Locomotory energetics in a marsupial, Setonix Brachyurus

1977 ◽  
Vol 25 (3) ◽  
pp. 423 ◽  
Author(s):  
RV Baudinette
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Sweat Gland ◽  
Stride Length ◽  
Stride Frequency ◽  
Sweat Glands ◽  
Total Production ◽  
Gait Patterns ◽  
Similar Body ◽  
Active Sweat Glands

The gait patterns, rates of oxygen consumption, body temperature and sweat gland activity were examined in S. brachyurus during locomotion on a treadmill. At speeds up to 12.6 km h-1 the animal moved in a quadrupedal bound occasionally punctuated by six or seven hops. At the higher speeds within this range, stride frequency became relatively constant and increases in stride length were the primary determinants of increased speed. Rates of oxygen consumption increased linearly with speed of locomotion up to 7.6 km h-1; above this range the animals would not run for prolonged periods when wearing a gas collection mask. The gradient of this line was similar to that predicted for a eutherian of similar body mass, but the extrapolation to zero speed was much higher than found in other mammals. As the quokka increased speed, a greater proportion of the heat produced while running was stored. At 7.6 km h-1, this was 60% of the total production. Active sweat glands were demonstrated on the limbs and feet during locomotion.

scholarly journals Energetic cost of locomotion as a function of ambient temperature and during growth in the marsupial Potorous tridactylus.

1993 ◽  
Vol 174 (1) ◽  
pp. 81-95
Author(s):  
R V Baudinette ◽  
E A Halpern ◽  
D S Hinds
Keyword(s):  
Oxygen Consumption ◽  
Ambient Temperature ◽  
Multiple Regression ◽  
Stride Length ◽  
Energy Use ◽  
Linear Increase ◽  
Stride Frequency ◽  
Energetic Cost ◽  
Cost Of Transport ◽  
Cost Of Locomotion

In the marsupial, the potoroo, multiple regression analysis shows that ambient temperature makes a minor (2%) contribution towards variation in oxygen consumption with speed. This suggests that the heat generated during running is substituted for heat which would otherwise have to be generated for temperature regulation. Maximum levels of oxygen consumption are also temperature-independent over the range 5-25 degrees C, but plasma lactate concentrations at the conclusion of exercise significantly increase with ambient temperature. Adult potoroos show a linear increase in oxygen consumption with speed, and multiple regression indicates that the most significant factor affecting energy use during running is stride length. Juvenile potoroos have an incremental cost of locomotion about 40% lower than that predicted on the basis of body mass. The smaller animals meet the demands of increasing speed by increasing stride length rather than stride frequency, as would be expected in a smaller species. Our results show that juvenile potoroos diverge significantly from models based only on adult animals in incremental changes in stride frequency, length and the cost of transport, suggesting that they are not simply scaled-down adults.

Locomotion in the North American mink, a semi-aquatic mammal. II. The effect of an elongate body on running energetics and gait patterns

1983 ◽  
Vol 105 (1) ◽  
pp. 283-295 ◽  
Author(s):  
T. M. Williams
Keyword(s):  
Stride Length ◽  
American Mink ◽  
Gait Pattern ◽  
Stride Frequency ◽  
Energetic Cost ◽  
Transport Costs ◽  
Gait Patterns ◽  
Aquatic Mammal ◽  
Transition Speed ◽  
The North

Oxygen consumption (VO2) of minks increased non-linearly with running speed over the range of 0.70-6.40 km h-1. A break in the VO2 vs speed relationship occurred at approximately 3.94 km h-1 and corresponded to the transition from a walking to a half-bounding gait pattern. Incremental transport costs associated with bounding were 36% lower than for walking at similar speeds. The lower energetic cost of bounding was attributed in part to low stride frequencies and in part to spinal flexion. The latter was particularly important in circumventing stride length restrictions associated with the short limbs of these animals. As a result, stride frequency and stride length of these elongate mustelids at the gait transition speed were similar to values predicted for conventionally-shaped mammals.

