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Arostegui I.,University of the Basque Country | Oron M.,AHAVA Dead Sea Laboratories | Gilliland D.,EU Joint Research Centre | Valsami-Jones E.,University of Birmingham
Nanotoxicology | Year: 2016

Metal-bearing nanoparticles (NPs) possess unique physico-chemical characteristics that make them useful for an increasing number of industrial products and applications, but could also confer them a higher toxicity due to their higher reactivity compared to bulk forms of the same materials. There is a considerable interest in the use of in vitro techniques in environmentally relevant species, such as marine mussels, to evaluate NPs toxicity. In the present work, mussel hemocytes and gill cells were used to assess the potential toxic effects of Au, ZnO and SiO2 NPs with different sizes and shapes in parallel with their respective ionic and bulk forms and additives used in the NPs preparations. Cytotoxicity (neutral red and MTT assays) was screened at a wide range of concentrations, and LC50 values were calculated. Uptake of fluorescently labeled SIO2 NPs of 27 nm by hemocytes was also investigated. Au, ZnO and SiO2 NPs were less toxic than the corresponding ionic forms but more toxic than the bulk forms. ZnO NPs were the most toxic NPs tested which could be related with their capacity to release free ions. SiO2 NPs were not taken up by hemocytes and were not toxic to either hemocytes or gill cells. Size-dependent toxicity was found for Au NPs. Shape influenced the cytotoxicity of ZnO NPs. Finally, the presence of the additives Na-citrate and Ecodis P90 contributed to the toxicity of Au and ZnO NPs, respectively. As a general conclusion, solubility appears to play a key role in NPs toxicity to mussel cells. © 2015 Informa UK Ltd.

Vanmaercke M.,Catholic University of Leuven | Vanmaercke M.,Research Foundation Flanders FWO | Kettner A.J.,University of Colorado | van Den Eeckhaut M.,EU Joint Research Centre | And 8 more authors.
Progress in Physical Geography | Year: 2014

Current models aiming to simulate contemporary sediment yield (SY) implicitly assume that tectonic effects are either irrelevant or are reflected by catchment topography. In this study we analyse the relation between SY and seismic activity, a component of tectonic processes. Results show a spatial correlation between SY and seismic activity expressed as the estimated peak ground acceleration (PGA) with a 10% exceedance probability in 50 years. PGA has a significant impact on the spatial variation of SY, even after correcting for cross-correlations with topography, lithology or other factors that may influence SY. Based on three distinct data sets, we demonstrate that this effect is significant both for small catchments in Europe (0.3-3940 km2) and for large river systems worldwide (1580-6.15×106 km2) and that seismic activity may be even more important for explaining regional variation in SY than land use or many other commonly considered factors (e.g. catchment area, climate). We show that explicitly considering seismic activity may lead to SY-estimates that easily deviate a factor 2 or more compared to estimates that do not consider seismic activity. This is not only the case for highly seismically active regions: also in regions with a weak to moderate seismic regime seismic activity helps explaining regional patterns in SY. We argue that these findings have important implications for a better understanding of SY and its sensitivity to human impacts, as well as for our comprehension of sediment fluxes at longer timescales. © The Author(s) 2014.

Katsumiti A.,University of the Basque Country | Gilliland D.,EU Joint Research Centre | Arostegui I.,University of the Basque Country | Cajaraville M.P.,University of the Basque Country
Aquatic Toxicology | Year: 2014

CdS quantum dots (QDs) show a great promise for treatment and diagnosis of cancer and for targeted drug delivery, due to their size-tunable fluorescence and ease of functionalization for tissue targeting. In spite of their advantages it is important to determine if CdS QDs can exert toxicity on biological systems. In the present work, cytotoxicity of CdS QDs (5. nm) at a wide range of concentrations (0.001-100. mg Cd/L) was screened using neutral red (NR) and thiazolyl blue tetrazolium bromide (MTT) assays in isolated hemocytes and gill cells of mussels (Mytilus galloprovincialis). The mechanisms of action of CdS QDs were assessed at sublethal concentrations (0.31-5. mg Cd/L) in the same cell types through a series of functional in vitro assays: production of reactive oxygen species (ROS), catalase (CAT) activity, DNA damage, lysosomal acid phosphatase (AcP) activity, multixenobiotic resistance (MXR) transport activity, Na-K-ATPase activity (only in gill cells) and phagocytic activity and damage to actin cytoskeleton (only in hemocytes). Exposures to CdS QDs lasted for 24. h and were performed in parallel with exposures to bulk CdS and ionic Cd. Ionic Cd was the most toxic form to both cell types, followed by CdS QDs and bulk CdS. ROS production, DNA damage, AcP activity and MXR transport were significantly increased in both cell types exposed to the 3 forms of Cd. CAT activity increased in hemocytes exposed to the three forms of Cd while in gill cells only in those exposed to ionic Cd. No effects were found on hemocytes cytoskeleton integrity. Effects on phagocytosis were found in hemocytes exposed to bulk CdS and to CdS QDs at concentrations equal or higher than 1.25. mg Cd/L but not in those exposed to ionic Cd, indicating a particle-specific effect on phagocytosis. In conclusion, cell-mediated immunity and gill cell function represent significant targets for CdS QDs toxicity. © 2014 Elsevier B.V.

