• Journal of Marine Bioscience and Biotechnology
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• v.5 no.4
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• pp.15-25
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• 2011

Marine sponges are a rich source of highly diversified bioactive compounds. These medicinally valuable molecules represent extreme physiological and ecological functions in sponges, more presumably involving in the resistance to the feeding by other marine organisms like fish and fouling by barnacles, bacteria, fungi, etc. This feature of attaining resistance made sponges as successful poriferans that possess an impressive array of biological properties ranging from antimicrobial to anticancerous activities. The diversified bioactive principle of sponges might be due to their spacio-temporal distribution and although, the gateway for exploiting the sponges for isolating these distinct, potential molecules is open, suitable technical and methodological approaches are yet to be implemented in order to bring the sponges as successful pharmaceutical leads in the field of marine biotechnology. Despite of the identified difficulties of marine sponge research from past few decades, one should concentrate not only on the basic and applied technical/methodological considerations, but also on the novel strategies like in vitro sponge cell, fragment and whole sponge culture; sponge symbiont cell culture; in situ and ex situ sponge cultivation; and sponge bioreactors and metagenomic approaches, for the successful exploitation of marine sponges towards the novelty in sponge biotechnology. The present review narrates the pros and cons of the nowadays-marine sponge research by focusing on the suggestive ecobiotechnological approaches, based on the latest studies for feasible ecological exploitation and biotechnological application of sponges from the sea.

• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.126-141
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• 2021

Fauna of freshwater fish and community structure were investigated at 13 sites in the Deogyusan National Park, Korea from 2014 to 2018. During the period, a total of 8 families, 21 species, and 8,716 individuals of fishes were collected. The number of fish collected over the past five years from 2014 to 2018, were 17 species and 2,280 individuals, 17 species and 1,579 individuals, 17 species 1,905 individuals, 17 species and 1,384 individuals, and 15 species and 1,568 individuals, respectively. There were 13 Korean endemic species including Iksookimia koreensis and Coreoleuciscus splendidus, etc. Only in Wondangcheon Stream, two endangered species were identified, and Hemibarbus mylodon was collected continuously except in 2015, and Pseudopungtungia nigra was observed every year. And two exotic species such as Oncorhynchus masou masou and Oncorhynchus mykiss occurred in Gucheongdongcheon Stream sites. The dominant species was Rhynchocypris oxycephalus and the sub-dominant species was Zacco koreanus and there was no difference by year. The fish community structure of Deogyusan National Park was varied depending on the sites and the year. Most of the survey sites located upper stream where the river structure is Aa river type showed poor community analysis results. On the other hand, the upper-mid stream sites including the Bb type showed better results. As a result, the Wondangcheon Stream sites had the most diverse and stable community structure. Similarity dendrogram was divided into 4 groups, mainly reflecting the characteristics of the habitat. The flagship species of the Deogyusan National Park, Rhynchocypris kumgangensis, was constantly observed during the investigation period. Compared to the previous survey, the number of species increased from 2004 (12 species) and decreased from 2009 (22 species).

• Journal of Korean Society of Environmental Engineers
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• v.38 no.2
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• pp.47-55
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• 2016

In this study, WUA (Weighted Usable Area) based on the Instream Flow Incremental Methodology (IFIM) was calculated to determine ecological flow at JeonJu-Cheon by using River2D model. To calibrate River2D, simulation results for low flow conditions of River2D were compared with calibrated HEC-RAS simulation results and the optimum parameters were determined. The results were RMSE (0.18), NSE (0.71) and coefficient of determination (0.78) for velocity and RMSE (0.02), NSE (0.71), coefficient of determination (0.73) for water depth. The result shows that the model successfully simulates the water flows. A selected target fish species to build the habitat suitability index were composed of Zaccoplatypus and Coreoleuciscus splendidus. These species showed the highest occurrences over the past decade in f ish monitoring. Also, The WUA-Discharge curve was calculated with the suitability index in a medium flow conditions. From the result, WUA is changed according to flowrate. In the flowrate-WUA/A graph, ecological flow can be determined at $1.8{\sim}2.0m^3/s$ for Zaccoplatypus $2.0m^3/s$ and Coreoleuciscus splendidus $1.8m^3/s$ at JeonJu-Cheon upstream. When compared with flow-duration analysis, it is demonstrative that simulation results fitted ecological flow considering quantity of available habitat for each fish species.

