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The bulk properties of β-Ga2O3 are sensitive to temperature and atmosphere; therefore, suitable annealing conditions are required. This study was performed to investigate the effects of annealing conditions on the ( 2 ¯ 0 1 ) surface of β-Ga2O3 crystal using atomic force microscopy, optical transmission/ luminescence spectroscopy, and X-ray photoelectron spectroscopy. Annealing was performed in air and in evacuated glass capsules at different temperatures. After annealing at 900 °C in air, the sample became a colorless insulator, and faceting was observed. On the other hand, sample decomposition was observed after annealing in the evacuated capsules. While, after annealing at 300 °C in air, step-terrace formation was observed. With increase of the annealing temperature, faceting was observed after annealing at 600 °C exposing the (1 0 0) and (0 0 1) surfaces. These results demonstrate the need for optimized annealing conditions for different surface orientations to obtain desirable β-Ga2O3 surfaces for heterointerfaces.

Juvenile Pacific bluefin tuna (Thunnus orientalis; PBT) often experience high mortality during ship transportation. This study investigated whether the addition of colours or patterns to the walls of tanks affected survival rate. In the first experiment, three colours and lattice patterns were tested: dark blue single-colour, red single-colour, and red–blue lattice pattern. Fish in all tanks exhibited abnormal behaviours when sunlight entered the tanks between 0800 and 1000 hours, but mortality only increased in the single-coloured tanks as a result of collision with the tank walls. In the second experiment, four colours and patterns were tested: dark blue single-colour, red–blue lattice pattern, red–blue lattice pattern with shade sheet and red–green lattice pattern with shade sheet. Again, we visually observed that fish in all treatment groups exhibited abnormal behaviour when sunlight entered the tanks, but there were no collision deaths in the lattice-patterned tanks and survival in this group was significantly higher than in the single-coloured tanks. Thus, the use of a high-contrast colour pattern can prevent mass death of juvenile PBT during ship transportation.

Following the successful development of Pacific bluefin tuna (PBT) aquaculture, it is of considerable importance to determine the muscle fiber types and their growth patterns for future development. Muscle fiber profiles of dorsal ordinary, lateral ordinary (LO) and dark muscles and their growth patterns in PBT from 3.0 to 54.3 kg body weight were studied. Muscle fibers were histochemically stained for NADH-diaphorase and myosin adenosine triphosphatase activity (mATPase), and immunohistochemically stained with S-58 slow-muscle myosin antibody. All muscle fibers in dorsal and LO muscles showed low NADH-diaphorase activity, and acid-labile (pH 4.0 or 4.3) and alkali-stable mATPase activity. In LO muscle adjacent to dark muscle, three intensities of mATPase activity were observed after acid pre-incubation at pH 4.5 or 5.0, and the activity was related to the muscle fiber diameter. In dark muscle, all small and some large fibers stained intensely for NADH-diaphorase activity, related to their high aerobic metabolism. The high-active fibers with NADH-diaphorase in dark muscle were positive for S-58 antibody. Some large fibers in dark muscle showed intermediate NADH-diaphorase activity and high mATPase activity after alkali pre-incubations. These are fast-twitch oxido-glycolytic fibers in dark muscle and transformed to red muscle fibers with increasing body weight.

The purpose of this study was to determine whether feeding cultured bluefin tuna with feed fish containing low levels of mercury results in a concomitant reduction in the total mercury levels in tuna. The control group was fed spotted mackerel with average mercury concentrations of 0.052 ppm, and the experimental group was fed horse mackerel in combination with Japanese sand lance, whose mercury concentrations were 0.016 ppm and 0.037 ppm (0.019 ppm in average), respectively. Mercury intake in the control and experimental groups' tunas decreased from 124 to 53 µg/kg body weight/month and from 60 to 19 µg/kg body weight/month over the duration of the 19- and 18 month rearing period, respectively. Three specimens from each group were harvested at approximately monthly intervals initially, and then less frequently as the tuna increased in size, and muscle tissue, internal organs, gill filaments, and blood samples were collected for analysis. In the control group, total mercury concentrations increased from 0.25 to 0.55 ppm in all muscle samples except the front ventral one. In contrast, total mercury concentrations in muscle tissues from the experimental group were less than 0.25 ppm, with no marked increases observed over time. The mercury concentrations of the internal organs in the experimental samples were also lower than those of the control. The study showed that feeding bluefin tuna horse mackerel supplemented with sand lance can decrease the accumulated total mercury levels lower than the maximum permitted level of mercury in fish in Japan (0.4 µg/g). This study is the first report to describe the production of bluefin tuna with such low levels of mercury.

