• Title/Summary/Keyword: immersion time

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Physical properties of novel composite using Portland cement for retro-filling material (치근단 역충전용 포틀랜드 시멘트 신복합재료의 물리적 성질 고찰)

  • Lee, Sang-Jin;Cho, Ok-In;Yum, Ji-Wan;Park, Jeong-Kil;Hur, Bock;Kim, Hyeon-Cheol
    • Restorative Dentistry and Endodontics
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    • v.35 no.6
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    • pp.445-452
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    • 2010
  • Objectives: The aim of this study was to compare apical sealing ability and physical properties of MTA, MTA - AH-plus mixture (AMTA) and experimental Portland cement - Epoxy resin mixture (EPPC) for a development of a novel retro-filling material. Materials and Methods: Forty-nine extracted roots were instrumented and filled with gutta-percha. Apical root was resected at 3 mm and the retro-filling cavity was prepared for 3 mm depth. Roots were randomly divided into 3 groups of 15 roots each. The retro-filling was done using MTA, AMTA, and EPPC as the groups divided. Four roots were used as control groups. After setting in humid condition for 24 hours, the roots were immersed in 1% methylene blue dye solution for 72 hours to test the apical leakage. After immersion, the roots were vertically sectioned and photos were taken to evaluate microleakage. Setting times were measured with Vicat apparatus and digital radiographs were taken to evaluate aluminum equivalent thickness using aluminum step wedge. The results of microleakage and setting time were compared between groups using one-way ANOVA and Scheffe's post-hoc comparison at the significance level of 95%. Results: AMTA and EPPC showed less microleakage than MTA group (p < 0.05). AMTA showed the highest radio-opacity than other groups and the novel EPPC showed 5 mm aluminum thickness radio-opacity. EPPC showed the shortest initial and final setting times than other groups while the MTA showed the longest (p < 0.05). Conclusions: Under the condition of this study, the novel composite using Portland cement-Epoxy resin mixture may useful for retro-filling with the properties of favorable leakage resistance, radio-opacity and short setting time.

Variation of Vital Sign according to Time in Full Immersion of Hot and Cool Bath (온.냉욕 전신침수욕시 기간에 따른 vital sign의 변화)

  • Yi, Seung-Ju
    • Journal of Korean Physical Therapy Science
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    • v.3 no.3
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    • pp.35-49
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    • 1996
  • This study was conducted to see variation of vital sign of hot and cool bath according to time, a questionnair survey and measurement was carried out for 32 students(sophomore) of department of physical therapy Andong Junior College on the 27th of June, 1995. The result were as follows: The average systolic blood pressure(SBP) of stability for 32 college students who were measured was 105.3mmHg, the average diastolic blood pressure(DBP) was 67.3mmHg, the average pulse frequency(PF) was 70.7(frequency/min), the average respiratory frequency (RF) was 15.6 (frequency/min), and the body temperature(BT) was $36.6^{\circ}C$. As time went on, SBP for 32 students who were measured in hot bath according to stability, 3 min, 6 min, 9 min, and 12 min was decreased(105.15 mmHg, 104.69mmHg, 104.24 mmHg, 103.03 mmHg, and 96.69 mmHg)(P=0.3006). SBP was decreased in cool bath, too(105.15 mmHg, 103.33 mmHg, 103.33 mmHg, and 100.91 mmHg), but it at 12 min was a little higher(l03.09 mmHg)(P=0.7566). As time went on, DBP according to stability, 3 min, 6 min, 9 min, and 12 minutes was decreased in hot bath(66.82 mmHg, 65.45 mmHg, 64.54 mmHg, 63.03 mmHg, and 59.39 mmHg)(P=0.0906). It was similar in cool bath(66.82 mmHg, 67.87 mmHg, 68.48 mmHg, 67.87 mmHg, and 68.78)(P=0.9654). As time went on, PF was significantly increased in hot bath(70.42 times, 86.96 times, 93.57 times, 99.30 times, and 101.78 times)(P=0.0001). It was a little increased in cool bath, too (70.42 times, 70.85 times, 71.63 times, 71.06 times, and 71.45 times)(P=0.9803). As time went on, RF was significantly increased in hot bath(15.75 times, 19.09 times, 22.09 times, 24.94 times, and 26.48 times)(P=0.0001). I t in cool bath of stability, 3 min, and 6 min was a little increased(15.75 times, 19.30 times, 19.39 times), but it in 9 min(18.67 times), and 12 min(18.09 times) was a little decreased(P=0.0176). As time went on, BT was significantly increased in hot bath($36.63^{\circ}C,\;37.45^{\circ}C,\;37.81^{\circ}C,\;38.12^{\circ}C,\;38.33^{\circ}C$)(P=0.0001). It was a little increased in cool bath of stability and 3 min($36.63^{\circ}C,\;37.40^{\circ}C$), but others are similar($37.33^{\circ}C,\;37.37^{\circ}C$, and $37.36^{\circ}C$)(P=0.0001). It was revealed by this study, SBP and DBP according to time in hot and cool bath were decreased. PF, RF, and BT in hot bath were higher, RF and BT in cool bath were higher too. but PF was similar.

