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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 34 (1983), S. 1-8 
    ISSN: 1570-7458
    Keywords: Glossina ; Tsetse ; Feeding ; behaviour ; Sound production ; Sound frequency ; Sound intensity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'étude a porté sur les sons produits pendant les comportements préalimentaire, alimentaire et postalimentaire de la mouche Tsétsé, Glossina morsitans morsitans. Les mâles et les femelles vierges chantent très rarement avant l'alimentation, mais les femelles fécondées chantent dans plus de 20% des cas avant de prendre un repas. La production de sons pendant la prise de nourriture était négligeable pour les trois catégories. Les sons postalimentaires étaient plus fréquents, les femelles fécondées chantant plus que les femelles vierges et l'ensemble des femelles plus que les mâles. La durée des sons postalimentaires ne différait pas suivant les sexes. Dans chaque catégorie, les sons postalimentaires ne changaient pas significativement avec l'âge. Il y a eu, cependant, des différences significatives dans les caractéristiques de la production de son postalimentaire lorsque les mâles étaient comparés aux femelles pendant une période de 8 semaines. Les oscillogrammes de ces sons différaient suivant le sexe et variaient de temps en temps. Les sons comportaient des fréquences jusqu' à 50 kHz, à l'exception des sons préalimentaires des mâles qui ne contenaient pas d'ultrasons. Les fréquences les plus dominantes étaient concentrées entre 1,5–2,5 kHz. Des pics étaient observés entre 0,5–0,8 kHz et autour de 5 kHz et 9 kHz. Les sons préalimentaires étaient plus faibles que les sons postalimentaires. On en suggère que les sons associés au comportement alimentaire jouent un rôle en attirant les mouches affamées vers un hôte convenable et que la plus grande partie de l'information acoustique est portée par les composantes à basse fréquence qui ont une intensité plus élevée (30–40 dB) que les fréquences ultrasoniques (10 dB).
    Notes: Summary Sounds produced during prefeeding, feeding and postfeeding behaviour of the tsetse, Glossina m. morsitans Westw. were investigated. Males and virgin ♀ ♀ very seldom sang before feeding but mated ♀ ♀ sang in more than 20% of the cases before taking a meal. Sound production during engorgement was negligible among all 3 groups. Postfeeding sounds were the most commonly produced, mated ♀ ♀ singing significantly more than virgin ♀ ♀ and both these groups more than ♂ ♂. The mean duration of the postfeeding sounds did not differ between the sexes. Within each group, postfeeding sound production did not significantly change with age. There were, however, significant differences in the patterns of postfeeding sound production when ♂ ♂ were compared to ♀ ♀ over a period of 8 weeks. Oscillograms of these sounds indicated that the songs differed between the sexes and also varied from time to time. The sounds were composed of frequencies up to 50 kHz with the exception of the ♂ prefeeding sounds which did not contain any ultrasonic components. The most dominant frequency was centered between 1.5–2.5 kHz. Peaks were also observed between 0.5–0.8 kHz and around 5 kHz and 9 kHz. Prefeeding songs were of a weaker intensity than postfeeding songs. It is suggested that the sounds associated with feeding behaviour play a role in attracting hungry flies to suitable hosts and that, the low frequency components having higher intensities (30–40 dB) than the ultrasonic frequencies (10 dB) carry the most important part of the acoustic information.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 15 (1980), S. 79-101 
    ISSN: 1432-1432
    Keywords: Molecules ; Interstellar ; Chemistry ; Isotopes ; Solar system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The study of interstellar molecules broadly includes two areas of interest. One area uses the unique ability of molecules to act as probes of the physical conditions in the cold, dense, visually opaque component of the interstellar medium. The physical properties of this and other components of the interstellar medium are summarized. The other area deals with the chemistry of interstellar molecules, recent aspects of which are emphasized in this review. Gas-phase chemistry, shock chemistry, and grain surface chemistry are discussed in the context of recent observations. No present observations suggest that surface reactions are relevant, but neither can they be ruled out. Ion-molecule reactions are clearly operative, at least for the simpler species. Chemical isotope fractionation is reviewed, andd it is concluded that the complexities of the chemistry allow no cosmological conclusions to be drawn from observations of deuterium in interstellar molecules, while the presence of13C in interstellar molecules permits an estimate of the12C/13C ratio which is consistent with the current concepts of the nucleosynthesis history of the Galaxy. Possible connections between interstellar molecules and the early molecular history of the solar system are discussed.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 118 (1980), S. 128-151 
    ISSN: 1420-9136
    Keywords: Galactic cosmic rays ; Solar proton events ; Particle precipitation ; Chemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract An assessment is made of the relative contribution of certain classes of energetic particle precipitation to the chemical composition of the middle atmosphere with emphasis placed on the production of odd nitrogen and odd hydrogen species and their subsequent role in the catalytic removal of ozone. Galactic cosmic radiation is an important source of odd nitrogen in the lower stratosphere but since the peak energy deposition occurs below the region where catalytic removal of O3 is most effective, it is questionable whether this mechanism is important in the overall terrestrial ozone budget. The precipitation of energetic solar protons can periodically produce dramatic enhancement in upper stratospheric NO. The long residence time of NO in this region of the atmosphere, where catalytic interaction with O3 is also most effective, mandates that this mechanism be included in future modelling of the global distribution of O3. Throughout the mesosphere the precipitation of energetic electrons from the outer radiation belt (60°≲Λ≲70°) can sporadically act as a major local source of odd hydrogen and odd nitrogen leading to observable O3 depletion. Future satellite studies should be directed at simultaneously measuring the precipitation flux and the concomitant atmosphere modification, and these results should be employed to develop more sophisticated models of this important coupling.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-0827
    Keywords: Bacterial amphophile ; Purification ; Chemistry ; Resorption ; Ca influx ; Cyclic AMP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The bone resorptive factor and amphipathic antigen (AcA) previously identified by us in preparations fromActinomyces viscosus have been partially purified, characterized chemically, and compared. They elute at the same location on chromatography with Ac 22. The fatty acid composition of AcA and the bone resorptive factor is the same. Some differences in carbohydrate composition are observed. TheActinomyces factor does not affect calcium influx or cyclic AMP in isolated bone cells. Therefore it is concluded that AcA stimulates resorption either by gaining entrance into bone cells or by way of a yet undetermined second messenger.
    Type of Medium: Electronic Resource
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