• Title/Summary/Keyword: Stress events

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Copper and Zinc Uptake Capacity of a Sorghum-Sudangrass Hybrid Selected for in situ Phytoremediation of Soils Polluted by Heavy Metals (식물정화를 위한 중금속 내성 작물의 선발과 수수-수단그라스 교잡종의 구리와 아연 흡수능력)

  • Oh, Soon-Ja;Koh, Seok-Chan
    • Journal of Environmental Science International
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    • v.24 no.11
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    • pp.1501-1511
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    • 2015
  • As essential trace elements, copper and zinc play important roles in many physiological events in plants. In excess, however, these elements can limit plant growth. This study selected a heavy metal-tolerant plant by analyzing seed germination and biomass of alfalfa (Medicago sativa), canola (Brassica campestris subsp. napus var. nippo-oleifera), Chinese corn (Setaria italica), and a sorghum-sudangrass hybrid (Sorghum bicolor ${\times}$ S. sudanense), and determined heavy metal uptake capacity by analyzing biomass, chlorophyll a fluorescence, and heavy metal contents under high external copper or zinc levels. The seed germination rate and biomass of the sorghum-sudangrass hybrid were higher under copper or zinc stress compared to the other three plants. The plant biomass and photosynthetic pigment contents of the sorghum-sudangrass hybrid seedlings were less vulnerable under low levels of heavy metals (${\leq}50ppm$ copper or ${\leq}400ppm$ zinc). The maximum quantum yield of PSII ($F_v/F_m$) and the maximum primary yield of PSII ($F_v/F_o$) decreased with increasing copper or zinc levels. Under high copper levels, the decline in $F_v/F_m$ was caused only by the decline in $F_m$, and was accompanied by an increase in non-photochemical quenching (NPQ). The $F_v/F_m$ declined under high levels of zinc due to both a decrease in the maximum fluorescence ($F_m$) and an increase in the initial fluorescence ($F_o$), and this was accompanied by a marked decrease in photochemical quenching (qP), but not by an increase in NPQ. Accumulations of copper and zinc were found in both aboveand below-ground parts of plants, but were greater in the below-ground parts. The uptake capacity of the sorghum-sudangrass hybrid for copper and zinc reached 4459.1 mg/kg under 400 ppm copper and 9028.5 mg/kg under 1600 ppm zinc. Our results indicate that the sorghum-sudangrass hybrid contributes to the in situ phytoremediation of copper or zinc polluted soils due to its high biomass yield.

Evaluation of MODIS NDVI for Drought Monitoring : Focused on Comparison of Drought Index (가뭄모니터링을 위한 MODIS NDVI의 활용성 평가: 가뭄지수와의 비교를 중심으로)

  • Park, Jung-Sool;Kim, Kyung-Tak
    • Spatial Information Research
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    • v.17 no.1
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    • pp.117-129
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    • 2009
  • South Korea has been undergoing spring drought periodically and diverse researches using vegetation index have been carried out to monitor spring droughts. The strength of the vegetation index-based drought monitoring is that the monitoring method enables efficient spatio-temporal grasp of changes in drought events. According to the development of low resolution satellite images such as MODIS, which are characterized by outstanding temporal resolution, the use of the method is expected to increase. Drought analysis using vegetation index considered only meteorological factor as a cause that affects vitality of vegetation. But many indirect and direct factors affect vegetation stress, So many uncertainties are involved in such method of analysis. To secure objectivity of drought analysis that uses vegetation index it is therefore necessary to compare the method with most representative drought analysis tools that are used for drought management. In this study, PDSI and SPI which a meteorological drought index that quantifies drought and that is used as a basic index for drought monitoring and MODIS NDVI are compared to propose correlation among them and to show usefulness of drought assessment that uses vegetation index. This study shows changing patterns of NDVI and SPI 6-month are similar and correlation between NDVI and SPI was highest in inland vegetation cover.

