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中国中生代昆虫化石研究新进展 总被引:6,自引:0,他引:6
回顾了1990年以来中国中生代昆虫化石研究的新进展,简述了我国学者在古昆虫分类学、昆虫内部形态学、昆虫系统学、古生态学、昆虫生物地层学、昆虫区系的历史演变、生物古地理学、昆虫与植物的关系等8个方面取得的突出贡献,并给出了我国发现的世界最低层位昆虫科级类群表。 相似文献
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中国昆虫区系的多元相似性聚类分析和地理区划 总被引:3,自引:0,他引:3
为了总结分析中国昆虫的分布规律, 为昆虫地理区划提出依据, 作者2008年创建了新的多元相似性聚类分析方法, 它与传统的聚类分析方法的主要不同是直接计算任意多个地区之间的相似性系数, 从而摈弃原来的合并环节。我们应用这种方法对中国823科17 018属93 662种昆虫的分布进行了定量分析。当种级水平相似性系数分别为0.19和0.14时, 全国64个基础地理单元聚类为20个小单元群和9个大单元群。根据聚类分析结果, 提出我国第一个由定量分析产生的9个昆虫区20个昆虫亚区的中国昆虫地理区划的初步方案。西北昆虫区、 东北昆虫区、 华北昆虫区、 青藏昆虫区稳定地组成中国北方昆虫大区, 江淮昆虫区、 华中昆虫区、 西南昆虫区、 华东昆虫区、 华南昆虫区稳定地组成中国南方昆虫大区。江淮昆虫区的设立是因为这里多平原和丘陵, 为重要农业区, 昆虫区系简单, 种类显著少于华东、 华中、 华南昆虫区, 而和华北昆虫区相当; 包括台湾在内的华东昆虫区是昆虫多样性最丰富地区之一, 显著高于邻近的华北、 江淮、 华南昆虫区。最后, 对昆虫地理定量分析中的重要环节进行讨论, 还对今后昆虫区系调查的薄弱地区提出建议。这项研究证明多元相似性聚类分析方法是简便、 快捷、 实用的, 能够在更广泛的范围应用, 这预示着生物地理学研究将会由定性研究进入到定量研究阶段。 相似文献
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《环境昆虫学报》2014,(5):805-813
昆虫是变温动物,温度对其生长发育、基本行为及进化途径都会产生很大的影响,种群的繁衍面临如何安全度过漫长而寒冷的冬季的挑战。通过长时间的进化,昆虫获得一系列完整的耐寒策略。绝大多数的昆虫都是耐寒昆虫,在陆地寒冷温度刺激下,昆虫受抗寒基因的调控,体内产生大量抗寒物质,如海藻糖、甘油、山梨醇、抗冻蛋白、热激蛋白等,提高昆虫的耐寒能力,使其得以在低温寒冷的条件下成功越冬。同样,经过冷驯化后的昆虫能显著提高昆虫的耐寒力。近年来,关于昆虫耐寒性、抗寒类蛋白的研究不断开展,研究内容涉及昆虫的耐寒性、抗寒基因HSPs和AFPs的调控、冷驯化诱导抗寒等方面。本文综述了昆虫耐寒性、主要耐寒策略及冷驯化诱发昆虫耐寒性增强等研究内容。有助于全面认识昆虫耐寒性及其作用机制,为天敌昆虫低温储存和提高生物防治等应用打下坚实的基础。 相似文献
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昆虫标本馆建设与昆虫系统学的未来 总被引:6,自引:0,他引:6
昆虫标本馆是昆虫标本的保藏、研究和科学教育的实体,代表国家或者区域水平,致力于研究昆虫多样性、揭示昆虫进化规律,为国民经济建设持续发展服务。昆虫系统学研究是昆虫标本馆研究人员的主要任务,它的发展与昆虫标本馆的建设唇齿相依。本文阐述了昆虫标本馆的功能与作用,建设昆虫标本馆的重要性和迫切性;展望了昆虫系统学的未来以及昆虫系统学发展的机遇。 相似文献
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基因组序列为昆虫分子生物学研究提供丰富的数据资源,推动系统生物学在古老的昆虫学中蓬勃发展。昆虫基因组学研究已经成为当前的研究热点,目前在NCBI登录注册的昆虫基因组测序计划有494项,其中已提交原始测序数据的昆虫有225种,完成基因组拼接的有215种,具有基因注释的有65种,公开发表的昆虫基因组有43篇。本文综述了测序技术发展的历史及其对昆虫基因组研究的推动作用、昆虫基因组的组装和注释及其存在的问题、昆虫基因组测序进展、昆虫基因组数据库的发展及基因数据挖掘利用的基本思路和对策,以及昆虫基因大数据在害虫防治和资源昆虫利用中的应用前景。 相似文献
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Myzostomids are minute, soft-bodied, marine worms associated with echinoderms since the Carboniferous. Due to their long history
as host-specific symbionts, they have acquired a highly derived body plan that obscures their phylogenetic affinities to other
metazoans. Because certain organs are serially arranged a closer relationship between polychaetes and myzostomids has repeatedly
been discussion. We presented here a review on the ultrastructure of myzostomids with the most recent analyses that concern
their phylogenetic position. The ultrastructure of the integument, digestive system, excretory system and nervous system are
summarized. Unpublished information on the gametogenesis and reproductive systems of myzostomids are also exposed with a view
on their reproductive process. 相似文献
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In this article, we review how two eminent Viennese system thinkers, Paul A Weiss and Ludwig von Bertalanffy, began to develop their own perspectives toward a system theory of life in the 1920s. Their work is especially rooted in experimental biology as performed at the Biologische Versuchsanstalt, as well as in philosophy, and they converge in basic concepts. We underline the conceptual connections of their thinking, among them the organism as an organized system, hierarchical organization, and primary activity. With their system thinking, both biologists shared a strong desire to overcome what they viewed as a "mechanistic" approach in biology. Their interpretations are relevant to the renaissance of system thinking in biology--"systems biology." Unless otherwise noted, all translations are our own. 相似文献
