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排序方式: 共有472条查询结果,搜索用时 15 毫秒
1.
Monoclonal antibodies to bovine viral diarrhea virus: cross-reactivities to field isolates and hog cholera virus strains. 总被引:2,自引:1,他引:1 下载免费PDF全文
Monoclonal antibodies to bovine viral diarrhea virus (BVDV) were examined for binding with a large number of North American BVDV isolates and eight strains of the serologically related pestivirus, hog cholera virus (HCV). No single BVDV monoclonal antibody reacted with all BVDV isolates. The most cross-reactive monoclonal antibody was an anti-p80/p125 antibody which showed a positive reaction with 173 of 180 (96%) North American isolates. From a fewer number of isolates tested, one anti-gp53 monoclonal antibody also showed a high cross-reactivity (94%). All BVDV isolates showed a positive reaction with at least one of the seven monoclonal antibodies in the panel. Thus, the results indicated that a pool of these monoclonal antibodies may be used in place of polyclonal antisera for the detection of BVDV contamination of cell lines or for virus isolation. For HCV, all three anti-p80/p125 monoclonal antibodies reacted positively with all eight virus strains. In contrast, none of the anti-gp53 monoclonal antibodies were reactive to HCV strains. Thus, the anti-gp53 monoclonal antibodies may be useful for distinguishing between usually innocuous BVDV infections and the highly significant HCV infections in swine for foreign animal disease surveillance. 相似文献
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Pille F Martens A Schouls LM Dewulf J Decostere A Vogelaers D Gasthuys F 《Veterinary journal (London, England : 1997)》2007,173(1):73-78
The objectives of the present study were to evaluate the accuracy of broad range 16S rRNA gene PCR compared to bacterial culture for the detection of synovial infection in horses. The study included 57 synovial fluid samples from horses with presumed synovial infection and a control group consisting of 31 synovial fluid samples originating from clinically normal horses and horses with aseptic synovial inflammation. All samples were analysed by 16S PCR with reverse line blot (RLB) hybridisation. Synovial fluid samples were cultured using conventional agar plate methods (APM) and/or blood culture medium (BCM). The results of the study showed a superior detection rate (89.5%) for 16S PCR with RLB. Bacterial culture had lower sensitivity, but highly acceptable detection rates (77.6%) were observed using BCM. APM had very low sensitivity (37.8%) and infection was never detected by plate isolation without positive incubation in BCM. The highest sensitivity (91.8%) for the detection of synovial infection was achieved when the results of incubation in BCM and 16S PCR were combined. For all the tests, the specificity was higher than 90%. 相似文献
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Journal of Plant Diseases and Protection - The host response of 17 cover crop cultivars to infection by single-species populations of Pratylenchus hippeastri, Pratylenchus vulnus and Pratylenchus... 相似文献
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Climatic changes and elevated atmospheric CO2 concentrations will affect crop growth and production in the near future. Rising CO2 concentration is a novel environmental aspect that should be considered when projections for future agricultural productivity are made. In addition to a reducing effect on stomatal conductance and crop transpiration, elevated CO2 concentration can stimulate crop production. The magnitude of this stimulatory effect (‘CO2 fertilization’) is subject of discussion. In this study, different calculation procedures of the generic crop model AquaCrop based on a foregoing theoretical framework and a meta-analysis of field responses, respectively, were evaluated against experimental data of free air CO2 enrichment (FACE) environments. A flexible response of the water productivity parameter of the model to CO2 concentration was introduced as the best option to consider crop sink strength and responsiveness to CO2. By varying the response factor, differences in crop sink capacity and trends in breeding and management, which alter crop responsiveness, can be addressed. Projections of maize (Zea mays L.) and potato (Solanum tuberosum L.) production reflecting the differences in responsiveness were simulated for future time horizons when elevated CO2 concentrations and climatic changes are expected. Variation in future yield potential associated with sink strength could be as high as 27% of the total production. Thus, taking into account crop sink strength and variation in responsiveness is equally relevant to considering climatic changes and elevated CO2 concentration when assessing future crop production. Indicative values representing the crop responsiveness to elevated CO2 concentration were proposed for all crops currently available in the database of AquaCrop as a first step in reducing part of the uncertainty involved in modeling future agricultural production. 相似文献
