• Journal of Plant Biology
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• v.38 no.1
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• pp.87-93
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• 1995

For understanding physiological nature of phototaxis in Synechocystis sp. PCC 6803 PTX(S. 6803 PTX), we examined the effects of some metabolic inhibitors and cation ionophore on the phototactic movement. In the presence of DCMU, which blocks the photosynthetic electron transport just after photosystem II acceptor, there was no inhibitory effect on the phototaxis up to $100\;\mu\textrm{M}$. Instead, the respiratory electron chain inhibitor such as sodium azide dramatically impaired the phototaxis in S. 6803 PTX. These observations indicate that the phototaxis is linked not to photo-phosphorylation, but to respiratory phosphorylation. When the cells were treated with un couplers such as CCCP or DNP, which dissipate the electrochemical gradient of proton($\Delta\mu_{H}+$) across the cytoplasmic membrane, these chemicals did not affect phototaxis. In contrast, when cells were treated with DCCD or NBD which deprive cells of A TP but leave $\Delta\mu_{H}+$ intact across the membrane, the phototactic movement was severly reduced. These results imply that ATP production, not proton motive force, is involved in the phototactic movement in this organism as a driving motive force. The application of specific calcium ionophore A23187 strongly impaired positive phototaxis. Calcium fluxes should be engaged in the sensory trans-duction of phototactic orientation. Finally, when ethionine was supplimented to culture media, the photomovement of this organism was inhibited. This implies that methylation/demethylation mechanism controls the process of phototaxis in S. 6803 PTX like chemotaxis in E. coli and Salmonella typhimurium.murium.

• Korean Journal of Optics and Photonics
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• v.25 no.3
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• pp.131-136
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• 2014

In this paper we have implemented a temperature-insensitive polarimetric fiber strain sensor based on a Sagnac birefringence interferometer composed of a short polarization-maintaining photonic crystal fiber (PM-PCF), a 3-dB fiber coupler, and polarization controllers. The PM-PCF used as a sensor head was 2 cm long, which is the shortest length for a sensing element compared to other polarimetric fiber strain sensors using a PM-PCF. The proposed sensor showed a strain sensitivity of ${\sim}0.87pm/{\mu}{\varepsilon}$ with a strain measurement range from 0 to $8m{\varepsilon}$. The temperature sensitivity was also investigated and measured as approximately $-12pm/^{\circ}C$, when ambient temperature changed from 30 to $100^{\circ}C$. This temperature sensitivity is about 82 times smaller than that of conventional polarization-maintaining fiber (approximately $-990pm/^{\circ}C$). In particular, from a practical perspective we have experimentally and theoretically confirmed that the wavelength selected for the indicator dip location does not make a significant difference in the strain sensitivity.

• Journal of Plant Biology
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• v.39 no.1
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• pp.31-40
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• 1996

The physiological and biochemical characterizations of the ethylene-related mutants in Arabidopsis thaliana - ethylene overproducing mutant (eto1-l) and ethylene insensitive mutants (etrl-3, ein2-l) - were detailed in this studies. Two or three week.old mature rosette leaves (before bolting) were used as the plant materials. Ethylene productions of eto1-l, etrl-3, and ein2-l mutants were about 200%, 400%, and 450% compared to that of wild type, respectively. ACC synthase and ACC oxidase activities of eto1-l mutant were similar to those of wild type. ACC content and ACC N-malonyltransferase activity, however, were 4.5 times and 3 times higher than those of wild type, respectively. SAM synthetase activity increased by 50% in eto1-l mutant plant. These results indicated that the alteration in the eto1-l mutant occured before the step of the conversion of SAM to ACe. In etrl-3 and ein2-l mutants, ACC synthase activities increased, but ACC oxidase activities decreased. ACC content and ACC N-malonyltransfcrase activity were 2 times higher than those of wild type. SAM synthetase activity in etrl-3 is similar to those of wild type, while it increased by 73% in ein2-l. These results showed that the block in ethylene action affected the autoregulation of ethylene biosynthesis, so that ACC synthase activity was not autoinhibited and ACC oxidase activity was not auto stimulated by ethylene. When the leaf tissues were used for in vitro kinase assay, a cytosolic protein (approximately 36 kDa) was phosphorylated only in eto1-l and ein2-l mutants.utants.

