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131.
Johannes Stökl Robert Twele Dirk H. Erdmann Wittko Francke Manfred Ayasse 《Chemoecology》2007,17(4):231-233
Summary.
Ophrys flowers mimic the female produced sex pheromone of their pollinator species to attract males for pollination. The males try
to copulate with the putative female and thereby pollinate the flower. Using electrophysiological and chemical analyses, floral
volatiles released by O. iricolor as well as the female sex pheromone of its pollinator species, Andrena morio are investigated. Overall, 38 peaks comprising 41 chemical compounds, were found to release reactions in the antennae of
male A. morio bees. Analyses using coupled gas chromatography-mass spectrometry revealed the presence of alkanes and alkenes with 20 to
29 carbon atoms, aldehydes (C9 to C24) and two esters. Almost all of those compounds were found in similar proportions in
both, the floral extracts of O. iricolor and cuticle surface extracts of A. morio females. The pattern of biologically active volatiles described here is very similar to that used by other Ophrys species pollinated by Andrena males. 相似文献
132.
133.
Gudrun Fricke Jörg Hellhammer Andreas Klamt Jan Meerkamp van Embden Manfred Rose Birgit Sewekow Rolf Wittlinger 《Environmental Sciences Europe》1995,7(5):275-279
The substituent chlorine is generally considered to be an agent which reduces the reactivity of organic molecules with regard to the indirect photodegradation by OH radicals. A systematic study of selected, representative classes of compounds, however, reveals that the deactivating influence of chlorine on the OH radical reactivity is actually rather moderate. In individual cases, for instance, chlorine substitution can even lead to an increase in this reactivity. This study is based on both experimental data and on the molecular orbital calculations of OH radical reactivity. 相似文献
134.
Sekretorisch tätige Zellen im Nervensystem von Ascaris 总被引:1,自引:0,他引:1
135.
The Science of Nature - Morphological indications and new experimental results demonstrate that neurosecretory peptides or low-molecular proteins, respectively, appear to effect as mediators in... 相似文献
136.
Patricia L. Jones Rachel A. Page Manfred Hartbauer Bj?rn M. Siemers 《Behavioral ecology and sociobiology》2011,65(2):333-340
Eavesdropping on prey communication signals has never before been reported for a Palearctic bat species. In this study, we
investigated whether lesser and greater mouse-eared bats, Myotis blythii oxygnathus and Myotis myotis, find tettigoniid bushcrickets (Tettigoniidae) by eavesdropping on their mate-attraction song. Tettigoniids are known to
be the most important prey item for M. blythii oxygnathus, while carabid beetles and other epigaeic arthropods are the most important prey for its sibling species, M. myotis, in many places in Europe. M. myotis locates walking beetles by listening for their rustling sounds. We compared these two species’ response to four acoustic
prey cues: calling song of two tettigoniid species, the rustling sound made by walking carabid beetles, and a control tone.
Individuals of both bat species attacked the speaker playing tettigoniid song, which clearly indicates that both species eavesdrop
on prey-generated advertisement signals. There were, however, species differences in response. M. blythii oxygnathus exhibited stronger predatory responses to the calling song of two species of tettigoniid than to the beetle rustling sound
or the control. M. myotis, in contrast, exhibited stronger predatory responses to the beetle rustling and to one tettigoniid species but not the other
tettigoniid or the control. Our study (1) for the first time demonstrates eavesdropping on prey communication signals for
Palearctic bats and (2) gives preliminary evidence for sensory niche partitioning between these two sympatric sibling bat
species. 相似文献
137.
Hybrid life-cycle assessment employing input–output analysis has advantages over conventional methods. In the inventory phase of a hybrid assessment, the data collection and the boundary selection can be tailored by using structural path analysis. This technique was applied to recent Australian data in order to determine environmentally important input paths in terms of energy consumption, land disturbance, water use, and emissions of greenhouse gases, NOx, and SO2, for all Australian industry sectors. Due to the complexity of inter-industrial transactions, up to third-order paths can be top-ranking. The identification of such paths is considerably more labour-intensive in conventional life-cycle assessments. 相似文献
138.
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140.
The populations of European great cormorants (Phalacrocorax carbo) and North American double-crested cormorants (Phalacrocorax auritus) have increased sharply over the last decades and these piscivorous birds are suspected to deplete valuable fish stocks and
compete with human fisheries. Beyond direct consumption of fish, cormorants are accused of injuring vast numbers of prey without
eating them. Using underwater video systems, one of them mounted onto the back of tame Chinese cormorants, we evaluated the
proportion of successful pursuits of cormorants on live fish. Trials were conducted with 6 great cormorants and 9 double-crested
cormorants and involved a total of 676 prey pursuits. We show that, although they are regarded as highly efficient predators,
cormorants aborted about half of their pursuits. However, detailed analysis of prey-capture behaviour in double-crested cormorants
revealed that only 0.4% of the prey pursued was injured without being ingested. Further studies using miniature video systems
deployed on free-ranging cormorants are required to complement our knowledge of their hunting tactics. 相似文献