• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.328-328
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• 2017

Drought is a major limiting factor that reduces rice production and occurs often especially under recent climate change. Plants have the ability to alter their developmental morphology in response to changing environment, which is known as phenotypic plasticity. In our previous studies, we found that one chromosome segment substitution line (CSSL50 derived from Nipponbare and Kasalath crosses) showed no differences in shoot and root growth as compared with the recurrent genotype, Nipponbare under non-stress condition but showed greater growth responses compared with Nipponbare under mild drought stress condition. We hypothesized that reducing root respiration as metabolic cost, which may be largely a consequence of aerenchyma formation would be one of the key mechanisms for root plasticity expression. This study aimed to evaluate the root respiration and aerenchyma formation under various soil moisture conditions among genotypes with different root plasticity. CSSL50 together with Nipponbare and Kasalath were grown under waterlogged conditions (Control) and mild drought stress conditions (20% of soil moisture content) in a plastic pot ($11cm{\times}14cm$, ${\varphi}{\times}H$) and PVC tube ($3cm{\times}30cm$, ${\varphi}{\times}H$). Root respiration rate was measured with infrared gas analyzer (IRGA, GMP343, Vaisala, Finland) with a closed static chamber system. There was no significant difference between genotypes in control for shoot and root growth as well as root respiration rate. In contrast, all the genotypes increased their root respiration rates in response to mild drought stress. However, CSSL50 showed lower root respiration rate than Nipponbare, which was associated by higher root aerenchyma formation that was estimated based on internal gas space (porosity) under mild drought stress conditions. Furthermore, there were significant negative correlations between root length and root respiration rate. These results imply that reducing the metabolic cost (= root respiration rate) is a key mechanism for root plasticity expression, which CSSL50 showed under mild drought.

• Journal of Korean Home Economics Education Association
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• v.31 no.1
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• pp.39-58
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• 2019

The purpose of this study was to investigate the home economics pre-service teachers' verbal interactions during their teaching practicum. For this purpose, the class interactions of four pre-service teachers were recorded, and the data were analyzed using advanced Flanders' verbal interaction analysis. The major findings are as follows: First, the item with the highest proportion of occurrences consisted of the pre-service teachers' 'lectures', 'nonverbal conditions' and 'asks questions'. 'forms a positive learning atmosphere' and 'praises or encourages' exhibited fewer occurrences, and there was little 'giving direction', 'criticizing students or justifying authority'. Second, the instances of class interactions appeared in the form of 'asks questions-student talk response' or 'lecture-asks questions', and in the last class were 'ask questions-student talk initiation' and 'accepts or uses ideas of students'. Third, trends of verbal interactions tend to be generally indirect, and students' remarks have appeared acceptable and compassionate. Fourth, according to expert analysis, 'class management questions' and 'diffusion questions' have increased. Pre-service teachers can guide students through their learning activities, and students can expand their thinking through the teachers' questions. As these results demonstrate, self-study analyses of pre-service teachers and active support in field are needed.

• Journal of The Korean Association For Science Education
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• v.19 no.1
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• pp.19-28
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• 1999

The major purposes of this study are to examine the effects of portfolio assessment on elementary school student's science knowledge, inquiry ability, science attitudes and to investigate students' perceptions on portfolio assessment. Control group consists of 45 fourth-graders at M-Elementary school located at Miwon, Chongwon-gun, Chung-buk and experimental group 36 fourth-graders of G-Elementary school located in Daejeon-si. The inventories of scientific knowledge I, inquiry ability, and science attitudes were administered to both groups as a pre-test. The experimental group was given portfolio assessment instruction and control group traditional instruction for about six weeks. Inventories about scientific knowledge 2, inquiry ability, and science attitudes were administered to both groups as a post-test. A questionnaire on the perception on portfolio assessment was given to experimental group after the treatment. The results were statistically analyzed with SPSS. Control group showed higher score on scientific knowledge than that of experimental group (p<0.5). No statistically meaningful difference was identified in inquiry ability and scientific attitude. More in-depth analysis revealed that scientific attitudes were improved statistically meaningfully by portfolio assessment. The students' perceptions on portfolio assessment is very positive. Students have positive responses on interests in portfolio assessment, feelings of involvement in learning, self-regulated learning, higher levels of thinking, intentions of participation in portfolio assessment.

• Journal of Christian Education in Korea
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• v.69
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• pp.139-162
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• 2022

This study verified the effect of learning motivation on immersion by non-face-to-face class method. For this purpose, 101 college students majoring in early childhood education were selected as research subjects. The average age of the study subjects was 22.6 years old, and 51 students took non-real-time non-face-to-face classes, and 50 students took real-time non-face-to-face classes. The study measured the level of immersion and the type of learning motivation after the non-face-to-face class was finished. The measured data were analyzed using descriptive statistical analysis and multiple regression analysis. As a result, in the results for all students, the performance approach goal had the most influence on immersion, and the mastery goal orientation had the next effect. Performance avoidance orientation had no effect. For students in non-face-to-face classes, performance approach goal orientation had an effect on immersion, and for students in real-time non-face-to-face classes, mastery goal orientation had an effect. The implications that can be obtained from the results of this study are as follows. First, non-real-time non-face-to-face classes should cover basic knowledge and skills so that there are no mistakes and failures. Second, non-real-time non-face-to-face classes should allow tasks with appropriate difficulty to be performed with a deadline. Third, real-time non-face-to-face classes should lower the fear of mistakes and failures.

