Effect of phenol on embryo development and expression of metallothionein in the sea urchin Hemicentrotus pulcherrimus     

Un-Ki Hwang  Ju-Wook Lee  Hyang-Mi Ryu  Ju-Chan Kang  Han Seung Kang 《Ocean Science Journal》2015,50(4):701-708

In this study, we identified and cloned the sea urchin Hemicentrotus pulcherrimus MT (Hp-MT) mRNA. We examined the gameto- and embryo-toxic effects and the expression of Hp-MT mRNA at various concentrations of phenol in H. pulcherrimus. We found that the normal embryogenesis rate was significantly inhibited when H. pulcherrimus was exposed to phenol (EC₅₀ = 1565.86 ppb, 95% Cl = 1183.47-2037.84 ppb). The no observed effective concentration (NOEC) and the lowest observed effective concentration (LOEC) of the normal embryogenesis rate were < 10 ppb and 100 ppb, respectively. Hp-MT cDNA is 651 bp in length and encodes a protein of 64 amino acids. We found that the expression of Hp-MT mRNA was significantly increased with phenol treatment in a concentrationdependent manner. These results suggest that phenol at greater than 100 ppb has a toxic effect during the early embryonic stages of H. pulcherrimus, and MT mRNA may be used as a biomarker for risk assessment of phenol contamination.  相似文献   

Hydrogeochemistry and environmental isotopes of ground water in Jeju volcanic island,Korea: implications for nitrate contamination     

Dong‐Chan Koh  Ho‐Wan Chang  Kwang‐Sik Lee  Kyung‐Seok Ko  Yongje Kim  Won‐Bae Park 《水文研究》2005,19(11):2225-2245

Ground water from springs and public supply wells was investigated for hydrochemistry and environmental isotopes of ³H, ¹⁸O and D in Jeju volcanic island, Korea. The wells are completed in a basaltic aquifer and the upper part of hydrovolcanic sedimentary formation. Nitrate contamination is conspicuous in the coastal area where most of the samples have nitrate concentrations well above 1 mg NO₃ N/l. Agricultural land use seems to have a strong influence on the distribution of nitrate in ground water. Comparison of stable isotopic compositions of precipitation and ground water show that ground water mostly originates from rainy season precipitation without significant secondary modification and that local recharge is dominant. ³H concentration of ground water ranged from nearly zero to 5 TU and is poorly correlated with vertical location of well screens. The occurrence of the ³H‐free, old ground water is due to the presence of low permeability layers near the boundary of the basaltic aquifer and the hydrovolcanic sedimentary formation, which significantly limits ground water flow from the upper basaltic aquifer. The old ground water exhibited background‐level nitrate concentrations despite high nitrate loadings, whereas young ground water had considerably higher nitrate concentrations. This correlation of ³H and nitrate concentration may be ascribed to the history of fertilizer use that has increased dramatically since the early 1960s in the island. This suggests that ³H can be used as a qualitative indicator for aquifer vulnerability to nitrate contamination. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Primary ‘cut-and-fill’ channels and gravitational diagenetic features     

Won C. Park  G. C. Amstutz 《Mineralium Deposita》1968,3(1):66-80

Ore beds with fluorite and sphalerite occur in the Cave-In-Rock fluorite district, Illinois in the upper part of the Mississippian System; in the upper parts of the Fredonia and Joppa Members of the Ste. Genevieve Formation and in the upper part of the Downeys Bluff Formation. Sedimentary structures within the upper two horizons are described and discussed. Primary cut-and-fill channels usually contain broken pieces of dolomite, limestone, shale, sandstone, fluorite and sphalerite. Some of the channels show geopetal features. Horizontal stylolitic seams bend downward and their thicknesses increase while their amplitudes decrease near and along the channel slopes. Another geopetal feature consists of clastic shale fragments which have mechanically filled from above into an open crack formed in the hydroplastic carbonate mud below. A number of features known as collapsed structures prove to be cut-and-fill structures of primary origin. During the compaction, carbonate beds were reduced in thickness by at least 37% through styloitization. The relationships between primary sedimentary channels and fluorite-sphalerite ore rocks suggest that the latter may have been deposited during or after the formation of such sedimentary structures, i. e., during various stages of diagenesis.

