昆虫种群生命系统研究的状态方程

应用状态空间法研究系统的控制,不仅有利于把系统划分为若干组分或子系统对各种因子分别进行动态描述,同时更好地解决多输入和多输出的研究技术,因而有可能成为种群生命系统控制研究的重要手段。本文拟通过网络模型着重讨论适应于昆虫种群研究的状态空间方程的建立问题。     

应用杀虫剂防治白背飞虱对褐稻虱种群数量的影响

本文应用昆虫生命表方法和干扰作用控制指数探讨噻嗪酮（扑虱灵）、叶蝉散、喹硫磷三种杀虫剂对白背飞虱种群的控制作用以及及防治白背飞虱对随后发生的褐稻虱种群数量发展趋势的影响。试验结果表明，主要作用于同翅目昆虫而不杀伤在敌的噻嗪酮，对两种飞虱的效果明显， 对害虫及天敌同样起作用的喹硫磷，反而引起这两种害虫种群数量上升，广谱性的杀虫剂不宜在稻地早期大面积应用。     

控制指数在水稻抗褐稻虱研究中的应用

应用昆虫生命表方法及害虫种群趋势控制指数,对新惠占1号等5个水稻品种对褐稻虱的田间抗性进行了研究,并与温室苗期抗性测定结果相印证,确定新惠占1号和“7915”为抗性品种,七桂早25、玻惠占1号为中抗品种,双桂1号为感虫品种。指出害虫种群趋势控制指数是测定和评价水稻品种抗虫性的重要指标。     

植物自身控制害虫的作用

本文介绍了植物与昆虫之间的关系、植物杀虫剂最近研究的进展、植物抗虫性的化学及其在抗虫育种中的作用、植物对昆虫的主动防御及其在害虫防治中应用的展望。主要从生物化学及生态学方面进行讨论,指出这四个问题具有内在的联系。对植物杀虫剂的探入研究,今后可能获得对环境安全而对害虫不产生抗药性的新一代农药。研究作物抗虫的遗传基因,可以培育出高抗优良品种。对于植物对害虫主动防御的探索,可以在害虫预测预报上获得新的进展。作者认为在我国开展植物自身控制害虫作用的研究具有深远的意义,将可使害虫综合防治获得划时代的突破。     

不同措施对稻纵卷叶螟防治效果的评价

本文通过考察防治对象(稻纵卷叶螟)、非防治对象(飞虱类)和稻田天敌的种群变动情况,综合评价几种措施对稻纵卷叶螟的防治效果。 试验应用昆虫生命表方法和定期的田间调查。结果表明,广谱性杀虫剂甲六粉、乙六粉由于严重杀伤天敌,不但没有控制稻纵卷叶螟的为害,反而助长了其他害虫(飞虱类)的数量,防治效果较差。散放赤眼蜂,提高了卵寄生率,相应地提高了以后各期的天敌作用,使稻纵卷叶螟的数量得到有效地控制,防治效果较好。杀虫脒对稻纵卷叶螟高效,对天敌比较安全,因而有效地控制稻纵卷叶螟的为害,降低飞虱类的虫口密度,防治效果远胜于甲六粉,杀虫双也有一定的选择性,对天敌的影响较乙六粉小,较杀虫脒稍大。 通过分析可知,单纯以作用虫期的死亡率和校正死亡率评价防治效果是不够全面的,防治效果应该综合考虑一种措施在经济上和生态上的效益。应用昆虫生命表的方法,有助于了解害虫的种群趋势和天敌的控制作用。在此基础上,辅以对生态系统中其他害虫,天敌数量的调查研究,能够对防治措施作出较全面的评价,为制订合理的综合防治策略提供可靠的依据。     

水4稻品种抗性对褐稻虱自然种群控制作用的评价

在水稻品种抗性对褐稻虱种群的控制作用研究中,大多数材料是在实验种群的试验中获得的,本文应用控制指数分析方法把实验种群的试验结果与自然种群的重要作用因子组合起来,对水稻品种抗性对褐稻虱自然种群的作用进行综合评价,结果说明,品种抗性作用于若虫存活率,与天敌的作用起着相辅相成的作用;而品种抗性对成虫繁殖力的影响,与捕食性天敌引起的成虫非正常死亡的共同作用,对褐稻虱种群后代卵量起着重要的控制作用。分析结果进一步明确品种抗性在种群系统控制中的优点,并为作物品种抗虫性对害虫自然种群作用的评价提供参考。     

捕食性天敌对褐稻虱种群的控制作用

本文将集中作用于褐稻虱若虫和成虫期的稻田捕食性天敌归纳为4个类群、分别作用于褐稻虱种群1～2龄若虫、3～5龄若虫和成虫3个状态,应用五因子二次回归正交旋转组合设计方法进行试验,结合生命表资料,建立褐稻虱这3个状态的控制指数方程,通过状态空间分析法和控制指数的综合分析,结果表明,稻田捕食性天敌对褐稻虱种群的控制作用是明显的。     

