• Animal cells and systems
• /
• 제16권5호
• /
• pp.351-356
• /
• 2012

Food is important to any animal, and a large part of the behavioral repertoire is concerned with ensuring adequate nutrition. Two main nutritional sensations, hunger and satiety, produce opposite behaviors. Hungry animals seek food, increase exploratory behavior and continue feeding once they encounter food. Satiated animals decrease exploratory behavior, take rest, and stop feeding. The signals of hunger or satiety and their effects on physiology and behavior will depend not only on the animal's current nutritional status, but also on its experience and the environment in which the animal evolved. In our novel, nutritionally rich environment, improper control of appetite contributes to diseases from anorexia to the current epidemic of obesity. Despite extraordinary recent advances, genetic contribution to appetite control is still poorly understood partly due to lack of simple genetic model systems. In this review, we will discuss current understanding of molecular and cellular mechanisms by which animals regulate food intake depending on their nutritional status. Then, focusing on relatively less known muscarinic and cGMP signals, we will discuss how the molecular and behavioral aspects of hunger and satiety are conserved in a simple invertebrate model system, Caenorhabditis elegans so as for us to use it to understand the genetics of appetite control.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
• /
• pp.297-306
• /
• 2004

This study investigated Austenite Grain Size (AGS) distribution in Low-Speed Round-Oval Rolling. Rolling experiments were done along with the AGS numerical modeling to characterize the final AGS distribution and its kinetics behavior. For bar rolling experiment, we utilized the pilot rolling mill, operating at 34 fixed rpm, at POSCO Technical Research Laboratories. To investigate the microstructural observation, the rigid-viscoplastic finite element analysis was combined with Hodgson's AGS evolution model. To consider the transient thermal history in the integrative AGS modeling, additivity rule was introduced. The integrated analysis revealed that static or meta-dynamic recrystallization is responsible for the AGS difference in the inner or outer region of rolled bar. Comparative study showed that the current AGS modeling approach can be used to model the overall AGS distribution in bar rolling processes. For more accurate AGS prediction, the AGS modeling method should be verified under the various rolling conditions such as different rolling speeds and different deformations.

• 수산해양교육연구
• /
• 제23권3호
• /
• pp.445-460
• /
• 2011

Recently, worldwide attention has been placed on being able to develop a person with interdisciplinary abilities. Specifically, there has been an emphasis on the integration of the previous STEM education and the arts, as well as the role of IT in technology and engineering education. Therefore, for this study, our goal is to help pave the way for the increased use of the teaching-learning methods of the IT-based STEAM education in developing people with interdisciplinary abilities. Firstly, we searched through domestic and foreign papers for example related to the recent trend towards the STEAM and integrative IT education models. In this study, we also presented a realistic teaching model based on STEAM education, applied mainly in the U.S., and on the teaching-learning methods of science and technology. The method we suggested is rated by expert assessments as a highly effective teaching-learning method for science and math. The use of educational IT technology in the STEAM education method is also analyzed with positive results.

• Animal cells and systems
• /
• 제8권2호
• /
• pp.77-80
• /
• 2004

To investigate the effect of host egg color dimorphism on the vinous-throated parrotbill (Paradoxornis webbianus) - common cuckoo (Cuculus canorus) interactions, we monitored breeding nests of vinous-throated parrotbills, and conducted model egg experiments, using two colors: white and blue. Of the 190 nests examined in this study, cuckoo parasitism occurred at 10 nests (8 blue and 2 white egg clutches, respectively), and only blue cuckoo eggs were found. This frequency was similar to the egg-color ratio of all host nests found (151 blue and 39 white egg clutches). Vinous-throated parrotbills showed high rejection rate towards both cuckoo eggs and model ones. There was a significant difference in rejection rates towards mimetic (blue) and non-mimetic (white) eggs in blue egg clutches. Mimetic eggs put in nests took significantly longer to be rejected than non-mimetic ones. The most common rejection method used by the hosts was egg ejection (puncture-ejection). The costs of ejecting non-mimetic eggs tended to be lower than those of ejecting mimetic eggs. These results indicate that egg-color dimorphism in this species favors the individuals having white egg clutches in terms of higher rejection rate and lower ejection costs of the parasitic eggs. This study also suggests that egg-color dimorphism of the vinous-throated parrotbill decreases the effect of cuckoo parasitism on host populations.

• Animal cells and systems
• /
• 제14권4호
• /
• pp.267-274
• /
• 2010

The decrease in sperm quality under heat stress causes a great loss in animal husbandry production. In order to reveal the mechanism underlying the sperm quality decrease caused by heat stress, we first established a mild heat-treated mouse model. Then, the sperm quality was identified. Further, the testicular proteome profile was mapped and compared with the control using 2D electrophoresis and mass spectrometry. Finally, the differential expressed proteins involved in the heat stress response were identified by real-time PCR and Western blotting. The results showed that heat stress caused a significant reduction in mouse sperm quality (P<0.05). Further, 52 protein spots on the 2D gel were found to differ between the heat-shocked tissues and the control. Of these spots, some repair proteins which might provide some explanation for the influence on sperm quality were found. We then focused on Bag-1, Hsp40, Hsp60 and Hsp70, which were found to be differently expressed after heat shock (P<0.05). Further analysis in this heat-shocked model suggests numerous potential mechanisms for heat shock-induced spermatogenic disorders.

