상수원의 오염에 대한 식물플랑크톤의 오수생물학적 연구 - 만경강 상류 하천 및 저수지를 중심으로 -

최민규,김백호 ( Min Kyu Choi,Baik Ho Kim ) 한국환경생물학회 1994 환경생물 : 환경생물학회지 Vol.12 No.2

Phytoplankton community and its physicochemical parameters were investigated at three reservoirs and four streams in the upper part of the Mankyeong River System from July, 1993 to June, 1994 on seasonal interval. Totally, 322 taxa were classified and composed of 33 families, 82 genera, 263 species , 52 varities and 7 forma Among them, 135 taxa of Bacillariophyceae was the highest record during this study. Total standing biomass of 1.11×10 exp (7)cells/㎖ was enumerated, and the high peak was in summer as 3.16×1010 exp (7)cells/㎖(28.5%), and also, reservoirs more higher than streams in biomass. Melosira granulata was much dominated and totally, 4.9×10 exp (5)cells/㎖ was counted As a whole, nine taxa of fourth species including Cyclotella meneghniana in streams and five taxa with Melosira varians in reservoirs were also domianted Synedra ulna and Melosira granulata were distributed either at stream or reservoirs. Species diversity indices(H` ) were showed the maximum at station 5 as above 2.0 without seasonality and the lowest at station 6 and 7 as below 1.0 in spring and summer. Similarity indices among sampling stations were the peak as 0.58 between station 4 and 5, the lowest between station 6 and 7 located at the same stream. In view of correlation between biological and physicochemical conditions at three reservoirs, station 3 and 6 were more related with organic nutrient, in other hand, station 7 was dependent with physicochemicals such as water temperature and dissolved oxygen. And also, water qualities of station and 6 with regard to total biomass of the major dominant species were ranged from oligotrophic to eutrophic, while station 3 on summer and autumn was eutrophic. The degree of pollution tolerance scores(PTS) was ranged from degree 1 to 4 Several bioindicators newly introduced, three common species were Melosira granulata, Synedra ulna and Melosira varians. Two taxa of Gomphonema olivaceum and Cyclotella meneghniana were showed only in degree 2, and also, two taxa of Achnanthes subsalsa and Melosira italica var. tenuissima were distributed only in degree 3. Microcystis aeruginosa was well dominated at eutrophic state as below degree 3. From this above results, we may evaluate the degree of water quality based on bioloical and physicochemical conditions that station 1 in summer and autumn was oligotrophic state as degree 1, station 3 in summer and winter was α-mesosaprotrophic as degree 3, and totally showed β-mesosaprotropnic as degree 2.

Fine Structure of Blue-green Algae, Microcystis aeruginosa Kutzing

최민규,김백호,문연자,정연태,이종빈,위인선,Choi, Min-Kyu,Kim, Baik-Ho,Mun, Yeun-Ja,Chung, Yeun-Tai,Lee, Jong-Bin,Wui, In-Sun Korean Society of Electron Microscopy 1996 Applied microscopy Vol.26 No.4