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Zusammenfassung Die Fluorit-Zinkblende-Vorkommen des Cave-In-Rock Distrikts von Illinois treten stratigraphisch in den oberen Partien des Mississippian System, speziell in der Fredonia und Joppa Serie der Ste. Genevieve Formation und in der Downeys Bluff Formation auf. Einige sedimentäre Strukturen in diesen beiden oberen Horizonten werden beschrieben und diskutiert. Primäre cut-and-fill channels enthalten im allgemeinen Bruchstücke von Dolomit, Kalk- und Sandstein, Schieferton, Fluorit und Zinkblende. Einige channels zeigen geopetale Gefüge, d. h. horizontale stylolithische Lagen sind mit zunehmender Mächtigkeit und abnehmender Amplitude der Fältelung in der Nähe oder entlang der Flanken der channel Strukturen nach unten durchgebogen. Ein weiteres geopetales Gefüge besteht aus Schieferton-Fragmenten, die mechanisch in eine offene Spalte des darunterliegenden hydroplastischen Karbonatschlammes eingesunken sind. Eine Anzahl von Gefügen, bekannt als collapsed structures scheinen cut-and-fill und slump Strukturen von primär subaquatischer Herkunft zu sein. Während der Diagenese wurden Karbonatbänke durch Stylolithbildung um mindestens 37% der ursprünglichen Mächtigkeit reduziert. Die Beziehungen zwischen den primären sedimentären channels und dem Fluorit-Zinkblende-Erz deuten darauf hin, daß das letztere während oder nach der Bildung der sedimentären Strukturen abgelagert wurde, d. h., während verschiedener Perioden der Diagenese.

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Use of an artificial neural network for analysis of the susceptibility to landslides at Boun,Korea   总被引：13，自引：0，他引：13  

Saro?LeeEmail author  Joo-Hyung?Ryu  Moung-Jin?Lee  Joong-Sun?Won 《Environmental Geology》2003,44(7):820-833

The purpose of this study was to develop landslide susceptibility analysis techniques using artificial neural networks and to apply the resulting techniques to the study area of Boun in Korea. Landslide locations were identified in the study area from interpretation of aerial photographs and field survey data. A spatial database of the topography, soil type, timber cover, geology, and land cover was constructed and the landslide-related factors were extracted from the spatial database. Using these factors, the susceptibility to landslides was analyzed by artificial neural network methods. The results of the landslide susceptibility maps were compared and verified using known landslide locations at another area, Yongin, in Korea. A Geographic Information System (GIS) was used to analyze efficiently the vast amount of data and an artificial neural network turned out to be an effective tool to analyze the landslide susceptibility.  相似文献   

Experimental Investigation and Optimization of Thermodynamic Properties and Phase Diagrams in the Systems CaO-SiO2, MgO-SiO2, CaMgSi2O6-SiO2 and CaMgSi2O6-Mg2SiO4 to 1{middle dot}0 GPa     

HUDON  PIERRE; JUNG  IN-HO; BAKER  DON R. 《Journal of Petrology》2005,46(9):1859-1880

Using experimental results at 1·0 GPa for the systemsCaO–SiO₂, MgO–SiO₂, CaMgSi₂O₆–SiO₂ and CaMgSi₂O₆–Mg₂SiO₄,and all the currently available phase equilibria and thermodynamicdata at 1 bar, we have optimized the thermodynamic propertiesof the liquid phase at 1·0 GPa. The new optimized thermodynamicparameters indicate that pressure has little effect on the topologyof the CaO–SiO₂, CaMgSi₂O₆–SiO₂, and CaMgSi₂O₆–Mg₂SiO₄systems but a pronounced one on the MgO–SiO₂ binary. Themost striking change concerns passage of the MgSiO₃ phase fromperitectic melting at 1 bar to eutectic melting at 1·0GPa. This transition is estimated to occur at 0·41 GPa.For the CaMgSi₂O₆–SiO₂ and CaMgSi₂O₆–Mg₂SiO₄ pseudo-binaries,the size of the field clinopyroxene + liquid increases withincreasing pressure. This change is related to the shift ofthe piercing points clinopyroxene + silica + liquid (from 0·375mol fraction SiO₂ at 1 bar to 0·414 at 1·0 GPa)and clinopyroxene + olivine + liquid (from 0·191 molfraction SiO₂ at 1 bar to 0·331 at 1·0 GPa) thatbound the clinopyroxene + liquid field in the CaMgSi₂O₆·SiO₂and CaMgSi₂O₆·Mg₂SiO₄ pseudo-binaries, respectively. KEY WORDS: CaO–SiO₂; CaMgSi₂O₆–Mg₂SiO₄; CaMgSi₂O₆–SiO₂; experiments; MgO–SiO₂  相似文献   

