• Korea journal of population studies
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• v.35 no.1
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• pp.181-209
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• 2012

Employment form and gender as stratification factors may generate health disparities in Korea. Previous studies have examined the existence of health disparities by employment form and gender. However, few studies examined how the health disparities can be reduced effectively. This study intends to confirm the existence of health disparities between employment-gender groups and explore the effective health resources which can reduce the possible disparities. Using a national probability sample of Korean adults collected in 2011, we attempts to test the interaction effects between employment-gender groups and health resources on self-rated health. For health resources, 24 variables of five dimensions(social relationship, psychological resource, activity factor, health behavior, and usage of medical service) are taken into account. In results, first, the health levels of the other three employment-gender groups are worse than that of male-regular workers. Second, the effective health resources which can reduce the health disparities are different across the employment-gender groups. An effective health resource for female-nonregular workers is a peaceful relationship with her children. Effective health resources for male-nonregular workers are peaceful relationships with his parents and siblings, low stress, religious activity, and exercise. An effective health resource for female-regular workers is interpersonal trust. These results imply that personal or social interventions for health of specific disadvantaged groups need to focus on specific resources which are more effective for the groups.

• Journal of Plant Biotechnology
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• v.35 no.1
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• pp.55-61
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• 2008

Previous studies on genetic transformation of chrysanthemum using cold regulated gene (BN115) have been conducted and the PCR and Real-Time PCR based method to determine the presence of the transferred cold regulated gene in the chrysanthemum was established. To check whether over-expression of BN115 gene in transgenic chrysanthemum will enhance their tolerance to cold stress, the transgenic chrysanthemum were grown under low temperature condition and several cold signalling including growth characteristics, stoma size and shape, SPAD value and ion leakage test were investigated. The transgenic chrysanthemum in the low temperature growth chamber grow much faster in term of the height, number and size of the leaves than those of wild-type plants and damage of transgenic plant caused by the low temperature was much less than that of wild-type plants. The stoma type and size of transgenic plant leaves grown at $5^{\circ}C$ were much similar to of wild-type plant cultured on $25^{\circ}C$ It has been found that SPAD value of transgenic plants was much higher than those of wild-type, but the EC density being lower under low temperature condition.

• Journal of Life Science
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• v.25 no.11
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• pp.1324-1330
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• 2015

The present study was performed to analyze and review the physical and immune responses to overtraining syndrome in humans. Overreaching refers to the initial phage of overtraining syndrome and has been known as a physical fatigue which is mainly from metabolic imbalance. It has been known that overtraining also results in a loss of adaptability which may lead to an attenuation of exercise performance, sleeping disorder, central fatigue, neurohormonal changes, difficulty recovery to physical stress, and immunological changes. Additionally, overtraining syndrome is characterized by persistent fatigue, poor performance in sport due to the prolonged and strenuous physical training. Also, previous studies reported that endurance athletes experienced a high incidence of URTI during intense training and the post training. And also, high-performance athletes reported that suppression of cell mediated and anti-body mediated immune function. NK cell numbers were also reduced in the period of overtraining syndrome. Major components of prevention and treatment for the overtraining syndrome are screening, education, and detraining. Furthermore, the combination of these prevention and treatment strategies will be much helpful. Therefore, the current review will be helpful for athletes and individuals who are at the risk of overtraining syndrome.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.133-137
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• 2011

Winterkill can be defined as any injury including freeze stress kill, winter desiccation, and low temperature disease to turfgrass plants that occurs during the winter period. The major damages from winterkill were low temperature kill, crown hydration, and winter desiccation. Low temperature kill is caused by air and soil temperature. Soil temperature affect more severe to turfgrass than air temperature because low soil temperature cause fetal damage to turfgrass crown. Crown hydration is a form of winter injury in which intercellular water within the plant freezes and causes physical injury to the cell membrane and wall. This is eventually resulted in dehydration of cell. Winter desiccation is the death of leaves or whole plants due to drought during the winter period. To reduce winterkill damage, cultivar selection is very important. If changing cultivar is not allowed, cold temperature hardiness needs to be increased by providing nutrients especially phosphorus and potassium in the late fall. Turf cover is effective way to reduce winterkill damage. Remaining snow is positive process to reduce winterkill damage by insulating soil temperature. The previous researches reported many materials as turf cover such as straw, polypropylene, polyester, and wood mat. Aeration and topdressing is one of the process against winterkill. Both methods are mainly conducted to reduce thickness of thatch layer. In recent, relatively new materials called black or winter topdressing sand are used to protect soil temperature from low air temperature and thaw ice crystal that may remain in soil.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.5
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• pp.463-474
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• 2009

