• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.134-134
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• 2017

Recently, host-induced gene silencing (HIGS) system has been successfully applied into development of resistant crops against insects, fungal and viral pathogens. To test HIGS-mediated resistance in rice against rice blast fungus, Magnaporthe oryzae, we first tested possibility of movement of small non-coding RNA from rice cells to rice blast fungus. The rice blast fungus expressing GFP transgene were inoculated to transgenic rice plants ectopically expressing dsRNAi construct targeting fungal GFP gene. Expression of dsRNAi construct for GFP gene in transgenic plants significantly suppressed GFP expression in infected fungal cells indicating that small RNAs generated in plant cells can move into infected fungal cells and efficiently suppress the expression of fungal GFP gene. Consistent with these results, expression of dsRNAi constructs against 3 fungal pathogenic genes of M. oryzae in transgenic rice specifically and efficiently suppressed not only the expression of fungal pathogenic genes, but also fungal infection. The conidia of M. oryzae applied on leaf sheath of transgenic rice expressing dsRNAs against 3 fungal pathogenic genes showed abnormal development of primary hyphae and malfunction of appressorium, which is consistent with the phenotypes of corresponding fungal knock-out mutants. Taken these results together, here, we suggest a novel strategy for development of antifungal crops by means of HIGS system.

• Journal of Plant Biotechnology
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• 제46권4호
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• pp.247-254
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• 2019

Flavonoids are widely distributed secondary metabolites in plants that have a variety biological functions, as well as beneficial biological and pharmacological activities. In barley (Hordeum vulgare L.), for example, high levels of saponarin accumulate during primary leaf development. However, the effect of saponarin biosynthetic pathway genes on the accumulation of saponarin in barley is poorly understood. Accordingly, the aim of the present study was to examine the saponarin contents and expression levels of saponarin biosynthetic pathway genes [chalcone synthase (CHS), chalcone isomerase (CHI), and UDP-Glc:isovitexin 7-O-glucosyltransferase (OGT)] during early seedling developmental and under several abiotic stress conditions. Interestingly, the upregulation of HvCHS, HvCHI, and HvOGT during early development was associated with saponarin accumulation during later stages. In addition, exposure to abiotic stress conditions (e.g., light/dark transition, drought, and low or high temperature) significantly affected the expression of HvCHS and HvCHI but failed to affect either HvOGT expression or saponarin accumulation. These findings suggested that the expression of HvOGT, which encodes an enzyme that catalyzes the final step of saponarin biosynthesis, is required for saponarin accumulation. Taken together, the results of the present study provide a basis for metabolic engineering in barley plants, especially in regards to enhancing the contents of useful secondary metabolites, such as saponarin.

• 한국산림과학회지
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• 제97권1호
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• pp.127-133
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• 2008

본 연구는 장뇌삼(Panax ginseng)의 효율적인 증식과 성공적인 토양 순화의 최적 조건을 구명하기 위해 수행되었다. 장뇌삼의 자엽을 시료로 사용하여 체세포배를 유도한 후, 유도된 체세포배를 발아시켜 얻은 자엽을 다시 시료로 사용하여 2차 체세포배를 유도함으로써 효율성을 증가시켰다. 2차 체세포배의 형성율은 MS 배지의 경우 약 53%이고, WPM 배지의 경우 약 48%인 것으로 나타나 1차 체세포 배의 형성율인 MS 배지와 WPM 배지의 각각 83%, 73%에 비해 약간 떨어지는 것으로 나타났다. 형성된 체세포배는 $GA_3$가 첨가된 WPM 배지에서 발아시키고, 무기염류의 양을 반감시키고, $GA_3$가 첨가된 WPM 배지에서 신장시킨 후, 무기염류를 줄인 SH 배지에서 대기 순화와 무당배양의 처리에 따른 줄기와 뿌리길이, 생존율 차이를 조사하였다. 기내에서 대기 순화와 무당배양 혼용처리 시 가장 정상적인 유식물체로 성장 시킬 수 있었고, 뿌리길이도 가장 길었으며, 생존율 또한 75%로써 가장 높은 생존율을 보였다.

• 대한간호학회지
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• 제22권2호
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• pp.238-247
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• 1992

