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41.
Salmonella infection of laying flocks in the UK is predominantly a problem of the persistent contamination of layer houses and associated wildlife vectors by Salmonella Enteritidis. Methods for its control and elimination include effective cleaning and disinfection of layer houses between flocks, and it is important to be able to measure the success of such decontamination. A method for the environmental detection and semi-quantitative enumeration of salmonellae was used and compared with a standard qualitative method, in 12 Salmonella-contaminated caged layer houses before and after cleaning and disinfection. The quantitative technique proved to have comparable sensitivity to the standard method, and additionally provided insights into the numerical Salmonella challenge that replacement flocks would encounter. Elimination of S. Enteritidis was not achieved in any of the premises examined although substantial reductions in the prevalence and numbers of salmonellae were demonstrated, whilst in others an increase in contamination was observed after cleaning and disinfection. Particular problems with feeders and wildlife vectors were highlighted. The use of a quantitative method assisted the identification of problem areas, such as those with a high initial bacterial load or those experiencing only a modest reduction in bacterial count following decontamination. 相似文献
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D. S. Jeffries D. L. Wales J. R. M. Kelso R. A. Linthurst 《Water, air, and soil pollution》1986,31(3-4):551-567
Data defining the major ion chemistry of lakes located in eastern Canada have been compiled for the purpose of evaluating the current status of surface water quality in relation to acidic deposition. A companion paper for lakes in the eastern United States (i.e. Part II, Linthurst et al., 1986) has been prepared also. Data sources in Canada included the National Inventory Survey, the Ontario Lake Sensitivity data set, and the National Aquatic Data base which provided an overall data base of approximately 5700 lakes. Only recently collected data (largely 1980 or later) were used in the analysis. Frequency distribution statistics were obtained for pH, acid neutralizing capacity (ANC), SO4 and organic anion (A?) concentrations. Acidic and low ANC waters in eastern Canada occur in a pattern explained by a combination of biogeochemical factors and atmospheric deposition. Nova Scotia contained the highest proportion of acidic and ultralow ANC lakes of any region surveyed in eastern North America; since this region receives approximately 20 kg.ha?1.yr?1 wet SO4 deposition, the proposed target loading may be too high to protect the highly sensitive waters of Maritime Canada. Compared to the rest of eastern Canada, lakes in Ontario have relatively high ANCs due to the influence of CaCO3 contained in the glacial till of the area. Variation in the SO4 concentration of lakes approximately follows expected gradients in wet SO4 deposition. Naturally occurring organic acids do not play a dominating role in the acidification of eastern Canadian lakes. 相似文献
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Sialomucin Complex (Muc4) Expression in Porcine Endometrium During the Oestrous Cycle and Early Pregnancy 总被引:1,自引:0,他引:1
The non‐invasive type of implantation in the pig is characterized by the maintenance of a thick glycocalyx coating on the uterine epithelial surface microvilli. Present study investigated the alteration in the sialomucin complex (Muc4) expression during the oestrous cycle and early pregnancy in the pig. Endometrial tissue samples were immunostained with the primary antibody to the Muc4 transmembrane subunit ASGP‐2. Muc4 immunostaining increased in the surface and glandular epithelia between days 5 and 10 of oestrous cycle. Immunostaining continued to increase on day 12 with the greatest intensity of uterine Muc4 immunostaining detected on day 15 of the oestrous cycle and early pregnancy. Endometrial Muc4 expression in cyclic gilts decreased dramatically during early proestrous but continued to remain abundant in the surface and glandular epithelium of pregnant gilts during the period of conceptus attachment to the uterine surface. 相似文献
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Peridotite xenoliths from the Cascade arc in the United States and in the Japan arc have neodymium and osmium isotopic compositions that are consistent with addition of 5 to 15 percent of subducted material to the present-day depleted mantle. These observations suggest that osmium can be partitioned into oxidized and chlorine-rich slab-derived fluids or melts. These results place new constraints on the behavior of osmium (and possibly other platinum group elements) during subduction of oceanic crust by showing that osmium can be transported into the mantle wedge. 相似文献
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Abstract CASE HISTORY: In 2008, a 3-year-old female Labrador Retriever was presented for routine breeding soundness evaluation. CLINICAL FINDINGS: Vaginal endoscopy revealed an 8-cm long and 1-cm thick vaginal septum. Surgical resection of the septum was performed under general anaesthesia using a bipolar high-frequency resectoscope. Three months later the bitch was naturally mated and subsequently delivered five male and two female puppies without complications. Both female puppies were examined at the age of 12 and 15 months and showed a vaginal septum with a diameter of 0.3 and 0.5 cm, respectively. DIAGNOSIS: Vaginal septa in three related bitches. CLINICAL RELEVANCE: This is the first report describing the use of a bipolar high-frequency resectoscope for vaginal surgery in dogs. The septum could be resected quickly, with preservation of surrounding structures. Furthermore, it is the first report collecting information about familial presentation of vaginal septa in female dogs. Based on this case, we suggest that consideration should be given to the possible risk of inheritance of vaginal septa before considering surgical resection and breeding of female dogs. 相似文献
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