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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Behavioral ecology and sociobiology 49 (2000), S. 24-30 
    ISSN: 1432-0762
    Keywords: Keywords  ; Testosterone ; Sexual selection ; Parental investment ; Mate attraction ; Sturnus vulgaris
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Previous studies have suggested that testosterone (T) profiles of male birds reflect a trade-off between mate attraction behaviours (requiring high T levels) and parental care activities (requiring low T levels). In this study, we experimentally elevated T levels of monogamous males in the facultatively polygynous European starling (Sturnus vulgaris), and compared mate attraction and paternal behaviour of T-treated males with those of controls (C-males). T-males significantly reduced their participation in incubation and fed nestlings significantly less often than C-males. Females paired to T-treated males did not compensate for their mate’s lower paternal effort. The observed reduction in a male’s investment in incubating the eggs was accompanied by an increased investment in typical female-attracting behaviours: T-males spent a significantly higher proportion of their time singing to attract additional females. They also occupied more additional nestboxes than C-males, although the differences just failed to be significant, and carried significantly more green nesting materials into an additional nestbox (a behaviour previously shown to serve a courtship function). T-males also behaved significantly more aggressively than C-males. During the nestling period, the frequency of mate-attracting behaviours by T-treated and control males no longer differed significantly. Despite the reduced paternal effort by T-males and the lack of compensation behaviour by females, hatching and breeding success did not differ significantly between T- and C-pairs.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 29 (1994), S. 103-111 
    ISSN: 1059-910X
    Keywords: Acetylcholinesterase ; NADHd ; NADPHd ; NOSynthase ; Enteric nervous system ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Using acetylcholinesterase (AChE), nicotinamide adenine dinucleotide diaphorase (NADHd), and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) enzyme histochemical techniques, the ganglionated plexuses of the porcine enteric nervous system were investigated in small intestine whole-mount preparations. Both AchE and NADHd techniques revealed a majority of the neurons in the ganglia of all three major plexuses. The AchE technique also demonstrated clearly the axodendritic networks of the plexus myentericus. Intraganglionic blank areas revealed the localization of negative cell groups. A very high correlation was found between the activity of both enzymes in one neuron, although this correlation was certainly not linear. Many neurons exhibited a stronger signal for one enzyme. A very small part of the positive nerve cells showed intense staining for both AchE and NADHd. The NADPHd technique demonstrated that the NADPHd-positive neurons fill the negative intraganglionic spaces in the ganglia. Double staining with the two other enzymes showed virtually no colocalization of NADPHd with either NADHd or AchE in the porcine jejunal enteric ganglia. Little negative intraganglionic spaces were seldom found, leaving room for perhaps still more negative enteric neurons. Based upon these results we suggest that the enteric neurons of the porcine small intestine can be subdivided into AchE-NADHd and NADPHd subpopulations. Since the latter colocalizes with the neuronal NO synthase enzyme, we further suggest a subdivision of the enteric nerve cells into AchE-NADHd and NOS-NADHd neurons. © 1994 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Publication Date: 2013-03-07
    Description: We experimentally validate a relatively recent electrokinetic formulation of the streaming potential (SP) coefficient as developed by Pride (1994). The start of our investigation focuses on the streaming potential coefficient, which gives rise to the coupling of mechanical and electromagnetic fields. It is found that the theoretical amplitude values of this dynamic SP coefficient are in good agreement with the normalized experimental results over a wide frequency range, assuming no frequency dependence of the bulk conductivity. By adopting the full set of electrokinetic equations, a full-waveform wave propagation model is formulated. We compare the model predictions, neglecting the interface response and modeling only the coseismic fields, with laboratory measurements of a seismic wave of frequency 500 kHz that generates electromagnetic signals. Agreement is observed between measurement and electrokinetic theory regarding the coseismic electric field. The governing equations are subsequently adopted to study the applicability of seismoelectric interferometry. It is shown that seismic sources at a single boundary location are sufficient to retrieve the 1D seismoelectric responses, both for the coseismic and interface components, in a layered model.
    Print ISSN: 1687-885X
    Electronic ISSN: 1687-8868
    Topics: Geosciences
    Published by Hindawi
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  • 4
    Publication Date: 1994-10-01
    Print ISSN: 1059-910X
    Electronic ISSN: 1097-0029
    Topics: Natural Sciences in General
    Published by Wiley
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  • 5
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    Unknown
    In:  CASI
    Publication Date: 2019-06-28
    Type: NACA-TM-608
    Format: application/pdf
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  • 6
    Publication Date: 2024-01-12
    Description: Morphometric analysis was carried out on wing muscles of the House Fly (Musca domestica), ranging from the pupation period to death. In the first week a clear increase was found in the percentage of food reserve consumed by the cell components. Both fibrils and sarcosomes increase in circumference during the first week. The sarcosomes then fuse.\nAfter the first week few changes occur. The sarcosomal volume increases in male flies. No disintegration or degeneration of the muscle cells appears with old age. Even the fact that the wing of the male flies exhibits abrasion earlier than that of females cannot be correlated with changes in the wing muscles. The ratio of fibrils to sarcosomes is greater than two to one. This ratio differs in males and females.\nA gradual decrease in the number of cristae per sarcosome was observed during ageing. This can influence the total activity of the sarcosome. The succinate dehydrogenase reaction is not dependent on age. The presence of two types of sarcosomes is unlikely. Sarcosomes with more cristae are of a darker colour than those with few cristae.
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/article
    Format: application/pdf
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