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52.
Westgarth C Pinchbeck GL Bradshaw JW Dawson S Gaskell RM Christley RM 《The Veterinary record》2008,162(14):436-442
This study investigated the nature and frequency of the contacts that occur between dogs, and between dogs and people, by means of a questionnaire survey of 260 dog-owning households in a community in Cheshire, uk. The contacts were highly variable and were affected by the size, sex and age of the dog, individual dog behaviours, human behaviours and human preferences in the management of the dog. A number of situations were identified that may be important in relation to zoonoses, including sleeping areas, playing behaviours, greeting behaviours, food sources, walking, disposal of faeces, veterinary preventive treatment and general hygiene. 相似文献
53.
SUMMARY: Biochemical profiles, restriction endonuclease analysis (REA) and ribotyping were used to investigate Pasteurella multocida isolates from outbreaks of fowl cholera on 7 turkey farms in New South Wales. While only a single isolate was available from 5 of the farms, multiple isolates, 4 and 12 respectively, were available from the other 2 farms. The available field evidence suggested that 8 outbreaks had occurred with one farm suffering 2 outbreaks. The isolates obtained were all confirmed as Pasteurella multocida . Biochemical profiles allocated the isolates to 4 groups, 3 being variants of P multocida subsp multocida and the fourth being P multocida subsp septica . REA performed with Hpall established 7 groups. Ribotyping using the Hpall digests probed with the 16S rRNA operon of Haemophilus paragallinarum recognised the same 7 groups as REA. Unlike the biochemical profiles, both REA and ribotyping provided a fine subdivision that identified outbreaks as either related or unrelated. The REA and ribotyping patterns as well as biochemical profiles were stable for all isolates from the outbreaks in which multiple isolates were obtained from either the same bird or from different birds. REA and ribotyping were found to be superior to biotyping methods for the investigation of fowl cholera outbreaks. 相似文献
54.
J.W.S. Bradshaw R. Baker C. Longhurst Judith C. Edwards Jennifer C. Lisk 《Crop Protection》1983,2(1):63-73
The efficiency of traps baited with synthetic sex attractants, (Z)-9- and (Z)-11-tetradecenyl acetates, for Panolis flammea (Denis & Schiffermüller) (Lepidoptera: Noctuidae) was tested with respect to trap design, capacity, height, alignment, position and dose of lure. For optimum catches, traps should not be obstructed by vegetation, and can be placed most conveniently in forest rides. The most important features of trap design were a heavy surface coating of sticky retentive material and a large catching area. The efficiency of capture decreased rapidly when 40 or more moths were present on a sticky surface of area 380 cm2. Numbers of moths caught increased regularly as the dose of lure increased from 1 μg to 5 mg. Males of Orthosia gothica (L.) (Lepidoptera: Noctuidae) were frequently caught in numbers similar to those of P. flammea in the same traps during the flight period of the latter insect. Increasing the relative quantity of the minor component, (Z)-11-tetradecenyl acetate, reduced catches of P. flammea, but not always those of O. gothica. 相似文献
55.
Several foraminiferal assemblages are recognized in Spartina-Salicornia marshes along the Pacific and Gulf of Mexico coasts. Continuous recordings in one Pacific marsh show considerable diurnal and seasonal variation in pH, oxygen, water temperature, and salinity. This is related to tidal flushing, air temperature variations, sunlight duration, and marsh plant metabolism. 相似文献
56.
In 1977, a fodder turnip breeding programme was started from seven cultivars with the primary aim of increasing dry‐matter yield. The breeding method chosen was population improvement by half‐sib family selection on a biennial cycle. Seed production in polythene tunnels with blowflies as pollinators was followed by assessing the resulting progenies in replicated yield trials and observation plots from which plants were selected for the next cycle. Six generations of selection resulted in a population with a yield that was 25% higher than the mean of the initial seven cultivars. This was remarkably close to the predicted superiority of the population, despite a significant discrepancy in one generation. It is concluded that the greatest response to selection per year would be achieved by selecting eight families from 128 assessed for 1 year in trials at two or three sites with an overall total of six replicates, given a resource limit of 800 plots. 相似文献
57.
Summary The use of the Commonwealth Potato Collection in potato breeding is set in the context of the evolution of the crop and the
need to widen its genetic base by introgression and base broadening. The introduction of the potato to Europe and its subsequent
worldwide spread is described. An introduction is given to the world's major potato genebanks, and the current status of the
Commonwealth Potato Collection is presented. Material from this genebank has been extensively used to improve the potato.
Work on wild species as sources of resistance to late blight started before the genebank was initiated, and since then CPC
accessions have provided major R-genes and durable resistance to breeders, greatly benefiting growers and consumers of the
potato. Progress identifying and exploiting resistance to viruses and potato cyst nematodes is described. New sources of further
pest and disease resistance genes are present in the germplasm in the collection, offering the potential to overcome current
and future pests and diseases. Use of the cultivated species in the collection for base broadening is described and discussed.
The collection also harbours a wide range of quality traits of use to breeders, including variation for cooking and crisping,
anthocyanins, carotenoids, ascorbate metabolism and others. As breeding and genetics become more precise, and as both the
knowledge of biochemical pathways and means of analysing chemical composition advance, new ways of accessing this variation
become possible. Possible strategies to achieve these goals are discussed. 相似文献
58.
Quantitative and qualitative differences were demonstrated in the amount of virus in a range of tissues from pigs infected with either the Weybridge or New South Wales (NSW) strains of hog cholera (HC) virus. The titre of the Weybridge strain in samples, as assessed by either virus titration in cell culture or by the density of specific fluorescing cells in tissue sections, was higher than that for the NSW strain. This correlated with the greater severity of the clinico-pathological syndrome induced by the Weybridge strain. The implications of the differences in the virus content of tissues in the diagnosis of HC is discussed as is the use of monoclonal antibodies to differentiate HC and bovine virus diarrhoea viruses. 相似文献
59.
60.