Bovine Cumulus Cell Life Span and Its Immortalization Capacity

WooJae Choi,Jihyun Lee,SooYoung Yum,JoonHo Moon,Palaksha K,ByeongChun Lee,Goo Jang 한국동물생명공학회(구 한국동물번식학회) 2012 발생공학 국제심포지엄 및 학술대회 Vol.2012 No.1

Extrapyramidal Signs and Risk of Progression from Mild Cognitive Impairment to Dementia: A Clinical Research Center for Dementia of South Korea Study

Woojae Myung,JinHong Park,SookYoung Woo,Seonwoo Kim,SangHa Kim,JaeWon Chung,HyoShin Kang,ShinnWon Lim,Junbae Choi,Duk L. Na,SeongYoon Kim,JaeHong Lee,SeolHeui Han,SeongHye Choi,SangYun Kim,Bernard J. 대한신경정신의학회 2017 PSYCHIATRY INVESTIGATION Vol.14 No.6

Objective-Extrapyramidal signs (EPS) are common in patients with mild cognitive impairment (MCI). However, few studies have assessed the effect of EPS on the clinical course of MCI. We aimed to evaluate whether patients with EPS show more frequent progression from MCI to Alzheimer’s disease (AD) and to other types of dementia. Methods-Participants (n=882) with MCI were recruited, and were followed for up to 5 years. The EPS positive group was defined by the presence of at least one EPS based on a focused neurologic examination at baseline. Results-A total of 234 converted to dementia during the follow-up period. The risk of progression to AD was lower in the patients with EPS after adjusting for potential confounders [hazard ratio (HR)=0.70, 95% confidence interval (CI)=0.53-0.93, p=0.01]. In contrast, the patients with EPS had a six-fold elevated risk of progression to dementia other than AD (HR=6.33, 95%CI=2.30–17.39, p<0.001). Conclusion-EPS in patients with MCI is a strong risk factor for progression of MCI to non-Alzheimer dementia. The careful neurologic examination for EPS in patients with MCI can yield important clinical information for prognosis.

Efficient PRNP deletion in bovine genome using gene-editing technologies in bovine cells.

Choi, WooJae,Kim, Eunji,Yum, Soo-Young,Lee, ChoongIl,Lee, JiHyun,Moon, JoonHo,Ramachandra, Sisitha,Malaweera, Buddika Oshadi,Cho, JongKi,Kim, Jin-Soo,Kim, SeokJoong,Jang, Goo Landes Bioscience 2015 Prion Vol.9 No.4

<P>Even though prion (encoded by the PRNP gene) diseases like bovine spongiform encephalopathy (BSE) are fatal neurodegenerative diseases in cattle, their study via gene deletion has been limited due to the absence of cell lines or mutant models. In this study, we aim to develop an immortalized fibroblast cell line in which genome-engineering technology can be readily applied to create gene-modified clones for studies. To this end, this study is designed to 1) investigate the induction of primary fibroblasts to immortalization by introducing Bmi-1 and hTert genes; 2) investigate the disruption of the PRNP in those cells; and 3) evaluate the gene expression and embryonic development using knockout (KO) cell lines. Primary cells from a male neonate were immortalized with Bmi-1and hTert. Immortalized cells were cultured for more than 180??days without any changes in their doubling time and morphology. Furthermore, to knockout the PRNP gene, plasmids that encode transcription activator-like effector nuclease (TALEN) pairs were transfected into the cells, and transfected single cells were propagated. Mutated clonal cell lines were confirmed by T7 endonuclease I assay and sequencing. Four knockout cell lines were used for somatic cell nuclear transfer (SCNT), and the resulting embryos were developed to the blastocyst stage. The genes (CSNK2A1, FAM64A, MPG and PRND) were affected after PRNP disruption in immortalized cells. In conclusion, we established immortalized cattle fibroblasts using Bmi-1 and hTert genes, and used TALENs to knockout the PRNP gene in these immortalized cells. The efficient PRNP KO is expected to be a useful technology to develop our understanding of in vitro prion protein functions in cattle.</P>

Association Between Functional Impairment, Depression, and Extrapyramidal Signs in Neuroleptic-Free Patients With Alzheimer Disease

