• 제목/요약/키워드: freshwater

검색결과 2,060건 처리시간 0.033초

해창만의 수질환경변동 및 담수방류의 영향평가 (Effect of the Freshwater Discharge on Water Quality Variation and in Haechang Bay, Korea)

  • 이대인;조현서;이문옥
    • 환경영향평가
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    • 제12권5호
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    • pp.341-348
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    • 2003
  • Seasonal characteristics of water quality and effect of the freshwater discharge during open the tide embankment in Haechang Bay were evaluated. In the freshwater, where interior of the tide embankment, COD and Chl-a exceeded about 4mg/L and $10mg/m^3$, respectively, independent of season, while in the seawater they showed high values in April and July in contrast to the other period due to input of freshwater and increase of phytoplankton, respectively. The content of seawater inorganic nitrogen maintained a relatively high level at inner part of the bay, whereas high values of inorganic phosphorus content was distributed at all over the bay. The limiting factor for algal growth was nitrogen with respect to the N/P ratio. The compass of influence by the freshwater discharge in April was quite different with water pollutants. As a result of the salinity variation with time, the freshwater extended strongly to offshore from the surface layer without mixing with depth when open the tide embankment, and reached within about one hour at a station which is 3.5km from the tide embankment. To effective water quality management of Haechang Bay, discharge rate and pollutant loads should be controlled.

Long-term Paradigm Analyses of Chlorophyll a and Water Quality in Reservoir Systems

  • Bach, Quang-Dung;Shin, Yong-Sik;Song, Eun-Sook
    • 생태와환경
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    • 제42권4호
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    • pp.432-440
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    • 2009
  • During the period of past fifteen years (1992~2006), variations of chlorophyll a in relation with water quality in freshwater reservoirs were investigated. This study compared total nitrogen (TN), total phosphorus (TP), chlorophyll a, Secchi depth (SD) and total suspended solids (TSS) between terrestrial freshwater reservoir and coastal freshwater reservoir systems based on their location. Regression analyses (linear and non-linear regressions) were applied for all study sites to examine relationship and interaction of these factors in the freshwater systems from in-land to coasts. The results demonstrated that chlorophyll a was significantly correlated to total phosphorus ($R^2=0.94$, P<0.0001) and was remarkably related to TSS increase ($R^2=0.63$, P<0.0001) in the selected reservoirs. The TN : TP ratio in the reservoir systems was higher than Redfield ratio (16 : 1) indicating that the reservoirs are potentially experiencing P limitation. Water quality of coastal freshwater reservoir system was more significantly decreased than the reservoirs located in in-land during the past fifteen years. The strict management of nutrient discharge into freshwater systems should implemented in the coastal reservoirs since the freshwater is introduced into coastal estuarine systems.

강원도 평창강 일대의 어류상과 하천유지수량의 감소로 예측되는 영향 (Freshwater Fish Fauna of the Pyongchankang and Expected Impacts of Reduce of Constant River Flood in Youngwolgun, Kangwondo)

  • 박병상
    • 한국환경생태학회지
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    • 제9권1호
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    • pp.42-48
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    • 1995
  • 충청북도 제천시의 상수도 취수를 목적으로 건설하는 취수장 예정지를 중심으로 평창강의 담수어류상을 1994년 9월 25일과 1994년 10월 7일부터 1994년 10월 9일까지 두 차례 조사하고 하천 유지수량의 변동이 어류의 생태에 미치는 영향을 조사하였다. 6개 조사 지역에서 총 6과 21속 28종의 담수어류가 관찰되었으며 천연기념물 및 한국 특산종이 많이 관찰되었다. 평창강은 사행천으로 다양한 담수어류가 서식하기에 적합한 환경과 유지수량을 갖는다. 취수를 위한 급격한 유지 수량의 감소는 평창강의 담수어류가 대부분 멸종할 우려가 매우 높다.

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A report of nine unrecorded bacterial species in the phylum Bacteroidetes collected from freshwater environments in Korea

  • Park, Sanghwa;Beak, Kiwoon;Han, Ji-Hye;Nam, Yoon-Jong;Lee, Mi-Hwa
    • Journal of Species Research
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    • 제7권3호
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    • pp.187-192
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    • 2018
  • During a comprehensive study of indigenous prokaryotic species in South Korea, nine bacterial species in the phylum Bacteroidetes were isolated from freshwater environmental samples that were collected from three major rivers in the Republic of Korea. High 16S rRNA gene sequence similarity (${\geq}98.7%$) and robust phylogenetic clades with the closely related species suggest that each strain was correctly assigned to an independent and predefined bacterial species. There were no previous reports of these nine species in Korea. Within the phylum Bacteroidetes, four species were assigned to the genus Flavobacterium, order Flavobacteriales, and five species to three genera of two families in the order Cytophagales. Gram reaction, colony and cell morphology, basic biochemical characteristics, isolation source, and strain IDs are described in the species description section.

