Organochlorine contamination in some odontoceti species from the North Pacific and Indian Ocean     

Maricar Prudente  Shinsuke Tanabe  Mafumi Watanbe  Annamalai Subramnian  Nobuyuki Miyazki  Pauline Suarez  Ryo Tatsukawa 《Marine environmental research》1997,44(4):415-427

Concentrations of persistent organochlorines were determined in the blubber and melon of 11 species of adult male odontocetis collected from the North Pacific, Indian Ocean and nearby seas. Mean concentrations of DDs (33 μg/g wet wt) were the highest followed by PCBs (32 μg/g wet wt), chlordane compounds (CHLs: 3.7 μg/g wet wt), HCHs (1.1 μg/g wet wt), and HCB (0.32 μg/g wet wt). Odontoceti species inhabiting temperate waters revealed maximum residual concentrations of these contaminants, and the elevated DDT and PCB residues detected seem to suggest that some of the present species might potentially be at high risk. Relatively high DDT concentrations were found in tropical water species, which could be attributed to the current usage of DDT in the tropics and the less movable nature of this compound via long-range atmospheric transport. The HCH levels in animals inhabiting cold and temperate waters were higher than those inhabiting tropical waters, a result that was perhaps reflective of atmospheric transport from the tropical source to the northern sinks. A similar pattern was also observed in PCBs, CHLs and HCB, probably indicating the ongoing discharge of these compounds from mid-latitudes as well as those originating in tropical regions.  相似文献   

cDNA cloning of an aryl hydrocarbon receptor from Baikal seals (Phoca sibirica)     

Kim EY  Hahn ME  Iwata H  Tanabe S  Miyazaki N 《Marine environmental research》2002,54(3-5):285-289

Species differences in sensitivity to related planar halogenated aromatic hydrocarbons (PHAH) add significant uncertainty in assessing the ecological risk to aquatic mammals. To investigate mechanisms of PHAH sensitivity in aquatic mammals, we cloned and sequenced the cDNA of Baikal seal aryl hydrocarbon receptor (AHR), an intracellular protein that initiates PHAH-mediated effects. The Baikal seal AHR cDNA has an open reading frame of 843 amino acid residues with a predicted molecular mass of 94.6 kDa. Comparison of AHR amino acid sequences indicated a high degree of sequence conservation (98%) between Baikal and harbor seals. The high conservation of AHRs between Baikal and harbor seals indicates that these seals express AHR proteins closely related structurally. In our previous report (Kim & Hahn, 2002), the dioxin-binding affinity of the harbor seal AHR was at least as high as that of the AHR from a dioxin-sensitive strain of mice, suggesting that this seal species may be sensitive to PHAH effects. This implies that Baikal seal may also be sensitive to dioxin effects.  相似文献   

Vertical transport and residence time of chlorinated hydrocarbons in the open ocean water column     

Shinsuke Tanabe  Ryo Tatsukawa 《Journal of Oceanography》1983,39(2):53-62

The vertical transport of PCBs and chlorinated hydrocarbon pesticides such as DDT compounds and HCH (BHC) isomers in the deep sea are discussed on basis of their vertical profiles and the proportion of their adsorbed and dissolved fractions in surface water surveyed in the Western Pacific, Eastern Indian and Antarctic Oceans.All chlorinated hydrocarbons determined were detected with measurable concentrations throughout the water column, even at depths of several thousand meters. The vertical distributions of PCBs and DDT compounds were found to show small variations in concentration throughout the water column, whereas HCH isomer concentrations decreased systematically with depth. A large portion of DDT compounds in surface water was adsorbed on suspended solids, while most of the HCH isomers were present in the filtered water. The proportion of PCBs adsorbed on suspended solids was smaller than the proportion of DDT compounds, but was much greater than that of HCH isomers. These observations suggest that HCH isomers have been slowly scavenged from the surface to the deeper layers in the water column, while PCBs and DDT compounds have been rapidly and abundantly transported downward by sinking particles.The percentages of chlorinated hydrocarbons adsorbed on suspended solids in surface water increased towards the high latitude locations, and the percentage seemed to be proportional to the concentration of suspended solids in the surface water. This implies that the residence time of chlorinated hydrocarbons in the water column will differ significantly among oceans that differ in primary productivity. According to our estimation based on the data presented in this study, the residence time ofHCH in the euphotic zone, the top 100 m of the water column, is more than 2 years, whereas those of PCBs andDDT are less than 1 year. The longest residence time, of from 5 to 10 years, was obtained forHCH in oligotrophic water of the western North Pacific. The shortest value, only 11 to 19 days, was estimated forDDT in the Antarctic Ocean.  相似文献   

