• KSBB Journal
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• v.14 no.3
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• pp.309-314
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• 1999

In order to produce high concentration of sodium gluconate, optimization of the fermentation conditions, such as glucose concentration, inoculum size, dissolved oxygen concentration and glucose feeding method, was examined. When the glucose concentration was maintained in the range of 30∼50 g/L during the batch fermentation, glucose conversion yield and productivity were 92.2% and 6.0 g/L/hr, respectively. In the case of the low concentration below 30 g/L, the yield decreased by about 25%. As the inoculum size increased above 20%(w/v), lag phase was shortened but the productivity decreased. The dissolved oxygen level of 60∼70% was shown to be the threshold point for 75% of increase in the productivity of sodium gluconate. Finally, optimal glucose feeding rate was determined using various feeding methods such as exponential feeding, feeding based on the average glucose consumption rate and was determined using various feeding methods such as exponential feeding, feeding based on the average glucose consumption rate and on the oxygen uptake rate and etc. Our result shows that glucose feeding, based on the oxygen uptake rate is a very simple, efficient and robust method, especially when oxygen is consumed as a substrate for the bioconversion. Using the above glucose feeding strategy under the optimized condition, 255 g/L of sodium gluconate concentration, 12 g/L/hr of productivity and 95% of glucose conversion yield were achieved with A. niger ACM53.

• Korean Journal of Environment and Ecology
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• v.21 no.4
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• pp.311-317
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• 2007

This study was conducted to determine the geographical distribution and habitat for Rana catesbeiana and Trachemys scripta elegans in order to obtain the current basic data on biota needed for establishing a database on non-indigenous species(NIS) in Jeju-do and to develop management plans applicable to Jeju, starting from March 2005 until May 2006. As a result of an inspection, it was found that the habitat for R. catesbeiana in Jeju includes Hankyeong-myeon, Daejeong-eup, and Ahndeok-myeon. These areas are all located on the western side of Jeju-do, and considered to have favorable conditions for R. catesbeiana to inhabit. Thus, it is unlikely that the population of R. catesbeiana will possibly decrease; what's worse, there exists even a risk that it could not only expand to other regions but also do damage to the population of native insecta, fishes, amphibians and reptiles, so this terrible species ought to be exterminated. More than 92 individuals of T. scripta elegans species were found to inhabit in 15 ponds around Jeju Island. T. scripta elegans. as the topmost predator, could destruct the pond ecosystem, and also cause a problem of water pollution due to its excrement. Counter-measures against T. scripta elegans could include publicity activities encouraging self-control of the release of captive T. scripta elegans, extermination plans using its ecological habits, and sign-posting publicizing its hazard to healthy ecosystem at the areas with high population density of T. scripta elegans or at its habitats with high foot traffic, together with the continuous management of NIS(none-indigenous species).

• Korean Journal of Ecology and Environment
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• v.52 no.4
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• pp.378-384
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• 2019

Red-eared slider, Trachemys scripta elegans, is one of the most famous species to disturb native ecosystems in the world. In South Korea, the species was imported as pet, and now it is found whole of the country. Recent, natural breeding and spreading of the turtle has been reported. In this paper, we investigated the environmental factors to affect the reproduction of T. s. elegans. We surveyed the distribution of the turtle in Jeju island, South Korea, between 2012 to 2017. We compared the land covers and climate of habitats from breeding sites and non-breeding sites. The species was found from 38 sites in Jeju island; 21 of breeding sites and 17 of non-breeding sites. The number of total and only adult turtles was significantly higher in breeding sites than non-breeding sites (P<0.05). In breeding site, the reproduction rate from the farmland was significantly higher than others(P<0.05). However, the rate of land covers was not significant in non-breeding site (P>0.05). The difference on the climate between breeding and non-breeding was not significant(P>0.05). Moreover, none of climate factors affected to reproduction of T. s. elegans(P>0.05). Our study showed that the land covers surrounding the habitats are more important than climate for reproduction of T. s. elegans in Jeju island. This result indicates investigating the habitat and surrounding is necessary for the control of reproduction and spreading of the introduced species.