Choi, Junbae,Myung, Woojae,Chung, Jae Won,Kang, Hyo Shin,Na, Duk L.,Kim, Seong Yoon,Lee, Jae-Hong,Han, Seol-Heui,Choi, Seong Hye,Kim, SangYun,Kim, Seonwoo,Carroll, Bernard J.,Kim, Doh Kwan SAGE Publications 2013 Journal of geriatric psychiatry and neurology Vol.26 No.3

<P><B>Background:</B></P><P>Extrapyramidal signs (EPSs) are commonly observed in patients with Alzheimer disease (AD). We report here the base rate of EPS in a large cohort of patients with AD who were not receiving neuroleptic drugs, and the associations of EPS with functional outcomes and depressive symptoms.</P><P><B>Methods:</B></P><P>In a consortium involving 56 clinics, we recruited 2614 patients with AD. We estimated basic activities of daily living (ADL) and instrumental ADL by the Barthel index and the Seoul-Instrumental Activities of Daily Living (S-IADL) scales, respectively. Depressive symptoms were assessed using the 15-item Geriatric Depression Scale (GDS-15). The EPS group was defined by the presence of at least 1 EPS based on a focused neurologic examination.</P><P><B>Results:</B></P><P>The prevalence of EPS-positive patients was 12%. These had lower Korean version of the Mini-Mental State Examination (K-MMSE) scores than the EPS-negative cases (<I>P</I> < .001). After controlling for demographic, medical, radiological, genetic, and cognitive (K-MMSE) factors, the proportion of patients with impaired ADL was significantly higher in the EPS group than in the non-EPS group (<I>P</I> < .001, odds ratio = 1.90, 95% confidence interval, 1.45–2.48, and logistic regression). The S-IADL scores were significantly higher in the EPS group than this in the non-EPS group (<I>P</I> < .001, regression coefficient = 3.19, and median regression). The GDS-15 scores were higher in the EPS group (<I>P</I> = .04, regression coefficient = 0.89, and median regression).</P><P><B>Conclusion:</B></P><P>The presence of EPS in patients with AD who were not receiving neuroleptic drugs was associated with more impaired basic and instrumental ADL functioning and with greater depression symptoms.</P>

팀장의 윤리적 리더십이 팀원의 변화자기효능감과 조직시민행동에 미치는 영향

최우재(Woojae Choi),천미림(Milim Chon),유재미(Jae-Mee Yoo) 대한경영학회 2021 大韓經營學會誌 Vol.34 No.8

제4차 산업혁명 시대가 요구하는 리더십은 무엇인가?

최우재(Woojae Choi),신제구(Je Goo Shin),백기복(Ki Bok Baik) 한국경영학회 2018 Korea Business Review Vol.22 No.3

본 연구는 제4차 산업혁명 시대가 요구하는 리더십역량을 탐색하는 데에 목적이 있다. 이를 위해 기존 리더십이론들을 구성하는 하위요인들을 중심으로 리더십역량을 도출하였다. 리더십역량은 Dinh et al.(2014)의 분류에 따라 전통적 리더십이론에서 16개의 리더십역량을 도출하고, 떠오르는 리더십이론들을 기반으로 17개의 리더십역량을 도출하였다. 도출된 리더십역량들에 대해서 경영 및 리더십 전공의 교수들과 산업계 HR 담당자, 컨설턴트 등을 대상으로 중요도를 묻는 설문조사를 실시하였다. 분석결과를 보면, 전체적으로 전통적 러더십이론을 통해 도출된 역량 중에서는 환경민감성, 영감적 동기부여, 전략적 비전수립, 직관력, 관계지향, 위험감수행동이 중요도가 높은 것으로 나타났다. 떠오로는 리더십이론을 통해 도출된 역량 중에서는 전략적사고, 이슈창안, 불확실성관리, 권한위임, 통섭, 인간존중이 중요도가 높은 것으로 나타났다. 이러한 결과를 학계(23명)와 산업계(52명)로 구분하여 살펴보면, 전통적 리더십이론을 통해 도출된 역량에서는 중요도에 큰 차이가 없는 것으로 나타났으나, 떠오르는 리더십이론에 있어서는 차이가 있었다. 학계에서는 창의성과 인간존중을 더욱 중요한 역량으로 인식하고 있었으나, 산업계에서는 이슈창안과 공감을 더욱 중요하게 인식하고 있었다. 본 연구는 제4차 산업혁명 시대가 요구하는 리더십역량을 기존 리더십이론을 통해 도출하고 중요도를 확인하였다. 최근 저서 및 기사, 사설, 기고문 등을 보면 제4차 산업혁명 시대는 그 어느 때보다 리더십의 역할이 중요하다고 주장하고 있으나, 체계적인 연구는 매우 미흡한 상황이다. 따라서 본 연구는 제4차 산업혁명 시대에 더욱 중요시 되는 리더십역량을 확인함으로써 리더십분야 연구와 리더육성의 방향을 제시하였다는 점에서 의의가 있다. This study aims to explore the leadership competencies requried by the 4<SUP>th</SUP> industrial revolution era. The existing leadership theories were reviewed to derive the leadership competencies. Based on the category of Dinh et al. (2014) sixteen competencies were derived from traditional leadership theories, and seventeen competencies were drawn from emerging leadership theories. Professors, HR managers, and business consultants responded to the importance of leadership competencies. The results showed that the importance came in order of environmental sensitivity, inspirational motivation, strategic vision, intuition, relationship orientation, and risk taking among the competencies of traditional leadership theories. In terms of emerging leadership theories, strategic thinking and issue creation were perceived as the highest priority, followed by uncertainty management, empowerment, consilience, and human dignity. Dividing these results into academia (n=23) and industry(n=52), there was no difference in the importance of the leadership competencies derived from traditional leadership theories. On the contrary, there was a difference in emerging leadership theories. Creativity and human dignity became more important in academia, whereas issue creation and empathy were thought of more critical in industrial sector. Based on the results of study, theoretical and practical implications are discussed.

