• Journal of Veterinary Science
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• 제21권5호
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• pp.78.1-78.15
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• 2020

Background: Enteritis is one of the most frequently reported symptoms in piglets infected with porcine circovirus type 2 (PCV2), but the immunopathogenesis has not been reported. Objectives: This study examined the effect of a PCV2 infection on the intestinal mucosal immune function through morphological observations and immune-related molecular detection. Methods: Morphological changes within the ileum of piglets during a PCV2 infection were observed. The expression of the related-molecules was analyzed using a gene chip. The immunocyte subsets were analyzed by flow cytometry. The secretory immunoglobulin A (SIgA) content was analyzed by enzyme-linked immunosorbent assay. Results: The PCV2 infection caused ileal villus damage, intestinal epithelial cells exfoliation, and an increase in lymphocytes in the lamina propria at 21 days post-infection. Differentially expressed genes occurred in the defense response, inflammatory response, and the complement and coagulation cascade reactions. Most of them were downregulated significantly at the induction site and upregulated at the effector site. The genes associated with SIgA production were downregulated significantly at the induction site. In contrast, the expression of the Toll-like receptor-related genes was upregulated significantly at the effector site. The frequencies of dendritic cells, B cells, and CD8⁺T cells were upregulated at the 2 sites. The SIgA content decreased significantly in the ileal mucosa. Conclusions: PCV2 infections can cause damage to the ileum that is associated with changes in immune-related gene expression, immune-related cell subsets, and SIgA production. These findings elucidated the molecular changes in the ileum after a PCV2 infection from the perspective of intestinal mucosal immunity, which provides insights into a further study for PCV2-induced enteritis.

• Educational Technology International
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• 제20권1호
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• pp.109-135
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• 2019

Rapid development of educational technology requires fundamental changes not only in the form of instruction and role of teachers in school education but also in the competency development of students. Specifically, the emergence of new technologies such as makerspace, virtual reality (VR), and robotics has made it more challenging for teachers and students in the 21st century. However, even with the argument for the changes, less has been discussed about how much in-service teachers are aware of and how they are preparing for such changes. Therefore, this study intends to explore what would be required to students and teachers, and for instructional changes with more technologies available through the lens of elementary school teachers. The study results suggest, similar to previous studies, in-service elementary teachers recognize that student competencies such as creativity, collaboration, communication, and problem-solving skills are important. They also perceived that teacher change in role and attitude, and for instructional method and classroom culture are crucial as catalysts of change. Unique and interesting finding from this study is about the importance of nurturing digital citizenship in technology-infused learning environment. The digital citizenship has been less highlighted in the past, but this study revealed it should be treated as a priority.

• Molecules and Cells
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• 제24권2호
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• pp.255-260
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• 2007

Bone marrow (BM) derived mesenchymal stem cells (MSC) are pluripotent cells which can differentiate into osteogenic, adipogenic and other lineages. In spite of the broad interest, the information about the changes in BM cell composition, in particularly about the variation of MSC number and their properties in relation to the age of the donor is still controversial. The aim of this study was to investigate the age associated changes in variations of BM cell composition, phenotype and differentiation capacities of MSC using a rat model. Cell populations were characterized by flow cytometry using light scattering parameters, DNA content and a set of monoclonal antibodies. Single cell analysis was performed by conventional fluorescent microscopy. In vitro culture of MSC was established and their phenotype and capability for in vitro differentiation into osteogenic and adipogenic cells was shown. Age related changes in tibiae and femurs, amount of BM tissue, BM cell composition, proportions of separated MSC and yield of MSC in 2 weeks of in vitro culture were found. At the same time, neither change in phenotype no in differentiation capacities of MSC was registered. Age-related changes of the number of MSC should be taken into account whenever MSC are intended to be used for investigations.

