首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 623 毫秒
1.
This paper is based on the author’s lecture presented at the conference Theoretical and Applied Entomology: Past, Present and Future, dedicated to the 150th anniversary of the Russian Entomological Society, which took place on April 2, 2009 in St. Petersburg. The lecture suggested a definition of the concept “experimental entomology” and listed the most popular research objects. A brief historical review of the origin and development of some trends in experimental entomology in the XX and XXI centuries in Russia was given. Special attention was paid to the contribution of Acad. L.A. Orbeli and his ideas concerning evolution of functions and functional evolution as well as to the importance of ideas of his collaborators and followers, G.V. Gershuni, L.G. Leibson and A.L. Polenov, in developing a number of present directions of experimental entomology. These classic and ultramodern directions include comparative genetics of behavior (M.E. Lobashev, A.K. Voskresenskaya, N.G. Lopatina, I.A. Nikitina, V.B. Savvateev, V.V. Ponomarenko, N.G. Kamyshev), genetics of higher nervous activity (N.G. Lopatina), neurogenetics (E.V. Savvateeva-Popova), biorhythmology (ecological concept of photoperiodism—A.S. Danilevsky, investigation of the physiological mechanisms of photoperiodic adaptations—V.P. Tyshchenko), immunology (S.I. Chernysh), neuroendocrinology and mechanisms of stress (I.Yu. Raushenbach, S.I. Chernysh, G.V. Ben’kovskaya), psychoneuroendocrinology (the hypothesis of “dynamic neuroendocrine integration”—A.N. Knyazev), etc. A special place in the lecture was assigned to sensory physiology of insects and, first of all, to the series of monographs by F.G. Gribakin, Yu.A. Elizarov, G.A. Mazokhin-Porshnyakov, R.D. Zhantiev, A.V. Popov, V.L. Svidersky, A.V. Skirkyavichus, L.I. Frantsevich awarded the USSR State Prize in 1987. The origin of a novel field, cognitive ethology (Zh.I. Reznikova) that emerged at the intersection of ethology, ecology, theory of evolution, and comparative psychology is noted in the final part of the lecture.  相似文献   

2.
This review considers studies carried out for the last few years, which confirms and develop the ideas of Prof. V.S. Il'in about biochemical principles of nervous trophics. These principles have been experimentally substantiated in the works of researchers of the Department of Biochemistry of the Institute of Experimental Medicine as early as in the 1960–1970s.  相似文献   

3.
The organization level of Precambrian fossils is the most reliable indicator of the state and parameters of the biosphere, such as the atmosphere composition, average temperature of the earth’s surface, and others. At present, cyanobacteria, unicellular and multicellular eukaryotes, and coelomates are considered to appear in the geological history of the Earth much earlier than it was supposed previously. Our knowledge and ideas of the early Earth are very important for considering the problems of the origin of life. A key boundary of the earliest period was probably about 4 Ga. This boundary is between the periods documented and undocumented by the geological record. The Earth history and probable surface conditions before 4 Ga are considered by L.M. Mukhina, A.V. Vityazeva, G.V. Pechernikova, and L.V. Ksanfomaliti in this volume.  相似文献   

4.
Limnology—the science about lakes—is the young and relatively closed area of studies; its existence is owing to several hundreds of scientists. The International Society of Limnologists holds its meetings since 1922. We used materials of these meetings to find out the main stages of development of this science; among these stages there were both fast and relatively calm periods. Based on analysis of these data, we constructed a model of development of the science, the same data being used for tuning and verification of the model. We have suggested that the main regularities and mechanisms of development of limnology can be extrapolated to other sciences. The main “acting person” in the model is population of scientists. Each scientist, with some probability, can propose new ideas as well as use in his studies some particular complex of the already accumulated knowledge and ideas. The model also takes into consideration how the scientific information is spreading, as well as some individual peculiarities of model scientists, such as age, experience, communicability. After the model parameters had been chosen in such a way that is described adequately development of limnology, we performed a series of experiments by changing some of the characteristics and obtained rather unexpected results published preliminary in the short work (Levchenko, V.F. and Menshutkin, V.V., Int. J. Comput. Anticip. Syst., 2008, vol. 22, pp. 63–75) and discussed here in the greater detail. It is revealed that development of science occurs irregularly and is sharply decelerated at low level of communication between scientists and the absence of scientific schools, while the age of “scientific youth” of scientist usually begins only after 40 years.  相似文献   

