The aim of this study was to determine whether a 350-s recovery period allows recovery of peak power output (PPO) to its initial value under the condition of a blood lactate (La) concentration higher than 10 mmol·L−1 during repeated cycling sprints (RCS). RCS (10×10-s cycling sprints) were performed under two conditions. Under one condition, the recovery period of RCS was fixed at 35 s (RCS35), and under the other condition, a 350-s recovery period was set before the 5th and 9th sets, and a 35-s recovery period was set before the other sets (RCScomb). In RCScomb, PPO in the 5th set recovered to that in the 1st set, but PPO in the 9th set did not. Under both conditions, blood La concentration progressively increased and reached approximately 14 mmol·L−1 at the end of the RCS. In RCScomb, VO2 immediately before the 5th set was not significantly different from that immediately before the 9th set. Mean power frequency (MPF) values estimated by a surface electromyogram from the vastus lateralis in the 5th and 9th sets were significantly higher in RCScomb than in RCS35. In conclusion, a 350-s recovery period does not allow recovery of PPO to its initial value under the condition of a blood La concentration of 14 mmol·L−1 during RCS.
The present study had as objectives (1) to compare the morphological and functional characteristics of the male judo players of the Brazilian Team A (n=7) with the judo players of Teams B and C (reserves; n=15), and (2) to verify the association between the variables measured. Thus, 22 athletes from the seven Olympic weight categories were submitted to: a body composition evaluation (body mass, height, ten skinfolds, eight circumferences, three bone diameters and percent body fat estimation); the Special Judo Fitness Test (SJFT); maximal strength tests (one repetition-maximum, 1 RM, in bench press, row, and squat); and the Cooper test. One-way analysis of covariance was used to compare the groups. The relationships between variables were determined by the Pearson coefficient correlation. The significance level was fixed at 5%. No significant difference was found in any variable between them. The main significant correlations observed were between the following variables: VO2max and number of throws in the SJFT (r=0.79); percent body fat and estimated VO2max (r=−0.83) and number of throws in the SJFT (r=−0.70); chest circumference and bench press 1 RM (r=0.90) and in the row (r=0.80); and thigh circumference and squat 1 RM (r=0.86). However, there was no significant correlation between circumferences and 1 RM/kg of body mass. According to these results the main conclusions are: (1) the physical variables measured do not discriminate performance when analysis is directed to the best athletes; (2) a higher percent body fat is negatively correlated with performance in activities with body mass locomotion (Cooper test and the SJFT); (3) judo players with higher aerobic power performed better in high-intensity intermittent exercise; (4) judo players with bigger circumferences present bigger absolute maximal strength.
Visual display terminals (VDT) are standard equipment for many office workers. Their use, however, may increase the risk of developing adverse conditions related to vision, the musculoskeletal system, and mental health. We carried out a survey among 3070 workers aged 18 to 67 years (mean, 39.9 years) at a prefectural administrative office, in which 76% of subjects were visual display terminal (VDT) users. We examined the relationship between duration of daily VDT use and eyestrain, neck or upper extremity pain, back pain, and mental health, and estimated the effect of breaks and rest during VDT work on these symptoms. The 12-item General Health Questionnaire (GHQ-12: total scores ranged from 0 to 12) was used to identify potential poor mental health status, and subjects with 4 or more were considered to have symptoms of psychological distress. Seventeen percent of subjects reported eyestrain, 19.1% reported upper extremity pain, 11.6% reported back pain, and 17% of subjects had GHQ-12 scores of 4 or higher. Logistic regression analysis showed that duration of daily VDT use and lack of breaks and rest during VDT work were significantly associated with eyestrain, neck or upper extremity pain, back pain, and psychological distress. In order to protect users from the adverse effects associated with VDT work, reducing daily VDT exposure, taking breaks, and rest during VDT work are important.
Initial physical anthropology studies into ethnic diversity were largely dependent on comparative whole body and craniometric measurements, and through time assessments of ethnic diversity based on these measures exhibited increasing statistical sophistication. Since the 1990s, in Asia as elsewhere in the world, human diversity studies have increasingly utilized DNA-based analyses, with Y-chromosome and mtDNA markers providing complementary perspectives on the origins and gene pool structures of different ethnic groups. This approach is illustrated in a study of population genetic structure in PR China, in which DNA samples from the Han majority and eight ethnic minorities were analyzed. The Y-chromosome and mtDNA data showed multiple paternal geographical and ethnic origins but restricted maternal ancestries. However, interpretive problems were apparent in the definition of a number of the ethnic study populations, which appear to reflect political as well as genetic influences. In all anthropological studies, whether based on anthropometry or genomic analysis, unambiguous and appropriate community identification is a prerequisite.
