Toxicogenomic analysis of immune system-related genes in Japanese flounder (Paralichthys olivaceus) exposed to heavy oil     

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   

Effects of heavy oil in the developing spotted halibut, Verasper variegatus     

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   

Unusual behavior of the Kuroshio Current System from winter 1996 to summer 1997 revealed by ADEOS-OCTS and other data— Suggestion of topographically forced alternating-jet instability     

Yoshiaki Toba  Hiroshi Murakami 《Journal of Oceanography》1998,54(5):465-478

While the Advanced Earth Observing Satellite (ADEOS) was operating, the Kuroshio and the Kuroshio Extension, or the Kuroshio Current System, exhibited unusual behavior from the winter of 1996 to the summer of 1997. This behavior of the Kuroshio Current System has been closely studied using a time series of satellite observation images of SST and ocean color obtained by ADEOS-OCTS, reinforced by SST images obtained by NOAA-AVHRR. Our findings include (i) a long lasting, very southerly path of the Kuroshio Extension; (ii) a Kuroshio path very distant from Japan with the following alternating-jet-like north-south flow pattern of the Kuroshio Extension, which occurred twice, once in February and once in April 1997, as independent events and which was observed to be affected by the bottom topography of the Izu-Ogasawara Ridge and Trench, and of the Japan Trench; (iii) cutting off of a cold water mass after the February event; and (iv) the formation of a vortex pair after the April event. A new mechanism is suggested for the formation of the alternating-jet flow pattern: a topographically forced alternating-jet instability (AJI). An SST-Chlorophyll Diagram (T-Chl Diagram) generated using simultaneous data from a single satellite is useful for analyzing the water mass structure of this region, including biological processes.  相似文献   

Age of the Solomon Sea Basin from magnetic lineations     

Masato Joshima  Yoshihisa Okuda  Fumitoshi Murakami  Kiyoyuki Kishimoto  Eiichi Honza 《Geo-Marine Letters》1987,6(4):229-234

Magnetic anomalies measured in the central to western half of the Solomon Sea, when considered with other magnetic data, reveal the existence of linear patterns. Magnetic lineation anomaly models of the Cenozoic, 65 to 0 Ma, suggest that an age between 34 and 28 Ma and a half-rate spreading speed of 5.8 cm/yr for the northern flank of a former spreading center best fits our present magnetic data in the Solomon Sea Basin. Heat flow and bathymetry data support this preferred model.  相似文献   

T_BB资料揭示的亚澳季风区季节转换及亚洲夏季风建立的特征   总被引：2，自引：0，他引：2  

何金海  朱乾根  M. Murakami 《热带气象学报》1996,12(1):34-42

发展了一个用于台风路径预报的初始场人造台风方案。该方案除包含对称台风环流外,也考虑了非对称风的作用。使用双向移动套网格模式作的试验预报结果表明,初始场中引入人造台风后能明显提高径预报的水平。  相似文献   

NATURE OF PRECIPITATION AND ACTIVITY OF CUMULUS CONVECTION DURING THE 1991 MEIYU SEASON OF CHANGJIANG-HUAIHE RIVER BASIN          下载免费PDF全文

陆尔  丁一汇 《Acta Meteorologica Sinica》1998,(1)

Seasonal variability regarding the nature of precipitation and the activity of cumulus convectionduring the 1991 Meiyu season of Changjiang-Huaihe River Basin(Jianghuai)has been investigatedby calculating apparent heat source/apparent moisture sink and analyzing TBB(cloud-topblackbody radiation temperature)data.It is found that three periods of strong ascending motionduring the Meiyu season lead to three episodes of heavy rain,and the latent heat due to theprecipitation is of the sole heat source of the atmosphere.The nature of precipitation showsdistinct seasonal variability,from frontal precipitation of the first episode to the extremely strongconvective precipitation of the third episode.TBB field of East Asia may well reflect not only theintensity of convection and rainfall,but also the movement of rain belt and convection belt.In thewhole Meiyu season.convection belt mainly stays in Jianghuai.but may shift within the domain ofEast Asia.Its locating in Jianghuai or not determines the maintenance or break of Meiyu.In thethird episode,the narrow convection belt over Jianghuai is mainly caused by southwest monsoonwhich takes moist and convective atmosphere from tropical ocean.  相似文献   

Data assimilation using the particle filter for identifying the elasto‐plastic material properties of geomaterials     

Akira Murakami  Takayuki Shuku  Shin‐ichi Nishimura  Kazunori Fujisawa  Kazuyuki Nakamura 《国际地质力学数值与分析法杂志》2013,37(11):1642-1669

