scholarly journals The evolution of two distinct strategies of moth flight

2021 ◽  
Vol 18 (185) ◽  
Author(s):  
Brett R. Aiello ◽  
Usama Bin Sikandar ◽  
Hajime Minoguchi ◽  
Burhanuddin Bhinderwala ◽  
Chris A. Hamilton ◽  
...  
Keyword(s):  
Body Weight ◽  
Three Dimensional ◽  
Force Production ◽  
High Amplitude ◽  
Wing Shape ◽  
Wing Morphology ◽  
Aerodynamic Modelling ◽  
Similar Body ◽  
Support Body Weight ◽  
Force Profiles

Across insects, wing shape and size have undergone dramatic divergence even in closely related sister groups. However, we do not know how morphology changes in tandem with kinematics to support body weight within available power and how the specific force production patterns are linked to differences in behaviour. Hawkmoths and wild silkmoths are diverse sister families with divergent wing morphology. Using three-dimensional kinematics and quasi-steady aerodynamic modelling, we compare the aerodynamics and the contributions of wing shape, size and kinematics in 10 moth species. We find that wing movement also diverges between the clades and underlies two distinct strategies for flight. Hawkmoths use wing kinematics, especially high frequencies, to enhance force and wing morphologies that reduce power. Silkmoths use wing morphology to enhance force, and slow, high-amplitude wingstrokes to reduce power. Both strategies converge on similar aerodynamic power and can support similar body weight ranges. However, inter-clade within-wingstroke force profiles are quite different and linked to the hovering flight of hawkmoths and the bobbing flight of silkmoths. These two moth groups fly more like other, distantly related insects than they do each other, demonstrating the diversity of flapping flight evolution and a rich bioinspired design space for robotic flappers.

scholarly journals Inactivation of the adrenergic receptor β2 disrupts glucose homeostasis in mice

2014 ◽  
Vol 221 (3) ◽  
pp. 381-390 ◽  
Author(s):  
Gustavo W Fernandes ◽  
Cintia B Ueta ◽  
Tatiane L Fonseca ◽  
Cecilia H A Gouveia ◽  
Carmen L Lancellotti ◽  
...  
Keyword(s):  
Body Weight ◽  
Energy Expenditure ◽  
Glucose Homeostasis ◽  
High Fat Diet ◽  
Liver Steatosis ◽  
Mrna Levels ◽  
High Fat ◽  
Adaptive Thermogenesis ◽  
Brown Adipose ◽  
Similar Body

Three types of beta adrenergic receptors (ARβ1–3) mediate the sympathetic activation of brown adipose tissue (BAT), the key thermogenic site for mice which is also present in adult humans. In this study, we evaluated adaptive thermogenesis and metabolic profile of a mouse withArβ2knockout (ARβ2KO). At room temperature, ARβ2KO mice have normal core temperature and, upon acute cold exposure (4 °C for 4 h), ARβ2KO mice accelerate energy expenditure normally and attempt to maintain body temperature. ARβ2KO mice also exhibited normal interscapular BAT thermal profiles during a 30-min infusion of norepinephrine or dobutamine, possibly due to marked elevation of interscapular BAT (iBAT) and ofArβ1, andArβ3mRNA levels. In addition, ARβ2KO mice exhibit similar body weight, adiposity, fasting plasma glucose, cholesterol, and triglycerides when compared with WT controls, but exhibit marked fasting hyperinsulinemia and elevation in hepaticPepck(Pck1) mRNA levels. The animals were fed a high-fat diet (40% fat) for 6 weeks, ARβ2KO mice doubled their caloric intake, accelerated energy expenditure, and inducedUcp1expression in a manner similar to WT controls, exhibiting a similar body weight gain and increase in the size of white adipocytes to the WT controls. However, ARβ2KO mice maintain fasting hyperglycemia as compared with WT controls despite very elevated insulin levels, but similar degrees of liver steatosis and hyperlipidemia. In conclusion, inactivation of the ARβ2KO pathway preserves cold- and diet-induced adaptive thermogenesis but disrupts glucose homeostasis possibly by accelerating hepatic glucose production and insulin secretion. Feeding on a high-fat diet worsens the metabolic imbalance, with significant fasting hyperglycemia but similar liver structure and lipid profile to the WT controls.

