海南岛发现黑翅鸢

黑翅鸢（Ｅｌａｎｕｓｃａｅｒｕｌｅｕｓ）,在国内仅广西、云南、浙江和河北有分布记录。笔者１９９７年５月获得一只采自儋州市的黑翅鸢幼鸟,饲养至今。同年９月又获得一只采自海口市丁村的成鸟,其量度衡如下（单位：ｇ、ｍｍ）：采集地年龄体重全长嘴峰翅长尾长跗?..     

糖类在植物组织培养中的效应

糖类是影响植物组织培养成功与否的关键之一。迄今为止,已用于植物组织培养的糖类有５０多种。在植物体细胞组织培养中,蔗糖一直作为标准碳源,然而其他糖类物质如：葡萄糖、麦芽糖和山梨醇对植物体细胞培养也产生了一定的影响。在植物花药培养中,蔗糖较好,但应注意麦芽糖对花药培养的促进作用。     

大鼠脑血管颈内动脉系肾上腺素能神经起源的观察

应用免疫组织化学技术,观察了30只Wistar大鼠脑血管颈内动脉系肾上腺素能神经的起始核团。正常组脑血管颈内动脉系均可见棕褐色的免疫反应阳性纤维。手术1组作一侧颈上神经节切除术,同侧大脑前动脉、大脑中动脉和大脑后动脉的阳性纤维较正常组减少约2／3,对侧同部位动脉的阳性纤维约减少1／3;手术Ⅱ组作双侧颈上神经节切除术,双侧大脑前动脉、大脑中动脉和大脑后动脉的阳性纤维基本消失。结果提示：脑血管一侧颈内动脉系的肾上腺素能神经纤维起源于双侧颈上神经节。讨论了交感神经对脑血管可能的作用。     

中季稻区稻田害虫—天敌—农药系统的模拟及其优化管理的研究(英文)

本文以中季稻区稻田主要害虫稻飞虱、稻纵卷叶螟和捕食天敌蜘蛛的田间系统调查资料为基础,以害虫—天敌—农药系统为研究对象,应用害虫管理系统工程的原理,处理害虫、捕食天敌与农药三者之间的关系。建立了稻纵叶螟—蜘蛛—甲胺磷和稻飞虱—蜘蛛—甲胺磷两系统优化管理模型,绘制了它们的优化反馈控制策略图,利用微机对系统进行最优监控。使用时输入当前田间害虫与天敌数量,就可对系统作出即时的预测和最优决策。该策略确立的控制害虫的最优性能指标,是使害虫对农作物的为害所造成的损失与防治费用之和最小,并且使害虫和天敌的数量处于系统平衡状态。文中比较分析了该策略与基于经济阈值的常规害虫管理策略,指出了新策略在害虫综合治理中对天敌数量进行控制和管理的作用及其意义。     

人hsp90β基因近端上游CpG位点甲基化状态的研究

真核细胞基因组ＤＮＡ的甲基化主要发生在ＣｐＧ二核苷酸对的胞嘧啶环上（ｍ５Ｃ）［１,２］．在真核细胞基因组ＤＮＡ内,约７０％的ＣｐＧ位点发生了甲基化．ＣｐＧ位点在基因组ＤＮＡ内并不是均匀分布的,多数聚集在一些基因的５’端．大量的实验证据表明,真核基因５...     

Inactivation and conformational changes of fatty acid synthase from chicken liver during unfolding by sodium dodecyl sulfate

Fatty acid synthase is an important enzyme participating in energy metabolism in vivo. The inactivation and conformational changes of the multifunctional fatty acid synthase from chicken liver in SDS solutions have been studied. The results show that the denaturation of this multifunctional enzyme by SDS occurred in three stages. At low concentrations of SDS (less than 0.15 mM) the enzyme was completely inactivated with regard to the overall reaction. For each component of the enzyme, the loss of activity occurred at higher concentrations of SDS. Significant conformational changes (as indicated by the changes of the intrinsic fluorescence emission and the ultraviolet difference spectra) occurred at higher concentrations of SDS. Increasing the SDS concentration caused only slight changes of the CD spectra, indicating that SDS had no significant effect on the secondary structure of the enzyme. The results suggest that the active sites of the multifunctional fatty acid synthase display more conformational flexibility than the enzyme molecule as a whole.     

