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1.
The Apteropanorpidae is a small family of scorpionflies endemic to Tasmania. The biology of the family is almost completely unknown. Here we present results of laboratory and field studies of the diet and feeding behavior of adult Apteropanorpidae. We describe the morphology of the alimentary canal and mouthparts and discuss the relationship between diet, feeding behavior and morphology. We compare these results to the feeding ecology of other extant Mecoptera, and speculate on the feeding strategies of fossil Mecoptera, placing all data in a phylogenetic context. Results show that adult Apteropanorpidae are most likely saprophagous in nature, predominantly on dead and decaying invertebrates.  相似文献   

2.
Polystyrene Petri dishes, aminated by a plasma deposition process, were surface modified by the covalent linking of two different enzymatically modified hairy regions (HRs) from pectin containing, for example, rhamnogalacturonan-I and xylogalacturonan structural elements. The two polysaccharide preparations share the same structural elements of apple pectin, but the relative amounts and lengths of the neutral side chains present differ. Surface analysis by X-ray photoelectron spectroscopy, contact angle measurement, and atomic force microscope (AFM) force-separation curves was used to characterize the effects on surface chemistry and interfacial forces of the surface modification process. Cell adhesion experiments using continuous L-929 fibroblasts and primary aortic smooth muscle cells were performed to evaluate the effect of the polysaccharide nature on cell adhesion. Results show that immobilization of the HR affects the interfacial field of forces and the cell behavior: "equilibrium" contact angles, obtained by a recently introduced vibrational approach, decrease after HR immobilization reaching a value close to 20 degrees . AFM force-separation curves show a more extended (or softer) interface in the case of the HR bearing longer side chains. Accordingly, depending on the HR preparation, cells shifted from spread morphology and adhesion behavior quantitatively comparable to that observed on conventional tissue culture polystyrene to rounded morphology and significantly lower adhesion. These data show that engineering of plant pectins can be a valuable tool to prepare novel and finely tuned polysaccharides having different chemico-physical and biological properties, to be used in the surface modification of medical devices and materials.  相似文献   

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External and internal thoracic structures of Nannochorista spp. are described in detail. The results are compared with conditions found in other endopterygote taxa, especially in members of Antliophora. Seventy-seven characters potentially useful for phylogenetic reconstruction are discussed, coded, presented as a data matrix and analysed cladistically. The thorax of Nannochorista shows a number of plesiomorphic characters compared with other mecopterans (except for Merope ) and members of the other antliophoran groups (e.g. presence of prospina and associated muscles). No specific affinities of thoracic features of Nannochoristidae and Diptera were found. The cladistic analysis results in strongly supported Antliophora (e.g. intraprofurcal muscle and ventral pleural arms present; bundle of M. mesonoto-pleuralis posterior originates on pleural arm). The thoracic characters do not support the monophyly of Mecoptera. This is possibly an artefact of the analysis. Several potential thoracic autapomorphies of the order are inapplicable in Boreidae, Siphonaptera and Diptera. Boreidae and Siphonaptera share a suite of characters related with flightlessness and are retrieved as sistertaxa when characters associated with wing reduction are predefined as irreversible. Merope appears exceptionally plesiomorphic in its thoracic morphology. Pistillifera (excluding Meropidae) and Panorpoidea (Panorpidae + Panorpodidae) are supported as clades. Due to the strongly modified thoracic morphology of Siphonaptera, the position of this group remains uncertain. The phylogenetic reconstruction using thoracic features alone is clearly impeded by far reaching modifications in Diptera in correlation with an advanced type of anteromotorism, and complex suites of reductional features in the secondary wingless forms.  相似文献   

5.
A new genus and species of fossil scorpionflies (Mecoptera) Baltipanorpa damzeni gen. et sp.n. is described from two well‐preserved male specimens in Baltic amber (middle Eocene: Lutetian). The most characteristic feature of the new taxon is an unusually developed postnotal organ on abdominal tergum IV. This is the most extremely developed example of this organ among Mecoptera and the only observation of notal and postnotal organs among fossil scorpionflies. The following combination of characters are provided to distinguish the new genus from other Panorpidae: Sc, short; R1 and R2 two‐branched; A1 joins posterior margin of wing only at same level as fork of vein Rs; unusual shape of abdomen, abdominal segments I–IV strongly reduced, abdominal segment V elongate and widened, segments VII and VIII strongly elongate; notal and postnotal organs present, strongly developed process (postnotal organ) on tergum IV, unknown in all described extant and fossil scorpionflies. Different types of notal organs of Mecoptera are compared and their function and morphology are discussed. Morphological analysis of notal and postnotal organs in extant species permits us to conclude that B. damzeni sp.n. is characterized by the most developed and complex notal organs in all Mecoptera.  相似文献   

