219 research outputs found

    Evaluation of landsat-8 thermal bands to monitor land surface temperature

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    Ponencia presentada en: IX Congreso de la Asociación Española de Climatología celebrado en Almería entre el 28 y el 30 de octubre de 2014.[ES]El nuevo Thermal Infrared Sensor (TIRS) a bordo del Landsat-8 (L8) dispone de dos bandas térmicas, 10 (11.60-11.19 μm) y 11 (11.50-12.51 μm), con una resolución espacial de 100m, con el fin de proporcionar temperaturas de la superficie terrestre (LST) de una manera más precisa que su predecesor Landsat-7 ETM+. El L8 fue lanzado en febrero de 2013, comenzando su adquisición operativa a mediados de abril. Los primeros estudios realizados por el equipo de calibración de L8 mostraron errores sistemáticos significativos para el TIRS, y en febrero de 2014 el archivo de imágenes L8 TIRS fue reprocesado para corregir dichos errores. En este estudio, con el fin de comprobar la calibración del L8 TIRS, realizamos medidas de campo en una zona llana y térmicamente homogénea dedicada al cultivo del arroz. A partir de estas medidas de LST simulamos las radiancias y temperaturas de brillo a nivel del satélite y las comparamos con los datos TIRS. Tal y como apuntaba el equipo de L8, nuestros resultados muestran una sobreestimación para la banda 11. Sin embargo, el recalibrado aplicado por dicho equipo para ambas bandas ha resultado no ser satisfactorio en nuestra zona experimental, ya que proponen sustraer errores sistemáticos mayores a los requeridos.[EN]The new Landsat-8 (L8) Thermal Infrared Sensor (TIRS) has two thermal bands, 10 (11.60- 11.19 μm) and 11 (11.50-12.51 μm) at 100-m spatial resolution, aimed to provide more accurate Land Surface Temperatures (LST) than Landsat-7 ETM+. L8 was launched on February 2013, and operational acquisitions started in middle April 2013. The first studies by the L8 Calibration Team showed significant TIRS temperature offsets, and in February 2014 the L8 TIRS archive was reprocessed to remove these offsets. In this study, ground LST measurements were performed in a flat and thermally homogeneous area of rice-crop fields for checking the calibration of the L8 TIRS bands. At-sensor radiances and brightness temperatures were simulated from ground-measured LSTs and compared with TIRS values. A significant overestimation was observed for band 11, in agreement with the L8 Calibration Team results. However, their recalibration was shown unsatisfactory in our test site for both bands, since they proposed subtracting higher offsets than required.This study was supported by the Spanish Ministerio de Economía y Competitividad (projects CGL2010-16364, CGL2010-17577/CLI, CGL2011-13579-E, CGL2011-30433 and GRACCIE Consolider-Ingenio 2010; and Dr. Niclòs "Ramón y Cajal" Research Contract) and Generalitat Valenciana (PROMETEO/2009/006 and PROMETEO/2009/086 projects)

    Prognostic classification for malignant tumors of the parotid gland

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    AbstractObjectiveThe histological classification of the World Health Organization (WHO), along with improved imaging studies, provide relevant information for the management of parotid carcinomas. However, the prognosis depends on factors other than histology and tumor extension. This article evaluates the usefulness of a prognostic classification of parotid cancers, including these factors in patients in a hospital area.MethodsA follow-up was conducted on 19 patients with parotid carcinomas, excluding lymphoid tumors or intra-parotid metastases, between 1998 and 2012. The prognostic index was obtained from the formulas proposed by Vander Poorten, with factors including age, tumor size, lymph node involvement, skin invasion, facial nerve involvement, perineural growth and margins of resection, before surgery (PS1) and after (PS2). Overall survival was related to 5 years for each patient based on their inclusion in any of the 4 risk groups defined.ResultsRisk stratification based on the results Vander Poorten PS2 was distributed into Risk Groups (GR) 1 (3 patients, 15.7%), 2 (5 patients, 26.3%), 3 (1 patient, 5.8%) and 4 (10 patients, 52.2%). The 6 patients who died during follow-up belonged to GR4. Only one of the 4 patients belonging to GR4 has exceeded the 5-year survival up to the current time.The comparison of the values that relate the pretreatment (PS1) and after treatment (PS2) results showed overall survival in patients with PS1<4.5 and PS2<4.9, whereas mortality was greater with indices of PS1>6.5 and PS2>7.7.ConclusionsVander Poorten index can be applied in hospital areas with small numbers of parotid carcinomas. It enables a more accurate prognosis for individual patients

    Seguimiento del balance de energía en superficie a través de la futur misión HyspIRI

