• 제목/요약/키워드: Alternation

검색결과 386건 처리시간 0.022초

Movement of Rhizobia Inside Tobacco and Lifestyle Alternation from Endophytes to Free-Living Rhizobia on Leaves

  • Ji, Kui-Xian;Chi, Feng;Yang, Ming-Feng;Shen, Shi-Hua;Jing, Yu-Xiang;Dazzo, Frank B.;Cheng, Hai-Ping
    • Journal of Microbiology and Biotechnology
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    • 제20권2호
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    • pp.238-244
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    • 2010
  • Rhizobia are well-known for their ability to infect and nodulate legume roots, forming a nitrogen-fixing symbiosis of agricultural importance. In addition, recent studies have shown that rhizobia can colonize roots and aerial plant tissues of rice as a model plant of the Graminaceae family. Here we show that rhizobia can invade tobacco, a model plant belonging to the Solanaceae family. Inoculation of seedling. roots with five GFP-tagged rhizobial species followed by microscopy and viable plating analyses indicated their colonization of the surface and interior of the whole vegetative plant. Blockage of ascending epiphytic migration by coating the hypocotyls with Vaseline showed that the endophytic rhizobia can exit the leaf interior through stomata and colonize the external phyllosphere habitat. These studies indicate rhizobia can colonize both below- and above-ground tissues of tobacco using a dynamic invasion process that involves both epiphytic and endophytic lifestyles.

LVDS를 이용한 daisy-chain 방식의 다중 LCD 시스템 개발 (Multiple LCD System Development of daisy-chain Method using LVDS)

  • 김재철
    • 한국정보통신학회논문지
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    • 제16권12호
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    • pp.2747-2754
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    • 2012
  • 본 논문에서 PC 컨텐츠의 활용을 극대화시키는 부가기능을 갖는 다중 LCD(Liquid Crystal Display) 시스템을 개발하였다. 이는 host LCD와 slave LCD로 구성되어 있다. Host LCD는 NTSC(National Television System Committee), PAL(Phase Alternation Line), SECAM(S$\acute{e}$quentiel couleur avec m$\acute{e}$moire) 신호를 받아 영상 및 음성을 데코딩하여 출력한다. 이 데코딩된 신호들을 LVDS(Low Voltage Differential Signaling) 신호로 변환하여 slave LCD단으로 전송을 하는 기능을 갖는다. 그리고 CF 메모리, USB 메모리등을 장착하여 멀티미디어 데이터를 출력하도록 한다. Slave LCD는 host LCD와 달리 튜너부분이 없고 메모리 장착이 되지 않아 자체 TV 신호 수신 및 영상 신호 재생을 하지 못한다. 다만, LVDS 영상 신호를 받아 LCD 팬널에 출력하는 기능만 갖도록 한다. 본 논문에서 개발한 다중 LCD 시스템은 제품이 단순하여 상대적으로 고장률이 낮고, 가격이 저렴하고 제어부분의 간소화로 디스플레이의 전력이 낮으며, host LCD의 채널, 볼륨 및 영상 출력에 대하여 전체 slave LCD를 제어할 수 있는 제품으로서의 가격 및 기능 경쟁력을 갖추고 있다.

Effects of Mancozeb on the Activities of Murine Peritoneal Macrophages In Vitro and Ex Vivo

