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21.
Murakami Y Kitamura S Nakayama K Matsuoka S Sakaguchi H 《Marine pollution bulletin》2008,57(6-12):524-528
It is well known that heavy oil (HO) on the sea surface causes serious problems in the aquatic environment. In particular, some species of teleosts which develop on the sea surface are thought to be affected by the HO which flows out from tankers or coastal industry. However, the toxicological effects of HO are not fully understood. We performed exposure experiments using the Pleuronectiformean fish, spotted halibut (Verasper variegatus), which is an important fishery resource in Japan. In course of the development, HO-exposed embryos showed remarkable delay in developmental processes including somite formation. We further observed abnormal development of the head morphology. Notably, treated embryos had relatively small eyes and craniofacial structures. These findings strongly suggest that HO seriously affects the cell proliferation and differentiation of the embryo. In addition, HO-exposed embryos showed abnormal neuronal development. We also performed the exposure in the larval stage. Treatment of post-hatching larvae with HO resulted in significantly greater mortality compared with controls. Through these observations, we finally conclude that HO is strongly toxic to halibut in their early life stages. 相似文献
22.
Nakayama K Kitamura S Murakami Y Song JY Jung SJ Oh MJ Iwata H Tanabe S 《Marine pollution bulletin》2008,57(6-12):445-452
Heavy oil contamination is one of the most important environmental issues. Toxicities of polycyclic aromatic hydrocarbons (PAHs), including immune toxicities, are well characterized, however, the immune toxic effects of heavy oil, as a complex mixture of PAHs, have not been investigated. In the present study, we selected Japanese flounder (Paralichthys olivaceus) as a model organism, and observed alteration of immune function by the exposure to heavy oil. To analyze the expression profiles of immune system-related genes, we selected 309 cDNAs from our flounder EST library, and spotted them on a glass slide. Using this cDNA array, alteration of gene expression profiles was analyzed in the kidneys of flounders exposed to heavy oil. Six Japanese flounders (mean body weight: 197 g) were acclimated to laboratory conditions at 19-20 degrees C. Three fish were exposed to heavy oil C (bunker C) at a concentration of 3.8 g/L for 3 days, and the others were kept in seawater without heavy oil and used as the control. After the exposure period, the fish were transferred into control seawater and maintained for 4 days, and then they were dissected and their kidneys were removed. Total RNA was extracted from the kidney samples to use in gene expression analyses. The microarray detected alteration of immune system-related genes in the kidneys of heavy oil-exposed flounders, including down-regulation of immunoglobulin light chain, CD45, major histocompatibility complex class II antigens and macrophage colony-stimulating factor precursor, and up-regulation of interleukin-8 and lysozyme. These results suggest that pathogen resistance may be weakened in heavy oil-exposed fish, causing a subsequent bacterial infection, and then proinflammatory genes may be induced as a defensive response against the infection. Additionally, we found candidate genes for use as biomarkers of heavy oil exposure, such as N-myc downstream regulated gene 1 and heat shock cognate 71 kDa proteins. 相似文献
23.
Yasunori Murakami Shin-Ichi Kitamura Kei Nakayama Satoru Matsuoka Hideo Sakaguchi 《Marine pollution bulletin》2008,57(6-12):524
It is well known that heavy oil (HO) on the sea surface causes serious problems in the aquatic environment. In particular, some species of teleosts which develop on the sea surface are thought to be affected by the HO which flows out from tankers or coastal industry. However, the toxicological effects of HO are not fully understood. We performed exposure experiments using the Pleuronectiformean fish, spotted halibut (Verasper variegatus), which is an important fishery resource in Japan. In course of the development, HO-exposed embryos showed remarkable delay in developmental processes including somite formation. We further observed abnormal development of the head morphology. Notably, treated embryos had relatively small eyes and craniofacial structures. These findings strongly suggest that HO seriously affects the cell proliferation and differentiation of the embryo. In addition, HO-exposed embryos showed abnormal neuronal development. We also performed the exposure in the larval stage. Treatment of post-hatching larvae with HO resulted in significantly greater mortality compared with controls. Through these observations, we finally conclude that HO is strongly toxic to halibut in their early life stages. 相似文献
24.
The distribution of aluminum (Al) in seawater has been investigated in the continental slope and the Okinawa Trough areas
of the East China Sea, which is one of the marginal seas in the western North Pacific Ocean. Aluminum concentration in waters
over the slope and the Trough ranged from 5.6 to 25 nmol/kg in the surface layer (0–100 m), and had a minima of 1.1 nmol/kg
between 400 and 500 m depth and ranged from 1.3 to 9.7 nmol/kg in the deep or bottom waters. Aluminum values were higher than
in the surface waters of the central North Pacific, while minimum values were similar to levels in the intermediate or deep
waters of the central North Pacific, except for the bottom water over the slope. This suggests that the high Al concentration
in the surface reflects the large atmospheric input of Asian dust around the western side of the North Pacific region. On
the continental slope, Al concentrations in the upper 500 m depth decreased slopeward. This horizontal gradient of Al can
be explained from the combination of dilution by upwelling of Al-poor water originated from the North Pacific Intermediate
Water (NPIW) which intrudes into the mid-depth of the Okinawa Trough and the scavenging of Al by biogenic particles in the
continental slope zone. 相似文献
25.
