广义LESLIE矩阵模型的稳定年龄结构及其性质

〔1〕提出了一个描述生物种群动态的矩阵模型——广义Leslie矩阵模型。这个模型是Leslie矩阵模型的一个推广,它考虑了昆虫发育过程中个体在虫态发育历期上的差异。因此与普通Leslie矩阵模型相比,该模型更适于描述昆虫种群的动态。〔2〕对广义Leslie矩阵模型的渐近性质做了分析,给出了相应的稳定年龄结构的表达式,同时从马氏链的观点出发,给出了种群年龄结构渐近稳定或周期变化的充要条件。本文是〔2〕的继续,将给     

昆虫种群动态模拟模型

昆虫是动物界中最大的类群,与人类有着密切的利害关系。对昆虫的数量预测与符合经济和生态规律的管理,一直都被国内外列入重点研究课题。种群动态模拟是害虫管理中重要的基础工作。近十年来,关于昆虫种群动态模型的理论和实验研究进展迅速。现分别从单种种群和多种种群两个方面对国内外近些年来昆虫种群动态模拟模型的研究进展进行了概括和总结。单种种群从两个方面阐述:一是最基本的种群动态模拟模型Log istic方程的研究成果,包括方程的修正、参数的拟合与最优捕获策略等;另一个方面是对种群动态模拟常用的矩阵模型的概述,主要介绍不等期年龄组、矩阵维数的变化、矩阵维数与历期的关系、个体之间的发育差异以及发育速率差异等等对昆虫种群动态模型的影响。多种群主要从建模和模型应用两个部分对国内外研究成果进行综述。最后,对种群动态模拟模型研究的发展方向做了深入地讨论,即在原有的数据采集工作的基础上,使用面向对象程序设计语言,把各种要素包括各种物种及各种环境条件抽象成类,用消息传递来表示昆虫种群内个体与个体、昆虫种群与环境之间的相互作用,再结合先进的数学算法,建立一个直观的、操作简单的昆虫种群动态模型库,使模型结构与现实世界有最大的相似性。这样就可以实现昆虫种群动态的可视化、立体化、实时化和精确化的监测及预测。     

具有时间依赖转移率的昆虫种群的稳定性理论

研究Leslie种群的稳定性一直是种群动态研究中的重要课题。近几年,这项工作已得到比较完满的解决。考虑到昆虫个体在发育历期上的差异,〔1〕对Leslie模型进行了推广,提出了广义Leslie矩阵模型。〔2〕在转移率为常数的情况下,讨论了有关广义Leslie种群的渐近稳定性等方面的问题。本文将研究具有时间依赖转移率的广义Leslie种群的稳定性,给出一个具有时间依赖转移率的昆虫种群渐近于一个稳定的年龄分布的充分条件。     

广义LESLIE矩阵模型的渐近分析

考虑昆虫种群的不等时间间隔的虫态历期和不同个体的历期差异,沈嘉骥等提出了广义Leslie矩阵模型。这是把Leslie矩阵模型推广到昆虫种群动态研究中一个很有意义的新进展。本文拟对该模型从数学理论上进行较深入的讨论。我们将看到,它是Leslie模型数学理论的一个自然推广。先将模型转述如下,我们用年表时间单位。设考虑的昆虫种群有m个虫态。N_i(k)=(n。(k),…,nτdi(k))(τ=1,…,m;k=1,2,…)。表示第七年的第i个虫态的年龄结构,d_i是第i虫态的最长历期。第k年的种群向量为n~T(k)=(n_1~T(k),…,n_m~T(k)),它的维数     

一种模拟昆虫种群动态的改进的变维矩阵模型

提出了一种模拟昆虫种群动态的改进的变维矩阵模型,该模型以发有历期为维数,采用分解与合成的方法变维,并考虑了个体间的发育差异。经模拟检验,模型模拟结果略优于徐汝梅等（1981）变维矩阵模型的结果。     

昆虫多状态发育的生存分析

针对昆虫种群变态发育过程,本文给出了一个多状态生存函数的模型。使用生存分析的方法对模型进行丁分析。本文还对有关的生存参数如各状态的死亡风险,发育风险,年龄特征死亡率,年龄特征发育率以及状态发育历期等进行了讨论并且给出了它们的极大似然估计值。关于马铃薯块茎蛾数值例子的分析表明所提出的摸型用来描述昆虫种群的发育过程是有效的。本文的结论可以做为组建描述昆虫种群多状发育的年龄一状态特征生命表的理论基础。     

