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• 1
Article
Language: English
In: Journal of Soils and Sediments, 2009, Vol.9(3), pp.168-179
Description: Byline: Steffen Keiter (1), Thomas Braunbeck (1), Susanne Heise (2), Stefan Pudenz (3), Werner Manz (4), Henner Hollert (1,5) Keywords: Classification; Ecological relevance; Fuzzy logic; Hazard assessment; Ranking Abstract: Background, aim, and scope Ecotoxicological risk assessment of sediments is usually based on a multitude of data obtained from tests with different endpoints. In the present study, a fuzzy logic-based model was developed in order to reduce the complexity of these data sets and to classify sediments on the basis of results from a battery of in vitro biotests. Materials and methods The membership functions were adapted to fit the specific sensitivity and variability of each biotest. For this end, data sets were categorized into three toxicity levels using the box plot and empirical methods. The variability of each biotest was determined to calculate the range of the gradual membership. In addition, the biotests selected were ranked according to the biological organisation level in order to consider the ecological relevance of the endpoints measured by selected over- or underestimation of the toxicity levels. In the next step of the fuzzy logic model, a rule-base was implemented using if...and...then decisions to arrive at a system of five quality classes. Results The results of the classification of sediments from the Rhine and Danube Rivers showed the highest correlation between the biotest results and the fuzzy logic alternative based on the empirical method (i.e. the classification of the data sets into toxicity levels). Discussion Many different classification systems based on biological test systems are depending on respective data sets therefore, they are difficult to compare with other locations. Furthermore, they don't consider the inherent variability of biotests and the ecological relevance of these test systems as well. In order to create a comprehensive risk assessment for sediments, mathematical models should be used which take uncertainties of biotest systems into account, since they are of particular importance for a reliable assessment. In the present investigation, the variability and ecological relevance of biotests were incorporated into a classification system based on fuzzy logic. Furthermore, since data from different sites and investigations were used to create membership functions of the fuzzy logic, this classification system has the potential to be independent of locations. Conclusions In conclusion, the present fuzzy logic classification model provides an opportunity to integrate expert knowledge as well as acute and mechanism-specific effects for the classification of sediments for an ecotoxicological risk assessment. Recommendations and perspectives In order to achieve a more comprehensive classification, further investigation is needed to incorporate results of chemical analyses and in situ parameters. Furthermore, more discussions are necessary with respect to the relative weight attributed to different ecological and chemical parameters in order to obtain a more precise assessment of sediments. Author Affiliation: (1) Department of Zoology, Aquatic Ecology and Toxicology Section, University of Heidelberg, Im Neuenheimer Feld 230, 69120, Heidelberg, Germany (2) Institut fur Biogefahrenstoffe und Umwelttoxikologie, Hamburg University of Applied Sciences (HAW), Lohbrugger Kirchstr. 65, Hamburg, 21033, Germany (3) Westlakes Scientific Consulting Ltd., Department of Environmental Science, Moor Row, Cumbria, CA24 3 LN, UK (4) German Federal Institute of Hydrology, Am Mainzer Tor 1, 56068, Koblenz, Germany (5) Institute for Environmental Research (Biology V), Department of Ecosystem Analysis, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany Article History: Registration Date: 04/05/2009 Received Date: 20/10/2008 Accepted Date: 27/03/2009 Online Date: 10/06/2009
Keywords: Classification ; Ecological relevance ; Fuzzy logic ; Hazard assessment ; Ranking
ISSN: 1439-0108
E-ISSN: 1614-7480
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• 2
Article
Language: English
In: PLoS ONE, 2013, Vol. 8(10)
Description: The estuary of the River Elbe between Hamburg and the North Sea (Germany) is a sink for contaminated sediment and suspended particulate matter (SPM). One major concern is the effect of human activities on the hydrodynamics, particularlythe intensive dredging activities in this area that may result in remobilization of sediment-bound pollutants. The aim of this study was to identify pollutants contributing to the toxicological risk associated with re-suspension of sediments in the Elbe Estuary by use of an effect-directed analysis that combines chemical and biological analyses in with specific fractionation techniques. Sediments were collected from sites along the Elbe Estuary and a site from a small harbor basin of the Elbe Estuary that is known to be polluted. The sixteen priority EPA-PAHs were quantified in organic extracts of sediments. In addition, dioxin equivalents of sediments were investigated by use of the 7-ethoxyresorufin O-deethylase assay with RTL-W1 cells and the Ah receptor-mediated luciferase transactivation assay with H4IIE-luc cells. Quantification of the 16 priorityPAHs revealed that sediments were moderately contaminated at all of the sites in the Elbe River Estuary (,0.02–0.906 mg/gdw). Sediments contained relatively small concentrations of dioxin equivalents (Bio-TEQ) with concentrations ranging from15.5 to 322 pg/g dw, which were significantly correlated with dioxin equivalents calculated based on toxicity referencevalues and concentrations of PAH. The concentration of Bio-TEQ at the reference site exceeded 200,000 pg/g dw. In apotency balance the 16 PAHs explained between 47 and 118% of the Bio-TEQ in the luciferase assay, which can be explained by the constant input of PAHs bound to SPM from the upper course of the Elbe River into its estuary. Successful identification of a significant portion of dioxin-like activity to priority PAHs in complex environmental samples such assediments has rarely been reported.
