• Journal of the Mineralogical Society of Korea
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• v.28 no.1
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• pp.71-81
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• 2015

This study was carried out in order to investigate the mineralogical characteristics of the core sediments (03GHP-02 and HB13-2), obtained from the Ulleung Basin and Hupo Basin, Korea. The results on mineral compositions, clay mineral compositions, and the total contents and sequential extraction of different fractions of the phosphorus in core samples showed that those values are different in two cores and also at different depths. In both samples, mineral compositions were the same, composed mainly of quartz, microcline, albite, calcite, opal A, pyrite, and clay minerals (illite, chlorite, kaolinite, and smectite). However, the sample from Hupo Basin contains more opal A. Both samples, especially the ones from Hupo Basin contains more smectite than those reported from East Sea, indicating the influence of paleo-Hwangwei River and the Tertiary Formation of Korea Peninsula. For the samples from Uleung Basin, at 0.7-3.5 m range in depth, the low content of opal A and the low illite crystallinity index can be inferred to indicate the relatively cool climate, corresponding to the ice age. Also, the content of total phosphorus was low in those samples. It was reported that East Sea at that time was isolated from the neighboring seas due to the decrease of the sea level, and as a result, the influx of sediments was supposed to be little through the strait and rivers. For the samples from Hupo Basin, there is no significant changes in clay mineral composition and the distribution of phosphorus with increasing depth. This little change can be interpreted to indicate that the sediments comprising the core might be deposited in a relatively short period of time or deposited in sedimentary environment in which there's no significant changes in sediment supplies. The values of crystallinity index of clay minerals are high in those samples, indicating that it was relatively warm during that time. Although the increase of fluctuation pattern can be observed, showing that the climate of this period often changed, it is supposed that it was generally warm.

• Korean Journal of Environmental Biology
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• v.33 no.1
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• pp.34-44
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• 2015

Fish fauna, difference of stable isotope ratio between freshwater and seawater, and trophic guilds of freshwater fishes were investigated in the lower Geum River. The study was conducted in 2011, and total study area was about 30 km of 20 km upstream and 10 km downstream from the Geum River estuary barrage. Only freshwater fishes were used for analyzing trophic guilds, and discriminant function analysis (DFA) was utilized to reclassify trophic guilds based on stable isotope ratio. Fish fauna in freshwater and seawater areas were entirely different each other, but small number of migratory species such as Coilia nasus and Chelon haematocheilus occurred both areas. Other species were not collected in the different areas because they did not have physiological ability to adapt different salinity concentrations. Stable isotope ration of two areas were different considerably due to food sources. Estuary and seawater fishes uptake food sources originated from marine, and freshwater fishes were from freshwater and terrestrial. Some migratory species showed reverse stable isotope ratio. Even though they collected in freshwater, they showed stable isotope ratio of seawater. This is because ecological characteristics of each species. Trophic guilds of freshwater fishes were reclassified by DFA, and showed slight difference with literatures. However, because this result is related with ontogenetic shift of species, more studies are needed to explain exact and correct trophic guilds. Stable isotope ratio can be changed among regions, seasons and ontogenetic stage, thus we always consider these aspects when analyzing results to get a right answer.

• Journal of Nutrition and Health
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• v.41 no.7
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• pp.602-611
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• 2008

We compared antiobese, hypocholesterolemic, antiplatelet and antioxidant effect of 10% green tea powder and 3% green tea extract in rats pair fed 5% cholesterol diets. The final body weight was decreased significantly compared with the control (p < 0.05). Plasma and liver total cholesterol were lower in group of green tea powder or extract, but not statistically different. HDL cholesterol was increased significantly in group of green tea powder compared with the control or green tea extract (p < 0.05). Plasma triglyceride was significantly decreased in group of green tea extract compared with green tea powder, and green tea powder compared with the control respectively (p < 0.05). Liver triglyceride was significantly decreased in group of green tea powder or green tea extract compared with the control (p < 0.01). Platelet aggregations in the maximum and initial slope were not different among groups. Hemolysis was significantly lower in group of green tea powder compared with the control (p < 0.05). Plasma TBARS production was decreased in group of green tea extract compared with the control (p < 0.05). Na passive leak in intact cells was not different, but Na leak in AAPH treated cell was significantly decreased in group of green tea powder than the control (p < 0.05). The leak increase (${\Delta}Na$ Leak) after AAPH treatment was significantly decreased in groups of green tea powder and extract compared with the control (p < 0.05). Isotope excretion after $^{14}C$-cholesterol ingestion was significantly increased in group of green tea extract compared with the control or the green tea powder (p < 0.05). Consumption of green tea in powder or extract may give beneficial effects in weight control and plasma lipid profiles, impeding metabolic syndrome. More studies are needed to clarify what component of green tea and what mechanism are involved in antiobese and hypolipedemic actions of green tea.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.685-691
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• 2005

