• Journal of The Korean Association For Science Education
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• v.27 no.9
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• pp.832-847
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• 2007

The purpose of the study was to analyze and interpret parent-child dyadic discourses in depth with emphases on the ZPD system in a museum, an informal learning setting. Second graders and their parents from Seoul and its environs were voluntarily participated in the study. Data were collected from the museum documents, the photos of exhibits, and the video recordings of dyadic discourses at and between exhibits. The documents and the photos were analyzed to investigate what the topics, medium and goals of the exhibits were. The video recordings were all transcribed and analyzed to understand what and how they talked to each other through the lens of the ZPD system; situation definition, intersubjectivity, and semiotic mediation, The results of the study consisted of two parts. First, it showed that parent-child dyadic discourses were categorized in four: (1) within the actual developmental level; (2) in the zone of proximal development; (3) toward the potential developmental level; and (4) out of developmental level. The most common categories were the dyadic discourses within the actual developmental level and in the zone of proxima I development. Second, the representative cases in each categories were described and interpreted to understand the nature of parent-child dyadic discourses. It can be concluded that we gained some important understandings of an intrinsic attribute of parent-child discourses in a museum, an informal learning setting. Based on the results of the study, it can be suggested that museums make efforts to cultivate the affordance of exhibit environment to promote visitor's learning.

• Journal of the Daesoon Academy of Sciences
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• v.49
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• pp.1-52
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• 2024

One notable characteristic of Daesoon Jinrihoe's view of time, is its perception of time as a passive entity. This signifies that, in the context of Daesoon Jinrihoe, time is subject to influence through experience, specifically undergoing re-calibration or governance. The summary of this perspective is as follows: Firstly, Daesoon Jinrihoe's understanding of time incorporates a historical viewpoint characterized by the law of entropy, which posits that disorder increases as time progresses. Secondly, within the world established by Daesoon Jinrihoe, time experiences transformation before and after the Great Opening. Prior to this event, time follows a helical model characterized by increasing chaotic disorder, whereas in the Later World, the helical model reflects only Mutual Beneficence, symbolizing progress and development in the era. Thirdly, the Great Opening re-calibrates time, serving as the criterion for determining human life. Prior to the Great Opening, time recorded human life in a manner marked by Mutual Contention, whereas afterward, it will record human life as being characterized by Mutual Beneficence. This re-calibration of time leads precisely to directional (spatial) re-calibration. Fourthly, the Great Opening re-calibrates the order of time and space. In the Former World, space held precedence over time. However, the Great Opening changes this dynamic, with time assuming precedence over space in the Later World. In this context, the integration of time and space establishes a worldview. Fifthly, in the worldview of Daesoon Jinrihoe, time serves as a vehicle for the governance of the Supreme God. The Supreme God governs all things by controlling time, orchestrating changes spanning birth (saeng, 生), growth (jang, 長), harvest (yeom, 斂), and storage (jang, 藏), much like how problems are resolved through natural progress without requiring deliberate action. Lastly, time functions as a medium through which entities that strive to achieve unification with the Dao come to govern all things. For this reason, achieving unification with the Dao in Daesoon Jinrihoe specifically refers to the governance of time.

• The Korean Journal of Mycology
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• v.32 no.1
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• pp.31-38
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• 2004

An endophytic bacterial strain EB215 that was isolated from cucumber (Cucumis sativus) roots displayed a potent in vivo antifungal activity against Colletotrichum species. The strain was identified as Burkholderia cepacia based on its physiological and biochemical characteristics, and 16S rDNA gene sequence. Optimal medium and incubation period for the production of antifungal substances by B. cepacia EB215 were nutrient broth (NB) and 3 days, respectively. An antifungal substance was isolated from the NB cultures of B. cepacia EB215 strain by centrifugation, n-hexane partitioning, silica gel column chromatography, preparative TLC, and in vitro bioassay. Its chemical structure was determined to be pyrrolnitrin by mass and NMR spectral analyses. Pyrrolnitrin showed potent disease control efficacy of more than 90% against pepper anthracnose (Colletotrichum coccodes), cucumber anthracnose (Colletotrichum orbiculare), rice blast (Magnaporthe grisea) and rice sheath blight (Corticium sasaki) even at a low concentration of $11.1\;{\mu}g/ml$. In addition, it effectively controlled the development of tomato gray mold (Botrytis cinerea) and wheat leaf rust (Puccinia recondita) at concentrations over $33.3\;{\mu}g/ml$. However, it had no antifungal activity against Phytophthora infestans on tomato plants. Further studies on the development of microbial fungicide using B. cepacia EB215 are in progress.

