• Development and Reproduction
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• v.22 no.2
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• pp.143-153
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• 2018

The large extracellular domain of glycoprotein hormone receptors is a unique feature within the G protein-coupled receptors (GPCRs) family. After interaction with the hormone, the receptor becomes coupled to Gs, which, in turn stimulates adenylyl cyclase and the production of cAMP. Potential phosphorylation sites exist in the C-terminal region of GPCRs. The experiments described herein represent attempts to determine the functions of the eel follicle-stimulating hormone receptor (eelFSHR). We constructed a mutant of eelFSHR, in which the C-terminal cytoplasmic tail was truncated at residue 614 (eelFSHR-t614). The eelFSHR-t614 lacked all potential phosphorylation sites present in the C-terminal region of eelFSHR. In order to obtain the eelFSHR ligand, we produced recombinant follicle-stimulating hormone ($rec-eelFSH{\beta}/{\alpha}$) in the CHO-suspension cells. The expression level was 2-3 times higher than that of the transient expression of eelFSH in attached CHO-K1 cells. The molecular weight of the $rec-eelFSH{\beta}/{\alpha}$ protein was identified to be approximately 34 kDa. The cells expressing eelFSHR-t614 showed an increase in agonist-induced cAMP responsiveness. The maximal cAMP responses of cells expressing eelFSHR-t614 were lower than those of cells expressing eelFSHR-wild type (eelFSHR-WT). The $EC_{50}$ following C-terminal deletion in CHO-K1 cells was approximately 60.4% of that of eelFSHR-WT. The maximal response in eelFSHR-t614 cells was also drastically lower than that of eelFSHR-WT. We also found similar results in PathHunter Parental cells expressing ${\beta}$-arrestin. Thus, these data provide evidence that the truncation of the C-terminal cytoplasmic tail phosphorylation sites in the eelFSHR greatly decreased cAMP responsiveness and maximal response in both CHO-K1 cells and Path-Hunter Parental cells expressing ${\beta}$-arrestin.

• Molecules and Cells
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• v.25 no.4
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• pp.559-565
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• 2008

Members of the TGA family of basic domain/leucine zipper transcription factors regulate defense genes through physical interaction with NON-EXPRESSOR OF PR1 (NPR1). Of the seven TGA family members, TGA4/octopine synthase (ocs)-element-binding factor 4 (OBF4) is the least understood. Here we present evidence for a novel function of OBF4 as a regulator of flowering. We identified CONSTANS (CO), a positive regulator of floral induction, as an OBF4-interacting protein, in a yeast two-hybrid library screen. OBF4 interacts with the B-box region of CO. The abundance of OBF4 mRNA cycles with a 24 h rhythm under both long-day (LD) and short-day (SD) conditions, with significantly higher levels during the night than during the day. Electrophoretic mobility shift assays revealed that OBF4 binds to the promoter of the FLOWERING LOCUS T (FT) gene, a direct target of CO. We also found that, like CO and FT, an OBF4:GUS construct was prominently expressed in the vascular tissues of leaf, indicating that OBF4 can regulate FT expression through the formation of a protein complex with CO. Taken together, our results suggest that OBF4 may act as a link between defense responses and flowering.

• Journal of Educational Research in Mathematics
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• v.9 no.1
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• pp.81-109
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• 1999