Functional implications of supercontracting muscle in the chameleon tongue retractors

2001 ◽  
Vol 204 (21) ◽  
pp. 3621-3627 ◽  
Author(s):  
Anthony Herrel ◽  
Jay J. Meyers ◽  
Peter Aerts ◽  
Kiisa C. Nishikawa
Keyword(s):  
Prey Capture ◽  
Three Dimensional ◽  
Force Production ◽  
Retractor Muscle ◽  
Muscle Physiology ◽  
Large Prey ◽  
Wide Range ◽  
Ambush Predators ◽  
Full Body

SUMMARYChameleons capture prey items using a ballistic tongue projection mechanism that is unique among lizards. During prey capture, the tongue can be projected up to two full body lengths and may extend up to 600 % of its resting length. Being ambush predators, chameleons eat infrequently and take relatively large prey. The extreme tongue elongation (sixfold) and the need to be able to retract fairly heavy prey at any given distance from the mouth are likely to place constraints on the tongue retractor muscles. The data examined here show that in vivo retractor force production is almost constant for a wide range of projection distances. An examination of muscle physiology and of the ultrastructure of the tongue retractor muscle shows that this is the result (i) of active hyoid retraction, (ii) of large muscle filament overlap at maximal tongue extension and (iii) of the supercontractile properties of the tongue retractor muscles. We suggest that the chameleon tongue retractor muscles may have evolved supercontractile properties to enable a substantial force to be produced over a wide range of tongue projection distances. This enables chameleons successfully to retract even large prey from a variety of distances in their complex three-dimensional habitat.

A Cadaveric and Magnetic Resonance Imaging Investigation of the Salpingopharyngeus

2021 ◽  
pp. 1-11
Author(s):  
Karen Perta ◽  
Eileen Kalmar ◽  
Youkyung Bae
Keyword(s):  
Magnetic Resonance Imaging ◽  
Body Weight ◽  
Magnetic Resonance ◽  
Three Dimensional ◽  
Hierarchical Regression ◽  
Resonance Imaging ◽  
Before And After ◽  
Velopharyngeal Function ◽  
The Relationship

Purpose The aim of the study was to update our information regarding the salpingopharyngeus (SP) muscle using cadaveric and in vivo magnetic resonance imaging (MRI) data. Primary objectives were to (a) observe the presence/absence of the muscle and (b) quantify and describe its dimensions and course. Method SP specimens from 19 cadavers (10 women, nine men) were analyzed. Following head bisection, measurements of SP, including width of the cartilaginous attachment (CW) and width of the superior muscle base (SMW), were taken before and after removal of the overlying mucosa. In addition, SP was analyzed in 15 healthy subjects (eight men, seven women) using high-resolution three-dimensional MRI data. CW and SMW measures were replicated in the paraxial MRI view. Results The presence of the salpingopharyngeal fold and muscle was confirmed bilaterally in all cadaveric and living subjects. Following mucosa removal, mean cadaveric CW and SMW measurements were 5.6 and 3.8 mm, respectively. Mean in vivo CW and SMW were 6.1 and 3.7 mm, respectively. Results from the hierarchical regression analyses revealed that, in both cadaveric and living groups, SMW is dependent on the relationship between age and body weight, after controlling for sex. Conclusions The salpingopharyngeal fold and SP muscle are always present bilaterally and can be quantified at the superior origin using both cadaveric and in vivo three-dimensional MRI data. Though both the superior origin and inferior course of SP are highly variable, the size of the SP muscle is dependent on characteristics known to affect muscle fibers, such as the relationship between age and body weight. Given the consistent and quantifiable presence of the SP muscle, its potential role in velopharyngeal function for speech and swallowing is reconsidered. Supplemental Material https://doi.org/10.23641/asha.14347859