• The Korean Journal of Mycology
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• v.27 no.4 s.91
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• pp.289-292
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• 1999

We investigated the isolation method of mushroom infesting pests, Lycoriella mali, Coboldia fuscipes, Histiostoma sp. from mushroom-growing compost. Sugar solution of different densities (0, 10, 20, 30, 40, 50%) was tested to provide a means of seperating mushroom pests from the compost media. Thus, 40% sugar solution was suitable for isolation. The sieve size to entrap the pests was $30{\sim}140$ mesh; Lycoriella mali was trappped mainly $30{\sim}65$ mesh sieve, Coboldia fuscipes was caught mainly $30{\sim}100$ mesh sieve, Histiostoma sp. was trapped mainly $65{\sim}140$ mesh sieve. An isolation procedure was as follows; The infested compost was disintegrated in water and poured onto a set of 16, 30, 80, 140-mesh sieve. The material caught in the sieve is added in 40% sugar solution and then most compost particle were massed at the bottom while the supernatant contains mushroom pests. The upperlayer material was poured into a Seperatory funnel and the sediment at the bottom is drained off. The remaining material are washed off examination dish for study.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.404-413
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• 1995

System parameters (extrusion temperature, extrusion pressure, specific mechanical energy, mean residence time) were analysed on three different screw configurations during twin-screw extrusion of wheat bran. Experiments were conducted over a screw speed of $280{\sim}380\;rpm$, feed rate of $22{\sim}38\;kg/hr$ and moisture content of $17{\sim}33%$ using screws assembled with 3, 4, and 5 reverse screw elements (RSE) adjacent to the heating zone of the barrel. Extrusion temperature increased with increasing RSE but it decreased with increasing feed rate and moisture content. Decreasing the filling ratio of the screw resulted in a lower extrusion pressure, and increasing the length of the RSE gave similar results due to the higher temperature and lower viscosity of melted dough. It was also observed that increasing the feed rate and decreasing moisture content resulted in the reduced extrusion pressure. Specific mechanical energy (SME) decreased when the feed rate and moisture content increased, and SME increased when using RSE posses from 3 to 5. Screw configuration posses with 4 RSE yielded the longest RT, and the smaller the die hole, the higher the RT. In contrast, RT decreased when the feed rate increased. With increasing moisture content RT for 3 RSE increased, but that for 4 and 5 RSE decreased.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.5
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• pp.519-524
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• 2005

Due to the low C/N ratio of domestic wastewater characteristic, addition of external carbon source for the effective N and P removal is necessary. High organic content of food waste can be used for the external carbon source in biological nutrient removal processes, The applicability of condensate of food waste (CFW), which is produced during the high-rate fermentation process, was examined in membrane bioreactor for the nutrient removal. Under the various operating conditions, nutrient removal efficiencies and membrane fouling characteristics were evaluated using synthetic wastewater. From nitrate utilization rate (NUR) test, denitrification rate was 0.19 g $NO_3-N/g$ VSS/day. With the addition of CFW increased, average removal efficiencies of T-N and T-P could be increased up to 64% and 41%, respectively. Also the optimal retention time was 3 hr/5 hr for anoxic/aerobic reactor. When applied to real sewage, membrane fouling resistance was increased up to 60%, which could be reduced from $10.4{\times}10^{12}m^{-1}$ to $5.9{\times}10^{12}m^{-1}$ with the control of influent suspended solid concentration. In summary, it was suggested that CFW could be used as an economical and effective carbon source for membrane assisted biological N and P removal.

• Korean Journal of Plant Tissue Culture
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• v.26 no.2
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• pp.121-126
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• 1999

Calli were induced from the petiole explants of Pimpinella brachycarpa on MS medium supplemented with 0.5 mg/L 2,4-D and 0.1 mg/L BA after four weeks of culture. Compact clusters of small and dense cells among these calli were selected and suspension-cultured as the source of embryogenic calli. When transferred to MS medium with 0.1 mg/L NAA, the suspension-cultured cells grew to embryogenic callus. Somatic embryos derived from these embryogenic calli developed into plantlets. The cDNA library was constructed in the embryogenic callus and in order to screen the cDNA library, these cDNAs were plated at a density 1.5 $\times$ 10^5 plaques per 15 cm petridish. Among 19 clones showing preferential hybridization with petiole HD-Zip gene, five clones were obtained after second screening. Four clones among them, were highly homologous to P. brachycarpa shoot-tip Phz4 gene, but one clone, Phc5 was about 1.5 kb which has an extra 163 bp to 5' upstream of Phz4. The Phc5 was 1,531 bp containing poly A tails of 18 bases. ATG start codon for Phc5, was located at position 284 with an open reading frame of 906 by which encodes a polypeptide of 302 amino acids. The Phc5 protein revealed that the polypeptides between 135 and 195 contain a homeodomain as the `leucine zipper' motif.

• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.223-230
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• 2020

The purpose of this study was to investigate the effect of ego-resilience, adult attachment, and interpersonal competence on academic stress in nursing students and to provide the basic data of to control academic stress. Data were collected from 287 nursing students in B and C city and analyzed by t-test, ANOVA, Pearson correlation coefficient, and multiple regression using SPSS/WIN 22.0. The degree of academic stress in nursing students was 2.28±.46. There were significant differences in academic stress with respect to grade(F=16.342, p<.001), economic status(F=3.331, p=.037), number of alcohol drinking(F=3.393, p=.035), satisfaction of major(F=40.539, p<.001), college life satisfaction(F=67.304, p<.001). There was positive correlation between academic stress and adult attachment(r=.557, p<.001), negative correlation were found between academic stress and ego-resilience(r=-.379, p<.001), between academic stress and interpersonal competence(r=-.423, p<.001). The factors affecting the academic stress of the study subjects were ego-resilience(r=-.379, p<.001), adult attachment(r=.557, p<.001), with an explanatory power of 34%. Through this research requires the fellow study to determine the factors affecting academic stress of nursing students.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.1
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• pp.24-32
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• 2008

