The Cooling Power of Pigeon Wings

1991 ◽  
Vol 155 (1) ◽  
pp. 193-202 ◽  
Author(s):  
ALBERT CRAIG ◽  
JACQUES LAROCHELLE
Keyword(s):  
Body Temperature ◽  
Heat Production ◽  
Heat Dissipation ◽  
Experimental System ◽  
Whole Body ◽  
Cooling Power ◽  
Wind Speeds ◽  
Maximum Value ◽  
Body Cooling ◽  
Whole Body Cooling

The rate of heat loss through the stretched wings (Hwings) was studied in resting pigeons preheated to a body temperature (43.7°C) within the range of those recorded during flight. The experimental system was designed to allow the calculation of Hwings from the increase in whole-body cooling rates resulting from exposure of the wings to various wind speeds (0–50 km h−1) at 23°C. The maximum value of HWings was 3.8 W, less than twice the heat production of a resting pigeon. This indicates that the contribution of the wings to heat dissipation during flight may not be nearly as important as has been supposed. At low windspeeds (0–12.5 km h−1), HWings corresponded to about 40% of the resting rate of heat production, and this value is discussed in connection with the various wing postures observed in hyperthermic birds.

The Cooling Power of Pigeon Legs

1988 ◽  
Vol 136 (1) ◽  
pp. 193-208 ◽  
Author(s):  
LUCIE MARTINEAU ◽  
JACQUES LAROCHELLE
Keyword(s):  
Wind Speed ◽  
Body Temperature ◽  
Air Temperature ◽  
Heat Production ◽  
Experimental System ◽  
Whole Body ◽  
Cooling Power ◽  
Aquatic Bird ◽  
Body Cooling ◽  
Whole Body Cooling

The rate of heat loss from legs and feet (HLEG) was studied in resting pigeons preheated to a body temperature (43.1°C) close to those recorded during flight. The experimental system was designed to allow the calculation of HLEG from whole-body cooling rates following exposure of the legs and feet to various combinations of wind speed (0–75 km h−1) and air temperature (5–25°C). The pigeons remained hyperthermic when their hindlimbs were kept insulated, but their bodies cooled markedly as a result of exposure of the legs and feet. With a 12.5km h−1 wind at 25°C, HLEG corresponded to 240% of the resting heat production. HLEG was increased by higher wind speed and lower air temperature, but it became essentially independent of wind speed above 37.5 km −1. The maximum values of HLEG were 4–6 times as large as the resting heat production and could account for 50–65 % of the total heat produced during flight. It is concluded that in a non-aquatic bird the legs and feet can play a major role in whole-body thermoregulation, both at rest and during flight.

scholarly journals Does Similar Whole Body Cooling Induce Gender-Specific Attention Stability Deterioration?

2018 ◽  
Vol 1 (96) ◽  
Author(s):  
Rima Solianik ◽  
Albertas Skurvydas ◽  
Marius Brazaitis
Keyword(s):  
Body Temperature ◽  
Heat Production ◽  
Metabolic Heat Production ◽  
Whole Body ◽  
Complex Task ◽  
Metabolic Heat ◽  
Induced Stress ◽  
Body Cooling ◽  
Whole Body Cooling ◽  
Gender Specific

Background. There is evidence of greater whole body cooling induced unpredictable task switching and memory deterioration in men than in women; however, it is not known how whole body cooling affects attention stability. This study aimed at identifying if there are any gender-specific differences in the effect of cold water immersion-induced stress on attention stability.Methods. Thirteen men and thirteen women were exposed to acute cold stress by immersion in 14°C water until rectal temperature reached 35.5°C or for a maximum of 170 min. Thermoregulatory response (i.e. changes of body temperature and metabolic heat production) and attention stability response (i.e. Schulte table (less cognitively demanding task) and Schulte-Gorbov table (more cognitively demanding task)) were monitored.Results. During cold stress, body temperature variables decreased (p < .05) and did not differ between genders. Metabolic  heat  production  was  greater  (p  <  .05)  in  men  than  in  women.  Body  cooling  significantly  increased  (p < .05) the duration of Schulte table performance for both genders, whereas an increase (p < .05) of the duration of Schulte-Gorbov table performance was observed only in men. Conclusion. This is the first study to find the evidence supporting the idea of gender-specific and task-dependent attention stability response after whole body cooling. Whole body cooling induced stress had similar influence on simple attention stability task in men and women, whereas more complex task was adversely affected only in men. This greater men’s decrement of complex task performance can be associated with their greater catecholamines-induced metabolic heat production.Keywords: men, women, cognitive performance, metabolic heat production, shivering.

