• Molecules and Cells
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• v.38 no.1
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• pp.14-19
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• 2015

Eph receptors and their ligands, ephrins, represent the largest group of the receptor tyrosine kinase (RTK) family, and they mediate numerous developmental processes in a variety of organisms. Ephrins are membrane-bound proteins that are mainly divided into two classes: A class ephrins, which are linked to the membrane by a glycosylphosphatidylinositol (GPI) linkage, and B class ephrins, which are transmembrane ligands. Based on their domain structures and affinities for ligand binding, the Eph receptors are also divided into two groups. Trans-dimerization of Eph receptors with their membrane-tethered ligands regulates cell-cell interactions and initiates bidirectional signaling pathways. These pathways are intimately involved in regulating cytoskeleton dynamics, cell migration, and alterations in cellular dynamics and shapes. The EphBs and ephrinBs are specifically localized and modified to promote higher-order clustering and initiate of bidirectional signaling. In this review, we present an in-depth overview of the structure, mechanisms, cell signaling, and functions of EphB/ephrinB in cell adhesion and migration.

• BMB Reports
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• v.52 no.5
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• pp.304-311
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• 2019

The cytoplasmic FMR1-interacting protein family (CYFIP1 and CYFIP2) are evolutionarily conserved proteins originally identified as binding partners of the fragile X mental retardation protein (FMRP), a messenger RNA (mRNA)-binding protein whose loss causes the fragile X syndrome. Moreover, CYFIP is a key component of the heteropentameric WAVE regulatory complex (WRC), a critical regulator of neuronal actin dynamics. Therefore, CYFIP may play key roles in regulating both mRNA translation and actin polymerization, which are critically involved in proper neuronal development and function. Nevertheless, compared to CYFIP1, neuronal function and dysfunction of CYFIP2 remain largely unknown, possibly due to the relatively less well established association between CYFIP2 and brain disorders. Despite high amino acid sequence homology between CYFIP1 and CYFIP2, several in vitro and animal model studies have suggested that CYFIP2 has some unique neuronal functions distinct from those of CYFIP1. Furthermore, recent whole-exome sequencing studies identified de novo hot spot variants of CYFIP2 in patients with early infantile epileptic encephalopathy (EIEE), clearly implicating CYFIP2 dysfunction in neurological disorders. In this review, we highlight these recent investigations into the neuronal function and dysfunction of CYFIP2, and also discuss several key questions remaining about this intriguing neuronal protein.

• Molecules and Cells
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• v.27 no.6
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• pp.651-656
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• 2009

The formation of ${\beta}$-amyloid peptide ($A{\beta}$) is initiated from cleavage of amyloid precursor protein (APP) by a family of protease, ${\alpha}$-, ${\beta}$-, and ${\gamma}$-secretase. Sub W, a substrate peptide, consists of 10 amino acids, which are adjacent to the ${\beta}$-cleavage site of wild-type APP, and Sub M is Swedish mutant with double mutations on the left side of the ${\beta}$-cleavage site of APP. Sub W is a normal product of the metabolism of APP in the secretary pathway. Sub M is known to increase the efficiency of ${\beta}$-secretase activity, resulting in a more specific binding model compared to Sub W. Three-dimensional structures of Sub W and Sub M were studied by CD and NMR spectroscopy in water solution. On the basis of these structures, interaction models of ${\beta}$-secretase and substrate peptides were determined by molecular dynamics simulation. Four hydrogen bonds and one water-mediated interaction were formed in the docking models. In particular, the hydrogen bonding network of Sub M-BACE formed spread over the broad region of the active site of ${\beta}$-secretase (P5-P3'), and the side chain of P2- Asn formed a hydrogen bond specifically with the side chain of Arg235. These are more favorable to the cleavage of Sub M by ${\beta}$-secretase than Sub W. The two substrate peptides showed different tendency to bind to ${\beta}$-secretase and this information may useful for drug development to treat and prevent Alzheimer's disease.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.73-78
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• 1999

This paper presents an effective construction method of adaptive multiple control systems utilizing some knowledge upon the plants. The adaptive multiple control system operates plants un-der widely changing environmental conditions. The adaptive multiple control system is composed of a family of candidate controllers together with a supervisor. The system does not require any identification schemes of environmental conditions. Monitoring outputs of the plant, the supervisor switches from one candidate controller to another, The basic ideas of adaptation are as follows: (1)each candidate controller is prepared for each environmental condition in advance; (2)the supervise. applies a sequence of speculative controls to the plant with candidate controllers just after the start of control or just after the detection of a change in the environmental condition. Each candidate controller can keep the system stable during one-step period of the speculative control and the most appropriate candidate controller for the environmental condition to which the system is exposed can be selected before the last trial of speculative control step comes to an end. We proposed a construction method of adaptive multiple control system without any knowledge of plant dynamics and applied the method to a cart-pole balancing problem and a vehicle anti skid braking system. In real applications, as we can often easily obtain a piece of knowledge upon plant dynamics beforehand, we intend to extend the method such that multiple control systems can be efficiently designed using the knowledge. We apply the new idea to the cart-pole balancing problem with variable length of the pole. The simulation experiments lead us to the conclusion that the new attempt can reduce the manpower to design the candidate controllers for adaptive multiple control systems.