People have positive aesthetic, emotional, and physiological responses to nature. Why is this so? The “savanna hypothesis,” proposed by Gordon Orians, predicts that some human responses are based on innate knowledge of productive human habitats. To test this, researchers have examined particular aspects of nature that should be associated with productive human habitats to see if they trigger positive responses in people. Tree form has emerged as an important factor in these studies. People prefer looking at trees with spreading forms much more than looking at trees with other forms. Trees with spreading forms existed on the African savanna and were associated with habitats that were good for early human habitation. We have shown that subjects also feel happier when looking at these trees than when looking at other trees or non-tree objects. Color is another variable that might be associated with people's responses to nature. Bright green colors could be an important cue for healthy plants with good nutrient qualities. We measured subjects' physiological responses to tree canopies of various colors and found that all colors were calming, but bright green trees were more calming than other tree colors, including less bright greens and oranges. Adult responses to plants are also influenced by their childhood interactions with nature. We have shown that the more interaction people have with nature as children, the more positive are their attitudes towards nature as adults. These positive responses have been documented in people from a wide range of backgrounds.
In the art and science of lighting, four traditional objectives have been to provide light that: 1) is optimum for visual performance; 2) is visually comfortable; 3) permits aesthetic appreciation of the space; and 4) conserves energy. Over the past 25 years, it has been demonstrated that there are nonvisual, systemic effects of light in healthy humans. Furthermore, light has been used to successfully treat patients with selected affective and sleep disorders as well as healthy individuals who have circadian disruption due to shift work, transcontinental jet travel, or space flight. Recently, there has been an upheaval in the understanding of photoreceptive input to the circadian system of humans and other mammals. Analytical action spectra in rodents, primates, and humans have identified 446–484 nm (predominantly the blue part of the spectrum) as the most potent wavelength region for neuroendocrine, circadian, and neurobehavioral responses. Those studies suggested that a novel photosensory system, distinct from the visual rods and cones, is primarily responsible for this regulation. Studies have now shown that this new photosensory system is based on a small population of widely dispersed retinal ganglion cells that are intrinsically responsive to light, and project to the suprachiasmatic nuclei and other nonvisual centers in the brain. These light-sensitive retinal ganglion cells contain melanopsin, a vitamin A photopigment that mediates the cellular phototransduction cascade. Although light detection for circadian and neuroendocrine phototransduction seems to be mediated principally by a novel photosensory system in the eye, the classic rod and cone photoreceptors appear to play a role as well. These findings are important in understanding how humans adapt to lighting conditions in modern society and will provide the basis for major changes in future architectural lighting strategies.
We examined the effects of monochromatic light on the time sense and the central nervous system. Nine young adult volunteers participated in this study. They were exposed to red-light and blue-light environments (illuminance was kept at 310 lx). We evaluated the time sense by time-production tests of 90 s and 180 s and measured the P300 event-related potentials during an auditory oddball task. The 90-s time intervals produced by subjects in the two monochromatic light conditions were not significantly different. However, the 180-s time interval produced in the red-light condition (163.2±50.4 s) was significantly (p<0.05) shorter than that in the blue-light condition (199.0±54.4 s). The peak latency of P300 in the red light (322.2±26.6 ms) was found to be significantly (p<0.05) shorter also than that in the blue light (332.6±20.2 ms). The feelings measured by the visual analogue scales in the two light conditions were not significantly different. These results indicate that the time sense ran faster in the red-light than in the blue-light condition. We suggest that the higher activity in the central nervous system that is accounted for by the shorter latency of P300 is related to the acceleration of the time sense.
Physical activity in childhood is important as it may establish adult behavior. However, few studies on physical activity in children have been conducted, especially in Asian children. We performed anthropometric measurements of 159 school children in two grades (grade 5: 10–11 years old and grade 8: 13–14 years old) from urban areas of Korea (n=79) and China (n=80). The total daily energy expenditure (TEE) was estimated for 7 consecutive days using an accelerometer. The mean height, weight, and body mass index (BMI) for boys and girls in both countries exceeded the US national reference median (CDC, 2000). Physical activity levels (PALs) were significantly higher in the grade 5 group (10–11 years old) and in girls than in boys for both grades. No significant difference in PALs or daily step-counts (STPs) was observed between ‘normal’ and ‘overweight’ subgroups based on BMI, although negative correlations were found between weight, BMI, or %body fat vs. PAL or STP among Korean girls and Chinese boys (r=0.32–0.38, all p<0.05). Daily variation in physical activity was observed in Korean children. In the Koreans (boys and girls, both grades pooled), TEE and STP were significantly lower than the 7-day average on Sundays, whereas for the Chinese population, STP did not clearly differ between the weekends and the week averages. In summary, PALs were higher in the fifth grade boys and girls than in the eighth grade children; interestingly, girls tended to have higher PALs than boys. Daily variation in physical activity was observed in Korea; children were less active on Sundays.
