scholarly journals The correlation between wing kinematics and steering muscle activity in the blowfly Calliphora vicina

2001 ◽  
Vol 204 (24) ◽  
pp. 4213-4226
Author(s):  
Claire N. Balint ◽  
Michael H. Dickinson
Keyword(s):  
Muscle Activity ◽  
High Speed ◽  
The Body ◽  
Calliphora Vicina ◽  
Strongly Correlated ◽  
Motor Patterns ◽  
Wing Kinematics ◽  
Wing Motion ◽  
The Relationship ◽  
Electromyographic Signals

SUMMARY Determining how the motor patterns of the nervous system are converted into the mechanical and behavioral output of the body is a central goal in the study of locomotion. In the case of dipteran flight, a population of small steering muscles controls many of the subtle changes in wing kinematics that allow flies to maneuver rapidly. We filmed the wing motion of tethered Calliphora vicina at high speed and simultaneously recorded multi-channel electromyographic signals from some of the prominent steering muscles in order to correlate kinematics with muscle activity. Using this analysis, we found that the timing of each spike in the basalare muscles was strongly correlated with changes in the deviation of the stroke plane during the downstroke. The relationship was non-linear such that the magnitude of the kinematic response to each muscle spike decreased with increasing levels of stroke deviation. This result suggests that downstroke deviation is controlled in part via the mechanical summation of basalare activity. We also found that interactions among the basalares and muscles III2–III4 determine the maximum forward amplitude of the wingstroke. In addition, activity in muscle I1 appears to participate in a wingbeat gearing mechanism, as previously proposed. Using these results, we have been able to correlate changes in wing kinematics with alteration in the spike rate, firing phase and combinatorial activity of identified steering muscles.

The C-start escape response ofPolypterus senegalus: bilateral muscle activity and variation during stage 1 and 2

2002 ◽  
Vol 205 (17) ◽  
pp. 2591-2603 ◽  
Author(s):  
Eric D. Tytell ◽  
George V. Lauder
Keyword(s):  
Muscle Activity ◽  
Escape Response ◽  
High Speed ◽  
Wave Speed ◽  
Activity Patterns ◽  
Motor Pattern ◽  
The Body ◽  
Wide Range ◽  
Fast Start ◽  
Stage 1

SUMMARYThe fast-start escape response is the primary reflexive escape mechanism in a wide phylogenetic range of fishes. To add detail to previously reported novel muscle activity patterns during the escape response of the bichir, Polypterus, we analyzed escape kinematics and muscle activity patterns in Polypterus senegalus using high-speed video and electromyography (EMG). Five fish were filmed at 250 Hz while synchronously recording white muscle activity at five sites on both sides of the body simultaneously (10 sites in total). Body wave speed and center of mass velocity, acceleration and curvature were calculated from digitized outlines. Six EMG variables per channel were also measured to characterize the motor pattern. P. senegalus shows a wide range of activity patterns, from very strong responses, in which the head often touched the tail, to very weak responses. This variation in strength is significantly correlated with the stimulus and is mechanically driven by changes in stage 1 muscle activity duration. Besides these changes in duration, the stage 1 muscle activity is unusual because it has strong bilateral activity, although the observed contralateral activity is significantly weaker and shorter in duration than ipsilateral activity. Bilateral activity may stiffen the body, but it does so by a constant amount over the variation we observed; therefore, P. senegalus does not modulate fast-start wave speed by changing body stiffness. Escape responses almost always have stage 2 contralateral muscle activity, often only in the anterior third of the body. The magnitude of the stage 2 activity is the primary predictor of final escape velocity.

scholarly journals Operation of the alula as an indicator of gear change in hoverflies

2011 ◽  
Vol 9 (71) ◽  
pp. 1194-1207 ◽  
Author(s):  
Simon M. Walker ◽  
Adrian L. R. Thomas ◽  
Graham K. Taylor
Keyword(s):  
High Speed ◽  
Aerodynamic Force ◽  
Angular Acceleration ◽  
The State ◽  
The Body ◽  
Kinematic Parameters ◽  
Wing Kinematics ◽  
Change Mechanism ◽  
The Third ◽  
Gear Change

