美国马传染性贫血监测与防控分析     

朱来华  王艳  季新成  周仲芳  顾志军  刘金龙  窦树龙  顾炳泉 《中国动物检疫》2018,35(2):48-52

马传染性贫血(EIA)的监测与防控成效关乎全球马业的健康发展。目前美国农业部对EIA实施被动监测程序,要求在马匹参加展览或竞赛等事项、跨州调运、变更马主、进入拍卖或销售市场、配种、引群、入境前,均需携带官方认可实验室的阴性检测报告,其主要检测方法包括ELISA、AGID及免疫印迹试验。一旦发现疫情,立即启动防控措施,如对阳性马实施安乐死,屠宰或隔离检疫,限制调运并永久标识。对同群马反复检测并移除阳性马,加强生物安全措施,防止病毒进一步传播与扩散。通过分析美国EIA监测与防控措施,建议我国在消灭EIA实践中,扩大监测范围和监测数量,加强监督与提高实验室检测能力,反复检测同群马,扑杀阳性动物等。  相似文献   

我国发展新能源汽车的重要意义及政策     

王诗平  陈丹  罗美琴 《湖南农机》2015,(4)

面对全球范围日益严峻的能源形势和环保压力，近年来，世界主要汽车生产国都把新能源汽车产业发展作为提高产业竞争力、保持经济社会可持续发展的重大战略举措。  相似文献   

基于SD模型的甘肃制种企业产业链发展策略分析     

窦学诚  黄炳凯 《草业科学》2016,33(6):1222-1231

以敦煌种业为例分析,总结甘肃制种企业产业链模式。在此基础上,本研究构建了制种企业的产业链SD仿真模型,并通过了历史数据吻合性检验和参数灵敏性测试,模型具有可信性。通过在不同企业战略下对制种产业链仿真模拟,本研究认为甘肃上市种子企业应该采用市场抢占策略提高市场占有率,坚持品种创新并进行严格的成本控制。  相似文献   

65％毒死蜱乳油防治桑螟虫试验     

都勇  黄传书  唐小平 《蚕学通讯》2009,29(1):23-26

对65％毒死蜱的药性及防治桑螟虫的效果进行了试验，结果表明：适时用3000倍65％毒死蜱乳油防治桑螟虫，防效可达100％；同时，做到用药时间和使用方法的合理，是保证防治效果的关键。  相似文献   

害虫对森林碳汇的影响及其机理     

景天忠  豆晓洁 《世界林业研究》2016,29(1):29-35

森林是陆地生态系统中最主要的固碳者。但森林常受到各种干扰, 使其固碳能力下降, 甚至变成碳源。文中主要介绍了叶部害虫、干部害虫和根部害虫干扰对森林碳汇的影响及其机理方面的研究进展。森林昆虫种类繁多, 危害方式及机理也各不相同。叶部害虫通过食叶或吸取汁液破坏叶绿素直接影响光合作用。研究表明, 与光合作用相关基因的表达下调或上调, 光合作用减弱或增强, 目前尚无一致的结论。在林分水平上, 失叶通常导致碳贮量下降。小蠹虫等蛀干害虫危害致树木死亡, 将森林由碳库变成碳源。根部害虫不但使根生物量下降, 还会影响植物光合作用, 但机理尚不清楚。害虫暴发后改变了土壤理化性质, 但在一定时间范围内对土壤呼吸并无显著影响, 其机理尚待揭示。  相似文献   

混沌动力学在森林工程中的应用初探   总被引：2，自引：0，他引：2  

董军  窦邃 《林业科学》2001,37(5):100-106

文中简述了混沌动力学的发展状况，进一步以森林工程学为背景提出了诸如非线性森林工程动力系统等概念及有关研究对象、方法，并通过一个简单的模型算例加以说明，最后对混沌动力学在森林工程中的应用提出了展望。  相似文献   

Biochemical and molecular characterisation of acetylcholinesterase in four field populations of Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)     

Wei Dou  Jin‐Jun Wang 《Pest management science》2012,68(12):1553-1563

BACKGROUND: The oriental fruit fly, Bactrocera dorsalis, is a major pest that infects fruits and agricultural products worldwide. The latest resistance monitoring of B. dorsalis from mainland China has identified high levels of resistance to insecticides. In this study, the biochemical and molecular characteristics of acetylcholinesterase (AChE) in four field populations of B. dorsalis are investigated. RESULTS: Among the four populations, the DG population and its purified AChE were found to be the least susceptible to malathion and five inhibitors, whereas the KM population and its purified AChE were the most susceptible. The highest catalytic activity of purified AChE was found for the KM population, and the catalytic activity of the DG population was the lowest. Among developmental stages, the AChE purified from larvae was found to be the most insusceptible to inhibitors, but its catalytic activity was the highest. Sequence analysis of the cDNA encoding AChE showed that some residue differences existed. However, no significant differences in expression levels of the AChE gene among populations and developmental stages were detected. CONCLUSION: The results suggest that the decrease in susceptibility of B. dorsalis was mainly caused by decrease in AChE activity, and they provide a broad view on the relation between AChE and resistance. Copyright © 2012 Society of Chemical Industry  相似文献   

