印楝素乳油x对-小菜蛾种群的控制作用

通过室内外系统试验探讨了印楝素乳油对小菜蛾Plutella xylostella种群的控制作用.结果表明,其控制作用主要表现在对成虫产卵的显著忌避作用、对幼虫的拒食作用以及对生长发育的影响和减少幼虫危害力等方面.印楝素乳油0.005 mL/L处理对成虫的忌避率为78.3%,对幼虫的选择性和非选择性拒食率分别为71.8%和62.9%,幼虫总取食量是对照的59.0%,使小菜蛾种群趋势指数(I值)降为2.4,干扰作用控制指数(1lpc)为0.1079.采用状态空间分析法就印楝素乳油施用后小菜蛾种群数量动态的模拟分析亦表明,其显著的控制作用表现在种群发展初期对成虫的忌避作用.     

印楝素乳油对荔枝蒂蛀虫种群的控制作用

利用生命表的方法和干扰作用控制指数评价了印楝素乳油对荔枝蒂蛀虫Conopomorpha sinensisBradley种群的控制作用,结果表明:0.3%印楝素乳油对荔枝蒂蛀虫成虫显著的产卵忌避作用是其对该种群控制的主要机理。在室内,0.3%印楝素乳油在6 mL/L和3 mL/L的浓度处理下,对荔枝蒂蛀虫成虫产卵的忌避率分别为89.3%和86.3%。田间的试验结果表明,在印楝素乳油浓度为6 mL/L和和3 mL/L的处理区中,荔枝蒂蛀虫的种群趋势指数分别为1.23和1.45,显著低于对照区的种群趋势指数11.60,干扰作用控制指数分别为0.106和0.112。这2个浓度的印楝素乳油对荔枝蒂蛀虫种群的控制效果分别可达89.4%和87.5%。     

植物提取物和药剂对蔬菜蚜虫种群的联合控制作用

研究白蝴蝶(Syngonium podophyllum)乙醇提取物、苍耳(Xanthium sibiricum)乙醇提取物、机油乳剂和0.3%印楝素乳油对桃蚜(Myzus persicae)和萝卜蚜(Lipaphis erysimi)的控制效果.室内四因子(1/2实施)二次正交回归旋转组合设计测试对有翅蚜的忌避作用,结果表明,对有翅桃蚜的主要忌避作用物为苍耳乙醇提取物,当苍耳提取物与白蝴蝶乙醇提取物混用,以及机油乳剂和印楝素混用时,对桃蚜有翅蚜的忌避效果提高;而对萝卜蚜有翅蚜的忌避作用主要受苍耳提取物和白蝴蝶提取物的影响.这些干扰作用均是非线性的.田间试验结果,单独使用白蝴蝶提取物对有翅成蚜有较强的驱避作用;对萝卜蚜自然种群的干扰控制作用以4种植物提取物和药剂混配效果最好,达95.7%;对桃蚜自然种群干扰控制效果最好的则是白蝴蝶提取物,控制效果达87%;同时,白蝴蝶提取物与印楝素乳油混配以及苍耳提取物与印楝素乳油混配,对两种蚜虫的控制效果均达80%以上.     

印楝素乳油对小菜蛾种群的控制作用

通过室内外系统试验探讨了印楝素乳油对小菜蛾Plutella xylostella种群的控制作用。结果表明,其控制作用主要表现在对成虫产卵的显忌避作用。对幼虫的拒食作用以及对生长发育的影响和减少幼虫危害为等方面,印楝素乳油0.005mL/59.0%,使小菜蛾种群趋势指数（I值）降为2.4干扰作用控制指数（IIPC）为0.1079,采用状态空间分析法就印楝素乳油施用后小菜蛾种群数量动态的模拟分析亦表明,其显的控制作用表现在种群发展初期对成虫的忌避作用。     