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Yong VW 《Nature reviews. Neuroscience》2005,6(12):931-944
The matrix metalloproteinases and related A disintegrin and metalloproteinase enzymes are implicated in various diseases of the nervous system. However, metalloproteinases are increasingly being recognized as having beneficial roles during nervous system development and following injury. This review discusses general principles that govern the expression of metalloproteinases in the nervous system and their detrimental outcomes. It then focuses on the roles of metalloproteinases and their mechanisms in regulating neurogenesis, myelin formation and axonal growth. It is clear that metalloproteinases are important determinants in enabling recovery from injury to the nervous system. 相似文献
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Eric Cascales Susan K Buchanan Denis Duché Colin Kleanthous Roland Lloubès Kathleen Postle Margaret Riley Stephen Slatin Danièle Cavard 《Microbiology and molecular biology reviews》2007,71(1):158-229
Colicins are proteins produced by and toxic for some strains of Escherichia coli. They are produced by strains of E. coli carrying a colicinogenic plasmid that bears the genetic determinants for colicin synthesis, immunity, and release. Insights gained into each fundamental aspect of their biology are presented: their synthesis, which is under SOS regulation; their release into the extracellular medium, which involves the colicin lysis protein; and their uptake mechanisms and modes of action. Colicins are organized into three domains, each one involved in a different step of the process of killing sensitive bacteria. The structures of some colicins are known at the atomic level and are discussed. Colicins exert their lethal action by first binding to specific receptors, which are outer membrane proteins used for the entry of specific nutrients. They are then translocated through the outer membrane and transit through the periplasm by either the Tol or the TonB system. The components of each system are known, and their implication in the functioning of the system is described. Colicins then reach their lethal target and act either by forming a voltage-dependent channel into the inner membrane or by using their endonuclease activity on DNA, rRNA, or tRNA. The mechanisms of inhibition by specific and cognate immunity proteins are presented. Finally, the use of colicins as laboratory or biotechnological tools and their mode of evolution are discussed. 相似文献
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The notion of an evolutive hierarchical system proposed in this paper is a mathematical model for systems, like organisms,
with more or less complex objects. This model, based on category theory, retains the following characteristics of natural
systems: they have an internal organization consisting of components with interrelations; they maintain their organization
in time though their components are changing; their components are divided into several levels corresponding to the increasing
complexity of their own organization, and the system may be studied at any of these levels (e.g. molecular, cellular...).
