• Animal Bioscience
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• 제37권2_spc호
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• pp.323-336
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• 2024

Molecular hydrogen (H₂) and formate (HCOO^-) are metabolic end products of many primary fermenters in the rumen ecosystem. Both play a vital role in fermentation where they are electron sinks for individual microbes in an anaerobic environment that lacks external electron acceptors. If H₂ and/or formate accumulate within the rumen, the ability of primary fermenters to regenerate electron carriers may be inhibited and microbial metabolism and growth disrupted. Consequently, H₂- and/or formate-consuming microbes such as methanogens and possibly homoacetogens play a key role in maintaining the metabolic efficiency of primary fermenters. There is increasing interest in identifying approaches to manipulate the rumen ecosystem for the benefit of the host and the environment. As H₂ and formate are important mediators of interspecies interactions, an understanding of their production and utilization could be a significant starting point for the development of successful interventions aimed at redirecting electron flow and reducing methane emissions. We conclude by discussing in brief ruminant methane mitigation approaches as a model to help understand the fate of H₂ and formate in the rumen ecosystem.

• Asian-Australasian Journal of Animal Sciences
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• 제8권5호
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• pp.505-513
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• 1995

The major factors affecting productivity on daily farms in Queensland, Australia, were determined using the stepwise linear regression approach. The data were obtained from a survey conducted on the total population of daily farms in Queensland in 1987. These data were divided into six major dailying regions. The technique was applied using 12 independent variables believed by a panel of experienced research and extension personnel to exert the most influence on milk production. The regression equations were all significant (p < 0.001) with the percentage coefficients of determination ranging from 62 to 76% for equations developed using' total farm milk: production as the dependent variable. Three of the variables affecting total farm milk: production were found to be common to all six regions. These were; the amount of supplementary energy fed, the area set aside to irrigate winter feed and the size of the area used for dailying. Higher production farms appeared to be more efficient in that they consistently produced milk production levels higher than those estimated from the regression equation for their region. Other methods of analysis including robust regression and non linear regression techniques were unsuccessful in overcoming this problem and allowing development of a model appropriate for farms at all levels of production.

• 한국해양학회지
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• 제2권1_2호
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• pp.13-23
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• 1967

Seasonal changes in the primary production of surface water in Suyong Bay, Pusan, were measured using a light-dark bottle method. Gross photosynthesis followed a distinct seasonal change with highest levels in spring and fall. Respiration of plankton community showed its maximum only in the late summer and early fall. Net photosynthesis of plankton community is considerably variable throughout year, but followed a seasonal change similar to gross photosynthesis. Seasonal changes in temperature and salinity are related to the seasonal change in plankton metabolism.

• 한국양식학회지
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• 제11권2호
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• pp.279-282
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• 1998

Effects of high concentration of intracellular calcium on estradiol-induced vitellogenin(VTG) induction were examined using ouabain in Primary hepatocyte culture in the rainbow trout Oncorhynchus mykiss. Ouabain increases cytosolic free calcium as a result of inhibition of $Na^+ - Ca^{2+}$ exchanger. Ouabain markedly reduced VTG production to the control level, despite of calcium concentrations in the incubatin medium. Therefore, ouabain would reduce VTG production not by increasing intracellular calcium bt directly by inhibiting $Na^+ - K^+$ ATPase.

• Fisheries and Aquatic Sciences
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• 제1권2호
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• pp.153-158
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• 1998

Effects of cyclic (c) AMP and G-protein related reagents (3-isobutyl-l-methyxanthine (IBMX), Forskolin (FSK), cholera toxin (CTX), and pertussis toxin (PTX≫ on estradiol-17$\beta$ induced vitellogenin (VTG) induction were examined in primary hepatocyte cultures in rainbow trout Oncorhynchus mykiss. The addition of IBMX, FSK, or CTX to the incubation medium markedly increased VTG production, while PTX was not effective in stimulating the production. It is well known that cAMP regulates phosphorylation and dephosphorylation through mediation of protein kinase A. These results suggest that VTG production is highly dependent on cAMP state in hepatocytes because of its highly phosphorylated nature.

• 한국해양학회지:바다
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• 제6권1호
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• pp.40-48
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• 2001

2000년 2월에 남태평양에서 수심 200m까지 수온, 염분, 용존산소, 영양염, 엽록소, 일차생산성의 수직분포를 조사하였다. 연구해역(남위 $24^{\circ}{\sim}41^{\circ}$, 서경 $80^{\circ}{\sim}168^{\circ}$)은 물리적으로 크게 두 해역으로 나누어진다. 서경 $110^{\circ}$을 경계로 동쪽해역에서는 수심 200m이하의 중층수가 표층으로 활발히 용승하였고, 서쪽해역에서는 중층수의 용승이 거의 일어나지 않았다. 따라서 해수의 화학조성도 다르게 나타났다. 동쪽해역에서는 영양염 농도가 높은 중층수의 용승에 의해 표층 100m에서 질산염+아질산염과 인산염 농도가 서쪽해역에 비해 상당히 높게 관측되었지만, 중층수의 용승에도 불구하고 규산염 농도는 오히려 서쪽해역보다 낮았다. 영양염 중에서 식물플랑크톤의 일차생산성에 영향을 미치는 주요 원소도 해역에 따라 달랐다. 동쪽해역에서는 규소에 의해 일차생산성이 가장 큰 영향을 받는 반면, 서쪽해역에서는 질소가 일차생산성에 가장 큰 영향을 미쳤다. 중층수의 용승에 의해 영양염 농도의 큰 차이에도 불구하고, 식물플랑크톤의 일차생산성은 두 해역이 서로 비슷한 값을 보였으며, 수심 200m까지 합한 엽록소 총량은 오히려 동쪽해역에 비해 서쪽해역에서 2배 가량 높게 측정되었다.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2007년도 한국음성과학회 공동학술대회 발표논문집
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• pp.285-287
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• 2007

