THE ENERGETIC COSTS OF CALLING IN THE BUSHCRICKET REQUENA VERTICALIS (ORTHOPTERA: TETTIGONIIDAE: LISTROSCELIDINAE)

1993 ◽  
Vol 178 (1) ◽  
pp. 21-37 ◽  
Author(s):  
W. J. Bailey ◽  
P. C. Withers ◽  
M. Endersby ◽  
K. Gaull
Keyword(s):  
Body Mass ◽  
Sound Pressure ◽  
Metabolic Cost ◽  
Acoustic Power ◽  
Metabolic Energy ◽  
Energetic Cost ◽  
Metabolic Efficiency ◽  
Metabolic Costs ◽  
Sound Pressure Levels ◽  
The Relationship

1. The metabolic costs of calling for male Requena verticalis Walker (Tettigoniidae: Listroscelidinae) were measured by direct recordings of oxygen consumption. The acoustic power output was measured by sound pressure levels around the calling bushcricket. 2. The average metabolic cost of calling was 0.143 ml g-1 h-1 but depended on calling rate. The net metabolic cost of calling per unit call, the syllable, was calculated to be 4.34×10-6+/−8.3×10-7 ml O2 syllable-1 g-1 body mass (s.e.) from the slope of the relationship between total V(dot)O2 and rate of syllable production. The resting V(dot)O2, calculated as the intercept of the relationship, was 0.248 ml O2 g-1 body mass h-1. 3. The energetic cost of calling for R. verticalis (average mass 0.37 g) was estimated at 31.85×10-6 J syllable-1. 4. Sound pressure levels were measured around calling insects. The surface area of a sphere of uniform sound pressure level [83 dB SPL root mean square (RMS) acoustic power] obtained by these measurements was used to calculate acoustic power. This was 0.20 mW. 5. The metabolic efficiency of calling, based on total metabolic energy utilisation, was 6.4 %. However, we propose that the mechanical efficiency for acoustic transmission is closer to 57 %, since only about 10 % of muscle metabolic energy is apparently available for sound production. 6. R. verticalis emits chirps formed of several syllables within which are discrete sound pulses. Wing stroke rates, when the insect is calling at its maximal rate, were approximately 583 min-1. This is slow compared to the rates observed in conehead tettigoniids, the only other group of bushcrickets where metabolic costs have been measured. The thoracic temperatures of males that had been calling for 5 min were not significantly different from those of non-calling males. 7. For R. verticalis, calling with relatively slow syllable rates may reduce the total cost of calling, and this may be a compensatory mechanism for their other high energetic cost of mating (a large spermatophylax).

scholarly journals Elastic energy savings and active energy cost in a simple model of running

2021 ◽  
Vol 17 (11) ◽  
pp. e1009608
Author(s):  
Ryan T. Schroeder ◽  
Arthur D. Kuo
Keyword(s):  
Elastic Energy ◽  
Energy Cost ◽  
Energy Savings ◽  
Mechanical Energy ◽  
Metabolic Cost ◽  
The Body ◽  
Metabolic Energy ◽  
Energetic Cost ◽  
Mass Model ◽  
Human Running

The energetic economy of running benefits from tendon and other tissues that store and return elastic energy, thus saving muscles from costly mechanical work. The classic “Spring-mass” computational model successfully explains the forces, displacements and mechanical power of running, as the outcome of dynamical interactions between the body center of mass and a purely elastic spring for the leg. However, the Spring-mass model does not include active muscles and cannot explain the metabolic energy cost of running, whether on level ground or on a slope. Here we add explicit actuation and dissipation to the Spring-mass model, and show how they explain substantial active (and thus costly) work during human running, and much of the associated energetic cost. Dissipation is modeled as modest energy losses (5% of total mechanical energy for running at 3 m s-1) from hysteresis and foot-ground collisions, that must be restored by active work each step. Even with substantial elastic energy return (59% of positive work, comparable to empirical observations), the active work could account for most of the metabolic cost of human running (about 68%, assuming human-like muscle efficiency). We also introduce a previously unappreciated energetic cost for rapid production of force, that helps explain the relatively smooth ground reaction forces of running, and why muscles might also actively perform negative work. With both work and rapid force costs, the model reproduces the energetics of human running at a range of speeds on level ground and on slopes. Although elastic return is key to energy savings, there are still losses that require restorative muscle work, which can cost substantial energy during running.