• Environmental and Resource Economics Review
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• v.14 no.3
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• pp.699-728
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• 2005

This article is basically an extension of Barten(1993), Brown et al. (1995), Holt and Bishop's(2002) price formation system. A new dynamic price formation system is attempted considering full rationality of the consumers' side. The underlying idea of the new dynamic price formation system is that consumers are rational and farsighted and thus consider past and future consumptions in addition to current consumption to accept the prices traders called. In an empirical application, the U.S. commercial fish demand data are particularly interesting to this analysis in which the species are over fished, including many of the most valuable species. Especially, the grouper-snapper complex are under management jurisdiction of the National Marine Fisheries Council. In the empirical section, it shows how to adapt the model to estimate the marginal values to consumers of commercial fisheries. Since it is conceived of regulations as inducing movements along the marginal value curves, it is of growing importance to regional and national policy makers who are confronted with competing claims on diminishing fish stocks by commercial fisheries interests. It performs well and shows the plausible signs and magnitudes of price flexibilities and interaction among species. It further contributes to the general methodology of applied economics.

• The Journal of Fisheries Business Administration
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• v.1 no.2
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• pp.1-22
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• 1970

Our fisheries protucts industry has developed rapidly during past 10 years ; production was about twice: fihing fleets increased twice in number and 3 times in tonnage ; export was 5 times. Govermment is trying to develop deep sea fisheries in order to surmount the depression of coast fisheries. At present more than 270 deep sea fishing boats are working with superior skill to other country at the South Pacific, the Atlantic, the Indian, and the North Pacific Ocean. Our deep sea fisheries is consisted of the tuna long line and the trawler. The tuna long line of them has 230 crafts in 1969 ana the deep sea trawler has 40 crafts, too. Comparing to 1962, the number of the deep sea fishing boats has been increased highly to 54 times, 7.71 times average per year increasing rate. The rate of the tuna long line to the trawler at the end of 1969 shows 85:15, More than half of them are 100~200 (equation omitted), if we classify them according to (equation omitted) or boat craft. 70% of them has less than 5 years ships age. The Korean Marine Industry Development Corporation has more than 1/3 fishing fleets, with 91 crafts, if We consider it according to corporation. Considering it according to the financial resources, dependence upon foreign loan is as high as 88%. Catches was 74, 450 M/T ($24, 663, 000)at the end of November in 1969 and it was increased to 113.5 times in catch amount and 118 times in value, comparing to those of 1962. Considering it according to the ocean, the order is arranged to the Pacific, the Atlantic, and the Indian Ocean. The average production amount of each craft is 250~400 S/T a year. The result of export took up 1/3 of total fisheries product export with $ 22, 398, 000 at the end of november in 1969. Employee cost of fishing coast is 8% higher than other fishing. The profit is highest in our fisheries. Most of the products except the trawler fishing are sofa at the fishing grounds to the processing company, and they lose much money. They buy most of bait from Japan, giving $8~10 for 1C/S(10kg). Fish price is $390~520 according to the kind of fish for S/T at the fishing grounds, and the rapid frozen fishes brought to Japan are about $ 800 for S/T. There is much difference. in price. Problems 1. Want of self capital. 2. To get the refrigeration boats enough. 3. International Fishing Regulation. 4. To get high price and to secure consuming grounds. 5. To get home-production of bait. 6. To exploit new fishing grounds. 7. To get larger boats. 8. To get mariner enough. When the problems mentioned above are solved, the Deep Sea Fisheries of oun courtry will be developed more largely.

• Journal of Environmental Impact Assessment
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• v.28 no.2
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• pp.129-140
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• 2019

Majangcheon is a small agricultural stream which is located in Chuncheon-si, Gangwon-do. To understand ecological characteristics of Majangcheon as biological habitats, we surveyed its physical environment and fishes from June 2016 to September 2016. The altitudinal difference between lowest and highest point of the stream was 3 meters and the first-order stream under a map drawn on a scale of 1:25,000. The flow rate of stream was slow in overall with $0.09-0.48m{\cdot}s^{-1}$. More than 50% of clay were found in all points except for the point St. 3 in the riverbed structure surveyed. A total of 2,532 individuals of 22 species in nine families were collected from Majangcheon. Of them, stillwater-living species (Acheilognathinae and Carassius auratus) and floating species (Zacco platypus and Oryzias sinensis) were mainly collected. In Majangcheon, thus, both of stillwater-living and floating fishes were specifically coexisted. The correspondence analysis, based on fishes collected from Majangcheon and past research, showed that Majangcheon is closer to the flat streams in Gyeonggi-do rather than the mountainous streams in Gangwon-do but it appeared as an independent group from those of two regions. As a result, Majangcheon is a stream with specificity of fish community.

