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  • 1
    Electronic Resource
    Electronic Resource
    Visual Cues in Mate Recognition by Males of the Damselfly, Coenagrion puella (L.) (Odonata: Coenagrionidae) (1998)
    Springer
    Journal of insect behavior 11 (1998), S. 73-92 
    Details
    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
    URL: http://dx.doi.org/10.1023/A:1020818617066
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  • 2
    Electronic Resource
    Electronic Resource
    Three-dimensional analysis of the arrangement and length distribution of fascicles in the triceps muscle of Galea musteloides (Rodentia, Cavimorpha) (2000)
    Springer
    Zoomorphology 120 (2000), S. 91-97 
    Details
    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
    URL: http://dx.doi.org/10.1007/s004350000026
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  • 3
    Electronic Resource
    Electronic Resource
    A new mechanosensory organ on the anterior spinnerets of the spider Cupiennius salei (Araneae, Ctenidae) (1996)
    Springer
    Zoomorphology 116 (1996), S. 7-14 
    Details
    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
    URL: http://dx.doi.org/10.1007/PL00008492
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  • 4
    Electronic Resource
    Electronic Resource
    Central projections of ovipositor sense organs in the damselfly, Sympecma annulata (Zygoptera, Lestidae) (1994)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 220 (1994), S. 139-146 
    Details
    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
    URL: http://dx.doi.org/10.1002/jmor.1052200204
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  • 5
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    Evidence for capillarity contributions to gecko adhesion from single spatula nanomechanical measurements (2005)
    National Academy of Sciences
    Details
    Publication Date: 2005-10-31
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
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  • 6
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    multiple vein joints in dragonfly wings (2016)
    Royal Society
    Details
    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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  • 7
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    Frog tongue adhesion (2015)
    Royal Society
    Details
    Publication Date: 2015-10-01
    Description: Frogs are well known to capture fast-moving prey by flicking their sticky tongues out of the mouth. This tongue projection behaviour happens extremely fast which makes frog tongues a biological high-speed adhesive system. The processes at the interface between tongue and prey, and thus the mechanism of adhesion, however, are completely unknown. Here, we captured the contact mechanics of frog tongues by filming tongue adhesion at 2000 frames per second through an illuminated glass. We found that the tongue rolls over the target during attachment. However, during the pulling phase, the tongue retractor muscle acts perpendicular to the target surface and thus prevents peeling during tongue retraction. When the tongue detaches, mucus fibrils form between the tongue and the target. Fibrils commonly occur in pressure-sensitive adhesives, and thus frog tongues might be a biological analogue to these engineered materials. The fibrils in frog tongues are related to the presence of microscopic papillae on the surface. Together with a layer of nanoscale fibres underneath the tongue epithelium, these surface papillae will make the tongue adaptable to asperities. For the first time, to the best of our knowledge, we are able to integrate anatomy and function to explain the processes during adhesion in frog tongues.
    Keywords: biomechanics, biomaterials, materials science
    Electronic ISSN: 2054-5703
    Topics: Natural Sciences in General
    Published by Royal Society
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  • 8
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    Dragonfly wing veins (2016)
    Royal Society
    Details
    Publication Date: 2016-02-27
    Description: Insect wing veins are biological composites of chitin and protein arranged in a complex lamellar configuration. Although these hierarchical structures are found in many ‘venous wings' of insects, very little is known about their physical and mechanical characteristics. For the first time, we carried out a systematic comparative study to gain a better understanding of the influence of microstructure on the mechanical characteristics and damping behaviour of the veins. Morphological data have been used to develop a series of three-dimensional numerical models with different material properties and geometries. Finite-element analysis has been employed to simulate the mechanical response of the models under different loading conditions. The modelling strategy used in this study enabled us to determine the effects selectively induced by resilin, friction between layers, shape of the cross section, material composition and layered structure on the stiffness and damping characteristics of wing veins. Numerical simulations suggest that although the presence of the resilin-dominated endocuticle layer results in a much higher flexibility of wing veins, the dumbbell-shaped cross section increases their bending rigidity. Our study further shows that the rubber-like cuticle, friction between layers and material gradient-based design contribute to the higher damping capacity of veins. The results of this study can serve as a reference for the design of novel bioinspired composite structures.
    Keywords: structural biology, biomimetics, computational biology
    Electronic ISSN: 2054-5703
    Topics: Natural Sciences in General
    Published by Royal Society
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  • 9
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    Porosity on Photoresponse of LCE (2016)
    Royal Society
    Details
    Publication Date: 2016-04-08
    Description: Azobenzene containing liquid crystal elastomers (LCEs) are among of the most prominent photoresponsive polymers due to their fast and reversible response to different light stimuli. To bring new functions into the present framework, novel modifications in bulk material morphology are required. Therefore, we produced azobenzene LCE free-standing films with different porosities. While the porosity provided macroscopic morphological changes, at the same time, it induced modifications in alignment of liquid crystal azobenzene units in the films. We found that a high porosity increased the photoresponse of the LCE in terms of bending angle with high significance. Moreover, the porous LCE films showed similar bending forces to those of pore-free LCE films.
    Keywords: materials science, mechanics
    Electronic ISSN: 2054-5703
    Topics: Natural Sciences in General
    Published by Royal Society
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  • 10
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    Material composition of the mouthpart cuticle in a damselfly larva (Insecta: Odonata) and its biomechanical significance (2018)
    Royal Society
    Details
    Publication Date: 2018-06-14
    Description: Odonata larvae are key predators in their habitats. They catch prey with a unique and highly efficient apparatus, the prehensile mask. The mandibles and maxillae, however, play the lead in handling and crushing the food. The material composition of the cuticle in the biomechanical system of the larval mouthparts has not been studied so far. We used confocal laser scanning microscopy (CLSM) to detect material gradients in the cuticle by differences in autofluorescence. Our results show variations of materials in different areas of the mouthparts: (i) resilin-dominated pads within the membranous transition between the labrum and the anteclypeus, which support mobility and might provide shock absorption, an adaptation against mechanical damage; (ii) high degrees of sclerotization in the incisivi of the mandibles, where high forces occur when crushing the prey's body wall. The interaction of the cuticle geometry, the material composition and the related musculature determine the complex concerted movements of the mouthparts. The material composition influences the strength, mobility and durability of the cuticular components of the mouthparts. Applying CLSM for extracting information about material composition and material properties of arthropod cuticles will considerably help improve finite-element modelling studies.
    Keywords: biomechanics, evolution
    Electronic ISSN: 2054-5703
    Topics: Natural Sciences in General
    Published by Royal Society
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