排序方式: 共有16条查询结果,搜索用时 15 毫秒
1.
KENTARO HONDA ALISTAIR J. HOBDAY RYO KAWABE NAOKI TOJO KO FUJIOKA YOSHIMI TAKAO KAZUSHI MIYASHITA 《Fisheries Oceanography》2010,19(2):151-158
Juvenile southern bluefin tuna (Thunnus maccoyii, SBT) were monitored in nearshore waters off southwest Australia using acoustic tagging and monitoring over five austral summers (2002/2003–2006/2007) to determine patterns in age‐based distribution of SBT. A total of 20–70 receivers were deployed in early December along one to three cross‐shelf transects and at three inshore topographic features (lumps) where SBT are known to occur; and a total of 59–84 juvenile SBT (41–90 cm fork length) were tagged and released each year. After several months, receivers were recovered, and data extracted. In 2002/2003 and 2003/2004, 2‐yr‐old SBT were detected more frequently in nearshore areas than did 1‐yr old fish. Similarly in 2004/2005 and 2006/2007, it was the larger 1‐yr‐old SBT that were detected more frequently at inshore lumps (>85% of detections) while small 1‐yr‐old SBT were detected more widely over the study area. In 2005/2006, although large 1‐yr‐old SBT were still detected more frequently at inshore lumps than small 1‐yr old SBT, the percentage of all detections at lumps was lower at 31.5%, indicating wider distribution of both small and large age‐1 fish. The observed age‐dependent distribution pattern may be enhanced by the distribution of prey, which disperse or concentrate depending on the local oceanography. 相似文献
2.
KO FUJIOKA ALISTAIR J. HOBDAY RYO KAWABE KAZUSHI MIYASHITA KENTARO HONDA TOMOYUKI ITOH YOSHIMI TAKAO 《Fisheries Oceanography》2010,19(3):183-195
The spatial habitat utilization of juvenile southern bluefin tuna in southern Western Australia was investigated using automated acoustic receivers with acoustic transmitters implanted in tagged fish during three austral summers (2004/2005, N = 79 fish, 2005/2006, N = 81, 2006/2007, N = 84). Seventy acoustic receivers were deployed at three cross-shelf lines and three coastal topographic features (lumps) between December and May. We observed markedly different patterns of habitat utilization between the three seasons: (i) aggregation at lumps in 2004/2005 and 2006/2007, and (ii) wide distribution over the continental shelf (i.e., few occurring at lumps) in 2005/2006. Vertical profile by conductivity-temperature-depth casts showed these spatial shifts were caused by interannual changes in the presence of sub-Antarctic water. The sub-Antarctic water was present in the subsurface layer close to the continental slope only during 2005/2006, and the area had higher chlorophyll-a concentrations than the coastal areas, including at the lumps. These environmental characters, related to the nutrient rich sub-Antarctic water, appear to have a strong influence on fish distributions in 2005/2006, and may occur generally during La Niña events. Interannual fluctuations in habitat utilization will influence detection of fish in recruitment monitoring surveys and thus bias the resulting juvenile abundance indices. 相似文献
3.
4.
Heat-induced structural changes and aggregation properties of walleye pollack myosin, light meromyosin (LMM) and heavy meromyosin (HMM) were investigated. According to the circular dichroism (CD) measurement, the α-helix content of the pollack myosin and LMM were estimated to be 72% and 90% at 5°C but decreased to 22% and 21% by increasing the temperature to 60°C with two transitions at 35°C and 50°C, respectively. In contrast, that of HMM decreased gradually from 37% to 33% by increasing the temperature from 5°C to 40°C, and decreased steeply to 20% above 50°C. These results indicate that the decrease in the α-helix content in the myosin molecule upon heating was attributable mainly to the decrease in the α-helix content in the LMM region. In contrast, 1-anilinonaphthalene-8-sulfonate (ANS) fluorescence and light scattering intensity of both myosin and HMM were remarkably increased above 25°C and 35°C, respectively, while those of LMM showed only a slight change even above 60°C. Although LMM alone formed no aggregates detectable by the light scattering measurement, it formed coprecipitates with myosin but not with HMM upon heating at 40°C for 10 min. These facts suggest that LMM bind to the LMM region of the myosin. Further, it was found that myosin gel formed in a test tube by the same heating conditions was significantly weakened by coexistence of LMM. These results suggest that the association of the LMM region of myosin molecules is essential for the heat-induced gelation of myosin. 相似文献
5.
