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Hisayuki Arakawa Yohei Ohi Akira Matsumoto Kenji Takio Takumi Kimoto Katsutoshi Kawabe 《Fisheries Science》2012,78(5):1083-1090
The populations of red alga Gelidium elegans along the coast of Miyakejima Island were severely damaged by a volcanic eruption in 2000. The effect of this volcanic eruption has been long lasting, and populations of this red alga still have not recovered. We investigated the effect of seabed sediment particles derived from volcanic ash on the substrate adhesion of G.?elegans spores. The analysis provides evidence that increasing amounts of sediment particles result in lower adhesion rates of G.?elegans spores, and that smaller sediment particles have a greater influence on adhesion. The amount of seabed sediment particles around Miyakejima Island was 9.3?C1815.4?mg/cm2. This amount has changed greatly from year to year. The adhesion rate of G.?elegans spores in water around Miyakejima Island was 0?% at all points in 2008 and 2010, but it was estimated as 6.3?C38.6?% in 2009. These results suggest that there is significant inhibition of algal spore adhesion by seabed sediment particles derived from volcanic ash around Miyakejima Island. 相似文献
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ABSTRACT: The effects caused by suspended particles in seawater and sediment cover of the substrate on the attachment to the substrate of zoospores, and on the subsequent growth and survival of gametophytes of the brown alga Eisenia bicyclis were examined in the laboratory. The attachment rate to the substrate of the zoospores was remarkably reduced by the sediment cover on the substrate, and it decreased to 3.8% of the no-sediment control by a slight sediment cover of 3.0 mg/cm2 (0.048 mm in thickness). The growth of gametophytes was not inhibited at 10 mg/cm2 or less of sediment cover, though it was stopped at 30 mg/cm2 . The survival rate of gametophytes became 39.4% at 5 mg/cm2 on the substrate, and gametophytes were all blighted at 30 mg/cm2 . The ratio of male to female of the surviving gametophytes became 81.5:18.5, when the sediment cover was 10 mg/cm2 . The rate of total loss ( TL [%]) of zoospores and gametophytes of Eisenia bicyclis was obtained from the following equation: TL = 100 (1 − exp[−0.0339 C ] exp[−1.24 Q ]), where, C (mg/L) and Q (mg/cm2 ) indicate the concentration of suspended particles in seawater and the sediment on the substrate, respectively. 相似文献
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Hayama Yoko Yanase Tohru Suzuki Moemi Unten Kazuhiko Tomochi Hisayuki Kakehi Mayu Shono Yukina Yamamoto Takehisa Kobayashi Sota Murai Kiyokazu Tsutsui Toshiyuki 《Tropical animal health and production》2018,50(1):209-215
Tropical Animal Health and Production - Akabane virus, the pathogen-causing Akabane disease, is an arthropod-borne virus (arbovirus) transmitted by the Culicoides biting midge. A nationwide... 相似文献
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Okumura Yutaka Matsuoka Hiromi Arakawa Hisayuki Tokanai Fuyuki Suzuki Atsushi Irizuki Toshiaki Kajita Hiroto Hara Motoyuki 《Fisheries Science》2021,87(1):121-130
Fisheries Science - Two sediment cores were collected from two sites in Nagatsura-Ura Lagoon, the mouth of which was destroyed in the 2011 Tohoku-oki tsunami. Although sediment conditions differed... 相似文献
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SUMMARY: The effects of nutrient salts eluted from artificial algal reef blocks made with sea-bottom sediment (hedoro) and cement to the growth and survival rate of the gametophytes and juveniles of Eisenia bicyclis were investigated. When each sample block was submerged in filtered seawater for 28 days, the nutrient salt content from the hedoro increased with time and, in particular, the amounts of NO3 − − N and NO2 − − N reached a constant level on day 10. We observed that the lower the cement ratio, the higher the concentrations of eluted NH4 + − N and PO4 3− − P. The growth of gametophytes as well as juveniles was highest in the elution of the block with the lowest cement ratio of 30%. In contrast, the survival rate of gametophytes and juveniles decreased linearly with time and the survival rate was higher for the hedoro blocks than for the block made of mortar. 相似文献
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Hisayuki Arakawa Ryo Okada Hisashi Okabe a Tsutomu Morinaga and Kazuya Taniguchi 《Fisheries Science》2000,66(3):473-480
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Tao Zhou Hisayuki Komaki Natsuko Ichikawa Akira Hosoyama Seizo Sato Yasuhiro Igarashi 《Marine drugs》2015,13(1):581-596
The incorporation pattern of biosynthetic precursors into two structurally unique polyketides, akaeolide and lorneic acid A, was elucidated by feeding experiments with 13C-labeled precursors. In addition, the draft genome sequence of the producer, Streptomyces sp. NPS554, was performed and the biosynthetic gene clusters for these polyketides were identified. The putative gene clusters contain all the polyketide synthase (PKS) domains necessary for assembly of the carbon skeletons. Combined with the 13C-labeling results, gene function prediction enabled us to propose biosynthetic pathways involving unusual carbon-carbon bond formation reactions. Genome analysis also indicated the presence of at least ten orphan type I PKS gene clusters that might be responsible for the production of new polyketides. 相似文献
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Yamada M Takashima H Takizawa T Mizuno K Nakamura K Furuoka H Masegi T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(8):997-1001
Two Japanese Black bull calves from a dam showed muscular weakness and became recumbent after birth. At necropsy, skeletal muscles, including face, neck, body and proximal and distal forelimb and hindlimb were extremely pale in color and edematous. Histopathological examination of skeletal muscles revealed degenerative changes as follows: replacement of muscle with fat, variation in muscle fiber diameter, internal nuclei, central core-like structures, and vacuolar and hyaline degeneration of muscle fibers. Ultrastructurally, the lesions were characterized by focal myofibrillar disorganization with streaming or irregularity of Z bands. The present cases seem to be classified as congenital myopathy based on pathological alterations and age of onset. 相似文献
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