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Berlin Brandenburg

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  • 1
    Language: English
    In: Ecotoxicology, 2013, Vol.22(5), pp.825-837
    Description: There is still controversy whether adverse effects by genotoxic anthropogenic pollutants are linked to the decline of fish populations. Further investigations into the relationship between genotoxic stress and detrimental effects on development and reproduction in fish are required. For this end, zebrafish (F0 generation) were exposed in vivo to the alkylating model genotoxin methyl methanesulfonate (MMS) from fertilization to the age of 1 year. F0 fish were mated over 6 months to check for reproductive capacities. F1 fish grew up without exposure in order to allow for regeneration. Mortality of F0 fish depended on MMS concentrations. In MMS-exposed F0 fish, times of first spawning were delayed and fertility was reduced. Using the alkaline comet assay and the micronucleus test, significant genotoxic effects were found in the livers, gills and gonads of either sex in the F0 generation. No detrimental effects on growth were found. In F1 fish with parental exposure, teratogenic effects were increased, and larval survival was reduced. However, fertility capacities of the non-exposed F1 generation had recovered. Development and survival rates further recovered in the F2 generation. Anthropogenic genotoxicants may thus play a considerable role in the decline of wild fish populations.
    Keywords: Zebrafish ; Reproduction ; Genotoxicity ; Teratogenicity ; Multigeneration study
    ISSN: 0963-9292
    E-ISSN: 1573-3017
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  • 2
    Language: English
    In: Science of the Total Environment, 2011, Vol.409(11), pp.2114-2119
    Description: The metal platinum is used for industrial and medical purposes. Due to its application in automobile catalytic converters and as an anti-cancer drug, Pt enters the aquatic environment road runoff and hospital sewage and raises concerns about its environmental impact and toxicity to organisms. Therefore, the genotoxicity of Pt at 0, 0.1, 1, 10, 50, 100 and 200 μg/l PtCl was tested on two freshwater organisms, zebrafish ( ) and ramshorn snail ( ) using the single cell gel electrophoresis, also called comet assay. PtCl did not show any genotoxicity for at the tested concentrations, whereas significantly elevated DNA damage was observed in at 1 μg/l PtCl and beyond. The results of the study suggest a high sensitivity of concerning the genotoxic impact of PtCl . ► We tested the genotoxicity of the heavy metal platinum using the comet assay. ► Model organisms were the freshwater species Danio rerio and Marisa cornuarietis. ► Genotoxicity of the tested concentrations was only found for M. cornuarietis.
    Keywords: Aquatic Organisms ; Ptcl 2 ; DNA Damage ; Comet Assay ; Environmental Sciences ; Biology ; Public Health
    ISSN: 0048-9697
    E-ISSN: 1879-1026
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  • 3
    Language: English
    In: Bulletin of Environmental Contamination and Toxicology, 2013, Vol.91(1), pp.89-95
    Description: Since generative tissues are a link between the generations, the detection of genetic damage in testis and ovary of fish is conductive to elucidating the relationship between genotoxicity and impairment of reproduction. In the current study, exposure of zebrafish to methyl methanesulfonate over two weeks caused concentration dependent genotoxic effects in gonads, liver and gills using the alkaline comet assay. Likewise, the micronucleus frequency was elevated in all of these organs. Thus, the comet assay and the micronucleus test proved appropriate for the detection of genotoxicity in primary male and female gonad cells and histological sections of the gonads from zebrafish, respectively.
    Keywords: Genotoxicity ; Zebrafish ; Comet assay ; Micronucleus test ; Gonads ; Methyl methanesulfonate
    ISSN: 0007-4861
    E-ISSN: 1432-0800
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  • 4
    Language: English
    In: Journal of environmental monitoring : JEM, May 2012, Vol.14(5), pp.1325-34
    Description: Existing methods for the comparison of genotoxic effects in the comet assay bear considerable disadvantages such as the problem to link information about concentration dependence and severity of effects. Moreover, given the lack of standardized protocols and the use of various standards, it may be extremely difficult to compare different studies. In order to provide a method for standardized comparative assessment of genotoxic effects, the concept of genotoxicity equivalents (Gene-TEQ) was developed. As potential reference compounds for genotoxic effects, three directly acting (N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), methyl-methanesulfonate, and N-methyl-N-nitrosourea) and three indirectly acting (cyclophosphamide, dimethylnitrosamine, and 4-nitroquinoline-oxide) genotoxic substances were compared with respect to their cytotoxic (neutral red) and genotoxic (comet assay) concentration-response profiles in the permanent fish cell line RTL-W1. For further comparison, two sediment extracts from the upper Danube River were investigated as environmental samples. Based on the results of cytotoxicity and genotoxicity testing, MNNG was selected as the reference compound. At several exposure levels and durations, genotoxic effects of both the other pure substances and the environmental samples were calculated as percentages of the maximum MNNG effect and related to the absolute MNNG effect (EC values). Thus, genotoxicity equivalent factors (Gene-TEQs) relative to MNNG could be calculated. Gene-TEQs can easily be applied to pure substances, mixtures and field samples to provide information about their toxicity relative to the reference compound. Furthermore, the Gene-TEQ concept allows a direct comparison of environmental samples from different laboratories.
