• Title/Summary/Keyword: Negative Feedback

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Physiological Regulation of Luteinizing Hormone(LH) Expression in Rat Mammary Gland during Differentiation (분화중인 흰쥐 유선내 Luteinizing Hormone (LH) 유전자 발현의 생리적인 조절)

  • 이성호
    • Development and Reproduction
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    • v.5 no.2
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    • pp.175-180
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    • 2001
  • The ectopic expression of gonadotropin releasing hormone(GnRH and luteinizing hormone(LH) in several tissues is a quite intriguing phenomenon. Recently, the presence of GnRH and its receptor has been clearly demonstrated in rodents and human mammary gland. In this context, one can postulate that the presence of local circuit composed of GnRH and LH in the gland. The present study was undertaken to elucidate whether there is a correlation between the LH expression in rat mammary gland and physiological status during the process of mammary differentiation. LH contents in mammary gland from cycling to weaning rats were measured by radioimmunoassay(RIA). In cycling rats, changes of the LH level in both serum and mammary gland showed similar pattern as the highest level in proestrus and the lowest level in diestrus II stage. While the serum LH levels were fluctuated from pregnant through involution stage, a sharp decline of mammary LH contents was observed in the lactating rats. This decrement was recovered in involuting rats to the level of proestrus stage. Reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot analyses demonstrated that the transcriptional activities of the mammary LH and GnRH were increased from diestrus I stage to estrus stage, and the increased levels were maintained in pregnant, lactation and involution stages. To test the hypothesis that the alteration in mammary LH expression might be steroid-dependant, ovariectomy(OVX) and steroid supplement model was employed. As expected, supplement of estradiol(E$_2$) after OVX remarkably decreased serum LH level compared to that in serum from vehicle-only treated rats. Likewise, administration of E$_2$ significantly reduced the mammary LH content. The present study demonstrated that (i) the LH expression in mammary gland could be altered by some physiological parameters such as estrous cycle, pregnancy, lactation and involution, and (ii) ovarian steroid especially estrogen seems to be one of major endocrine factors which are responsible for regulation of mammary LH expression.

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A Study for Quality of Life in Musically Talented Students Using Experience Sampling Method (경험표집법(ESM)을 통해 본 음악영재의 삶의 질)

  • Lee, Hyun-Joo;Choe, In-Soo
    • Journal of Gifted/Talented Education
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    • v.21 no.1
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    • pp.57-81
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    • 2011
  • The purpose of this study was to explore the quality of life of musically talented students as measured by their external experiences (e.g., activities, companions) and internal experiences (e.g., flow, emotion). The participants in this study were 33 musically talented students (10 males, 23 females) aged 13 to 19. Study data were collected for 7 consecutive days using the Experience Sampling Method (ESM), which employs a cellular-phone as a signaling device. The results were as follows: First, in response to the 1625 random signals, musically talented students reported that 40.9% of their time was spent on productive activities. An additional 33.4% of time was used for maintenance activities and the rest of their time was spent on leisure/social activities. Also, musically talented students reported that 48.5% of their time was spent alone. When they were alone, they spent a lot of time engaging in productive activities (44.3%). Second, in order to measure the flow of their life, two methods were used. One used a 4-channel flow model (i.e. apathy, boredom, flow, anxiety) and the other used 8 dimensions and conditions of the flow experience (i.e. concentration, self-consciousness disappears, action and awareness merge, distorted sense of time, freedom from worry about failure, clear goals, immediate feedback, balance between challenges and skills). According to the former, when engaged in music-related activities, musically talented students usually reported flow (54.0%), while they felt apathy (41.3%) for daily routines activities. According to the latter method, musically talented students experienced flow for most productive activities, while they experienced flow least for maintenance activities. Emotional variables of ESF are comprised of 10 semantic scales (i.e. happy-sad, strong-weak, active-passive, sociablelonely, proud-ashamed, involved-detached, excited-bored, clear-confused, relaxed-worried, cooperative-competitive). Musically talented students reported experiencing the most positive emotion for social activities and experiencing the most negative emotion for maintenance activities. Results of this study assert that musically talented students had to trade off immediate enjoyment for developing their special gifts. They could not afford as much time for socializing with friends, and they had to spend more time alone compared to their peers without such gifts. Consequently, they were found to deprive themselves of the spontaneous good times that teenagers usually thrive on. They were helped in this respect by their autotelic personality traits, especially their strong need for achievement and endurance. The downside, however, is that the moment-to-moment quality of their moods suffered. The argument concerning musically talented students applies for all adolescents. The choices that talented students must make between immediate gratification and long-term development, and between solitude and companionship, are the same choices every young person must make, regardless of her or his level of talent. All of us have gifts that are potentially useful and worthy of being appreciated. But to develop these latent talents we must cultivate them, and this takes time and the investment of mental energy. The lifestyle that musically talented students develop can show us some of the choices all of us must make in order to cultivate our gifts.

