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  • 1
    Electronic Resource
    Electronic Resource
    The “pre-metaphase stretch” and kinetochore orientation in phasmids (1950)
    Springer
    Chromosoma 3 (1950), S. 1-21 
    Details
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. The pre-metaphase stretch is found to be a normal stage in male meiosis in six species of phasmids. 2. Its essential features are a precocious orientation of the kinetochores and their movement toward opposite poles of the developing spindle in first meiotic prophase, — with a consequent stretching of the chromosomes. It is followed by recontraction of the chromosomes and their movement to the equator. Attraction beween kinetochore and center, reinforced by the effect of elongation of the spindle, is considered responsible for the movements of the stretch. 3. The pre-metaphase stretch in phasmids differs from that of mantids in (1) its timing relative to meiotic stage, and (2) its expression in one species in the prophase of both meiotic divisions. 4. The distribution of the stretch in nature, and its significance for the mechanism of mitosis are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319466
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  • 2
    Electronic Resource
    Electronic Resource
    Reversion of XO to XY sex chromosome mechanism in a phasmid (1950)
    Springer
    Chromosoma 3 (1950), S. 52-65 
    Details
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The sex chromosomes of the male phasmid Isagoras schraderi Rehn comprise an X and a Y, — each with a submedian kinetochore, and one euchromatic and one heterochromatic arm. At meiosis X and Y form an unequal sex bivalent in which the euchromatic arms are terminally associated. Relatively recent reversion from the XO-XX mechanism characteristic of the Phasmidae is indicated by the presence of the euchromatic arm in both X and Y. The diploid number of the male is 34. Unequal autosomal bivalents are found at meiosis in two other species of Isagoras — Isagoras subaquiles Rehn and Isagoras sp. — and in Pseudophasma menius Westwood. The chromosome complements of these species are described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319469
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  • 3
    Electronic Resource
    Electronic Resource
    Expulsion of the sex chromosome from the spindle in spermatocytes of a mantid (1950)
    Springer
    Chromosoma 3 (1950), S. 257-270 
    Details
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. In the primary spermatocytes of the mantid Humbertiella indica the separation of the centers during late prophase is accompanied by corresponding movements of the nuclear membrane. Center and membrane thus remain in close juxtaposition suggesting that some form of attraction operates between them. 2. Interpolar distances are subject to a series of changes definitely associated with the successive mitotic phases. At the initiation of spindle formation the distance between the centers is large; it decreases sharply until metaphase; then remains constant until mid anaphase; and progressively increases to an extreme degree during late anaphase and early telophase. 3. At first metaphase the autosomal bivalents orient in a typical equatorial plate, but the X chromosome lies out in the cytoplasm, spatially separated from the spindle body by a wall of mitochondria. 4. Expulsion of the X chromosome from the spindle is correlated with a delay in its kinetochore-center interaction. 5. The anaphase movement of the autosomes is associated with a progressive shortening of the chromosomal fibers during the entire anaphase, accompanied during late anaphase by an elongation of the spindle body. But in the case of the X chromosome shortening of the chromosomal fiber occurs only during late anaphase. 6. Subsidiary conclusions on the cytoplasmic origin of the chromosomal fiber of the X, the relation of the bouquet stage to the double polarization of late prophase, the non-chiasmate structure of the autosomal bivalents, and the absence of the premetaphase stretch stage are recorded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319479
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  • 4
    Electronic Resource
    Electronic Resource
    The chromosomes of mantids (Orthoptera: manteidae) in relation to taxonomy (1950)
    Springer
    Chromosoma 4 (1950), S. 1-55 
    Details
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distinguishing cytological characters, including chromosome number and sex chromosome mechanism, have been tabulated for all mantids thus far studied cytologically—including 16 species (starred in Table 1) not hitherto examined. Data on 46 species in 17 subfamilies are reviewed. The XO♂—XX ♀ sex chromosome mechanism represents the ancestral condition for the family and has been retained in 14 of the subfamilies sampled. The distribution of the X1X2Y♂—X1X1X2X2♀ mechanism, previously known in the subfamilies Manteinae and Choeradodinae, is extended to include Mellierinae, Acromantinae and Vatinae. Cytological evidence indicates a monophyletic origin of the compound sex chromosomes and necessitates a reconsideration of the taxonomic association of XO and X1X2Y forms in the same subfamily, specifically of Miomantis and Callimantis with the other Manteinae, and Aethalocroa with Vates and Phyllovates in the Vatinae. The pre-metaphase stretch is established as a regular stage in male meiosis in 14—and is absent in 3—of the species checked for this character. It should prove of taxonomic value when a wider sampling of the lower categories is available. The prolongation of parallel pairing of homologous chromosomes in male meiosis appears to be characteristic of the Manteidae as a whole. No correlation is apparent between the degree of its expression and taxonomic category. Since it provides a mechanism, additional or alternative to chiasmata, for the post-pachytene association of homologues, its establishment permits the evolution of non-chiasmate meiosis in the group. Two structural types of bivalents—one with, one without chiasmata—are found. Present evidence favors the multiple origin of the non-chiasmate type within the family, and since both types may coexist in the karyotype of the same sex of a single species, presence or absence of chiasmata cannot be considered a valid taxonomic criterion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00325766
