Larval rearing without aeration: a case study of the seven-band grouper <Emphasis Type="Italic">Epinephelus septemfasciatus</Emphasis> using a wave maker     

Yoshitaka Sakakura  Shigeaki Shiotani  Masashi Shiozaki  Atsushi Hagiwara 《Fisheries Science》2007,73(5):1199-1201

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Changes in seawater tolerance during the development of eyed-stage embryos in shishamo smelt Spirinchus lanceolatus (Hikita)     

Shinya Mizuno  Yoshitaka Sasaki  & Kazushi Imada 《Aquaculture Research》2005,36(6):615-619

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Estimation of flow in a rearing tank of marine fish larvae by simplified numerical computation—a case of two-dimensional flow     

Shigeaki Shiotani  Atsushi Hagiwara  Yoshitaka Sakakura  Hisashi Chuda   《Aquacultural Engineering》2005,32(3-4):465-481

Marine fish larvae are fragile against physical stress. However, few studies have been conducted to evaluate the flow field in a rearing tank, which is assumed to provide a high degree of physical stress to marine fish larvae. The flow field in a rearing tank (volume of 1 m³) is generated by aerators, which are commonly used to provide oxygen.

This paper is a report on the estimation of stationary flow in the rearing tank of marine fish larvae. The larvae are seven band grouper larvae of Epinephelus septemfasciatus, which have a very low survival rate immediately after the hatching of eggs. The experiments of rearing of seven band grouper larvae were carried out using rearing tanks with four aeration rates (1000, 200, 50 ml/min, and no aeration). The effects of aeration on the survival and floating death of seven band grouper larvae were examined. The experiments confirmed that the mass mortality of seven band grouper larvae depends on the flow rate in the rearing tank. Aeration at 200 ml/min resulted in the highest survival and growth rates of grouper larvae.

Larvae-rearing experiments provided evidence that the flow rates of the rearing tanks are very important design aspects of rearing tanks. The estimation of flow in a rearing tank for an aerating rate of 200 ml/min was carried out by numerical calculation. The computation was simplified by a two-dimensional flow based on experimental results. The calculated flow in the rearing tank was compared with the experimental one. The calculation of the stationary flow in the rearing tank showed good qualitative and quantitative agreement with the experimental results. The numerical estimation of the flow in a rearing tank of marine fish larvae was confirmed to be effective and satisfactory for the design of a tank that would provide optimum performance.  相似文献   

Validation of a food-frequency questionnaire for cohort studies in rural Japan     

Ogawa K  Tsubono Y  Nishino Y  Watanabe Y  Ohkubo T  Watanabe T  Nakatsuka H  Takahashi N  Kawamura M  Tsuji I  Hisamichi S 《Public health nutrition》2003,6(2):147-157

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Three new algorithms to calculate the irreplaceability index for presence/absence data     

Nobuyuki Tsuji  Yoshitaka Tsubaki 《Biological conservation》2004,119(4):487-494

The irreplaceability index is used for determining the priority of sites for conservation. We propose three new and simple algorithms for calculating it from presence/absence data without any statistical assumptions when the representative combination size is the minimum. The rare species algorithm gives accurate results but takes the longest calculation time. The species richness algorithm gives approximated results and takes the shortest calculation time. The combined algorithm is intermediate in accuracy and calculation time. We applied the combined algorithm to real data of butterflies in the Kanto district, central Japan, and derived irreplaceability values.  相似文献   

Comparison of collagen content, distribution and architecture among the pectoralis, iliotibialis lateralis and puboischiofemoralis muscles with different myofiber composition in Silky cocks     

Yoshi-Nori NAKAMURA  Hisao IWAMOTO  Shoji TABATA  Yoshitaka ONO  Nobuya SHIBA  Shotaro NISHIMURA 《Animal Science Journal》2003,74(2):119-128

The total amount of collagen, the relative distributions of types I and III collagens in perimysium and endomysium, and the collagen fiber architecture were compared among the pectoralis (PT), iliotibialis lateralis (ITL) and puboischiofemoralis (PIF) muscles in Silky cocks. All of the myofibers in the PT muscle were type IIB, the myofibers in the ITL muscle were divided into type IIA, 41.7% and IIB, 58.3%, and the PIF muscle was composed of type I, 24.6%; IIA, 64.6%; and transitional, 10.8%. The total amount of collagen differed significantly among the PT (2.92 mg/g), PIF (4.20 mg/g) and ITL (8.06 mg/g) material, where only the PIF was a whole muscle with epimysium. On the image analysis of the immunohistochemical preparations, the percentage area of perimysial collagen to the total area in each type differed significantly among the PIF, PT and ITL muscles, where it was 26.8, 50.0 and 74.4% for the type I collagen and 27.4, 32.9 and 61.7% for the type III collagen, respectively. In the scanning electron micrography of the perimysium in macerated preparations, thick bundles of collagen fibers were observed in the ITL muscle, thinner but broad platelets in the PT muscle, and a coarse tissue of thinner collagen fibers in the PIF muscle. However, the endomysial fabric of collagen fibrils was similar among the muscles. Small, transverse collagen fibers, which branched off from the thicker perimysia, occupied narrow interendomysial spaces and separated the primary myofiber fasciculi. The results indicate that the ITL muscle, localized in the distorted and overextended part of the leg and subject to strong external forces, had highly developed perimysial collagen fiber bundles, but the ITL endomysial collagen architecture was similar to that of the PT and PIF muscles.  相似文献   