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AbstractThe effect of different rice-based crop rotation sequences on the population densities of Meloidogyne graminicola and on the yield of rice was evaluated in a microplot experiment under lowland rice field conditions. Ten treatments of cropping sequences were grown in four successive growing seasons: continuous growing of the susceptible rice cultivar Thihtatyin (rice-rice-rice-rice), four treatments of 1- season crop rotation sequences (rice-rice-chickpea-rice, rice-rice-black gram-rice, rice-rice-soybean-rice, rice-rice-cowpea-rice), and five treatments of 2-season crop rotation sequences (groundnut-rice-chickpea-rice, green gram-rice-black gram-rice, cowpea-rice-soybean-rice, sesame-rice-cowpea-rice, sunflower-rice-sesame-rice). Population densities of M. graminicola recovered from the rice plants and the nematode multiplication factors (Mf) in the soil in the continuous rice cropping sequence (rice-rice-rice-rice) was the highest among the ten cropping sequences. Lowest nematode Mf in the soil was observed in the 2-season crop rotation sequence sunflower-rice-sesame-rice and the highest was observed in the 1-season crop rotation sequence rice-rice-cowpea-rice among the nine crop rotation sequences. Highest rice yield was obtained in the 2-season crop rotation sequences green gram-rice-black gram-rice, sesame-rice-cowpea-rice and sunflower-rice-sesame-rice, which were about 2 times higher compared with the 1-season crop rotation sequences and about 3 times higher compared with the continuous rice cropping sequence. 相似文献
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Sintayehu Legesse Gebre Dirk Cattrysse Esayas Alemayehu Jos Van Orshoven 《国际水土保持研究(英文)》2021,9(4):490-501
Land allocation has been an important issue in land use planning research studies. Land allocation involves different multifunctional activities of maximizing environmental, economic and social benefits. Multi-criteria decision making (MCDM) method is the most popular tool to optimize land allocation problems by considering decision variables, conflicting objectives, and criteria. Hence, decision-makers face problems on how to optimize the land allocation while minimizing the conflicting trade-offs existing in the decision analysis. With this review study, we aim at identifying and extracting information on MCDM methods to solve land allocation problems from English language articles published between 2000 and 2019 and indexed by four scientific literature databases (Web of Science, Science Direct, Scopus, Google scholar). To this end, we applied a systematic literature review approach, i.e. the Preferred Reporting Items for Systematic Reviews and Meta-Analysis procedure (Moher et al., 2009), with a structured database search expression. 120 articles were selected of which, after careful screening of title, keywords and abstract, 69 were retained for detailed review. This review study report compiles comprehensive information by classifying the papers into application area, optimization objectives, criteria used, decision techniques, publication year and study region. In summary, we found that in the last two decades, the use of the MCDM method has increased, particularly in Europe and China. AHP (analytical hierarchal process) is frequently used for multi-attribute land allocation problems with reference to ecotourism and ecosystem management. LP (linear programming) and SA (simulating annealing) methods are predominantly used to optimize multi-objectives complex agricultural and forest land allocation problems respectively. 相似文献
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Marine fisheries target and catch fish both for direct human consumption (DHC) as well as for fishmeal and fish oil, and other products. We derived the fractions used for each for 1950–2010 by fishing country, and thus provide a factual foundation for discussions of the optimal use of fisheries resources. From 1950 to 2010, 27% (~20 million tonnes annually) of globally reconstructed marine fisheries landings were destined for uses other than DHC. Importantly, 90% of fish destined for uses other than DHC are food‐grade or prime food‐grade fish, while fish without a ready market for DHC make up a much smaller proportion. These findings have implications for how we are using fish to feed ourselves or, more appropriately, how we are not using fish to feed ourselves. 相似文献