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801.
A comparative analysis of epigenetic variation has been performed in nine European populations and population groups of the American mink. It has been shown that differentiation of samples in nonmetric characters is due mainly to endogenous processes that have occurred in introduced populations in the course of colonization of new territory by the invasive species. Environmental factors have played a secondary role, with the influence of the geographic (latitudinal) origin of a given sample being considerable and stronger than that of macroclimatic factors.  相似文献   
802.
The probable source of stone moroko, Pseudorasbora parva (Temminck & Schlegel, 1846), populations in lake- and stream-type Dnieper reservoirs was revealed. The dynamics and specific growth rates of these populations over 20 years were analyzed. The dynamic phase portrait method was used to determine the timing of stages in the process of invader naturalization and the periods when its populations were in equilibrium. The potential growth rates of P. parva populations in the Kremenchug and Dneprodzerzhinsk reservoirs were estimated.  相似文献   
803.
Fluctuating asymmetry (FA) of the mandible shape has been analyzed in bank voles from the zones affected by pollution from three copper smelters in the Urals. It has been shown that there is the necessity for a detailed analysis of the material, since the level of FA may depend on population parameters. Regardless of the pollution level, FA of the mandible region including the lower part of the mandibular body, ramus and processes is higher than in the diastema region. A gradient effect of toxic exposure on FA has been revealed: an increase in its level under increasing technogenic impact is clearly manifested along local pollution gradients.  相似文献   
804.
The dynamics and correlations of ecophysiological parameters have been studied in two spatially separated multispecies communities of murine rodents and ixodid tick larvae and nymphs that parasitize them. It has been shown that all the processes under consideration have nonstationary, oscillatory dynamics. The long-term dynamics of connectivity of ecophysiological characteristics within communities and their synchronization by weather–climatic factors are, by nature, wavelike processes of transitions between the states with stronger and weaker linkage between parameters, which, along with nonstationarity, can contribute to the maintenance of stability and integrity of communities.  相似文献   
805.
The aim of this paper was to explore the implications of planned obsolescence (PO) and the associated product lifetime on the environmental impact of products. To achieve this task, a literature review was performed to assess both the historical context and recent situation of planned obsolescence. A search in scholarly journals was performed to evaluate to what extent product lifetime and PO have been discussed in the recent literature. Based on the findings, selected cases of PO are discussed and trends in the practice of limiting product lifetime are identified. Factors considered to have a significant influence on product lifetime have been identified and discussed. The discussion of case studies made it possible to establish the links between product design, manufacturing and associated impacts of lifetime. The role of the actors along the value chain is also considered to propose a business scheme, where the influences of consumer behaviour and design choices are crucial. Finally, strategies to facilitate the definition of different scenarios are given. These strategies may serve to increase the reliability of environmental assessment throughout a product life cycle.  相似文献   
806.
Fire history within the northern larch forests of Central Siberia was studied (65 + °N). Fires within this area are predominantly caused by lightning strikes rather than human activity. Mean fire return intervals (FRIs) were found to be 112 ± 49 years (based on firescars) and 106 ± 36 years (based on firescars and tree natality dates). FRIs were increased with latitude increase and observed to be about 80 years at 64°N, about 200 years near the Arctic Circle and about 300 years nearby the northern range limit of larch stands (~71° + N). Northward FRIs increase correlated with incoming solar radiation (r = ?0.95). Post-Little Ice Age (LIA) warming (after 1850) caused approximately a doubling of fire events (in comparison with a similar period during LIA). The data obtained support a hypothesis of climate-induced fire frequency increase.  相似文献   
807.
ABSTRACT

Public apprehension over the environmental, social, and health impacts of unconventional gas drilling, or fracking, prompts various responses from oil and gas industries. Natural gas discourses operating in the Marcellus Shale Region, USA, for example, counter claims of environmental harm by emphasizing the economic growth that industry spurs. This article argues that corporate narratives operating in the Marcellus renew the jobs versus environment dichotomy by romanticizing labor identities in the region, binding Rust Belt identities to extraction in the past, present, and future of the region. The danger of this discursive move is the exclusion of alternative possibilities for working, living, and being without fossil fuel industries. I employ a critical analysis of one corporate advertising campaign, “Drilling Is Just the Beginning,” produced by the natural gas drilling company Range Resources, to demonstrate how extraction discourses construct futures that depend on shale gas development, thereby marginalizing possibilities for ecologically sensible alternatives.  相似文献   
808.
