Morphometry of the second, third and fourth metacarpal bone was performed on hand-wrist radiograms of both hands in a sample of 434 male and 549 female adult subjects. Mor-phometric data (bone length-L, total diaphysis width-T and medullary canal width-M) and age were processed using principal factor analysis with oblique rotation, separately for males and females. In both sexes three factors accounting for 74.7% of the total variance were extracted, but their patterns of variation differed. Factors-"cumulative environmental-genetic factor", "longitudinal factor", and "transversal factor"-are discussed within the context of their biologi-cal meaning affecting the. phenotypic formation of metacarpal skeleton in a given population

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Sustained contractions were compared between with (AW) and without (NAW) spontaneous alternations of working arm to investigate the fatigue level at which the contraction is felt to be stopped. Subjects maintained an upper limb in the horizontally flexed position at 5%, 10%, 15% and 20% of maximum voluntary contraction strength (MVC). Contractions were continued until they felt exhausted or 45min. had passed. Fatigue level was evaluated with 4 levels of fatigue sensations and surface electromyogram (EMG) of the deltoid. Mean ampli-tude (AEMG) and relative power in 8-40Hz (RPLF) of EMG were calculated. The following results were obtained. Fatigue level was lower in AW than in NAW for the same amount of work done by one arm. As AEMG often decreased with time, fatigue was estimated by relating AEMG to RPLF. At 20% MVC in AW the alternation interval decreased and the muscle fatigued with repeated contractions though the fatigue level was not severe. Contrac-tion was felt to be stopped when the first fatigue sensation occurred. But it was not necessary to stop the contraction until considerable tiredness or apparent pain occurred

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In a factory involved in heavy industry, an investigation of noise levels was carried out ; measurements were made of environmental noise, a questionnaire was given to the workers, and their hearing was tested with audiometer. The subjects were 795 male ivorkers, 47.7±8.8 years of age (Mean i SD). There are many noisy machines in the factory : airblowers, sanders, steel-presses etc. Some of these put out high noise levels in operation, over 100dB (A) near the laborer's ear. About 60 percent of the laborers were working in a noise level below 85dB (A). Some are in the area of 85-90dB (A). There are a few laborers at the area over 90dB (A). The laborers had the following complaints : hearing loss (about 30 percent), tinnitus (15 percent), and dizziness (10 percent) etc. Hearing levels with 6 divided estimation method of many laborers were 15 to 19dB (25 percent) and 20 to 24dB (24 percent). Hearing levels become higher with aging. The group over 35 years of age showed higher hearing levels at sound frequency 4000Hz, i.e. such as c5 dip phenomenon. Most laborers are using ear plug, but some use them only occasionally. More industrial hygiene education should be given the laborers ; routine noise measurements and regular medical checkups are needed

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The purpose of this study was to investigate the ethnic differences in the body composition, thickness of subcutaneous fat and muscle between Japanese and American white females. Thirty-six Japanese (aged 20-30 years) and 42 American white females (aged 20-29 years) served as subjects. Percentage of fat weight (%fat) and fat free weight (FFW) were assessed by hydrostatic weighing. Subcutaneous fat and muscle thickness were measured by using B-scan ultrasound equipment with a 5MHZ transducer at eight sites : forearm, biceps, triceps, subscapular, abdomen, quadriceps, hamstrings and posterior calf. There were no significant differences in %fat between Japanese and American subjects. However, American subjects had significantly higher values in FFW compared to Japanese. The Americans showed higher muscle thickness than Japanese at every site and higher fat thickness of biceps, triceps and hamstrings compared to Japanese subjects. For fat thickness at the abdomen, however, Japanese indicated siginificantly higher values than American. In both Japanese and Amer-icans, relative values of fat weight (FW) and FFW per unit of height2 were significantly related to each of the sum of fat and muscle thicknesses obtained from every measurement site respectively. There were no differences in fat thickness at a given FW/height² between Japanese and Americans. However, Americans showed higher values in muscle thickness than Japanese even at the Same level of FFW/height². Therefore although ethnic differences in fat and muscle thickness are related to that of FW and FFW respectively, Americans are superior to Japanese in muscle development. There were no significant differences in upper/lower extremity ratio of fat and muscle thickness between Japanese and Americans.

