Types of narrow-skulled vole (<Emphasis Type="Italic">Lasiopodomys gregalis</Emphasis>) colonies in Northern Kulunda and seasonal dynamics of their demographic composition

Demographic structure and its seasonal dynamics have been studied in colonies of narrow-skulled voles (Lasiopodomys gregalis Pall.) in Northern Kulunda. Three types of colonies have been distinguished: (I) true colonies (large, complex families), (II) simple families (nuclear or incomplete), and (III) all-male colonies. Changes in their sex, age, and functional composition (based on animal migration activity) during the breeding season have been analyzed.     

Exoautometabolic regulation of transgenes in microorganisms

Data on the existence of a specific system regulating the growth, size, and structure of enterobacterial populations are first summarized in terms of the chemical ecology concept formulated by S.S. Shvarts. The role of this system in transgene functioning is described using the example of the lux operon integrated into Escherichia coli. A relatively simple test for estimating such interactions is proposed.Translated from Ekologiya, No. 2, 2005, pp. 91–96.Original Russian Text Copyright © 2005 by Pshenichnov, Maslennikova, Nikitina.     

Uranium bioassay and radioactive dust measurements at some uranium processing sites in Egypt--health effects

The safety of radiation workers in the uranium mining industry requires close and continuous monitoring of their working conditions. In this study, external radiation surveillance, radioactive dust monitoring and the bioassay of uranium were carried out in some processing sites. As dust represents one of the most important sources of radiation exposure in mills and mines, dust monitoring and bioassays were performed for a sample of workers on the production lines. The concentration of uranium in air ranged from 22.6 x 10(-7) to 11.1 x 10(-5) Bq cm-3, and the exposure levels ranged from 1 to 80 microSv h-1. Laser fluorimetric determination of uranium in urine samples showed concentrations in the range 8.4-29.2 micrograms L-1. Renal function parameters, such as serum creatinine and urea, and hematological parameters were determined in an attempt to correlate them with radiation exposure and the health status of the workers. Urine specimens collected from workers at the ore crushing and separation site showed elevated concentrations of uranium (up to 29.2 micrograms L-1) and a strong correlation between these concentrations and the registered serum creatinine. The mean uranium excretion in the investigated group was more than 20 times the occupational exposure decision level for urine uranium of 0.8 microgram L-1.     

Singular Spectrum Analysis of Hydroecological Parameter Dynamics of Lake Naroch’ in the Years 1978–2015

Singular Spectrum Analysis (SSA) has been used to decompose continuous series of data on certain characteristics of Lake Naroch’ ecosystem during the vegetative seasons of years 1978–2015 into a long-time trend, a periodic component, and a residue not amenable to decomposition. The contribution of each component to changes in this variable has been assessed. The trends accounted for 78–97% of parameter variability, and the periodic components accounted for 2.5–15%. The fluctuations of phytoplankton and zooplankton biomass dynamics were the most diverse, and the contribution of these components was the greatest (15 and 8%, respectively). The periodic components in the changes of all parameters could be divided into four groups according to period duration (17–22, 7–15, 4–7, and less than 4 years). Multidimensional factor analysis of seven biotic parameters was performed in order to identify fluctuations in the ecosystem. Five major factors accounting for 93.6% of ecosystem changes together were identified, and each factor variable was subjected to SSA analysis. The period durations were similar for the oscillatory components identified. The first factor was interpreted as a trophic status of the water body, the second was taken to be the geographical location that defines the amount of solar radiation energy available, the third was taken to be the availability of biogenic elements (phosphorus in particular), and the fourth was interpreted as specific developmental cycles of live components of the ecosystem.     

Variation in the Composition of Secondary Metabolites in <Emphasis Type="Italic">Flavocetraria</Emphasis> Lichens from Western Siberia

The composition and contents of secondary metabolites in Flavocetraria lichens from Eastern Siberia were analyzed using herbarium specimens. Based on the composition of identified metabolites, three F. cucullata chemotypes and two F. nivalis chemotypes were distinguished. Distinct geographic differentiation between the F. cucullata chemotypes was revealed, probably reflecting their adaptation to environmental conditions. The content of usnic acid in F. cucullata thalli was found to correlate with the latitude of growing region. This may be regarded as evidence for a protective role of this metabolite in lichens growing at high latitudes and exposed to excess solar irradiation during the polar day.     

Ecophysiological indicators of the state of animal populations exposed to damaging factors

Indices of abundance and reproduction rate are considered in some groups of aquatic and terrestrial vertebrates from the zones of technogenic disasters. Upon a critical population decline caused by external destructive factors, such as emissions of acute ecotoxicants, the ecophysiological and behavioral compensatory mechanisms are activated, which provide for restoration of the total population size to the optimum within a short period of time. Environmental pollution with substances disturbing the reproductive function has the gravest consequences for animals. In this case, population size may remain fairly high, and, therefore, the effect of enhanced reproduction as a response to population decline does not take place, which eventually leads to a gradual but irreversible destruction of the population. Pathologies of reproduction should be used as a criterion for assessing the state of animals in the zones of technogenic disasters.Translated from Ekologiya, No. 1, 2005, pp. 32–38.Original Russian Text Copyright © 2005 by Shilova, Shatunovskii.     