  • Chung Ae-Hee;Pyo Myoung-Yun
    • Archives of Pharmacal Research
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    • 제28권1호
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    • pp.100-105
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    • 2005
  • Mancozeb (MCZ) is known to have detrimental effects on the reproductive system, but the toxicity of MCZ on immune responses has not been systematically investigated. We investigated the effects of MCZ exposure on the activities of murine peritoneal macrophages through evaluation of MCZ-induced alteration of nitric oxide (NO) production and tumor necrosis $factor-{\alpha}(TNF-\alpha)$ synthesis. Macrophages were examined ex vivo from mice orally treated with various doses of MCZ for 5 consecutive days per week for 4 weeks (subacute exposure, 250, 1000, 1500 mg/kg/day) followed by culture for 2 $(TNF-{\alpha})$ or 3 days (NO) in the presence of LPS plus $IFN-{\gamma}$. Macrophages from naive mice were also cultured with various concentrations of MCZ (0.05, 0.25, 0.5, 1 and 2 ${\mu}g//mIL$ in the presence of LPS plus $IFN-{\gamma}$ for 2 $(TNF-{\alpha})$ or 3 days (NO) in vitro. NO production was decreased with the in vitro exposure to all concentrations of MCZ. However, the amount of NO production by peritoneal macrophages from MCZ-subacutely exposed mice was increased in comparision with that of control group. In vitro, MCZ suppressed $(TNF-\alpha)$ secretion with significant reduction at 2 ${\mu}g/mL$ MCZ. Conversely, $(TNF-{\alpha})$ release was enhanced ex vivo. This study provides the substantial evidence on MCZ-induced alternation in macrophage activity. In order to clearly understand the contrasting effect of MCZ on peritoneal macrophage activity, it is necessary to further investigate the influence of major metabolite of MCZ (ETU) exposure on the NO production and $(TNF-{\alpha})$ synthesis.

퇴적암에서 수분값과 화학적 풍화지수(CIA) 간의 상관관계 (Correlation between Water Values and Chemical Index of Alteration (CIA) in Rocks)

  • 박경근;신재열
    • 대한지리학회지
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    • 제50권5호
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    • pp.505-514
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    • 2015
  • 본 연구는 경상북도 구미시 천생산 지역의 조립질 퇴적암을 대상으로 수분값과 풍화지수를 측정하여 상관관계를 분석하고 있다. 암석시료 20개를 대상으로 함수율과 흡수율, 수분측정기를 이용한 계측값 등 다양한 수분값을 구하였으며, 이를 XRF 분석을 통해 얻은 화학적 풍화지수(CIA)와 비교분석함으로써 각각의 상관성을 검토하였다. 분석 결과, 퇴적암의 경우 역의 함유량이 많거나 치밀도가 낮은 암석일수록 함수율과 흡수율은 높게 나타나며 흡수율이 증가할수록 $SiO_2$$Al_2O_3$는 증가하는 경향을 보이는 반면 CaO와 $Na_2O$는 장석류의 풍화로 인해 감소하는 경향이 확인된다. 이는 흡수율이 증가함에 따라 화학적 풍화지수도 함께 증가하는 사실을 보여주는 것으로 화강암을 대상으로 한 기존의 연구들과 유사한 결과를 보여주고 있다.

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사천시 다평리 해안에서 발달한 풍화혈에 관한 연구 (The Study on Weathering Hollows Developed on the Coast of Dapyeong-ri, Sacheon-si)

  • 탁한명
    • 대한지리학회지
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    • 제50권5호
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    • pp.459-472
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    • 2015
  • 다양한 암석에서 발달하는 풍화혈은 기반암의 암석학적 특징과 형성과정에 대해 활발하게 논의되고 있는 지형이다. 사천시 다평리 해안은 이암과 사암의 호층이 분포하는 곳으로 사암이 노출된 지역의 쇼어플랫폼과 해식애에서 다양한 풍화혈이 발달하였다. 절리의 발달, 광맥의 관입, 암석의 물리 화학적 특성에 따른 풍화혈의 발달 특성과 분포의 공간적 한계를 분석하기 위해 지형조사, XRD분석, 편광현미경 관찰을 수행하였다. 조사 및 분석결과 이곳은 타포니와 나마가 동일한 지역에 분포하는 지역적 특성을 보이며, 절리의 확대, 성장에 의해 기존 풍화혈이 파괴되고 새로운 타포니가 형성되고 있다. 석영맥으로 밝혀진 광맥은 절리와 결합하여 풍화혈의 발달을 가속화시키기도 하지만, 풍화혈의 성장방향에 수직으로 관입한 광맥은 성장을 방해하기도 한다. 일반적으로 풍화혈은 암석의 종류에 관계없이 발달하는 것으로 알려져 있으나, 암석학적 특성을 분석한 결과 이암과 같이 쪼개짐과 깨짐이 발달한 미립질의 암석에서는 풍화혈의 성장이 제한된다.

