• 환경생물
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• 제39권4호
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• pp.495-506
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• 2021

In this study, using a continuous behavior measurement technique, the short-term behavioral responses and tolerance limits of red seabream Pagrus major fingerlings to sudden exposure to low salinity in a controlled environment were observed. The activity of the fingerlings suddenly exposed to 21.4, 17.3, and 9.8 psu increased temporarily at the initial exposure to show irregular swimming behavior, but then recovered a stable activity pattern through rapid salinity adaptation. However, the organisms suddenly exposed to 7.3 and 4.3 psu could not withstand the salinity stress, and their swimming behavior was severely disturbed and all individuals died within 48 hours. The findings suggest that red seabream underwent a temporary salinity stress process at the beginning of the exposure to concentrations of 10.0 psu or higher. At these concentrations, osmotic control was possible within at least 11 hours, so stable metabolic activity was also possible. However, organisms suddenly exposed to concentrations below 5.0 psu exceeded the tolerance to low salinity and the sublethal limit. In red seabream exposed to this concentration range, severe behavioral and metabolic disturbances were observed, and death was observed due to osmotic control failure. In conclusion, a salinity range of 5.0 to 10.0 psu can be predicted to correspond to a concentration range in which the osmotic control ability of the red seabream fingerlings is lost, and sub-lethal reactions occur.

• The Plant Pathology Journal
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• 제39권1호
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• pp.123-135
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• 2023

Previously, Pseudomonas plecoglossicida YJR13 and Pseudomonas putida YJR92 from a sequential screening procedure were proven to effectively control Phytophthora blight caused by Phytophthora capsici. In this study, we further investigated the anti-oomycete activities of these strains against mycelial growth, zoospore germination, and germ tube elongation of P. capsici. We also investigated root colonization ability of the bacterial strains in square dishes, including cell motility (swimming and swarming motilities) and biofilm formation. Both strains significantly inhibited mycelial growth in liquid and solid V8 juice media and M9 minimal media, zoospore germination, and germ tube elongation compared with Bacillus vallismortis EXTN-1 (positive biocontrol strain), Sphingomonas aquatilis KU408 (negative biocontrol strain), and MgSO₄ solution (untreated control). In diluted (nutrient-deficient) V₈ juice broth, the tested strain populations were maintained at >10⁸ cells/ml, simultaneously providing mycelial inhibitory activity. Additionally, these strains colonized pepper roots at a 10⁶ cells/ml concentration for 7 days. The root colonization of the strains was supported by strong swimming and swarming activities, biofilm formation, and chemotactic activity towards exudate components (amino acids, organic acids, and sugars) of pepper roots. Collectively, these results suggest that strains YJR13 and YJR92 can effectively suppress Phytophthora blight of pepper through direct anti-oomycete activities against mycelial growth, zoospore germination and germ tube elongation. Bacterial colonization of pepper roots may be mediated by cell motility and biofilm formation together with chemotaxis to root exudates.

• 대한본초학회지
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• 제39권3호
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• pp.97-105
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• 2024

Objective : This study examined the effects of yaksun recipe on the anti-fatigue and endurance enhancement properties in the forced swimming test (FST). Methods : The treatment groups were divided randomly into three groups: water-treated FST (control), 200 mg/kg of red ginseng-treated FST (RG200), 200 mg/kg of water extract of yaksun recipe-treated FST (YS200). After FST, an autopsy was performed, and the tissue and serum were collected. Results : The swimming exhaustion time in the RG200 and YG200 groups were significantly increased compared to the control group. The YG200 group fatigue indicators, D-Lactate, LDH(lactate dehydrogenase), creatine kinase, and ammonia content, significantly decreased compared to the control group. In addition, liver glycogen content significantly increased in the YG200 and tended to increase in RG200. Likewise, the glucose contents were significantly increased compared to the control group. The muscle damage indicators GPT (glutamic pyruvic transaminase) and BUN (blood urea nitrogen), a protein metabolite, in the YG200 group significantly decreased compared to the control group. Furthermore the concentration of liver lipid peroxidation, MDA(malondialdehyde) levels significantly decreased in the RG200 and YG200 compared to control group. Conclusions : These results suggest that YG200 can increase the endurance exercise capacity by decreasing the fatigue indicators, saving glycogen, and elevating the antioxidant defense system.

