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Analysis of the Phylogenetic Relationships in the Genus Spiraea Based on the Nuclear Ribosomal DNA ITS Region (핵 리보솜 DNA ITS 부위에 의한 조팝나무속 식물종의 계통 관계 분석)

  • Huh, Man-Kyu
    • Journal of Life Science
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    • v.22 no.3
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    • pp.285-292
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    • 2012
  • Genus Spiraea is composed of many long-lived woody species that are primarily distributed throughout Asia and Europe. In this study, we evaluated a representative sample of the 38 taxa in the world, including 14 in Korea, with nuclear ribosomal DNA internal transcribed spacer sequences (ITS) to estimate genetic relationships within the genus. The molecular data allowed us to resolve well-supported clades in the taxa. In 47 world accessions (38 taxa: 14 Korean taxa, 33 world taxa, and 9 overlapping taxa), total alignment length was 689 positions, of which 452 were parsimony informative, 527 variable, 75 singleton, and 159 constant characters. Although the phylogenic tree showed that many taxa of genus Spiraea were well separated from each other, many branches were not congruent with the morphological characteristics and geographical distributions of the genus. There were 430 segregating sites and the nucleotide diversity (${\pi}$) value was 0.281. Under the neutral mutation hypothesis, the probability that the Tajima test statistic (D) is positive (2.325) is more than 0.5. Therefore, there may be a site at which natural selection, which increases genetic variation, is operating.

Correlation between Dental Hygiene Student's Gender Sensitivity and Gender Role Stereotypes

  • Hwang, Ji-Min;Han, Ji-Hyoung
    • Journal of dental hygiene science
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    • v.21 no.4
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    • pp.213-218
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    • 2021
  • Background: The purpose of this study is to identify the gender sensitivity and gender role stereotypes of students in dental hygiene and to provide basic data to expand social awareness of equal gender sensitivity and gender role in dental hygiene and students by identifying the degree of correlation. Methods: The purpose of this study was to study dental hygiene students at colleges in Gyeonggi and Chungcheong areas. The survey was conducted from April 1 to April 30, 2021. The final sample was analyzed on 157 subjects. T-test and ANOVA analysis were performed to compare gender sensitivity and gender role stereotypes according to general characteristics. Equal variances were tested using the Levene statistic, and significant differences between groups were identified through Scheffe's post hoc analysis. Pearson's correlation analysis was performed to confirm the correlation between gender sensitivity and gender role stereotypes. Results: Gender sensitivity was 2.69 and gender role stereotypes were 1.83. Among the sub-areas of gender sensitivity, gender role openness was the highest at 2.86, and non-violence was the lowest at 2.50. As for gender role stereotypes, social stereotypes were the highest among sub-areas at 1.71. Among the general characteristics, there was a statistically significant difference in gender sensitivity according to the presence or absence of opposite sex friends (p=0.011). The gender identity openness of gender sensitivity and the physical sub-areas of gender role stereotypes showed the highest positive correlation(r=0.955). Among the sub-areas of gender sensitivity, gender role openness and domestic stereotypes showed the lowest negative correlation (r=-0.404) among the sub-areas of gender role stereotypes. Conclusion: Dental hygiene students should be able to critically analyze and solve problems of not only sexual violence but also gender discrimination and imbalance in social life. For this, environmental factors such as school education and professor guidance must be strengthened.

A Study on the Management Strategies of Korean Enterprises against the Factors of Locally Political Circumstance in Russia - Focusing on the Empirical Analysis of Structural Equation Modeling - (러시아 진출 한국기업의 현지 정치적 환경에 대응하는 경영전략에 관한 연구 - 구조 방정식 모형 분석을 중심으로 -)

  • Shin, Kwang-Ha;Park, Myung-Chan
    • International Area Studies Review
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    • v.12 no.3
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    • pp.111-133
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    • 2008
  • This study tries to analyze what the most significant factors are in Russia, where the Korean investing enterprises have to overcome and adapt to various difficulties, especially in terms of local circumstance politically. This main purpose of the research is to test empirically some relations between the managing strategy of Korean enterprises and the circumstance factors of politics in Russia while this is conducted in two stages. First, the research model is designed by reviewing relevant theories, previous studies, and the current investment conditions in local Russia. Second, the survey of Korean enterprises engaged in investment activities in there is done by collecting questionnaires from them with this survey. And the statistic method of structural equation modeling is used to testing some hypotheses. Explaining the analyzing tools, SPSS 12.0 for windows is being used for Correlation, Reliability, Validity and Multi regression and Finally the Path analysis is implemented by AMOS 7.0 for windows.

