218 research outputs found

    River flows in the Ebro basin: A century of evolution, 1913-2013

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    The water forecast is a major uncertainty in the design of strategies to cope with potential restrictions and ensure the availability of water, even during extreme events such as drought. In this context, our study aimed to present and analyze an updated broad temporal and geographical overview of the evolution of river flows for the most important river in Spain, the Ebro river, from 1913 to 2013. Our main findings indicate a decreasing trend in water resources from 1913 to the present, and a significant level of volatility that reveals a striking irregularity, with asymmetric cycles and dry years. These findings question the current irrigation policies and together with a need to rethink their implementation should drive further researc

    Study of evolution of microbiological properties in sewage sludge-amended soils: A pilot experience

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    Large amounts of sewage sludge are generated in urban wastewater treatment plants and used as fertilizer in agriculture due to its characteristics. They can contain contaminants such as heavy metals and pathogenic microorganisms. The objective of this research work is to study, in real conditions, the evolution of microbial concentration in agricultural soils fertilized by biologically treated sewage sludge. The sludge (6.25 tons Ha-1 ) was applied in two agricultural soils with different textures and crops. A microbiological (total coliforms, Escherichia coli, Staphylococcus aureus, Enterococcus sp., Pseudomonas sp., Salmonella sp. and total mesophylls) and physical-chemical characterization of the sludge, soils and irrigation water were carried out. The evolution of these parameters during sowing, growth and harvesting of crops was studied. Initially, sewage sludge had a higher concentration of microorganisms than soils. Irrigation water also contained microorganisms, fewer than sewage sludge amendment but not negligible. After amendment, there were no differences in the microbiological evolution in the two types of soil. In general, bacterial concentrations after crop harvest were lower than bacterial concentrations detected before sewage sludge amendment. Consequently, the application of sludge from water treatment processes did not worsen the microbiological quality of agricultural soil in this study at real conditions

    Europeanization vs. Globalization? A deeper look into income and employment embodied in intra-European trade

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    Production processes are nowadays increasingly global, implying interdependent structures linking goods, processes and countries. Traditional economic blocks and sectoral intra-country linkages coexist with increasing worldwide dependencies. Recent literature supports the hypothesis of a new globalization process taking place in the late 1990s and the 21st century, centred on the consolidation of increasingly competitive macro-regions at a global level, with a growing specialization of countries within them. We propose a multiregional input-output (MRIO) model of the European Union (EU) to analyse whether the generation of employment and income in Europe in recent decades can be defined as a process that is mainly regional or global (involving countries within the region versus countries outside Europe). Our results show that intra-EU trade is an important factor contributing to income and employment growth, more oriented to intermediate inputs, in the same way as extra-EU trade, despite the fact that some European countries are more specialized in final goods, mainly driven by high-income EU countries. Los procesos de producción son hoy en día cada vez más globales, lo que implica estructuras interdependientes que vinculan bienes, procesos y países. Los bloques económicos tradicionales y los vínculos sectoriales dentro del país coexisten con dependencias mundiales crecientes. La literatura reciente respalda la hipótesis de un nuevo proceso de globalización que tuvo lugar a fines de los años 90 y el siglo XXI, centrado en la consolidación de macro-regiones cada vez más competitivas a nivel global, con una creciente especialización de los países dentro de ellas. Proponemos un modelo multirregional input-output (MRIO) de la Unión Europea (UE) para analizar si la generación de empleo e ingresos en Europa en las últimas décadas se puede definir como un proceso que es principalmente regional o global. Nuestros resultados muestran que el comercio intracomunitario es un factor importante que contribuye al crecimiento de los ingresos y el empleo, más orientado a los inputs intermedios, de la misma manera que el comercio extracomunitario, a pesar del hecho de que algunos países europeos están más especializados en productos finales, principalmente demandados por países de altos ingresos de la UE

    The effect of data analysis strategies in density estimation of mountain ungulates using distance sampling

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    Distance sampling is being extensively used to estimate the abundance of animal populations. Nevertheless, the great variety of ways in which data can be analyzed may limit comparisons due to the lack of standardization of such protocols. In this study, the influence of analytical procedures for distance sampling data on density estimates and their precision was assessed. We have used data from 21 surveys of mountain ungulates in the Iberian Peninsula, France and the Italian Alps. Data from such surveys were analyzed with the program Distance 6.0. Our analyses show that estimated density can be higher for higher levels of data truncation. We also confirm that the estimates tend to be more precise when data are analyzed without binning and without truncating. We found no evidence of size biased sampling as group size and distances were uncorrelated in most of our surveys. Despite distance sampling being a fairly robust methodology, it can be sensitive to some data analysis strategies

    Validation of Immunoassay-Based Tools for the Comprehensive Quantification of Aß40 and Aß42 Peptides in Plasma

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    Recent advances in neuroimaging and cerebrospinal fluid (CSF) biomarker assays have provided evidence of a long preclinical stage of Alzheimer''s disease (AD). This period is being increasingly targeted for secondary prevention trials of new therapies. In this context, the interest of a noninvasive, cost-effective amyloid-ß (Aß) blood-based test does not need to be overstated. Nevertheless, a thorough validation of these bioanalytical methods should be performed as a prerequisite for confident interpretation of clinical results. The aim of this study was to validate ELISA sandwich colorimetric ABtest40 and ABtest42 for the quantification of Aß40 and Aß42 in human plasma. The validation parameters assessed included precision, accuracy, sensitivity, specificity, recovery, and dilution linearity. ABtest40 and ABtest42 proved to be specific for their target peptide using Aß peptides with sequence similar to the target. Mean relative error in the quantification was found to be below 7.5 for both assays, with high intra-assay, inter-assay, and inter-batch precision (CV <9.0 on average). Sensitivity was assessed by determination of the limit of quantification fulfilling precision and accuracy criteria; it was established at 7.60 pg/ml and 3.60 pg/ml for ABtest40 and ABtest42, respectively. Plasma dilution linearity was demonstrated in PBS; however, dilution in a proprietary formulated buffer significantly increased the recovery of both Aß40 and Aß42 masked by matrix interactions, allowing a more comprehensive assessment of the free and total peptide levels in the plasma. In conclusion, both assays were successfully validated as tools for the quantification Aß40 and Aß42 in plasma
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