[Assessment of cyto- and genotoxicity of natural waters in the vicinity of radioactive waste storage facility using Allium-test].

Efficacy of bioassays of "aberrant cells frequency" and "proliferative activity" in root meristem of Allium cepa L. is studied in the present work for a cyto- and genotoxicity assessment of natural waters contaminated with 90Sr and heavy metals in the vicinity of the radioactive waste storage facility in Obninsk, Kaluga region. The Allium-test is shown to be applicable for the diagnostics of environmental media at their combined pollution with chemical and radioactive substances.

Effects of chronic exposure in populations of Koeleria gracilis Pers. from the Semipalatinsk nuclear test site, Kazakhstan.

Morphological and cytogenetic abnormalities were examined in crested hairgrass (Koeleria gracilis Pers.) populations inhabiting the Semipalatinsk nuclear test site (STS), Kazakhstan. Sampling of biological material and soil was carried out during 3 years (2005-2007) at 4 sites within the STS.

Geno-toxicity assay of sediment and water samples from the Upper Silesia post-mining areas, Poland by means of Allium-test.

Genotoxic potential of two environmental compartments (water and sediment) from the Upper Silesia Coal Basin (USCB), Poland were evaluated and compared by employing root meristem cells of Allium cepa. The clear genotoxic effect of water and sediment sampled was shown, with an important contribution of severe types of cytogenetic abnormalities. The most biologically relevant pollutants were revealed through multivariate statistical analysis of relationships between biological effects registered and the environment contamination.

[Biological effects of chronic radiation exposure on plant populations].

The findings from long-term field studies on biological effects in plant populations inhabiting radioactively contaminated territories contrast in levels and compositions of dose-forming radionuclides are presented. Plant populations developing under radioactive impact show enhanced frequencies of gene and chromosome mutations, and their reproductive potential is inferior to reference populations. Even relatively low levels of technogenic impact are able to increase genetic diversity and destroy regularities inherent for intact populations.

[Cytogenetic effects in Koeleria gracilis Pers. populations from the Semipalatinsk proving ground].

The proliferative activity and the frequency of cytogenetic disturbances in apical meristem of coleoptile sprouts at germination of seeds collected from crested hairgrass populations inhabiting contrast in level of radioactive contamination sites of the Semipalatinsk test site (Kazakhstan) are studied. Sampling of biological material and soil was carrying out during three years (2005-2007). The absorbed dose to critical organs of crested hairgrass vary depending on a site from 2.

[Genetic variability in Scots pine populations from the Bryansk region contaminated by radioactive pollutants as a result of the Chernobyl NPP accident].

The method of isozymic analysis of megagametophytes is used for an estimation of genetic variability in populations of Scots pine (Pinus sylvestris L.), inhabiting contrast on the level of radioactive contamination (60-17800 Bq/kg on 137Cs) sites in the Bryansk region, undergone to radioactive pollution as a result of the Chernobyl accident. Values of all investigated parameters of genetic variability (heterozygosity, frequency of polymorphic loci, Jivotovski index) and frequencies of the mutations for loss of enzymatic activity increase with a doze absorbed by critical organs of pine trees.

[Cytogenetic effects in Scots pine populations from the Briansk region contaminated by radioactive pollutants as a result of the Chernobyl NPP accident].

Aberrant cell frequency in root meristem of germinated seeds collected from four populations of Scots pine in the Bryansk Region that was radioactively contaminated as a result of the accident at the Chernobyl NPP in 1986 significantly exceeded the control level durring all three years of study (2003-2005). An analysis of cytogenetic disturbances occurrence in dependence on radiation situation characteristics such as 137Cs and 90Sr content in pine cones, 137Cs specific activity in soil, and calculated doses absorbed by pine tree generative organs shows an increase in biological effect with dose burden increasing. Findings obtained are in agreement with the results of our previous studies on cytogenetic effects induction in Scots pine populations experiencing chronic radiation (the 30-km zone of the ChNPP) and technogenic (a radioactive waste reprocessing facility) impact.

The dust halo of Saturn's largest icy moon, Rhea.

Saturn's moon Rhea had been considered massive enough to retain a thin, externally generated atmosphere capable of locally affecting Saturn's magnetosphere. The Cassini spacecraft's in situ observations reveal that energetic electrons are depleted in the moon's vicinity. The absence of a substantial exosphere implies that Rhea's magnetospheric interaction region, rather than being exclusively induced by sputtered gas and its products, likely contains solid material that can absorb magnetospheric particles.

Cytogenetic effect of low dose gamma-radiation in Hordeum vulgare seedlings: non-linear dose-effect relationship.

The induction of chromosome aberrations in Hordeum vulgare germinated seeds was studied after ionizing irradiation with doses in the range of 10-1,000 mGy. The relationship between the frequency of aberrant cells and the absorbed dose was found to be nonlinear. A dose-independent plateau in the dose range from about 50 to 500 mGy was observed, where the level of cytogenetic damage was significantly different from the spontaneous level.

Cassini dust measurements at Enceladus and implications for the origin of the E ring.

During Cassini's close flyby of Enceladus on 14 July 2005, the High Rate Detector of the Cosmic Dust Analyzer registered micron-sized dust particles enveloping this satellite. The dust impact rate peaked about 1 minute before the closest approach of the spacecraft to the moon. This asymmetric signature is consistent with a locally enhanced dust production in the south polar region of Enceladus.

