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排序方式: 共有1392条查询结果,搜索用时 15 毫秒
1.
Hidekatsu Yamazaki Wataru Aoyama Eiji Masunaga Mamoru Tanaka 《Aquaculture Research》2019,50(4):1107-1116
A field campaign was conducted around salmon cages, using a combination of a towed ADCP and a free‐fall multi‐parameter profiler, in order to investigate flow structures and the possible distribution of effluent materials. Two transect observations showed that hydrographic conditions changed dramatically within 5 days, from highly stratified open water conditions to weak stratification. Three‐dimensional observation revealed that flow was blocked behind the cages and that the blockage was reduced as the distance from the cages increased. The flow speed was positively correlated with the intensity of the backscattering signal. The R2 value was high immediately behind the cages and decreased with distance from the cages. The flow time series behind the cages exhibited a k–2 power law spectrum that was consistent with a typical internal wave spectrum. This suggests that eddies shed from the cages were highly influenced by stratification. We estimated the rate of kinetic energy dissipation, , from YODA Profiler data based on the Thorpe scale approach. We also estimated the eddy diffusivity coefficient, . Both and followed a lognormal probability density function. The mean was consistent with a one‐dimensional diffusion model assessed from the R2 values of flow speed and backscatter intensity. 相似文献
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Nor Zulkiply Amalina Zulperi Dzarifah Mohammad Noor Azmai Amal Mohd Termizi Yusof Mohd Zamri‐Saad Nurhidayu Al‐saari Mami Tanaka Sayaka Mino Tomoo Sawabe Md Yasin Ina‐Salwany 《Aquaculture Research》2019,50(11):3202-3210
Vibrio infections are common among marine fish and lead to serious problems in the aquaculture sector. This study reports a recent occurrence of Vibrio species (spp.) isolated from cultured groupers in Peninsular Malaysia using the gyrB and pyrH genes. A total of 147 Vibrio strains were successfully isolated from 77 (64%) groupers using culture method and subjected to gyrB and pyrH sequencing for species identification and confirmation. Results showed that 89% of Vibrio strains were identified and clustered to six groups of Vibrio spp., while 11% were not clustered to any Vibrio spp. using the gyrB sequences. Meanwhile, by analysis of the pyrH sequences all the 147 Vibrio strains (100%) were successfully identified and clustered into 11 groups of Vibrio spp., including the gyrB non‐identified strains. The pyrH gene provides a better resolution for identification of Vibrio spp. compared with the gyrB gene. Thus, the pyrH gene was more suitable for a rapid determination of Vibrio spp. distribution in Peninsular Malaysia. Using the pyrH gene, our study found higher prevalence of Vibrio vulnificus (33%), V. alginolyticus (24%) and V. parahaemolyticus (22%), followed by V. rotiferianus (5%), V. harveyi (3%), V. tubiashii (2%), V. campbellii (2%), V. ponticus (1%), V. diabolicus (1%), V. owensii (1%) and others Vibrio sp. (7%). Thus, the results of this study revealed that the occurrence of pathogenic vibrios among grouper fish is still high in Malaysian aquaculture. In addition, the pyrH gene was proved as a suitable marker for rapid identification of Vibrio species compared with the gyrB gene. 相似文献
4.
Tanaka Tatsuya Ikeda Ryunosuke Yuta Yuta Tsurukawa Kanji Nakamura Satoshi Yamaguchi Takeharu Komeyama Kazuyoshi 《Fisheries Science》2019,85(6):1037-1043
Fisheries Science - In aquaculture, periodic measurement of fish body size is required to suitably assess growth progress. The aim of this study is to monitor the growth of free-swimming red sea... 相似文献
5.
S. Tanaka S. Suzuki T. Teshima R. Yamashita Y. Hamamoto Y. Hara 《The Journal of small animal practice》2023,64(2):111-117
An 8.0-kg 8-year-old male dachshund was presented for surgical treatment of suspected pituitary-dependent hyperadrenocorticism with portal vein thrombosis. Advanced diagnostic imaging revealed a thrombus in the splenic and portal veins. For the portal vein thrombus, CT angiography showed an enhanced timing delay in the lateral right and caudate liver lobes. Blood tests showed a marked increase in the liver panel, including total bile acid. Brain MRI revealed a pituitary mass, suggesting pituitary-dependent hyperadrenocorticism. The mass was completely resected. The preoperative antithrombotic therapy of rivaroxaban (0.66 mg/kg, PO, once per day) and clopidogrel sulphate (1.66 mg/kg, PO, once per day) was continued postoperatively. Six months after resection of the pituitary mass, the thrombus had disappeared. Further studies are required to prove a causal association between the disappearance of the thrombus and the treatments provided. 相似文献
6.
