Flexion Lines Research Articles

A new species of Metaspathius (Hymenoptera: Braconidae: Mesostoinae) from New Zealand

ABSTRACTMetaspathius gorgasoma Quicke & Ward sp. n. is described from specimens collected from litter samples. It is mainly characterised by the mesoscutum being strongly declivous anteriorly, a derived morphological feature not found in congeners. Wing structure of the new species including shape and loss of posterior longitudinal flexion lines (claval furrows) of both fore and hind wings indicate its close relationship with M. hemipterus Belokobylskij from which it is distinguished.

Morphology and evolution of the wing bullae in South American Leptophlebiidae (Ephemeroptera).

Insects were the first animals to take to the skies, and have been flying for over 320 million years. The order Ephemeroptera is, or at least is part of, the most early-diverging lineage of extant winged insects. The extant species present a very short adult life span, mainly dedicated to reproduction and dispersal of eggs. Mating and egg-laying behavior depend on flight. Wings are structures to fly and as such face a number of physical and physiological challenges. The convex curvature along the anterior-posterior axis of the wing generates a camber that must be carefully regulated. One of the most interesting ways of wing bending is provided by the bullae, which have been defined as short sections of flexible chitin, where the flexion lines cross veins. Although the bullae have been frequently used as taxonomic characters, there is no study focused on their morphology, although their prevalence on the wings of mayflies strongly suggests a role in flight. In order to identify evolutionary trends of these structures within Ephemeroptera, we constructed a matrix with comparative anatomy data of the bullae from whole mounts of the wings of 300 specimens belonging to 70 species of several mayfly families, as well as scanning microscopy samples of selected specimens. We also surveyed the number of bullae and their distribution in the wings of the different species within the South American Leptophlebiidae clade. We optimized the characters onto the latest published phylogeny for Leptophlebiidae.

Investigation of span-chordwise bending anisotropy of honeybee forewings.

ABSTRACTIn this study, the spanwise and chordwise bending stiffness EI of honeybee forewings were measured by a cantilevered bending test. The test results indicate that the spanwise EI of the forewing is two orders of magnitude larger than the chordwise EI. Three structural aspects result in this span-chordwise bending anisotropy: the distribution of resilin patches, the corrugation along the span and the leading edge vein of the venation. It was found that flexion lines formed by resilin patches revealed through fluorescence microscopy promoted the chordwise bending of the forewing during flapping flight. Furthermore, the corrugation of the wing and leading edge veins of the venation, revealed by micro-computed tomography, determines the relatively greater spanwise EI of the forewing. The span-chordwise anisotropy exerts positive structural and aerodynamic influences on the wing. In summary, this study potentially assists researchers in understanding the bending characteristics of insect wings and might be an important reference for the design and manufacture of bio-inspired wings for flapping micro aerial vehicles.

Development of a Low Cost, High Function 3D Printed Hand Prosthesis Using the Wrist Extension as Activator

Objective: The authors have developed a prosthesis for hand amputees or malformations that can be activeted mecanically through the moviment of the wrist using the wrist tenodesis pattern and not the the wrist flexion - finger flexion model available. The majority of models for this level of amputation available for free download on the internet, are activated by the the flexion of the wrist, not respecting the physiological and natural sinergical movement of extension of the wrist and flexion of fingers. Method: The 3D prosthesis device is composed by a forearm suport, a hand component with the metacarpals and carpals and four or five fingers, depending on the level of deformity or amputation, polyester lines flex the fingers and elastic bands extend the fingers on a return force and an adjustable traction of the lines that flex the fingers. Results: The invertion of the moving pattern was possible thanks to a mechanism composed by two concentric arcs at the axis of the wrist joint, where one is positioned at the hand and the other on the forearm support. Through a rolling part attached to the hand arc, the finger flexion lines are pulled by the extension of the wrist. The curve ratio of the arcs was projected to use only 20º of extension to produce a displacement of up to 30mm of the flexion lines in relation to the forearm support. This displacement may vary, according to the need, to finger sizes and force needed to perform the activities. Conclusion: Prosthesis prototyped on 3D printers are becoming very known world wide. The possibility of having a low cost device that can improve function and is not meant to substitute the limb, but better, improve the possibilities of action and interaction with the ambient.

