Regulation of Heat Production by Large Moths

1967 ◽  
Vol 47 (1) ◽  
pp. 21-33
Author(s):  
JAMES EDWARD HEATH ◽  
PHILLIP A. ADAMS
Keyword(s):  
Oxygen Consumption ◽  
Heat Loss ◽  
Low Temperatures ◽  
Cooling Curve ◽  
O2 Consumption ◽  
Internal Temperature ◽  
Warm Up ◽  
Temperature Changes ◽  
Thoracic Temperature ◽  
Silk Moth

1. Moths ‘warm-up’ prior to flight at mean rates of 4.06° C./min. in Celerio lineata and 2.5° C./min. in Rothschildia jacobae. The abdominal temperature rises only 2-3° C. during activity. 2. Oxygen consumption of torpid sphinx moths increases by a factor of 2.27 as temperature changes from 26° to 36° C. 3. Oxygen consumption during ‘warm-up’ increases with duration of ‘warm-up’ from about 1000 µl./g. min during the initial 30 sec. to nearly 1600µl./g. min. during the 3rd min. This increase compensates for increasing heat loss from the thorax during ‘warm-up‘. 4. When the moths are regulating thoracic temperature, oxygen consumption increases with decreasing air temperature from a mean of about 400µl./g. min at 31° C. to about 650µl./g. min. at 26° C 5. Values of O2 consumption calculated from the cooling curve of C. lineata are about 85% of the measured values of O2 consumption. 6. The giant silk moth, Rothschildia jacobae, regulates thoracic temperature during activity between about 32° and 36° C. at ambient temperature from 17° to 29° C. Moths kept at high temperatures are active longer, have more periods of activity and expend more energy for thermoregulation than moths kept at low temperatures. 7. Large moths increase metabolism during active periods to offset heat loss and thereby maintain a relatively constant internal temperature. In this regard they may be considered endothermic, like birds and mammals. 8. We estimate that male moths use 10% of their stored fat for thermoregulation, while females may use 50%.

Effect of three different warm-up regimens on heat balance and oxygen consumption of thoroughbred horses

1996 ◽  
Vol 80 (6) ◽  
pp. 2190-2197 ◽  
Author(s):  
R. J. Lund ◽  
A. J. Guthrie ◽  
H. J. Mostert ◽  
C. W. Travers ◽  
J. P. Nurton ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Heat Loss ◽  
Respiratory System ◽  
Heat Balance ◽  
O2 Consumption ◽  
Active Recovery ◽  
O2 Uptake ◽  
Central Venous ◽  
Warm Up ◽  
Thoroughbred Horses

Horses were exercised at 105% of their maximal O2 uptake until fatigued after three different warm-up regimens (no warm-up, a light warm-up, and a warm-up until the central venous temperature was > 39.5 degrees C) to assess the effect of the warm-up on the various avenues of heat loss. Approximately 12.79, 15.10, and 18.40 MJ of heat were generated in response to the warm-up and exercise after the three different warm-up regimens, respectively. Of the heat generated, 17.5, 17.2, and 17.4% remained as stored heat after 20 min of active recovery. Heat loss from the respiratory system was 63.6, 33.7, and 40.3% of the heat produced during and after the three warm-up intensities, respectively. The balance of the heat loss was assumed to be via the evaporation of sweat. On this basis, the heat loss by sweating was 14.9, 49.1, and 42.3% of the heat produced during and after the three warm-up intensities, which represented evaporation of 0.8, 3.1, and 3.0 liters of sweat, respectively. O2 consumption during exercise and heart rates 20 min postexercise, after two of the warm-up regimens, was significantly lower than that after no prior warm-up.

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.

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.

Instantaneous Measurements of Oxygen Consumption During Pre-Flight Warm-Up and Post-Flight Cooling in Sphingid and Saturniid Moths

1981 ◽  
Vol 90 (1) ◽  
pp. 17-32 ◽  
Author(s):  
GEORGE A. BARTHOLOMEW ◽  
DAVID VLECK ◽  
CAROL M. VLECK
Keyword(s):  
Oxygen Consumption ◽  
Body Mass ◽  
Warm Up ◽  
Open Flow ◽  
Metabolic Scope ◽  
Thoracic Temperature

A method for instantaneous measurement of oxygen consumption in an open flow respirometry system is described. During pre-flight warm-up in both sphingids and saturniids, oxygen consumption reaches levels 20 to 70 times resting values. VOO2 required to maintain the thorax at flight temperature by intermittent wing-quivering and fluttering is about one-third the maximum VOO2 during warm-up. The Q10 of resting VOO2 averages 2·4 in both sphingids and saturniids. At any given thoracic temperature, VOO2 during post flight-cooling exceeds VOO2 at rest. Factorial scope (maximum VOO2÷resting VOO2) during warm-up is independent of mass and thoracic temperature. In sphingids it averages 39, in saturniids, 43. Absolute metabolic scope in both groups increases with thoracic temperature and is roughly proportional to VOO2. In saturniids about 49% of the heat produced during warm-up is stored in the thorax; in sphingids the figure is about 73%. The data on metabolic scope, power requirements for flight, Q10 and body mass are used to develop equations that predict thoracic temperature during flight for both sphingids and saturniids.

