• 생명과학회지
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• 제11권2호
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• pp.166-172
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• 2001

Various types of the seeding of bottle gourd widely used as a rootstock of watermelon has been required to satisfy the farmers need. The study was done to determine the effect of light quality of blue, red and far-red lights treated with light emitting diodes on growth and morphology of bottle goured seeding and chlorophyll content of its cotyledons. The lights were treated in the growth chamber for 7 days to the seeding elapsed 8 days after sowing under natural condition, and 64 hole trays with commercial bedsoil. Plant height, length and diameter of hypocotyl, leaf area of cotyledon and first true leaf, its leaf length, number of true leaves, fraction and total dry weight were measured. Red light shortened and slenderized the hypocotyl, which lengthened by far-red light and thickened by blue light. Plant height was declined in order of far-red light treatment, blue and red lights mainly due to difference of hypocotyl length, Area and length of the first true leaf became smaller and shorter under far-red light than under the other lights. However, blue light increased leaf area of cotyledons. Two cultivars cv. Yongjadaemok and cv. Kunghap had different response to the light treatments in total seedling dry weight(dw); far-red and red light treatments showed the greatest and the least dw of hypocotyl, respectively, while blue and red lights did the greatest dw of the other organs. Among the ratio of each organ dw to total dw, those of hypocotyl and true leaves were different between the light treatments; the highest ratio of hypocotyl dw to total dw was observed in far-red light treatment but the lowest was in red light treatment. Those of the true leaves were the lowest in far-red light and similar response in blue or red light treatment. Chlorophyll content of cotyledons was decreased in order of red light treatment, blue and far-red lights, meaning that short period light treatment may influence photosynthesis of seeding and afterward its growth.

• 한국식품영양과학회지
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• 제34권5호
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• pp.681-686
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• 2005

동백잎의 채취시기에 따른 일반성분, 유리당, 유기산, 아미노산, catechin, chlorophyll 및 total polyphenol 등의 함량은 다음과 같다. 동백 잎의 조단백과 조지방 및 ascorbic acid 함량은 채취시기가 늦을수록 감소하였고, 조회분과 조섬유 함량은 채취 시기가 늦을수록 증가하는 경향을 보였다. 유리당은 fructose, glucose, sucrose 등 3개의 당이 확인되었고, 총 유리 당 함량은 채취시기가 늦을수록 증가하였다. 유기산은 citric acid, tartaric acid, succinic acid, acetic acid 등이 검출되었고, 채취 시기가 늦을수록 총함량은 증가하였다. 동백잎의 주된 유리아미노산은 aspartic acid, glutamic acid, histidine이었고, 채취시기가 늦을수록 총유리 아미노산 함량은 감소하였다. 동백잎의 주된 구성아미노산은 histidine, alanine이었고, 채취시기가 늦을수록 구성아미노산의 함량은 감소하였으며, 총아미노산에 대한 필수아미노산의 비율은 증가하였다. 동백 잎에 함유된 무기질은 P, Ca, K, Na, Fe등으로 채취시기가 늦을수록 함량은 증가하였으며, 동백 잎의 chlorophyll 함량과 total polyphenol 함량은 채취 시기가 늦을수록 증가하였다.

• 한국작물학회지
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• 제50권1호
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• pp.39-44
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• 2005

This study was conducted to examine the physiological and biochemical responses against UV-B radiation in the seedling of 15 different rice cultivars, having the different physiological sensitivities. Out of 15 rice cultivars tested, moderate and susceptible groups showed significant decreases in biomass and RGR (relative growth rate). Contents of total chlorophyll were reduced remarkedly by irradiation of UV-B. In all rice cultivars tested, the content of chlorophyll a was strongly decreased, while the contents of chlorophyll b were slightly reduced without showing clear different among three groups and 15 cultivars. Carotenoid content was largely reduced by UV-B radiation, whereas polyamine content was moderately increased. The contents of MDA (malondialdehyde) that reflect the level of lipid peroxidation of cell membranes were clearly increased by UV-B stress, showing higher content in susceptible cultivars than moderate and torelant cultivars. The physiological important parameters highly related to visible injury were leaf color, chlorophyll, carotenoid, and lipid peroxidation, whereas biomass and polyamines were not closely correlated. Based on this results, it was concluded that changes of visible injury and the contents of chlorophyll and MDA could be adequately applied and utilized as physiological indicators to UV-B radiation.

• 한국해양학회지
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• 제12권2호
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• pp.57-66
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• 1977

무기물에서 유기물을 생산하는 곳으로서 뿐만 아니라 인류의 마지막 식량공급처로서의 해양에 대한 기초생산의 중요성이 날로 높아져 국제인도양조사때나 Kuroshio해역조사때 생산력이 측정되었고 북서태평양(Sorokin and Koblentz-Miskke; 1958, Ichimura and Saijo; 1959, Saijo and Ichimura; 1960, Aruga and Monsi; 1962, 천촌;1963), 인도네시아 주변해역(Doty et al;1963)등에서도 기초생산이 측정된 바 있다. 일본의 주요 9개만에서는 월별측정(송평 등;1964)이 되었다. 우리 나라 연안에서는 최와 정(1966)이 $C^{14}$를 이용하여 광합성량을 측청하였고 Kang(1967) 은 수영만에서 계절별로 산소소모에 의한 광합성량을 측정했다.다.

