Dendrophylliidae cold-water corals in a warm ocean: the effect of exposure duration on their physiological response

Author(s):  
Stéphanie Reynaud ◽  
Covadonga Orejas ◽  
Andrea Campagno ◽  
Cécile Rottier ◽  
Carlos Jimenez ◽  
...  
Sports ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 130 ◽  
Author(s):  
Jørgen Melau ◽  
Maria Mathiassen ◽  
Trine Stensrud ◽  
Mike Tipton ◽  
Jonny Hisdal

Low water temperature (<15 °C) has been faced by many organizers of triathlons and swim-runs in the northern part of Europe during recent years. More knowledge about how cold water affects athletes swimming in wetsuits in cold water is warranted. The aim of the present study was therefore to investigate the physiological response when swimming a full Ironman distance (3800 m) in a wetsuit in 10 °C water. Twenty triathletes, 37.6 ± 9 years (12 males and 8 females) were recruited to perform open water swimming in 10 °C seawater; while rectal temperature (Tre) and skin temperature (Tskin) were recorded. The results showed that for all participants, Tre was maintained for the first 10–15 min of the swim; and no participants dropped more than 2 °C in Tre during the first 30 min of swimming in 10 °C water. However; according to extrapolations of the results, during a swim time above 135 min; 47% (8/17) of the participants in the present study would fall more than 2 °C in Tre during the swim. The results show that the temperature response to swimming in a wetsuit in 10 °C water is highly individual. However, no participant in the present study dropped more than 2 °C in Tre during the first 30 min of the swim in 10 °C water.


1983 ◽  
Vol 54 (3) ◽  
pp. 661-665 ◽  
Author(s):  
B. H. Natelson ◽  
C. A. Nary ◽  
G. A. Curtis ◽  
D. Creighton

Thirteen young healthy human volunteers immersed their faces in warm or cold water on one day while breathing through a snorkel and on another day while breath holding. The magnitude of the elicited bradycardia was most prominently due to water temperature, with apnea playing a less important role. Perceived stress could affect the magnitude of the response, but it was less important than the other variables. Thus statistically significant nonparametric correlations were found for the group but not for most individuals between a scoring technique that assessed perceived stress and heart rate. In contrast to animals, these data indicate that bradycardia may be reliably elicited in humans by face immersion in cold water and that stress is neither necessary nor sufficient to produce this phenomenon. Adaptation did not seem to play a role in the development of this physiological response.


2016 ◽  
Vol 37 (6) ◽  
pp. 1345-1359 ◽  
Author(s):  
Samuel E. Georgian ◽  
Sam Dupont ◽  
Melissa Kurman ◽  
Adam Butler ◽  
Susanna M. Strömberg ◽  
...  

Author(s):  
Walter J. Sapp ◽  
D.E. Philpott ◽  
C.S. Williams ◽  
K. Kato ◽  
J. Stevenson ◽  
...  

Space flight, with its unique environmental constraints such as immobilization, decreased and increased pressures, and radiation, is known to affect testicular morphology and spermatogenesis. Selye, summarized the manifestations of physiological response to nonspecific stress and he pointed out that atrophy of the gonads always occurred. Reports of data collected from two dogs flown in space for 22 days (Cosmos 110) indicate that there was an increase of 30 to 70% atypical spermatozoa when compared to ground based controls. Seventy-five days after the flight the abnormalities had decreased to the high normal value of 30% and mating of these dogs after this period produced normal offspring, suggesting complete recovery. Effects of immobilization and increased gravity were investigated by spinning rats and mice at 2x g for 8-9 weeks. A decrease in testicular weight was noted in spun animals when compared to controls. Immobilization has been show to cause arrest of spermatogenesis in Macaca meminstrins.


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