• Journal of Life Science
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• v.13 no.5
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• pp.732-739
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• 2003

The purpose of this study was to determine if the addition of spermatozoa into the culture medium could influence the nuclear maturation of denuded porcine germinal vesicle (GV) oocytes in vitro. Cumulus-oocyte complexes were collected from follicles of 3 to 5 mm in diameter, The cumulus and corona cells were removed from oocytes. Porcine denuded oocytes were cultured in tissue culture medium containing spermatozoa. After 48 h culture, oocytes were examined for the evidence of GV breakdown, metaphase I, anaphase-telophase I, and metaphase II (M II). The proportion of oocytes reaching M II stage was significantly (P<0.01) increased in the oocytes cultured in media containing spermatozoa compared to those in media without spermatozoa $(31.9\pm1.8%\; vs\; 14.9\pm1.0%)$.No differences in the rates of M II were observed among the different period of spermatozoa exposure nor among the spermatozoa from different species. The proportion of oocytes reaching M II stage was significantly different between high and low concentrations of spermatozoa. The present study suggests that mammalian spermatozoa contain a substance(s) that improves nuclear maturation in vitro of GV oocytes. Enhancing effect of spermatozoa for oocytes maturation in vitro is a highly dose-dependent.

• Journal of the Korean Applied Science and Technology
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• v.38 no.2
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• pp.587-594
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• 2021

The purpose of this study is to examine how college students' stress coping in the post-corona era affect leisure constraint negotiations. To achieve the purpose of this study, from January 25th to February 19th, 2021, 247 copies were used for this study, excluding 13 questionnaires from Jeonbuk, Jeonnam, and Busan. For data analysis, descriptive statistics, confirmatory factor analysis, ANOVA and hierarchical regression analysis were performed using SPSS 21.0 and AMOS 18.0. As a result, there was a difference in leisure constraint negotiations according to changes in the types of leisure before and after COVID-19. According to the stress coping method of college students, it appears that it has a positive effect on the part of leisure constraint negotiations, so it is necessary to consider a detailed approach to the coping plan. In particular, it was confirmed that the active stress coping method(Active problem solving, Social support seeking) had a positive effect on the leisure constraint negotiations. Therefore, future research will require efforts to verify their relationship with various approaches to leisure constraints, leisure constraints negotiations, and stress and stress response strategies with COVID-19.

• Journal of Cadastre & Land InformatiX
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• v.50 no.2
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• pp.21-35
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• 2020

Due to the coronavirus pandemic and diplomatic disputes, governments are actively developing a policy to revitalize·reshore manufacturing and to diversify international cooperations. In order to develop such a policy, it is very important to compare and analyze domestic·international geospatial information. Over the decade, the US·EC governments have conducted a series of national researches to build data-based tools that can monitor·analyze regional geospatial information driven by government R&D investments. In the case of the EC system, it can compare geospatial information in domestic and international(including Korea) regions. Compared to US·EC cases, Korean examples of national researches with available data analplatform need future improvements. Current study is investigating an automated analysis methodologies using "National Institute of Science and Technology Information (NTIS)" DB, which was national security data until recently. Research on data-mining regional geospatial information can contribute to support policy fields that need to discover new issues in response to unexpected social problems such as recently faced corona and trade disputes.