鸡Ii结合Rab5a和Rab7b分子的分析     

陈芳芳  桂亚萍  于凤梅  张俊  谈阳  李锦春  刘翠艳  查丽莎 《畜牧兽医学报》2021,52(12):3588-3597

本研究旨在探明鸡恒定链（invariant chain，Ii）与内吞体转运蛋白Rab5a和Rab7b结合的结构域和在细胞内共定位的特征。首先，用PCR和基因突变技术将Ii胞浆区与跨膜区[Ii_{（Cyt-Tra）}]、Ii CLIP （class Ⅱ-associated invariant chain peptide）-三聚体区[Ii_{（CLIP-TRIM）}]和Ii突变体[Ii_{（M81-87aa）}、Ii_{（M91-99aa）}和Ii_{（M81-99aa）}]分别插入pET-32a和pEGFP-C1构建相应的原核和真核重组质粒。其次，将构建的含有绿色荧光蛋白的重组质粒与实验室保存的含有红色荧光Rab5a和Rab7b的重组质粒共转染至人胚胎肾细胞系293 T，观察它们的共定位。将构建的原核重组质粒进行表达和纯化，最后用拉下法和免疫印迹检测Ii与Rab5a和Rab7b的结合域。结果表明，成功构建Ii结构域及Ii突变体的重组质粒。Ii_{（Cyt-Tra）}及Ii突变体均能与Rab5a和Rab7b在细胞内共定位，而Ii_{（CLIP-TRIM）}与空载体却不能。Ii的胞浆区和跨膜区是与Rab5a和Rab7b结合的功能结构域，而不是CLIP与三聚体区。综上所述，鸡Ii与Rab5a和Rab7b共定位和结合的区域是其胞浆区和跨膜区，而不是内质网腔区。这些结果提示Rab分子参与了Ii在胞内细胞器的转运机制，为进一步研究Ii及其载体在细胞内的转运机制和功能提供了新的途径。  相似文献   

谈复合型网络信息咨询人才的培养   总被引：2，自引：0，他引：2  

田英萍 《农业网络信息》2006,(9):68-69

本文就网络信息咨询的定义，分析了网络信息咨询需要复合型人才的原因，并着重对复合型网络信息咨询人才的素质要求及复合型网络信息咨询人才的培养进行了探讨。  相似文献   

佐剂对鸡补体水平影响的研究     

马本江  王君伟 《黑龙江畜牧兽医》1993,(10):1-3

６０只未免疫的伊莎褐雄鸡雏分成４组，于２４日龄开始用试管法以５０％溶血度为标准样检测补体。３１日时Ａ，Ｂ，Ｃ三组分别皮下注射司盘－８０＋白油，氢氧化铝胶和ＢＣＧ，Ｄ组对照；４６日龄时再次注射。从３１日龄至５６日龄每隔５天检测一次。结果表明，佐剂使鸡的补体水平普遍升高。于每次注射后第５天达到高峰，第１０天左右接近正常。其中ＢＣＧ影响现大，并于５１日龄时天对照组异显著（０．０１＜Ｐ＜０．０５）．  相似文献   

Assessing the sustainability of cropping systems in single- and multi-site studies. A review of methods     

《European Journal of Agronomy》2016

The multiple new challenges facing agriculture require the development of innovative cropping systems with high environmental, economic and social performances. Many research programmes are currently focusing on the design of such cropping systems. Some include the multicriteria assessment of cropping systems by diverse methods and approaches. Some of these research programmes are supported by experimental or farmers’ networks, generating new opportunities for data analysis and raising new research and methodological questions. In this article, we provide an overview based on a review of 56 articles, comparing the various methods for sustainability assessment in single- and multi-site studies. Articles were classified according to three characteristics: (i) their objectives, (ii) the study design (single- vs. multi-site), (iii) the type of system assessed (fictitious vs. real). Our analysis was structured around four items: (i) the variables used to describe cropping systems and production situations and the use of these variables in the assessment process, (ii) the criteria and associated indicators assessed, (iii) the methods used to explore multiple aspects of the performance of cropping systems, (iv) the use of reference values. We identified key points to be taken into account in multi-site studies. The application of the proposed guidelines to experimental networks should facilitate the identification of high-performance cropping systems and the identification of the drivers of cropping system performance.  相似文献   

关于农业工程类计算机网络课程教学的改革与探索     

曾立华  冯娟 《农业网络信息》2016,(7):138-140

随着社会信息化进程的加快和对农业院校人才培养模式改革的迫切需要,围绕如何提高学生利用网络的能力,增强业务素质这一主题,从教学内容、教学方法及教学手段等方面进行了改革和探索,收到了良好的效果。  相似文献   

