The purpose of this study was to clarify the synchronization function of external and spontaneous rhythm and exercise in the left prefrontal cortex (Left-PFC) and the right prefrontal cortex (Right-PFC) in humans. This study examined whether there is functional difference in rhythm movement synchronization in Left-PFC and Right-PFC, or whether the synchronism with exercise differs depending on rhythm such as external rhythm and spontaneous rhythm. Subjects performed a finger tapping exercise with the right index finger with seven rhythms which consisted of six external rhythms (1 Hz to 6 Hz) and spontaneous rhythm (2.4 ± 0.3 Hz). During synchronization of rhythm and exercise, the increased amount of oxygenated hemoglobin (Oxy-Hb) in Right-PFC showed a significant increase in all rhythms (p < 0.01). The amount of Oxy-Hb in Left-PFC also showed a significant increase (p < 0.05) in all rhythms. The Oxy-Hb increase in Right-PFC was significantly higher (p < 0.01) than the Oxy-Hb increase in Left-PFC in all rhythms. Therefore, it is suggested that regardless of the difference between external and/or spontaneous rhythm, Right-PFC plays a major role with respect to the synchronization function of rhythm and movement.

　Motor fitness and haemoglobin concentration (Hb) of Karate and Judo athletes have been reported from different countries while pertinent data are unavailable in Indian Judo and Karate athletes. The present study was therefore aimed to evaluate the haemoglobin concentration and motor fitness of Judo and Karate athletes of Kolkata, India and also to compare the data with their control group and overseas counterparts. State level male Judo (n = 40, age: 22.61 ± 0.91 yrs) and Karate athletes (n = 40, age: 22.36 ± 0.97 yrs) were recruited in the study from different sports academies of Kolkata, India. Sedentary (n = 40) control subjects (age: 22.73 ± 0.97 yrs) were sampled from same area. Motor fitness parameters and haemoglobin were measured by standard methods. Judo and Karate athletes had significantly (p < 0.001) greater values of motor fitness parameters and haemoglobin than the sedentary control group. The study depicted that Judo and Karate training improve motor fitness and haemoglobin. It is hypothesized that training duration has close relationship with the betterment in these parameters. The present data would serve as the national standard in Eastern Indian male Judo and Karate athletes and this will also help the coaches and athletic trainers to implement more specific training for betterment of performance in these athletic populations.

Knowledge about the functioning of the motor cortex during muscle fatigue is important to appropriately understand the condition, and it is also important in improving the competitive skills of endurance competitors. This study aimed to examine the time-course oxygenation of the bilateral motor cortex during a high-intensity exhaustive pinching task in well-trained athletes. Twelve healthy right-handed male athletes participated in the present study. Near-infrared spectroscopy (NIRS), positioned over the bilateral motor cortices, measured the activation/oxygenation throughout the pinching task until voluntary exhaustion. Subjects sustained 80% of maximal voluntary contraction (MVC) during the task until peak voluntary exhaustion. After the start of the motor task, contralateral motor cortex oxygenation increased significantly compared with the resting values (p < 0.05). However, with time, when exhaustion occurred, it significantly decreased to the lower value compared with the resting level (p < 0.01). In contrast, in the ipsilateral motor cortex, no change was observed in oxygenation/activation immediately after the start of exercise. However, in the latter phase of the motor task, oxygenation/activation significantly increased compared with the resting level (p < 0.001). These results suggest that complementary activation in the ipsilateral motor cortex to activation in the contralateral motor cortex occurs during fatiguing exercise in well-trained athletes.Keywords: muscle fatigue; bilateral hemisphere interaction; top athletes

High sociality is a prominent characteristic of humans. To further understand this aspect, the present study has interest in behaviour related to communication and interaction between two individuals in everyday life. The author exploratorily observed 518 dyads sitting outside by using more than 107-hour videos from a webcam set up in New York’s Times Square in 2018. Such a unique method enabled observation of people in a natural setting with little intervention with the subjects. Probably, most of the subjects were tourists. The observation found that all subjects uttered something (moved their mouth) while they were seated and that they occasionally used gesture and did body contact. More than half of the dyads stayed there shorter than about seven minutes. Results of multiple linear regressions showed that both subjects’ characteristics, such as sex and age, and day/time conditions affected nonverbal types of behaviour. Potential sex differences in opposite-sex pairs are also considered. This observation contributes to accumulating novel fundamental results on social behaviour. These findings are discussed from biosocial perspectives, including reference to the evolution of language. This paper carefully explains merits and limitations of the new methodology, and then gives some implications for future work.

Occupational risk factors are one of the major causes of respiratory symptoms among carpenters. The main aim of the present study was to determine the prevalence of respiratory symptoms and compare the lung function values with the control subjects. A total of 80 carpenters and 70 unexposed control subjects were randomly selected and their demographic characteristics, occupational history, respiratory symptoms, and lung function values were recorded. The result showed a significantly lower p-value <0.001 in lung function and respiratory symptoms among carpenters as compared to the control group. The prevalence of respiratory symptoms was nose irritation (86.3%), eye irritation (45.0%), dyspnea (41.3%), phlegm (33.8%), chest tightness (30.0%) and chronic cough (28.8%). This study concludes that the exposure to wood dust in carpentry work adversely influenced the respiratory functions and lung function values of the carpenters.