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41.
Ulrike Kammann Scarlett Biselli Ninja Reineke Werner Wosniok Dirk Danischewski Heinrich Hühnerfuss Angelika Kinder Arne Sierts-Herrmann Norbert Theobald Hans-Heinrich Vahl Michael Vobach Johannes Westendorf Hans Steinhart 《Journal of Soils and Sediments》2005,5(4):225-232
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Part I: Determination and identification of organic pollutants Part II: Results of the biotest battery and development of a biotest index-
Preamble. This series of two papers presents the results of an interdisciplinary research project (ISIS) dealing with bioassay-directed fractionation of marine sediment extracts. Part I presents the extraction and fractionation procedure as well as the results of chemical analysis, including non-target analysis of sediments. Part II describes the results of the biotest battery in relation to chemicals possibly causing parts of the observed effects. A biotest index is used to compare the toxicities of the samples.-
AUTHORS / AFFILIATIONS Ninja Reineke (3), Werner Wosniok (4), Dirk Danischewski (1), Heinrich Hühnerfuss (3), Angelika Kinder (5), Arne Sierts-Herrmann (5), Norbert Theobald (2), Hans-Heinrich Vahl (6), Michael Vobach (1), Johannes Westendorf (6) and Hans Steinhart (5).-
(1) Federal Research Centre for Fisheries, Institute for Fishery Ecology, Palmaille 9, 22767 Hamburg, Germany (2) Federal Maritime and Hydrographic Agency, Bernhard-Nochtstr. 78, 20359 Hamburg, Germany (3) University of Hamburg, Institute for Organic Chemistry, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany (4) University of Bremen, Institute of Statistics, Bibliothekstr. 1, 28334 Bremen, Germany (5) University of Hamburg, Institute for Food Chemistry, Grindelallee 117, 20146 Hamburg, Germany (6) University of Hamburg, University Hospital Hamburg-Eppendorf, Department for Toxicology, Vogt-Kölln-Str. 30, 22527 Hamburg, Germany (7) Eurofins Wiertz-Eggert-Jörissen, Stenzelring 14b, 21107 Hamburg, GermanyGoal, Scope and Background
The ecological relevance of contaminants in mixtures is difficult to assess, because of possible interactions and due to lacking toxicity data for many substances present in environmental samples. Marine sediment extracts, which contain a mixture of environmental contaminants in low concentrations, were the object of this study. The extracts were investigated with a set of different biotests in order to identify the compound or the substance class responsible for the toxicity. For this goal, a combination of biotests, biotest-directed fractionation and chemical analysis has been applied. Further on, a strategy for the development of a biotest index to describe the toxicity of the fractions without a prior ranking of the test results is proposed. This article (Part II) focuses on the biological results of the approach.Methods
The toxicological potential of organic extracts of sediments from the North Sea and the Baltic Sea was analyzed in a bioassay-directed fractionation procedure with a set of biotests: luciferase reporter gene assays on hormone receptor and Ah receptor, arabinose resistance test, fish embryo test (Danio rerio), comet assay, acetylcholinesterase inhibition test, heat-shock protein 70 induction, oxidative stress and luminescence inhibition test (Vibrio fischeri). The test results provided the basis for the calculation of a biotest index by factor analysis to compare the toxicity of the samples and fractions.Results and Discussion
Results of 11 biotests on different fractionation levels of the samples were described and discussed with regard to the occurrence of contaminants and their toxic potentials. Polychlorinated biphenyls, polycyclic aromatic hydrocarbons, quinones, brominated indoles and brominated phenols were in the focus of interest. A biotest index was constructed to compare the toxic responses in the samples and to group the biotest results.Conclusion
The procedure presented in this study is well suited for bioassay-directed fractionation of marine sediment extracts. However, in relatively low contaminated samples, high enrichment factors and sufficient fractionation is necessary to allow identification of low concentrations of contaminants which is required to link effects and possible causes. In the present case, the relation between substances and effects was difficult to uncover due to relatively low concentrations of pollutants compared to the biogenic matrix and to the remaining complexity of the fractions. The results, with respect to the brominated phenols and indoles in the samples, highlight the successful use of bioassay directed fractionation in the case of high concentrations and high toxicity.Recommendation and Outlook
In general, it has been shown that a marine risk assessment requires focusing on the input of diffuse sources and taking into account the fact of mixture toxicity. Effects resulting from biogenic substances will make the assessment of the influence of anthropogenic substances even more difficult. 相似文献42.
