Veterinary photodynamic therapy     

Lucroy MD  Edwards BF  Madewell BR 《Journal of the American Veterinary Medical Association》2000,216(11):1745-1751

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Bethanechol-responsive bladder atony in a colt foal after cystorrhaphy for cystorrhexis     

Booth TM  Howes DA  Edwards GB 《The Veterinary record》2000,147(11):306-308

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Survival and inactivation of classical swine fever virus   总被引：2，自引：0，他引：2  

Edwards S 《Veterinary microbiology》2000,73(2-3):175-181

Classical swine fever virus, like many enveloped viruses, may be regarded as moderately fragile. It shows a short but variable survival time in the environment, depending on physical conditions, but may remain viable for prolonged periods in favourable circumstances as found, for example, in stored meat. Published information is reviewed on the survival time of the virus under a variety of physical and chemical conditions, including the variable influence of environmental factors. The principles of virus inactivation by heat, pH or chemicals are discussed, with a consideration of the principles of containment for laboratories working with the virus.  相似文献   

有效利用肉种鸡的生活习性最优化其生产性能     

Ron Meijerhof 《中国家禽》2007,29(19):43

在某些情况下采用技术手段来提高生产性能,结果可能会适得其反,理解鸡的“行为准则“以及鸡的自我日程安排有助于管理好种禽,并获得最佳的生产性能.……  相似文献   

Sustainable management of the western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), in infested areas: experiences in Italy, Hungary and the USA     

M. Boriani  M. Agosti  J. Kiss  C. R. Edwards 《EPPO Bulletin》2006,36(3):531-537

The western corn rootworm, Diabrotica virgifera virgifera LeConte, is the most important pest of maize in the Midwestern USA, and since its detection in 1992 in Europe, also in several countries of Central and Eastern Europe. Methods for managing this pest vary from region to region, depending upon: the different cultural practices in maize production, climatic conditions, soil types, pest behaviour, infestation level and socio-economic conditions. Factors including date of planting, amount of rotated or continuous maize, irrigation, date of rootworm hatching and differences in behaviour of the pest, necessitate developing different management strategies in different areas of the infested countries. Pest monitoring, damage evaluation, threshold development, use of insecticides, risk estimation and crop rotation are some of the starting points in the development of management strategies. Approaches and experiences in D. v. virgifera control and management in Italy, Hungary and the USA, based on the understanding of local agro-ecosystems and socio-economic conditions, are reported.  相似文献   

Effects of plastic mulches on root zone temperature and on the manifestation of tomato spotted wilt symptoms and yield of tomato   总被引：1，自引：0，他引：1  

Juan C. Díaz-Pérez  Ron Gitaitis  Bikash Mandal 《Scientia Horticulturae》2007

Tomato spotted wilt (TSW) disease is a serious constraint to tomato production in various regions of the world. The effect of TSW on tomato yield is largely influenced by time of infection. Early infection usually results in severe stunting of the seedling and even death of the plant. Plastic film mulches affect both the incidence of TSW, and plant growth and yield of tomato. The objective of the present study was to determine the effect of root zone temperature (RZT) as affected by plastic film mulch on the manifestation of symptoms of TSW, and growth and yield of tomato plants either artificially inoculated with tomato spotted wilt virus (TSWV) or under natural TSW infection. In artificially inoculated plants as well as in plants under natural TSW infection, vegetative top fresh weight (FW) and fruit FW both increased with the length of time after transplanting that the plants remained free from TSW symptoms. The root zone temperature was highest under black mulch (seasonal mean = 27.5 °C), followed by gray (27.0 °C), silver (25.8 °C), and white (24.8 °C) mulches. The plants grown on black mulch showed the earliest appearance of TSW symptoms, and had significantly reduced vegetative growth and fruit yields compared to plants on the other mulches. In conclusion, utilization of plastic mulches that created conditions of high RZT stress resulted in reduced plant growth and yield and predisposed the plants to earlier expression of TSW symptoms compared to plants grown at RZTs more favorable to tomato plant growth (optimal RZT = 26.1 °C [Díaz-Pérez, J.C., Batal, K.D., Granberry, D., Bertrand, D., Giddings, D., Pappu, H., 2003. Vegetative top growth and yield of tomato grown on plastic film mulches as affected by the appearance of symptoms of Tomato spotted wilt virus. HortScience 38, 395–399]). Since these plant responses to TSW under heat stress occurred in artificially inoculated plants as well as in plants under natural TSW infection, high RZTs probably affected the plants directly, independently of any possible effects on the thrips vectors.  相似文献   

