• 제목/요약/키워드: Science activities

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Antioxidant Activities and Total Phenolics of Ethanol Extracts from Several Edible Mushrooms Produced in Korea

  • Choi, Young-Min;Ku, Ja-Bi;Chang, Hoo-Bong;Lee, Jun-Soo
    • Food Science and Biotechnology
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    • 제14권5호
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    • pp.700-703
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    • 2005
  • Eight edible mushrooms grown in Korea were extracted with ethanol at room temperature for 24 hr. The extracts were investigated for their antioxidant activities as measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging activities. Among the mushroom extracts evaluated in this study, the ethanolic extracts from Ganoderma lucidum and Pleurotus eryngii showed the greatest potential antioxidant activity, by producing 85 and 88% inhibition in DPPH radical scavenging method and 219 and 165 mg ascorbic acid equivalent antioxidant capacity (AEAC), respectively. Total phenolics and total flavonoids in the ethanolic extracts were determined by spectrophotometric method. Positive correlations were found between total phenolic contents in the extracts and their antioxidant activities, suggesting that phenolic contents in the mushrooms extracts are mainly responsible for their antioxidant activities.

Effect of Protein and Fiber Levels on Ethanol-Induced Brain Damage in Rats

  • Cho, Soo-Yeul;Lee, Mi-Kyung;Kim, Myung-Joo
    • Preventive Nutrition and Food Science
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    • 제3권4호
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    • pp.351-355
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    • 1998
  • The purpose of this study was to investigate the effect of protein and dietary fiber levels on the activities of ehanol metabilizing enzymes of the brain in acute and chronic ethanol-treated rats. Male Sprague-Dwley rats were fed on diets containing two levels of protein(7%, 20%)) with two levels of fiber(5%, 105) for 5 weeks. Rats were orally administered 40% (v/v) ethanol(5g/body weight) 90 min before decapitation in the acute ethanol-treated groups and 25% (v/v) ethanol (5g/kg body weight) once a day for 5 weeks in the chronic ethnol-treated groups. Cytosilic alcohol dehydrogenase (ADH) activities were higher than those of mitochondrial ADH. The ADH activities were increased by 20% protein and %% fiber levels in the diet in two fractions , but were decreased by chronic ethanol treatment. Mitochondrial aldehyde dehydrogenase (ALDH) activities did not change by ethanol treatment but were increased by the 20% protein level. However, cytosilic ALDH activities were decreased by chronic ethanol treatment at the 5% fiber level and did not change with protein levels. Both ALDH activities were higher in the 10% fiber groups than the 5% fiber groups. Cytochrome P-450 contents were significantly increased in the chronic ethanol-treated groups but xanthine oxidase (XO) activities did not change. P-450 contents and XO activities were significantly decreased in both the low protein and fiber groups.

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'거울과 그림자' 단원 수업 활동의 인지요구도와 학생의 인지수준과의 관계 분석 (Analysis of Correlation between Students' Cognitive Level and Cognitive Demand of Activities in 'Mirror and Shadow' Unit)

  • 이도이;전영석
    • 한국초등과학교육학회지:초등과학교육
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    • 제37권3호
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    • pp.285-295
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    • 2018
  • The purpose of this study is comparing cognitive development of elementary $4^{th}$ graders and cognitive demand of activities in lesson 'The mirror and the shadow.' Also, the researchers tried to reveal how cognitive development of elementary $4^{th}$ graders and cognitive demand of textbook activities affects the achievement of students. To study students' cognitive development, the researchers use GALT(Group Assessment of Logical Thinking). Piaget's scientific thinking is used to evaluate cognitive demand of textbook activities. With several experts in science education the researchers discussed which scientific thinking is contained in each activities. The results were followed as : (1) The third of activities are significantly affected by students' cognitive development. (2) The another third of activities are influenced by not only students' cognitive development but also other factors experimental instrument. (3) The environmental factors had meaningful impact on the other third of activities.

품질경영활동, 조직학습, 기업성과의 관계: 제조기업을 중심으로 (Relationship among Quality Management Activities, Organizational Learning and Firm Performance: with a Focus on Manufacturing Corporations)

  • 김영섭;나상균
    • 대한안전경영과학회지
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    • 제14권2호
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    • pp.193-204
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    • 2012
  • This paper deals with an empirical analysis of the structural relationship among the factors such as quality management activities, organizational learning and firm performance of manufacturing corporations. The findings of the analysis are expected to make lots of contribution to manufacturing corporations establishing strategies for quality management activities and organizational learning. From the analysis, following conclusions and suggestions could be drawn: First, an analysis of the relationship between quality management activities and organizational learning showed that most activities of quality management turned out to exercise great influence upon the factors of organizational learning. This means that the activities of quality management will prompt the members of an organization to actively engage in learning activities individually, by team and organizationally, motivating them to spread such activities across the whole organization, leading ultimately to fundamental renovation of the very organization. Second, from an analysis of the relationship between organizational learning and firm performance, that is, financial and non-financial performances of a company, it was found that most factors of organizational learning have tremendous impact upon financial and non-financial performances of the company. Such result implies that decision and management of the things to be performed in the process of organizational performances are essential to determining firm performance because firm performance depend largely on the outcomes of organizational learning.

