314 research outputs found

    Preface: Earth Observation for Integrated Water and Basin Management: Challenges for adaptation to a changing environment

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    Integrated river basin management involves a sound knowledge of water and land interactions, and impacts from and feedbacks to human activity. Remote sensing has been an efficient and increasingly promising means of gathering direct information of the Earth surface, as well as information on water and energy fluxes. The recent generation of high-resolution sensors offers a huge potential for monitoring, assessing, and modelling our changing environment in a context of uncertainty about how future climate conditions will affect the current water resource and basin management framework. Moreover, large amounts of data are now available posing a challenging opportunity to the scientific community for both exploring and transforming these data into readily usable information products for different end-users in our societies

    Exploring TanDEM-X Interferometric Products for Crop-Type Mapping

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    The application of satellite single-pass interferometric data to crop-type mapping is demonstrated for the first time in this work. A set of nine TanDEM-X dual-pol pairs of images acquired during its science phase, from June to August 2015, is exploited for this purpose. An agricultural site located in Sevilla (Spain), composed of fields of 13 different crop species, is employed for validation. Sets of input features formed by polarimetric and interferometric observables are tested for crop classification, including single-pass coherence and repeat-pass coherence formed by consecutive images. The backscattering coefficient at HH and VV channels and the correlation between channels form the set of polarimetric features employed as a reference set upon which the added value of interferometric coherence is evaluated. The inclusion of single-pass coherence as feature improves by 2% the overall accuracy (OA) with respect to the reference case, reaching 92%. More importantly, in single-pol configurations OA increases by 10% for the HH channel and by 8% for the VV channel, reaching 87% and 88%, respectively. Repeat-pass coherence also improves the classification performance, but with final scores slightly worse than with single-pass coherence. However, it improves the individual performance of the backscattering coefficient by 6–7%. Furthermore, in products evaluated at field level the dual-pol repeat-pass coherence features provide the same score as single-pass coherence features (overall accuracy above 94%). Consequently, the contribution of interferometry, both single-pass and repeat-pass, to crop-type mapping is proved.This work was funded by the Spanish Ministry of Science and Innovation, the State Agency of Research (AEI) and the European Funds for Regional Development (EFRD) under Project TEC2017-85244-C2-1-P, and by the European Commission, H2020 Programme, under Project MOSES (Managing crOp water Saving with Enterprise Services)

    SPARC regulation of PMN clearance protects from pristane-induced lupus and rheumatoid arthritis

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    The secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein with unexpected immunosuppressive function in myeloid cells. We investigated the role of SPARC in autoimmunity using the pristane-induced model of lupus that, in mice, mimics human systemic lupus erythematosus (SLE). Sparc−/− mice developed earlier and more severe renal disease, multi-organ parenchymal damage, and arthritis than the wild-type counterpart. Sparc+/- heterozygous mice showed an intermediate phenotype suggesting Sparc gene dosage in autoimmune-related events. Mechanistically, reduced Sparc expression in neutrophils blocks their clearance by macrophages, through defective delivery of don't-eat-me signals. Dying Sparc−/− neutrophils that escape macrophage scavenging become source of autoantigens for dendritic cell presentation and are a direct stimulation for γδT cells. Gene profile analysis of knee synovial biopsies from SLE-associated arthritis showed an inverse correlation between SPARC and key autoimmune genes. These results point to SPARC down-regulation as a leading event characterizing SLE and rheumatoid arthritis pathogenesis

    Effect of the water stress on gross primary production modeling of a Mediterranean oak savanna ecosystem