• Journal of fish pathology
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• v.27 no.2
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• pp.91-97
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• 2014

Since the "Aquatic life disease control act" was established in 2009, we have monitored OIE notifiable and legally designated diseases which are associated with white shrimp Litopenaeus vannamei but are as yet outbreak in South Korea. We had monitored only two viral diseases of YHD and IMN, but further added IHHN, TS and WTD in an attempt to reinforce monitoring as a countermeasure against the increasing possibility of imported diseases led by continuous growth in global fisheries trade. We also increased the number of monitoring areas, and shrimp farms. In 2013, we examined a total of 2,650 white shrimp from 29 hatcheries and farms to check whether they were infected with any of the 5 diseases (YHD, IMN, IHHN, TS, WTD). The result showed that none of the samples contained the viruses. To regulation of the exotic diseases from landing in our country and to strengthen prevention, management and control of the diseases on a national level, we must continue the surveillance monitoring of the diseases.

• Korean Journal of Environment and Ecology
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• v.35 no.4
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• pp.347-376
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• 2021

Investigating and evaluating regionally distributed plant resources provide fundamental information (inventory) to conserve plant diversity in target areas. Nevertheless, the examination of inventory to collect information in areas with little interest has been insufficient. In this study, the vicinity of Mt. Baegamsan(1,004m) was investigated for plant resources in the central and southern part of the Korean peninsula, which has received low interest. Nine surveys identified a total of 638 taxa consisting of 108 families, 339 genera, 572 species, 12 subspecies, 49 varieties, and 5 forms. One taxon was designated to be the endangered wild plant by the Ministry of Environment, and a total of 29 taxa were designated to be endemic species in Korea. Floristic target species identified by the surveys included 1 taxon for grade V, 13 taxa for grade IV, 36 taxa for grade III, 29s taxa for grade II, and 34 taxa for grade I. A total of 38 taxa were identified to be naturalized plants, and 3 of them were designated as invasive alien plants by the Ministry of Environment. There was a difference in plant distribution between western and eastern areas of Mt. Baegamsan. The endangered and valuable plants for conservation were mainly identified from Mt. Baegamsan peak area, the ridge, and the western area. Considering the plant distribution, the Mt. Baegamsan region, located on Nakdong-jungmaek, was estimated to be dispersal routes for plant expansion and retreat.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.112-112
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• 2022

외래잡초인 애기수영(Rumex acetosella)는 생태계 교란종으로 생물다양성을 감소시키고, 우리나라 목초지에 우점하고 있어 큰 문제를 야기한다. 애기수영의 경우, 살초효과 및 제초활성물질인 chrysophanic acid와 catechd이 밝혀져 있지만, 톨페스큐(Festuca arundinacea)에 대한 살초 효과 연구는 미비하다. 이에 본 연구는 톨페스큐 종자에 대해 애기수영 MeOH 추출물을 처리한 Seed bioassay를 진행해 IC₅₀ 값을 구하고, 톨페스큐에 애기수영 MeOH 추출물을 경엽처리를 진행한 후 생육조사를 진행했다. Seed bioassay의 경우, petri dish 위에 톨페스큐 종자 20개가 치상하고, 애기수영 지상부 추출물과 지하부 추출물을 각각 20,000 mg L^-1, 10,000 mg L^-1, 5,000 mg L^-1, 2,500 mg L^-1 농도로 serial dilution 하여 1mL씩 분주한 뒤, 일주일 뒤에 발아한 종자에 대해 생체중을 조사하고 Prizm 프로그램을 이용해 IC₅₀을 구하였다. 경엽처리의 경우, 톨페스큐 종자 파종4주 뒤에 IC₅₀값이 더 낮았던 지상부 추출물을 100,000 mg L^-1, 50,000 mg L^-1, 25,000 mg L^-1, 12,500 mg L^-1, 6,250 mg L^-1 농도로 serial dilution 한 뒤 5mL씩 일주일 간격으로 3회 경엽처리를 진행하였고, 마지막 처리 일주일 뒤 초장, 근장, 생체중, 건물중을 조사하였다. Seed bioassay 결과, 애기수영 지하부 추출물에 대한 톨페스큐의 IC₅₀값은 3274가 나왔고, 애기수영 지상부 추출물에 대한 톨페스큐의 IC₅₀값은 2728가 나왔다. Seed bioassay 결과를 바탕으로 효과적 이 었던 지상부 추출물을 이용해 톨페스큐 경엽처리를 진행하였다. 애기수영 지상부 추출물 경엽처리 결과, 톨페스큐 초장과 생체중이 추출물 처리량이 높아짐에 따라 낮아졌으며, 100,000 mg L^-1 처리구는 Control과 비교해 유의적으로 감소하였고, 처리량이 높아짐에 따라 근장이 감소했지만, 유의적인 차이는 없었다. 그리고 건물중은 100,000 mg L^-1 처리구가 Control, 12,500 mg L^-1, 6,250 mg L^-1 처리구와 비교해 유의적으로 낮았다.

