• Korean Journal of Ecology and Environment
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• v.47 no.2
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• pp.71-81
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• 2014

A survey was carried out to understand the influence of hydrology on the composition, abundance and adaptive strategies of phytoplankton in artificial Lake Hwaseong, an estuarine reservoir with seawater exchange through a sluice. Samples were collected seven times from May to October 2012. Hydrological events (seawater exchange, rainfall) resulted in a wide variation in salinity along with nutrients and turbidity. Shifts in the dominant phytoplankton composition occurred on every survey. Chlorophyll-a ranged from 9.7 to $104.1{\mu}g\;L^{-1}$. Multivariate analysis allowed us to identify the four phases on phytoplankton community change. Phase I (May~June) was characterized by small-sized Gymnodinium sp. and Heterosigma akashiwo dominated in warm temperature and high salinity derived from seawater exchange, and followed by Cylindrotheca closterium blooms due to rainfall and winds during phase II (July and September). During phase III (August), the dominance of Oscillatoria spp. was correlated with high temperature and low salinity. Abundant cryptomonads were associated with lower temperature during phase IV (October). Adaptive strategies were identified in the phytoplankton as morphological and physiological characteristics. These strategies identified small-sized flagellates as CR-strategists, fast-growing opportunistic species, which might favor the weak stratification of lake due to the seawater exchange during phase I and IV. Dominant species during phase II and III were characterized with R-strategists, medium-sized stress-tolerant species, which might favor turbulence by river flow. The results indicate that stronger stratification following the termination of seawater exchange for the freshening might intensify the predominance of smaller flagellates. In conclusion, this study suggests that hydrology may drive phytoplankton community change and blooms through the controls of salinity, turbulence and nutrients.

• Economic and Environmental Geology
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• v.4 no.4
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• pp.167-215
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• 1971

