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961.
本研究应用生物信息学方法,以ORFV NZ2毒株的CBP蛋白氨基酸序列为研究对象,对CBP蛋白的理化特性、亲水性、跨膜区、信号肽、二级结构、三级结构、B细胞表位和T细胞表位进行了预测分析。结果显示,CBP蛋白的相对分子质量为31.179 89 kDa,理论等电点为4.68,半衰期为30 h,稳定系数为43.06,脂肪族指数为81.78,总平均亲水性为-0.383。CBP蛋白为亲水性蛋白,无跨膜区,不属于跨膜蛋白,存在信号肽;二级结构中α螺旋、β折叠、β转角、无规卷曲分别占38.11%、33.91%、5.94%和10.48%,三级结构形似倒立的哑铃,上下对称。筛选出了6个优势B细胞表位、3个CTL细胞表位,无Th细胞表位。CBP蛋白为亲水性膜外蛋白,细胞表位较少,在细胞膜外为ORFV逃避宿主免疫反应发挥作用。本研究为CBP蛋白的功能研究与ORFV的致病机制研究提供了理论依据。 相似文献
962.
[目的]探讨轮状病毒感染与乳糖不耐受症的临床相关性,为建立适用于规模化养猪场的仔猪轮状病毒感染检测方法提供理论依据.[方法]随机选择腹泻仔猪和健康仔猪各63头,采用醋酸铅—氢氧化铵法和pH试纸法分别检测仔猪粪便的乳糖和pH值,粪便乳糖大于或等于++且pH≤5.5为继发性乳糖不耐受症;然后运用猪轮状病毒诊断试剂检测乳糖不耐受病例的猪轮状病毒感染情况.[结果]与健康仔猪相比,腹泻仔猪粪便乳糖大于或等于++为36例,其中pH≤5.5有23例,即发生乳糖不耐受症的病例23例,占总腹泻仔猪数的36.51%.对23例乳糖不耐受病例进行轮状病毒感染检测,结果发现仔猪继发性乳糖不耐受症与猪感染轮状病毒所引起腹泻的吻合率高达100%.[结论]由猪轮状病毒所引起的仔猪腹泻,多会发生继发性乳糖不耐受症,采用醋酸铅—氢氧化铵法能及时鉴别诊断猪轮状病毒感染,且具有廉价、方便、快捷等优势,适合在基层猪场大规模使用. 相似文献
963.
Kei Oyoshi Nobuhiro Tomiyama Toshio Okumura Shinichi Sobue Jun Sato 《Paddy and Water Environment》2016,14(4):463-472
In Asia, rice is a staple cereal crop and the continent accounts for about 90 % of the global rice production and consumption. Statistics on the areas planted with rice or production of paddy rice are fundamental to agriculture-related decisions or policy-making. Asia-Rice Crop Estimation & Monitoring (Asia-RiCE) aims to develop rice-related information, such as paddy field maps, rice growing conditions, yield, and production, using remote sensing tools and disseminate the same at the local and global scales. In this paper, we propose a methodology for the identification of rice-planted areas by using multi-temporal SAR images; a software named INternational Asian Harvest mOnitoring system for Rice (INAHOR) was developed to manipulate the proposed algorithm. The INAHOR uses the imagery observed both at the time of planting of rice and grown-up stages. In this study, two thresholds needed for the INAHOR were optimized based on the detailed land cover data collected through a field survey. Rice-planted areas across the study area in Japan were identified by the INAHOR using the RADARSAT-2 Wide Fine beam mode data. The classification results of RADARSAT-2 VV and VH polarizations were compared. The data with VH polarization showed a higher total accuracy of 83 % with ?20.5 dB and 3.0 dB for the minimum and range thresholds, respectively. The INAHOR is currently being used with the RADARSAT-2, ALOS, and ALOS-2 SAR data in the Southeast Asian countries to assess the robustness of the thresholds and classification accuracies under the framework of Asia-RiCE. 相似文献
964.
不同生态型小麦品种旗叶光合性能的研究 总被引:17,自引:3,他引:17
为明确不同生态型小麦品种的光合作用机制 ,以不同生态型小麦品种为材料研究了小麦旗叶的光合性能。结果表明 ,不同生态型小麦品种旗叶生育期间的气孔限制和非气孔限制具有相同的特点 ,在叶片功能旺盛的前中期 ,光合底物 CO2 对光合速率的限制主要是非气孔限制 ,在叶片老化后期 ,光合底物 CO2 对光合作用的限制同时存在着气孔限制和非气孔限制 ;不同生态型品种小麦旗叶光合功能和碳代谢特性具有与生态型表现相关的规律。春性品种叶绿素含量高 ,光合面积大 ,功能高值期 (RSP、PAD)长 ,叶源量 (L SC)大。半冬性品种光合速率高 ,叶绿素含量较低 ,功能高值期较短 ,叶源量最小。冬性品种叶绿素含量最低 ,功能高值期最短 ,叶面积和光合速率与半冬性品种差异较小 相似文献
965.
