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Pregnancy and lactation in dogs induced a marked suppression of their immunological responsiveness as judged by in vitro phytomitogen- and Toxocara canis antigen-induced lymphocyte transformation. In addition, the eosinophilia otherwise seen following infection with T. canis was suppressed during the periparturient period. Coincidental with this periparturient immunosuppression was the occurrence of heavy infections with T. canis in the intestine of lactating bitches and the establishment of such infections perhaps may be related to the suppressed immune reactivity observed. These infections in the bitch appeared to be acquired primarily through the ingestion of immature stages of T. canis passed in the faeces of their puppies. The results demonstrate that the lactating bitch can be a major source of contamination of the environment with eggs of T. canis.  相似文献   
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A questionnaire was used to collect information on attitudes toward dogs and cats as companion animals. Thirty-nine attitudinal questions on dogs were grouped using principal component analysis (PCA) into six independent major factors; whereas, 38 items on cats were grouped using principal component analysis (PCA) into four independent major factors. In addition, 18 items which did not fit the PCA model but that were related to the respondents' attitudes towards dogs and cats as companion animals were analysed separately. The hypotheses tested, using analysis of variance (ANOVA) were that there was no significant relationship between the factors and five variables, i.e., pet ownership, age or sex of the respondents and their like or dislike of either dogs or cats. The respondents' like or dislike of dogs or cats influenced their attitudes towards ownership of companion animals. Furthermore, nonowners stated they derive minimal value from a dog or cat as a pet and viewed the negative characteristics of the animal itself per se as a more important factor in determining ownership. Female respondents were more emotionally involved and younger owners derived more of a feeling of importance-vanity from dog or cat ownership.  相似文献   
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The impacts of ocean warming resulting from recent climate change on the abundance patterns of marine species have been well documented in temperate seas of the northern hemisphere, but the impacts of a widening tropical belt are largely unexplored. Using measurements of sea surface temperature and spear‐fishing records for 84 species spanning a 19‐yr period, we examined the effects of ocean warming on a sub‐tropical reef‐fish community on the southeastern coast of Africa. Corresponding with a 0.46°C increase in average sea surface temperature between the time periods 1989–97 and 2002–2007, the ratio of species showing an overall decrease/ no change/increase in abundance was 1 : 3 : 2 among six species at the northern limits of their distribution in the region (temperate species), 1 : 15 : 6 among 22 broadly distributed species, and 1 : 5 : 9 among 15 species at the southern limits of their distribution (tropical species). Also, the relative abundance of temperate species as a whole decreased by 10–13% whereas that of tropical species increased by 9%, and broadly distributed species showed little change. Average species richness and diversity increased 33 and 15% respectively between the two time periods. These results are broadly consistent with a predicted poleward shift in species ranges and a predicted increase in species richness and diversity with increasing sea temperature. Our findings confirm that large‐scale climate change causing a widening of the tropical belt and subsequent ocean warming is having a profound impact on marine species abundance patterns and community composition at a local scale in the sub‐tropics.  相似文献   
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Melioidosis in a dog   总被引:1,自引:0,他引:1  
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