Double symmetric patch repair of existing structures always causes membrane action only, however, in many cases this technique is not practical. On the other hand, the bending stiffness of the patch and the skin increases as tensile loading is increased and affects the bending deformation significantly in the case of single-sided patch repair. In this study, the p-convergent full layerwise model has been proposed to determine the stress concentration factor in the vicinity of a circular hole as well as across the thickness of plates with single-sided patch repair. In assumed displacement field, the strain-displacement relations and 3-D constitutive equations of a layer are obtained by the combination of 2-D and 3-D hierarchical shape functions. The transfinite mapping technique has been used to represent a circular boundary and Gauss-Lobatto numerical integration is implemented in order to directly obtain stresses occurred at the nodal points of each layer without other extrapolation techniques. The accuracy and simplicity of the present model are verified with comparison of the previous results in literatures using experiment and conventional 3-D finite element. Also, the bending effect has been investigated with various patch types like square, circular and annular shape.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.20-20
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• 2017

Plant genomes include heterochromatic loci that consist of repetitive sequences and transposable elements. LTR retrotransposon is the major class of transposons in advanced plants in terms of proportion in plant genome. The elements contribute not only to genome size but also to genome stability and gene expression. A number of cases have been reported transposon insertions near genic regions affect crop traits such as fruit pigments, stress tolerance, and yields. Functional LTR retrotransposons produce extrachromosomal DNA from genomic RNA by reverse transcription that takes place within virus-like-particles (VLPs). DECREASED DNA METHYLATION 1 (DDM1) plays important roles in maintaining DNA methylation of heterochromatin affecting all sequence contexts, CG, CHG, and CHH. Previous studies showed that ddm1 mutant exhibits massive transcription of retrotransposons in Arabidopsis, but only few of them were able to create new insertions into the genome. RNA-dependent RNA POLYMERASE 6 (RDR6) is known to function in restricting accumulation of transposon RNA by processing the transcripts into 21-22 nt epigenetically activated small interfering RNA (easiRNA). We purified VLPs and sequence cDNA to identify functional LTR retrotransposons in Arabidopsis ddm1 and ddm1rdr6 plants. Over 20 LTR copia and gypsy families were detected in ddm1 and ddm1rdr6 sequencing libraries and most of them were not reported for mobility. In ddm1rdr6, short fragments of ATHILA gypsy elements were detected. It suggests easiRNAs might regulate reverse transcription steps. The highest enriched element among transposon loci was previously characterized EVADE element. It has been reported that active EVADE element is more efficiently silenced through female germline than male germline. By genetic analyses, we found ddm1 and rdr6 mutation affect maternal silencing of active EVADE elements. DDM1-GFP protein accumulated in megaspore mother cell but was not found in mature egg cell. The fusion protein was also found in early embryo and maternal DDM1-GFP allele was more dominantly expressed in the embryo. We observed localization of DDM1-GFP in Arabidopsis and DDM1-YFP in maize and found the proteins accumulated in dividing zone of root tips. Currently we are looking at cell cycle dependency of DDM1 expression using maize system. Among 10 AGO proteins in Arabidopsis, AGO9 is specifically expressed in egg cell and shoot meristematic cells. In addition, mutation of AGO9 and RDR6 caused failure in maternal silencing, implying 21-22 nt easiRNA pathway is important for retrotransposon silencing in female gametophyte or/and early embryo. On the other hand, canonical 24 nt sRNA-directed DNA methylation (RdDM) pathways did not contribute to maternal silencing as confirmed by this study. Heat-activated LTR retrotransposon, ONSEN, was not silenced by DDM1 but the silencing mechanisms require RdDM pathways in somatic cells. We will propose distinct mechanisms of LTR retrotransposons in germline and somatic stages.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.97-97
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• 2017

