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The uncalibrated predictive ability of four preferential flow models (CRACK‐NP, MACRO/MACRO_DB, PLM, SWAT) has been evaluated against point rates of drainflow and associated concentrations of isoproturon from a highly structured and heterogeneous clay soil in the south of England. Data were available for four plots for a number of storm events in each of three successive growing seasons. The mechanistic models CRACK‐NP and MACRO generally gave reasonable estimates of drainflow over the three seasons, but under‐estimated concentrations of isoproturon over a prolonged period in the first season and over‐estimated them in the two remaining seasons. CRACK‐NP simulated maximum concentrations of isoproturon over the first two events of each of the three seasons of 156, 527 and 24.4 µg litre?1, respectively, and matched the observed data (465, 65.1 and 0.65 µg litre?1) slightly better than MACRO (69.1, 566 and 58.5 µg litre?1). Automatic selection of parameters from soils information within MACRO_DB reduced the emphasis on preferential flow relative to the stand‐alone version of MACRO. This gave a poor simulation of isoproturon breakthrough and simulated maximum concentrations were 0, 50.1 and 35.1 µg litre?1, respectively. The capacity model PLM gave the best overall simulation of total drainflow for the first two events in each season, but over‐estimated concentrations of isoproturon (967, 808 and 51.3 µg litre?1). The simple model SWAT represented total drainflow reasonably well and gave the best simulation of maximum isoproturon concentrations (140, 80.2 and 8.2 µg litre?1). There was no clear advantage here in using the mechanistic models rather than the simpler models. None of the models tested was able to simulate consistently the data set, and uncalibrated modelling cannot be recommended for such artificially drained heavy clay soils. © 2001 Society of Chemical Industry  相似文献   
13.
The isolation of herpesviruses from skin ulcers in domestic cats   总被引:1,自引:0,他引:1  
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14.
Objective To study the course of intraocular pressure (IOP) after cataract surgery in 50 dogs. Design Prospective study. Animals Fifty dogs without preoperative ocular hypertension were selected for cataract surgery. Methods All dogs underwent cataract surgery: 25 by manual extracapsular extraction and 25 by phacoemulsification. For each dog, intraocular pressure was measured before surgery, and 1, 3, 5, 18 h, 1 week and 1 month post surgery. Results No significant difference of mean intraocular pressure between the two surgical methods was observed for each time measurement. Nine dogs had postoperative hypertension (IOP > 25 mmHg) during the first 5 hours post surgery. Incidence of postoperative hypertension was not significantly different with manual extracapsular extraction (16%) vs. phacoemulsification (20%). A decrease of mean IOP was observed 1 h after surgery (8.49 mmHg vs. 10.91 mmHg), then an increase 3 and 5 h post surgery (12.3 and 13.32 mmHg, respectively). At 18 h, 1 week and 1 month post surgery, mean IOP decreased. Mean IOP was 10.38, 10.38 and 8.84 mmHg, respectively. Conclusion In this study incidence of POH is not high. However, a follow‐up of IOP in the first hours after cataract surgery is required to avoid complications of the retina and optic nerve and to administer hypotensive treatment if necessary.  相似文献   
15.
Sensitivity analyses using a one-at-a-time approach were carried out for leaching models which have been widely used for pesticide registration in Europe (PELMO, PRZM, PESTLA and MACRO). Four scenarios were considered for simulation of the leaching of two theoretical pesticides in a sandy loam and a clay loam soil, each with a broad distribution across Europe. Input parameters were varied within bounds reflecting their uncertainty and the influence of these variations on model predictions was investigated for accumulated percolation at 1-m depth and pesticide loading in leachate. Predictions for the base-case scenarios differed between chromatographic models and the preferential flow model MACRO for which large but transient pesticide losses were predicted in the clay loam. Volumes of percolated water predicted by the four models were affected by a small number of input parameters and to a small extent only, suggesting that meteorological variables will be the main drivers of water balance predictions. In contrast to percolation, predictions for pesticide loss were found to be sensitive to a large number of input parameters and to a much greater extent. Parameters which had the largest influence on the prediction of pesticide loss were generally those related to chemical sorption (Freundlich exponent nf and distribution coefficient Kf) and degradation (either degradation rates or DT50, QTEN value). Nevertheless, a significant influence of soil properties (field capacity, bulk density or parameters defining the boundary between flow domains in MACRO) was also noted in at least one scenario for all models. Large sensitivities were reported for all models, especially PELMO and PRZM, and sensitivity was greater where only limited leaching was simulated. Uncertainty should be addressed in risk assessment procedures for crop-protection products.  相似文献   
16.
An indirect ELISA was developed as a possible tool to detect the seroprevalence of antibodies to Salmonella spp in semidomesticated reindeer. To cover a broad spectrum of serogroups a lipopolysaccharide mix of S. typhimurium and S. choleraesuis was used as antigen in this pilot study. Sera from 31 culture-negative reindeer with no clinical or historical evidence of salmonellosis were used as negative serum control. After immunisation with an inactivated S. typhimurium vaccine, pooled sera from 6 reindeer were used as positive serum control as no serum from naturally infected animals was available. A seroprevalence of 0.6% in 2000 clinically healthy, slaughter-reindeer from Norway was determined by using this ELISA. No more information on Salmonella in reindeer in Norway is known to the authors. This is the first ELISA established for indirect detection of Salmonella in reindeer.  相似文献   
17.
The i-STAT portable clinical analyzer (PCA) was evaluated for performance in avian species. With the EG7+ cartridge, which provided results for hydrogen ion concentration, oxygen tension, carbon dioxide tension, sodium, potassium, ionized calcium, hematocrit, and various calculated parameters, analytical accuracy and precision were tested by comparing obtained values to those of established traditional blood gas and chemistry analyzers. Deming's regression and bias plots were used to compare i-STAT results with those obtained by laboratory professionals using benchtop analyzers. The reliability of the i-STAT PCA with EG7+ cartridges was good, with 0-5.7% system failures in measured values. Regression statistics were good for all blood gas analytes and acceptable for electrolytes and calculated parameters, except for potassium and base excess, for which the regression data or the discrepancy between the methods was too large. The system was reliable and easy to use and had an overall acceptable accuracy in avian species. These features, together with portability and small required blood volumes, make the i-STAT suitable for point-of-care use in critical avian patients, although single values require careful interpretation.  相似文献   
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Tineola bisselliella is a common pest on natural fabrics of economic importance. Two commercially available repellents for use against adult webbing clothes moths were tested for their efficacy in dual- and no-choice bioassays. Oil of cloves and citral in combination, as well as citronellol scented with oil of lavender showed promising repellent effects for 4 weeks when applied in small compartments of a wardrobe. Although the repellent efficacy was not 100% under the conditions tested, the usage of essential oils in combination with other infestation prevention techniques is discussed.
Zusammenfassung Die KleidermotteTineola bisselliella Hum. ist einer der wirtschaftlich bedeutenden tierischen Wollzerstörer. Auch Pelze, Felle, Polsterhaare und Federn werden von dem weit verbreiteten Kleinschmetterling aus der Familie der Tineidae befallen. In der Praxis gilt es vor allem Kleidungsstücke, die z. B. saisonbedingt für längere Zeit ungenutzt in einem Kleiderschrank aufbewahrt werden, vor dem Befall durch die Kleidermotte zu schützen. Hierfür stehen dem Verbraucher neben den konventionellen Bekämpfungsmitteln mit den Wirkstoffen Kampfer, Naphthalin und Paradichlorbenzol sowie pyrethrum- und pyrethroidhaltige Mittel auch Präparate zur Verfügung, die auf die repellierende Wirkung von ätherischen Ölen zurückgreifen. Die abstoßende Wirkung von Nelkenöl in Kombination mit Citral und von Citronellol parfümiert mit Lavendelöl auf die Falter der Kleidermotte wurde auf vergleichbare Eigenschaften untersucht. In Wahlversuchen wurden deutliche Repellent-Wirkungen der Mottenschutz-Präparate sichtbar. Die Präparate zeigten gute Wirkungen, wenn sie zum Schutz gegen den Zuflug von Kleidermotten an wollhaltigen Stoffen in kleinen Kompartimenten eines Kleiderschrankes ausgelegt waren. Auch in Zwangsversuchen hatte dieser Befund zum Teil Bestand. Bei längeren Versuchszeiten wurden allerdings verstärkt Fraßschäden durch Larven an den Wollstoffen festgestellt. Dies ist darauf zurückzuführen, daß Mottenweibchen nicht mehr in dem Maße repelliert wurden und ihre Eier an den Stoffen ablegten.