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Effect of water storage on the fracture toughness of dental resin cement used for zirconia restoration (수분이 지르코니아 수복물 전용 레진시멘트의 파괴인성에 미치는 영향에 관한 연구)

  • Goo, Bon-Wook;Kim, Sung-Hun;Lee, Jai-Bong;Han, Jung-Suk;Yeo, In-Sung;Ha, Seung-Ryong;Kim, Hee-Kyung
    • The Journal of Korean Academy of Prosthodontics
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    • v.52 no.4
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    • pp.312-316
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    • 2014
  • Purpose: The aim of this study was to compare the fracture toughness of currently available resin cements for zirconia restorations and evaluate the effect of water storage on fracture toughness of those resin cements. Materials and methods: Single-edge notched specimens ($3mm{\times}6mm{\times}25mm$) were prepared from three currently available dual cure resin cements for zirconia restorations (Panavia F 2.0, Clearfil SA luting and Zirconite). Each resin cement was divided into four groups: immersed in distilled water at $37^{\circ}C$ for 1 (Control group), 30, 90, or 180 days (n=5). Specimens were loaded in three point bending at a cross-head speed of 0.1 mm/s. The maximum load at specimen failure was recorded and the fracture toughness ($K_{IC}$) was calculated. Data were analyzed using one-way ANOVA and multiple comparison $Scheff{\acute{e}}$ test (${\alpha}$=.05). Results: In control group, the mean $K_{IC}$ was $3.41{\pm}0.64MN{\cdot}m^{-1.5}$ for Panavia F, 2.0, $3.07{\pm}0.41MN{\cdot}m^{-1.5}$ for Zirconite, $2.58{\pm}0.30MN{\cdot}m^{-1.5}$ for Clearfil SA luting respectively, but statistical analysis revealed no significant difference between them. Although a gradual decrease of $K_{IC}$ in Panavia F 2.0 and gradual increases of KIC in Clearfil SA luting and Zirconite were observed with storage time, there were no significant differences between immersion time for each cement. Conclusion: The resin cements for zirconia restorations exhibit much higher $K_{IC}$ values than conventional resin cements. The fracture toughness of resin cement for zirconia restoration would not be affected by water storage.

Growth Effect of Oncorhychus masou by Recombinant Myostatin Prodomain Proteins Derived from Fish (어류 유래 마이오스타틴 프로도메인 단백질에 의한 시마연어(Oncorhychus masou) 성장효과)

  • Kim, Jeong-Hwan;Lee, Sang-Beum;Cho, Mi-Jin;Ahn, Ji-Young;Lee, Suk-Keun;Hong, Sung-Youl;Seong, Ki-Baik;Jin, Hyung-Joo
    • Journal of Life Science
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    • v.21 no.8
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    • pp.1149-1155
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    • 2011
  • Myostatin (MSTN) belongs to the transforming growth factor-${\beta}$ superfamily or growth and differentiation factor 8 (GDF-8), and functions as a negative regulator of skeletal muscle development and growth. Previous studies in mammals have suggested that myostatin knock-out increased muscle mass and decreased fat content compared to those of the wide type. Recently, several studies on myostatin have beenconducted on the block myostatin signal pathway with myostatin antagonists and the MSTN regulation with RNAi to control myostatin function. This study was performed to analyze growth and muscle alteration of Oncorhychus masou by treatment with recombinant myostatin prodomains derived from fish. We designed myostatin prodomains derived from P. olivaceus (pMALc2x-poMSTNpro) and S. schlegeli (pMALc2x-sMSTNpro) in a pMALc2x expression vector, and then purified the recombinant proteins using affinity chromatography. The purified recombinant proteins were treated in O. masou through an immersion method. Recombinant protein treated groups did not show a significant difference in weight, protein, or lipid composition compared to the control. However, there was a difference in the average number and area for histological analyses in the muscle fiber. At twelve and twenty-two weeks from the initial treatment, there were differences in averagefiber number and area between the 0.05 mg/l treated-group and the control, but the numbers were similar to those of the control during the same time period. At twelve weeks, however, 0.2 mg/l treated-group had an increase in average fiber number and decrease in average fiber area compared to the control. At twenty-two weeks, the pMALc2x-sMSTNpro 0.2 mg/l treated-group was induced and showed a decrease in average fiber number and increase in average fiber area. The results between twelve and twenty-two weeks showed that the fiber numbers had decreased, whereas average fiberarea had increased due to sMSTNpro. It is understood that the sMSTNpro induced only hyperplasia at twelve weeks, after which it induced hypertrophy. Recombinant myostatin prodomains derived from fish may induce hyperplasia and hypertrophy in O. masou depending upon the time that has elapsed.