• 한국해양바이오학회지
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• 제6권2호
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• pp.102-109
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• 2014

Cetaceans (whales, dolphins, and porpoises) are aquatic mammals that experienced drastic changes during the transition from terrestrial to aquatic environment. Morphological changes include streamlined body, alterations in the face, transformation of the forelimbs into flippers, disappearance of the hindlimbs and the acquisition of flukes on the tail. For a prolonged diving, cetaceans acquired hypoxia-resistance by developing various anatomical and physiological changes. However, molecular mechanisms underlying these adaptations are still limited. CREB-binding protein (CREBBP) is a transcriptional co-activator critical for embryonic development, growth control, metabolic homeostasis and responses to hypoxia. Natural selection analysis of five cetacean CREBBPs compared with those from 15 terrestrial relatives revealed strong purifying selection, supporting the importance of its role in mammals. However, prediction for amino acid changes that elicit functional difference of CREBBP identified three cetacean specific changes localized within a region required for interaction with SRCAP and in proximal regions to KIX domain of CREBBP. Mutations in CREBBP or SRCAP are known to cause craniofacial and skeletal defects in human, and KIX domain of CREBBP serves as a docking site for transcription factors including c-Myb, an essential regulator of haematopoiesis. In these respects, our study provides interesting insights into the functional adaptation of cetacean CREBBP for aquatic lifestyle.

• 산업경영시스템학회지
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• 제39권1호
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• pp.140-152
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• 2016

It is very important for the competitiveness and sustainable management of enterprises that the rapid changes in the managerial environments quickly and accurately are responded. For example, the large-scale investment accompanied by bad alternatives in accordance with misunderstanding of the managerial environments yields the huge cost and effort to modify and improve. In firm management, the quality of products and the productivity are influenced by changes of the endogenous factors yielded in manufacturing process and the exogenous factors as market, etc. These changes include not only changes in 4M (man, machine, material, method) but also those in the market, competitors, and technologies in the process of commodification, i.e., first, such disturbances make dispersion of the process big and odd. By Shewhart chart it can be checked that the process monitored is control-in or out. Business administration executes activities for input stabilization by monitoring changes in 4Ms, comparing with the standards, and taking measures for any abnormality. Second, TRM (technology road map) is to prospect product deployment and technological trend by predicting technologies in the competitive environment as the market, and to suggest the future directions of business. So, TRM must be modified and improved according to DR (design review) stages and changes in mass-production like input material change. Therefore, a role of TRM in input stabilization for reducing cost and man-hour is important. This study purposed to suggest that the environment changes are classified into endogenous factors and exogenous factors in production process, and then, quality and productivity should be stabilized efficiently through connection between TRM and input stabilization, and to prove that it is more effective for the display industry to connect TRM with input stabilization rather than to use TRM separately.

• 대한치과교정학회지
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• 제48권3호
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• pp.172-181
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• 2018

Objective: This study was performed to investigate buccal facial depth (BFD) changes after extraction and nonextraction orthodontic treatments in post-adolescent and adult female patients, and to explore possible influencing factors. Methods: Twelve and nine female patients were enrolled in the extraction and nonextraction groups, respectively. Changes in BFD in the defined buccal region and six transverse and two coronal measuring planes were measured after registering pretreatment and posttreatment three-dimensional facial scans. Changes in posterior dentoalveolar arch widths were also measured. Treatment duration, changes in body mass index (BMI), and cephalometric variables were compared between the groups. Results: BFD in the buccal region decreased by approximately 1.45 mm in the extraction group, but no significant change was observed in the nonextraction group. In the extraction group, the decrease in BFD was identical between the two coronal measuring planes, whereas this differed among the six transverse measuring planes. Posterior dentoalveolar arch widths decreased in the extraction group, whereas these increased at the second premolar level in the nonextraction group. The treatment duration of the extraction group was twice that of the nonextraction group. No differences were found in BMI and Frankfort horizontal-mandibular plane angle changes between the groups. BFD changes in the buccal region moderately correlated with treatment duration and dental arch width change. Conclusions: BFD decreased in adult female patients undergoing extraction, and this may be influenced by the long treatment duration and constriction of dentoalveolar arch width. However, nonextraction treatment did not significantly alter BFD.

• 대한지리학회지
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• 제39권2호
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• pp.241-255
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• 2004

본 논문의 주 목적은 한국의 대중국 해외직접투자의 지리적 변화에 대한 근본적인 원인을 밝히고자 하는데 있다. 특히 1990년대 후반 이후 대중국 투자전략 전환으로 인한 투자 업종 및 입지의 변화는 한국 투자기업이 기업특유 우위(ownership-specific advantages), 내부화우위(internalization advantages) 및 입지우위(locational advantages)에 이론적 기반을 둔 것이 아니라, 시장, 제도 및 기술을 중심으로 한국과 중국 양 국가의 수요가 접합되는 지점의 변화, 즉 통합적 전략의 변화에 기반을 두고 있다고 주장한다. 다시 말해, 1990년대 후반 이후 한국 대중국 직접투자 입지 변화는 2000년 이후 중국시장구조의 변화, 투자유입에 대한 중국의 제도적 변화, 한국기업의 기술역량 제고에 기인한다는 것이다. 이와 더불어 본 논문은 2000년 이후 급속히 증가하고 있는 CDMA 이동통신 투자경험을 사례로 한국 대중국 직접투자에 대한 시상, 제도 및 기술의 입지효과를 밝히고자 하였다.