미호강 수계 생물막의 환경유전자를 이용한 담수해파리 (Craspedacusta sowerbii Lankester, 1880) 유전자 탐색 (Detection of Freshwater Jellyfish (Craspedacusta sowerbii Lankester, 1880) by Biofilm eDNA in Miho River Watershed)

  • 김건희;조현진;김정희;양윤모;주현지;정현기
    • 생태와환경
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    • 제56권3호
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    • pp.250-258
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    • 2023
  • 담수해파리는 담수에서만 발견되는 해파리로써 다양성은 낮지만 전 세계적으로 보고 되고있다. 하지만 이들의 생태 및 발생 원인에 대해서는 정확하게 밝혀진 바가 없다. 따라서 모니터링을 통해 유생에서 폴립(polyp)단계를 통해 성장하는 담수해파리의 분포를 파악하는 것은 이들의 생태를 이해하는 데 중요하다. 본 연구는 미호강 수계 생물막(biofilm)의 환경유전자(eDNA)를 이용하여 담수해파리의 COI 유전자를 탐색하고 환경유전자를 이용한 담수해파리 탐색 가능성을 확인하고자 하였다. 미호강 수계 내 12개 지점 중 8개 지점에서 담수해파리 유전자가 확인되었으며, 대부분 상류에 저수지가 위치한 특성을 보였다. 이들 유전자는 대표적인 담수해파리로 알려진 소워비꽃모자해파리(Craspedacusta sowerbii)의 유전자로 확인되었으며 미호강 조사 지점에서 발견된 C. sowerbii는 이탈리아에서 발견된 종과 같은 계통이었다. 결과적으로 생물막의 환경유전자를 이용한 담수해파리 유전자 탐색방법은 담수해파리 출현 가능성이 높은 지역을 선택적으로 빠르게 선별(screening)할 수 있으며 이는 국내 담수해파리의 분포와 발생기작을 이해하는 데 중요한 단서를 제공할 수 있을 것으로 판단된다.

갈대 발효추출물의 이화학적 특성 및 생리활성 연구 (Physicochemical Characteristics of Fermented Phragmites communis Extract and Its Biological Activity)

  • 강창희;김상철;정상철;한웅;이승영;유상미;진현미;김영수
    • 생약학회지
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    • 제47권3호
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    • pp.273-279
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    • 2016
  • This study evaluates the tyrosinase, elastase inhibitory and antioxidant activities of isolated Lactobacillus rhamnosus fermented extracts of Phragmites communis Trinius. After culture for 4 days at $30^{\circ}C$ using 1% P. communis extract, the cell mass of L. rhamnosus reached $1.4{\times}10^{10}CFU/mL$. The number of cells on P. communis extract and MRS medium was similar. This results indicated that P. communis extract can be used as an economical medium for industrial lactic acid bacteria production. The fermented P. communis extract exhibited 4 fold higher tyrosinase inhibitory effect than non fermented P. communis extract. The non fermented P. communis extract has no inhibitory effect on elastase. However the fermented P. communis extract show high inhibitory effect on elastase ($IC_{50}$; $249{\mu}g/mL$). These results indicated that the fermented P. communis extract can potentially be used for developing new cosmetic or health food ingredients.

Schisandrae Fructus: A Potential Candidate Functional Food Against Muscle Atrophy and Osteoarthritis Prevention

  • Lee, Seung Young;Jin, Hyun Mi;Ryu, Byung-Gon;Jung, Ji Young;Kang, Hye Kyeong;Choi, Hee Won;Choi, Kyung Min;Jeong, Jin Woo
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2018년도 춘계학술발표회
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    • pp.8-8
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    • 2018
  • Muscle atrophy, known as a sarcopenia, is defined as a loss of muscle mass resulting from a reduction in muscle fiber area or density due to a decrease in muscle protein synthesis and an increase in protein breakdown. Many conditions are associated with muscle atrophy, such as aging, denervation, disuse, starvation, severe injury and inflammation, prolonged bed rest, glucocorticoid treatment, sepsis, cancer, and other cachectic diseases. On the other hand, osteoarthritis (OA) is the most common form of joint disease and is wide spread in the elderly population and is characterized by erosion of articular cartilage, osteophyte formation, and subchondral bone sclerosis. The cytokine network plays an important role in the development and progression of OA with the inflammatory cytokine. Schisandrae Fructus (SF) derived from the ripe fruit of Schisandra chinensis (Turcz.) Baill. (Magnoliaceae) has been extensively used in traditional herbal medicines in Asia. It was originally used as a tonic and has been traditionally used for the treatment of many uncomfortable symptoms, such as cough, dyspnea, dysentery, insomnia, and amnesia for a long time. Previous reports have shown that SF and its related compounds possess various biological activities such as antioxidant, anti-inflammatory, anticancer, anti-microbial, antiseptic, anti-aging, hepatoprotective and immunostimulating effects. However, the therapeutic effects of SF on muscle atrophy and OA has not yet been evaluated. In the present study, we aimed to determine whether extracts of SF, the dried fruit of S. chinensis, mitigates the development of muscle atrophy and OA.