A study on an application of 'Virtual Reality Therapy' concerning a technology of real-time interaction. (실시간 상호작용 기술의 '가상현실치료' 적용에 관한 연구)

  • Kim, Jeong-Hwan
    • Cartoon and Animation Studies
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    • s.22
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    • pp.81-97
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    • 2011
  • The technology of 'Virtual Reality' has placed in advanced tools for human beings' joy and anger together with sorrow and pleasure in our generation. It has recently tried in a variety ways to use as an implication for treatment in the field of Cognitive Psychology. Especially, it widely approaches to human in terms of that a sense of reality in a virtual world through the five senses should reinterpret the meaning of cognition in the real world. Based on this paradigm shift, it allows for new treatment using the technology of virtual reality. A typical example is a field of Therapy in order to overcome panic disorder. It has advantages that in particular development of flexible interaction technologies in a virtual space can lead patients to experience psychological environments rather than physical one. the interaction technology provides environments in which users' five senses can be actively stimulated, it is very useful that information from the experiences in the virtual world allows people to learn through real experiences by renewing potential energies, advantages of Virtual Reality Therapy can be customized treatment by depending on symptoms in patients with panic disorder and are capable of differentiate application for the cure at each stage. It is to treat by leading patients to get accustomed to environments and situations in real world through care process with each symptom and stage. It is helpful that based on A Human-Sensibility Ergonomics, technologies like immersive virtual reality equipment, force-relative feedback and stereophonic sound, and like stimulating the sense of smell make people to induce experiences by stimulating human's five senses. There are many advantages of immersion in virtual world in that the phenomenon such as challenge, interaction, reality, illusion, and cooperation is expanded. As an application for therapy by growing such augmented reality, virtual space and sharing of data through the Internet and also inexpensive its availability have recently expanded the base. There are other benefits of Virtual Reality Therapy offering active interaction environments for cognitive experience which can provide appropriately adjusted environments for patients who are hard to overcome the real situation because of phobia. In addition to that it is safe and economical and patients' confidentiality is assured. Moreover, due to the principles of applying real-time navigation the Virtual Reality Therapy makes modification and supplementation easier and also it can reduce cybersickness because of the supply of Lenticular allowing people to see stereoscopy without eyeglasses, which makes sense of presence clearer. On top of that due to the development of interactive technologies, it is becoming close to sense of reality similar to real world by leading users to navigate by themselves and to operate objects in a virtual space. This paper will therefore examine, although it is of limited, characteristics of application of virtual reality technology based on A Human-Sensibility Ergonomics used for treatment for a disorder. this paper will analyse a range of its application and problems and it will suggest the future possibilities.

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Syllabus Design and Pronunciation Teaching

