Induced and spontaneous IgE antibodies to Dermatophagoides farinae in dogs and cats: evidence of functional heterogeneity of IgE   总被引：1，自引：1，他引：0  

Halliwell  Gilbert  & Mei Lian 《Veterinary dermatology》1998,9(3):179-184

Enzyme-linked immunosorbent assays (ELISAs) were developed to measure IgE antibodies specific for Dermatophagoides farinae in dogs and cats. Although higher levels were detected in atopic dogs and cats than in normal animals without skin disease, the differences were not statistically significant. On the other hand, levels in dogs and cats that were reared under laboratory conditions, and thus presumably not exposed to house dust mites, were either very low or undetectable. IgE antibodies were induced in 10 laboratory-reared cats using low-dose antigenic stimulation in aluminium hydroxide. All cats developed detectable IgE, but not all developed positive skin tests. However, serum from those cats with positive skin tests were able to give positive Prausnitz–Küstner (PK) tests. The canine data, together with previous work on basophil histamine release, suggests that the distinction between atopic and normal dogs may result from a heterogeneity of either IgE or of the high-affinity mast cell receptor. The feline data can only be explained by the existence of a heterogeneity of IgE.  相似文献   

Osmotic Adjustment in Maize (Zea mays L.): Changes with Ontogeny and its Relationship with Phenotypic Stability   总被引：1，自引：0，他引：1  

J. H. Lemcoff  C. A. Chimenti  T. A. E. Davezac 《Journal of Agronomy and Crop Science》1998,180(4):241-247

Genetic variation for osmotic adjustment was examined in a group of maize hybrids during vegetative and silking stages. Estimates of osmotic adjustment were derived from measurements of leaf relative water content (RWC) and osmotic potential (Ψ o ) before day-break. The degree of adjustment was estimated from the In RWC/In Ψ o relationship. All cultivars examined showed some degree of osmotic adjustment and significant differences (P < 0.05) were found among them. The utility of measurements in early vegetative stages as a mean of selection for osmotic adjustment in silking stage was established. A positive tendency was observed between osmotic adjustment and phenotypic stability.  相似文献   

义乌游泳馆屋盖风荷载的试验研究     

李寿英  陈政清  黄磊  祝志文 《湖南农业大学学报(自然科学版)》2007,34(5)

义乌游泳馆采用凹形屋盖,对这种屋盖结构的风荷载研究还比较少.为此,制作了比例为1:100的刚性模型,采用同步测压技术,进行了义乌游泳馆凹形屋盖的风压测量,得到了其屋盖上的平均风压系数分布并与凸形屋盖的试验结果进行比较.结果表明:凹形屋盖上的“吸力”要远大于凸形屋盖上的“吸力”;迎风向挑棚上、下表面压力出现不利的负相关,应引起设计人员的注意;周边建筑对义乌游泳馆屋盖风荷载的影响不大.最后还给出了义乌游泳馆屋盖上的前10个最小极值风压.  相似文献   

Phenotypic character gradient variation of Melia azedarach     

Shiming Cheng  Gu Wanchun 《Frontiers of Forestry in China》2007,2(2):210-216

Canonical Correlation Analysis (CCA) was applied on the research data of five geographical-climatic factors and 18 phenotypic characters of 729 trees of 24 populations of Melia azedarach distributed in China. The eigenvalue of the first canonical variable is 0.997 9 (significant at 0.01 level), accounting for 78% of all eigenvalues. A study on the principal component analysis (PCA) was done, taking the first canonical variable coordinate values as the phenotypic character gradient axes (PCGA). The isogram of the PCGA was drawn out with 0.2 contours, which showed a geographical model with a northeast-southwest variation trend of the phenotypic characters of M. azedarach. Meanwhile, the path analysis results show the direct and indirect effects of phenotypic characters with phenotypic character gradient values, which prove that the propagative organs, are steadily changing. __________ Translated from Scientia Silvae Sinicae, 2006, 42(5): 29–34 [译自: 林业科学]  相似文献   

气助式静电喷头设计及试验研究     

刘春景  王科元 《林业机械与木工设备》2007,35(8):25-27

设计了一种气助式静电感应喷头,对其工作原理和性能试验和荷电效果试验.由试验结果分析了充电电压、气体压力和流量、液体压力和流量、喷孔直径等参数对雾化质量和荷电效果的影响.  相似文献   

