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61.
This work has been supported by the Centre National de la Recherche Scientifique (C.N.R.S.) through the Action Thématique Programmée Matières Organiques des sols. We thank Dr. B. Guillet and Prof. B. Souchier, Centre de Pédologie Biologique du C.N.R.S., Nancy, for helpful discussions and advice in collecting the samples; we further thank E. Krempp and P. Wehrung for technical assistance in NMR and MS measurements. 相似文献
62.
A. Albrecht J. C. G. Ottow G. Benckiser I. Sich R. Russow 《Die Naturwissenschaften》1997,84(4):145-147
63.
Rhizosphere bacteria influence plant growth through several mechanisms. Beneficial interactions are often difficult to identify and isolate for study, and therefore favorable effects on plant productivity are not easily described in quantitative terms. Major beneficial activities of soil bacteria include solubilization of minerals, fixation of nitrogen, production of growth-promoting hormones and competitive suppression of pathogens. Most recent research to improve crop responses has emphasized the study of nitrogen-fixing bacteria indigenous to rhizospheres of cereal crops and other grasses. The amount of nitrogen available to crops from fixation by these organisms is significant under some circumstances, but efforts to control and increase fixation activity have not been consistently successful. Despite considerable research, inoculation experiments frequently fail to improve rates of nitrogen fixation. However, substantial progress has been achieved in understanding mechanisms involved in plant—bacterial interactions, and in defining conditions which control them. Also, recent studies show clearly that bacterial inoculation can be highly beneficial even when nitrogen fixation is not affected. Further research is needed to develop new and effective methods for suppressing growth of competing microorganisms, and promoting dominance of those most useful to plants. Environmental manipulation may not be sufficient to achieve this objective. Genetic development of both plant and bacterial lines which enhance desired interactions is likely to be the most productive research effort for the future. 相似文献
64.
In 1995-1998 the contents of polychlorinated dibenzodioxins and dibenzofurans of 184 pooled fish samples were analysed. Sampling focused on fish and fishery products with a market share of more than 1% and covered all fishing grounds important for the supply of the German market. Investigation included 15 different fish species, shrimp, mussel and squid samples and various fishery products, typically on the German market. Generally lean fish species like cod, saithe or Alaska pollock were less contaminated on fresh weight basis than fat fish species like herring, Greenland halibut and sardine. In herring the dioxin content is related to the fishing ground. Low concentrations were found in North Sea herring, high concentrations measured in samples from the Baltic Sea. Dioxin contents in fishery products did not differ significantly from the raw fish samples. Results allow an estimation of the daily intake of dioxins and furans via fish consumption in Germany. Based on a daily fish consumption of 20 g the average intake of dioxins via fish is 6.2 pg WHO-PCDD/F-TEQs per person and day. 相似文献
65.
Satoshi Saitoh Albrecht Melber Hiroshi Ohbayashi Satoshi Nakai Masakuni Matsuoka Masaaki Hosomi 《Journal of Material Cycles and Waste Management》2008,10(1):71-78
We discuss the use of the Schmidt graphical method to calculate the time required to heat a polychlorinated biphenyl (PCB)-contaminated
capacitor in the vacuum thermal recycling process to the processing temperature of 400°C, and we evaluate the results of the
heating time calculation by comparing the calculated values with the corresponding experimental values. The thermal conductivity
and specific heat of the insulating paper and the carbonized paper in the capacitor were unknown, so we determined their values
from experimental data obtained during the vacuum thermal recycling process. The capacitor element is a multilamination of
aluminum foil and insulating paper, so we used an equation for a multilayer plane wall to calculate the value of the thermal
conductivity. For the thermal conductivity and specific heat of the insulating paper impregnated with PCBs, we used values
calculated from the mass ratios and thermal conductivities and specific heats of the individual materials. In addition, the
physical properties vary according to the treatment because of the evaporation of PCBs and the carbonization of the insulating
paper, so we modified the values of the thermal conductivity, specific heat, and density at the boiling point of the PCB and
the carbonization point of the insulating paper before performing the calculations. Our calculated heating times were almost
the same as, or were above, the experimental values, so we concluded that our method can be used as a simple calculation of
the heating time. 相似文献
66.
