135 research outputs found

    Evaluación del riesgo volcánico en Tenerife, Islas Canarias. Resultados del análisis de susceptibilidad

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    Los mapas de riesgo han demostrado ser una herramienta útil para poder pronosticar y disminuir el tiempo de respuesta respecto a los procesos naturales catastróficos. Las erupciones volcánicas representan para la sociedad actual un problema de gran envergadura, debido a la localización de áreas urbanas en zonas de riesgo. Esto se acentúa en la isla de Tenerife debido a la gran expansión urbanística que ha experimentado en las últimas décadas y al aumento significativo del turismo. En esta contribución se analiza una propuesta para la elaboración de un mapa de riesgo volcánico para Tenerife utilizando diferentes bases de datos en un entorno SIG. El proyecto de construcción del mapa de riesgo volcánico de Tenerife incluye cuatro fases distintas. En la primera se han de realizar mapas de susceptibilidad para cada tipo de erupción. Posteriormente se aplicarán sobre ellos modelos físicos de simulación para diferentes tipos de erupciones, obteniendo así mapas de peligrosidad. Paralelamente se genera el mapa de vulnerabilidad con información socio-económica de la zona. El mapa de riesgo, en último lugar, se obtendrá a partir de los datos anteriores. Como una primera aportación a este proyecto se presenta un mapa de susceptibilidad elaborado para erupciones basálticas. Este se realiza a partir de la superposición de diversas capas, en las cuales se representan los diferentes criterios que se tendrán en cuenta a la hora de evaluar una posible erupción. Se incluye información geológica (cartografía de localización y depósitos de los centros eruptivos existentes); información de deformación superficial (mediante datos tomados con interferometría SAR); información geoquímica (mapa de desgasificación difusa); datos sobre el campo de esfuerzos (mediante un modelo numérico y otro estructural de medidas de campo) e información sísmica (con la elaboración de un mapa de distribución de epicentros). La combinación de las diferentes capas de información permite la obtención del mapa de probabilidad espacial para erupciones basálticas basado en criterios objetivos, constituyendo el primer paso necesario para la obtención de los mapas de peligrosidad y riesgo de Tenerife.Peer ReviewedPostprint (published version

    Asteroids' physical models from combined dense and sparse photometry and scaling of the YORP effect by the observed obliquity distribution

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    The larger number of models of asteroid shapes and their rotational states derived by the lightcurve inversion give us better insight into both the nature of individual objects and the whole asteroid population. With a larger statistical sample we can study the physical properties of asteroid populations, such as main-belt asteroids or individual asteroid families, in more detail. Shape models can also be used in combination with other types of observational data (IR, adaptive optics images, stellar occultations), e.g., to determine sizes and thermal properties. We use all available photometric data of asteroids to derive their physical models by the lightcurve inversion method and compare the observed pole latitude distributions of all asteroids with known convex shape models with the simulated pole latitude distributions. We used classical dense photometric lightcurves from several sources and sparse-in-time photometry from the U.S. Naval Observatory in Flagstaff, Catalina Sky Survey, and La Palma surveys (IAU codes 689, 703, 950) in the lightcurve inversion method to determine asteroid convex models and their rotational states. We also extended a simple dynamical model for the spin evolution of asteroids used in our previous paper. We present 119 new asteroid models derived from combined dense and sparse-in-time photometry. We discuss the reliability of asteroid shape models derived only from Catalina Sky Survey data (IAU code 703) and present 20 such models. By using different values for a scaling parameter cYORP (corresponds to the magnitude of the YORP momentum) in the dynamical model for the spin evolution and by comparing synthetics and observed pole-latitude distributions, we were able to constrain the typical values of the cYORP parameter as between 0.05 and 0.6.Comment: Accepted for publication in A&A, January 15, 201

    Causas de falta de respuesta primaria y pérdida de respuesta secundaria a inhibidores del factor de necrosis tumoral alfa en la artritis reumatoide