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Geometric and Kinematic Characteristics of Fracture System in the Sancheong Anorthosite Complex, Korea (산청 회장암복합체 내 발달하는 단열계의 기하학적·운동학적 특성)

  • Lee, Deok-Seon;Kang, Ji-Hoon
    • The Journal of the Petrological Society of Korea
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    • v.25 no.4
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    • pp.389-400
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    • 2016
  • The study area, which is located in the southeastern part of the Jirisan province of the Yeongnam massif, Korea, consists mainly of the Precambrian Sancheong anorthosite complex and the Jirisan metamorphic rock complex, the Mesozoic granitoids which intruded them. Several fracture sets with various geometric indicators, which determine their relative timing and shear sense, are well observed in the Sancheong anorthosite complex. The aim of this study is to determine the development sequence of extension fractures, the movement sense and development sequence of shear fractures in the Sancheong anorthosite complex on the basis of detailed analysis of their geometric indicators. This study suggests fracture system of the Sancheong anorthosite complex was formed at least through five different fracturing events, named as Dn to Post-Dn+3 phases. (1) Dn phase: extension fracturing event of NNW trend. The fracture set experienced the reactivations of dextral ${\rightarrow}$ sinistral shearing with the change of stress field afterward. (2) Dn+1 phase: extension fracturing event of (N)NE trend. The fracture set experienced the reactivations of sinistral ${\rightarrow}$ sinistral ${\rightarrow}$ dextral. (3) Dn+2 phase: extension fracturing event of NW trend. The fracture set experienced the activated of dextral shearing. (4) Dn+3 phase: extension fracturing event of N-S trend. (5) Post-Dn+3 phase: extension fracturing event of (E)NE trend. Dn deformation formed during the early Songnim orogeny. Dn+1 deformation formed during the late Songnim orogeny. Dn+2 deformation formed during the Daebo orogeny. Dn+3 deformation formed during the Bulguksa orogeny.

Changes of soil water content and soybean (Glycine max L.) response to groundwater levels using lysimeter

  • Lee, Sanghun;Jung, Ki-Yuol;Chun, Hyen-Chung;Choi, Young-Dae;Kang, Hang-Won
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.299-299
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    • 2017
  • Due to the climate changes in Korea, the numbers of both torrential rain events and drought periods have increased in frequency. Water management practice against water shortage and flooding is one of the key interesting for field crop cultivation, and groundwater often serves as an important and safe source of water to crops. Therefore, the objective of this study is to evaluate the effect of groundwater table levels on soil water content and soybean development under two different textured soils. The experiment was conducted using lysimeter located in Miryang, Korea. Two types of soils (sandy-loam and silty-loam) were used with three groundwater table levels (0.2, 0.4, 0.6m). Mean soil water content during the soybean growth period was significantly influenced by groundwater table levels. With the continuous groundwater level at 0.2m from the soil surface, soil water content was not statistically changed between vegetative and reproductive stage, but the 0.4 and 0.6m groundwater table level was significantly decreased. Lower chlorophyll content in soybean leaves was found in shallow water table treatment in earlier part of the growing season, but the chlorophyll contents were non-significant among water table treatments. Groundwater table level treatments were significantly influenced on plant available nitrogen content in surface soil. The highest N contents were observed in 0.6m groundwater table level. It is probably due to the nitrogen loss by denitrification as the result of high soil water content. The length and dry weight of primary root was influenced by groundwater level and thus the highest length and dry weight of root were observed in 0.6m water table level. This result showed that soybean root growth did not extend below the groundwater level and increased with the depth of groundwater table level. The results of this study show that the management of groundwater level can influence on soil characteristics, especially on soil water content, and it is an important practice of to reduce yield loss caused by the water stress during the crop growing season.

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Self-Sensing of Single Carbon Fiber/Carbon Nanotube-Epoxy Composites Using Electro-Micromechanical Techniques and Acoustic Emission (전기적-미세역학시험법과 음향방출을 이용한 단일 탄소섬유/탄소나노튜브-에폭시 나노복합재료의 자체-감지능)