• The Korean Journal of Ecology
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• 제28권4호
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• pp.193-198
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• 2005

This study investigated the characteristics of the eggs and yolk sac larvae of Korean striped bitterling, Acheilognathus yamatsutae, spawned and grown In mussels. The number of eggs in the ovary was small ($358{\pm}108$ SD). The eggs were oval and large, and the formation of the perivitelline space was narrow. The eggs were hatched at only 41 hours after fertilization but the hatched larvae were underdeveloped. The development of yolk projection and minute tubercles on the skin surface was notable, along with the vividly moving tail in the hatched larvae. The yolk projection and minute tubercles were disappeared upon enhancement of the motor ability of the larvae was enhanced. The formation of eyes and body pigments of the larvae was relatively delayed in comparison with that of other cyprinid larvae. After completely consuming the yolks the larvae escaped from the mussel for free swimming and exogenous feeding.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.870-875
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• 2008

The main objective of this paper is to control a trajectory tracking of the fish-mimetic robot by CPG (Central Pattern Generator), which is biological approach. CPG is biological neural networks that generate rhythmic movements for locomotion of animals, such as walking, running, swimming and flying. Animals show marvelous ability of autonomous dynamic adaptation for an unsteady fluid dynamic environment or various environments. So, we propose the 3-DOF CPG controller to track the trajectory of the fish robot in plane motion. The conformity of the proposed control algorithm is validated by simulation for a fish robot model, which is made by a commercial dynamic package.

• 수산해양기술연구
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• 제46권4호
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• pp.449-457
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• 2010

This study shows that the vertical migration speed of sound scattering layers (SSLs), which is distributed in near Funka Bay, were measured by 3D velocity components acquired from a bottom moorng ADCP. While the bottom mooring type has a problem to measure the velocity vectors of sound scattering layer distributed near to surface, both the continuous vertical migration patterns and variability of backscatterers were routinely investigated as well. In addition, the velocity vectors were compared with the vertical migration velocity estimated from echograms of Mean Volume Backscattering Strength, and estimated to produce observational bias due to SSLs which is composed of backscatterers such as euphausiids, nekton, and fishes have swimming ability.

• Animal Bioscience
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• 제36권2호
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• pp.307-314
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• 2023

Objective: Chicken essence and branched chain amino acid (BCAA) supplementation has been recognized to significantly relieve fatigue. To obtain chicken essence with high amounts of BCAA, spent hens herein was used to prepare dripped chicken essence (SCE) and compared with commercial dripped chicken essence (CCE) for in vivo anti-fatigue effect. Methods: To determine the effect on anti-fatigue by dripped chicken essence, the exhaustive swimming was performed. Thirty-two 7-week ICR mice were divided into four groups, which included the control group (CG), CCE, SCE-1X and SCE-2X. The mice were given daily oral administration (0.012 mL/g body weight/d). The fatigue index analysis was conducted weekly. Results: The results showed that SCE had a higher BCAA level as expected, and mice treated with dripped chicken essence (CCE and SCE) could significantly improve exercise performance. The lower blood lactate level, blood urea nitrogen level and creatine phosphokinase activity were found in the supplement of SCE group compared with the CCE group, which suggested that the SCE possessed strong anti-fatigue ability. This could possibly be due to the higher content of BCAA. Conclusion: In this study, SCE promoted recovery from physical fatigue in mice and elevated endurance ability. Among them, the double dose (SCE-2X) showed the strongest anti-fatigue ability. Taken together, spent chickens could be a good source of chicken essence to improve the effect of anti-fatigue.

