Flight energetics in sphinx moths: heat production and heat loss in Hyles lineata during free flight

1976 ◽  
Vol 64 (3) ◽  
pp. 545-560
Author(s):  
T. M. Casey
Keyword(s):  
Body Weight ◽  
Heat Loss ◽  
Heat Dissipation ◽  
Heat Budget ◽  
Thermal Conductance ◽  
Unit Weight ◽  
Ambient Temperatures ◽  
Thoracic Temperature ◽  
The Difference ◽  
Thoracic And Abdominal

1. Mean thoracic temperature of free-flying H. lineata in the field and in the laboratory increased from about 40 degrees C at Ta=16 degrees C to 42–5 degrees C at Ta=32 degrees C. At a given Ta, thoracic temperature was independent of body weight and weakly correlated with wing loading. 2. The difference between abdominal temperature and air temperature increased from 2 degrees C at low Ta to 4-2 degrees C at high Ta. At a given Ta, the difference between Tab and Ta was positively correlated with thoracic temperature. 3. Oxygen consumption per unit weight did not appear to vary with Ta from 15 to 30 degrees C and was inversely proportional to body weight. 4. Thermal conductance of the abdomen (Cab) was greater than thermal conductance of the thorax (Cth) in still air and at wind velocities up to 2-5 m/s. In moving air at speeds approximating flight, Cth was twice as high as in still air. Under the same conditions Cab was 3-4 times as high as in still air. 5. Thoracic and abdominal conductance are inversely proportional to their respective weights. 6. These data are consistent with the hypothesis that thoracic temperature is controlled by regulation of heat loss. However, a heat budget derived from these data suggests that heat dissipation may not be sufficient to offset the decrease in passive cooling of the thorax at high ambient temperatures.

Thermoregulation of African and European Honeybees during Foraging, Attack, and Hive Exits and Returns

1979 ◽  
Vol 80 (1) ◽  
pp. 217-229 ◽  
Author(s):  
HEINRICH BERND
Keyword(s):  
Metabolic Rate ◽  
Ambient Temperature ◽  
Heat Loss ◽  
Warm Up ◽  
Ambient Temperatures ◽  
Thoracic Temperature

1. While foraging, attacking, or leaving or returning to their hives, both the African and European honeybees maintained their thoracic temperature at 30 °C or above, independent of ambient temperature from 7 to 23 °C (in shade). 2. Thoracic temperatures were not significantly different between African and European bees. 3. Thoracic temperatures were significantly different during different activities. Average thoracic temperatures (at ambient temperatures of 8–23 °C) were lowest (30 °C) in bees turning to the hive. They were 31–32 °C during foraging, and 36–38 °C in bees leaving the hive, and in those attacking. The bees thus warm up above their temperature in the hive (32 °C) before leaving the colony. 4. In the laboratory the bees (European) did not maintain the minimum thoracic temperature for continuous flight (27 °C) at 10 °C. When forced to remain in continuous flight for at least 2 min, thoracic temperature averaged 15 °C above ambient temperature from 15 to 25 °C, and was regulated only at high ambient temperatures (30–40 °C). 5. At ambient temperatures > 25 °C, the bees heated up during return to the hive, attack and foraging above the thoracic temperatures they regulated at low ambient temperatures to near the temperatures they regulated during continuous flight. 6. In both African and European bees, attack behaviour and high thoracic temperature are correlated. 7. The data suggest that the bees regulate thoracic temperature by both behavioural and physiological means. It can be inferred that the African bees have a higher metabolic rate than the European, but their smaller size, which facilitates more rapid heat loss, results in similar thoracic temperatures.

Effect of heating rate on evaporative heat loss in the microwave-exposed mouse

1982 ◽  
Vol 53 (2) ◽  
pp. 316-323 ◽  
Author(s):  
C. J. Gordon
Keyword(s):  
Body Temperature ◽  
Heat Loss ◽  
Heat Dissipation ◽  
Dew Point ◽  
Whole Body ◽  
Evaporative Heat Loss ◽  
Heat Absorption ◽  
Deep Body Temperature ◽  
The Difference ◽  
Body Heat