This study aims to reflect the basic principles and teaching-teaming principles of Realistic Mathematics Education in order to suppose an way in which mathematics as an activity is carried out in primary school. The development of what is known as RME started almost thirty years ago. It is founded by Freudenthal and his colleagues at the former IOWO. Freudenthal stressed the idea of matheamatics as a human activity. According to him, the key principles of RME are as follows: guided reinvention and progressive mathematisation, level theory, and didactical phenomenology. This means that children have guided opportunities to reinvent mathematics by doing it and so the focal point should not be on mathematics as a closed system but on the process of mathematisation. There are different levels in learning process. One should let children make the transition from one level to the next level in the progress of mathematisation in realistic contexts. Here, contexts means that domain of reality, which in some particular learning process is disclosed to the learner in order to be mathematised. And the word of 'realistic' is related not just with the real world, but is related to the emphasis that RME puts on offering the students problem situations which they can imagine. Under the background of these principles, RME supposes the following five instruction principles: phenomenological exploration, bridging by vertical instruments, pupils' own constructions and productions, interactivity, and interwining of learning strands. In order to reflect how to realize these principles in practice, the teaming process of algorithms is illustrated. In this process, children follow a learning route that takes its inspiration from the history of mathematics or from their own informal knowledge and strategies. Considering long division, the first levee is associated with real-life activities such as sharing sweets among children. Here, children use their own strategies to solve context problems. The second level is entered when the same sweet problems is presented and a model of the situation is created. Then it is focused on finding shortcomings. Finally, the schema of division becomes a subject of investigation. Comparing realistic mathematics education with constructivistic mathematics education, there interaction, reflective thinking, conflict situation are many similarities but there are alsodifferences. They share the characteristics such as mathematics as a human activity, active learner, etc. But in RME, it is focused on the delicate balance between the spontaneity of children and the authority of teachers, and the development of long-term loaming process which is structured but flexible. In this respect two forms of mathematics education are different. Here, we learn how to develop mathematics curriculum that respects the theory of children on reality and at the same time the theory of mathematics experts. In order to connect the informal mathematics of children and formal mathematics, we need more teachers as researchers and more researchers as observers who try to find the mathematical informal notions of children and anticipate routes of children's learning through thought-experiment continuously.

• Journal of Gifted/Talented Education
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• v.22 no.3
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• pp.639-662
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• 2012

The purpose of this study is to develop the evaluation model of gifted curriculum in visual art. For this purpose, first, it discusses about what kinds of issues raised about gifted education in visual art. Second, it critically reviews the evaluation models of gifted curriculum, and investigates the suitable model for developing curriculum evaluation model of gifted in visual art. Third, it suggests the appropriate perspective and evaluation model of gifted curriculum in visual art. Along with the change in the concept of creativity, recent studies on gifted education in visual art concentrate that gifted learners who have the potential find their own way of creating art. Also they emphasize the contextual implementation which recognizes the significance of interaction among field, domain and individual. Based of these inquiry, existing evaluation models of gifted curriculum have limitations in suitability as a evaluation model of gifted curriculum in visual art. This study suggests that the curriculum evaluation of visual art gifted programs should be approached from the decision-making perspective. Also it develops the conceptual framework and the evaluation model of gifted curriculum in visual art based on the CIPP model, which is the representative model of decision-making approach. It concludes with its implications and the discussion about the role of evaluators.

• Journal of the Korean Chemical Society
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• v.38 no.8
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• pp.547-551
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• 1994

A series of samples in the $Nd_{1-x}Ba_xFeO_{3-y}$ system has been prepared by heating the reactants to$1200^{\circ}C$ under an ambient atmosphere, and the solid solutions were identified by X-ray power diffraction analysis. The crystal systems of samples with x = 0.00 and 0.25 were found to be orthorhombic whose local symmetry is similiar to the distorted octahedral with orthoferrite type one, whereas those with x = 0.50 and 0.75 to be the cubic system. Since Fe ions in the solid solutions are a mixed valence state between $Fe^{3+}\;and\;Fe^{4+}$ ions, the nonstoichiometric chemical formulas could be determined from the mole ratio of $Fe^{4+}$ ion and oxygen vacacies. According to the Mossbauer spectroscopic analysis, the presence of 5-coordinated $FeO_5$ was evidenced only in the barium compounds along with $FeO_6,\;and\;FeO_4$, but not in the strontium and calcium compounds. The samples with x = 0.25 and 0.50 show a spectrum of superparamagnetism, which might be due to the formation of a domain of the ferromagnetic interaction between the $Fe^{3+}\;and\;Fe^{4+}$ ions. The electrical conductivities of all samples are within semiconducting range. Since the $Fe^{4+}$ ion acts as an electron acceptor level during the electron transfer between the Fe through intermediate $O^{2-}$ ions, the activation energy of the compounds decreases with the increment of $Fe^{4+}$ content.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.1
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• pp.9-18
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• 2016