변혁적리더십과 과업성과의 관계 : 개인-환경적합성의 조절효과를 중심으로

최우재 ( Woojae Choi ) 한국생산성학회 2019 生産性論集 Vol.33 No.3

This study examined the effect of transformational leadership on an individual's task performance. In particular, the moderating effects of person-environment fit were regarded as a contextual factor. The results showed that transformational leadership had a positive impact on an individual's task performance. Also it has been shown that the relationship between transformational leadership and an individual's task performance was moderated by person-environmental fits including person-job fit and person-organization fit. In order words, the stronger the perosn-environment fits the stronger the relationship between transformational leadership and an individual's task performance. This study addressed that transformational leadership has a positive impact on the effectiveness of individual level. These results contributes to expanding the knowledge of existing studies of transformational leadership. Existing studies has shown that transformational leadership had a positive impact on individual attitudes and performance. However, little has been known about the context where the effects could be increased or decreased. The results of the study presented that person-job fit and person-organization fit were critical situational factors which could bring change on the relationship between transformational leadership and its outcomes. This study has practical implications as well as theoretical implications. One is that transformational leadership promotes a sense of common goal. The more they approach problems in various ways, the more they help not only achieve their own goals. The requirements charged to individuals in an organization needs to clearly present specific guidance on the responsibilities and roles given by groups or teams. Additionally, organizations need to make efforts to inform members that individual efforts to achieve common goals can be helpful in personal task performance due to knowledge, information, experience, and know-how acquired through the interaction of the process of trying to gain common goals. Managers need to develop their own leadership competency model. It is possible to design a sub-factor of transformational leadership in the model. With the leadership competency model, managers can design leadership development programs and modify current development programs. Thus, the development of HR analytics techniques contributes to the improvement of individual and organizational performance by more systematically matching the skills, knowledge, experience, achievement, characteristics and abilities required by an organization or team. Although it was supported that transformational leadership has a positive impact on an individual's task performance, and that person-environment fit can strengthen the relationship, there are several limitations. In this line, this study also presents some agenda for future studies.