In order to understand the morphological differences between two different organic loadings by its upstream, and to compare with other algal groups with references, the fine structure of blue-green algae, Microcystis aeruginosa Kitzing, taken from two branches, Tongbok and Bosung stream of Lake Chuam, Korea pennisula was examined. It showed extinct differences in most physicochemical factors between both branches, except water temperature and pH values. The concentrations of total phosphorus in Tongbok branch were twice as those of Bosung. M. aeruginosa cells were enumerated totally $1.2X10^4cells/ml$ and these individuals in branch of Tongbok were close to two times as much as Bosung. In light and electron microscopy, natural M. aeruginosa colonies formed irregular shape and non-directional array in amorphous matrix. They were consisted of many kinds of cells, youngs or olds in cell division, solitary, and various size of cells. Each cell ranged from 2.61 to $5.40{\mu}m$ in diameter, and averaged as $3.54{\pm}0.19{\mu}m$. In cytoplasm, they contained a number of inclusions in various size, shape and appearances. Among them, polyhedral bodies or carboxysomes, a structured granules, photosynthetic lamellae or thylakoids, and gas vacuoles were prominent and easy to recognize. Although it was failed to find the definable morphological variations in the ultrastructure of M. aeruginosa in terms of algal habitual environments, some useful characters were founded, outer layer of cell wall, polyhedral bodies and gas vacuoles, in blue-green algal classification and taxonomy. 주암호의 유입하천중 이화학적 조건이 서로 다른 보성천과 동복천에서 채집된 남조 Microcystis aeruginosa Kutzing의 미세구조에 대한 형태학적 관찰을 시행하여 다음과 같은 결과를 얻었다. 수온과 pH를 제외한 다른 환경요인들은 두지점간에 큰 차이를 보였다. M. aeruginosa의 광학 및 전자현미경적 관찰 결과, 세포는 부정형 군체를 형성하며, 투명한 점액질로 싸여 있었다. 세포는 난형 또는 구형에 가깝고, 크기는 $2.61{\sim}5.40{\mu}m$의 범위로서, 평균 $3.54{\pm}0.19{\mu}m$였다. 세포질내에는 많은 다양한 구조물을 가지고 있으며, polyhedral bodies(carboxysomes), polyphosphate, cyanophycin granules 외에 photosynthetic lamellae와 gas vacuoles 등이 비교적 뚜렷하였다. 두 채집장소간의 형태학적 차이는 보이지 않았으나, 영양염류 수준이 높은 표본에서 polyphosphate와 cyanophycin granules이 숫적 증가를 보였다. 세포분열은 이분법으로 초기에 정중앙부의 좌우로부터 합입이 일어났으며, 주로 세포벽의 제1층과 제2층이 관여하였다. 세포벽의 외부층은 크게 두가지 형태의 filaments층이 잘 발달되어 있었다.

주암호의 식물플랑크톤의 출현과 동태

최민규,김백호,정연태,위인선 ( Min Kyu Choi,Baik Ho Kim,Yeun Tai Chung,In Sun Wui ) 한국하천호수학회 1994 생태와 환경 Vol.27 No.1

A short-term survey was carried out to understand the species composition and standing biomass of phytoplankton in Lake Chuam, where severe the eutrophication have took place on summer, 1992. Totally 130 taxa of phytoplankton were collected and consisted of 6 classes, 10 orders, 7 suborders, 23 families, 55genera, 116 species, 13 varieties and 1 forma. Phytoplankton compositions in each class were divided in 57 taxa of Chlorophyceae (43.8%), 44 taxa of Bacillariophyceae (33.9%), 20 taxa of Cyanophyceae (15.4%), 6 taxa of Euglenophyceae (4.6%), 2 taxa of Dinophyceae and 1 taxa of Chrysophyceae. The composition of species and standing biomass was reached to maximum, 72.31% and 42.67% at Site 3, respectively. Dominant species were Microcystis aeruginosa (51.65%), Melosira granulata (4.96%). The next major phytoplankton except these two species were ceratium hirundinella, Eudorina elegans, Anabaena flos-aquae, Dictyosphaerium pulchellum, Coelastrum microporum, Coelasphaerium kuetzingianum, and staurastrum paradoxum var. longipes. These groups were 73.1% of total biomass. And also, species diversity was high at Site 3 throughout the sampling times. Coelastrum-Coelasphaerium-Eudorina-Staurastrum assemblages were much distributed in centering of Site 3, the upper part of lake, inflowed sufficient nutrient from many tributaries. Especially, the high frequency (2.7% of totals) of Staurastrum paradoxum var. longipes was very interesting and new to Korea. In physicochemical factors, suspended solids, electric conductivity and chlorophyll a were reached the maximum, 34.5mg/l, 103μhmos/Cm, 6.7mg/m^3 only at Site 3 in June, closely associated with green algal assemblages. But other data were not showed any relationship between biological and physical conditions of phytoplankton community. The above mentioned results indicate that Lake Chuam has a wide range from eutrophic to oligotrophic state according to Hutchinson(1967), and divided into two regions, Site 1,2 and Site 3 in a view of phytoplankton distribution and biomass and its environmental condition. We conclude that Site 3 was in situation of considerable organic pollution.