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    Dehesa ecosystem consists of widely-spaced oak trees combined with crops, pasture and Mediterranean shrubs. It is located in the southwest of the Iberian Peninsula, where water scarcity is recurrent, severely affecting the multiple productions and services of the ecosystem. Upscaling in situ Gross Primary Production (GPP) estimates in these areas is challenging for regional and global studies, given the significant spatial variability of plant functional types and the vegetation stresses usually present. The estimation of GPP is often addressed using light use efficiency models (LUE-models). Under soil water deficit conditions, biomass production is reduced below its potential rate. This work investigates the effect of different parameterizations to account for water stress on GPP estimates and their agreement with observations. Ground measurements of GPP are obtained using an Eddy Covariance (EC) system installed over an experimental site located in Córdoba, Spain. GPP is estimated with a LUE-model in the footprint of the EC tower using several approaches: a fixed value taken from previous literature; a fixed value modified by daily weather conditions; and both formulations modified by an additional coefficient to explicitly consider the vegetation water stress. The preliminary results obtained during two hydrological years (2015/2016 and 2016/2017) are compared, focusing on specific wet and dry periods.</p

    EFFECT OF COPPER OXIDE NANOPARTICLES TO SHEEPSHEAD MINNOW (CYPRINODON VARIEGATUS) AT DIFFERENT SALINITIES

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    Nanotechnologies research has become a significant priority worldwide. Many engineered nano-sized materials have been increasingly used in consumer products. But the adverse effects of these nanoparticles on the environment and organisms have recently drawn much attention. The present study investigated the effects of different concentrations of copper oxide nanoparticles (CuO NPs) on the sheepshead minnow (Cyprinodon variegatus) at different salinity regimes, since it is able to withstand a wide range of salinities. The results indicated that CuO NPs could cause behavioral changes in the fish, such as increased mucus secretion, less general activity and loss of equilibrium. No mortality was observed at the presence of CuO NPs during the experiments. But higher oxidative stress was determined at half strength seawater than seawater exposure medium, which can be associated with the decreasing toxicity of CuO NPs as salinity increases. In addition, Cu contents in the tissues of the fish were significantly higher (p&lt;0.05) in the low salinity

    DNA damage and transcriptional regulation in iPSC-derived neurons from Ataxia Telangiectasia patients

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    Abstract Ataxia Telangiectasia (A-T) is neurodegenerative syndrome caused by inherited mutations inactivating the ATM kinase, a master regulator of the DNA damage response (DDR). What makes neurons vulnerable to ATM loss remains unclear. In this study we assessed on human iPSC-derived neurons whether the abnormal accumulation of DNA-Topoisomerase 1 adducts (Top1ccs) found in A-T impairs transcription elongation, thus favoring neurodegeneration. Furthermore, whether neuronal activity-induced immediate early genes (IEGs), a process involving the formation of DNA breaks, is affected by ATM deficiency. We found that Top1cc trapping by CPT induces an ATM-dependent DDR as well as an ATM-independent induction of IEGs and repression especially of long genes. As revealed by nascent RNA sequencing, transcriptional elongation and recovery were found to proceed with the same rate, irrespective of gene length and ATM status. Neuronal activity induced by glutamate receptors stimulation, or membrane depolarization with KCl, triggered a DDR and expression of IEGs, the latter independent of ATM. In unperturbed A-T neurons a set of genes (FN1, DCN, RASGRF1, FZD1, EOMES, SHH, NR2E1) implicated in the development, maintenance and physiology of central nervous system was specifically downregulated, underscoring their potential involvement in the neurodegenerative process in A-T patients

    Use of canopy coefficients obtained from satellite data to estimate evapotranspiration over high mountain Mediterranean watersheds

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    This work explores the dynamics of the water consumed by the vegetation in two Mediterranean watersheds of Sierra Nevada Mountains (Southern Spain). This region has experienced an increase in the demand of water in the last years due to the growth of irrigated areas, and a new water resources plan is required. The evapotranspiration (ET) of irrigated horticultural crops and natural communities were monitored for the hydrological years 2013/14 and 2014/15, using an approach based on the concept of reference evapotranspiration (ETo) and canopy coefficients derived from the computation of vegetation indices (VIs), which we will call the VI-ETo approach. A set of Landsat-8 and MODIS images has been used as remote input data. The results were used for the spatial analysis of water consumption in terms of the main land cover types in the area. The annual runoff obtained with a simple surface water balance, using the ET values estimated by the VI-ETo approach, was comparable to that obtained by the HBV (Hydrologiska Byrans Vattenbalansavdelning) model, a precipitation-runoff generation model that reproduces the observed river discharge at the outlet of the watershed.</p

    Indices de eficiência do distrito de irrigação "Sector BXII del bajo Guadalquivir", Sul da Espanha, por sensoriamento remoto.