Male CBA/J mice were administered heat loads of 0–28 J X g-1 at specific absorption rates (SARs) of either 47 or 93 W X kg-1 by exposure to 2,450-MHz microwave radiation at an ambient temperature of 30 degrees C while evaporative heat loss (EHL) was continuously monitored with dew-point hygrometry. At an SAR of 47 W X kg-1 a threshold heat load of 10.5 J X g-1 had to be exceeded before EHL increased. An approximate doubling of SAR to 93 W X kg-1 reduced the threshold to 5.2 J X g-1. Above threshold the slopes of the regression lines were 1.15 and 0.929 for the low- and high-SAR groups, respectively. Thus the difference in threshold and not slope attributes to the significant increase in EHL when mice are exposed at a high SAR (P less than 0.02). In separate experiments a SAR of 47 W X kg-1 raised the deep body temperature of anesthetized mice at a rate of 0.026 degrees C X s-1, whereas 93 W X kg-1 raised temperature at 0.049 degrees C X s-1. Hence the sensitivity of the EHL mode of heat dissipation is directly proportional to the rate of heat absorption and to the rate of rise in body temperature. These data contradict the notion that mammals have control over whole-body heat exchange only (i.e., thermoregulation) but instead indicate that the EHL system is highly responsive to the rate of heat absorption (i.e., temperature regulation).

Consumption of oxygen by thoracic and abdominal aorta of the rat

1963 ◽  
Vol 205 (6) ◽  
pp. 1200-1202 ◽  
Author(s):  
Robert E. Priest
Keyword(s):  
Nitrogen Content ◽  
Thoracic Aorta ◽  
Abdominal Aorta ◽  
Deoxyribonucleic Acid ◽  
Unit Weight ◽  
Liver And Kidney ◽  
The Difference ◽  
Thoracic And Abdominal ◽  
Low Nitrogen

Consumption of oxygen in vitro by thoracic and abdominal aorta and of liver and kidney of rats was measured by direct Warburg manometry and related to the weight of tissue and to the content of nitrogen and of deoxyribonucleic acid (DNA). On the basis of numbers of cells present, as determined by the content of DNA, thoracic aorta respires at a rate one-fifth that of liver. Thoracic aorta respires more actively than abdominal aorta but also contains more nitrogen and more DNA per unit weight than abdominal aorta. The difference in consumption of oxygen between these two segments of aorta can be explained largely, although not entirely, on the basis of numbers of cells present. Because of the lesser content of nitrogen and DNA in abdominal aorta, it must contain larger amounts of some substance which contributes to weight and has a low nitrogen content.

scholarly journals ENDOTHERMY IN THE SOLITARY BEE ANTHOPHORA PLUMIPES: INDEPENDENT MEASURES OF THERMOREGULATORY ABILITY, COSTS OF WARM-UP AND THE ROLE OF BODY SIZE

1993 ◽  
Vol 174 (1) ◽  
pp. 299-320 ◽  
Author(s):  
G. N. Stone
Keyword(s):  
Ambient Temperature ◽  
Heat Loss ◽  
Body Mass ◽  
Thermal Power ◽  
Thermal Conditions ◽  
Energetic Cost ◽  
Solitary Bee ◽  
Warm Up ◽  
Ambient Temperatures ◽  
Thoracic Temperature

1. This study examines variation in thoracic temperatures, rates of pre-flight warm-up and heat loss in the solitary bee Anthophora plumipes (Hymenoptera; Anthophoridae). 2. Thoracic temperatures were measured both during free flight in the field and during tethered flight in the laboratory, over a range of ambient temperatures. These two techniques give independent measures of thermoregulatory ability. In terms of the gradient of thoracic temperature on ambient temperature, thermoregulation by A. plumipes is more effective before flight than during flight. 3. Warm-up rates and body temperatures correlate positively with body mass, while mass-specific rates of heat loss correlate negatively with body mass. Larger bees are significantly more likely to achieve flight temperatures at low ambient temperatures. 4. Simultaneous measurement of thoracic and abdominal temperatures shows that A. plumipes is capable of regulating heat flow between thorax and abdomen. Accelerated thoracic cooling is only demonstrated at high ambient temperatures. 5. Anthophora plumipes is able to fly at low ambient temperatures by tolerating thoracic temperatures as low as 25 sC, reducing the metabolic expense of endothermic activity. 6. Rates of heat generation and loss are used to calculate the thermal power generated by A. plumipes and the total energetic cost of warm-up under different thermal conditions. The power generated increases with thoracic temperature excess and ambient temperature. The total cost of warm-up correlates negatively with ambient temperature.

