scholarly journals Effects of duration of stay in temperate area on thermoregulatory responses to passive heat exposure in tropical south-east Asian males residing in Japan

2012 ◽  
Vol 31 (1) ◽  
Author(s):  
Titis Wijayanto ◽  
Sayo Toramoto ◽  
Hitoshi Wakabayashi ◽  
Yutaka Tochihara
Keyword(s):  
East Asian ◽  
Heat Exposure ◽  
Duration Of Stay ◽  
Temperate Area ◽  
Thermoregulatory Responses

scholarly journals Autonomic thermoregulatory dysfunction in neurofibromatosis type 1

2016 ◽  
Vol 74 (10) ◽  
pp. 796-802 ◽  
Author(s):  
Luciana G Madeira ◽  
Renata LF Passos ◽  
Juliana F de Souza ◽  
Nilton A Rezende ◽  
Luiz O. C. Rodrigues
Keyword(s):  
Neurofibromatosis Type 1 ◽  
Diastolic Pressure ◽  
Sweat Rate ◽  
Heat Exposure ◽  
Neurofibromatosis Type ◽  
Passive Heating ◽  
Thermoregulatory Responses ◽  
Sweat Function ◽  
Eccrine Sweat

ABSTRACT Objective Neurofibromatosis type 1 (NF1) causes neural and cutaneous disorders and reduced exercise capacity. Exercise/heat exposure increasing internal temperature must be compensated by eccrine sweat function and warmed skin vasodilation. We suspected NF1 could adversely affect eccrine sweat function and/or vascular thermoregulatory responses (VTR). Methods The eccrine sweat function and VTR of 25 NF1 volunteers (14 males, 11 females; 16–57 years old) were compared with 23 non-NF1 controls matched by sex, age, height and weight (CG). Sweating was induced by 1) pilocarpine 1% iontophoresis (PILO); and 2) by passive heating (HEAT) via the lower third of the legs being immersed in 42°C water for one hour. Previously established eccrine sweat function and VTR protocols were used. Results The NF1 group showed: a) lower sweat rate than the CG group during PILO; b) a smaller diastolic pressure decrease; and c) higher tympanic temperatures than controls during HEAT (p < 0.05). Conclusion Reduced sweating and vascular thermoregulatory responses suggest autonomic dysfunction in NF1 individuals.

Thermoregulatory responses of rats acclimated to heat given daily at a fixed time

1995 ◽  
Vol 78 (5) ◽  
pp. 1720-1724 ◽  
Author(s):  
N. Sugimoto ◽  
O. Shido ◽  
S. Sakurada
Keyword(s):  
Core Temperature ◽  
Exposure Time ◽  
Heat Exposure ◽  
Fixed Time ◽  
Body Core Temperature ◽  
Electric Heater ◽  
Dark Phase ◽  
Thermoregulatory Responses ◽  
Body Core ◽  
Pronounced Reduction

Body core temperature of rats acclimated to heat given daily at a fixed time falls during the previous heat exposure time. In the present study, thermoregulatory responses of heat-acclimated rats were examined during the specific period. Heat-acclimated rats were subjected to an ambient temperature of 32 degrees C for approximately 5 h in the first half or last half of the dark phase for 14 days while control rats were kept at 24 degrees C. Then the rats were placed in a direct calorimeter and were warmed for 30 min with an intraperitoneal electric heater. Measurements were made twice in the first and last halves of the dark phase. Body warming significantly increased body core temperature in all rats. In the heat-acclimated rats, heat production (M) was significantly depressed during the previous heat exposure time but not during the other period. Body warming had little effect on M in the control rats during either period. The results suggest that rats acclimated to heat given at a fixed time daily respond to an acute heat load with a pronounced reduction of M. However, such a response was observed only during the period when the rats had been previously exposed to heat.

Effects of modafinil on heat thermoregulatory responses in humans at rest

2002 ◽  
Vol 80 (8) ◽  
pp. 796-803 ◽  
Author(s):  
Jean-Claude Launay ◽  
Yves Besnard ◽  
Angélique Guinet ◽  
Germain Bessard ◽  
Christian Raphel ◽  
...  
Keyword(s):  
Heat Storage ◽  
Sweat Rate ◽  
Heat Exposure ◽  
Body Temperatures ◽  
Metabolic Heat ◽  
Thermoregulatory Responses ◽  
The Central Nervous System ◽  
Male Subjects ◽  
Skin Temperatures ◽  
Body Heat