• Microbiology and Biotechnology Letters
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• v.33 no.1
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• pp.16-23
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• 2005

In order to develop a new microbial fungicide using endophytic bacteria for the control of anthracnoses occurring on various crops, a total of 260 bacterial strains were isolated from fresh tissues of 5 plant species. After they were cultured in broth medium, their antifungal activities were tested for in vivo antifungal activity against cucumber anthracnose caused by Colletotrichum orbiculare. As the results, liquid cultures of 28 strains showed potent antifungal activities more than $90\%$ against cucumber anthracnose. At 3-fold dilutions of liquid cultures, 18 strains inhibited the development of cucumber anthracnose of more than $70\%$. They were further tested for in vivo antifungal activity against red pepper anthracnose caused by C. coccodes and in vitro antifungal activity against C. acutatum, a fungal agent causing red pepper anthracnose. Among 18 strains, a bacterial strain EB215 isolated from cucumber roots displayed the most potent antifungal activity against Colletotrichum species. It was identified as Burkholderia cepacia based on its physiological and biochemical characteristics, Biolog test and 16S rDNA gene sequence. It also controlled effectively the development of rice blast (Magnaporthe grisea), rice sheath blight (Corticium sasaki), tomato gray mold (Botrytis cinerea), and tomato late blight (Phytophthora infestans). Studies on the characterization of antifungal substances produced by B. cepacia EB215 are in progress.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.2
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• pp.195-201
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• 2014

Body fluid has been studied for diverse fields like Ringer's solutions, artificial joint fluids, cell growth culture media because it plays a crucial role in controlling body temperature and acts as a solvent for diverse metabolite processes in the body and delivery media of mineral, energy source, hormone, signal and drug from and to cell via blood or lymphatic vessel by osmotic pressure or active uptake. Stratum corneum containing extracellular lipids and NMF (natural moisturizing factor) absorbs atmospheric water residing outside of cells and utilize it to hydrate inside of their own. This process is related to skin barrier function. In this study, we conducted the cell viability test with Cell Bio Fluid $Sync^{TM}$, which mimicks body fluids including amino acids, peptides, and monosaccharides to strengthen skin barrier, and the clinical skin improvement test with cosmetics containing Cell Bio Fluid $Sync^{TM}$. In the cell viability test, HaCaT cell was treated with PBS for 3 hours, followed by the treatment of a cell culture medium (DMEM) and isotonic solution (PBS) and Cell Bio Fluid $Sync^{TM}$ for 3 hours each. Then, MTT assay and image analysis were conducted. In the clinical skin improvement test, twenty-one healthy women participated. Participants applied cosmetics containing Cell Bio Fluid $Sync^{TM}$ on their face for a week and evaluated the skin hydration, skin roughness, brightness and evenness. All measurements were conducted after they washed off their face and took a rest under the constant temperature ($22{\pm}2^{\circ}C$) and constant humidity conditions ($50{\pm}5%$) for 20 minutes. All the data were analyzed by SPSS (version 21) software program. Results showed that Cell Bio Fluid $Sync^{TM}$ improved both the cell viability and in vivo skin conditions such as skin hydration, roughness, brightness and evenness.