Food efficiency in relation to estimated growth of body components in cattle

1975 ◽  
Vol 20 (3) ◽  
pp. 315-335 ◽  
Author(s):  
L. S. Monteiro
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Weight Gain ◽  
Food Intake ◽  
Linear Model ◽  
Unit Weight ◽  
Fat Percentage ◽  
Non Linear ◽  
The Difference ◽  
Maintenance Requirements

SUMMARYA model is proposed to establish a functional relationship between food intake, weight gain and body composition during growth, based on the differential energy requirements for fat, fat-free tissues and contents of the digestive tract. If constant specific nutrient requirements are assumed for fat and fat-free tissues, these requirements can be directly estimated from changes in food intake and body composition during growth. By introducing an allometric function relating changes in fat-free tissue to changes in body weight, the model is extended to include situations where direct measures of body composition are not available. This enabled the model to be fitted to data on food intake, body weight and growth rate up to 2 years of age in Friesians and Jerseys fed ad libitum on a complete diet. The nonlinear model is contrasted with a linear relationship where food intake i s related to body weight and weight gain. The linear model was unable to account for the changes in food intake over the whole period of growth. The non-linear model allowed a gradual decline n i maintenance requirements per unit weight and indicated an increase in the net conversion coefficient of food into gain, consistent with an increase from early to late growth in proportion of fat deposited.For the period studied the Jerseys were less efficient in transforming food into weight gain than Friesians. On the non-linear model, about half of the difference was attributable to the higher metabolic rate per unit weight of Jerseys, the remainder to poorer utilization of nutrients for weight gain. If, as the model indicated the conversion coefficients of food into body constituents were the same in the two breeds, the difference in efficiency may be attributable to a higher proportion of fat in the overall gain of Jerseys. The pattern of estimated fat deposition also differed in the two breeds with Jerseys appearing to be less mature in fat percentage at all stages.

Comparative energetics of coat colour polymorphs in the eastern grey squirrel, Sciurus carolinensis

1979 ◽  
Vol 57 (3) ◽  
pp. 585-592 ◽  
Author(s):  
S. Innes ◽  
D. M. Lavigne
Keyword(s):  
Heat Loss ◽  
Thermal Conductance ◽  
Coat Colour ◽  
Body Core Temperature ◽  
Sciurus Carolinensis ◽  
Grey Squirrel ◽  
Ambient Temperatures ◽  
Northern Portion ◽  
Lower Heat ◽  
Colour Morphs

Heat loss at various environmental temperatures was examined in colour morphs of the eastern grey squirrel, Sciurus carolinensis, during summer and winter.In winter pelage, melanistic squirrels had significantly (p < 0.05) lower heat losses and lower basal metabolic rates than grey morphs at ambient temperatures between −20 and 25 °C. No such differences were observed between colour morphs in summer pelage.Thermal conductances were significantly higher in summer animals. However, there were no significant differences in conductance associated with pelage colouration in either summer or winter squirrels.Melanistic S. carolinensis thus appear to have a lower energy cost for existence during winter than do grey morphs. This may contribute to the apparent superior fitness of melanistic morphs in the northern portion of the species' range. Lower heat loss by melanistic squirrels during winter, without a concomitant reduction in thermal conductance, may be associated with a lower body core temperature.

scholarly journals Heat loss from humans measured with a direct calorimeter and heat-flow meters

1980 ◽  
Vol 43 (1) ◽  
pp. 87-93 ◽  
Author(s):  
W. H. Close ◽  
M. J. Dauncey ◽  
D. L. Ingram
Keyword(s):  
Heat Flow ◽  
Ambient Temperature ◽  
Heat Loss ◽  
Skin Surface ◽  
Total Heat Loss ◽  
Flow Meters ◽  
Ambient Temperatures ◽  
External Insulation ◽  
The Subject ◽  
The Difference

1. Heat loss from three men and three women was measured in a direct calorimeter over 2 or 3 h periods and compared with that determined simultaneously from heat-flow meters attached to the skin surface at the waist. The comparisons were made at each of four ambient temperatures, 15, 20, 25 and 30°. Each subject wore a cotton boiler-suit and minimal underwear.2. Oral temperatures and skin and clothing temperatures on both trunk and forearm were determined, thus enabling the subjects' internal and external insulation to be calculated.3. Heat loss determined by the meters was lower than that determined by the calorimeter. The difference increased with increase in ambient temperature. ‘Meter’ heat loss decreased linearly as ambient temperature was raised.4. It was concluded that heat-flow meters could provide a useful estimate of total heat loss when the evaporative component is low. The estimate might be improved if the subject is calibrated while wearing the meters in a calorimeter over several short periods. Heat-flow meters could therefore be of particular value in sedentary individuals, when the heart-rate method for estimating energy expenditure can be inappropriate.

