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61.
Vladimir A. Masch 《The Environmentalist》2013,33(1):43-59
In the twenty-first century, the goals of mankind are evolving from rising prosperity to attaining long-range sustainable survival in an acceptable state. Such change will lead to a paradigm shift predicted by Thomas Kuhn. This situation motivates two novel generalized systems, Risk-Constrained Optimization (RCO) and its derivative, Risk-Constrained Optimization/Decision Network (RCO/DN). RCO aims for flexible and robust strategies across large ranges of scenarios and risks. It assumes that for any “serious” (complex and long-range) planning and decision-making problem, externalities are important and uncertainty is radical. Therefore, it rejects the very concept of the correct or the best strategy, replacing it with a strategy that is the most acceptable to decision-maker(s). RCO considers decision-support systems, models, and algorithms to be tools of analysis, rather than methods of selection of the best. It replaces the artificial and risky paradigm of maximization by a cautious natural and evolutionary paradigm of catastrophe avoidance. RCO filters out the worst and riskiest candidate strategies, leaving for judgmental selection a small set of flexible, robust, and reasonably safe strategies. For that purpose, RCO employs enhanced stochastic multiscenario (ESMS) models, transforming them into optimizing filters. It is important that this operation is achieved in accordance with a new principle—changing the overall solution by affecting the values of scenario-specific, rather than general, outcome variables. Furthermore, RCO screens decisions and strategies by several synthetic criteria in a framework of novel strategic frontiers. Thus, RCO embeds ESMS into an ensemble of mutually supporting risk management techniques, legitimizing high-level analytical use of a computer plus optimization model combination. 相似文献
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Nikolay Kluyev Andrei Cheleptchikov Efim Brodsky Vladimir Soyfer Vladimir Zhilnikov 《Chemosphere》2002,46(9-10)
A new method for reductive dechlorination of polychlorinated dibenzo-p-dioxins (PCDDs) and remediation of contaminated soils is described that uses zerovalent iron as the dechlorination agent and subcritical water as reaction medium and extractive solvent. It is found that the zerovalent iron can be applied for stepwise dechlorination of octachlorinated dibenzo-p-dioxin (OCDD) on various matrixes in subcritical water. By using iron powder as matrix higher chlorinated congeners were practically completely reduced to less than tetra-substituted homologues. A significant part of residual OCDD, when it was spiked in to soils, and formed less chlorinated congeners are extracted with water in the given conditions. The solubility of OCDD was increased by a 4–6 orders over its solubility at ambient conditions. The new method of contentious-flow extraction is described. 相似文献
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Roman Schoula Jana Hajšloviá Pavel Gregor Vladimir Kocourek Vladimir Bencko 《毒物与环境化学》2013,95(1-2):263-274
The persistence of lipophilic organochlorine substances leads to their incorporation into the food chain and subsequent uptake by humans. Due to their use in the past, Czech and Slovak countries belong to the countries with a relatively high body burden of organochlorines. Levels of PCBs in human tissues based on the congener‐specific analysis are reported in this paper. Samples were analysed for the most abundant PCB congeners. Prevalent persistent organochlorine pesticides and their isomers/metabolites have also been included. The present study is focused on following areas: i) distribution of analysed substances in the various human tissue samples from selected regions of the Czech and Slovak Republic and ii) comparison with the results from other foreign and local studies. 相似文献
65.
Two different methods to predict biotic integrity were tested and compared in the present paper. The first one tries to predict the fish indices of biotic integrity (IBI) at the state or regional scale based on the most similar observations to a specific target site of interest using the simple to implement k-nearest neighbors (or kNN) method. Two different distance functions were considered to find the k-nearest neighbors: the Euclidean and the Mahalanobis. The second method was applied on the same datasets and consisted of a step-wise multiple regression. The two modeling approaches yielded similar results but kNN proved to be more time-efficient and very fast computationally for the given dataset sizes, which allowed applying a leave-one-out cross validation.In an attempt to reveal the importance of scale in the prediction of IBI, regression models were constructed at the state (or regional) scale and at the more refined cluster of sampling sites scale. Clusters of sites were extracted using Kohonen's self-organizing maps (SOM) followed by k-means clustering of the SOM neurons. Cluster-level regression models, constructed after site patterning, performed better in IBI prediction than global regression models constructed without any previous site patterning. The importance of identifying groups of sites with similar environmental characteristics affecting the IBI was revealed. The combined use of site patterning and regression modeling for IBI prediction also helped identifying important variables acting at the local scale which remain latent at the global scale. 相似文献
66.
Olivia Lee Russel D. Andrews Vladimir N. Burkanov Randall W. Davis 《Marine Biology》2014,161(5):1165-1178
The ontogeny of diving and foraging behavior of northern fur seal pups from a stable population on Bering Island, Russia, was recorded with animal-borne instruments during their first few months at sea, a critical period during their first year at sea. Thirty-five pups were instrumented with satellite-linked time-depth recorders and stomach temperature pills. Diving occurred predominantly at night with deeper and longer dives as the pups matured. Mean dive depths were correlated with lunar illumination, whereas mean dive durations were also correlated with time of day and sex. Foraging success did not differ between sexes, and there was no relationship between meal size (as indicated by feeding event duration and minimum stomach temperature) and lunar illumination fraction or maximum foraging depth. Although most pups were able to successfully forage within 3 days of starting their migration, the number of feeding events recorded each day remained low (mean 1.6 events day?1). There was no indication of an appreciable increase in meal size after the first 2 weeks of the migration despite an increase in dive frequency and depth. The results are consistent with observations that pups do not gain mass during their first year and emphasize the risk of starvation from infrequent foraging in cold water. 相似文献
67.
Vadim Ermakov Leonid Perelomov Sabsbakhor Khushvakhtova Sergey Tyutikov Valentina Danilova Vladimir Safonov 《Environmental monitoring and assessment》2017,189(12):641
The biogeochemical and ecological assessment of the industrial city territory including urban soils and trees was carried out. Chemical (macroelement and microelement) composition of the city soils, morphological and biochemical properties of the linden leaves, possible impact of de-icing salts on soil and tree state, the correlation between the content of trace elements, and the S-containing plant compounds (phytochelatins) were included in the assessment. It was found that concentrations of trace elements in the soils near road with intensive traffic are changed from the soils, located at a distance of 40–50 m from the road. They have higher concentrations of As, Fe, Mn, Se, and Sr and lower concentration of Zn. The linden leaves from the roadside were characterized by the increase in As, Cu, Fe, Zn, and Cr and sharp decrease in the Mn and Sr concentrations. The analysis of soil water extracts showed a slight decrease of pH and low content of Ca, Mg, K, and Na for the distant sites. The phytochelatin test of linden leaves was weakly effective as well as asymmetry degree study of leaf lamina. The main differences were observed in the damage symptoms of leaves (chlorosis and necrosis) and the content of pigments (chlorophyll and carotenoids). The biochemical and ecological assessment of soils and trees showed relatively satisfactory ecological state of the investigated area in Moscow. The data obtained shows the weak local impact of the application of de-icing salts and automobile emissions. 相似文献
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