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Antioxidant Effects of Scutellaria baicalensis Georgi Against Hydrogen Peroxide-induced DNA Damage and Apoptosis in HaCaT Human Skin Keratinocytes

  • Lee, Seung Young;Jin, Hyun Mi;Ryu, Byung-Gon;Jung, Ji Young;Kang, Hye Kyeong;Choi, Hee Won;Choi, Kyung Min;Jeong, Jin Woo
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2018년도 춘계학술발표회
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    • pp.68-68
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    • 2018
  • In this study, we investigated whether S. baicalensis rhizome ethanol extract (SBRE) has antioxidant capacities against oxidative stress induced cellular damage in the HaCaT keratinocytes. Our results revealed that treatment with SBRE prior to hydrogen peroxide ($H_2O_2$) exposure significantly increased the HaCaT cell viability. SBRE also effectively attenuated $H_2O_2$ induced comet tail formation, and inhibited the $H_2O_2$ induced phosphorylation levels of the histone ${\gamma}H2AX$, as well as the number of apoptotic bodies and Annexin V positive cells. In addition, SBRE exhibited scavenging activity against intracellular ROS generation and restored the mitochondria membrane potential loss induced by $H_2O_2$. Moreover, $H_2O_2$ enhanced the cleavage of caspase-3 and degradation of poly (ADP-ribose)-polymerase as well as DNA fragmentation; however, these events were almost totally reversed by pretreatment with SBRE. Furthermore, SBRE increased the levels of HO-1 associated with the induction of Nrf2. Therefore, we believed that SBRE may potentially serve as an agent for the treatment and prevention of neurodegenerative diseases caused by oxidative stress.

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담수환경에서 발굴된 Didymella속 3종의 국내 최초 보고 (First Report of Three Didymella Species Isolated from Freshwater Ecosystem in Korea)

  • 문혜연;고재덕;오유선;정애란;정남일
    • 한국균학회지
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    • 제46권1호
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    • pp.1-8
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    • 2018
  • 국내에 보고되지 않은 3종의 균류가 담수환경으로 부터 분리되었다. NNIBRFG108은 강원도 삼척의 담수침전식물체에서 분리되었고, NNIBRFG1139와 NNIBRFG1480은 경북 김천과 제주지역의 토양으로부터 분리되었다. 형태적 특징 및 internal transcribed spacers (ITS), 18S rDNA, 28S rDNA 및 ${\beta}$-tubulin 유전자를 이용한 분자계통학적 분류를 통해 동정한 결과, NNIBRFG108, NNIBRFG1139, NNIBRFG1480 균주는 각각 Didymella segeticola, D. ellipsoidea 및 D. aeria으로 확인되었다. 이는 국내에서는 발견되지 않은 미기록종으로 본 보고가 국내 최초이다.

경계면 수치 모델을 이용한 해안 지역 이중 양수정의 해수침투 저감 효과 (Effectiveness of Double Negative Barriers for Mitigation of Sewater Intrusion in Coastal Aquifer: Sharp-Interface Modeling Investigation)

  • 정은태;이성준;이미지;박남식
    • 한국수자원학회논문집
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    • 제47권11호
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    • pp.1087-1094
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    • 2014
  • 해안지역에서 지하수 해수침투 저감을 위하여 해수 양수 관정을 가동할 때 해수정으로 많은 양의 담수가 낭비되는 사례가 있다. 해수 침투를 저감시키고 낭비되는 담수를 유용하게 활용하기 위하여 이중 양수정이 제안된 바 있다. 이중 양수정은 해수 양수를 위한 해안 쪽의 해수정과 담수 양수를 위한 내륙 쪽의 담수정으로 구성된다. 선행 연구에서는 담수정의 해수 비율을 최소화시키기 위한 해수정의 양수량을 산정하였으나 담수정의 해수비율이 1~15% 범위로 나타나 담수정에서 담수를 확보하기 어렵다고 판단하였다. 본 연구에서는 이송이 지배적인 상황에서 이중 양수정의 효과를 분석하였다. 연구 결과 담수정에서 저염도 지하수를 확보할 수 있음을 밝혔다. 또한 해안 유역 차원의 적정 지하수관리를 위해서는 담수정의 해수비율을 최소화하는 것 외에도 해수정으로 낭비되는 담수량을 최소화하는 것도 함께 고려해야한다.