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1.
Thirlwall RE Commander NJ Brew SD Cutler SJ McGiven JA Stack JA 《Veterinary research communications》2008,32(3):209-213
This report describes the use of cell mediated immunity to improve specificity of current diagnosis for Brucella suis. Diagnosis is problematic due to cross reactions that lead to false positive serological reactions (FPSR) in the standard
diagnostic tests. A common cause of this cross reactivity is infection with the organism Yersinia enterocolitica O:9. Gottingen™ mini-pigs were experimentally infected with B. suis biovar I field strain or Y. enterocolitica serotype O:9 biotype 3. Infection was followed for 70 days. During this time whole blood stimulation assays were set up using
Brucella specific antigen. IFNγ was measured in the supernatants (SN) from these assays by ELISA. Concurrent standard serological
tests were carried out. The results indicate that the IFNγ assay is specifically able to distinguish Y. enterocolitica O:9 infection from a B. suis infection in experimentally infected mini-pigs. These results represent an improvement in diagnostic specificity compared
to currently used serological tests. Thus suggesting that in a surveillance setting this test could be applied as a confirmatory
test in the face of FPSR.
The authors are British Civil Servants and as such their work is subject to British Crown Copyright. This means the exclusive
copyright for the article cannot be transferred. 相似文献
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Potential negative impacts of climate change provide compelling arguments for action and adaptive measures to help mitigate pressure on water resources, agricultural production and environmental quality. To explore the possible impacts and evaluate the effectiveness of different adaptation strategies, an integrated modelling framework that allows linkage and integration of climate models, basin‐ and field‐scale hydrological models is of great importance. This paper describes an assessment of climate change impacts on water resources, agriculture and the environment in the Zayandeh Rud irrigation system of Esfahan (Iran) using simulation models. The paper also focuses on alternative adaptation strategies to mitigate the negative impacts. Results of the simulations show that potential impact of climate change could cause the Zayandeh Rud irrigation system to face more frequent and severe water shortage problems. Among the evaluated adaptation strategies, change in cropping patterns was found to be the best possible measure to mitigate the negative impacts of climate change. Results also show the capability of the modelling system to deliver the required simulations using readily available data. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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The ecological engineering of rivers has been emphasized in recent years; however, scant attention has been focused on the ecological environments of paddy fields and irrigation canals. In this study, a paddy field in Yuanli Township, Miaoli County, Taiwan, was used as a test field. We improved the ecological corridor, ensuring the continuity of the irrigation canal and paddy field, thereby enabling a constant flow of water in the longitudinal section of the paddy field corridor to facilitate smooth upstream migration of fish. Fish could also migrate upstream in the lateral section of the paddy field. Subsequently, loach were used to assess the effect of an enhanced rock pile in a pool area of the simplified paddy fishway, and fish were allowed to migrate up and down the paddy field and irrigation canal. The results indicated that the difference in water levels (i.e. a bottleneck for creating an ecological corridor) was enhanced by the simplified paddy‐field fishway and enhanced rock pile. In addition, removing bottlenecks along the ecological corridor enabled fish and shrimp to migrate in the longitudinal and lateral directions. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Irrigation schemes with sediment‐laden water are generally performing significantly below expectation and potential. Managing such irrigation schemes is challenging as in most cases the management aspects of sediment transport were not included in the design process and in some cases the proposed management plans are difficult to follow. The sediment transport process is affected by the flow conditions in the canal, and the latter are affected by the canal operation modes. Hence, system management is one of the important aspects that influence the sediment transport process. The mathematical model SETRIC has been used to analyse the existing management mode and its effect on the sediment transport process of the Sunsari Morang Irrigation Scheme in Nepal. Evaluation showed that the sub‐secondary canals of the Secondary Canal S9 have different sediment transport capacities. Some canals are facing more deposition problems than others. The problem is further increased by the existing water delivery mode. The modelling results show that it is possible to reduce sedimentation problems by improving existing water management practices. The proposed water management plan, based on the existing infrastructure, could be implemented to address the sediment transport problems in this scheme and other schemes with appropriate adaptation. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
7.
P. Panigrahi R. K. Sharma S. S. Parihar M. Hasan D. S. Rana 《Irrigation and Drainage》2013,62(1):67-73
The profitability of regulated deficit irrigation (RDI), sustained deficit irrigation (SDI), and SDI with partial root zone drying (PRD) strategies was compared to that with full irrigation (FI: 100% crop evapotranspiration) in drip‐irrigated Kinnow mandarin in northern India. RDI was scheduled with two irrigation levels: no irrigation and 50% crop evapotranspiration (ETc.) imposed in the early fruit growth period (EFGP) and final fruit growth period (FFGP) singly and in combination, whereas SDI was scheduled at 50% ETc and 75% ETc with and without the PRD technique. The highest fruit yield was recorded with FI, which was statistically on a par (p > 0.05) with that with SDI at 50% ETc with PRD (PRD50). Economic‐based comparison shows that all the treatments were economically viable since their profitability (net return, INR 137 000–1 300 000 ha‐1 and benefit–cost ratio, 2.1–14.3) were viable. The net return generated with PRD50 was statistically (p > 0.05) at par with that generated with FI. However, the benefit–cost ratio and economic water productivity calculated with PRD50 were found to be significantly (p < 0.05) higher (36 and 87%, respectively) than that with FI. These results lead us to conclude that the PRD50 strategy could be used to improve irrigation water productivity substantially in commercial Kinnow mandarin orchards in sandy loam soil. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
8.
Irrigated agriculture is often criticized for its poor resource‐use efficiency in the case of sprinkler systems in comparison with localized irrigation. Water losses due to evaporation of droplets during flight and wind drift of droplets out of the target area are often generalized regardless of the context in which they were measured, and may reveal the evaporation capacity of the measurement facility rather than that of the irrigation system itself. Using an approach combining in situ measurement (rainfall, electric conductivity) and simulations, losses were estimated according to droplet size distribution. Droplets less than 1 mm in diameter displayed the highest losses. Losses due to evaporation represented 30‐50% of total loss; the remaining 50–70% were due to wind causing small droplets to drift outside the target zone. With a Rain Bird 46 sprinkler, total losses for the different periods of the day should not represent more than 20% at any time, or less than 4% for a 24‐h irrigation period in the climate conditions that prevail in summer in the south of France. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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In this paper, the role of subsurface drainage in irrigated agriculture in semi‐arid and arid regions is discussed based on experiences obtained in Egypt, India and Pakistan. Agriculture in these countries is predominantly practiced by small, marginal farmers with landholdings of often less than one hectare. In general, they do not have the means to pay for the investments in irrigation and drainage themselves. Consequently, most irrigation and drainage projects are funded by the (local) governments. Shallow horizontal pipe drainage systems have proved to be a technically feasible and cost‐effective tool to combat the twin problem of waterlogging and salinity. Their large scale implementation is, however, hampered by a number of institutional and socio‐economic reasons. The paper discusses why subsurface drainage is needed to safeguard investments in irrigated agriculture and to conserve land resources, as well as what the challenges are to make subsurface drainage work. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献