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Flavonoid Biosynthesis: Biochemistry and Metabolic Engineering (Flavonoid 생합성:생화학과 대사공학적 응용)

  • Park, Jong-Sug;Kim, Jong-Bum;Kim, Kyung-Hwan;Ha, Sun-Hwa;Han, Bum-Soo;Kim, Yong-Hwan
    • Journal of Plant Biotechnology
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    • v.29 no.4
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    • pp.265-275
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    • 2002
  • Flavonoid biosynthesis is one of the most extensively studied areas in the secondary metabolism. Due to the study of flavonoid metabolism in diverse plant system, the pathways become the best characterized secondary metabolites and can be excellent targets for metabolic engineering. These flavonoid-derived secondary metabolites have been considerably divergent functional roles: floral pigment, anticancer, antiviral, antitoxin, and hepatoprotective. Three species have been significant for elucidating the flavonoid metabolism and isolating the genes controlling the flavonoid genes: maize (Zea mays), snapdragon (Antirrhinum majus) and petunia (Prtunia hybrida). Recently, many genes involved in biosynthesis of flavonoid have been isolated and characterized using mutation and recombinant DNA technologies including transposon tagging and T-DNA tagging which are novel approaches for the discovery of uncharacterized genes. Metabolic engineering of flavonoid biosynthesis was approached by sense or antisense manipulation of the genes related with flavonoid pathway, or by modified expression of regulatory genes. So, the use of a variety of experimental tools and metabolic engineering facilitated the characterization of the flavonoid metabolism. Here we review recent progresses in flavonoid metabolism: confirmation of genes, metabolic engineering, and applications in the industrial use.

Systematic Study on the Fishes of the Family Cobitidae(Pisces, Cypriniformes). 2. Taxonomic Study on the Cobitis taenia complex from Korea (기름종개과(family Cobitidae)어류의 계통분류에 관한 연구 2. 한국산 Cobitis taenia complex의 분류학적 고찰)

  • 양서영;이혜영;양홍준;전상린;박병상;김재흡
    • Animal Systematics, Evolution and Diversity
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    • v.9 no.2
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    • pp.151-170
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    • 1993
  • Morphometric, band-pattern and electrophoretic analysis on Cobitis taenia complex were performed to investigate the morphological and genetic differentiation and to clarify their taxonomic status. Intermediate types of band-pattern (C and D type) were more frequently expressed than that of types of C. t. taenia(type A) and C. t. lutheri (type B). Sexual dimorphism of band-pattern was observed not only in C. t. taenia(type A) and C. t. lutheri(type B). Sexual dimorphism of band-pattern was observed not only in C. t. lutheri but also in C. t. taenia and C. t. striata as well. Discriminant function analysis based on 19 morphological characters shows no significant differences among C. taenia complex. The degree of genic variation of C. t. striata was higher ( =1.48, P=31.2%, HD=0.009) than those of C. t. striata was higher( =1.48, P=31.2%, HD=0.082 and HG=0.009) than those of C. t. lutheri ( =1.37, P=2.7%, HD=0.058 and HG=0.065). The average genetic similarities between C. t. lutheri and C. t. taenia-C. t. striata were S=0.62 and S=0.66 respectively and these values indicate that C. t. tanenia has evolved specific level of differentiation. C. t. striata and C. t. lutheri show subspecifc level of close genetic similarity (S=0.82). Based on the divergent time estimate (Nei, 1975) it is assumed that C. t. tanenia was branched off from the other subspecies about two million years before present (MYBP) and C. t. striata and C. t. lutheri were differentiated about 0.6 MYBP. The use of C. sinesis an the scientific name for the Korean C. t. taenia, proposed by Kim and Lee (1988) seems incorrect since they are quite different in the structure of lamina circularis (Vladycov, 1935), the external morphology and distribution (Cheng and Zheng, 1987) and the chromosome number(Yu et al., 1989). Kim and Lee(1988) also argued that C.t. striata and C. t. lutheri should be treated as distinct species but the present study and other reports (Kim and Lee, 1984; Kim and Yang, 1993) do not support it. We conclude that C. t. taenia is a good species and C. t. striata and C. t. lutheri are subspecific status. Their scientific names should be revised in the future.

