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1.
In 1983 plants showing symptoms typical of watercress chlorotic leafspot agent (WCLSA) were found in Kent (GB). Later, plants showing similar symptoms were found in Dorset (1986) and Hampshire (1987), the main watercress-producing regions of England. These plants, unlike those infected with WCLSA, contained virus particles which were isometric with diameters of 37-38 nm. An antiserum to the virus was produced, with a titre in immunodiffusion tests of 1/128 and this gave good results in immunosorbent electron microscopy (ISEM) and ELISA tests on crude plant sap. Purified preparations of the virus reacted positively in ISEM and immunodiffusion tests with an antiserum to watercress yellow spot virus, a partially described virus occurring in France. Tests suggest that the crook root fungus Spongospora subterranea f.sp. nasturtii is probably the vector of this virus but other means of transmission cannot be excluded. Virus incidence within watercress beds varied, with little or no infection in the water inlet region of the bed where there are also low levels of crook root infection, higher levels in the central region and highest levels at the outlet region where crook root infection is also highest.  相似文献   
2.
Dogs given parenteral anticholinergic drugs have been thought to be at risk for development or exacerbation of elevated intraocular pressure (IOP). In a randomized, blinded, placebo-controlled study, we evaluated the effect of intramuscular glycopyrrolate (0.01 mg/kg) on pupil diameter and IOP in unanesthetized normal dogs. Treatment with glycopyrrolate did not change pupil diameter or IOP from baseline, nor were there differences between glycopyrrolate and saline-treated (control) dogs. In addition, the authors retrospectively reviewed the medical records of 2,828 dogs undergoing general anesthesia between April 1987 and September 1990 to determine if there was an association between parenteral anticholinergic medication and postanesthetic elevation in IOP. The authors also determined the frequency of bradycardia requiring anticholinergic therapy during anesthesia in dogs with glaucoma. Of the 2,828 cases reviewed, the records of 46 dogs coded for glaucoma were examined in detail. The 46 dogs underwent 62 episodes of anesthesia, with 23 episodes including exposure to an anticholinergic drug. An increase in IOP from preanesthetic to postanesthetic measurement occurred in three dogs. One of these dogs received anticholinergic medication for bradycardia during anesthesia. The postanesthetic elevation in IOP in this dog was probably not drug related. Preanesthetic anticholinergic administration did not affect the incidence of anticholinergic administration for bradycardia during the anesthetic episode. Anticholinergic therapy during anesthesia was more frequent when the preanesthetic medication included an opiate drug. These studies do not indicate an association between parenteral anticholinergic administration and elevations in IOP.  相似文献   
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4.
漳河水库由观音寺水库和鸡公尖水库通过半天然明槽相互连通组成,因受库水位观测、明槽输水计算、动库容计算误差等的复杂影响,以往多次建立的洪水预报方案均未达到可供应用的水平。在分析漳河水库入库洪水误差产生特点的基础上,通过建立抗误差产汇流预报模型和自适应实时校正技术,使漳河水库洪水预报方案平均确定性系数达91.09%,洪峰合格率达100%,峰现时间合格率达90.91%;观音寺水库洪水预报方案的平均确定性系数达90.63%,洪峰合格率达100%,峰现时间合格率达100%,终于建立了达到甲等水平的漳河水库洪水预报应用方案。  相似文献   
5.
Atrazine carryover often limits growers to production of atrazine-tolerant crops the year following application, and allows the increase of triazine-tolerant weed species such as Panicum miliaceum L. (wild proso millet). Tiriazine-resistant Brassica napus L. cv. ‘Triton’ (oilseed rape) was tested to characterize the nature of interspecific interference with P. miliaceum. In a greenhouse study, atrazine at 2.2 kg ha?1 depressed oilseed rape fruit (siliqua) number and fruit dry weight, and delayed flowering, but did not significantly affect height or weight of shoots, Oilseed rape fruit weight was reduced at 200 P. miliaceum plants m?2. fruit number and shoot weight were inhibited at 400 weeds m?2. and height was reduced and flowering delayed at 600 weeds m?2. Number and weight of fruits were reduced by one-third after 8 weeks of interference as compared to oilseed rape grown with the weed for 4 weeks. Oilseed rape height was reduced by 29% and shoot weight by 55% by 600 weeds m?2 and 2–2 kg ha?1 atrazine, while fruit number and weight were reduced by 72%. Oilseed rape shoot weight was reduced by 74% by 600 weeds m?2 for 12 weeks of interference, while fruit number and weight were reduced by 85% and 82%. respectively. In a field study, fluazifop reduced early season P. miliaceum cover by 72%, but did not increase oilseed rape cover. Mid-season P. miliaceum shoot weight was decreased by 97% by fluazifop and oilseed rape shoot weight was increased by 34%. P. miliaceum control increased oilseed rape biomass by 38% at 89 days, but biomass of oilseed rape sown at 11.2 kg ha?1 with 2.2 kg atrazine ha?1 was not decreased by P. miliaceum interference at 89 days.  相似文献   
6.