Response of Negro and white males to cold

1959 ◽  
Vol 14 (5) ◽  
pp. 798-800 ◽  
Author(s):  
P. F. Iampietro ◽  
R. F. Goldman ◽  
E. R. Buskirk ◽  
David E. Bass
Keyword(s):  
Heat Production ◽  
Cold Injury ◽  
Water Bath ◽  
Whole Body ◽  
Group Differences ◽  
Body Temperatures ◽  
White Males ◽  
Body Cooling ◽  
Whole Body Cooling

Heat production and body temperatures were measured in matched groups of U.S. Negro and white soldiers during whole body cooling and finger temperatures were measured when only the digits were cooled. Whole body cooling was accomplished by having the subjects, clad only in shorts, sit for 2 hours in a chamber at 50℉ with a 5-mph wind. Digital cooling was accomplished by having the subjects immerse the fingers in a water bath at 32℉ for 45 minutes. During whole body cooling there were no group differences with respect to the following: heat production, skin and rectal temperatures. During digital cooling white subjects had higher finger temperatures and the ‘hunting’ reaction was more pronounced than for Negroes. In addition, the white subjects required a shorter period for the onset of the first ‘rewarming’ of the fingers. The implications of these findings with reference to the reported higher incidence of cold injury among Negro soldiers are discussed. Submitted on February 19, 1959

SIGNIFICANCE OF THE HYPOTHERMIA LEVEL FOR NEUROPHYSIOLOGICAL REACTIONS OF HUMAN ORGANISM TO EXPERIMENTAL WHOLE-BODY COOLING

2020 ◽  
Vol 54 (5) ◽  
pp. 57-64
Author(s):  
D.B. Demin ◽  
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
External Auditory Meatus ◽  
Total Sample ◽  
Whole Body ◽  
Human Organism ◽  
Low Level ◽  
Body Cooling ◽  
Whole Body Cooling ◽  
High Level

Effects of hypothermia on the character of changes in central hemodynamics, heart rate variability (HRV) and EEG were studied during an experimental whole-body cooling of 30 healthy male subjects at the age of 18–20 years. The subjects were divided into 2 equal groups by the median body temperature in the total sample (34.1 °С) during cooling. The experiment consisted of 3 steps: rest at +20 °С, 10-min exposure to -20 °С in a hypothermal chamber and rewarming at +20 °С. The parameters registered at each step included EEG, blood pressure (BP), heart rate (HR) and temperature in the external auditory meatus. In the cooling chamber, body temperature lowered reliably by 1.4–3.1 °С on the average. In both groups hypothermia reduced the index of regulatory systems strain, increased total HRV power and BP, and decreased HR. During rewarming all these parameters tended to return to baseline values. Subjects with a more distinct hypothermia (33.1 °С) displayed a weakened baroreflex reaction (slight HR reduction) accompanied by a stronger vascular reaction (significant BP rise). High baroreflex stability in the subjects with low-level hypothermia (35 °С) was evidenced by a significant HR decrease in response to the BP rise. Changes in the EEG amplitude and frequency patterns during cooling declared themselves by enhancement of the subcortex regulatory activity (reliable rise in the theta-activity). Also, the alpha-activity was increased in the subjects with high-level hypothermia and decreased in 73 % of the subjects with a low-level hypothermia which points to desynchronization of the main rhythm.

scholarly journals Distribution and Severity of Hypoxic-Ischemic Lesions on Brain MRI Following Therapeutic Cooling: Selective Head Versus Whole Body Cooling

2011 ◽  
Vol 70 ◽  
pp. 722-722
Author(s):  
S Sarkar ◽  
J R Bapuraj ◽  
S M Donn ◽  
I Bhagat ◽  
J D Barks
Keyword(s):  
Brain Mri ◽  
Whole Body ◽  
Body Cooling ◽  
Whole Body Cooling

The effect of whole body cooling in asphyxiated neonates with resource limitation: Challenges and experience