Feeding Behavior of One-year-old Silver Carp, Hypophthalmichthys molitrix, on Dominant Phytoplankton During a Summer in the Enclosure of Shallow-hypertrophic Lake

최민규,김백호,Choi, Min-Kyu,Takamura, Noriko,Kim, Baik-Ho 한국하천호수학회 2000 생태와 환경 Vol.33 No.4

수심이 얕은 부영양호수에서 우점하는 식물플랑크톤에 대한 1년생 백련어의 섭식특성을 조사하고자, 1997년 5월 23일부터 9월 18일까지 호수의 연안에 4개의 enclosure를 설치하고, 어류투입 이후의 각 enclosure수중과 어류의 장 내용물 중의 식물플랑크톤 군집의 변화를 비교하였다. 조사기간동안 각 enclosure의 수온, 플랑크톤의 총생물량, 어류 아가미의 여과공 등은 시간에 따라 른 변화가 없었으며, 어류성장은 주로 투입된 어류의 밀도에 의존되었다. 어류의 내용물에 의하면, 저밀도 투입 enclosure에서 수중과 어류 전장간의 플랑크톤군집의 유사도가 높게 나타났으며(p<0.05), 전체적으로 모든 enclosure에서 크기가 큰(>$100,000{\mu}m^3$) 식물플랑크톤-Oscillatoria, Anabaena, Melosira등은 어류투입이후 크게 감소되지 않았다. 어류의 먹이선택지수(${\alpha}$)와 플랑크톤의 크기 (Ingestion unit)사이에도 매우 낮은 상관성을 보였다(r = 0.001, p>0.5). 식물플랑크톤의 분석결과, 백연은 남조나 녹조에 비해 규조를 더 선호하였는데, 이는 규조의 세포벽이 다른 조류에 비해 소화과정동안 쉽게 파괴되지 않고, 저배율의 현미경적시야에서도 간단히 확인된다는 점 등,선택지수를 과대평가하게 되는 단점이 있기 때문에 백련어의 먹이습성에 대한 방법론적 개선이 필요하다고 판단된다. The feeding behavior of 1-year-old silver carp, Hypophthalmichthys molitrix (Val.) on phytoplankton species in a shallow hypertrophic lake was studied from 22 May to 18 September, 1997. Over the experimental period, the filter-pore sizes of the fish, the total biomass of the phytoplankton and the water temperature in each enclosure changed little with time. The fish biomass in each enclosure increased with time, while their percentage of weight gain correlated negatively to the stocking density, due perhaps to competition for prey. An analysis of gut contents of silver carp showed a strong similarity between the algal communities in the foregut and the water, and was significant for the fish enclosure with a low density (p<0.05). The presence of silver carp rarely suppressed the abundance of phytoplankton such as Oscillatoria, Anabaena and Melosira even at high ingestion levels. There were weak relationships between the IU values of each phytoplankton and the selectivity of fish on them (r = 0.001, p>0.5). There was no doubt that the silver carp fed unselectively when cyanobacteria populations were high, even though the selectivity index for diatoms was slightly higher than those for cyanobacteria, green algae and cryptomonads. Improvements in methodologies are needed to clearly understand and generalize the feeding behavior of silver carp.

