The effect of phenylamide fungicides on the control of potato late-blight (Phytophthora infestans) in England and Wales from 1978 to 1992     

N. J. BRADSHAW  & T. B. VAUGHAN 《Plant pathology》1996,45(2):249-269

During the period 1978–1992, phenylamide fungicides in co-formulation with the dithiocarbamate fungicide mancozeb were tested for the control of potato late-blight in 51 separate field experiments in England and Wales. Whilst there was a general trend over all the experiments which indicated that foliage blight was less severe where the phenylamide + dithiocarbamate mixture had been used, the benefit was more marked in some than in others. Despite the detection of phenylamide resistance, at some sites the mixture gave better control of foliage blight than the dithiocarbamate alone. At one site where continuous data were available, the additional benefit of the phenylamide compound for control of foliage infection was lost after 1986 coinciding with a rise in phenylamide resistance from 31.7% in 1986 to 81% in 1987. Where foliar blight epidemics occurred, yield responses to fungicide programmes compared with unsprayed controls ranged from 0 to +118.5% with a mean response of +30.2%. This is equivalent to 30.8 and 12.92 t/ha respectively. Standardized yield differences were calculated to allow inter-trial and inter-year comparisons and showed no benefit from the phenylamide fungicide applied at 14-day intervals in 33 out of 38 experiments where foliar blight epidemics occurred. At one site, Cusum analysis of standardized yield differences following treatment with the phenylamide + dithiocarbamate mixture and the dithiocarbamate alone showed a mean benefit from the phenylamide mixture of 2.23 t/ha during the period 1978 to 1986. From 1987 to 1992, the yield benefit dropped to a mean level of 0.68 t/ha a decrease of 69.5%. In experiments where blight was not recorded, fungicide treatments had no deleterious effect on yields. Over all the trials, there was no effect of fungicide treatment on the incidence of tuber blight at harvest.  相似文献   

Cross-protective immunity and the serological classification system for Bacteroides nodosus     

DJ STEWART  JA VAUGHAN  TC ELLEMAN†  PA HOYNE†  KJ BURNS  JH DUFTY 《Australian veterinary journal》1991,68(2):50-53

The relationship between the serological classification system for serogroup B and for serogroup H of Bacteroides nodosus and cross-protection between subgroups within these serogroups was examined. Protection against ovine footrot following vaccination was achieved against other subgroup strains provided sufficient cross-reactive antibody was induced by shared pilus antigens. Within serogroup B, better cross-protection against one subgroup was obtained with a pili vaccine than a whole cell vaccine which correlated with higher pilus antibody titres induced by the former. For serogroup H, a lack of cross-protection and serological reactivity between subgroups was demonstrated, which indicates that the prototype strain of subgroup H2 should be designated a new serogroup.  相似文献   

Influence of natural and synthetic humic substances on the activity of urease   总被引：1，自引：0，他引：1  

D. VAUGHAN  B. G. ORD 《European Journal of Soil Science》1991,42(1):17-23

The activity of a purified urease, obtained from Bacillus pasteurii, was inhibited by humic and fulvic acids obtained from an agricultural soil. Enzyme kinetic studies showed that the humic substances affected the affinity of the enzyme for its substrate (K_m) and the maximum velocity of the reaction (V_max). The V_max was inhibited to the same extent by both humic (HA) and fulvic (FA) acids, the precise effect depending on the pH and concentration of humic substance. At pH 4.0, HA concentrations of 25 pg cm^?3 and 10 μg cm^?3 inhibited the V_max by 38.5% and 20% respectively. HA and FA had similar effects on the K_m but in this case the lowering of the affinity of the enzyme for its substrate was not concentration dependent in the range 0–25 μg cm^?3 of humic substance. Typically, the affinity was decreased from a K_M of 50 mM in the control to 67 mM in the presence of HA and FA. The effects were not due primarily to the ash or N contents of the humic substances because de-ashed humic acid and synthetic model humic (made from catechol, guaiacol, pyrogallol, resorcinol and protocatechuic acid) and fulvic acid (made from polymaleic acid), containing virtually no ash or N, were equally as effective. The effect was not related to the phenolic monomers which, before polymerization, had no effect on urease activity.  相似文献   

