排序方式: 共有27条查询结果,搜索用时 0 毫秒
11.
Anhand des Anwendungsbeispiels einer bewohnten Altlast wird eine probabilistische Expositionsabsch?tzung durchgeführt und es werden M?glichkeiten aufgezeigt, Variabilit?t und Unsicherheit in der Sch?tzung separat zu erfassen. Zur Charakterisierung der Variabilit?t personenspezifischer Variablen (z.B. K?rpergewicht) werden in das Expositionsmodell Wahrscheinlichkeitsverteilungen eingesetzt; die stoffspezifischen Expositionsparameter werden konstant gehalten. Zus?tzlich wird die Ungewi?heit einer ausgew?hlten Variablen (Bodeningestionsrate) modelliert. Der Vergleich mit denworst-case-Sch?tzungen zeigt, da? diese in den oberen Randbereichen bzw, au?erhalb der Bereiche der probabilistischen Sch?tzung liegen und somit sehr konservative, u.U. unrealistische Sch?tzungen liefern. 相似文献
12.
13.
Habitat Matrix Effects on Pond Occupancy in Newts 总被引:9,自引:0,他引:9
Pierre Joly ‡ Claude Miaud § Anthony Lehmann † and Odile Grolet 《Conservation biology》2001,15(1):239-248
Abstract: In farmlands, the population viability of many amphibians is suspected to depend on the resistance the matrix of crop fields presents to movements between ponds and terrestrial sites and movements among ponds. Over recent decades the increase in cereal growing at the expense of cattle breeding has caused a drastic change in habitat matrix in many European regions. We investigated the effect of such change on populations of three newt species ( Triturus helveticus , T. alpestris , and T. cristatus ) by comparing their abundances in sites that varied in amount of cultivated ground. A multivariate regression analysis of the relationship of newt abundance to both pond and landscape variables demonstrated the negative influence of cultivated ground on abundance. The width of the uncultivated sector linking the pond to the forest was a good predictor of abundance after the influences of both pond area and fish presence were removed. Moreover, newt presence was positively related to the number of ponds within that 50-ha surrounding area, highlighting the role of metapopulation functioning in newt occupancy of ponds. The relationship between newt abundance and width of uncultivated sectors agrees with present knowledge of the orientation mechanisms that underlie migration movements in urodeles. Such a relationship between connectedness and sector width shows that narrow, linear corridors such as hedgerows may not be useful in newt conservation. Our study also highlights the need to incorporate a behavioral component of habitat use into models of connectivity in conservation biology. 相似文献
14.
Doumas Patrick Munoz Marguerite Banni Mohamed Becerra Sylvia Bruneel Odile Casiot Corinne Cleyet-Marel Jean-Claude Gardon Jacques Noack Yves Sappin-Didier Valérie 《Regional Environmental Change》2018,18(3):677-692
Regional Environmental Change - Abandoned mines are a recurrent problem for nearby communities in Mediterranean regions because mine tailings represent a major source of polymetallic contamination.... 相似文献
15.
16.
17.
18.
Marie Maud Bear Delphine Mallarde Valérie Langlois Solo Randriamahefa Odile Bouvet Philippe Guerin 《Journal of Polymers and the Environment》1999,7(4):179-184
Sixteen Pseudomonas strains have been tested with a view to developing medium-chain length polyhydroxyalkanoates. Four strains were selected and it is shown that their ability for producing three different polyesters with variable properties was dependent on the strains and substrates. Otherwise, Pseudomonas oleovorans was grown on a mixture of sodium octanoate and undecenoate salts at a 90/10 mol/mol ratio. The corresponding copolymer, bearing lateral double bonds, was chemically modified in the carboxy group. Finally, the ability to tailor-make functional bacterial polyesters aimed at temporary therapeutic applications is demonstrated. 相似文献
19.
20.