scholarly journals Muscle Metabolic Energy Costs While Modifying Propulsive Force Generation During Walking

2020 ◽  
Author(s):  
Richard E. Pimentel ◽  
Noah L. Pieper ◽  
William H. Clark ◽  
Jason R. Franz
Keyword(s):  
Young Adults ◽  
Metabolic Cost ◽  
Metabolic Energy ◽  
Energy Costs ◽  
Joint Power ◽  
Lower Limb Muscles ◽  
Age Related ◽  
Musculoskeletal Models ◽  
Metabolic Costs ◽  
Related Increase

AbstractWe pose that an age-related increase in the metabolic cost of walking arises in part from a redistribution of joint power where muscles spanning the hip compensate for insufficient ankle push-off and smaller peak propulsive forces (FP). Young adults elicit a similar redistribution when walking with smaller FP via biofeedback. We used targeted FP biofeedback and musculoskeletal models to estimate the metabolic costs of operating lower limb muscles in young adults walking across a range of FP. Our simulations support the theory of distal-to-proximal redistribution of joint power as a determinant of increased metabolic cost in older adults during walking.

scholarly journals Multi-objective control in human walking: insight gained through simultaneous degradation of energetic and motor regulation systems

2019 ◽  
Vol 16 (158) ◽  
pp. 20190227
Author(s):  
Kirsty A. McDonald ◽  
Joseph P. Cusumano ◽  
Peter Peeling ◽  
Jonas Rubenson
Keyword(s):  
Energy Minimization ◽  
Metabolic Cost ◽  
Metabolic Energy ◽  
Energetic Cost ◽  
Leg Length ◽  
Multi Objective ◽  
Speed Regulation ◽  
Speed Error ◽  
Objective Control ◽  
Error Regulation

Minimization of metabolic energy is considered a fundamental principle of human locomotion, as demonstrated by an alignment between the preferred walking speed (PWS) and the speed incurring the lowest metabolic cost of transport. We aimed to (i) simultaneously disrupt metabolic cost and an alternate acute task requirement, namely speed error regulation, and (ii) assess whether the PWS could be explained on the basis of either optimality criterion in this new performance and energetic landscape. Healthy adults ( N = 21) walked on an instrumented treadmill under normal conditions and, while negotiating a continuous gait perturbation, imposed leg-length asymmetry. Oxygen consumption, motion capture data and ground reaction forces were continuously recorded for each condition at speeds ranging from 0.6 to 1.8 m s −1 , including the PWS. Both metabolic and speed regulation measures were disrupted by the perturbation ( p < 0.05). Perturbed PWS selection did not exhibit energetic prioritization (although we find some indication of energy minimization after motor adaptation). Similarly, PWS selection did not support prioritization of speed error regulation, which was found to be independent of speed in both conditions. It appears that, during acute exposure to a mechanical gait perturbation of imposed leg-length asymmetry, humans minimize neither energetic cost nor speed regulation errors. Despite the abundance of evidence pointing to energy minimization during normal, steady-state gait, this may not extend acutely to perturbed gait. Understanding how the nervous system acutely controls gait perturbations requires further research that embraces multi-objective control paradigms.

scholarly journals Optimized hip–knee–ankle exoskeleton assistance at a range of walking speeds

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Gwendolyn M. Bryan ◽  
Patrick W. Franks ◽  
Seungmoon Song ◽  
Alexandra S. Voloshina ◽  
Ricardo Reyes ◽  
...  
Keyword(s):  
Walking Speed ◽  
Metabolic Cost ◽  
Metabolic Energy ◽  
Positive Power ◽  
Fast Walking ◽  
Slow Walking ◽  
Limited Success ◽  
Ankle Exoskeleton ◽  
Walking Speeds ◽  
The Relationship

