Sports and activities that take place in nature, such as marathons, open-water swimming, mountain climbing, and underwater leisure activities, have become popular in recent years. When these sports and leisure activities are performed in cold environments with low ambient temperatures or cold water, thermoregulatory responses such as cutaneous vasoconstriction, shivering and non-shivering thermogenesis occur to prevent a decrease in body core temperature. Furthermore, during exercise, heat production in active muscles occurs with exercise in addition to the thermoregulatory responses, and it is thought that the body core temperature is unlikely to drop. However, “accidental hypothermia,” an excessive drop in body core temperature (<35°C), occurs during leisure activities and exercise in cold environments. Because accidental hypothermia occurs despite heat production associated with exercise in addition to the thermoregulatory responses, it is thought that “specific factors” that differ from the normal heat balance are responsible for the onset of hypothermia during exercise and have been investigated in several studies to date. This review aims to help humans safely perform sports and activities in cold environments and achieve high performance. We will review the thermoregulatory responses that occur in cold environments and the effects of exercise on them, and consider the mechanisms of hypothermia that occur even during exercise and how to prevent it.

Women with femoral amputations are more prone to edema. Consequently, changes in the stump circumference can lead to socket malfunctions. However, few studies have analyzed and assessed diurnal fluctuations and monthly interdiurnal fluctuations in the stump circumference of female femoral amputees. Using a 3D scanner to measure the stump circumference during the menstrual cycle and administering a questionnaire survey on gender differences, this study aimed to clarify changes in the stump circumference during menstruation and in doing so, assist in adapting sockets to the needs of female femoral amputees.

The study included 13 women (5 with and 8 without a femoral amputation). A 3D scanner was used to measure the circumference of the transected area during the menstrual cycle. The results showed significantly larger values on the distal 60 mm of the femur in 8 women without amputations during their menstrual phase as compared to their proliferative phase. In contrast, larger values were observed across all measurement points during menstruation for all study subjects. Moreover, similar to women without amputations, the greatest change among female femoral amputees was observed at the distal 60 mm.

The questionnaire on gender differences was administered to 28 amputees, (9 women and 19 men). The results showed that there was a significant difference between women and men in their awareness of diurnal change in the stump circumference. There was also a significant trend in their awareness of inter diurnal change as well.

These findings indicate that changes in the stump circumference during the menstrual cycle should be considered when fabricating prosthetic leg sockets for female femoral amputees. Importantly, given the risk of fabricating an overly large socket, fabrication should not be conducted during the menstrual period.

From January 18, 2022 to April 17, 2022, we recorded the daily number of infected people during the COVID-19 Omicron strain epidemic (6th wave) that occurred in Niigata Prefecture by 9 facilities and 12 prefectural public health centers, and Niigata City, which is an ordinance-designated city, and analyzed the occurrence of these clusters. There are nine categories of facilities: kindergartens, schools, facilities for the elderly, welfare facilities, companies, medical facilities, sports facilities, government offices, and restaurants.

As a result, when looking at each facility where clusters occurred, the total number of infected people, the number of consecutive days, and the maximum number of people per day differed greatly. There have been cases of explosive increases in the number of infected people in kindergartens, schools, welfare facilities, and companies, and there have also been cases of long-term infections in kindergartens, schools, facilities for the elderly, and welfare facilities. We confirmed the importance of taking proactive measures such as accurately capturing the initial movement and suppressing clusters early.

Tracking clusters of 5 people was effective in capturing about half of the total number of infected people who occurred, but if the cluster size is 10 or more people, the mesh is too large and the capture rate is extremely low. However, it was found that it was inadequate to suppress the infection.

Omicron strains often remain asymptomatic or mild cases, making it difficult to confirm the chain of infection. However, it was confirmed that the chain of infection would not be maintained unless a cluster was formed, and it is considered that measures against clusters in Niigata Prefecture have achieved a certain degree of success under difficult circumstances.

Grade Point Average is widely used as a numerical value that can express a student’s overall performance in a university program. According to a 2017 survey, 100% of national universities, 80% of public universities, and 93% of private universities have introduced GPA. GPA is obtained by giving grade points such as 4, 3, 2, 1, 0, to a student’s grades in a certain subject, multiplying the number of credits in that subject, and dividing the sum by the total number of credits taken. It is used as a criterion for selecting students eligible for scholarships and tuition fee exemptions and grasping the course registration status and advice for learning. Still, there are serious problems with the current GPA. One is that the original score numbers are rounded at the time of the transformation to the grade point, which causes a reversal phenomenon of grades among students. Second, it is challenging to grasp student performance from the GPA values because it replaces the 100-point test scores widely used in Japan with Grade Points. Therefore, in this paper, we proposed dGPA, in which the original scores are divided by ten without rounding, and the sum multiplied by the number of credits is divided by the total number of credits taken. Since dGPA does not cause a reversal phenomenon in grades, it can be used confidently as a criterion for selecting students eligible for scholarships and tuition fee exemption. Since it is easy to judge overall performance based on the numerical value, it can be expected to be used as a familiar presence for students and parents. Furthermore, since the dGPA accurately reflects the performance of a student, it is also suitable for institutional research use by university management.

Japan’s total population peaked at 128.08 million in 2008 and has continued to decline since then. In Niigata Prefecture, many people move out of the prefecture to go to university or to find work after graduation, and the total prefectural population peaked at 2.49 million in 1997 and has been declining ever since. Niigata Prefecture has put in place various measures to curb the population outflow and promote migration from outside the prefecture, and universities in the prefecture are likely to accelerate their efforts to curb the outflow and encourage students to settle down in the prefecture after graduation by improving their attractiveness. As a preliminary step towards measures to promote the settlement of university students, a survey was conducted on the hometowns and post-graduation settlement trends of the students of the N University hardball club, which has one of the largest numbers of members among university clubs in Niigata Prefecture. Of these, 38.3% were from Niigata Prefecture. 75.3% of those from Niigata Prefecture continued to work or go on to higher education in Niigata Prefecture after graduation. In addition, 12.2% of those who were outside Niigata Prefecture had found a job or continued their education in Niigata Prefecture after graduation. In the future, we would like to conduct a survey of both in-prefecture and out-of-prefecture residents on the factors that made them “settle down” in Niigata Prefecture after graduation, and devise measures to encourage them to remain attached to Niigata Prefecture and “settle down” there after graduation. We would like to take these initiatives as the first step towards creating new value for the existence of university activities in rural areas where population decline is an issue.

In this study, a survey was conducted on students belonging to a college volleyball team to clarify whether their awareness changes due to performing various online activities in addition to training in response to the COVID-19 pandemic. The results revealed that all the subjects felt that the online activities had a positive impact on their team and gym practices. In addition, from the results of text mining of reflection by free description answer, words such as “easy to relate to,” “easy to take,” “easy to listen to,” and “communication” were extracted.

Furthermore, the students were actively engaged even in the practice sessions in the gymnasium after the restrictions were lifted, as evidenced by an increase in conversation. The reason all the subjects evaluated the online activities favorably was presumed to be that informal communication was promoted not only through training but also through various activities, communication within the team. Moreover, in the regular action plan, setting goals and tasks suitable for online and face-to-face activities, and in parallel, conducting exercises to deepen communication may function as a strategy that leads to team growth.