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541.
The process of a bioindication of genotoxic effects of complex mixtures on the environment using higher plants is very appropriate and effective. We present the results of an in situ indication of the genotoxic effects of polluted environment near Žilina city. For a more complex monitoring we used: the Tradescantia micronucleus (Trad-MCN) assay, the Tradescantia microspore test and an evaluation of the abortivity of the pollen grains of native plant species. We found significant differences in the frequency of the micronuclei when using the Trad-MCN test in local of Dubeň. The Tradescantia pollen abortivity test showed significant differences in the frequency of the abortive pollen grains between the exposed groups and the control group. By using native plant species in the pollen abortivity test we found significant differences in both of the two locations for the four following species during two consecutive years: Artemisia vulgaris, Melilotus albus, Trifolium pratense, Typha latifolia.  相似文献   
542.
The siliceous spongeGeodia cydonium Jameson was used to study the influence of pollution in marine environments on selected parameters of the intracellular signal transduction pathway. The parameters chosen were: intracellular distribution of protein kinase C (PK-C),ras-gene expression and DNA polymerasealpha (DNA Polalpha) activity. Both PK-C andras-gene product (ras-protein) have previously been established to be key molecules in the intracellular signalling pathway in sponges; increased level ofras-protein mediates events following sponge cell-cell contact. Three unpolluted and three polluted sites in the off-shore seawater around Rovinj (Yugoslavia) were selected for the study in 1989. The state of pollution of these sites has been well-defined in a series of previous studies (1976 to 1989). Transplantation of regenerating sponge cubes ofG. cydonium to the polluted sites resulted in pronounced changes in the parameters chosen, compared to controls exposed to unpolluted environments. Expression ofras gene was increased by three- to five-fold after exposure of regenerating sponge tissue to the impacted sites. At the site with the highest pollutional load,ras mRNA level was about 50% of that at the reference sites. In parallel experiments it was established that, in response to pollution, a translocation of PK-C from the cytosolic to membrane fraction occurred. At the most impacted site, most of the enzyme activity was cytosolic. DNA Polalpha-activity, as a measure of sponge cell proliferation, decreased in a pollutioncorrelated manner. Our results indicate that the intracellular signalling system within sponge cells is activated in response to moderate pollution but is depressed in heavily polluted environments.  相似文献   
543.
544.
Results of systematic measurements of radiocaesium activities in milk after the Chernobyl nuclear accident are summarized. 137Cs fallout activity affects milk activity, the coefficient of correlation being 0.89. The 137Cs activities in milk in Croatia are log-normally distributed, reflecting the exponential decrease of activity. After the Chernobyl nuclear accident the 134Cs:137 Cs activity ratio in milk was 0.5, and did not differ from that for other environmental samples. The dose due to radiocaesium ingestion by milk consumption was estimated for the Croatian population, the annual collective equivalent dose being approximately 205 manSv in 1986 and 1.5 manSv in 1994.  相似文献   
545.
Pavičić  J.  Raspor  B.  Martinčić  D. 《Marine Biology》1993,115(3):435-444
Electrochemical quantitation of metallothionin-like proteins (MLP) in mussels was based on the determination of their constituent cysteinyl residues according to Brdika's catalytic reaction. Calibration was performed by an internal MLP standard isolated from the digestive gland of Mytilus galloprovincialis for which protein concentration had been estimated by Bradford's spectrophotometric method. For that purpose three metal-binding proteins [MLP-I, MLP-II and Cu-BP (binding protein)] were separated by DEAE-Sephadex A-25 chromatography from the digestive gland of mussels previously exposed to Cd. The most negatively changed MLP-II fraction was characterized by the fact that it contained the largest amount of both total metal and sulphydryl (-SH) content per mass of protein, although this was approximately two times lower than the-SH level of commercially available MT from rabbit liver. Exposure of mussels to a relatively low level of cadmium (0.2 g Cd l-1) added into the seawater either by itself or as a mixture with other metals (2 g Cu l-1 and 1.6 g Pb l-1) resulted in a measurable level of MLP induction within 14 d in comparison to the control specimens. The effect of the metal mixture on MLP synthesis appears to be less than additive, suggesting a competitive interaction between metal ions for uptake and binding sites as well as differing potentials for MLP induction. Variations in the MLP content observed in the digestive gland of mussels seasonally collected from the same location are in the range 2.1±0.4 mg g-1 on a wet weight basis. The methodological and conceptual aspects of the application of MLP induction in the Mytilus sp. as a biomarker in seawater trace metal monitoring are critically evaluated.  相似文献   
546.