Use of BMI as a surrogate for body fat percentage is debatable and universal BMI cut-off points do not seem appropriate; lower cut-off points than currently recommended by WHO should be used in some populations, especially in Asia. The adult WHO BMI database indicates that, on average, women are more obese than men, while men are more likely to be pre-obese than women. Urban rates of overweight and obesity are generally higher than rural rates in both sexes. The trend in pre-obesity and obesity over time is generally upward, with very marked increases in the USA and UK in both sexes over the last 10 years.
The purpose of the present study was to elucidate the existence of individual differences of pupil response to light stimulation, and to confirm the reproducibility of this phenomenon. Furthermore, the relationship between the individual differences in nocturnal melatonin suppression induced by lighting and the individual differences of pupillary light response (PLR) was examined. The pupil diameter and salivary melatonin content of 20 male students were measured at the same period of time (00:00–02:30 hr) on different days, accordingly. Illumination (530 nm) produced by a monochromatic light-emitting diode (LED) was employed as the light stumilation: pupil diameter was measured with 4 different levels of illuminance of 1, 3, 30 and 600 lux and melatonin levels were measured at 30 and 600 lux (respective controls were taken at 0 lux). Oral temperature, blood pressure and subjective index of sleepiness were taken in experiments where melatonin levels were measured. Changes of the pupil diameter in response to light were expressed as PLR and light-induced melatonin suppression was expressed as a control-adjusted melatonin suppression score (control-adjusted MSS), which was compared to the melatonin level measured at 0 lux. In the PLR, the coefficients of variation obtained at 30 lux or less were large (51.5, 45.0, 28.4 and 6.2% at 1, 3, 30 and 600 lux, respectively). Correlations of illuminance of any combination at 30 lux or less were statistically significant at less than 1% level (1 vs. 3 lux: r=0.68; 1 vs. 30 lux: r=0.64; 3 vs. 30 lux: r=0.73), which showed the reproducibility of individual differences. The control-adjusted MSS at 600 lux (−1.14±1.16) was significantly (p<0.05) lower than that registered at 30 lux (−0.22±2.12). PLR values measured at 30 and 600 lux were then correlated with control-adjusted MSS; neither indicated a significant linear relationship. However, the control-adjusted MSS showed around 0 under any of the illuminance conditions in subjects with high PLR. In control-adjusted MSS of low values (i.e., melatonin secretions were easily suppressed), subjects indicated typically low PLR. In subjects with low control-adjusted MSS (n=3), characteristic changes in the autonomic nervous system, such as body temperature and blood pressure, were noted in subjects exposed to low illuminance of 30 lux. The fact that the relationship between PLR and control-adjusted MSS portray a similar pattern even under different luminance conditions suggests that MSS may not be affected in those with high PLR at low illuminance, regardless of the illuminance condition.
The purpose of this study is to examine the physiological effects of Shinrin-yoku (taking in the atmosphere of the forest). The subjects were 12 male students (22.8±1.4 yr). On the first day of the experiments, one group of 6 subjects was sent to a forest area, and the other group of 6 subjects was sent to a city area. On the second day, each group was sent to the opposite area for a cross check. In the forenoon, the subjects were asked to walk around their given area for 20 minutes. In the afternoon, they were asked to sit on chairs and watch the landscapes of their given area for 20 minutes. Cerebral activity in the prefrontal area and salivary cortisol were measured as physiological indices in the morning at the place of accommodation, before and after walking in the forest or city areas during the forenoon, and before and after watching the landscapes in the afternoon in the forest and city areas, and in the evening at the place of accommodation. The results indicated that cerebral activity in the prefrontal area of the forest area group was significantly lower than that of the group in the city area after walking; the concentration of salivary cortisol in the forest area group was significantly lower than that of the group in the city area before and after watching each landscape. The results of the physiological measurements show that Shinrin-yoku can effectively relax both people's body and spirit.
Wood is widely accepted as a human-friendly material. Many people use a large amount of wood in their living space. However, information on why and how humans are affected by wood is insubstantial. Understanding what a person is focusing on when looking at wood is an important first step in solving the above problem. The manner and style of our wood observation can be extracted directly by using an eye-tracker. The purpose of this study is to characterize the distribution pattern of eye fixation pauses in observing wood including many knots. Fifty-five kinds of wood panel images were prepared as visual stimuli. Various sizes of knots appeared on most of them. Twenty subjects observed these images for about 20 seconds per image freely with the eye-tracker on their heads. Their eye movements were recorded as eyemarks during the observations, and many eye fixation pauses on each image were extracted for each subject. To express the distribution pattern of the eye fixation pauses quantitatively, two numerical indexes, the aspect ratio and the rate of expansion, were proposed in this study. The former index indicated the overall shape of the distribution, and the latter corresponded to the size of the observation area. Based on the relationships between these indexes, the distribution patterns were classified into three types.