진성리더십이 부하의 심리적 웰빙과 적응적 수행성과에 미치는 영향

최우재(Woojae Choi),조윤형(Yoonhyung Cho) 한국인사조직학회 2013 인사조직연구 Vol.21 No.1

Authenticity as a leadership value is gaining traction of late research study, as corporations suffer from public condemnation over high profile scandals and cases of gross mismanagement. Authentic leadership theory addresses positive and developmental interaction between leaders and followers. A leader who exercises authenticity influences not only their own well-being, but also the well-being, self-concept, and lives of their followers in the workplace. Authentic leaders are those who aware of their own strengths and weaknesses, keep their personal moral values, and clearly communicate the rationale and goals behind their actions. Such behaviors encourage positive organizational climate characterized by happiness, integrity, and trust, and this climate should contribute to the development of followers. Given the potential benefits, it is essential to understand how authentic leadership helps to develop followers’ psychological well-being and adaptive performance. In particular, we consider followers’ self-efficacy as a mediating role in this regard. Based on this reasoning, we advance the following. Hypothesis 1 : Authentic leadership will have a positive impact on the psychological well-being of followers. Hypothesis 2 : Authentic leadership will have a positive impact on the adaptive performance of followers. Hypothesis 3 : The impact of authentic leadership on psychological well-being of followers is mediated by followers’ self-efficacy. Hypothesis 4 : The impact of authentic leadership on adaptive performance of followers is mediated by followers’ self-efficacy. We collected data from a custom survey of 275 employees. The sample consisted of 172 males and 103 females. The mean tenure of participants was 7.0 years. We designed a robust research model in order to assess model fit and avoid issues of common method variance. Using the verified model, standardized path coefficients were examined to test research hypotheses. We found strong support for hypotheses 1 and 2, demonstrating that authentic leadership has a clearly positive impact on the psychological well-being and adaptive performance of followers. The results suggested that self-efficacy only partially mediates the effect of authentic leadership on followers’ psychological well-being and adaptive performance. Authentic leadership appears to have a positive relationship on followers’ self-efficacy because authentic leaders apply a positive perspective as they communicate through their words and deeds while showing their respect, trust, and confidence toward followers. Followers who work with an authentic leader tend to behave confidently and sincerely, which leads to a more positive sense of psychological well-being and better adaptive performance. Overall, our findings suggest that followers’ positive state of mind and performance outcomes can be determined by the degree of authentic leadership. This study was planned to investigate how authentic leadership influences followers’ psychological well-being and adaptive performance, while noting the mediating role of effect of followers’ self-efficacy. This study adds valuable insight into research design and also new knowledge regarding the theory and practice. First, authentic leaders who are in the high levels of self-awareness and high self-regulation provide followers with the sense of identification with leaders. Authentic leader who understand of his or her own strengths and weaknesses are cognizant of his or her impact on other people. Authentic leader also present his or her authentic self to others. Such behavior promotes trust though disclosure that includes openly sharing information and expression of one’s true thoughts and feelings. In this reasons, authentic leader encourages followers’ self-determination and establishes positive relationship with followers while trying to minimize displays of inappropriate emotions. 본 연구는 진성리더십이 심리적 웰빙과 적응적 수행성과에 미치는 영향과 이들 간의 관계에 있어서 자기권능감의 매개역할을 살펴보았다. 진성리더십은 기존 리더십 이론들이 리더의 스킬이나 스타일을 강조함으로써 리더십의 본질인 ‘진정성’이 간과되어 왔다는 점을 지적하고 있다. 진성리더십은 리더 스스로의 진정성을 넘어 부하와 진실된 관계를 형성하기 때문에 부하들로 하여금 사회적 존재로서 가지는 심리적 웰빙의 수준을 높이고, 새롭고 도전적 상황하에서 능동적이고 효과적으로 대처할 수 있는 적응적 수행성과를 높일 것으로 예상된다. 또한, 긍정인지로써의 자기권능감은 진성리더십과 결과변수들과의 관계에서 주요한 매개효과를 가질 것으로 예상된다. 실증분석을 위해 표본으로 설정한 25개 업체에서 275명이 설문에 응답하였으며, 구조방정식을 통해 연구모형의 적합도와 가설을 검증하였다. 연구가설은 주효과 가설과 매개효과 가설로 구분된다. 분석결과를 살펴보면 다음과 같다. 주효과 가설검증에 있어서 진성리더십은 부하의 심리적 웰빙과 적응적 수행성과에 직접적인 영향력을 보이는 것으로 나타났다. 매개효과 가설 검증에 있어서 진성리더십은 부하의 자기권능감을 부분적으로 매개하여 심리적 웰빙과 적응적 수행성과에 영향력을 보이는 것으로 나타났다. 실증분석 결과를 통해 진성리더는 부하들이 현재의 즐거움과 만족을 넘어서 참된 잠재력을 발견하고 자아를 찾는 과정에서 경험하게 되는 심리적 웰빙의 수준을 높인다는 것을 확인하였다. 또한 진성리더는 부하들이 변화하는 업무환경하에서 새로운 아이디어와 해결책을 모색하고 다양한 접근 방법을 시도하며 주변의 정보를 통합하는 등의 행위를 유도하는 것으로 나타났다. 이는 업무 수행을 위한 정보의 부족과 예기치 못한 상황에 대해서도 유연하게 대응하는 적응적 수행성과에 긍정적인 영향력을 보이고 있기 때문이다. 매개효과의 검증결과를 살펴보면, 부하의 자기권능감은 진성리더십이 심리적 웰빙과 적응적 수행성과에 미치는 총 영향력에서 각각 21.8%와 31.3%의 효과크기(effect size)를 보였다. 본 연구를 통해 진성리더십은 부하의 심리적 웰빙과 같은 감정적 상태(state)뿐 아니라 부하의 성과에 직접적인 영향을 미친다는 것을 확인하였다. 또한, 진성리더십은 부하의 자기권능감을 향상시키고 향상된 자기권능감은 긍정적인 결과로 이어질 수 있으며, 부하의 상태와 성과에 추가적인 영향력을 발휘한다는 것을 알 수 있다. 따라서 진성리더십이 부하의 긍정적 성과로 이어지는 프로세스를 제시하였다는 점에서 의의를 가지고 있다.