Pathological characteristics of thyroid glands from Japanese Black Cattle living in the restricted area of the Fukushima Daiichi Nuclear Power Plant accident     

Jun Sasaki  Megumi Uehara  Itaru Sato  Hiroshi Satoh  Yoshitaka Deguchi  Hiroyuki Chida  Masahiro Natsuhori  Takahisa Murata  Kenji Ochiai  Kumiko Otani  Keiji Okada  Nobuhiko Ito 《Animal Science Journal》2019,90(9):1333-1339

To study the effect of ionizing radiation on thyroid glands, 66 Japanese Black cattle residing in the restricted area of the Fukushima Daiichi Nuclear Power Plant in 2013–2017 were pathologically examined. There were no clinical symptoms of thyroid disease in these cattle. Three cases of goiter and seven of atrophy were found in two among the four farms examined. Cases of goiter exhibited normal morphological structure without mass or nodule formation in thyroid glands. Cellular atypia or capsular invasion of the follicular epithelium was absent. The estimated integrated dose of external radiation in goiter cases ranged from maximum 797 mSv to minimum 24 mSv. All lobules in the seven atrophic thyroid glands were affected, but pathological findings, such as inflammatory cell infiltration or stromal fibrosis, were not observed. The estimated integrated dose of external radiation in atrophic thyroids ranged from maximum 589 mSv to minimum 8 mSv. Immunohistochemical analysis of anti‐nitroguanosine and the TUNEL method in goiter and atrophic thyroid glands did not reveal any positive findings. The present study indicates that there was no significant relationship between a radiation effect and pathological findings in any thyroid glands.  相似文献   

Decreased blood cell counts were not observed in cattle living in the “difficult‐to‐return zone” of the Fukushima nuclear accident     

Itaru Sato  Jun Sasaki  Hiroshi Satoh  Yoshitaka Deguchi  Hiroyuki Chida  Masahiro Natsuhori  Kumiko Otani  Keiji Okada 《Animal Science Journal》2019,90(1):128-134

White blood cells, especially lymphocytes, are susceptible to radiation exposure. In the present study, red blood cell, total white blood cell, and lymphocyte counts were repeatedly measured in cattle living on three farms located in the “difficult‐to‐return zone” of the Fukushima nuclear accident, and compared with two control groups from unaffected areas. Blood cell counts differed significantly between the two control groups, although almost all the values fell within the normal range. The blood cell counts of the cattle in the “difficult‐to‐return zone” varied across sampling times even on the same farms, being sometimes higher or lower than either of the two control groups. However, neither a statistically significant decrease in blood cell counts nor an increase in the rate of cattle with extremely low blood cell counts was observed overall. The estimated cumulative exposure dose for the cattle on the most contaminated farm was within a range of 500–1000 mSv, exceeding the threshold for the lymphopenia. Because of the low dose rate on these farms, potential radiation damages would have been repaired and have not accumulated enough to cause deterministic effects.  相似文献   

Effect of environmental factors on fertility of Holstein–Friesian cattle in Japan   总被引：1，自引：1，他引：0  

Yoshitaka Nagamine  Osamu Sasaki 《Livestock Science》2008,115(1):89-93

We investigated the environmental factors in Japan, including meteorological conditions, on the fertility of a European cattle breed, Holstein–Friesian, by examining conception rates in different regions. First artificial insemination and associated conception details were recorded for 69,952 Holstein female cattle. In general, meteorological conditions vary considerably according to latitude in Japanese islands. Conception rates were higher in the Northern (above 37°N) than the Southern (below 37°N) region (61.3% vs. 53.3%). All the factors analyzed in the statistical model, including insemination year, region, month, AI technician, service sire and interaction between region and month, had significant effects on the conception rate. In the Southern region, conception rates were lower in the summer months (average temperature, 27.8 °C, and maximum temperature, 32.3 °C). However, this seasonal decline was not observed in the Northern region (average temperature, 23.7 °C, and maximum temperature, 28.4 °C). Regression analysis of conception rate in relation to temperature showed highly significant negative regression coefficients (− 0.66 to − 0.63% per °C; p < 0.001) in the Southern region, but non-significant coefficients in the Northern region. Humidity had a minimal effect on conception rate in both regions. Our data collectively suggest that 37°N latitude is a threshold that affects Holstein–Friesian conception rates in Japan.  相似文献   

Anther culture in rice proportionally rescues microspores according to gametophytic gene effect and enhances genetic study of hybrid sterility     

Yoshitaka Kanaoka  Daichi Kuniyoshi  Eri Inada  Yohei Koide  Yoshihiro Okamoto  Hideshi Yasui  Yuji Kishima 《Plant methods》2018,14(1):102

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