5.
Limnology--the science about lakes is the young and relatively closed area of studies; its existence is owing to several hundreds of scientists. The International Society of Limnologists holds its meetings since 1922. We used materials of these meetings to find out the main stages of development of this science; among these stages there were both fast and relatively calm periods. Based on analysis of these data, we constructed a model of development of the science, the same data being used for tuning and verification of the model. We have suggested that the main regularities and of development of limnology can be extrapolated to other sciences. The main "acting person" in the model is population of scientists. Each scientist, with some probability, can propose new ideas as well as use in his elaborations some particular complex of the already accumulated knowledge and ideas. The model also takes into consideration how the scientific information is spreading, specifically some individual peculiarities of model scientists, such as age, experience, communicability. After the model parameters had been chosen in such a way that is described adequately the development of limnology, we performed a series of experiments by changing some of the characteristics and obtained rather unexpected results published preliminary in the short work (Levchenko V. F and Menshutkin V. V. Int. J. Comp. Anticip. Syst., 2008, vol. 22, p. 63-75) and discussed here in the greater detail. It is revealed, that the development of science is passing irregularly and sharply decelerated at low level of scientists communication and absence of scientific schools, and that the age of "scientific youth" of scientist begins usually only after 40 years.  相似文献   

6.
Macaques which developed high-titer neutralizing antibodies (htNAb) after immunization with a virion-derived oligomeric envelope glycoprotein subunit vaccine were protected against a homologous simian immunodeficiency virus SIVmac challenge. Here we demonstrate that the htNAb could be overcome by V1-env region variants isolated ex vivo from an SIVmac-infected macaque. The results further suggest that the development of V1-env region neutralization escape mutants is also necessary for survival of the virus in infected macaques. The immunological capacity of a single variable region to induce neutralizing antibodies in vaccinated and infected macaques initiate new ideas for a successful vaccine strategy.  相似文献   

7.
8.
9.
Electrical charge transport through thiophene-dithiol-based molecular wires attached to gold electrodes with three different types of crystallographic orientations (<1,1,1>, <1,1,0 >?and <1,0,1?>) was investigated. Electron transport in the systems under consideration was evaluated systematically by analyzing current values, transmission spectrum, projected device density of states and zero bias orbital analysis utilizing density functional theory in conjunction with non-equilibrium Green’s function. Investigations proved that tuning of conductance in nano-molecular junctions is possible through different electrode orientations. As the HOMO–LUMO gap in the <1,1,0?>?oriented thiophene dithiol junction is drastically less than that of the other configurations under consideration, the <1,1,0?> configuration exhibited superior constructive conductance in comparison to other junction orientations. This provided us with ideas for designing pioneering hetero-cyclic nano-scale electronics devices. Also, <1,1,0?>?has been found to show negative differential conductance behavior above +2.6 V and below ?2.6 V, and hence has potential applications in oscillating and switching circuits.  相似文献   

10.
N. I. Vavilov first published his concept of centres of origin of cultivated plants in 1926. For over fifty years it profoundly influenced thinking about the origins and spread of agriculture by bitanists, geograhers, anthropologists and archaeologists. The genesis of the concept and its exposition by Vavilov is examined, and its influence on the ideas of such scholars as C. O. Sauer, I. H. Burkill, C. D. Darlington, A. I. Kuptsov, R. Porteres, J. R. Harlan and J. G. Hawkes is traced. It is concluded that Vavilov's concept, which for so long conditioned ideas about the origins of agriculature, has now outlived its usefulness in thet field sof study.  相似文献   

11.
An assessment of the global freshwater crab diversity is presented. A total of 1,476 species in 14 families are currently known from all zoogeographical regions (except Antarctica), including 1,306 species in eight exclusively freshwater families (Pseudothelphusidae, Trichodactylidae, Potamonautidae, Deckeniidae, Platythelphusidae, Potamidae, Gecarcinucidae and Parathelphusidae). Estimates of true freshwater crab diversity including likely numbers of undescribed taxa suggest that the field remains largely in a “discovery” phase. Main ideas on the origins, diversification, and phylogeny of true freshwater crabs are briefly discussed. The economic importance of freshwater crabs is also highlighted. Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens Freshwater Animal Diversity Assessment  相似文献   

