295 research outputs found

    An assessment of the role of homogenization protocol in the performance of daily temperature series and trends: Application to northeastern Spain

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    [EN] This paper gives the complete details of the protocols applied for developing a spatially and temporarily high-resolution dataset of temperature for northeastern Spain. Our methodologies used data from a large number of observatories (1583) spanning some portions of the period between 1900 and 2006. The raw dataset was first tested for internal and external consistency to check data quality. To improve data completeness, a linear regression model was then utilized to infill gaps in the daily temperature series using the best correlated data from nearby sites. Discontinuities in the reconstructed series were determined by combining the results of three homogeneity-relative tests: the Standard Normal Homogeneity Test (SNHT), the Eastrerling and Peterson two-phased regression method and the Vincent test. To assess the possible impact of data homogenisation on trends and statistical properties of the final series, a set of tests (e.g. semivariance models and L-moment statistics) was applied to the series before and after correction. Semivariance models suggest a significant improvement in the spatial dependence of the corrected dataset on both seasonal and annual timescales. Also, L-moments gave no evidence of significant changes in the probability distribution of daily temperature series after correction. Taken together, the newly compiled dataset seems to be more robust and reveals more coherent spatial and temporal patterns of temperature compared with the original dataset. From the temporal and spatial perspectives, the new dataset comprises the most complete register of temperature in northeast Spain (1900-2006), with a reasonably spatial coverage. Accordingly, this database can provide a more reliable base for studying temperature changes and variability in the region. This dataset can also be of particular relevance to a number of meteorological, ecological, hydrological and agricultural applications on local, regional and continental scales. © 2011 Royal Meteorological Society.We are indebted to the anonymous reviewers for their constructive comments which were most helpful in improving this paper. We would like to thank the Agencia Estatal de Meteorologia for providing the temperature data used in this study. This work has been supported by the research projects CGL2006-11619/HID, CGL2008- 01189/BTE, CGL2011-27574-CO2-02, CGL2011-27753- CO2-01 and CGL2011-27536 financed by the Spanish Commission of Science and Technology; and also FEDER, EUROGEOSS (FP7-ENV-2008-1-226487) and ACQWA (FP7-ENV-2007-1- 212250) financed by the VII Framework Programme of the European Commission, La nieve en el Pirineo Aragones y su respuesta a ´ la variabilidad climatica, and Efecto de los escenarios ´ de cambio climatico sobre la hidrolog ´ ´ıa superficial y la gestion de embalses del Pirineo Aragon ´ es, financed by ´ Obra Social La Caixa and the Aragon Government and ´ Influencia del cambio climatico en el turismo de nieve, ´ CTTP01/10, financed by the Comision de Trabajo de los ´ Pirineos.Peer Reviewe

    Toxicity Assessment of Buprofezin, Lufenuron, and Triflumuron to the Earthworm Aporrectodea caliginosa

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    Earthworms are particularly important soil macroinvertebrates and are often used in assessing the general impact of pesticide pollution in soil. The present study was conducted in order to investigate the toxicity of three insect growth regulators (IGRs) buprofezin, lufenuron, and triflumuron, at different application rates and exposure times toward mature earthworms Aporrectodea caliginosa. The effects of these pesticides on the growth rate in relation to the activities of acetylcholinesterase (AChE) and glutathione S-transferase (GST) as biochemical indicators were evaluated to elucidate the mechanisms of action. Toxicity studies indicated that lufenuron was the most harmful pesticide to mature earthworms, followed in descending order by buprofezin and triflumuron. A reduction in growth rate in all pesticide-treated worms was dose-dependent over the 28-day exposure period, which was accompanied by a decrease in AChE and GST activities. Relationships between growth rate, AChE, and GST provided strong evidence for the involvement of pesticidal contamination in the biochemical changes in earthworms, which can be used as a bioindicator of soil contamination by pesticides

    ESTROGENS IMPROVE THE CARDIOVASCULAR ALTERATIONS IN FRUCTOSE-INDUCED INSULIN RESISTANT OVARIECTOMIZED RATS

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    Objective: The present study aimed to investigate the possible improving effects of 17-β estradiol (EST) and genistein (GEN) on the cardiovascular changes associated with fructose (21% in drinking water for 8 weeks)-induced insulin resistance.Methods: Sham-operated and ovariectomized mature female rats were included in this study. Insulin-resistant ovariectomized animals were sc treated with EST (100 µg/kg) or GEN (1 mg/kg) on the daily basis for 21 consecutive days.Results: Induction of insulin resistance in both sham-operated and ovariectomized rats decreased the vascular responsiveness of isolated aortic rings towards the vasoconstrictor norepinephrine and the vasodilator acetylcholine (Ach) with no changes towards the vasodilator sodium nitroprusside. Fructose-induced insulin resistance was also associated with an elevation in the blood pressure (BP) with decreased serum level of nitric oxide (NO). Treatment of insulin-resistant ovariectomized rats with either EST or GEN improved the vascular responsiveness of isolated aortic rings towards Ach and succeeded to reduce the elevated BP. Moreover, both EST and GEN decreased the insulin resistance/compensatory hyper insulinaemia. Treatment with EST increased serum NO level.Conclusion: EST and GEN have the ability to improve the endothelium-dependent relaxation in insulin-resistant ovariectomized rats and modulate the elevated BP.Â