• Journal of Embryo Transfer
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• v.20 no.3
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• pp.191-200
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• 2005

Many studies have shown that the development of mouse early 2-cell embryos in vitro is related with the intracellular $Ca^{2+}$ changes. In ICR strain mouse, the development of embryos arrests at early 2-cell stage, but the arrested early 2-cell embryos can be rescued by the addition of $Ca^{2+}$-related materials. Acetylcholine (ACh) increases intracellular $Ca^{2+}$ concentration ([$Ca^{2+}$]i) via the mAChR-PLC-IP3 pathway in mouse oocytes. We examined whether ACh rescues 2-cell block in mouse. In early 2-cell embryos, ACh increased [$Ca^{2+}$]i in a dose-dependent manner (p<0.001), and had an effect on rescue of 2-cell block and embryonic development. To identify the signal pathway involved in ACh-induced rescue of 2-cell block, we first applied an agonist of ACh receptor (AChR). Like ACh, carbachol increased intracellular $Ca^{2+}$ concentration ([$Ca^{2+}$]i) and atropine, an antagonist of ACh receptor, blocked the ACh-induced $Ca^{2+}$ increase. In $Ca^{2+}$-free medium, ACh also increased [$Ca^{2+}$]i, indicating that $Ca^{2+}$ increased by ACh is mainly released from the intracellular $Ca^{2+}$ store. The ACh-induced $Ca^{2+}$ increase was blocked by PLC inhibitor (U73122), ryanodine receptor (RyR) antagonist (dantrolene), and CaM KII inhibitor (KN-93), but not by IP3R antagonists (xestospongin C). These results show that ACh increases intracellular $Ca^{2+}$ concentration via mAChR/PLC/RyR, and this contributes to the rescue of 2-cell block.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.438-446
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• 2020

Meju and nuruk (respectively soybean and malt) are traditional Korean fermentation starters that are vulnerable to contamination by harmful microorganisms such as aflatoxigenic fungi and their associated aflatoxins (AFs). In this study, Aspergillus spp. were isolated and identified from a total of 57 meju and 18 nuruk samples collected from Korean markets. Their potential aflatoxigenicity was investigated by examining the presence of three aflatoxin biosynthetic genes (aflO, aflP, and aflR) using multiplex polymerase chain reaction (mPCR) assays. Thereafter, aflatoxin production of isolates and the natural occurrence of AFs in meju and nuruk samples were analyzed by high-performance liquid chromatography (HPLC). A total of 177 Aspergillus isolates were identified and 130 isolates were obtained from meju samples. Of these, 25 isolates (19.2%) contained all three aflatoxin biosynthetic genes, and five (20%) of these isolates produced aflatoxins. Forty-seven of the Aspergillus isolates were obtained from nuruk samples, five of which (10.6%) expressed all three AF biosynthetic genes; however, none of these strains produced AFs. HPLC analysis showed that 88% (51/58) of the meju samples and 39% (7/18) of nuruk samples were not contaminated with AFs (below limit of detection). Among the isolates isolated from meju and nuruk, there were aflatoxigenic strains containing all three aflatoxin biosynthetic genes or producing aflatoxin in medium, but the frequency of aflatoxin contamination was low in the meju and nuruk samples.

• Journal of Embryo Transfer
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• v.21 no.2
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• pp.137-146
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• 2006

The objective of this study was to examine the effect of donor cell types, the source of recipient oocytes and estrous synchronization on pregnancy and delivery rates of somatic cell nuclear transfer (SCNT) embryos in Korean native goats. Recipient oocytes were surgically collected after superovulation. Ear cells and fetal fibroblasts were collected and cultured in serum-starvation condition (TCM-199 + 0.5% FBS) for cell confluence. The zonae pellucidae of in vivo- and in vitro-matured oocytes were partially drilled using a laser system. Single somatic cell was transferred into the enucleated oocyte. The reconstructed oocytes were electrically fused with 0.3 M mannitol. After the fusion, embryos were activated by Ionomycin+6-DMAP. NT embryos were cultured in mSOF medium supplemented with 0.8% BSA at $39^{\circ}C$ in an atmosphere of 5% $CO_2$, 5% $O_2$, 90% $N_2$ for 12 to 20 hr. One hundred and two SCNT embryos were transferred into 20 recipients and pregnancy rate at days 30 was 20.0%. Of them, one developed to term and delivered 1 kid. Ear cells showed significantly higher fusion (63.8 vs. 26.5%) and pregnancy rates (20.0 vs. 0.0%) than those of fetal fibroblast (p<0.05). The recipients synchronized by CIDR showed significantly lower pregnancy rates compared to that of recipient in natural estrus ($0.0{\sim}25.0%$ vs. 100%) (p<0.05). Cloned kid was born from the recipient in natural estrus. For the synchronization of estrus between recipient and donor, there was no difference between treatments (${\pm}0$ vs. +12 hr) in pregnancy rate. The first healthy cloned kid (Jinsoonny) was produced by transfer of SCNT embryos derived from in vivo oocytes and ear cells into a recipient goat whose estrus was synchronized with the donor. These results imply that donor cells for nuclear transfer may affect the success rate, and the estrus synchronization between donor and recipient animals can also be important.