小菜蛾经历"保卫德"后产卵选择行为的变化

植食性昆虫成虫对非寄主植物源驱避素的经历,可导致其对这类化合物产生习惯性反应或诱导嗜好性.让小菜蛾雌蛾对源于印楝的驱避剂——“保卫德”(BIOACT-T^TM EC508)经历2～6次或2～6日后,测定它们对经过保卫德处理的白菜植株的产卵选择行为.结果表明,保卫德对2日龄、4日龄、6日龄无经历雌蛾均有很强的驱避作用,它们在经过保卫德处理的白菜植株上的相对产卵率均只有10%左右;对保卫德有2次或2 d经历的2日龄雌蛾,该产卵率平均上升到17%;对保卫德有4次或4 d经历的4日龄雌蛾,该产卵率上升到21%～24%;对保卫德有6次或6 d经历的6日龄雌蛾,该产卵率上升到29%.表明经历可导致雌蛾对保卫德产生习惯性反应或诱导嗜好性,使保卫德的驱避作用下降,但这种经历导致的产卵选择行为变化在个体之间存在较大差异.     

印楝素乳油对斜纹夜蛾的生物活性及田间防效研究

在室内测定了印楝素乳油对斜纹夜蛾(Spodopteralitura)的生物活性,并进行了田间防治试验.结果表明,印楝素乳油对斜纹夜蛾具有多种生物活性,主要表现在对幼虫的拒食作用、生长发育的抑制作用和一定的毒杀活性,以及对成虫产卵的忌避作用.经印楝素处理后,幼虫平均发育历期延长、幼虫体重、蛹重、化蛹率和蛹羽化率显著低于对照,印楝素乳油12μl·L^-1浓度处理3龄幼虫5和7d后的体重分别是对照组的36.8%和14.5%,而幼虫平均发育历期比对照组延长6d左右,化蛹率和蛹羽化率分别是27.79%和37.23%,显著低于对照组85.66%和82.11%.印楝素对低龄幼虫有一定的毒杀活性,而对高龄幼虫活性则很低.田间防治试验表明,印楝素乳油对斜纹夜蛾种群有良好的控制作用,施药7d后其防治效果要优于化学农药10%除尽悬浮剂.     

植物提取物和药剂对蔬菜蚜虫实验和自然种群的联合控制作用

研究白蝴蝶（Syngonium podophyllum ）乙醇提取物、苍耳（Xanthium sibiricum ）乙醇提取物、机油乳剂和0.3%印楝素乳油对桃蚜（Myzus persicae）和萝卜蚜（Lipaphis erysimi）的控制效果.室内四因子（1/2实施）二次正交回归旋转组合设计测试对有翅蚜的忌避作用,结果表明,对有翅桃蚜的主要忌避作用物为苍耳乙醇提取物,当苍耳提取物与白蝴蝶乙醇提取物混用,以及机油乳剂和印楝素混用时,对桃蚜有翅蚜的忌避效果提高;而对萝卜蚜有翅蚜的忌避作用主要受苍耳提取物和白蝴蝶提取物的影响.这些干扰作用均是非线性的.田间试验结果,单独使用白蝴蝶提取物对有翅成蚜有较强的驱避作用;对萝卜蚜自然种群的干扰控制作用以4种植物提取物和药剂混配效果最好,达95.7%;对桃蚜自然种群干扰控制效果最好的则是白蝴蝶提取物,控制效果达87%;同时,白蝴蝶提取物与印楝素乳油混配以及苍耳提取物与印楝素乳油混配,对两种蚜虫的控制效果均达80%以上.     

植物提取物和药剂对瓜蚜控制作用的室内和田间效果评价

测试机油乳剂、0 .3%印楝素乳油和苍耳XanthiumsibiricumPetr .etWidd .提取物、白蝴蝶SyngoniumpodophyllumSchott提取物对瓜蚜AphisgossypiiGlover的控制效果。室内实验结果 ,几种药剂和植物提取物对一龄若蚜存活影响的大小次序是 :0 .3%印楝素乳油 (2 0 0 0× ) >机油乳剂 (4 0 0× ) >白蝴蝶提取物 (0 .0 4gDW·ml- 1) >苍耳提取物 (0 .0 4 gDW·ml- 1) ;机油乳剂与植物提取物的不同组合中 ,以机油乳剂单独使用对有翅成蚜忌避效果较好 ;田间试验结果 ,以四种药剂和植物提取物混配 ,对有翅成蚜的驱避作用和种群增长的控制效果最为理想 ,种群增长量只有对照的 2 5 .9%。     

