• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.365-373
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• 2000

The purpose of this study was to investigate the effects of the fusion pulses and fusion media on fusion rate and the development of embryos produced by somatic cell nuclear transfer in Hanwoo (Korean cattle). Nuclear donor cumulus and fetal fibroblast cells were cultured in Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum at 38.5$^{\circ}C$ in a humidified atmosphere of 5% $CO_2$in air. The in vitro matured oocytes were enucleated and then the isolated donor cells were introduced. The cumulus cell and cytoplast were fused using one pulse of 70 volts for 40$mutextrm{s}$, two pulses of 70 volts for 40$mutextrm{s}$ and one pulse of 180 volts for 15$mutextrm{s}$. The fetal fibroblast cell and cytoplast were fused using one pulse of 180 volts for 15$mutextrm{s}$ or 30$mutextrm{s}$. The cumulus cell and cytoplast were fused using mannitol and Zimmerman cell fusion medium (ZCFM) as a fusion medium. The fused embryos were activated after the fusion with 10 $\mu$M calcium ionophore for 5 min and 2 mM 6-dimethyl- aminopurine for 3 h. The nuclear transfer embryos were cultured in 500 ${mu}ell$ well of modified CR1aa supplemented with 3 mg/$m\ell$ BSA in th $\varepsilon$ four well dish cove red with mineral oil. After 3 days culture, culture medium was changed into modified CRlaa medium containing 1.5 mg/$m\ell$ BSA and 5% FBS for 4 days. The incubation environment was 5% $CO_2$, 5% $O_2$, 90% $N_2$ at 38.5$^{\circ}C$. When the cumulus cells were fused with enucleated oocytes by three different fusion pulses, one pulse of 180 volts for 15 $mutextrm{s}$ yielded the highest fusion rate and developmental rate to blastocyst among the pulses (P＜0.05). When the fetal fibroblast cells were fused with enucleated oocytes, one pulse of 180 volts for 30$mutextrm{s}$ yielded significantly higher fusion rate compared with that for 15 $mutextrm{s}$(P＜0.05). The present result indicates that the fusion rate between karyoplast and cytoplast was affected by the cell type and the optimal fusion condition was different according to cell type or size. When the fusion was conducted by the use of mannitol and ZCFM, the fusion rate was 71.2% and 65.8%, respectively. The developmental rates to blastocyst were 37.8% and 39.8%, respectively. There was no significant difference between two fusion media in the developmental rate of cumulus cell nuclear transfer embryos. These results indicate that optimal electric current should be selected according to cell type.

• Korean Journal of Animal Reproduction
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• v.25 no.1
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• pp.71-77
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• 2001

This experiment was designed to improve the production efficiency of germ-line chimeric mice from phospholipase C (PLC)-$\beta$3 or peroxiredoxin (Prx) E -targeted ($\Delta$) ES cells by the investigating the manipulation conditions and characteristics of Jl ES cells. Four targeting clones were isolated to investigate the karyotypical and morphological stability prior to injection. All clones ($\Delta$PLC$\beta$-3 C3, $\Delta$Prx II C3, C10 and I5) showed more than 80% euploidism, however, most of $\Delta$PLC$\beta$-3 C3 clones were extensively differentiated compared to the other clones. Nine of 13 $\Delta$Prx II chimeras appeared to have at least 80% chimerism, whereas $\Delta$PLC$\beta$-3 C3 chimeras had 20% chimerism at most. Therefore, the morphological stability of ES cells under stable euploidism might mainly affect the production rate of high-coat chimeric mice. To increase the collection rate of injectable blastocysts (IBs), 5 to 10 week -aged C57BL/6J female mice were sacrificed at 3.5 days post-coitum. Ten week-aged mice were the most optimal IB donors by showing the highest collection rate (2.94/mouse) of injectable blastocysts without increase of non-injectable embryos (0.29/mouse). Foster mothers might be another factor because ICR x C57BL/6J F1 foster mother showed more increased productivity in litter size (2.8 vs. 5.6) and chimera (0 vs. 35.3%) than those of ICR foster mothers. In conclusion, the efficient production of germ-line chimeras mainly depends on the maintenance of ES cell morphology during targeting procedure, and the establishment of manipulation conditions might be a key point to maximize it.