Yasunori Nejoh 《Astrophysics and Space Science》1992,198(2):309-319
We derive a mixed modified Korteweg-de Vries (MK-dV) equation from a semi-relativistic ion acoustic wave with hot ions by the fluid approximation. The positive cubic nonlinearity of the mixed MK-dV equation give rise to the periodic progressive waves and the algebraic solitary waves. The periodic wave bears a series of solitary pulses, and the algebraic solitary wave reduces the rarefactive solitary wave in the limit of the particular boundary condition. These nonlinear wave modes explain, respectively, the periodic pulse of the potential and the rarefactive solitary wave of the fine structure observed in space. 相似文献
26.
Feeding Habits of the Mesopelagic Fish Gonostoma gracile in the Northwestern North Pacific 总被引:1,自引:0,他引:1
The diet of Gonostoma gracile, a numerically abundant mesopelagic fish in the Subtropical Region and the Transition Domain of the northwestern North Pacific,
was examined using 520 specimens collected during June–July 1988, June 1995 and November 1995. The prey included mainly copepods,
ostracods, amphipods and euphausiids. Copepods and ostracods were the most abundant, comprising approximately 70% of the total
diet. There was little evidence of an ontogenetic dietary shift; Pleuromamma copepods were the most abundant prey for all size classes of fish ranging from 19 to 116 mm in standard length. The size
range of prey increased with growth, but all fish sizes examined fed mainly on 1–4 mm long prey. Luminescent copepods and
ostracods were the most abundant prey, suggesting that G. gracile detects its prey visually.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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28.
基于银因其具有良好的广谱抗茵活性和低毒性而在医学方面有着较为广泛的应用,对银离子(硝酸银)和含银不锈钢的抗茵活性进行了初步研究。实验结果表明,在10^6CFu/mL的初始接种浓度下,银离子对枯草杆菌、大肠杆菌和假单胞茵的最小抑茵质量浓度和最小杀菌质量浓度分别为2,6,8mg/L和2,8,10mg/L。大肠杆菌经8mg/L的银离子处理2h后,有99.9%以上的细菌被破坏。含银不锈钢也表现了较强的抗菌性能。在普通的、银合金和银涂层的sus304不锈钢表面附着的单层生物膜浸泡在PBS溶液中3d后,经CFDA-DAPI双染色和荧光显微镜观察计数获得的假单胞菌的平均存活率为98.0%,38.5%和15.1%。 相似文献
29.
Heavy oil exposure induces high moralities in virus carrier Japanese flounder Paralichthys olivaceus
The relationship between chemical exposure and disease outbreak in fish has not been fully defined due to the limitations of experimental systems (model fish and pathogens). Therefore, we constructed a system using the Japanese flounder, Paralichthys olivaceus, and viral haemorrhagic septicemia virus (VHSV), and evaluated it by heavy oil (HO) exposure. The fish were exposed to HO at 0.3, 0.03, 0.003, and 0 g/L following VHSV infection at doses of 10(2.5) or 10(3.5) tissue culture infectious dose (TCID)50/fish. As a result, groups given the dual stressors showed more than 90% mortality. Although VHSV infection at 10(2.5) and 10(3.5) TCID50/fish without HO exposure also induced high mortality, at 68.8% and 81.3%, respectively, HO exposure induced faster and higher mortality in the virus carrier fish, indicating that chemical stressors raise the risk of disease outbreak in fish. The experimental system established in this study could be useful for chemical risk assessment. 相似文献
30.
A Human Damage Prediction Method for Tsunami Disasters Incorporating Evacuation Activities 总被引:1,自引:0,他引:1
This study presents a tsunami human damage prediction method employing numerical calculation and GIS (Geographical Information System) for Usa town, Tosa City, Shikoku Island, Japan. Sometime near the end of the first half of the twenty-first century, a huge earthquake is predicted to occur along the Nankai trough and costal areas facing the Pacific ocean of Shikoku Island. Much damage due to the resultant tsunamis will be caused, therefore, it is necessary to predict the extent of human damage for every town in high-risk areas.The number of tsunami victims was estimated by population in areas of maximum inundation. The number of deaths as a result of tsunami was estimated by a method which employed accumulated death toll of every area in terms of time and space, taking into account consideration of time necessary to begin to seek refuge after an earthquake, tsunami inundation depth on land, flow velocity and evacuation speed. As a result of this study a rapid decrease in death toll by early evacuation was shown quantitatively for the first time.Thus, with the method presented here, it is possible to estimate the extent of tsunami human damage on coastal regions, and may be useful as a tsunami human damage countermeasure. 相似文献