• 제목/요약/키워드: Science Activities

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Preservice Biology Teachers' Learning to Teach Science through Science Methods Courses

  • Kim, Sun Young
    • Journal of The Korean Association For Science Education
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    • v.32 no.9
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    • pp.1427-1442
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    • 2012
  • This study tracked the changes of preservice biology teachers' pedagogical knowledge along with science teaching efficacy throughout sequentially developed science methods course I and II over two consecutive semesters. Two courses, science methods course I and II, aimed these preservice teachers to discuss the notion of science teaching with teaching and learning theories, to learn science instructional models, to design lessons utilizing science instructional models, and to eventually implement microteaching. The preservice teachers were mainly engaged in cooperative instructional planning activities through science methods course I, and engaged in cooperative microteaching activities through the science methods course II. This study revealed that preservice teachers successfully developed pedagogical knowledge and science teaching efficacy after two science methods courses. The science methods course I where cooperative instructional planning activities occurred helped the preservice teachers to improve pedagogical knowledge but not science teaching efficacy. Based on their pedagogical knowledge development, then, these preservice teachers increased science teaching efficacy belief after completion of the science methods course II.

Effects of Drying Conditions on the Antioxidant Activities and Volatile Compounds of Chrysanthemi Flos Flowers

  • Bae, Sung-Mun;Na, Ae-Sil;Seo, Hye-Kyeong;Lee, Seung-Cheol
    • Preventive Nutrition and Food Science
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    • v.14 no.4
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    • pp.329-334
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    • 2009
  • The effects of drying conditions on the antioxidant activities, luteolin, and volatile compounds of Chrysanthemi Flos flowers were evaluated. The flowers were dried with hot-air or far-infrared radiation at 40${^{\circ}C}$, 50${^{\circ}C}$ and 60${^{\circ}C}$, respectively, to reach 22$\pm$1% of moisture content. Each 10 g of the dried flowers were extracted with 100 mL of 95% ethanol. Increasing temperature in hot-air dried (HAD) conditions increased the antioxidant activities of the flower extracts. However, increasing temperature in far-infrared dried (FID) conditions decreased the antioxidant activities of the extracts. Luteolin, one of main flavonoids of Chrysanthemi Flos flowers, was present in the highest content at 60${^{\circ}C}$ FID flowers with a value of 139 $\mu$g/mL. Thirteen volatile compounds including camphor and β-caryophyllene were identified in chromatograms. Higher amount of the volatiles were found at 50${^{\circ}C}$ HAD and 40${^{\circ}C}$ FID. The results indicated that the antioxidant activities and volatile compounds of Chrysanthemi Flos flowers were significantly affected by drying conditions.

The Effects of the Science Activities using Drawing on Young Children's Scientific inquiry competences and attitudes (그리기를 활용한 과학 활동이 유아의 과학적 태도와 과학적 탐구능력에 미치는 효과)

  • Chae, Young-Ran;Shin, Soo-Kyung
    • Korean Journal of Human Ecology
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    • v.17 no.4
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    • pp.601-608
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    • 2008
  • The purpose of this study was to examine the effects of science activities using drawing on young children's scientific inquiry competences and scientific attitudes. The subjects of this research were a total of 40 young children at age 5 from two classes in G and C child care center which located in G city. The subjects were randomly assigned to two groups. The collected data were analyzed by t-test using SPSS program. The results of this study were as follow: First, experimental group which conducted the science activities using drawing showed significantly higher improvement in sub-factors of scientific inquiry competences, 'perseverance', 'creative', 'critical', and 'volunteering'. Second, experimental group which conducted the science activities using drawing showed significantly higher improvement in sub-factors of scientific attitudes, 'observing', 'measuring', and 'discussion'. Therefor, it might be concluded that science activities using drawing contributed to the development of scientific inquiry competences and scientific attitudes of young children.

