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1.
Preference was studied of one of the forelimbs during performance of different manipulating movements in white rats. High degree of "handedness" was observed in all studied movements. However it was not absolute--no animals performed all movements by one and the same limb. Degree and character of "handedness" were different for different movements, though the number of "righthanded" rats in most tests as a whole exceeded the number of "lefthanded" ones. The "handedness" depends on the individuality of the animal, the character of the motor task, learning and interference of different motor tasks during training.  相似文献   

2.
A comparative study of the haemoglobins of 648 animals distributed over 300 species of vertebrates and belonging to different classes has been made by horizontal starch gel electrophoresis is tris EDTA-borate pH 8.6. Multiple haemoglobins were found within the different classes. The percentage of multiple haemoglobins varies from class to class. The frequency-distribution of the mobility values of haemoglobins is rather specific for the different classes and in certain instances for the different orders.  相似文献   

3.
长叶榧黄酮类化合物含量及成分分析   总被引:4,自引:0,他引:4  
对长叶榧不同营养器官和不同居群的3种营养器官黄酮类化合物含量进行测定,并利用聚酰胺薄层层析法对黄酮类化合物的成分进行分析。结果表明:(1)长叶榧各个营养器官均含有黄酮类化合物,其含量高低顺序依次是一年生叶>一年生枝>幼根>老根>树皮>老枝>茎;(2)长叶榧不同营养器官其黄酮类化合物的种类有很大的差异,以一年生叶、一年生枝最多,幼根次之,老根、老枝第三,树皮、茎最少;(3)不同长叶榧居群3种营养器官黄酮类化合物含量各不相同,但均以一年生叶最高,一年生枝次之,老枝最低;(4)不同长叶榧居群一年生叶黄酮类化合物含量差异不显著,一年生枝、老枝差异较大;(5)不同长叶榧居群3种营养器官其黄酮类化合物的种类在一年生叶中没有差异,一年生枝中差异较小,老枝中差异较大。  相似文献   

4.
商城肥鲵消化道的解剖学观察   总被引:12,自引:2,他引:12  
该文首次报道了商城肥鲵消化道各部分的形态结构、长度及其组织学结构。结果表明,除口腔外,消化道管壁由粘膜层、粘膜下层、肌层和浆膜层构成,消化道各部分的差别主要在粘膜层和肌层食道粘膜为复层柱状上皮,食完纵肌层,胃、肠粘膜上皮为单层柱状上皮,胃、肠肌层由内环外纵两层平滑肌组成。粘膜上皮的皱褶程度、腺体分布情况、肌层的相对厚度等在消化道各部分也存在差异。  相似文献   

5.
A comparative reappraisal of the general problem of evolutionary trends and constraints of the locomotion phenomenon from prokaryotes to protozoa to metazoa was carried on. They elaborated different propulsive systems, different control systems of motion and different analysis systems of the stimuli. A general understanding of the locomotion phenomenon was reached and ciliate behaviour was positioned within the wider context of the evolution of biological displacement.  相似文献   

6.
Under nembutal narcosis on cats, intracellular electrophysiological studies have been made of common properties and differences in the neuronal organization of the nucleus reticularis tegmenti pontis and intrinsic pontine nuclei. Reciprocal connections of all the nuclei with the cerebellum and sensorimotor cortex were revealed. It was shown that the cerebellar peduncles are involved to a different extent in the transmission of cerebellofugal signals from the nucleus reticularis tegmenti pontis and the pontine nuclei; all these nuclei have different projections to the central cerebellar nuclei and receive different descending cortical impulsation. Functionally, the investigated cortico-cerebellar pontine relay structures supplement and duplicate each other.  相似文献   

7.
The neurons of the first optic ganglion (the lamina) in the desert ant, Cataglyphis bicolor, have been studied with the light microscope after Golgi silver impregnation. The different types of retinal and laminal fibres and their configuration are compared with the results obtained in the bee. The first synaptic region in the visual system of the ant lies proximally to the fenestrated layer below the basement membrane and the layer containing the monopolar cell bodies. The synaptic region can be separated into three morphologically different zones: (1) The most distal layer where the short visual fibres end at two different levels. The short visual fibres and some laminal fibres (monopolar cell fibres) also show lateral elements in this region. (2) The second layer appears almost free of branches of retinal and laminal fibres. (3) The most proximal layer, which has a characteristically dense horizontal structure resulting from the lateral elements of long visual, centrifugal, monopolar and tangential fibres. Nine cell axons arising from each ommatidium leave the retina. Six of these are short visual fibres and end at two different levels in the lamina. Three different types of short visual fibres can be distinguished by their different terminal depths and lateral branching pattern. The remaining three fibres, the long visual fibres, terminate in the medulla. They can be distinguished from each other by their lateral elements in the lamina neuropile. The five morphologically different laminal fibre types (axons of the monopolar cells in the lamina) have different shapes and different arborizations at different levels. Tangential, centrifugal and incerta sedis-fibres, which originate either from cell bodies in the cell body layer at the periphery of the outer chiasma or more centrally, terminate in the synaptic region of the lamina. Consideration is given to the clearly demarkated arrangement and length of the branching pattern of retinal and laminal fibres at different levels of the synaptic region of the lamina. In addition, a hypothetical connectivity pattern is discussed.  相似文献   

