养禽场废弃物的处理方法     

Ritt.  WF 吴迪 《国外畜牧科技》1993,20(5):40-43

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Achalasia of the esophagus with megaesophagus in a dog     

STACK WF  THOMSON JD  SUYAMA A 《Journal of the American Veterinary Medical Association》1957,131(5):225-226

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UFO's and Leprechauns     

Burke-Gaffney MW  Cannon WF 《Science (New York, N.Y.)》1966,154(3756):1502-1504

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Radar Observations of Mars     

Goldstein RM  Gillmore WF 《Science (New York, N.Y.)》1963,141(3586):1171-1172

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Radioactive fallout and radioactive strontium     

LIBBY WF 《Science (New York, N.Y.)》1956,123(3199):657-660

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Barley yellow dwarf virus: phenotypic mixing and vector specificity     

Rochow WF 《Science (New York, N.Y.)》1970,167(3919):875-878

Although the aphid Rhopalosiphum padi does not regularly transmit the MAV isolate of barley yellow drawf virus from singly infected oats, it often transmits MAV, together with the serologically unrelated RPV isolate, from plants doubly infected by MAV and RPV. Vector specificity of the virus isolates appears to be a function of the virus capsid. Some MAV nucleic acid becomes coated with RPV capsid protein during simultaneous synthesis of the two isolates in the doubly infected plant.  相似文献   

Evaluating predictors of apple scab with receiver operating characteristic curve analysis     

Turechek WW  Wilcox WF 《Phytopathology》2005,95(6):679-691

ABSTRACT Apple scab (Venturia inaequalis) is a perennial threat to apple production in temperate climates throughout the world. In the eastern United States, apple scab is managed almost exclusively through the regular application of fungicides. Management of the primary phase of disease is focused on preventing infection by ascospores. Management of secondary cycles of infection is largely dependent on how well primary infections were controlled. In this study, we used receiver operating characteristic curve analysis to evaluate how well mid-season assessments of the incidence of apple scab on cluster leaves, clusters (i.e., the whorl of cluster leaves), or immature fruit can serve as predictors of apple scab on harvested fruit (harvest scab) and whether these mid-season assessments of scab could be used reliably to manage scab under various damage thresholds. Results showed that assessment of scab on immature fruit was superior at predicting harvest scab than were assessments made on clusters or cluster leaves at all damage thresholds evaluated. A management action threshold of 7% scab incidence on immature fruit was identified by Youden's index as the optimal action threshold to prevent harvest scab incidence from exceeding 5%. Action thresholds could be higher or lower than 7% when economic assumptions were factored in to the decision process. The utility of such a predictor is discussed.  相似文献   

Toxicity, pathogenicity, and genetic differentiation of five species of fusarium from sorghum and millet     

Leslie JF  Zeller KA  Lamprecht SC  Rheeder JP  Marasas WF 《Phytopathology》2005,95(3):275-283

ABSTRACT Fusarium isolates recovered from sorghum and millet are commonly identified as F. moniliforme, but with the recognition of new species in this group, the strains given this name are being re-evaluated. We analyzed five strains each from five Fusarium species (F. andiyazi, F. nygamai, F. pseudonygamai, F. thapsinum, and F. verticillioides) often associated with sorghum and millet for their ability to produce fumonisin and moniliformin, their toxicity to ducklings, and their ability to cause disease on sorghum seedlings in vitro. These species can be distinguished with isozymes (fumarase, NADP-dependent isocitrate dehydrogenase, and malate dehydrogenase) and with banding patterns resulting from amplified fragment length polymorphisms. Two species, F. pseudonygamai and F. thapsinum, produced high levels of moniliformin, but little or no fumonisins, and were consistently highly toxigenic in the duckling tests. Two species, F. verticillioides and F. nygamai, produced high levels of fumonisins, but little or no moniliformin, and also were toxigenic in the duckling tests. F. andiyazi produced little or no toxin and was the least toxigenic in the duckling tests. In sorghum seedling pathogenicity tests, F. thapsinum was the most virulent followed by F. andiyazi, then F. verticillioides, and finally F. nygamai and F. pseudonygamai, which were similar to each other. Thus, these five species, which would once have all been called F. moniliforme, differ sufficiently in terms of plant pathogenicity and toxin production profile, that their previous misidentification could explain inconsistencies in the literature and differences observed by researchers who thought they were all working with the same fungal species.  相似文献   

Neurofibromatosis in cattle: a report of two cases     

GOODMAN M  FINCHER MG  KENNEDY PC  STACK WF 《The Cornell veterinarian》1955,45(2):229-238

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Surface tension and surface structure of water     

Claussen WF 《Science (New York, N.Y.)》1967,156(3779):1226-1227

The surface tension-temperature relationship for water is smooth and linear when account is taken of the expansion of the surface with temperature. This plot permits the calculation of thermodynamic properties for 1 square centimeter of surface. Molar surface quantities are derived by assuming a hexagonal water surface structure.  相似文献