生物农药白僵菌原药急性毒性实验

白僵菌(beauvtria bassiana)是当今世界上防治害虫应用较广的一种虫生真菌，对多种农林害虫具有致死作用。为了解白僵菌原药的毒性情况对其进行了急性毒性和致敏试验。     

昆虫种群控制系统的信息处理（二）：多种群共存系统的信息处理问题

在昆虫种群控制系统中,往往遇到多种捕食性天敌共同作用于对象种群的问题。每一种天敌的作用,与本身的密度有关,与对象种群的密度有关,与其他被捕食者的密度有关,还有各种天敌相互作用的情况。在这种情况下如何提取控制作用的信息,这是昆虫种群系统研究中较难解决的问题。本文应用二次回归旋转组合设计,通过3种天敌2种害虫相互作用的试验,建立多种群共存系统相互作用模型,提出多种群共存系统信息处理的研究途径,为多种群共存系统及昆虫种群系统的控制研究提供参考。     

异小杆线虫生物学特性及人工繁殖的研究简报

近年来,国外对昆虫病原线虫进行了较多的研究,Bedding,R. A.(1981)应用异小杆线虫防治葡萄象(虫甲)害虫取得了一定成效。由于较好地解决了线虫低成本的人工大量繁殖问题,使昆虫病原线虫成为害虫生物防治剂的可能性更加明朗。在我国,广东省昆虫研究所对引进的昆虫病原线虫Neoaplectana spp.进行了保种、人工繁殖及应用的研究,也取得了一定的成果。但对国内的异小杆线虫尚未见有正式的研究报道。为开     

杀虫剂对褐稻虱种群控制作用的评价

本文应用干扰作用控制指数分析不同类型杀虫剂对褐稻虱的作用.褐稻虱繁殖力强,天敌作用明显,试验结果说明,广谱性杀虫剂喹硫磷,由于对天敌作用的明显干扰,干扰作用控制指效值达2.69倍。即其下代数量将为对照的2.69倍;特异性杀虫剂扑虱灵,对褐稻虱的作用明显,对其天敌比较安全,其干扰作用控制指数值为0.37。即其下代数量明显下降,收到良好效果,干扰作用控制指数表达了杀虫剂对害虫种群的控制作用、包括对天敌干扰作用的总体效果。特异性杀虫剂在解决有害生物协调管理将会起着良好的作用。     

对社区流动人口结核病管理的循证评价

目的调查分析社区流动人口结核病管理和治疗措施,并对其进行系统评价,考察结核病控制管理的效果,为专门针对流动人口制定科学可行的干预方案,亦为进一步探索和更新流动人口结核病管治策略提供可靠依据。方法计算机检索中同医院数字图书馆、万方医学网及中国知网等数据库和手工检索有关医学期刊、专著;纳入1998—2010年发表的关于流动人门结核病治疗、管理、护理干预的文献;同时采用非慨率目的性抽样方法,在获得访谈对象知情同意后进行现场访谈。结果共检索到符合纳入标准的已发表文献137篇,通过查看全文,最后评价为1级证据9篇,2,3级15篇。从纳入评价的文献及访谈结果显示：运用各种有效的管理措施包括健康促进、提供激励机制、跨区域转诊追踪、对病人实行DOTS管理等,均取得一定的效果;但流动人口对结核病相关知识和免费治疗政策了解有限,看法不一,结核病防治的意识较差,居住不稳定,缺乏有效的联系方式,致使对流动人口的追踪督导刚难,流动结核病人的管理亟待加强。结论有必要对流动病人扩大免费治疗及相应的费用补贴,丌展全方化、多形式的社区防痨知识及旧家对结核病控制政策的宣传,加强社区结核病督导的力度．开展个体化循环且动式的健康教育,提高结核病人遵医的依从性。     

Integration of Genotoxic and Population Genetic Endpoints in Biomonitoring and Risk Assessment