The primary goal of this study is to find out how the effect of speaking rate has some influence on the production and perception across languages. Through both experiments of production and perception, an English native speaker changes both production and perception simultaneously. Especially the production of the temporal features changes relatively fast. On the contrary, Chinese and Korean speakers changes their production rather than perception by following the speaking rate.

• The Korean Journal of Physiology and Pharmacology
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• 제18권5호
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• pp.397-402
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• 2014

Microglia are activated by inflammatory and pathophysiological stimuli in neurodegenerative diseases, and activated microglia induce neuronal damage by releasing cytotoxic factors like nitric oxide (NO). Activated microglia synthesize a significant amount of vitamin $D_3$ in the rat brain, and vitamin $D_3$ has an inhibitory effect on activated microglia. To investigate the possible role of vitamin $D_3$ as a negative regulator of activated microglia, we examined the effect of 25-hydroxyvitamin $D_3$ on NO production of lipopolysaccharide (LPS)-stimulated microglia. Treatment with LPS increased the production of NO in primary cultured and BV2 microglial cells. Treatment with 25-hydroxyvitamin $D_3$ inhibited the generation of NO in LPS-activated primary microglia and BV2 cells. In addition to NO production, expression of 1-${\alpha}$-hydroxylase and the vitamin D receptor (VDR) was also upregulated in LPS-stimulated primary and BV2 microglia. When BV2 cells were transfected with 1-${\alpha}$-hydroxylase siRNA or VDR siRNA, the inhibitory effect of 25-hydroxyvitamin $D_3$ on activated BV2 cells was suppressed. 25-Hydroxyvitamin $D_3$ also inhibited the increased phosphorylation of p38 seen in LPS-activated BV2 cells, and this inhibition was blocked by VDR siRNA. The present study shows that 25-hydroxyvitamin $D_3$ inhibits NO production in LPS-activated microglia through the mediation of LPS-induced 1-${\alpha}$-hydroxylase. This study also shows that the inhibitory effect of 25-hydroxyvitamin $D_3$ on NO production might be exerted by inhibiting LPS-induced phosphorylation of p38 through the mediation of VDR signaling. These results suggest that vitamin $D_3$ might have an important role in the negative regulation of microglial activation.

• 한국수산과학회지
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• 제56권6호
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• pp.930-935
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• 2023

This study aimed to analyze the structure of the value chain of the olive flounder aquaculture industry to increase the value of this industry. Based on the value chain theory, olive flounder aquaculture industry activities were classified as primary and support activities. The primary activities included seed production, fish production, producer distribution, consumer distribution, and consumption. The support activities were production infrastructure, organization and specialization, R&D, and government policy. A survey was conducted on the costs of seed and fish production in the primary activities to investigate the business structure, and the distribution structure was analyzed to examine distribution costs and margins. In the support activities, the recent trends in R&D and government policy were mainly examined, based on which, a measure to reduce costs and maximize profits was suggested. It is necessary to reduce costs across the production processes by improving seed quality and reducing labor, feed, and management costs, which are strongly associated with support activities. Therefore, lowering costs will be possible in the olive flounder aquaculture industry when R&D outcomes, such as species development, feed quality improvement, and aquaculture system development, are stably diffused and applied in tandem with government policy regarding the industry.

• 임산에너지
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• 제18권2호
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• pp.92-99
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• 1999

임분밀도에 따른 소나무림의 biomass생산량, 밀도변화에 따른 임목의 부위별 biomass배분특성 및 교목, 관목, 초본 등 수직층위별 biomass의 분포특성을 파악하고자 중국 백두산 동북부 지역 소나무 천연림에서 연구를 수행하였다. 임분의 밀도를 5등급으로 나누어 각각 교목층, 관목층, 초본층별로 biomass량을 추정하였다. 교목층에서 부위별로 교목층 소나무 biomass량 추정식을 유도한 결과 줄기,수피 및 지상부 전체 biomass량의 경우, logW=a＋blog(D2H)＋c(D2H)식의 적합도가 높게 나타났고 가지, 침엽의 biomass량 및 엽면적의 경우, logW=a＋blogD＋cDtlr의 적합도가 높게 나타났다. 밀도가 증가함에 따라 교목층의 biomass량은 증가하였고 관목과 초본층의 biomass량은 감소하는 추이를 나타내었다. 소나무 천연림내 교목층 임목의 부위별 순생산량은 밀도가 증가함에 따라 모두 증가하였다. 침엽이 지상부 전체 biomass 순생산량 중 차지하는 비율은 밀도가 증가함에 따라 감소함으로써 침엽의 교목층 지상부 biomass량에 대한 생산성은 증가하였다. 밀도가 다른 소나무천연림에서 부위별 순생산량은 모두 줄기>침엽>가지>수피 순이었다.