• Journal of Popular Narrative
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• v.25 no.2
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• pp.73-116
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• 2019

In recent years, television dramas have adopted an emerging approach of imagining a just society via fantasy. This study set out to examine by stages the patterns of social justice in I Hear Your Voice, Pinocchio, and While You Were Sleeping written by Park Hye-ryeon, who has been leading this trend. I Hear Your Voice shows why social justice is needed, as it is set against the backdrop of a society in which legal justice has collapsed. In this drama, the collapse of the legal justice system indicates that democratic society is falling apart at the roots. As a result, pain and suffering is propagated among the petit bourgeois, with social justice being demanded as an alternative to this problematic reality. The supernatural power of reading the thoughts of others is used to remind viewers of the value of truth and trust and raises the possibility of the existence of a true heart as an alternative from a social justice perspective. Set in a society in which media justice is distorted, Pinocchio makes an attempt at changing ideas about social justice. In this drama, the corrupt media justice covers up truth and becomes a parasite to power, creating victims that are falsely accused. In this situation, the Pinocchio Syndrome, which makes people hiccup when telling a lie, shows paradoxically that truth can be distorted, and ultimately destroys absoluteness that is not truth. Finally, While You Were Sleeping inherits the world views of the two previous dramas and proposes a type of social justice called 'common good' as an alternative. A completely unfair society is created when legal justice collapses and media justice is distorted. In this situation, the ability to see the future is an ability to imagine a world of possibilities. Altruistic choices based on trust in others help us to realize a positive future. Social justice as common good to enable solidarity among subjects in a way that transcends the limitations of time and space is proposed as an alternative to overcome the problem of an unfair society. Given the recent reality of South Korean society, this common good and these ways of life might literally seem like a fantasy. When social justice is represented by efforts and reconstruction processes to overcome the current social issues and make a better future, common good based on the understanding and sympathy of others can be an alternative to improve a reality that is problematic at its root. Ultimately, Park's three works explore the feasibility of a just society that is yet to come from the aspect of the common good.

• Journal of agricultural medicine and community health
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• v.48 no.2
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• pp.132-143
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• 2023

Objectives: We aimed to describe the reporting patterns of 6 notifiable surveillance diseases in the Republic of Korea, including water- and foodborne infections, from 2012 to 2021. Methods: For the 12,296 cases that met the reporting criteria, we calculated the number of reported cases, including the number of cases confirmed by lab tests or suspected by a physician, the number of cases with delayed reporting and their average days of delay, and the median days required to report the confirmatory test results. Results: The overall number of reported cases consistently increased over the ten years, with a significant rise in the reported cases of typhoid fever, paratyphoid fever, and EHEC. Ninety-five percent of all reported cases were timely reported within one day of diagnosis. Vibrio vulnificus had the highest rate of delayed reporting (6.8% delayed over 1 day, 3.0% delayed over 3 days), while cholera had the lowest rate (1.9% delayed over 1 day, 0.1% delayed over 3 days). The average days of delayed reporting was 6.1 days: the highest for paratyphoid fever (10.8 days) and the lowest for cholera (2.7 days). For typhoid fever and paratyphoid fever, there has been an increase in the proportion of cases with negative test results. For vibrio vulnificus, there has been an increase in the proportion of cases with confirmed positive test results. As for EHEC, there has been a recent increase in cases with no confirmatory tests. Conclusions: Reported cases of water- and foodborne infectious diseases increased, indicating improved surveillance system completeness. However, for paratyphoid fever, improvements are needed in terms of timely notification by healthcare facilities and timely reporting of confirmatory test results.

• Journal of agricultural medicine and community health
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• v.48 no.2
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• pp.103-117
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• 2023

Objectives: This study aims to reveal the relationship between social relations and physical activity in the young-old and old-old elderly. Methods: Data from 2020 National survey of Older Koreans were used, and a total of 10,097 subjects over the age of 65 were included in analysis. The dependent variable was physical activity, and the independent variables were social relations barrier and motivational factors. x²-test and binary logistic regression were performed for data analysis. Results: The physical activity rate in the elderly were 40.8% in the young-old and 29.2% in the old-old. The socio-demographic characteristics affecting physical activity were the young-old elderly were sex, residential area, employment status and household income, and the old-old elderly were sex, age, residential area, education level and household income. The social relations barrier factors affecting physical activity were the young-old elderly were number of close friends, family care, exercise information search and video viewing, and the old-old elderly were household type, number of close friends, participation in exercise education, exercise information search and video viewing. The social relations motivational factors affecting physical activity were the young-old elderly were call with children/relative/friend, participation in sports activity, access time from home to parks, and the old-old elderly were call with children/relative/friend, participation in sports activity, satisfaction with green spaces. Conclusions: It was found that social relations barrier and motivational factors of the elderly are important factors to consider when developing physical activity promotion strategy, and there are also difference between the age of the elderly.