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The present study was designed to investigate the effects of color temperature of lighting sources on a contingent negative variation (CNV). Eleven male students (mean age, 23.2) volunteered as subjects. The CNV was recorded under three different color temperature conditions (3000°K, 5000°K and 7500°K). The illuminance level was kept at 1000lx. The lighting condition caused no effect on the reaction time of the performance included in the CNV paradigm. On the other hand, the CNV was suggested to be influenced by the lighting condition. Especially, the CNV between 1025 msec to ll25 msec after the warning stimulus (S1) under 7500°K was obviously larger than that under 3000°K. This tendency was observed within the range between 800 msec and 1300 msec. Judging from no correlation between the light condition and reaction time, the concept of readiness potentials has little possibility for explaining the difference in CNV between the lighting conditions. Therefore, the difference in CNV between 3000°K and 7500°K was conclud-ed to be originated from some differences in orienting response. The color temperature of 7500°K was considered to be more activating than the color temperature of 3000°K from the view, point of reticular activating system in CNV mechanism

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The present study was desigend to examine the effects of illuminance and color tempera-ture of room lighting. Four male students volunteered as subjects. Each of them performed a calculation task for 95 minutes under nine different lighting environments consisting of a combination of three levels of illuminance (320lx, 1000lx and 2000lx) and three levels of color temperature (3000°K, 5000°K and 7500°K). Three types of fluorescent lamps were used as a light source to vary the color temperature. Blood pr.essure, critical flicker frequency (CFF) and accommodation time of eye movements were measured every 30 minutes during the task. The accommodation time was significantly influenced by the illuminance level and both the relaxation time and contraction time were prolonged under 2000lx. The diastolic blood pressure was significantly affected by the color temperature level and increased under 7500°K. As for the CFF, the interaction between illuminance and color temperature was significant. These results mean that not only the illuminance but also color temperature produces physio-logical effects. The present study may be the first to recognize the effect of color temperature on the blood pressure

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The effect of acoustic environment on the impression of the landscape and the effect of the landscape on the impression of the acoustic environment were investigated by a multivariate technique using a semantic differential method. The resulting five dimensions were interpreted as "Calmness", "Activity, "Uniqueness", and "Volume (Magnitude)" for both landscape and sound evaluations. These common psychological qualities are considered to be the intermodalities of visual and auditory processing. Further, the consonance phenomenon through the intermodalities, a kind of interaction between auditory and visual processing which changes the psychological qualities to the same direction, was observed when the combination of the acoustic environment and landscape was evaluated to be matched. These results may be the basis of the soundscape design under various kinds of landscape

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Physiological tremor, which is the invisible mechanical vibration of body part, was mea-sured for five fingers. It was obtained that the power spectrum always has two peaks at 10 and 25Hz for each of the five fingers. The peaks were considered to be generated in the following two loop systems : The component of the lower frequency originated from the central nervous system as a long loop, and that of the higher frequency originated from the muscle-spine loop system as a short loop. The total power, which was the sum of power spectra ranging from 1.5 to 50Hz, was defined as an evaluation index, and it showed character-istic results for the five fingers. The muscular load produced by two hours of typing work was responsible mainly for the increase of total power and for the change of peak frequencies. The mechanism for the change of the power spectrum due to muscular load was well explained by the two-loop theory. It was found that the fatigue of the fingers due to muscular load could be evaluated by the total power

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The effect of muscle vibration during voluntary self-paced elbow movements were studied in normal human subjects. Vibrations (10Hz, 30Hz, 50Hz, 70Hz) were applied to the m. deltoid, m. forearm extensor and flexor : vibration was turned off between movements. During non-visually guided (eyes closed) movements (reproductive movements), an undershoot of the required movement was observed in cases where vibration (30Hz, 50Hz, 70Hz) was applied to the m. forearm extensor and flexor. On the contrary, no effect was observed in cases where vibration (80Hz) was applied to the m. deltoid. These findings suggest that sensory information from the m. forearm extensor and flexor might play a role in reproductive elbow extension and flexion movements

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