THE MARINE BIOLOGFICAL STATION OF THE UNIVERSITY OF TEXAS     

Edwards CL 《Science (New York, N.Y.)》1893,21(538):284-285

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Soil S availability in upland pastures of NE Scotland: relationship of extractable soil S and soil respiration to soil and site characteristics     

D. Donald  S.J. Chapman  A.C. Edwards  D. Atkinson 《Soil Use and Management》1999,15(4):213-220

Abstract. The mean extractable sulphur (S) concentration in 315 upland topsoil samples collected in 1988/89 from beneath pasture in NE Scotland was 13 μg S g⁻¹ (range 2–77 μg S g⁻¹). More than two thirds of the samples had S concentrations less than that acceptable for productive soils. Continued decreases in atmospheric S inputs may have increased this proportion subsequently. The analysis of herbage S also indicated that two-thirds of the samples were below 0.2% S. A 'respirometric index', namely CO₂ produced during cellulose decomposition without added S as a percentage of that produced with added S, was significantly less than 100% in a quarter of the soils. Results of three different extraction procedures suggested that sulphate in the soils was present mainly as free plus adsorbed rather than precipitated forms. Soil extraction identified a significant non-sulphate S fraction, presumably organic S. The variability in extractable S stemmed from a combination of geographical, depositional and local site and soil factors. Extractable S was significantly correlated with soil organic matter content and inversely with soil pH and together these factors explained 37% of the variability. While significant differences in mean concentrations between geographical area, soil association and drainage status were evident, no trends could be observed between the major soil subgroups or with altitude.  相似文献   

Letters to the Editor ◆ Lettres À La Rédaction: Foreign locums the answer to shortage of large animal practitioners          下载免费PDF全文

Ron Mentz 《The Canadian veterinary journal. La revue veterinaire canadienne》1997,38(11):679

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Mechanisms of drought response in Thuja occidentalis L. II. Post-conditioning water stress and stress relief     

Edwards DR  Dixon MA 《Tree physiology》1995,15(2):129-133

We examined the extent of osmotic adjustment and the changes in relative water content (RWC) and transpiration rate (i.e., relative stomatal function) that occur in water-deficit-conditioned 6-year-old Thuja occidentalis L. (eastern white cedar) trees in response to a severe drought. Trees conditioned by successive cycles of mild or moderate nonlethal water stress (conditioning) and nonconditioned trees were exposed to drought (i.e., -2.0 MPa predawn water potential) to determine if water deficit conditioning enhanced tolerance to further drought stress. Following drought, all trees were well watered for 11 days to evaluate how quickly osmotic potential, RWC and transpiration rate returned to preconditioning values. Both nonconditioned trees and mildly conditioned trees exhibited similar responses to drought, whereas moderately conditioned trees maintained higher water potentials and transpiration rates were 38% lower. Both conditioned and nonconditioned trees exhibited a similar degree of osmotic adjustment (-0.39 MPa) in response to drought relative to the well-watered control trees. The well-watered control trees, nonconditioned trees and mildly conditioned trees had similar leaf RWCs that were about 3% lower than those of the moderately conditioned trees. Following the 11-day stress relief, there were no significant differences in osmotic potential between the well-watered control trees and any of the drought-treated trees. Daily transpiration rates and water potential integrals (WPI) of all drought-treated trees approached those of the well-watered control trees during the stress relief period. However, the relationship between cumulative transpiration and WPI showed that previous exposure to drought stress reduced transpiration rates. Leaf RWC of the moderately conditioned trees remained slightly higher than that of the nonconditioned and mildly conditioned trees.  相似文献