I. Purpose and Importance of the Study The purpose of the present study is to clarify to geological, mineralogical, and physico-chemical properties of the clay minerals deposits imbedded in the Tertiary sediments in the areas between. Pohang and Ulsan along southeastern coastal region of Korea. These clays are being mined and utilized for filter and insecticide after activation or simple pulverizing, nontheless activated clays are short coming as chemical industry in Korea has been rapidly grown in recent years. In spite of such increase in clay demand, no goological investigation on clay deposits nor physico-chemical properties of the clays have been carried out up to date. Consequently activated clays produced in Korea is not only of low grade but also of shortage in supply, so that Korea has to import activated clays of better grade. The importance of the present study lies, therefore, on that guiding principle could be laid down by knowing stratigraphical horizons, of clay deposits and fundamental data of improving grade of activated clays might be derived from the results of physico-chemical examinations. II. Contents and Scope of the study The contents of the study are pinpointed down in the following two subjects: 1) General geological investigation of Tertiary formations distributed in the areas between Pohang and UIsan, and detail geological study of the bentonitic clay deposits imbedded in them. 2) To clarifty physico-chemical characteristics of the clays by means of chemical analysis, X-ray diffraction and electron microscope. The scope of the study involves the following there points: i) Regional geological investigation-This investigation has been carried out in order to find out the distribution of Tertiary sediments and exact location of clay mineral deposits in the areas between Pohang and UIsan. ii) Detail geological investigation-This has been concentrated in and around the clay deposits which. had been found out by the regional investigation. iii) Laboratory researchs include i) age determination and correlation of Tertiary sediments by paleontological study, and ii) Chemical analysis, X-ray diffraction, and electron microscopic studies on clays, samples taken from various clay deposits. III. Research Results and Suggestions 1) The geology of the area investigated is composed mainly of Janggi and Beomgokri groups of Miocene age in ascending order rested on the upper Silla system, Balkuksa granite and volcanic rocks of upper Cretaceous age as base. 2) Janggi group is composed in ascending order of Janggi conglomerate, Nultaeri rhyolitic tuff, Keumkwangdong shale, two beds of lignite-bearing formations which consist of alternation of conglomerate, sandstone and mudstone, and andesitic, rhyolitic, and basaltic tuff beds. 3) Beomgokri group is mainly composed of andesitic to rhyolitic tuff interlayered by conglomerate and tuffaceous sandstone. In the areas around boundary between North-and South Kyeongsang-do is distributed Haseori farmation which is composed of conglomerate, sandstone, mudstone and andesitic to rhyolitic tuff, and which is correlated to Eoilri formation of Janggi group. 4) Clay deposits of the area are interbedded in Eoilri, Haseori, Nultaeri tuff, Keumkwangdong shale, upper and lower horizon of the lower lignite-bearing seam, and Keumori rhyolitic tuff formations of Janggi group; and are genetically classi.fied into four categories, that is, i) those derived from volcanic ash beds(Haseori and Daeanri deposits), ii) those of secondary residual type from rhyolitic tuff beds(Seokupri deposits), iii) Clay beds above and beneath the lignite seams, (Janggi and Keumkwangdong deposits), and iv) those derived from rhyolitic tuff beds(Sangjeong and Tonghae deposits). 5) Mineral constituents of clay deposits are, according to X-ray diffraction, montmorillonite accompanied in different degree by cristobalite, plagioclase, quartz, stilbite, and halloysite in rare occasion. The clays are grouped according to mineral composition into four types; i) those consist mostly of montmorillonite, ii) those composed of montmorillonite and cristobalite, iii) those composed of montmorillonite and plagioclase, and iv) those composed of montmorillonite, plagioclase and quartz. 6) Clays interbedded in Haseori formation and vicinity of lignite seams belong to the first type, are of good quality and derived either from volcanic ash bed, or primary clay beds near lignite seams. Clays belonged to other types are derived from weathering of rhyolitic tuff formations and their quality varies depending upon original composition and degree of weathering. Few clays in secondary residual type contain small amount of halloysite. 7) Judging from analytical data, content of silica($SiO_2$) varies proportionally with content of cristobalite, and alumina($Al_2O_3$) content does not vary with that of plagioclase, but increases in the sedimentary bedded type of deposits. 8) It is unknown whether or not these days could be upgraded by beneficiation since no grain size of these impurities nor beneficiation test had been studied. 9) Clay beds derived from valcanic ash layers or sedimentary layers at the vicinity of lignite seams are thin in thickness and of small, discontinueous lenticular shape, although they are of good quality; and those derived from rhyolitic tuff formations or residual type from tuff are irregular in both occurrence and quality. It is, therefore, not only very difficult but also meaningless to calculate its reserve, and reserve estimation, even if done, will greatly be deviated from practically minable one. Consequently, way of discovery and exploitation of clay deposits in the area under consideration is to check the geologically favorable areas whenever needed.

• Journal of Food Hygiene and Safety
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• v.4 no.2
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• pp.119-132
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• 1989

Gamma irradiation as a new physical treatment was applied to comparative investigates with a conventional ethylene oxide fumigant on the microbiological and physicochemical qualities of selected spices and dry vegetables such as powdered red pepper, black pepper, welsh onion, onion, garlic, carrot, korean cabbage and instant ramyon soup. The microorganisms contaminated in the sample, including total viable count, thermophilic bacteria, aerobic spore and fungi counts between the $10^4\;to\;10^6/g$ range. Coliforms were found only in black pepper and welsh onion powder as the $10^2\;to\;10^3/g$ level. A radiation dose of 7 to 10 KGy were sterilized completely to the contaminated microorganisms, while ehthylene oxide (E.O.) fumigation reduced of them to the $10^3/g$ level. An optimum dose of irradiation was less detrimental than E.O. fumigation to the physicochemical properties of the sample. Sensory evaluation after three months of storage at room temperatures showed that the overall acceptability of irradiated sample was higher than that of the non treated control as well as E.O. fumigated samples. Comparison gamma irradiation with E.O. gas treatment showed that E.O. treatment was less effective than radiation in cotrolling microbial contamination of spices and vegetables.