Baritz R.,Federal Institute for Geosciences and Natural Resources | Seufert G.,EU Joint Research Centre | Montanarella L.,EU Joint Research Centre | Van Ranst E.,Ghent University
Forest Ecology and Management | Year: 2010

This study presents the results of a series of evaluations of a continent-wide soil database (EU/UN-ECE Level I) with the aim to estimate baseline soil carbon concentrations and stocks. The methodology included the biogeographic stratification of soil carbon measurements throughout Europe using climatic zones derived from the Soil Regions Map of Europe. The presented stock estimates range from 1.3 to 70.8. t. C/ha for the O-layer, and from 11.3 to 126.3. t. C/ha for the mineral soil 0-20. cm (Germany: 0-30. cm) (5 and 95 percentiles). Histosols were excluded because of methodological differences and data gaps. When looking at the median values of the strata investigated, relationships were found. For example, carbon stocks in the O-layer of sandy soils are distinctly higher than those of fine-textured soils. However, the variability is so high that some of these relationships disappear. For example in western and central Europe, the level of carbon stocks in the mineral soil between shallow soils (Leptosols) and more deeply developed soils (Podzols and Cambisols) do not differ very much. It was also found that just the investigation of topsoils is not sufficient to understand the regional pattern of organic matter in forest soils - unless the subsoil becomes included as well. It is hypothesized that for Europe, the impact of site factors such as climate, texture and relief are difficult to extract from such a database if the data are only stratified according to macro-climatic areas. It has to be considered that the effect of systematic error in the database is quite large (but cannot be identified on the level of the current data availability). In order to receive a first impression of the landscape-level distribution of carbon, a map of carbon concentrations in the topsoil was generated. The results support the relationships found between carbon stocks and site factors, such as climatic zones and soil type. Compared to the much lower carbon concentrations of agricultural soils, the results demonstrate clearly the importance of forest soils for the terrestrial carbon cycling in Europe. © 2010 Elsevier B.V.

Jennings P.,Innsbruck Medical University | Schwarz M.,University of Tübingen | Landesmann B.,EU Joint Research Centre | Maggioni S.,Instituto Of Ricerche Farmacologiche Mario Negri | And 4 more authors.
Archives of Toxicology | Year: 2014

There is an urgent need for the development of alternative methods to replace animal testing for the prediction of repeat dose chemical toxicity. To address this need, the European Commission and Cosmetics Europe have jointly funded a research program for ‘Safety Evaluation Ultimately Replacing Animal Testing.’ The goal of this program was the development of in vitro cellular systems and associated computational capabilities for the prediction of hepatic, cardiac, renal, neuronal, muscle, and skin toxicities. An essential component of this effort is the choice of appropriate reference compounds that can be used in the development and validation of assays. In this review, we focus on the selection of reference compounds for liver pathologies in the broad categories of cytotoxicity and lipid disorders. Mitochondrial impairment, oxidative stress, and apoptosis are considered under the category of cytotoxicity, while steatosis, cholestasis, and phospholipidosis are considered under the category of lipid dysregulation. We focused on four compound classes capable of initiating such events, i.e., chemically reactive compounds, compounds with specific cellular targets, compounds that modulate lipid regulatory networks, and compounds that disrupt the plasma membrane. We describe the molecular mechanisms of these compounds and the cellular response networks which they elicit. This information will be helpful to both improve our understanding of mode of action and help in the selection of appropriate mechanistic biomarkers, allowing us to progress the development of animal-free models with improved predictivity to the human situation. © 2014, Springer-Verlag Berlin Heidelberg.