Growth and DNA synthesis inhibitory effects of doenjang methanol extract and its solvent fractions on AGS human gastric adenocarcinoma cells, Hep 3B human hepatocellular carcinoma cells, HT-29 human colon cancer cells and MG-63 human osteosarcoma cells were studied. The treatment of doenjang methanol extract ($ 200{\mu}g/ml $) with the AGS, Hep 3B, HT-29 and MG-63 cancer cells after 6 days of incubation inhibited the growth of cancer cells by $32\%$, $51\%$, $84\%$ and $33\%$, respectively. To separate active compounds of doenjang, doenjang methanol extract was fractionated with dichloromethane, ethylacetate, and buthanol. Among the solvent fractions, the dichloromethane and ethylacetate fractions showed the highest growth inhibitory effects on various cancer cells. For example, the dichloromethane and ethylacetate fractions ($200a{\mu}g/ml$) sig-nificantly inhibited the growth of various cancer cells by $89\∼96\%$ and$62\∼86\%$, respectively. DNA synthesis of AGS and Hep 3B cancer cells was significantly inhibited by adding dichloromethane fraction ($200{\mu}g/ml$) up to $94\%$ and $80\%$, respectively. Similarly, the ethylacetate fraction ($ 200\mug/ml $) showed a $ 95\% $ inhibition rate of DNA synthesis in AGS cells. These results suggest that the dichloromethane and ethylacetate fractions have specific active compounds, which will explain this anticancer effect of doenjang.

• Journal of Life Science
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• v.19 no.2
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• pp.264-270
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• 2009

We investigated the effect of black soybean and doenjang with black soybean on production of cytokines including interleukin-2 (IL-2), interleukin-6 (IL-6) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) compared with yellow soybean and doenjang with yellow soybean. We also determined inhibitory effect of two types of soybeans and doenjang on tumor metastasis produced by colon 26-M3.1 carcinoma cells. The cytokine productions of mouse splenocytes increased by the exposure of lipopolysaccharide (LPS, 1 ${\mu}g$/ml) compared to without treatment of LPS. The LPS-induced IL-2 production was highest in the black soybean methanol extract, while the methanol extract from black soybean doenjang fermented for 2 mo showed the higher levels of IL-2 without LPS (p<0.05). In case of LPS-induced IL-6 production, the methanol extracts from control, yellow soybean, black soybean doenjang fermented for 2 and 7 mo showed higher levels of IL-6 compared to those of black soybean, and yellow soybean doenjang fermented for 2 mo (p<0.05). The methanol extract of black soybean doenjang fermented for 2 mo showed significantly higher levels of TNF-${\alpha}$ in both with and without LPS (p<0.05). In experiment of tumor metastasis, the treatment (1 mg/mouse) of methanol extract from black soybean doenjang fermented for 7 mo inhibited tumor metastasis by 50% and had the highest inhibitory effect among other samples (p<0.05). From these results, doenjang manufactured with black soybean modulated the production of cytokine and showed anticancer effect, suggesting that this effect was increased with increased periods of fermentation.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.2
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• pp.78-91
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• 2015