• 한국수자원학회논문집
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• 제37권7호
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• pp.541-552
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• 2004

본 연구에서는 설치어도조사법을 적용하여 한강 하류부 잠실수중보의 회유성 어류 이동을 위해 설치된 계단식 어도에 대해 어류소상기능을 조사하고 피 개선방안을 제시하였다. 조사기간 동안에 어도 출구에서 채집된 어도이용 소상어류는 체장이 29cm 이상인 강준치가 361개체로서 대부분을 차지하였으며, 그 강준치에 대한 소상능력은 최대 2.53${\times}$10^{-3}$ 개체/hr/g으로 나타났다. 잠실수중보의 계단식 어도는 한강에 서식하는 어류의 다양성을 만족시키기 어려운 형태일 뿐만 아니라 어도 출구의 월류격벽 낙차가 너무 크고 과도한 유량이 유입되기 때문에 유영력이 약한 어류가 이용할 수 없다. 따라서 이 어도는 유영력이 큰 강준치와 누치 이외의 다른 어류에 대해서는 소상기능을 발휘하지 못하고 있는 것으로 확인되었다. 어도의 기능을 향상시키기 위해서는 다양한 어류가 이용할 수 있는 형식으로 어도 구조를 변경하고, 어도 시설의 기능을 고려하여 가동보를 운영하여야 한다. 또한 고정보 전체의 상시 월류로 인해서 생기는 어도의 설치효과 저하에 대해서는 저수로 양안 측에 어도를 추가 설치할 필요가 있는 것으로 판단된다.

• 한국미생물·생명공학회지
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• 제43권4호
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• pp.357-366
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• 2015

쿼럼센싱은 세포 간의 의사소통 방법이며 박테리아의 병원성과 관련된 유전자들의 조절메커니즘이다. 박테리아는 다양한 생리학적 과정들을 제어하기 위해 이 쿼럼센싱 시스템을 활용한다. 본 연구에서 석류(Punica granatum L.) 껍질 추출물이 바이오 리포터 균주인 Chromobacterium violaceum 과 C. violaceum CV026에서 쿼럼센싱 억제능을 갖는 것으로 1차 선별되어 식중독균인 Y. enterocolitica에서 편모에 의한 운동능과 바이오필름형성 억제능에 대한 석류껍질 추출물의 효과에 대한 다음 실험을 수행하였다. 추가로 N-acylhomoserine lactones (AHLs)의 합성(yenI and yenR)과 편모 레귤론(fliA, fleB and flhDC) 에 관련된 특정유전자의 발현변화를 역전사 중합효소연쇄반응법으로 평가하였다. 결과는 석류껍질 추출물이 C. violaceum CV026에서 쿼럼센싱으로 제어되는 바이오레신 생산을 78.5%까지 억제하였으며, Y. enterocolitica에서는 세포의 성장에 영향을 주지 않고 바이오필름 형성과 편모 운동성을 현저히 감소시키는 것을 확인할 수 있었다. 이러한 억제 효과는 AHLs의 합성과 운동성에 관여하는 유전자 발현을 down-regulation 하는 결과와도 일치하였다. 본 연구의 결과는 석류껍질 추출물의 임상 적용을 위하여 생체 내 특성에 대한 추가적인 연구가 필요하다는 것뿐 아니라 석류껍질 추출물이 사람의 위장관염을 방지하기 위한 잠재적인 치료제가 될 수 있다는 것을 보여준다.

• Journal of the Korean Data and Information Science Society
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• 제22권1호
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• pp.57-64
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• 2011

이 연구에서는 최근 체육영재선정에 공통적으로 사용되고 있는 스포츠영재성 검사 항목과 코스타스 점수간의 연관성 분석을 통해 상대적으로 중요한 검사 항목과 그렇지 않은 검사 항목을 통계적으로 밝혀내는 데 목적이 있다. 이 연구를 위해 2010년도 서울지역 (강동구, 송파구, 노원구, 광진구 등)과 경기지역 (의정부시, 가평군, 구리시 등) H대학 체육영재양성사업에 지원한 201명의 초등학교 학생들의 자료가 사용되었으며, 육상 네 종목 (투척, 도약, 단거리, 중장거리), 수영 및 체조 종목의 코스타스 점수와 1차 스포츠영재성 검사에서 얻은 기본 체격, 체력 운동능력, 생리적 기능 정보를 이용하였다. 구체적으로 순수한 연관성 분석을 위해 피어슨상관계수와 편상관계수를 사용하였으며, 중요한 검사 항목 선택을 위해 단계적 회귀분석을 이용하였다. 그 결과 골연령, 체중, 흉위와 50m달리기, 하프스쿼트점프가 6개 코스타스 점수에 미치는 영향이 상대적으로 미약한 것으로 나타났다.