An investigation of factors influencing the participation of stroke survivors in social and leisure activities

  • Ahn, Si-Nae;Hwang, Sujin
    • Physical Therapy Rehabilitation Science
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    • 제7권2호
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    • pp.67-71
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    • 2018
  • Objective: Participation restrictions are serious problems that stroke survivors experience while reintegrating into family, work, community, and social situations after participating in rehabilitation programs. The purpose of this study was to explore the factors affecting participation in activities of daily living (ADL), as well as social and leisure activities of individuals with hemiparetic stroke. Design: Cross-sectional study. Methods: The study involved 96 participants who were diagnosed with a first stroke 6 months before the study (58 men, 38 women; $60.3{\pm}14.3years$). The Berg Balance Scale, Modified Barthel Index, Manual Function test, and Activity Card Sort were used to assess static and dynamic balance function, upper limb function, level of independence, and their level of participation within the community. A regression analysis was used to identify the influence of factors affecting participation in ADL, social and recreational activities. Results: The Activity Card Sort scores were significantly affected by the Manual Function test and Modified Barthel Index scores (p<0.05). Participation in leisure activities was affected by the level of independence. Participation in social activities was affected by the balance function and level of independence of the participants. Conclusions: The results of this study have shown that participation restrictions are affected by upper limb function, balance function, and the level of independence in individuals with hemiparetic stroke.

학교과학교육에서 실험 활동의 목적: 전문가 커뮤니티를 통한 델파이 연구 (Aims of Laboratory Activities in School Science: A Delphi Study of Expert Community)

  • 양일호;조현준;정진우;허명;김영신
    • 한국과학교육학회지
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    • 제26권2호
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    • pp.177-190
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    • 2006
  • 많은 과학교육자들이 과학 실험활동의 목적에 대하여 연구해 왔지만, 연구자에 따라 매우 다양하게 제시되고 있다. 그러나 불행하게도 지금까지도 과학교육 전문가 커뮤니티에 의해 합의된 실험목적이 없다. 이 연구의 목적은 델파이 기법을 사용하여 과학실험활동에서 추구되어야 할 목적을 전문가 커뮤니티로부터 합의된 견해를 얻고자 하는 것이다. 전문가 커뮤니티는 4명의 과학자, 4명의 과학교육전문가, 6명의 초등교사, 7명의 중등교사로 구성되었다. 이들로부터 얻은 실힘목적이 수렴되고 있는지를 확인하기 위해 윌콕슨 부호검정을 시행하였다. 연구결과 각 학교급에 따른 실험목적이 얻어졌다. 초등학교 과학 실험 활동의 목적은 7 항목이며, 중등학교 과학 실험 활동 목적은 9 항목, 대학교의 과학 실험 활동 목적은 13개 항목이다.

창의적 체험활동 프로그램이 과학개념 및 자기주도적 학습능력에 미치는 효과 (The Effects of Science Lessons Using Creative Activities on Scientific Concepts and Self Directed Learning Ability)

  • 이용섭;김윤경
    • 대한지구과학교육학회지
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    • 제8권3호
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    • pp.399-408
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    • 2015
  • This study is to find out that the effects of a creative experience activity program to scientific concepts and self-directed learning skills. This study has been aimed at 2 class 40 students of 4th grade in D metropolitan city A elementary school in 2015, one class 20 students are the research group to apply Scientific research program using creative experience activity, another class 20 students were comparison groups to apply general science classes. The related class section of this study is 4th grade 2 semester of science 4 chapters, 'The Earth and the moon' This section is in fourth grade elementary science curriculum revision in 2009 is a Sections to learn for the first time about astronomical area. Target research group in club activities as part of the creative activities implemented using scientific inquiry and analyzed the results. In addition, in order to better research based on the results of this study as follows. First, the science curriculum in elementary schools, as well as applied research about the creative experience activity classes in other subjects is required. The ongoing research is needed to classes utilizing the characteristics of creative experience activities in several subjects of the elementary school curriculum. Second, Creative experiential learning is only effective when it is done consistently, it is worth studying for long periods of time.

