Effects of polychlorinated biphenyls on liver function and sexual characteristics in Japanese medaka (Oryzias latipes)     

Nakayama K  Sei N  Handoh IC  Shimasaki Y  Honjo T  Oshima Y 《Marine pollution bulletin》2011,63(5-12):366-369

The effects of polychlorinated biphenyls (PCBs) on liver function and their differences between sexes were analyzed in Japanese medaka (Oryzias latipes) exposed to PCB126 or Kanechlor-400 (KC-400) using microarray. PCB exposure induced vitellogenin 1 expression in female medaka while suppressing choriogenin genes, which suggests that the effects of PCBs on estrogen-responsive genes do not occur directly through an estrogen receptor-mediated pathway. Reduction of androgen receptor alpha expression was also observed, and the gene expression pattern in PCB-exposed males changed to become more similar to that of females. Furthermore, changes in glycolysis-related genes indicate that PCB exposure might enhance glucose production via gluconeogenesis in the liver of medaka. Taken together, our results suggest that PCBs disrupt the endocrine system, especially androgen function, and may have the potential to cause demasculinizing effects. Additionally, induction of gluconeogenesis might be a response to maintain glucose levels consumed as a result of PCB exposures.  相似文献   

Thermal effect of the sea breeze on the structure of the boundary layer and the heat budget over land   总被引：2，自引：1，他引：1  

Tsuneo Kuwagata  Junsei Kondo  Masatoshi Sumioka 《Boundary-Layer Meteorology》1994,67(1-2):119-144

The daytime boundary-layer heating process and the air-land heat budget were investigated over the coastal sea-breeze region by means of observations over the Sendai plain in Japan during the summer. In this area, the onset of the sea breeze begins at the coast around 0900 LST, intruding about 35 km inland by late afternoon. The cold sea breeze creates a temperature difference of over 10°C between the coastal and inland areas in the afternoon. On the other hand, warm air advection due to the combination of the counter-sea breeze and land-to-sea synoptic wind occurs in the layer above the cold sea breeze in the coastal region. Owing to this local warm air advection, there is no significant difference in the daytime heating rate over the entire atmospheric boundary layer between the coastal and inland areas. The sensible heat flux from the land surface gradually decreases as distance from the coastline increases, being mainly attributed to the cold sea breeze. The daytime mean cold air advection due to the sea breeze is estimated asQ _adv ^local =–29 W m^–2 averaged over the sea breeze region (035 km from the coastline). This value is 17% of the surface sensible heat fluxH over the same region. The results of a two-dimensional numerical model show that the value ofQ _adv ^local /H is strongly affected by the upper-level synoptic wind direction. The absolute value ofQ _adv ^local /H becomes smaller when the synoptic wind has the opposite direction of the sea breeze. This condition occurred during the observations used in the present study.  相似文献   

河南省舞阳县贾湖遗址出土的鲤科鱼类咽齿研究     

中岛经夫  吕鹏  张居中  中岛美智代  模林启介  袁靖 《第四纪研究》2015,35(1)

本文对贾湖遗址出土的鲤科鱼类进行了研究,发现有11种可以确定到属或种的鲤科鱼类.现在生存在中国南方的鲤科鱼类在贾湖遗址的出土,证明当时这个地区的气候比现在要温暖.这些鲤科鱼类是当时居住在贾湖遗址的先民有选择性地进行捕捞的.该研究有助于推进考古遗址出土鱼类遗存的动物考古学研究.  相似文献   

Temporal Trends in Apparent Oxygen Utilization in the Upper Pycnocline of the North Pacific: 1980–2000     

Steven Emerson  Yutaka W. Watanabe  Tsuneo Ono  Sabine Mecking 《Journal of Oceanography》2004,60(1):139-147

We present a compilation of apparent oxygen utilization (AOU) changes observed in the upper pycnocline of the North Pacific Ocean over the last several decades. The goal here is to place previously-published data in a common format, and assess the causes of the observed changes. The general trend along repeat cross sections of the eastern and western subtropical ocean and the subarctic ocean is an increase in AOU from the mid 1980s to the mid 1990s. AOU has also been increasing in a time-series study in the northwest subarctic Ocean off of Japan since the late 1960s. Observed AOU changes south of 35°N in the subtropical ocean are 10–20 μmol kg⁻¹, with much greater changes, reaching 60–80 μmol kg⁻¹ in isolated areas, in the subtropical/subarctic boundary and the subarctic ocean. Analysis of changes in both AOU and salinity on isopycnals suggests that there are significant salinity-normalized increases that must be due to alteration in the rate of ventilation or organic matter degradation. A common feature in the data is that the maximum increase in AOU is centered near the density horizon σ_θ= 26.6. Time series results from the Oyashio Current region near the winter outcrop area of this density horizon indicate that surface waters there have become fresher with time, which may mean this density surface has ceased to outcrop in the latter decades of the 20th century. Whether this is due to natural decadal-scale changes or anthropogenic influences can be decided by determining future trends in AOU on these density surfaces. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Temporal Change of Dissolved Inorganic Carbon in the Subsurface Water at Station KNOT (44°N, 155°E) in the Western North Pacific Subpolar Region     