改进RBF神经网络在我国大豆价格预测中的应用研究   总被引：1，自引：0，他引：1  

石波  张冬青  马开平  刘欢 《大豆科学》2016,(2):310-314

我国大豆价格受国内外多种因素共同影响,具有非线性、随机性和高噪音等特点,采用传统数学模型进行预测,不仅分析难度大,预测误差也很大。RBF神经网络以其优良的逼近性能而被广泛应用于非线性时间序列预测之中。本文提出一种基于遗传算法优化RBF神经网络的我国大豆价格预测模型,该模型为多维输入单维输出的多变量预测模型,模型的初始输入由大豆价格的历史数据和相关影响因素数据组成。采用遗传算法对RBF神经网络输入层节点数、基函数中心、扩展常数和输出层权值进行优化,模型可以从初始输入变量中自主选择最合适的输入变量组合作为模型的输入。采用2009-2014年的大豆价格数据进行预测研究,用2009-2013年的数据作为训练集,2014年的数据作为测试集,改进RBF神经网络通过自主识别和选取中国大豆进口量、中国消费者信心指数和进口大豆到港分销价格3个因素作为相关影响因素的输入。结果表明:模型预测精度较高、泛化能力较强,能够很好捕捉大豆价格变化规律,可为大豆市场价格的准确预报提供参考借鉴。  相似文献   

基于径向基神经网络的非寿险公司财务预警研究     

邓庆彪  文辉 《湖南农业大学学报(自然科学版)》2011,(1):25-29

选取我国保险行业中40家非寿险公司2006~2008年的混合非平衡面板数据作为研究样本，采用径向基神经网络模型从偿付能力、盈利能力、成长能力三个角度对非寿险公司财务预警进行研究。实证表明，此模型可以为管理层的财务预警提供更有有效的信息，并且在我国保险业具有样本量小，有效数据少的情况下，有着良好的运用前景。  相似文献   

The optimal nutrition of maize in the hungarian national long‐term field experimental network     

Tamás Kismányoky  Katalin Debreczeni 《Archives of Agronomy and Soil Science》2013,59(3-4):251-264

In Hungary, maize is grown on 1 million ha and occupies more than 20% of the arable land. The rich assortment of maize cultivars of different vegetation periods and different responses to nutritional effects, water supply etc. gives the growers the possibility to choose the cultivars suiting best the site characteristics (Jolânkai et al. 1999). Among the cereals maize has the highest genetical potential. To utilize its yield and quality potential, soil types of high nutrient content and regular nutrient supply are required (Gyõrffy, 1979). Both over‐ and under‐fertilization have an unfavourable effect on the yield and quality of maize (Debreczeni, 1985). Crops can be supplied with the appropriate nutrient amounts only with the knowledge of soil characteristics in the different agro‐ecological regions (nutrient content, water supply, soil compactness, pH, nutrient supplying capacity etc.). In Hungary, a network of long‐term field fertilization trials with uniform fertilizer treatments has been maintained at nine experimental sites representing different agro‐ecological regions of the country. This experimental network gives a basis to test the nutrient responses of our main crops and calibrate their optimal nutrient supply (Kismányoky, 1991).  相似文献   

Research on Cooperative Design Network Security Based on IP-VPN     

FU Hong qiao  HE Yu lin  XIAN Zhi ling  WANG Xu xia 《保鲜与加工》2002,(4):32-35

As the important method and instrument of agile manufacture,the technology of distributed collaborative design and manufacturing has become the hotspot of manufacturing. The basic concept and key technologies of IP_VPN are introduced in this paper,and a collaborative design network model based on IP_VPN is presented. Distributed collaborative design is a multi_user,multitask involved system, which is consisted of lots of collaborative processs,so the network security is the key of distributed collaborative design. We research on the security of collaborative design network based on IP_VPN, hence get a conclusion:we can construct an economical?practical and secure collaborative design network system by the application of data encryption,user authentication and access control based on the role,etc.  相似文献   

汽车仪表总成终检台系统开发     

刘宇虹  沈继刚  施美雅 《拖拉机与农用运输车》2005,(4):64-68

针对“汽车仪表总成终检台”系统的开发,,论述了系统设计的背景、设计原理和设计思想:该系统应用于汽车仪表总成出厂前的各项性能测试,并把实测的各项指标存放于数据库中,使得产品的可追溯性得以实现,它对国产汽车仪表总成的各项性能检测趋于科学化、规范化、批量化,使其能达到国际汽车工业的同等水平。  相似文献