Mangrove Mapping Using Landsat Imagery and Aerial Photographs: Kemaman District, Terengganu, Malaysia

Classification and distribution of mangrove vegetation are vital information for the proper development of a mangrove management plan. In this study, classification for the mangroves of the district of Kemaman were done using both 1 : 5000 aerial photographs and Landsat TM imageries. The coverage by aerial photographs is limited to the coastal and estuarine areas only. Thus, for areas further upstream of the aerial photo coverage, Landsat TM imageries were used. Analysis of aerial photographs and remote sensing images revealed that the mangroves of Kemaman could be classified into 14 different classes of vegetation. All the 14 classes were identified from areas covered by the aerial photographs. For areas covered by the Landsat images only 7 classes of vegetation were identified. The accuracy for aerial photograph and Landsat images are 91.2% and 87.8%, respectively. It can be concluded that although both techniques are useful in determining the mangrove vegetation classes, the large 1 : 5000 aerial photographs are more accurate and provided more detailed information comparatively.     

Dynamics of Tree and Shrub Vegetation in the Eastern Sayan Mountain Tundra

Russian Journal of Ecology - Climate change entails shifts in the ranges of woody plants along both latitudinal and altitudinal gradients in the boreal forest biome. In this study,...     

Fluoride and health hazards: community perception in a fluorotic area of central Rajasthan (India): an arid environment

India is among the 23 nations around the globe where health problems occur due to excess ingestion of fluoride (>1.5 mg/l) by drinking water. In Rajasthan, 18 out of 32 districts are fluorotic and 11 million of the populations are at risk. An exploratory qualitative survey was conducted to describe perception of the community regarding fluoride and related health problems in Central Rajasthan. A study on distribution and health hazards by fluoride contaminate in groundwater was performed in 1,030 villages of Bhilwara district of Central Rajasthan. One thousand thirty water samples were collected and analyzed for fluoride concentration. Fluoride concentration in these villages varies from 0.2 to 13.0 mg/l. Seven hundred fifty-six (73.4%) villages have fluoride concentration above 1.0 mg/l. Sixty (5.83%) villages have fluoride concentration above 5.0 mg/l with maximum numbers (24, 19.5%) from Shahpura tehsil. A detailed fluorosis study was carried out in 41 villages out of 60 villages having fluoride above 5.0 mg/l in the study age, sex, and occupation data were also collected. Four thousand, two hundred fifty-two individuals above 5 years age were examined for the evidence of dental fluorosis, while 1998 individuals above 21 years were examined for the evidence of skeletal fluorosis. The overall prevalence of dental and skeletal fluorosis was found to be 3,270/4,252 (76.9%) and 949/1,998 (47.5%), respectively. Maximum of 23.9% (1,016) individuals have mild grade of Dean’s classification. Three hundred seventy-four (8.8%) individuals have severe type of dental fluorosis. The Dean’s Community Fluorosis Index for the studied area in total is 1.62. Maximum CFI 3.0 was recorded from Surajpura of Banera Tehsil. Five hundred sixty-six (28.3%) individuals have Grade I type of skeletal fluorosis while only 0.6% (12) individuals have Grade III skeletal fluorosis. In conclusion, the prevalence and severity of fluorosis increased with increasing fluoride concentration. It was interesting to note that in some villages, the prevalence and severity of fluorosis were highest in subjects belonging to the economically poor community. Similarly, male laborers showed highest prevalence of fluorosis. Prevalence and severity of fluorosis were observed higher in subjects using tobacco, bettle nuts, and alcoholic drinks. In contrast, subjects using citrus fruits and having good nutritional status showed low prevalence.     

Community analysis in stream biomonitoring: what we measure and what we don't

Diatom assemblages from 83 epilithic samples taken from the Mesta River, Bulgaria, were regressed against three sets of predictor variables, i.e. environmental, spatial, and temporal. Redundancy analysis (RDA) of species and environmental data explained 36% of the diatom variance and extracted several important gradients of species distribution, associated with a downstream increase in nutrient levels, pH, temperature, and organic pollution. The inclusion of spatial and temporal variables in the RDA model captured additional 24% of the diatom variance and revealed three more gradients, a spatial gradient represented by higher order polynomial terms of latitude and longitude, and two temporal gradients of annual and seasonal variation. Partial RDAs demonstrated that the unique contribution of each predictor set to the explained diatom variance was the highest in the spatial dataset (16%), followed by the environmental (9%), and the temporal (7%) datasets. The remaining 28% of the variance was explained by the covariance of the predictor sets. This suggests that in biomonitoring of single stream basins, the cheap and simple account of space and time would explain most of the variance in assemblage composition obviating the necessity of expensive and time-consuming environmental assessments. The nature of the underlying environmental mechanisms can be easily inferred from the diatom composition itself.