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    La artritis reumatoide (AR) es una enfermedad inflamatoria sistémica crónica que requiere tratamiento a largo plazo. Dado que el daño articular en pacientes con AR habitualmente es progresivo y éstos requieren tratamiento durante largos periodos de tiempo, es necesario un seguimiento a largo plazo para evaluar la eficacia y la seguridad de los tratamientos e intervenciones. Los fármacos biológicos han supuesto un gran avance terapéutico en el tratamiento de las enfermedades inflamatorias inmunomediadas. La European League Against Rheumatism (EULAR) define la falta de respuesta primaria como una reducción ≤0,6 del Disease Activity Score (DAS) en 28 articulaciones, valorando la velocidad de sedimentación glomerular (DAS28‑VSG) inicial tras 12-24 semanas de tratamiento y la pérdida de respuesta secundaria como un aumento en DAS28-VSG >0,6 o un aumento de actividad de la enfermedad. Uno de los pilares del tratamiento de la AR en la actualidad son los inhibidores del factor de necrosis tumoral alfa (iTNFα); sin embargo, se ha descrito que un 33% de los pacientes con AR no responden inicialmente a estos fármacos, y hasta el 30% pierden la respuesta clínica inicial con el tiempo. Esta variabilidad e incapacidad de predecir la respuesta a los iTNFα se ha descrito como intrínseca a la terapia biológica para la AR. Identificar a los pacientes con mayor probabilidad de presentar pérdida de respuesta, tanto primaria como secundaria, podría permitir que un número significativo de ellos alcanzara su objetivo terapéutico realizando los ajustes adecuados. Así, el objetivo principal de este estudio es la revisión de la evidencia que incluya información sobre las causas de falta o pérdida de respuesta, así como de los factores que influyen en la predicción de la respuesta a los iTNFα en la AR. Palabras clave: Artritis reumatoide, agente biológico, monitorización farmacocinética

    Pathogenic NR2F1 variants cause a developmental ocular phenotype recapitulated in a mutant mouse model

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    Pathogenic NR2F1 variants cause a rare autosomal dominant neurodevelopmental disorder referred to as the Bosch-Boonstra-Schaaf Optic Atrophy Syndrome. Although visual loss is a prominent feature seen in affected individuals, the molecular and cellular mechanisms contributing to visual impairment are still poorly characterized. We conducted a deep phenotyping study on a cohort of 22 individuals carrying pathogenic NR2F1 variants to document the neurodevelopmental and ophthalmological manifestations, in particular the structural and functional changes within the retina and the optic nerve, which have not been detailed previously. The visual impairment became apparent in early childhood with small and/or tilted hypoplastic optic nerves observed in 10 cases. High-resolution optical coherence tomography imaging confirmed significant loss of retinal ganglion cells with thinning of the ganglion cell layer, consistent with electrophysiological evidence of retinal ganglion cells dysfunction. Interestingly, for those individuals with available longitudinal ophthalmological data, there was no significant deterioration in visual function during the period of follow-up. Diffusion tensor imaging tractography studies showed defective connections and disorganization of the extracortical visual pathways. To further investigate how pathogenic NR2F1 variants impact on retinal and optic nerve development, we took advantage of an Nr2f1 mutant mouse disease model. Abnormal retinogenesis in early stages of development was observed in Nr2f1 mutant mice with decreased retinal ganglion cell density and disruption of retinal ganglion cell axonal guidance from the neural retina into the optic stalk, accounting for the development of optic nerve hypoplasia. The mutant mice showed significantly reduced visual acuity based on electrophysiological parameters with marked conduction delay and decreased amplitude of the recordings in the superficial layers of the visual cortex. The clinical observations in our study cohort, supported by the mouse data, suggest an early neurodevelopmental origin for the retinal and optic nerve head defects caused by NR2F1 pathogenic variants, resulting in congenital vision loss that seems to be non-progressive. We propose NR2F1 as a major gene that orchestrates early retinal and optic nerve head development, playing a key role in the maturation of the visual system

    An epidemiological model for prediction of endometrial cancer risk in Europe

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    Endometrial cancer (EC) is the fourth most frequent cancer in women in Europe, and as its incidence is increasing, prevention strategies gain further pertinence. Risk prediction models can be a useful tool for identifying women likely to benefit from targeted prevention measures. On the basis of data from 201,811 women (mostly aged 30–65 years) including 855 incident EC cases from eight countries in the European Prospective Investigation into Cancer and Nutrition cohort, a model to predict EC was developed. A step-wise model selection process was used to select confirmed predictive epidemiologic risk factors. Piece-wise constant hazard rates in 5-year age-intervals were estimated in a cause-specific competing risks model, five-fold-cross-validation was applied for internal validation. Risk factors included in the risk prediction model were body-mass index (BMI), menopausal status, age at menarche and at menopause, oral contraceptive use, overall and by different BMI categories and overall duration of use, parity, age at first full-term pregnancy, duration of menopausal hormone therapy and smoking status (specific for pre, peri- and post-menopausal women). These variables improved the discriminating capacity to predict risk over 5 years from 71 % for a model based on age alone to 77 % (overall C statistic), and the model was well-calibrated (ratio of expected to observed cases = 0.99). Our model could be used for the identification of women at increased risk of EC in Western Europe. To achieve an EC-risk model with general validity, a large-scale cohort-consortium approach would be needed to assess and adjust for population variation

