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排序方式: 共有489条查询结果,搜索用时 18 毫秒
1.
Yuki Midorikawa Tomohito Shimizu Tetsuya Sanda Katsuyuki Hamasaki Shigeki Dan Mohammad Tamrin Bin Mohamad Lal Goshi Kato Motohiko Sano 《Journal of fish diseases》2020,43(5):541-549
Mass mortality due to necrosis signs occurred in hatchery-reared zoea stage larvae of the mud crab Scylla serrata in Okinawa, Japan, and a causative bacterium was isolated. In this study, we identified and characterized the bacterium by genome analysis, biochemical properties and pathogenicity. The bacterium was a Gram-negative, non-motile, long rod, forming yellow colonies on a marine agar plate. It grew at 20–33°C (not at 37°C) and degraded chitin and gelatin. Phylogenetic analysis of the 16S rRNA gene sequence identified the bacterium as Aquimarina hainanensis. Genome sequence data obtained from Illumina MiSeq generated 29 contigs with 3.56 Mbp in total length and a G + C content of 32.5%. The predicted 16 chitinase genes, as putative virulence factors, had certain homologies with those of genus Aquimarina. Experimental infection with the bacterium conducted on larvae of four crustacean species, brine shrimp Artemia franciscana, freshwater shrimp Caridina multidentata, swimming crab Portunus trituberculatus and mud crab S. serrata, revealed that this bacterium was highly virulent to these species. The present study suggests that the bacterium caused mass mortality in mud crab seed production was A. hainanensis and can be widely pathogenic to crustaceans. 相似文献
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In many disaster settings, top‐down responses emphasise ‘expert‐led’ solutions that often involve relocating disaster‐affected communities. While the intention might be to move people from harm's way and facilitate recovery, failure to attend to local pre‐disaster circumstances as well as the interplay between power, resilience and vulnerability within and around affected communities often sees resettlement reconfigure as displacement or disconnection. This oversight may even usher in a new phase of dispossession and disadvantage for marginalised groups (particularly in colonial settings). This paper explores experiences in Australia, Japan and Taiwan to reflect on what issues of local sociality, local culture and local resilience need to be attended to in framing ‘better’ disaster responses. 相似文献
3.
Turbid water induces refuge behaviour of a commercially important ayu: A field experiment for interstream movement using multiple artificial streams 下载免费PDF全文
Terutaka Mori Yasumitsu Kato Tetsuya Takagi Yukio Onoda Yuichi Kayaba 《Ecology of Freshwater Fish》2018,27(4):1015-1022
Riverine systems are inherently dendritic in nature, and turbid water may not necessarily flow equally throughout an entire catchment. Tributaries have the potential to serve as refugia from temporarily turbid water in the main stem. As ayu (Plecoglossus altivelis) are one of the important species for the inland fisheries industry and recreational fishing, their behaviour in a branched river network is a primary concern. We released ayu with radio‐transmitting tags into two experimental streams that joined at a downstream pool. Turbid water was released into one of the streams, and we identified whether avoidance movement of ayu between the two experimental streams was triggered by flowing turbid water. The suspended solid concentration elevated rapidly after adding the turbid water and was maintained at more than 400 mg/L for 3 hr. Avoidance movement of ayu was triggered when the suspended solid concentration exceeded approximately 200 mg/L. Then, most ayu moved from the turbid stream to the nonturbid one, leading to a difference in ayu density between the two streams. Therefore, we demonstrated that turbid water induced interstream movement of a commercially important ayu as refuge behaviour, suggesting that river connectivity is important for the persistence of the ayu. 相似文献
4.