The Roles of FGF-4 on the Differentiation of Trophoblast Stem (TS) Cells

최민규(Min-Kyu Choi),오정택(Jung-Taek Oh),오재민(Jay-Min Oh) 대한해부학회 2004 Anatomy & Cell Biology Vol.37 No.2

FGF-4는 세포의 증식, 분화, 이동, 침투, 혈관생성, 및 여러 세포에서 apoptosis를 포함한 stress에 대하여 세포를 보호하는 기능 등의 많은 작용을 가지고 있다. 그러나 이렇게 많은 기능을 가지고 있음에도 불구하고 태반이나 trophoblast에서 fibroblast growth factor-4 (FGF-4)의 역할에 대한 연구는 거의 없는 실정이다. 따라서 본 실험은 태반의 발달과정에서의 FGF-4의 역할에 대하여 알아보기 위하여 TS cell의 분화과정에 미치는 FGF-4의 역할을 조사하였다. Trophoblastic stem (TS) cell에 처리된 FGF-4는 48시간 후에 태반의 조기발달을 유도하는 Eomesodermine의 mRNA발현을 증가시켰고 태반발달과 정 중에 태반의 혈관형성에 중요한 역할을 하는 p38의 활성화와 Dlx-3의 발현을 유도 시켰을 뿐만 아니라 내피세포만 특이적으로 자랄 수 있는 firbinogen-thrombin gel에서 TS cell을 건강한 상태로 유지시켰다. 또한 extracellular-signal regulated kinase를 활성화 시키고 focal adhesion kinase의 활성을 억제 시킴으로써 TS cell의 분화를 억제하고 TS cell의 증식상태를 활발하게 유지하였다. 이러한 결과들을 종합하여 볼 때, FGF-4는 태반의 발달과정에 필요한 TS cells의 전 분화과정에 중요한 역할을 하리라고 생각한다. Fibroblast growth factor-4 (FGF-4) has various functions, affecting many signaling pathways, and leading to cellular proliferation and differentiation and to the regulation of cell migration, invasion, and angiogenesis. However, there are few reports of the relationship between TS cells and FGF-4 even if FGF-4 is located in inner cell mass of embryo and Fibroblast growth factor receptor (FGFR) is located in TS cells. Therefore the physiologic effects of FGF-4 on TS cells were investigated for identifying the effects of FGF-4 on TS ell differentiation. FGF-4 was involved in early stage development of the trophoblast via upregulation of eomesodermin mRNA expression. In addition, FGF-4 suppressed the differentiation of TS cells through activation of extracellular-signal regulated kinase (Erk) and suppression of focal adhesion kinase (FAK) activation, which in TS cells is an important indicator of early trophoblast cell differentiation, migration and invasion. FGF-4 was involved in angiogenesis in the trophoblast through the activation of p38 and the induction of Dlx-3 mRNA expression in TS cells. In addition, TS cells cultured with FGF-4 for 4 days in a thrombinfibrinogen gel culture system, a specific culture system for endothelial cells, showed a healthy appearance, while TS cells cultured without FGF-4 were severely damaged. Taken together, these data suggest that FGF-4 is closely involved in differentiation of TS cells for development of placenta.

병원급식에 관한 연구(선호 경향에 따른 잔식량에 대하여)

최민규 ( Min Kyu Choi ) 국군의무사령부 1983 대한군진의학학술지 Vol.14 No.1

인쇄전자 적용을 위한 1kV, 1kA, 12kW 펄스 모듈레이터 IGBT의 스너버 설계

최민규(Min-Kyu Choi),송승호(Seung-Ho Song),이주영(Joo-Young Lee),정우철(Woo-Cheol Jeong),진희성(Hee-Sung Jin),박현일(Hyun-Il Park),류홍제(Hong-Je Ryoo) 한국조명·전기설비학회 2022 한국조명·전기설비학회 학술대회논문집 Vol.2022 No.5

연구보문 : 자연과학 ; 호남평야지에서 벼 무논점파 재배시 적정 파종기 구명

최민규 ( Min Kyu Choi ),구본일 ( Bon Il Ku ),강신구 ( Shin Gu Kang ),상완규 ( Wan Gyu Sang ),백남현 ( Nam Hyun Back ),김영두 ( Young Doo Kim ),박홍규 ( Hong Kyu Park ),최원영 ( Won Young Choi ),박태선 ( Tae Seon Park ),김보경 ( Bo 한국국제농업개발학회 2012 韓國國際農業開發學會誌 Vol.24 No.3