    Monitorización de agentes biológicos en la artritis reumatoide

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    Los fármacos biológicos se han convertido en agentes clave para el tratamiento de las enfermedades inflamatorias inmunomediadas (IMID). Sin embargo, la terapia biológica está condicionada por la gran variabilidad farmacocinética (PK) inter/ intraindividual. La monitorización terapéutica (TDM), basada en las concentraciones de fármaco biológico y los anticuerpos antifármaco, es una herramienta apropiada para la optimización del tratamiento de las IMID con el objetivo de individualizar la posología para cada paciente. Así, la determinación de concentraciones plasmáticas de los agentes biológicos, junto con la interpretación de los valores clínicos y analíticos, permitiría una evaluación global del estado del paciente, optimizar la exposición al fármaco y mejorar la respuesta clínica. La monitorización de concentraciones plasmáticas se puede realizar en caso de no respuesta (TDM reactiva) o en caso de remisión para mantener una exposición al fármaco adecuada (TDM proactiva). En este artículo se resume la información disponible sobre la TDM de los agentes biológicos para la optimización del tratamiento de la artritis reumatoide (AR). A pesar de la evidencia disponible sobre la asociación entre las concentraciones séricas de fármacos y el resultado clínico en AR, se requieren más datos PK y de coste-efectividad que permitan obtener más información para consolidar la TDM como una intervención en reumatología. Palabras clave: Artritis reumatoide, agente biológico, monitorización farmacocinética

    Comprehensive Constitutional Genetic and Epigenetic Characterization of Lynch-Like Individuals

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    The causal mechanism for cancer predisposition in Lynch-like syndrome (LLS) remains unknown. Our aim was to elucidate the constitutional basis of mismatch repair (MMR) deficiency in LLS patients throughout a comprehensive (epi)genetic analysis. One hundred and fifteen LLS patients harboring MMR-deficient tumors and no germline MMR mutations were included. Mutational analysis of 26 colorectal cancer (CRC)-associated genes was performed. Pathogenicity of MMR variants was assessed by splicing and multifactorial likelihood analyses. Genome-wide methylome analysis was performed by the Infinium Human Methylation 450K Bead Chip. The multigene panel analysis revealed the presence of two MMR gene truncating mutations not previously found. Of a total of 15 additional MMR variants identified, five -present in 6 unrelated individuals- were reclassified as pathogenic. In addition, 13 predicted deleterious variants in other CRC-predisposing genes were found in 12 probands. Methylome analysis detected one constitutionalMLH1epimutation, but no additional differentially methylated regions were identified in LLS compared to LS patients or cancer-free individuals. In conclusion, the use of an ad-hoc designed gene panel combined with pathogenicity assessment of variants allowed the identification of deleterious MMR mutations as well as new LLS candidate causal genes. Constitutional epimutations in non-LS-associated genes are not responsible for LLS

    Sports, morality and body. The voices of sportswomen under Franco's dictatorship

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    The aim of this research is to study sportswomen's perceptions and experiences of women's sport in Francoist Spain (1939-1975). The main objective is to analyse the social, moral and aesthetic elements that are present in the experience of these athletes. This study was carried out with an intentional sample of 24 women from Andalusia, Aragon, Asturias, Basque Country, Catalonia and Valencia. They were interviewed by a network of researchers from six universities. Outstanding results show the existence of social limitations to start sports practice (particularly in the post-war period); the importance of sport as a character-building aspect; sport's remarkable influence on their body self-concept; and the incidence on sports of the mainstream moral discourse, which created a female model that even affected sports clothing. The main conclusion is that sportswomen in that period were pioneers and had to fight against most of society in order to develop their facet as athletes, as they would not follow the established model

    Seismically induced landslide hazard and exposure modelling in Southern California based on the 1994 Northridge, California earthquake event

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    Quantitative modelling of landslide hazard, as opposed to landslide susceptibility, as a function of the earthquake trigger is vital in understanding and assessing future potential exposure to landsliding. Logistic regression analysis is a method commonly used to assess susceptibility to landsliding; however, estimating probability of landslide hazard as a result of an earthquake trigger is rarely undertaken. This paper utilises a very detailed landslide inventory map and a comprehensive dataset on peak ground acceleration for the 1994 Mw6.7 Northridge earthquake event to fit a landslide hazard logistic regression model. The model demonstrates a high success rate for estimating probability of landslides as a result of earthquake shaking. Seven earthquake magnitude scenarios were simulated using the Open Source Seismic Hazard Analysis (OpenSHA) application to simulate peak ground acceleration, a covariate of landsliding, for each event. The exposure of assets such as population, housing and roads to high levels of shaking and high probabilities of landsliding was estimated for each scenario. There has been urban development in the Northridge region since 1994, leading to an increase in prospective exposure of assets to the earthquake and landslide hazards in the event of a potential future earthquake. As the earthquake scenario magnitude increases, the impact from earthquake shaking initially increases then quickly levels out, but potential losses from landslides increase at a rapid rate. The modelling approach, as well as the specific model, developed in this paper can be used to estimate landslide probabilities as a result of an earthquake event for any scenario where the peak ground acceleration variable is available
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