Abstract Background Autonomous exoskeletons will need to be useful at a variety of walking speeds, but it is unclear how optimal hip–knee–ankle exoskeleton assistance should change with speed. Biological joint moments tend to increase with speed, and in some cases, optimized ankle exoskeleton torques follow a similar trend. Ideal hip–knee–ankle exoskeleton torque may also increase with speed. The purpose of this study was to characterize the relationship between walking speed, optimal hip–knee–ankle exoskeleton assistance, and the benefits to metabolic energy cost. Methods We optimized hip–knee–ankle exoskeleton assistance to reduce metabolic cost for three able-bodied participants walking at 1.0 m/s, 1.25 m/s and 1.5 m/s. We measured metabolic cost, muscle activity, exoskeleton assistance and kinematics. We performed Friedman’s tests to analyze trends across walking speeds and paired t-tests to determine if changes from the unassisted conditions to the assisted conditions were significant. Results Exoskeleton assistance reduced the metabolic cost of walking compared to wearing the exoskeleton with no torque applied by 26%, 47% and 50% at 1.0, 1.25 and 1.5 m/s, respectively. For all three participants, optimized exoskeleton ankle torque was the smallest for slow walking, while hip and knee torque changed slightly with speed in ways that varied across participants. Total applied positive power increased with speed for all three participants, largely due to increased joint velocities, which consistently increased with speed. Conclusions Exoskeleton assistance is effective at a range of speeds and is most effective at medium and fast walking speeds. Exoskeleton assistance was less effective for slow walking, which may explain the limited success in reducing metabolic cost for patient populations through exoskeleton assistance. Exoskeleton designers may have more success when targeting activities and groups with faster walking speeds. Speed-related changes in optimized exoskeleton assistance varied by participant, indicating either the benefit of participant-specific tuning or that a wide variety of torque profiles are similarly effective.

Estimating instantaneous energetic cost during non-steady-state gait

2014 ◽  
Vol 117 (11) ◽  
pp. 1406-1415 ◽  
Author(s):  
Jessica C. Selinger ◽  
J. Maxwell Donelan
Keyword(s):  
Steady State ◽  
Energy Use ◽  
Mitochondrial Dynamics ◽  
Metabolic Cost ◽  
The Body ◽  
Metabolic Energy ◽  
Energetic Cost ◽  
Control Mechanisms ◽  
Input Output ◽  
Linear Differential

Respiratory measures of oxygen and carbon dioxide are routinely used to estimate the body's steady-state metabolic energy use. However, slow mitochondrial dynamics, long transit times, complex respiratory control mechanisms, and high breath-by-breath variability obscure the relationship between the body's instantaneous energy demands (instantaneous energetic cost) and that measured from respiratory gases (measured energetic cost). The purpose of this study was to expand on traditional methods of assessing metabolic cost by estimating instantaneous energetic cost during non-steady-state conditions. To accomplish this goal, we first imposed known changes in energy use (input), while measuring the breath-by-breath response (output). We used these input/output relationships to model the body as a dynamic system that maps instantaneous to measured energetic cost. We found that a first-order linear differential equation well approximates transient energetic cost responses during gait. Across all subjects, model fits were parameterized by an average time constant (τ) of 42 ± 12 s with an average R2 of 0.94 ± 0.05 (mean ± SD). Armed with this input/output model, we next tested whether we could use it to reliably estimate instantaneous energetic cost from breath-by-breath measures under conditions that simulated dynamically changing gait. A comparison of the imposed energetic cost profiles and our estimated instantaneous cost demonstrated a close correspondence, supporting the use of our methodology to study the role of energetics during locomotor adaptation and learning.

scholarly journals Energy demand during exponential growth of Octopus maya: exploring the effect of age and weight

