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61.
抗菌肽(antibacterial peptides)是生物体内经诱导产生的一种具有生物活性的多肽,是天然免疫的重要组成部分.为了提高抗菌肽的表达量以及很方便地检测抗菌肽的表达情况,本研究利用口蹄疫病毒(Foot-and-mouth disease virus,FMDV) 2A将荧光蛋白dTomato基因和3个串联的MagaininⅡ基因融合到一个开放阅读框中(open reading frame,ORE),融合的基因被置于pPIC9K载体醇氧化酶基因(AOX1)启动子的下游,构建分泌型重组酵母表达载体pPIC9K-dTomato -2A-3M,将线性化的重组酵母表达载体通过电击法转入毕赤酵母(Pichia pastoris )GS115中,经G418筛选和PCR鉴定得到阳性转化子,然后将其转至摇瓶,在30℃、0.5%甲醇的条件下进行诱导表达,连续诱导3d.SDS-PAGE电泳图谱显示,在31 kD(dTomato)和9.5kD(3M)处有蛋白条带出现,在荧光显微镜下观察酵母表达上清发出红色荧光,对大肠杆菌(Escherichia coli)和金黄色葡萄球菌(Staphylococcus aureus)抑菌试验结果表明,重组抗菌肽串联的MagaininⅡ具有明显的抑菌效果.结果表明,由2A连接的融合基因(荧光蛋白dTomato和串联的MagaininⅡ)在毕赤酵母中成功的进行了表达,FMDV 2A在其C端剪切多聚蛋白,得到dTomato和串联的MagaininⅡ两个独立而有活性的蛋白,为小分子抗菌肽的表达提供一个高效的检测方法. 相似文献
62.
为了比较婆罗门牛和BMY牛的雌二醇(E2)、孕酮(P4)水平及胚胎生产潜力,并探讨MOET技术在BMY牛扩繁中的应用前景,采用进口激素(日本产FSH 24~36 mg+美国产PG 35 mg)和国产激素(国产FSH 10~12 mg+国产PG 0.8 mg)对全放牧婆罗门牛和BMY牛进行超排,并于超排前(同期发情第7天)、超排开始、超排第3天、超排发情当天和胚胎回收当天采集血液,采用RIA法分析血浆中的E2和P4水平。结果表明,BMY牛的黄体数和获胚(卵)数、可用胚数分别较婆罗门牛高2.09个和0.95、0.36枚,但差异不显著(P>0.05);BMY牛的排卵率较婆罗门牛高18.46%(P<0.01),而可用胚率则较婆罗门牛低2.55%(P<0.01)。BMY牛在5个处理时段的E2和P4平均值分别较婆罗门牛高0.58 pg/mL(P<0.01)和1.44 ng/mL(P>0.05),在各处理时段的P4水平变化规律几乎与婆罗门牛一致,E2/P4值为婆罗门牛的5.16倍。结果提示,BMY母牛的E2和P4水平高于婆罗门牛,在激素水平和繁殖性能方面表现出一定的杂种优势;E2水平低是婆罗门牛发情微弱和排卵率低的主要原因之一;在同等放牧管理和超排处理条件下,婆罗门牛及其杂种BMY牛对外源激素的敏感性基本一致,具有同等的胚胎生产潜力。 相似文献
63.
64.
沉积物重金属污染是水环境污染评价的重要内容,重金属含量水平常被作为水环境质量的重要指标之一。为了掌握华北平原的府河和白洋淀中沉积物重金属的污染水平,研究了19个沉积物样品和3个土壤样品中7种重金属的污染特征,利用地积累指数法、潜在生态危害指数法及生物效应浓度法评估了重金属的环境风险,并初步分析了污染来源。结果表明,府河和白洋淀沉积物受多种重金属复合污染,其中Zn、Pb、Cu和Cd污染较为严重,府河沉积物的潜在生态环境危害强于白洋淀。相关分析显示府河和白洋淀重金属污染具有相似污染源,保定市工业废水、生活污水及府河沿岸金属冶炼企业很可能是白洋淀地区重金属的主要来源。从城市环境管理、生态环境修复、宣传教育等方面提出白洋淀区域重金属污染控制对策与建议,为白洋淀区域生态环境保护提供科技支撑。 相似文献
65.
66.
《Biological conservation》1987,41(4):279-289
The causes of the recent heavy elephant mortality in the Tsavo ecosystem between 1975 and 1980 were investigated. Poaching and drought conditions were thought to be the main reason.Whether the cause of death was poaching or other factors was ascertained from the examination of carcasses in the field. In the former case the front part of the cranium was cut while those of the unpoached animals were intact. Rainfall data were analysed to assess whether drought conditions occurred during this period, which might have caused the recent mortality. Other possible causes of mortality were assessed from interviews with park wardens and rangers and from records on poaching incidents and ivory recoveries.The overall results of this study show that the recent heavy elephant mortality in Tsavo ecosystem was caused mainly by poaching preceded by drought. It is therefore recommended that future conservation measures for the remaining elephant population require control of poaching, especially in wet season dispersal areas which are not under park management. 相似文献
67.