12.
The discovery of new highly active molecules from natural products is a common method to create new pesticides. Celangulin V targeting Mythimna separate (M. separate) midgut V-ATPase H subunit, has received considerable attention for its excellent insecticidal activity and unique mechanism of action. Therefore, combined with our preliminary work, thirty-seven sulfonamide derivatives bearing propargyloxy or pyridine groups were systematically synthesized to search for insecticidal candidate compounds with low cost and high efficiency on the H subunit of V-ATPase. Bioactive results showed that compounds A2-A4 and A6-A7 exhibited a better bioactivity with median effective concentration (LC50) values (2.78, 3.11, 3.34, 3.54 and 2.48 mg/mL, respectively) against third-instar larvae of M. separate than Celangulin V (LC50=18.1 mg/mL). Additionally, molecular docking experiments indicated that these molecules may act on the H subunit of V-ATPase. Based on the above results, these compounds provide new ideas for the discovery of insecticides.  相似文献   

13.
【目的】 研究微生物电解池(Microbial electrolysis cell, MEC)利用复杂有机物作为底物的运行特性, 对其在废水处理中的应用有着重要的意义。【方法】 以模拟牛奶废水为基质, 通过构建MEC反应器来考察在不同外加电压条件下产电菌群的性能。【结果】 当外加电压升高到1.2 V时, 最大电流密度可达到261 A/m3, 产氢速率可达0.048 m3 H2/m3 d, 分别比外加电压为0.4 V的情形提高了467%和700%。外加电压为1.2 V时, 系统对COD和蛋白质去除率可分别达59%和74%, 其中COD去除较之0.4 V的情形提高了22.5%。PCR-DGGE的分子生物学分析结果表明, 阳极生物膜中以Geobacter sp.作为优势菌, 说明在利用大分子有机物作为基质时产电菌与非产电菌的协同作用更为明显。【结论】 MEC能够利用牛奶废水作为燃料, 在实现高效降解的同时以产氢的形式进行能量产出, 这为MEC的实际应用提供了研究思路。  相似文献   

14.
Processes of ultrastructural organization of cardiac myocytes have been studied in the Russian sturgeon (Acipenser güldenst?dti colchicus V. Marti) during germinal, prelarval, larval periods of development and in mature specimens. One of the main peculiarities of early cardiogenesis in this representative of Chondrostei fishes is a prolonged, observed during germinal and early prelarval periods, repression in multiplication of myocardial cells. Decreasing amount and size of yolk platelets in cytoplasm of these cells at the end of the germinal period could be connected with their intensive specific differentiation and increasing functional activity. Accumulation of free lipids during this period and their decreasing contents in early prelarval period demonstrate a certain transition to another way of metabolism. The data obtained on ultrastructure in mature specimens corresponds mainly to modern ideas on organization of the cardiac muscular tissue in other species of lower vertebrates.  相似文献   

15.
Computations in the early visual cortex.   总被引:1,自引:0,他引:1  
This paper reviews some of the recent neurophysiological studies that explore the variety of visual computations in the early visual cortex in relation to geometric inference, i.e. the inference of contours, surfaces and shapes. It attempts to draw connections between ideas from computational vision and findings from awake primate electrophysiology. In the classical feed-forward, modular view of visual processing, the early visual areas (LGN, V1 and V2) are modules that serve to extract local features, while higher extrastriate areas are responsible for shape inference and invariant object recognition. However, recent findings in primate early visual systems reveal that the computations in the early visual cortex are rather complex and dynamic, as well as interactive and plastic, subject to influence from global context, higher order perceptual inference, task requirement and behavioral experience. The evidence argues that the early visual cortex does not merely participate in the first stage of visual processing, but is involved in many levels of visual computation.  相似文献   

16.
17.
In this review, the development of understanding of the biological functions of carnosine is briefly discussed. Carnosine was first described as a component of meat in 1900 by V. S. Gulevitch. Changes in the concepts of the role of carnosine in metabolism are followed starting from the early suggestion that it is the end product of protein degradation to the modern ideas based on demonstrating its specific involvement in intracellular signaling regulation in excitable tissue cells. The discovery of the ability of carnosine to regulate expression of early response genes broadens the concept about carnosine as a cellular peptide regulator. The first attempts for application of carnosine in sport and medical practice are described.  相似文献   

