This study was undertaken to establish an approach for the investigation of age-related changes in indices of body composition during childhood in Japan. It provides current reference values for total body fat mass (TBFM) and lean body mass (LBM) as indices of body composition in an urban population of 3- to 6-year-old Japanese children. Moreover, we assessed the age-specific patterns of body fat distribution [subcutaneous fat mass (SFM) and internal fat mass (IFM)] during childhood. Measurements of body composition by bioelectrical impedance were made in 141 boys and 139 girls, all apparently healthy, aged 3-6 years. Determinations of impedance were made using a four-terminal impedance analyzer (TP-95K; Toyo Physical, Inc., Fukuoka, Japan). LBM was calculated using the equation of Kushner et al. (1992) and Goran et al. (1993). SFM was calculated using a modification of the equation derived by Skerjl et al. (1953). IFM was calculated as the difference between TBFM and SFM. From ages 3 through 6 years, the mean LBM increased with age in boys and girls, and showed significant age differences. Between the ages of 3 and 6, the average increment in LBM was 5.1 kg in boys and 4.4 kg in girls. On average, boys gained 0.5 kg of TBFM each year, whereas girls gained 0.4 kg of TBFM each year. Furthermore, both groups gained 0.3 kg of SFM each year. Percentage body fat decreased in both genders until approximately the age of 5, and increased again slightly at the age of 6. The age-specific pattern of fat accumulation during childhood was characterized by an almost linear increase in SFM in girls, but a transient decrease in IFM in boys. We conclude that further research is required, including longitudinal assessment of body composition variables, in order to unravel the dynamics of body composition change in Japanese children.
Moisture inside the footwear can considerably affect the thermal insulation. In this study with a thermal foot model there was simulated three sweat rates (3, 5 and 10 g/h). Five types of footwear with various insulation levels (dry insulation from 0.19 to 0.50 m2·K/W) were tested. The footwear insulation reduction was calculated for 1.5 hour period. The reduction in insulation was related to sweating rate and initial insulation. The footwear with high insulation lost even in percentile more insulation than thin boots under the same conditions (9-19% at 3 g/h, 13-27% at 5 g/h and 19-36% at 10 g/h). A relationship between insulation decrease and sweating rate was established. An 8-hour sweating test (5 g/h) and a test for determining evaporative heat losses were carried out in addition. The insulation reduction during the first 1.5 hours of the 8-hour test answered for more than half of the total reduction.
The purpose of the present study was to clarify the characteristics of ADL ability among different ambulatory level groups. The subjects were 448 partially dependent older adults (PD; 126 male, 81.7 ± 8.22 year; 322 female, 82.5 ± 7.25 year) over 60 years of age, and they were divided into 3 groups based on ambulatory activity level; G1 could not walk without assistance; G2 could walk with a stick; G3 could walk without assistance. The PD were asked 17 ADL questionnaires representing seven ADL domains to evaluate the ADL ability. Total and domain ADL scores, and achievement rates for each item were calculated, and compared among different ambulatory activity groups. It is confirmed that ADL ability level in PD significantly relates to ambulatory level and becomes gradually higher as the ambulatory activity level advances. It is considered that in the G1, lower limb ability level is low, and the contribution of ability level regarding changing posture and manual activities to total ADL ability level is high. On the other hand, in the G3 the achievement levels in manual activities and high-difficulty ADLs using lower limbs reflects the differences in the ADL ability level among individuals. Gender differences for ADL ability are not found in any ADL domain, while age differences are found in only the G3. It is inferred that for the G1, the achievement levels of ADLs are largely influenced by disease morbidity and age contributes very little to the decline of ability level.
The effects on cognitive performance of breathing air, oxygen and nitrox gas mixtures at surface ambient pressures were investigated during an expedition to the Everest region of Nepal. A slight improvement in grammatical reasoning at altitude was found under nitrox (p<0.05) and mathematical reasoning showed improvement at altitude on air (p<0.05), oxygen (p<0.01) and nitrox (p<0.01). There were non-significant trends towards decreasing mathematical ability, coupled with an increase in variance on both grammatical and mathematical test performance, with increasing pO2 (all p>0.05). The results suggest that there is a subtle interaction on cognition as indicated by a significant three-way interaction between subject x altitude x gas (p<0.05).
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