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

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.     

新发现的阿拉伯海东北部走滑板块边界

阿拉伯板块和欧亚板块的聚合形成了位于伊朗和巴基斯坦近海的莫克兰聚合边界俯冲带。在地球的俯冲带中 ,莫克兰（Ｍａｋｒａｎ）具有最大的加积沉积物厚度 ,沿纬度６０°Ｅ至６３°Ｅ的变形前缘其厚度约为７ｋｍ。２０世纪７０～８０年代的地震反射剖面显示了由阿拉伯板块上刮削下来的厚达３．４ｋｍ的沉积物堆形成的巨大的增生楔 ,而下部沉积物剖面则位于板块之下或被俯冲。早期的解释认为莫克兰构造是一个穿刺叠瓦状的横向连续的构造建造。对莫克兰增生楔的详细研究是１９９７年秋季德国ＲＶＳｏｎｎｅ的ＳＯ１２３航次 ,在此期间联合做了…     

乌干达Albertine地堑石油地质条件与油气勘探潜力

Albertine地堑是乌干达共和国具有油气勘探潜力的中新生代断陷。通过野外考察、重磁数据处理、地堑结构分析、地球化学和储层物性分析及其综合研究 ,对 Albertine地堑的油气潜力有了进一步认识。盆地具有双层地质结构 ,沉积巨厚 ,局部重力高反映可能发育中央隆起带 ;地堑区至少     

Sm-Nd dating of Fig Tree clay minerals of the Barberton greenstone belt, South Africa

Sm-Nd isotopic data from carbonate-derived clay minerals of the 3.22-3.25 Ga Fig Tree Group, Barberton greenstone belt, South Africa, form a linear array corresponding to an age of 3102 +/- 64 Ma, making these minerals the oldest dated clays on Earth. The obtained age is 120-160 m.y. younger than the depositional age determined by zircon geochronology. Nd model ages for the clays range from approximately 3.39 to 3.44 Ga and almost cover the age variation of the Barberton greenstone belt rocks, consistent with independent evidence that the clay minerals are derived from material of the belt. The combined isotopic and mineralogical data provide evidence for a cryptic thermal overprint in the sediments of the belt. However, the highest temperature reached by the samples since the time of clay-mineral formation was <300 degrees C, lower than virtually any known early Archean supracrustal sequence.     

青海省天峻县木里煤田聚乎更矿区构造轮廓和地层格架

木里煤田聚乎更矿区是全球陆上中纬度、高海拔冻土带天然气水合物的发现地,也是当前青藏高原地质研究的热点地区之一.依据近年来的煤炭地质勘查资料,对聚乎更矿区的构造轮廓、含煤地层、沉积相和聚煤作用进行深入分析,认为聚乎更矿区位于祁连坳褶带西段,受大通山北缘和托莱山南缘对冲断裂组的制约,构造线总体方向为北西-南东向,构造轮廓表...     

四极杆电感耦合等离子体质谱仪测定动物牙化石中U和Th同位素

四极杆电感耦合等离子体质谱仪(Inductively Coupled Plasma-Quadrupole Mass Spectrometry,简称 ICP-QMS)可用于U和Th同位素分析。目前,ICP-QMS能实现精度大约为0.3 % (U)和1 % (Th)的测量分析,可提供误差在1 % ~10 % 的 230 Th/U年代数据。本文用ICP-QMS分析了采自意大利南都Loreto旧石器地点的4颗马牙化石样品,并对已发表的UTEVA树脂提纯U和Th的流程做了进一步改进,使其适用于动物牙化石样品。样品中的U和 Th含量的平均测量精度(2σ)分别为0.3 % 和0.6 %; 234 U/238 U和 230 Th/238 U活度比平均精度(2σ)分别为0.3 % 和0.8 % 。数据表明同一颗牙化石的不同组织的U含量可有数量级差别,同时它们的U-Th同位素活度比也可显著地离散( >2σ),从而导致不一致的 230 Th/U 年代结果。如今测定的各牙组织的U-Th同位素数据可用于模拟U的迁移历史; U-系分析与电子自旋共振测年技术相结合或可更好地估计样品的地质年代。     

Isotopic Ages of the Penglai Group in the Jiaobei Belt and Their Geotectonic Implications

The Penglai Group in the Jiaobei Belt is the only remaining cover of the Archaean to Early Proterozoic crystalline basement in eastern Shandong. The ages of deposition of the Penglai Group and of its deformation and metamorphism have long been a subject of speculation. Whole-rock Rb-Sr ages, illite-whole-rock pair Rb-Sr ages and illite K-Ar ages recently obtained from the Penglai Group slates are reported and interpreted in this paper. On the basis of structural and metamorphic studies coupled with analyses of illite crystallinity, XRD and SEM , a whole-rock age of 473±32 Ma (Ordovician) is interpreted as the time of termination of burial metamorphism experienced by the Penglai Group. Therefore, the age of the Penghai Group is older than Ordovician. The first-phase folding and syntectonic low greenschist facies metamorphism in the Penglai Group, i.e. the Penglai Movement, took place before 299±4 Ma B.P., i.e in the Late Carboniferous. The Penglai Movement that occurred in the Jiaobei Belt on the south     

煤中As的赋存状态及其在燃烧过程中的转化

对煤中砷的赋存状态进行了综述,总结了砷在燃煤过程中的迁移转化行为。从飞灰演化的角度探讨了飞灰对砷的富集机制,认为飞灰对砷的富集是伴随飞灰的演化过程进行的。飞灰对砷的富集主要有4种形式,即发生化学反应生成含砷稳定化合物,进入粘土矿物晶格内部,飞灰对砷及其化合物的吸附和冷凝     

FUZZY SYNTHETIC EVALUATION ON RESIDENT''''S PERCEPTIONS OF TOURISM IMPACTS——Case of Jiuzhaigou National Park, Sichuan Province, China

1INTRODUCTIONCommunity residents form an important part of tourismdestinations and play a crucial role in the protection anddevelopment oftourism resources. The Tourism Agenda21 advocates that the development of tourism industryshouldconsider the interestsofthe host residentsand en-sure long-term viability beneficial towards destinationcommunity (LIU, 2000). Yet in manyinstances tourismdevelopment proves detrimental to host communities(LANKFORD and HOWARD, 1994; LIU and VAR,1986)…