Cytogenetic effects of combined radioactive (137Cs) and chemical (Cd, Pb, and 2,4-D herbicide) contamination on spring barley intercalar meristem cells.

The frequency of cytogenetic effects in spring barley intercalar meristem cells was studied in the presence of a range of different stressors. There was a non-linear dependence on the concentrations of 137Cs, Cd, Pb, and dichlorophenoxyacetic acid (2,4-D) herbicide contamination in the exposure ranges used. The frequency of cytogenetic effects increased at the lower concentrations of the pollutants more rapidly than at the higher concentrations.

Bio-monitoring the genotoxicity of populations of Scots pine in the vicinity of a radioactive waste storage facility.

Results of a long-term (1997-2002) study of the Scots pine populations growing in the vicinity of the radioactive waste storage facility ('Radon' LWPE) are presented. Cytogenetic disturbances in reproductive (seeds) and vegetative (needles) tissues sampled from Scots pine populations were studied to examine whether Scots pine trees have experienced environmental stress in areas with relatively low levels of pollution. The data clearly indicate the presence of mutagenic contaminants in the environment of the pine trees.

[The radiation-increased synthesis of phytochelatins in roots of gamma-irradiated barley seedlings].

It was shown that gamma-irradiation and cadmium nitrate increased synthesis of phytochelatins in roots of barley seedlings. The stimulation of synthesis of phytochelatins in gamma-irradiated plants was shown for the first time. The results obtained indicate more important role of phytochelatins in intercellular metabolism than heavy-metal-binding.

Bioindication of the anthropogenic effects on micropopulations of Pinus sylvestris, L. in the vicinity of a plant for the storage and processing of radioactive waste and in the Chernobyl NPP zone.

Results of a comparative analysis of the frequency and spectrum of cytogenetic anomalies are presented for reproductive (seeds) and vegetative (needles) samples taken from Scotch pine (Pinus sylvestris, L.) micropopulations growing at sites with differing levels of radioactive contamination in the Chernobyl NPP 30 km zone, and at the location of a facility for the processing and storage of radioactive wastes (the 'Radon' LWPE, near the town of Sosnovy Bor in the Leningrad Region). The data obtained indicate the presence of genotoxic contaminants in the environment of the tree micropopulations.

Genetic consequences of radioactive contamination by the Chernobyl fallout to agricultural crops.

The genetic consequences of radioactive contamination by the fallout to agricultural crops after the accident at the Chernobyl NPP in 1986 have been studied. In the first, acute, period of this accident, when the absorbed dose was primarily due to external beta- and gamma-irradiation, the radiation injury of agricultural crops, according to the basic cytogenetic tests, resembled the effect produced by acute gamma-irradiation at comparable doses. The yield of cytogenetic damage in leaf meristem of plants grown in the 10-km zone of the ChNPP in 1987-1989 (the period of chronic, lower level radiation exposure) was shown to be enhanced and dependent on the level of radioactive contamination.

[Effect of combined radioactive and chemical (heavy metals, herbicides) pollution on the yield of cytogenetic disruptions in the intercalary meristem of spring barley].

The yield of aberrant cells and their loading with lesions of intercalary meristem of spring barley in conditions of the combined action of 137Cs, heavy metals and 2.4-D herbicide was studied. At simultaneous insertion of 137Cs and Cd into the soil, the type of non-linearity of the yield of aberrant cells was determined by radioactive pollution: in a range of low concentrations the synergistic effects took place, in a range of higher ones the antagonistic effects did.

[Effect of separate radioactive and chemical pollutants on the yield of cytogenetic disruptions in the intercalary meristem in spring barley].

Dependencies of the yield of cytogenetic disturbances within intercalary meristem cells of spring barley on the soil level of 137Cs (1.48-14.8 MBq/m2), Cd, Pb (2-50 and 30-300 mg per kilogram of the soil) and 2.

Induction of chromosome aberrations is non-linear within the low dose region and depends on dose rate.

The low dose region was evaluated for meristem cells of spring barley. A study of the cytogenetic damage in the low dose range was carried out to determine the genuine shape of the dose curve. The relationship between the frequency of aberrant cells and the absorbed dose is shown to be non-linear with a site at low doses within which the cytogenetic damage exceeds the control level significantly and does not depend on dose value.

[An analysis of the cytogenetic sequelae of chronic low-dose irradiation in plantings of agricultural crops].

There is a tendency for a decrease in the yield of cytogenetic disturbances with time elapsed from the Chernobyl accident. But an increased rate of cytogenetical damages significantly dependent on the level of radioactive contamination was observed even in several years after the incident. The rate of decline with time in cytogenetic disturbances induced by chronic exposure considerably lagged behind that of radiation exposure.

[A non-destructive sensitive reagent for lipid detection on TLC plates].

The aqueous solutions of 3 acidic and 14 basic dyes used as reagents for detection of lipids without their destruction are tested on plates for highly effective TLCh with the silicagel layer fixed by the silicic acid sol. It is shown that 0.002% solution of basic fuchsin in 1% boric acid reveals neutral, phospho- and glycolipids with the sensitivity compared with such in detection of sulphuric acid.

[Electrophoretic study of products of wall-eyed pollock and bovine rhodopsins fragmented by papain].

Fragmentation of wall-eyed pollock and bovine rhodopsins by papain in the photoreceptor membrane was studied by sodium dodecyl sulfate electrophoresis. A scheme of step-wise rhodopsin proteolysis is presented. The molecular weights and localization of the carbohydrate and chromophore components of the fragments formed were determined.