• Journal of Animal Science and Technology
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• v.48 no.3
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• pp.479-486
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• 2006

The current study was conducted to examine the effect of feeding and management practices on milk quality and dairy farm productivity in Korea. Fifty dairy farms in Gyunggi (11), Gangwon (22), Chungnam (17) provinces were surveyed to collect data on the herd size, housing style, feeding management, waste disposal, milking practices and milk yield. Milk tank samples from all farms under study were also collected to enumerate its composition and quality parameters. Large dairy herds are equiped with better housing, milking and waste control facilities than medium and small dairy herds. Higher concentrate feeding to lactating cows was noticed in small dairy herds (47.51 %) than in medium (32.59 %) and large dairy herds (31.82 %). The decrease in concentrate feeding to lactating cows with increase in number of cows per farm resulted in a simultaneous increase in the use of imported forages. Bacterial count in milk was affected by housing and milking facilities at dairy farms. Higher bacterial counts (Coliform and E. coli) in milk were observed in cows housed in stanchion than those under free stall with saw dust bedding. The bacterial counts were higher with bucket milking system than with pipe-line and parlour systems. The increase in the number of dairy cows per farm and thus better management and milking facilities resulted in a reduction in somatic cell score. Milk yield (per cow) was higher in herds with less somatic cell score. Average milk protein concentration was between 2.89 to 2.98 % and milk urea nitrogen was between 21.81 to 23.31mg/ml on surveyed dairy farms. This study concluded that large herd size with better dairy cow management facilities is crucial to produce quality milk with better dairy farm income.

• Food Science of Animal Resources
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• v.27 no.1
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• pp.122-126
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• 2007

Expenditure on meat and meat products has been increased in Korea due to the increase of income and the change of diet. From raising farm animals to eating the meat, various hazardous elements can make their ways into the meat and meat products. Recently the issues on food safety and hygiene are drawing a lot of attention, and the current system for managing the safety of foods is still needed to be improved. This survey was aimed to monitor the current situation of country-of-origin labels and hygiene for the meat markets at 4 regions Korea. The survey was performed by collecting samples from whole- sale and retail stores in the nation, which were selling beef. The markets were divided into groups as to territory and the size of the market (Large size, Medium size, and Small size). In terms of size distribution, small butcher shops occupied the highest percentage. On the itemized suitability test of unpacked and packed beef, all the market of 4 regions showed good agreements. However, such labels indicating the methods of cooking and storage were not properly posted on the products. Especially for Ho-nam region, corrections are needed. The results of monitoring sanitation conditions for the butcher shops at 4 regions in Korea showed relatively low suitability. Especially, there were serious lack of knowledge about wearing the sanitation clothing, caps, and shoes. The problem with food safety is so complicated that producer, consumer, food manufacturer, the press, the government, and scholar should solve altogether. It is necessary to educate farmers, food handlers, consumers, etc. and provide them with an accurate information and knowledge.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1186-1192
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• 2003

The food components and quality characteristics of two kinds of boiled-dried anchovies (Engraulis japonica) in the Korean market such as the Jukbang-Myoel (JM) and Kwonhyunmang-Myeol (KM) were investigated. KM was higher in moisture content, and lower in crude protein and lipid contents than JM. Volatile basic nitrogen was higher in KM than in JM, whereas TBA value showed higher levels in JM. Total combined amino acid contents of KM and JM were 41.9∼46.6 g/100 g and 42.0∼49.2 g/100 g, respectively, and large sized boiled-dried anchovies revealed higher contents than small sized ones in both samples. Their major amino acids were Glu, Asp, His, Leu, Ala and Arg. Total lipids of KM and JM were consisted of 55.4 ∼ 68.4%, 53.0 ∼ 68.0% neutral lipid and 31.6∼44.6%,32.0∼47.0% polar lipid, respectively, and their major fatty acids were 14:0, 16:0, 16:1n-7, 18:1n-9, 20:5n-3 and 22:6n-3. In taste compounds of boiled-dried anchovies, free amino acid contents of Km and JM were 953.7 ∼ 1,044.8 mg/100 g and 968.8 ∼ 1,306.4 mg/100 g, respectively, and main free amino acids were Tau, His, Ala, 1-methyl his, Lys, Glu and Gly. The contents of other taste-active components such as IMP, total creatinine, TMAO and inorganic ions were not significantly different between KM and JM. The results of sensory evaluations for organoleptic characteristics, small sized JM showed no difference in sensory qualities, whereas large sized JM showed good qualities for appearance, taste and odor compared with KM.