Mechanisms for the Control of Body Temperature in the Moth, Hyalophora Cecropia

1970 ◽  
Vol 53 (2) ◽  
pp. 349-362
Author(s):  
JAMES L. HANEGAN ◽  
JAMES E. HEATH
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Air Temperature ◽  
The Body ◽  
Warm Up ◽  
Thoracic Temperature ◽  
Hyalophora Cecropia ◽  
Theoretical Minimum ◽  
Maximum Minimum ◽  
Lowered Body

1. Thoracic temperature in the moth, Hyalophora cecropia, is correlated with gross patterns of behaviour. 2. The animal warms up to a minimum of 34.8°C body temperature before initiating flight. The rate of warm-up is linear and the duration of the warm-up period increases with decreasing air temperature. 3. Thoracic temperature at the initiation of flight and during maintained flight remain constant at any given air temperature, however, decreases 0.25°C per °C gradient as air temperature is decreased. 4. Distribution of the maximum and minimum thoracic temperatures during active periods indicate that the animal maintains its body temperature within a favourable range. The animal uses behavioural mechanisms to maintain the thoracic temperature within this range when the body temperature reaches the limits, 33.4 and 37.8 °C. 5. The minimum thoracic temperature for flight (34.8°C) and the shade-seeking temperature (38.5°C) correspond closely to the limits predicted from the maximum-minimum distribution of thoracic temperatures. 6. The theoretical minimum and maximum rates of oxygen consumption were calculated from cooling curves and warm-up curves. Both rates increase when the gradient between body temperature and air temperature increases (air temperature is lowered, body temperature remains relatively constant). 7. Directly measured rates of oxygen consumption in flying animals increase as air temperature decreases. These values fall within the calculated maximum and minimum in all cases. 8. Oxygen consumption measured in torpid animals indicates a normal poikilothermic response, increasing with increased air temperature. The Q10 for this response is 2.25 over the range 20-30 °C. 9. A model for the regulation of body temperature in active moths is discussed.

Oxygen Consumption in Platelets of Newborn Infants before and after Stimulation by Thrombin.

1976 ◽  
Vol 35 (03) ◽  
pp. 712-716 ◽  
Author(s):  
D. Del Principe ◽  
G Mancuso ◽  
A Menichelli ◽  
G Maretto ◽  
G Sabetta
Keyword(s):  
Oxygen Consumption ◽  
Cord Blood ◽  
Umbilical Cord ◽  
Newborn Infant ◽  
Umbilical Cord Blood ◽  
Newborn Infants ◽  
O2 Consumption ◽  
Adult Control ◽  
Healthy Newborn ◽  
Before And After

SummaryThe authors compared the oxygen consumption in platelets from the umbilical cord blood of 36 healthy newborn infants with that of 27 adult subjects, before and after thrombin addition (1.67 U/ml). Oxygen consumption at rest was 6 mμmol/109/min in adult control platelets and 5.26 in newborn infants. The burst in oxygen consumption after thrombin addition was 26.30 mμmol/109/min in adults and 24.90 in infants. Dinitrophenol did not inhibit the burst of O2 consumption in platelets in 8 out of 10 newborn infants, while the same concentration caused a decrease in 9 out of 10 adult subjects. Deoxyglucose inhibited the burst in O2 consumption in newborn infant and adult platelets by about 50%. KCN at the concentration of 10−4 M completely inhibited basal oxygen consumption but did not completely inhibit the burst after thrombin. At the concentration of 10−3 M, it inhibited both basal O2 consumption and the burst in infants and adult subjects.

scholarly journals The influence of air movement and atmospheric conditions on the heat loss from a cylindrical moist body

1939 ◽  
Vol 39 (1) ◽  
pp. 60-89 ◽  
Author(s):  
Alan J. Canny ◽  
C. J. Martin
Keyword(s):  
Heat Exchange ◽  
Heat Loss ◽  
Wind Velocity ◽  
Effective Temperature ◽  
Physical System ◽  
Square Root ◽  
Atmospheric Conditions ◽  
Internal Temperature ◽  
Air Movement ◽  
Internal Conductivity