The physiological effects of “Shinrin-yoku” (taking in the atmosphere of the forest) were examined by investigating blood pressure, pulse rate, heart rate variability (HRV), salivary cortisol concentration, and immunoglobulin A concentration in saliva. Subjective feelings of being “comfortable”, “calm”, and “refreshed” were also assessed by questionnaire. The subjects were 12 male university students aged from 21 to 23 (mean±SD: 22.0±1.0). The physiological measurements were conducted six times, i.e., in the morning and evening before meals at the place of accommodation, before and after the subjects walked a predetermined course in the forest and city areas for 15 minutes, and before and after they sat still on a chair watching the scenery in the respective areas for 15 minutes. The findings were as follows. In the forest area compared to the city area, 1) blood pressure and pulse rate were significantly lower, and 2) the power of the HF component of the HRV tended to be higher and LF/(LF+HF) tended to be lower. Also, 3) salivary cortisol concentration was significantly lower in the forest area. These physiological responses suggest that sympathetic nervous activity was suppressed and parasympathetic nervous activity was enhanced in the forest area, and that “Shinrin-yoku” reduced stress levels. In the subjective evaluation, 4) “comfortable”, “calm”, and “refreshed” feelings were significantly higher in the forest area. The present study has, by conducting physiological investigations with subjective evaluations as supporting evidence, demonstrated the relaxing and stress-relieving effects of “Shinrin-yoku”.
This study investigated the relationship between the force applied to a finger and the differential threshold of the force. Further, it presented an improvement function for tactile perception in archers by adapting to circumstances in which enhanced tactile perception and finger dexterity are required to practice archery on a daily basis. For this purpose, a tactile display using an air jet was developed. The air was aimed at the center of the fingertip of the index finger. The inner diameter of the nozzle was set to 3 mm. In this study, a psychophysical experiment was conducted to obtain the differential threshold from two subject groups—an archery athlete group and a control group. A total of six levels of standard stimuli ranging from 2.0 gf to 7.0 gf was obtained. As a result, the differential threshold of the archery group was significantly higher than that of the control group. The Weber ratio of the archery group remained around 0.13 and that of control group was 0.10. The experiment also revealed that the differential threshold for archers exhibited less fluctuation between the trials and between the days, which implied that the tactile perception of archery athletes may be more stable than that of non-experienced subjects. This may be a plasticity property of tactile perception.
The aim of this study was to examine the relationship between the stress score measured using the Inventory to Measure Psychosocial Stress (IMPS) and biomedical parameters regarding health status among apparently healthy subjects in order to evaluate the validity of the IMPS. Out of the 1,941 public school workers in Kyushu and Okinawa, Japan, who were admitted to a hospital for medical check-ups, 1,499 workers responded to questionnaires which assessed the degree of stress response (i.e., stress score) measured using the IMPS, and the degree of stress tolerance capacity (i.e., stress intolerance score) measured using the Inventory to Measure Stress Tolerance Capacity (IMST). One thousand two-hundred and one workers (684 men and 517 women) were analyzed, excluding 298 subjects who were taking medication for hypertension, hyperuricemia, hyperlipidemia and diabetes, or had a value for glycosylated hemoglobin (HbA1c) ≥6.0 percent. An increase in the stress score was positively associated with an increase in both body fat percentage and glycosylated hemoglobin values among men, while it was positively associated with an increase in plasma triglyceride concentrations among women. The stress score significantly correlated with the value for glycosylated hemoglobin even after controlling for age, body mass index, alcohol consumption, smoking, and exercise among men. An increase in the stress intolerance score was positively associated with an increase in body fat percentage among men, while it was positively associated with an increase in body weight, body mass index, and body fat percentage among women. Our result that the stress score measured using the IMPS was associated with obesity and unfavorable glycemic changes is in congruency with the model that psychosocial stress has a detrimental effect on humans by inducing obesity and insulin resistance, suggesting that the IMPS is a valid means to evaluate psychosocial stress levels among an otherwise healthy population.
