Eight decades of invasion by Chromolaena odorata (Asteraceae) and its biological control in West Africa: the story so far

ABSTRACT

Chromolaena odorata (L.) R.M. King and H. Robinson (Asteraceae) is a perennial weedy shrub of neotropical origin and a serious biotic threat in its invasive range. The Asian-West Africa (AWA) biotype of C. odorata present in West Africa is both morphologically and genetically different from the southern African (SA) biotype. The AWA biotype was first introduced into Nigeria in the late 1930s and rapidly spread across West Africa. Currently, 12 of the 16 countries in West Africa have been invaded, with significant negative effects on indigenous flora and fauna. However, locals in West Africa have found several uses for the weed. As chemical, physical and other conventional methods were unsustainable, costly and largely ineffective, three biological control agents, Apion brunneonigrum (Coleoptera: Brentidae), Pareuchaetes pseudoinsulata (Lepidoptera: Erebidae) and Cecidochares connexa (Diptera: Tephritidae), have been released in West Africa between the 1970s and the early 2000s. However, only C. connexa and P. pseudoinsulata established, contributing to the control of the weed, in six and four countries in West Africa respectively. Limited research funding, the absence of post-release evaluations of the established agents, and the ‘conflict of interest’ status of C. odorata (i.e. being beneficial for local use but damaging to ecosystem services and agriculture), are serious factors deterring the overall biological control effort. Here, using historical records and field surveys, we examine the invasion history, spread, impacts, and management of C. odorata in West Africa and make recommendations for the sustainable management of C. odorata in the region.     

重楼活性单体pp-10通过抑制PI3K/Akt通路诱导人胃癌细胞BGC-823凋亡和自噬

目的:探讨重楼/七叶一枝花(Paris polyphylla)的醇提物单体pp-10诱导人胃癌BGC-823细胞凋亡和自噬及其分子机制。方法:采用MTT法和克隆形成抑制实验观察不同浓度的重楼单体pp-10对人胃癌BGC-823细胞的增殖抑制作用;Hoechst33342染色法检测pp-10作用于人胃癌BGC-823细胞后细胞核形态的改变;Annexin V-FITC/PI双染法检测细胞凋亡;Western blotting检测重楼单体pp-10对细胞凋亡和自噬相关蛋白Caspase-3、Caspase-9、(ADP-核糖)聚合酶(PARP)、Bax、Bcl-2、LC3、P62以及PI3K/Akt信号通路相关蛋白(Akt、p-Akt、m TOR、p-m TOR、P70s6k、p-P70s6k)表达的影响。结果:重楼单体pp-10能显著抑制BGC-823细胞的生长,作用呈时间-效应关系及剂量-效应关系;克隆形成抑制实验表明随着pp-10浓度的增加,细胞克隆形成逐渐减少,与对照组相比有显著差异;在荧光显微镜下观察可见其细胞核固缩、边聚、裂解等细胞凋亡形态学变化;流式细胞术检测显示,随着作用药物浓度的增高,其凋亡率逐渐升高;Western blotting结果表明,随着药物浓度的增加,线粒体相关凋亡信号通路蛋白Caspase9、Caspase3及PARP均出现酶切活化条带,细胞促凋亡蛋白Bax的表达水平增加,抗凋亡蛋白Bcl-2减少,自噬相关蛋白Ⅱ型LC3增加,P62蛋白减少,p-Akt蛋白的表达水平下降,Akt下游蛋白p-m Tor、p-p70S6K表达减少。结论:重楼单体pp-10通过抑制BGC-823细胞增殖,诱导细胞凋亡和自噬,与下调P13K/Akt信号通路有关。     

施钙对干旱胁迫下花生生理特性、产量和品质的影响

以花生品种606为试材,在旱棚池栽人工控水条件下,研究了钙肥不同用量对花针期和结荚期干旱胁迫下花生的营养生长、生理特性、产量及品质的影响.结果表明:干旱胁迫下施钙,可以促进花生的营养生长,提高叶片的叶绿素含量、净光合速率和根系活力,提高干旱后复水过程中花生的恢复能力,缓解干旱对花生的不利影响;增加了花生荚果和籽仁的产量,尤其是增加了单株结果数和出仁率.施钙提高了籽仁中的脂肪和蛋白质含量,改善了干旱胁迫下花生的籽仁品质.在本试验条件下,施钙量为300 kg·hm-2时效果最佳.     