The alula is a hinged flap found at the base of the wings of most brachyceran Diptera. The alula accounts for up to 10 per cent of the total wing area in hoverflies (Syrphidae), and its hinged arrangement allows the wings to be swept back over the thorax and abdomen at rest. The alula is actuated via the third axillary sclerite, which is a component of the wing hinge that is involved in wing retraction and control. The third axillary sclerite has also been implicated in the gear change mechanism of flies. This mechanism allows rapid switching between different modes of wing kinematics, by imposing or removing contact with a mechanical stop limiting movement of the wing during the lower half of the downstroke. The alula operates in two distinct states during flight—flipped or flat—and we hypothesize that its state indicates switching between different flight modes. We used high-speed digital video of free-flying hoverflies ( Eristalis tenax and Eristalis pertinax ) to investigate whether flipping of the alula was associated with changes in wing and body kinematics. We found that alula state was associated with different distributions of multiple wing kinematic parameters, including stroke amplitude, stroke deviation angle, downstroke angle of incidence and timing of supination. Changes in all of these parameters have previously been linked to gear change in flies. Symmetric flipping of the alulae was associated with changes in the symmetric linear acceleration of the body, while asymmetric flipping of the alulae was associated with asymmetric angular acceleration of the body. We conclude that the wings produce less aerodynamic force when the alula is flipped, largely as a result of the accompanying changes in wing kinematics. The alula changes state at mid-downstroke, which is the point at which the gear change mechanism is known to come into effect. This transition is accompanied by changes in the other wing kinematic parameters. We therefore find that the state of the alula is linked to the same parameters as are affected by the gear change mechanism. We conclude that the state of the alula does indeed indicate the operation of different flight modes in Eristalis , and infer that a likely mechanism for these changes in flight mode is the gear change mechanism.

The relationship between the body shape of living pigs and their carcass morphology and composition

2004 ◽  
Vol 79 (1) ◽  
pp. 73-83 ◽  
Author(s):  
A. B. Doeschl ◽  
D. M. Green ◽  
C. T. Whittemore ◽  
C. P. Schofield ◽  
A. V. Fisher ◽  
...  
Keyword(s):  
Linear Regression ◽  
Body Length ◽  
Live Weight ◽  
The Body ◽  
Strongly Correlated ◽  
Muscle Weight ◽  
Data Set ◽  
Weight Variation ◽  
Rate Of Increase ◽  
The Relationship

AbstractThe conformation, tissue composition, and chemical composition of three types of pigs, given food ad libitum and slaughtered over a nominal live weight range of 35 to 115 kg, was assessed in relation to data provided on the live animals by a visual image analysis (VIA) system. The pig types were named as ‘3⁄4 Landrace’, ‘1⁄2 Pietrain’, and ‘1⁄4 Meishan’ types, representing ‘attenuated’, ‘blocky’, and ‘flabby’ types. Three analyses of the shape, conformation and composition data were performed. First, the relationship between conformation and age/size was assessed using linear regression of logarithmically transformed VIA and carcass data. In relation to age, ‘1⁄2 Pietrain’ pigs were found by both VIA and carcass measurements to have the widest shoulders. Both analyses also found this type to have the widest ham, trunk, and shoulders in relation to body length across most of the body length range studied, although the greatest rate of increase in ham width in relation to body length was found in the ‘1/4 Meishan’ type pigs. Second, the relationship between composition and VIA shape was examined using linear regression of transformed and standardized data. Significant relationships were found between fat, lipid, muscle, and protein weight and VIA shape, although relationships were weaker for protein and muscle weight. For fat and lipid, the VIA shape measures from the trunk region proved the most informative, whereas the VIA ham measures proved the most informative for muscle and protein. Third, detrended measures of composition/conformation and shape were used to remove the effect of animal size from the data. Removal of the variation due to growth generally led to substantial decreases in the adjusted R2statistics and in the R2-like statistics for prediction. Although in the models without detrending, relative fat and lipid weight had been found most strongly correlated with VIA shape, relative muscle was found most strongly correlated with shape in the detrended data. This was considered to result from the low between-animal variation in the data set combined with greater across-weight variation in fat and lipid weights than muscle and protein weights in the data without trend removal. Future trials with greater between-animal variation imposed would allow more precise determination of the relationship between conformation and shape.

