The glyoxylate cycle is required for fungal virulence.

Candida albicans, a normal component of the mammalian gastrointestinal flora, is responsible for most fungal infections in immunosuppressed patients. Candida is normally phagocytosed by macrophages and neutrophils, which secrete cytokines and induce hyphal development in this fungus. Neutropenic patients, deficient in these immune cells, are particularly susceptible to systemic candidiasis. Here we use genome-wide expression profiles of the related yeast Saccharomyces cerevisiae to obtain a signature of the events that take place in the fungus on ingestion by a mammalian macrophage. Live S. cerevisiae cells isolated from the phagolysosome are induced for genes of the glyoxylate cycle, a metabolic pathway that permits the use of two-carbon compounds as carbon sources. In C. albicans, phagocytosis also upregulates the principal enzymes of the glyoxylate cycle, isocitrate lyase (ICL1) and malate synthase (MLS1). Candida albicans mutants lacking ICL1 are markedly less virulent in mice than the wild type. These findings in fungi, in conjunction with reports that isocitrate lyase is both upregulated and required for the virulence of Mycobacterium tuberculosis, demonstrate the wide-ranging significance of the glyoxylate cycle in microbial pathogenesis.     

植物病原菌凝集素用于筛选生防木霉菌

提取并纯化了番茄早疫病、黑根霉、棉花立枯病菌和黄瓜灰霉病菌等8个植物病原菌菌株的凝集素，试验观察凝集素与供试19个木霉菌株的凝集反应效价，结果表明除番茄早疫病外，木霉菌分生孢子不同浓度悬浮液与植物病原菌产生的凝集素均有凝集反应，并且木霉菌分生孢子与病原菌凝集素的凝集反应效价与木霉菌对其防效有显相关性，统计分析表明镰刀菌产生的凝集素与木霉菌的凝集反应效价与木霉菌对它的防效具有显相关性．因此可以利用凝集素筛选木霉高效生防菌株．     

Plant pathogens and integrated defence responses to infection.

Plants cannot move to escape environmental challenges. Biotic stresses result from a battery of potential pathogens: fungi, bacteria, nematodes and insects intercept the photosynthate produced by plants, and viruses use replication machinery at the host's expense. Plants, in turn, have evolved sophisticated mechanisms to perceive such attacks, and to translate that perception into an adaptive response. Here, we review the current knowledge of recognition-dependent disease resistance in plants. We include a few crucial concepts to compare and contrast plant innate immunity with that more commonly associated with animals. There are appreciable differences, but also surprising parallels.     

Release of invasive plants from fungal and viral pathogens

Invasive plant species both threaten native biodiversity and are economically costly, but only a few naturalized species become pests. Here we report broad, quantitative support for two long-standing hypotheses that explain why only some naturalized species have large impacts. The enemy release hypothesis argues that invaders' impacts result from reduced natural enemy attack. The biotic resistance hypothesis argues that interactions with native species, including natural enemies, limit invaders' impacts. We tested these hypotheses for viruses and for rust, smut and powdery mildew fungi that infect 473 plant species naturalized to the United States from Europe. On average, 84% fewer fungi and 24% fewer virus species infect each plant species in its naturalized range than in its native range. In addition, invasive plant species that are more completely released from pathogens are more widely reported as harmful invaders of both agricultural and natural ecosystems. Together, these results strongly support the enemy release hypothesis. Among noxious agricultural weeds, species accumulating more pathogens in their naturalized range are less widely noxious, supporting the biotic resistance hypothesis. Our results indicate that invasive plants' impacts may be a function of both release from and accumulation of natural enemies, including pathogens.     

Green synthesized ZnO nanoparticles against bacterial and fungal pathogens

Zinc oxide nanoparticles are known to be one of the multifunctional inorganic nanoparticles with effective antibacterial activity. This study aims to determine the antimicrobial efficacy of green and chemical synthesized ZnO nanoparticle against various bacterial and fungal pathogens. Various microbiological tests were performed using varying concentrations of green and chemical ZnO NPs with sizes 40 and 25 nm respectively. Results prove that green ZnO nanoparticles show more enhanced biocidal activity against various pathogens when compared to chemical ZnO nanoparticles. Also effectiveness of nanoparticles increases with increasing particle dose, treatment time and synthesis method. In addition, the current study has clearly demonstrated that the particle size variation and surface area to volume ratio of green ZnO nanoparticle are responsible for significant higher antimicrobial activity. From the results obtained it is suggested that green ZnO NPs could be used effectively in agricultural and food safety applications and also can address future medical concerns.     