PMab-219: A monoclonal antibody for the immunohistochemical analysis of horse podoplanin

Monoclonal antibodies (mAbs) against human, mouse, rat, rabbit, dog, cat, and bovine podoplanin (PDPN), a lymphatic endothelial cell marker, have been established in our previous studies. However, mAbs against horse PDPN (horPDPN), which are useful for immunohistochemical analysis, remain to be developed. In the present study, mice were immunized with horPDPN-overexpressing Chinese hamster ovary (CHO)-K1 cells (CHO/horPDPN), and hybridomas producing mAbs against horPDPN were screened using flow cytometry. One of the mAbs, PMab-219 (IgG_2a, kappa), specifically detected CHO/horPDPN cells via flow cytometry and recognized horPDPN protein using Western blotting. Furthermore, PMab-219 strongly stained CHO/horPDPN via immunohistochemistry. These findings suggest that PMab-219 is useful for investigating the function of horPDPN.     

Dipsticks for rapid detection of Plasmodium in vectoring Anopheles mosquitoes

Malaria remains the most serious vector-borne disease, affecting some 300-500 million people annually, transmitted by many species of Anopheles mosquitoes (Diptera: Culicidae). Monoclonal antibodies developed against specific circumsporozoite (CS) proteins of the main malaria parasites Plasmodium falciparum and P. vivax have been used previously for enzyme-linked immunosorbent assays (ELISA), widely employed for detection of malaria sporozoites in vector Anopheles for local risk assessment, epidemiological studies and targeting vector control. However, ELISA procedures are relatively slow and impractical for field use. To circumvent this, we developed rapid wicking assays that identify the presence or absence of specific peptide epitopes of CS protein of the most important P. falciparum and two strains (variants 210 and 247) of the more widespread P. vivax. The resulting assay is a rapid, one-step procedure using a 'dipstick' wicking test strip. In laboratory assessment, dipsticks identified 1 ng/ mL of any of these three CS protein antigens, with sensitivity nearly equal to the CS standard ELISA. We have developed and are evaluating a combined panel assay that will be both qualitative and quantitative. This quick and easy dipstick test (VecTest Malaria) offers practical advantages for field workers needing to make rapid surveys of malaria vectors.     

高校病理生理学双语教学探析

双语教学作为蕴含着全新教育理念的教学形式,是我国高等教育改革的一项新措施,适应新时代背景下社会对高质量人才的需求。探析双语教学引入高校病理生理学中的可行意义、病理生理学双语教学中存在的问题、病理生理学双语教学的改进路径,有利于高校病理生理学双语教学的实践,对高校教育改革及医学专业人才培养起到积极的推动作用。     

水土保持与生态农业旅游技术研究--以四川省南充市嘉陵区木老乡生态农业旅游区为例

嘉陵江流域水土流失日趋严重,已成为农业生态环境最突出的问题。从治理水土流失的角度出发,提出了以营造经果林和水保林为主,配合蔬菜、花卉、生草及植被恢复,结合观光旅游和农民培训的“生态农业旅游”技术与示范。取得了良好的社会效益与经济效益。通过对试验区和试验辐射区的研究,提出了在发展生态农业旅游时必须坚持的原则和注意的问题。     

草鱼呼肠孤病毒RNA聚合酶基因的表达与产物纯化

草鱼呼肠孤病毒是引起草鱼出血病的主要病原,隶属于呼肠孤病毒科水生呼肠孤病毒属.序列分析表明,GCRV S2 片段长为3 877核苷酸,编码一个分子量为138kDa 的蛋白VP2,具有RNA聚合酶性质.为进一步了解该病毒 RNA聚合酶特性,本研究在对GCRV RNA聚合酶基因(GCRV-RdRp)保守区(约1.5kb)重组质粒pR/RRp高效表达的基础上,分别构建了编码GCRV RNA聚合酶保守区N端与C端部分基因的 pR/RRpN及pR/RRpC重组表达载体,并在原核细胞中获得成功表达.筛选的重组表达菌株经IPTG诱导培养,得到分子量分别为98kDa、103kDa的目的表达融合蛋白.Western blot分析表明,该表达产物与兔抗GCRV-VP2血清呈阳性反应.通过ProBond柱亲和层析,纯化了融合有6个组氨酸的重组表达产物,并获得约90%纯的目的蛋白.上述结果为GCRV RNA聚合酶特性分析提供了依据.     

Structural basis for GroEL-assisted protein folding from the crystal structure of (GroEL-KMgATP)14 at 2.0A resolution

Nucleotide regulates the affinity of the bacterial chaperonin GroEL for protein substrates. GroEL binds protein substrates with high affinity in the absence of ATP and with low affinity in its presence. We report the crystal structure of (GroEL-KMgATP)(14) refined to 2.0 A resolution in which the ATP triphosphate moiety is directly coordinated by both K(+) and Mg(2+). Upon the binding of KMgATP, we observe previously unnoticed domain rotations and a 102 degrees rotation of the apical domain surface helix I. Two major consequences are a large lateral displacement of, and a dramatic reduction of hydrophobicity in, the apical domain surface. These results provide a basis for the nucleotide-dependent regulation of protein substrate binding and suggest a mechanism for GroEL-assisted protein folding by forced unfolding.