It is emphasized that as heat exchange is controlled by the temperature of that boundary layer of molecular dimensions which separates a cooling body from its environment and from which evaporation occurs, attempts to relate heat loss with internal temperature have resulted only in empirical formulae. A rational formula involving the temperature of the evaporating surface is suggested, and it is shown how in the case of a system of sufficient simplicity all the terms can be either measured or derived from experiments.The results of experiments with a small moistened cylinder are detailed illustrating the effect of wind velocity upon evaporative and convective heat loss under the one condition when the evaporating surface remains at constant temperature notwithstanding variations in wind, namely, when the whole system has been cooled to wet-bulb temperature. Evaporative loss is found to vary as V0.65, convective as V0.70.Experiments are next described showing the effect of wind upon evaporative and convective losses when, the internal temperature being constant, the temperature of the evaporating surface fluctuates in consequence of varying wind velocity. Heat loss now varies very closely as V0.5 at velocities greater than 1 m./sec. At velocities below 1 m./sec. the same relation of heat loss to velocity obtains if due allowance be made for natural convection. This square root function is fortuitous, and heat loss varied between the square root and cube root of the velocity as the internal conductivity was diminished.Attention is drawn to the impossibility of forming general conclusions from observations on any particular system, as the way in which the rate of heat loss varies with the velocity of the wind depends not only upon the internal conductivity of the system but also on its size and shape.Observations are described showing the influence of varying the internal temperature on total and evaporative heat loss with constant wind velocity and constant atmospheric conditions. These experiments furnish data from which the surface temperature can be derived from measurements of evaporation, and show that the temperature of the surface and the rate of loss of heat by convection are both linear functions of the internal temperature at any one wind velocity. They also show that the values of the constants of the system derived from experiments at the temperature of the wet bulb are applicable when the cylinder is heated.An analysis of the results of the experiments with varying internal temperature indicates that the temperature of the evaporating surface (ts) is related to the internal temperature (t1) and that of the wet bulb (tw) by the expression The value of C with varying wind velocity is ascertained by experiments, thus affording another means of arriving at the temperature of the evaporating layer. Values of ts obtained in this way are compared with those determined by observing the rate of evaporation and show reasonable agreement.It is shown how, knowing the temperature of the evaporating layer, the constants of the system employed and the effect of velocity of wind upon heat exchange, the rate of loss of heat by evaporation and by convection under given conditions can be predicted. Instances of the agreement between predicted and observed values are given.From the formula representing the influence of atmospheric conditions on heat loss it can be shown, by calculation, that if the wet-bulb temperature remains constant considerable variations in the temperature of the dry-bulb influence but slightly the heat loss from the moist cylinder.It will be seen that the analysis of the effects of environmental changes on the heat loss from a simple physical system such as was used presents no serious difficulties. Such an analysis, unfortunately, does not enable deductions to be made with reference to systems of different physical characteristics. How observations on such systems can be related in other than a qualitative manner to the effects of corresponding changes on living creature differing in size and shape and degree of moistening of their surfaces is not clear. When account is taken of the ability of living beings to alter the vascularity of their surface tissues and so to vary the temperature of the body surface while other factors remain constant, the difficulties in relating the cooling of any physical system to the loss of heat from animals become painfully apparent.The most hopeful method of assessing the effect of air movement and atmospheric conditions on the heat loss from the human body seems to be in terms of a subjectively determined standard such as the effective temperature scale of Houghton & Yaglou. The validity of such a scale has received support from observations by Houghton et al. (1924) and Vernon & Warner (1932) on the relation of pulse rate, body temperature, metabolism and other physiological variables to “effective temperature”.

Numerical Simulation on Quenching Temperature Field of 40Cr Steel

2010 ◽  
Vol 154-155 ◽  
pp. 417-420
Author(s):  
Di Cui ◽  
He Liang
Keyword(s):  
Field Work ◽  
Cooling Curve ◽  
Work Piece ◽  
Security Assessment ◽  
Quenching Temperature ◽  
Temperature Changes ◽  
Complex Process ◽  
Medium Flow ◽  
Quenching Process ◽  
40Cr Steel

The quenching process is a complex process, which involves quenching medium flow field, work piece temperature and stress field. In this paper, the 40Cr steel belt wheel is chosen for the sample of finite element method to simulate the quenching process. The temperature changes with time at any position in the work piece are directly reflected in the actual quenching process. The cooling curves of center and general surface are obtained after simulation. Combined with cooling curve of transformation of under cooled austenite, it is easy to predict whether the technological results meet the performance of organization, and conduct a security assessment of the work piece.

GASEOUS METABOLISM IN PREMATURE INFANTS AT 32-34°C AMBIENT TEMPERATURE

PEDIATRICS ◽  
1964 ◽  
Vol 33 (1) ◽  
pp. 75-82
Author(s):  
Forrest H. Adams ◽  
Tetsuro Fujiwara ◽  
Robert Spears ◽  
Joan Hodgman
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Premature Infants ◽  
Rectal Temperature ◽  
Respiratory Quotient ◽  
Carbon Dioxide Production ◽  
Open Circuit ◽  
Co2 Production ◽  
O2 Consumption ◽  
Rate Of Increase

Thirty-four measurements of oxygen consumption, carbon dioxide production, respiratory quotient, and rectal temperature were made on 22 premature infants with ages ranging from 2½ hours to 18 days. The studies were conducted at 32-34°C utilizing an open circuit apparatus and a specially designed climatized chamber. Oxygen consumption and carbon dioxide production were lowest in the first 12 hours and increased thereafter. The rate of increase in O2 consumption was greater than that of CO2 production, with a consequent fall in respiratory quotient during the first 76 hours of life. A reverse relation of O2 consumption and CO2 production was found following the 4th day of life with a consequent rise in respiratory quotient. There was a close correlation between O2 consumption and rectal temperature regardless of age. A respiratory quotient below the value of 0.707 for fat metabolism was observed in 7 premature infants with ages ranging from 24 to 76 hours.

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