astrophysic

    Propiedades magnéticas de los sedimentos de tipo estuarino. El caso de las Rías Baixas.

    Get PDF
    Este trabajo establece la utilidad de la susceptibilidad magnética como indicador de la influencia marina y evolución diagenética en sedimentos costeros de las Rías Baixas. Para ello se investigó la variabilidad geográfica de la susceptibilidad en 200 muestras de sedimentos marinos superficiales en las Rías de Vigo y Pontevedra. Su variabilidad vertical se estudió en 80 muestras de tres testigos de entre 60 y 90 cm de longitud extraídos en la Ría de Pontevedra. La susceptibilidad de las muestras superficiales aumenta progresivamente hacia mar abierto, y a medida que nos alejamos de las zonas de mayor influencia continental, estando relacionada con la textura y composición del sedimento, y por tanto, con su procedencia. Los testigos, más homogéneos litológicamente, mostraron una disminución muy importante de la susceptibilidad con la profundidad, estando ésta asociada a la evolución diagenética del sedimento. Para estudiar mejor estos procesos, se determinó la composición elemental y mineralógica, y además se midieron otras propiedades magnéticas de muestras representativas. Estos resultados se analizaron conjuntamente con los datos sedimentológicos disponibles, lo que permitió establecer que la variabilidad de 151 D. Rey et al. Propiedades magnéticas de los sedimentos de tipo estuarino... la susceptibilidad dependía de tres factores principales: (a) procedencia y origen de los sedimentos, (b) régimen hidrodinámico de la zona y (c) presencia de partículas contaminantes discretas de origen antropogénico. También puede concluirse que la evolución de las fases magnetomineralógicas durante la diagénesis temprana está controlada por el contenido en materia orgánica, lo que a su vez determina el potencial de oxidación-reducción.Meassurement of magnetic susceptibility has allowed the assesment of the marine influence and diagenetic evolution of coastal sediments from the Rías Baixas. This is based on geographically and vertically distributed data. The lowfield susceptibility () of over 200 samples of surficial seabed sediments of the Rias of Vigo and Pontevedra showed a significant increase towards the open sea and away from continental influenced areas. Vertical variability of the susceptibility was evaluated in 80 samples obtained from three 60 to 90 cm long gravity corers in the Ria de Pontevedra. These samples showed a very strong decrease in susceptibility with depth. The surficial susceptibility values correlated well with the textural characteristics of the sediments, suggesting a link between sediment provenance and origin of the magnetic signal. To further evaluate these relationships, the available sedimentological data were completed with a number of elemental and mineralogical analysis. In addition some basic magnetic parameters were obtained for selected specimens. The combined analysis of these data showed that the spatial variability of the susceptibility observed in the different granulometric fractions can be spatially related to: (a) sediment provenance and origin, (b) hydrodynamic regime established between the Rias and the adjacent shelf, (c) antropogenic solid particulate pollution. It can also be concluded that the evolution of the magnetomineralogical phases during the early stages of burial and diagenesis is controlled by the organic matter content which in turn controls the redox potential

    Simultaneous Surface Plasmon Resonance and X-ray Absorption Spectroscopy

    Full text link
    We present here an experimental set-up to perform simultaneously measurements of surface plasmon resonance (SPR) and X-ray absorption spectroscopy (XAS) in a synchrotron beamline. The system allows measuring in situ and in real time the effect of X-ray irradiation on the SPR curves to explore the interaction of X-rays with matter. It is also possible to record XAS spectra while exciting SPR in order to detect the changes in the electronic configuration of thin films induced by the excitation of surface plasmons. Combined experiments recording simultaneously SPR and XAS curves while scanning different parameters can be carried out. The relative variations in the SPR and XAS spectra that can be detected with this set-up ranges from 10-3 to 10-5, depending on the particular experiment

    Economic Analysis of Thrombo inCode, a Clinical-Genetic Function for Assessing the Risk of Venous Thromboembolism

    Get PDF
    Background: Patients with venous thromboembolism (VTE) commonly have an underlying genetic predisposition. However, genetic tests nowadays in use have very low sensitivity for identifying subjects at risk of VTE. Thrombo inCode is a new genetic tool that has demonstrated very good sensitivity, thanks to very good coverage of the genetic variants that modify the function of the coagulation pathway. Objective: To conduct an economic analysis of risk assessment of VTE from the perspective of the Spanish National Health System with Thrombo inCode (a clinical-genetic function for assessing the risk of VTE) versus the conventional/standard method used to date (factor V Leiden and prothrombin G20210A). Methods: An economic model was created from the National Health System perspective, using a decision tree in patients aged 45 years with a life expectancy of 81 years. The predictive capacity of VTE, based on identification of thrombophilia using Thrombo inCode and using the standard method, was obtained from two case-control studies conducted in two different populations (S. PAU and MARTHA; 1,451 patients in all). Although this is not always the case, patients who were identified as suffering from thrombophilia were subject to preventive treatment of VTE with warfarin, leading to a reduction in the number of VTE events and an increased risk of severe bleeding. The health state utilities (quality-adjusted life-years [QALYs]) and costs (in 2013 EUR values) were obtained from the literature and Spanish sources. Results: On the basis of a price of EUR 180 for Thrombo inCode, this would be the dominant option (more effective and with lower costs than the standard method) in both populations. The Monte Carlo probabilistic analyses indicate that the dominance would occur in 100 % of the simulations in both populations. The threshold price of Thrombo inCode needed to reach the incremental cost-effectiveness ratio (ICER) generally accepted in Spain (EUR 30,000 per QALY gained) would be between EUR 3,950 (in the MARTHA population) and EUR 11,993 (in the S. PAU population). Conclusion: According to the economic model, Thrombo inCode is the dominant option in assessing the risk of VTE, compared with the standard method currently used
    corecore