  • Amakawa, Yukiko
    • Proceedings of the KSPS conference
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    • 2000.07a
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    • pp.235-240
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    • 2000
  • In the age of global communication, more human exchange is extended at the grass-roots level. In the old days, language policy and language planning was based on one nation-state with one language. But high waves of globalizaiton have allowed extended human flow of exchange beyond one's national border on a daily basis. Under such circumstances, homogeneity in Japan may not allow Japanese to speak and communicate only in Japanese and only with Japanese people. In Japan, an advisory report was made to the Ministry of Education in June 1996 about what education should be like in the 21st century. In this report, an introduction of English at public elementary schools was for the first time made. A basic policy of English instruction at the elementary school level was revealed. With this concept, English instruction is not required at the elementary school level but each school has their own choice of introducing English as their curriculum starting April 2002. As Baker, Colin (1996) indicates the age of three as being the threshold diving a child becoming bilingual naturally or by formal instruction. Threre is a movement towards making second language acquisition more naturalistic in an educational setting, developing communicative competence in a more or less formal way. From the lesson of the Canadian immersion success, Genesee (1987) stresses the importance of early language instruction. It is clear that from a psycho-linguistic perspective, most children acquire basic communication skills in their first language apparently effortlessly and without systematic and formal instruction during the first six or seven years of life. This innate capacity diminishes with age, thereby making language learning increasingly difficult. The author, being a returnee, experienced considerable difficulty acquiring L2, and especially achieving native-like competence. There will be many hurdles to conquer until Japanese students are able to reach at least a communicative level in English. It has been mentioned that English is not taught to clear the college entrance examination, but to communicate. However, Japanese college entrance examination still makes students focus more on the grammar-translation method. This is expected to shift to a more communication stressed approach. Japan does not have to aim at becoming an official bilingual country, but at least communicative English should be taught at every level in school Mito College is a small two-year co-ed college in Japan. Students at Mito College are basically notgood at English. It has only one department for business and economics, and English is required for all freshmen. It is necessary for me to make my classes enjoyable and attractive so that students can at least get motivated to learn English. My major target is communicative English so that students may be prepared to use English in various business settings. As an experiment to introduce more communicative English, the author has made the following syllabus design. This program aims at training students speak and enjoy English. 90-minute class (only 190-minute session per week is most common in Japanese colleges) is divided into two: The first half is to train students orally using Graded Direct Method. The latter half uses different materials each time so that students can learn and enjoy English culture and language simultaneously. There are no quizes or examinations in my one-academic year program. However, all students are required to make an original English poem by the end of the spring semester. 2-6 students work together in a group on one poem. Students coming to Mito College, Japan have one of the lowest English levels in all of Japan. However, an attached example of one poem made by a group shows that students can improve their creativity as long as they are kept encouraged. At the end of the fall semester, all students are then required individually to make a 3-minute original English speech. An example of that speech contest will be presented at the Convention in Seoul.

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STUDIES ON THE EXTRACTION OF SEAWEED PROTEINS 1. Extraction of Water Soluble Proteins (해조단백질의 추출에 관한 연구 1. 수용성 단백질의 추출)

  • RYU Hong-Soo;LEE Kang-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.10 no.3
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    • pp.151-162
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    • 1977
  • Distribution of marine algae is diverse in Korea and the resource of edible algae is abundant marking 239,037 tons of yearly production in 1976. They have been known as a protein source and used as a supplement in Korean diet. It is necessary to estimate the potentiality and properties of usable algal proteins especially as food resources and studies of extraction and separation of the proteins, therefore, are basically required for this purpose. In this study, the influence of various factors including the sample treatment, extraction time and temperature, sample us extraction solvent ratio and pH upon the extractability of the water soluble protein was determined. And the effect of precipitation treatment for isolation of the algal protein from the extracts was also tested. Nine species of algae, the major ones in consumption as food namely Porphyra suborbiculata, Undaria pinnatifida, Hizikia fusiforme, Sargassum fulvellu, Enteromorpha linza, Codium fragile, Sargassum kjellmanianum and Ulva pertusa were collected as fresh from Kijang, Yangsan Gun, in the vicinity of Busan city. The content of crude protein $(N\times6.25)$ of the algae ranged from $9.46\%\;to\;24.14\% showing the highest value in Porphyra suborbiculata and the minimum in Hizikia fusiforme. In the effort of maceration of blending methods on the extractability, immersion freezing in dry ice-methanol solution appeared most effective yielding 1.5 to 2.5 times extractability than that of the mortar grinding method. The effect of the ratio of sample vs solvent on extractability differed from species. It was enhanced at the ratio of 1:20 (w/v) in Ulva pertusa and Enteromorpha linza while the ratio was 1:30 (w/v) for Cedium fragile, Undaria pinnatifida, Hizikia fusiferme, Sargassum fulvellum and Porphyra suborbiculata and 1:40 for Sargassum kjellmanianum respectively. The effect of extraction time and temperature was revealed differently from species which might be caused by differences in the constitution of algal tissues resulting in that the extraction for 1 hour at $50^{\circ}C$ gave the maximum extractabilily in Ulva pertusa and Enteromorpha linza, 2 hours in Porphyra suborbiculata, Hikikia fusiforme, Undaria pinnatifida, Sargassum kjellmanianum and 3 hours in Codium fragile. And the extractability was higher at $50^{\circ}C$ to $60^{\circ}C$ for the most of the tested samples except Hizikia fusiforme. The optimum pH for the extraction was 9 to 12. The recovery of extractable nitrogen to the total nitrogen was $63\%$ in average with the first extracts and $8.6\%$ with the second extracts respectively. Both extracts were prepared by 2 hour extraction at $50{\pm}1^{\circ}C$ with dry ice-methanol frozen and seasand macerated materials. And these conditions assumed to be an optimum for the extraction of water soluble algal proteins since the nitrogen content after the first extraction covered $90\%$ of the total water extractable nitrogen. In the precipitation of the extracted proteins, Barnstein method and methanol treatment seemed to be more efficient than other precipitation methods.