• Korean Journal of Environment and Ecology
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• v.37 no.2
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• pp.151-162
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• 2023

This study investigated the characteristics of fish communities and inhabiting status of the endangered species, Rhodeus pseudosericeus, in the Geumdang Stream in Korea from March to October 2021. A total of 1,698 fish in 5 families and 25 species were collected from 7 survey stations during the survey period. The dominant species was Zacco platypus (relative abundance, 46.5%), and the subdominant species was Squalidus gracilis majimae (16.7%), followed by Rhynchocypris oxycephalus (12.0%), Z. koreanus (5.7%), Pungtungia herzi (3.2%), R. pseudosericeus (2.0%), R. notatus (1.9%), and Acheilognathus rhombeus (1.8%). Nine Korean endemic species (36.0%) were collected, including R. pseudosericeus, R. uyekii, Sarcocheilichthys variegatus wakiyae, Microphysogobio yaluensis, S. gracilis majimae, Z. koreanus, Cobitis nalbanti, Iksookimia koreensis, and Odontobutis interrupta. An exotic species, Micropterus salmoides, designated as an invasive alien species (IAS), was collected downstream. The investigation of the habitat patterns of the endangered species (class II), Rhodeus pseudosericeus, showed a habitat range of about 6 to 7 km in the middle of Geumdang Stream (RP-1 to RP-4), and this species inhabited the edge with water depths of 0.3 through 1.0 m with slow water flow and many aquatic plants. According to the community analysis results, the overall dominance and evenness indexes were low, while diversity and richness indexes were high, and the cluster structure was largely divided into upstream and middle-downstream areas. The river health (fish assessment index) evaluated using fish was assessed as good (3 stations), normal (3 stations), and bad (1 station), and water quality was evaluated as good both upstream and downstream. Compared to previous studies, the number of species was relatively similar, and among the species that appeared in the past, 13 species did not appear in this survey, while 6 species appeared for the first time in this survey. Disturbance factors included river construction, many weirs, and the appearance of the ecosystem-disturbing species, M. salmoides. Since Geumdang Strem has high conservation value because it is home to many species in the Acheilognathinae subfamily, including the endangered species R. pseudosericeus, continuous attention and systematic conservation measures are required.

