• ALGAE
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• v.26 no.3
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• pp.237-241
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• 2011

The toxic dinoflagellate Karlodinium veneficum has been implicated in numerous fish kill events around the world. Since this species commonly co-occurs with other morphologically similar dinoflagellates, field monitoring of this species in natural waters via light microscopy only has been problematic. In this study, we investigated temporal changes in K. veneficum's abundance in the waters of Obido, Tongyeong, using a species-specific real-time polymerase chain reaction (PCR) assay. The field survey, from April to December 2010, revealed K. veneficum occurred at low densities (12 to 425 cells $L^{-1}$) during this time and that cell numbers peaked in June (early summer in Korea), indicating this species generally occurs in the warmer season (mostly at $16.9-22.3^{\circ}C$ and 33.4-34.5‰) in the Obido area.

• Journal of Environmental Science International
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• v.15 no.11
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• pp.1035-1043
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• 2006

Large scale of fish kills by red tides has been occurred every year in coastal water fisheries of Korea. To suppress red tide spreading out over the south coastal water of the Korean Peninsula large amount of loess has been applied every year because loess is known to be effective in removing red tide organisms. Effects of loess application in ecosystem of underwater near sea shore were investigated with some physical characteristics of loess. Loess used for the red tide reduction consisted of very fine particles, of which size was mostly less than 0.1 mm. Particles of loess blocked light penetration, which is essential for the underwater ecosystem. Loess also pushed pH down by the hydrolysis activities of aluminium and iron It was found that underwater ecosystems where loess was applied near sea shore were devastated. Sea plants such as sea weeds were gone leaving only their roots. Clams and snails were dead under the loess dust blanket. And fishes were not found at all where loess has been sprayed lot long time. It was found that even if loess has some capacity to reduce red tide temporarily, loess application should be slopped to protect underwater ecosystems.

• The Korean Journal of Food And Nutrition
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• v.25 no.1
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• pp.69-76
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• 2012

Intense pulsed light(IPL) has been highlighted as an innovative nonthermal sterilization technology that can kill spoilage or pathogenic microorganisms by using short-duration pulses of intense broad-spectrum electromagnetic radiation. This paper examines the inactivation effects of IPL on Listeria monocytogenes, Escherichia coli O157:H7, and Pseudomonas aeruginosa inoculated on seafood products such as salmon, flatfish, and shrimps and evaluates the possibility of extending the shelf-life of seafood products. The results indicate that the inactivation of microorganisms increased with an increase in IPL energy density($J/cm^2$) and a decrease in the distance between the sample surface and the lamp. In addition, temperature increases on the fish fillets during the treatments were well controlled within the range of 5.7~$9.8^{\circ}C$. The IPL treatment had a significant positive effect on the storage stability of seafood products at the storage temperature of $4^{\circ}C$ for 12 days. These results suggest that the storage period for fish fillets can be extended from 4 days to 6~8 days through the IPL treatment.

• Journal of fish pathology
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• v.23 no.1
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• pp.123-129
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• 2010

The infestation status of anisakid type larvae was investigated in migrating chum salmon (Oncorhynchus keta), with different condition (captured area, sex, body portion) during 2006~2008. The mean infection number of anisakid larvae per individual female and male fish captured from Namdae river was $98{\pm}27$, $103{\pm}27$, respectively. The mean infection number of anisakid larvae per individual female and male fish captured from the coastal area of Yangyang was $63{\pm}18$ and $108{\pm}17$, respectively. The anisakid larvae were mainly found in abdominal muscles (85%) but only a little in the visceral portion. Two types of anisakid larvae (A. simplex, Contracaecum type) were identified but other anisakid larvae were not detected. To investigate the effect of storing temperature on the viability of anisakid larvae, the section of abdominal muscle were stored at different temperature (room temperature, $4^{\circ}C$, $-20^{\circ}C$, $-80^{\circ}C$). As a result, it was necessary to store at $-20^{\circ}C$ for more than 6 hrs to kill the larvae. The present results revealed that chum salmon caught in Korea are heavily infected with anisakid larvae, mainly in the abdominal muscle, and A. simplex was dominantly found in this study.