• Journal of Korea Water Resources Association
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• v.56 no.2
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• pp.115-124
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• 2023

Currently, as the frequency of extreme weather events increases, the scale of damage increases when extreme weather events occur. This has been providing forecast information by investing a lot of time and resources to predict rainfall from the past. However, this information is difficult for non-experts to understand, and it does not include information on how much damage occurs when extreme weather events occur. Therefore, in this study, a risk matrix based on heavy rain damage rating was presented by using the impact forecasting standard through the creation of a risk matrix presented for the first time in the UK. First, through correlation analysis between rainfall data and damage data, variables necessary for risk matrix creation are selected, and PERCENTILE (25%, 75%, 90%, 95%) and JNBC (Jenks Natural Breaks Classification) techniques suggested in previous studies are used. Therefore, a rating standard according to rainfall and damage was calculated, and two rating standards were synthesized to present one standard. As a result of the analysis, in the case of the number of households affected by the disaster, PERCENTILE showed the highest distribution than JNBC in the Yeongsan River and Seomjin River basins where the most damage occurred, and similar results were shown in the Chungcheong-do area. Looking at the results of rainfall grading, JNBC's grade was higher than PERCENTILE's, and the highest grade was shown especially in Jeolla-do and Chungcheong-do. In addition, when comparing with the current status of heavy rain warnings in the affected area, it can be confirmed that JNBC is similar. In the risk matrix results, it was confirmed that JNBC replicated better than PERCENTILE in Sejong, Daejeon, Chungnam, Chungbuk, Gwangju, Jeonnam, and Jeonbuk regions, which suffered the most damage.

• Analytical Science and Technology
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• v.22 no.4
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• pp.285-292
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• 2009

It has been observed that, after long term storage, some ammunitions are misfired by tamping (combustionstopping) due to aging of the chemicals loaded in the ammunitions. Used in ammunitions are percussion powder which provides the initial energy, igniter which ignites the percussion powder, and a delay system that delays the combustion for a period of time. The percussion powder is loaded first, followed by the igniter and then the delay system, and the ammunitions explode by the energy being transferred in the same order. Tamping occurs by combustion-stopping of the igniter or insufficient energy transfer from the igniter to the delay system or the combustion-stopping of the delay system, which are suspected to be caused by low purity of the components, inappropriate mixing ratio, size distribution of particulate components, type of the binder, blending method, hydrolysis by the humidity penetrated during the long term storage, and chemical changes of the components by high temperature. Goal of this study is to find the causes of the combustion-stopping of the igniter and the delay system of the ammunitions after long term storage. In this study, a method was developed for testing of the combustion-stopping, and the size distributions of the particulate components were analyzed with field-flow fractionation (FFF), and then the mechanism of chemical change during long term storage was investigated by thermal analysis (differential scanning calorimetry), XRD (X-ray diffractometry), and XPS (X-ray photoelectron spectroscopy). For the ignition system, M (metal)-O (oxygen) and M-OH peaks were observed at the oxygen's 1s position in the XPS spectrum. It was also found by XRD that $Fe_3O_4$ was produced. Thus it can be concluded that the combustion-stopping is caused by reduction in energy due to oxidation of the igniter.

• Korean Journal of Poultry Science
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• v.50 no.2
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• pp.91-99
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• 2023

