• Journal of Embryo Transfer
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• v.19 no.3
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• pp.191-199
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• 2004

This study was conducted to examine in vitro development of porcine embryos constructed by the microinjection of cultured fetal fibroblast cells into porcine oocytes matured in vitro. Single fetal donor cells were deposited into the perivitelline space of enucleated oocytes, followed by electrical fusion and activation. Activated embryos were cultured in NCSU-23 medium supplemented with 5％ FBS, at 38.5$^{\circ}C$ for 6 to 8 days in 5％ $CO_2$ and air. In experiment 1, fusion rates of nuclear transfer embryos did not differ for fetal fibroblast cells incubated in 5％ FBS + NCSU-23 or 5％ FBS + TL Heaps medium, nor did fusion rates of donor cells differ between 1-8 hr incubation durations. Fusion rates for the four treatment subclasses ranged from 72.1％ to 78.0％. In experiment 2, Pre-synchronization in medium containing 0.1 $\mu\textrm{g}$/m Hoechst 33342 an increase from 0 and 8 versus 15 h culture an increased percentage of porcine fibroblast cells in G2/M at the end of the synchronization period (12.4％, 17.5％ and 47.6％). Neither an increase in the concentration of H 33342 (0.2-1.6 $\mu\textrm{g}$/$m\ell$) nor a longer exposure time (12h, 18h and 24h) increased the proportion of porcine G2/M fibroblasts. In experiment 3, fusion rates did not differ significantly far nuclear transfer embryos constructed using donor cells cultured in 5％ FBS + NCSU-23 medium for 1-2, 6-8 or 12-14 days (60.0％, 73.3％ and 62.5％), respectively. The cleavage rate for nuclear transplant embryos using fetal fibroblast cells cultured for 1-2 days was 44.0％, significantly less than 56.7％ and 50.0％. for 6-8 or 12-14 days duration of culture, respectively. In experiment 4, the proportions of nuclear transfer embryos that developed to the $\geq$2 cell and to the blastocyst stage were not affected significantly by culture medium (5％ FBS + NCSU-23 or 5％ FBS + TL-Heaps) or by $O_2$ concentration of the culture (5％ vs 10％). Rates of development to the $\geq$2 cell stage ranged from 65.9％ to 70.1％, and development rates to the blastocyst stage ranged from 9.8％ to 12.5％ for the four treatment subclasses. Developmental rate was highest for embryos cultured in 5％ FBS + NCSU-23 under a gas atmosphere of 5％ $O_2$ in air.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.222-226
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• 2008

The construction industry has remained stagnant for a long time. So many researchers have wanted to solve this problem not only focusing on enhancement of construction process, but also introducing the culture of cooperation. The Last Planner System(LPS), one of the elementary techniques of Lean Construction, aims for improving the work reliability and reducing variability by measuring and managing the daily or weekly performance for overcoming the weakness of recent complex schedule management tools such as Critical Path Method. This research propose a framework for implementation of LPS conducted by owner focused on construction stage and introduce optimal owner participation model in plant construction, based on needs analysis for construction participants. Furthermore, this research introduce a modified needs analysis, so called IPBA(Importance-Performance-Betterment Analysis), and an advanced LPS procedure which add the needs analysis during pre-LPS and(or) main LPS stages.

• The Journal of Art Theory & Practice
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• no.1
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• pp.7-22
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• 2003

What is 'Art Theory'? In the western sense, the term poses a vague ambiguity, and in the eastern, it is rather an abstract and metaphysical concept. As for etymology, theory is derived from theoria and theoria from theoros. It refers to an act of viewing or seeing, of course not in a metaphysical sense. Plato understood it as 'eide'. During the time of Plotinus, theoria encompassed gazing at every possible reality, and this gazing, that is theoria, is closely related to reality as aunit that theoriacan perceive. However, we tend to distinguish, as other scientists of dualism have done, studio art from theory since a pre-modern approach to art has been particularly tuned to studio practice, set apart from theory. Therefore, in studio classes, students are expected to learn the subject based on the foundational curriculum methods such as medium, genre, technique:, rather than bringing out their own interpretations and discussing theories. As a result, students have become artists, who are not able to understand their own art. Art professors who conduct class in studio are required to proceed with specific 'theories' as well as 'intellectual reflections'. In this respect, this thesis presents poiesis and an idea of 'acting out'. Although art history and aesthetic theory tend to view art as a finished product, actual art-making and related theories should not only be acknowledged as 'completion' (finition) but also be accompanied by theoretic interpretations of the act itself and process. Accordingly, it is to accept and appreciate art as finished result in view of current theory and aesthetics thus boils down to aisthesis. Likewise, poietics starts from a point where an artist is related to studio and examines the 'work process' that extends as far as to the exact end of work. Through the study of such relationship, it is possible that theory understands 'studio' and 'process', and an artist can grant an independent meaning to studio where s/he pours her/his heart out creating a work of art. Theory is a study on artistic discovery thus should be equipped with functions that can accommodate fortuity, imitation, thinking, culture, and surrounding.