The slender structures such as high rise building or marine riser are highly susceptible to dynamic force exerted by fluid-structure interactions among which vortex-induced vibration(VIV) is the main cause of dynamic unstability of the structural system. If VIV occurs in natural frequency regime of the structure, fatigue failure likely happens by so-called lock-in phenomenon. This study presents the numerical analysis of dynamic behavior of both structure and fluid in the lock-in regimes and investigates the subjacent phenomena to hold the resonance frequency in spite of the change of flow condition. Unsteady and laminar flow was considered for a two-dimensional circular cylinder which was assumed to move freely in 1 degree of freedom in the direction orthogonal to the uniform inflow. Fluid-structure interaction was implemented by solving both unsteady flow and dynamic motion of the structure sequentially in each time step where the fluid domain was remeshed considering the movement of the body. The results show reasonable agreements with previous studies and reveal characteristic features of the lock-in phenomena. Not only the lift force but also drag force are drastically increasing during the lock-in regime, the vertical displacement of the cylinder reaches up to 20% of the diameter of the cylinder. The correlation analysis between lift and vertical displacement clearly show the dramatic change of the phase difference from in-phase to out-of-phase when the cylinder experiences lock-in. From the results, it can be postulated that the change of phase difference and flow condition is responsible for the resonating behavior of the structure during lock-in.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.1
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• pp.9-14
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• 2003

Recent studies indicated that cancer cells become resistant to ionizing radiation (IR) and chemotherapy drugs by enhanced DNA repair of the lesions. Therefore, it is expected to increase the killing of cancer cells and reduce drug resistance by inhibiting DNA repair pathways that tumor cells rely on to escape chemotherapy. There are a number of key human DNA repair pathways which depend on multimeric polypeptide activities. For example, Ku heterodimer regulatory DNA binding subunits (Ku70/Ku80) on binding to double strand DNA breaks (DSBs) are able to interact with 470-kDa DNA-dependent protein kinase catalytic subunit (DNA-PKcs), and are essential for DNA-dependent protein kinase (DNA-PK) activity. It has been known that DNA-PK is an important factor for DNA repair and also is a sensor-transmitting damage signal to downstream targets, leading to cell cycles arrest. Our ultimate goal is to develop a treatment of breast tumors by targeting proteins involved in damage-signaling pathway and/or DNA repair. This would greatly facilitate tumor cell cytotoxic activity and programmed cell death through DNA damaging drug treatment. Therefore, we designed a domain of Ku80 mutants that binds to Ku70 but not DNA end binding activity and used the peptide in co-therapy strategy to see whether the targeted inhibition of DNA-PK activity sensitized breast cancer cells to irradiation or chemotherapy drug. We observed that the synthesized peptide (HNI-38) prevented DNA-PKcs from binding to Ku70/Ku80, thus resulting in inactivation of DNA-PK activity. Consequently, the peptide treated cells exhibited poor to no DNA repair, and became highly sensitive to IR or chemotherapy drugs, and the growth of breast cancer cells was inhibited. Additionally, the results obtained in the present study also support the physiological role of resistance of cancer cells to IR or chemotherapy.

