2,066 research outputs found
蛹寄生蜂アオムシヒラタヒメバチの繁殖戦略に関連した栄養の獲得と配分と利用に関する研究
Chapter1.General Introduction Chapter2.The importance of food for female reproduction of I.naranyae Chapter3.The cost of reproduction of I.naranyae Chapter4.Food and egg production of I.naranyae Chapter5.Food and investment in egg size of I.maranyae Chapter6.Egg size and reproductive success of I.naranyae Chapter7.General conclution SUMMARY ACKNOWLEDGEMENTS REFERENCESMade available in DSpace on 2013-07-10T06:46:01Z (GMT). No. of bitstreams: 1 agr662.pdf: 2417994 bytes, checksum: def6d0ee323cabb4ad3fb2210f5a8e72 (MD5) Previous issue date: 2012-03-27Submitted by 愛 遠藤 ([email protected]) on 2013-07-10T06:46:01Z No. of bitstreams: 1 agr662.pdf: 2417994 bytes, checksum: def6d0ee323cabb4ad3fb2210f5a8e72 (MD5)主1-参1生物資源開発管理The primary aim of evolution ecology has been to explain the divergent patterns in life-history among and within animal species, Insect parasitoids are one of the most diverse groups of insects with divergent life-history strategines, and have been shown as an excellent test organism in evolutionary ecology . Also, because parasitoids often play an important role in suppressing pest populations in agriculture, revealing the life-history characteristics of parasitoids has been the primary approach to assess their importance and effectiveness in biological control of agricultural pests. Since the environment is instable in time and space, parasitoids have life history traits that are adapted to the environmental changes. Itoplectis naranyae Ashmead(Hymenoptera : Ichneumonidae)is a solitary endoparasitoid wasp that attacks a variety of lepidopterous pupae. This parasitoid is widespread and abundant in rice paddies of japan and other East Asia, where it is an important natural enemy of lepidopteran pests such as rice leaf folder. I.naranyae is typically synovigenic and produces relatively large yolk-rich enggs throughout the relatively long span; adult females must gain nutrients to sustain their activity and egg production throughout the lifetime. I.naranyae is a destructive host-feeding species; host feeding allows the female to nutrients for egg production, but hosts fed on become unsuitable for oviposition. The present thesis aims to examin: (1) the cost and benefit of different food types in adult diet of female I.naranyae; (2) the effect of adult body size on reproductive traits; (3) the factors restrict the development and nutrient carried over before adult emergence. Finally, the interaction of these lifetime traits that lead to a variable life-history strategy of I.naranyae is discussed. The longevity and fecundity of female I.naranyae were enhanced when feeding on carbohydrates; they lived more than 1.5 months with a sugar source, but no more than two weeks without it. Dissecting experiments revealed that both the egg production and maturation were improved when sufficient carbohydrates were given. The fecundity also uncreased host fluids were artificially provided. The egg production however was best enhanced when both host- and sugar feedings were allowed. In addition, the females produced larger eggs when food was sufficiently available. Female I.naranyae offered with host blood only produced relatively smaller eggs than those with carbohydrates in their diet, indicating it can modify the investment to each egg and regulate reproductive output in response to different food conditions. Curiously, the longevity of I.naranyae was shorter in the presence of hosts than those deprived of hosts, indicating the presence of a trade-off between reproduction and life expectancy, i.e., cost of reproduction. Body size of female I.naranyae positively affected their lifetime traits from different aspects. The longevity increased as the body size