    Keywords: Comet Assay -- Standards ; Mutagens -- Toxicity
    ISSN: 14640325
    E-ISSN: 1464-0333
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  • 5
    Language: English
    In: Journal of Environmental Monitoring, 2012, Vol.14, pp.1325-1334
    Description: Existing methods for the comparison of genotoxic effects in the comet assay bear considerable disadvantages such as the problem to link information about concentration dependence and severity of effects. Moreover, given the lack of standardized protocols and the use of various standards, it may be extremely...
    Keywords: Natural Sciences ; Earth And Related Environmental Sciences ; Environmental Sciences ; Naturvetenskap ; Geovetenskap Och Miljövetenskap ; Miljövetenskap ; Enviromental Science ; Miljövetenskap
    ISSN: 1464-0325
    Source: SwePub (National Library of Sweden)
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  • 6
    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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  • 7
  • 8
    In: Geophysical Research Letters, 28 August 2017, Vol.44(16), pp.8404-8413
    Description: Surface ocean carbon chemistry is changing rapidly. Partial pressures of carbon dioxide gas (CO) are rising, pH levels are declining, and the ocean's buffer capacity is eroding. Regional differences in short‐term pH trends primarily have been attributed to physical and biological processes; however, heterogeneous seawater carbonate chemistry may also be playing an important role. Here we use Surface Ocean CO Atlas Version 4 data to develop 12 month gridded climatologies of carbonate system variables and explore the coherent spatial patterns of ocean acidification and attenuation in the ocean carbon sink caused by rising atmospheric CO. High‐latitude regions exhibit the highest pH and buffer capacity sensitivities to CO increases, while the equatorial Pacific is uniquely insensitive due to a newly defined aqueous CO concentration effect. Importantly, dissimilar regional pH trends do not necessarily equate to dissimilar acidity ([H]) trends, indicating that [H] is a more useful metric of acidification. Chemical thermodynamics imparts a coherent spatial pattern of carbonate chemistry responses to anthropogenic carbon accumulation Nonuniform ocean acidification is anticipated with rising sea surface pCO2 The use of [H+] trends rather than pH trends is necessary to accurately decipher regional differences in ocean acidity change
    Keywords: Ocean Acidification ; Carbon Sink ; Revelle Factor ; Carbon Cycle
    ISSN: 0094-8276
    E-ISSN: 1944-8007
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  • 9
    In: Geophysical Research Letters, 16 May 2016, Vol.43(9), pp.4467-4476
    Description: Correlations between aragonite saturation state (Ω) and calcification have been identified in many laboratory manipulation experiments aiming to assess biological responses to ocean acidification (OA). These relationships have been used with projections of Ω under continued OA to evaluate potential impacts on marine calcifiers. Recent work suggests, however, that calcification in some species may be controlled by the ratio of bicarbonate to hydrogen ion, or the substrate‐to‐inhibitor ratio (SIR), rather than Ω. SIR and Ω are not always positively correlated in the natural environment, which means that Ω can be a poor indicator of the calcifying environment when Ω‐〉1. Highly variable carbonate chemistry in the coastal zone challenges our ability to monitor fluctuations in Ω, SIR, and the Ω‐SIR relationship making it difficult to assess biological OA exposures and vulnerability. Careful consideration of natural variability throughout ocean environments is required to accurately determine the influence of OA on biological calcification. Alternative indicators of biological calcification have implications for how carbonate chemistry variations are interpreted in OA studies The design of many CO2 manipulation experiments gives rise to ΩAr correlations that can be misleading Coastal carbonate system dynamics may complicate accurate assessments of ocean acidification impacts on some species
    Keywords: Saturation State ; Calcification ; Coastal ; Ocean Acidification ; Oceanography ; Biogeochemistry
    ISSN: 0094-8276
    E-ISSN: 1944-8007
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  • 10
    Language: English
    In: Physical review letters, 26 April 2013, Vol.110(17), pp.177201
    Description: We report on pairs of converging-diverging spin vortices in Co/Rh/NiFe trilayer disks. The lateral magnetization distribution of these effective spin merons is directly imaged by means of element-selective x-ray microscopy. By this method, both the divergence and circulation states of the individual layers are identified to be antisymmetric. Reversal measurements on corresponding continuous films reveal that biquadratic interlayer exchange coupling is the cause for the effective meron pair formation. Moreover, their three-dimensional magnetization structure is determined by micromagnetic simulations. Interestingly, the magnetic induction aligns along a flux-closing torus. This toroidal topology enforces a symmetry break, which links the core polarities to the divergence configuration.
    ISSN: 00319007
    E-ISSN: 1079-7114
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