• Journal of Korean Academy of Nursing
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• v.26 no.3
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• pp.531-543
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• 1996

This study was done to develop a Maternal Identity Scale for Pregnant Women and to test the validity and reliability of the scale. A convenience sample of 161 pregnant women were asked to complete the MISP questionnaire which consisted of 45 item, this was done from December 20, 1995 to January 15, 1996. The research procedure were as follows. The first step was to identify a conceptual definition of maternal identity using Robin(1984)'s maternal identity and maternal experience during pregnancy. The second step was to operationalize the maternal identity, that is, perception of image possible of selves as mother, maternal role play by imagination, and the experiences of various emotional responses which are embedded in the mother-fetus dyad. The third step was item development which resulted in 45 items as appropriate measurement of maternal identity are except for the perception of image possible of selves as mother. The result findings were as follows : 1) Four factors for MISP (finally 40 items) were extracted through the principal component analysis and varimax rotation, and these contributed 49.3% of the variance in the total score. All 40 items in the scale loaded above .43 on one of 4 factors. 2) Each factor was named : factor 1 was named maternal role imagery and has 10 items, factor 2 was named happiness and has 11 items, factor 3 was named maternal fetal interaction and has 10 items, and the last factor 4 was named negative emotion and has 9 items. 3) Cronbach's -alpha coefficient for internal consistsncy was .92 for the total 40 items and .89, .90, .86, .78 for the four subscales in that order. Recommendations are suggested below : 1) The developed MISP be used to assess maternal readiness in pregnancy. 2) Replication study be done to test validity and relaibility. 3) For the overall measure of Maternal Identity in Pregnancy, scale for the perception of image possible of selves as mother, and cognitive domain be reorganized for the maternal identity in pregnancy. 4) It is necessary to identify variables that influences maternal pregnancy. 5) It Is necessary to identify that maternal identity in pregnancy is a reliable index of motherhood, to do correlation studies on maternal identity and major maternal variables in maternal transition period, to reoperationalize the maternal identity in postpartum, and finally to designate a longitudinal study of the maternal identity changes or stabilities.

• Journal of The Korean Association For Science Education
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• v.18 no.4
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• pp.527-537
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• 1998

This article is a part of a research on the elementary science curriculum development to enhance creative problem-solving abilities. The components of the curriculum have been identified as 'scientific knowledge', 'process skills' & 'divergent/critical thinking'. Among these components, construction of the scientific knowledge that enables creative problem-solving abilities has been selected as an intensive research topic for the purpose of the present research. To avoid or to prevent the knowledge learned from separate facts and concepts, five themes have been selected so as to incorporate with all three areas of the elementary science curriculum, i.e., physical science, earth science and life science. The five themes are, 'structure', 'change', 'interaction', 'energy' and 'stability'. The contents of elementary science, which have been selected from the 3rd, 6th and 7th National Elementary Science curriculum, were reconstructed based on the five themes given above. The results of reconstruction are presented in the form of matrix, such that the vertical axis represents how the concepts are related within each domain of science, while the horizontal axis shows how the concepts are interconnected between domains of science. Therefore, based upon the five themes, individual or separate knowledge can be put into more unified knowledge so that contribution of knowledge transfer to new ones can be expected for leaners who will be creative in problem-solving. The process and products of the curriculum development as well as the background of the present research are described and discussed in detail.

• Journal of The Korean Association For Science Education
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• v.33 no.5
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• pp.1041-1054
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• 2013

Big ideas are overarching principles that help students to build a holistic understanding of domain-specific knowledge and assimilate individual facts and theories. This study aims to design a standard-based integrated science curriculum framework based on Big Ideas. The core contents were extracted by analysing the 2009 National Science Standards curriculum of primary and middle schools. Four Big Ideas, 'diversity,' 'structure,' 'interaction,' and 'change,' were generated after the process of examination and categorization of core contents. The scientific facts, disciplinary concepts, and interdisciplinary concepts of every scientific domains included in each Big Idea are represented as a knowledge pyramid. Essential questions guiding the direction of curriculum design were proposed on each Big idea. Based on the framework, teaching modules for 'structure' were developed for grades 5~6.