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.283-293
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• 2008

The objectives of the study were firstly to provide fundamental data for establishment of total maximum daily load (TMDL) management in Ulsan City, and secondly to make practical application of stream health assessment with tolerance range by each species when physiochemical and fish investigations were carried out together. A total of 44 sites in Taehwa River, Hoiya River, Dong Stream, and Cheongryang Stream were selected to monitor water qualities seasonally and fish investigation was performed in August 2006. Among the parameters of water quality, biological oxygen demand (BOD) and dissolved oxygen (DO) related to respiration, total nitrogen (T-N) and total phosphorus (T-P) related to nutrient and eutrophication, and total suspended solids (TSS) and $NH_4$-N were compared with vertical box plot by 8 dominant species. According to the fish investigation, 12 families 33 species were found including endangered species (Pungitius kaibarae) and introduced species (Lepomis macrochirus, Micropterus salmoides), and appearance rate of Korean endemic species was greater in Taehwa River (29.2%) than others. As the results of tolerance range by species, Zacco koreanus, Rhynchocypris oxycephalus, Iksookimia longicorpa, and Squalidus gracilis majimae had limited low range by water quality parameters indicating preference of good water quality. Whereas, Carassius auratus and Pseudorasbora parva were found downstream and urban-streams which were exposed from frequent inflow of pollutants. It concludes that the results help distinguishing sensitive, intermediate, and tolerant species when we evaluate stream health assessment with fish, and further making practical application for conservation and restoration of aquatic ecosystem.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.1
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• pp.34-42
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• 1997

Enuresis is repeated involuntary or intentional voiding of urine into bed or clothes over age 5. Though it would be a self-remitting disorder, it could be serious problem in emotional and socio-adaptational aspects. The author reviewed the enuretic patients of Child & Adolescence psychiatric section in Chungnam National University Hospital during past 3 years. 46(4.9%) of 936 patients were diagnosed as enuresis in DSM-Ⅳ. The author evaluated their comorbidity by the data of diagnostic review made in two psychiatrists, and emotional aspects(self-concept, anxiety, depression) through the self-rating scales (Piers-Harris children’ self concept scales, RCMAS, state-trait anxiety inventory for children, child’s depresson inventory). Thirty(65.2%) of the 46 enuretic patients had additional diagnoses such as attention deficit hyperactive disorder, mental retardation, encopresis, oppositional defiant disorder, depression, anxiety disorder, autism, somatoform disorder, tic disorder, obsessive-compulsive disorder, sleep disorder, etc. Sixteen enuretic patients had at least one comorbid disorder. Eleven patients had two, and three patients had more than three. Fourteen of 46 enuretic patients were evaluated through self-rating scales of self-concept, anxiety and depression. But we couldn’t obtain meaningful results. Maybe it was due to the small sample size(N＝14) and the influence of the comorbid disorders. Finally, it was an impressive evidence that there exist many comorbid disorders in enuresis(esp. attention deifict/hyperactive disorder). In emotional aspects, the author thought that further evaluation should be needed for more meaningful results.

• The Korean Journal of Mycology
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• v.16 no.4
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• pp.220-225
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• 1988

This study was carried out to investigate the effect on the system of crop rotation of sesame(Sesamum indicum L). The results of infected plant percentage and yield of sesame wilting disease, fluctuation of density of Fusarium oxysporum and Actinomycetes, and their pathogenicity test on Fusarium spp isolated from sesame cultural soil were investigated. Density of F. oxysporum was the highest in a sesame continuous cropping soil but that of Actinomycetes was the lowest in that soil. And that of F. oxysporum and Actinomycetes according to investigation date was the highest at June. 30 and July. 30, respectively. Their pathogenicity of F. oxysporum and F. solani isolated from sesame cultural soil to sesame, peanut and green gram were recognized to all isolates except one isolate among F. oxysporum 8 isolates and one isolate to sesame, 2 isolates to peanut and all isolates to green gram among F. solani 4 isolates. F. oxysporum density and infected plant of wilting disease were increased as a result of replanted cultivation of sesame, and yield of that was prominantly reduced. Relation between density of F. oxysporum in cultural soil and infected plant percentage showed positive correlation and yield index highly negative. There was little difference between sesame-upland rice and sesame-peanut in the system of crop rotation.