Masahide?WakitaEmail author  Shuichi?Watanabe  Yutaka?W.?Watanabe  Tsuneo?Ono  Nobuo?Tsurushima  Shizuo?Tsunogai 《Journal of Oceanography》2005,61(1):129-139

The dissolved inorganic carbon (DIC) and related chemical species have been measured from 1992 to 2001 at Station KNOT (44°N, 155°E) in the western North Pacific subpolar region. DIC (1.3∼2.3 µ mol/kg/yr) and apparent oxygen utilization (AOU, 0.7∼1.8 µmol/kg/yr) have increased while total alkalinity remained constant in the intermediate water (26.9∼27.3σ_θ). The increases of DIC in the upper intermediate water (26.9∼27.1σ_θ) were higher than those in the lower one (27.2∼ 27.3σ_θ). The temporal change of DIC would be controlled by the increase of anthropogenic CO₂, the decomposition of organic matter and the non-anthropogenic CO₂ absorbed at the region of intermediate water formation. We estimated the increase of anthropogenic CO₂ to be only 0.5∼0.7 µmol/kg/yr under equilibrium with the atmospheric CO₂ content. The effect of decomposition was estimated to be 0.8 ± 0.7 µmol/kg/yr from AOU increase. The remainder of non-anthropogenic CO₂ had increased by 0.6 ± 1.1 µmol/kg/yr. We suggest that the non-anthropogenic CO₂ increase is controlled by the accumulation of CO₂ liberated back to atmosphere at the region of intermediate water formation due to the decrease of difference between DIC in the winter mixed layer and DIC under equilibrium with the atmospheric CO₂ content, and the reduction of diapycnal vertical water exchange between mixed layer and pycnocline waters. In future, more accurate and longer time series data will be required to confirm our results.  相似文献   

Large-scale freezing work for subway construction in Japan     

Michio Miyoshi  Tsuneo Tsukamoto  Shiro Kiriyama   《Engineering Geology》1979,13(1-4):397-415

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Alteration of gene expression profiles in the brain of Japanese medaka (Oryzias latipes) exposed to KC-400 or PCB126     

Kei Nakayama  Naomi Sei  Yuji Oshima  Kosuke Tashiro  Yohei Shimasaki  Tsuneo Honjo 《Marine pollution bulletin》2008,57(6-12):460

Polychlorinated biphenyls (PCBs) are known as neurotoxic chemicals and possibly alter animal behavior. We previously reported that PCB-exposure induced abnormal schooling behavior in Japanese medaka (Oryzias latipes). This abnormal behavior might be caused by the functional alteration of central or terminal nervous system. To understand the mechanism(s) of behavioral change by PCB-exposure, we analyzed the gene expression profiles in the brain of medaka exposed to 3,3′,4,4′,5-pentachlorobiphenyl (PCB126) or a PCB mixture (Kanechlor-400: KC-400) using a cDNA microarray that we constructed. Twelve FLF-II strain medaka (six individuals per treatment) were dietary exposed to PCB126 (0.01 μg/g b.w./day) or KC-400 (1 μg/g b.w./day) for three weeks. For the control, six fish were fed a control diet. After the exposure period, fish were dissected, and the brain samples were collected. The samples from control fish were pooled and used as a common reference in the microarray experiment. Microarray data were normalized by the LOWESS method, and we screened the genes whose expression levels were altered more than 1.5-fold. Gene expression profiling showed 97 down-regulated and 379 up-regulated genes in the brain of medaka exposed to PCB126. KC-400 exposure suppressed 15 genes and induced 266 genes in medaka brain. Among these genes, the expression levels of 7 and 188 genes were commonly down- or up-regulated, respectively in both treatment groups. On the other hand, 31 gene expressions were significantly different between PCB126 and KC-400 treatment groups, and three out of 31 genes were received opposite effects. In addition, the microarray data showed that thyroid hormone-responsive genes were up-regulated by PCB-exposure, which may imply that PCBs or their metabolites mimic thyroid hormone effects in the brain of PCB-exposed medaka.  相似文献   

Alteration of gene expression profiles in the brain of Japanese medaka (Oryzias latipes) exposed to KC-400 or PCB126     

Nakayama K  Sei N  Oshima Y  Tashiro K  Shimasaki Y  Honjo T 《Marine pollution bulletin》2008,57(6-12):460-466