The ultimate purpose of the study is to develop a discomfort glare forecasting formula that can be practically used in Korea in order to effectively forecast discomfort glare considering the optical characteristics of the Koreans. The study was to examine the relations between discomfort glare and the variables such as luminance, background luminance, solid angle, luminous area and louver. To this end, experiments were conducted in a mock-up office that emulates the lighting environment of an ordinary office. The study was conducted by four steps as follow. First, previous studies on discomfort glare rating to define and rate discomfort glare were analyzed and modified to be applied to the experiments of this study. Second, experiment variables, variable scope, evaluation objects and evaluation points were determined after review on existing discomfort glare evaluation experimental formulas. Third, experiments were conducted in a mock-up office to be able to control variables. Finally, sensitivity of experiment variables were analyzed through examination of the relation between discomfort glare and the variables such as luminance, solid angle, louver, luminous area and subject's position. The result showed that the most influential variables on discomfort glare of an artificial light source is luminance and louver, luminous area and subject's position(solid angle) followed.

• Proceedings of the KSCN Conference
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• 2003.11a
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• pp.1061-1062
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• 2003

현대사회에서 청소년기에 발생하는 영양문제 중 가장 빈번히 나타나는 청소년기 비만은 성인 비만으로 이행되기 쉬우며, 당뇨병, 지방간, 고혈압과 같은 각종 성인병의 발생과도 관련이 있다. 또한 체형에 대한 관심이 증가하고 있는 현대사회에서 편견의 대상이 됨으로 인한 심리적 장애를 발생시키기도 한다. 이에 따라 비만인의 체중조절을 위한 다양한 교육프로그램들이 실시되고 있는데, 현재까지의 실시되고 있는 프로그램들은 강의식교육이 주류를 이루고 있어 적극적인 교육효과를 이끌어 내는데 많은 한계점을 가지고 있었다. 이에 본 연구자들은 지역보건소를 중심으로 2박 3일간의 청소년 캠프 프로그램을 통하여 VTR감상, CAN-Pro를 이용한 섭취 식단의 평가 및 영양상담, 영양뷔페, 역할극, 다양한 영양지식 응용게임, 일상생활에서 활용가능 한 운동교육, 비만의 원인과 건강과의 관련성 및 식사요법 등에 대한 강의를 실시하였다. 캠프 참가자들은 부천시에 거주하는 중학생으로 사전에 신장과 체중에 대한 조사를 바탕으로 비만으로 판정된 총 42명(남 28명, 여 14명)으로 하였다. 캠프 시작전과 후에 설문조사를 통하여 영양지식, 영양태도, 자아만족도에 관한 조사를 실시하여 프로그램 직후의 효과를 판정하였고, 일상적인 영양소섭취상태를 평가하기 위해 24시간 회상법을 통하여 캠프참가 전날의 식이섭취 조사를 실시하였다. 대상자의 평균 연령은 13.9세로 남녀학생 간에 유의적인 차이가 없었으며, 신장은 남학생이 160.7cm, 여학생이 156.8cm였다. 체중, 체질량지수, 비만지수, 허리엉덩이둘레비 및 체지방 함량은 남학생이 각각 75.5kg, 29.1kg/$m^2$, 30.1, 0.89, 33.3%이었고, 여학생이 각각 67.8kg, 27.5kg/$m^2$, 25.3, 0.81, 34.6%였다. 영양소 섭취량에 대한 분석결과 열량의 경우 남학생이 2137.7㎉, 여학생이 2059.7㎉ 섭취수준을 보였으며, 총열량에 대한 당질, 단백질, 지질의 섭취 비율은 남학생 57:14:29, 여학생 60:13:26으로 남여학생 모두 총열량에 대한 지질의 섭취 비율이 높았다. 프로그램의 효과 평가를 위하여 남녀중학생을 모두 합하여 비교하였을 때 프로그램 실시 후 영양태도가 유의적으로 향상되었으며(p<0.001), 자아만족도 및 영양지식에 있어서는 유의적인 변화가 나타나지 않았다. 그러나, 성별로 분류하여 비교 시 남학생은 영양태도(p<0.01)와 영양지식(p<0.05)이 유의적으로 향상되었고, 여학생의 경우에는 영양태도(p <0.01)에서만 유의적인 향상을 나타내었다. 이상의 결과에서 2박 3일간의 청소년 캠프는 남녀 비만중학생에 있어 영양태도의 향상을 가지고 왔으며, 남학생의 경우에는 영양지식에도 유의적인 향상이 나타났다. 그러나 영양교육의 효과가 실제적인 영양소섭취 및 비만도의 변화에 영향을 미치는지를 알아보기 위해서는 지속적인 추적 관리를 통한 효과판정이 필요한 것으로 보여진다.