Keywords: Natural Sciences ; Earth And Related Environmental Sciences ; Environmental Sciences ; Naturvetenskap ; Geovetenskap Och Miljövetenskap ; Miljövetenskap ; Enviromental Science ; Miljövetenskap
ISSN: 1932-6203
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• 3
Article
Language: English
In: Diseases of Aquatic Organisms, 2010, Vol. 23, pp. 235-248
Description: Despite intensive efforts and tightened guidelines for improvement of water quality over the last 2 decades, declines of fish populations have been reported for several rivers around the world. The present study forms part of a comprehensive weight-of-evidence approach, which aims to identify potential causes for the decline in fish catches observed in the Upper Danube River. The major focus of the present study is the investigation of the health status of wild barbel Barbus barbus L. collected from 3 locations along the Danube River, which experienced different levels of contamination. Whereas the comparison of the condition factor (CF) of field fish with that of control fish revealed no differences, ultrastructural investigations indicated severe disturbance of hepatic cell metabolism in field fish from the more contaminated sites Rottenacker and Ehingen, compared to both control fish and field fish from the less contaminated site Riedlingen. The ultrastructural analysis provided information about reactions of e.g. the rough endoplasmic reticulum, peroxisomes, andmitochondria, indicating an impaired health status of barbel at the sampling sites Rottenacker and Ehingen. Even though a straightforward cause-effect relationship between sediment contamination and ultrastructural alterations could not be established, based on a meta-analysis and toxicity assays it may be suggested that sediment-bound xenobiotics at least partly account for the hepatocellular changes. A relationship between impaired fish health status and the decline of fish catches along the Upper Danube River cannot be excluded.
Keywords: Danube River ; Fish ; Population Decline ; Liver Ultrastructure ; Barbus Barbus ; Condition Factor ; Sediment ; Natural Sciences ; Earth And Related Environmental Sciences ; Environmental Sciences ; Naturvetenskap ; Geovetenskap Och Miljövetenskap ; Miljövetenskap ; Enviromental Science ; Miljövetenskap
ISSN: 0177-5103
E-ISSN: 16161580
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• 4
Article
Language: English
In: Reproductive Toxicology, April 2012, Vol.33(2), pp.245-253
Description: ► This study analyzes the usability of transcriptomics for the characterization of sediment extract toxicity. ► Altered gene expression was compared to data from established bioassays as well as to chemical analysis. ► Gene expression profiling could be documented as a useful tool for the investigation of sediment extracts. ► Only a limited number of altered gene expression could be explained by analytical chemistry or biological effects. The zebrafish embryo has repeatedly proved to be a useful model for the analysis of effects by environmental toxicants. This proof-of-concept study was performed to investigate if an approach combining mechanism-specific bioassays with microarray techniques can obtain more in-depth insights into the ecotoxicity of complex pollutant mixtures as present, e.g., in sediment extracts. For this end, altered gene expression was compared to data from established bioassays as well as to results from chemical analysis. Mechanism-specific biotests indicated a defined hazard potential of the sediment extracts, and microarray analysis revealed several classes of significantly regulated genes which could be related to the hazard potential. Results indicate that potential classes of contaminants can be assigned to sediment extracts by both classical biomarker genes and corresponding expression profile analyses of known substances. However, it is difficult to distinguish between specific responses and more universal detoxification of the organism.
Keywords: Microarray ; Transcriptomics ; Zebrafish ; Sediment Extract ; Comet Assay ; Erod Assay ; Ames Test ; Neutral Red Assay ; Chemistry ; Anatomy & Physiology ; Public Health
ISSN: 0890-6238
E-ISSN: 1873-1708
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• 5
Article
Language: English
In: Analytical and Bioanalytical Chemistry, 2008, Vol.390(8), pp.2009-2019
Description: This study is a consequence of a distinct fish decline in the Danube river since the beginning of the 1990s. In contrast to the decline of fish population, former studies have repeatedly documented that the water quality along the Danube river is improving. However, the conclusion of a pilot study in 2002 was that a high hazard potential is associated with local sediments. The present study documents that sediment samples from the Danube river showed comparatively high aryl hydrocarbon receptor mediated activity in biotests, using the cell lines GPC.2D.Luc, H4IIE (DR-CALUX®) and RTL-W1. The combination of chemical analysis, fractionation techniques and different in vitro tests revealed that priority pollutants could not explain the main induction, even though the concentrations of priority polycyclic aromatic hydrocarbons (PAHs) were very high (maximum in the tributary Schwarzach, sum of 16 EPA PAHs 26 μg/g). In conclusion, this investigation shows that nonpriority pollutants mainly mediate the high induction rates. Nevertheless, owing to the effects of PAHs towards fish and the connection between dioxin-like activity and carcinogenicity, the link between contamination and the fish population decline cannot be ruled out.