    Assessment of vapor pressure deficit variability and trends in Spain and possible connections with soil moisture

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    The Vapor Pressure Deficit (VPD) is one of the most relevant surface meteorological variables; with important implications in ecology, hydrology, and atmosphere. By understanding the processes involved in the variability and trend of the VPD, it is possible to assess the possible impacts and implications related to both physical and human environments, like plant function, water use efficiency, net ecosystem production, atmospheric CO2 growth rate, etc. This study analysed recent temporal variability and trends in VPD in Spain between 1980 and 2020 using a recently developed high-quality dataset. Also, the connection between VPD and soil moisture and other key climate variables (e.g. air temperature, precipitation, and relative humidity) was assessed on different time scales varying from weekly to annual. The objective was to determine if changes in land-atmosphere feedbacks connected with soil moisture and evapotranspiration anomalies have been relevant to assess the interannual variability and trends in VPD. Results demonstrate that VPD exhibited a clear seasonality and dominant positive trends on both the seasonal (mainly spring and summer) and annual scales. Rather, trends were statistically non-significant (p > 0.05) during winter and autumn. Spatially, VPD positive trends were more pronounced in southern and eastern of Spain. Also, results suggest that recent trends of VPD shows low contribution of variables that drive land-atmosphere feedbacks (e.g. evapotranspiration, and soil moisture) in comparison to the role of global warming processes. Notably, the variability of VPD seems to be less coupled with soil moisture variability during summertime, while it is better interrelated during winter, indicating that VPD variability would be mostly related to climate variability mechanisms that control temperature and relative humidity than to land-atmosohere feedbacks. Overall, our findings highlight the importance of assessing driving forces and physical mechanisms that control VPD variability using high-quality climate datasets, especially, in semiarid and sub-humid regions of the world

    Geophysical site assessment of an active urban development site, South Eastern Suburb of Cairo, Egypt

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    There has been significant structural damage of newly-built residential buildings in Quarter-27 District in the South of Cairo, Egypt. The proximity of an active limestone quarry may also be affecting ground stability. This paper shows how a near-surface geophysics survey could characterize the site, unusually after the initial housing construction had already been undertaken. Geophysical surveys included seismic refraction (acquired between phases of quarry blasting), electrical resistivity and ground penetrating radar 1D and 2D datasets. Geophysical results produced maps of a 3D ground model that also included water table depth, known major faults and a saturated layer that may have caused the building damage. ERT and GPR data was deemed optimal of the geophysical techniques trialled. This study shows that it is possible to undertake geophysical surveys to characterize a restricted urban site development

    Increased Vegetation in Mountainous Headwaters Amplifies Water Stress During Dry Periods

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    The dynamics of blue and green water partitioning under vegetation and climate change, as well as their different interactions during wet and dry periods, are poorly understood in the literature. We analyzed the impact of vegetation changes on blue water generation in a central Spanish Pyrenees basin undergoing intense afforestation. We found that vegetation change is a key driver of large decreases in blue water availability. The effect of vegetation increase is amplified during dry years, and mainly during the dry season, with streamflow reductions of more than 50%. This pattern can be attributed primarily to increased plant water consumption. Our findings highlight the importance of vegetation changes in reinforcing the decrease in water resource availability. With aridity expected to rise in southern Europe over the next few decades, interactions between climate and land management practices appear to be amplifying future hydrological drought risk in the region.This work was supported by projects CGL2017-82216-R, PCI2019-103631, and PID2019-108589RA-I00 financed by the Spanish Commission of Science and Technology and FEDER; CROSSDRO project financed by AXIS (Assess-ment of Cross(X)-sectoral climate Impacts and pathways for Sustainable transformation), JPI-Climate co-funded call of the European Commission and INDECIS which is part of ERA4CS, an ERA-NET initiated by JPI Climate, and funded by FORMAS (SE), DLR (DE), BMWFW (AT), IFD (DK), MINECO (ES), ANR (FR) with co-funding by the European Union (Grant 690462). Dhais Peña-Angulo received a “Juan de la Cierva” postdoctoral contract (FJCI-2017-33652 Spanish Ministry of Economy and Competitiveness, MEC). Miquel Tomas-Burguera received a “Juan de la Cierva” postdoctoral contract (FJCI-2019-039261-I Spanish Ministry of Science and Innovation). C. Azorin-Molina and S. Grainger. acknowledge funding from the Irish Environmental Protection Agency grant 2019-CCRP-MS.60. C. Juez acknowl-edges funding from the H2020-MSCA-IF-2018 programme (Marie Sklodows-ka-Curie Actions) of the European Union under REA grant agreement, number 834329-SEDILAND

    The SPEIbase: A new gridded product for the analysis of drought variability and drought impacts

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    22 Pag., 17 Fig.The SPEIbase is a global SPEI dataset at time scales from 1 to 48 months with a spatial resolution of 0.5° for the period 1901-2006. It is based on the CRU TS3 dataset, the most complete and up-to-date source of gridded temperature and precipitation data for the entire World. It is also based on the same grid and time structure. Monthly temperature data was used to compute the ET0 based on the approximation of Thornthwaite (1948). Overview of the talk: 1. The SPEI: motivation, advantages 2. The SPEIbase: methodology, data sources, distribution 3. Examples of use 4. Data distributionPeer reviewe
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