A computational method, incorporating the finite element model (FEM) into data assimilation using the particle filter, is presented for identifying elasto‐plastic material properties based on sequential measurements under the known changing traction boundary conditions to overcome some difficulties in identifying the parameters for elasto‐plastic problems from which the existing inverse analysis strategies have suffered. A soil–water coupled problem, which uses the elasto‐plastic constitutive model, is dealt with as the geotechnical application. Measured data on the settlement and the pore pressure are obtained from a synthetic FEM computation as the forward problem under the known parameters to be identified for both the element tests and the ground behavior during the embankment construction sequence. Parameter identification for elasto‐plastic problems, such as soil behavior, should be made by considering the measurements of deformation and/or pore pressure step by step from the initial stage of construction and throughout the deformation history under the changing traction boundary conditions because of the embankment or the excavation because the ground behavior is highly dependent on the loading history. Thus, it appears that sequential data assimilation techniques, such as the particle filter, are the preferable tools that can provide estimates of the state variables, that is, deformation, pore pressure, and unknown parameters, for the constitutive model in geotechnical practice. The present paper discusses the priority of the particle filter in its application to initial/boundary value problems for elasto‐plastic materials and demonstrates a couple of numerical examples. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Evaluation of ADEOS-II GLI ocean color atmospheric correction using SIMBADA handheld radiometer data     

Hajime Fukushima  Mitsuhiro Toratani  Hiroshi Murakami  Pierre-Yves Deschamps  Robert Frouin  Akihiko Tanaka 《Journal of Oceanography》2007,63(3):533-543

The performance of the “version 2” Global Imager (GLI) standard atmospheric correction algorithm, which includes empirical absorptive aerosol correction and sun glint correction, was evaluated using data collected with handheld above-water SIMBADA radiometers during 23 cruises of opportunity (research vessels, merchant ships), mostly in the North Atlantic and European seas. A number of 100 match-up data sets of GLI-derived and SIMBADA-measured normalized water-leaving radiance (nL _W ) and aerosol optical thickness (AOT) were sorted out, using objective selection criteria, and analyzed. The Root-Mean-Square (RMS) difference between GLI and SIMBADA nL _W was about 0.32 μW/cm²/nm/sr for the 412 nm band, showing improvement by 30% in RMS difference with respect to the conventional “version 1” GLI atmospheric correction algorithm, and the mean difference (or bias) was reduced significantly. For AOT, the RMS difference was 0.1 between GLI estimates and SIMBADA measurements and the bias was small (a few 0.01), but the ?ngstr?m exponent was systematically underestimated, by 0.4 on average, suggesting a potential GLI calibration offset in the near infrared. The nL _W differences were not correlated to AOT, although performance was best in very clear conditions (AOT less than 0.05 in the 865 nm band). Despite the relatively large scatter between estimated and measured nL _W , the derived chlorophyll-a concentration estimates, applying the same ratio algorithm (GLI OC4V4) to GLI and SIMBADA, were consistent and highly correlated in the range of 0.05–2 μg/l. The large variability in chlorophyll-a concentration estimate for clear clean water areas (e.g. with the concentration range lower than about 0.05 μg/l) turns out to be due to the nature of the “band ratio” based in-water algorithm.  相似文献   

Future changes in tropical cyclone activity in the North Indian Ocean projected by high-resolution MRI-AGCMs     

Hiroyuki Murakami  Masato Sugi  Akio Kitoh 《Climate Dynamics》2013,40(7-8):1949-1968

New and previous versions of the high-resolution 20- and 60-km-mesh Meteorological Research Institute atmospheric general circulation models are used to investigate potential future changes in tropical cyclone (TC) activity in the North Indian Ocean (NIO). Fifteen ensemble experiments are performed under the International Panel on Climate Change A1B scenario. Most of the ensemble future (2075–2099) experiments do not project significant future changes in the basin-scale TC genesis number; however, they commonly show a substantial increase (by 46 %) in TC frequency over the Arabian Sea and a decrease (by 31 %) in the Bay of Bengal. Projected future changes in TC genesis frequency show a marked seasonal variation in the NIO: a significant and robust reduction during the pre-monsoon season, an increase during the peak-monsoon season, and a westward shift during the post-monsoon season. Several large-scale thermodynamic and dynamical parameters are analysed to elucidate the physical mechanism responsible for the future changes in TC activity; this analysis reveals a seasonal dependence of the relative contribution of these parameters to the projected future changes in TC genesis frequency.  相似文献   

Study of a Bistatic Radar System Using VLBI Technologies for Detecting Space Debris and the Experimental Verification of its Validity   总被引：1，自引：0，他引：1  

Masanobu Yajima  Kazutomo Tsuchikawa  Toshiyuki Murakami  Kazuyoshi Katsumoto  Tadashi Takano 《Earth, Moon, and Planets》2007,100(1-2):57-76

Space debris are increasing around the Earth. The observation of space debris is a key issue for the investigation and monitoring of space environment. But the observation opportunities and the detection ability are limited in existing monostatic radar systems. This paper proposes a bistatic radar which is composed of a transmitting station and a receiving-only station. A carrier wave modulated by PN-PSK signals is used in combination with a VLBI (Very Long Baseline Interferometry) recorder for range measurement between space debris and stations. The receiving radio wave is processed on the basis of VLBI techniques. Accordingly, the system is shown to have significant advantages over a monostatic radar. We actually formed a bistatic radar system, and observed a satellite in order to experimentally verify the validity. The configuration of the system, data analysis and the experimental results are described.  相似文献