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    Ponencia presentada en: IX Congreso de la Asociación Española de Climatología celebrado en Almería entre el 28 y el 30 de octubre de 2014.[ES]La estimación operativa y a escala global del balance de energía en superficie requiere de datos de temperatura desde satélite con alta frecuencia y resolución espacial. Sus 8 bandas en el térmico, los 60 m de tamaño de píxel y los 5 días de revisita, convierten a la misión HyspIRI en el futuro de la teledetección térmica multiespectral. En este trabajo se han simulado productos HyspIRI de flujos energéticos a partir de vuelos MASTER, de muy alta resolución espacial, sobre las reservas experimentales de Jornada y Sevilleta, situadas en el suroeste de EEUU. Para ello se ha utilizado un modelo de balance de energía de dos fuentes, combinado con datos meteorológicos registrados en la zona. Los resultados muestran la estabilidad del modelo aplicado a las imágenes simuladas HyspIRI, y permiten hacer un análisis del efecto de la pérdida de resolución espacial sobre la variabilidad de los flujos energéticos en zonas áridas.[EN]Frequent and high resolution remote sensing temperature data are needed for global scale, operational estimation of the surface energy balance. Its 8 thermal bands, 60-m pixel size and 5-day revisit time make the HyspIRI mission the future of the multispectral thermal remote sensing. In this work HyspIRI products of surface energy fluxes were simulated from very high spatial resolution MASTER flights, over the Jornada and Sevilleta experimental ranges, southwest USA. A two-source energy balance model, together with meteorological data, were used in this work. Results show the stability of the model when applied to simulated HyspIRI images, and allow performing an analysis of the effect of the spatial resolution degradation on the surface variability in arid areas in terms of energy fluxes.Los autores desean expresar su agradecimiento por la financiación recibida a NASA (10- HYSPIRI1 0-13), al Ministerio de Economía y Competitividad (CGL2010-17577/CLI) y a la Generalitat Valenciana (PROMETEO/2009/086)

    Brood parasitism is associated with increased bacterial contamination of host eggs: bacterial loads of host and parasitic eggs

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    Factors related to bacterial environment of nests are of primary interest for understanding the causes of embryo infection and the evolution of antimicrobial defensive traits in birds. Nest visitors such as parasites could act as vectors for bacteria and/or affect the hygienic conditions of nests and hence influence the nest bacterial environment. In the present study, we explored some predictions of this hypothetical scenario in the great spotted cuckoo (Clamator glandarius)-magpie (Pica pica) system of brood parasitism. Great spotted cuckoos visit the nests of their magpie hosts and frequently damage some of the host eggs when laying eggs or on subsequent visits. Therefore, it represents a good system for testing the effect of nest visitors on the bacterial environment of nests. In accordance with this hypothesis, we found that the bacterial load of magpie eggshells was greater in parasitized nests, which may suggest that brood parasitism increases the probability of bacterial infection of magpie eggs. Moreover, comparisons of bacterial loads of cuckoo and magpie eggs revealed that: (1) cuckoo eggshells harboured lower bacterial densities than those of their magpie hosts in the same nests and (2) the prevalence of bacteria inside unhatched eggs was higher for magpies than for great spotted cuckoos. These interspecific differences were predicted because brood parasitic eggs (but not host eggs) always experience the bacterial environments of parasitized nests. Therefore, the results obtained in the present study suggest that parasitic eggs are better adapted to environments with a high risk of bacterial contamination than those of their magpie hosts

    A relict oasis of living deep-sea mussels Bathymodiolus and microbial-mediated seep carbonates at newly-discovered active cold seeps in the Gulf of Cádiz, NE Atlantic Ocean

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    Extensive beds of the deep-sea mussel Bathymodiolus mauritanicus (currently also known as Gigantidas mauritanicus) linked to active cold seeps related to fissure-like activity on Al Gacel mud volcano, Gulf of Cádiz, were filmed and sampled for the first time during the oceanographic expedition SUBVENT-2 aboard R/V Sarmiento de Gamboa. Al Gacel mud volcano is one of up to 80 fluid venting submarine structures (mud volcanoes and mud volcano/diapir complexes) identified in the Gulf of Cádiz as result of explosive venting of hydrocarbon-enriched fluids sourced from deep seated reservoirs. This mud volcano is a cone-shaped edifice, 107 m high, 944 m in diameter constituted by mud breccias and, partially covered by pavements of seep carbonates. Extensive beds of this deep-sea mussel were detected at the northern flank at 810–815 m water depth associated with bacterial mats around intermittent buoyant vertical bubble methane plumes. High methane concentrations were measured in the water column above living mussel beds. Other chemosymbiotic species (Siboglinum sp., Solemya elarraichensis, Isorropodon sp., Thyasira vulcolutre and Lucinoma asapheus) were also found in different parts of Al Gacel mud volcano. Al Gacel mud volcano may currently represent one of the most active mud volcanoes in the Gulf of Cádiz, delivering significant amounts of thermogenic hydrocarbon fluids which contribute to foster the extensive chemosynthesis-based communities detected. This finding is of paramount importance for linking extremophile bivalve populations along the North Atlantic, including cold seeps of the Gulf of México, hydrothermal vents of the Mid-Atlantic Ridge and now, detailed documented at the Gulf of Cádiz.Versión del edito

