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排序方式: 共有250条查询结果,搜索用时 15 毫秒
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The broad-spectrum fungicide CGA 219417 inhibits mycelial growth of Botrytis cinerea Pers ex Fr. Pseudocercosporella herpotrichoides (Fron.) Deighton and Helminthosporium oryzae B. de Haan on defined media lacking amino acids. The growth inhibition of B. cinerea is reversed by the addition of a mixture of 19 amino acids at a concentration of 100 μM each or by the addition of methionine or homocysteine in concentrations of 100 μM or 1 mM, respectively. In the case of B. cinerea, the reversal of growth inhibition by methionine could also be shown for pyrimethanil and mepanipyrim. These findings suggest that the pyrimidinamine fungicides inhibit the biosynthesis of methionine in phytopathogenic fungi. 相似文献
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We tested a combined application of neem and two predatory mite species, Amblyeius cucumeris and Hypoaspis miles, against a spontaneous infestation of a Western Flower thrips population (Frankliniella occidentalis) under greenhouse conditions. We treated the infested plants and the soil twice at an interval of 8 days with neem solutions of 0.3% and 0.5%, respectively. Four days after the second treatment, we released the two predatory mite species. We monitored the thrips population with blue insect traps and counted the insects caught regularly. From the 21st week (monitored till the 52nd week) after the beginning of the treatment with neem, we registered no further thrips on the insect traps. 相似文献
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In even-aged, 120-year-old Norway spruce stands with underplanted beech (in 1995) four permanent research plots were established, each 100 × 100 m in size. Twelve subplots were selected on each plot along a light gradient from complete canopy closure to open light conditions. On each plot, photon flux density (PFD) was measured continuously, and during same time interval (August 2008, 2009), color digital hemispherical photographs were taken. Cumulative PFD values for measuring points were compared with potential PFD radiation obtained from hemispherical photograph analysis for different angle of hemisphere and different parameters from hemispherical image analysis (gap fraction, total openness and direct, indirect and total amount of radiation). Cumulative and average daily values for the plots were compared; 120° hemispherical photograph angle, gap fraction and total openness were the variables that explained the largest proportion of variance in light transmittance. Determination coefficients between direct and total light component were highest for the total potential radiation and lowest for the diffuse light component. Comparison between potential and instantaneous light measurements for radial, height increment and SLA of young beech showed that instantaneous radiation measurements explained height increment best; 120° of hemisphere proved to be the best explaining angle. 相似文献
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Central bearded dragons (Pogona vitticeps) are one of the most popular reptile pets in Australia and around the world. Diseases, including metabolic bone disease, periodontal disease, and gastrointestinal endoparasites commonly affect captive animals. To determine the common reasons these lizards were presented to the veterinarian and to establish the prevalence of disease seen in captive P. vitticeps in Australia, this retrospective study evaluated the clinical records of three exotic pet veterinary hospitals. Records from 724 P. vitticeps were analysed, with 70 reasons for presentation and 88 diseases identified across 1000 visits to the veterinarian. Lethargy was the most reported reason for presentation (n = 181). The gastrointestinal tract (18.25%) and skin (18.25%) were the equally most commonly affected organ systems, followed by the musculoskeletal system (15.17%). Endoparasites were the most common single disease process (n = 103), followed by metabolic bone disease (n = 65), skin wounds (n = 59) and periodontal disease (n = 48). Of the patients that presented for routine preventive health examinations (n = 159), 45.30% received some form of intervention to treat or prevent disease. Many of the conditions that were identified by the veterinarians in this study are traditionally correlated with suboptimal husbandry and may be easily prevented. This study identified the common reasons for presentation to the veterinarian and the prevalence of disease in captive P. vitticeps in Australia, providing the first extensive retrospective analysis of objective reference literature for central bearded dragon owners and aspiring reptile veterinarians. 相似文献
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Kresse G Schmid M Napetschnig E Shishkin M Köhler L Varga P 《Science (New York, N.Y.)》2005,308(5727):1440-1442
The well-ordered aluminum oxide film formed by oxidation of the NiAl(110) surface is the most intensely studied metal surface oxide, but its structure was previously unknown. We determined the structure by extensive ab initio modeling and scanning tunneling microscopy experiments. Because the topmost aluminum atoms are pyramidally and tetrahedrally coordinated, the surface is different from all Al2O3 bulk phases. The film is a wide-gap insulator, although the overall stoichiometry of the film is not Al2O3 but Al10O13. We propose that the same building blocks can be found on the surfaces of bulk oxides, such as the reduced corundum (0001) surface. 相似文献