Energy metabolism and heart rate during treadmill exercise in the Marabou stork

1980 ◽  
Vol 49 (3) ◽  
pp. 491-496 ◽  
Author(s):  
O. S. Bamford ◽  
G. M. Maloiy
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Stride Length ◽  
Treadmill Exercise ◽  
Vertical Movement ◽  
Stride Frequency ◽  
Horizontal Movement ◽  
Slope Analysis ◽  
The Cost ◽  
Marabou Stork

Oxygen consumption (VO2), heart rate, body temperature, and stride frequency were measured in Marabou storks walking on a treadmill at a range of speeds and gradients. VO2 was linearly related to speed at gradients up to 11 degrees and speeds up to 1.4 m . s-1, and the slope of the VO2/speed regression increased with the treadmill angle up to 9 degrees. At 11 degrees there was a fall in the slope. Analysis indicates the cost of horizontal movement of about 1.1 ml O2 . m-1 (mean wt 4.5 kg). The cost of vertical movement is 7.13 ml O2 . m-1 and the efficiency about 30%. Maximum recorded VO2 was about five times resting, and there was no indication of an oxygen debt at any value for VO2. Heart rate was directly proportional to vO2 over the range studied, and at high heart rates successive cardiac cycles overlapped. Body temperature did not change significantly during exercise. Stride frequency was linearly related to walking speed but with a nonzero intercept so that stride length changed with speed, but there was no observed change in gait with speed. These data are discussed in comparison with published scaling equations and with data from mammals.

Neural factors underlying variations in electrical resistance of apparently nonsweating skin

1962 ◽  
Vol 17 (6) ◽  
pp. 999-1002 ◽  
Author(s):  
P. E. Thomas ◽  
Aikoh Kawahata
Keyword(s):  
Sweat Gland ◽  
Skin Resistance ◽  
Sweat Glands ◽  
Low Resistance ◽  
Insensible Perspiration ◽  
Neural Factors ◽  
Sudomotor Activity ◽  
Relationship Of ◽  
The Relationship ◽  
Active Sweat Glands

Many investigators have demonstrated that sympathetic sudomotor activity sufficient to cause visible sweating is accompanied by a decrease in electrical skin resistance (ESR). Furthermore, the reciprocal of resistance (conductance) was shown to be linearly related to the amount of perspiration and the number of visibly active sweat glands. The present study examines the relationship of ESR to sweat-gland activation under apparently nonsweating circumstances, and clarifies the significance of topographical differences in ESR observed in human studies conducted at moderate (nonsweating) temperatures; results also suggest a neural influence on insensible perspiration. Comparisons in adjacent high- and low-resistance areas were made of the sweat gland responses produced by intradermal injections of drugs that directly stimulate sweat glands. When just-threshold quantities of acetylcholine (ACh), pilocarpine, or epinephrine were used, the low-resistance areas always responded with more numerous activated glands. When both high- and low-resistance areas were injected with procaine approximately 10 min prior to ACh injection, activated sweat gland response was essentially similar in both areas. At moderate temperatures, sweat glands evidently receive sudomotor impulses at a rate that does not produce visible sweating, but does increase transcutaneous water transfer and electrolyte conductance Submitted on February 21, 1961

The Reliability and Variability of Running Economy in 7-, 8-, and 9-Year-Old Children

1994 ◽  
Vol 6 (3) ◽  
pp. 287-296 ◽  
Author(s):  
Danette M. Rogers ◽  
Kenneth R. Turley ◽  
Kathleen I. Kujawa ◽  
Kevin M. Harper ◽  
Jack H. Wilmore
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Body Surface ◽  
Stride Length ◽  
Respiratory Exchange Ratio ◽  
Running Economy ◽  
Intraindividual Variability ◽  
Stride Frequency ◽  
Single Test ◽  
Reliability Estimates

This study was designed to examine the reliability and variability of running economy in 7-, 8-, and 9-year-old boys and girls. Forty-two children (21 boys and 21 girls) participated in two submaximal treadmill tests to determine running economy at two absolute work rates (5 mph and 6 mph). Reliability and variability were determined for oxygen consumption (V̇O2), heart rate (HR), respiratory exchange ratio (RER), stride frequency, and stride length. With the exception of RER and V̇O2 relative to body surface area, reliability estimates were moderate to high (.80 to .94). Mean variability of all responses were similar to those reported for adults, however, the range of intraindividual variability was slightly greater. These results indicate that two submaximal measurements result in higher reliability estimates than a single test and may therefore provide a more appropriate description of a child’s running economy.