Early sex determination of Turkey by observation of differences in body weight between male and female

2021 ◽  
Vol 31 (3) ◽  
pp. 218-226
Author(s):  
S Akter ◽  
SC Das ◽  
AS Apu ◽  
T Ahmed ◽  
A Lahiry ◽  
...  
Keyword(s):  
Body Weight ◽  
Male And Female ◽  
Live Body Weight ◽  
Commercial Broiler ◽  
Percent Accuracy ◽  
Similar Body ◽  
Black Color ◽  
Average Body ◽  
Average Body Weight

The present study was conducted to determine the early sex in turkeys by observation of the differences in body weight between male and female birds. A total of 30-day old black color unsexed poults having almost similar body weight at hatching were considered for the experimentation and housed at the Poultry Farm of Bangladesh Agricultural University, Mymensingh-2202, Bangladesh. All birds were reared up to 12 weeks of age under intensive management with supplementation of commercial broiler starter and grower feeds. Birds were reared under similar management conditions. Significantly higher (p<0.01) body weight was attained in male poults (104g/bird) than the female (90g/bird) at the end of 1st week of age. Similarly, at the end of 2nd week of age higher (p<0.01) body weight attained by male poults (198.31g/bird) than the female (162.13g/bird). At the end of 3rd weeks of age male poults attained higher (p<0.01) body weight (307.23g/bird) than the female (251.33g/bird). After 4 weeks of rearing, male turkeys attained significantly higher (p<0.01) live body weight (424.46g/bird) than the female turkeys (347.87g/bird). The weekly average body weight gains of male and female birds were 94.18g/bird and 76.5g/bird, respectively. Thus, the male and female birds were successfully identified on the basis of differences in their body weight. Weekly feed intake for both the male and female birds was also increased with their age. Up to 4 weeks of age, both the male and female poults consumed same amount of feed (753.46g/bird). The FCR of male and female poults differed non-significantly in 1st, 3rd and 4th week. On the contrary, in 2nd week of age the FCR of male poults (1.60) was significantly lower (p<0.01) than female (2.11). Survivability was 100% up to 4th week of age irrespective of sex of the poults. The birds were reared up to 12 weeks of age until to confirm their sex by observation of the phenotypic appearance. Results of the phenotypic observation of male and female birds correspondence hundred percent accuracy with the results obtained in body weight based differences between male and female birds. It is therefore concluded that farmers can identify male or female poults as early as first week of age on the basis of body weight differences. Progressive Agriculture 31 (3): 218-226, 2020

scholarly journals Variable Thumb Moment Arm Modeling and Thumb-Tip Force Production of a Human-Like Robotic Hand

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Taylor D. Niehues ◽  
Ashish D. Deshpande
Keyword(s):  
Physical Simulation ◽  
Three Dimensional ◽  
Force Production ◽  
Human Hand ◽  
Robotic Hand ◽  
Motion Data ◽  
Moment Arms ◽  
Musculoskeletal Structure ◽  
Thumb Motion ◽  
Force Vectors

The anatomically correct testbed (ACT) hand mechanically simulates the musculoskeletal structure of the fingers and thumb of the human hand. In this work, we analyze the muscle moment arms (MAs) and thumb-tip force vectors in the ACT thumb in order to compare the ACT thumb's mechanical structure to the human thumb. Motion data are used to determine joint angle-dependent MA models, and thumb-tip three-dimensional (3D) force vectors are experimentally analyzed when forces are applied to individual muscles. Results are presented for both a nominal ACT thumb model designed to match human MAs and an adjusted model that more closely replicates human-like thumb-tip forces. The results confirm that the ACT thumb is capable of faithfully representing human musculoskeletal structure and muscle functionality. Using the ACT hand as a physical simulation platform allows us to gain a better understanding of the underlying biomechanical and neuromuscular properties of the human hand to ultimately inform the design and control of robotic and prosthetic hands.