• Ocean and Polar Research
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• 제30권3호
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• pp.289-301
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• 2008

Community structure of heterotrophic protists and their grazing impact on phytoplankton were studied in Northwest Pacific Ocean during October, 2007. The study area was divided into four regions based on physical properties (temperature and salinity) and chlorophyll-a distribution. They were Region I of North Equatorial Currents, Region II of Kuroshio waters, Region III of shelf mixed water, and Region IV of Tsushima warm current from East China Sea. The distribution of chlorophyll-a concentrations and community structure of heterotrophic protists were significantly affected by physical properties of the water column. The lowest concentration of chlorophyll-a was identified in Region I and II, where pico-sized chlorophyll-a was most dominant (>80% of total chlorophyll-a). Biomass of heterotrophic protists was also low in Region I and II. However, Region III was characterized by low salinity and temperature and high chlorophyll-a concentration, with relatively lower pico-sized chlorophyll-a dominance. The Highest biomass of heterotrophic protists appeared in Region III, along with the relatively less important nanoprotists. In Region I, II and IV, heterotrophic dinoflagellates were dominant among the protists, while ciliates were dominant in Region III. Community structure varied with physical(salinity and temperature) and biological (chlorophyll-a) properties. Biomass of heterotrophic protists correlated well with chlorophyll-a concentration in the study area ($r^2=0.66$, p<0.0001). The potential effect of grazing activity on phytoplankton is relatively high in Region I and II. Our result suggest that biomass and size structure of heterotrophic protists might be significantly influenced by phytoplankton size and concentration.

• 생명과학회지
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• 제18권12호
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• pp.1705-1711
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• 2008

상추식물에서 저온 처리를 하였을 때 저온 적응성 획득 메카니즘과 관련된 APX와 DHAR의 활성도와 mRNA 발현 수준 등과의 관련성을 조사한 결과는 다음과 같다. 잎 조직내 과산화수소의 함량은 일정하게 증가하다가 $20^{\circ}C$에서 저온처리를 회복시키면 그 함량이 정상상태로 회복하는 경향을 보였으나 단백질의 함량은 반대의 경향을 나타내었다. 엽록소의 함량은 저온스트레스를 처리할 경우 엽록소 a와 b 및 총 엽록소의 함량이 점차 감소하는 경향을 보였으며 저온스트레스 회복 시 다시 증가하는 경향을 보였으나 카로티노이드 함량의 변화는 거의 일어나지 않고 일정한 수준을 유지하는 것으로 나타났다. 총 엽록소에 대한 엽록소a의 비율은 저온처리 12시간까지는 증가하다가 24시간 이후 급격하게 감소하게 되고 저온스트레스를 회복시켰을 때 정상 수준으로 회복되는 경향을 나타내었다. APX와 DHAR의 활성도는 저온 처리가 진행됨에 따라 상추의 잎 조직 내에서 급격하게 증가하는 경향을 보이고 있으나 적온으로 회복시키면 정상 수준으로 유지되었다. 저온처리 시간이 경과함에 따라 APX와 DHAR의 mRNA의 발현 수준이 크게 증가하는 경향을 보였다가 원래 수준으로 회복되었다. APX의 활성도와 과산화수소의 함량과의 상관관계는 상추의 잎 조직 내 과산화수소의 함량이 증가하면 APX의 활성도가 증가하는 경향 ($R^2$=0.8715)을 보였으며, DHAR의 활성도와 과산화수소의 함량도 동일한 경향으로 증가($R^2$=0.8643)하였다. 그러나 과산화수소의 생성량이 증가함에 따라 엽록소의 함량과 단백질의 함량은 저온 스트레스처리로 과산화수소의 생성량이 증가하면 엽록소의 함량($R^2$=0.5021)과 수용성단백질의 함량과는 감소하는 경향($R^2$=0.8915)을 보였다.