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    Avaliação do desempenho dos distritos de irrigação é estratégica para a melhoria da qualidade da gestão da água em grandes áreas ou bacias hidrográficas. Há diversos índices de eficiência, dentre estes se destacam evapotranspiração relativa - RET; coeficiente de déficit hídrico - CDH; índice de uso consumptivo - ICUC; suprimento relativo da irrigação - RIS e suprimento relativo de água (chuva mais irrigação) - RWS e de produtividade da água - WP. O estudo teve como objetivo avaliar o desempenho do distrito de irrigação ?Sector BXII del Bajo Guadalquivir?, região Sul da Espanha, por meio da definição de índices de eficiência e produtividade da água de irrigação

    Evolution of evapotranspiration and water stress of oak savanna vegetation in the Iberian Peninsula (2001-2015)

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    [EN] The objective of this work is to provide new insights about the effect of soil water deficit on the vegetation of Mediterranean oak savanna. The evolution of evapotranspiration (ET) and vegetation water stress over this ecosystem, in the Iberian Peninsula, has been monitored for fifteen years through the application of a remote sensing thermal-based energy balance model. The Surface Energy Balance System (SEBS) has been applied, on a monthly timescale from January 2001 to December 2015, using input satellite and meteorological reanalysis databases. The model performance has been evaluated under these conditions by comparison with field measurements. The estimation of energy fluxes yielded reasonable agreements with observations (RMSD=14-20 W·m–2 for the radiative fluxes and RMSD=26-29 W·m–2 for the turbulent ones) and have led to characterize the main drought events occurred during the study period, and to quantify their effects on the vegetation coverage and production. The most generalized and severe events (2004/2005 and 2011/2012) and their impact on different vegetation strata, oaks and grasslands, are further analyzed.[ES] Este trabajo pretende profundizar en el efecto del déficit de agua en el suelo sobre la vegetación de los ecosistemas de dehesa. Para ello, se ha realizado un seguimiento de la evapotranspiración (ET) y el estrés hídrico de este sistema en la Península Ibérica a lo largo quince años, mediante la aplicación de un modelo de balance de energía basado en datos térmicos procedentes de imágenes de satélite. El modelo SEBS (Surface Energy Balance System) se ha aplicado, a escala mensual desde enero de 2001 a diciembre de 2015, haciendo uso de datos remotos e información meteorológica procedente de reanálisis. Los resultados han permitido evaluar el funcionamiento del modelo en estas condiciones usando observaciones experimentales, obteniendo estimaciones suficientemente precisas (RMSD=14-20 W·m–2 para los flujos radiativos y RMSD=26-29 W·m–2 en los convectivos) para realizar un seguimiento de los flujos de energía, incluyendo ET, y el estrés hídrico de la vegetación en las condiciones estudiadas. Se han caracterizado los principales episodios de sequía ocurridos en dicho período, cuantificando su efecto sobre la cobertura de la vegetación y su producción. Por último, se ha profundizado en el análisis de los dos años más secos de la serie (2004/2005 y 2011/2012) y su impacto sobre los diferentes estratos de vegetación, herbáceos y arbóreo, del ecosistema de dehesa.Los autores desean agradecer la financiación re-cibida de INIA y FEDER 2014-2020 (Programa operativo de crecimiento inteligente) mediante el proyecto RTA2014-00063-C04-02, y del Co-operative Research Programme (CRP): Biological Resource Management for Sustainable Agricultural Systems de la OECD.González-Dugo, MP.; Chen, X.; Andreu, A.; Carpintero, E.; Gómez-Giráldez, P.; Su, Z. (2017). Evolución de la evapotranspiración y el estrés hídrico de la vegetación de dehesa en la Península Ibérica (2001-2015). Revista de Teledetección. (50):27-36. https://doi.org/10.4995/raet.2017.8916SWORD27365
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