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Yoshitaka Sakakura Shigeaki Shiotani Hisashi Chuda Atsushi Hagiwara 《Fisheries Science》2006,72(5):939-947
The water flow in larval rearing tanks has been indicated to cause mass mortality of the seven-band grouper Epinephelus septemfasciatus larvae. Therefore, a new aerating method was tested in an actual scale intensive rearing tank (8.0 m in diameter, 1.87 m
of water depth, 100 m3 of volume), in which an aerator was positioned at the center of the rearing tank surrounding cylindrical drain (1.2 m in
diameter) to generate the flow field, and seven larval rearing trials were performed. The survival rate with the former aeration
methods were compared, in which several aerators were located in the rearing tank. The survival rate at 10 days after hatching
with the new aeration method (61.5±5.1%, n=7) was approximately three times higher than the former methods (21.2±13.7%, n=6). The flow environment of rearing tanks was also examined by quantifying the flow field, and the relationship between the
flow field in the rearing tank, behavior of larvae and survival discussed. It was confirmed that the vertical circulating
flow was observed in rearing tanks, and determined effectively the survival and the behavior of grouper larvae in patchiness. 相似文献
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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
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Asagiri M Hirai T Kunigami T Kamano S Gober HJ Okamoto K Nishikawa K Latz E Golenbock DT Aoki K Ohya K Imai Y Morishita Y Miyazono K Kato S Saftig P Takayanagi H 《Science (New York, N.Y.)》2008,319(5863):624-627
Cathepsin K was originally identified as an osteoclast-specific lysosomal protease, the inhibitor of which has been considered might have therapeutic potential. We show that inhibition of cathepsin K could potently suppress autoimmune inflammation of the joints as well as osteoclastic bone resorption in autoimmune arthritis. Furthermore, cathepsin K-/- mice were resistant to experimental autoimmune encephalomyelitis. Pharmacological inhibition or targeted disruption of cathepsin K resulted in defective Toll-like receptor 9 signaling in dendritic cells in response to unmethylated CpG DNA, which in turn led to attenuated induction of T helper 17 cells, without affecting the antigen-presenting ability of dendritic cells. These results suggest that cathepsin K plays an important role in the immune system and may serve as a valid therapeutic target in autoimmune diseases. 相似文献
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M.A. Awal Takeshi Ohta Kazuho Matsumoto Tae Toba Kenichi Daikoku Shigeaki Hattori Tetsuya Hiyama Hotaek Park 《Urban Forestry & Urban Greening》2010,9(3):261-270
Urbanisation is increasing tremendously in some parts of the world. Consequently, many rural forests may become depleted, although many opportunities exist for urban forests to increase. However, few studies have quantified the carbon (C) sequestration capacities of urban and rural forests in specific climatic zones. The present study compared carbon sequestration in two temperate deciduous forests located in Nagoya and Toyota, central Japan. The Nagoya University forest represented an urban forest, and a site in Toyota represented a rural forest. The urban forest at Nagoya University had comparatively smaller areas of green space and larger areas of buildings and roads. Land uses for building and road, which are typical of urban areas, result in smaller diurnal temperature ranges but higher air temperature, vapour pressure deficit, and atmospheric carbon dioxide (CO2) concentration. The urban forest in this study exhibited higher gross ecosystem exchange (GEE), especially in the active growing season from May to September, suggesting the possible effect of CO2 fertilisation. However, higher air temperatures caused comparatively smaller net ecosystem exchange (NEE) because of higher ecosystem respiration (RE). Although both forests functioned as CO2 sinks at annual time scales, the rural Toyota forest site (5.43 t C ha–1 yr–1) had 36% higher net ecosystem production (NEP=–NEE; the negative sign indicates uptake by the forest ecosystem from the atmosphere) than that at the urban forest. The higher normalised respiration (i.e., RE/GPP ratio; GPP=–GEE where GPP represents gross primary production) at the Nagoya University forest might be attributable to factors associated with the degree of urbanisation. Thus, in temperate forests, factors associated with urbanisation may reduce the atmospheric carbon sink function by accelerating respiration. This is an issue of global interest, as many countries are experiencing rapid urbanisation. 相似文献
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A stemflow (SF) estimation model, based on the correlation between coefficients (a andb) of the regression equation (SF=aP
g −b, whereP
g is gross rainfall) obtained from sample tree and their diameter at breast height (DBH), is presented. Estimation by the model
forSF from two deciduous broad-leaved forests shows favorable agreement with the measurement. Once the equations for regression
coefficients are determined, the model has the potential to easily estimateSF from an entire stand through sampling of some representative trees. However, the model is site-specific. In order to mitigate
the weakness of this model, the combination of previous results provided generalized equations for the coefficients. The generalized
equation adequately estimatedSF of some forests while its estimation was biased for other forests, which indicates thatSF variation between forests is closely related to structural differences. Actually, theSF frequency distribution of two forest stands was significantly different. So, influence of structural factors onSF was also studied using funneling ratio (FR) that integrates the efficiency of trunk and canopy characteristics toSF. Comparison ofFR showed thatSF was significantly correlated to crown-projection area (CPA) and basal area at breast height (BA). Parameters (β
1 andβ
2) within the model were significantly correlated to respective stand density and leaf area index (LAI).