• 조명전기설비학회논문지
• /
• 제29권5호
• /
• pp.65-70
• /
• 2015

Lightning is one of hazards affecting the rapid-transit railway system. There are two effects, which are direct lightning surge to electric car line and induced lightning surge. Protection methods for the direct lightning surge are studied with various occasions, however, study of induced lightning surge is insufficient in spite of a large or small effects. In this paper, it is analysed the way that serge voltage is induced to electric car line by lightning strikes. By modeling the propagation process and the coupling phenomenon of electromagnetic wave produced by lightning strikes, it is achieved to make integrative circuit model combined with existing electric car model. The study is conducted into three different waveform of electromagnetic wave produced by lightning; rectangular wave, double exponential distribution wave, triangle wave. It is also simulated that the inducing serge is coupled to electric car line in an arbitrary location. The simulation results in that, when rapidly changing rectangular wave is supplied, maximum power is induced to electric car line.

• Journal of Information Processing Systems
• /
• 제14권1호
• /
• pp.140-149
• /
• 2018

Social data such as users' comments are unstructured in nature and up-to-date technologies for analyzing such data are constrained by the available storage space and processing time when fast storing and processing is required. On the other hand, it is even difficult in using a huge amount of dynamically generated social data to analyze the user features in a high speed. To solve this problem, we design and implement a topic association analysis system based on the latent Dirichlet allocation (LDA) model. The LDA does not require the training process and thus can analyze the social users' hourly interests on different topics in an easy way. The proposed system is constructed based on the Spark framework that is located on top of Hadoop cluster. It is advantageous of high-speed processing owing to that minimized access to hard disk is required and all the intermediately generated data are processed in the main memory. In the performance evaluation, it requires about 5 hours to analyze the topics for about 1 TB test social data (SNS comments). Moreover, through analyzing the association among topics, we can track the hourly change of social users' interests on different topics.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2022년도 추계학술대회
• /
• pp.20-20
• /
• 2022

Herein, we demonstrate that butein (1) can prevent swelling in a murine lymphedema model by suppressing tumor necrosis factor α (TNF-α) production. Butein derivatives were synthesized and evaluated to identify compounds with in vitro anti-inflammatory activity. Among them, 20 µM of compounds 7j, 7m, and 14a showed 50% suppression of TNF-α production in mouse peritoneal macrophages after lipopolysaccharide stimulation. Compound 14a, exhibited the strongest potency with an in vitro IC₅₀ of 14.6 µM and suppressed limb volume by 70% in a murine lymphedema model. The prodrug strategy enabled a six-fold increase in kinetic solubility of compound 1 and five-fold higher levels of active metabolite in the blood for compound 14a via oral administration in the pharmacokinetics study. We suggest that the compound 14a could be developed as a potential therapeutic agent targeting anti-inflammatory activity to alleviate lymphedema progression.

• Molecules and Cells
• /
• 제38권7호
• /
• pp.643-650
• /
• 2015

The use of conditioned medium from mesenchymal stem cells may be a feasible approach for regeneration of bone defects through secretion of various components of mesenchymal stem cells such as cytokines, chemokines, and growth factors. Mesenchymal stem cells secrete and accumulate multiple factors in conditioned medium under specific physiological conditions. In this study, we investigated whether the conditioned medium collected under hypoxic condition could effectively influence bone regeneration through enhanced migration and adhesion of endogenous mesenchymal stem cells. Cell migration and adhesion abilities were increased through overexpression of intercellular adhesion molecule-1 in hypoxic conditioned medium treated group. Intercellular adhesion molecule-1 was upregulated by microRNA-221 in mesenchymal stem cells because microRNAs are key regulators of various biological functions via gene expression. To investigate the effects in vivo, evaluation of bone regeneration by computed tomography and histological assays revealed that osteogenesis was enhanced in the hypoxic conditioned medium group relative to the other groups. These results suggest that behavioral changes of endogenous mesenchymal stem cells through microRNA-221 targeted-intercellular adhesion molecule-1 expression under hypoxic conditions may be a potential treatment for patients with bone defects.

• 문화기술의 융합
• /
• 제10권4호
• /
• pp.285-294
• /
• 2024

본 연구는 실용음악 교육프로그램을 활용하여 학습자의 창의·융합적 사고를 증진시켜 수월성 높은 작품 활동과 그를 통한 다학문의 융합을 목적으로 한다. 이를 위해 PDIE 모형을 적용한 실용음악 창의·융합 교육프로그램을 설계하였고, 개발된 프로그램의 내용 타당성을 검증하였다. 우리는 이 과정을 통해, 실용음악교육에서 활용 할 수 있는 다학문의 연구 방법에 관해 연구 기술하였는데, 본 논문에서는 4회차에 해당하는 실용음악과 수학의 창의·융합 교육에 관한 연구를 다루었다. 이 연구에서 관심 있게 주목한 수학적 이론은 피보나치수열로 예술의 황금 분활의 비의 근간이 되는 피보나치수열을 학습하고 이를 통하여 균형감 있고 수월성 높은 창작활동을 가능하게 함을 목적으로 한다. 또한 제시된 지도안을 비롯하여 15주차의 수업으로 진행된 본 수업지도안의 타당성 및 효과성을 검증하기 위하여 연구 대상 및 내용 검증에 참여한 연구 참가자들, 연구의 절차, 사용된 연구 도구, 다양한 자료의 수집 및 분석 방법을 구체적으로 정리하였다. 우리는 이를 통하여 실용음악 고등교육안에서의 창의·융합 교육의 가능성을 확인하고 후속 연구를 통하여 다양한 창의적 인재 양성을 위한 교육 방법론을 도모하였다.