Matinga M.N.,P.O Box 31632 | Pinedo-Pascua I.,EU Joint Research Centre | Vervaeke J.,EU Joint Research Centre | Monforti-Ferrario F.,EU Joint Research Centre | Szabo S.,EU Joint Research Centre
Energy Policy | Year: 2014

This paper uses Q methodology to reveal stakeholder perceptions on how best to address energy issues in Africa. We sampled a group of stakeholders involved in various energy sub-sectors to uncover perspectives on how to achieve and promote access to modern energy, energy efficiency and renewable energy in Africa, whether the perceptions could be correlated to educational or geographical background and implications such patterns could have on policies and current dialogues.We found that all stakeholders agree on the need to prioritise sustainability but had different views on how to achieve sustainable energy for all in Africa, depending on the relevance given to each energy driver. Stakeholders could be categorised into four groups: (I) preference of large-scale high-impact projects; (II) supporters of targeted sectoral solutions with preference for small-scale technology and microfinance; (III) supporters of centralised solutions with preference for grid extension, and (IV) supporters of local entrepreneurship with scepticism about centralised solutions. The results show that differences in stakeholders' perceptions can be associated with respondents' educational but not geographical background. This implies that dialogues on energy in Africa should focus on inter-disciplinary understanding while further examining the trans-continent consensus that appears to have been established. © 2013 Elsevier Ltd.

Sangiorgi G.,University of Milan Bicocca | Ferrero L.,University of Milan Bicocca | Perrone M.G.,University of Milan Bicocca | Bolzacchini E.,University of Milan Bicocca | And 2 more authors.
Environmental Pollution | Year: 2011

A novel approach for measuring vertical profiles of HCs and particle number concentrations was described and applied in the low troposphere over Milan (Italy) during typical spring and summer days. Particle profiles yielded nearly homogeneous concentrations below the mixing height, with level-to-ground concentration ratios of 92-97%, while HCs showed a more pronounced decrease (74-95%). Vertical mixing and photochemical loss of HCs were demonstrated to cause these gradients. Much lower concentrations were observed for the profiles above the mixing height, where the HC mixtures showed also a different composition, which was partially explained by the horizontal advection of air with HC sources different to those prevailing at the site. The application of pseudo-first order kinetics for reactions between HCs and the hydroxyl radical allowed for the estimation of the vertical mixing time scale in the order of 100 ± 20 min. © 2011 Elsevier Ltd. All rights reserved.

Chen D.,University of Liverpool | Shams S.,Islamic University of Technology | Carmona-Moreno C.,EU Joint Research Centre | Leone A.,EU Joint Research Centre
Journal of Hydro-Environment Research | Year: 2010

The European Commission is developing, under the responsibility of the Joint Research Centre and in close collaboration with international and national partners, the Water Knowledge Management Platform. This platform will integrate a dynamic management of different support tools and guidelines for the water management sector in developing countries. The support tools will be based on open source desktop GIS technologies in order to provide the final users in developing countries with a sustainable technology from both financial and technological points of view. In this study, a comprehensive list of several hundred open sources GIS software packages are put together by an extensive search and then screened to obtain a list of 31 packages for further consideration. Various criteria were developed to exclude 17 packages and the remaining 14 went through a series of installation and performance tests; firstly on a PC (Pentium (R), E5200 @ 2.50. GHZ, 1.98. Gb of RAM, Microsoft Windows XP Professional, Version 2002, Service Pack2). Several packages were dropped due to the general suitabilities and functionalities. Four packages (QGIS, gvSIG, MapWindow and openJUMP) performed well in map rendering of large file sizes (up to 125 Mb) and were further tested on a Pentium III computer. The QGIS package outperformed others in very poor computing conditions. The gvSIG and openJUMP packages performed reasonably well but their startup times were long, while MapWindow struggled. QGIS, gvSIG, openJUMP and MapWindow were recommended for the EU Water Knowledge Management Platform (WKMP). © 2010 International Association for Hydro-environment Engineering and Research, Asia Pacific Division.

PubMed | EU Joint Research Centre
Type: Journal Article | Journal: Alternatives to laboratory animals : ATLA | Year: 2014

Currently, the assessment of risk to human health from exposure to manufactured chemicals is mainly based on experiments performed on living animals (in vivo). Substantial efforts are being undertaken to develop alternative solutions to in vivo toxicity testing. This new paradigm, based on the Mode-of-Action (MoA) framework, postulates that any adverse human health effect caused by exposure to an exogenous substance can be described by a series of causally-linked biochemical or biological key events with measurable parameters. The elaboration of mechanistic knowledge through literature research is necessary for a MoA-driven design of integrated testing strategies using in vitro methods for in vivo predictions. The objective of our ongoing research is to demonstrate the feasibility of an integrated approach to predict human toxicity following the Adverse Outcome Pathway (AOP) framework. In our previous work on MoA with the HepaRG cell model, we developed a strategy to identify chemicals that were hepatotoxic. This pioneered an innovative way of using data from in vitro experiments to group chemicals based on their MoA, which is likely to be an important step in a toxicity testing strategy.

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