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81.
82.
A stochastic simulation model to investigate the transmission of classical swine fever (CSF) virus within an infected farm is described. The model is structured according to the processes that occur within and between management groups (pig units or houses). It uses the individual pig as the unit of interest and estimates the number of animals in the states 'susceptible', 'infected', 'infectious', and 'removed' for each day of the disease incident. Probabilities are assigned to the transitions between states. The probability of a pig becoming infected is made dependent on the probability of contact between a susceptible and an infectious pig as well as the probability of transmission. The more pigs become infected in one unit, the more likely is subsequent spread to another management group on the farm. Ultimately, the probability that a shipment of pigs from the farm will include at least one infected pig can be estimated in order to identify high-risk movements during a CSF epidemic. The model results were compared with experimental data on CSF transmission within one pig unit (management group). It could be shown that the model was capable of reproducing the experimentally observed infection and mortality rates. To improve the input parameters and for further model validation, more experimental data and field data from CSF outbreaks are needed. 相似文献
83.
Phenotypical characterization of T and B cell areas in lymphoid tissues of dogs with spontaneous distemper 总被引:5,自引:0,他引:5
CD3, CD4, CD5, and CD8 antigen expression of T cells and IgG expression of B cells and canine distemper virus (CDV) antigen distribution were immunohistochemically examined in lymphoid tissues (lymph node, spleen, thymus, and tonsil) of control dogs and animals with spontaneous canine distemper. In addition, CNS tissue of all animals was studied for neuropathological changes and CDV antigen distribution. Based on the degree of depletion distemper dogs were classified into two groups. Group I represented animals with moderate to marked lymphoid depletion, while group II dogs displayed mild or no depletion. CDV antigen was mainly found in lymphocytes and macrophages of group I dogs, whereas CDV expression was most prominent in dendritic cells of group II animals. In group I dogs, a marked loss of CD3, CD4, CD5, CD8, and IgG expression was noticed, hereby loss of CD4+ cells was more prominent than depletion of CD8+ cells. In the lymphoid tissues of group II animals, a significant increase in the number of T and B cells was observed compared to group I dogs. The number of CD3+, CD4+, and CD8+ cells in group II dogs was similar to the findings in controls, however, CD5 and IgG expression was mildly reduced in T and B cell areas, respectively. Additionally, in groups I and II dogs, CD3+ and CD5- T cells were detected in T cell areas. Whether this cell population represents a cell type with autoimmune reactive potential remains to be determined. Surprisingly in group II animals, viral antigen was found predominantly in dendritic cells indicating a change in the cell tropism of CDV during chronic infection and a possible mechanism of viral persistence. The two patterns of lymphoid depletions correlated to two different types of canine distemper encephalitis (CDE). Group I dogs displayed acute non-inflammatory CDE, whereas group II dogs suffered from chronic inflammatory demyelinating CDE, indicating a pathogenic relationship between lymphocytic depletion and inflammatory brain lesions in distemper. 相似文献
84.
A mailed questionnaire survey was done to study dog-owners' knowledge of canine inherited diseases and the present screening and control programs in Finland, as well as to study the importance of health-related matters and well-being to dog-owners. The purpose was also to study the owners' role in programs and the influence of health and well-being in their decision-making process and choices when purchasing a puppy. This study showed that dog-owners highly valued health-related matters and well-being. The present programs were considered to have a positive effect on the prevention of canine inherited diseases. Dog-owners estimated that their own knowledge could be better but they believed in veterinarians' and dog-breeders' ability to inform them. Inherited skeletal and ocular diseases were thought to be important to canine well-being; the importance of other diseases or behaviour problems was assessed to be lower. In choosing a suitable breed, behaviour and temperament were the most-important factors but health-related matters were essential in actually choosing a puppy's breeder and the litter. Well-being and health were also considered very important to the image of the dog hobby. 相似文献
85.