• Journal of the Korean Geographical Society
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• v.31 no.2
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• pp.106-127
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• 1996

In Korea, modern geomorphology has developed as one of main subjects in geography, such as in Europe. Geomorphology is one of the most advanced specialties in the geography dicipline, since foundation of Korean Geographical Society in 1945. Untill 1960's study, first generation of the Korean geomorphologists trained the younger ones, together with energetic research activities. Their great works in education and research established the base of ulterier development of the geomorphology in Korea. Since 1970s, research manpower and quality has incresed rapidly, partly due to the various international activities and cooperations of Korean geomorphologists. Owing to above development, Korean geomorphologist was able to found "The Geomorphological Association of Korea" in 1990 and publish "Journal of GAK", since 1994. Furthermore, geomorphologists are playing important roles in interdisciplinary academic societies, such as "The Korean Quaternary Assocition". Still 1960s, our research had focused on the identification and interpretation of erosional surfaces in Korea Peninsular. Of course, W.M. Davis's "Geographical Cycle Theory" and L.C. King's "Pedimentation Theory" had a great influence on the Koerans' works. After 1970s, the study of erosional surface played the important role in setting up the morphoclimatic viewpoint and methodology. Research scope tend to be notably broad and various than it was untill 1960's. Disposotion of the scientific methods and techniques become more and more apparent. These trends of research has settled precise descreption and interpretation of actual landforms, based on the careful field works, scientific measuring, and analisis, rather than methodology focused on the particular master theories. Recent geomorphological researches show the scope from climatic geomorphology and Quaternary geomorphology to granite and limestone weathering, pedo-geomorphogenic environment and periglacial landforms, focused on the small-to-medium scales. And then there have been new trying to interprete erosional surfaces such as hillslopes and terraces. Also, studies of coastal and plain landforms have been successfully developed. Recent new trends show the quantitative and analytic modelling using field measurement and laboratory work, and study on the human impacts on the natural landforms.y on the human impacts on the natural landforms.

• Journal of Life Science
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• v.23 no.4
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• pp.542-553
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• 2013

The aim of this work was to establish the optimal conditions for the production of cellobiase by a marine bacterium, Cellulophaga lytica LBH-14, using response-surface methodology (RSM). The optimal conditions of rice bran, ammonium chloride, and the initial pH of the medium for cell growth were 100.0 g/l, 5.00 g/l, and 7.0, respectively, whereas those for the production of cellobiase were 91.1 g/l, 9.02 g/l, and 6.6, respectively. The optimal concentrations of $K_2HPO_4$, NaCl, $MgSO_4{\cdot}_{7H2}O$, and $(NH_4)_2SO_4$ for cell growth were 6.25, 0.62, 0.28, and 0.42 g/l, respectively, whereas those for the production of cellobiase were 4.46, 0.36, 0.27, and 0.73 g/l, respectively. The optimal temperatures for cell growth and for the production of cellobiase by C. lytica LBH-14 were 35 and $25^{\circ}C$, respectively. The maximal production of cellobiase in a 100 L bioreactor under optimized conditions in this study was 92.3 U/ml, which was 5.4 times higher than that before optimization. In this study, rice bran and ammonium chloride were developed as carbon and nitrogen sources for the production of cellobiase by C. lytica LBH-14. The time for the production of cellobiase by the marine bacterium with submerged fermentations was reduced from 7 to 3 days, which resulted in enhanced productivity of cellobiase and a decrease in its production cost. This study found that the optimal conditions for the production of cellobiase were different from those of CMCase by C. lytica LBH-14.