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1.
We have developed an antibody detection enzyme-linked immunosorbent assay (ELISA) for the identification of animals infected by feline immunodeficiency virus (FIV). The ELISA solid-phase antigen consists of recombinant FIV gag proteins expressed in bacteria. The proteins are purified from bacterial lysates as insoluble inclusion bodies. In the case of bacterially expressed p24gag, it is shown that all of the linear, sequential epitopes presented by viral p24 during infection are retained. Purified preparations can be substituted for solid-phase whole virus in the IDEXX PetChektm immunoassay. The antibody ELISA duplicates the sensitivity and specificity of the whole virus based PetChek plate assay.  相似文献   
2.
The objective of this study was to investigate epidemiological risk factors for porcine non-specific colitis (NSC). Forty-seven Scottish pig farms, with and without a clinical history of diarrhoea during the growing period (15-40 kg), were selected. The study included farm visits, clinical inspection of pigs, completion of farm management questionnaires, pathological tests into the cause of the diarrhoea and analysis of the non-starch polysaccharide (NSP) content of feeds. The results from 17 farms designated as NSC and 10 control farms suggest dietary associations with NSC. Farms with NSC fed diets with significantly higher levels of NSPs, especially containing the sugars glucose, arabinose and xylose. Few management factors were identified, although the high prevalence of infectious colitis reduced the power of the study.  相似文献   
3.
Analysis of the chemical components from the culture broth of the marine bacterium Saccharomonospora sp. CNQ-490 has yielded three novel compounds: saccharobisindole (1), neoasterric methyl ester (2), and 7-chloro-4(1H)-quinolone (3), in addition to acremonidine E (4), pinselin (5), penicitrinon A (6), and penicitrinon E (7). The chemical structures of the three novel compounds were elucidated by the interpretation of 1D, 2D nuclear magnetic resonance (NMR), and high-resolution mass spectrometry (HRMS) data. Compound 2 generated weak inhibition activity against Bacillus subtilis KCTC2441 and Staphylococcus aureus KCTC1927 at concentrations of 32 μg/mL and 64 μg/mL, respectively, whereas compounds 1 and 3 did not have any observable effects. In addition, compound 2 displayed weak anti-quorum sensing (QS) effects against S. aureus KCTC1927 and Micrococcus luteus SCO560.  相似文献   
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Lead-salt tunable diode lasers (TDLs) are the only devices currently available that can generate tunable monochromatic radiation at arbitrary wavelengths between 3 and 30 micrometers and are particularly useful for high-resolution spectroscopy over a wide range of spectral regimes. Detailed observations of TDLs show that the observed instrumental linewidth is actually a temporal average of many narrow (less than 0.5 megahertz) emission "modes." The time scale characteristic of these "modes," which appear to be of relatively constant intensity, is of the order of a microsecond. The laser's behavior is highly suggestive of a chaotic process, that is, seemingly random excursions of a dynamic variable (frequency) within a bounded range. This report shows experimentally that TDL emissions are indeed chaotic. Furthermore, in a simple and robust fashion, this chaotic behavior has been successfully controlled with the use of recent techniques that take advantage of chaos to produce a narrow band laser output.  相似文献   
6.
The thermal histories of archeological cereal grains were examined by electron spin resonance spectroscopy. Studies with modern samples of heated cereal grain showed that the parameters of the electron spin resonance signal characterize the maximum temperature to which the sample had previously been heated. This technique has applicability in archeology and other disciplines.  相似文献   
7.
The roles of photoperiodism and related light-dependent and hormonal processes in plants are not well understood. Rapid growth, aquatic habit, and adaptability to axenic culture make the Lemnaceae, or duckweeds, excellent material for investigating these topics and others in which highly defined conditions or the presence of organic substances are crucial. As a major example among several that are described, recent work with one species suggests a relation between some features of carbon dioxide flux and the photoperiodic timing mechanism, thus providing a system in which the biochemical basis of the latter may be explored.  相似文献   
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For effective management, information on the stock composition of a fishery is essential. Here, the utility of a resident trout, Salmon trutta L, microsatellite baseline to determine the origins of sea trout entering the rivers Tamar, Tavy and Lynher in south‐west England is highlighted – all share a common estuary and have major runs of sea trout. There is a high degree of geographical structuring of the genetic variation in the baseline rivers. Testing with simulated and real data sets showed fish can be assigned to reporting group with a high degree of accuracy. Mixed stock analysis of >1000 sea trout showed that fish entering the Tamar and Tavy constituted mixed stocks. Significantly, in the Tamar, non‐natal origin sea trout are restricted to the lower catchment. As well as providing insight into sea trout behaviour, this study also has important implications for the management of recreational rod and line fisheries.  相似文献   
10.
Leishmaniosis is an important sand fly transmitted protozoan disease of dogs and humans. In northern Europe, infection is mainly restricted to dogs that have travelled to and/or from endemic areas of the Mediterranean region during periods when there is high sand fly exposure, mostly between March and November. Infected dogs in these areas in northern latitudes are a potential reservoir should incursion of a competent vector occur. However, information on the scale of the potential reservoir in the UK is lacking. Confirmed cases of canine leishmaniosis entering the United Kingdom between 2005 and 2007 were identified using diagnostic samples submitted to the Department of Clinical Veterinary Science, University of Bristol and from collaborating laboratories (n = 257). All study dogs had clinico-pathological signs compatible with leishmaniosis, as typically reported in endemic countries and were leishmania positive in real time or conventional PCR tests, IFA serology and/or tissue microscopic examination for amastigote identification. Information obtained from each case included travel history, habitat, clinico-pathological findings and geographical location once located in the UK. The majority of dogs with complete travel history (n = 183) had spent at least 6 months in Spain (105/183), 28/183 were rescued from re-homing centres in the country of origin and 26/183 entered the UK with confirmed leishmaniosis. Once located in the UK, the majority of positive cases were resident in south and central England. The spectrum of clinico-pathological signs for this group of dogs is similar to that reported in endemic countries. These data confirm that a potentially significant reservoir of infected dogs is resident in areas where future climatic conditions may support introduction of competent vectors.  相似文献   
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