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Development of Customer Sentiment Pattern Map for Webtoon Content Recommendation (웹툰 콘텐츠 추천을 위한 소비자 감성 패턴 맵 개발)

  • Lee, Junsik;Park, Do-Hyung
    • Journal of Intelligence and Information Systems
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    • v.25 no.4
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    • pp.67-88
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    • 2019
  • Webtoon is a Korean-style digital comics platform that distributes comics content produced using the characteristic elements of the Internet in a form that can be consumed online. With the recent rapid growth of the webtoon industry and the exponential increase in the supply of webtoon content, the need for effective webtoon content recommendation measures is growing. Webtoons are digital content products that combine pictorial, literary and digital elements. Therefore, webtoons stimulate consumer sentiment by making readers have fun and engaging and empathizing with the situations in which webtoons are produced. In this context, it can be expected that the sentiment that webtoons evoke to consumers will serve as an important criterion for consumers' choice of webtoons. However, there is a lack of research to improve webtoons' recommendation performance by utilizing consumer sentiment. This study is aimed at developing consumer sentiment pattern maps that can support effective recommendations of webtoon content, focusing on consumer sentiments that have not been fully discussed previously. Metadata and consumer sentiments data were collected for 200 works serviced on the Korean webtoon platform 'Naver Webtoon' to conduct this study. 488 sentiment terms were collected for 127 works, excluding those that did not meet the purpose of the analysis. Next, similar or duplicate terms were combined or abstracted in accordance with the bottom-up approach. As a result, we have built webtoons specialized sentiment-index, which are reduced to a total of 63 emotive adjectives. By performing exploratory factor analysis on the constructed sentiment-index, we have derived three important dimensions for classifying webtoon types. The exploratory factor analysis was performed through the Principal Component Analysis (PCA) using varimax factor rotation. The three dimensions were named 'Immersion', 'Touch' and 'Irritant' respectively. Based on this, K-Means clustering was performed and the entire webtoons were classified into four types. Each type was named 'Snack', 'Drama', 'Irritant', and 'Romance'. For each type of webtoon, we wrote webtoon-sentiment 2-Mode network graphs and looked at the characteristics of the sentiment pattern appearing for each type. In addition, through profiling analysis, we were able to derive meaningful strategic implications for each type of webtoon. First, The 'Snack' cluster is a collection of webtoons that are fast-paced and highly entertaining. Many consumers are interested in these webtoons, but they don't rate them well. Also, consumers mostly use simple expressions of sentiment when talking about these webtoons. Webtoons belonging to 'Snack' are expected to appeal to modern people who want to consume content easily and quickly during short travel time, such as commuting time. Secondly, webtoons belonging to 'Drama' are expected to evoke realistic and everyday sentiments rather than exaggerated and light comic ones. When consumers talk about webtoons belonging to a 'Drama' cluster in online, they are found to express a variety of sentiments. It is appropriate to establish an OSMU(One source multi-use) strategy to extend these webtoons to other content such as movies and TV series. Third, the sentiment pattern map of 'Irritant' shows the sentiments that discourage customer interest by stimulating discomfort. Webtoons that evoke these sentiments are hard to get public attention. Artists should pay attention to these sentiments that cause inconvenience to consumers in creating webtoons. Finally, Webtoons belonging to 'Romance' do not evoke a variety of consumer sentiments, but they are interpreted as touching consumers. They are expected to be consumed as 'healing content' targeted at consumers with high levels of stress or mental fatigue in their lives. The results of this study are meaningful in that it identifies the applicability of consumer sentiment in the areas of recommendation and classification of webtoons, and provides guidelines to help members of webtoons' ecosystem better understand consumers and formulate strategies.