It is more crucial than ever to consider the elderly when designing products. One of the important things to remember is the legibility of characters, since this influences the accessibility and usability of products. We studied the effects of character attributes on legibility using 70 subjects (60 aged 46–79 with no apparent ocular problems except presbyopia, and 10 aged 68–80 with cataracts). Thirty 10-key television remote control models were made. The characters on each were different, and were based on combinations of three attributes—height (5 levels), thickness (3 levels), and display mode (2 levels; positive: black characters on a white background, negative: white characters on a black background). Participants subjectively evaluated the legibility of the characters for each 10-key sample under two ambient illuminance conditions: 500 lx and 50 lx. They also performed paired comparisons on samples with the same height and thickness but different display modes. Subjective data were analyzed using a three-way factorial ANOVA for character height, thickness, and display mode. Legibility was significantly affected by all factors for those without cataracts under both illuminance conditions, and the interaction between thickness and display mode was significant. A two-way factorial ANOVA was performed for height and display mode for each thickness. Legibility was, in general, better for thinner characters in negative mode and was better in negative mode under dark illuminance for those with and without cataracts. This tendency was more pronounced in the elderly (over 65 years old). Paired comparisons showed that legibility was better in negative mode under both illuminance conditions, especially with medium and thin characters, for those with and without cataracts. Although there are few accounts of the effects of positive and negative modes in various existing guidelines, this finding would suggest that legibility can be enhanced by using the negative mode.
The purpose of this study was to compare the cardiovascular responses to different types of mental stress. Ten healthy males performed a mental arithmetic task (MA) on one day and were exposed to white noise (WN, 80dB) on another day. Both the MA and the WN were composed of four 5-min consecutive periods with a 3-min rest between them. On each day, the systolic and diastolic blood pressure (SBP and DBP), mean arterial pressure (MAP), cardiac output (CO), and total peripheral resistance (TPR) were measured continually during the entire experimental period. The changes from the baseline (Δ) in all periods were calculated for both mental stresses. As for the results, the ΔMAP, ΔCO, ΔHR, and ΔTPR in the MA did not significantly change during the task periods. However, in the WN, the ΔMAP and ΔTPR showed significant increases over the time of the consecutive periods. In addition, we discuss the response patterns for the two mental stresses. We examine three hemodynamic reactivity patterns: a cardiac pattern characterized by increased CO and decreased TPR, a mixed pattern characterized by a moderate increase in both CO and TPR, and a vascular pattern characterized by increased TPR and decreased CO. The results show that throughout all task/exposure periods, the response pattern remained the same for six subjects in each stress. Furthermore, of these six subjects, half showed the same response pattern in both the MA and the WN. In conclusion, compared to the MA task, consecutive WN exposure showed an accumulation of stress responses. A change in TPR contributed to a gradual increase in MAP in the WN. It is also possible that among the subjects there were different types of response to the MA and WN.
Spectral components of heart rate variability (HRV) were repeatedly measured (4–8 measurements; mean: 6 measurements) in 75 healthy Japanese male subjects (age range: 20–61) under two postural conditions (standing and supine). Low-frequency (LF) and high-frequency (HF) components and mean heart rate (HR) were analyzed with special reference to individual variations, which were classified into two types: inter- (interV) and intra-individual variations (intraV). The percent contributions and coefficients of variations were calculated for both interV and intraV. Percent contributions of intraV (intraV%) of HR with standing and supine postures were 15.8 and 12.9%, respectively. The intraV% of HF and LF on standing were 31.5 and 26.5%, while those in the supine posture were 27.8 and 35.5%, respectively. The coefficients of interV (interCV) and intraV (intraCV) were also calculated. The interCVs of HR, HF, and LF on standing were 14.9, 41.4, and 48.4%, while those in the supine posture registered 16.2, 42.9, and 44.2%, respectively. The intraCVs of HR, HF, and LF on standing were 5.0, 19.7, and 21.2%, while those in the supine posture indicated 4.7, 20.1, and 23.0%, respectively. We also calculated the interV and intraV of logarithmic-transformed HRV indexes. The log-transformation remarkably diminished both variables: interCV and intraCV registered 14–16 and 6–7%, respectively. Although interV variations were considerabley large, intraV variations of HRV were negligibley small. The HRV indexes decreased with age, although HR remained unchanged. The coefficients of determination (r2) were 14–34%. In the case of log-transformed HRV indexes, the coefficients of determination registered 9–15%, suggesting that 14–34% (raw) or 9–15% (log) of the observed interV may be due to variations in age.
This study investigated thermal swimsuits (TSS) effects on body temperature and thermal insulation of prepubescent children during moderate-intensity water exercise. Nine prepubescent children (11.0±0.7 yrs) were immersed in water (23°C) and pedalled on an underwater cycle-ergometer for 30 min with TSS or normal swimsuits (NSS). The rectal temperature (Tre) was maintained slightly higher with TSS than with NSS. The total insulation (Itotal) was significantly higher with TSS. The ΔTre, Δmean body temperature (T¯b), and tissue insulation (Itissue) in the NSS condition were correlated with % body fat, which indicated that the insulation layer of subjects with low body fat was thinner than that of obese subjects, and tended to decrease body temperature. Wearing TSS increased Itotal, thereby reducing heat loss from subjects' skin to the water. Consequently, subjects with TSS were able to maintain higher body temperatures. In addition, TSS is especially advantageous for subjects with low body fat to compensate for the smaller Itissue.