scholarly journals The Relationship between Simple Snoring and Sleep Bruxism: A Polysomnographic Study

2020 ◽  
Vol 17 (23) ◽  
pp. 8960
Author(s):  
Monika Michalek-Zrabkowska ◽  
Mieszko Wieckiewicz ◽  
Piotr Macek ◽  
Pawel Gac ◽  
Joanna Smardz ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Body Position ◽  
Sleep Bruxism ◽  
The Body ◽  
Study Group ◽  
Upper Aerodigestive Tract ◽  
Obstructive Sleep ◽  
Supine Sleep ◽  
The Relationship ◽  
Simple Snoring

Simple snoring is defined as the production of sound in the upper aerodigestive tract during sleep, not accompanied by other pathologies. Sleep bruxism (SB) refers to repetitive phasic, tonic, or mixed masticatory muscle activity during sleep. In this study, we investigated the relationship between simple snoring and SB in patients without obstructive sleep apnea (OSA). A total of 565 snoring subjects underwent polysomnography. After examination, individuals with OSA were excluded from the study group. Finally, 129 individuals were analyzed. The bruxism episode index was positively correlated with maximum snore intensity. Phasic bruxism was positively correlated with snore intensity in all sleep positions. Bruxers had a significantly decreased average and minimum heart rate compared with non-bruxers. Supine sleep position seemed to have a significant impact on snore intensity and SB. In summary, our study showed the relationship between SB, snore intensity, and body position. Phasic bruxism was positively correlated with snore intensity despite the body position, which is an interesting and novel finding.

Environmental effects on undulatory locomotion in the American eel Anguilla rostrata: kinematics in water and on land

1998 ◽  
Vol 201 (7) ◽  
pp. 949-961 ◽  
Author(s):  
G. B. Gillis
Keyword(s):  
Muscle Activity ◽  
High Speed ◽  
Activity Patterns ◽  
The Body ◽  
Anguilla Rostrata ◽  
American Eel ◽  
Terrestrial Locomotion ◽  
Average Maximum ◽  
Undulatory Locomotion ◽  
Longitudinal Position

Historically, the study of swimming eels (genus Anguilla) has been integral to our understanding of the mechanics and muscle activity patterns used by fish to propel themselves in the aquatic environment. However, no quantitative kinematic analysis has been reported for these animals. Additionally, eels are known to make transient terrestrial excursions, and in the past it has been presumed (but never tested) that the patterns of undulatory movement used terrestrially are similar to those used during swimming. In this study, high-speed video was used to characterize the kinematic patterns of undulatory locomotion in water and on land in the American eel Anguilla rostrata. During swimming, eels show a nonlinear increase in the amplitude of lateral undulations along their bodies, reaching an average maximum of 0.08L, where L is total length, at the tip of the tail. However, in contrast to previous observations, the most anterior regions of their bodies do not undergo significant undulation. In addition, a temporal lag (typically 10–15 % of an undulatory cycle) exists between maximal flexion and displacement at any given longitudinal position. Swimming speed does not have a consistent effect on this lag or on the stride length (distance moved per tailbeat) of the animal. Speed does have subtle (although statistically insignificant) effects on the patterns of undulatory amplitude and intervertebral flexion along the body. On land, eels also use lateral undulations to propel themselves; however, their entire bodies are typically bent into waves, and the undulatory amplitude at all body positions is significantly greater than during swimming at equivalent speeds. The temporal lag between flexion and displacement seen during swimming is not present during terrestrial locomotion. While eels cannot move forwards as quickly on land as they do in water, they do increase locomotor speed with increasing tailbeat frequency. The clear kinematic distinctions present between aquatic and terrestrial locomotor sequences suggest that eels might be using different axial muscle activity patterns to locomote in the different environments.