2010 ◽  
Vol 67 (7) ◽  
pp. 1501-1508 ◽  
Author(s):  
Felipe Briceño ◽  
Maite Mascaró ◽  
Carlos Rosas
Keyword(s):  
Food Intake ◽  
Body Mass ◽  
Respiration Rate ◽  
Exponential Growth ◽  
Mass Production ◽  
Energy Demand ◽  
Metabolic Cost ◽  
Metabolic Energy ◽  
Octopus Maya ◽  
Effect Of Age

Abstract Briceño, F., Mascaró, M., and Rosas, C. 2010. Energy demand during exponential growth of Octopus maya: exploring the effect of age and weight. – ICES Journal of Marine Science, 67: 1501–1508. Recent work has reported changes associated with physiological, morphological, and behavioural adaptation during the absorption of yolk reserves. The holobenthic endemic species Octopus maya was used to explore the energy supply needed from the food intake (I; J animal−1 d−1) to supply the rate of production energy needed for body mass (P; J animal−1 d−1) and respiration rate (R; J animal−1 d−1) as a function of weight and age during the exponential early growth phase of the animal. Individually housed juveniles from hatching (1 d) to 105 d after hatching (DAH) were used, with the age and weight known, and the relationship between oxygen consumption (VO2; mg O2 animal−1 d−1) and weight (g) was established. Projections of I, R, and P as a function of age (Z) were made. The food intake destined to supply body mass production (%P/I) and respiration rate energy (%R/I) was analysed for an extended age range of 1–150 DAH. When O. maya juveniles hatched, they had a greater requirement for R than for P from the food intake, 61% (%R/I) and 13% (%P/I), respectively, suggesting high metabolic cost associated with post-hatching (during yolk absorption). Within the period where ZR > ZP (1–105 DAH), there was sufficient metabolic energy to satisfy the demands for sustaining exponential body mass production. The age at which %R/I = %P/I delimits the point where P cannot increase for reasons of metabolic constraint.

Construction Noise Annoyance among the Public Residents

2015 ◽  
Vol 74 (4) ◽  
Author(s):  
Nadirah Darus ◽  
Zaiton Haron ◽  
Siti Nadia Mohd Bakhori ◽  
Lim Ming Han ◽  
Zanariah Jahya ◽  
...  
Keyword(s):  
Sound Pressure ◽  
Construction Sites ◽  
Noise Sources ◽  
High Noise ◽  
The Public ◽  
Noise Annoyance ◽  
Sound Pressure Levels ◽  
Relationship Of ◽  
The Relationship

Construction activities generate construction noise may cause noise annoyance among the public residents. The aim of this study is to investigate the noise annoyance level due to the sound pressure levels and the distances from the construction sites. Three public resident areas around Johor which located near to the construction sites have been selected. Two important indicators such as sound pressure levels and distances between the receiver and the noise sources were measured. 42 questionnaires were randomly distributed to the public residents who live near to the construction sites. The results showed that all respondent have different annoyance levels due to the construction noise. The sound pressure levels received by the public residents are increasing with the decreasing of the distance between the receiver and the noise sources. Thus, the relationship of noise annoyance levels is directly proportional to the sound pressure levels produced from construction sites. Meanwhile, the noise annoyance levels are decreasing with the increasing of the distances. As a conclusion, the public residents who live nearer to the construction sites suffered from a high noise annoyance level as expected.

Energetics of ascent: insects on inclines

1990 ◽  
Vol 149 (1) ◽  
pp. 307-317 ◽  
Author(s):  
R. J. Full ◽  
A. Tullis
Keyword(s):  
Oxygen Consumption ◽  
Minimum Cost ◽  
Metabolic Cost ◽  
Metabolic Energy ◽  
Stride Frequency ◽  
Energetic Cost ◽  
Incline Angle ◽  
Small Animals ◽  
Cost Of Locomotion ◽  
The Cost