BI-MODAL PALM PRINT AND KNUCKLE PRINT RECOGNITION SYSTEM

This paper proposed an innovative contact-less palm print and knuckle print recognition system. Palm print is referred to as line textures, which contains principal lines, wrinkles and ridges on the inner surface of the palm. On the other hand, knuckle print is denoted as the flexion lines on the inner skin of the knuckles of the fingers. These line patterns are unique and stable, and they offer abundance of useful information for personal recognition. We present a novel palm print and knuckle print tracking approach to automatically detect and capture these features from low resolution video stream. No constraint is imposed and the subject can place his/her hand naturally on top of the input sensor without touching any device. The palm print and knuckle print features are extracted using our proposed Wavelet Gabor Competitive Code and Ridget Transform methods. Several decision-level fusion rules are used to consolidate the scores output by the palm print and knuckle print experts. The fusion of these features yields promising result of EER=1.25% for verification rate.

The function of resilin in honeybee wings

The present work aimed to reveal morphological characteristics of worker honeybee (Apis mellifera) wings and demonstrate the function of resilin on camber changes during flapping flight. Detailed morphological investigation of the wings showed that different surface characteristics appear on the dorsal and ventral side of the honeybee wings and the linking structure connecting the forewing and hindwing plays an indispensable role in honeybee flapping flight. Resilin stripes were found on both the dorsal and ventral side of the wings, and resilin patches mostly existed on the ventral side. On the basis of resilin distribution, five flexion lines and three cambered types around the lines of passive deformation of the coupled-wing profile were obtained, which defined the deformation mechanism of the wing along the chord, i.e. concave, flat plate and convex. From a movie obtained using high-speed photography from three orthogonal views of free flight in honeybees, periodic changes of the coupled-wing profile were acquired and further demonstrated that the deformation mechanism is a fundamental property for variable deformed shapes of the wing profile during flapping flight, and, in particular, the flat wing profile achieves a nice transition between downstrokes and upstrokes.

ERRATUM: Kukalová-Peck J. & Beutel R.G. 2012: Is the Carboniferous †Adiphlebia lacoana really the "oldest beetle"? Critical reassessment and description of a new Permian beetle family. Eur. J. Entomol. 109(4): 633-645.

Kukalova-Peck J. & Beutel R.G. 2012: Is the Carboniferous †Adiphlebia lacoana really the oldest beetle? Critical reassessment and description of a new Permian beetle family. Eur. J. Entomol. 109(4): 633-645.Legend to Fig. 6 in the above paper failed to state the source of the photograph used in Fig. 6A. The source was the same paper by Bethoux et al. (2010) as for Fig. 6B. We reprint below the corrected legend for Fig. 6. Fig. 6. †Strephocladidae: †Homocladus grandis Carpenter, 1966, Late Carboniferous, Mazon Creek, Illinois. A - Fore wing, holotype, Fig. 1 from Bethoux et al. (2010) with lettering added. 1 - subcostal bulge; 2 - m brace formed by a cross-vein; 3 - flight-important mp-cua brace/fusion shared by Endoneoptera + Hemineoptera; 4 - claval line short, concave. B - †Homocladus cf. grandis, hind wing, Bethoux et al., 2010, Fig. 4. C - Same, venation and flexion lines verified by us with a photograph, fully homologized and identified by unified nomenclature as endoneopteran.

