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排序方式: 共有133条查询结果,搜索用时 46 毫秒
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Leigh Cuttell Maria Angeles Gómez-Morales Beth Cookson Peter J. Adams Simon A. Reid Paul B. Vanderlinde Louise A. Jackson C. Gray Rebecca J. Traub 《Veterinary parasitology》2014,199(3-4):179-190
Trichinella surveillance in wildlife relies on muscle digestion of large samples which are logistically difficult to store and transport in remote and tropical regions as well as labour-intensive to process. Serological methods such as enzyme-linked immunosorbent assays (ELISAs) offer rapid, cost-effective alternatives for surveillance but should be paired with additional tests because of the high false-positive rates encountered in wildlife. We investigated the utility of ELISAs coupled with Western blot (WB) in providing evidence of Trichinella exposure or infection in wild boar. Serum samples were collected from 673 wild boar from a high- and low-risk region for Trichinella introduction within mainland Australia, which is considered Trichinella-free. Sera were examined using both an ‘in-house’ and a commercially available indirect-ELISA that used excretory–secretory (E/S) antigens. Cut-off values for positive results were determined using sera from the low-risk population. All wild boar from the high-risk region (352) and 139/321 (43.3%) of the wild boar from the low-risk region were tested by artificial digestion. Testing by Western blot using E/S antigens, and a Trichinella-specific real-time PCR was also carried out on all ELISA-positive samples. The two ELISAs correctly classified all positive controls as well as one naturally infected wild boar from Gabba Island in the Torres Strait. In both the high- and low-risk populations, the ELISA results showed substantial agreement (k-value = 0.66) that increased to very good (k-value = 0.82) when WB-positive only samples were compared. The results of testing sera collected from the Australian mainland showed the Trichinella seroprevalence was 3.5% (95% C.I. 0.0–8.0) and 2.3% (95% C.I. 0.0–5.6) using the in-house and commercial ELISA coupled with WB respectively. These estimates were significantly higher (P < 0.05) than the artificial digestion estimate of 0.0% (95% C.I. 0.0–1.1). Real-time PCR testing of muscle from seropositive animals did not detect Trichinella DNA in any mainland animals, but did reveal the presence of a second larvae-positive wild boar on Gabba Island, supporting its utility as an alternative, highly sensitive method in muscle examination. The serology results suggest Australian wildlife may have been exposed to Trichinella parasites. However, because of the possibility of non-specific reactions with other parasitic infections, more work using well-defined cohorts of positive and negative samples is required. Even if the specificity of the ELISAs is proven to be low, their ability to correctly classify the small number of true positive sera in this study indicates utility in screening wild boar populations for reactive sera which can be followed up with additional testing. 相似文献
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Relative Contributions of Uranium, Thorium, and Potassium to Heat Production in the Earth 总被引:1,自引:0,他引:1
Data from a wide variety of igneous rock types show that the ratio of potassium to uranium is approximately 1 X 10(4). This suggests that the value of K/U approximately 1 X 10(4) is characteristic of terrestrial materials and is distinct from the value of 8 X 10(4) found in chondrites. In a model earth with K/U approximately 10(4), uranium and thorium are the dominant sources of radioactive heat at the present time. This will permit the average terrestrial concentrations of uranium and thorium to be 2 to 4.7 times higher than that observed in chondrites. The resulting models of the terrestrial heat production will be considerably different from those for chondritic heat production because of the longer half-life of U(238) and Th(238) compared with K(40). 相似文献
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Global air pollution crossroads over the Mediterranean 总被引:3,自引:0,他引:3
Lelieveld J Berresheim H Borrmann S Crutzen PJ Dentener FJ Fischer H Feichter J Flatau PJ Heland J Holzinger R Korrmann R Lawrence MG Levin Z Markowicz KM Mihalopoulos N Minikin A Ramanathan V De Reus M Roelofs GJ Scheeren HA Sciare J Schlager H Schultz M Siegmund P Steil B Stephanou EG Stier P Traub M Warneke C Williams J Ziereis H 《Science (New York, N.Y.)》2002,298(5594):794-799
The Mediterranean Intensive Oxidant Study, performed in the summer of 2001, uncovered air pollution layers from the surface to an altitude of 15 kilometers. In the boundary layer, air pollution standards are exceeded throughout the region, caused by West and East European pollution from the north. Aerosol particles also reduce solar radiation penetration to the surface, which can suppress precipitation. In the middle troposphere, Asian and to a lesser extent North American pollution is transported from the west. Additional Asian pollution from the east, transported from the monsoon in the upper troposphere, crosses the Mediterranean tropopause, which pollutes the lower stratosphere at middle latitudes. 相似文献
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Meron Moshe Chen Assaf Rabinovitz Onn Traub Eliezer Levine-Orlov Valerie Marchaim Uri 《Precision Agriculture》2022,23(3):894-911
Precision Agriculture - Irrigation uniformity in a semi-arid climate remains one of the main factors of water use efficiency (WUE) regardless of the level of agronomic advance, since over- and... 相似文献
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SUMMARY A three-year-old neutered female Border Collie was presented with in-appetence, vomiting and diarrhoea. Abdominal radiographs revealed an obstructive pattern but no physical obstruction was evident at laparotomy. A diagnosis of chronic intestinal pseudo-obstruction was made based on histopathological changes in intestinal biopsies. Treatment was unsuccessful and the dog deteriorated progressively until euthanased five weeks after presentation. 相似文献
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