抗纹枯病、根腐病的转SN1基因小麦的获得与鉴定   总被引：3，自引：0，他引：3  

王金凤  杜丽璞  李钊  黄素萍  叶兴国  冯斗  张增艳 《作物学报》2012,38(5):773-779

SN1是源于马铃薯的一种抗菌肽, 可以抑制多种植物病原菌的生长。小麦纹枯病(主要病原菌为禾谷丝核菌Rhizoctonia cerealis)和根腐病(主要病原菌为平脐蠕孢菌Bipolaris sorokiniana)是小麦的主要土传真菌病害。本研究利用基因工程技术构建了SN1基因的单子叶植物表达载体pA25-SN1, 它受玉米泛素(ubiquitin)启动子的控制;采用基因枪法将pA25-SN1转化小麦推广品种扬麦18幼胚愈伤组织4 000块, 获得203株再生植株, 通过PCR检测出阳性植株55株, 转化率为1.38%。对转SN1基因小麦T₀~T₂代植株, 进行外源基因的PCR、Southern blot、RT-PCR、荧光定量RT-PCR(Q-RT-PCR)分析和小麦纹枯病菌与根腐病菌接种及其抗病性鉴定。结果表明, 转入的SN1基因已经整合到转基因小麦的基因组中, 能够在转基因小麦中遗传、转录与表达。SN1基因的表达提高了转基因植株对小麦纹枯病和根腐病的抗性, 其抗病性可以遗传。  相似文献   

New antioxidant and antiglycation active triterpenoid saponins from the root bark of Aralia taibaiensis   总被引：1，自引：0，他引：1  

Bi L  Tian X  Dou F  Hong L  Tang H  Wang S 《Fitoterapia》2012,83(1):234-240

Four new oleanane type triterpenoid saponins (1-4) and a known saponin (5) were isolated from the root bark of Aralia taibaiensis Z.Z. Wang et H.C. Zheng. The structures of the four new compounds were elucidated as 3-O-{β-d-glucopyranosyl-(1 → 2)-[β-d-glucopyranosyl-(1 → 3)]-β-d-glucurono-pyranosyl}-olean-11,13(18)-diene-28-oic acid 28-O-β-d-glucopyranosyl ester (1), 3-O-{β-d-gluco-pyranosyl-(1 → 3)-[α-l-arabinofuranosyl-(1 → 4)]-β-d-glucuronopyranosyl}-olean-11,13(18)-diene-28-oic acid 28-O-β-D-glucopyranosyl ester (2), 3-O-{β-d-glucopyranosyl-(1 → 2)-[α-l-arabinofuranosyl-(1 → 4)]-β-d-glucuronopyranosyl}-oleanolic acid 28-O-β-D-glucopyranosyl ester (3) and 3-O-{β-d-glucopyranosyl-(1 → 2)-[β-d-glucopyranosyl-(1 → 3)]-β-d-glucuronopyranosyl}-oleanolic acid 28-O-β-d-glucopyranosyl ester (4), on the basis of extensive spectral analysis and chemical evidence. Compounds 1-5 exhibited moderate effects on antioxidant and antiglycation activities, which correlated with treatment of diabetes mellitus.  相似文献   

Reconstruction of corneal epithelium with cryopreserved corneal limbal stem cells in a rabbit model     

Qu L  Yang X  Wang X  Zhao M  Mi S  Dou Z  Wang H 《Veterinary journal (London, England : 1997)》2009,179(3):392-400

The integrity and transparency of the cornea plays a key role in preserving vision. This paper reports a procedure to create an artificial sheet of corneal epithelium from cryopreserved limbal stem cells (LSCs) and to use this for corneal transplantation. Corneal LSCs were isolated from biopsy specimens of rabbit limbal lamellar and cryopreserved in liquid nitrogen at 2–4 passages. The cells were grown in culture medium for 12–14 days on top of a cell-free human amniotic membrane framed on a nitrocellulose sheet. The corneal epithelium generated was transplanted into the right eyes of 14 LSC deficient (LSCD) rabbits (seven experimental animals, seven controls) with corneal damage. The seven LSCD rabbits in the experimental group were transplanted with a corneal epithelial sheet generated from the cryopreserved corneal LSCs. Four LSCD rabbits were used as the vehicle control and were transplanted with a cell-free amniotic membrane, and the remaining three LSCD rabbits were negative controls without transplantation. Over a 2-month recovery period, 2/7 animals in the experimental group recovered completely, four recovered partially and one did not respond. In the control groups, three negative controls and three vehicle controls lost their vision completely, and one of the vehicle controls partially recovered transparency of the cornea Following treatment, corneal transparency of the experimental rabbits was significantly improved compared to controls (P < 0.05). The results indicated that cryopreserved corneal LSCs can repair damaged rabbit cornea, suggesting a possible new clinical approach to reconstruction of corneal epithelium.  相似文献