The article surveys the development of legislation to the slaughtering of warm-blooded animals in Germany since 1933. It examines the ritual slaughtering of the Jews (Schechita) on the one hand, and of the Moslems (Dabh) on the other hand. While 1933 the legislation was coined by the political situation, after 1949, legal setting and decisions reflected the changing sensibility to animals' protection. Before 1945, Schechita was the matter of legal dispute, more recently, the discussion has centred on the ritual slaughtering of the Moslems, with different arguments. The "Law on the Slaughtering of Animals" of 21-04-33 was part and parcel of the Third Reich's policy against Jews implicating a nation wide practical inhibition of Schechita by decreeing a general obligation of stunning before slaughtering. In 1945, the inhibition of Schechita became invalid after the occupation of the Reich by the Allied Forces. For the first time, the "First Amendment to the Animal Protection Law" of 1986 permitted ritual slaughtering by the way of exception as long as it was covered by the religious obligations. In 1995 the Federal Administrative Court judged that an inhibition of the ritual slaughtering by Moslems could be possible, because there are no religious obligations for Moslems. Nowadays, the ritual slaughtering of the Moslems is, de facto, forbidden, Schechita is performed in some cities for the needs of the residential Jewish population. 相似文献
86.
Ryan M O'Handley Merle E Olson 《Veterinary Clinics of North America: Food Animal Practice》2006,22(3):623-643
Although they differ considerably with respect to their biology, both Giardia duodenalis and Cryptosporidium parvum are common in ruminants, whereas Cryptosporidium andersoni is not. G. duodenalis infections are acquired during the first few months of life, tend to be chronic, and may be a production-limiting disease of ruminants. C. parvum infections remain an important cause of diarrhea in neonatal ruminants. Abomasal cryptosporidiosis, caused by C. andersoni, is an emerging disease of cattle that may affect both beef and dairy herds. This article reviews the life cycles, production impacts, treatments, controls, and zoonotic potentials of these important ruminant parasites. 相似文献
87.
Kyuchukova M. A. Büttner C. Gabler J. Bar-Yosef B. Grosch R. Kläring H.-P. 《植物病害和植物保护杂志》2006,113(3):113-119
Journal of Plant Diseases and Protection - A method for the quantification of Pythium aphanidermatum density in cucumber roots based on an indirect enzyme-linked immunosorbent assay (Elisa) was... 相似文献
88.
89.
Preliminary evidence for the presence of Helicobacter-like bacteria was sought in 395 porcine gastric samples by a urease test. Of the samples, 37% (146/395) were urease-positive and 82% (82/100) of the Gram-stained urease-positive samples showed large, tightly spiralled organisms. Several methods were applied to culture the organisms but isolation was unsuccessful, contaminant organisms being considered to be one of the major problems. PCR with Helicobacter genus-specific primers for 16S rRNA and ureB genes, and primers for H. pylori vacA and cagA genes were tested with 102 urease-positive biopsy samples. The PCR results showed some evidence for the presence of the urease and the vacA genes in porcine Helicobacter-like bacteria and raises the possibility of pathogenicity by these organisms. 相似文献
90.
Die Steigerung der naturalen Erträge unserer Kulturpflanzen ist gegenwärtig kein wissenschaftlicher Arbeitsgegenstand der produktionsorientierten landwirtschaftlichen Forschung. Es bestehen häufig Bedenken, daß mit einer zunehmenden Ertragshöhe unerwünschte Wirkungen auf die Umwelt verbunden sind. An ausgewählten Beispielen wird dargelegt, daß es zum einen nicht möglich ist, aus der Ertragshöhe oder den Ertragssteigerungen pauschal auf negative Umweltwirkungen der ackerbaulichen Produktion zu schließen. Zudem wird diskutiert, welche Bedeutung die Steigerung der Erträge von Kulturpflanzen für die Sicherung der technologischen, aber auch der ökologischen Ansprüche hat. Ein Rückgang der Forschungs‐ und Publikationsleistungen zu Anbauverfahren bzw. dem Ertragsmanagement wird für die letzten Jahre dargelegt und dessen Bedeutung für die wissenschaftlichen Arbeiten der landwirtschaftlichen Produktion erörtert. 相似文献