Polychlorinated biphenyls (PCBs) are known as neurotoxic chemicals and possibly alter animal behavior. We previously reported that PCB-exposure induced abnormal schooling behavior in Japanese medaka (Oryzias latipes). This abnormal behavior might be caused by the functional alteration of central or terminal nervous system. To understand the mechanism(s) of behavioral change by PCB-exposure, we analyzed the gene expression profiles in the brain of medaka exposed to 3,3',4,4',5-pentachlorobiphenyl (PCB126) or a PCB mixture (Kanechlor-400: KC-400) using a cDNA microarray that we constructed. Twelve FLF-II strain medaka (six individuals per treatment) were dietary exposed to PCB126 (0.01 microg/g b.w./day) or KC-400 (1 microg/g b.w./day) for three weeks. For the control, six fish were fed a control diet. After the exposure period, fish were dissected, and the brain samples were collected. The samples from control fish were pooled and used as a common reference in the microarray experiment. Microarray data were normalized by the LOWESS method, and we screened the genes whose expression levels were altered more than 1.5-fold. Gene expression profiling showed 97 down-regulated and 379 up-regulated genes in the brain of medaka exposed to PCB126. KC-400 exposure suppressed 15 genes and induced 266 genes in medaka brain. Among these genes, the expression levels of 7 and 188 genes were commonly down- or up-regulated, respectively in both treatment groups. On the other hand, 31 gene expressions were significantly different between PCB126 and KC-400 treatment groups, and three out of 31 genes were received opposite effects. In addition, the microarray data showed that thyroid hormone-responsive genes were up-regulated by PCB-exposure, which may imply that PCBs or their metabolites mimic thyroid hormone effects in the brain of PCB-exposed medaka.  相似文献   

A New Automatic Subsurface Gas Monitoring System for Seismogeochemical Studies, Installed in Haruno Borehole, Shizuoka Prefecture, Central Japan     

Kazuya Miyakawa  Ruka Takama  Iwao Kawabe  Shinnichi Kariya  Tsuneo Yamauchi 《Pure and Applied Geophysics》2010,167(12):1561-1575

The results of subsurface gas monitoring by application of gas chromatography (GC) to the gas composition of bubbles associated with groundwater for seismogeochemical studies are reported. An automated gas monitoring system was used to determine gas compositions in a 500-m borehole at the Haruno Crustal Movement Observation Site (HOS), central Japan during period 1, from December 1999 to December 2000. The average ± two standard deviation (2SD) compositions of gases in this period were He = 82 ± 29 ppmV, H₂ = 170 ± 62 ppmV, Ar = 0.05 ± 0.07%, N₂ = 50 ± 8%, and CH₄ = 45 ± 6%. A new automated gas monitoring system equipped with a micro-GC was installed in the borehole at the HOS, and gas bubbles from the borehole were monitored during period 2, from December 2006 to March 2007. The average ± two standard deviation (2SD) compositions of gases in this period were He = 8 ± 7 ppmV, H₂ = 13 ± 15 ppmV, Ar = 0.6 ± 0.3%, N₂ = 66 ± 7%, and CH₄ = 14 ± 14%. The gas concentration ratios (He/Ar, H₂/Ar, N₂/Ar, and CH₄/Ar) fluctuated significantly over time and repeatedly showed abrupt spike-like increases during period 2. The gas compositions obtained in period 1 and 2 were markedly different. Over the period from 2006 to 2007, the gas bubbles were depleted in He, H₂, and CH₄ of deep origin, but enriched in Ar and N₂ of atmospheric origin. This difference can be interpreted as being due to an irreversible change of the aquifer/gas system. The present deep component in the HOS gas is estimated to have composition He = 63 ppmV, H₂ = 37 ppmV, Ar = 0.17%, N₂ = 63%, and CH₄ = 37%. The new monitoring system is able to analyze the gas composition using a smaller volume of sample gas and with greater precision than the previous system. During the 3-month monitoring period 2, the separation capacity of the capillary column of the micro-GC was sufficiently maintained to determine gas-chromatographic peak areas for the five gaseous species examined. This study confirms that the new monitoring system with micro-GC is promising for continuous subsurface gas monitoring for earthquake prediction studies.  相似文献   

Appearance pattern of tooth germs with developmental process inMylopharyngodon piceus     

Yue Pei-qi  Nakajima Tsuneo 《中国海洋湖沼学报》1995,13(2):155-161

The pharyngeal dental formula ofMylopharyngodon piceus is 4–5 as a rule, and the dentition is asymmetrical. It is difficult to identify each tooth in the larval dentition. In this paper the appearance pattern of tooth germ with development process in this fish is described in detail. The formation pattern of the left dentition is contrasted with that of the right one. In the developmental process, the left pharyngeal dentition lacks teeth at position An3. Thus the left dentition is D-type as designated by Nakajima (1984), while the right one is A-type. This project was funded by the International Cooperation of Japan-China and the National Natural Science Foundation of China.  相似文献