Carsten Albrecht Brühl Bernd Guckenmus Markus Ebeling Ralf Barfknecht 《Environmental science and pollution research international》2011,18(1):31-37
Background, aim and scope
Seed treatments are widely used on cereals and other annual crops throughout Europe. Most of the formulated pesticide is found on the outside of the seed, the husk. Risk assessments of seed treatments are especially needed for granivorous mice living in the agricultural landscape e.g. for registration using the guidance for risk assessment for birds and mammals (EFSA 2009). The dehusking of seeds before consumption is a known behaviour of these mammals, but so far, no quantitative data on the reduction of exposure of seed treatments by dehusking were published. Therefore, we aimed at providing a first quantitative estimate of this behaviour-related exposure reduction for the wood mouse (Apodemus sylvaticus) with different seed types. 相似文献67.
Ulla Raab Michael Albrecht Ursula Preiss Wolfgang Völkel Ursula Schwegler Hermann Fromme 《Chemosphere》2013
The aim of the Bavarian Monitoring of Breast Milk (BAMBI) project was to examine 10 organochlorine pesticides (OPs), 3 nitro musks, 6 indicator polychlorinated biphenyls (PCBs), 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), 12 dioxin-like PCBs (dl-PCBs) and several perfluorinated alkyl compounds in breast milk samples. A total of 516 breast milk samples were collected from seven regions in Bavaria and were analyzed by means of GC/ECD, GC/HRMS, and LC/MS-MS. 相似文献
68.
Membrane-enclosed sorptive coating (MESCO) is a miniaturised monitoring device that enables integrative passive sampling of persistent, hydrophobic organic pollutants in water. The system combines the passive sampling with solventless preconcentration of organic pollutants from water and subsequent desorption of analytes on-line into a chromatographic system. Exchange kinetics of chemicals between water and MESCO was studied at different flow rates of water, in order to characterize the effect of variable environmental conditions on the sampler performance, and to identify a method for in situ correction of the laboratory-derived calibration data. It was found that the desorption of chemicals from MESCO into water is isotropic to the absorption of the analytes onto the sampler under the same exposure conditions. This allows for the in situ calibration of the uptake of pollutants using elimination kinetics of performance reference compounds and more accurate estimates of target analyte concentrations. A field study was conducted to test the sampler performance alongside spot sampling. A good agreement of contaminant patterns and water concentrations was obtained by the two sampling techniques. 相似文献
69.
Stefan Gartiser Christoph Hafner Christoph Hercher Kerstin Kronenberger-Schäfer Albrecht Paschke 《Environmental science and pollution research international》2010,17(5):1149-1157
Background, aim and scope
Toxicity testing has become a suitable tool for wastewater evaluation included in several reference documents on best available techniques of the Integrated Pollution Prevention and Control (IPPC) Directive. The IPPC Directive requires that for direct dischargers as well as for indirect dischargers, the same best available techniques should be applied. Within the study, the whole effluent assessment approach of OSPAR has been applied for determining persistent toxicity of indirectly discharged wastewater from the metal surface treatment industry. 相似文献70.
Terje Laskemoen Tomas Albrecht Andrea Bonisoli-Alquati Jaroslav Cepak Florentino de Lope Ignacio G. Hermosell Lars Erik Johannessen Oddmund Kleven Alfonso Marzal Timothy A. Mousseau Anders P. Møller Raleigh J. Robertson Geir Rudolfsen Nicola Saino Yoni Vortman Jan T. Lifjeld 《Behavioral ecology and sociobiology》2013,67(2):301-309
Spermatozoa vary greatly in size and shape among species across the animal kingdom. Postcopulatory sexual selection is thought to be the major evolutionary force driving this diversity. In contrast, less is known about how sperm size varies among populations of the same species. Here, we investigate geographic variation in sperm size in barn swallows Hirundo rustica, a socially monogamous passerine with a wide Holarctic breeding distribution. We included samples from seven populations and three subspecies: five populations of ssp. rustica in Europe (Czech, Italy, Norway, Spain, and Ukraine), one population of ssp. transitiva in Israel, and one population of ssp. erythrogaster in Canada. All sperm traits (head length, midpiece length, tail length, and total length) varied significantly among populations. The variation among the European rustica populations was much lower than the differences among subspecies, indicating that sperm traits reflect phylogenetic distance. We also performed a test of the relationship between the coefficient of between-male variation in total sperm length and extrapair paternity levels across different populations within a species. Recent studies have found a strong negative relationship between sperm size variation and extrapair paternity among species. Here, we show a similar negative relationship among six barn swallow populations, which suggests that the variance in male sperm length in a population is shaped by the strength of stabilizing postcopulatory sexual selection. 相似文献