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41.
In this paper we propose a decision support system that can provide information on the environmental impact of anthropic activities by examining their effects on groundwater quality. We use the combined value of both intrinsic vulnerability of a specific local aquifer, obtained by implementing a parametric managerial model (SINTACS), and a degree of hazard value, which takes into account specific human activities. Incomplete information is notoriously common in environmental planning. To overcome this deficiency we apply an algorithmic and a qualitative approach, based on expert judgment incorporated into the system's knowledge base. The decision support system takes into account the uncertainty of the environmental domain by using fuzzy logic and evaluates the reliability of the results according to information availability.  相似文献   
42.
Sharing waters: Post-Rio international water management   总被引:4,自引:0,他引:4  
Transcending human-defined political and administrative boundaries, the world's transboundary freshwater resources pose particularly challenging management problems. Water resource users at all scales frequently find themselves in direct competition for this economic and life-sustaining resource, in turn creating tensions, and indeed conflict, over water supply, allocation, and quality. At the international scale, where the potential for conflict is of particular concern, significant efforts are underway to promote greater cooperation in the world's international river basins, with notable achievements in the past decade following the Dublin and Rio conferences. Over the past ten years, the international community has adopted conventions, declarations, and legal statements concerning the management of international waters, while basin communities have established numerous new basin institutions. Despite these developments, significant vulnerabilities remain. Many international basins still lack any type of joint management structure, and certain fundamental management components are noticeably absent from those that do. An understanding of these weaknesses, however, offers an opportunity for both the international and basin communities to better respond to the specific institution-building needs of basin communities and thereby foster broader cooperation over the world's international water resources.  相似文献   
43.
Some gelatine films were tested in order to evaluate their ability in collecting fog water droplets, and to calculate the magnification ratio (ratio between the size of the crater on the gelatine and the size of the original droplet). The films were prepared by industrial procedure, by a photographic material manufacturer, in order to assure uniformity of the gelatine layer and reproductibility of the chemical composition. An explanation is given for the behaviour and the characteristics of the different surfaces.  相似文献   
44.
Concentrations and enantiomeric signatures of organochlorine pesticides were determined in Antarctic krill, emerald rockcod and Adélie penguin from the Ross Sea, Antarctica. HCB and DDTs were prevalent contaminants in penguin eggs. The highest concentrations of SigmaHCHs (1.35 +/- 0.72 ng/g) were found in the rockcod muscle, where gamma-HCH (1.23 +/- 0.67 ng/g) was the principal isomer. The ratio gamma-HCH/alpha-HCH was evaluated. Enantioselective gas chromatography was used for the evaluation of enantiomeric fractions (EFs) for alpha-HCH and oxychlordane. An increase of 14% in the (+)alpha-HCH enantiomer was found from krill through penguin, suggesting the enantioselective biotransformation increased proportionately with trophic level. Polybrominated diphenyl ethers (PBDEs) were measured and their concentrations were 5.6 +/- 1.12, 5.81 +/- 2.32, 4.57 +/- 0.17 and 3.06 +/- 3.27 ng/g lipids in krill, rockcod muscle, rockcod homogenate and penguin eggs, respectively. The detection of BDE28, BDE47, BDE99 and BDE100 in Antarctic organisms confirmed their global transport and distribution; the detection of lower brominated congeners suggested a potential long-range transport.  相似文献   
45.
Genotoxicity of freshwater pollution was assessed by measuring DNA damage in haemocytes of caged freshwater crayfish Astacus leptodactylus by the means of Comet assay and micronucleus test, integrated with the measurements of physiological (total protein concentration) and immunological (total haemocyte count) haemolymph parameters as biomarkers of undergone stress. Crayfish were collected at the reference site (River Mre?nica) and exposed in cages for 1 week at three polluted sites along the Sava River (Zagreb, Sisak, Krapje). The long term pollution status of these locations was confirmed by chemical analyses of sediments. Statistically significant increase in DNA damage measured by the Comet assay was observed at all three polluted sites comparing to the crayfish from reference site. In addition, native crayfish from the mildly polluted site (Krapje) cage-exposed on another polluted site (Zagreb) showed lower DNA damage than crayfish from the reference site exposed at the same location indicating adaptation and acclimatisation of crayfish to lower levels of pollution. Micronuclei induction showed similar gradient of DNA damage as Comet assay, but did not reach the statistical significance. Observed increase in total haemocyte count and total protein content in crayfish from polluted environments in the Sava River also confirmed stress caused by exposure to pollution. The results of this study have proved the applicability of caging exposure of freshwater crayfish A. leptodactylus in environmental genotoxicity monitoring using Comet assay and micronucleus test.  相似文献   
46.