Butyltin concentrations along the Japanese coast from 1997 to 1999 monitored by Caprella spp. (Crustacea: Amphipoda)     

Takeuchi I  Takahashi S  Tanabe S  Miyazaki N 《Marine environmental research》2004,57(5):397-414

The concentrations of butyltins along the Japanese coastline were investigated from 1997 to 1999, 7 to 9 years after implementation of legislation limiting the use of tributyltin (TBT) in Japan. Seawater was sampled at 0.5 m depth, and Caprella spp. were collected from Sargassum spp. and aquaculture facilities from 18 areas within four broad areas along the coastline of Japan, i.e., the Pacific coast of northern Japan, the coast along the Sea of Japan, Tokyo Bay and adjacent areas, and western Japan. Butyltins (MBT, DBT and TBT) were detected in 32 of the 63 seawater samples with average concentrations of 4.6 ng MBT/l, 4.5 ng DBT/l and 6.8 ng TBT/l, respectively. Butyltin concentrations in seawater from western Japan indicate "hot spots" even in unpopulated areas. Butyltins (MBT, DBT and TBT) were detected in all samples of Caprella spp., varying from 2.3 ng BTs /g wet wt in C. penantis R-type from Tobishima Island in the Sea of Japan to 464 ng BTs /g wet wt in C. decipiens Mayer from Amakusa, western Kyushu. The BT concentrations in Caprella spp. form western Japan were significantly higher than those from other areas, including Tokyo Bay and adjacent areas, where large scale industry and international ports are located. These results indicate that butyltin contamination still remains even in unpopulated areas after the regulation on TBT usage, and that the regulation governing TBT usage since 1990 has not been effective enough to concede recovery of shallow water ecosystems around Japan.  相似文献   

Joule heating and temperature in the upper atmosphere     

Susumu Kato 《Planetary and Space Science》1962,9(12):939-946

Joule heating has been shown to be very effective in increasing electronic temperature in the upper atmosphere. It is found theoretically that the electronic temperature can rise up to several thousands °K soon after certain ionospheric current disturbances occur, while the temperature of neutral particles increases only very slowly. Temperatures in various conditions have been computed and are found to be compatible with observation. It is also possible that the high electronic temperatures may explain the excitation of certain auroral glows.  相似文献   

Mechanical properties of cementitious sand and sand with small cyclic shear strain to assess aging effects on liquefaction     

Toyota  Hirofumi  Takada  Susumu 《Acta Geotechnica》2022,17(7):2825-2840

Liquefaction damage from earthquakes frequently indicates effects of sand aging on liquefaction resistance: Liquefaction damage in natural or aged reclaimed ground has been much less than that in young reclaimed ground. However, the mechanisms underlying aging effects remain unclear. Cementation and stress history of sand strongly influence aging effects: Cementation raises liquefaction resistance, whereas liquefaction history sometimes reduces liquefaction resistance. Small cyclic shear strain, from which the induced density change is almost negligible, was adopted as representing the stress history. To evaluate liquefaction resistance, initial shear modulus, and deformation characteristics of sand, we prepared specimens by adding cement and by applying a small cyclic shear strain. In cementitious sand, liquefaction resistance increased when cement contents exceeded 0.3% by mass. The initial shear modulus apparently increased at the same degree of cement addition as that which increased the liquefaction resistance. For sand with a small cyclic shear strain, the liquefaction resistance increased when the applied cyclic axial strain exceeded 0.01%. Application of small cyclic shear strain only slightly increased the initial shear modulus, but the linear elastic region tended to expand to greater shear strain. Shear properties of sand with small cyclic shear strain resembled those found for sand that had been consolidated for a long time.