This article reports the results of research only. Mention of a proprietary product or pesticide does not constitute an endorsement or a recommendation for its use by the Federal Biological Research Centre for Agriculture and Forestry or by the USDA-ARS.  相似文献   
20.
The influence of genetic determination and environment on the variability of secondary resin canal traits was investigated on 15–19-year-old Norway spruce (Picea abies (L.) Karst.) clones grown in Lower Austria (Pressbaum and Ulmerfeld) and southern Sweden (Knutstorp and Hermanstorp). Eleven and 20 clones were present on the two Austrian and the two Swedish sites, respectively. The sites differed in their water availability, as indicated by different annual precipitation and soil type. Resin canal traits measured were the number of epithelial cells per canal, the number of resin canals per unit tangential wood surface area, the mean resin canal area and the total resin canal area per unit tangential wood surface area. The latter three traits are known to be related to the constitutive resin flow of Norway spruce.

Environment had an influence on the variability of resin canal traits but the most important factor for the variability was the tree’s genetic disposition. Within countries, clones from the drier sites (Pressbaum and Hermanstorp) showed significantly smaller resin canals. Trees from Pressbaum also had smaller total resin canal areas than trees from Ulmerfeld. The number of epithelial cells and the number of canals did not differ between sites.

Resin canal traits had wide genetic variation and high broad sense heritabilities (H2), with values between 0.28 and 0.82. Highest heritability values were reached for the number of epithelial cells and the number of canals (H2 > 0.8). Genotypic correlations across trials were high for the resin canal traits and approached 1 in both the Austrian and the Swedish trials, indicating that there was little genotype by environment interaction for these traits and thus the ranking of clones was very similar in the different environments.

The number of epithelial cells, the mean area and the total resin canal area showed either moderately significant positive genotypic correlations with tree growth traits or none at all.

In a breeding context, our results are encouraging and indicate that high constitutive defence potential against bark beetles, such as Ips typographus, is not aligned with low volume growth. But it should be taken into consideration that environment and forestry practices can also have an impact on the resin reservoir provided by the radial resin canals.  相似文献   

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