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831.
E. Scarlata J. J. Salguero J. Hervs F. Chacon M De Lara J. Jahn J. C. G . mez-Villamandos 《Zoonoses and public health》1999,46(6):375-380
This paper concerns a disease affecting a group of African grey parrots, which involves intranuclear inclusion bodies composed of filamentous material. The disease was characterized by either sudden death or death within 2–3 days from onset of non-specific symptoms. At necropsy, gross lesions included enlarged liver, mild hepatic congestion and focal necrosis. Samples from five birds were fixed in 10% formol and routinely processed for light and electron microscopy. In four birds, numerous hepatocytes displayed an enlarged nucleus, with peripheral margination of chromatin; the nucleus was partially or wholly filled by a basophilic inclusion body. In the remaining bird, inclusion bodies were acidophilic and completely filled the nucleus; nuclear enlargement was less evident than in the other birds. At ultrastructural examination, and in both types of IIB, nuclei contained looped filaments but no evidence of viral structures. However, virion-like structures were observed in the cytoplasm of some hepatocytes. 相似文献
832.
Van den Hout K. D. Bakker D. J. Berdowski J. J. M. Van Jaarsveld J. A. Reinds G. J. Bril J. Breeuwsma A. Groenenberg J. E. De Vries W. Van Pagee J. A. Villars M. Sliggers C. J. 《Water, air, and soil pollution》1999,109(1-4):357-396
In the pilot study ESQUAD the impact of atmospheric deposition of three heavy metals (cadmium, copper and lead) and two persistent organic pollutants (benzo(a)-pyrene and lindane) on the quality of European soils and seawater has been calculated. Calculations have been made of atmospheric transport and deposition using a detailed emissions database for Europe. This enabled deposition maps to be produced to a resolution of approximately 50 km. The distribution of pollutant concentrations in forest soils was calculated for each grid cell using a database of soil property parameters in Europe. For the North Sea, a model was used to map long-term concentrations in water and sediment, which are due to atmospheric deposition and other, non-atmospheric sources. The model calculations allowed detailed comparisons of deposition fluxes and concentrations of the substances studied with critical loads and environmental quality threshold values, including critical loads. Although significant uncertainties were identified, the study gives insight in how threshold exceedance rates in Europe relate to pollutant type, threshold type, environmental compartment and chemophysical phase (adsorbed, dissolved). For all pollutants and for all compartments exceedances were calculated for at least some of the quality thresholds that were chosen. 相似文献
833.
Martinelli Luiz A. Krusche Alex V. Vicgoria Reynaldo L. De Camargo Plinio B. Bernardes Marcelo Ferraz Epaminondas S. De Moraes Jorge M. Ballester Maria Victoria 《Water, air, and soil pollution》1999,110(1-2):67-79
Water samples were collected from 7 locations along major rivers of Piracicaba River basin for 22 months. The 4 upstream points represent non-polluted sites and the 3 downriver points represent polluted sites. Due to sewage input, concentrations of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), major conservative cations and anions increased significantly in the polluted sites. The major increases were observed for sodium, chloride and sulfate. Nitrate was an exception for this pattern, with similar concentrations between polluted and non-polluted sites. The probable cause was reduction of nitrate to ammonium in the polluted sites, where anoxic conditions prevail. Most of the variables had an inverse correlation with water discharge, especially in the polluted points. The sewage load was diluted by precipitation and surface waters. 相似文献
834.
L. Leita M. De Nobili C. Mondini G. Muhlbachova L. Marchiol G. Bragato M. Contin 《Biology and Fertility of Soils》1999,28(4):371-376
We studied the long-term effects (12 years) of municipal refuse compost addition on the total organic carbon (TOC), the amount
and activity of the microbial biomass (soil microbial biomass C, BC and metabolic quotient qCO2) and heavy metal bioavaiability in soils as compared to manuring with mineral fertilizers (NPK) and farmyard manure (FYM).