Bioaugmentation and Detoxification Potential for Mitigating Acetaminophen Contamination using a Pseudomonas sp.

Donggeon Choi,Sangeun Park,Youngjun Kim,Seungyong Cheon,Hyeonji Lee,Jiwoo Choi,Woojae Jang,Seungdae Oh 대한환경공학회 2019 대한환경공학회 학술발표논문집 Vol.2019 No.-

공유리더십이 직무성과에 미치는 영향 : 집단주의 성향의 조절효과를 중심으로

최우재 ( Woojae Choi ) 한국생산성학회 2019 生産性論集 Vol.33 No.2

This study examined the effect of shared leadership on an individual's job performance. In particular, the moderating effect of collectivism was regarded as a contextual factor. The results showed that shared leadership had a positive impact on an individual's job performance. Also it has been shown that the relationship between shared leadership and an individual's job performance was moderated by the individual's collectivist tendency. In order words, the stronger the tendency of individuals to collectivism, the stronger the relationship between shared leadership and an individual's job performance. To date, most studies have found that shared leadership has positive effect on team efficacy and team potential, and team performance. However, there is a lack of research into the effect of the individual level effectiveness. This study addressed that shared leadership has a positive impact on the effectiveness of individual level as well as team level. This suggests that shared leadership studies can be extended to the individual level effectiveness. Another implication is that the effectiveness of shared leadership can be moderated by individual value orientation. This study found that when members of the team have a collectivism tendency, the effectiveness of shared leadership further strengthened when prioritizing commnon goals by temporarily or continuously sacrificing or yielding their own interests. In group with stronger collectivism, trust and interdependence among members These results contributes to expanding the knowledge of existing studies of shared leadership. Existing studies has shown that the effectiveness of shared leadership increases as the tasks requried such as creative problem solving of the members are highly dependent on their work. Howerer, the results of this study are significant in that it has supported not only the nature of the task but also the individual's value orientation as a contextual factor. This study has practical implications as well as theoretical implications. One is that horizontal leadership promotes a sense of common goal. The more they approach problems in various ways, the more they help not only achieve their own goals but also shared goals. The requirements charged to individuals in an organization needs to clearly present specific guidance on the responsibilities and roles shared by groups or teams, as well as the individual's ones. In addition, organizations need to make efforts to inform members that individual efforts to achieve common goals can be helpful in personal job performance due to knowledge, information, experience, and know-how acquired through the interaction of the process of trying to gain common goals. Thus, because an individual's social, psychological and cognitive resources are not infinite, individuals need to allocate their resources appropriately to achieve their common and individual goals. Managers need to redesign tasks that contribute common and individual job requirements. In particular, members of the New Millennical generation are more individualistic compared to the older generation. This is the result of the social, institutional and technical environment experience by individuals. They have a strong sense of solidarity with society or the world that extends beyond the boundaries of organization. They are simultaneously inclined to address their common goals through a new type of connection, depending on the individual's values, ideology or preferences. Although it was supported that shared leadership has a positive impact on an individual's job performance, and that collectivism among the members can strengthen the relationship between shared leadership and job performance, there are several limitations. In this line, this study also presents some agenda for future studies.