Immigration of Koreans to the United States has increased since the 1960's. Adjusting to life in the United States produces a great deal of stress for immigrants. Despite better economic opportunites, many see the U.S. culture as threatening to their family and cultural values. Differences in culture, language, expectations and social behavior can lead to misunderstandings between health care providers and clients. These misunderstanding can leaf to frustration on the part of each. The ultimate result of this is that often Korean-immigrants do not get their health care needs met and stress response symptoms can lead to disease if there is no appropriate care. To determine the health care needs and concerns of Korean-Americans, a health needs assessment is needed. Appropriate and adequate information about the health care needs of these individuals is important as it relates to American policy changes allowing greater numbers of immigrants to enter the U.S. The purpose of this prospective study was to describe Korean-American stress response. This study focused on the primary presenting problems for which subjects reported having sought care. These included a variety of stress-related symptoms, including peripheral manifestations, cardiopulmonary symptoms, central-neurological symptoms, gastrointestinal symptoms, muscle tension, habitual patterns, depression, anxiety, emotional irritability and cognitive disorganization. Of the 300 subjects who entered the study, 80% (N＝223) completed the questionnaire in full. Demographically, the percentage of females and males was 50% each and they ranged in age from 20 to 69 years. Ninety percent of the subjects were highly educated, 25% owners of business, 25% white collar professionals, 15% employed in sales or as skilled /unskilled labor, 30% had no occupation : and 5% were housewives or students. The SOS inventory is designed to quantify self-perception of behavioral, cognitive, and physiological components of the stress response. It consisted of 94 items divided into 10 subscales. The result of this study are as follows : The total mean 505 of all subjects (N＝223 was .8129 ; the mean 505 for male(N＝114) was .7665 and for females, (N＝108) .8594. The level of symptoms for central-neurologic and muscle tension was higher for than for males. The highest stress response of all subjects was emotional irritability symptoms(1.0644) : the lowest stress response of all subjects was peripheral manifestation symptoms.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.449-451
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• 2007

In the commercially managed timber lands, the information such as height, age, stand density, canopy closure and leaf area index need to be collected periodically. Stand volume is the most fundamental information in the valuation of timber, however, stand age information is the primary element of forest inventory and these two are highly correlated. Conventional method of collecting stand age information by field surveys such as ring count method is accurate; however, it is expensive, labor-intensive and time consuming. In the present study it was aimed to collect stand age information using modem techniques in a commercially managed timberland situated in Tennessee, USA. The Landsat Thematic Mapper (TM), Enhanced Thematic Mapper (ETM+) of three different periods, Shuttle Radar Topography Mission (SRTM), National elevation dataset (NED) and field inventory data were used. Normalized difference vegetation index (NDVI) and Tasselled Cap (TC) transformation techniques were applied on the TM and ETM+ data. The regression analysis was carried out to identify the correlation between stand age and NDVI, TC. In the present study about 2,469 datasets were analyzed. The $R^{2}$ value for stand age estimation was 0.713. The NDVI, TC2 and TC3 were found to produce accurate timber age information.

• 한국공간정보시스템학회 논문지
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• 제7권3호
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• pp.55-65
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• 2005

본 논문은 이동체의 잦은 갱신에 의해 발생하는 색인 재구성에 대한 비용을 줄이기 위해 이동체의 지연 다량 삽입 기법을 제안한다. 기존 이동체 색인에 대한 연구는 주로 색인 구성 후에 발생하는 질의 처리 효율성에 초점을 두었다. 이들은 이동체 데이터의 갱신 연산에 의한 색인 재구성에 대한 디스크 접근 오버헤드를 거의 고려하지 않았다. 이러한 이동체 데이터의 갱신 연산에 대한 비용을 줄이기 위해 다량 삽입 기법과 여러 색인이 제안되었다. 하지만 제안된 기법들은 매우 가변적이고 대량인 데이터를 효율적으로 처리하는데 많은 디스크 I/O 비용을 필요로 한다. 본 논문에서는 빠른 데이터 생성 속도에 적합하도록 디스크 접근 오버헤드를 고려해서 R-트리를 관리할 수 있는 현재색인에 대한 다량 삽입 기법을 제안한다. 이 기법에서는 다차원 색인 구조에서의 다량 삽입 기법을 위한 버퍼링 기법을 사용한다. R-트리의 단말 노드 정보를 관리하는 보조 색인을 추가하여 노드의 분할과 합병을 예상한다. 또한 연산을 종류에 따라 분류하여 불필요한 삽입과 삭제 연산을 줄인다. 노드의 변환를 최소화하는 방향으로 이동 객체의 처리 순서를 정하여 데이터 갱신에 따른 노드의 분할과 합병을 최소화한다. 실험을 통해 제안한 기법을 이용한 다량 삽입 기법이 기존의 삽입 기법들보다 색인의 갱신 비용을 감소시키는 것을 알 수 있다.