This study aimed to develop a high-productivity breed of Korean native Samgye chicken. We evaluated the production performance of six Korean native chicken combinations (KNC-SCYC, SCYD, SDYC, SDYD, SYYC, SYYD) and GSP-Hanhyup Korean native chickens, with Baeksemi chickens used as a control group. The performance test was conducted from hatching to 7 weeks of age on 756 chickens, and we measured survival rate, body weight, shank length, feed utility, and carcass yield. The overall survival rate was nearly 100% for all strains. However, body weight showed significant differences between strains at all ages (P<0.01), with Baeksemi weighing 863.8±76.9 g, GSP-Hanhyup weighing 804.7±72.5 g, and KNC-combinations weighing 543.0±61.8 g at 5 weeks of age. The duration needed to reach 850 g was estimated to be 34.5 days for Baeksemi, 37.5 days for GSP-Hanhyup, and 45.8-48.8 days for KNC-combinations. Carcass yield percentage was highest for KNC-SYYD combination at 63.3%, followed by Baeksemi at 60.4%, and GSP-Hanhyup at 56.1%. Shank length at 850 g body weight was 7.6 cm for KNC-SYYD combination, 7.8 cm for Baeksemi, and 8.0 cm for GSP-Hanhyup. The feed conversion ratio at 850 g body weight was 1.81 for Baeksemi, 2.17 for GSP-Hanhyup, and 2.27 for KNC-SCYC combination. Our results suggest that the KNC-SYYD combination and GSP-Hanhyup breed have the potential to be used in Samgye production due to their moderate growth performance, higher carcass yield, and shorter shank length, despite their lower growth productivity and feed efficiency when compared to Baeksemi.

• Korean Journal of Social Welfare Studies
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• v.41 no.4
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• pp.161-187
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• 2010

This study begins with two research interests. Firstly, there seems to be a break of research in the field of family policy in Korea which exists especially in regard to family law. Family law was originally the core of state interventions in family life, but has been neglected because of the lack of literature with comparative research methods. This shortcoming needs to be addressed. Secondly, through inquiry into the definition of family or family policy with the lens of the law, the definition of family or family policy can be correctly extended. With these two interests combined, this research tries to derive an analytical tool - maintenance community - of the law and compare some important points of the family law of Korea with those of 16 EU-countries in terms of regime classification. The method used is, firstly, to describe the subjects of family law with a focus on partnering and parenting without subjective interpretation, and secondly, to classify the countries' family-law regimes with the criteria of privacy and autonomy using cluster analysis. The results show that the countries can be classified into three clusters: Nordic (Norway and Sweden), West-Northern (Denmark, France, England, Finland, and Belgium) and Middle South (Italy, Spain, Austria, Portugal, Netherlands, Greece, Ireland, Germany, and Korea). This result can be compared to a precedent research result which showed that 21 OECD countries can be classified in three clusters according to family policy. The number of the clusters is the same as this study, but some countries belong to other clusters; for example Denmark and Finland belong to the Nordic cluster according to family policy, while they belong to the West-Northern according to family law, and Austria, Germany, and Ireland belong to the Middle-South cluster according to family law, while they belong to the Continental according to family policy. From this result we can interpret Korean family law to be in the middle range according to both criteria of privacy and autonomy like other South-European countries including some Continental countries. We can make some theoretical suggestions. The fact that both family law and family policy regimes in countries can be classified into three clusters can be interpreted to mean that there exists parallelism between family law and family policy in a broad sense. But from the fact that some countries belong to different clusters according to family law and family policy, we can say that the family policy in a country is not always consistent with family law.

• Korean Journal of Poultry Science
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• v.50 no.3
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• pp.133-141
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• 2023

We conducted a 5 × 5 diallel cross-combination test using 1,060 chickens from pure lines of Korean Rhode-C, -D, Korean Leghorn-F, -K, and Korean Native Yellowish-brown chicken (KNC-Y) to develop a new Korean native chicken layer breeder. The laying performance and combining ability, including livability, body weight, age of first egg-laying, hen-day egg production, and egg weight, were analyzed. The livability from birth to 48 weeks was 72.1±24.0%, with the highest observed in the YC and the lowest in the DK combination (P<0.01). The YC combination exhibited the highest general combining ability (GCA), while the YD combination showed the highest specific combining ability (SCA). Regarding body weight, combinations involving Leghorn showed lighter weights compared to combinations with Rhode and KNC-Y (P<0.01). Additionally, the offspring from the KNC-Y combination reached sexual maturity earlier than those from the Rhode combination. The hen-day egg production was 70.7±12.0%, with the highest seen in the CK combination at 86% (P<0.01). The effects of GCA and SCA on hen-day egg production were similar, with the SCA being highest in the YD combination and the GCA being highest in the Rhode-C. Significant differences in egg weight were observed among the combinations, with the eggs from Rhode and Leghorn combinations being heavier than those from combinations with KNC-Y (P<0.01). In conclusion, the YC and YD combinations, characterized by excellent livability, are highly desirable paternal strains, while the CF and CK combinations, with excellent laying performance and moderate egg weight, are preferred maternal strains for Korean native chicken layer breeders.