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  • 5
    Electronic Resource
    Electronic Resource
    The rate of growth of asterionella formosa Hass. in relation to its ecology (1962)
    Springer
    Archives of microbiology 42 (1962), S. 117-129 
    Details
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In Windermere, and some other lakes in the English Lake District, the vernal increase of Asterionella formosa ceases when the concentration of silica in the water falls to approximately 0.5 mg/l. When this planktonic diatom is cultivated in water from one of these lakes, Windermere, the addition of small amounts of phosphate phosphorus permits the growth of so large a crop that all the silica present is incorporated into the cells. The intensity and duration of the illumination and the temperature of the water effect this relationship between silica, phosphorus and the growth Asterionella. Therefore, the regular, observed relationship between the concentration of silica and the vernal maximum of Asterionella in nature may be related to the amount of this substance in the water, to the amount of phosphate phosphorus present and to the rate of growth imposed upon this diatom by the light and temperature conditions in the lake during the period concerned. The possible importance of the relatively low concentration of phosphate phosphorus in certain very unproductive lakes is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00408168
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  • 6
    Electronic Resource
    Electronic Resource
    Biological control of snails exerted byEuglandina rosea (Ferussac) in Bermuda (1963)
    Springer
    BioControl 8 (1963), S. 219-222 
    Details
    ISSN: 1573-8248
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Résumé Cet article relate un essai de lutte biologique effectué aux Bermudes contre deux Gastéropodes nuisibles:Rumina decollata (Linné) (Achatinidae) etOtata lactea Muller (Helicidae) au moyen du mollusque carnivoreEuglandina rosea (Ferussac). 845Euglandina, ont été libérés dans l'île en 1958 et 1960. Dès 1962, il était évident que l'opération se soldait par un succès complet contreOtata mais par un échec contreRumina. 500Euglandina ont été récoltés en quelques jours aux Bermudes et expédiés à l'île Maurice, à Hong-kong, Nord-Bornéo et les Bahamas pour de semblables essais.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02376092
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  • 7
    Electronic Resource
    Electronic Resource
    Studies on the life history and biological control of the spittlebug,Clastoptera undulata uhler (Cercopidae: Hemiptera) (1963)
    Springer
    BioControl 8 (1963), S. 49-66 
    Details
    ISSN: 1573-8248
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Résumé Une invasion deClastoptera undulata fut découverte aux Bermudes en 1959 et il a été tenté de lutter contre cet insecte par l'introduction de l'EncyrtideCarabunia myersi, parasite des larves originaires de la Jamaïque. Les recherches accomplies sur le cycle deClastoptera undulata aux Bermudes sont présentées ainsi que les observations faites dans la nature sur une espèce voisine,C. flavidorsa, à la Jamaïque. Des informations sur la biologie deCarabunia myersi et un compte rendu sur son introduction et son établissement aux Bermudes sont donnés. Aux Bermudes, la plupart des individus deC. undulata hivernent à l'état d'œuf et les effets possibles sur la population du parasite sont discutés.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02381338
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  • 8
    Electronic Resource
    Electronic Resource
    The comparative enhancement of the depressant action of alcohol by eight representative ataractic and analgesic drugs (1962)
    Springer
    Cellular and molecular life sciences 18 (1962), S. 468-470 
    Details
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Zusammenfassung Eine Methode zur Messung der Potenzierung von Tranquilizern und Analgetika auf Äthanoldepression wird beschrieben. Unbeweglichkeit von Mäusen wird als Kriterium der Depression genommen. Die fünf Tranquilizer, die gebraucht wurden, haben Äthanol in verschiedenen Graden potenziert. Von den drei analgetischen Drogen hat Morphin, nicht aberd-Propoxyphen und Codein, Äthanolnarkose potenziert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02175865
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  • 9
    Electronic Resource
    Electronic Resource
    Totally synthetic (±)-13-Alkyl-3-hydroxy and methoxy-gona-1,3,5(10)-trien-17-ones and related compounds (1963)
    Springer
    Cellular and molecular life sciences 19 (1963), S. 394-396 
    Details
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Zusammenfassung Von mehreren (±) 3-Oxy- und (±) 3-Methoxy-13-alkylgona-1,3,5(10)trien-17-onen und verwandten Verbindungen, einschliesslich von Vertretern der (±) 13-Alkylgon-4-en-3-on-Reihe, werden Totalsynthese und biologische Wirksamkeit beschrieben.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02171503
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  • 10
    Electronic Resource
    Electronic Resource
    The synthesis of corticosteroids methylated at C21 (1960)
    Springer
    Cellular and molecular life sciences 16 (1960), S. 357-358 
    Details
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Zusammenfassung Die Darstellung der beiden epimeren C21-Methylderivate des 9α-Fluorprednisolons wird beschrieben. 9α-Fluor-21-methyl-1, 4-pregnadien-11β, 17α, 21B-triol-3, 20-dion-21-azetat ist ein hochwirksames entzündungshemmendes Steroid, vollkommen frei von Nebenwirkungen der Natrium- und Wasserretention des C21-unsubstituierten 9α-Fluorprednisolons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02157901
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