• Biomolecules & Therapeutics
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• v.32 no.3
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• pp.390-398
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• 2024

FoxO1, a member of the Forkhead transcription factor family subgroup O (FoxO), is expressed in a range of cell types and is crucial for various pathophysiological processes, such as apoptosis and inflammation. While FoxO1's roles in multiple diseases have been recognized, the target has remained largely unexplored due to the absence of cost-effective and efficient inhibitors. Therefore, there is a need for natural FoxO1 inhibitors with minimal adverse effects. In this study, docking, MMGBSA, and ADMET analyses were performed to identify natural compounds that exhibit strong binding affinity to FoxO1. The top candidates were then subjected to molecular dynamics (MD) simulations. A natural product library was screened for interaction with FoxO1 (PDB ID-3CO6) using the Glide module of the Schrödinger suite. In silico ADMET profiling was conducted using SwissADME and pkCSM web servers. Binding free energies of the selected compounds were assessed with the Prime-MMGBSA module, while the dynamics of the top hits were analyzed using the Desmond module of the Schrödinger suite. Several natural products demonstrated high docking scores with FoxO1, indicating their potential as FoxO1 inhibitors. Specifically, the docking scores of neochlorogenic acid and fraxin were both below -6.0. These compounds also exhibit favorable drug-like properties, and a 25 ns MD study revealed a stable interaction between fraxin and FoxO1. Our findings highlight the potential of various natural products, particularly fraxin, as effective FoxO1 inhibitors with strong binding affinity, dynamic stability, and suitable ADMET profiles.

• Korean Journal of Child Studies
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• v.33 no.6
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• pp.207-225
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• 2012

This study examined the meanings of reflective utterances fathers regarding their paternal role and the relationship of this to the process of a reflective parent education program for fathers whose children had been referred to psychotherapy. The subjects were 2 fathers aged in their late-thirties of 2 children with emotional behavioral problems. The father education program consisted of contents based on object relation theory. The reflective dialogues between fathers and the parent educator in the process of the program were analyzed. The meanings of the reflective utterances made by the fathers were indicated to be the understanding of the relationship between child's problematic behaviors and family dynamics, a reflection on their oppressive child rearing behaviors, the awareness of the necessity for emotional exchange with family members, the importance of cooperation between both the mother and father when it comes to child rearing, and the values at the heart of being together with children. The implications of the results were also discussed.

• Korean Journal of Human Ecology
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• v.3 no.2
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• pp.58-67
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• 2000

The purpose of this study was to investigate the level and the reasons of son preference. and the relative importance of related variables among middle-and old-aged Koreans in Chon-buk and Chung-nam area. Subjects were 487 parents of high school girls(243 fathers and 244 mothers). with a mean age of 45.7 years. It was revealed that more than a half of the respondents(52.293) preferred'a son'for the first child, followed by'either nx'(32.6%) and'a daughter'(14.8%). For the second child, a son was preferred nlost(43.7%) , followed by'a daughter'(31.4%) and'either sex'(23.4%) . As the reasons of son preference,'to continue tradition and name of family'marked the highest score (3.42) , followed by'parents prefer son for various reasons'(3.37) , 'should have at least one son'(3.32). and'feel obliged to produce a son for in-law's sake'(3.06). It appeared that sociocultural background was more important for son Preference than individual, economic factors. The most important factors related to a strong son preference were the number of sons at the present, son preference for the first child, parental attitudes and expectations toward children. and income. Suggestions wire made in regard to efforts for gender equality in family and society. and the needs for parent education and population education.