Genetic ecotoxicology is a multifaceted discipline that examines the effects of xenobiotic compounds on the structure and function of DNA. This paper discusses the role of genetic ecotoxicology in environmental biomonitoring and risk assessment. Genetic ecotoxicology may include somatic effects (e.g., DNA damage) or population genetic effects (changes in genetic diversity or gene frequencies). Traditionally, genetic ecotoxicology studies have focused on either one of these sub-disciplines, but integration of these two approaches would be advantageous for three reasons. First, at the population level, concordant responses between changes in population genetic structure and elevated levels of DNA damage may provide evidence that the population genetic changes are influenced by exposure to genotoxic chemicals. Second, if the frequencies of alleles or other genetic markers differ between genotoxicant-contaminated and reference populations, associations between relative amount of DNA damage and genotype may provide evidence that these changes are due to genotoxicant-induced selection. Third, genetic analysis of gene flow may provide insight into patterns of dispersal that could obscure differences between contaminated and reference populations. In order to demonstrate the application of these ideas, three lines of research are summarized herein. The first is a series of studies that focus on radionuclide-contaminated populations of mosquitofish (Gambusia). This research identified RAPD markers that may be indicative of genetic adaptation to radionuclide stress. Relative amounts of DNA damage among genotypes presented evidence that these markers may be indicators of relative radioresistance. The second study examined DNA damage and population genetic structure in radionuclide-contaminated kangaroo rat (Dipodomys) populations. It was found that between-population differences in genetic diversity paralleled those for DNA damage and relative levels of contamination. Also, population genetic analysis indicated that there was dispersal between contaminated and reference populations, and that between-population differences in the amount of DNA damage could not be detected until this dispersal was taken into account. In the third study, populations of redbreast sunfish (Lepomis auritis) from streams contaminated with complex mixtures of industrial chemicals were examined. It was found that the genetic distances between populations within the contaminated stream corresponded with the relative magnitude of molecular and community-level effects. It was concluded that genetic ecotoxicology could make significant contributions to the fields of environmental biomonitoring and ecological risk assessment, and that integration of genotoxicology and population genetic studies would be a definite advantage toward this end.     

Bioenergetics-based matrix population modeling enhances life-cycle toxicity assessment of tilapia Oreochromis mossambicus exposed to arsenic

The objective of this study was to integrate a bioenergetics-based modeling approach into a population stage structure to enhance life-cycle toxicity assessments of the effects of waterborne arsenic (As) on the population dynamics of the tilapia Oreochromis mossambicus. The proposed mathematical model links a Leslie matrix population model and a universal ontogenetic growth model embedding the population-level growth rate and stage-specific modes of toxic action. We present data analyses of key parameters and distributions and discuss the processes of data capture and analysis and the impact of acute/chronic As toxicity responses on population-level effects. We employed a three-parameter Hill equation model to describe the relationship between tilapia whole-body burden and mortality in order to estimate the probability of stage-specific vital rate of survival. Using the DEBtox theory, we distinguished three modes of toxic action (MOA): direct effects on growth and indirect effects via maintenance and food consumption on inhibition by arsenic of the growth of a tilapia population. The asymptotic population growth rate decreased from lambda = 1.0027 for the control group to lambda = 0.9935 for tilapia population exposed to 4 microg mL(-1) As, indicating a potential risk of population intrinsic growth rates for tilapia exposed to higher levels of waterborne As. Our results estimated that an As concentration of 1.02 microg mL(-1) would cause a 50% reduction in the tilapia population. We found that the interplay between external stressors of waterborne As concentration and internally generated modes of action decreasing feeding in the juvenile stage and increasing the maintenance cost in the adult stage had a pronounced influence on the population stage structure of tilapia.     

Capturing ecology in modeling approaches applied to environmental risk assessment of endocrine active chemicals in fish

Endocrine active chemicals (EACs) are widespread in freshwater environments and both laboratory and field based studies have shown reproductive effects in fish at environmentally relevant exposures. Environmental risk assessment (ERA) seeks to protect wildlife populations and prospective assessments rely on extrapolation from individual-level effects established for laboratory fish species to populations of wild fish using arbitrary safety factors. Population susceptibility to chemical effects, however, depends on exposure risk, physiological susceptibility, and population resilience, each of which can differ widely between fish species. Population models have significant potential to address these shortfalls and to include individual variability relating to life-history traits, demographic and density-dependent vital rates, and behaviors which arise from inter-organism and organism–environment interactions. Confidence in population models has recently resulted in the EU Commission stating that results derived from reliable models may be considered when assessing the relevance of adverse effects of EACs at the population level. This review critically assesses the potential risks posed by EACs for fish populations, considers the ecological factors influencing these risks and explores the benefits and challenges of applying population modeling (including individual-based modeling) in ERA for EACs in fish. We conclude that population modeling offers a way forward for incorporating greater environmental relevance in assessing the risks of EACs for fishes and for identifying key risk factors through sensitivity analysis. Individual-based models (IBMs) allow for the incorporation of physiological and behavioral endpoints relevant to EAC exposure effects, thus capturing both direct and indirect population-level effects.     

建立阿奇霉素在中国健康人群中的群体药代动力学模型

目的建立中国人群中阿奇霉素(大环内酯类抗生素)的群体药代动力学模型。方法对20例健康自愿者的血药浓度和生化指标,用非线性混合效应模型法进行群体药代动力学分析,估算药代动力学参数,分析固定效应的影响以及个体内/间的变异,建立群体药代动力学模型。结果口服阿奇霉素呈一级吸收的二室模型,体质量对CL1和CL2及年龄对V1均有影响。结论用非线性混合效应模型法建立的中国人群中阿奇霉素的群体药代动力学模型,结构稳定,预测准确。