• Nutrition Research and Practice
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• v.15 no.6
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• pp.798-806
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• 2021

BACKGROUND/OBJECTIVES: Obesity is associated with chronic inflammation. The spleen is the largest organ of the lymphatic system and has an important role in immunity. Obesity-induced inflammatory responses are triggered by Toll-like receptor (TLR)-myeloid differentiation primary response 88 (MyD88) pathway signaling. Phenethyl isothiocyanate (PEITC) and 3,3'-diindolylmethane (DIM), major dietary glucosinolates present in cruciferous vegetables, have been reported to produce anti-inflammatory effects on various diseases. However, the effects of PEITC and DIM on the obesity-induced inflammatory response in the spleen are unclear. The purpose of this study was to examine the anti-inflammatory effects of PEITC and DIM on the spleen and their mechanism in high fat/cholesterol diet (HFCD)-fed C57BL/6 mice. MATERIALS/METHODS: We established an animal model of HFCD-induced obesity using C57BL/6 mice. The mice were divided into six groups: normal diet with AIN-93G diet (CON), high fat diet (60% calories from fat) with 1% cholesterol (HFCD), HFCD with PEITC 30 mg/kg/day or 75 mg/kg/day (HFCD+P30, HFCD+P75), and HFCD with DIM 1.5 mg/kg/day or 7.5 mg/kg/day (HFCD+D1.5, HFCD+D7.5). Enzyme-linked immunosorbent assay was used to evaluate pro-inflammatory cytokine secretion. Western blot and quantitative polymerase chain reaction were used to analyze protein and mRNA levels of nuclear factor kappa B (NF-κB) p65, interleukin 6 (IL-6), cyclooxygenase 2 (COX-2), TLR2, TLR4, and MyD88 in spleen tissue. RESULTS: Serum IL-6 levels were significantly higher in the HFCD group than in groups fed a HFCD with PEITC or DIM. Levels of NF-κB p65 protein and TLR2/4, MyD88, NF-κB p65, IL-6, and COX-2 mRNA were significantly higher in the HFCD group than in the CON group and were reduced by the PEITC and DIM supplements. CONCLUSIONS: PEITC- and DIM-supplemented diets improved splenic inflammation by modulating the TLR2/4-MyD88 pathway in HFCD-fed mice. We suggest that dietary glucosinolates may at least partially improve obesity-induced inflammation of the spleen.

• Journal of agricultural medicine and community health
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• v.35 no.1
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• pp.89-98
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• 2010

Objectives: The purpose of this research was to evaluate the ability of completing death certificates among medical students. Methods: The self-administered questionnaires were completed, during May to August 2007, by 380 medical students in senior. The questionnaire was composed of 10 cases to write the death certificate. The cause-of-deaths written by students were compared with the gold standards and their errors in the certificates also evaluated. Results: Mean agreement score for 10 underlying cause-of-deaths completed on the lowest line of part I in the death certificate (UC1) was $4.8{\pm}1.7$, and for underlying cause-of-death selected by a coder of the death certificates (UC2) was $5.6{\pm}1.5$. The UC1 and UC2 were significantly higher among the students having the case-oriented education for death certificate than others. For the major errors in the certificates completed by students, the students having the error with no antecedent cause were highest, the error with two or more conditions secondly highest. Mean number of errors was significantly lower in the case-oriented education group than others. Conclusions: Errors are common in the death certificates completed by medical students in senior. The accuracy of death certification may be more improved with the case-oriented education than the traditional method.

• Journal of Gifted/Talented Education
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• v.10 no.2
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• pp.1-23
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• 2000