• Tuberculosis and Respiratory Diseases
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• v.64 no.3
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• pp.200-205
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• 2008

Background: Tumor angiogenesis plays an important role in tumor growth, maintenance and metastatic potential. Tumor tissue produces many types of angiogenic growth factors. Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) have both been implicated to have roles in tumor angiogenesis. In this study, the expression of tissue VEGF and bFGF from non-small cell lung cancer (NSCLC) patients were analyzed. Methods: We retrospectively investigated 35 patients with a histologically confirmed adenocarcinoma or squamous cell carcinoma of the lung, where the primary curative approach was surgery. An ELISA was employed to determine the expression of VEGF and bFGF in extracts prepared from 35 frozen tissue samples taken from the cancer patients. Results: VEGF and bFGF concentrations were significantly increased in lung cancer tissue as compared with control (non-cancerous) tissue. The VEGF concentration was significantly increased in T2 and T3 cancers as compared with T1 cancer. Expression of VEGF was increased in node-positive lung cancer tissue as compared with node-negative lung cancer tissue (p=0.06). VEGF and bFGF expression were not directly related to the stage of lung cancer and patient survival. Conclusion: Expression of VEGF and bFGF were increased in lung cancer tissue, and the expression of VEGF concentration in lung cancer tissue was more likely related with tumor size and the presence of a lymph node metastasis than the expression of bFGF. However, in this study, expression of both VEGF and bFGF in tissue were not associated with patient prognosis.

• Journal of Preventive Medicine and Public Health
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• v.25 no.3 s.39
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• pp.312-329
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• 1992

The purpose of this study is to estimate cesarean section rate in Korea and analyze the socioeconomic variables and health resources which affect regional variation in the rate. Samples were drawn from the record of vaginal and cesarean section deliveries based upon insurance claim bills which have been submitted to the National Federation of Medical Insurance for the first three months, January through March, 1991. The results are obtained as follows : It was found that. cesarean section rate was increasing rapidly up to 23.1% in 1991. Cesarean section per 10 thousand insured people was 4.8 and the number of cesarean section per 10 thousand insured eligible($15{\sim}49$ years old) female was 7.6. The fee for normal delivery was 109,489 won and that for cesarean section was 390,024 won. The average days of hospitalization in normal delivery was 2.3 days, and those in cesarean section was 7.6 days. On the average cesarean section has a longer of stay as much as by 4.3 days and cost 3.6 times more than normal deliveries. Cesarean section rates vary among medical facilities 19.8% at clinics 37.6% in small-scale hospitals, and 29.1% in general hospitals. The regional variation of cesarean section rates was also fairly prominent. The South Cheju Gun has the highest rate of cesarean section, 56.2%. Meanwhile no cesarean section cases has been reported in Sunchang Gun during the period of this study. The variation is noted among provinces. The rate for Cheju province has been 3.4 times higher than that for Chunnam. The number of cesarean section per 10 thousand insured people vary greatly among regions, too. This study has found that there exists significant regional variations among various geographic units in terms of average length of stay, average cost, number of obsretricians and number of beds. Multiple regression analysis was done to identify factors explaining the regional variance of various cesarean section rates : In the urban areas, no significant explaining variables were noted except the number of beds for the dependent variable of cesarean section cases per 10 thousand insured eligible females. The smaller the number of bed, the more cases of cesarean section was noted for an urban area. The is mostly because the rate of cesarean section is higher in medium-size hospitals than in large general hospitals. In the rural areas, the factor of education has been found significant for all three deplendent variables. The higher the educational level, the rate of cesarean section is most likely to rise. An income variable measured by the amount of monthly insurance contribution has been identified a powerful predictor in explaining the valiance of cesarean section rates. The same has been noted for the number of obstetricians. Similar findings are observed for the country as a whole. The income level has veen found as the most powerful explaining factor in the regional variance of cesarean section rates. In general the rate is higher in the urban areas, and lower in the area with more small hospitals. As this is the initial attempt to identify the factors relevant to the regional difference in the rates of cesarean section, more elaborated study is urgently required.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.296-301
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• 2014

