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Bioaccumulation of organic chemicals in contaminated soils: evaluation of bioassays with earthworms 总被引:5,自引:0,他引:5
Jager T van der Wal L Fleuren RH Barendregt A Hermens JL 《Environmental science & technology》2005,39(1):293-298
Earthworms live in close contact with the soil and can thus be considered representative for the bioavailability of chemicals at contaminated sites. Bioavailability can either be assessed by analyzing earthworms from contaminated locations or by exposing laboratory-reared specimens to soil samples from the field (bioassays). In this study, we investigate the relevance of bioassays by using an extended experimental design (to identify signs of depletion of the bioavailable phase by the earthworms) and by using two species of earthworm (the standard test species Eisenia andrei and the field-relevant Aporrectodea caliginosa). Furthermore, bioassay results are compared to body residues of worms collected from the field site: a heavily polluted polder, amended with dredge spoil. We focused on telodrin, dieldrin, hexachlorobenzene, and eight PCBs. With our bioassay design, it was shown that depletion was unlikely, although more subtle effects could have occurred (e.g., changes in sorption during the experiments). E. andrei is a good choice for bioassays because its body residues correlate well to those in A. caliginosa, as well as to those in the field-collected worms. Nevertheless, E. andrei accumulated slightly more than the other species and appeared to be more sensitive to the conditions in soil from one of our sites. 相似文献
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Camelia Matei Ghimbeu Martine Lumbreras Maryam Siadat Joop Schoonman 《Materials Science in Semiconductor Processing》2010,13(1):1-8
This paper presents the electrostatic spray deposition of tungsten oxide (WO3) films for the detection of different pollutant gases. The influence of several types of precursors on the structure and morphology of the films was studied by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. This preliminary study allowed to select the proper precursor for the preparation of pure and porous WO3 films which offer high gas response (Rair/Rgas=1200) to low concentrations of H2S (10 ppm) at low operating temperature (200 °C). The gas response to NO2 and SO2 is low at this temperature suggesting no possible interference with these two gases during the H2S detection. Furthermore, the films are able to detect very low concentrations of NO2 (less than 1 ppm) at 150 °C. 相似文献
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Kuipers Oscar P.; Kerver Jana; van Meersbergen Joop; Vis Roel; Dijkman Ruud; Verheij Hubertus M.; de Haas Gerard H. 《Protein engineering, design & selection : PEDS》1990,3(7):599-603
Residue 31 of porcine pancreatic phospholipase A2 (PLA2) islocated at the entrance to the active site. To study the roleof residue 31 in PLA2, six mutant enzymes were produced by site-directedmutagenesis, replacing Leu by either Trp, Arg, Ala, Thr, Seror Gly. Direct binding studies indicated a three to six timesgreater affinity of the Trp31 PLA2 for both monomeric and micellarsubstrate analogs, relative to the wild-type enzyme. The otherfive mutants possess an unchanged affinity for monomers of theproduct analog n-decylphosphocholine and for micelles of thediacyl substrate analog rac-l,2-dioctanoylamino-dideoxy-glycero-3-phosphocholine.The affinities for micelles of the monoacyl product analog n-hexadecylphosphocholinewere decreased 920 times for these five mutants. Kineticstudies with monomeric substrates showed that the mutants haveVmax values which range between 15 and 70% relative to the wild-typeenzyme. The Vmax values for micelles of the zwitterionic substratel,2-dioctanoyl-sn-glycero-3-phosphocholine were lowered 350times. The Km values for the monomeric substrate and the kmvalues for the micellar substrate were hardly affected in thecase of five of the six mutants, but were considerably decreasedwhen Trp was present at position 31. The results of these investigationspoint to a versatile role for the residue at position 31: involvementin the binding and orientating of monomeric substrate (analogs),involvement in the binding of the enzyme to micellar substrateanalogs and possibly involvement in shielding the active sitefrom excess water. 相似文献
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Joop P.M. Van Lammeren 《Journal of Electronic Testing》1999,14(1-2):33-38
This paper describes a test method for analogue (parts of) ICs that determines whether an IC is good or not by measuring the currents flowing through its constituent circuits. The ICCQ test method is not a full functional test. It is aimed primarily at finding faulty circuits during wafer testing. Both static and dynamic currents can be tested with this test method. 相似文献
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Emerging renewable energy technologies cannot break through without the involvement of entrepreneurs who dare to take action amidst uncertainty. The uncertainties that the entrepreneurs involved perceive will greatly affect their innovation decisions and can prevent them from engaging in innovation projects aimed at developing and implementing emerging renewable energy technologies. This article analyzes how perceived uncertainties and motivation influence an entrepreneur's decision to act, using empirical data on biomass gasification projects in the Netherlands. Our empirical results show that technological, political and resource uncertainty are the most dominant sources of perceived uncertainty influencing entrepreneurial decision-making. By performing a dynamic analysis, we furthermore demonstrate that perceived uncertainties and motivation are not stable, but evolve over time. We identify critical factors in the project's internal and external environment which influence these changes in perceived uncertainties and motivation, and describe how various interactions between the different variables in the conceptual model (internal and external factors, perceived uncertainty, motivation and previous actions of the entrepreneurs) positively or negatively influence the decision of entrepreneurs to continue entrepreneurial action. We discuss how policymakers can use these insights for stimulating the development and diffusion of emerging renewable energy technologies. 相似文献
90.
van der Velde Frank W.; van der Pligt Joop; Hooykaas Christa 《Canadian Metallurgical Quarterly》1994,13(1):25
Investigates the perceived risk of an HIV infection. Cognitive antecedents of biases in risk perception and their effects on behavioral intentions were investigated. The purpose of this study was to determine the relative accuracy of risk assessments for samples that vary in actual risk for AIDS. Ss were citizens of Amsterdam, heterosexuals with private partners, gay men, and heterosexuals with prostitution partners. Although optimistically biased in all samples, perceptions of risk were related to previous risk behavior in high-risk samples only. Pessimism was more pronounced in samples higher at risk. Optimists had lower levels of previous risk behavior and increased intentions to adopt safe sex practices. Ss in samples higher at risk had, therefore, relatively adequate perceptions of risk. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献