Quality of Sikhe Incorporated with Hot Water Extract of Omija (Schisandra chinensis Baillon) Fruit (오미자 열매 추출액을 첨가한 식혜의 품질특성)

  • Lee, Jun-Ho
    • Food Engineering Progress
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    • v.15 no.1
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    • pp.80-84
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    • 2011
  • The effects of incorporating hot water extract of Schisandra chinensis fruit on the physicochemical and sensory properties of Sikhe were investigated. The extract was incorporated at 5 levels (0, 10, 20, 30, 40, and 50%, v/v) by replacing equivalent amount of distilled water. The pH decreased while the soluble solids content increased significantly with the increase in the extract replacement (p<0.05). Redness ($a^*$-value) increased significantly as the extract concentration increased (p<0.05); on the other hand, lightness ($L^*$-value) and yellowness ($b^*$-value) did not show any direct relationships with the extract replacement. Color, sour taste, and sweet taste except for Sikhe flavor were distinctively classified by the sensory analyses (p<0.05). Correlation analysis indicated that level of extract incorporation was well-correlated with all the physicochemical and sensory properties studied except for $L^*$- and $a^*-$ value. Finally, the consumer test based on Friedman-type statistic, suggested that 10% incorporation of the hot water extract of Omija fruit was recommended for making Sikhe.

Associations between Hashimoto Thyroiditis and Clinical Outcomes of Papillary Thyroid Cancer: A Meta-Analysis of Observational Studies

  • Moon, Shinje;Chung, Hye Soo;Yu, Jae Myung;Yoo, Hyung Joon;Park, Jung Hwan;Kim, Dong Sun;Park, Young Joo
    • Endocrinology and Metabolism
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    • v.33 no.4
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    • pp.473-484
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    • 2018
  • Background: Epidemiological studies have suggested an association between Hashimoto thyroiditis (HT) and papillary thyroid cancer (PTC) development. Other studies, however, have reported a protective role of HT against PTC progression. Through this updated meta-analysis, we aimed to clarify the effects of HT on the progression of PTC. Methods: We searched citation databases, including PubMed and Embase, for relevant studies from inception to September 2017. From these studies, we calculated the pooled odds ratios (ORs) of clinicopathologic features and the relative risk (RR) of PTC recurrence with 95% confidence intervals (CIs) using the Mantel-Haenszel method. Additionally, the Higgins $I^2$ statistic was used to test for heterogeneity. Results: The meta-analysis included 71 published studies with 44,034 participants, among whom 11,132 had HT. We observed negative associations between PTC with comorbid HT and extrathyroidal extension (OR, 0.74; 95% CI, 0.68 to 0.81), lymph node metastasis (OR, 0.82; 95% CI, 0.72 to 0.94), distant metastasis (OR, 0.49; 95% CI, 0.32 to 0.76), and recurrence (RR, 0.50; 95% CI, 0.41 to 0.61). Conclusion: In this meta-analysis, PTC patients with HT appeared to exhibit more favorable clinicopathologic characteristics and a better prognosis than those without HT.

Domestic Research Trend of College Students' Start-up and Entrepreneurship (국내 대학생 창업에 대한 연구 동향)

  • Kim, Kyu-Tae
    • Journal of the Korea Convergence Society
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    • v.10 no.7
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    • pp.199-211
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    • 2019
  • This study analyzed the research trends of college students' entrepreneurship in 172 scholarly articles in the registered journals of the Korea Research Foundation from 2010 to 2018. The results of this study are as follows: First, the research areas and topics on university students' entrepreneurship focuses on not only characteristics of entrepreneurship and entrepreneur but also entrepreneurship education. Also, the research method was dependent on the quantitative research method coupled with the statistic techniques such as descriptive statistics, correlation, t-test, ANOVA, regression analysis, and structural equation modeling. In future research, it is necessary to expand research areas to startup idea design, startup business environment and policies. Also, it is necessary to explore various variables related to entrepreneurship, not focusing on specific variables such as entrepreneurship, entrepreneurship education as well as to analyze meta analysis of the relationship between the variables influencing on the entrepreneurial intention. In addition, qualitative research and mixed research are needed to explore the process of developing entrepreneurship and the factors affecting the process of entrepreneurship.

Kinematic and Kinetic Analysis of Taekwondo Poomsae Side Kick according to Various Heights of the Target (태권도 품새 옆차기시 타겟 높이 변화에 따른 운동학적 분석)

  • Hong, Ah Reum;So, Jae Moo
    • Korean Journal of Applied Biomechanics
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    • v.29 no.3
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    • pp.129-135
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    • 2019
  • Objective: The purpose of this study is to present the scientific and quantitative data by finding the common points and differences of the side-kick according to the height change through the difference of the side kick motion performance according to the three target height changes and the function of the lower limbs muscle in side kick motion of Taekwondo Poomsae. Method: For this, total 14 players were selected who were registered in Korea Taekwondo Association and skilled group 7 players who had a medal from national competition and 7 players who did not have Taekwondo experience from department of physics. 4 video cameras to the feature on side kick per target height, and the subjects' support foot was located on the ground reactor and the practice was conducted 3 times: waist, chest, and head as the target height. the basic materials were collected by using Kwon 3D XP program and the T-test was conducted to verify the statistic difference between groups (SPSS 24.0). At this time, the statistics significance level was set as .05 and the following conclusion was obtained. Results: The lower the proficiency and the higher the height, the more the joint coordination between the hip and the knee. Conclusion: Summary of the result shows a common point that the change of target's height makes the lower the proficiency and the higher the height, the more the joint coordination between the hip and the knee. Also, the higher the target's height became, the greater angular momentum of thighs, shanks, foot became in common.