The Schoolwide Enrichment Model(SEM) is a representative model for the gifted education. As the model seems to be more conceptual in nature, it is hard to respond to the different interests and changing needs of the gifted learners. Also it does not provide specific procedures and prescriptions in teaching-learning processes for the teachers. Therefore, SEM needs to be modified into a Systemic Model that is more flexible and procedural. The paper proposes an Instructional Systems Design(ISD) model for SEM. The Systemic Model for SEM consists of 5 major steps. These are as follows: Planning, Diagnosis, Prescription, Implementation, Evaluation. In Planning step, there is a six-stage procedure for initiating the implementation of the SEM. In Diagnosis step, there are two-phases in identifying students for participation in the SEM and assessing strengths, interests, and talents of the learners and recording in The Total Talent Portfolio(TTP). In Prescription step, Curriculum Compacting is administered as a systematic procedure for modifying thecurriculum for above-average ability students. In Implementation step, Enrichment Learning and Teaching is an instructional strategy designed to promote active engagement in learning for teachers and students. Whenever each step has completed, Evaluation step should be followed. These 5 steps are repetitive, cycling and interactive. That is, each one becomes input for the next step, process for itself, and output for the previous step. Each step is monitored through the process of Review and Revision step. In conclusion, the paper suggests six strengths of the Systemic Model for SEM; The Model (1) provides the specific procedure in teaching-learning process; 92) has interactive relations with each component; (3) can be revised continuously for creation of the most effective system; (4) can be implemented more flexibly; (5) can be developed as an unique system for each school; (6) facilitates communications between teachers and students.

• Journal of The Korean Association For Science Education
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• v.18 no.3
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• pp.415-425
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• 1998

The purpose of this study is to investigate the difference and relations in science related attitudes and science achievement in highschool students. Investigated differences between science related attitudes and science achievement and evaluated variations within city type, gender, grade level group. 404 high school students in Korea were sampled by cluster sampling method. Two instruments were used in this study. The ABC inventory(affection. behavioral intention. cognition scale of attitude toward science) was developed by the researcher(Lee, 1996, 1997). And MSAS(modified scientific attitude scale) has modified previous one. The major results are as follows: 1. Highschool students' Attitude toward Science is 3.24, 5-rating summative Likert scales. It showed slightly positive and favorable. 2. Highschool students' Scientific Attitude is 3.37, 5-rating summative Likert scales. It showed slightly positive tendencies of scientific attitude. 3. Findings indicated that middle' small city's students scored higher in Attitude toward Science and Scientific Attitude than metropolitan students. 4. The relationship between Attitude Toward Science and Scientific Attitude is 0.5716. The relationship between Scientific Attitude and Science Achievement is weaker than the relationship Attitude Toward Science and Science Achievement. 5. The results of three-way ANOVA indicated that were significant group differences(p<.05) in Attitude toward Science and Scientific Attitude. 6. After adjustment for the covariate(Scientific Attitude's score), statistically significant main effects of all group were found on the Attitude toward Science(p>.05). But after adjustment for the covariate(Attitude toward Science's score), statistically no significant main effects of all group were found on the Scientific Attitude(p>.05).

• Journal of The Korean Association For Science Education
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• v.30 no.4
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• pp.452-471
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• 2010

As the Korean College scholastic Ability Test (CSAT) has been implemented for 17 years since 1994, it is becoming more and more difficult to make new items that haven't been previously used to measure students' thinking ability. Therefore, it is necessary to keep conducting research on making new test items that can measure students' scholastic ability reliably. For this reason, multiple choice items on the Japanese university entrance exam, which is a Japanese National Center Test for University Admissions (NCTUA) equivalent of CSAT, were analyzed in order to draw implications for CSAT item development. In this study, we analyzed the Japanese NCTUA administered in January 2009 to investigate the structure of its science test. We also analyzed the NCTUA items by the domains of contents and behaviors, and tried to predict item difficulty from the perspective of Korean applicants. Major findings are as follows: Most NCTUA items measure understanding knowledge or low level thinking ability. Also the alloted time for each item is longer than CSAT. The number of test items, and the number of choice and alloted points for each item are diverse, unlike CSAT. The number of items using real-life materials are much more, but the items are not rigorous in sentence expression compared to CSAT. And the difference of difficulty level among science tests were larger with reference to CSAT. Also science score is required for most applicants regardless whether they are taking liberal arts or going onto the science track.

• Korean Journal of Food Science and Technology
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• v.23 no.2
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• pp.141-149
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• 1991

The essential oils of the two cultivars of Korean ginger were isolated by simultaneous steam distillation and extraction method. Then the essential oils were fractionated into one hydrocarbon fraction and two oxygented hydrocarbon fractions by using silica gel column chromatography. The composition of the resulting oils were investigated by GC-MS spectrometry. The volatile oil contents of the two fresh cultivars were 0.32%(wb) and consisted of 68.1% hydrocarbon and 31.9% oxygenated hydrocarbons. Out of 101 characterized compounds, 54 were identified by comparing GC retentions and mass spectral data with authentic samples and 47 were tentatively identified according to mass spectral data only. The major compounds of hydrocarbon fraction were camphene, ${\beta}-phellandrene$, zingiberene, ${\gamma}-bisabolene,\;{\bate}-sesquiphellandrene$, and of oxygenated hydrocarbon fractions were 1,8-cineol, neral, geranial, geranyl acetate, citronellol, geraniol and ${\alpha}-terpeneol+borneol$. Comparing the yield and composition of Korean ginger oil with those from other origins reported, Korean ginger oils showed good yields of oil, whilst those contained higher amounts of sesquiterpene hydrocarbons.