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  • 1
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les corpora allata des ouvrières adultes d'abeilles ont deux phases de croissance. Lors de la première phase, la croissance est inhibée par la phéromone de la reine, tandis que la deuxième phase ne se produit qu'en présence d'une reine. Une corrélation entre le volume des corpora allata et la croissance des oocytes suggère que l'oogenèse dépend d'une hormone des corpora allata. Or, un autre facteur au moins est encore nécessaire pour la maturation des oocytes. Il est probablement sécrété par les cellules de la pars intercerebralis du cerveau. La croissance des noyaux des cellules neurosécrétrices du cerveau est inhibée par la reine, mais le mode d'action de la phéromone dans cette inhibition reste inconnu.
    Abstract: Summary The corpora allata of adult worker bees show growth periods. During the first period growth is inhibited by queen substance while the second growth period only occurs when a queen is present. A correlation between the volume of the corpora allata and oocyte suggests that oocyte maturation is dependent on the presence of a hormone of the corpora allata. Besides of the hormone of the corpora allata at least one other factor is necessary for oocyte maturation. It is probably contained in the neurosecretory material produced in the pars intercerebralis of the brain. The growth of the nuclei of the neurosecretory cells of the brain is inhibited by the presence of a queen, but it is doubtful whether this is due to the action of queen substance.
    Notes: Zusammenfassung Die Corpora allata der Bienearbeiterinnen machen während des Adultlebens zwei Wachstumsphasen durch. Im Laufe der ersten Phase wird das Wachstum durch Königinnensubstanz gehemmt; die zweite dagegen tritt nur bei Anwesenheit einer Königin auf. Das Wachstum der Corpora allata weiselloser Bienen ist mit der Eireifung korreliert. Ein Hormon der Corpora allata dürfte für die Eireifung notwending sein (Abb. 4). Ausser dem Hormon der Corpora allata muss für das Oocytenwachstum ein weiterer Faktor vorhanden sein. Wahrscheinlich handelt es sich um ein Sekret der neurosekretorischen Zellen der Pars intercerebralis des Gehirns. Die Königin hemmt direkt oder indirekt das Kernwachstum in den neurosekretorischen Zellen der Arbeiterin. Es ist fraglich, ob es sich auch hier um eine Wirklung der Königinnensubstanz handelt.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochemical and Biophysical Research Communications 80 (1978), S. 14-21 
    ISSN: 0006-291X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    BBA - Protein Structure 446 (1976), S. 463-471 
    ISSN: 0005-2795
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 11 (1981), S. 0 
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The simplified oscillation method was adapted to register nasal resistance because complicated and difficult procedures limited other known rhinomanometric tests. An initial study of thirty-nine subjects compared the effect of different-sized masks, revealing that the smaller the face mask, the smaller the capacitance and the higher the effective resistance. After an initial measurement, a second study group of twenty healthy and twenty pollinosis patients aged from 4 to 40 years underwent nasal provocation with grass pollen extract. Both study groups showed that despite high resistance, reactances were minor. This occurs because the nose acts as an aperture and an aperture has minimal reactances. With increasing concentrations of pollen extract, the nasal resistance of pollinosis subjects increased steadily, whereas the controls showed no change. Passive anterior rhinomanometry was measured for comparison and results contrasted sharply with the oscillation method: prior to provocation, initial values of control and pollinosis groups were already significantly different; after provocation, there was a statistically significant rise in resistance amongst the control as well as the pollinosis subjects. Further, the oscillation method for measuring nasal resistance proved to be simple, effective, and suitable for children.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-0703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract In the Rhine-delta, accumulation of microcontaminants in floodplain foodwebs has received little attention in comparison with aquatic communities. To investigate organochlorine and metal concentrations in a terrestrial foodchain, samples of soil, earthworms (Lumbricus rubellus), and shrew (Crocidura russula, Sorex araneus) livers and kidneys were taken from two moderately to heavily polluted floodplains. Chlorobiphenyl residues in earthworm fat were 0.10 to 3.5 times the concentrations in soil organic matter, whereas ratios for other organochlorines varied between 0.87 and 8.8. These ratios are one order of magnitude lower than expected from laboratory experiments with earthworms, and laboratory and field studies on aquatic invertebrates. Bioconcentration ratios for heavy metals are in accordance with literature values for other locations, confirming the high potential for cadmium accumulation in Lumbricidae. Concentrations of organochlorines in shrew liver lipids were 1.0 to 13 times the residues in earthworm fat. These values are higher than lipid-corrected biomagnification ratios for laboratory rodents, but equal to those measured for benthivorous birds in the Rhine-delta. On a dry weight basis, kidney-earthworm ratios for cadmium were about one order of magnitude lower than previously reported values for insectivores. Soil concentrations of many compounds in both floodplains did not meet Dutch quality standards. Yet, hexachlorobenzene, chlorobiphenyl 153 (PCB153), γ-hexachlorocyclohexane, ΣDDT, and dieldrin residues in earthworms and shrews did not exceed diet levels expected to be safe for endothermic species. An exception was noted for cadmium in worms and shrew kidneys. Heavy metal pollution in soil was close to levels that are critical to earthworms in laboratory studies. Cadmium concentrations in shrew kidneys were below levels suggested to be safe for Sorex araneus, but above those that were critical to the rat.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 32 (1899), S. 137-145 
    ISSN: 0365-9496
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 31 (1898), S. 2726-2731 
    ISSN: 0365-9496
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 31 (1898), S. 1339-1344 
    ISSN: 0365-9496
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 31 (1898), S. 2954-2957 
    ISSN: 0365-9496
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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