陕西不同地区栓皮栎种群年龄结构动态模型的研究

栓皮栎种群动态模型能阐明其自然种群动态的规律,揭示种群的内在机制和对种群行为进行预测。矩阵模型是一种i状态分布方法,依靠矩阵形式来处理种群的特征分布,可以模拟和预测种群中各个年龄组的数量动态和年龄结构的变化,它能够从目前已知的年龄结构及种群的生存率和生育率,来推测种群的未来年龄结构。在研究栓皮栎种群动态时,也借用该模型对栓皮栎种群各年龄组的结构和数量动态作出预测。Leslie矩阵模型就是该模型中的一种,利用该模型的理论和方法,对栓皮栎种群的自然变化过程进行了模拟和预测。结果发现,从分布中心到分布边缘,随着生境的差异,栓皮栎种群产生幼苗的年龄级、内禀增长率、生育力和幼苗的数量都发生变化,预测结果与实际反映的情况基本一致,表明Leslie矩阵模型是一种较为理想的反映种群动态的模型。模型表达形式简单,参数生态学意义确切,应用精度高,从而达到准确预测栓皮栎种群动态的目的。     

昆虫种群动态模拟方法的一点改进──三化螟种群动态模拟模型的研究

以Ｒｕｅｓｉｎｋ（１９７６）的模型为基础,根据昆虫个体一般不同步地进入下一发育阶段的状况,当昆虫各虫态发育到完成该虫态发育所需要的最低年龄级数后,假定各年龄级的昆虫种群均以一定的概率分布函数值进入下一个发育阶段,同时根据有效积温向前推进。据此,对昆虫种群动态模拟方法作了一点改进。该方法综合了已有的种群模型的优点,因而较Ｒｕｅｓｉｎｋ（１９７６）和ＣｈｉＨｓｉｎ等（１９８５）提出的方法更真实地反映了昆虫种群动态的变化规律。根据三化螟自然种群生命表的资料,分析和确定逐日存活率、逐日发育率和逐日生殖率,对三化螟种群进行逐日动态模拟和预测,同时引入环境因素对种群的控制作用,研究不同环境条件下的种群动态,经验证,模型基本能够反映田间三化螟的发生规律。     

昆虫种群的生长──扩散模型研究

根据昆虫种群生长规律和空间扩散规律,本文提出了建立昆虫种群生长-扩散统一模型的条件,并提出了12种可能的生长-扩散统一模型．其中的模型包括了指数增长（减少）,逻辑斯蒂增长和威布尔生长规律,同时包括幂率衰减,指数衰减和随机扩散等扩散规律;同时这些模型可以单独描述单一的生长过程或扩散过程。文中以水稻害虫青翘蚁形隐翘虫的扩散和种群数量消长为例,研究了文中模型的应用问题,结果表明本文的模型用于描述昆虫种群的方向性扩散一指数衰减生长的过程是合适的。     

褐飞虱种群动态的模拟模型(英文)

本文根据种群生命系统的概念和分析,组建了模拟褐飞虱(Nilaparvata lugens St(?)l)种群动态的计算机模型。该模型包括一个多列矩阵和一组差分方程。多列矩阵用于描述褐飞虱种群的龄期重叠现象及其年龄——虫态结构;差分方程用于计算种群的增长过程。在建模时,我们把10日度作为褐飞虱发育的一个年龄,用天作为模拟的时间步长,同时利用了褐飞虱特定龄期的发育速率,根据生命表数据计算的特定龄期存活率、长翅型成虫的迁飞类型及数量、雌成虫的生殖力等有关资料。经过采用福建省龙海、福州和沙县三个地方1896—1990的实际观测资料与模型的预测结果进行比较,验证了该模型的有效性和准确性;通过改变模型的主要输入变量,得到了各种不同的输出结果,由此对模型的行为及真实性作了分析。笔者认为该模型可用于进一步研究褐飞虱的生物学、生态学以及综合治理的基础,稍作改进,也可用于描述其它昆虫的种群生命系统。     

成虫期长于幼期的昆虫实验种群生殖力表参数估计模型的改进

针对昆虫的某些类群成虫期长于幼期的实际情况,利用矩阵建立了内禀增长力估计的改进型模型,使得因成虫期过长而引起的世代重叠情况下,子孙后代在母代成虫存活期内的繁殖量得到表达.对成虫期远长于幼期而引发的当代成虫生殖期间,出现的世代重叠和生殖量进行估计,使得内禀增长力rm的计算与实际较为吻合.经rm的精确值估计模型的验算,证明新模型比原模型在估计rm值时,更加接近精确值.     

