大蒜叶凝集素基因ASAL的克隆与表达载体的构建

大蒜叶凝集素基因(Allium sativum leaf agglutinin,ASAL)是一种高活性的凝集素基因,且具显著的抗虫性。克隆大蒜ASAL基因将为其在转基因作物中抗虫特性研究奠定基础。本文以GenBank公布的ASAL基因序列设计特异引物,采用RT-PCR法从当地大蒜品种二水早和新都软叶的幼苗中克隆ASAL基因。结果表明,克隆的两个ASAL基因与已知基因的碱基序列相似性分别为98.7%和98.9%,氨基酸序列相似性为98.3%。将其亚克隆至表达载体中,经菌落PCR和酶切鉴定,成功构建了重组质粒。将该载体导入农杆菌EHA5a进行保存。

Insight to the Mode of Action of <i>Allium sativum</i>Leaf Agglutinin (ASAL) Expressing in T₃Rice Lines on Brown Planthopper

Brown planthopper, the sap sucking hemipteran pest, is one of the major contributors to the yield loss of rice through the world. To combat the situation researchers are interested identifying genes from plant origin having potentiality to develop hemipteran pest resistance. Interestingly, it was observed that rice plants expressing ASAL, a monocot mannose binding lectin, showed significant resistance to brown planthopper and green leafhopper. Additionally, antibiotic resistant marker gene free ASAL expressing rice lines were developed to overcome the biosafety issues. However, the basis behind the resistance against planthoppers is still not clearly understood. Ligand blot assay was performed with total BBMV protein from BPH and a ~56 kDa receptor protein was detected. LC MS/MS analysis revealed that the receptor protein is NADH quinone oxidoreductase (NQO), a key player in electron transport chain, insect defense response and male/female gametogenesis. Presumably interaction of ASAL with NQO may lead to toxicity and loss of fecundity among BPH feeding on ASAL expressing transgenic rice plants. These findings provide a stable scientific basis for considering these transgenic ASAL expressing rice plants as significant product for combating BPH attack associated yield loss of rice.

Trends of Extreme Temperature and Rainfall Indices for Arid and Semi-Arid Lands of South Eastern Kenya

Extreme climate events have profound impacts on economies and livelihoods of many regions of the world. In Kenya, the extreme climate events often have strong impacts on agriculture production systems in the Arid and Semi-Arid Lands (ASALs). A small change in the mean climate condition can cause large changes in these production systems. There is a paucity of information on trends in climate and climate extremes in the country. However, a joint World Meteorological Commission for Climatology/World Climate Research Programme (WCPRP) project on climate Variability and Predictability (WMO CCl/CLIVAR) Expert Team (ET) on Climate Change Detection, Monitoring and Indices has defined 27 core climate indices mainly focusing on extreme events which can be derived through the use of RClimDex Software. In this study, therefore, the RClimDex software has been used to derive climate extreme indices for five stations in the ASALs of South-Eastern Kenya based on climate data for the period 1961 to 2009. The objective was to examine trends in these extremes to aid agricultural planning and practice. These indices have shown decreasing trends in annual rainfall, rainfall intensity and consecutive wet days but increasing trends in consecutive dry days. Steady warming patterns were evident in both the maximum and minimum temperature indices. This paper concludes that indeed significant changes in climate extremes are apparent in the ASALs of the country and recommends a re-thinking of planning and practice of rain-fed agriculture in the ASALs of South-Eastern Kenya.

Climate Change and Pastoral Economy in Kenya:A Blinking Future

This paper examines the changing climatic scenarios and the associated effects on livestock farming in the arid lands(ASALs)of Kenya which covers over 80%of the country.This study was carried out in the semi-arid Mukogodo Division of Laikipia District.This division received a mean annual rainfall of about 507.8 mm and the main source of livelihood was livestock farming.Questionnaire, structured interview,observation and literature

防止ADSL数据对话音的干扰

介绍了ADSL的数据信道与话音信道以及ADSL的频带衰减,并对防止数据信号干扰电话信号进行了分析研究。

轻油火车密闭装车设备创新设计

分析了现有炼厂轻质成品油出厂装车设备存在的问题和缺陷,从整体结构到主要部件汽缸、鹤管、锁紧机构等进行了创新设计,新的设备既满足了使用要求,同时在提高设备性能、促进环保、降低成本等方面都取得了较好的成效。

Zai Pit Effects on Selected Soil Properties and Cowpea (<i>Vigna unguiculata</i>) Growth and Grain Yield in Two Selected Dryland Regions of Kenya