Isolation and characterization of an attenuated strain of an Orthotospovirus,melon yellow spot virus
Shimomoto Yoshifumi Ishikawa Koichi Okada Tomoyuki Oki Tomoka Hayashi Kazusa Yano Kazutaka Morita Yasuaki Takeuchi Shigeharu 《Journal of General Plant Pathology》2021,87(5):300-306
Journal of General Plant Pathology - An attenuated mutant strain of melon yellow spot virus (MYSV), an Orthotospovirus, designated as SA08-8, was obtained from a pathogenic isolate, C95S, via high... 相似文献
6.
MICHIO AOYAMA HIROHITO GOTO HITOMI KAMIYA IKUO KANEKO SATOSHI KAWAE HIROKI KODAMA YASUSHI KONISHI KENN-ICHI KUSUMOTO HISATO MIURA EIICHI MORIYAMA KIYOSHI MURAKAMI TOSHIYA NAKANO FUTOSHI NOZAKI DAISUKE SASANO TAKAO SHIMIZU HIROKI SUZUKI YASUSHI TAKATSUKI AKITO TORIYAMA 《Fisheries Oceanography》2008,17(3):206-218
Impact of climate change on marine biogeochemical parameters and ecosystem is one of the important issues of our environment. Direct evidence of marine pelagic ecosystem changes is found with warming of sea water and sea‐level rise in the main stream of the Kuroshio in the East China Sea and the western North Pacific during these three decades based on the analysis of long‐term comprehensive hydrographic observations. In terms of annual mean, the warming rate of surface air temperature and sea surface temperature ranged from 0.15 to 0.21°C per decade in and around the main stream of the Kuroshio in the East China Sea, which exceed the global mean warming rate of 0.128 ± 0.026°C per decade during the period from 1956 to 2005 reported in IPCC 2007. One of the features in this rapid warming region is an increase of number of Pterosagitta draco, a cosmopolitan warm‐water zooplankton. Biogeochemical parameters, such as wet weight of zooplankton, plant pigment and nutrients concentration in the upper 200 m have been decreasing while dissolved oxygen content and seawater temperature have been increasing in the upper 200 m in the main stream of the Kuroshio in the East China Sea. These observed linear trends of the biogeochemical parameters would be foresights for temperate oceans in the future. 相似文献
7.
Takehiro HIMAKI Taka‐aki YOKOMINE Masahiro SATO Sonshin TAKAO Kazuchika MIYOSHI Mitsutoshi YOSHIDA 《Animal Science Journal》2010,81(5):558-563
The present study was carried out to examine the effects of post‐activation treatment of trichostatin A (TSA), a histone deacetylase inhibitor, on in vitro development and transgene function of somatic cell nuclear transfer (SCNT) embryos derived from Clawn miniature pig embryonic fibroblast (PEF) transfected with a bacterial endo‐β‐galactosidase C gene (removal of the α‐galactosyl (Gal) epitope). SCNT embryos were incubated with or without TSA (50 or 100 nmol/L) after activation, cultured in vitro and assessed for cleavage, blastocyst formation and transgene function. The rate of blastocyst formation was significantly higher in SCNT embryos treated with 50 nmol/L TSA than that in control (P < 0.05), whereas the rate of cleavage and cell number of blastocyst did not differ. Following labelling with fluorescein isothiocyanate‐labelled BS‐I‐B4 isolectin, the intensity of fluorescence observed on cell‐surface was dramatically reduced in transgenic SCNT blastocyst in comparison with non‐transgenic SCNT blastocyst. However, the reduction of α‐Gal epitope expression in transgenic SCNT blastocyst was not affected by TSA treatment. The results of this study showed that post‐activation treatment with 50 nmol/L TSA is effective to improve in vitro developmental capacity of transgenic SCNT miniature pig embryos without the modification of transgene function. 相似文献
8.