Stable reproduction is essential for supplying artificially hatched fish to tuna aquaculture. We observed testes maturation in reared Pacific bluefin tuna (PBT) Thunnus orientalis at 2+ years of age. The incidence of males with mature testes was 25.0%, and 40% of the males had developing testes that contain spermatozoa, while oocytes of the same aged females were not mature. These fish were wild-caught at 0+ years old in August 1997 and the gonads were examined in October 1998 and January–February 2000. Therefore, the age at examination in 2000 was estimated to be 2 years and 7–10 months old considering the spawning season of the wild PBT and the size when captured. Histological examination of thematured and developing testes showed that they contained spermatozoa, spermatids, spermatocytes, and spermatogonia. All the spermatozoa were observed to be motile in sea water under light microscopy. From the results of this and previous studies, matured males are probably fertile for at least 5 months a year in Kushimoto. The testes maturation observed at young age in captivity is considered promising to reduce the cost of brood-stock maintenance for the juvenile production of PBT, especially if the sperm are cryopreserved.

Rainbow trout (Oncorhynchus mykiss) head kidney phagocytes precultured with a synthetic cytidine-phosphate-guanosine (CpG) oligodeoxynucleotide (ODN) displayed significantly higher phagocytic activity against Vibrio ordalii than phagocytes precultured with non-CpG ODN. However, head kidney phagocytes precultured with CpG ODN did not show enhanced phagocytic activity against polystyrene particles.

In recent years, the amount of children with sleep disorders that cause arousal during sleep or light sleep is increasing. Attention-deficit hyperactivity disorder (ADHD) is a cause of this sleep disorder; children with ADHD have frequent body movement during sleep. Therefore, we investigated the body movement during sleep of children with and without ADHD using video imaging. We analysed large gross body movements (GM) that occur and obtained the GM rate and the rest duration. There were differences between the body movements of children with ADHD and normally developed children. The children with ADHD moved frequently, so their rest duration was shorter than that of the normally developed children. Additionally, the rate of gross body movement indicated a significant difference in REM sleep (p

Recently, nursing care service is harder because of shorter hospital day, ambulant patient and shortage of nurse. Medical accident has occurred and patient has been endangered by nurse’s carelessness. Thus, time study for nurse has done to improve nursing care service. Time study is that observer records nursing work contents and required time. If nursing work contents and required time would be figured out accurately, patient transportation has to be particularly reduced. So, we developed the system to automate time study about transporting patient with wheel chair. As the result of experiment, developed system could calculate wheel chair’s migration length and locus.

Substantial amounts of mercury are usually present in tuna muscle, with levels in excess of 10 times the standard safety value present in some individuals. Inspection of individual fish for mercury content would be desirable but may not be cost-effective. In this study, we tried to establish a low-cost system for checking the mercury content of tuna by using a tail muscle that is usually discarded. The samples used in this experiment were bluefin tuna, cultured in the Fisheries Laboratory of Kinki University (Oshima Experimental Station, Wakayama, Japan). They were raised from eggs spawned in 2002. Ninety-eight individuals, weighing 22.3 to 61.6 kg, were selected between December 2004 and November 2005. In nine individuals, the mercury content of the tail was compared with that of the whole body. The total mercury level was measured using the reduction vaporizing atomic absorption method after acid digestion. Except for the front of the abdomen, where the mercury content was lower (0.490 ppm), the mercury content of other parts of the fish did not differ from that of the tail muscle (0.631 ppm). Therefore, the overall mercury concentration in bluefin tuna could be estimated to be almost the same and/or lower than that of the tail muscle. On the basis of these results, for 1 year we investigated the quantity of mercury in full-cycle cultured bluefin tuna that were shipped. The mercury concentration showed no increase irrespective of increases of body weight.