印楝油对印楝素的增效作用和保护作用

印楝油对印楝素具有增效作用,印楝素A和印楝种子石油醚抽提物和印楝种子植物油分别按1：10(m／m)混用处理斜纹夜蛾3龄幼虫,共毒系数分别为150．17和226．87,印楝素B和两者混用后的共毒系数分别为166．00和242．18。印楝种子植物油对印楝素具有保护作用,在54℃下热贮7d,印楝油(甲醇：印楝油=9-1,v／v)对印楝素A和印楝素B的保护效果分别为56．96％和50．86％;热贮14d,保护效果分别为26．72％和38．42％。     

10种植物乙醇提取物对金银花蚜虫的生物活性研究

采用微量滴定法测定了10种植物乙醇提取物对金银花蚜虫的生物活性.结果表明,10种植物乙醇提取物对金银花蚜虫均有一定的驱避活性和毒杀作用.在10 mg/mL的浓度下,臭椿、曼陀罗和桂花的提取物对金银花蚜虫的驱避作用较强,其在12 h的驱避率分别为78.74％、77.54％、75.11％;夏枯草提取物的驱避效果最弱,12 h的驱避率为58.53％.随着处理时间的延长,各植物提取物的驱避效果均呈下降趋势;印楝提取物的毒杀活性最强,72 h后的校正死亡率达68.30％;曼陀罗和苦瓜的作用次之,72 h后的校正死亡率分别为66.41％和63.70％;夏枯草提取物的作用最低,72 h后的校正死亡率仅为26.47％.进一步的毒力分析表明,印楝提取物对金银花蚜虫的毒力较强,24h的Lc.值为11.0836 mg,/mL.     

Chemical information transfer between wounded and unwounded plants: backing up the future

This special issue on “Chemical information transfer between wounded and unwounded plants” provides an overview of past and ongoing experiments on plant-to-plant communication. Since the studies on plant responses to single gaseous compounds were not particularly emphasised, the actual number of studies relevant to the subject is underestimated. All in all, we think the amount of data on damage-induced plant-to-plant information transfer makes that the phenomenon can no longer be denied and deserves intensified attention by the scientific community. In this epilogue we highlight a couple of issues which received little attention and present some speculative ideas. First we concentrate on functional aspects of plant-plant communication we stress the concept of damage-induced signalling as an ecological cost to the signal-sending plant and we discuss the theoretical development on interplant signalling, which is still in its infancy. With respect to mechanisms, we compare above- to belowground signalling, discuss potential cues and stress the possibility that responses in signal-exposed plants may be hidden. Finally, we address some future prospects which may help in the further development of the still underexposed phenomenon of damage-induced plant-to-plant information transfer.     

化学交联质谱技术的研究进展

化学交联质谱技术是解析蛋白质结构和研究蛋白质相互作用的重要工具。近5年以来,该技术在方法和应用上都取得了很大的进步。方法上,一方面可断裂交联剂与新型分离富集方法展现了较好的应用前景,另一方面更加高效的交联肽段搜索引擎和质量控制方法为交联质谱数据分析提供了有力的工具。应用上,一方面与冷冻电镜技术结合解析了大量蛋白质的结构,另一方面从研究蛋白质复合物的相互作用发展到研究全蛋白质组水平的相互作用网络。化学交联质谱技术在方法和应用上的蓬勃发展,体现了这一技术的重要作用。本文对化学交联质谱技术的各个环节进行了详细的综述,包括交联剂选择、交联反应、酶切、交联肽段富集、液质联用、交联肽段鉴定、质量控制和生物学应用,重点介绍了最近5年的研究进展。最后,讨论了化学交联质谱技术面临的挑战及未来的发展方向。     

基于硫醇自组装的肌红蛋白单克隆抗体金膜固相载体的构建

为了在金膜固相载体上固定肌红蛋白单克隆抗体 (MbAb),通过在金膜上生长一层巯基酸和巯基醇的混合自组装分子膜 (SAMs),用原子力显微镜 (AFM) 和X射线光电子能谱仪 (XPS) 分析样品的性质,再以1-(3-二甲基氨基丙基) 3-乙基碳化二亚胺盐酸 (EDC·HCl) 作为催化剂,自组装膜和抗体的氨基发生偶联反应,将抗体固定在金膜表面,并进行肌红蛋白抗原 (MbAg) 的测定。结果显示,通过条件优化实验,发现50 mmol/L的巯基16酸和巯基11醇混合乙醇溶液,60 ℃处理金膜3 h后,再偶联     