Forewing asymmetries during auditory avoidance in flying locusts

1997 ◽  
Vol 200 (17) ◽  
pp. 2323-2335 ◽  
Author(s):  
J Dawson ◽  
K Dawson-Scully ◽  
D Robert ◽  
R. M. Robertson
Keyword(s):  
High Speed ◽  
Stimulus Onset ◽  
Wingbeat Frequency ◽  
Motor Patterns ◽  
Wing Kinematics ◽  
Roll Torque ◽  
High Speed Cinematography ◽  
Left And Right ◽  
The Asymmetry ◽  
Stroke Amplitude

Flying locusts orient to sounds in their environment. Sounds similar to those produced by echolocating bats cause a flying locust to change its flight path. We used high-speed cinematography and videography to study changes in body posture and wing kinematics of tethered locusts in response to stimulation with bat-like sounds. Locusts showed both negative and positive phonotaxis to this stimulus. Within a few wingbeats of stimulus onset (between 126 and 226ms), locusts deflected their abdomens to one side, and the angle of the left and right forewings with respect to the dorsal­ventral body axis became asymmetrical during the downstroke. This forewing asymmetry, in which the forewing on the inside of the turn became more depressed, ranged from 20 to 45° (37±9.7°, mean ± s.d.) and was correlated with the direction and magnitude of abdomen deflection, a measure of steering in tethered, flying locusts. Hindwing stroke angle asymmetries were minimal or non-existent after stimulation. Coincident with changes in forewing asymmetry and abdomen deflection was a decrease in stroke amplitude (19±6.5°) of the forewing on the inside of the attempted turn. Motor patterns from forewing first basalar (M97) muscles showed an asymmetry in the timing of left and right depressor activation that ranged from 10.4 to 1.6ms (4.23±2.85ms). The number of spikes per depressor burst increased to a maximum of three spikes in the muscle on the inside of the attempted turn, and depressor frequency (wingbeat frequency) increased by approximately 2Hz (2.17±0.26Hz). We suggest that the asymmetry in forewing first basalar activity is causally related to the asymmetry in the timing of the initiation of the downstroke, resulting in an asymmetry in the ranges of the stroke angles of the forewings, which would impart a roll torque to the locust. This would augment the steering torques generated by concurrent changes in the angle of attack of the fore- and hindwings and changes in abdomen position to effect rapid avoidance manoeuvres.

Independent Velocity Measurement of Small Underwater High-Speed Moving Body Based on External Turbine

2013 ◽  
Vol 300-301 ◽  
pp. 967-973
Author(s):  
Yong Chen ◽  
He Zhang ◽  
Qi Jiang ◽  
De Zhang Shen
Keyword(s):  
Rotational Speed ◽  
Velocity Measurement ◽  
High Speed ◽  
The Body ◽  
Dynamics Simulation ◽  
Signal Process ◽  
Speed Measurement ◽  
Moving Body ◽  
The Relationship ◽  
Process Method

Combining with rotational speed measurement methods and underwater environment particularity, an independent velocity measurement scheme applicable to small underwater high-speed moving body was proposed in this paper. The structural design of the measurement device was designed and signal process method was improved, and the relationship between turbine rotational speed and speed of the body was obtained by FLUNET dynamics simulation and water tunnel experiments. Finally, the simulation and experimental results were analyzed. The results show that this method is effective and feasible within a certain range of accuracy.