• Journal of Construction Engineering and Project Management
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• 제2권3호
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• pp.8-16
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• 2012

After the 2008 global financial crisis, the construction environment in South Korea continued change in the construction environment. Construction orders in 2011 have shown a downward trend compared with the previous year. Along with these changes in the construction market, the professional capabilities of construction project managers that are perceived as important also changed after the global financial crisis. Accordingly, this study was conducted to identify the major business capabilities of the current construction project managers and to determine which of these capabilities have undergone changes in terms of the importance accorded to them after the global financial crisis, and ultimately, to derive the construction project manager capability areas that need to be strengthened according to the changes in the construction environment. The capabilities of construction project managers were surveyed at two different time points: in 2007 and in 2010. The results show that the year 2010, after the global financial crisis, an increase in the perceived important capabilities of construction project managers compared with 2007. This results the impact of the changes in the construction environment on the importance of construction project managers. This study derived the ramifications of the early identification of systems and prospects according to the changes in the construction circumstances on more efficient onsite and human resources management, by considering the appropriate capabilities of the construction project managers.

• International Journal of Advanced Culture Technology
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• 제11권2호
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• pp.210-220
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• 2023

We analyzed and compared factors such as changes in the degree of difficulty of concepts presented in Chemistry I textbook, changes in class types (non-face-to-face, face-to-face), etc. on academic achievement by level (upper, middle, and lower). Students from A high school in Gyeongsangnam-do were selected for the subjects of the study. As a result of analyzing the change in the degree of difficulty of concepts, the total score of chemistry I combined by non-face-to-face and face-to-face classes during the second semester was lower than that of the first semester. As a result of analyzing the impact of factors such as changes in conceptual difficulty, changes in class types, etc. on academic achievement by level, students' grades at the 'lower level' by non-face-to-face classes were lower than those by face-to-face classes. In particular, at the lower level of the second semester, there was a large difference in grades between non-face-to-face and face-to-face classes. In the results of these studies, it was found that instructors' active feedback is important to identify difficulties in understanding learning contents for students with low levels of academic achievement and improve them at the same time.

• 한국가정과교육학회지
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• 제12권3호
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• pp.65-76
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• 2000

Comparative Study on Historical Changes of Practical Arts Education and Technology-Home Economics Education in Korea and Japan This dissertation is a comparative study on Practical Arts(Home Economics) Education and Technology-Home Economics Education of Korea and Japan. I established two research objectives to conduct the research : To understand the differences in historical changes in Practical Arts Education and Technology-Home Economics of the two countries: And to grope for the new direction of Home Economics Education. Research findings are as follows : Japan was also ahead of Korea for about two decades in terms of putting Home Economics Education in practice at elementary schools. Practical Arts Education Started to emerge in Elementary school system in 1955, which had been originated in vocational education before the year 1945 in Korean However, from the 3th curriculum Practical Arts Education Curriculum put emphasis on home lives. Regarding the characteristics of education from the perspectives of historical changes at Korean Junior-high schools after the year 1945. Home Economics Education had been regarded as “female subject”until the 1980s and was integrated into regular curricula for co-education in the middle of the 1990s. when the 6th Curriculum was activated. Technology-Home Economics started to emerge in Japan in 1962. while the subject Home Economics Education was integrated into curricula for males in high school as well in 1989. In the Korean 7th Curriculum, the combined subject Technology-Home Economics is divided into three categories. A remarkable difference from japanese Technology-Home Economics is that korean curriculum has no division between required and elective. In conclusion. I observe that both Korean and Japanese curricula for Home Economics Education were originated in Confucianism. However, unlike Korean situation, current Japanese Home Economics Education takes a significant part as a continuing and required subject for both primary and secondary co-education.