8.
The visual brain consists of many different visual areas, which are functionally specialized to process and perceive different attributes of the visual scene. However, the time taken to process different attributes varies; consequently, we see some attributes before others. It follows that there is a perceptual asynchrony and hierarchy in visual perception. Because perceiving an attribute is tantamount to becoming conscious of it, it follows that we become conscious of different attributes at different times. Visual consciousness is therefore distributed in time. Given that we become conscious of different visual attributes because of activity at different, functionally specialized, areas of the visual brain, it follows that visual consciousness is also distributed in space. Therefore, visual consciousness is not a single unified entity, but consists of many microconsciousnesses.  相似文献   

9.
北草蜥几种消化酶活力比较   总被引:1,自引:0,他引:1  
应用酶学分析法测定了越冬后北草蜥胃、肠组织中蛋白酶、淀粉酶、纤维素酶的活力。结果表明 ,不同年龄、性别的北草蜥同一组织中消化酶活力有显著差异 ;不同地理种群的北草蜥同一组织中消化酶活力有显著差异 ;不同消化酶在北草蜥同一组织中的活力有显著差异 ;在北草蜥不同的组织中同一消化酶的活力有显著差异。说明北草蜥消化酶的活力与年龄、性别、部位和地理环境等因素有关 ,受食物组成、能量需求和遗传等因素的影响 ,产生了不同的酶活力和分布。这也说明生物长期适应环境 ,形成了不同的代谢水平  相似文献   

10.
Two pairs of chiral stationary phases (CSPs) with different C(2)-symmetric central parts were prepared and evaluated by chromatography of a series of structurally different racemates. Within each pair, the selectors on which the CSPs are based had different lengths of their achiral spacers. The CSPs based on selectors with short spacers showed higher enantioselectivity than the phases incorporating long spacers. On one pair of the phases, a study of the influence from different retention modifiers was performed for a series of benzodiazepinones. This demonstrated the importance of the polymer structure formed from the selectors with different spacer lengths for the enantiodiscriminating ability of the CSPs.  相似文献   

11.
电导率与极端低温分布在闽中桉树引种决策上的研究   总被引:3,自引:0,他引:3  
依据闽中地区永安市1971~2005年的极端低温与极值分布数学模型和气象学原理,探讨5~10 a内该区域不同海拔高度可能出现的极端异常低温,利用电导率测定引种区所引种的不同抗寒程度的桉树种的半致死温度,事前评价引种的可行性.首次提出利用极端低温与电导率进行引种决策,并把该方法称作"极端环境反应法".结果表明:在出现10 a以上异常低温时,邓恩桉(Eucalyptus dunnii)在该区域垂直分布可达海拔775 m,巨桉(E.grandis)及相近抗寒能力的桉树可在海拔467 m以下栽植,赤桉(E. camaldulensis)可在海拔960 m以下栽植.该方法可广泛应用于其它区域与不同树种引种的事前评价与决策.  相似文献   

12.
The composition of the causative agents of suppurations, isolated from suppurating wounds of patients hospitalized at different departments of the Sklifosovski? Emergency Aid Institute was studied. The proportion of representatives of different microbial families among more than 18,000 strains of the causative agents of wound infection was estimated. Fluctuations in the amount and structure of the agents were analyzed in different clinics over the period of 1967-1987. Under the conditions of emergency aid hospital Staphylococcus aureus proved to be the most frequent causative agent of suppurative inflammatory processes at different departments. At the same time no tendency towards an increase of the etiological role of any microbial family in the development of wound infections was noted. The incidence of different causative agents of suppurations was found to vary at different departments, depending on their specialization and season. The results of observations on the composition of the causative agents of wound infection may be used for the planning and evaluation of antiepidemic measures.  相似文献   

13.
The results of the study of the immunological structure of the population at the western section of the Baikal-Amur Railroad in respect to influenza virus at different seasons of the year and with different intensity of the epidemic process are presented. The dynamics of the total level and properties of immunoglobulins of three classes (IgM, IgG and IgA) has been followed. The potential human capacity for immune response to infections under the conditions of the construction of the Baikal-Amur Railroad has been shown to remain unchanged.  相似文献   