Dipteran insect flight dynamics. Part 1 Longitudinal motion about hover

This paper presents a reduced-order model of longitudinal hovering flight dynamics for dipteran insects. The quasi-steady wing aerodynamics model is extended by including perturbation states from equilibrium and paired with rigid body equations of motion to create a nonlinear simulation of a Drosophila-like insect. Frequency-based system identification tools are used to identify the transfer functions from biologically inspired control inputs to rigid body states. Stability derivatives and a state space linear system describing the dynamics are also identified. The vehicle control requirements are quantified with respect to traditional human pilot handling qualities specification. The heave dynamics are found to be decoupled from the pitch/fore/aft dynamics. The haltere-on system revealed a stabilized system with a slow (heave) and fast subsidence mode, and a stable oscillatory mode. The haltere-off (bare airframe) system revealed a slow (heave) and fast subsidence mode and an unstable oscillatory mode, a modal structure in agreement with CFD studies. The analysis indicates that passive aerodynamic mechanisms contribute to stability, which may help explain how insects are able to achieve stable locomotion on a very small computational budget.     

Comparing thyroid and insect hormone signaling

Transitions between different states of development, physiology,and life history are typically mediated by hormones. In insects,metamorphosis and reproductive maturation are regulated by aninteraction between the sesquiterpenoid juvenile hormone (JH)and the steroid 20-hydroxy-ecdysone (20E). In vertebrates andsome marine invertebrates, the lipophilic thyroid hormones (THs)affect metamorphosis and other life history transitions. Interestingly,when applied to insects, THs can physiologically mimic manyfacets of JH action, suggesting that the molecular actions ofTHs and JH/20E might be similar. Here we discuss functionalparallels between TH and JH/20E signaling in insects, with aparticular focus on the fruit fly, Drosophila melanogaster,a genetically and physiologically tractable model system. Comparingthe effects of THs with the well defined physiological rolesof insect hormones such as JH and 20E in Drosophila might provideimportant insights into hormone function and the evolution ofendocrine signaling.     

A mathematical model for the motion of mechanoreceptor hairs in fluid environments.

A differential equation has been derived for the motion of the mechanosensory hairs of animals when they are stimulated by the motion of their fluid environment. Specific solutions of the equation are obtained for three states of fluid flow including steady-state sinusoidal oscillations. The model is specifically applied to crayfish sensilla in an aqueous medium, but the assumptions of the model are also shown to be valid in air for the sensory hairs of insects. The calculations are consistent with available experimental data.     

Debraining and diapause development in Manduca sexta pupae

Debraining experiments with wounded and normal controls were done at three different ages on diapausing Manduca sexta pupae of Kentucky and Illinois stocks. With early ages of both stocks debrained pupae escaped from diapause over an extended period of time, but wounded insects developed much earlier and at the same time as the normals. With later ages of Kentucky insects there was an immediate developmental response to wounding, and debrained insects showed initiation of pharate adult development over an extended period of time. With later ages of Illinois pupae both wounded and debrained animals showed an immediate developmental response. The responses of Illinois insects to debraining were shown to occur in insects overwintering under natural conditions. The results indicate that at least four endocrine states are possible for diapausing Lepidoptera pupae.     