Plant genomes include heterochromatic loci that consist of repetitive sequences and transposable elements. LTR retrotransposon is the major class of transposons in advanced plants in terms of proportion in plant genome. The elements contribute not only to genome size but also to genome stability and gene expression. A number of cases have been reported transposon insertions near genic regions affect crop traits such as fruit pigments, stress tolerance, and yields. Functional LTR retrotransposons produce extrachromosomal DNA from genomic RNA by reverse transcription that takes place within virus-like-particles (VLPs). DECREASED DNA METHYLATION 1 (DDM1) plays important roles in maintaining DNA methylation of heterochromatin affecting all sequence contexts, CG, CHG, and CHH. Previous studies showed that ddm1 mutant exhibits massive transcription of retrotransposons in Arabidopsis, but only few of them were able to create new insertions into the genome. RNA-dependent RNA POLYMERASE 6 (RDR6) is known to function in restricting accumulation of transposon RNA by processing the transcripts into 21-22 nt epigenetically activated small interfering RNA (easiRNA). We purified VLPs and sequence cDNA to identify functional LTR retrotransposons in Arabidopsis ddm1 and ddm1rdr6 plants. Over 20 LTR copia and gypsy families were detected in ddm1 and ddm1rdr6 sequencing libraries and most of them were not reported for mobility. In ddm1rdr6, short fragments of ATHILA gypsy elements were detected. It suggests easiRNAs might regulate reverse transcription steps. The highest enriched element among transposon loci was previously characterized EVADE element. It has been reported that active EVADE element is more efficiently silenced through female germline than male germline. By genetic analyses, we found ddm1 and rdr6 mutation affect maternal silencing of active EVADE elements. DDM1-GFP protein accumulated in megaspore mother cell but was not found in mature egg cell. The fusion protein was also found in early embryo and maternal DDM1-GFP allele was more dominantly expressed in the embryo. We observed localization of DDM1-GFP in Arabidopsis and DDM1-YFP in maize and found the proteins accumulated in dividing zone of root tips. Currently we are looking at cell cycle dependency of DDM1 expression using maize system. Among 10 AGO proteins in Arabidopsis, AGO9 is specifically expressed in egg cell and shoot meristematic cells. In addition, mutation of AGO9 and RDR6 caused failure in maternal silencing, implying 21-22 nt easiRNA pathway is important for retrotransposon silencing in female gametophyte or/and early embryo. On the other hand, canonical 24 nt sRNA-directed DNA methylation (RdDM) pathways did not contribute to maternal silencing as confirmed by this study. Heat-activated LTR retrotransposon, ONSEN, was not silenced by DDM1 but the silencing mechanisms require RdDM pathways in somatic cells. We will propose distinct mechanisms of LTR retrotransposons in germline and somatic stages.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.5
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• pp.471-478
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• 2010

Thin films play an important role in many technological applications including microelectronic devices, magnetic storage media, MEMS and surface coatings. It is well known that a thin film's material properties can be very different from the corresponding bulk properties and thus there has been a strong need for the development of a reliable test method to measure the mechanical properties of a thin film. We have developed an alternative and convenient test method to overcome the limitations of previous membrane deflection experiment and uniaxial tensile test by adopting a white light interferometer having sub-nanometer out-of-plane displacement resolution. The freestanding aluminium specimens are tested to verity the effectiveness of the test method developed and get the tensile properties. The specimens are 0.5 rum wide, $1{\mu}m$ thick and fabricated through MEMS processes including sputtering. 1 to 5 specimens are fabricated on Si dies. The membrane deflection experiments are carried out by using a homemade tester consisted of a motor-driven loading tip, a load cell, and 6 DOF alignment stages. The test system is compact enough to set it up beneath a commercial white light interferometric microscope. The white light fringes are utilized to align a specimen with the tester. The Young's modulus and yield point stress of the aluminium film are 62 GPa and 247 MPa, respectively.