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Measurement and Monte Carlo Simulation of 6 MV X-rays for Small Radiation Fields (선형가속기의 6 MV X-선에 대한 소형 조사면 측정과 몬테 카를로 시뮬레이션)

  • Jeong Dong Hyeok;Lee Jeong Ok;Kang Jeong Ku;Kim Soo Kon;Kim Seung Kon;Moon Sun Rock
    • Radiation Oncology Journal
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    • v.16 no.2
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    • pp.195-202
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    • 1998
  • Purpose : In order to obtain basic data for treatment plan in radiosurgery, we measured small fields of 6 MV X-rays and compared the measured data with our Monte Carlo simulations for the small fields. Materials and Methods : The small fields of 1.0, 2.0 and 3.0 cm in diameter were used in this study. Percentage depth dose (PDD) and beam Profiles of those fields were measured and calculated. A small semiconductor detector, water phantoms, and a remote control system were used for the measurement Monte Carlo simulations were Performed using the EGS4 code with the input data prepared for the energy distribution of 6 MV X-rays, beam divergence, circular fields and the geometry of the water phantoms. Results : In the case of PDD values, the calculated values were lower than the measured values for all fields and depths, with the differences being 0.3 to 5.7% at the depths of 20 to 20.0 cm and 0.0 to 8.9% at the surface regions. As a result of the analysis of beam profiles for all field sizes at a depth of loom in water phantom, the measured 90% dose widths were in good agreement with the calculated values, however, the calculated Penumbra radii were 0.1 cm shorter than measured values. Conclusion : The measured PDDs and beam profiles agreement with the Monte Carlo calculations approximately. However, it is different when it comes to calculations in the area of phantom surface and penumbra because the Monte Carlo calculations were performed under the simplified geometries. Therefore, we have to study how to include the actual geometries and more precise data for the field area in Monte Carlo calculations. The Monte Carlo calculations will be used as a useful tool for the very complicated conditions in measurement and verification.

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The Development of Students' Scientific Perspectives on Historical Heritages through the Science Field Trip of Hwasong Fortress (수원 화성 과학 탐방을 통한 문화재에 대한 과학적 안목 형성 지도)

  • Choi, Jae-Hyeok;Pak, Sung-Jae
    • Journal of The Korean Association For Science Education
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    • v.24 no.5
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    • pp.930-936
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    • 2004
  • Science field trip on historical heritages in Korea has developed since 1998. There are a few discussion of effectiveness of science field trip on historical heritages. In this research, the aim of science field trip on historical heritages was discussed in view of developing scientific perspectives on historical heritages with cases of science field trip of Hwasong fortress. Material for science field trip of Hwasong fortress was developed and instructional strategy was designed. The material contained convergent and divergent scientific inquiry activities. The goal of the activity was to help students to build scientific perspectives on the historical heritage, so they can evaluate the scientific excellency of historical heritage. The subjects were ten ninth grade students of middle school science club in Seoul. A questionnaire, "evaluation of scientific excellency of historical heritage" was administered before and after the field trip. From the analysis of a change in perspective by field trip, it was investigated how the scientific perspective on historical heritages was developed. The first draft of material for science field trip of Hwasong fortress was developed based on science education experts' discussion. The material has three parts; activities before the trip, activities during the trip and activities after trip. Instructor's guide has the same structure. Before the field trip, students watched the videotape and learned the short history lesson about Hwasong fortress to develop familiarity. During the trip, there were exploring stage and intensive inquiring stage. These activities were designed to develop scientific perspective on historical heritage. After the field trip, evaluation activity about scientific value of Hwasong was done based on the activities done during the trip. After the science field trip of Hwasong fortress, most of students showed positive changes. Some of them reflected on their previous thoughts. Some recognized the necessity of the proper criteria for scientific excellency of historical heritage. All changed in their perspective on evaluating scientific aspects on historical heritage, such as considering the social environment, scientific principles and the influence of science and technology of that age on the society, when the fortress was built. These results show that the science field trip focused on the criteria for evaluating the scientific excellency of historical heritage was significant in helping students to develop the scientific perspective on historical heritage.

