Fumio Nakaya

In Japan, there are many disasters such as earthquakes and typhoons; thus, the acquisition of knowledge and skills related to disaster preparation by the public is a key issue. In disaster preparation education, learning should be sustained until the disaster situation, not immediately after learning. In this study, we examined the effects of disaster education events on learning disaster preparation knowledge among elementary school children. We conducted two tests—a post-test and a post-post-test—immediately after the disaster education event in 2019 and six months after the event, respectively. These scores were used to measure persistence of learning. We confirmed that the improvement of knowledge and skills related to disaster reduction was sustained even after a certain period had passed since the disaster preparation education.

This research aimed to reveal the consciousness of Japanese secondary science teachers when dealing with content relating to social and ethical issues in science classes. In a survey, we analyzed responses obtained from 266 science teachers at junior high schools and 206 science teachers at high schools in Osaka Prefecture. We found the following three points: 1) Their knowledge, awareness, and experience about “science, technology, and society” in science classes increased with age and teaching experience, 2) However, these trends differed according to subject in high school science teachers. The consciousness of biology teachers tended to be higher than physics and chemistry teachers’, 3) In class, they more often set up opportunities to learn about various people’s values and opinions about ethical issues with science and technology than to ask students to express their opinions. These results showed science teachers’ awareness of handling contents relating to social and ethical issues with science and technology in class. The results also indicated the necessity to develop training programs and teaching materials that deal with the relationship between advanced science technology and society.

In this paper, we propose a teacher training system that incorporates educational digital portfolios using the Social Networking Service (SNS). We considered the situation in which the student teaching period occurs and focused on the educational benefits of using the SNS to communicate remotely. A challenging issue during the teacher training practicum is ensuring efficient communication and consistent evaluation between the university professor, host school mentor and university student. Our proposed system promotes the development of effective teaching and evaluation methods by sharing knowledge and practice records concerning the teaching practicum.

In the late 1990s, the once prolific populations of the coral Acropora intermedia surrounding Okinawa, Japan, dramatically declined because of thermal stress, bleaching caused by heat stress, and consequent mortality. Before the bleaching event, 72 fragments (about 15 cm in length) were collected and transferred to the Okinawa Churami Aquarium. Through growth and repeated fragmentation, these original fragments developed into about 100 colonies that spawned from 1999 to 2009. In this study, we compared gametogenesis, fertilization, survival, and O2 consumption in cultured and wild colonies of A. intermedia and their offspring. Cultured A. intermedia had larger oocytes and higher fertilization and survival rates than samples from wild colonies. O2 consumption of cultured embryos was similar to that of wild embryos. These results suggest that cultured A. intermedia and their offspring are as viable as wild colonies. Aquaria can play a role in the conservation of endangered corals, and their cultured colonies could be used to re-establish devastated species on the Okinawa reefs.

In order to characterize the energy expenditure of Paramecium, we simultaneously measured the oxygen consumption rate, using an optic fluorescence oxygen sensor, and the swimming speed, which was evaluated by the optical slice method. The standard metabolic rate (SMR, the rate of energy consumption exclusively for physiological activities other than locomotion) was estimated to be 1.18×10-6Jh-1 cell-1 by extrapolating the oxygen consumption rate into one at zero swimming speed. It was about 30% of the total energy consumed by the cell swimming at a mean speed of 1 mms -1, indicating that a large amount of the metabolic energy (about 70% of the total) is consumed for propulsive activity only. The mechanical power liberated to the environment by swimming Paramecium was calculated on the basis of Stokes' law. This power, termed Stokes power, was 2.2×10 -9Jh-1 cell-1, indicating extremely low efficiency (0.078%) in the conversion of metabolic power to propulsion. Analysis of the cost of transport (COT, the energy expenditure for translocation per units of mass and distance) revealed that the efficiency of energy expenditure in swimming increases with speed rather than having an optimum value within a wide range of forced swimming, as is generally found in fish swimming. These characteristics of energy expenditure would be unique to microorganisms, including Paramecium, living in a viscous environment where large dissipation of the kinetic energy is inevitable due to the interaction with the surrounding water.

The energy consumption of echinoderms is low in comparison with that of other invertebrates. We demonstrated this by measuring the oxygen consumption rate per unit of body weight (VO2) of the sea cucumber Actinopyga mauritiana: VO2 was 1/8 that of the "standard" invertebrates. Low energy consumption in echinoderms has been attributed to their high skeletal content and to catch connective tissues (CCTs) that maintain body posture by altering their mechanical properties with little energy expenditure. The former is not applicable to holothurians, and the latter has not been proven experimentally. We postulated that the large content of dermal connective tissue, which maintaines posture economically, contributes to the low energy consumption in holothurians. Body-wall dermis occupied 53.5% of wet body weight, whereas body-wall muscles, including those of tube feet, occupied 5.1%. VO2 of the dermis in the stiff state (2.45 μl · g -1 · h-1) was 1/10 that of the longitudinal body-wall muscle in contraction. The mechanical tests revealed that the stress at an imposed strain of 2% strain was 7 times greater in CCT than in muscles. These results showed that CCT could maintain posture more economically than muscles could. We concluded that the high content of connective tissue with energy-saving posture-maintenance activities contributed to the low energy consumption of holothurians. © 2009 Marine Biological Laboratory.

O2 consumption of a single embryo/planula at each developmental stage was monitored in the reef-building coral Acropora intermedia using an optical O2-sensing system with our original micro-chamber system (6.28 μ1). The lowest rate of O2 consumption was observed in unfertilized eggs. After fertilization, O2 consumption increased and remained constant until the prawn chip blastula stage. However, O2 consumption began to increase again during the bowl-shaped blastula stage, which involves the formation of 2 germ layers and corresponds to the beginning of gastrulation. The rate of O2 consumption peaked during the teardrop-shaped planula stage. During this stage planulae are able to swim actively, especially in the vertical plane, so an increase in energy consumption during this stage is to be expected. O2 consumption began to decrease gradually 5 d after spawning. At this stage, the larvae frequently touched the substrate with their concave aboral end, which features numerous spirocysts required for substrate attachment. When the planulae began to settle, 7 d after spawning, the rate of O2 consumption dropped to that of unfertilized eggs, suggesting that the planulae slowly use stored energy for crawling/settlement behavior and/or post-settlement growth and survivorship. © Inter-Research 2008.