• Reproductive and Developmental Biology
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• v.33 no.3
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• pp.163-169
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• 2009

Many biological systems are regulated by an intricate set of feedback loops that oscillate with a circadian rhythm of roughly 24 h. This circadian clock mediates an increase in body temperature, heart rate, blood pressure, and cortisol secretion early in the day. Recent studies have shown changes in the amplitude of the circadian clock in the hearts and livers of streptozotocin (STZ)-treated rats. It is therefore important to examine the relationships between circadian clock genes and growth factors and their effects on diabetic phenomena in animal models as well as in human patients. In this study, we sought to determine whether diurnal variation in organ development and the regulation of metabolism, including growth and development during the juvenile period in rats, exists as a mechanism for anticipating and responding to the environment. Also, we examined the relationship between changes in growth factor expression in the liver and clock-controlled protein synthesis and turnover, which are important in cellular growth. Specifically, we assessed the expression patterns of several clock genes, including Per1, Per2, Clock, Bmal1, Cry1 and Cry2 and growth factors such as insulin-like growth factor (IGF)-1 and -2 and transforming growth factor (TGF)-${\beta}1$ in rats with STZ-induced diabetes. Growth factor and clock gene expression in the liver at 1 week post-induction was clearly increased compared to the level in control rats. In contrast, the expression patterns of the genes were similar to those observed after 5 weeks in the STZ-treated rats. The increase in gene expression is likely a compensatory change in response to the obstruction of insulin function during the initial phase of induction. However, as the period of induction was extended, the expression of the compensatory genes decreased to the control level. This is likely the result of decreased insulin secretion due to the destruction of beta cells in the pancreas by STZ.

• Korean Journal of Ichthyology
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• v.31 no.3
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• pp.150-158
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• 2019

We examined the food habits of larval Acanthogobius flavimanus using 260 specimens collected from February to April 2011 in the Nakdong River estuary, Korea. We found that larval A. flavimanus are carnivorous, feeding mainly on copepods and tintinnids. Their diet also included small quantities of larval polychaetes, macrostomids, larval bivalves, rotifers, barnacles, diatoms and unidentified materials. To assess ontogenetic changes in diet composition, the larvae were separated into three developmental stages: preflexion (<7 mmNL), flexion (7~9 mmNL), and postflexion (>9 mmNL). The preflexion group frequently preyed on tintinnids. But as the larvae of A. flavimanus grew, the consumption of copepods for flexion group, and polychaetes for postflexion group, increased respectively. The larvae of A. flavimanus showed one peak for feeding incidence at dusk, but the mean number of preys per individual was high until midnight.

• The Journal of Korean Academy of Sensory Integration
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• v.18 no.3
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• pp.27-38
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• 2020

Objective : The purpose of this study is to apply interactive metronome (IM) training to a child with praxis problems who are attending elementary school and to measure the change in participants' timing following IM training. Methods : A total of 11 sessions were conducted using a single subject design. The participant was a boy aged 12 years and two months. During period A, the IM Long Form Assessment (LFA) and the Short Sensory Profile (SSP) were administered along with clinical observation. During period B, IM training was conducted. During all sessions, tasks 1 and 2 of the IM Short Form Assessment (SFA) were carried out, and changes in the participant's timing were recorded. Results : As a result of the initial assessment, the participant was suspected to have bilateral integration and sequencing deficits. In SFA tasks 1 and 2, the accuracy of the participant's timing increased during the B period compared to the A period. In addition, the trend line of SFA task 1 showed a negative slope during the B period but a positive slope during the A period. Conclusion : This study indicates that IM has a positive effect on the timing of children who have problems with praxis. This result provides a basis for applying IM training in clinical practice.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.240-245
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• 2011

Vegetation changes were studied for 16 yr in clearcut logged Pinus densiflora forests in the southern Gangwon-do province in Korea by applying chronosequence approach. Ambient temperature and relative humidity, Detrended Correspondence Analysis (DCA), Multiple Responses Permutation Procedure (MRPP), Indicator Species Analysis (ISPAN) were used to examine successional trajectory and compositional changes. After clearcutting, canopy openness was increased abruptly at three folds (1yr 68.3% and R1 23.0%) and then decreased, but relative moisture was slightly decreased (6%) compare to control site. In the result of DCA, right after clear cutting, vegetation composition was developed heterogeneously compared to control sites, and then approached to control sites within 16 years. Based on MRPP, species composition of each developmental stages (1yr, 3yr, 10yr and 16yr) revealed signigicant differences to that of control vegetation (R1, R3, R10 and R16). Indicator species in 1yr and 3yr samples included various woody species rather than herbaceous species, but in 10yr and 16yr, herbaceous were more abundant. Earlier succession of pine forests likely can explain to Initial Floristic Composition (IFC) Model.

