In this study, we examine the aftereffects of the train radio communication system, which is not directly related to a train driver’s duties, on task performance. In the experiment, participants were made to perform simulated visual tasks associated with train driving (tracking task/signal monitoring task/mental calculation task) while train messages were simultaneously being transmitted. We found that the participants’ reaction times for the signal monitoring task were shorter after important messages from a preceding train were transmitted on the train radio, as compared to cases where important messages were transmitted from a following train. The result reveals that train drivers expect abrupt changes in railway signaling and attend to the corresponding signal in advance. Therefore, it seems reasonable to conclude that they make effective use of important train radio messages to aid them in train driving.
An idiopathic disease with meningitis-like symptoms in infants, a so-called meningitis in infancy (SCMI), was endemic in Japan during the period of 30 years from the middle period of the Meiji Era to the late Taisho Era (early 20th century). In 1923, Professor Ikutaro Hirai at Kyoto University reported that SCMI was a chronic lead-poisoning disease caused by white lead in the mothers’ cosmetic powder. After his first report, so many articles on SCMI were published. Although a few authors were against the Hirai’s lead-poisoning theory, the great majority of authors presented evidence in support of his theory. In this study, we reviewed the SCMI articles published in a pediatric journal, Acta Paediatrica Japonica, which were issued in the period of the late Taisho Era (1923 – 1926). The articles which we dealt within this sketch included reviews, statistics, surveys, case-reports and clinical experiences.
In recent years, in the night and shiftwork research, the main interest has switched over to the early morning shift from the night shift. The reason is that there is deterioration of “sleep quality” in the nocturnal sleep before the early morning shift. In this study, therefore, our objective is to investigate “sleep quality” before the early morning shift in a commercial air pilot. Then, we will address his cardiovascular load during sleep from the viewpoint of “karoshi”. The sleep stages and the heart rate during consecutive 24 days were measured by means of “Nemuri Monitor” developed by Aisin Seiki Co., Ltd. The roster of this pilot study consisted of 12 domestic flight days, 9 days off, two standby days, and one layover of an international flight day. The average wake-up time in days of seven early morning flights was 6 hours 12 ± 43 min. And the sleep duration and sleep stages except S 1 reduced with significant differences (p<0.05) compared to those on days off. This trend was showed in SWS (p=0.088) and REMS (p=0.039) even if sleep before the early morning flights added on daytime naps. Heart rate levels of SWS and REMS in sleep before the four consecutive early morning flights increased until the third night (p<0.05), although it returned at the fouth night.