By estimating the deflection velocity from the center of foot pressure (COP), this study aims to prove that the characteristics of the backward stepping reaction in the elderly are related to the strength of the antigravity muscles. The participants in this study were 10 elderly (average age 75.6±7.6 years) and 13 young (average age 22.0±2.6 years) subjects. Using force plate analysis, we measured the shift in the deflection velocity (V-RMS) and the maximum deflection velocity (V-MAX) from the beginning of the COP movement to the onset of the stepping reaction. Furthermore, we measured the strength of the antigravity muscles using a hand-held dynamometer. We correlated the V-RMS, V-MAX, and the rate of change of the deflection velocity (MAX/RMS) with muscular strength. When compared with the young subjects, the elderly showed significantly lower values of V-RMS (p<0.05) and significantly higher values of MAX/RMS (p<0.01). Furthermore, when compared with the young subjects, the elderly showed significantly lower values of muscular strength for all muscles studied (p<0.001). We established a significant correlation between the V-RMS, MAX/RMS, and muscular strength by carrying out a regression analysis (V-RMS: gluteus maximus (r=0.50, p<0.05) and rectus abdominis (r=0.48, p<0.05); MAX/RMS: adductor magnus (r=−0.66, p<0.001) and flexor digitorum longus (r=−0.62, p<0.01)). Differences were observed in the V-RMS and MAX/RMS during the backward stepping reaction; it was proposed that these differences were related to the age and muscular strength of the subjects. Therefore, further investigations should be undertaken in order to understand the effects of aging on the stepping reaction. In other words, the change-in-support strategy, including the preparatory phase of the stepping reaction, and its relationship with muscular strength should be further investigated.
An electrogastrogram (EGG) is considered to be an index to the autonomic nervous system of the digestive organs. In the present study, we attempted to clarify whether or not an EGG can be used to evaluate the influence of illumination, and what kinds of effect taste stimuli and illumination have on the autonomic nervous system. In this study, we used the ratio of the normal wave component of the EGG (EGG-NR: 2–4.5 cpm power/1–10 cpm power) and the amplitude of a normal wave (EGG-NI: integrated EGG of 2–4.5 cpm). Thirteen healthy males participated in 16 experimental conditions (4 lighting conditions×4 taste stimuli). The four lighting conditions were set by combinations of illuminance levels of 200 and 1500 lx and color temperatures of 3000 and 7500 K. The four taste stimuli were sweet (glucose), salty (salt), sour (acetic acid), and bitter (quinine). The changes in EGG-NR and EGG-NI were compared for different taste conditions. The results showed that EGG-NI was not significantly affected by the different taste conditions. However, the main effect of taste on EGG-NR was significant: sweet and salty tastes were significantly higher than the bitter taste. EGG-NR and EGG-NI in different lighting conditions were also compared. The main effect of different color temperatures was also significant, but the illuminance level did not affect EGG-NR. EGG-NR increased significantly at the lower color temperature. On the other hand, EGG-NI significantly increased at the lower illuminance. These results suggest that parasympathetic nervous activity has a predominant effect on gastric activity in different lighting environments. Therefore, EGG measurements may be useful indicators for illumination environment studies.
To compare the activity of lower extremity muscles during land walking (LW), water walking (WW), and deep-water running (DWR), 9 healthy young subjects were tested at self-selected low, moderate, and high intensities for 8 sec with two repetitions. Surface EMG electrodes were placed on the tibialis anterior (TA), soleus (SOL), medial gastrocnemius (GAS), rectus femoris (RF), and biceps femoris (BF). During DWR, the SOL and GAS activities were lower than LW and WW. The BF activities were higher during DWR than LW and WW. It was considered that the lower activity of SOL and GAS depended on water depth, and higher activity of BF occurred by greater flexion of the knee joint or extension of the hip joint during exercise.
