Effect of Illuminance Transition Rate on Survival of Juvenile Pacific Bluefin Tuna,Thunnus orientalis     

Tomoki Honryo  Michio Kurata  Tokihiko Okada  Yoshifumi Sawada  Yasunori Ishibashi 《Journal of the World Aquaculture Society》2014,45(5):523-531

To investigate the reason for the high mortality of cultured juvenile Pacific bluefin tuna (PBT), especially during land‐based culture, we examined the effect of the rate of light‐intensity change during the dawn period. Juvenile PBT kept in a natural light environment (control) were compared with those exposed to an artificially slowed change in light intensity during the dawn period (test group). For the test group, lamps, which were connected to automatic timers and placed above the rearing tank, were switched on from 0345 to 0515 h at 15‐min intervals. After 9 d, the survival rate of the test and control group was identical. Between Day 1 and Day 6, whole‐body cortisol levels were not different between groups. However, whole‐body glucose levels in the test group were significantly higher than those in the control group. Both groups displayed a diel rhythm in plasma cortisol concentration that peaked at 0300–0600 h. These results suggest that slowing the increase in light intensity during the dawn period did not improve survival and that low light intensity itself induces high mortality in cultured PBT juveniles.  相似文献   

Effect of presence of rumen protozoa on degradation of cell wall constituents in gastrointestinal tract of cattle     

Natsuki KASUYA  Itsuko WADA  Mimune SHIMADA  Hiroshi KAWAI  Hisao ITABASHI 《Animal Science Journal》2007,78(3):275-280

The cell wall constituents of feces from three faunated and three defaunated (without ruminal ciliate protozoa) cattle fed on a Sudangrass hay and concentrate mixture (8:5) were analyzed. There was little difference in digestibility of dry matter between the faunated and defaunated cattle. Analysis of the fecal sugar residues revealed that the digestibilities of arabinose and galactose, derived from pectic and hemicellulosic substances located within the compound middle lamella, were higher in the defaunated cattle than the faunated cattle (P < 0.05), whereas the digestibilities of glucose and xylose, derived mainly from cellulose and xylan, were unchanged by the removal of protozoa. The digestibility of lignin was not different between the faunated and defaunated cattle, but those of mannose and p‐coumaric acid were lower in the defaunated than in the faunated animals (P < 0.05). The ratio of primary cell wall to secondary cell wall in fecal plant materials was lower for the defaunated than for the faunated cattle. The results in this study suggested that the defaunation enhanced the microbial degradation of the thin cell walls, but depressed the degradation of developed cell walls.  相似文献   

Aloe ring spot,a new disease of aloe caused by <Emphasis Type="Italic">Haematonectria haematococca</Emphasis> (Berk. &; Broome) Samuels &; Nirenberg (anamorph: <Emphasis Type="Italic">Fusarium</Emphasis> sp.)     

Yuuri Hirooka  Takao Kobayashi  Jun Takeuchi  Tsuyoshi Ono  Yasunori Ono  Keiko T. Natsuaki 《Journal of General Plant Pathology》2007,73(5):330-335

A ring spot disease of Aloe vera was found on leaves of potted seedlings of Aloe vera in Hachijojima and Chichijima Islands, Tokyo. From tissue of ring spot lesions, a fungus producing Fusarium-type conidia was consistently isolated. After 1 month, reddish perithecia of nectriaceous fungus had formed on the colonies of this isolate on PDA. These nectriaceous and Fusarium fungi were identified as Haematonectria haematococca and Fusarium sp., respectively. From a single ascospore isolation, the former was confirmed to be the teleomorph of the Fusarium sp. Typical ring spot lesions were reproduced by artificial inoculations using single ascospore and single conidium isolates. Inoculations of five species of genus Aloe revealed that they were highly susceptible except for A. arborescens. This is the first report of a disease on Aloe caused by H. haematococca (anamorph: Fusarium sp.) in Japan, and it was named aloe ring spot.  相似文献   

Detection of the staphylococcal enterotoxin D-like gene from staphylococcal food poisoning isolates over the last two decades in Tokyo     

Yasunori SUZUKI  Makiko KOBAYASHI  Shigeru MATSUSHITA  Satomi UEHARA  Rei KATO  Yusuke SATO’O  Hisaya K. ONO  Kenji SADAMASU  Akemi KAI  Yoichi KAMATA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(8):905-911

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Reddish coloration of Chinese quince (Pseudocydonia sinensis) procyanidins during heat treatment and effect on antioxidant and antiinfluenza viral activities     

Hamauzu Y  Kume C  Yasui H  Fujita T 《Journal of agricultural and food chemistry》2007,55(4):1221-1226