Characteristics of Middle School Students in a Biology Special Class at Science Gifted Education Center: Self-regulated Learning Abilities, Personality Traits and Learning Preferences (과학영재교육원 생물반 중학생들의 특성: 자가조절학습능력에 따른 개인적 성향 및 학습선호도)

  • Seo, Hae-Ae
    • Journal of Gifted/Talented Education
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    • v.19 no.3
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    • pp.457-476
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    • 2009
  • The research aimed to investigate characteristics of middle school students in a biology class as science gifted education in terms of self-regulated learning abilities, personality traits and learning preferences. The twenty subject in the study responded to questionnaires of a self-regulated learning ability instrument, a personality trait tool, and a learning preference survey in March, 2009. It was found that the research subjects showed higher levels of cognitive strategies, meta-cognition, and motivation than those students in a previous study(Jung et. al., 2004), while environment was opposite. The level of cognitive strategies was significantly correlated with meta-cognition(r=.610, p=.004) and motivation (r=.538, p=.014) and meta-cognition with environment(r=.717, p=.000). Those students who showed highest levels of self-regulated learning ability displayed various personality traits. One male student with the highest level of self-regulated learning ability showed a personality of hardworking, tender-minded, and conscientious traits and wanted to be a medical doctor. The female student with the second highest level of self-regulated learning ability presented a personality as creative, abstract and divergent thinker and she showed a strong aspiration to be a world-famous biologist with breakthrough contribution. The five students with highest levels of self-regulated learning ability showed a common preference in science learning: they dislike memory-oriented and theory-centered lecture with note-taking from teacher's writings on chalkboard; they prefer science learning with inquiry-oriented laboratory work, discussion among students as well as teachers. However, reasons to prefer discussion were diverse as one student wants to listen other students' opinions while the other student want to present his opinion to other students. The most favorable science teachers appeared to be who ask questions frequently, increase student interests, behave friendly with students, and is a active person. In conclusion, science teaching for the gifted should employ individualized teaching strategies appropriate for individual personality and preferred learning styles as well as meeting with individual interests in science themes.

Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014 (설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.7
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    • pp.380-394
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    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

The Effect of Ginseng Saponins on the Biosynthesis of Prostaglandins (인삼 Saponin이 Prostaglandin 대사에 미치는 영향)

  • Park C.W.;Lee S.H.
    • Proceedings of the Ginseng society Conference
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    • 1988.08a
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    • pp.77-80
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    • 1988
  • The effects of ginseng saponins and some phenolic acids on the in vitro biosynthesis of prostaglandins was examined in order to identify the role of some ginseng components on the regulaion of arachidonic acid metabolism. The productions of prostaglandin $E_2(PGE_2).$ prostaglandin $F_2{\alpha}(PGF_2{\alpha}).$ thromboxane $B_2(TxB_2)$ and 6-keto-prostaglandin $F_1{\alpha}(6-keto-PGF_1{\alpha})$ from $[^3H]-arachidonic$ acid were evaluated with rabbit kidney microsome. human platelet homogenate and bovine aortic microsome. The amounts of the total cyclooxy-genase products from arachidonic acid did't show significant changes in the presence of ginseng saponins. Panaxadiol. panaxatriol and all of the ginsenosides used in these experiments reduced the formation of $TxB_2.$ while increased the $6-keto-PGF_1{\alpha}$ production dose dependently. Ginseng saponins did't inhibit the ADP($10{\mu}M$) induced platelet aggregation. but sodium arachidonate (0.5 mM) induced platelet aggregation. but sodium arachidonate (0.5 mM) induced platelet aggregation was signiticantly inhibited. These findings suggest that ginseng saponins seem to playa role in the regulation of the arachidonate metabolism. probably by affecting the divergent biosynthetic pathway of prostaglandins from endoperoxide.

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Laying the Siting of High-Level Radioactive Waste in Public Opinion (고준위 방폐장 입지 선정의 공론화 기초 연구)

