The port of Fukuyama, locating in Bingo-nada in the central part of the Seto Inland Sea, is semi-enclosed area with infrequent water exchange. Polydora cornuta Bosc 1802 was found to have an uneven distribution in the inner part of the port. It overwinters as a benthic from January to May, and pelagic larvae are dominant in other seasons. In the laboratory, life cycles were found to range from 13 to 41 days depending on rearing temperature ranging from 18 to 28°C with longer life cycles with lower water temperature. The development of P. cornuta larvae was faster at higher temperature. The temperature of the water and/or bottom sediment were suggested to influence growth and reproduction of P. cornuta. The life-cycle duration in the inner part of Fukuyama port, based on 11.5 to 18.2°C temperature of bottom mud during January to May, is estimated to be 40 to 59 days, and three generations are completed in 5-month benthic phase.

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This study analyzed the effects on the psychological state of high school students of having plants in the classroom and of raising plants. Two separate experiments were carried out, using students from three classes of Ehime University Senior High School. Analysis of psychological state was carried out using Semantic Differential Method and Profile of Mood States, along with analysis of brain waves. The subjects also completed a questionnaire. In the first experiment, the three classes were divided into three groups. The classroom of the foliage plant group and the flower group contained foliage plants and live roses placed in the classroom, respectively. As the results, the foliage plant group was evaluated higher for “sense of tranquility” than the flower group and the control group, and more students in the foliage plant group than the flower group felt positive effects. In the second experiment, students were divided into three groups: Group A, no selection of plants and no care of plants; Group B, no selection of plants but care of plants; and Group C, selection of plants and care of plants. A single foliage plant was distributed to every student and students were allowed to place their plants where they liked. As the results, scores were high for the first factor (pleasant) and the second factor (emotional changes) in group. Proactive involvement with plants in the Group B and C increased attachment to and interest in plants, and was effective as a method for relieving stress and increasing communication.

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Effects of bubble size in foam fractionation on the removal of organic carbon, protein, and trace elements (Fe, Co, Cu, Zn, and Sr) from the closed recirculating culture of Japanese flounder were investigated. Twenty juvenile fish of 5 g body weight were stocked in a glass culture tank of 57 L water volume equipped with a submerged bio-filter, a foam fractionator, a blower and diffusers, and were fed commercial pellet diet twice daily 6 days a week for 116 days at 20°C. Two bubble sizes (0.55 mm in diameter, SB; 1.50 mm, LB) were prepared with different pore size of ceramic air stones as experimental groups in duplicates. Foam fractionator was not operated for the control group. Air was supplied to foam fractionator by 0.4 mL/min flow rate for 8 hours a day 5 days a week from the 79th day of the experiment. Total volume of foam condensate obtained during 79th to 116th day in SB group was 8.6±1.4 L, and was significantly higher than that in LB group of 1.0±0.3 L (P<0.05). Concentration of organic carbon and protein in the foam condensate were 1.4 to 9.1 times higher than those in the rearing water. Seventy % of total organic carbon and protein in the foam condensate were particulate form in SB group, while, dissolved form occupied 60% for LB group. Trace elements in the foam condensate were higher than those in the rearing water, and the concentration rates (foam/ rearing water) depended on the trace elements.

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