Effects of Ambient Temperature on Warm-Up in the Moth Hyalophora Cecropia

1973 ◽  
Vol 58 (2) ◽  
pp. 503-507
Author(s):  
GEORGE A. BARTHOLOMEW ◽  
TIMOTHY M. CASEY
Keyword(s):  
Ambient Temperature ◽  
Heat Production ◽  
Cooling Curves ◽  
Warm Up ◽  
Ambient Temperatures ◽  
Logarithmic Plot ◽  
Thoracic Temperature ◽  
Hyalophora Cecropia ◽  
The Difference ◽  
Straight Lines

The rates of pre-flight warm-up in adult Hyalophora cecropia (mean weight 3.10g) were measured 24-36 h after eclosion at 15, 20, 25, and 30 °C in still air. 1. The rate of thoracic warm-up increased linearly with ambient temperature, averaging 2.6 °C/min at 15 °C and 6.5 °C/min at 30 °C. 2. Thoracic temperatures typically reached 37-39 °C while abdominal temperatures rarely rose more than 3 °C above ambient. 3. The cooling curves of the thorax at 15° and 25 °C were straight lines and had similar slopes on a semi-logarithmic plot. 4. Our data are compatible with the idea that heat production is dependent on thoracic temperature, and are incompatible with the theory that it depends on the difference between thoracic and ambient temperatures.

scholarly journals Temperature Regulation of Honey Bees (Apis Mellifera) Foraging in the Sonoran Desert

1985 ◽  
Vol 114 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Paul D. Cooper ◽  
William M. Schaffer ◽  
Stephen L. Buchmann
Keyword(s):  
Apis Mellifera ◽  
Temperature Regulation ◽  
Heat Balance ◽  
Honey Bees ◽  
Sonoran Desert ◽  
Heat Budget ◽  
Stomach Contents ◽  
Pollen Foraging ◽  
Ambient Temperatures ◽  
Thoracic Temperature

A heat budget for foraging honey bees (Apis mellifera L.) indicated that at 30–35°C all bees are in positive heat balance during flight. Observations of honey bees returning to their hives at high ambient temperatures support the conjecture that honey bees regulate head and thorax temperatures at high Ta by regurgitating droplets of honey stomach contents which are then evaporated. The proportion of returning bees with a droplet on the tongue increased with increasing shade temperature (Ts), from essentially no bees at 20°C to 40% of returning bees at 40°C. Pollen foragers carry relatively little fluid during the hottest periods, and pollen foraging decreased at high ambient temperatures. Thoracic temperatures of pollen collectors are significantly higher than thoracic temperatures of water and nectar gatherers at 40°C (46.13 vs 44°C). Additionally, water and nectar foragers with extruded droplets have slightly cooler heads and thoraces (38.94 and 43.22°C) than bees not extruding droplets (40.28 and 44.18°C). Wingloading and thoracic temperatures of bees are inversely correlated at high ambient temperatures (35°C) and this is probably caused by a higher propensity of heavier bees to extrude fluid, thus reducing thoracic temperature.

Effect Analysis of Nitrogen Injection on the Variation of “Oxidation Zone” in Coal Mine Gob Based on Numerical Simulation

2016 ◽  
Vol 9 (1) ◽  
pp. 47-54
Author(s):  
Jing Shen ◽  
Mingran Chang
Keyword(s):  
Numerical Simulation ◽  
Coal Mine ◽  
Heat Dissipation ◽  
Spontaneous Combustion ◽  
Oxidation Zone ◽  
Effect Analysis ◽  
Mine Fire ◽  
Nitrogen Injection ◽  
The Difference ◽  
Residual Coal

One of the main reasons for coal mine fire is spontaneous combustion of residual coal in gob. As the difference of compaction degree of coal and rock, the underground gob can be considered as a porous medium and divided into “three zones” in accordance with the criteria. The “three zones” are “heat dissipation zone”, “oxidation zone” and “choking zone”, respectively. Temperature programming experiments are taken and numerical simulation with obtained experimental data is utilized to analyze the distribution of “three zones” in this paper. Different width and depth of “oxidation zone” are obtained when the inlet air velocity is changed. As the nitrogen injection has inhibition effect on spontaneous combustion of residual coal in gob, nitrogen is injected into the gob. The widths of “oxidation zone” are compared before and after nitrogen injection. And ultimately the optimum location and volume of nitrogen injection are found out.

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