Virus isolated from inclusion conjunctivitis of newborn (inclusion blennorrhea)     

HANNA L  ZICHOSCH J  JAWETZ E  VAUGHAN DG  THYGESON P 《Science (New York, N.Y.)》1960,132(3440):1660-1661

An infant developed acute conjunctivitis 7 days after birth. Smears of the mucopurulent discharge contained many typical elementary-body inclusions. From conjunctival scrapings a virus resembling trachoma was grown in eggs. When instilled into monkey eyes, it produced an acute conjuctivitis resembling the human disease. Nine other patients with inclusion conjunctivitis of similar intensity failed to yield viruses.  相似文献   

Preparation of tritiated proteins by the Wilzbach method     

STEINBERG D  VAUGHAN M  ANFINSEN CB  GORRY J 《Science (New York, N.Y.)》1957,126(3271):447-448

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In vitro studies on the action of sulfonamide hypoglycemic agents     

VAUGHAN M 《Science (New York, N.Y.)》1956,123(3203):885-886

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Abnormalities of the volar and plantar sesamoid bones in Rottweilers     

L. C. VAUGHAN  C. FRANCE 《The Journal of small animal practice》1986,27(9):551-558

The fore and hind feet of 50 unselected Rottweilers were examined clinically and radiographically for abnormalities of their volar and plantar sesamoid bones. Lesions were found in 22 (44 per cent), invariably affecting the No. 2 and/or No. 7 sesamoids. The majority occurred in the forelimb. Clinical signs were detected in only five dogs and local analgesia in these cases indicated that the sesamoid changes were not the cause of the presenting lameness. Radiographically the defect varied from small radiodense foci separated from an otherwise normal sesamoid, to gross distortion of the bone into a number of calcified bodies. In none of these dogs was the sesamoid abnormality demonstrated to cause lameness and it was not necessary, therefore, to treat the condition surgically. It is postulated that these lesions result from disordered ossification with subsequent degenerative changes.  相似文献   

Surgery of the Reproductive Tract in Large Animals, 3rd ed     

John E. Cox  J. T. VAUGHAN 《Veterinary surgery : VS》1989,18(1):56-56

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Pathogens occurring on ten varieties of ryegrass at Rothamsted in 1973–74     

R. T. PLUMB  J. F. JENKYN  ROBERTA BOWEN 《Grass and Forage Science》1976,31(2):65-67

Six varieties oi Loliumperenne, three of L. multiflorum and one hybrid (L. multiflorum × L. perenne) were assessed for diseases over two harvest years. Crown rust (Puccinia coronata) and mildew (Erysiphe graminis) occurred on some varieties in 1973. Leaf spotting (Drechslera spp.) was common, but slight on most varieties, in both years. Ryegrass mosaic virus (RMV) and its mite vector, Abacarus hystrix were present on all varieties in the second year. The relative susceptibility of varieties to RMV was similar in the field and in glasshouse tests.  相似文献   

Thoracodorsal and Caudal Superficial Epigastric Axial Pattern Skin Flaps in Cats     

A. M. REMEDIOS DVM  MVSC    M. S. BAUER DVM  DiplomateACVS  C. V. BOWEN FBSC 《Veterinary surgery : VS》1989,18(5):380-385

Nonselective angiography, selective angiography, and gross dissection of 15 cadavers were performed to delineate direct cutaneous arteries in the cat. The omocervical, deep circumflex iliac, thoracodorsal, and caudal superficial epigastric arteries were identified by nonselective angiography. Selective angiography and gross dissection allowed assessment of the origin and vascular territories of the thoracodorsal and caudal superficial epigastric arteries. Orthotopic and heterotopic transfers of thoracodorsal and caudal superficial epigastric island flaps were performed on eight cats. All flaps were successful although areas of necrosis at the caudodistal tips were evident in most of the thoracodorsal flaps. The rotated thoracodorsal flaps extended to the carpi. Caudal superficial epigastric flaps enabled coverage to the metatarsus. Seroma formation and partial dehiscence were minor complications.  相似文献