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151.
152.
Anne Theenhaus Reinhard Zeitler Wolfgang von Brackel Helmut -Julius Botsch Wolfgang Baumeister Ludwig Peichl 《Environmental Sciences Europe》2002,14(4):229-236
Ecological monitoring of genetically engineered plants (GEPs) is being developed in the Bavarian Environmental Protection Agency. Focusing on oilseed rape (Brassica napus, Cruciferae), a method is being established to measure the impact of the commercial release of GEPs on plant communities. Oilseed rape is known to escape from cultures and to establish outside the fields. It also produces hybrid offspring with wild relatives of the European flora. The study site is located in Bavaria (Germany) and comprises an area of 5700 ha. It is characterized by a mosaic of protected natural habitats in close vicinity to intensively cultivated farmland. In this region species composition and population density of Cruciferae is documented prior to a possible commercial release of GEPs. Furthermore Cruciferae of the study site are tested for the presence of transgenes. Therefore, plant material of selected Cruciferae is randomly sampled. We also test oilseed rape honey from the study site and pollen from pollen traps for the presence of hybrid pollen. The molecular method used is the ‘real-time PCR’. In addition, an intensive monitoring program is established in two types of biotopes, which are located in the study site. Multivariate statistics are being used to correlate plant community data with soil parameters. 相似文献
153.
Jon R Miller 《Journal of Environmental Economics and Management》1981,8(1):19-26
An alternative derivation of the irreversibility concept, with an application to the preservation of endangered species, is presented in this paper. The analysis involves a standard intertemporal welfare maximization procedure and is interested in the allocation of land between the production of economic goods and the preservation of species. Conversion of habitat is assumed to be irreversible. It is shown that the existence of utility value for species stocks, combined with increasing severity of the irreversibility constraint implies less conversion of species habitat than would occur in the absence of irreversibility. 相似文献
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Dr Boris Tutschek Jon Sherlock Ashutosh Halder Joy Delhanty Charles Rodeck Matteo Adinolfi 《黑龙江环境通报》1995,15(10):951-960
Transcervical cell (TCC) samples have been shown to contain fetal cells amenable to molecular analysis. However, the presence of ‘contaminating’ maternal cells limits their use for prenatal diagnoses. In this report we show that clumps of fetal cells can be isolated from transcervical samples by micromanipulation and tested by fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR). Out of 129 clumps, isolated from mucus aspirates and transcervical lavages from 29 patients, 29 clumps from 11 patients were found to be exclusively of fetal origin as judged by the detection of chromosome 21-specific polymorphic DNA markers and Y-derived DNA sequences by PCR and FISH. One case of a male triploid fetus, diagnosed by the analysis of TCC samples obtained by mucus aspiration and lavage, was confirmed by testing clumps of cells isolated by micromanipulation. 相似文献
157.
Unai?IriarteEmail author Jon?I?aki?álvarez-Uriarte Rubén?López-Fonseca Juan?Ramón?González-Velasco 《Environmental Chemistry Letters》2003,1(1):57-61
The relatively recent discovery of disinfection by-products has driven the main regulatory organisms to set maximum contaminant
levels for certain substances in drinking water. Trihalomethanes can be deemed as the most important group of by-products
in chlorinated surface waters. The present work has focused on trihalomethane formation in a full-scale water treatment plant.
We studied the effect of several factors, including ozonation, on trihalomethane levels in chlorinated treated water. The
treatment scheme also includes an ozonation step.
Electronic Publication 相似文献
158.
Jon D Harford 《Journal of Environmental Economics and Management》1976,3(3):215-225
Consideration is given to various reasons for changing standards on emissions, effluents, and ambient air and water quality. It is proposed that adjustment costs may be of significant practical importance in determining the optimal time path of waste treatment (at least currently). The problem of minimizing the present value of the sum of treatment plus damage plus adjustment costs is placed in a calculus of variations framework and the optimal time path of waste treatment is characterized as well as the corresponding optimal tax. An example is used to illustrate some features of the solution. 相似文献
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