Experiences and lessons learned from two virtual,hands-on microbiome bioinformatics workshops

In October of 2020, in response to the Coronavirus Disease 2019 (COVID-19) pandemic, our team hosted our first fully online workshop teaching the QIIME 2 microbiome bioinformatics platform. We had 75 enrolled participants who joined from at least 25 different countries on 6 continents, and we had 22 instructors on 4 continents. In the 5-day workshop, participants worked hands-on with a cloud-based shared compute cluster that we deployed for this course. The event was well received, and participants provided feedback and suggestions in a postworkshop questionnaire. In January of 2021, we followed this workshop with a second fully online workshop, incorporating lessons from the first. Here, we present details on the technology and protocols that we used to run these workshops, focusing on the first workshop and then introducing changes made for the second workshop. We discuss what worked well, what didn’t work well, and what we plan to do differently in future workshops.     

污染环境中单种群生存分析

本文研究了污染环境中种群的动力学模型,基于已有结果,考虑了内禀增长率为非线性函数的情形.利用微分方程定性理论中的比较定理,对于种群的持续生存与绝灭给出了判别条件.     

Teleost polarization vision: how it might work and what it might be good for

In this review, we will discuss the recent literature on fish polarization vision and we will present a model on how the retina processes polarization signals. The model is based on a general retinal-processing scheme and will be compared with the available electrophysiological data on polarization processing in the retina. The results of this model will help illustrate the functional significance of polarization vision for both feeding behaviour and navigation. First, we examine the linkage between structure and function in polarization vision in general.     

Sequential establishment of marks on soluble histones H3 and H4

Much progress has been made concerning histone function in the nucleus; however, following their synthesis, how their marking and subcellular trafficking are regulated remains to be explored. To gain an insight into these issues, we focused on soluble histones and analyzed endogenous and tagged H3 histones in parallel. We distinguished six complexes that we could place to account for maturation events occurring on histones H3 and H4 from their synthesis onward. In each complex, a different set of chaperones is involved, and we found specific post-translational modifications. Interestingly, we revealed that histones H3 and H4 are transiently poly(ADP-ribosylated). The impact of these marks in histone metabolism proved to be important as we found that acetylation of lysines 5 and 12 on histone H4 stimulated its nuclear translocation. Furthermore, we showed that, depending on particular histone H3 modifications, the balance in the presence of the different translocation complexes changes. Therefore, our results enabled us to propose a regulatory means of these marks for controlling cytoplasmic/nuclear shuttling and the establishment of early modification patterns.     

Counterfactual thinking and emotions: regret and envy learning

Emotions like regret and envy share a common origin: they are motivated by the counterfactual thinking of what would have happened had we made a different choice. When we contemplate the outcome of a choice we made, we may use the information on the outcome of a choice we did not make. Regret is the purely private comparison between two choices that we could have taken, envy adds to this the information on outcome of choices of others. However, envy has a distinct social component, in that it adds the change in the social ranking that follows a difference in the outcomes. We study the theoretical foundation and the experimental test of this view.     

A new chapter for a better Bioscience Reports

As Bioscience Reports enters its fifth decade of continuous multidisciplinary life science publishing, here we present a timely overview of the journal. In addition to introducing ourselves and new Associate Editors for 2021, we reflect on the challenges the new Editorial Board has faced and overcome since we took over the editorial leadership in June of 2020, and detail some key strategies on how we plan to encourage more submissions and broader readership for a better and stronger journal in the coming years.     

SIR传染病模型的参数反演

本文将Adams微分方程数值求解方法和神经网络技术相结合,提出了一种适合于SIR传染病模型参数反演的新方法,该方法可以根据不同的传染病类型和传染病发展的不同阶段反演得到SIR模型参数,从而为分析疫情的发展、制定和评判控制措施提供依据.最后本文以北京2003年公布的SARS疫情数据,采用上述方法进行参数反演,计算结果表明反演参数得到的SIR模型计算结果与实测数据相吻合.