  • Park, Joung-Man;Jang, Jung-Hoon;Wang, Zuo-Jia;Kwon, Dong-Jun;Park, Jong-Kyu;Lee, Woo-Il
    • Journal of the Korean Society for Nondestructive Testing
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    • v.30 no.5
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    • pp.411-422
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    • 2010
  • Self-sensing on micro-failure, dispersion degree and relating properties, of carbon nanotube(CNT)/epoxy composites, were investigated using wettability, electro-micromechanical technique with acoustic emission(AE). Specimens were prepared from neat epoxy as well as composites with untreated and acid-treated CNT. Degree of dispersion was evaluated comparatively by measuring volumetric electrical resistivity and its standard deviation. Apparent modulus containing the stress transfer was higher for acid-treated CNT composite than for the untreated case. Applied cyclic loading responded well for a single carbon fiber/CNT-epoxy composite by the change in contact resistivity. The interfacial shear strength between a single carbon fiber and CNT-epoxy, determined in a fiber pullout test, was lower than that between a single carbon fiber and neat epoxy. Regarding on micro-damage sensing using electrical resistivity measurement with AE, the stepwise increment in electrical resistivity was observed for a single carbon fiber/CNT -epoxy composite. On the other hand, electrical resistivity increased infinitely right after the first carbon fiber breaks for a single carbon fiber/neat epoxy composite. The occurrence of AE events of added CNT composites was much higher than the neat epoxy case, due to micro failure at the interfaces by added CNTs.

Effects of Family Value on Family Adaptation in Family Who has a Child with Cancer (가족 가치관이 암환아 가족의 적응에 미치는 영향)

  • Park In-Sook;Tak Young-Ran;Lee Jung-Aee
    • 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.

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Fracture Analysis of Implant Components using Scanning Electron Microscope : Part II - Implant Retaining Screw (임플란트 구성요소의 파절면에 관한 주사전자현미경적 연구 : Part II - 임플란트 유지나사)

  • Lim, Kwang-Gil;Kim, Dae-Gon;Cho, Lee-Ra;Park, Chan-Jin
    • Journal of Dental Rehabilitation and Applied Science
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    • v.26 no.4
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    • pp.373-388
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    • 2010
  • Fracture causes serious problems in many instance of prosthetic failures. But it is hard to find the definite causes when fractures occur. Fractography encompasses the examination of fracture surfaces that contain features resulting from the interaction of the advancing crack with the microstructure of the material and the stress fields. All fractured specimens(implant retaining screw) retrieved from Gangneung-Wonju national university dental hospital for 3 years(from 2007 to 2009). After pretreatment of samples, the scanning electon microscope were used for surface examination and fracture analysis. In case of most of the fractured specimens, fracture took place by fatigue fracture and fractured surface represents fatigue striation. Fatigue striation indicate the progression of the crack front under cyclic loading, are characteristic of stage 2 crack growth. The site of crack initiation and stage 1 crack growth were not easily identified in any of the failure, presumably because of the complex microstructural features of the polycrystalline sample. In case of fractured by overload, dimpled or cleavage surface were observed. Using the interpretation of characteristic markings(ratchet mark, fatigue striation, dimple, cleavage et al) in fracture surfaces, failure events containing the crack origin, crack propagation, material deficiency could be understand. Using the interpretation of characteristic markings in fracture surfaces, cause and mechanism of fractures could be analyzed.

A Study on Urinary Incontinence of Elderly Women in a Community (노인여성의 요실금 실태)