Virtual Intraaortic Endoscopy in Severe Calcific Aortic Stenosis

A 93-year-old woman with calcific aortic stenosis who required long-term hemodialysis was referred to our department because of hypotension during hemodialysis. Her echocardiogram showed severe calcific aortic stenosis and concentric left ventricular hypertrophy. Before and after hemodialysis, the left ventricular dimensions changed, and a peak pressure gradient varied from 92 to 53 mm Hg. The morphologic evaluation of the aortic valve was not reliable because of a poor acoustic window. At cardiac catheterization, the valve was not crossed with a catheter. Virtual intraaortic endoscopy was reconstructed from a cardiac electrocardiogram-gated 64-slice computed tomography image (Aquilion 64, Toshiba Medical Systems Corp, Tochigi-ken, Japan). Using the Ziostation 3-dimensional workstation software (Ziosoft Inc, Tokyo, Japan), the movement of the aortic valve could be demonstrated dynamically in all phases of the cardiac cycle, similar to a real intraaortic endoscopic image (Fig 1A; end diastole, 1B; end systole; LCO = left coronary ostium; RCO = right coronary ostium). The cusps were immobilized during systole by the calcific deposits along their flexion lines at their bases. Only the free borders of the cusps were mobilized (Fig 1B). Measurement of the aortic valve area showed it was 0.8 cm2 (Fig 2; LCO = left coronary ostium; RCO = right coronary ostium).Fig 2View Large Image Figure ViewerDownload (PPT) The patient underwent aortic valve replacement with a 17-mm Regent valve (St. Jude Medical, St. Paul, MN). Intraoperative findings confirmed the preoperative virtual endoscopic findings. The patient's postoperative course was uneventful. As the population continues to age, a greater number of patients with senile calcific aortic stenosis will become candidates for aortic valve replacement. We suggest that virtual intraaortic endoscopy might be an alternative diagnostic method to Doppler imaging and catheterization, particularly in patients with severe calcific aortic stenosis.

Bioprosthetic Valves and Laudable Inflammation?

In this issue of Circulation , Dr Manji and colleagues1 from the University of Alberta (Canada) report a series of animal experiments designed to test the mythic role of gluteraldehyde in preventing recognition of bioprosthetic heart valve antigenicity with subsequent rejection and failure. Gluteraldehyde–cross-linked xenograft tissues (initially porcine) have been used in the manufacturing of stented (and now stentless) heart valves since 1970. Original theories for the clinical efficacy of gluteraldehyde were based on its ability to irreversibly cross-link collagen and thus to increase mechanical strength and durability over fresh untanned cardiovascular tissues. Porcine valve leaflets, bovine pericardium, equine pericardium, and bovine jugular vein, among other structures, have been treated this way for clinical applications. Since its introduction, however, limitations and unexpected consequences of gluteraldehyde and similar chemical treatments have been recognized clinically. As pointed out by the authors, durability is quite variable, tending to be better in older patients whereas younger patients suffer early deterioration, calcification, and fibrocalcific failure.2,3 The good news has been that the failures tend to be progressive rather than catastrophic, leading to semielective reoperations. Additionally, the xenograft bioprostheses have been extremely helpful in avoiding warfarin in the very young and the very old, reducing the risk of thromboembolism. The traditional explanation for the fibrocalcific degeneration of the nonvital gluteraldehyde-treated bioprosthetic heart valves has been a combination of physical and chemical effects leading to calcification and a fixation of the structural proteins that prevent protein recycling and renewal. Mechanical theories of fatigue-induced wear resulting in calcification have been proposed, especially along the flexion lines of the cusps. Others have proposed that the gluteraldehyde has serendipitously “masked” the antigenicity of xenograft proteins, retained cells, and cellular debris, thus prolonging the period to calcification. This well-designed series of studies buttresses other studies demonstrating that gluteraldehyde fixation …

Hymenopteran wing kinematics: a qualitative study

(With 9 plates and 2 figures in the text)Wing deformations were studied in representatives of several hymenopteran families during free Right in hovering or near hovering conditions. The claval furrow, costal break, stigma and a variety of flexion lines occupying the wing apex are all involved in regulating forewing profile during the flight cycle in lchneumonidae and Tenthredinidae. In these families, as well as in the sphecid Sphex rujocincius, the median flexion line of the hindwing is also active in the terminal stages of supination. The plaiting fold of the vespid forewing plays an important role in profile control during the upstroke, reversing its polarity compared to rest. Little wing distortion was observed in the large scolids Scotia flavifrons and S. hirta, possibly attributable to the presence of strengthening ridges and grooves in the wing apex.