• The Journal of Korean Philosophical History
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• no.32
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• pp.337-370
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• 2011

The academic circle of the Qing Dynasty has seen a new trend, mostly based on Han-Hak through the event of the publication of "Sagojeyo" and sought a new change in the sector of Spring Autumn-Hak as well. This study is focused on understanding and evaluation of the developmental process of especially the traditional Spring Autumn-Hak view, among some views of "Sagojeyo" by the book. "Sagojeyo" does a critical analysis of Gongyang-Hak and Gokryang-Hak and the interpretation of "Spring Autumn" made by Song-Hak scholars, and which seems a kind of preparatory step to build up a new research methodology for Spring Autumn-Hak. "Sagojeyo" emphasizes the importance of "Jwacijeon" and also points out its weaknesses and strongly demands the acceptance of strengths "Gongyangjeon" and "Gokryangjeon" have in order to compensate such demerits. Even further, it tries to evaluate Spring Autumn-Hak of the Song Dynasty objectively and reasonably as possible with no prejudice. Such analysis attitude made it possible for Spring Autumn-Hak to get a new turning point starting from the publication of "Sagojeyo". The new research methodology that comprehensively judges historical research and fidelity discourse could be one of important achievements discovered in the Han-Hak-centered academic circle in the early Qing Dynasty.

• Korean Journal of Cognitive Science
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• v.33 no.1
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• pp.23-50
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• 2022

Source memory is a cognitive process that combines the representation of the origin of the episodic experience with an item. By studying this daily process, researchers have made fundamental discoveries that make up the foundation of brain and behavior research, such as executive function and binding. In this paper, we review and conduct a bibliometric analysis on source memory papers published from 1989 to 2020. This review is based on keyword co-occurrence networks and author citation networks, providing an in-depth overview of the development of source memory research and future directions. This bibliometric analysis discovers a change in the research trends: while research prior to 2010 focused on individuality of source memory as a cognitive function, more recent papers focus more on the implication of source memory as it pertains to connectivity between disparate brain regions and to social neuroscience. Keyword network analysis shows that aging and executive function are continued topics of interest, although frameworks in which they are viewed have shifted to include developmental psychology and meta memory. The use of theories and models provided by source memory research seem essential for the future development of cognitive enhancement tools within and outside of the field of Psychology.

• Journal of Korea Entertainment Industry Association
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• v.15 no.4
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• pp.187-206
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• 2021

The purpose of this study is to analyze the compositions and characteristics in cultural programs of the 1988 Seoul Olympics and the 2018 PyeongChang Winter Olympic Games. A research method was considered the developmental aspects of Cultural Olympics in all-time Olympic Games and the cases of Cultural Olympics in a host country through a documentary research method. The compositions and characteristics in cultural programs of the 1988 Seoul Olympics and the 2018 PyeongChang Winter Olympic Games were diversely analyzed. The results are as follows. First, a concept of a cultural program was deepened and developed at the 1992 Barcelona Olympics. In the wake of the 2010 Vancouver Olympics, IOC published the Cultural Olympic Guide. Through the 2012 London Olympics, the Cultural Olympic Guide was revised. Second, the cultural programs of the 1988 Seoul Olympics and the 2018 PyeongChang Winter Olympic Games showed the characteristics of image change & status and of the international exchange strengthening in a host country and a holding city. Third, in terms of cultural programs, the 1988 Seoul Olympics comprised the celebrations, performances & exhibitions amid the Culture and Arts Festival, and the International Academic Conference. The 2018 PyeongChang Winter Olympic Games were composed of performances, exhibitions, festivals, humanities & experience, and educational events. Fourth, the 1988 Seoul Olympics included the key element of forming a program that equally has the characteristics with the harmony between tradition and modernity, with the promotion of the excellence in Korean traditional culture & the spread in a bond of sympathy, and with various cultures and arts in each region. Also, the 2018 PyeongChang Winter Olympic Games pushed ahead with the strategy dubbed 'The Olympics in which there is culture day after day, in which provincial residents participate, and in which the cultural heritage is left' in order to systematically expedite the cultural Olympics.