The state of the system at a given instant is modeled by a category whose objects are its components, the state transition
by a functor, a complex object by the (direct) limit of a pattern of linked objects (which describes its internal organization).
The properties of limits in a category make it possible to ‘measure’ the emergence of properties for a complex object with
respect to its components, and to reduce the study of a hierarchical system to that of its components of the lowest degree
and their links. Categorical constructions describe the formation of a hierarchical evolutive system stepwise, by means of
the operations: absorption of external objects, destruction of some components, formation of new complex objects. 相似文献
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Wolfgang Stein 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2009,195(11):989-1009
Neuromodulation by peptides and amines is a primary source of plasticity in the nervous system as it adapts the animal to
an ever-changing environment. The crustacean stomatogastric nervous system is one of the premier systems to study neuromodulation
and its effects on motor pattern generation at the cellular level. It contains the extensively modulated central pattern generators
that drive the gastric mill (chewing) and pyloric (food filtering) rhythms. Neuromodulators affect all stages of neuronal
processing in this system, from membrane currents and synaptic transmission in network neurons to the properties of the effector
muscles. The ease with which distinct neurons are identified and their activity is recorded in this system has provided considerable
insight into the mechanisms by which neuromodulators affect their target cells and modulatory neuron function. Recent evidence
suggests that neuromodulators are involved in homeostatic processes and that the modulatory system itself is under modulatory
control, a fascinating topic whose surface has been barely scratched. Future challenges include exploring the behavioral conditions
under which these systems are activated and how their effects are regulated. 相似文献
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Abnormalities in the awareness and control of action 总被引:19,自引:0,他引:19
Frith CD Blakemore SJ Wolpert DM 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2000,355(1404):1771-1788
Much of the functioning of the motor system occurs without awareness. Nevertheless, we are aware of some aspects of the current state of the system and we can prepare and make movements in the imagination. These mental representations of the actual and possible states of the system are based on two sources: sensory signals from skin and muscles, and the stream of motor commands that have been issued to the system. Damage to the neural substrates of the motor system can lead to abnormalities in the awareness of action as well as defects in the control of action. We provide a framework for understanding how these various abnormalities of awareness can arise. Patients with phantom limbs or with anosognosia experience the illusion that they can move their limbs. We suggest that these representations of movement are based on streams of motor commands rather than sensory signals. Patients with utilization behaviour or with delusions of control can no longer properly link their intentions to their actions. In these cases the impairment lies in the representation of intended movements. The location of the neural damage associated with these disorders suggests that representations of the current and predicted state of the motor system are in parietal cortex, while representations of intended actions are found in prefrontal and premotor cortex. 相似文献
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Eric Cascales Susan K. Buchanan Denis Duch Colin Kleanthous Roland Lloubs Kathleen Postle Margaret Riley Stephen Slatin Danile Cavard 《Microbiological reviews》2007,71(1):158-229
Colicins are proteins produced by and toxic for some strains of Escherichia coli. They are produced by strains of E. coli carrying a colicinogenic plasmid that bears the genetic determinants for colicin synthesis, immunity, and release. Insights gained into each fundamental aspect of their biology are presented: their synthesis, which is under SOS regulation; their release into the extracellular medium, which involves the colicin lysis protein; and their uptake mechanisms and modes of action. Colicins are organized into three domains, each one involved in a different step of the process of killing sensitive bacteria. The structures of some colicins are known at the atomic level and are discussed. Colicins exert their lethal action by first binding to specific receptors, which are outer membrane proteins used for the entry of specific nutrients. They are then translocated through the outer membrane and transit through the periplasm by either the Tol or the TonB system. The components of each system are known, and their implication in the functioning of the system is described. Colicins then reach their lethal target and act either by forming a voltage-dependent channel into the inner membrane or by using their endonuclease activity on DNA, rRNA, or tRNA. The mechanisms of inhibition by specific and cognate immunity proteins are presented. Finally, the use of colicins as laboratory or biotechnological tools and their mode of evolution are discussed. 相似文献