The Effect of Body Position and Number of Supports on Wall Reaction Forces in Rock Climbing

1997 ◽  
Vol 13 (1) ◽  
pp. 14-23 ◽  
Author(s):  
Franck Quaine ◽  
Luc Martin ◽  
Jean-Pierre Blanchi
Keyword(s):  
Body Weight ◽  
Contact Force ◽  
Body Position ◽  
Three Dimensional ◽  
Rock Climbing ◽  
Contact Forces ◽  
Vertical Posture ◽  
Reaction Forces ◽  
Force Data ◽  
Lower Contact

This manuscript describes three-dimensional force data collected during postural shifts performed by individuals simulating rock-climbing skills. Starting from a quadrupedal vertical posture, 6 expert climbers had to release their right-hand holds and maintain the tripedal posture for a few seconds. The vertical and contact forces (lateral and anteroposterior forces) applied on the holds were analyzed in two positions: an “imposed” position (the trunk far from the supporting wall) and an “optimized” position (the trunk close to the wall and lower contact forces at the holds). The tripedal postures performed in the two positions were achieved by the same pattern of vertical and contact forces exerted by the limbs on the holds. In the optimized position, the transfer of the forces was less extensive than in the imposed position, so that the forces were exerted primarily on the ipsilateral hold. Moreover, a link between the contact force values and the couple due to body weight with respect to the feet was shown.

scholarly journals Mechanical evidence that flamingos can support their body on one leg with little active muscular force

2017 ◽  
Vol 13 (5) ◽  
pp. 20160948 ◽  
Author(s):  
Young-Hui Chang ◽  
Lena H. Ting
Keyword(s):  
Body Weight ◽  
Joint Torque ◽  
Body Sway ◽  
Active Muscle ◽  
Reduced Body ◽  
Weight Support ◽  
Energetic Expenditure ◽  
Distal Joint ◽  
Support Body Weight ◽  
Muscle Contractile

Flamingos (Phoenicopteridae) often stand and sleep on one leg for long periods, but it is unknown how much active muscle contractile force they use for the mechanical demands of standing on one leg: body weight support and maintaining balance. First, we demonstrated that flamingo cadavers could passively support body weight on one leg without any muscle activity while adopting a stable, unchanging, joint posture resembling that seen in live flamingos. By contrast, the cadaveric flamingo could not be stably held in a two-legged pose, suggesting a greater necessity for active muscle force to stabilize two-legged versus one-legged postures. Our results suggest that flamingos engage a passively engaged gravitational stay apparatus (proximally located) for weight support during one-legged standing. Second, we discovered that live flamingos standing on one leg have markedly reduced body sway during quiescent versus alert behaviours, with the point of force application directly under the distal joint, reducing the need for muscular joint torque. Taken together, our results highlight the possibility that flamingos stand for long durations on one leg without exacting high muscular forces and, thus, with little energetic expenditure.

scholarly journals Metabolic cost of generating horizontal forces during human running

1999 ◽  
Vol 86 (5) ◽  
pp. 1657-1662 ◽  
Author(s):  
Young-Hui Chang ◽  
Rodger Kram
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Metabolic Cost ◽  
Ground Reaction Forces ◽  
Vertical Force ◽  
Order Of Magnitude ◽  
Reaction Forces ◽  
The Cost ◽  
Support Body Weight ◽  
Human Running

Previous studies have suggested that generating vertical force on the ground to support body weight (BWt) is the major determinant of the metabolic cost of running. Because horizontal forces exerted on the ground are often an order of magnitude smaller than vertical forces, some have reasoned that they have negligible cost. Using applied horizontal forces (AHF; negative is impeding, positive is aiding) equal to −6, −3, 0, +3, +6, +9, +12, and +15% of BWt, we estimated the cost of generating horizontal forces while subjects were running at 3.3 m/s. We measured rates of oxygen consumption (V˙o 2) for eight subjects. We then used a force-measuring treadmill to measure ground reaction forces from another eight subjects. With an AHF of −6% BWt,V˙o 2 increased 30% compared with normal running, presumably because of the extra work involved. With an AHF of +15% BWt, the subjects exerted ∼70% less propulsive impulse and exhibited a 33% reduction inV˙o 2. Our data suggest that generating horizontal propulsive forces constitutes more than one-third of the total metabolic cost of normal running.