Genetic Implications of Two Different Ultramafic Rocks from Hongseong Area in the Southwestern Gyeonggi Massif, South Korea     

Jieun Seo  Seon Gyu Choi  Chang Whan Oh  Sung Won Kim  Suck Hwan Song 《Gondwana Research》2005,8(4):539-552

Two distinct ultramafic bodies occur in Baekdong and Bibong in the Hongseong area within Gyeonggi massif of South Korea. The Hongseong area is now extensively documented as an extension of the Dabie-Sulu collision belt in China. The Baekdong ultramafic body has a NWW elongation direction. This elongation trend is similar to the general trend of the Dabie-Sulu collision belt. The Bibong ultramafic body is elongated in a NNE direction and runs parallel to the direction of the main fault in the study area. The Baekdong ultramafic bodies show porphyroclastic and mylonitic textures while those at Bibong exhibit a mosaic texture. Both were grouped into peridotite and serpentinite based on their modal abundance of serpentine. In the olivine (Fo) vs. spinel [Cr# = Cr/ (Cr+Al)] diagram, both ultramafic rocks fall with in olivine spinel mantle array. The compositions of olivine, orthopyroxene and spinel indicate that the Baekdong ultramafic rock formed in deeper parts of the upper-mantle under passive margin tectonic setting. The SREE content of Baekdong ultramafic rock vary from 0.19 to 5.7, exhibits a flat REE pattern in the chondrite-normalized diagram, and underwent 5% partial melting. Conversely, large variation in SREE (0.5 21.53) was observed for Bibong ultramafic rocks with an enrichment of LREE with a negative slope and underwent 17 24% partial melting. The Baekdong ultramafic rocks experienced three stages of metamorphism after a high pressure residual mantle stage. The first stage of metamorphism occurred under the eclogite-granulite transitional facies (1123 911°C, >16.3 kb) the second under the granulite facies (825 740°C, 16.3 11.8 kb) and the third is the retrogressive metamorphism under amphibolite facies (782 718°C, 8.2 8.7 kb) metamorphism. The Baekdong ultramafic rocks had undergone high-P/T metamorphism during subduction of the South China Block, and experienced a fast isothermal uplift, and finally cooled down isobarically. Evidences for metamorphism were not identified in Bibong ultramafic rocks. Hence, the Baekdong ultramafic rocks with in the Hongseong area may indicate a link on the Korean counterpart of Dabie-Sulu collision belt between North and South China Blocks.  相似文献   

Petrology of an intrusion-related high-grade migmatite: implications for partial melting of metasedimentary rocks and leucosome-forming processes   总被引：7，自引：1，他引：6  

S. JUNG  K. MEZGER  P. MASBERG  E. HOFFER  & S. HOERNES 《Journal of Metamorphic Geology》1998,16(3):425-445

Intrusion-related migmatites comprise a substantial part of the high-grade part of the southern Damara orogen, Namibia which is dominated by Al-rich metasedimentary rocks and various granites. Migmatites consist of melanosomes with biotite+sillimanite+garnet+cordierite+hercynite and leucosomes are garnet- and cordierite-bearing. Metamorphic grade throughout the area is in the upper amphibolite to lower granulite facies (5–6 kbar at 730–750 °C). Field evidence, petrographic observations, chemical data and mass balance calculations suggest that intrusion of granitic magmas and concomitant partial melting of metasedimentary units were the main processes for the generation of the migmatites. The intruding melts were significantly modified by magma mixing with in situ partial melts, accumulation of mainly feldspar and contamination with garnet from the wall rocks. However, it is suggested that these melts originally represented disequilibrium melts from a metasedimentary protolith. The occurrence of LILE-, HFSE- and LREE-enriched and -depleted residues within the leucosomes implies that both quartzo-feldspathic and pelitic rocks were subjected to partial melting. Isotope ratios of the leucosomes are rather constant (¹⁴³Nd/¹⁴⁴Nd (500 Ma): 0.511718–0.511754, ε Nd (500 Ma): ?3.54 to ?5.11) and Sr (⁸⁷Sr/⁸⁶Sr (500 Ma): 0.714119–0.714686), the metasedimentary units have rather constant Nd isotope ratios (¹⁴³Nd/¹⁴⁴Nd (500 Ma): 0.511622–0.511789, ε Nd (500 Ma): ?3.70 to ?6.93) but variable Sr isotope ratios Sr (⁸⁷Sr/⁸⁶Sr (500 Ma): 0.713527–0.722268). The most restitic melanosome MEL 4 has a Sr isotopic composition of ⁸⁷Sr/⁸⁶Sr (500 Ma): 0.729380. Oxygen isotopes do not mirror the proposed contamination process, due to the equally high δ¹⁸O contents of metasediments and crustal melts. However, the most LILE-depleted residue MEL 4 shows the lowest δ¹⁸O value (<10). Mass balance calculations suggest high degrees of partial melting (20–40%). It is concluded that partial melting was promoted by heat transfer and release of a fluid phase from the intruding granites. High degrees of partial melting can be reached as long as the available H₂O, derived from the crystallization of the intruding granites, is efficiently recycled within the rock volume. Due to the limited amounts of in situ melting, it seems likely that such regional migmatite terranes are not the sources for large intrusive granite bodies. The high geothermal gradient inferred from the metamorphic conditions was probably caused by exhumation of deep crustal rocks and contemporaneous intrusion of huge masses of granitoid magmas. The Davetsaub area represents an example of migmatites formed at moderate pressures and high temperatures, and illustrates some of the reactions that may modify leucosome compositions. The area provides constraints on melting processes operating in high-grade metasedimentary rocks.  相似文献   