《Computers and Electronics in Agriculture》2009,65(2):307-317
The quality label “Protected Designation of Origin” (PDO) protects and controls product quality. It is a normalized mode of typification and valuation. On the basis of the model proposed by Persano Oddo et al. [Persano Oddo, L., Piana, M.L., Barbattini, R., Ferrazzi, P., Longhitano, N., Piro, R., Ricciardelli D’Albore, G., Sabatini A.G., 2002. “La valorizzazione del miele attraverso le denominazioni di origine geografica”, proc. of Atti del Convegno AMA “Il ruolo della ricerca in apicoltura”, Bologna, 14-16 March, pp. 185–216] and the design of Bernardinelli et al. [Bernardinelli, I., Della Vedova, G., Milani, N., 2005. “Un approccio metodologico per la gestone del nomadismo in apicultura mediante i GIS: Esperienza nelle Valli del Natisone (Friuli Venecia Giulia)”. Ati dell’ Incontro-Siminario Mappatura delle aree nettarifere. Firenze], a Geographic Information System (GIS) was created for the management of honey produced in Sierra Morena (Andalusia, Southern Spain), and its development phases are presented in this work. Beekeeping is an activity closely related to this territory, and the GIS tool will be of great assistance in its management. A powerful, easy-to-update, and inexpensive open source code-based GIS web site was created to fulfill the needs of a work team characterizing the honeys entering the Protected Designation of Origin. The application is called SMHGIS (Sierra Morena Honey Geographic Information System). Extension and area delimitation aspects and orographic, orogenesic, climatic, and agronomic (nectar sources) features have been considered. An ordnance survey map of the area (1/10,000), data of the apiary census and honey production, and analysis and data for the characterization of honey subject to designation were used. The aim of this work is to describe the design and possibilities of GIS as a visualization tool for honey characterization and, secondly, as a management tool for the regulation of a Protected Designation of Origin. 相似文献
68.
In the present study, we used nucleotide and protein sequences of avian influenza virus H5N1, which were obtained in Asia and Africa, analyzed HA proteins using ClustalX1.83 and MEGA4.0, and built a genetic evolutionary tree of HA nucleotides. The analysis revealed that the receptor specificity amino acid of A/HK/213/2003, A/Turkey/65596/2006 and etc mutated into QNG, which could bind with á–2, 3 galactose and á–2, 6 galactose. A mutation might thus take place and lead to an outbreak of human infections of avian influenza virus. The mutations of HA protein amino acids from 2004 to 2009 coincided with human infections provided by the World Health Organization, indicating a “low–high–highest–high–low” pattern. We also found out that virus strains in Asia are from different origins: strains from Southeast Asia and East Asia are of the same origin, whereas those from West Asia, South Asia and Africa descend from one ancestor. The composition of the phylogenetic tree and mutations of key site amino acids in HA proteins reflected the fact that the majority of strains are regional and long term, and virus diffusions exist between China, Laos, Malaysia, Indonesia, Azerbaijan, Turkey and Iraq. We would advise that pertinent vaccines be developed and due attention be paid to the spread of viruses between neighboring countries and the dangers of virus mutation and evolution. 相似文献
69.
Numerous wildlife species are known pests of California agriculture. Effective management of these pests is required to maximize agricultural production, yet it is unclear how the importance of various wildlife pest species and associated management strategies may vary regionally throughout California. Accounting for these regional differences should yield management programs that are specifically tailored to the regions constituents and should be considered when managing wildlife pests at a more localized level. Therefore, we developed a survey to provide quantitative data on regional differences in research and management needs to better guide future research efforts in developing more effective, practical, and appropriate methods for managing wildlife pests. We found that coyotes were a more common pest in the mountain region, ground squirrels were a greater concern in the central and desert valley region, while birds were most commonly listed as pests by individuals working in multiple regions of California. Coyote damage varied regionally, with livestock depredation the greatest concern throughout most of California, although damage to irrigation tubing and sprinklers was of equal concern in the central and desert valley region. For bird pests, exclusionary devices were the most common and most effective methods of control in the coastal region. Frightening devices were the most commonly used method for bird control in all other regions, although the efficacy associated with frightening devices was considered far lower than their level of use, suggesting that better management options are needed for bird control in these regions. For all wildlife pests, nonlethal control options (e.g., exclusionary devices, habitat modification) were generally preferred in the coastal region while lethal removal options ranked higher in the central and desert valley region (e.g., baiting, burrow fumigation). Efficacy was considered the most important attribute of a control method for all regions, while Integrated Pest Management programs were considered the most effective method for controlling wildlife pests in all regions except for the central and desert valley region. Collectively, the importance of wildlife pests and the perception of associated control methods varied throughout California and reflects the need to consider these regional differences in order to optimize damage management strategies at the regional level. 相似文献
70.
《Physiological and Molecular Plant Pathology》2011,76(4):157-162
The present study investigated resistance against Botrytis cinerea after heat shock treatment in melon plants. Heat shock at 50 °C for 20 s 0–24 h before inoculation resulted in maximal B. cinerea symptom reduction and peroxidase gene expression, which peaked 12 and 72 h post-treatment and decreased 24–48 h post-treatment, suggesting pathogenesis-related protein expression priming. Hot water dipping did not directly inhibit mycelia growth. Plants treated with 2-benzisothiazol-3(2H)-one 1,1-dioxide, which induces systemic acquired resistance, demonstrated higher peroxidase gene expression but no B. cinerea resistance, indicating possible involvement of additional novel mechanisms in heat shock-activated resistance of melon against B. cinerea. 相似文献