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Doris Van Der Krol Ingolf Schuphan Brigitte Thiede Burkhard Schmidt 《Pest management science》1995,45(2):143-152
By means of standardized procedures, the metabolism of [ring-2,6-14C]-parathion was investigated in carrot (Daucus carota L.), purple foxglove (Digitalis purpurea L.), soybean (Glycine max Merrill cv. ?Mandarin’?, and Glycine max Merrill cv. ?Harosoy 63’? cultivated on B5 and Miller media, respectively), thorn apple (Datura stramonium L.), and wheat (Triticum aestivum L.) cell suspension cultures. In the wheat and soybean (Mandarin) cells only 2.9 and 8.9%, respectively, of the applied parthion remained unmetabolized after 48 h of incubation, while 51.2, 57.9, 60.3, and 62.4% of the unchanged parent were detected in the D. purpurea, D. Stramonium, carrot and soybean (Harosoy) cultures, respectively. In all suspensions, paraoxon and 4-nitrophenol were found as phase I metabolites, thus demonstrating that plant tissues can catalyse oxidative desulfuration and dearylation of parathion. 4-Nitrophenol was also glycosylated with glucose and possibly galactose. Further, as yet unidentified, metabolites indicated that bio-transformations had also occurred at the aromatic moiety. Large amounts of non-extractable residues were detected in the wheat suspension (38.3%), while the other cultures showed a lower incorporation of 14C into insoluble cell material (0.9-9.4%). For a prospective ecotoxicological evaluation of the metabolic fate of pesticides and xenobiotics in plants in general, the differential metabolic capacity of plant cell cultures and plants should be taken into account. 相似文献
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Montzka SA Krol M Dlugokencky E Hall B Jöckel P Lelieveld J 《Science (New York, N.Y.)》2011,331(6013):67-69
The oxidizing capacity of the global atmosphere is largely determined by hydroxyl (OH) radicals and is diagnosed by analyzing methyl chloroform (CH(3)CCl(3)) measurements. Previously, large year-to-year changes in global mean OH concentrations have been inferred from such measurements, suggesting that the atmospheric oxidizing capacity is sensitive to perturbations by widespread air pollution and natural influences. We show how the interannual variability in OH has been more precisely estimated from CH(3)CCl(3) measurements since 1998, when atmospheric gradients of CH(3)CCl(3) had diminished as a result of the Montreal Protocol. We infer a small interannual OH variability as a result, indicating that global OH is generally well buffered against perturbations. This small variability is consistent with measurements of methane and other trace gases oxidized primarily by OH, as well as global photochemical model calculations. 相似文献
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The jejunal and medial iliac lymph nodes of 53 clinically normal dogs between the age of 4 and 6 weeks were examined ultrasonographically. At least two jejunal and both left and right medial iliac lymph nodes were seen in all dogs. One hundred forty‐five jejunal, 53 right medial iliac and 53 left medial iliac lymph nodes in six litters of dogs, for a total of 251 lymph nodes, were measured for cross sectional maximum diameters. Mean jejunal lymph node length was 16.4 mm (range 6.4–34.9 mm) and mean width was 6.0 mm (range 2.3–15.7 mm). The mean medial iliac lymph node length was 13.6 mm (range 7.2–27.8 mm) and mean width was 4.4 mm (range 1.9–8.2 mm). Significant differences of lymph node size, noted between and within breeds, may not be of clinical significance. The mean size of the combined left and right medial iliac nodes was within previously published ranges for normal adult dogs. Lymph nodes were described in four litters of dogs (162 lymph nodes). Lymph nodes were either uniformly hypoechoic (108/163, 66%) or centrally hyperechoic with a hypoechoic rim (55/163, 34%). Although most (60%) lymph nodes were oval, a variety of shapes were seen, including vermiform and complex branching shapes. We concluded that in 4‐ to 6‐week‐old dogs, medial iliac lymph nodes are similar in size to adult dogs and jejunal lymph nodes are multiple, routinely seen, are larger than in adults and often have unconventional shapes. 相似文献
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S Houweling B Badawy DF Baker S Basu D Belikov P Bergamaschi P Bousquet G Broquet T Butler JG Canadell J Chen F Chevallier P Ciais GJ Collatz S Denning R Engelen IG Enting ML Fischer A Fraser C Gerbig M Gloor AR Jacobson DB Jones M Heimann A Khalil T Kaminski PS Kasibhatla NY Krakauer M Krol T Maki S Maksyutov A Manning A Meesters JB Miller PI Palmer P Patra W Peters P Peylin Z Poussi MJ Prather JT Randerson T Röckmann C Rödenbeck JL Sarmiento DS Schimel M Scholze A Schuh P Suntharalingam 《Science (New York, N.Y.)》2012,337(6098):1038-1040
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Reduction of pesticide residues on produce by rinsing 总被引：6，自引：0，他引：6
Krol WJ Arsenault TL Pylypiw HM Incorvia Mattina MJ 《Journal of agricultural and food chemistry》2000,48(10):4666-4670
In 1997 this laboratory initiated a research program with the objective of examining the effect that rinsing of produce with tap water would have on pesticide residues. Samples were obtained from local markets and/or grown at our experimental farm. Because approximately 35% of produce from retail sources contains pesticide residues, growing and treating produce at an experimental farm had the advantage that all such samples contain pesticide residues. Pesticides were applied under normal field conditions to a variety of food crops and the vegetation was allowed to undergo natural weathering prior to harvest. The resulting samples contained field-incurred or "field-fortified" residues. This experimental design was employed to mimic as closely as possible real world samples. Crops were treated, harvested, and divided into equal subsamples. One subsample was processed unwashed, whereas the other was rinsed under tap water. The extraction and analysis method used was a multi-residue method developed in our laboratory. Twelve pesticides were included in this study: the fungicides captan, chlorothalonil, iprodione, and vinclozolin; and the insecticides endosulfan, permethrin, methoxychlor, malathion, diazinon, chlorpyrifos, bifenthrin, and DDE (a soil metabolite of DDT). Statistical analysis of the data using the Wilcoxon signed-rank test showed that rinsing removed residues for nine of the twelve pesticides studied. Residues of vinclozolin, bifenthrin, and chlorpyrifos were not reduced. The rinsability of a pesticide is not correlated with its water solubility. 相似文献