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교각의 기하학적 형상에 따른 유사 및 유속의 변화 특성 (Study on the Sediment and Velocity Characteristics around Bridge Based on Shape of the Piers)

  • 안승섭;이효정;서명준;이증석
    • 한국환경과학회지
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    • 제18권2호
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    • pp.221-230
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    • 2009
  • In this study, a river basin with a lot of measured data such as water level, flow rate, current speed, and sediment rate from the past to now was selected and geometrical shape of a pier was re-analyzed, in order to study the effects of the flow around the pier area as well as the riverbed alternation characteristics. A finite element mesh of the entire river was prepared, and via parameter revision, the section that the pier has influence on was decided, to analyze the shape of the pier using RMA-2 and SED2D-WES models. With regards to the section that the pier has influence on, analysis was done on the four pier shapes, namely circle, square, rectangle, and octagon. The results showed that the shape with the least influence around the pier around is the octagon, followed by circle, rectangle, and square, showing the different geometrical effects that the shapes have on the pier. Furthermore, it was shown that the distribution of sediment concentration had effect from about (+) 110 m of the upstream to about (-) 130 m of the downstream, from the pier installation point. Also, it was shown after analyzing drag forces for different sediment particle distributions that the shape with the greatest drag is the octagon, followed by circle, square, and rectangle.

시공 중 비탈면의 붕괴 특성에 대한 충청지역 사례연구 (A Case Study on Collapse Characteristics of Slope during Construction in the Chung-Cheong Area)

  • 이준대;배우석
    • 한국지반환경공학회 논문집
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    • 제16권10호
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    • pp.23-32
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    • 2015
  • 비탈면 붕괴와 관련된 대부분의 연구는 안정화되어 공용 중인 사면에서 발생되는 붕괴사례를 중심으로 이루어져 왔으며, 안정화가 이루어지지 않은 시공 중에 발생되는 비탈면의 붕괴특성에 대한 연구는 많지 않다. 따라서 본 연구에서는 충청지역을 대상으로 시공 중 또는 시공 직후의 비탈면에서 붕괴가 발생된 79개소를 대상으로 정밀조사를 수행하고 그 결과를 통해 기하학적인 특성과 파괴특성, 설계 및 보강방법 등의 특성을 평가하였다. 분석결과 충북권은 평면형 붕괴와 표층 붕락이 두드러지며, 충남권은 평면형 붕괴가 대다수이나 충북권에 비해 퇴적암의 표층부 붕락이나 유실이 큰 것으로 나타났다. 또한 주된 파괴인자는 충북권이 절리의 교호(53%)와 풍화(25%)로 나타났고 다방향 절리로 인한 블록화와 천매암 지역의 엽리가 영향을 미치고 있으며, 충남권도 발달된 절리(55%)가 주요요인이나 단층, 탄질셰일 등 퇴적암의 지질학적 성인(36%)도 상당한 영향을 미치고 있어 지질학적, 기후적, 환경적 특성이 비탈면의 안정에 영향을 미치는 것으로 분석되었다.

구도심 재래시장의 특성 분석 연구 -공주 산성시장 및 중동상점가를 중심으로- (Analysis on the Characteristics of Traditional Markets in an Old Town Center - focusing Gongju Sanseong market and middle eastern shopping district -)