• 생태와환경
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• 제46권3호
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• pp.319-331
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• 2013

Recent climate change, which is mostly ascribed to anthropogenic activities, is believed to be a major factor leading to biodiversity decreases and ecosystem service deteriorations. I have reviewed recent studies on climate change effects for many ecological processes involved with plants, in order to improve our understanding of the nature of ecological complexity. Plants in general have better growth and productivity under high levels of $CO_2$, although the long term effects of such $CO_2$ fertilizers are still controversial. Over the last 30 years, the Earth has been greening, particularly at higher latitudes of the Northern Hemisphere, perhaps due to a relaxation of climatic constraints. Human appropriation of net primary productivity (NPP), which corresponds up to 1/3 of global NPP, is ultimately responsible for climate change and biodiversity decreases. Climate change causes phenological variations in plants, especially in regards to spring flowering and fall leaf coloring. Many plants migrate polewards and towards higher altitudes to seek more appropriate climates. On the other hand, tree mortality and population declines have recently been reported in many continents. Landscape disturbance not only hinders the plant migration, but also makes it difficult to predict the plants' potential habitats. Plant and animal population declines, as well as local extinctions, are largely due to the disruption of species interactions through temporal mismatching. Temperature and $CO_2$ increase rates in Korea are higher than global means. The degree of landscape disturbances is also relatively high. Furthermore, long-term data on individual species responses and species interactions are lacking or quite limited in Korea. This review emphasizes the complex nature of species responses to climate change at both global and local scales. In order to keep pace with the direction and speed of climate change, it is urgently necessary to observe and analyze the patterns of phenology, migration, and trophic interactions of plants and animals in Korea's landscape.

• 한국식물병리학회지
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• 제14권5호
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• pp.408-412
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• 1998

In order to illustrate the role of conidia of Mycosphaerella nawae as a secondary inoculum in nature, pseudothecial development on persimmon leaves was investigated microscopically. The fungal ascospores have been believed as the primary or only inoculum source in nature, however, pseudothecia were readily formed on persimmon leaves infected naturally and artificially by conidia. The pseudothecia of M. nawae were found to form in the tissues of infected leaves while the leaves were still hanging on the trees. The size of pseudothecia were approximately 51.0~122.4$\times$51.0~112.2 ${\mu}{\textrm}{m}$ (82.8 $\times$72.5 ${\mu}{\textrm}{m}$in average), the shapes were spherical, ovoid or occidental pear type. The sizes of asci were approximately 30.6~61.2$\times$8.2~10.2 ${\mu}{\textrm}{m}$(46.6$\times$9.4 ${\mu}{\textrm}{m}$ in average) and the shapes were cylinder or banana. The ascospores were mostly spindle type, and the sizes were 10.2~12.2$\times$3.1~4.1 ${\mu}{\textrm}{m}$ (11.4$\times$3.2 ${\mu}{\textrm}{m}$ in average)-like. The pseudothecial formation was initiated before defoliation and morphological characteristics of the pseudothecia, ascus and ascospores on the infected leaves were fully illustrated in this study. Results indicated that conidia of M. nawae induce circular leaf spot of persimmon as much as ascospores, and might play an important role of the disease epidemics in nature.

• 농촌계획
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• 제16권4호
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• pp.109-116
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• 2010

Climate change is known to affect both natural and managed ecosystems, and will likely impact on the terrestrail carbon balance. This paper reports the effects of climate change on spatial-temporal changes in carbon reductions in South Korea's during 2000-2100. Future carbon (C) stock distributions are simulated for the same period using various spatial data sets including land cover, net primary production(NPP) and leaf area index (LAI) obtained from MODIS(Moderate Resolution Imaging Spectroradiometer), and climate data from Data Assimilation Office(DAO) and Korea Meteorological Administration(KMA). This study attempts to predict future NPP using multiple linear regression and to model dependence of soil respiration on soil temperature. Plants store large amounts of carbon during the growing periods. During 2030-2100, Carbon accumulation in vegetation was increased to $566{\sim}610gC/m^2$/year owing to climate change. On the other hand, soil respiration is a key ecosystem process that releases carbon from the soil in the form of carbon dioxide. The estimated soil respiration spatially ranged from $49gC/m^2$/year to $231gC/m^2$/year in the year of 2010, and correlating well with the reference value. This results include Spatial-Temporal C reduction variation caused by climate change. Therefore this results is more comprehensive than previous results. The uncertainty in this study is still large, but it can be reduced if a detailed map becomes available.

• 대한수학교육학회지:학교수학
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• 제9권1호
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• pp.45-64
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• 2007

본 연구는 초등학교 6학년 학생들의 그래프 이해 능력을 알아보기 위해, 자료 읽기, 자료 사이의 관계 찾기, 자료 해석하기, 상황 이해하기의 4가지 과제 유형을 설정하고 초등학교에서 학습하는 6가지의 그래프를 대상으로 검사 문항을 구성하였다. 이를 이용하여 서울 시내 초등학교 6학년 학생 187명을 대상으로 검사를 실시한 후, 과제유형별 반응과 그래프 종류별 반응을 분석하였다. 분석 결과 그래프를 보고 자료 읽기와 자료 사이의 관계 찾기 과제에서는 높은 이해도를 보였으나 자료 해석하기와 상황 이해하기에서는 상대적으로 낮은 이해도를 나타냈다. 또한 같은 수준의 과제 내에서도 그래프의 종류에 따라 상당히 다른 이해도를 보였다. 이를 통해 그래프 교수 학습 방향에 대한 시사점을 도출하였다.