Macrobenthic community was studied at 87 stations including intertidal and subtidal area in Yoja Bay, south coast of Korea in summer season of July 2001. Duplicate sediment samples were taken using a van Veen grab ($0.1m^2$) in each station. Mud facies of the sediments were widly distributed in the bay. And relatively high content of sand was shown in the Bulgyo-cheon stream estuary. A total of 274 species was occurred with a mean density of $2,346ind./m^2$ and a mean biomass of $78.2g/m^2$. The polychaetes were species- and density-dominant faunal group with a total of 122 species (44.5% of the total number of species), and mean density of $1,543ind./m^2$ (65.8% of the mean density). Meanwhile, molluscs were biomass-dominant faunal group with $44.4g/m^2$. Bio-Env. analysis showed that the combination of bottom salinity and sand content of the surface sediments was highly correlated to the major macrobenthic communities. The macrobenthic species number, decreasing toward inner bay from mouth of the bay, was significantly correlated to the sediment environmental variables and bottom water salinity. The spatial distribution of abundance showed significant correlation to the sand and mud contents and mean grain size of the surface sediments. Major dominant species were Minuspio japonica (polychaete) with a mean density of $1,167ind./m^2$ at upper part of the bay where salinity was low and Eriopisella sechellensis (amphipod) with $152ind./m^2$ in central part of the bay. Species diversity (H') was $3.0{\leq}$ in the mouth part of the bay and ranged 2.0-3.0 in the inner part of the bay, which showed a significant positive correlation to bottom salinity. Total number of species also showed significant correlations to the sediment composition and bottom salinity. Based on the cluster analysis the macrobenthic community of the bay was classified into five station groups from the bay mouth toward the inner part of the bay depending on the species composition. From the SIMPER analysis Minuspio japonica, Eriopisella sechellensis and Sternaspis scutata mainly contributed to the classification of station group. These results suggested that the macrobenthic communities of the bay were mainly influenced by bottom salinity together with sediment composition, and that the studies of spatial distributions of major dominant species and benthic communities should be conducted continuously to monitor the Yeoja Bay benthic environment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.118-126
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• 1986

Vibrio vulnificus is a recently recognized halophilic organism that nay cause serious human infections. Patients infected with V. vulnificus often have a history of exposure to the sea, suggesting that the organism may be common inhabitant of marine environment. The purpose of this experiment is to investigate the distribution and bacteriological characteristics of V. vulnificus. The strain used in this experiment was isolated from sea water and sea products such as common octopus (Octopus variabilis), ark shell (Anadara broughtonii), blue crab (Ericheir japonica), and sea squirt (Synthia roretzi) collected in Pusan area from July to October in 1985. V. vulnificus was frequently isolated in August when temperature of sea water was around $26^{\circ}C$ and rarely isolated in October when temperature of sea water was around $18.5^{\circ}C$. The distinctive biochemical characteristics of V. vulnificus were ONPG hydrolysis positive and fermented lactose and not grown in peptone water contained $8\%$ NaCl. The optical density at 660 nm of the growth of V. vulnificus was reached maximum level after 8 hours of culture at $35^{\circ}C$ in brain heart infusion broth but that of V. vulnificus was little increased at $15^{\circ}C$ for 14 hours. Optimum temperature and pH for the growth of V. vulnificus were around $35^{\circ}C$ and 8.0. The specific growth rate and the generation time of V. vulnificus isolated from the samples were $1.21\;hr^{-1}$, 34 min at $35^{\circ}C$ and $0.61\;hr^{-1}$, 69 min at $25^{\circ}C$, respectively. V. vulnificus did not grow on eosin-methylene-blue agar, salmonella-shigella agar, deoxycholate agar but grew well on Endo agar, xylose-lysine-deoxycholate agar and hektoen enteric agar. On Endo agar, the colonies of V. vulnificus were red and achieved a diameter of 2 to 4 mm as a feature enabling differentiation of V. vulnificus from other Vibrio spp. V. vulnificus grow well on TCBS agar forming green colonies. V. vulnificus refrigerated at $4^{\circ}C$ exhibited a linear decline of its viablity as 1 log cycle in every 16 hours storage, while V. vulnificus freezed at $-18^{\circ}C$ almost became extinct.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.4
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• pp.285-294
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• 2000