家蚕品种最适环境片区的划分 总被引:2,自引:0,他引:2
对家蚕品种最适环境片区划分进行了研究,初步得到如下结果:参试的8个地区可以划分为两个环境片区。第一个环境片区包括四川、重庆和浙江;第二个环境片区包括陕西、山东、安徽、湖北和镇江;第一个环境片区的最适基因型是品种B;第二个环境片区的最适基因型是品种C。如果在各环境片区推广相应最适基因型比在所有地区只推广品种C,则全区平均万蚕收茧量可提高2.1%。 相似文献
966.
967.
Russell Fairfax Rod Fensham Don Butler Kelvin Quinn Bernice Sigley James Holman 《Landscape Ecology》2009,24(10):1363-1373
There is circumstantial evidence that grasslands on the Bunya Mountains were once maintained by Aboriginal burning, and with
lack of fire under European management are being colonised by trees. To assess the efficacy of burning for maintaining grasslands,
119 fires were lit between 1996 and 2006. The total area of unburnt grasslands decreased by 27%, while grasslands burnt at
least once decreased by 1%. The density of invading trees was recorded from fixed plots on 23 grasslands burnt between one
and six times. Cassinia was virtually eliminated and the density of the Rainforest species guild slowly but continually declined. Acacia irrorata exhibited a humped response, with initial increases resulting from vegetative resprouting and gradual decline with persistent
burning. Phyllodinous Acacia and Woodland trees were the least fire sensitive guilds, having stable or increased density with repeated burning. Multi-factor
regression modelling detected no significant relationships between changes in woody plant density and the interval between
fires, fire intensity, the initial density of large trees, an index of soil moisture, or the cumulative number of fires for
any species guild. The survivorship of both Cassinia and Rainforest guilds was significantly lower with summer burning than winter burning, but a seasonal effect of burning was
not evident for other guilds. The findings suggest that regardless of fire conditions, frequent burning will reduce the number
of adult trees, maintain resprouts in an immature state, facilitate further fire and reduce the rate of grassland loss. Woodland
species are especially resilient to fire, and burning to maintain grassy ecosystems will be most successful where the main
colonisers are rainforest species and burning is conducted in summer. The findings suggest that the montane grasslands of
the Bunya Mountains were maintained by anthropogenic burning and active fire management will prolong their existence. 相似文献
968.
969.
Xiao-juan Li Xiong-fei Yan You-qing Luo Gui-fang Tian Yin-jie Nian Hong Sun 《中国林学(英文版)》2010,12(1):26-30
Cellulase activities of Anoplophora glabripennis (Motsch.) adults from two host plants (Populus simonii × P.pyramidliscr cv.Opera Hsu.and Salix matsudana Koidz) fed on three different host tree species (Acer negundo Linn.,S.matsudana Koidz and P.simonii × P.pyramidliscr cv.Opera Hsu.) were investigated.Enzyme activities of endoglucanase and β-glucosidase in the intestines of the insects were measured.The results show that there are no statistically significant differences in the enzyme activities of endoglu... 相似文献
970.
Sarah I. Beldin Bruce A. Caldwell Phillip Sollins Elizabeth W. Sulzman Kate Lajtha Susan E. Crow 《Biology and Fertility of Soils》2007,43(6):837-841
The cation exchange capacity (CEC) of a soil depends on the type and amount of both mineral and organic surfaces. Previous
studies that have sought to determine the relative contribution of organic matter to total soil CEC have not addressed differences
in soil organic matter (SOM) composition that could lead to differences in CEC. The objectives of this study were (1) to compare
the CEC of two distinct SOM pools, the “light fraction (LF)” composed of particulate plant, animal, and microbial debris,
and the “heavy fraction (HF)” composed of mineral-bound organic matter; and (2) to examine the effects of differences in aboveground
vegetation on CEC. Soil samples were collected from four paired grassland/conifer sites within a single forested area and
density fractionated. LF CEC was higher in conifer soils than in grassland soils, but there was no evidence of an effect of
vegetation on CEC for the HF or bulk soil. LF CEC (but not HF CEC) correlated well with the C concentration in the fraction.
The mean CEC of both fractions (per kg fraction) exceeded that of the bulk soil; thus, when the LF and HF CEC were combined
mathematically by weighting values for each fraction in proportion to dry mass, the resulting value was nearly twice the measured
CEC of bulk soil. On a whole soil basis, the HF contributed on average 97% of the CEC of the whole soil, although this conclusion
must be tempered given the inflation of CEC values by the density fractionation procedure. 相似文献