• BMB Reports
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• v.31 no.4
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• pp.355-363
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• 1998

MHC unrestricted, antigen nonspecific killing by $CD4^+$ T-cells against virally-infected target cells was induced following cross-linking of CD4 molecules. The cytotoxicity of antibody-activated $CD4^+$ T-cells was abolished by genistein (4',5,7-trihydroxyisoflavone), a protein tyrosine kinase (PTK) inhibitor, but not by H-7, a protein kinase C (PKC) inhibitor. Genisteintreated human or bovine peripheral blood $CD4^+$ T-cells lacked PTK activity and failed to kill virally-infected target cells even after cross-linking of CD4 molecules. The cross-linking of CD4 molecules did not induce effector cell proliferation or the transcription of TNF ${\beta}$. TNF ${\beta}$ synthesis was up-regulated by incubating antibody activated effector cells with bovine herpesvirus type 1 (BHV-1) infected D17 target cells. Anti-TNF ${\beta}$ antibody partially abrogated direct effector cell-mediated antiviral cytotoxicity. On the other hand, this antibody effectively neutralized antiviral activity of effector and target cell culture supernatants against BHV-1 infected D17 cells. The inhibition level of the antiviral activity by the antibody was dependent on effector and target cell ratio. These findings have importance to define the mechanisms of how CD4 cytotoxic cells control viral infection.

• Journal of Korean Society on Water Environment
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• v.27 no.1
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• pp.36-43
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• 2011

This study is selected two points of combined sewer that occurred Fish Kill after first flush, that analyzed generation of pollutants and stream runoff generation of combined sewer overflows (CSOs) as fine weather and rainfall. In addition, this study was to analyze the relationship between CSOs and sediments, to propose measures to reduce the sediment relevant with CSOs and rainfall runoff from entering sewage treatment plants and measures for discharged directly into streams when indicate relatively good water quality after overflow. Sediments in combined sewer system was discharged about 50~80% as overflows during rainfall and we can reduce the amount of the CSOs at least 50% or more if the sewer does not exist in the sediments because of the amount of discharge about the amount of intercept has been investigated by 3~5 times. Because of velocity at sediment interval in sewer is very low, sewage velocity of about 3~5 times as much as it can increase the amount of sediment can be reduced if the separation wall is installed. Effective control of BOD overflow load is respectively 77.5%, 75.8% at first point, second point by the separation wall is installed. Drainage area greater than area in this study or many combined sewer overflows region is increased the more effective control of separation wall. Turbidity to measure changes in water quality of overflows can be used as an factor to control the intercept flows because the intercept flows(3Q) after the first flush has lowered removal efficiency and increases the operational load of sewage treatment plants. Sewage water quality after a overflow when the reasonable turbidity was measured at this point flows to excluded intercept flow(1Q) can be discharged to stream.

• Journal of Life Science
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• v.22 no.6
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• pp.788-793
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• 2012

High concentration of antibiotics has been used to treat the outbreak of edwardsiellosis caused by Edwardsiella tarda in aquaculture. However, not all of the bacteria have been killed with high concentrations of antibiotics treatment by the formation of persister cells with a dormant state. The main objective of this study was to kill persister cell using antibiotics with the addition of natural plant compounds. Antibiotics used in this study consist of 100 mg/ml florfenicol and 100 mg/ml amoxicillin. Ten natural plant compounds with persister cell inhibitor activity to E. coli were obtained from Protein Engineering and Systems Biology Lab. of Sungkyunkwan University. The persister cell inhibition activities of those natural plant compounds were evaluated in test tube. Concentrations of the antibiotics were in the ranges of 25~200 ${\mu}g/ml$. The persister cell formation was observed after 16 hours of culture. Persister cells were killed by antibiotics with natural plant compounds. Among ten natural plant compounds, Gynostemma pentaphyllum, Mallotus japonicus, and Orixa japonica showed persister cell formation inhibition activities. The optimal concentrations of G. pentaphyllum, M. japonicus, and O. japonica for the inhibitor of persister cell formation were 100 ${\mu}g/ml$, 100 ${\mu}g/ml$, and 200 ${\mu}g/ml$, respectively. In vivo study was carried out to evaluate the effect of the antibiotics with natural plant compounds using aquacultural fish, olive flounder, as test animals. G. pentaphyllum, M. japonicus, and O. japonica of 30 ${\mu}g/ml$, 10 ${\mu}g/ml$, and 10 ${\mu}g/ml$ with antibiotics reduced cumulative mortalities, showing the effectiveness of persister cell inhibition.

• Parasites, Hosts and Diseases
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• v.26 no.3
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• pp.175-178
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• 1988

In an attempt to analyze the clonorchicidal activity of linoleic acid and ethyl linoleate in vitro, the wormicidal effects on Clonorchis sinensis were chronologically monitored in dose titration experiments. Encysted metacercariae were killed within a period of 31, $0{\pm}4.0$ min, 149.3k4. 1 min and $207.0{\pm}13.5$ min with 100.0 mg, 0.1 mg and 0.001 mg linoleic acid, respectively. The time required for the linoleic acid to kill adult worms was 167, $0{\pm}0.8$ min with 100.0mg, $253.0{\pm}0.8$ min with 0.1mg, and $277.0{\pm}0.8$ min at 0.001mg titration. Clonorchicidal activity of ethyl linoleate was relatively delayed as death was observed within $263.3{\pm}2.9$ min, $286.0{\pm}0.5$ min, and $318.0{\pm}0.8$ min for 100.0 mg/ml, 0.1 mg/ml and 0.001 mg/ml concentrations, respectively. The wormicidal effects observed with these pure anti-clonorchal substances were found to be similar to the biological activity of native products derived from the mucus of the fresh water fish.

• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.340-349
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• 2009

The natural type section of Gap Stream was divided into 7 sites, such as, closed pool, runs, riffle, opened pool, pool, reek-scattered riffle, and Dam-type pool. The ecological characteristics of fish community at each site was examined from April, 2007 to October, 2008. During the survey period, 29 species belonging to 8 families were collected, and Carassius auratus (St. 1), Coreoleuciscus splendidus (St. 3), Acheilognathus lanceolatus (St. 4) and Zacco platypus (St. 2, 5, 6, 7) were characteristic species that represent each habitat. The species of C. auratus preferred physical habitat with sand-bottom pool, moderate depth of 65$\sim$90 cm, and stagnant water. The species of C. splendidus mainly preferred physical habitat with cobbles and pebbles are scattered riffles (St. 3), moderate depth of 65$\sim$90 cm, and flow velocity is 0.14$\sim$0.85 m $sec^{-1}$. It also preferred where concentration of BOD, COD, TN, TP and SS is low and DO's value is high, because the flow velocity is fast. A. lanceolatus preferred where the depth of water is low (3$\sim$44 cm) like an opened pool (St. 4) and the flow velocity is slow (0.01$\sim$0.02 m $sec^{-1}$). Z. platypus dominated in a variety of habitats such as runs (St. 2), pool (St. 5), rock-scattered riffles (St. 6) and D-type pool (St. 7), and it preferred places where flow is abundant and riverbed structure is diverse. On the other hand, 4 individuals of Iksookimia choii appeared at reek-scattered riffles (St. 6). I. choii appeared in this research lived in where the width of river is 24 m, the depth of water is 3$\sim$35 cm and the flow velocity is 0.01$\sim$0.49 m $sec^{-1}$, and riverbed structure was diversely formed with boulder to sand. Also, water temperature, EC, BOD, COD, TN and TP was low, but concentrations of DO and SS were high comparatively. Therefore, it seems that I. choii can live only in physical and chemical environment with similar conditions.

• Korean journal of food and cookery science
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• v.18 no.6
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• pp.704-715
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• 2002

This study intended to compare dietary and snack habits of primary students in the schools providing and non-providing lunch to clarify the correlation between those conditions and the occurrence of dental caries. Furthermore, this study also focused on evaluating educational effects by providing children with nutritional education program. 1. As a result of dietary habit analysis, it was found that children from the school providing lunch were better in terms of breakfast regularity, eating speed. optimum amount of intake, and meal time regularity than those from the school non-providing lunch. In particular, it was noted that children from the school providing lunch took a little more meat, fish, seaweed and milk or dairy products than those from school non-providing lunch. Thus, it could be assumed hat children provided with lunch have more reasonable dietary habit than those without lunch program. In general, it was found that there was a slight positive change in children's dietary habit after nutritional instruction than before, suggesting that the nutritional education had effects on improving their dietary habit. 2. It was found that primary students often took snacks causing dental caries such as caramel, chocolate, sweets and biscuits, and children from the school providing lunch were more willing to reduce those snacks upon recognizing the causes of dental caries than those from the school non-providing lunch. For the children who chewed gum with physical cleansing effects, it was shown that the highest frequency wat twice or three times a week. Moreover, the ratio of children who took snacks following dinner which might affect their dental caries and the ratio of children who selected snacks because of TV commercial were both reduced after nutritional education. Also the consumption of detergent foods like vegetable, fruit, protein. seaweed. milk or dietary products after nutritional education was increased. 3. It was found that children from the school providing lunch took more often all food groups except for food group IV affecting dental caries than those from the school non-providing lunch. The average number of consuming foods which cause dental caries was 5.04 times per person a day, and most of those were rather taken by liquid than solid food. The average eating times of rinsing foods which kill the bacteria on the surface of teeth and prevent from dental caries, was 9.33 for a person a day, which was a little higher than recommended time. Exposed time for dental caries for a person a day was 100.9 min, of which liquid dental caries was 56.2 min and solid dental caries was 44.6 min, suggesting that liquid food had a high potential to cause dental caries.