To investigate the effects of processing Chinese quince fruit on the denaturation of phenolics and their food functions, fruit phenolic extracts were heated together with organic acid for up to 12 h. Chinese quince phenolic (mostly procyanidins) solution subjected to heat treatment changed from almost colorless, pale yellow, to a reddish color. Before heat treatment, the absorption spectra of polymeric procyanidins were observed only around 280 nm; after heat treatment, absorption occurred between 400 and 600 nm, which is related to the reddish color appearance. Thioacidolysis of denatured reddish phenolics showed that (-)-epicatechin subunits decreased during heat treatment and, in contrast, cyanidin increased. In addition, novel substances that could not be degraded by thioacidolysis were formed. Meanwhile, antioxidant activities, assessed by linoleic acid peroxidation, 1,1-diphenyl-2-picrylhydrazyl (DPPH), Folin-Ciocalteu, and FRAP methods, increased during heat treatment. The antiinfluenza viral activity of denatured reddish phenolics was inferior to that of intact fruit phenolics; however, they retained moderate activity. These results indicate that red coloration of fruit products of Chinese quince was mainly due to the spectral (i.e. structural) changes of procyanidins accompanied with formation of cyanidin. Increasing the length of heat treatment increased the antioxidant capacity of phenolics, and the resultant reddish phenolics retained moderate antiinfluenza viral activity.  相似文献   

Rearing of squid hatchlings, Heterololigo bleekeri (Keferstein 1866) up to 2 months in a closed seawater system     

Yuzuru Ikeda  Ikuko Sakurazawa  Kingo Ito  Yasunori Sakurai  & Gen Matsumoto 《Aquaculture Research》2005,36(4):409-412

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Erythrophagocytosis Enhances Heme-Dependent Cytotoxicity of Antimalarial Drugs in Canine Histiocytic Sarcoma Cell Line DH82     

Seishiro CHIKAZAWA  Yasunori KITAHARA  Erika ANDO  Yasutomo HORI  Fumio HOSHI  Kazutaka KANAI  Naoyuki ITO  Seiichi HIGUCHI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(2):249-253

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In vitro antibacterial activity of the combination of sulphadiazine and trimethoprim on bacterial fish pathogens     

T. KIMURA  M. YOSHIMIZU  M. WADA 《Journal of fish diseases》1983,6(6):525-532

Abstract. The in vitro bacteriostatic activity of a combination of sulphadiazine (SDZ) and trimethoprim (TMP) against representative bacterial fish pathogens was studied. In general, the minimum inhibitory concentrations (MIC) of TMP were much smaller than comparable values for SDZ. When SDZ and TMP were combined, the bacteriostatic effect was enhanced in a synergistic manner for all bacteria tested except Pseudomonas fluorescens . The synergism was most remarkable in the case of bacterial strains that were sensitive to the action of SDZ alone. This degree of synergism was observed when the ratios of SDZ and TMP in combination were in the range of 1:1 io 5:1. The MIC of SDZ plus TMP combined was less than 3.13 μg/ml for SDZ resistant strains and as low as 0.2 to 0.78 μ/ml for SDZ sensitive strains. The possible usefulness of a combination of these two compounds for therapy or control of bacterial fish disease is discussed.  相似文献   

Changes in the retinal cone density distribution and the retinal resolution during growth of juvenile Pacific bluefin tuna <Emphasis Type="Italic">Thunnus orientalis</Emphasis>     

Shinsuke Torisawa  Tsutomu Takagi  Yasunori Ishibashi  Yoshifumi Sawada  Takeshi Yamane 《Fisheries Science》2007,73(5):1202-1204

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Indirect evaluation of hardness and delamination strength of Akoya cultured pearl nacre based on UV fluorescence intensity     

Hiramatsu  Junichi  Iwahashi  Yasunori  Nagai  Kiyohito 《Fisheries Science》2022,88(6):805-813

The durability of Akoya pearls is closely related to the mechanical strength of the nacre. Therefore, obtaining information about the mechanical strength of the nacre is very important in the quality control of pearls. The nacre of Akoya pearls is composed of aragonite contained within an organic matrix. The presence of the organic matrix provides mechanical strength and fracture toughness much higher than that of monolithic aragonite. In this study, we investigated the hardness and delamination strength of Akoya cultured pearls classified into four levels by “Gray Value (GV)”, a score given by a non-destructive inspection method based on UV fluorescence intensity that provides an indication of the condition of the nacre’s organic components. Pearl hardness decreased significantly with decreasing GV. Furthermore, delamination strength of the pearl surface layer was very low when the GV was very low. These results suggest that the GV indirectly represents the mechanical strength of the nacre and could be used as a non-destructive quality-control method to maintain the quality of pearls used as jewelry.

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