2018 ◽  
Vol 7 (1) ◽  
pp. 7
Author(s):  
Rahul Sinha ◽  
K Venkatnarayan ◽  
Vandana Negi ◽  
Kirandeep Sodhi ◽  
BM John
Keyword(s):  
Resource Limitation ◽  
Whole Body ◽  
Body Cooling ◽  
Whole Body Cooling

scholarly journals An In Vivo Assessment of Regional Brain Temperature during Whole-Body Cooling for Neonatal Encephalopathy

2020 ◽  
Vol 220 ◽  
pp. 73-79.e3
Author(s):  
Tai-Wei Wu ◽  
Jessica L. Wisnowski ◽  
Robert F. Geisler ◽  
Aaron Reitman ◽  
Eugenia Ho ◽  
...  
Keyword(s):  
Brain Temperature ◽  
Whole Body ◽  
Neonatal Encephalopathy ◽  
Regional Brain ◽  
Body Cooling ◽  
Whole Body Cooling ◽  
In Vivo Assessment

Subcutaneous fat necrosis, a rare but serious side effect of hypoxic-ischemic encephalopathy and whole-body hypothermia

2019 ◽  
Vol 47 (9) ◽  
pp. 986-990 ◽  
Author(s):  
Mahdi Alsaleem ◽  
Lina Saadeh ◽  
Valerie Elberson ◽  
Vasantha H.S. Kumar
Keyword(s):  
Therapeutic Hypothermia ◽  
Subcutaneous Fat ◽  
Whole Body ◽  
Subcutaneous Fat Necrosis ◽  
P Values ◽  
Life Threatening ◽  
The Mean ◽  
Body Cooling ◽  
Whole Body Cooling ◽  
Ischemic Encephalopathy

Abstract Objective To describe the clinical characteristics and risk factors in infants with subcutaneous fat necrosis (SFN) following therapeutic hypothermia for hypoxic-ischemic encephalopathy (HIE). Methods A case-control study was performed by a retrospective chart review of infants with moderate or severe HIE admitted to a level IV regional perinatal center and who underwent whole-body cooling. Results A total of 14 (8.1%) of 171 infants with moderate or severe HIE who underwent whole-body cooling developed SFN during hospitalization. There were more females [71% (10/14)] and large-for-gestational age (LGA) infants [28% (4/14)] in the SFN group vs. 36% females (57/157) and 8% LGA infants (13/157) in the group without SFN (P-values of 0.009 and 0.015, respectively). The mean lowest platelet count was lower 108 ± 55 109/L vs. 146 ± 62 109/L and the mean highest calcium level was higher 11.3 ± 2.5 vs. 10.6 ± 0.8 mg/dL in infants with SFN vs. infants without SFN, respectively (P-values of 0.0078 and 0.006, respectively). Distribution of skin lesions followed distinctive patterns representing the areas with direct contact with the cooling blanket. One infant developed severe, life-threatening hypercalcemia that required aggressive management, including diuretics, corticosteroids and bisphosphonates. Conclusion Although SFN is a rare complication of therapeutic hypothermia, it can be a life-threatening condition if complicated by severe hypercalcemia. Infants who undergo therapeutic hypothermia for HIE need regular skin examinations to evaluate for SFN. If SFN is identified, monitoring of serum calcium levels to prevent life-threatening hypercalcemia is recommended.

scholarly journals The nitric oxide dependence of cutaneous microvascular function to independent and combined hypoxic cold exposure

2020 ◽  
Vol 129 (4) ◽  
pp. 947-956
Author(s):  
Josh T. Arnold ◽  
Alex B. Lloyd ◽  
Stephen J. Bailey ◽  
Tomomi Fujimoto ◽  
Ryoko Matsutake ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Nitrite Reduction ◽  
Whole Body ◽  
Local Cooling ◽  
Cutaneous Reflex ◽  
Body Cooling ◽  
Whole Body Cooling ◽  
Oxide Removal ◽  
Oxide Synthase

When separated from local cooling, whole body cooling elicited cutaneous reflex vasoconstriction via mechanisms independent of nitric oxide removal. Hypoxia elicited cutaneous vasodilatation via mechanisms mediated primarily by nitric oxide synthase, rather than xanthine oxidase-mediated nitrite reduction. Cold-induced vasoconstriction was blunted by the opposing effect of hypoxic vasodilatation, whereas the underpinning mechanisms did not interrelate in the absence of local cooling. Full vasoconstriction was restored with nitric oxide synthase inhibition.

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