The Gait Patterns of Olympic Dressage Horses

1990 ◽  
Vol 6 (2) ◽  
pp. 198-226 ◽  
Author(s):  
Nancy R. Deuel ◽  
Jong-Jin Park
Keyword(s):  
Motion Picture ◽  
Stride Length ◽  
Olympic Games ◽  
Stride Frequency ◽  
Special Test ◽  
Gait Patterns ◽  
Contact Patterns ◽  
World Class ◽  
Left Lead

Limb contact variables of the gaits of dressage horses were determined for competitors at the 1988 Seoul Summer Olympic Games in the team and individual dressage competitions. Two 16-mm motion picture cameras filming at 100 fps were aimed perpendicular to the plane of equestrian motion along the HXF and MXK diagonals of the standard dressage arena. Eighteen competitors in team dressage were filmed during the Grand Prix test while executing the extended walk, extended trot, and left lead extended canter. Fifteen horses selected as finalists for individual dressage medals were filmed during the Grand Prix Special test executing the extended trot, one-stride canter lead changes, two-stride canter lead changes, and the left lead extended canter. Velocities of the extended walk, extended trot, and extended canter were positively related to stride length. Velocities of the Grand Prix extended walk and Grand Prix Special extended trot were positively related to stride frequency. Limb contact patterns of the extended walk stride appeared to have relatively little importance in scoring. Certain characteristics of the extended trot and extended canter were strongly related to scores attained in Grand Prix Special dressage tests, with highest scores achieved by horses with the longest, fastest strides. For canter strides involving lead changes, no limb contact variables were detected that were significantly related to scores. This study provided the first objective documentation of the limb contact patterns of the walk, trot, and canter of world-class dressage horses.

Instrumentation for Concurrent, Dynamic Monitoring of Active Sweat Glands and Perspiration Volume

1997 ◽  
Vol 25 (1) ◽  
pp. 39-53 ◽  
Author(s):  
Tomoya Kamei ◽  
Ken Naitoh ◽  
Koji Nakashima ◽  
Toshio Ohhashi ◽  
Shinya Kitagawa ◽  
...  
Keyword(s):  
Dynamic Monitoring ◽  
Sweat Glands ◽  
Active Sweat Glands

Body temperature regulation and oxygen consumption in young chicks fed thyroid hormone

1991 ◽  
Vol 69 (7) ◽  
pp. 1842-1847 ◽  
Author(s):  
Gregory K. Snyder ◽  
Joseph R. Coelho ◽  
Dalan R. Jensen
Keyword(s):  
Oxygen Consumption ◽  
Thyroid Hormone ◽  
Body Temperature ◽  
Ambient Temperature ◽  
Cold Exposure ◽  
Elevated Serum ◽  
Body Temperatures ◽  
Serum Thyroid Hormone ◽  
Regulate Body Temperature ◽  
Young Chicks

In chicks the ability to regulate body temperature to adult levels develops during the first 2 weeks of life. We examined whether the ability of young chicks to regulate body temperature is increased by elevated levels of the thyroid hormone 3,3′5-triiodothyronine. By 13 days following hatch, body temperatures of chicks were not significantly different from those expected for adult birds. Furthermore, at an ambient temperature of 10 °C, 13-day-old control chicks were able to maintain body temperature, and elevated serum thyroid hormone levels did not increase rates of oxygen consumption or body temperature above control values. Six-day-old chicks had body temperatures that were significantly lower than those of the 13-day-old chicks and were not able to regulate body temperature when exposed to an ambient temperature of 10 °C. On the other hand, 6-day-old chicks with elevated serum thyroid hormone had significantly higher rates of oxygen consumption than 6-day-old control chicks, and were able to maintain constant body temperatures during cold exposure. The increased oxygen consumption rates and improved ability to regulate body temperature during cold exposure were correlated with increased citrate synthase activity in skeletal muscle. Our results support the argument that thyroid hormones play an important role in the development of thermoregulatory ability in neonate birds by stimulating enzyme activities associated with aerobic metabolism.

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