    Micro-morphologies, habitats and associated biodiversity in a fluid venting submarine structure using ROV underwater images: Mercator mud volcano (Gulf of Cádiz)

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    Mercator mud volcano has been explored by direct visual observations using a ROV at 350 to 370 m depth. Underwater images, taken mainly at the summit, have allowed characterizing the fluid venting environment, where different microforms, habitats and associated biota, with typical seepage components have been identified. Chemosynthetic bacterial communities were detected and sampled at the northeastern side of the summit at 350 m, next to pockmark-like depressions with diameters ranging 1 to 3 m, bioturbation marks, sediment mounds and authigenic carbonates of different sizes (0.1-5m length). Chemosynthesis-based communities were mainly composed by bacterial mats (patch diameter 10-30 cm), however some remains of cold seep chemosymbiotic bivalves (Lucinoma asapheus) were also found on the sediment. Habitat types at Mercator MV are influenced by oceanographic and sedimentation processes deposition and favouring fauna colonizing diverse substrate types, such as large sponges on slabs and sea-pens and annelids on soft bottoms

    Seafloor deformation related to Quaternary tectonics in the Majorca Channel, Balearic Promontory (Western Mediterranean)

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    El análisis morfotectónico del sector central del Promontorio Balear, entre las islas de Ibiza y Mallorca, mediante batimetría multihaz y perfiles sísmicos de muy alta resolución ha permitido diferenciar varios rasgos morfológicos relacionados con la tectónica a dos escalas. Los elementos de gran escala, de dirección NE-SO, son: i) el escarpe Émile Baudot; ii) el monte submarino Émile Baudot, y iii) la alineación de montes submarinos Ausiàs March y Ses Olives. Los elementos de pequeña escala son: i) dos elevaciones longitudinales (ENE-OSO); ii) escarpes rectilíneos (NO-SE a NE-SO); iii) depresiones tectónicas (NNE SSO a NE-SO); y iv) alineaciones rectilíneas de pockmarks (NO-SE a NNE-SSO). Los elementos de mayor tamaño responden a la configuración estructural neógeno-cuaternaria. El escarpe Émile Baudot limita el Promontorio Balear y la cuenca oceánica del Mediterráneo Occidental. La alineación de montes submarinos Ausiàs March y Ses Olives está generada por una fase extensional, y el monte submarino Émile Baudot forma parte de una alineación volcánica NO-SE asociada a la Zona de Fractura de Ibiza. Los elementos de pequeña escala están relacionados con estructuras tectónicas activas que deforman las unidades sedimentarias del Cuaternario y el fondo marino. Las elevaciones longitudinales están generadas por pliegues anticlinales, mientras que el resto de estructuras están asociadas a la actividad de fallas normales de buzamiento alto.A morphotectonic analysis has been carried out between the islands of Ibiza and Majorca in the central sector of the Balearic Promontory using multibeam bathymetry and very high-resolution seismic profiles. Several morphological features related to tectonics at two different scales have been differentiated. The large-scale features have a NE-SW direction, they are: i) the Émile Baudot Escarpment; ii) the Émile Baudot seamount, and iii) the Ausiàs March and Ses Olives seamounts alignment. The differentiated small-scale elements are i) two longitudinal elevations (ENE-WSW); ii) rectilinear scarps (NW-SE to NE-SW); iii) tectonic depressions limited by one or two scarps (NNE-SSW to NE-SW), and iv) rectilinear pockmarks alignments (NW-SE to NNE-SSW). The largest elements respond to the Neogene-Quaternary structural configuration. The Émile Baudot escarpment is the limit between the Balearic Promontory and the Western Mediterranean oceanic basin. The alignment of the Ausiàs March and Ses Olives seamounts respond to the last extensional phase, and the Émile Baudot seamount forms part of a NW-SE volcanic alignment that could be associated with the Ibiza Fracture Zone. The smaller elements are related to active tectonic structures that deform Quaternary sedimentary units and the seafloor. The longitudinal elevations correspond to anticlinal folds, while the rest of the structures are associated to the activity of near vertical normal faults.En prens