Cytotoxic Activities of Green and Brown Seaweeds Collected from Jeju Island against Four Tumor Cell Lines

  • Kim, Kil-Nam;Lee, Ki-Wan;Song, Choon-Bok;Jeon, You-Jin
    • Preventive Nutrition and Food Science
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    • v.11 no.1
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    • pp.17-24
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    • 2006
  • Methanolic and aqueous extracts from 37 seaweed species (10 green and 27 brown seaweeds) collected from Jeju Island coast were prepared at high ($70^{\circ}C$) and room ($20^{\circ}C$) temperatures and examined for cytotoxic activity against 4 tumor cell lines: U937 (human monoblastoid leukemia cell line), HL60 (human promyelocytic leukemia cell line), HeLa (woman cervical carcinoma cell line) and CT26 (mouse colon carcinoma line). Both MeOH extracts of Desmarestia tabacoides and Dictyota dichotoma possessed strong cytotoxic activities against all the tumor cell lines tested, but the aqueous extract exhibited no activity. On the other hand Ecklonia cava showed strong cytotoxic activities for the $20^{\circ}C$ aqueous extract against the three tumor cells except HeLa cell. Sagassum coreanum and Sagassum siliquastrum $20^{\circ}C$ aqueous extracts also exhibited strong cytotoxic activities against U937, HL60, HeLa cells. Even though green seaweeds showed less activity than brown seaweeds, $20^{\circ}C$ aqueous extracts of Codium contractum and Codium fragile exhibited strong cytotoxic activities against HL60 or CT26 cells, respectively.

Antioxidative Activities of the Ethyl Acetate Fraction from Heated Onion (Allium cepa)

  • Lee, Youn-Ri;Hwang, In-Guk;Woo, Koan-Sik;Kim, Dae-Joong;Hong, Jin-Tae;Jeong, Heon-Sang
    • Food Science and Biotechnology
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    • v.16 no.6
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    • pp.1041-1045
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    • 2007
  • Heated onion juice was partitioned using the solvents hexane, chloroform, ethyl acetate, and butanol. The ethyl acetate fraction showed the strongest scavenging effect on the ABTS radical. The antioxidant activities of the ethyl acetate fraction from raw and heated onion (120, 130, and $140^{\circ}C$) were evaluated using radical scavenging assays. Radical and nitrite scavenging activities were higher in heated onion than raw onion, and the higher the temperature of heat treatment, the greater the radical and nitrite scavenging activities. Heated onion ($140^{\circ}C$, 2 hr) was more effective than raw onion, having higher DPPH radical scavenging (5.7-fold), hydroxyl radical scavenging (6.4-fold), superoxide radical scavenging (2.3-fold), hydrogen peroxide scavenging (11.8-fold), and nitrite scavenging (4.3-fold) activities. Onion increased its physiologically active materials after heating, and in this regard, heated onion can be used as biological material for the manufacture of health foods and supplements.

Antioxidant and Antitumor Activities of Methanolic Extracts from Humulus japonicus (환삼덩굴 메탄올 추출물의 in vitro 항산화 및 항암 활성)

  • Lee, Youn-Ri;Kim, Ki-Youn;Lee, Sang-Hoon;Kim, Min-Young;Park, Hye-Jin;Jeong, Heon-Sang
    • The Korean Journal of Food And Nutrition
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    • v.25 no.2
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    • pp.357-361
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    • 2012
  • To evaluate the antioxidant and potential of Humulus japonicus, total polyphenol and flavonoid content, radical scavenging activities, and antitumor activities were measured. The total polyphenol and flavonoid contents of the methanol extracts from Humulus japonicus were $30.13{\pm}1.13$ and $13.61{\pm}0.49$ mg gallic acid equivalent/g extract, respectively. DPPH radical and hydroxyl radical scavenging activities of methanol extracts of Humulus japonicus were 60% and 35%, respectively. The Humulus japonicus higher activities of anticancer activities on liver cancer cell lines compared to other cancer cell lines.