  • Lee, Soo-Jang
    • Journal of Environmental Policy
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    • v.7 no.4
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    • pp.105-134
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    • 2008
  • Local opposition and protest constitute single greatest hurdle to the siting of locally unwanted land uses(LULUs), especially siting of high-level radioactive disposal not only throughout Korea but also throughout the industrialized world. It can be attributed mainly to the NIMBYism, equity problem, and lack of participation. These problems are arisen from rational planning process which emphasizes instrumental rationality. But planning is a value-laden political activity, in which substantive rationality is central. To achieve this goals, we need a sound planning process for siting LULUs, which should improve the ability of citizens to influence the decisions that affects them. By a sound planning process, we mean one that is open to citizen input and contains accurate and complete information. In other word, the public is also part of the goal setting process and, as the information and analyses developed by the planners are evaluated by the public, strategies for solutions can be developed through consensus-building. This method is called as a co-operative siting process, and must be structured in order to arrive at publicly acceptable decisions. The followings are decided by consensus-building method. 1. Negotiation will be held? 2. What is the benefits and risks of negotiation? 3. What are solutions when collisions between national interests and local ones come into? 4. What are the agendas? 5. What is the community' role in site selection? 6. Are there incentives to negotiation. 7. Who are the parties to the negotiation? 8. Who will represent the community? 9. What groundwork of negotiation is set up? 10. How do we assure that the community access to information and expert? 11. What happens if negotiation is failed? 12. Is it necessary to trust each other in negotiations? 13. Is a mediator needed in negotiations?

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An analysis of current condition of student's selection process in Hansung science highschool (한성과학고등학교 학생 선발과정의 현황 분석)

  • Dong, Hyo-Kwan;Jhun, Young-Seok
    • Journal of Gifted/Talented Education
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    • v.13 no.4
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    • pp.65-94
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    • 2003
  • The purpose of this study is to acquire the information on the current situation of students' selection process in order to renovate the system of picking up the students. As a first step of the study, we examined the validity of the factors of the single-out system such as qualification and the process for the application and the standards and proceeding of the selection. Then we analysed the result of the entrance examination of Hansung Science Highschool in 2002. The analysis was on the correlation between the result of entrance examination and the achievement in the school and the decision of the course after graduation. To know on the achievement of the students, we investigated the records of regular tests and asked the teachers' opinion in math and science classes. As a result, we gained the following points: First, the present single-out system has a danger of excluding students who are much talented in science and math field because it is based on students' achievements in middle schools; Second, the new selection system should consider the character and attitude of the applicants in addition to their knowledge; Third, the continuous observation of the teacher in middle school should be an important factor of the picking up system; Fourth, more questions requiring divergent thinking ability and inquiry skill should be developed as selective examination question. Also examination questions should cover the various contents from mathematics to science, and do not affect pre-learning; Finally, the system of present letting all students stand in one line should be changed into that of letting students in various lines. We can consider using multi-step selection system.

A Study on a Korean-Translated Version of the Pediatric Volitional Questionnaire (PVQ) (Pediatric Volitional Questionnaire의 국내적용을 위한 번역연구)

  • Ra, Dae-Yeop;Chang, Ki-Yeon;Kong, Myung-Ja;Lee, Sun-Wook
    • The Journal of Korean Academy of Sensory Integration
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    • v.16 no.3
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    • pp.34-49
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    • 2018
  • Objective : This study aimed to examine the psychometric properties of Korean version of Pediatric Volitional Questionnaire (PVQ-K) using classical test theory. Methods : For the translation of Pediatric Volitional Questionnaire (PVQ), as recommended in the literature, four-stage translation method was used. For the psychometric properties of Korean version of the Pediatric Volitional Questionnaire (PVQ-K), internal consistency reliability, content validity, and construct validity of the test using the known groups method and convergent and divergent methods were examined. For the recruitment of participants, a convenience sampling method is used. Participants of this study were 10 children with neuro-developmental disabilities hospitalized two different rehabilitations center and 10 children with typical development living in Daejeon, South Korea. All 20 participants were in aged from two to five years. Results : In terms of the content validity index, it was over 0.78, confirmed by nine experts of children development. PVQ-K successfully discriminated the scores of children with typical development from those with neurodevelopmental disabilities (p < .05). It is found that there is significant correlations between achievement stage of PVQ-K and the Korean Developmental Screening Test for Infants & Children (K-DTS)(.652 ~ .799 for subcategory, .706 for total scale). The internal consistency was .944 (Cronbach's ${\alpha}$). In qualitative content analysis, it was examined that how Korean children behave and respond in the environment, and how children's volition was strengthened or weakened by the environment. Conclusion : The results propose that PVQ-K can be a useful occupation-focused measure. This study recommend further study on PVQ-K with larger samples combined with the item-response theory approach.