Rotavirus is a major cause of acute gastroenteritis in young children in developed and developing countries. The use of probiotics for the treatment of gastrointestinal diseases is both safe and easily accessible. In this study, we evaluated the anti-rotaviral activities of probiotic mixtures in a Sprague-Dawley rat. 24 litters with their dams were randomly assigned to four groups; placebo, phosphate buffered saline (PBS), and two probiotic mixture (PRO-1 and PRO-2) groups. All rats were inoculated with rotavirus at dose of 8 log plaque forming units per rat at 5 days old. Animals in the PRO-1 and PRO-2 groups were orally administered probiotic mixtures 1 or 2, respectively, at a dose of 8 log colony forming units daily during 4 days. For control purposes, placebo and PBS groups were orally administered the same amount of placebo (containing maltose and polydextrose) or PBS once daily for 4 days, respectively. Antiviral analysis was performed by real-time quantitative PCR (RT-qPCR) and observing intestinal villi. As a result, weights of small intestines were greater in the PRO-1, PRO-2 groups than in control groups. Villi were short and villous epithelial necrosis was exhibited in control groups, but these morphological changes were not observed in PRO-1, PRO-2 treated rats. RT-qPCR analysis showed that VP7 gene level of rotavirus in fecal samples and small intestinal epithelial cells were lower in the PRO-1 and PRO-2 groups. These findings suggest that probiotic mixtures may be useful probiotics for the treatment of or as alternative therapies for rotaviral gastroenteritis.

• Korean Journal of Heritage: History & Science
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• v.50 no.4
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• pp.122-147
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• 2017

The Jungsandong sites are distributed across quartz and mica schist formations in Precambrian, and weathering layers include large amounts of non-plastic minerals such as mica, quartz, felspar, amphibole, chlorite and so on, which form the ground of the site. Neolithic pottery from Jungsandong exhibits various brown colors, and black core is developed along the inner part for some samples, and sharp comb-pattern and hand pressure marks can be observed. Their non-plastic particles have various composition, size distribution, sorting and roundness, so they are classified into four types by their characteristic mineral compositions. I-type (feldspar pottery) is including feldspar as the pain component or mica and quartz. II-type (mica pottery) is the combination of chloritized mica, talc, tremolite and diopside. III-type (talc pottery) is with a very small amount of quartz and mica. IV-type (asbestos pottery) is containing tremolite and a very small amount of talc. The inner and outer colors of Jungsandong pottery are somewhat heterogeneous. I-type pottery group shows differences in red and yellow degree, depending on the content of feldspar, and is similar to III-type pottery. II-type is similar to IV-type, because its red degree is somewhat high. The soil of the site is higher in red and yellow degree than pottery from it. The magnetic susceptibility has very wide range of 0.088 to 7.360(${\times}10^{-3}$ SI unit), but is differentiated according to minerals, main components in each type. The ranges of bulk density and absorption ratio of pottery seem to be 1.6 to 1.7 and 13.1 to 26.0%, respectively. Each type of pottery shows distinct section difference, as porosity and absorption ratio increase in the order as follows: I-type (organic matter fixed sample) < III-type and IV-type < I-type < II-type (including IV-type of IJP-15). The reason is that differences in physical property occur according to kind and size of non-plastic particles. Although Jungsandong pottery consists of mixtures of various materials, the site pottery has a geological condition on which all mineral composition of Jungsandong pottery can be provided. There, it is thought that raw materials can be supplied from weathered zone of quartz and mica schist, around the site. However, different constituent minerals, size and rock fragments are shown, suggesting the possibility that there can be more raw material pits. Thus, it is estimated that there may be difference in clay and weathering degree.