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K. Theo von der Trenck Joachim Ruf Manfred Flittner 《Environmental science and pollution research international》1994,1(4):253-261
The treatment of hazardous sites in Baden-Württemberg is based on three legal documents: the state waste disposal art (LAbfG, 1990), the assessment committee directive (KommissionsVO, 1990), and the guide values directive (UM & SM B-W, 1993). The guide values directive was commonly issued by the Ministry of Labor, Health and Social Affairs and the Ministry of the Environment of the state of Baden-Württemberg (UM & SM B-W, 1993) and contains a three-level hierarchy of numerical criteria and rules which serve as both screening levels during the investigation and as remediation objectives. The decision for the appropriate level of remediation is based on feasibility and environmental balance considerations. The levels are ordered as follows: ? Level 1 (Background-Values) On principle, all remediations have to be based first on background levels. In the case of lack of feasibility or negative environmental balance for level-1 objectives use-specific requirements are considered next. ? Level 2 (Assessment-Values for Worst Case Exposure Conditions) The generic requirements underlying level 2 afford appropriate protection for humans regarding the most sensitive uses of the environment. At least four resources are considered on this level: Ground-water as such and its use, the health of humans on contaminated sites, and soil with respect to growth and quality of plants. Barriers against migration of the contaminants, the effect of dilution, and abandonment of certain uses, etc., are not taken into consideration on level 2. ? Level 3 (Site-Specific Requirements) Lack of feasibility or a negative environmental balance of level-2 objectives lead to consideration of site-specific circumstances which may alleviate the requirements. With respect to groundwater, the distinction is again necessary between groundwater as a resource and the use of groundwater. On level 3 the guideline gives rules of how to derive site-specific remediation objectives for groundwater in the form of concentrations and fluxes of contaminants after taking into account barriers, dilution, and the abandonment of uses. The guideline is the only directive of its kind in the world that regulates both concentrations and fluxes of contaminants into groundwater. 相似文献
334.
Robert J. Paxton Nicole Weißschuh Wolf Engels Klaus Hartfelder J. Javier G. Quezada-Euan 《Die Naturwissenschaften》1999,86(3):143-146
Queens of the large, pantropical and fully eusocial taxon Meliponinae (stingless bees) are generally considered to be singly
mated. We indirectly estimated queen mating frequency in two meliponids, Melipona beecheii and Scaptotrigona postica, by examining genotypes of workers at microsatellite DNA loci. Microsatellites were highly variable, providing suitable markers
with which to assign patrilinial origin of workers within colonies headed by single queens. Queen mating frequency varied
between 1 and 3 (M. beecheii) and 1 and 6 (S. postica), representing the first clear documentation of polyandry in the Meliponinae. Effective paternity frequency, m
e
, was lower, although above 2 for S. postica. Stingless bees may provide suitable subjects for the testing of recent inclusive fitness arguments describing intracolony
kin conflict in social Hymenoptera.
Received: 26 August 1998 / Accepted in revised form: 18 November 1998 相似文献
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Chemical investigation of the deepwater sponge Macandrewia azorica, collected from the flanks of the Gettysburg and Ormonde Sea Mount, North Atlantic, from a depth of 600 m, has led to the isolation of a new sterol with an unusual side chain (1), along with S-methylergothioneine (2). The structures of compounds 1 and 2 were established by employing spectroscopic techniques (NMR, MS, UV, IR and polarimetry). This is the first report of metabolites of a sponge belonging to the genus Macandrewia. 相似文献
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Rainer Brüggemann Andreas Kaune Joachim Klein Reinhard Zellner 《Environmental Sciences Europe》1996,8(2):89-96
Using four dynamic criteria, the following environmental changes were evaluated: Global warming; destruction, of the stratospheric ozone layer; eutrophication and acidification of aquatic ecosystems; photochemical smog; reduction of the available area of agricultural soils; loss of species diversity; consumption of resources; reduction of crop yield; forest decline; noise, and smell. These ecosystem changes, or negative effects, were characterized by four dynamic criteria: 1) Regional importance, 2) extent of alteration, 3) resilience and 4) irreversibility. A multi-criteria assessment, accounting simultaneously for all four criteria, requires a generalized concept of order. Here, the concept of partially ordered sets, visualized by Hasse diagrams, was used to derive a priority list of environmental changes. Highest priority was equally assigned to the loss of species diversity, the consumption of resources and the destruction of the ozone layer. However, these ecosystem changes are incomparable to each other concerning the four criteria used and thus require different management strategies. 相似文献
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