The Effects of Open-Ended Mathematical Problem Solving Learning on Mathematical Creativity and Attitudes of Elementary Students (개방형 문제해결학습이 초등학생들의 수학적 창의성 및 수학적 태도에 미치는 영향)

  • Seo, YoungMin;Park, Mangoo
    • Communications of Mathematical Education
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    • v.35 no.3
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    • pp.277-293
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    • 2021
  • The purpose of this study was to find out how problem solving learning with open-ended mathematics problems for elementary school students affects their mathematical creativity and mathematical attitudes. To this end, 9 problem solving lessons with open-ended mathematics problems were conducted for 6th grade elementary school students in Seoul, The results were analyzed by using I-STATistics program to pre-and post- t-test. As a result of the study, problem solving learning with open-ended problems was effective in increasing mathematical creativity, especially in increasing flexibility and originality, which are sub-elements of creativity. In addition, problem solving learning with open-ended problems has helped improve mathematical attitudes and has been particularly effective in improving recognition needs and motivation among subfactors. In problem solving learning with open-ended problems, students were able to share various responses and expand their thoughts. Based on the results of the study, the researchers proposed that it is necessary to continue the development of quality materials and teacher training to utilize mathematical problem solving with open-ended problems at school sites.

Analysis of stage III stomach cancer using the restricted mean survival time (제한된 평균 생존시간을 이용한 위암 3기 자료 분석에 관한 연구)

  • Kim, Bitna;Lee, Minjung
    • The Korean Journal of Applied Statistics
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    • v.34 no.2
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    • pp.255-266
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    • 2021
  • The purpose of this study is to compare the effects of treatment on stage III stomach cancer data obtained from the SEER program of the National Cancer Institute and to identify the significant risk factors for the survival rates of stage III stomach cancer. Since the proportional hazards assumption was violated for treatment, we used the restricted mean survival time as an alternative to the proportional hazards model. The restricted mean survival time was estimated using pseudo-observations, and the effects of treatment were compared using a test statistic based on the estimated restricted mean survival times. We conducted the regression analysis using a generalized linear model to investigate the significant predictors for the restricted mean survival time of patients with stage III stomach cancer. We found that there was a significant difference between the restricted mean survival times of treatment groups. Age at diagnosis, race, substage, grade, tumor size, surgery, and treatment were significant predictors for the restricted mean survival time of patients with stage III stomach cancer. Surgery was the most significant predictor for increasing the restricted mean survival time of patients with stage III stomach cancer.

Availability and Utilization of Library Portal Services for Research in University Libraries in Nigeria

  • Ejikeme, Anthonia Nwamaka;F., Obayi Uche.;Ukamaka, Eze Jacintha
    • International Journal of Knowledge Content Development & Technology
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    • v.11 no.1
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    • pp.49-64
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    • 2021
  • This research paper delved into the availability and utilization of library portal services for research in university libraries in Nigeria. Two research questions and two null hypotheses were formulated to guide the study. A structured questionnaire was used for data collection. The study was carried out in Nnamdi Azikiwe Library, University of Nigeria Nsukka (UNN) and Felix Aghagbo Nwako Library, Nnamdi Azikiwe University Library (UNIZIK), Awka. A total of 70 professionals (librarians and system analysts) in these libraries supplied data for the study. Data collected was analyzed using mean and standard deviation. These were used to answer the research questions while the null hypotheses were tested using t-test statistic at 0.05 level of significance and 68 degree of freedom. Major findings showed that portal services available in the library showed that the areas of availability of library portal services in Nnamdi Azikiwe Library, U.N.N. includes Agriculture, Health Sciences, Engineering, Environmental Sciences and information about institution, Social Sciences, Arts and Humanities, Natural Sciences. In Festus Aghagbo Nwako Library, Awka, the areas of Portal Library Services include Career Development, Federal Government Programs, Environmental Sciences, Biological Sciences, Social Sciences, Arts and Humanities, Engineering, and Health Sciences. Findings on extent of utilization of portal services available in the libraries indicated that portal services are utilized to a low extent in the university libraries. Furthermore, librarians did not significantly differ in their opinions on the availability of library portal services and on the extent of utilization of library portal services in the libraries under study. It is therefore recommended that provisions should be made by the universities and library management to provide and update required portal services in addition to creating enabling environment for enhanced access and utilization of these services. The governments must make an effort to provide funds for policy implementation, necessary technology training for librarians and users, and develop general information infrastructure.