• Journal of Korean Society of Steel Construction
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• v.22 no.2
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• pp.139-150
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• 2010

Reinforced-concrete (RC) columns are frequently designed and constructed. other types of columns includes composite types such as concrete-filled tube columns (CFT). Hollow RC columns may be effective in reducing both the self weight of columns and total amount of materials used. This is due to the fact that a hollow RC column possesses larger moment of inertia than that of solid RC columns of same cross sectional area. Despite the effectiveness the hollow RC column has not been popular because of its poor ductility performance. While the transverse reinforcements are effective in controlling the brittle failure of the outside concrete, they are not capable of resisting the failure of concrete of inner face which is in unconfined state of stress. To overcome these drawbacks, the internally confined hollow reinforced concrete (ICH RC), a new column type, was proposed in the previous researches. In this study, the fire resistance performance of the ICH RC columns was analyzed through a series of extensive heat transfer analyses using the nonlinear-material model program. Also, effect of factors such as the hollowness ratio, thickness of the concrete, and thickness of the internal tube on the fire resistance performance were extensively studied. Then the factors that enhance the fire-resistant performance of ICH RC were presented and analyzed.

• Child Health Nursing Research
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• v.7 no.4
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• pp.494-510
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• 2001

As a family respond to any stressful situation as a whole system, cancer diagnosis of a child, as a serious life event, could be emotional shock to destroy homeostasis of the family system. A family has a resilient capacity to adjust and adapt to stressful events. Previous studies have been focused on family stress and adaptation, but little attention has been given to family value as one of resilient factors. The data for model testing were collected from July 18, 2000 to August 30, 2000 and the analysis included 309 parents of children who are diagnosed as cancer, 18 or less years of age, and treated either hospitalized or at the outpatient clinics. The data analysis utilized SAS 6.12 and LISREL 8 for descriptive statistics, correlation, cluster analysis, factor analysis, and LISREL. The study findings are as follows. 1) Monthly income (γ=-0.28, t=-5.81) was the most important factor to explain family strain along with family support (γ=-0.11, t=-2.43), severity of children's illness (γ=0.26, t=5.22), and family stressor (γ=0.22, t=4.62). All of these factors together explained 40％ of variance in family strain. 2) Among general family value, the relationship with the parents (γ=0.28, t=4.89) and relationship with the children (γ=0.20, t=3.60) showed positive effects to family value for cancer children, while relationship with the spouse (γ=-0.19, t=-3.22) and the age of the cancer children (γ=-0.11, t=-2.21) showed negative effects. These predictors together explained 22％ of variance in family value for cancer children. 3) Family hardiness was explained mostly by family strain (γ=-0.53, t=-8.65) along with direct negative effects of family persistency and indirect negative effects of severity of children's illness, family stressor, relationship with the spouse, and the children's age. Family value for cancer children was the most important predictor with positive effect (γ=0.44, t=6.76) along with indirect effects of monthly income, relationship with the parents, relationship with the children, support from family and significant others, and confidence with the health professionals. 51％ of variance in family hardiness was explained by all of these predictors. 4) The most important predictor for family adaptation was family stressor (γ=-0.50, t=-6.85) with direct and indirect negative effects along with the severity of children's illness (γ=-0.27, t=-5.21). However, family value for cancer children showed compromised total effect (γ=-0.13, t=-1.99) with negative direct effects (γ=-0.28, t=-3.43) and positive indirect effects (γ=0.14, t=3.01). Similarly, confidence with the health professionals also showed compromised total effect (γ=0.09, t=1.99) with positive direct effects and negative indirect effects. Family hardiness showed the biggest positive direct effects while other factors such as monthly income, family stressor, family persistence, support of family and significant others, relationship with the parents, relationship with the children, and relationship with the spouse, and children's age showed indirect effects only. 39％ of variance in family adaptation was explained by all of these predictors.