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Contamination of Tris(4-Chlorophenyl) Methane and Tris(4-Chlorophenyl) Methanol in Marine Mammals from Russia and Japan: Body Distribution, Bioaccumulation and Contamination Status     

Mafumi Watanabe  Shinsuke Tanabe  Nobuyuki Miyazaki  Evgeny A. Petrov  Walter M. Jarman 《Marine pollution bulletin》1999,39(1-12):393-398

Four seal species (Phoca caspica, Phoca sibirica, Phoca hispida and Phoca largha) and one whale (Orcinus orca) from Russia and Japan were examined to determine the body distribution, bioaccumulation and contamination status of tris(4-chlorophenyl) methane (TCPMe) and tris(4-chlorophenyl) methanol (TCPMOH). Lipid normalized concentrations of TCPMe and TCPMOH were comparable in various organs and tissues, implying that their body distribution is followed to the lipid-dependent accumulation, similar to that for other organochlorines. The highest body burden of these compounds was found in the blubber. Bioaccumulation potential of TCPMe and TCPMOH was high and comparable to PCBs and DDTs. Relatively higher concentrations of TCPMe and TCPMOH were observed in Caspian seal than in other seal species examined. TCPMOH concentration in killer whale was the highest of the marine mammals examined. Another peak detected had similar mass spectrum to TCPMOH, however, at a different retention time, suggesting the presence of an isomer of TCPMOH.  相似文献   

Simulations of measures to control lava flows     

Eisuke Fujita  Masataka Hidaka  Akio Goto  Susumu Umino 《Bulletin of Volcanology》2009,71(4):401-408

We evaluated the quantitative effects of artificial barriers, water-cooling and guiding channels on lava flow using the lava simulation program LavaSIM. Lava flow is basically subject to the topography around the path, effusive rate and viscosity. To prevent damage due to lava flow, we conducted experiments in controlling the flow direction, velocity and temperature. The simulation demonstrated that artificial barriers can successfully change the direction of a lava flow and is more effective when placed nearly parallel to the flow direction at a point where the topography is not very steep, while a barrier placed perpendicular to the flow direction can only stop the flux temporarily, ultimately allowing the solidified crust to accumulate and causing the following mass to go over the barrier. The water-cooling trial was also effective in controlling the direction and temperature, although the amount of water was as much order as 10⁵ m³. The guiding channels successfully control the direction and inundated area but only in local areas.  相似文献   

Arsenic species and their accumulation features in green turtles (Chelonia mydas)     

Tetsuro Agusa  Kozue Takagi  Hisato Iwata  Shinsuke Tanabe   《Marine pollution bulletin》2008,57(6-12):782

Total arsenic (As) and its compounds were determined in liver, kidney, muscle, and stomach contents of green turtles (Chelonia mydas). Total As concentrations in the muscle were higher than those in the kidney and liver. Arsenobetaine (AB) was the predominant compound in all the three tissues and its levels were positively correlated with total As concentrations. This indicates that AB greatly contributes to As accumulation in green turtles. Higher concentrations of remaining As in the sample after extraction were detected in the liver, implying that lipid-soluble or protein bound As compounds accumulate in the liver of green turtles. Total As levels in tissues showed significant negative correlations with standard carapace length. The size-dependence of As accumulation in green turtles may be related to their feeding habit, shifting from carnivore to herbivore at different growth stages. Concentrations of AB and dimethylarsinic acid (DMA) were low in the stomach contents but high in the tissues, implying bioaccumulation of these arsenicals in green turtles.  相似文献   

Toxicogenomic analysis of immune system-related genes in Japanese flounder (Paralichthys olivaceus) exposed to heavy oil   总被引：1，自引：1，他引：0  

Kei Nakayama  Shin-Ichi Kitamura  Yasunori Murakami  Jun-Young Song  Sung-Ju Jung  Myung-Joo Oh  Hisato Iwata  Shinsuke Tanabe 《Marine pollution bulletin》2008,57(6-12):445

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 °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