Habitat corridors are important tools for maintaining connectivity in increasingly fragmented landscapes, but generally they have been considered in single‐species approaches. Corridors intended to facilitate the movement of multiple species could increase persistence of entire communities, but at the likely cost of being less efficient for any given species than a corridor intended specifically for that species. There have been few tests of the trade‐offs between single‐ and multispecies corridor approaches. We assessed single‐species and multispecies habitat corridors for 5 threatened mammal species in tropical forests of Borneo. We generated maps of the cost of movement across the landscape for each species based on the species’ local abundance as estimated through hierarchical modeling of camera‐trap data with biophysical and anthropogenic covariates. Elevation influenced local abundance of banded civets (Hemigalus derbyanus) and sun bears (Helarctos malayanus). Increased road density was associated with lower local abundance of Sunda clouded leopards (Neofelis diardi) and higher local abundance of sambar deer (Rusa unicolor). Pig‐tailed macaque (Macaca nemestrina) local abundance was lower in recently logged areas. An all‐species‐combined connectivity scenario with least‐cost paths and 1 km buffers generated total movement costs that were 27% and 23% higher for banded civets and clouded leopards, respectively, than the connectivity scenarios for those species individually. A carnivore multispecies connectivity scenario, however, increased movement cost by 2% for banded civets and clouded leopards. Likewise, an herbivore multispecies scenario provided more effective connectivity than the all‐species‐combined scenario for sambar and macaques. We suggest that multispecies habitat connectivity plans be tailored to groups of ecologically similar, disturbance‐sensitive species to maximize their effectiveness. Evaluación de la Conectividad de Terrenos Multiespecie en una Comunidad Tropical de Mamíferos  相似文献   
47.
ABSTRACT: In this paper we seek to identify historical indicators of international freshwater conflict and cooperation and to create a framework to identify and evaluate international river basins at potential risk for future conflict. We derived biophysical, socioeco‐nomic, and geopolitical variables at multiple spatial and temporal scales from GIS datasets of international basins and associated countries, and we tested these variables against a database of historical incidents of international water related cooperation and conflict from 1948 to 1999. International relations over freshwater resources were overwhelmingly cooperative and covered a wide range of issues, including water quantity, water quality, joint management, and hydropower. Conflictive relations tended to center on quantity and infrastructure. No single indicator—including climate, water stress, government type, and dependence on water for agriculture or energy—explained conflict/cooperation over water. Even indicators showing a significant correlation with water conflict, such as high population density, low per capita GDP, and overall unfriendly international relations, explained only a small percentage of data variability. The most promising sets of indicators for water conflict were those associated with rapid or extreme physical or institutional change within a basin (e.g., large dams or internationalization of a basin) and the key role of institutional mechanisms, such as freshwater treaties, in mitigating such conflict.  相似文献   
48.
Numerous studies have demonstrated the utility of extremely low frequencies (ELF) electromagnetic fields in the treatment of pain. Moreover, the effects of these fields seems to depend on their respective codes. In our study we want to value the effects and the safety of the TAMMEF (Therapeutic Application of a Musically Modulated Electromagnetic Field) system, which field is piloted by a musical signal and its parameters are modified in time, randomly varying within the respective ranges, so that all possible codes can occur during a single application. Ninety subjects, affected by chronic low back pain, were enrolled in the study and randomly divided into three groups of 30 patients each: A exposed to TAMMEF, B exposed to ELF, C exposed to a simulated field. All subjects underwent a cycle of 15 daily sessions of 30 minutes each and a clinical examination upon enrolment, after 7 days of therapy, at the end of the cycle and at a follow-up 30 days later. All the patients of groups A and B completed the therapy without the appearance of side effects: they presented a significant improvement of the subjective pain and the functional limitation, which remained stable at the follow-up examination. In group C, there was no improvement of the pain symptoms or articular functionality. This study suggests that the TAMMEF system is efficacious and safe in the treatment of patients with chronic low back pain.  相似文献   
49.
50.
Feedstock and compost samples were collected from twenty composting plants and analysed from the microbiological point of view. Faecal indicator organisms were determined in order to evaluate the efficacy of processes for the removal of pathogenic micro-organisms with similar survival characteristics and to verify their suitability as appropriate markers of microbial quality of composted products. In addition to the classical bacterial indicators, selected organisms, such as Salmonella, Giardia, Cryptosporidium, Clostridium spores and helminth ova, were investigated. Statistically significant differences in the removal of the different micro-organisms were observed with regard to both the different composting plants (P < 0.05) and feedstock composition (P < 0.05). In fact, compost obtained by feedstock containing sewage sludge was shown to have a better hygienic quality in comparison with compost containing green discards and municipal solid waste as raw matter. Giardia cysts, Cryptosporidium oocysts and helminth ova were not effective indicators of hygienic quality of compost, whereas Clostridium perfringens spores, because of their high resistance to treatments, could be considered as an additional model for assessing the composting process, especially with regard to more resistant pathogen reduction.  相似文献   
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