increased, no matter food source types or the availability of host pupae. Larger females carried more eggs in their ovary. Moreover, the body size positively affected on the size of eggs produced. Larger females tend to produce more female offspring. Although body size itself has no effects on the fitness of their offspring, larger female offspring. Although body size itself had no effects on the fitness of their offspring, larger eggs required shorter developmental time, suggesting production of large eggs is advantageous under larval competition. In this dissertation, I employed two indexes for body size of I.naranyae, which are body weight at parasitoid emergence and forewing length. Although these two parameters were significantly correlated with each other, the effects were not. The forewing length seemed to be a better predictor of body size of females I.naranyae; while in the study of fecundity and egg size, the body weight at emergence was better. Large size benefits parasitoids directly in competing fitness functions, such as survival and reproduction, but it is also assumed that large size would have negative impacts on some life-time traits, such as energy consumption, mobility and development. Forewing length is directly correlated with ability and consume of flight and other daily activities, so it would be more suitable in the test of life span. On the other hand, the body weight of an individual can directly reflect capability of resource acquiring and/or storing. Hence, it may be more suitable in the research of nutrition acquisition and allocation of parasitoids. The egg size of I.naranyae is variable, is positively correlated with hatching time and the size of the hatching larva. Becouse the super- and multi-parasites are common the field, faster development may be the superiority to overcome the competition of both inter- more in each egg. Life-history strategies of I.naranyae are complex and flexible, and they are affected by both internal (i.e. body size egg production, age) and external factors (i.e. nutrition both prey and non-prey, host availability, environment). These factors combine together and interact with each other to influence the traits throughout life time. Such flexible strategies would allow I.naranyae to cope with variable food conditions, competitive environments, and different types of hosts they develop
苯丙胺对铜绿微囊藻的生物效应研究
研究了不同浓度苯丙胺在不同条件下对铜绿微囊藻的生长及毒性效应。结果表明 ,低浓度苯丙胺在弱碱性条件下促进铜绿微囊藻的生长 ;高浓度的苯丙胺则抑制其生长。苯丙胺对铜绿微囊藻 2 4、48、72、96h的EC50 值分别为 2 4 .52、1 6 .51、1 0 .76、9.60mg/L ,且其毒性随时间的延长而增
Use of the dnaJ Gene for the Detection and Identification of All Legionella pneumophila Serogroups and Description of the Primers Used to Detect 16S rDNA Gene Sequences of Major Members of the Genus Legionella
博士論文 (Doctoral dissertation)doctoral thesi
Interactions between Chinese associations and education in postwar Singapore:A socio-economic perspective
本文以战后初期华人社团在新加坡华文教育发展中的作用为讨论的切入点 ,重点分析会馆如何重建或新办学校、筹措资金以及提供师资与领导等方面的活动。本文也将通过详细的统计资料 ,探讨会馆属下学校的董事、教师、学生及其家庭的社会经济和教育背景 ,以期厘清华文教育、会馆以及社会经济变迁这三者之间交错复杂的关系。This paper examines the interactions between clan associations and education in Singapore, with a focus on the 1945-1954 period. By using rich statistics data from the clan associations/school publications, this paper establishes the patterns of their close interplay and the socio-economic background of the school teachers/pupils. It concludes that Chinese schools epitomized of the heterogeneous nature of Singapore Chinese community and constituted the fertile ground for socialization and identity formation, which underwent a localization process during the period under consideration
对我国投资体制改革的理论思考
一、新制度经济学———对我国投资体制变迁的思考在回答关于经济增长的推动因素是什么这个问题上,传统的西方经济增长理论把技术进步、物质资本的投资以及人力资本的投资,视为经济增长的主要源泉。与传统经济理论不同,新制度经济学将制度因素纳入到经济模型之中,认为..