Ayano OMURA Wataru ANZAI Daisuke KOYABU Hideki ENDO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(9):1043-1048
Clarification of the trunk structure in Urodela is important in understanding the
locomotive evolution of basal tetrapods. The components of the muscular trunk wall among
Urodela using different modes of locomotion were compared. Since the whole trunk may be
used for swimming and the effect of limbs may be small in the more aquatic species, they
showed smaller differences in the trunk muscles among anterior, middle and posterior
sections of the trunk. By contrast, in the more terrestrial species, the dorsal and
abdominal muscles are larger in the middle section than those in the anterior and
posterior sections. High compressive stresses occur in the supporting limbs and their
insertion at the trunk on the ventral side, and spread from the forelimbs along the back
to the supporting hindlimbs on the dorsal side. Tensile stresses occur in the middle
ventral part. The components of the trunk muscles among the three sections may reflect
differences in stresses occurring in the trunk of the more terrestrial species. The
findings also suggest that in the middle section, larger dorsal muscles for stiffening the
back to maintain posture and larger abdominal muscles are responsible for balancing the
body weight while it is supported by the limbs in the more terrestrial species. 相似文献
7.
Kent MORI Satoshi SUZUKI Daisuke KOYABU Junpei KIMURA Sung-Yong HAN Hideki ENDO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(5):571-578
Although the sea otter (Enhydra lutris) is a complete aquatic species,
spending its entire life in the ocean, it has been considered morphologically to be a
semi-aquatic animal. This study aimed to clarify the unique hindlimb morphology and
functional adaptations of E. lutris in comparison to other Mustelidae
species. We compared muscle mass and bone measurements of five Mustelidae species: the sea
otter, Eurasian river otter (Lutra lutra), American mink
(Neovison vison), Japanese weasel (Mustela itatsi) and
Siberian weasel (M. sibirica). In comparison with the other 4 species,
E. lutris possessed significantly larger gluteus, popliteus and
peroneus muscles, but smaller adductor and ischiopubic muscles. The popliteus muscle may
act as a medial rotator of the crus, and the peroneus muscle may act as an abductor of the
fifth toe and/or the pronator of the foot. The bundles of the gluteus superficialis muscle
of E. lutris were fused with those of the tensor fasciae latae muscle and
gluteofemoralis muscles, and they may play a role in femur abduction. These results
suggest that E. lutris uses the abducted femur, medially rotated crus,
eversion of the ankle and abducted fifth digit or extended interdigital web as a powerful
propulsion generator. Therefore, we conclude that E. lutris is a complete
aquatic animal, possessing differences in the proportions of the hindlimb muscles compared
with those in other semi-aquatic and terrestrial mustelids. 相似文献
8.
Anna Kakehashi Akihiro Hagiwara Norio Imai Min Wei Shoji Fukushima Hideki Wanibuchi 《Journal of toxicologic pathology》2015,28(1):27-32
In the present study, in continuation of our previous experiment in order to investigate the mode of action (MOA) of ethyl tertiary-butyl ether (ETBE) hepatotumorigenicity in rats, we aimed to examine alterations in cell proliferation, that are induced by short-term administration of ETBE. F344 rats were administered ETBE at doses of 0, and 1,000 mg/kg body weight twice a day by gavage for 3, 10, 17 and 28 days. It was found that the previously observed significant increase of P450 total content and hydroxyl radical levels after 7 days of ETBE administration, and 8-OHdG formation at day 14, accompanied by accumulation of CYP2B1/2B2, CYP3A1/3A2, CYP2C6, CYP2E1 and CYP1A1 and downregulation of DNA oxoguanine glycosylase 1, was preceded by induction of cell proliferation at day 3. Furthermore, we observed an increase in regenerative cell proliferation as a result of ETBE treatment at day 28, followed by induction of cell cycle arrest and apoptosis by day 14. These results indicated that short-term administration of ETBE led to a significant early increase in cell proliferation activity associated with induction of oxidative stress, and to a regenerative cell proliferation as an adaptive response, which could contribute to the hepatotumorigenicity of ETBE in rats. 相似文献
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10.
Summary Structural factors in a Pinus densiflora tree grown under the influence of strong wind were measured. No
difference for cellulose molecules was noticed between compression and opposite wood, but the
was somewhat lower in the region where the compression wood was concentrated. The degree of crystallinity of cellulose was 45–50% in compression wood, about 50% in normal wood, and 50–60% in opposite wood. The crystallinity decreased with increasing height above the ground. The maximum point of crystallographic b-axis (fiber axis) orientation distribution for cellulose crystallites in compression wood was located at 30°, in normal wood at 25° and in opposite wood at 0°. The cellulose crystallite dimension in the transverse direction was 3.2 nm, corresponding to four cellulose unit cells, a value that was almost constant throughout the wood. In the longitudinal direction, there were large differences in cellulose crystallite dimensions between compression and opposite woods. In compression wood the cellulose crystallite dimensions was 12 nm corresponding to 11–12 cellulose unit cells. In opposite wood it was 17–32.5 nm corresponding to 17–32 cellulose unit cells. These structural factors were apparently affected by the environmental conditions, and the mechanical properties of the wood were influenced by these factors. Opposite wood had longer crystallites, a higher degree of crystallinity and a better orientation distribution of cellulose crystallites in the longitudinal direction. Compression wood, on the other hand, had shorter crystallites, a lower degree of crystallinity and a large angle between the stem and the direction of the crystallites. 相似文献