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This paper presents one of the first integrated analyses of acidification and climate change on a geographically-detailed basis, and the first linkage of integrated models for acid deposition (RAINS) and for climate change (IMAGE 2). Emphasis in this paper is on Europe. Trends in driving forces of emissions are used to compute anthropogenic SO2 emissions in 13 world regions. These emissions are translated into regional patterns of sulfur deposition in Europe and global patterns of sulfate aerosols using source-receptor matrices. Changes in climate are then computed based on changes in sulfate and greenhouse gases. Finally, we compute ecosystem areas affected by acid deposition and climate change based on exceedances of critical loads and changes in potential vegetation. Using this framework, information from global and regional integrated models can be used to link sulfur emissions with both their global and regional consequences. Preliminary calculations indicate that the size of European area affected by climate change in 2100 (58%) will be about the same as that affected by acid deposition in 1990. By the mid 21st century, about 14% of Europe's area may be affected by both acid deposition and climate change. Also, reducing sulfur emissions in Europe will have both the desirable impact of reducing the area affected by acid deposition, and the undesirable impact of enhancing climate warming in Europe and thus increasing the area affected by climate change. However, for the scenarios in this paper, the desirable impact of reducing sulfur emissions greatly outweighs its undesirable impact. 相似文献
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ABSTRACT: BACKGROUND: Quantification of leaf movement is an important tool for characterising the effects of environmental signals and the circadian clock on plant development. Analysis of leaf movement is currently restricted by the attachment of sensors to the plant or depended on visible light for time-lapse photography. The study of leaf growth movement rhythms in mature plants under biological relevant conditions, e.g. diurnal light and dark conditions, is therefore problematic. RESULTS: Here we present OSCILLATOR, an affordable system for the analysis of rhythmic leaf growth movement in mature plants. The system contains three modules: (1) Infrared time-lapse imaging of growing mature plants (2) measurement of projected distances between leaf tip and plant apex (leaf tip tracking growth-curves) and (3) extraction of phase, period and amplitude of leaf growth oscillations using wavelet analysis. A proof-of-principle is provided by characterising parameters of rhythmic leaf growth movement of different Arabidopsis thaliana accessions as well as of Petunia hybrida and Solanum lycopersicum plants under diurnal conditions. The amplitude of leaf oscillations correlated to published data on leaf angles, while amplitude and leaf length did not correlate, suggesting a distinct leaf growth profile for each accession. Arabidopsis mutant accession Landsberg erecta displayed a late phase (timing of peak oscillation) compared to other accessions and this trait appears unrelated to the ERECTA locus. CONCLUSIONS: OSCILLATOR is a low cost and easy to implement system that can accurately and reproducibly quantify rhythmic growth of mature plants for different species under diurnal light/dark cycling. 相似文献
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Robin M. Overstreet Kenneth C. Stuck Rena A. Krol William E. Hawkins 《Journal of the World Aquaculture Society》1988,19(4):175-187
Infections of the virus Baculovirus penaei (BP) have historically impacted penaeid shrimp production in both hatcheries and ponds. BP causes cytopathological alterations and mortality in at least four species, including Penueus vannamei . This study established experimental infections with BP in laboratory-reared P. vannamei . The most useful protocol involved BP infection in third substage protozoea (P3 ) induced by feeding virus-contaminated material to rotifers and, in turn, feeding those rotifers to the shrimp larva. Infections were also established by delivering virus-containing brine shrimp to mysis (M) and postlarval (PL) stages. When virus originating from infected adults and juveniles was fed to P3 's, the shrimp exhibited patent infections with hypertrophic nuclei, polyhedra, free virions, and occluded virions five or six days after being fed the virus. In contrast, when the source of virus material was from bioassay larvae rather than from adults and juveniles, similar patent infections developed in P3 's by one to two days. A significant mortality in the resulting M's and PL's was associated with the infections with short but not long prepatent periods. In experimentally infected shrimp, examination by light microscopy and transmission electron microscopy revealed extensive viral infection in many cells in the anterior midgut and as many as 80–90% of the proximal and medial hepatopancreatic tubular cells. Free and occluded virions capable of producing disease ruptured into the gut lumen soon after infections became patent. Tests conducted in 1 L Imhoff cones, 160 L spat-cones, and aquaria all produced infections, usually with a prevalence of 100%. The system provides a useful method to detect and assay for infective agents, to amass infective material for research purposes, and to assess the biology of and host response to the virus under different conditions. 相似文献