Small animals use more metabolic energy per unit mass than large animals to run on a level surface. If the cost to lift one gram of mass one vertical meter is constant, small animals should require proportionally smaller increases in metabolic cost to run uphill. To test this hypothesis on very small animals possessing an exceptional capacity for ascending steep gradients, we measured the metabolic cost of locomotion in the cockroach, Periplaneta americana, running at angles of 0, 45 and 90 degrees to the horizontal. Resting oxygen consumption (VO2rest) was not affected by incline angle. Steady-state oxygen consumption (VO2ss) increased linearly with speed at all angles of ascent. The minimum cost of locomotion (the slope of the VO2ss versus speed function) increased with increasing angle of ascent. The minimum cost of locomotion on 45 and 90 degrees inclines was two and three times greater, respectively, than the cost during horizontal running. The cockroach's metabolic cost of ascent greatly exceeds that predicted from the hypothesis of a constant efficiency for vertical work. Variations in stride frequency and contact time cannot account for the high metabolic cost, because they were independent of incline angle. An increase in the metabolic cost or amount of force production may best explain the increase in metabolic cost. Small animals, such as P. americana, can easily scale vertical surfaces, but the energetic cost is considerable.

Inexpensive load carrying by rhinoceros beetles

1996 ◽  
Vol 199 (3) ◽  
pp. 609-612 ◽  
Author(s):  
R Kram
Keyword(s):  
Body Mass ◽  
Metabolic Cost ◽  
Added Mass ◽  
Metabolic Energy ◽  
Direct Proportion ◽  
Total Load ◽  
Load Carrying ◽  
Cost Of Locomotion ◽  
Conventional Models ◽  
Energy Cost Of Locomotion

These experiments determined the magnitude of loads that rhinoceros beetles (Scarabaeidae) can carry and also the metabolic energy required for carrying loads. I hypothesized that, like many other animals, these beetles would have metabolic rates in direct proportion to the total load (body mass plus added mass). Eight beetles (Xylorctes thestalus) walked at 1 cm s-1 on a motorized treadmill enclosed in a respirometer. The beetles could sustain this speed with loads of more than 30 times their body mass. In addition to being strong, these beetles carry loads with remarkable economy. The metabolic cost of moving a gram of additional load was more than five times cheaper than that of moving a gram of body mass. This phenomenon cannot be explained by conventional models that link the biomechanics and metabolic energy cost of locomotion.

scholarly journals Metabolic costs of growth and maintenance in the toad, Bufo bufo

1988 ◽  
Vol 138 (1) ◽  
pp. 319-331 ◽  
Author(s):  
C. B. Jorgensen
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Maximum Growth ◽  
Bufo Bufo ◽  
Maximum Growth Rate ◽  
The Body ◽  
Published Data ◽  
African Catfish ◽  
Metabolic Costs ◽  
The Relationship

Metabolic costs of growth and maintenance were determined from the relationship M (metabolism) = m + nG (growth), where m is the metabolic rate at the feeding level at which growth is zero. In the past, the slope n was interpreted as indicating the metabolic costs of growth, and the costs of maintenance that arise with the increase in body mass were disregarded. These costs are included in n. In female toads, Bufo bufo, feeding at different rates, the uncorrected value of n was 0.44, when metabolism and growth were expressed as kJ kJ-1. After correction for increased metabolic maintenance expenditure with increased body mass, the value became 0.35, indicating that the physiological costs of growth were equivalent to about one-third of the body mass deposited. Metabolic costs of growth accounted for 80% of the increase in metabolism with growth, leaving 20% for costs of maintenance. At maximum growth rate the metabolic costs of growth amounted to about 60% of the total metabolism, total mass-specific metabolic rate being 2.5 times the rate at zero growth. The physiological costs of growth in young toads were compared with the costs in teleosts. Recalculation of published data on the relationship between metabolism and growth in the African catfish Clarias lazera indicated that the metabolic costs of growth amounted to about 28% of body mass deposited. The costs represented about 80% of the increase in metabolism with growth. The physiological costs of growth are several times higher than the net biochemical costs of synthesis of the macromolecules constituting the increase in body mass.

Sign in / Sign up

Export Citation Format

Share Document