• Journal of Plant Biotechnology
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• v.31 no.3
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• pp.203-207
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• 2004

To establish high frequency shoot formation from two cultivars (Cheongyangjaerae and Myungan) of boxthorn (Lycium chinense Mill.), hypocotyl segments with cotyledons from seedlings were used as explants. High frequency adventitious shoot formation (more than 80%) were obtained from hypocotyl segments with cotyledon on MS medium supplemented with 1.0 mg/L zeatin, when precultured for 3 weeks under dark conditions followed by transfer to light conditions. But there was no shoot induction in the explants cultured without preculture under dark conditions. Roots were induced from the shoots when transferred to rooting medium supplemented with 1.0 mg/L IAA for 4 weeks. Regenerated plantlets were grown to normal mature plants in soil.

• KIEAE Journal
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• v.10 no.2
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• pp.39-48
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• 2010

PAJU Book City Plan was designed to integrate two concepts of "Publishing Productive City" and "Ecological City" with the goal of "bringing of human being and nature together". This research on the post occupancy evaluation on PAJU Book City has two aims; One is to define how people, mainly working there rather than living, recognize the city and the other is to identify the problems resulted from the first phase of planning process and to suggest feasible solutions at the same time. It would be desirable that the outcome of this research should be used as data sources to improve the second phase of the plan. The evaluation criteria were created by the pre-survey on the basis of previous researches and "Pa Ju publishing city architectural design guide book (1999)". With those criteria, on-site questionnaire was conducted among people who work in PAJU Book City and stratified sampling was used for the proper sampling. The result is as follows; the visual-aesthetic criteria had positive response, which also closely related to a city satisfaction. Considering this result, construction type, circumferential environment of the building and a place of building form were found appropriate. The evaluation on the physical-ecological criteria was relatively low. Respondents were unsatisfied with green space and required better ecological waterway and more roadside tree. As green space was given a lot of weight in satisfaction survey, more green urban areas should be planned in the next phase. The evaluation on the social-behavior criteria got the lowest score. Particularly, the accessibility and convenient facilities were remarkably low. Nonetheless, the self-conceit about PAJU Book City was highly evaluated and played a crucial role in a city satisfaction. In order to achieve the goal, physical beauty, characteristics as a publication city as well as an ecologically sustainable city should be main agenda in the second phase of Paju Book City Plan. Consequently, it is important to strike a balance between the external environment and image media in order that PAJU Book City should be re-born as a culture city.

• Child Studies in Asia-Pacific Contexts
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• v.4 no.1
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• pp.27-45
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• 2014

The present study investigated the developmental pattern of Korean mothers' depressive symptoms from a week prior to birth through four months postpartum in a nationally represented survey sample in Korea, using a Latent Growth Curve model. Mother-reported four factors-maternal self-efficacy in parenting, father's participation in childcare, a number of hours mothers worked per week, child's emotional temperament-were examined as the predictors of depressive symptoms over time in the context of Korean culture. Effects of maternal depressive trajectories on their infants' developmental outcomes at the first year were also examined. Findings were as follows: First, mothers' reports of depressive symptoms decreased at the first month after birth and then increased again during the first 4 months postpartum. Second, mothers' perceived low spousal involvement in childcare, low parental self-efficacy, and their infants' difficult temperament at four-month old had significantly positive relations to the initial level of maternal depressive symptoms whereas the low spousal involvement in childcare and low maternal self-efficacy factors significantly predicted the changes of trajectories of maternal depressive symptoms. Third, the trajectories, in turn, predicted warm and responsive maternal parenting style at the fourth month. Subsequently, the parenting style had a significant longitudinal impact on the development of children's communication, problem-solving, and personal-social abilities. Based on these findings, awareness, preventive and interventional programs might be built to facilitate Korean mothers suffering severe postpartum depressive symptoms and further promote optimal early development of Korean children.

• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.474-480
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• 2018

Most angiogenesis assays are performed using endothelial cells. However, blood vessels are composed of two cell types: endothelial cells and pericytes. Thus, co-culture of two vascular cells should be employed to evaluate angiogenic properties. Here, we developed an in vitro 3-dimensional angiogenesis assay system using spheroids formed by two human vascular precursors: endothelial colony forming cells (ECFCs) and mesenchymal stem cells (MSCs). ECFCs, MSCs, or ECFCs+MSCs were cultured to form spheroids. Sprout formation from each spheroid was observed for 24 h by real-time cell recorder. Sprout number and length were higher in ECFC+MSC spheroids than ECFC-only spheroids. No sprouts were observed in MSC-only spheroids. Sprout formation by ECFC spheroids was increased by treatment with vascular endothelial growth factor (VEGF) or combination of VEGF and fibroblast growth factor-2 (FGF-2). Interestingly, there was no further increase in sprout formation by ECFC+MSC spheroids in response to VEGF or VEGF+FGF-2, suggesting that MSCs stimulate sprout formation by ECFCs. Immuno-fluorescent labeling technique revealed that MSCs surrounded ECFC-mediated sprout structures. We tested vatalanib, VEGF inhibitor, using ECFC and ECFC+MSC spheroids. Vatalanib significantly inhibited sprout formation in both spheroids. Of note, the $IC_{50}$ of vatalanib in ECFC+MSC spheroids at 24 h was $4.0{\pm}0.40{\mu}M$, which are more correlated with the data of previous animal studies when compared with ECFC spheroids ($0.2{\pm}0.03{\mu}M$). These results suggest that ECFC+MSC spheroids generate physiologically relevant sprout structures composed of two types of vascular cells, and will be an effective pre-clinical in vitro assay model to evaluate pro- or anti-angiogenic property.

• Korean Journal of Veterinary Service
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• v.37 no.4
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• pp.253-261
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• 2014

Porcine circovirus disease (PCVD) is a major problem of swine industry worldwide, and diagnosis of PCV2, causal agent of PCVD, has been doing in clinical laboratories of pig disease by polymerase chain reaction (PCR) methods. But the PCR analyses have a serious problem of misdiagnosis by contamination of DNA, in particular, from carryover contamination with previously amplified DNA or extracted DNA from field samples. In this study, an uracil DNA glycosylase (UNG)-based direct PCR (udPCR) without DNA extraction process and DNA carryover contamination was developed and evaluated on PCV2 culture and field pig samples. The sensitivity of the udPCR combined with dPCR and uPCR was same or better than that of the commercial PCR (cPCR) kit (Median diagnostics, Korea) on PCV2-positive serum, lymph node and lung samples of the pigs. In addition, the udPCR method confirmed to have a preventing ability of mis-amplification by contamination of pre-amplified PCV2 DNA from previous udPCR. In clinical application, 170 pig samples (86 tissues and 84 serum) were analysed by cPCR kit and resulted in 37% (63/170) of positive reaction, while the udPCR was able to detect the PCV2 DNA in 45.3% (77/170) with higher sensitivity than cPCR. In conclusion, the udPCR developed in the study is a time, labor and cost saving method for the detection of PCV2 and providing a preventing effect for DNA carryover contamination that can occurred in PCR process. Therefore, the udPCR assay could be an useful alternative method for the diagnosis of PCV2 in the swine disease diagnostic laboratories.

• Parasites, Hosts and Diseases
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• v.31 no.4
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• pp.379-381
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• 1993

We experienced the partial Inhibition of entry of Taxoplasma gondii Into MDCK cells when the FBS was depleted from media. MDCK cells and Toxoplasma (RH strains) were co-cultured, the penetration was inhibited up to 60-80% with concentration-dependence of FBS. Inhibitory effect was clear when the conc. of FBS was over 1% (v/v) with 50% inhibition comic. of 5%. When ToxopLosma was pre-incubated with FBS and then applied to MDCK cells, there were no inhibitory effect, but when FBS was added to Toxoplasma- MDCK co-culture, the time of adding was c10cal with rapid inhibition. And when FBS was further treated with heat ($95^{\circ}C$, 10 min), the Inhibitory effect was decreased slightiy in both raw and inactivated FBS. The FBS factor(s) might participate to neutralize secreted materials which enhancing penetration or Intervene between receptor-ligand blnding at the moment of entry through sterically rather than functionally.

• Cross-Cultural Studies
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• v.48
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• pp.223-252
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• 2017

This study explores effects of two types of chatbots - voice-based and text-based - on Korean EFL learners' speaking competence and learner perception. Participants were 80 freshmen students taking an English-speaking class at a university in Korea. They were divided into two experimental groups at random. During the sixteen-week experimental period, participants engaged in 10 chat sessions with the two different types of chatbots. To take a close examination of effects on the improvement of speaking competence, they took the TOEIC speaking test as pre- and post-tests. Structured questionnaire-based surveys were conducted before and after treatment to determine if there are changes in perception. Findings reveal two chatbots effectively contribute to improvement of speaking competence among EFL learners. Particularly, the voice-based chatbot was as effective as the text-based chatbot. An analysis of survey results indicates perception of chatbot-assisted language learning changed positively over time. In particular, most participants preferred voice-based chatbot over text-based chatbot. This study provides insight on the use of chatbots in EFL learning, suggesting that EFL teachers should integrate chatbot technology in their classrooms.