• Journal of the Korean Home Economics Association
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• v.30 no.3
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• pp.285-305
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• 1992

The purpose of this study was to describe the current status of dual-earner families in Seoul. The specific aims of this study were to examine the dynamics of marital relationship, parent-child relationship and old mother-daughter/daughter in law relationship in the same family. The sample consised of 265 dual-earner families was selected based on wives' jobs, primarily non-professional. The information was gathered from working couples and their school-aged children. The findings of this study were as follows: 1. Sex role attitude of husbands was more traditional than their wives. Therefore, housework sharing of husbands was very low and wives' perception of inequity was high. Wives' marital satisfaction was affected by the wives' perception of inequity, joint leisure activity, sexual satisfaction, and wives' job satisfaction. Husbands' marital satisfaction was affected by sexual satisfaction, perceived difficulties and problems of the husbands caused by wives' employment, and the degree of their housework participation. 2. The emotional uneasiness of children during mothers' absence was reported. The communication about mothers' job was helpful to gain children's understanding toward mothers' job. Mothers suffered from guilty feeling of neglecting their children in spite of their good performance of mothering role. 3. The employed daughters/daughters in law perceived high rewards and low cost in relationships with their mothers/mothers in law. The perceived quality of daughter-mother relationship was higher with low cost and high rewards than that of daughter in law/mother in law. Finally practical and policy implications were suggested.

• Weed & Turfgrass Science
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• v.4 no.2
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• pp.95-103
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• 2015

In this study, we surveyed the distribution pattern and dominance of weeds occurred in four summer crop fields, hot pepper, soybean, maize, and Chinese cabbage in Gyeongbuk province. The weeds were summarized as 32 family and 132 species in hot pepper field, 31 family and 116 species in soybean field, 37 family 134 species in maize field, finally 35 family and 170 species in Chinese cabbage field. Among these weeds occurred in the four summer crop fields, the compositae was commonly dominant family, it occupied 17.4% in hot pepper field, 18.1% in soybean field, 11.9% in maize field, and 16.5% in Chinese cabbage field. The major five families including compositatae, graminae, polygonaceae, convolvulaceae and cruciferae were occupied 43.2% in hot pepper field, 47.4% in soybean field, 42.5% in maize field, and 43.5% in Chinese cabbage field, respectively. Furthermore, the most dominant weed in the hot pepper, soybean, maize, and Chinese cabbage fields was Portulaca oleracea, Digitaria ciliaris, and Rorippa palustris, respectively. This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in food crop fields of Gyeongbuk province.

• Journal of the Korean Society of School Health
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• v.13 no.1
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• pp.85-96
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• 2000

This study was conducted to examine the effect of family environment on smoking behavior, smoking knowledge and smoking attitude in primary school students. For the purpose of the study, a questionnaire-based examination was made with 1,476 sixth-grade students in Taegu from November 1st to 30th, 1998. The results of the study are summarized as follows. Out of 22 points for smoking knowledge, the male student group got 12.9 points, and the female student group 13.0 points. For both groups, students with better school achievement showed a significantly higher score (p<0.01). For the female student group, those who had nonsmoking fathers showed a significantly higher score(p<0.05). A perfect score for smoking attitude was 20 points. The male student group received 14.9 points and the female student group 16.3. For both groups, the score appeared to be significantly higher in the students who had better school achievement and no smoking experience. For the female group, the score was higher if they were living with widowed mothers or had nonsmoking parents. The percentage of smoking experience was 22.0% for the male group and 4.7% for the female group. The present smoking percentage of both groups accounted for 0.3% and 0.1%, respectively. The percentage of the male group's smoking experience was significantly higher if school achievement was poor, if the mother has religious, and if her occupation belonged to significantly different category. For the female group, it was significantly higher if a mother's educational background was less than the primary school level, or if a mother smokes. Family adaptability and cohesion were not significant variables for both groups. The score for smoking knowledge according to family cohesion was highest if male and female members were in an enmeshed state. For the female group, the higher the family adaptability, the significantly higher the score for smoking knowledge. The score for smoking attitude according to family cohesion showed a significant difference for both groups. The family adaptability was not a significant variable for both groups. The results of multiple regression analysis, with the scores for smoking knowledge and smoking attitude were used as a dependent variable, revealed that, for both groups, the better the school achievement. For the female group, the higher the family cohesion, the significantly higher the score(p<0.01). For the male group, the score for smoking attitude was significant1y higher if school achievement was better, if students were living with a widowed mother or father, if they had drinking mothers, if family adaptability was low, if family cohesion was high, or if the score for smoking knowledge was high. For the female group, the score for smoking attitude was higher if school achievement was better. Also, if famale student had nonsmoking fathers, if the family adaptability was lower, on the higher the score for smoking knowledge, a smoking attitude scored higher. The results of a multiple logistic analysis, with smoking experience as a dependent variable, revealed that, for the male student group, the worse the school achievement, the higher the score for smoking knowledge, the lower the score for smoking attitude, or the lower the family adaptability, the higher the percentage of smoking experience. For the female student group, the higher the score for smoking knowledge or the lower the score for smoking attitude, the higher the percentage of smoking experience. In conclusion, family environment, including smoking of parents and family functions, had a great effect on smoking knowledge, smoking attitude and smoking experience of students, and it is required to adjust subjects and methods for smoking and nonsmoking education as smoking attitude and smoking behavior greatly differ according to sex.