Transition Economy, Restructuring and Corporate Governance
本文将企业重组置于经济体制转轨的大背景下来加以研究,把企业重组模式与公司治理结构有机的融合起来,探讨了转轨经济中企业重组的主要模式面临的问题、障碍、应用前景,是结合国情对企业重组模式进行研究探讨的一次尝试。与西方学者对企业重组模式的分类不同,基于转轨经济的特征,本文将我国企业重组的模式分为扩张型、收缩型和治理型三大类。全文共分五章,各章内容分述如下: 第一章为“经济转轨与企业重组”。在界定企业重组内涵的基础上,研究了我国企业重组的动因、类型和基本特征。鉴于政府在企业重组中的重要作用,本章进一步分析了经济转轨期企业重组中的政府行为。 第二章为“扩张型企业重组模式”。在市场经济发达的国家里,兼...China is in the transition from Planned Econnomy to Market Economy. Enterprise restrcturing especially state-owned enterprise restructuring is now arising more and more people's attention. What kinds of characteristic does enterprise restructuring have in Transition Economy? What are the main problems? What kinds of modes have been formed in China? And what kinds of enlightenments should we take f...学位:经济学博士院系专业:经济学院财政金融系_财政学(含税收学)学号:B19981201
On architectural style of Taiwan local based on architectural semiotic
对符号学、符号学在建筑上的应用、符号学的层次等进行了介绍,研究了符号学的观点,指出结构符号学的理论产生跟后现代建筑的兴起有着相辅相成的关系,通过对建筑符号的理论分析,帮助人们认识建筑的文化意涵及设计策略。The author introduces semiotic,application of semiotic on architecture,levels of semiotic,etc.,studies view of semiotic,points out that the theory production of structural semiotic has complementary relationship with the development of post-modern architecture,based on the theory analysis of architectural semiotic,helps the people recognize the culture significance and design scheme of the architecture
An Inquiry into the Unstable Factors in the Renminbi Exchange Rate Regime and the Effectiveness of Monetary Policy
现行人民币汇率制度是与美元挂钩的固定汇率制度 ,这种固定汇率制度具有内在的不稳定性 ,缺乏烫平汇率波动的功能 ,一定程度上削弱了央行货币政策效力。因此 ,对现行人民币汇率制度 ,应从政策上进行调整。The existing Renminbi exchange rate regime is a fixed exchange rate regime pegge d at the US dollar, which is inherently unstable, lacks the function of ironing out exchange rate fluctuations and, to some extent, weakens the effectiveness of the central bank's monetary policy. Therefore, policy adjustments should be mad e to the present Renminbi exchange rate regime
论我国利率平价机制的制度约束及表现形式
人民币实际汇率与利率平价理论对人民币汇率所做预测并不契合,原因在于我国的利率平价机制受三大制度约束:利率管制性强、国际资本的有限流动性和人民币汇率缺乏有效波动。当前,我国利率平价机制调节利率、汇率和国际资本流动之间相互关系的作用还十分微弱,在现有制度约束下还尚不具备完善利率平价机制发挥作用所要求的条件,改善制度环境是解决问题的关键所在
Theoretical Studies of Carbon/Phosphor Binary Cluster Anion
本文对碳/磷二元原子团簇负离子CnPm-(m=1-5,n=1-7)进行了系统的研究,在结构和能量的分析和比较中,探讨并总结出结构规律,很好地解释了碳/磷二元原子团簇飞行时间质谱图的奇偶变化规律。本文的计算结果将为进一步理论研究提供依据,可望为新型二元原子团簇材料的合成提供线索。 根据m大小分五个系列进行研究,分别为CnP-(n=2-7)、CnP2-(n=1-7)、CnP3-(n=2-8)、CnP4-(n=1-7)、CnP5-(n=1-7)。在每个系列中首先用分子图形软件设计出多种CnPm-的结构模型,并进行B3LYP密度泛函几何构型优化和振动频率计算。通过同分异构体总能量比较,确定基态结构;...In this paper, we carried out systematic study about C/P binary non-metal cluster anion CnPm-(m=1-5, n=1-7). In the way of analysis and compare of the structures and energies, we discuss and summarize the structural rules, and the result can interpret the parity alternation in the time-flight mass spectra of C/P anions binary cluster. The outcome can serve as helpful guidelines for the further stu...学位:理学硕士院系专业:化学化工学院化学系_物理化学(含化学物理)学号:20002506
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