초등학교 과학 디지털교과서에 제시된 테크놀로지를 활용한 탐구 활동의 특징 - 가상실험, 가상현실, 증강현실 활용 사례들을 중심으로 - (The Features of Inquiry Activities Using Technology in Elementary Science Digital Textbook - Focusing on the Cases of Using Virtual Experiment, Virtual Reality and Augmented Reality -)

  • 장진아;박준형;송진웅
    • 한국초등과학교육학회지:초등과학교육
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    • 제38권2호
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    • pp.275-286
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    • 2019
  • The purpose of this study is to investigate the features of inquiry activities using technology in the 2015 revised elementary science digital textbooks. For this, we analyzed the features of inquiry context and inquiry method presented in inquiry activities using three kinds of technology: Virtual experiment, virtual reality and augmented reality. As a result, firstly, the most common types of 77 inquiry activities were realistic type which shows the phenomenon actually and vividly as possible and realistic-abstract type which shows the phenomena with the abstract concepts. Second, the ways of using three technologies were different depending on the processes of inquiry and the sub-domains of science. For example, virtual experiment technologies were mostly used in the contents of physics and chemistry with the inquiry context of realistic-abstract type for investigating the relationship between variables of experiments and describing the phenomena mechanically. On the other hand, virtual reality and augmented reality techniques tended to be used more frequently in biology and earth science contents with the inquiry context of realistic type for observing and describing the phenomena. Finally, we discussed educational implications in terms of developing and applying technology-based inquiry activities.

자연탐사활동이 과학고 학생들의 환경인식에 미치는 효과 (The Effect of Natural Exploration Activity on Environmental Perception of the Science High School Students)

  • 김순식;최성봉
    • 한국환경과학회지
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    • 제19권3호
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    • pp.343-351
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    • 2010
  • Since the effect of environmental education at class using textbooks or materials related to environment is limited, the importance of activities for field experience is getting increased day by day. Thereby, the education tends to change into the type of education providing students with direct environmental experience. Students attending the science high school have excellent aptitude and ability for science and will lead the development of science in the future. Now it is urgent to develop various experiential programs which are helpful for them to establish desirable values on environment. However, the field of environmental education that allows science high school students equipped with ample environmental knowledge to improve environment sensitivity and have proper environment awareness is quite restricted as of now. Natural exploration activities are the programs which provide science high school students having lack of chance for environmental education with good opportunities to contact nature and also play significant roles in arousing their interest in issues related with environment. Therefore, it is thought that they will let science high school students explore the natural features of Korea, understand the importance of preserving environment and ecosystem profoundly, and encourage environmental awareness and will of environmental practice. Thereupon, with the study subjects of 121 first and second graders at U Science High School, this article analyzed their recognition of the necessity for environmental education and environmental pollution problems before and after the natural exploration activities, and conducted a survey on their satisfaction after the natural exploration activities and analyzed it. The result of this research is as follows. First, it was shown that the natural exploration activities were effective to raise the science high school students' awareness of issues related with environmental pollution. Second, the natural exploration activities had effect upon enhancing the students' willingness of environmental practice. Third, there was statistically significant correlation between the science high school students' satisfaction with the natural exploration activities and their achievement in the science subject. Fourth, there also was a statistically non or weakness significant correlation between their satisfaction with the natural exploration activities and preference for the science subject. In particular, it was found that students preferring biology indicated higher satisfaction.

Antioxidant and Antiproliferative Activities of Methanol Extracts from Leafy Vegetables Consumed in Korea

  • Kim, Hoi-Kyung;Bang, Chan-Sook;Choi, Young-Min;Lee, Jun-Soo
    • Food Science and Biotechnology
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    • 제16권5호
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    • pp.802-806
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    • 2007
  • There has been growing interest in the antioxidative and anticarcinogenic effects of vegetables. This study was aimed at evaluating the antioxidative and antiproliferative activities of 13 leafy vegetables consumed in Korea. New-beet and ornamental kale contained >1,000 mg of polyphenolics/100g fresh weight (FW), which was the greatest amount among the test vegetable extracts. Ornamental kale also contained the greatest amount (232.84 mg/100g FW) of flavonoids. With the exception of chicory, values of 1.1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activities showed similar trends. New-beet was found to be the greatest antioxidant among the test vegetable extracts. New-beet exhibited the highest antiproliferative activity (>60%) against all tumor cells. No relationship was found between antiproliferative activity and antioxidant contents or antioxidant activities among samples.