Effect of arbuscular mycorrhizal fungi (AMF) on heavy metal tolerance of alfalfa (Medicago sativa L.) and oat (Avena sativa L.) on a sewage-sludge treated soil In pot experiments with a sewage sludge treated soil, the influence of two arbuscular mycorrhizal fungi (AMF) isolates of Glomus sp. (T6 and D13) on plant growth and on the uptake of heavy metals by alfalfa (Medicago sativa L.) and oat (Avena sativa L.) was investigated. Alfalfa showed an increase of biomass with mycorrhizal infection only to a small extent. In oat AMF inoculation increased the growth of both root and shoot by up to 70% and 55% respectively. Mycorrhization raised the P-content and -uptake in alfalfa, but not in oat, in both roots and shoots. Mycorrhizal alfalfa showed lower Zn-, Cd- and Ni-contents and uptake in roots and shoots. The root length was significantly decreased in mycorrhizal alfalfa plants (up to 38%). The translocation of heavy metals into the shoot of mycorrhizal alfalfa was slightly increased. Mycorrhizal infection of oat led to higher concentrations of Zn, Cd and Ni in the root but to less Zn in the shoot. The translocation of heavy metals to the oat shoot was clearely decreased by mycorrhizal colonisation. This may be based on the ability of fungal tissues to complex heavy metals at the cell walls, thus excluding metals from the shoot. This conclusion is supported by the enhanced root length (up to 78%) of mycorrhizal oat plants in this experiment. The mycorrhizal infection seemed to protect plants against heavy metal pollution in soils. It was obvious that different host plants reacted in different ways. 相似文献
43.
Werner Müller-Ahlten 《植物养料与土壤学杂志》1994,157(1):1-9
On the genesis of tidal marsh soils I. The influence of sediment- and soil-structure The significance of sediment structure for soil structure has often been disregarded when discussing the properties and genesis of tidal marsh soils. After defening several terms that are often misinterpreted, three types of tidal-marsh-soils with different structure are described: 1 . the typical clayey tidal-marsh-soils with very various aggregate structures: The well aired and permeable “SEEMARSCH” (marine-tidal-marsh-soil) with polyhedral and prismatic structure, which is formed from the flaky “card-house” structure of marine sediments rich on salt; the densely paked “BRACKMARSCH” (brackish-tidal-marsh-soil), whose moisture is due to perched water, which coarse prismatic to columnar structure, which is formed from the mainly horizontally orientet structure of brackish sediments due to dispersion; the moderately permeable “FLUSSMARSCH” (tidal-river-marsh-soil), whose wetness is often due to groundwater, with medium to coarse prismatic structure, which is formed from the finely aggregated structure of perimarine tidal-river sediments; 2 . the tidal marsh soils poor in clay, rich in silt and very fine sand with coherent structure and low air porosity, due to a strong tendency towards puddling of the top soil by raindrops, causes the formation of “HAFTNÄSSEMARSCH” (marsh soil whose moisture is due to capillar water); 3 . the tidal-marsh-soils rich in plant remains, clay and with a high level of groundwater often extremly acid, with coherent structure, which formed the generally highly permeable “ORGANOMARSCH”. The conditions of formation of these soils and the soil parameters are discussed also. 相似文献
44.
The secretion of O2 by rice roots results in aerobic conditions in the rhizoshere compared to the bulk flooded soil. The effect of this phenomenon on the adsorption/desorption behavior and on the availability of phosphorus (P) in a flooded soil was investigated in a model experiment. An experimental set‐up was developed that imitates both O2 release and P uptake by the rice root. The results showed that O2 secretion significantly reduced P adsorption/retention and increased P desorption/release in the “rhizosphere” soil, compared to the anaerobic bulk soil. The P uptake by an anion exchange resin from both unfertilized and P‐amended soil was significantly increased. The results confirm that the O2 secretion is an important mechanism to enhance P availability and P uptake of rice under flooded conditions, where the “physico‐chemical” availability of P in the anaerobic bulk soil is strongly reduced. The decrease of P availability in the P‐amended flooded bulk soil was mainly associated with the almost complete transformation of the precedingly enriched Al‐P fraction into Fe‐bound P with extremely low desorption/release characteristics during the subsequent flooding. 相似文献
45.
As repeatedly reported, soil flooding improves the availability of P to rice. This is in contrast with an increased P sorption in paddy soils. The effects of soil flooding on the transformation of Fe oxides and the adsorption/desorption of P of two paddy soils of Zhejiang Province in Southeast‐China were studied in anaerobic incubation experiments (submerging with water in N2 atmosphere). Soil flooding significantly increased oxalate‐extractable Fe (Feox), mainly at the expense of dithionite‐soluble Fe (FeDCB), as well as oxalate‐extractable P (Pox), but decreased the ratio of Pox/Feox. Flooding largely increased both, P adsorption and the maximum P adsorption capacity. The majority of newly sorbed P in the soils was Pox, but also more newly retained P was found to be not extractable by oxalate. Flooding also changed the characteristics of P desorption in the soils. Due to a decrease of the saturation index of the P sorption capacity, P adsorbed by flooded soils was much less desorbable than that from non‐flooded soils. There are obviously significant differences in the nature of both, the Feox and Pox fractions under non‐flooded and flooded conditions. The degree of the changes in Feox, Pox, P adsorption and P desorption by flooding depended on the contents of amorphous and total Fe oxides in non‐flooded soils. Our results confirm that the adsorption and desorption behavior of P in paddy soils is largely controlled by the transformation of the Fe oxides. The reasons of the often‐reported improved P availability to rice induced by flooding, in spite of the unfavorable effect on P desorbability, are discussed. 相似文献
46.