The effects of modafinil on heat thermoregulatory responses were studied in 10 male subjects submitted to a sweating test after taking 200 mg of modafinil or placebo. Sweating tests were performed in a hot climatic chamber (45°C, relative humidity <15%, wind speed = 0.8 m·s–1, duration 1.5 h). Body temperatures (rectal (Tre) and 10 skin temperatures (Tsk)), sweat rate, and metabolic heat production (Mdot) were studied as well as heart rate (HR). Results showed that modafinil induced at the end of the sweating test higher body temperatures increases (0.50 ± 0.04 versus 0.24 ± 0.05°C (P < 0.01) for deltaTre and 3.64 ± 0.16 versus 3.32 ± 0.16°C (P < 0.05) for deltaTbarsk (mean skin temperature)) and a decrease in sweating rate throughout the heat exposure (P < 0.05) without change in Mdot, leading to a higher body heat storage (P < 0.05). DeltaHR was also increased, especially at the end of the sweating test (17.95 ± 1.49 versus 12.52 ± 1.24 beats/min (P < 0.01)). In conclusion, modafinil induced a slight hyperthermic effect during passive dry heat exposure related to a lower sweat rate, probably by its action on the central nervous system, and this could impair heat tolerance. Key words: modafinil, heat, human, thermoregulation.

Human thermoregulatory responses during heat exposure after artificially induced sunburn

1992 ◽  
Vol 262 (4) ◽  
pp. R610-R616 ◽  
Author(s):  
K. B. Pandolf ◽  
R. W. Gange ◽  
W. A. Latzka ◽  
I. H. Blank ◽  
K. K. Kraning ◽  
...  
Keyword(s):  
Heart Rate ◽  
Venous Blood ◽  
Heat Exposure ◽  
Plasma Osmolality ◽  
Cycle Ergometer ◽  
The Body ◽  
Left Forearm ◽  
Thermoregulatory Responses ◽  
Ergometer Exercise ◽  
Before And After

Thermoregulatory responses in the heat (ambient temperature 49 degrees C, 20% relative humidity, 1 m/s wind) were investigated in 10 unacclimated men during 50 min of cycle ergometer exercise (approximately 53% of maximal aerobic power) after a 10-min rest before as well as 24 h and 1 wk after twice the minimal erythemal dose of UV-B radiation that covered approximately 85% of the body surface area. In 7 subjects esophageal temperature (Tes) was recorded while in all 10 subjects five-site skin and rectal temperatures, heart rate, and back, left forearm, and shielded (12 cm2 area) right forearm sweating rates (msw) were recorded at 15-s intervals. Venous blood was collected before and after exercise-heat stress. Mean skin temperature, Tes, rectal temperature, heart rate, and total body sweating rate were not significantly (P greater than 0.05) affected by sunburn. Pre- and postexercise values of hematocrit, hemoglobin, plasma protein, plasma volume, and plasma osmolality were also not affected (P greater than 0.05) by sunburn. Analysis of presunburn and post-sunburn data showed that the Tes intercept for sweating (degrees C) was unaffected (P greater than 0.05), but msw/Tes and final msw from the left forearm (msw/Tes 0.24 +/- 0.02 vs. 0.17 +/- 0.01 mg.cm-2.min-1. degrees C-1, P less than 0.05; msw 0.60 +/- 0.05 vs. 0.37 +/- 0.02, mg.cm-2.min-1, P less than 0.05) and back (msw/Tes 0.43 +/- 0.03 vs. 0.36 +/- 0.01 mg.cm-2.min-1. degrees C-1, P = 0.052; msw 1.08 +/- 0.09 vs. 0.74 +/- 0.05 mg.cm-2.min-1, P less than 0.05) were significantly reduced 24 h postsunburn.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Thermoregulation of competitive artistic gymnastic athletes and non-athlete girls exercising in the heat

2016 ◽  
Vol 18 (2) ◽  
pp. 143
Author(s):  
Gabriela Tomedi Leites ◽  
Paulo Lague Sehl ◽  
Giovani Dos Santos Cunha ◽  
Adriano Detoni Filho ◽  
Flavia Meyer
Keyword(s):  
Heart Rate ◽  
Relative Humidity ◽  
Thermal Comfort ◽  
Rectal Temperature ◽  
Perceived Exertion ◽  
Thermal Sensation ◽  
Heat Exposure ◽  
Thermoregulatory Responses ◽  
Rate Of Perceived Exertion ◽  
C 50

DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n2p143 It’s unclear whether the combination of intense, chronic training and heat exposure during prepubescence improves thermoregulatory responses to exercise in artistic gymnastics athletes. The objective of this study was to compare thermoregulatory and perceptual responses between artistic gymnastics athletes and non-athlete girls while exercising both in heat and thermoneutral conditions. Seven athletes (8.7 ± 1.3 yrs) and 7 nonathletes (9.4 ± 1.5 yrs) cycled for 30 min at load (W) of ~55% VO2peak, on two separate occasions in a randomized order: heat (35˚C, 40% relative humidity) and thermoneutral conditions (24˚C, 50% relative humidity). Rectal temperature, heart rate, rate of perceived exertion, thermal sensation, thermal comfort and irritability were measured throughout the exercise. Initial rectal temperature was similar between athletes and non-athletes in both heat (37.2 ± 0.4 vs. 37.4 ± 0.2˚C, respectively) and thermoneutral conditions (37.3 ± 0.2 vs. 37.3 ± 0.3˚C). Final rectal temperature was similar between groups (38.0 ± 0.2 vs. 38.2 ± 0.2˚C in heat and 37.8 ± 0.2 vs. 37.9 ± 0.2˚C in thermoneutral conditions). Initial heart rate was lower in athletes in the heat (76 ± 7 vs. 91 ± 11 bpm, P = 0.01); however, throughout cycling, it became similar between groups. Athletes reported similar perceptual responses compared to non-athletes, with the exception of higher thermal comfort in the 10th minute of exercise in thermoneutral conditions (P = 0.003). It was concluded that athletes were similar to non-athletes with respect to thermoregulatory and perceptual responses during 30 min of cycling at similar relative intensities.

Thermoregulatory responses to acute body heating in rats acclimated to continuous heat exposure

1990 ◽  
Vol 68 (1) ◽  
pp. 59-65 ◽  
Author(s):  
O. Shido ◽  
T. Nagasaka
Keyword(s):  
Heat Load ◽  
Heat Exposure ◽  
Thermal Conductance ◽  
The Other ◽  
Electric Heater ◽  
Acclimation Temperature ◽  
Metabolic Heat ◽  
Thermoregulatory Responses ◽  
Colonic Temperature ◽  
Continuous Heat

Thermoregulatory responses to an acute heat load with intraperitoneal heating (IH) or indirect external warming (EW) by increasing ambient temperature (Ta) were investigated with direct and indirect calorimetry in rats acclimated to environments of 24.0 degrees C (Cn), 29.4 degrees C (H1), and 32.8 degrees C (H2) for greater than 15 days. The rats were placed in a direct calorimeter where the air temperature was maintained at 24 degrees C for the initial 3 h. IH was then made for 30 min through an electric heater implanted chronically (6.5 W.kg-1) in the peritoneal cavity, and EW was performed by raising the jacket water temperature surrounding the calorimeter from 24 to 39 degrees C (0.19 degrees C.min-1). Hypothalamic (Thy) and colonic temperature immediately before the start of the heat load tended to be higher as the acclimation temperature increased. During IH, the threshold Thy for the tail skin vasodilation (Tth) was significantly higher in H2 than in Cn rats. During EW, however, there was no difference in Tth between the groups. Metabolic heat production (M) was slightly suppressed during IH and significantly depressed only in H2 rats. During EW, M was suppressed in all the groups. The magnitude and duration of suppression were greater in H2 rats than in the other two groups. The responses in nonevaporative heat loss and thermal conductance (C) to the rise in Thy did not differ among the three groups during IH. According to the rise in Thy, however, there was a greater C increase in H2 than in Cn and H1 rats during EW.(ABSTRACT TRUNCATED AT 250 WORDS)

Maxims of Foreign Policy

Itinerario ◽  
2000 ◽  
Vol 24 (2) ◽  
pp. 62-79
Author(s):  
W.J. Boot
Keyword(s):  
Foreign Policy ◽  
Sixteenth Century ◽  
Foreign Relations ◽  
East Asian ◽  
Modern Period ◽  
Cultural Sphere ◽  
Japanese Identity

In the pre-modern period, Japanese identity was articulated in contrast with China. It was, however, articulated in reference to criteria that were commonly accepted in the whole East-Asian cultural sphere; criteria, therefore, that were Chinese in origin.One of the fields in which Japan's conception of a Japanese identity was enacted was that of foreign relations, i.e. of Japan's relations with China, the various kingdoms in Korea, and from the second half of the sixteenth century onwards, with the Portuguese, Spaniards, Dutchmen, and the Kingdom of the Ryūkū.

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