18.
Despite the structural similarities between cholesterol oxidase from Streptomyces and that from Brevibacterium, both enzymes exhibit different characteristics, such as catalytic activity, optimum pH and temperature. In attempts to define the molecular basis of differences in catalytic activity or stability, substitutions at six amino acid residues were introduced into cholesterol oxidase using site-directed mutagenesis of its gene. The amino acid substitutions chosen were based on structural comparisons of cholesterol oxidases from Streptomyces and BREVIBACTERIUM: Seven mutant enzymes were constructed with the following amino acid substitutions: L117P, L119A, L119F, V145Q, Q286R, P357N and S379T. All the mutant enzymes exhibited activity with the exception of that with the L117P mutation. The resulting V145Q mutant enzyme has low activities for all substrates examined and the S379T mutant enzyme showed markedly altered substrate specificity compared with the wild-type enzyme. To evaluate the role of V145 and S379 residues in the reaction, mutants with two additional substitutions in V145 and four in S379 were constructed. The mutant enzymes created by the replacement of V145 by Asp and Glu had much lower catalytic efficiency for cholesterol and pregnenolone as substrates than the wild-type enzyme. From previous studies and this study, the V145 residue seems to be important for the stability and substrate binding of the cholesterol oxidase. In contrast, the catalytic efficiencies (k(cat)/K(m)) of the S379T mutant enzyme for cholesterol and pregnenolone were 1.8- and 6.0-fold higher, respectively, than those of the wild-type enzyme. The enhanced catalytic efficiency of the S379T mutant enzyme for pregnenolone was due to a slightly high k(cat) value and a low K(m) value. These findings will provide several ideas for the design of more powerful enzymes that can be applied to clinical determination of serum cholesterol levels and as sterol probes.  相似文献   

19.
Kin selection and reciprocity in flight formation?   总被引:1,自引:0,他引:1  
The reasons for conspicuous "V" and other flight formationsin birds are debated. Theory and recent empirical advances showthat energy saving is one important function of flight formations,but some aspects remain poorly understood. Combining theoriesof animal flight and sociality, we suggest that some of thevariation in flight formations has its base in kin selectionand reciprocation. The bird leading an acute V formation savesless energy than does the trailing participants. The disadvantageof leading is reduced in more obtuse formations, and when thelongitudinal distance between neighbors is small, the leadingbird can save about as much energy as others. Therefore, acuteV formations are predicted to occur mainly in circumstancesconducive to kin selection or reciprocity. These mechanismsseem possible, for example, in small flocks of adults with offspring,such as in swans, geese, and cranes. Inclusive fitness advantagesmay then favor an energetically expensive leader role for adults.In small groups, reciprocity is also possible among unrelatedadults that recognize each other and take turns leading theV formation. In contrast, obtuse formations are expected inlarge flocks of unrelated individuals, such as spring flocksof waders migrating long distances. Possibilities for testingthese ideas are discussed.  相似文献   

20.
The aim of this study is to explore whether matrices and MP trees used to produce systematic categories of organisms could be useful to produce categories of ideas in history of science. We study the history of the use of trees in systematics to represent the diversity of life from 1766 to 1991. We apply to those ideas a method inspired from coding homologous parts of organisms. We discretize conceptual parts of ideas, writings and drawings about trees contained in 41 main writings; we detect shared parts among authors and code them into a 91-characters matrix and use a tree representation to show who shares what with whom. In other words, we propose a hierarchical representation of the shared ideas about trees among authors: this produces a “tree of trees.” Then, we categorize schools of tree-representations. Classical schools like “cladists” and “pheneticists” are recovered but others are not: “gradists” are separated into two blocks, one of them being called here “grade theoreticians.” We propose new interesting categories like the “buffonian school,” the “metaphoricians,” and those using “strictly genealogical classifications.” We consider that networks are not useful to represent shared ideas at the present step of the study. A cladogram is made for showing who is sharing what with whom, but also heterobathmy and homoplasy of characters. The present cladogram is not modelling processes of transmission of ideas about trees, and here it is mostly used to test for proximity of ideas of the same age and for categorization.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号