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31.
Václav Zelený 《Folia Geobotanica》1970,5(3-4):369-400
Die Arbeit befasst sich mit der Nomenklatur, Morphologie, Phytogeographie, Chorologie, Phytozönologie und Ökologie der ArtLeucanthemum rotundifolium (W. K.) DC. innerhalb ihres Gesamtareals. Auf Grund der Analyse aller untersuchten Faktoren werden die Endergebnisse vom taxonomischen Gesichtspunkte vorgelegt.L. rotundifolium wird mit der am nächsten verwandten ArtL. vulgare Lam. s. l. verglichen. 相似文献
32.
M. Spurný 《Biologia Plantarum》1968,10(2):98-111
In order to interpret the mechanism of elongation growth of the hypocotyl with radicle in the first stages of germination of the pea seed (Pisum sativum L.) a cybernetic model utilizing feed-back as a mechanism of correcting the wrong direction of growth was proposed (Spurný 1966, 1967). In the present study, the effect of amputation of the root tip as the control centre on the trajectory of the growing radicle was investigated. The results have shown that the hypocotyl grows, elongates—the rate of growth being slightly lower than that of the standard, but that no spiral oscillations at all are executed by the organ after amputation of the root tip. This finding appears to confirm the applicability of the proposed cybernetic model, for amputation of the root tip means that not only the control block is eliminated, but also that the channel of feed-back impulses to zone of elongation is interrupted. 相似文献
33.
Zusammenfassung An Paraffinschnitten durch perfusionsfixierte Gehirne von erwachsenen Katzen werden in der Wand des Aquaeductus cerebri zwei von cranial nach caudal verlaufende Gliafaserbündel beschrieben, deren eines in das Velum medullare anterius einstrahlt, während das andere Anschluß an ein Faserbündel gewinnt, welches in der Seitenwand des IV. Ventrikels verläuft. — Es wird gezeigt, daß im Boden des IV. Ventrikels am Eingang in den Recessus lateralis sowie im Boden des gesamten Recessus lateralis unmittelbar unter dem Ependym einzeln gelegene Nervenzellen vorkommen. Diese bisher unbekannten Zellen werden als ein flächenhaft ausgebreitetes Kerngebiet mit enger Beziehung zum Ventrikelsystem angesehen.
Mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft. 相似文献
On the structure of the walls of the aquaeductus mesencephali and of the IVth ventricle of the cat
Summary In paraffin sections through the brains of adult cats two thick bundles of glia fibres are shown to be running in the cranio-caudal direction within the wall of the aqueductus cerebri. One of the bundles enters the velum medullare anterius whereas the other is continuous with a bundle of glia fibres that runs within the lateral wall of the IVth cerebral ventricle. — In the floor of the IVth ventricle near the entrance to the lateral recess and in the floor of the entire lateral recess nerve cells are shown to occur immediately underneath the ependyma. These cells, which so far have not been described, are thought to constitute an extremely thin nucleus having a special relationship to the ventricular system.
Mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft. 相似文献
34.
The use of induced primuline fluorescence led to the discovery of a new type of yeast scars (multiple scars) in the generaKloeckera, Saccharomycodes, Nadsonia andHanseniaspora. The structure and ultrastructure of their surface was studied by electron microscopy, using carbon replicas and isolated cell walls. 相似文献
35.
V. Chaloupecký 《Folia microbiologica》1964,9(4):232-237
- 1.It was found that growing cells always contained more different groups of ribosomes and their total amount was greater than in non-growing cells or spores, in which only two ribosome groups with different sedimentation constants, according to the species of microorganism, were consistently found. 相似文献
36.
Changes in the radioresistance of bacteria after the inhibition of proteosynthesis in the preirradiation phase 总被引:2,自引:1,他引:1
The strain ofEscherichia coli WP2 (tryv) was irradiated with UV light, at a dosage of 240 erg/mm. Proteosynthesis was inhibited by the elimination of the essential
amino acid from the cultivation medium. Changes in radioresistance were followed during 45 minutes of starvation and during
the subsequent 45 minutes of restitution after the addition of the essential amino acid. The radioresistance of the cells
showed a linear increase immediately after the removal of the essential amino acids, proportional to the duration of the inhibition
of proteosynthesis. The increase in radioresistance was shown to be reversible. After the addition of the essential amino
acid there was an immediate decrease in radioresistance which was most marked in the first 15 minutes. 相似文献
37.
The existence of six amylase heterogeneity variants in serum and urine has been discovered in a group of 111 families with twins, and the frequence of each variant was determined. It had been shown that each of these amylase heterogeneity variants is inherited codominantly, and the mode of inheritance is demonstrated schematically.These amylase heterogeneity variants may be used as an aid to twin zygosity determination and also in paternity problems. 相似文献
38.
From the results obtained in the present work it is concluded that gamma globulin of the 7 S type (γG) which represents the main immunoglobulin component of pig colostrum, differs from serum γG globulin by the presence of another type of polypeptide chain, designed L2; the latter was detected after S-sulfonation in starch gel electrophoresis as the fastest moving component and its immunoelectrophoretic pattern shows the presence of two precipitating components. Preparation of soluble heavy and light chains enabled us to study them imunochemically. The heavy chain is represented by two zones; the fainter one was not detected in comparative analysis of the heavy chain of serum γG globulin. The L1 chain of colostral gamma globulin and the light chain of serum gamma globulin seem to contain three precipitating components, one of which appears due to aging of the chain solution in the presence of glycine. The material from colostrum seems to contain a larger amount of this component than serum. Further it was shown that the component arising in this way is antigenically closely related to the heavy chain. 相似文献
39.
R. Řetovský 《Folia microbiologica》1965,10(4):230-235
Colour tests for study of the nuclear apparatus ofChlorella cells are described. It can be concluded from the results thatChlorella cell nucleus contains a relatively large nucleolus; the peripheral layers of the nucleus are rich in chromatin only in the nuclear division phase. The nucleus divides by a simplified form of mitosis, characterized morphologically by simple constriction. 相似文献
40.