Wing folding and free‐flight kinematics in Coleoptera (Insecta): a comparative study

Relative movements of the main wing areas around the major flexion lines are compared during wing folding at rest, and during the supinatory phase of the flight cycle, which involves considerable wing deformation. Folding of the wing apex at rest is achieved by a combination of movements around the median flexion line (the main longitudinal flexion line), the principal transverse fold, and a variety of smaller, oblique ‘tucking’ folds. During flight, wing tip deformation is strongly influenced by elastic forces involved in the normal wing folding and unfolding processes. Those beetles possessing an inwardly sprung wing apex display partial folding at supination, associated with the temporary relaxation of the forces opposing spring recoil. These beetles also show enhanced mobility about the median flexion line which facilitates leading edge supination. The presence of the principal transverse fold may help to concentrate ventral flexure towards the wing tip. The wings of beetles possessing an outwardly‐sprung apex are much less affected by the presence of the flexion lines associated with folding. In these cases, enhanced supination of the leading edge, in the face of an overall increase in wing membrane stiffness, may be related to the presence of the highly‐sclerotized pterostigma.

Kinematics of take‐off and climbing flight in butterflies

High speed flash photography (flash duration 0.1 ms) was used to analyse wing movements in over 30 species of butterfly. With few exceptions, the insects showed a clap and peel mechanism of lift production at the start of the downstroke. Early in the upstroke the wings showed pronounced ventral flexure which, combined with inertial lag in the posterior parts of both wing pairs and delayed supination in the hind wing, led to the formation of a funnel‐like space between the wings. These movements, and the resultant airflow patterns, appear to be an axi‐symmetric equivalent of the ‘near’ clap and peel (here referred to as the funnel). Hind wing movements throughout the stroke are hinged upon the claval furrow. The expanded anal lobes of the hind wing lying medially to the claval furrow help to provide an air‐tight seal around the abdomen between the upper and lower wing surfaces, which increases the efficiency of the peel and funnel mechanisms. The role of the intercalary flexion lines in controlling changes in wing surface corrugation during the cycle is also investigated.

A Comparative Study of the Flight Mechanism of Diptera

ABSTRACT The mechanism of dipteran flight has been investigated in a comparative study involving thorax manipulation, analysis of high-speed films and direct observation of tethered flies under stroboscopic illumination. The click action observed in CCl4-anaesthetized Calliphora was found to be due to an interaction between the radial stop and the pleural wing process at the top of the upstroke. The movements occurring during unanaesthetized tethered flight were quite different as these structures were vertically separated except towards the bottom of the downstroke (Miyan & Ewing, 1985a,b). Results of observations on tethered insect flight and on morphology did not give full support to either the click mechanism (Boettiger & Furshpan, 1952) or the model of Miyan & Ewing. A novel model for the wingbeat is proposed. Distortion of the thorax brought about by the flight muscles results in upward and outward movement of the lateral scutum during the downstroke and inward and downward movement during the upstroke. In more advanced flies flexion lines result in a differentiated scutellar lever and parascutal shelf. Distortion is thereby limited largely to the posterior scutum. The parascutal shelf moves as a part of the scutal distortion, not as an independent element in the articulation, and the system is not bistable. The automatic changes in angle of attack are caused by inertial and aerodynamic forces acting around the torsional axis of the wing during the beat, which twist the compliant wing base.

Homology and function in the wings of Heteroptera

Abstract. The homology of veins and other wing characters in Heteroptera is reviewed in the light of palaeontology and new functional studies. A cladogram is given for the higher taxa of Hemiptera. It is probable that the vannus is an autapomorphy of Auchenorrhyncha+Heteropteroidea; that the leading edge vein of heteropteran fore‐ and hindwings is C+Sc; that Rs cannot be distinguished from R; that the hamus is part of M; that the glochis is a secondary structure. The difficulty of defining a vein is stressed. The functional significance of the hemielytron, cuneal fracture and longitudinal flexion lines is discussed. A preliminary ground‐plan for Heteroptera wings is presented.