Dissipation of fluroxypyr in North Dakota lake waters was examined in three laboratory studies: photolysis, aerobic metabolism, and anaerobic metabolism. Photolysis was negligible in sterilized water, with and without natural photosensitizers. In 1:10 sediment:water systems, 50% disappearance times of 0.5–2 weeks were observed in the metabolism studies (25°C). Major metabolites (>10%) included the dichloropyridinol and 3-chloropyridinol derivatives, while the 5-chloropyridinol derivative appeared (<7%) in anaerobic systems. The pyridinols disappeared readily in aerobic but more slowly in anaerobic systems. In typical pond and lake waters, fluroxypyr and pyridinols are expected to disappear by the end of the growing season. Devenir de fluroxypyr dans l'eau La dissipation du fluroxypyr dans les eaux de lac dans le Dakota Nord a étéétudiée dans 3 études de laboratoires: photolyse, métabolisme aérobique et métabolisme anaérobique. La photolyse était négligeable dans I'eau stérilisée, avec et sans photosensibilisants naturels. Dans des systémes sédiments/eau de 1/10 des temps de disparition 50% de 0-5-2 semaines ont été observées dans les études de meéabolisme (25°C). Les principaux metabolites (>10%) comprenaient les dérivés dichloropyridinol et 3-chloropyridinol, tandis que le dérivé 5-chloro-pyridinol apparaissait (<7%) dans les systemés anaérobiques. Les pyridinols disparaissent rapidement en aérobie mais lentement dans les systémes anaerobiques. Dans les eaux typiques de mares et d'étangs, le fluroxypyr et les pyridinols sont supposés avoir disparu à la fin de la saison de croissance. Verhalten von Fluroxypyr in Wasser Der Verlust an Rückständen von Fluroxypyr im Wasser aus Seen in North Dakota wurde hinsichtlich der Photolyse sowie des aeroben und anaeroben Metabolismus untersucht. Die Photolyse war in sterilisiertem Wasser mit und ohne natürlichen Photosensitizern vernachlässigbar. Bei den Metabolismusuntersuchungen bei 25°C in l:10-Sediment:Wasser-Systemen lagen die Zeiten für 50%igen Verlust bei 0,5.2 Wochen. Zu den Hauptmetaboliten (>10%) zählten Dichlorpyridinol und 3-Chlor-pyridinol-Derivate, während 5-Chlorpyridinol-Derivate in anaeroben Systemen unter 7% blieben. Die Pyridinole verschwanden rasch in aeroben, aber viel langsamer in anaerobischen Systemen. In solchen Gewässern werden Fluroxypyr und Pyridinole erwartungsgemäß zum Ende einer Vegetationsperiode verschwunden sein.  相似文献   
7.
A retrospective histopathological and immunopathological study was conducted on 86 dogs with Malassezia dermatitis. West Highland White terriers, English Setters, Shih Tzus, Basset Hounds, American Cocker Spaniels, spayed females, and castrated males were found to be at increased risk. The histopathological reaction pattern of lymphocytic superficial perivascular to interstitial dermatitis with parakeratotic hyperkeratosis, irregular epidermal hyperplasia, diffuse intercellular oedema and lymphocytic exocytosis was found to be consistent with a diagnosis of Malassezia dermatitis whether yeast were histologically visible (73.3% of the cases) or not (26.7%). Immunopathological studies revealed that 60– > 90% of the inflammatory cells within the epidermis, and 25–75% of those within the dermis were CD3+T lymphocytes, and that the only immunoglobulin-positive cells were dermal plasma cells.  相似文献   
8.
An orthotopic colon graft based on the middle colic artery and vein was implanted with microvascular technique and a stapling instrument in five dogs. The grafts were successful in four dogs. A similar colon autograft was used to replace the entire thoracic esophagus in five dogs. The recipient vessels were the left carotid artery and left external jugular vein. Four of the grafts failed because of kinking and thrombosis of the arterial supply (2 dogs) or the venous outflow (2 dogs). One graft, which had a viable vascular supply, developed a severe leak at the colon-to-stomach anastomosis, and the dog was euthanatized on day 3. The recipient vascular pedicle was modified and used successfully to replace a portion of the cervical esophagus in three dogs. The grafts survived, the dogs could swallow liquids and semisolid food well, and, at necropsy after 4 weeks, the anastomotic sites were well healed. The graft sites contained essentially normal colon mucosa.  相似文献   
9.
Abstract— Four black and two red Doberman Pinschers with a slowly progressive, dorsal hypotrichosis were studied. All six dogs developed the hair loss as adults and hypotrichosis was permanent. Skin biopsies showed changes compatible with follicular dysplasia.
Résumé— L'etude porte sur 4 Dobermans noirs et 2 Dobermans marrons présentant une hypotrichose dorsale d'extension progressive. L'hypotrichose dorsale d'extension progressive. L'hypotrichose s'est développée chez les 6 chiens à l'âge adulte et est permanente. Les biopsies cutanées ont montré des images compatibles avec le diagnostic de dysplasie folliculaire.
Zusammenfassung— Bei vier schwarzen und zwei roten Dobermännern wurde eine langsam fortschreitende dorsale Hypotrichose festgestellt. Alle 6 Hunde verloren als adulte Tiere permanent Haare. Die histologischen Untersuchungen zeigten Veränderungen, die einer Follikeldysplasie entsprechen.
Resumen  Se describe la presencia de una hipotricosis dorsal de progresión lenta en cuatro perros de raza Doberman color negro y dos perros de raza Doberman y color rojo. En los seis animales la hipotricosis se inició cuando eran adultos y se mantuvo de forma permanente. Las biopsias cutáneas mostraron cambios histopatológicos compatibles con una displasia folicular.  相似文献   
10.
GONG  Y.L.; SWAINE  M.D.; MILLER  H.G. 《Forestry》1991,64(2):157-168
An enumeration was carried out in 1989 to assess the effectsof fencing and ground treatment 11 years previously on survivaland growth of naturally disseminated Scots pine seedlings inthe native pinewood at Glen Tanar, Aberdeenshire. Results showeda significant difference between unfenced and fenced plots onpine seedling density and height in 1989. Initial effects ofseedbed treatment on Scots pine seedling density, 2 years afterthe experiment began had largely disappeared by 1989. If removalof ground cover is used to enhance pine seed germination, theexposed seedlings may need to be protected from browsing byfencing. Received 19 March 1990.  相似文献   
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