Perception of Visitors on Traditional Marketplaces becoming Tourist Attractions and Supporting Policies - Focused on Tongin Market, Seoul - (전통시장의 관광지화 및 지원정책에 대한 이용객들의 인식 - 서울 통인시장을 중심으로 -)

  • Kim, Yelim
    • Journal of the Korean Institute of Landscape Architecture
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    • v.45 no.6
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    • pp.76-89
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    • 2017
  • Tourism is being used as a tool to regenerate declining spaces. Therefore, the government is carrying out various projects to create tourist attractions to revitalize the traditional marketplace, which is declining nationwide. Because of these government-led projects, traditional marketplaces have been transformed into tourist attractions, and some markets have received enough positive feedback that they have been successfully revitalized economically. However, as marketplaces have become tourist destinations, negative views about government support projects are also increasing. This also leads to conflicts due to differences in perception and interests of stakeholders. This paper examines the process of the marketplace becoming a tourist destination focused on the Tongin Market, in Seoul which has been regenerated as a tourist attraction through a government support project. The purpose of this study is, first, to examine the background of tourist markets becoming tourist attractions and the issues surrounding them. The second was to explore in depth the types of conflict perceptions of visitors, residents and tourists, and the perception of their responses. As a research method, the process of the revitalization of traditional markets through news and existing literature, issues and the difference of perceptions about tourist-centric traditional marketplaces were examined. In addition, the Q methodology was used, which is a qualitative research methodology that can measure the difference of viewpoints and perceptions of specific events in order to analyze the difference of perception among visitors in traditional marketplaces. The results of the study show that there are three main perspectives of difference among visitors' perceptions about government support projects in traditional marketplaces and the marketplace becoming a tourist attraction. The 'policy dependent perspective' emphasizes the necessity of government regulations, a 'critical perspective' criticizes the government's traditional marketplace support policy, and the 'neutral perspective' acknowledges the need for government-led projects and accentuating the internal competitiveness of the marketplace. The study provided the environment for academic discussion about traditional marketplaces, which are becoming tourist attractions nationwide. In addition, this paper can contribute to providing implications for future government projects by analyzing the perception of marketplace visitors.

Organization and function of shoot apical meristem affecting growth and development in plants (식물의 생장과 발달에 영향을 미치는 슈트 정단분열조직의 체제와 기능)

  • Lee, Kyu Bae
    • Journal of Plant Biotechnology
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    • v.41 no.4
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    • pp.180-193
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    • 2014
  • In plants, a shoot apex has a small region known as the shoot apical meristem (SAM) having a group of dividing (initiating) cells. The SAM gives rise to all the groundabove structures of plants throughout their lifetime, and thus it plays important role in growth and development of plants. This review describes theories to explain the SAM organization and function developed over the last 250 years. Since in 1759 German botanist C. F. Wolff has described firstly the SAM, in 1858 Swiss botanist C. N${\ddot{a}}$geli proposed the apical cell theory from the observation of a large single apical cell in the SAM of seedless vascular plants: however, this view was recognized to be unsuitable to seed plants. In 1868, German botanist J. Hanstein suggested the histogen theory: this concept subdividing the SAM into dermatogen, periblem, and plerome was unable to generally apply to seed plants. In 1924, German botanist A. Schmidt proposed the tunica-corpus theory from the examination of angiosperm SAM in which two parts show different planes of cell division: this theory was proved to be not suitable to gymnosperm SAM, not have stable surface tunica layer. In 1938, American botanist A. Foster described zones in gymnosperm SAM based on the cytohistologic differentiation and thus called it a cytohistological zonation theory. With works by E. Gifford, in 1954, this zonation pattern was demonstrated to be also applicable to angiosperm SAM. As another theory, in 1952 French botanist R. Buvat proposed the m${\acute{e}}$rist${\grave{e}}$me d'attente (waiting meristem) theory: however, this concept was confuted because of its negation of function during vegetative growth phase to central initial cells. Rescent studies with Arabidopsis thaliana have found that formation and maintenance of the SAM are under the control of selected genes: SHOOTMERISTEMLESS (STM) gene forms the SAM, and WUSCHEL (WUS) and CLAVATA (CLV) genes function in maintaining the SAM; signaling between WUS and CLV genes act through a negative feedback loop.