A Study on the Design and Development of Interactive Non-Face-to-Face Real-Time Classes using EduTech : A Case Study of Christian Education Class (에듀테크를 활용한 상호작용적 비대면 실시간 수업 설계 및 개발 연구 : 기독교교육과 수업 사례를 중심으로)

  • Nam, Sunwoo
    • Journal of Christian Education in Korea
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    • v.66
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    • pp.343-382
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    • 2021
  • This study is a case study in which the interactive non-face-to-face classes using Edutech were applied to the Department of Christian Education. The subjects were 20 students from the Christian education department of A University located in the metropolitan area. The course was 'Instructional Methods and Educational Technology' in the first semester of 2020. In theory, I studied non-face-to-face classes and interaction, and edutech and interaction. Afterward, it designed and developed interactive non-face-to-face classes using edutech. The interactive non-face-to-face classes using edutech were developed as a process of applying Flipped-PBL based interactive edutech. In addition, Edutech was selected for active interaction according to the Flipped-PBL process to be carried out in a non-face-to-face situation. In particular, in the process of developing the problem of PBL, it was built around the situation of the church. As a result of applying the class, first, learners showed high satisfaction and interest in the class. Second, positive transference appeared in the space of learning and the space of living. Third, interactive non-face-to-face classes using Edutech have generated active interaction. In particular, interactive edutech and learning methods have become the main factors enabling active interaction. Through this, learners have improved learning efficiency, immersion, and satisfaction. Also, as an alternative to face-to-face classes, I was able to experience online classes. In other words, the satisfaction and interest of learning, and the transference of learning space, were also possible through active interactions generated through learning methods using interactive Edutech used in class. Furthermore, disabilities in the online communication(Internet) environment and learners' unfamiliarity with the online environment have been found as factors that hinder learning satisfaction and interaction. During learning, obstacles to the online communication environment hinder the utilization of interactive Edutech, preventing active interactions from occurring. This results in diminishing satisfaction and interest in learning. Therefore, we find that designing interactive non-face-to-face classes using Edutech requires sufficient learner learning and checking of the online communication(Internet) environment in advance for Edutech and learning methods. In response, this study confirmed the possibility by applying interactive non-face-to-face classes using Edutech to Christian education classes as an alternative method of education that allows active interaction and consistent transference of learning and life. Although it is a case study with limited duration and limitations of the number of people, I would like to present the possibility as an alternative Christian education method of an era where the direction of online classes should be presented as an alternative to a face-to-face class.

Inhibitory Effect of Quercetin on the Expression of HSP70 Gene Induced by High Water Temperature in Tilapia (고수온에 의한 틸라피아 HSP70 유전자 발현과 Quercetin의 발현 억제 효과)

  • Kwon, Joon-Yeong;Kim, Su-Mi
    • Development and Reproduction
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    • v.15 no.4
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    • pp.365-371
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    • 2011
  • Water temperature governs various biological events in many aquatic animals including fish. Temperature changes the rates of gametogenesis and development, in some cases, is even capable of reversing fish sex. Treatments of fish with unusually high temperature are known to induce the expression of HSP70 gene. Development of an effective inhibitor for HSP70 gene expression is, thus, crucial to study the role of HSP70 in the temperature sensitive biological events. We have investigated the inhibitory effect of quercetin, 3,3',4',5,7-pentahydroxyflavon, a natural flavonid, on the expressions of HSP70 gene induced by high temperature ($36^{\circ}C$) in the Nile tilapia, Oreochromis niloticus, larvae and juveniles (10~13 cm in total length). The expression of HSP 70 gene was significantly decreased in tilapia larvae immersed in 50 ${\mu}M$ or 100 ${\mu}M$ quercetin solution for 6 hours before the exposure to high temperature (P<0.05). In particular, the level of HSP70 expression in fish treated with 100 ${\mu}M$ was as low as that of fish without high temperature treatment. Juveniles of tilapia were individually injected with 0.1 $m{\ell}$ of either 0.5 mM, 5 mM or 20 mM of quercetin solution before the exposure to high temperature. As the results, the expression of HSP70 gene in the gonad and brain of juvenile fish was significantly inhibited by the injection of 0.5 mM quercetin solution (P<0.05), but not by higher concentrations. We report, for the first time in the fish, that quercetin effectively inhibits the expression of HSP70 gene induced by high temperature and 100 ${\mu}M$ for the immersion of larvae and 0.5 mM for the injection to juvenile can be used for the effective concentrations for the study of temperature sensitive biological events in tilapia.