  • Park, Ok-Hee;Kwon, In-Soo;Kang, Young-Sil
    • Women's Health Nursing
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    • v.7 no.4
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    • pp.536-546
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    • 2001
  • The purposes of this descriptive study were to identify the prevalence rate of urinary incontinence(UI) and the differences in frequency of incontinent and normal women by general characteristics, obstetrical history, and the conditional events for urinary incontinence of the elderly women in a community. By the results of this study, it is intended to provide nursing practice guidelines for incontinent women. The research design of this study was a preliminary descriptive study. The 173 subjects were 55 years old and over, and resided in a small city area. Data were collected from June 20 to July 20, 2001, by an interview or a self-report with questionaire. The questionaire was composed of items of general characteristics, obstetrical characteristics, and conditions of UI by the modified Henderickon's Stress Incontinence Scale(1981). The results were summariezed as follows: 1. The UI prevalence rate of the sample was 64.2%. Of the incontinent women, 31.5% had experienced UI for a period of three to five years, and 84.7% had never treated or managed their UI. Frequency of UI was once or twice times per month(46.8%). 2. The total mean of UI on the scale in the incontinent women was 25.50 of 85, ranging from 18 to 41. 3. The most frequent condition of UI was coughing, followed by laughing, sneezing, heavy exercise, and preparation of urination in descending order. 4. There were significant differences in age, education, social activity, and urinary difficulty between the incontinent women and the normal women. 5. There were significant differences in frequency of spontaneous abortion, age of menopause between the incontinent women and the normal women. 6. There were no significant differences in number of delivery, frequency of artificial abortion, age of the last delivery, and postal health management between the incontinent women and the normal women. In conclusion, the incidence of UI in this study was high, but there were no effective treatments or management. It is suggested to provide the adult women with knowledge about UI, and to educate preventive behavior and control skill of urinary incontinence. Also episodes of urinary incontinence were high in the situation of sudden increase of abdominal pressure. This data can be used for the prevention strategy of urinary incontinence, In future research it is recommended to identify comprehensive factors related to urinary incontinence including psychosocial factors, and effective strategies of urinary incontinence.

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The Autophagic Response to Exercise Training of the Skeletal Muscle Fibers in Young and Old Mice (노화에 따른 골격근에서 운동훈련에 의한 자식작용 반응)

  • Kim, Yong-An;Kim, Young-Sang
    • Journal of Life Science
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    • v.21 no.3
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    • pp.400-405
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    • 2011
  • Autophagy, a highly conserved mechanism of internal quality control, is essential for the maintenance of cellular homeostasis and for the orchestration of an efficient cellular response to stress. During aging, the efficiency of autophagic degradation declines and intracellular waste products accumulate. Therefore, the aim of this study is to investigate the effects of exercise on autophagic response in skeletal muscle. Twenty-four Young (4 month) and Old (12 month) ICR-type white male mice were divided into a control group (CON: n=6) and exercise training group (Tr: n=6) after an adaptation period of 1 week. Exercise consisted of treadmill running at 16.4 m/min with a 4% incline, 40 min/day and 5 days/week for 8 weeks. Cervical dislocation was performed at 48 hours after the last round of exercise, after which the gastrocnemius skeletal muscle were immediately collected. The results of verifying autophagy formation showed that the Sarcopenia index was decreased in the Old mice compared to the Young. However, it increased with exercise training in the Old. Lipidation LC3-II, Becline-1, and Atg7 were decreased in the Old mice compared to the Young. However, Lipidation LC3-II was significantly increased in the trained Old mice (Young:1 Vs Old:$1.32{\pm}0.042$, p<0.05). Based on these data, we suggest that autophagy regulatory events are the attenuated in Old mice, but that they are enhanced with exercise training.

A Study of Developing Collaboration Between Teacher Librarians and Parents to Increase Students' Ego-Resilience (학생의 자아 탄력성 신장을 위한 사서교사와 학부모의 협력 관계 활성화 방안에 대한 연구)

  • Song, Gi-Ho
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.23 no.2
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    • pp.69-86
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    • 2012
  • Collaboration between teacher librarians and parents is one of the very important elements for school library management in characteristics of learning communities and expanding its' administration. These partnerships are necessary to relieve stress and risk conditions and improve ego-resilience of students. This study analyzed cases of student guidance within the partnerships between teacher librarians and parents and then inquired into formal or informal communication channels for their partnerships through written interview with 10 teacher librarians. The results of analyses teacher librarians have appreciated the necessity of collaboration with parents, and they have experienced student guidance, career guidance, reader's advisory and balancing acts between classroom teachers and parents. It turns out that reading programs with parents are formal communication channel rather than institutional committee such as School Library Council and Parents' Library-Assisting Volunteers and Parent Association and Training in the school library are informal communication channels. The teacher librarians also provide periodic reading events and training for parents and they utilize the School Homepage and Educational Newsletters as the main ways of public relation. In order to promote students' ego-resilience through their collaboration, parents should involve in School Library Council as an essential way for formal communication. And parents' role in school library management should be expanded from offering helping hands to activities to read book, library instruction, assisting teacher librarians in the Library-Assisted Instruction and production of teaching mediums.