Hakala P Lampi AM Ollilainen V Werner U Murkovic M Wähälä K Karkola S Piironen V 《Journal of agricultural and food chemistry》2002,50(19):5300-5307
The steryl ferulate contents of rye and wheat grains and their milling fractions were analyzed using a reversed-phase high-performance liquid chromatographic (HPLC) method. HPLC-mass spectrometry was used for identification. In addition, steryl ferulates of some selected milling byproducts were determined. The total steryl ferulate contents of rye and wheat grains were 6.0 and 6.3 mg/100 g, respectively. Uneven distribution of steryl ferulates in the grains led to considerable differences in the milling products; their steryl ferulate contents ranged from trace amounts in flours with low ash content to 20 and 34 mg/100 g in rye and wheat brans, respectively. Campestanyl ferulate and sitostanyl ferulate were the main components, followed by campesteryl ferulate and sitosteryl ferulate, whereas sitosterol was the main component in total sterols. Among the other samples, a byproduct of rice milling (pearling dust) was the best source of steryl ferulates, its total steryl ferulate content being 119 mg/100 g, whereas no measurable amounts of steryl ferulates were measured in oat bran or pearling dust of barley. The results indicated that rye and wheat and especially their bran fractions are comparable to corn as steryl ferulate sources. 相似文献
47.
48.
Daniel C Full J González L Lupulescu C Manz J Merli A Vajda S Wöste L 《Science (New York, N.Y.)》2003,299(5606):536-539
Femtosecond high-resolution pump-probe experiments have been used together with theoretical ab initio quantum calculations and wave packet dynamics simulations to decode an optimal femtosecond pulse that is generated from adaptive learning algorithms. This pulse is designed to maximize the yield of the organometallic ion CpMn(CO)3 while hindering the competing fragmentation. The sequential excitation and ionization of the target ion are accomplished by an optimized field consisting of two dominant subpulses with optimal frequencies and time delays. 相似文献
49.
Traver D Akashi K Manz M Merad M Miyamoto T Engleman EG Weissman IL 《Science (New York, N.Y.)》2000,290(5499):2152-2154
Dendritic cells (DCs) are critical in both initiating adaptive immune responses and maintaining tolerance to self antigens. These apparently contradictory roles have been suggested to depend on different subsets of DCs that arise from either myeloid or lymphoid hematopoietic origins, respectively. Although DC expression of CD8alpha is attributed to a lymphoid origin, here we show that both CD8alpha+ and CD8alpha- DCs can arise from clonogenic common myeloid progenitors in both thymus and spleen. Thus, expression of CD8alpha is not indicative of a lymphoid origin, and phenotypic and functional differences among DC subsets are likely to reflect maturation status rather than ontogeny. 相似文献
50.
Michel E Baglin A Auvergne M Catala C Samadi R Baudin F Appourchaux T Barban C Weiss WW Berthomieu G Boumier P Dupret MA Garcia RA Fridlund M Garrido R Goupil MJ Kjeldsen H Lebreton Y Mosser B Grotsch-Noels A Janot-Pacheco E Provost J Roxburgh IW Thoul A Toutain T Tiphène D Turck-Chieze S Vauclair SD Vauclair GP Aerts C Alecian G Ballot J Charpinet S Hubert AM Lignières F Mathias P Monteiro MJ Neiner C Poretti E de Medeiros JR Ribas I Rieutord ML Cortés TR Zwintz K 《Science (New York, N.Y.)》2008,322(5901):558-560
Oscillations of the Sun have been used to understand its interior structure. The extension of similar studies to more distant stars has raised many difficulties despite the strong efforts of the international community over the past decades. The CoRoT (Convection Rotation and Planetary Transits) satellite, launched in December 2006, has now measured oscillations and the stellar granulation signature in three main sequence stars that are noticeably hotter than the sun. The oscillation amplitudes are about 1.5 times as large as those in the Sun; the stellar granulation is up to three times as high. The stellar amplitudes are about 25% below the theoretic values, providing a measurement of the nonadiabaticity of the process ruling the oscillations in the outer layers of the stars. 相似文献