In case of an avian-influenza-derived human flu pandemic, an inordinately high use of medicines over several weeks is predicted, in particular for the recommended influenza antiviral oseltamivir (Tamiflu). While the risk of oseltamivir to sewage works and freshwater bodies has already been assessed, the fact that a large percentage of the human population worldwide lives relatively close to the sea raises concern for its environmental compatibility in coastal marine waters. The potential risk of high oseltamivir use to the marine compartment is assessed in this publication, based on the 2003 European Community Technical Guidance Document (TGD) for risk assessment. Subchronic embryo–larval ecotoxicity tests with three marine invertebrates (Pomatoceros triqueter, Annelida; Mytilus edulis, Mollusca; Paracentrotus lividus, Echinodermata) and chronic growth inhibition tests with two different groups of marine microalgae (Isochrysis galbana, Haptophyta; Skeletonema costatum, Heterokontophyta) were performed with the active substance oseltamivir carboxylic acid to derive a dependable marine predicted no-effect concentration (PNEC). This was compared to a predicted environmental concentration (PEC) for oseltamivir in coastal waters, based on the worst-case freshwater PEC. The PEC/PNEC risk characterisation ratio for the marine compartment is well below 1, which in the terminology of the TGD signifies no immediate concern. Further, while oseltamivir may be persistent (P), it is not bioaccumulative (B) nor highly ecotoxic (T) and therefore not a PBT substance. In conclusion, even a high pandemic use of oseltamivir would not lead to a significant risk for the marine compartment, in confirmation of the risk assessment for sewage works and freshwaters.  相似文献   
809.
Large-scale studies are essential to assess the emission patterns and spatial distribution of organohalogenated pollutants (OHPs) in the environment. Bird eggs have several advantages compared to other environmental media which have previously been used to map the distribution of OHPs. In this study, large-scale geographical variation in the occurrence of OHPs, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs), was investigated throughout Europe using eggs of a terrestrial residential passerine species, the great tit (Parus major). Great tit eggs from 22 sampling sites, involving urban, rural and remote areas, in 14 European countries were collected and analysed (5-8 eggs per sampling site). The environmentally most important congeners/compounds of the analysed pollutants were detectable in all sampling locations. For PCBs, PBDEs and OCPs, no clear geographical contamination pattern was found. Sum PCB levels ranged from 143 ng/g lipid weight (lw) to 3660 ng/g lw. As expected, PCB concentrations were significantly higher in the sampled urban compared to the remote locations. However, the urban locations did not show significantly higher concentrations compared to the rural locations. Sum PBDEs ranged from 4.0 ng/g lw to 136 ng/g lw. PBDEs were significantly higher in the urbanized sampling locations compared to the other locations. The significant, positive correlation between PCB and PBDE concentrations suggests similar spatial exposure and/or mechanisms of accumulation. Significantly higher levels of OCPs (sum OCPs ranging from 191 ng/g lw to 7830 ng/g lw) were detected in rural sampling locations. Contamination profiles of PCBs, PBDEs and OCPs differed also among the sampling locations, which may be due to local usage and contamination sources. The higher variance among sampling locations for the PCBs and OCPs, suggests that local contamination sources are more important for the PCBs and OCPs compared to the PBDEs. To our knowledge, this is the first study in which bird eggs were used as a monitoring tool for OHPs on such a large geographical scale.  相似文献   
810.
This study has indicated that there is close relationship between development density and environmental quality; therefore, it is necessary to decide the form of development carefully beforehand. The form of development is shaped either by new development or urban renewal which is a major tactic nowadays adopted by the Hong Kong Government to improve the living condition of the citizens and the quality of the built environment. This study is limited to urban renewal and aims to find out the major urban design considerations for sustaining the environment. Through a questionnaire survey carried out in Hong Kong, the opinions of architects, planners, property development managers, and local citizens were sought and evaluated, and critical design factors for enhancing environmental sustainability of urban renewal projects are highlighted. The results derived from factor analysis indicated that certain design considerations should be incorporated for sustaining the urban environment. “Land Use Planning”, “Quality of Life”, “Conservation & Preservation”, “Integrated Design”, “Provision of Welfare Facilities”, and “Conservation of Existing Properties” were believed to be the significant underlying factors for achieving environmental sustainability of local urban renewal projects. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   
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