A cell surface protein controls endocrine ring gland morphogenesis and steroid production

Identification of signals for systemic adaption of hormonal regulation would help to understand the crosstalk between cells and environmental cues contributing to growth, metabolic homeostasis and development. Physiological states are controlled by precise pulsatile hormonal release, including endocrine steroids in human and ecdysteroids in insects. We show in Drosophila that regulation of genes that control biosynthesis and signaling of the steroid hormone ecdysone, a central regulator of developmental progress, depends on the extracellular matrix protein Obstructor-A (Obst-A). Ecdysone is produced by the prothoracic gland (PG), where sensory neurons projecting axons from the brain integrate stimuli for endocrine control. By defining the extracellular surface, Obst-A promotes morphogenesis and axonal growth in the PG. This process requires Obst-A-matrix reorganization by Clathrin/Wurst-mediated endocytosis. Our data identifies the extracellular matrix as essential for endocrine ring gland function, which coordinates physiology, axon morphogenesis, and developmental programs. As Obst-A and Wurst homologs are found among all arthropods, we propose that this mechanism is evolutionary conserved.     

昆虫基质金属蛋白酶研究进展

经过长期的进化,昆虫已形成了完善的变态发育和天然免疫机制以适应自然界环境变化。在昆虫变态发育和免疫过程中产生的冗余蛋白质和瞬时蛋白质需要及时地降解,以保证变态发育和免疫反应的平衡。基质金属蛋白酶(matrix metalloproteases, MMPs)是一类能够降解基底膜和胞外基质中多数蛋白质的蛋白水解酶,也是一类参与昆虫变态发育和天然免疫调节的重要锌离子依赖型蛋白酶。MMPs可降解关键的胞外基质和肽类激素,参与变态发育过程中的组织重构及天然免疫反应强度的调节。本文重点综述了基质金属蛋白酶参与调控昆虫发育和免疫的功能,并对昆虫基质金属蛋白酶研究中存在的问题、潜在的研究方向进行了探讨。     

Peritrophic matrix proteins

The peritrophic matrix (or peritrophic membrane) lines the gut of most insects at one or more stages of the life cycle. It has important roles in the facilitation of the digestive processes in the gut and the protection of the insect from invasion by microorganisms and parasites. The traditional view of the peritrophic matrix as a relatively insert sieve, composed largely of proteins and glycosaminoglycans embedded in a chitinous matrix, is under revision as more is learned about the molecular characteristics of the peritrophic matrix proteins. This review summarizes emerging knowledge of the main protein constituents of the peritrophic matrix. The availability of the first sequences of integral peritrophic matrix proteins has coincided with the explosion of information in sequence databases. It is therefore possible to examine common structural themes in this family of proteins as well as in proteins of unknown location and function from a variety of other insects, nematodes and viruses. The review concludes with speculation about the biological functions of the proteins in this matrix.     

鳞翅目昆虫抗病毒免疫反应的研究进展

鳞翅目昆虫种类繁多,对农业生产和人类生活产生重大影响,宿主昆虫与病毒相互关系的研究对于利用病毒杀虫剂进行害虫治理和益虫病毒性疾病的预防具有重要意义.因此,鳞翅目昆虫与病毒的互作研究显得尤为重要,宿主昆虫的免疫系统在抗病毒感染过程中发挥着关键作用,对病毒产生不同程度的免疫反应.本文综述了昆虫围食膜和中肠对病毒入侵的防御作用,病毒进入体腔后昆虫所产生的细胞免疫和体液免疫反应,以及RNAi、细胞的自噬与凋亡、Toll、Imd、JAK-STAT和STING信号通路等相关的抗病毒免疫途径,并对昆虫抗病毒免疫研究的制约因素和未来鳞翅目昆虫抗病毒免疫的研究重点进行了讨论,以期为害虫的生物防治和益虫疾病的防控提供理论依据.     

Antioxidant systems in insects

Insects possess a suite of antioxidant enzymes and small molecular weight antioxidants that may form a concatenated response to an onslaught of dietary and endogenously produced oxidants. Antioxidant enzymes such as superoxide dismutase, catalase, glutathione transferase, and glutathione reductase have been characterized in insects. Water-soluble and lipid-soluble antioxidants such as ascorbate, glutathione, tocopherols, and carotenoids have not been well studied in insects but may play very important antioxidant roles. Additionally, the peritrophic matrix and trehalose may possess important antioxidant functions in insects. The enzymatic recycling of ascorbate, first noted in green plants, may also exist in insects. A greater understanding of these antioxidant systems may provide greater understanding about the ecological relationships of insects with their hosts. © 1995 Wiley-Liss, Inc.