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  • 1
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Non-uniformity of fascicle parameters (fascicle lengths and orientation) within one skeletal muscle is well known. These parameters have an effect on the physiological cross-sectional area and lengthening rate of the skeletal muscle. Using a binocular microscope with a table driver (q- and p-axes) and vertical drive (v-axis) as a tool for reconstruction of the spatial orientation of single muscle fascicles, we developed an approach for three-dimensional analysis of the arrangement and length distribution in the skeletal muscle of small mammals. Two subunits of the triceps brachii muscle of the Galea musteloides forelimb, triceps longum and triceps laterale, were quantified and compared. Our data show that in the triceps laterale the fascicles are significantly longer (10.23 mm, SD=1.19, n=41) than those in the triceps longum (6.58 mm, SD=2.88, n=39). In the triceps laterale, the fascicle orientation is more or less uniform, whereas, in the triceps longum, there are two areas with different orientation of fascicles: anterior and posterior ones. Different inner architecture of the subunits can be interpreted as an adaptation to the main locomotory function of the triceps muscle, namely production of propulsive force during limb transfer phase and keeping dynamic stability during stance phase. Comparison of our data on the fascicle length and geometry with our previous histochemical results on G. musteloides, shows that the anterior region of the triceps longum, which differs in the fascicle orientation, also contains a significantly larger percent of slow muscle fibres. It is hypothesised here that this small region is involved in keeping posture.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Zoomorphology 116 (1996), S. 7-14 
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We describe hitherto unknown mechanoreceptors on the anterior spinnerets of the spider Cupiennius salei. These receptors are found at the base of the spigots of the major ampullate glands which produce the dragline used by the spider as a safety thread in various behavioral situations. There are 40–60 mechanoreceptors associated with two spigots of each anterior spinneret. They are likely to provide information on the forces pulling on the dragline and also on its orientation in space. A single sensillum consists of a hole in the cuticle covered by a thin cuticular membrane. It much resembles spider slit sensilla, which are known to detect strains in the exoskeleton. Each sensillum is supplied by two dendrites most likely belonging to two bipolar sensory cells. One of the dendrites ends at the covering membrane and the other more proximally. The sensilla are arranged with their long axes roughly parallel to the circumference of the spigots. External forces, transmitted by the dragline, result in deformation of the central part of the cuticular plate at the base of the spigots and thus in stimulation of the sensilla. This is shown electrophysiologically. Considering their morphology, topo- graphy, and electrophysiology, these mechanoreceptors are suggested to be important in the sensory control of dragline release by the spider.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of insect behavior 11 (1998), S. 73-92 
    ISSN: 1572-8889
    Keywords: sexual behavior ; female polymorphism ; releasers ; Odonata ; Coenagrion puella
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Coenagrion puella males search actively for mates and are not aggressive to other males. To study the role of visual cues in male–female discrimination, four types of models were used: (1) bodies of intact insects, (2) models of painted males, (3) models of male–female chimerae, and (4) models of female body parts. Abdomen coloration pattern and presence of wings were the most important cues for sexual recognition by males. Step-by-step elimination of male coloration pattern leads to an increase in the tandem response rate. A female model painted as a male repelled males like the intact male model. The absence of either the head or the thorax slightly decreased the number of tandem responses, but models without both the head and the thorax were not recognized as a mate. Abdomen thickness larger than that of a normal female decreased the attractiveness of the model. Models of the gynochrome female were significantly more attractive than models of the androchrome one. Female models containing male parts were less attractive than models without any structure at this place. Using principal-components analysis, it is shown that models repelling males usually were those containing an intact male abdomen or a female abdomen painted with blue. The results indicate that C. puella males can distinguish males from females visually by morphological structures and coloration pattern.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Plant ecology 131 (1997), S. 215-221 
    ISSN: 1573-5052
    Keywords: Ant-plant interactions ; Growth dynamics ; Microsites ; Seed dispersal ; Soil seed bank