玛咖不同颜色种子表型性状及活力特性分析          下载免费PDF全文

尚瑞广  王兵益 《林业科学研究》2015,28(1):122-126

比较分析棕黄色、棕红色和黑色3种颜色玛咖种子的大小、萌发特性、幼苗生长特性和酶活力,探讨3种颜色玛咖种子的表型性状及其与种子活力之间的相关性。结果表明,棕黄色和黑色种子的长、厚、厚宽比、千粒质量、发芽势、发芽率、发芽指数、活力指数、幼苗苗长、根长、单株鲜质量和干质量、POD活性、脱氢酶活性等性状之间无显著差异,但均显著高于棕红色种子(P<0.05);棕黄色和黑色种子的新鲜不发芽种子数、死种子数和不正常幼苗数均显著低于棕红色种子(P<0.05)。不同颜色玛咖种子的千粒质量与种子的长、厚存在显著正相关(P<0.05),种子发芽势、发芽率、发芽指数、活力指数均与千粒质量、POD和脱氢酶呈极显著正相关(P<0.01)。说明棕黄色和黑色种子活力高于棕红色种子,萌发能力更强。  相似文献   

作物表型信息获取机器人底盘设计与试验     

徐圣林  朱立成  韩振浩  王瑞雪  徐庆钟  贾晓峰 《农业机械学报》2023,54(S2):388-399

为进一步提升农业机器人底盘田间适应性和行驶稳定性,面向我国山东地区小麦表型信息获取作业场景,设计了一种四轮独立驱动转向的农业机器人底盘。根据小麦种植农艺需求和行驶地形环境,确定了底盘总体布局方案和主要技术参数。分别开展了底盘驱动部件、转向部件以及摆臂平衡部件设计,并进行了参数校核和元件选型。建立了关键部件ANSYS有限元模型,分别进行了摆臂平衡机构的应力形变分析和车架振动模态模拟,仿真结果表明,摆臂平衡机构的强度和刚度均能满足设计要求,车架能够有效避免因地形激励产生的共振。建立底盘ADAMS动力学仿真模型,分别进行纵向、横向稳定性分析和单侧凸起、凹坑越障性分析,仿真结果表明,底盘横纵向稳定性能够满足设计要求,摆臂平衡机构能够有效补偿单侧障碍造成的质心高度变化,提高了底盘的行驶稳定性。田间试验表明,机器人底盘具有良好的行驶性能,硬质地面直线行驶平均偏驶率为0.51%,田间地面平均偏驶率为1.13%。原地转向中心点偏移量为3.1mm,阿克曼转向最小转向半径为1.125mm。纵向翻倾角为34°,横向翻倾角为28°。单侧越障最大高度为160mm,单侧跨坑最大深度为160mm。  相似文献   

中国板栗36个叶片表型性状的多样性     

郭燕  张树航  李颖  张馨方  王广鹏 《中国农业科学》2022,55(5):991-1009

【目的】揭示中国板栗（Castanea mollissima Bl.）叶片表型性状的变异规律及多样性特征,为中国板栗资源的保护、开发和科学利用提供依据。【方法】对中国10个省份（群体）240份资源的36个叶片表型性状（31个数量性状和5个质量性状）进行检测,运用方差分析、多重比较、相关分析和聚类分析等方法,探讨板栗叶片表型多样性水平及其与原产地的地理、环境因子关系。【结果】巢式方差分析表明,31个数量性状在群体内存在极显著差异（P<0.01）,同时叶片长、叶片宽、叶片长/宽、锯齿高度等15个数量性状及3个质量性状（叶片形状、叶基形状和叶缘锯齿特征）在群体间存在显著或极显著差异（P<0.05或P<0.01）,说明板栗叶片表型在群体内和群体间均存在丰富变异。群体间叶片表型分化系数V_ST为7.95%,远小于群体内的92.05%,说明叶片表型变异主要来源于群体内部。板栗叶片表型的平均变异系数（CV）和平均多样性指数（H′）分别为18.05%和1.27,5个质量性状中以叶片形状的CV和H′最高（35.67%,0.86）,叶缘特征最低（5.60%,0.07）;31个数量性状的CV在8.68%（叶片长/宽）—32.73%（锯齿深度）,H′在1.54（叶背茸毛密度）—2.09（叶片结构疏松度）。叶片外观形态、生理指标和解剖性状的平均H′分别为2.03、2.04和2.04,CV由高到低分别为15.27%（外观形态）>15.18%（生理指标）>12.17%（解剖结构）。10个群体表型性状CV均值在17.11%（陕西）—19.66%（山东）,H′均值在0.99（安徽）—1.80（河北）。板栗叶片大多表型性状与地理气候因子之间存在显著或极显著相关,其中年均气温等温度指标和年降水量与叶基形状、锯齿高度等性状呈负相关（经度和纬度与之呈正相关）,与叶片长/宽呈正相关（经度和纬度与之呈负相关）。【结论】板栗叶片表型在群体间和群体内均存在丰富变异,但变异主要来源于群体内（个体基因型间的变异）,因而以叶片表型性状作为研究对象,进行抗逆性、高光合效率等特异品种选育或相关研究时,研究重点应该放到广泛的个体基因型调查上,变异较为丰富均匀的群体可作为重点参考。板栗叶片大多外观形态和生理指标性状呈现以温度和降雨量因子为主导的梯度规律性。  相似文献   