An Interdisciplinary Approach to the Human/Posthuman Discourses Emerging From Cybernetics and Artificial Intelligence Technology (4차 산업혁명 시대의 사이버네틱스와 휴먼·포스트휴먼에 관한 인문학적 지평 연구)

  • Kim, Dong-Yoon
    • Journal of Broadcast Engineering
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    • v.24 no.5
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    • pp.836-848
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    • 2019
  • This paper aims at providing a critical view over the cybernetics theory especially of first generation on which the artificial intelligence heavily depends nowadays. There has been a commonly accepted thought that the conception of artificial intelligence could not has been possible without being influenced by N. Wiener's cybernetic feedback based information system. Despite the founder of contemporary cybernetics' ethical concerns in order to avoid an increasing entropy phenomena(social violence, economic misery, wars) produced through a negative dynamics of the western modernity regarded as the most advanced form of humanism. In this civilizationally changing atmosphere, the newly born cybernetic technology was thus firmly believed as an antidote to these vices deeply rooted in humanism itself. But cybernetics has been turned out to be a self-organizing, self-controlling mechanical system that entails the possibility of telegraphing human brain (which are transformed into patterns) through the uploading of human brain neurons digitalized by the artificial intelligence embedded into computing technology. On this background emerges posthuman (or posthumanism) movement of which concepts have been theorized mainly by its ardent apostles like N. K. Hayles, Neil Bedington, Laurent Alexandre, Donna J. Haraway. The converging of NBIC Technologies leading to the opening of a much more digitalizing society has served as a catalyst to promote the posthuman representations and different narratives especially in the contemporary visual arts as well as in the study of humanities including philosophy and fictional literature. Once Bruno Latour wrote "Modernity is often defined in terms of humanism, either as a way of saluting the birth of 'man' or as a way of announcing his death. But this habit is itself modern, because it remains asymmetrical. It overlooks the simultaneous birth of 'nonhumaniy' - things, or objects, or beasts, - and the equally strange beginning of a crossed-out God, relegated to the sidelines."4) These highly suggestive ideas enable us to better understand what kind of human beings would emerge following the dazzlingly accelerating advancement of artificial intelligence technology. We wonder whether or not this newly born humankind would become essentially Homo Artificialis as a neuronal man stripping off his biological apparatus. However due to this unprecedented situation humans should deal with enormous challenges involving ethical, metaphysical, existential implications on their life.

A Qualitative Case Study of Service Learning in Small Christian Universities : Focusing on service learning effect and learning emotion (소규모 기독교 대학의 서비스러닝 질적사례 연구: 서비스러닝 효과와 학습정서를 중심으로)

  • Kim, Hyun Woo;Lee, Jeong Mee
    • Journal of Christian Education in Korea
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    • v.71
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    • pp.61-96
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    • 2022
  • This study tried to explore the ways to operate service learning more effectively by analyzing the educational effects of service learning and changes in learning sentiments that appeared in the service learning operation process established for the realization of the Christian educational philosophy at a small local Christian university. The analysis was conducted using NVivo11, focusing on the reflection journals of students who participated in service learning in the first semester of 2022 at J University. As a result of the study, through service learning, personal competence growth, self-reflection and will to change, self-esteem and self-efficacy, social and civic aspects, social responsibility enhancement, community (community) empathy and awareness of participation, and helping others There were educational effects such as an increase in the breadth of understanding. In addition, learning emotions that appeared in the service learning process included positive emotions such as gratitude, challenge recognition, pride, confidence, and responsibility, and negative emotions such as worry (difficulty), upset, regret, and awkwardness. It is a measure to increase the educational effect based on the learning emotion shown in the service learning process. When operating service learning, the service period at the visiting institution is increased to 6 weeks or more, and based on close interaction and detailed analysis of the educational environment in the planning stage, Suggest to develop and operate a plan. In addition, if you have the opportunity to receive feedback from your professors and colleagues through demonstrations and mock presentations in the classroom before visiting the institution, and finally have the opportunity to visit the institution again after the results of service learning are announced, more quality service learning education will be operated. Based on the results of this study, it is expected that more valuable and meaningful service learning education opportunities will be provided to learners by designing and operating a practical and sophisticated service learning curriculum.