γ-Oryzanol is a main oleophilic component in rice bran oil and has been well recognized as a good dietary supplement for human health, as well as having uses in industrial materials. japonica-type rice cultivars generally showed significantly higher contents of total γ-oryzanol in brown rice compared with indica-type cultivars, although within-group variation was significant. The objective of this study was to explore quantitative trait loci (QTLs) responsible for the difference in the γ-oryzanol content between japonica-type and indica-type rice cultivars, using recombinant inbred lines (RILs), backcross inbred lines (BILs), and corresponding chromosome segment substitution lines (CSSLs) derived from crosses between japonica-type and indica-type. Results from RILs and BILs showed that eight QTLs were detected with R2 from .09 to .16. Nine candidate regions for QTL were also suggested from corresponding CSSLs. These QTLs from RILs and BILs and the candidate regions from CSSLs were not overlapped, although one QTLs was mapped near the boundaries of the respective candidate region. At four QTLs and three candidate regions, alleles or segments from japonica-type caused higher contents than those from indica-type. On the other hand, at the other four QTLs and six candidate regions, alleles or segments from indica-type caused higher contents than those from japonica-type, which is a reverse result to the parental differences. This result strongly suggested that alleles with increasing effects on γ-oryzanol content could be accumulated not only from japonica-type but also from indica-type, leading to a potential for increase in γ-oryzanol content in future breeding programs. 相似文献
5.
Ryota MATSUYAMA Naotoshi KUNINAGA Tomoya MORIMOTO Tetsuya SHIBANO Akiko SUDO Kazunari SUDO Makoto ASANO Masatsugu SUZUKI Tetsuo ASAI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(9):1179-1181
Plesiomonas shigelloides is a causal agent of gastroenteritis, sepsis
and meningitis in humans. We examined the prevalence of P. shigelloides
among great cormorants (Phalacrocorax carbo hanedae) in Japan and the
antimicrobial susceptibility of isolates. P. shigelloides was isolated
from 33 (47.8%) of 69 fecal samples from great cormorants in 2014. All 33 isolates were
subjected to antimicrobial susceptibility testing using broth microdilution methods, which
showed resistance to ampicillin (31 isolates, 93.9%), tetracycline (two isolates, 6.1%)
and trimethoprim (one isolate, 3.0%). The high prevalence of P.
shigelloides in the great cormorants implicates the possible microbiological
risk to public health. 相似文献
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8.
Takahisa Nakai Hiroyuki Yamamoto Masatoshi Hamatake Tetsuya Nakao 《Journal of Wood Science》2006,52(6):539-543
This study investigated the relationship between the initial shape of the stress (σ)-strain (ε) curve of a Chamaecyparis obtusa wood specimen subjected to repeated combined compression and vibration stresses at various angles between the fiber direction
and load direction and the piezoelectric behavior. The main findings of the study are: (1) the σ-ε curve became convex initially, and then the stress was proportional to the strain. The σ-ε curve had almost the same shape during both loading and unloading. (2) The σ-piezoelectric voltage (P) curve was nonlinear, with a maximal point or cusp on the curve, which had almost the same shape during both loading and
unloading, as was also observed for the σ-ε curve. (3) The plot of the first derivative of the stress [dσ/dε (= σ′)] against ε was nonlinear. The σ′-ε and P-ε curves at various angles were fairly similar. (4) The stress at the maximal point (or cusp) of the σ-P curve decreased with an increase in the angle between the fiber direction and load direction. The tendency of the stresses
was very similar to that of Young’s modulus and compression strength calculated from Hook’s law and Hankinson’s law, respectively. 相似文献
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We determined if callose formation in 1-cm-long root apices of European chestnut (Castanea sativa Mill.) seedlings is affected by naturally occurring high concentrations of aluminum (Al) under laboratory conditions and by low base saturation (BS) of soils under forest field conditions. Under controlled conditions in the laboratory, seedlings were treated with simulated soil solutions in the presence or absence (control) of Al. One day after exposing seedlings to a simulated soil solution containing 168 microM Al, callose formation in the root apices had increased significantly. After 7 days, callose concentration in root apices was significantly correlated with the concentration of free Al3+ ions recovered in the simulated soil solution and with the concentration of Al in fine roots. At four field sites in southern Switzerland, seedlings were grown for five months in either A-horizon soil with a BS above 17% or in a B-horizon soil with a BS below 5%. Callose concentrations were significantly higher in root apices in the B horizon than in the A horizon. Callose concentrations in root apices were negatively correlated with Ca/Al molar ratio in fine roots. We conclude that callose in the root apices of European chestnut could be a useful physiological parameter for assessing Al toxicity under both laboratory and field conditions. 相似文献