6.
Many animal species have evolved signalling traits to mediate various intra-specific interactions. Signals are particularly important for inter-sexual selection, where females use male signalling traits to select mates. Female preferences are therefore a major selective force in the evolution of these male signals, and these preferences can facilitate rapid changes in these traits in an evolutionary timeframe. This introduction of high levels of variation in inter-sexual signals may overshadow any phylogenetic patterns present. Such shadowing effects, however, should be dependant on the characteristics of traits (e.g. morphological, physiological and behavioural). Using male advertisement calls from 72 species of anuran amphibians, we tested the levels of phylogenetic signal present for a variety of call features in relation to trait types, and for calls as whole units using phylogenetic principal components analysis. We found that most call features displayed some level of phylogenetic autocorrelation (or signal), with traits that are dependent on morphology having much stronger phylogenetic signals than those based on behaviour. In addition, when calls were analysed as whole units, closely related species were found to be similar to each other, indicating that phylogenetic patterns had not been cancelled out by selection via female preferences. We suggest that signal functions, such as indicating male quality (e.g. mediated by body size) to potential mates, may place constraints on the amount of variation that can be introduced by female preferences. More research, particularly studies on other taxa, will be required to elucidate whether the patterns found in anurans are general across the animal kingdom.  相似文献   

7.
Immunosensor using surface plasmon resonance (SPR) onto self-assembled protein G layer was developed for the detection of Legionella pneumophila. A self-assembled protein G layer on gold (Au) surface was fabricated by adsorbing a mixture of 11-mercaptoundecanoic acid (MUA) and hexanethiol (molar ratio of 1:2) and the activation process for chemical binding between free amine (-NH(2)) of protein G and 11-(MUA) using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDAC) in series. The formation of self-assembled protein G layer on Au substrate and the binding of antibody and antigen in series were confirmed by SPR spectroscopy. The surface morphology analyses of self-assembled protein G layer on Au substrate and monoclonal antibody against L. pneumophila immobilized on protein G were performed by atomic force microscope (AFM). The immunosensor for detection of L. pneumophila using SPR was developed and its detection limit could find up to 10(5) cells/ml.  相似文献   

8.
中国蕨类植物孢子形态的研究 Ⅰ. 海金沙科   总被引:9,自引:0,他引:9  
此文是中国蕨类植物孢子形态研究的第一部分。首次利用扫描电镜对国产海金沙科Lygodiaceae 海金沙属Lygodium 10种植物的孢子形态进行了观察,并利用透射电镜对孢壁的结构进行了研究。此 外,还对采自国外的另外10种海金沙属植物的孢子进行了比较观察。海金沙属孢子为三裂缝,少数为单 裂缝,其表面纹饰可分为4种类型:①瘤状纹饰,海金沙属多数种类的孢子具此类型;②表面平滑,L. palmatum、L. subareolatum、L.yunnanense、L. volubile 等属此类型;③疣状纹饰,L. dimorphum、L.digita- tum、L. kingii等属此类型;④网穴状纹饰,L. scandens,L.reticulatum等属此类型。网状纹饰类型的孢子表面轮廓是由外壁形成,其余类型的孢子表面轮廓由周壁形成。此文还对海金沙属的孢子特征及其在分类上的意义进行了探讨。  相似文献   

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To explore the molecular mechanisms responsible for the variation in smooth muscle contractile kinetics, the influence of MgATP, MgADP, and inorganic phosphate (P(i)) on force and shortening velocity in thiophosphorylated "fast" (taenia coli: maximal shortening velocity Vmax = 0.11 ML/s) and "slow" (aorta: Vmax = 0.015 ML/s) smooth muscle from the guinea pig were compared. P(i) inhibited active force with minor effects on the V(max). In the taenia coli, 20 mM P(i) inhibited force by 25%. In the aorta, the effect was markedly less (< 10%), suggesting differences between fast and slow smooth muscles in the binding of P(i) or in the relative population of P(i) binding states during cycling. Lowering of MgATP reduced force and V(max). The aorta was less sensitive to reduction in MgATP (Km for Vmax: 80 microM) than the taenia coli (Km for Vmax: 350 microM). Thus, velocity is controlled by steps preceding the ATP binding and cross-bridge dissociation, and a weaker binding of ATP is not responsible for the lower V(max) in the slow muscle. MgADP inhibited force and V(max). Saturating concentrations of ADP did not completely inhibit maximal shortening velocity. The effect of ADP on Vmax was observed at lower concentrations in the aorta compared with the taenia coli, suggesting that the ADP binding to phosphorylated and cycling cross-bridges is stronger in slow compared with fast smooth muscle.  相似文献   

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