Mahmoud HY Suzuki K Tsuji T Yokoyama M Shimojima M Maeda K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(11):1535-1537
In Japan, most pig populations are now free from pseudorabies virus (PRV) due to the recent success of an extensive eradication program. However, PRV infection persists in Japanese wild boars (Sus scrofa leucomystax), representing another potential reservoir for the virus in Japan. In this study, the seroprevalence of PRV in wild boars captured in three different prefectures was ascertained. A virus neutralization (VN) test showed that 6 of 173 serum samples (3%) were positive for VN antibody; glycoprotein E-ELISA revealed infection with the wild-type, but not the available vaccine strain, PRV. These results indicate that PRV has continued to spread among wild boars in Japan. 相似文献
9.
Daisuke Nakazawa Tomonari Kishimoto Takeru Sato Tomoka Saito Junji Amano Sachiko Kuwayama Hajime Okuno Toshinari Godo Yusuke Watanabe Dong-Sheng Han Masaru Nakano 《Euphytica》2011,181(2):197-202
Some intergeneric hybrids produced by the crosses among several colchicaceous ornamentals, Gloriosa superba ??Lutea?? (2n = 2x = 22), G. ??Marron Gold?? (2n = 4x = 44), G. ??Verschild?? (2n = 7x = 77), Littonia modesta Hook. (2n = 2x = 22), and Sandersonia aurantiaca Hook. (2n = 2x = 24), were subjected to genomic in situ hybridization (GISH) analysis in order to clarify their genome constitutions. Chromosome preparation was made from root tip cells of L. modesta × G. superba ??Lutea??, L. modesta × S. aurantiaca, S. aurantiaca × G. superba ??Lutea??, L. modesta × G. ??Marron Gold??, S. aurantiaca × G. ??Marron Gold?? and G. ??Verschild?? × S. aurantiaca. Total DNA of one parent was labeled with digoxigenin or biotin and used as probe, and chromosomes were counterstained with 4??-6-diamidono-2-phenylindole (DAPI). For all the nine intergeneric hybrids, chromosomes from each parent could be clearly distinguished by GISH analysis. Thus GISH analysis is a powerful tool for identifying the genome constitution of intergeneric hybrids in colchicaceous ornamentals. The results obtained by GISH analysis study may be important for further progress in breeding of colchicaceous ornamentals. 相似文献
10.
Masaharu MURATA Kotaro FUKUSHIMA Tomoka TAKAO Hiroyuki SEKI Satoru TAKEDA Norio WAKE 《The Journal of reproduction and development》2013,59(1):7-13
Oxidative stress has been recognized as an important factor in the pathophysiology of
preeclampsia. It has been reported that the expression of xanthine oxidase (XO) in the
cytotrophoblast and plasma hydrogen peroxide (H2O2) level are
significantly higher in preeclamptics than in control women. The aim of this study was to
clarify the biological influence of reactive oxygen species (ROS) produced by XO on
extravillous trophoblast (EVT) cells. TCL1 cells, a human immortalized EVT cell line, were
incubated with xanthine and XO (X/XO). We then measured the cell number, urate level of
the culture media and the apoptotic cell ratio. Similar experiments were performed with
additional administration of allopurinol, catalase, L-NAME or D-NAME, and with
administration of H2O2 in substitution for X/XO. We assessed the
effects of H2O2 on invasion ability, tube-like formation and protein
expression of HIF1A and ITGAV of TCL1. Finally, the apoptotic cell ratio using primary
cultured trophoblasts was measured following exposure to H2O2. X/XO
decreased the relative cell number and increased the urate level and apoptotic cell ratio
significantly. Elevation of the urate level and apoptotic cell ratio was attenuated by
allopurinol and catalase, respectively. L-NAME and D-NAME had no influence on these
effects. H2O2 also decreased the relative cell number. Pretreatment
with H2O2 significantly inhibited the invasion ability, tube-like
formation and HIF1A and ITGAV of TCL1. H2O2 also induced apoptosis
in primary cultured trophoblasts. In conclusion, ROS produced by XO induced apoptosis and
affected EVT function including invasion and differentiation. 相似文献