ROUTE DEVELOPMENT,ANTIVIRAL STUDIES,FIELD EVALUATION AND TOXICITY OF AN ANTIVIRAL PLANT PROTECTANT NK0238     

Wentao XU  Hao TIAN  Hongjian SONG  Yuxiu LIU  Yongqiang LI  Qingmin WANG 《农业科学与工程前沿(英文版)》2022,9(1):110

• Developed a two-step synthetic route to anti-plant-virus candidate NK0238. • NK0238 exhibited a broad antivirus spectrum in greenhouse. • NK0238 showed comparable antivirus activities as controls in field trials. • NK0238 was safe to birds, fish, bees and silkworms. • NK0238 has a very good prospect in commercial development. It has previously been shown that tryptophan, the biosynthesis precursor of Peganum harmala alkaloids, and its derivatives have anti-TMV activity both in vitro and in vivo. Further exploration of this led to the identification of NK0238 as a highly effective agent for the prevention and control of diseases caused by plant viruses, but the existing routes are unsuitable for its large-scale synthesis. This study optimized a route for two-step synthesis of this virucide candidate via reaction of l-tryptophan with triphosgene to produce l-tryptophan-N-carboxylic anhydride, which then reacts with n-octylamine to give NK0238 at up to 94% yield and nearly 97% HPLC purity. In addition, the route was used for the preparation of NK0238 on a>40 g scale permitting further assessment of its antivirus activity in the greenhouse and field experiments, and toxicity tests. NK0238 exhibited useful antiviral activities against a variety of viruses both in greenhouse and field experiments. The toxicity tests showed that NK0238 was not acutely toxic to birds, fish, honey bees and silkworms. The optimized route provides a solid foundation for its large-scale synthesis and subsequent efficacy and toxicity studies, its excellent activity and safety make NK0238 a promising drug candidate for further development.  相似文献   

利用多时序激光点云数据提取棉花表型参数方法     

阳旭  胡松涛  王应华  杨万能  翟瑞芳 《智慧农业(中英文)》2021,3(1):51-62

当前,能够实现作物表型参数高效、准确的测量和作物生育期表型参数的动态量化研究是表型研究和育种中亟待解决的问题之一。本研究以棉花为研究对象,采用三维激光扫描LiDAR技术获取棉花植株的多时序点云数据,针对棉花植株主干的几何特性,利用随机抽样一致算法（RANSAC）结合直线模型完成主干提取,并对剩余的点云进行区域增长聚类,实现各叶片的分割;在此基础上,完成植株体积、株高、叶长、叶宽等性状参数的估计。针对多时序棉花激光点云数据,采用匈牙利算法完成相邻时序作物点云数据的对齐、叶片器官对应关系的建立。同时,对各植株表型参数动态变化过程进行了量化。本研究针对3株棉花的4个生长点的点云数据,分别完成了主干提取、叶片分割,以及表型参数测量和动态量化。试验结果表明,本研究所采用的主干提取及叶片分割方法能够实现棉花的枝干和叶片分割。提取的株高、叶长、叶宽等表型参数与人工测量值的决定系数均趋近于1.0;同时,本研究实现了棉花表型参数的动态量化过程,为三维表型技术的实现提供了一种有效的方法。  相似文献