The structure of weakly compressible grid-generated turbulence

2001 ◽  
Vol 432 ◽  
pp. 219-283 ◽  
Author(s):  
G. BRIASSULIS ◽  
J. H. AGUI ◽  
Y. ANDREOPOULOS
Keyword(s):  
Mach Number ◽  
Large Scale ◽  
Isotropic Turbulence ◽  
Three Dimensional ◽  
High Amplitude ◽  
Time Dependent ◽  
Wide Range ◽  
Dynamical Flow ◽  
Set Up ◽  
Decay Exponent

A decaying compressible nearly homogeneous and nearly isotropic grid-generated turbulent flow has been set up in a large scale shock tube research facility. Experiments have been performed using instrumentation with spatial resolution of the order of 7 to 26 Kolmogorov viscous length scales. A variety of turbulence-generating grids provided a wide range of turbulence scales with bulk flow Mach numbers ranging from 0.3 to 0.6 and turbulent Reynolds numbers up to 700. The decay of Mach number fluctuations was found to follow a power law similar to that describing the decay of incompressible isotropic turbulence. It was also found that the decay coefficient and the decay exponent decrease with increasing Mach number while the virtual origin increases with increasing Mach number. A possible mechanism responsible for these effects appears to be the inherently low growth rate of compressible shear layers emanating from the cylindrical rods of the grid. Measurements of the time-dependent, three dimensional vorticity vectors were attempted for the first time with a 12-wire miniature probe. This also allowed estimates of dilatation, compressible dissipation and dilatational stretching to be obtained. It was found that the fluctuations of these quantities increase with increasing mean Mach number of the flow. The time-dependent signals of enstrophy, vortex stretching/tilting vector and dilatational stretching vector were found to exhibit a rather strong intermittent behaviour which is characterized by high-amplitude bursts with values up to 8 times their r.m.s. within periods of less violent and longer lived events. Several of these bursts are evident in all the signals, suggesting the existence of a dynamical flow phenomenon as a common cause.

scholarly journals A comparative study of different acceleration sensors in measuring energy consumption of human martial arts

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Qixia Jia ◽  
Zengyin Yan ◽  
Yongyong Wang
Keyword(s):  
Body Weight ◽  
Energy Consumption ◽  
Body Mass ◽  
Martial Arts ◽  
Three Dimensional ◽  
Male Adolescents ◽  
Normal Body ◽  
Acceleration Sensors ◽  
Normal Body Weight ◽  
Mass Group

AbstractAt present, there are many acceleration sensors for measuring human martial arts in the market. However, due to the inaccurate measurement of some acceleration sensors, people who love martial arts are deeply troubled and unable to find an excellent acceleration sensor specifically for energy consumption detection of human martial arts. The development of this sensor is imminent, which is of great significance for the comparative study of energy consumption measurement of human martial arts in our country. In this study, 160 students aged 11–14 years were selected, and the subjects were divided into normal body mass group and abnormal body mass group. Of the 96 male adolescents, 32 were obese body mass, which was determined as male abnormal body mass Group; 64 male adolescents were normal body weight and male normal body weight group; female 64 adolescents were normal body weight and set as female normal body mass group. Using a built-in accelerometer and a mobile phone three-dimensional accelerometer, the subjects were subjected to a 3–8 km/h human martial arts exercise load test (each speed is continuously performed for 5 min). The two acceleration sensors collectively assess the accuracy of the prediction of the use of force in human martial arts experiments. The average power consumption of human art exercises uses a frequency of 60 times/min, 90 times/min and 120 times/min compared to two acceleration sensors. Test results show that the data points for the mobile accelerator eraser are scattered, and the distance between the data varies. The data points of the three-dimensional acceleration sensor are more concentrated and present a certain trend. The use of three-dimensional acceleration sensors to measure martial arts can fully reflect the energy consumption of human activities, and achieve an energy consumption measurement accuracy of more than 94%.

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