In addition, we studied the relationships between among the available fraction [Diethylenetriaminopentacetic acid (DTPA) extractable]
of heavy metals and their total content, TOC and BC. After 12 years of repeated treatments, the TOC and BC of control and mineral fertilized plots did not differ. Soils treated with FYM and composts showed a significant increase
in TOC and BC in response to the increasing amounts of organic C added. Values of the BC/TOC ratio ranged from 1.4 to 2, without any significative differences among soil treatments. The qCO2 increased in the organic-amended soil and may have indicated microbial stress. The total amounts of metals in treated soils
were lower than the levels permitted by the European Union in agricultural soils. DTPA-extractable metals increased in amended
soils in response to organic C. A multiple regression analysis with stepwise selection of variables was carried out in order
to discriminate between the influence exerted on DTPA-extractable metals by their total content, TOC and BC. Results showed that each metal behaved quite differently, suggesting that different mechanisms might be involved in metal
bioavailability
Received: 31 October 1997 相似文献
835.
836.
细粒棘球蚴细胞系(13G-5)细胞代谢抗原的免疫原性和反应原性 总被引:2,自引:0,他引:2
应用培育成功的人源细粒棘球蚴细胞系(13G-5)细胞的天然代谢抗原,接种昆明小鼠,于接种后第14天给免疫小鼠接种人源细粒棘球蚴原头节约1 000 个,于200 d 剖检观察有无包囊形成,病理切片鉴定;并用该抗原作为诊断抗原,使用间接血凝(IHA)、琼脂扩散(AGD)试验,检测临床确诊的细粒棘球蚴病人血清。以多房棘球蚴病人血清、细颈囊尾蚴羊血清及正常人血清作为对照。结果表明,该抗原能使60% 的小鼠获得完全抵抗细粒棘球蚴原头节攻击的能力,未完全获得保护的小鼠形成包囊的数量、大小较对照组明显减少,且为不育囊;使用该抗原IHA 检测31 份血清,阳性24 份,阳性率77.42% ,AGD检测30 份血清,阳性13 份,阳性率43.33% ,2 种方法对多房棘球蚴病人血清和细颈囊尾蚴羊血清及正常人血清不起反应。 相似文献
837.
An intensive vertically integrated monitoring program for broiler breeders and their offspring was set up in a Belgian poultry integration between 1993 and 1997. Serology for anti-reovirus antibodies was performed by enzyme-linked immunosorbent assay on blood samples taken from the broiler parents throughout rearing and production and also on blood samples taken at day-old and at slaughter from the broilers. Furthermore, production parameters of the birds were registered. All data were used two by two in a simple correlation study to calculate the degree to which these variables were linearly correlated. The reovirus antibody pattern indicated frequent field infections breaking through vaccinal immunity in the broiler parents. Under the epidemiologic conditions of this study, high antibody titers in the parents or in the broilers at day-old were significantly correlated with poor feed conversion, increased mortality, increased slaughterhouse condemnation, and low production score in the broilers. These correlations strongly support the view that reovirus infections can be economically important under European conditions of broiler production. Improvement of reovirus vaccines or the vaccination scheme in broiler parents or both may lead to better production results in the broiler offspring. 相似文献
838.
梅花鹿幼鹿人工培育技术的研究 总被引:3,自引:0,他引:3
本试验首先通过幼鹿日粮调配寻求最佳合理的日粮配合,首次制定出了幼鹿发育阶段精料年供量曲线。通过对幼鹿采用直线培育措施,加强饲养管理,取得了显著的效果。其中日增重提高35 % ,初角茸产量提高了3 倍,头锯茸产量提高了77-9 % ,创造了历史最高产,幼公鹿出生5 个月开始产茸,幼母鹿培育至17 个月即可参加配种,配种准胎率100 % ,仔鹿成活率达到92 % 。 相似文献
839.
840.