• BMB Reports
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• v.33 no.2
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• pp.184-187
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• 2000

Prostaglandin $E_2$ ($PGE_2$) plays an important role in the regulation of various gastric functions, and the growth-inhibitory activities on tumor cells are studied in vitro and in vivo. Although the mechanisms have attracted many researchers in the past decade, the molecular mechanisms of cell cycle arrest, or induction of apoptosis by $PGE_2$, is unclear. We investigated the effects of $PGE_2$ on the growth of the human gastric carcinoma cell line SNU1 and genes that are regulated by $PGE_2$ and isolated them using differential display RT-PCR (DD RT-PCR). FACS analysis suggested that SNU1 cells were arrested at the G1 phase by $PGE_2$ treatment. This growth inhibitory effect was in a time- and dose-dependent manner. Treatment of SNU1 cells with $10\;{\mu}g/ml$ $PGE_2$, followed by DD RT-PCR analysis, revealed differently expressed bands patterns from the control. Among the differently expressed clones, we found an unidentified cDNA clone (HGP-27) overexpressed in $PGE_2$-treated cells. The full-length cDNA of HGP-27 was isolated using RACE, which consisted of a 30-nt 5'-noncoding region, a 891-nt ORF encoding the 296 amino acid protein, and a 738-nt 3'-noncoding region including a poly(a) signal. This gene was localized on the short arm of chromosome number 11. Using the Motif Finder program, a myb-DNA binding repeat signature was detected on the ORF region. The COOH-terminal half was shown to have similarity with the $NH_3$-terminal domain of thioredoxin (Trx). This relation between HGP-27 and Trx implied a potential role for HGP-27 in modulating the DNA binding function of a transcription factor, myb.

• Korean Journal of Environment and Ecology
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• v.18 no.3
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• pp.326-332
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• 2004

A study of freshwater ichthyofauna was conducted in order to clarify its significance at 14 upstream sites in Muju, Jangsu, Geochang and Hamyang districts in Deogyusan National Park, enclosing Baekdudaegan. The freshwater fish fauna of the Park was measured at the 14 sampling locations from May 2003 to September 2003. The fifteen species gauged included four Korean endemic species and or subspecies (Squalidus japonicus coreanus, Iksookimia longicorpa, Coreoperca herzi, Odontobutis platycephala). Fourteen species were found in the Keum River and seven species in the Nakdong River. However, common species were Punchocypris, Rhynchocypris oxycephalus, Zacco temmincki, Misgurnus anguillicaudatus, Coreoperca herzi, and Odontobutis pzatycephala. The dominant species of these regions were Zacco temmincki and Rhynchocypris oxycephalus. Past studies conducted in Baekdudaegan mostly concernedflora and vegetation. In the future, new study concepts for stream corridors involving both animal and plant should be introduced.

• Parasites, Hosts and Diseases
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• v.45 no.3
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• pp.219-223
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• 2007

A case of Diphyllobothrium latum infection in a 49-year old man is described, and diphyllobothriasis latum in the Republic of Korea is briefly reviewed. An incomplete strobila of a tapeworm, 95 cm in length, without scolex and neck, was spontaneously discharged in the feces of a patient. On the basis of morphologic characteristics of the worm and eggs, the worm was identified as D. latum. The patient was successfully treated with a single dose (15 mg/kg) of praziquantel. The most probable source of infection was salmon flesh according to the past history of the patient. The first case of D. latum infection was documented in 1971, and this is the 43rd recorded case in the Republic of Korea. The 43 cases were briefly reviewed. The patients' main complaints were gastrointestinal troubles, such as mild abdominal pain, indigestion, and diarrhea, and discharge of tapeworm segments in the feces. The suspected infection sources included raw or improperly cooked flesh of fresh or brackish water fish, including the perch, mullet, salmon, and trout.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.2111-2114
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• 2016

Opisthorchiasis is a health problem in Thailand particularly in northeast and north regions where have been reported the highest of cholangiocarcinoma. Active surveillance is required, therefore a cross-sectional surveyed was conducted in Nong Bunnak sub-district of Nakhon Ratchasima province, Thailand. A total of 367 participants were selected by multistage sampling from 5 villages located near natural water resources. Participants completed a predesigned questionnaire containing behavior questions regarding liver fluke disease, covering reliability and validity knowledge (Kuder-Richardon-20) = 0.80, attitude and practice (Cronbach's alpha coefficient) = 0.82 and 0.79, respectively. Descriptive statistics included frequencies, percentages, means, and standard deviations. The majority of the participants were female (58.3%), age group between 21-30 years old (42.5%), with primary school education (59.9%), occupation in agriculture (38.1%), and married (80.9%). They had past histories of raw fish consumption (88.3%), stool examination (1.4%), anti-parasite medication used (4.6%). Heads of villages, village health volunteers, television, and village newstations were the main sources for disease information. Participants had a moderate level of behavior regarding liver fluke disease. The mean scored of knowledge regarding liver fluke life cycle, transmission, severities, treatment, prevention and control was 10.9 (SD=0.5), most of them had a moderate level, 95.1%. The mean score for attitude regarding liver fluke prevention and control was 45.7 (SD=9.7), and for practice was 30.6 (SD=10.5). Participants had a moderate level of attitude and practice, 94.5% and 47.7, respectively. This study indicates that health education is required in this community including stool examination for liver fluke as further active surveillance screening.