  • 박훈
    • 한국농촌건축학회논문집
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    • 제15권1호
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    • pp.1-11
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    • 2013
  • The Gongju Sanseong Traditional Market, the subject of this study, was formed in the early 1900's, and along with the development of Gongju, it has been constantly changed and expanded up until now. The Sanseong Traditional Market located in Gongju, the Korea's representative historic city, exhibits merits in the aspects as a city based on the symbolic significance of the city where it is located and historical characteristics; however, it also presents some problems as well in consideration of user convenience and accessibility. Thereupon, this study conducted literature review on traditional markets, field research with a field trip, and a survey in order to analyze the spatial characteristics of the market environment and grope for the methods of activation. The conclusion suggested through this is as written below: First, the changes of types regarding spatial use according to the modernization project of traditional markets are essential, so about the spatial use according to the spatial changes, it is needed to distribute it balancedly considering the central space of the market. Second, with the understanding of the spatial types of traditional markets, it is needed to build a plan for alternation in the types of physical space based on that. Third, it is necessary to suggest the methods of integrated spatial use among standing markets and 5-day markets. In particular, through the approaches from the aspects of architectural and urban design and through reasonable spatial planning, a systematic approach considering the convenience of the users and merchants using it as their living space should be prioritized. And lastly, it is needed to reorganize the space according to the physical and non-physical methods in order to figure out the methods of activating traditional markets in agricultural areas and minor cities. With the complex approaches above, we can grope for the methods of activating traditional markets.

Columnar 구조를 갖는 비정질 $As_{40}Ge_{10}Se_{15}S_{35}$ 박막에서 선형이색성의 저온특성 (Low temperature characteristics of linear dichroism in columnar structural a-$As_{40}Ge_{10}Se_{15}S_{35}$ thin films)

  • 전진영;김종기;박수호;이현용;정홍배
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 D
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    • pp.1252-1254
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    • 1998
  • The characteristics of linear dichroism with temperature were investigated in normally($0^{\circ}$) and $80^{\circ}$-obliquely deposited amorphous $As_{40}Ge_{10}Se_{15}S_{35}$ thin films using low temperature equipment. The saturated dichroism($D_{sat}$) of a $80^{\circ}$-obliquely deposited film shows approximately 6% which is the larger value than 4.2 % of normally($0^{\circ}$) deposited film. The $D_{sat}$ of $80^{\circ}$-deposited film was increased to 25 % at 77 K, which is four times larger than that at room temperature. The $D_{sat}$ decreased with increasing temperature and was completely disappeared at about 335K. This could be explained as the tunneling effect due to the thermal excitation of lone-pair electrons in intimate valence alternation pairs(IVAPs) which are considered to be the origin of anisotropy. The decrease of $D_{sat}$ with increasing temperature from 77K to room temperature satisfied Gaussian approximation with a standard deviation of 158K.

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Factors affecting the vertical distribution of Betula platyphylla var. japonica and Betula ermanii on Mt. Neko in Nagano Prefecture, Japan

  • Jiro, Otsubo;Shigeru, Mariko;Ichiroku, Hayashi
    • Journal of Ecology and Environment
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    • 제33권2호
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    • pp.121-131
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    • 2010
  • Betula platyphylla var. japonica and Betula ermanii segregate vertically at an elevation of approximately 1,850 m on Mt. Neko in Nagano Prefecture, Japan. B. platyphylla var. japonica and B. ermanii were the dominant species below and above this altitude, at which the mean-annual and growing-season air temperatures were $4^{\circ}C$ and $14.1^{\circ}C$, respectively. Based on a modification of Kira's warmth index which employs cumulative temperature represented as $^{\circ}C$ day, leaf unfolding in both species was observed to be initiated at $58^{\circ}C$ day and $169^{\circ}C$ day, respectively. In 1996, leaf unfolding was initiated on 18 May in B. platyphylla var. japonica (+/-6 days) and on 5 June in B. ermanii (+/-8 days), shortly after the last frost which occurred on 5 May 1995 above 1,850 m; below this elevation there was no risk of frost at the time. At elevations above 1,850 m, the unfolded leaves of B. platyphylla were damaged by late frost, while B. ermanii escaped injury because the leaves were still protected by winter buds. The optimum temperature for seed germination in both B. platyphylla and B. ermanii was $30^{\circ}C$. Temperature alternation from 10 to $30^{\circ}C$ and moist storage of seeds at $4^{\circ}C$ (stratification) prior to incubation increased germination rates in both species. The seedlings of B. ermanii had a greater survival rates than those of B. platyphylla var. japonica when planted above 1,850 m. Comparisons of the timing of leaf unfolding and the latest frost at a site appeared to be the main factors affecting the vertical distribution of these species.