• Korean journal of applied entomology
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• v.60 no.2
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• pp.193-199
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• 2021

Solenopsis japonica, which is belonging to Formicidae in Hymenoptera, is a native ant species in Korea. However, it had not been studied for cold hardiness of S. japonica to understand on its overwintering mechanisms in field so far. Cold tolerance on developmental stages was measured at different cold temperature with various exposure times. Workers showed more survival at 5℃ and 10℃ compared with other stages and elevated cold tolerance when workers were exposed at 15℃ for more than 12h incubation as a rapid cold hardening (RCH) condition. RCH treatment not only increased survival of workers at cold temperatures, but also decreased supercooling point (SCP) and freezing point (FP). RCH group increased the survival rate by 44% at 10℃ compared with Non-RCH group. SCP and FP were depressed from -10.0 to -14.2℃ and from -11.3 to -15.3℃, respectively, after RCH treatment. Cold temperature increased expression level of cold- and stress-related genes such as glycerol kinase and heat shock protein. These results indicate unacclimated cold tolerance of S. japonica and its acclimation to low temperature by RCH.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.69-69
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• 2001

The cell cycle phase in which donor nuclei exist prior to nuclear transfer is an important factor governing developmental rates of reconstituted embryos. It was suggested that quiescent G0 and cycling G1 cells could support normal development of reconstituted embryos. In a quest of optimized donor nuclei treatment prior to nuclear transfer, this study was undertaken to examine the cell cycle characteristics of bovine fetal and adult somatic cells when cultured under a variety of culture treatments and the cell cycle change with the lapse of time after trypsinization. This was archived by measuring the DNA content of cells using flow cytometry, Cultured fetal fibroblast cells, adult skin and muscle cells, and cumulus cells were divided by 3 culture treatments; 1) grown to 60-70% confluency (cycling), 2) serum starved culture, 3) culture to confluency. Trypsinized cells were fixed by 70% ethanol and stained with propidium iodide. For one experiment, trypsinized cells were resuspended in DMEM＋10% FBS and incubated for 1.5, 3 and 6 h with occasional shaking before ethanol fixation. Cell cycle phases were determined by flow cytometry enabling calculation of percentages of G0＋G1, S and G2＋M. The majority of cells were in G0＋Gl stage regardless of origin of cells. Cultures that were serum starved or cultured to confluency contained significantly (P<0.05) higher percentages of cells in G0＋G1 (89.5-95.4%). For every cell lines and culture treatments, percentages of cells in existing in G0＋G1 increased with decreasing of the cell size from large to small. In the serum starved and confluency groups, about 98% of small cells were in G0＋G1 Serum starved culture contained higher percentages of small-sized cells (38.5-66.9%) than cycling and confluent cultures regardless of cell lines (P<0.05). After trypsinization of fetal fibroblast and adult skin cells that were serum starved and cultured to confluency, the percentages of cells in G0＋G1 significantly increased by incubation for 1.5(95.7-99.5%) and 3.0 h (95.9-98.6%). The results suggest that the efficient synchronization of bovine somatic cells in G0＋G1 for nuclear transfer can be established by incubation for a limited time period after trypsinization of serum starved or confluent cells.

• Development and Reproduction
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• v.12 no.3
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• pp.261-266
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• 2008

In the present study, we investigated in vivo effects of Manchurian trout recombinant gonadotrophin hormone (mt-rGTH) on the induction of maturation in female eel, Anguilla japonica. The brood stock, female eel (450$\pm$50 g) were weekly injected intramuscularly with different doses of 0.1, 1, 10 ${\mu}g\m{\ell}$/fish (mt-rFSH or mt-rLH) for 10 week. The effects of r-mtGTH were analyzed by gonadosomatic index (GSI), ovarian follicle diameter and sex steroid levels. All groups did not exhibit significant differences in the GSI values. Whereas plasma testosterone (T) and estradiol-17$\beta$ (E2) levels did not change significantly in control group, plasma levels of T and E2 by injection of the r-mtFSH or r-mtLH were increased at 2 or 4 week after injection. In addition, injection of the mt-rFSH (1, 10 ${\mu}g/m{\ell}$/fish) or mt-rLH (0.1, 1, 10 ${\mu}g/m{\ell}$/fish) significantly increased follicle diameters comparing to the control group. These results demonstrate that the recombinant hormone may affect early ovary development and maturation in female eel. Taken together, these results suggest that the recombinant Manchurian trout FSH and LH are effective for reproductive activities in female eel.