Influence of Water-Splash Formation by a Hydrophilic Body Plunging Into Water

2011 ◽  
Author(s):  
Yoshihiro Kubota ◽  
Osamu Mochizuki
Keyword(s):  
Formation Process ◽  
High Speed ◽  
Film Formation ◽  
Water Film ◽  
Acrylic Resin ◽  
The Body ◽  
Water Splash ◽  
The Difference ◽  
Film Separation ◽  
The Relationship

The objective of this study is to understand the relationship between water-splash formation and the surface conditions of bodies plunging into the water’s surface by considering hydrophilicity strength. A hydrophilic body (constructed with hydrogel), as well as an acrylic resin body, was created to understand the influence of hydrophilicity on splash formation. The strength of hydrophilicity was determined by investigating degrees of swelling. We obtained consecutive images of splash formation by using a high-speed CMOS camera. We show that water-splash formation is related to water-film formation by studying: 1) droplets formed at the film edge, 2) mushroom-or dome-type splashes caused by film impinging, and 3) crown-type splash caused by film separation. The strength of hydrophilicity affects the splash-formation process of the mushroom- and crown-type splashes. The difference in formation process is caused when the film velocity increases with hydrophilicity. As the film velocity increases with strong hydrophilicity, the film flow separates from the body surface and an air cavity forms. Crown-type splashes form with hydrophilic bodies because such film separation occurs. Moreover, the relationship between the strength of hydrophilicity and film velocity was examined empirically. These results indicate that the hydrophilic body does not alter the splash-formation process.

Experimental and Numerical Study on Flapping Wing Kinematics and Aerodynamics of Coleoptera

2006 ◽  
Vol 326-328 ◽  
pp. 175-178 ◽  
Author(s):  
Saputra ◽  
Do Young Byun ◽  
Yung Hwan Byun ◽  
Hoon Cheol Park
Keyword(s):  
Cross Section ◽  
High Speed ◽  
Numerical Study ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Wing Kinematics ◽  
Wing Motion ◽  
Edge Vortex ◽  
Flapping Mechanism ◽  
Aerodynamic Simulation

In this study we have experimentally and numerically analyzed the flapping mechanism and wing kinematics of coleoptera (Propylea japonica Thunberg). Using digital high speed camera, we captured the continuous wing kinematics and visualized the flight motion of the free-flying coleoptera. The experimental visualization shows that the elytra flapped concurrently with the main wing both in the downstroke and upstroke motions. In order to define the wing kinematics of coleoptera, the displacement of a wing cross section (50% span-wise) was measured for each sequence of the wing motion. Using these data, the flight motion of coleoptera was numerically simulated to investigate the aerodynamic performance. The computational aerodynamic simulation shows that leading edge vortex shedding plays a key role in generating lift to keep the insect aloft.

scholarly journals Morfometrik Genus Terebellobranchia sp. (Kelas : Polychaeta, Famili: Terebellidae) di Daerah Intertidal Pulau Lemukutan, Kabupaten Bengkayang

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Heru Winarko Junardi, Tri Rima Setyawati
Keyword(s):  
Body Weight ◽  
Data Analysis ◽  
Body Size ◽  
The Body ◽  
Strongly Correlated ◽  
High Level ◽  
Relationship Of ◽  
The Relationship ◽  
Number Of Segments ◽  
Digital Caliper

Terebellobranchia sp. is a member of the Terebellidae family, which is known to have a high level of morphological variation. The aims of research was to know morphometric variations and the relationship of body size and uncini of Terebellobranchia sp. in Lemukutan Island. The measurements body and uncini were carried out on complete specimens with digital caliper, while uncini measuring under a microscope with eyepiece micrometer. Data analysis with t test in 64 individuals. The Terebellobranchia sp. found in station 2 had a significantly different size with Terebellobranchia sp. in other stations. The body length of Terebellobranchia sp. shows a strong correlation with the width, number of segments and body weight, meanwhile the width of the segment strongly correlated with size of uncini.

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