Abundant bog oak trunks occur in alluvial deposits of the Raba River in the village of Targowisko (southern Poland). Several of them contain galleries of the great capricorn beetle (Cerambyx cerdo L.). A well-preserved subfossil larva and pupa, as well as adults of this species, are concealed in some of the galleries. These galleries co-occur with boring galleries of other insects such as ship-timber beetles (Lymexylidae) and metallic wood borers (Buprestidae). A dry larva of a stag beetle (Lucanidae) and a mite (Acari) have been found in the C. cerdo galleries. Selected samples of the trunks and a sample of the C. cerdo larva were dated, using radiocarbon and dendrochronological methods, to the period from 45 bc to ad 554; one sample was dated to the period from 799 to 700 bc. Accumulation of the channel alluvia containing the bog oak trunks is synchronous with the Roman Warm Period (late antiquity/Early Mediaeval times). The most recent part of this period correlates with massive accumulations of fallen oak trunks noted from various river valleys in the Carpathian region and dated to ad 450–570. The results indicate that C. cerdo was more abundant within the study area during the Roman Warm Period than it is today.  相似文献   
547.
Potato starch was blended with defatted milk in proportions providing a 4:1, 3:1, 2:1, 1:1, 1,:2, 1:3, and 1:4 starch/casein ratio. Precipitation was achieved by addition of either hydrochloric acid or leaven. Composition of precipitated products was determined based on elemental analysis for nitrogen. Generally, differences between attempted and achieved casein-to-starch proportions did not exceed 10%. Products coprecipitated with hydrochloric acid were slightly richer in casein than products obtained with leaven. Aqueous solubility, water binding capacity, IR spectra, and thermal analysis (thermogravimetry, TG, and differential thermogravimetry, DTG) were recorded for the precipitates. Analyses revealed that the precipitates were not simple physical mixtures of the components. Partial insolubility in 7 M aqueous urea showed that casein and potato starch are chemically bound. Comparison of the spectra and thermograms suggested that complexes of the 1:1 composition were formed constituting a nucleus of the aggregates carrying excessive amounts of either starch or casein.  相似文献   
548.
The aim of the study was to compare accumulation efficiency of Al, Ba and nutritional elements (Ca, Fe, K, Mg, Mn, Na) exhibited by six edible mushrooms collected in particular regions of Poland during the last 20 years. The studied mushroom species were Boletus edulis, Cantharellus cibarius, Lactarius deliciosus, Leccinum aurantiacum, Suillus luteus and Xerocomus badius. The highest and the lowest concentrations of the elements in tested mushroom species were 11 – 410, 34 – 337, 16785 – 34600, 140 – 607, 12 – 75 and 16 – 143 mg kg?1d.m., respectively. The highest average concentrations of Al, Mg and Mn were observed in Suillus luteus fruiting bodies, while for Ba, Ca, K and Na it was in Lactarius deliciosus. BCF >1 was found for K and Mg in all tested mushroom species and additionally for the highest Ca and Na concentrations of all tested mushroom species except for C. cibarius and S. luteus, respectively. For the other tested elements (Al, Ba, Fe and Mn) BCF values < 1 were recorded.  相似文献   
549.
The use of willows (Salix amygdalina L) to manage landfill leachate disposal is an effective and cost-effective method due to the high transpiration ability of the willow plants. A 2-year lysimetric experiment was performed to determine an optimum leachate hydraulic loading rate to achieve high evapotranspiration but exert no harmful influence on the plants. The evapotranspiration rate of a soil-plant system planted with the willow was 1.28-5.12-fold higher than the rate measured on a soil surface lacking vegetation, suggesting that soil-willow systems with high volatilization rates are a viable landfill leachate treatment method. Of the soil-willow systems, the one with willow growing on sand amended with sewage sludge soil at an hydraulic loading rate of 1 mm day(-1) performed best, with evapotranspiration ranging from 2.25 to 3.02 mm day(-1) and a biomass yield of 8.0-9.85 Mg dry matter ha(-1). The organic fraction of the soil increased as much as 2.5% of dry matter, due to the sewage sludge input, which exerted a positive effect on the biomass yield as well as on transpiration and evaporation. It was observed that the plants in the sand-and-sewage sludge soil systems displayed higher resistance to toxic effects from the applied landfill leachate relative to plants in the sand-soil systems.  相似文献   
550.
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