Tryptophan can be metabolized via 5-hydroxytryptamine=serotonin to melatonin by a series of 4 enzymes in pineal body. Lack of serotonin in body fluid in the brain during daytime can lead to several psychiatric disorders, while shortage of plasma-melatonin at night can be related to sleep disorders. The Morningness–Eveningness (M–E) questionnaire and the original questionnaire including questions on sleep habits, mental symptoms, and contents of meals were administered to 1055 infants aged 0–6 yrs, 751 students attending an elementary school, and 473 students attending junior high school in Kochi City (33°N). The index of tryptophan taken at breakfast (Trp-Index) was calculated as tryptophan amount per one meal based on the tryptophan included in each 100 g of the foods and a standard amount of food per one meal. A significant positive-correlation between M–E scores and Trp-Index was not shown by relatively older students, aged 9–15 yrs (Pearson's test, r=0.044–0.123, p=0.071–0.505), whereas a significant positive correlation was shown by infants and young elementary school students aged 0–8 yrs (r=0.180, 0.258, p<0.001). The more frequently the infants had difficulty falling asleep at bedtime and waking up in the morning, the less the Trp-Indices taken at breakfast were (Kruskall–Wallis-test, p=0.027 for difficulty falling asleep; p=0.008 for difficulty waking up). The more frequently infants became angry even by a little trigger, or depressed, the lower (more evening-typed) the M–E scores were (Kruskal–Wallis test: p≤0.001). Tryptophan ingested at breakfast is very important for children to keep a morning-type diurnal rhythm, high quality of sleep, and indirectly good mental health, presumably, through the metabolism of tryptophan to serotonin in daytime and further to melatonin at night.
The purpose of this study was to examine the seasonal variations of melatonin secretion of subjects and of their surrounding light conditions. Eight Japanese female students (20.1±2.6 yrs, Mean±SD) living in Fukuoka, Japan, participated in the present study. Saliva samples were collected every 3 hours over the course of a day, and the light intensity during daily life was measured every 1 min for 5 days in the four seasons. Almost all subjects had different melatonin secretory profiles in autumn, with only two subjects showing similar rhythms in all four seasons. The peak values of melatonin secretion calculated by a spline interpolation were higher in autumn than those in other seasons (p<0.001, Fisher's PLSD) and its peak time in this season was significantly delayed compared with those in spring and summer (p<0.05, Fisher's PLSD). The amount of time during daytime exposure to light of >1,000 lux was at least thirty minutes in all the seasons, and there were no significant differences among them. The relationship between peak level of melatonin secretion and amount of time of daytime light exposure to >1,000 lux was significant only in the autumn. During this season, there was a significant positive correlation (r=0.83, p<0.05, n=6), except for two subjects, whose melatonin secretion remained low.
We are currently investigating the physiological polymorphism of wheelchair users with profound cerebral palsy and the properties of the Seating Buggy (developed by S. Nishimura, 1998) to clarify important and general elements of wheelchairs for widespread use. Cerebral palsy is a diagnostic term used to describe a group of motor syndromes resulting from disorders in early brain development. Recently, it has been shown that the Seating Buggy produces functional head-neck alignments and active control of sitting balance for people with profound cerebral palsy. The Seating Buggy is a wheelchair for the profoundly disabled and features a wide adjustment range from heights of 120 cm to 175 cm. Its seating support surface is comprised of a sling-seat. To examine the relationships between the postural adaptation of patients with profound cerebral palsy and the configuration of the Seating Buggy's seating, we assessed the postural alignment of the Seating Buggy's user and then measured the configuration of its resulting seating support surface with a three dimensional scanning system. Twenty-one subjects were used for the purposes of this investigation in their everyday environment. Postural adaptation and wheelchair fitting in the Seating Buggy were assessed from the viewpoint of the Active Balanced Seating by a seating expert. The subjects fell into two categories, as follows: 11 for appropriate or nearly appropriate fitting, and 10 for ill-fitting. The depth of thoracic support and the forward distance of lumbar support for those who claimed that it was ill-fitting were significantly reduced compared with that of those who claimed that the Seating Buggy offered an appropriate or nearly appropriate fitting. It was suggested that the properly adjusted depth of thoracic support and distance of the lumbar support were related to the resulting satisfactory head-neck alignment and sitting balance of the patients with profound cerebral palsy.
As the most common inflammatory skin disease in children, atopic dermatitis begins in infancy or early childhood, with about 90% of cases appearing under age of 5. The prevalence of atopic dermatitis has rapidly increased among children in recent years. Physiological and psychological abnormalities and social impact are also well known in children with atopic dermatitis and in their families. Atopic dermatitis not only seriously affects the quality of life of the children and their families but also is leading chronic disease in children with hard-to-cure. Recently, we found that the fermented extract of several plants had considerable potential to treat juvenile atopic dermatitis. This extract therefore is now under investigation to find the underlying immunopathological mechanism by determining its inhibitory effects on nitric oxide (NO) release and T cell proliferation. The fermented extract dose dependently blocked NO production. In particular, the inhibitory effect of the extract was maximized up until 80-fold dilution of the original extract. This extract did not induce cytotoxic effects up to 80-fold dilution. Interestingly, doses between 320- and 80-fold dilution significantly protected cell death mediated by LPS-induced NO production. The fermented extract also significantly suppressed CD3 induced T cell proliferation in a dose dependent manner.