木霉菌产生的葡聚糖酶和植物病害防治

木霉菌能够产生不同类型的葡聚糖酶，包括α-1，3-、β-1，3-、β-1，4-和β-1，6-葡聚糖酶，酶的产生受葡萄糖抑制，而为葡萄糖聚合体如真菌细胞壁所诱导。已经克隆了几个萄聚糖酶的编码基因。该酶是木霉菌产生的重要抑菌蛋白，能够与几丁质酶或抗生素协同抗菌，用于改良植物病害生物防治菌和植物。     

船舶运动的混合智能控制

将混合智能算法应用于船舶航向，转向控制，充分发挥了模糊逻辑，神经网络和遗传算法各自的优势采用GA发优与BP算法学习模糊神经网络参数，通过竞争学习算法从样本数据中获得取模糊控制规则，并与专家经验有机结合，弥补了各自的不足，仿真表明上述算法为改进船舶运动提供了一个有效途径。     

The potential role of pathogens in biological control

It is now well established that pathogens such as viruses, fungi bacteria and protozoans can have profound effects on the dynamics of their invertebrate host populations. Theoretical models of invertebrate host-pathogen interactions which assume uniform structure of the pathogen population may reasonably explain the oscillatory behaviour observed in some systems, but do not adequately describe the existence of more constant populations found in other host-pathogen interactions. An examination of the literature relating to these relatively stable systems suggests that the common thread is the eventual transmission of some of the more protected, longer-lived stages of the pathogen occurring in reservoirs, such as the soil, host cadavers on trees, or the live host itself. In this letter, I propose a new theoretical model which incorporates this population structure and accounts for the range of dynamics observed in natural systems. In particular, I show that host populations may be regulated to low and relatively constant densities if sufficient numbers of pathogens are trans-located from pathogen reservoirs to habitats where transmission can occur. An understanding of pathogen reservoirs may be of value in the design of biological control programmes and may greatly increase the effectiveness of pathogens as biological control agents.     

木霉菌的几丁质酶与植病生防

木霉菌的几丁质酶是其防治植物真菌性病原菌的主要机制之一，它能降解真菌的细胞壁。木霉菌的几丁质酶具有结构和编码基因多样性。已经纯化的木霉菌几丁质酶有内切和外切几丁质酶，壳二糖酶和N—乙酰—β—D—葡萄糖胺酶。已经克隆的有编码33和42—KDa内切几丁质酶和编码73—KDa的N—乙酰—β—D—葡萄糖胺酶基因。42—KDa内切几丁质酶是目前研究最多的，已经用于转基因植物的培育；对它的表达和调控也有部分了解。     

Symbiotic fungal endophytes control insect host-parasite interaction webs

Symbiotic microorganisms that live intimately associated with terrestrial plants affect both the quantity and quality of resources, and thus the energy supply to consumer populations at higher levels in the food chain. Empirical evidence on resource limitation of food webs points to primary productivity as a major determinant of consumer abundance and trophic structure. Prey quality plays a critical role in community regulation. Plants infected by endophytic fungi are known to be chemically protected against herbivore consumption. However, the influence of this microbe-plant association on multi-trophic interactions remains largely unexplored. Here we present the effects of fungal endophytes on insect food webs that reflect limited energy transfer to consumers as a result of low plant quality, rather than low productivity. Herbivore-parasite webs on endophyte-free grasses show enhanced insect abundance at alternate trophic levels, higher rates of parasitism, and increased dominance by a few trophic links. These results mirror predicted effects of increased productivity on food-web dynamics. Thus 'hidden' microbial symbionts can have community-wide impacts on the pattern and strength of resource-consumer interactions.     

混合驱动踝足假肢阻抗控制方法简

本文建立并分析了一种主被动混合驱动踝足假肢动力学模型,提出了一种基于步态有限状态机阻抗规划和前馈补偿力内环的实时阻抗控制算法。为了检验该控制方法的有效性,建立了假肢的多体动力学模型和阻抗控制器模型,并进行了联合仿真研究。研究结果表明,该算法能够有效地控制动力踝足假肢关节完成平地步行,并实现步态中的关节变阻抗行为。该控制算法改善了主被动混合驱动踝足假肢控制的可控性,提高了关节阻抗的控制性能。     

基于Fuzzy-PID控制的UPS电源仿真

本文引入Fuzzy-PID控制,将其应用在UPS逆变系统中。Fuzzy-PID控制结合了模糊控制优良的动态性能、灵活的控制特性和PID稳态控制性能的优点,提高了系统的性能。运用Matlab对系统进行建模仿真,仿真结果表明,将Fuzzy-PID控制应用到UPS逆变系统中,系统的动态和稳态性能得到了很大程度的提高。     

食源性病原微生物检测与控制技术研究新进展

最近在食源性病原微生物流行病学调查,检测手段以及致病因子控制方面出现了许多新的研究进展.特别是基因组序列以及基因组学和后基因组学工具的广泛应用,为病原微生物遗传学和生理学提供了丰富信息,也为病原微生物快速检测和控制研究提供了大量新手段.主要针对最近关于食源性病原微生物的检测和控制技术研究进展进行综述.目的是为食品安全管理以及食源性病原微生物控制策略提供技术支撑和带来一些新思考.     