In order to determine the horizontal and vertical distributions of metals and prospect the recent metal pollution history in Nakdong Estuary, we took surface and core sediments. Maximum value of organic matter occurs at the upstream site located 4 km from Nakdong barrage, and the concentration of trace metals (Zn, Cu, and Pb etc.) decrease seaward in the estuary. The sedimentation rates, based on $^{210}$Pb$_{ex}$ and $^{137}$Cs activities, were 0.34 cm/yr in inside of barrage (core 1) and 0.25 cm/yr in Changrim (core 4). Sediment mixing layer does not exist in core 1, where anoxic condition is known to be prevail. The topmost sediment layer of core 4 (<3.5 cm) is severely mixed. At sites 1 and 4, concentrations of Cu slowly increased during the period of 1920-1970, rapidly increased during 1970-1990, and followed by slight decrease after 1990. Zn contents increased in early 1960s and peaked in 1993, and followed by decrease after 1990s. Pb has increased continuously since early 1970s. At the downstream of the barrage, Cu and Zn have increased in the topmost layer. The trend of increase of Cu is evident after 1950 (11 cm in sediment depth). Overall trend of heavy metal concentration clearly indicates the pollution has been increasing after the construction of the barrage.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.4
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• pp.305-319
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• 2000

A total of 50 diatom species and 1 subspecies belonging to 31 genera except Chaetoceros resting spores were identified in the 45 sediments subsampled from a gravity core GH98-1223 collected from the western Hokkaido Island located in the northeastern East Sea (Sea of Japan). The most dominant species is Thalassionema nitzschioides (Grunow) Hustedt, ranging 29 to 59% of the total assemblages, and most species including Denticulopsis seminae (Simonsen and Kanaya) Simonsen and Pseudoeunotia doliolus (Wallich) Grunow were less than 5% in average. Frequencies of cold-water species are generally higher than those of warm-water species and the vertical distribution of cold-water species was largely opposite to that of warm-water species in spite of ecological habitat difference. Frequency of cold-water species, D. seminae is reverse to that of P. doliolus, an indicator of the Tsushima Warm Current, which is consistent with diatom temperature value (T$_{d}$ value). The variation of T$_{d}$ values shows that the upper part of core with greater-than-average T$_{d}$ values represents postglacial warming trend. These T$_{d}$ values clearly demonstrate that the study area located in the northern part of the East Sea is gradually influenced by Tsushima Warm Current. In addition, the zig-zag variation in the lower part reflects the unstable seawater for diatom habitat. Chaetoceros resting spores indicating productivity and upwelling was 5.3 to 40%, with maximum peak at 80 cm. Chaetoceros resting spores/Chaetoceros vegetative cells, an indicator of relative amounts of biogenic material in the sediments was high at the upper 80 cm level, corresponding to the change of T$_{d}$ values. On the basis of diatom assemblages, the northeastern part of East Sea has experienced the effects of Tsushima Warm Current during the postglacial period of Holocene, which is similar to the modem climatic environment. However, the variation of P. doliolus reflects that the intensity of Tsushima Warm Current has been oscillated in the East Sea.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.2
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• pp.131-146
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• 2014

High-resolution seismic profiles coupled with sediment sampling were analyzed to investigate the acoustic characters and distribution patterns of the late Holocene sediments in Gamak Bay of the South Sea, Korea. The mean grain size of surficial sediment lies around $6.3{\sim}9.7{\Phi}$. Sediments in the bay consist of silt and clay with progressive decrease toward the inner bay. The seismic sedimentary sequence overlying the acoustic basement can be divided into two sedimentary units (GB I and II) by a prominent mid-reflector (Maximum Flooding Surface; MFS). The acoustic basement occurs at the depth between 20 m and 40 m below the sea-level and deepens gradually southward. The GB I, mostly occupying the channel-fill, is characterized by reflection-free seismic facies. It can be formed as late Transgressive System Tract (TST), interpreted tidal environment deposits. MFS appears at the depth of about 15~28 m below the sea-level and is well defined by even and continuous reflectors on the seismic profile. The GB II overlying MFS is composed of acoustically transparent to semitransparent and parallel internal reflectors. GB II is interpreted as the Highstand System Tract (HST) probably deposited during the last 6,000 yrs when the sea level was close to the present level. Especially, it is though that the GB II was subdivided into two layers (GB II-a and II-b) by a HST-reflector and this was classified by wind, sea water flux, and tidal current.