Biomarkers in marbled flounder (Pleuronectes yokohamae) from contaminated and reference sites in South Korea     

Jee Hyun Jung  R.F. Addison  Un Hyuk Yim  Sang Hee Hong  Sungyong Ha  Won Joon Shim   《Marine pollution bulletin》2009,58(11):1754-1759

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Seasonal characteristics of the Tsushima Current in the Tsushima/Korea Strait obtained by a fine-resolution numerical model     

Y.H. Seung  Y.-J. Kim  J.-H. Yoon 《Continental Shelf Research》2007

The horizontal distribution of the Tsushima Current in the Tsushima/Korea Strait is assessed by a fine-resolution numerical experiment. The comparison of the model results with the observations along a section crossing the strait shows that the model represents relatively well, the general tendency of what was observed, such as the separation of the Tsushima Current into the western and eastern streams by the Tsushima Island. In summer, strong and relatively uniformly distributed surface currents enhance the formation of the wake downstream of the Tsushima Island. The axis of the countercurrent, embedded in the wake, is closer to the western stream. Anti-cyclonic eddies are shed near the downstream tip of the Tsushima Island and propagate along the boundary between the western stream and the wake. The exchange of water between the western stream and the wake takes place through the intermediation of these eddies. There is a net water supply from the western stream to the wake, which is then carried to the eastern stream by the countercurrent via the eastern coast of the Tsushima Island. In winter, currents, strongly barotropic, tend to have banded structures, especially in the region downstream of the western channel where isobaths converge in the downstream direction. The eddies found in this region in winter appear to be fundamentally different from those associated with the Tsushima Island wake. The necessary condition for barotropic instability is satisfied for the monthly mean currents in this region, suggesting that the currents are barotropically unstable in this region in winter.  相似文献   

Coaxial coil towed EMI sensor array for UXO detection and characterization     

Haoping Huang  Bill SanFilipo  Alex Oren  I.J. Won 《Journal of Applied Geophysics》2007,61(3-4):217-226

A new broadband electromagnetic induction (EMI) array sensor, GEM-5, for detecting and characterizing Unexploded Ordnance (UXO) has been developed in order to provide high production rates for EMI surveys. The sensor consists of a single rectangular loop transmitter around a linear array of seven pairs of coaxial receiver coils, with each coil in a pair located at the same vertical distance above and below the loop transmitter. The coil pairs are wired in an inverted series so that the signal consists of the difference between the voltage induced in the upper and lower coils. This particular configuration provides a high degree of primary field cancellation, dense spatial sampling rate due to simultaneous and continuous operation of all sensors, suppression of motion-induced and environmental noise, and strong source fields at typical UXO burial depths providing deep detection range. Our prototype tests indicate that the array yields a lower static and motion-induced noise over the critical low frequencies than that of existing sensors, and in particular, the signal-to-noise ratio at 90 Hz is 32 dB higher. Environmental noise can be largely removed from the difference measurements. The field test results from UXO test sites show that the prototype sensor has smoother background and appears to detect more seeded targets than the GEM-3 concentric sensor, however some of that gain can be attributed to higher power transmitter electronics.  相似文献