一维混杂控制系统可生存域计算

讨论了一维混杂控制系统在闭区间里的最大可生存域的计算问题.采用混杂微分包含描述混杂控制系统,针对系统为一维的情况作了合理的简化.将一维混杂控制系统的最大可生存域的计算问题转化为一个优化问题,并给出了具体的例子来说明这一结果.     

Operation control strategy of series-parallel hydraulic hybrid vehicle

A series-parallel hydraulic hybrid system applied to public buses is put torwaro, ano parameters of key components are analyzed and determined. Energy management strategy based on logic thresh- old is designed which is aimed at efficient operation of the overall system considering the operational characteristic of the components and taking the curves of engine, hydraulic pump/motor and hydrau- lic pump as the main design basis; regenerative control strategy which makes regenerative brake sys- tem and frictional brake system work harmoniously is designed to raise recovery rate of regenerative brake energy. System dynamic modeling and simulation results show that the energy control strategy designed here is able to adapt system to changes of working condition and switch the operating mode reasonably. The regenerative braking control strategy is effective in raising the utilization of energy and improving fuel economy.     

水生病原体：检测与水处理控制

饮用水水质的微土物风险和化学风险是我国城镇普遍面临的突出问题。本文对美国供水协会（AWWA）关注的几种水生病原体的检测及控制进行综述。针对我国饮用水消毒的化学风险正逐步得到重视,而微生物风险研究与控制仍很薄弱的现实,提出了饮用水生产与管理中几个值得注意的问题。     

一类混杂系统的优化控制

采用基于混合逻辑动态的建模方法,将系统的连续动态过程、逻辑部分和操作约束表示为带有混合整数不等式约束的线性状态方程的形式.在混合逻辑动态建模原理基础上,采用二次型的性能指标,将混杂系统的优化控制问题归结为求解一个混合整数二次规划(mixed integer quadratic pro-gramming,MIQP)问题.最后,针对混杂系统的优化控制问题,作了数值仿真计算.研究结果表明:基于混合逻辑动态模型的优化控制能够满足控制要求,并且进一步说明MIQP方法是解决一类混杂系统优化控制问题有效的且具有发展前景的方法.     

架空线移动机器人主被动混合控制

在分析架空线移动机器人总体环境特点的基础上,针对典型的架空线移动机器人对比分析了行走越障运动特点及其控制方法,包括手臂运动控制及质心调节等.分析了质心调节过程对行走及跨越障碍过程的影响,提出了一种基于构型重组及主被动控制结合的架空线路移动机器人控制方法.     

基于RCP的HEV动力总成控制系统

基于dSPACE数字信号处理与应用系统,通过运用快速控制原型技术(RCP)对串联式混合动力系统的多能源动力总成控制单元选择3种不同的控制策略和控制算法进行了实时仿真和系统台架试验.应用快速原型控制技术的仿真分析与台架试验表明,在串联式混合动力系统控制中,采用兼顾电池充电安全与系统能量需求的控制策略比功率跟随型和能量补偿型更适合实际系统工作的需要.     

Enhancing rice resistance to fungal pathogens by transformation with cell wall degrading enzyme genes from Trichoderma atroviride

Three genes encoding for fungal cell wall degrading enzymes (CWDEs), ech42, nag70 and gluc78 from the biocontrol fungus Trichoderma atroviride were inserted into the binary vector pCAMBIA1305.2 singly and in all possible combinations and transformed to rice plants. More than 1800 independently regenerated plantlets in seven different populations (for each of the three genes and each of the four gene combinations) were obtained. The ech42 gene encoding for an endochitinase increased resistance to sheath blight caused by Rhizoctonia solani, while the exochitinase-encoding gene, nag70, had lesser effect. The expression level of endochitinase but exochitinase was correlated with disease resistance. Nevertheless, exochitinase enhanced the effect of endochitinase on disease resistance when the two genes co-expressed in transgenics. Resistance to Magnaporthe grisea was found in all kinds of regenerated plants including that with single gluc78. A few lines expressing either ech42 or nag70 gene were immune to the disease. Transgenic plants are being tested to further evaluate disease resistance at field level. This is the first report of multiple of expression of genes encoding CWDEs from Trichoderma atroviride that result in resistance to blast and sheath blight in rice.