Erratic rainfall and temperature regimes, strongly affect agricultural productivity. To address the reduction in production, this study assessed the effect of Zai pit depths on selected soil properties and cowpea growth and grain yield. “Zai” pit technology was tested in two locations falling under Agroecological Zone IV (relatively dry areas) i.e. Katumani in Machakos County and Naivasha in Nakuru County, Kenya, aiming to determine the combined effect of four “Zai” pit depths and two levels of manure (plots with manure and plots without manure) on selected soil properties, growth and yield of cowpea. Experiment was laid out in split plot arrangement, with manure levels as the main plot factor and “Zai” pit depths (Flat: Z0, 30 cm: Z30, 45 cm: Z45 and 60 cm: Z60) as subplot factor, replicated four times. Cowpea (M66 variety) was used as the test crop. Inorganic N and extractable P were significantly (P < 0.05) higher, at 1.37 mg⋅kg−1 for Nin and 80.4 mg⋅kg−1 for Pex in Zai pits compared to flat plots which were at 0.91 mg⋅kg−1 for Nin and 47.1 mg⋅kg−1 for Pex. The values of Nin and Pex also varied depending on depths, with Z45 having highest Nin at 1.17 against the least, at 0.89 in the Z0, while Pex was highest in Z30 at 102.3 mg⋅kg−1 while Z0 having the least Pex of 89.7 mg⋅kg−1. Generally, crops in “Zai” pitted plots were larger in diameter at 0.46 cm than crops in flat plots at 0.42 cm. Better performance was observed in yield, with Z30 yielding 30.5% against 18.2% Flat plots in Machakos while 27.9% in Z30 against 22.5% from Flat plots in Naivasha. This study demonstrated great potential of “Zai” pit technology on crop production, as reflected on improved growth and yield of cowpeas. Combining “Zai” pits with manure increases soil Nin, Pex and is a guarantee of great crop performance in terms of high final yields.

鼻内翻性乳头状瘤恶变相关因素的研究

鼻腔、鼻窦内翻性乳头状瘤是鼻腔鼻窦的良性病变，占鼻肿瘤的0．15％～4％，具有侵袭性、高复发率（6％-48％）、易恶变（7％-27％）和转移及多中心的临床特点。近年来已引起人们的注意，目前其发病机制和癌变机制尚不明确。本文对近几年鼻内翻性乳头状瘤的恶变相关因素的研究进展作一综述。

抗过敏药物联合鼻腔局部应用糖皮质激素治疗慢性鼻-鼻窦炎的疗效观察

目的观察小剂量长期使用抗过敏药物联合鼻腔局部应用糖皮质激素治疗无局部解剖结构异常的慢性鼻-鼻窦炎(CRS)的临床效果。方法 CRS患者146例,按照就诊顺序随机分成对照组和观察组各73例。对照组单纯给予抗组胺药地氯雷他定治疗,观察组地氯雷他定和鼻内糖皮质激素联合治疗,比较2组患者的临床疗效、鼻窦CT评分。结果治疗前后,观察组Lund鼻窦CT平均评分由(7.16±2.11)降至(2.61±1.57)分(P<0.05),对照组由(6.42±1.94)降至(2.34±1.72)分(P<0.05);治疗后,观察组疗效优于对照组(P<0.05)。观察组在治疗后12个月内复发率明显低于对照组(P<0.05);2组患者治疗前后主观自评疗效结果与Lund鼻窦CT评分相似。结论抗过敏药物联合鼻腔局部应用糖皮质激素治疗CRS,可以提高临床疗效,改善预后。

鼻腔黏膜修复敷料的生物学评价

目的考察鼻腔黏膜修复敷料的生物安全性。方法按照医疗器械生物学评价标准中的迟发型超敏反应试验、体外细胞毒性试验、刺激性试验分别对3个厂家的鼻腔黏膜修复敷料进行安全性评价。结果 3批鼻腔黏膜修复敷料的安全性检查结果均符合规定。结论 3批鼻腔黏膜修复敷料安全、可用。

盐酸恩丹西酮鼻用凝胶剂的制备与质量控制

目的设计盐酸恩丹西酮鼻用凝胶剂处方,并建立其质量控制方法.方法以卡波姆-940和甘油作为凝胶基质和主要辅料,用三乙醇胺调节pH值,制备盐酸恩丹西酮鼻用凝胶剂,采用紫外分光光度法对凝胶剂中盐酸恩丹西酮的含量进行测定.结果所得凝胶剂质量稳定,含量准确,盐酸恩丹西酮平均回收率为100.15%.结论该制剂制备工艺简便、稳定性好,质量控制方法简便、快速、准确.

3S技术在桉树枝瘿姬小蜂监测预警中的应用前景

通过分析3S技术及其在森林病虫害预警中的应用现状,结合桉树枝瘿姬小蜂(Leptocybe invasaFisher et 1.aSalle)的发生危害特点,综述3S技术在桉树枝瘿姬小蜂监测预警中的应用前景。