SIMULATION AND OPTIMAL MANAGEMENT OF THE PEST-NATURAL ENEMY-INSECTICIDE SYSTEM OF PADDY FIELDS IN MIDDLE SEASON RICE CROPPING REGION*

Abstract Investigations on the pest-natural enemy-insecticide system, including rice leaf roller-spider-tamaron and planthopper-spider-tamaron system, were carried out in the paddy fields in middle season rice cropping region. The relationship among insect pest, natural enemy and insecticide were studied based on the principle of the pest management system engineering. The optimal management models of the two systems were developed. Their diagrams of optimal feedback control strategy were contoured for computer monitoring of the pest-natural enemy-insecticide system. The population densities of pest and natural enemy in the future could be forecasted and the optimal strategy could be made when the current field densities of pest and natural enemy were input into the computer. The optimal performance index, which is a combination of the total cost of using the chemical and the total cost of pest damage to crops, for pest control is minimized. The objective of the system management is to drive the state of the system towards a beneficial equilibrium of the system generally. A comparison of the new IPM strategy with the ordinary strategy based on a single economic threshold is conducted in this paper. The optimal control strategies suggest that both pest and natural enemy populations should be controlled in the integrated pest management.     

向日葵CMS育性恢复的研究

向日葵细胞质雄性不育（Ｃｙｔｏｐｌａｓｍｉｃｍａｌｅｓｔｅｒｉｌｉｔｙ,ＣＭＳ）育性恢复的机理是非常复杂的。运用遗传学和分子生物学方法,分析了具代表性的４种不同细胞质类型的ＣＭＳ育性被恢复的频率和２０种向日葵自交系对１９种ＣＭＳ的恢复能力及个别ＣＭＳ植株自发恢复的原因。实验结果表明,４种ＣＭＳ品系育性被恢复的频率分别为５８．８％．５６．３％．１１．８％和０％．２０种自交系的恢复力为５．９－７５．０％。部分ＣＭＳ品系和大多数自交系含有恢复基因,恢复基因的数量及类型决定了ＣＭＳ品系被恢复的程度及自交系的恢复能力。同时,提出并证实了线粒体不育基因变异是导致ＡＲＧ１ＣＭＳ植株自发恢复育性的主要原因。     

Biophysical meanings of orientation and deformation of RBCs in shear flow field of low viscosity with new Ektacytometry

ＥｋｔａｃｙｔｏｍｅｔｒｙｍｅａｓｕｒｉｎｇＲＢＣｄｅｆｏｒｍａｂｉｌｉｔｙｗａｓｆｉｒｓｔｄｅｖｅｌｏｐｅｄｂｙＢｅｓｓｉｓｅｔａｌ.ｉｎ1975[1].Ｔｈｉｓｔｅｃｈｎｉｑｕｅｈａｓｂｅｅｎｗｏｒｌｄｗｉｄｅａｃｃｅｐｔｅｄｎｏｗ.Ｈｏｗｅｖｅｒ,ｔｈｅｍｅａｎｉｎｇｏｆｄｅｆｏｒｍａｔｉｏｎｉｎｄｅｘ(ＤＩ)ｍｅａｓｕｒｅｄｗｉｔｈｔｈｉｓｍｅｔｈｏｄｉｓｓｔｉｌｌｗｏｒｔｈｓｔｕｄｙｉｎｇ.ＴｈｅｔｒａｄｉｔｉｏｎａｌＥｋｔａｃｙｔｏｍｅｔｒｙｕｓｅｓｓｕｓｐｅｎｄｉｎｇｍｅｄｉｕｍｏｆｈｉｇｈｖｉ…     

Breathing route dependence of upper airway muscle activity during hyperpnea

Exercise (Ex) and hypercapnia (HC) both lead toincreases in ventilation and upper airway muscle (UAM) activity. Todetermine whether different breathing routes (nasal vs. oral) orstimuli produced differential UAM activation, electromyographic (EMG) activity of the alae nasi (AN) and genioglossus (GG) were measured inseven normal subjects seated on a bicycle ergometer. Subjects performedpaired runs during both progressive Ex and HC while breathing throughthe nose alone (N) or the mouth alone (O). During hyperpnea, AN EMG wasgreater when the subjects were breathing via N [81 ± 6%maximum (HC) and 69 ± 7% maximum (Ex)] than when they werebreathing via O [30 ± 5% maximum (HC) and 27 ± 5%maximum (Ex); both P < 0.01],whereas the GG EMG did not differ between N and O. Both AN and GG EMGwere similar for Ex and HC when the subjects were breathing via thesame route. We conclude that UAM activation was independent of thenature of the stimulus. However, the AN muscle but not the GG muscledemonstrated breathing-route dependence of activity.