The influence of physical activity on body mass components has been studied using a sample of Moscow children. 195 girls and 259 boys of Russian ethnicity from 12 to 17 years old were investigated cross-sectionally in 2005 in different Moscow schools. According to the level of physical activity they were divided into three groups: 1–those who did not take part in regular physical exercise (44 boys and 50 girls); 2–those who took part in special sports programs in general education schools (82 boys and 82 girls); 3–students of special sports schools with a high sports ranking (133 boys and 63 girls). The program included anthropometric measurements, evaluation of sexual maturation indices, somatotypes, and “functional” traits (diastolic and systolic blood pressure, pulse rate, hand grip, etc). For the study of body composition, bioelectrical impedance analysis (BIA) was used. The estimates of body mass components were also calculated using the anthropometric measurements. For the fat component, the estimates obtained by BIA and the anthropometric methods were highly correlated: r=0.85–0.88. Age changes of BIA measurements and body components were analysed. With multiple regression analysis it was shown that BIA measurements are dependent on a great number of morphological and functional traits, with the most informative sets of traits being selected. The degree of physical activity has a strong effect on body components: the contents of fat-free mass (FFM) and total body water (TBW) significantly increase, and the fat mass (FM) in girls decreases.
This study investigated the bathing conditions of elderly Japanese, and sought to find factors relating to regional differences in death rates from bathtub accidents. A questionnaire survey was carried out in 11 areas of Japan. Questionnaires including questions regarding the length of time since houses had been built, types of facilities, and subjects' indoor thermal sensations and behavior while bathing were distributed to detached houses in each area twice, once in summer and once in winter. Completed questionnaires were collected from approximately 160 elderly people over 65 years old. Information regarding thermal sensations of rooms in winter revealed that a prefabricated bath and insulating window glass eased the cold in the bathroom. Unexpectedly, more subjects in the southern region than in the northern region reported being cold or a little cold while bathing in winter. In the present study, thermal sensations and behaviors while bathing seemed to be more affected by facilities and the location of houses than by the sex and age of the subjects.
C-reactive protein (CRP) is an inflammatory marker, which at low-level elevations is associated with increased cardiovascular risk. Although CRP has been extensively investigated in North American and European settings, few studies have measured CRP among non-Western groups. The present study used dried whole blood spot samples to examine high-sensitivity CRP concentrations among the Yakut (Sakha) of Siberia (85 females, 56 males; 18–58 years old). Our goals were: (1) to compare Yakut CRP concentrations with other populations; (2) to investigate sex differences; and (3) to explore anthropometric correlates of CRP. Results indicate that serum equivalent CRP concentrations are similar to those from industrializing nations, lower than US and European values, and greater than Japanese concentrations. Yakut men and women display similar CRP concentrations; however, CRP was significantly higher among men after adjustment for body fat, age, and smoking. Positive associations were documented between CRP and BMI, body fat, and central adiposity.
The purpose of this study is to evaluate the usefulness of salivary amylase activity as an indicator of the acute psychological sedative effects of fragrances used in household products such as clothing softeners. Twenty seven healthy Philippine female subjects in their late 30 s were enrolled (38.7±5.2 yr). This study was undertaken to investigate the favorite fragrance of Asian and Pacific Islander women. Our results indicated that (i) a mixed floral fragrance might be a favorite fragrance for Filipinas; (ii) fragrances contained in a softener significantly induced a sedative effect in humans, as assessed by both analysis of the biochemical marker and subjective evaluation; (iii) salivary amylase activity has the potential to be an excellent indicator for the evaluation of the acute psychological sedative effects of fragrance.
This paper describes the main quality control methods for determining human observer measurement error and instrument error focusing on intra-observer and inter-observer technical error of measurements (TEMs) and relative TEM, and the coefficient of reliability (R). R values above 0.95 are indicative of small errors. To compare variances between different variables, the coefficient of variation, a measure of relative variability, is used. The total variation of a character can be partitioned into genetic, environmental, and error components. Determination of the genetic component of variation (heritability) is usually obtained from twin studies or other family studies. A good environment improves the population mean, whereas a poor environment can lower the population mean without any change in the underlying genetic structure. Worked examples of how to calculate TEM, R, and heritability are provided.
Preliminary experiments were carried out to investigate the feasibility of using an electroencephalogram and heart rates to evaluate the efficacy of finger acupressure on the key points of planta pedis (both soles). Continuous electroencephalograms were recorded from 19 electrodes based on the International 10–20 electrode placement system on 22 university students (21±2.3 years). Spectral power changes were obtained at each electrode site. The power of the α1 frequency range (8–10 Hz) increased slightly during acupressure although no statistical significance was observed, while heart rates decreased in all subjects (p<0.05). Cerebral cortex asymmetry in the spectral power changes was not clearly observed during the right and left sole acupressure. This preliminary study suggests that a classification of subjects is necessary in understanding brain wave data during acupressure on soles.