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排序方式: 共有96条查询结果,搜索用时 15 毫秒
71.
Equine viral arteritis 总被引:2,自引:0,他引:2
72.
Haematological and biochemical reference values were established from 45 clinically healthy koalas. Statistical analysis revealed no significant differences for sex and season of sampling. Immature koalas had significantly higher alkaline phosphatase and inorganic phosphate values, and significantly lower total protein concentrations due to low globulins values. Enzyme reference values tended to be wide and could limit their usefulness in detecting disease. In the reference values for leukocytes, neutrophils and lymphocytes, the inclusion of low values which were not actually seen may interfere with the detection of reduced levels due to disease. 相似文献
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JB MOLLOY PM BOWLES DP KNOWLES TF McELWAIN RE BOCK TG KINGSTON GW BLIGHT RJ DALGLIESH 《Australian veterinary journal》1999,77(4):245-249
OBJECTIVE: To compare a recently developed recombinant MSP-5 competitive inhibition ELISA with a card agglutination test for detection of antibodies to Anaplasma marginale and Anaplasma centrale in Australian cattle. MATERIALS AND METHODS: The ELISA was compared with the card agglutination test using 208 sera from cattle in Anaplasma-free herds, 86 sera from cattle experimentally infected with A marginale or A centrale and 757 sera from cattle in areas endemic for A marginale. RESULTS: The specificity of the ELISA, based on testing 208 sera from cattle in Anaplasma-free areas, was 99.5%, and the sensitivities for detection of antibodies to A marginale and A centrale in sera from the experimentally infected cattle were 98.0% and 100%, respectively. For the same sets of sera, the specificity of the card agglutination test was 98.6% and the sensitivities for detection of antibodies to A marginale and A centrale were 98.0% and 100%, respectively. For the 757 sera collected from cattle in areas endemic for A marginale, the agreement between the ELISA and the card agglutination test depended on the positive threshold selected for the ELISA. The maximum achievable agreement was 91.5% (kappa = 0.73; 95% confidence interval 0.66, 0.79). CONCLUSION: We conclude that the competitive inhibition ELISA is a useful alternative to the card agglutination test for detection of A marginale or A centrale infection in cattle. The assay should be particularly useful for epidemiological applications such as prevalence studies and control programs. 相似文献
76.
Adrien Rusch Muriel Valantin-Morison Jean-Pierre Sarthou Jean Roger-Estrade 《Landscape Ecology》2011,26(4):473-486
Improving our understanding about how natural enemies respond to semi-natural habitats and crop management scattered in the
landscape may contribute to the development of ecologically based pest management strategies maximising biological control
services. We investigated how soil tillage and semi-natural habitats influenced the parasitism rates of pollen beetle (Meligethes aeneus F.) larvae at 8 different spatial scales (from 250 to 2000 m radius circular sectors) in 42 oilseed rape (OSR) fields. We
used multimodel inference approaches to identify and rank the influence of soil tillage and semi-natural habitats on parasitism
rates, and to quantify the importance of each scale. Parasitism rates were due to three univoltine parasitoid species (Tersilochus heterocerus, Phradis morionellus and P. interstitialis) and varied from 0 to 98%. We found that both fine and large scales contributed to explain significantly parasitism rates,
indicating that biological control of pollen beetle is a multi-scale process. At the 250 m scale, parasitism rates of T. heterocerus were positively related to the proportion of semi-natural habitats and the proximity to previous year OSR fields. At large
scales (1500 to 2000 m), parasitism rates of T. heterocerus were positively related to semi-natural habitats and negatively related to the proportion of previous year OSR fields with
conventional soil tillage. Parasitism rates of Phradis spp. were only positively related to the proportion of semi-natural habitats at the 1250 and 1500 m scales. These multi-scale
effects are discussed in relation to the influence of semi-natural habitats and soil tillage on parasitoid populations and
their movement behaviours within the landscape. 相似文献
77.
In the current survey, there was no clear evidence that GM (genetically modified) crops are higher yielding than those conventionally bred<fnoteref rid="fn1">1</fnoteref>. Furthermore, there were no trials to support valid comparisons of yield per se. This article investigates GM crop yields, introducing the importance of hybrid vigour and a non-stress environment for higher percentage heritability selection and therefore more productive conventional plant breeding and improved crops. GM technology and crops are compared with proven plant breeding methods, with respect to hybrid vigour and the economic viability of both systems. These proven methods of plant breeding are (1) traditional landrace cropping, (2) conventional Mendelian breeding and (3) Isolection Mendelian breeding, and are also considered historically. 相似文献
78.
El-Kaderi HM Hunt JR Mendoza-Cortés JL Côté AP Taylor RE O'Keeffe M Yaghi OM 《Science (New York, N.Y.)》2007,316(5822):268-272
Three-dimensional covalent organic frameworks (3D COFs) were synthesized by targeting two nets based on triangular and tetrahedral nodes: ctn and bor. The respective 3D COFs were synthesized as crystalline solids by condensation reactions of tetrahedral tetra(4-dihydroxyborylphenyl) methane or tetra(4-dihydroxyborylphenyl)silane and by co-condensation of triangular 2,3,6,7,10,11-hexahydroxytriphenylene. Because these materials are entirely constructed from strong covalent bonds (C-C, C-O, C-B, and B-O), they have high thermal stabilities (400 degrees to 500 degrees C), and they also have high surface areas (3472 and 4210 square meters per gram for COF-102 and COF-103, respectively) and extremely low densities (0.17 grams per cubic centimeter). 相似文献
79.
80.
Predatory dinosaur remains from madagascar: implications for the cretaceous biogeography of gondwana 总被引:1,自引:0,他引:1
SD Sampson LM Witmer CA Forster DW Krause PM O'Connor P Dodson F Ravoavy 《Science (New York, N.Y.)》1998,280(5366):1048-1051
Recent discoveries of fossil vertebrates from the Late Cretaceous of Madagascar include several specimens of a large theropod dinosaur. One specimen includes a nearly complete and exquisitely preserved skull with thickened pneumatic nasals, a median frontal horn, and a dorsal projection on the parietals. The new materials are assigned to the enigmatic theropod group Abelisauridae on the basis of a number of unique features. Fossil remains attributable to abelisaurids are restricted to three Gondwanan landmasses: South America, Madagascar, and the Indian subcontinent. This distribution is consistent with a revised paleogeographic reconstruction that posits prolonged links between these landmasses (via Antarctica), perhaps until late in the Late Cretaceous. 相似文献