14.
The paper represents a review and analysis of different trends in the evolution of tissue parasitism. Data are given on different ways of departure of parasites from the host's immune response, inhibition of its immunity, antigenic mimicry, capsule formation. The paper considers in detail the mechanism of origin, structure and functions of capsules, which are induced by various groups of parasites in vertebrate and invertebrate hosts. Uniformity in the structure of capsules, which are formed in different host-parasite systems, suggests the universality of mechanisms ensuring their formation.  相似文献   

15.
Neutral maltase from human granulocytes has a different substrate specificity from the human neutral maltase of kidney, though it has been reported that these two enzymes are immunologically similar. We report here that human granulocyte neutral maltase is similar to the neutral maltase from rat's kidney as regards the substrate specificity and the inhibition by Tris and maltodextrins. We also report a different thermal stability that might imply some structural differences between the two enzymes.  相似文献   

16.
In order to preserve genetic information in stress conditions, bacterial DNA is organized into higher order nucleoid structure. In this paper, with the help of Atomic Force Microscopy, we show the different structural changes in mycobacterial nucleoid at different points of growth in the presence of different concentrations of glucose in the medium. We also observe that in Mycobacterium smegmatis, two different Dps proteins (Dps1 and Dps2) promote two types of nucleoid organizations. At the late stationary phase, under low glucose availability, Dps1 binds to DNA to form a very stable toroid structure. On the other hand, under the same condition, Dps2-DNA complex forms an incompletely condensed toroid and finally forms a further stable coral reef structure in the presence of RNA. This coral reef structure is stable in high concentration of bivalent ion like Mg(2+).  相似文献   

17.
Cytochrome bd oxidase is a bacterial terminal oxygen reductase that was suggested to enable adaptation to different environments and to confer resistance to stress conditions. An electrocatalytic study of the cyt bd oxidases from Escherichia coli, Corynebacterium glutamicum and Geobacillus thermodenitrificans gives evidence for a different reactivity towards oxygen. An inversion of the redox potential values of the three hemes is found when comparing the enzymes from different bacteria. This inversion can be correlated with different protonated glutamic acids as evidenced by reaction induced FTIR spectroscopy. The influence of the microenvironment of the hemes on the reactivity towards oxygen is discussed.  相似文献   

18.
Structural changes of the cytoskeleton of the frog urinary bladder granular cells were examined during low and high water permeability of the epithelium. A tight connection of the microfilaments and microtubules with vacuolar membranes and a great increase in the number of microtubules during a stimulated water flow was shown using different electron microscopic methods. Two populations of microtubules were discovered, respectively, with different diameter and different rate of stability. It is suggested that the thicker microtubules while interacting with actin microfilaments through associated electron dense globules may fulfil the transport function in the cell.  相似文献   

19.
Summary Seven morphologically different types of neurosecretory granules have been found in the axon terminals of the sinus gland of the blue crab, Callinectes sapidus. They differ from each other in size, shape, staining characteristics, solubility characteristics, core matrix characteristics, axon terminal matrix characteristics, presence or absence of space between the granule membrane and granule core matrix, and frequency of occurrence. Five of the types are segregated in different axon terminals and are believed to represent different hormone-protein complexes. Two of the types, which have lost part or all of their granular contents, are thought to be variants of the other five types. The differences in granular morphology are better revealed by some fixation procedures than others. Palade's acetate-veronal buffered osmium tetroxide, in particular, reveals striking differences. The following observations suggest that different hormone-protein complexes are segregated in different axon terminals and that these complexes may be morphologically distinguished at the level of the electron microscope.Supported by USPHS-NIH Training Grant GM-00669 and Grant GB-7595X from the National Science Foundation.  相似文献   

20.
Models of the rhizosphere   总被引:5,自引:0,他引:5  
P. R. Darrah 《Plant and Soil》1991,138(2):147-158
A mathematical model has been developed which is capable of simulating the population dynamics of microbial biomass surrounding a root which is releasing soluble and insoluble carbon compounds into the soil. The model simulates the interconversions of C between different pools within the soil as well as the diffusion and mass flow of soluble carbon. Two main aspects of carbon release were examined: (i) a strategy where exudate was released uniformly over the root surface was compared to the case where exudation was confined to a small region behind the root tip; (ii) the situation in which all the C released was in soluble form was compared to the case of an approximately equal partition between soluble and insoluble forms. Substantial differences between the different simulations were found. It was shown that the maximum concentration and penetration of soluble exudates differed markedly between different simulations and the implications of this for micronutrient acquisition by phytosiderophores and for colonisation of the rhizosphere by root pathogens were discussed. The different simulations also predicted very different biomass distributions in the rhizosphere in both space and time.  相似文献   

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