To recommend optimal rice seeding date for direct hill seeding on puddled paddy surface in Honam plain area, Hopumbyeo (Oryza sativa L.) was seeded 6 times by 10-day interval from April 30 to June 19 in 2009 and 2010. Seedling stand was the highest in two seeding dates, May 20 and May 30, and other seeding dates showed acceptable seedling stand except April 30. Tiller numbers at panicle formation stage were increased up to May 30 and decreased thereafter. Heading date of the seeding on May 20 and May 30 were August 19 and August 23, respectively, and the seeding on June 19 was August 31. In 2009, panicle numbers per m2 was the highest in the seeding on May 20 and decreased in the later seeding dates. However, the seeding on June 19 showed the highest panicle number and the others were not significantly different in 2010. Number of grains per panicle was the highest in the first planting date and was decreasing as seeded later. Milled rice yield was the largest in the seeding date of May 20 in 2009, and in the seedling date of May 30 in 2010. The head rice ratio was increased up to May 20 and similar in the later seeding dates. Protein content was lower in earlier seeding dates. According to the above results, the optimal seeding date of direct hill seeding on puddled paddy in Honam plain area was considered to be May 30. The last seeding date related to the limit date of safe heading was June 19.

연구보문 : 자연과학; 벼 무논점파 재배시 입모 향상을 위한 물관리 방법

최민규 ( Min Kyu Choi ),구본일 ( Bon Il Ku ),강신구 ( Shin Gu Kang ),상완규 ( Wan Gyu Sang ),백남현 ( Nam Hyun Back ),김영두 ( Young Doo Kim ),박홍규 ( Hong Kyu Park ),최원영 ( Weon Young Choi ),박태선 ( Tae Seon Park ),김보경 ( B 한국국제농업개발학회 2013 韓國國際農業開發學會誌 Vol.25 No.3

Water management and weed control in rice direct seeding on puddled paddy surface is important for seedling establishment and early growth. To develop management method for enhancing seedling stands and weed control, three experiments were conducted with rice variety Hopum (midmaturing) at experimental station of National Institute of Crop Science, in Iksan in 2010-2011. In experiment 1, germinated rice seeds were sowed on 1, 2, 3, and 4 days after puddling to find the optimum drying days of paddy surface. The average numbers of seedling stands in 2 and 3 days drying were 117 and 114 per m2, respectively, and those were higher than in the 1 and 4 days. Plant height and root length were increased as drying up to 3 days, but decreased in the 4th day. In experiment 2, non-irrigation and intermittent irrigation started 2, 4, and 6 days after seeding were evaluated. The average numbers of seedlings in intermittent irrigation from 2 and 4 days after seeding were 117 and 113 per m2, respectively. The seedlings in irrigation after 6 days was 92 per m2, and 84 per m2 in non-irrigation. Shoot lengths were highest in the irrigation treatments of 2 days and 4 days after seeding. In experiment 3, herbicide was treated on 10, 12, 14, and 16 days after seeding. Rice seedling and root length was increased in the later herbicide treatments. Weeds were not occurred until the 12 days, but observed in the later two treatments. According to these findings, drying paddy for 3 days after puddling, intermittent irrigating after 2 days from seeding, and herbicide treatment on 12 days after seeding is recommended for direct seeding on puddled paddy surface.

선체블록의 오버헤드 도장장비 적용 연구

최민규(Min-kyu Choi),이성균(Sung-kyun Lee),허병동(Byung-dong Heo) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

This paper presents the application of the automatic overhead painting machine for the bottom side of ship’s block. The developed overhead painting system consists of 4 automatic spray guns, spray pressure monitoring and autonomous traveling system. Fixed multi-gun spray method instead of weaving single gun method was chosen taking consideration of simplicity of gun movement control system. Effect of the overlap ratio between the spray guns, the spray width, the distance between the spray nozzle and the surface and the spray pressure on the film thickness distribution were studied by the spray experiments using typical anti corrosion paint. It was found that film thickness distribution would mainly depend on overlap ratio.