Keywords: Danube ; Fish decline ; Dioxin-like activity ; Aryl hydrocarbon receptor agonists ; Weight of evidence
ISSN: 1618-2642
E-ISSN: 1618-2650
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• 6
Article
Language: English
In: Mut.Res.-Genetic Toxicology and Environmental Mutagenesis, 2008, Vol.652(1), pp.38-45
Description: The present study forms part of a weight-of-evidence framework including genotoxicological studies in the upper Danube River basin, which aim at elucidating the reasons for the decline in fish catch. The major focus of this paper is the assessment of genotoxicity of sediments from the Danube River basin by use of the comet assay with RTL-W1 cells and with embryos of zebrafish ( ). A frequently discussed question in this type of approach is how to aggregate and compare the data obtained from genotoxicity testing. There is a need to develop mathematical method combining the information from dose–response curves and level of effectiveness (maximum genotoxic effect). For comparison and ranking of the genotoxic potential of samples from different locations along the Danube River, several methods based on EC , Lowest Observed Effect Concentration (LOEC), and maximum induction factor were compared with respect to their validity. An evaluation system termed the “3-step analysis” was developed to facilitate consideration of a maximum number of aspects of the raw data. The so-called “concentration-dependent induction factor” (CDI) introduces an index for a straightforward, precise and realistic assessment of the genotoxic potential of any kind of field sample or genotoxic agent.
Keywords: Comet Assay ; Danube Basin ; Evaluation ; Genotoxicity ; Sediment Contact Assay ; Zebrafish ( Danio Rerio) ; Biology ; Public Health
ISSN: 1383-5718
E-ISSN: 1879-3592
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• 7
Article
Language: German
In: Umweltwissenschaften und Schadstoff-Forschung, 2009, Vol.21(3), pp.260-263
Description: Background and aim Despite intensive and continuous stocking and improvement of water quality since the 1970s, fish populations, especially those of the grayling (Thymallus thymallus), have declined over the last two decades in the upper Danube River (Germany). In order to assess 1) possible links between...
Keywords: Natural Sciences ; Biological Sciences ; Naturvetenskap ; Biologiska Vetenskaper ; Natural Sciences ; Chemical Sciences ; Naturvetenskap ; Kemi ; Danube ; Effect-Directed Analysis ; European Water Framework Directive ; Fish Decline ; Weight-Of-Evidence ; Natural Sciences ; Biology ; Naturvetenskap ; Biologi ; Natural Sciences ; Chemistry ; Naturvetenskap
ISSN: 0934-3504
E-ISSN: 18655084
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• 8
Article
Language: English
In: The European Physical Journal C, 2013, Vol.73(3), pp.1-34
Description: The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of $\sqrt{s} = 900~\mbox{GeV}$ and 7 TeV collected during 2009 and 2010. Then, using the decay of K s and Λ particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2–5 % for central isolated hadrons and 1–3 % for the final calorimeter jet energy scale.
Keywords: High Energy Physics - Experiment;
ISSN: 1434-6044
E-ISSN: 1434-6052
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• 9
Article
Language: English
In: The European Physical Journal C, 2012, Vol.72(9), pp.1-21
Description: The results of a search for the production of second generation scalar leptoquarks are presented for final states consisting of either two muons and at least two jets or a muon plus missing transverse momentum and at least two jets. A total of 1.03 fb −1 integrated luminosity of proton-proton collision data produced by the Large Hadron Collider at $\sqrt{s}=7~\mbox{TeV}$ and recorded by the ATLAS detector is used for the search. The event yields in the signal regions are found to be consistent with the Standard Model background expectations. The production of second generation leptoquarks is excluded for a leptoquark mass m LQ 〈594 (685) GeV at 95 % confidence level, for a branching ratio of 0.5 (1.0) for leptoquark decay to a muon and a quark.
Keywords: High Energy Physics - Experiment;
ISSN: 1434-6044
E-ISSN: 1434-6052
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• 10
Article
Language: English
In: The European Physical Journal C, 2012, Vol.72(7), pp.1-22
Description: This letter reports on a search for hypothetical heavy neutrinos, N , and right-handed gauge bosons, W R , in events with high transverse momentum objects which include two reconstructed leptons and at least one hadronic jet. The results were obtained from data corresponding to an integrated luminosity of 2.1 fb −1 collected in proton–proton collisions at $\sqrt{s}=7~\mathrm{TeV}$ with the ATLAS detector at the CERN Large Hadron Collider. No excess above the Standard Model background expectation is observed. Excluded mass regions for Majorana and Dirac neutrinos are presented using two approaches for interactions that violate lepton and lepton-flavor numbers. One approach uses an effective operator framework, the other approach is guided by the Left–Right Symmetric Model. The results described in this letter represent the most stringent limits to date on the masses of heavy neutrinos and W R bosons obtained in direct searches.
Keywords: Letter;
ISSN: 1434-6044
E-ISSN: 1434-6052
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