Clinical Application of Combination of Isotonic in Proprioceptive Neuromuscular Facilitation (고유수용성 신경근 촉진법중 등장성수축 결합의 임상적용)

  • Bae Sung-soo;Hwang-bo Gak;Kim Mi-hyun;Kim Jae-Hun;Choi Jae-Won
    • The Journal of Korean Physical Therapy
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    • v.16 no.3
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    • pp.205-216
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    • 2004
  • The purpose of this study is to find application of combination of insotonic(CI) in clinical approach. This is a literature study with books and clinical experience. CI was developed after Margaret Knott that is very useful in clinically. CI has two lever system. It has class II lever system for eccentric contraction and class III lever system for concentric contraction. Therefore it make two different contraction that is not only magnitude of motion and speed increase of motion but also biomechanical advantage. Application of CI has much variety by patient position and treatment position. Especially, it is very effectable on mat activities and training for mid stance period. CI apply in supine position on treatment table, mat or high mat activities, bridging activities, all fourth activities and sit on chair activities. CI apply serially with different techniques. These are rhythmic initiation, dynamic reversal, approximation, rhythmic stabilization and replication.

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In vitro Antioxidative Activities and Phenolic Composition of Hot Water Extract from Different Parts of Cudrania tricuspidata

  • Jeong , Chang-Ho;Choi, Gwi-Nam;Kim, Ji-Hye;Kwak, Ji-Hyun;Heo, Ho-Jin;Shim, Ki-Hwan;Cho, Bok-Rai;Bae, Young-Il;Choi, Jine-Shang
    • Preventive Nutrition and Food Science
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    • v.14 no.4
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    • pp.283-289
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    • 2009
  • We evaluated total phenolics and antioxidative activities of water extracts from different parts of Cudrania tricuspidata (specifically, the leaves, stems, roots, and fruits). The antioxidative activities of these samples were determined using five methods, including 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical scavenging, reducing power, ferric reducing ability of plasma (FRAP), and $\beta$-carotene/linoleic acid system. The water extract of leaves exhibited the higher DPPH, ABTS radical scavenging activities, reducing power, and FRAP than water extract of stem, roots, and fruits. Inhibition values on linoleic oxidation of water extracts from leaves, stems, roots, and fruits were calculated as 45.98%, 33.03%, 39.73%, and 25.48% at 10 mg/mL, respectively. The water extract of C. tricuspidata leaves had the highest amount of toal phenolics (73.60$\pm$0.28 mg/g). High-performance liquid chromatography (HPLC) analysis showed that quercetin is the predominant phenolic compound in water extract of leaves. Thus, our study verified that the water extract of leaves has strong antioxidant activities which are correlated with its high level of phenolic compounds, particularly quercetin. This water extract of C. tricuspidata leaves can be used as an effective and safe source of antioxidants.

Effects of Process-Based Integrated Mathematics·Science Activities on Children's Science Process Skills and Scientific Attitudes (수·과학의 과정중심 통합 활동이 유아의 과학적 탐구능력과 태도에 미치는 효과)

  • Kim, Yong-Sook;Ham, Eun-Suk;Seo, Eui-Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.10
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    • pp.4462-4470
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    • 2012
  • This study aims to examine the effects of process-based integrated Mathematics Science Activities on children's science process skills and scientific attitudes and arrange efficient teaching and learning environment in the field. The subjects of research were 89 three-year and five-year old children attending kindergarten attached to W university in I city, Jeollabuk-do and process-based integrated Mathematics Science activities were conducted with themes. For data analysis, paired t-test was conducted with SPSS for Windows program and as a result of performing process-based integrated Mathematics Science activities, it was found that there were significant differences in sub-factors of science process skills and scientific attitude by age and sex. These results suggested that process-based integrated activities had positive influences on three-year and five-yeard old children.

A search for economic model in library activities (도서관 활동의 경제모형 연구)

  • 정영재
    • Journal of Korean Library and Information Science Society
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    • v.21
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    • pp.231-252
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    • 1994
  • Library authorities are responsible for allocating its resources to best achieve library goals. This means the question of benefits and costs for library activities, as well as a n.0, pplication of economic theory to it. To consider these, this study dealt with theoretical analysis: 1) the nature of economic models, 2) economic theory to library activities, 3) and its a n.0, pplicability. However, economic model method allows us to use an analytic technique that is founded on library production and consumption. Thus, its major contribution is creation of a framework or system for maximizing the efficient library activities.

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