Analyzing Topic Trends and the Relationship between Changes in Public Opinion and Stock Price based on Sentiment of Discourse in Different Industry Fields using Comments of Naver News (네이버 뉴스 댓글을 이용한 산업 분야별 담론의 감성에 기반한 주제 트렌드 및 여론의 변화와 주가 흐름의 연관성 분석)

  • Oh, Chanhee;Kim, Kyuli;Zhu, Yongjun
    • Journal of the Korean Society for information Management
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    • v.39 no.1
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    • pp.257-280
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    • 2022
  • In this study, we analyzed comments on news articles of representative companies of the three industries (i.e., semiconductor, secondary battery, and bio industries) that had been listed as national strategic technology projects of South Korea to identify public opinions towards them. In addition, we analyzed the relationship between changes in public opinion and stock price. 'Samsung Electronics' and 'SK Hynix' in the semiconductor industry, 'Samsung SDI' and 'LG Chem' in the secondary battery industry, and 'Samsung Biologics' and 'Celltrion' in the bio-industry were selected as the representative companies and 47,452 comments of news articles about the companies that had been published from January 1, 2020, to December 31, 2020, were collected from Naver News. The comments were grouped into positive, neutral, and negative emotions, and the dynamic topics of comments over time in each group were analyzed to identify the trends of public opinion in each industry. As a result, in the case of the semiconductor industry, investment, COVID-19 related issues, trust in large companies such as Samsung Electronics, and mention of the damage caused by changes in government policy were the topics. In the case of secondary battery industries, references to investment, battery, and corporate issues were the topics. In the case of bio-industries, references to investment, COVID-19 related issues, and corporate issues were the topics. Next, to understand whether the sentiment of the comments is related to the actual stock price, for each company, the changes in the stock price and the sentiment values of the comments were compared and analyzed using visual analytics. As a result, we found a clear relationship between the changes in the sentiment value of public opinion and the stock price through the similar patterns shown in the change graphs. This study analyzed comments on news articles that are highly related to stock price, identified changes in public opinion trends in the COVID-19 era, and provided objective feedback to government agencies' policymaking.

Conceptual Characteristics Analysis of Interest in Science Perceived by Elementary Pre-Service Teachers (초등 예비교사들이 인식하는 과학 흥미에 대한 개념적 특성 분석)

  • Yoon-Sung Choi
    • Journal of Science Education
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    • v.47 no.3
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    • pp.225-237
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    • 2023
  • The purpose of this study is to explore the perceptions of elementary pre-service teachers regarding their interest in science. A survey was conducted among 187 elementary pre-service teachers enrolled at Non-Metropolitan Area A University of Education. Data collection was carried out concurrently with three elementary pre-service teachers who agreed to participate in online interviews. The survey responses provided by the elementary pre-service teachers were analyzed using a qualitative text analysis method. Interest in science was observed to decrease during middle school, followed by the upper grades of elementary school and then the lower grades. The reasons for the decline in interest in science were interpreted as stemming from negative experiences with science education within the context of individual circumstances in the school setting. Strategies to address the decline and enhance interest in science were discussed across individual, family, school, teacher, local community, and national levels, considering both short-term and long-term perspectives. These strategies encompassed various inquiry activities and experiences related to the field of science, engagement in science-related activities, student-centered instruction, teacher professional development, support for elementary students and teachers, and policy measures. The multifaceted approach and efforts aimed to open avenues for positive feedback regarding science on an individual level and foster experiences related to science were interpreted as part of an effort to counteract the decline in interest in science. Lastly, given the current situation of declining interest in science and the need to enhance students' interest, it was implicitly and explicitly discussed that pre-service teachers should focus on improving their expertise in curriculum instruction. This research, by exploring the conceptual characteristics of interest in science, perceptions of changes, and educational needs related to interest in science among elementary pre-service teachers, is expected to have academic significance as foundational research data for the current status of declining interest in science.