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Non-myrmecochorous plant species are able to colonize Formica polyctena mounds. Galium aparine has been chosen as a model to study this kind of ant-plant association. In order to understand benefits to ants and plants, we have studied removal rates of fruits by ant workers, and compared soil seed material, seedling pattern and development of plants of the nest versus forest. Ant workers remove fruits at very low rates; removal time for half of the sample of 10 seeds was on average 5 h. Removed fruits were usually lost within 20–30 cm distance of the ant route. The soil samples from the nests contained a higher number of fruits, than those from randomly chosen sites in the forest. Seeds start to germinate in late August; on the F. polyctena mounds significantly earlier than at surrounding places. The seedling density was higher within experimental quadrats located on mound sites especially in late September–early October. The highest density of seedlings was on the slope of the mound. Plants from mounds are significantly longer, have a higher number of nodes during all stages of development and a higher mortality rate than that at surrounding places. The interactions between G. aparine and F. polyctena ants are asymmetrical. In spite of higher mortality rate of seedlings on mounds, ants provide some benefits to the plant. Firstly, workers are additional dispersal agents for G. aparine fruits. Furthermore, the soil peculiarities of ant mounds are beneficial for seed germination and seedling growth. G. aparine does not provide ants with energetically valuable food like plants with elaiosome-bearing seeds. Moreover, the high density of seedlings and plants on the mounds shades the nest.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 220 (1994), S. 139-146 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Central projections of sensilla on different parts of the endophytic ovipositor of the lestid damselfly Sympecma annulata are traced. Sensilla include apical hairs of the stylus (STh), hair rows on the ventral part of the valvula (Vh), and distal campaniform sensilla of upper (ULc) and lower (LLc) ovipositor leaves. Backfilling of afferent fibers, using anterograde cobalt fills, reveals the presence of contralaterally projecting fibers for all organs. The main fiber bundle of the LLc enters the terminal ganglion laterally via the genital nerve, but the fibers from ULc enter via the posterior nerve. Main fiber bundles of both leaves end in a lateral part of the ganglion called the lateral neuromere; they demonstrate that sensory information from the two leaves has the same target area. It is hypothesized that the independent pathways of nerves from upper and lower ovipositor leaves (ULc and LLc) may indicate the phylogenetic origin of these appendages from different abdominal segments - the lower leaf from the 8th and upper from 9th. The convergence of afferent fibers from the sensilla of the different ovipositor parts (median, anterior, and lateral processes) in common ganglionic centers may provide the anatomical basis to account for coordination of the movements of different ovipositor parts during oviposition. © 1994 Wiley-Liss, Inc.
    Additional Material: 25 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Publication Date: 2005-10-31
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
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  • 7
    Publication Date: 2003-09-05
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
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  • 8
    Publication Date: 2006-06-01
    Print ISSN: 0034-6748
    Electronic ISSN: 1089-7623
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
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  • 9
    Publication Date: 2015-09-15
    Print ISSN: 0091-7613
    Electronic ISSN: 1943-2682
    Topics: Geosciences
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  • 10
    Publication Date: 2016-03-25
    Description: Dragonfly wings are known as biological composites with high morphological complexity. They mainly consist of a network of rigid veins and flexible membranes, and enable insects to perform various flight manoeuvres. Although several studies have been done on the aerodynamic performance of Odonata wings and the mechanisms involved in their deformations, little is known about the influence of vein joints on the passive deformability of the wings in flight. In this article, we present the first three-dimensional finite-element models of five different vein joint combinations observed in Odonata wings. The results from the analysis of the models subjected to uniform pressures on their dorsal and ventral surfaces indicate the influence of spike-associated vein joints on the dorsoventral asymmetry of wing deformation. Our study also supports the idea that a single vein joint may result in different angular deformations when it is surrounded by different joint types. The developed numerical models also enabled us to simulate the camber formation and stress distribution in the models. The computational data further provide deeper insights into the functional role of resilin patches and spikes in vein joint structures. This study might help to more realistically model the complex structure of insect wings in order to design more efficient bioinspired micro-air vehicles in future.
    Keywords: biomimetics
    Electronic ISSN: 2054-5703
    Topics: Natural Sciences in General
    Published by Royal Society
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