    The complex influence of ENSO on droughts in Ecuador

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    48 Pags.- 1 Tabl.- 18 Figs. The definitive version is available at: http://link.springer.com/journal/382In this study, we analyzed the influence of El Niño–Southern Oscillation (ENSO) on the spatio-temporal variability of droughts in Ecuador for a 48-year period (1965–2012). Droughts were quantified from 22 high-quality and homogenized time series of precipitation and air temperature by means of the Standardized Precipitation Evapotranspiration Index. In addition, the propagation of two different ENSO indices (El Niño 3.4 and El Niño 1 + 2 indices) and other atmospheric circulation processes (e.g., vertical velocity) on different time-scales of drought severity were investigated. The results showed a very complex influence of ENSO on drought behavior across Ecuador, with two regional patterns in the evolution of droughts: (1) the Andean chain with no changes in drought severity, and (2) the Western plains with less severe and frequent droughts. We also detected that drought variability in the Andes mountains is explained by the El Niño 3.4 index [sea surface temperature (SST) anomalies in the central Pacific], whereas the Western plains are much more driven by El Niño 1 + 2 index (SST anomalies in the eastern Pacific). Moreover, it was also observed that El Niño and La Niña phases enhance droughts in the Andes and Western plains regions, respectively. The results of this work could be crucial for predicting and monitoring drought variability and intensity in Ecuador.This work was supported by the EPhysLab (UVIGO-CSIC Associated Unit) and the research projects I-COOP H2O 2013CD0006: “Test multisectorial y actividades demostrativa sobre el potencial desarrollo de sistemas de monitorización de sequías en tiempo real en la región del oeste de Sudamérica” financed by the Spanish National Research Council, CGL2011-27574-CO2-02, CGL2014-52135-C03-01 and Red de variabilidad y cambio climático RECLIM (CGL2014-517221-REDT), financed by the Spanish Commission of Science and Technology and FEDER, and “LIFE12 ENV/ES/000536-Demonstration and validation of innovative methodology for regional climate change adaptation in the Mediterranean area (LIFE MEDACC)” financed by the LIFE programme of the European Commission. Cesar Azorin-Molina was supported by the JCI-2011-10263 Grant. Arturo Sanchez-Lorenzo was supported by the JCI-2012-12508 Grant. Miquel Tomas-Burguera was supported by a doctoral grant by the Ministry of Economy and Competitiveness and Natalia Martin-Hernandez was supported by a doctoral grant by the Aragón Regional Government. E. Aguilar was funded by the Grant CCI-009-ATN/OC-12439-RG-2012 from the Banco Iberoamericano de Desarrollo.Peer reviewe

    Controlled trial of balance training using a video game console in community-dwelling older adults

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    gamification is a potentially attractive option for improving balance and reducing falls. to assess the effect of balance training using the NintendoTM Wii game console on balance (primary outcome), falls and fear of falling. quasi-randomised, open-label, controlled clinical trial in parallel groups, carried out on community-dwelling patients over 70 years, able to walk independently. Participants were assigned 1:1 to the intervention or control group. Balance training was conducted using the Nintendo WiiFit TM twice a week for 3 months. Balance was assessed using the Tinetti balance test (primary outcome), the unipedal stance and the Wii balance tests at baseline, 3 months and 1 year. Falls were recorded and Fear of falling was assessed by the Falls Efficacy Scale (Short-FES-I). 1,016 subjects were recruited (508 in both the intervention and the control group; of whom 274 and 356 respectively completed the 3-month assessment). There was no between-group difference in the Tinetti balance test score, with a baseline mean of 14.7 (SD 1.8) in both groups, and 15.2 (1.3) at 3 months in the intervention group compared to 15.3 (1.7) in controls; the between-group difference was 0.06 (95% CI 0.30-0.41). No differences were seen in any of the other balance tests, or in incident falls. There was a reduction in the fear of falling at 3 months, but no effect at 1 year. the study found no effect of balance training using the Nintendo TM Wii on balance or falls in older community-dwelling patients. The study protocol is available at clinicaltrials.gov under the code NCT02570178

    Monitoring ground subsidence in the Vega Media of the river Segura through Differential SAR Interferometry (DInSAR)

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    Ground subsidence caused by aquifer exploitation is a geotechnical hazard that affects wide areas, causing important economic damages. This phenomenon is due to soil consolidation produced by the increase of effective stress caused by piezometric depletion. In this work a Remote Sensing Technique called Coherent Pixel (CPT) is applied to monitor subsidence in the Vega Media of the Segura River during a period of eleven year
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