• 상하수도학회지
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• 제35권6호
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• pp.417-424
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• 2021

Algal bloom is an ongoing issue in the management of freshwater systems for drinking water supply, and the chlorophyll-a concentration is commonly used to represent the status of algal bloom. Thus, the prediction of chlorophyll-a concentration is essential for the proper management of water quality. However, the chlorophyll-a concentration is affected by various water quality and environmental factors, so the prediction of its concentration is not an easy task. In recent years, many advanced machine learning algorithms have increasingly been used for the development of surrogate models to prediction the chlorophyll-a concentration in freshwater systems such as rivers or reservoirs. This study used a light gradient boosting machine(LightGBM), a gradient boosting decision tree algorithm, to develop an ensemble machine learning model to predict chlorophyll-a concentration. The field water quality data observed at Daecheong Lake, obtained from the real-time water information system in Korea, were used for the development of the model. The data include temperature, pH, electric conductivity, dissolved oxygen, total organic carbon, total nitrogen, total phosphorus, and chlorophyll-a. First, a LightGBM model was developed to predict the chlorophyll-a concentration by using the other seven items as independent input variables. Second, the time-lagged values of all the input variables were added as input variables to understand the effect of time lag of input variables on model performance. The time lag (i) ranges from 1 to 50 days. The model performance was evaluated using three indices, root mean squared error-observation standard deviation ration (RSR), Nash-Sutcliffe coefficient of efficiency (NSE) and mean absolute error (MAE). The model showed the best performance by adding a dataset with a one-day time lag (i=1) where RSR, NSE, and MAE were 0.359, 0.871 and 1.510, respectively. The improvement of model performance was observed when a dataset with a time lag up of about 15 days (i=15) was added.

• 한국식품저장유통학회지
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• 제15권3호
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• pp.352-360
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• 2008

해양 녹조류인 청각에 함유되어 있는 chlorophyll을 유기용매를 사용하여 추출한 후 chlorophyll의 안정성을 증가시키기 위한 조건을 확립하였다. 추출 용매로 사용된 acetone, ethanol 그리고 methanol 중 methanol이 가장 효과적이었으며, 추출 수율은 건조 중량으로 $25.0{\pm}2.10\;mg/g$ 이었다. TLC 및 HPLC 분석을 통하여 청각 색소에는 chlorophyll a 와 chlorophyll b가 주성분이며, 이들은 각각 0.40 mg/g and 1.94 mg/g의 함량으로 존재하였다. 청각 색소에 함유된 총 엽록소 함량은 빛이 있는 곳과 없는 곳에서 30주간 $40^{\circ}C$로 저장하였을 경우, 초기 양의 23.2 %와 58.4 %로 각각 잔존하였다. 황산구리, 황산아연, 황화철, 황산마그네슘으로부터 해리 된, 구리, 아연, 철, 마그네슘과 같은 금속이 이온이 색소의 저장 안정성에 미치는 영향을 분석한 결과, 구리가 가장 효과적이었으며, 아연이 그 다음으로 효과적이었다. 구리와 아연이 1 mM의 농도가 존재할 경우, 청각색소는 30주 후에, 빛이 있는 상태에서는 초기 양의 47.0%, 빛이 없는 상태에서는 88.8 %로 잔존하였다. 청각 색소를 안정화시키는 구리와 아연의 최적 농도는 빛이 없는 조건에서 구리는 0.1 mM, 아연은 0.5 mM이었다.

• The Korean Journal of Ecology
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• 제6권4호
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• pp.21-28
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• 1983

The relationship of Paramecium bursaria with its symbiiotic Chlorella was studied in the view-point of photosynthesis and its product movement. The following results were obtained. In 1/10 dilution of bacterized medium green Paramecium grew and survived better than colorless Paramecium. P. bursaria was competitively related to its symbiotic algae as far as the change of total chlorophyll contents was concerned. Therefore, in continuous darkness total chlorophyll contents of green Paramecia decreased proportionally to the time course. Under the condition, on the other hand, that the bacterized medium was not replenished over 10 days, total chlorophyll contents in P. bursaria increased by over 2 times as much as those in normal condition. By means of Oxygen Diometer it was assured that green Paramecium was able to utilize thoitic the great part of oxygen evolved photosynthetically by its symbiotic algae. Also when was given many starch grains were found in symbiotic chlorella through electron micrography. These data suggested that P. bursaria was photosynthetically given lots of benifit by its symbiotic chlorella.

• 한국자원식물학회지
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• 제33권3호
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• pp.170-182
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• 2020

Wheat is an economically important cereal worldwide and is a staple food in many countries. Extensive researches have been performed on the nutritional value and antioxidant potentials of sprouts of legumes like soybean, however very limited studies have been carried out on the sprouts of Korean wheat cultivar. The objective of this study was to investigate the phytochemical and antioxidant potentials of Korean wheat sprouts. The sprouts were grown for 10 (WS-10), 20 (WS-20), and 30 (WS-30) days at room temperature. The pH, color, chlorophyll, free amino acid, 1,1-diphenly-2-picrylhydrazyl (DPPH), and total polyphenol content of the sprout samples were determined. The pH of sprouts was increased in the older sprouts. Color values were significantly influenced by the age of sprouts. The chlorophyll content was lowest but the total free amino acid content was highest in WS-30. On the other hand, the DPPH free radical scavenging potential and total polyphenol content were lower in WS-30. The results suggested that Korean wheat sprouts could be a potential source of nutrients and natural antioxidants.