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Volume 45 (2008)
- Issue 4 Pages 109-
- Issue 2 Pages 57-
- Issue 1 Pages 5-
Volume 45, Issue 2
Displaying 1-4 of 4 articles from this issue
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Original Articles
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Akio Tsuchiya2008 Volume 45 Issue 2 Pages 57-71
Published: 2008
Released on J-STAGE: September 05, 2008
JOURNAL FREE ACCESSThermal dissipation probes (TDP) were plugged into the stems of red pines at Hiroshima University’s campus in order to calculate hydraulic conductivity. The data were developed to describe sap flow velocity (cm·s−1) and sap flow (l·h−1). The observed results show that except for rainy days when the transpiration dulls, a few litters of sap flow were absorbed up within an hour during the daytime of sunny days, and the amount was dependent on the diameter of the stems. Sap flow decreased to zero at night, and was small in the daytime in winter as well. Among micro-meteorological parameters obtained in the measurements from April to May, the saturation deficit was found out to be related to sap flow. An empirical equation between stem diameter and annual sap flow was calculated, and was employed to estimate the horizontal transpiration in the middle slope of Saijo Basin where the dieback of red pines has been progressing. As a result, horizontal transpiration on the slope was found to be 146,000 m3·Km−2·yr−1, while the transpiration at the mountain ridge with little dieback was about 644,000 m3, and the areal average was estimated to be about 245,000 m3. On the other hand, evapotranspiration was about 384,000 m3·Km−2·yr−1 from rainfall and discharge at the watershed level. It is thought that the difference between the values includes not only the amount of transpiration of hardwood individuals, but also interception loss of rainfall, and transpiration by paddy rice.
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Hiromi Ohta, Yoko Tanabe, Yoshihiko Nishino, Megumi Maruyama, Masanori ...2008 Volume 45 Issue 2 Pages 73-84
Published: 2008
Released on J-STAGE: September 05, 2008
JOURNAL FREE ACCESSWe investigated effects of summertime redecoration of a hospital isolation room with natural materials on thermoregulatory, cardiovascular and hormonal responses of healthy subjects. Two isolation rooms in Shimane University Hospital were used. One room (redecorated room, RD) was redecorated with wood paneling and Japanese paper, while the other (control room, CN) was unchanged. Both rooms were ventilated using the hospital air and humidity control system. Additionally, individual air conditioners were used in the daytime in each room at the same levels. Seven healthy male subjects stayed in each room for 24 h. Their rectal temperature, heart rate, arterial blood pressures, and vascular compliance were measured. Blood was sampled after the stay in the rooms. Room temperature did not differ between the two rooms throughout the day. In CN, relative humidity (RH) dropped by 15% when the air conditioner was used, whereas it fell by only 5% in RD. Diurnal rectal temperature levels of subjects were significantly lower in CN than in RD. Redecoration had minimal effects on cardiovascular parameters and plasma levels of catecholamines and antidiuretic hormone. Plasma cortisol level was lower after staying in RD than in CN. The results indicate that in summer season, redecoration with natural materials prevents a sudden decrease of RH in association with the usage of air conditioners, facilitating a physiological rise in core temperature of subjects in the morning and early afternoon. It seems that room redecoration may have a beneficial effect on isolated subjects.
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Tomoya Kashiwagi, Osamu Kashimura, Kazuhiro Minami2008 Volume 45 Issue 2 Pages 85-93
Published: 2008
Released on J-STAGE: September 05, 2008
JOURNAL FREE ACCESSIn this study, we hypothesized that, in rats, adaptation to high altitude (2500 m) plus training at low altitude (610 m), “Living high and Training low”, improves pulmonary diffusing capacity at low altitude. However, whether the pulmonary circulation could be altered after “Living high and Training low” still remain unclear in rats. The purpose of this study was to examine the change of pulmonary resistance with the increases of a pulmonary perfusion rate. In the extraction perfused lung preparation. Rats were divided into for four groups: living at low altitude (LL), living and training at low altitude (LL+TL), living at high altitude (LH), living at high altitude and training at low altitude (LH+TL). The programs for living at high altitude involved raising rats under hypobaric hypoxia (equivalent to 2500 m), and the training program consisted of running on a treadmill at low altitude. All groups were raised at each altitude and trained to run at 15–34 m/min for 30–90 min/day, 5 days/week for 5 weeks. Right ventricular wall weight and base-line resistance of pulmonary circulation were significantly increased in the LH+TL groups than in the LL groups. However, pulmonary circulating resistance with increments of a pulmonary perfusion rate was inhibited in LL+TL groups when compared with other groups. From the above, it could be concluded that LH+TL depression pulmonary arterial pressure increment with exercise. In addition, if the pulmonary diffusing capacity was increased during endurance exercise, if was shown that vasodilation, capillary recruitment and arterializations may be increased by LH+TL.
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Osamu Kashimura, Tomoya Kashiwagi, Kazuhiro Minami, Seiichi Nakai2008 Volume 45 Issue 2 Pages 95-100
Published: 2008
Released on J-STAGE: September 05, 2008
JOURNAL FREE ACCESSA purpose of this study review thermoregulatory and circulatory responses during endurance exercise under hot environmental conditions in history and non-history of heat disorders of long distance runners, and it was to clarify characteristics of thermoregulation in history of heat disorders. The average of heart rate during running was not found in the significant differences between history and non-history of heat disorders. The quantity of water intake during running was not found in the significant differences between history and non-history of heat disorders. The quantity of loss of body weight during running was not found in the significant differences between history and non-history of heat disorders. But, increase of sublingual temperature during running was significantly greater in history of heat disorders than non-history of heat disorders. There is a possibility of decrease in skin blood flow increment induced by running under hot environmental conditions in history of heat disorders of long-distance runners. There is a little skin blood flow to result from running.
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