Part of this study was supported by Aichi Prefecture Collaboration of Regional Entities for the Advancement of Technological
Excellence, Japan Science and Technology Corporation. 相似文献
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Inoue K Yoshida M Takahashi M Cho YM Takami S Nishikawa A 《Journal of toxicologic pathology》2009,22(3):195-198
Neoplasms of skeletal muscle origin are very rare in the rat. Recently, we experienced a case of rhabdomyosarcoma as a white mass involving the junction of the esophagus and stomach in the abdominal cavity of a 12-month-old female Donryu rat. Histopathologically, the neoplastic cells composing the mass invasively spreaded from the lamina propia to the tunica serosa in the stomach as well as the esophagus. Although the neoplastic cells varied in appearance, pleomorphic atypical cells with abundant eosinophilic cytoplasm were prominent. Some tumor cells were stained blue with phosphotungstic acid hematoxylin. The nuclei of spindle-shaped neoplastic cells were arranged longitudinally like beads. Multinucleate giant cells and mitotic figures were also frequently observed. Immunohistochemically, these neoplastic cells were positive for desmin and myoglobin, whereas they were negative for alpha-smooth muscle actin. Taken together these findings, this tumor was diagnosed as a pleomorphic rhabdomyosarcoma, probably derived from the muscle layer of the lower part of the esophagus. This is the first report of rhabdomyosarcoma in a Donryu rat. 相似文献
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Okada K Nakae N Kuramochi K Yin SA Ikeda M Takami S Hirata T Goryo M Numakunai S Takeshima SN Takahashi M Tajima S Konnai S Onuma M Aida Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(12):1231-1235
Sheep were inoculated with high tax coded pBLV-IF (H group, Nos.1-5) of bovine leukemia virus (BLV), wild tax coded pBLV-IF (W group, Nos. 6-11), or control plasmid (C group, Nos. 12-14). During the observation period (4 to 46 months), 5 of 5 cases in H group and 3 of 6 cases (Nos. 6, 7, 9) in W group became positive for gp 51. Only 1 case in H group became leukemic, and one case each of H and W groups developed lymphoma. In No. 3, lesions were found in multiple organs including the lymph nodes, gastrointestinal tract following abomasum, and heart. In No. 6, lesions of lymphoma were found only in the jejunum and heart. Morphologically, small to middle-sized lymphocytic neoplastic (NP) cells were found in both cases, but lymphoblastic NP cells were found only in No. 3. By immunohistochemical examination, the phenotypes of NP cells were determined as CD1-, CD4-, CD5- -, CD8alpha-, sIgM+, lambda light chain+, B-B4+, MHC class II+ in both case. The results of this study indicate that inoculation of pBLV-IF can induce lymphocytic and lymphoblastic leukemia/lymphoma in sheep. Additionally, it is suggested that the expression rate of tax gene is not associated with the development of leukemia/lymphoma in sheep experimentally inoculated with pBLV-IF. 相似文献
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Ho-Taek Park Shigeaki Hattori Takafumi Tanaka Gyung-Soo Cha 《Journal of Forest Research》1999,4(4):261-269
This study was conducted to document the effects of canopy change on radiation and energy balances in a deciduous broad-leaved
forest. Global solar radiation was highly variable with a maximum close to 28.7 MJ m−2 day−1 and a minimum of about 0.7 MJ m−2 day−1. The high daily variation of net radiation was the result of the frequency and duration of rainfall. The mean annual albedo
in this study site was 0.126. Seasonal variation of albedo was characterized by steadily decreasing values with leaf-fall,
but at the time when new leaves sprouted the trend did turn upwards. The mean annual radiation efficiency at this study site
was 0.564, and the seasonal variation of the radiation efficiency was dependent upon the net long-wave radiation rather than
albedo. This study also illustrated the seasonal variation of the proportion of the actual evaporation to the equilibrium
evaporation as a means for estimating the latent heat flux from forest using the equilibrium evaporation model. Seasonal variation
of the proportion of the actual evaporation to the equilibrium evaporation reflected the physiological and productive activities
of trees. Latent heat flux dominated the energy balance and, in particular, reached about 96% of net radiation in July. 相似文献