• 제목/요약/키워드: HOST

검색결과 7,154건 처리시간 0.035초

Exploitation of Reactive Oxygen Species by Fungi: Roles in Host-Fungus Interaction and Fungal Development

  • Kim, Hyo Jin
    • Journal of Microbiology and Biotechnology
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    • 제24권11호
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    • pp.1455-1463
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    • 2014
  • In the past, reactive oxygen species (ROS) have been considered a harmful byproduct of aerobic metabolism. However, accumulating evidence implicates redox homeostasis, which maintains appropriate ROS levels, in cell proliferation and differentiation in plants and animals. Similarly, ROS generation and signaling are instrumental in fungal development and host-fungus interaction. In fungi, NADPH oxidase, a homolog of human $gp91^{phox}$, generates superoxide and is the main source of ROS. The mechanism of activation and signaling by NADPH oxidases in fungi appears to be largely comparable to those in plants and animals. Recent studies have shown that the fungal NADPH oxidase homologs NoxA (Nox1), NoxB (Nox2), and NoxC (Nox3) have distinct functions. In particular, these studies have consistently demonstrated the impact of NoxA on the development of fungal multicellular structures. Both NoxA and NoxB (but not NoxC) are involved in host-fungus interactions, with the function of NoxA being more critical than that of NoxB.

On the Origin of the Correlation between Hubble Residual and Mass of the Type Ia Supernova Host Galaxies

  • Kang, Yijung;Kim, Young-Lo;Lim, Dongwook;Chung, Chul;Lee, Young-Wook
    • 천문학회보
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    • 제39권1호
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    • pp.36.1-36.1
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    • 2014
  • The correlation between mass of Type Ia Supernova (SN Ia) host galaxies and Hubble residual is now well-established. The origin of this relation, however, is yet to be understood. We have used low-resolution spectra of early-type hosts from YONSEI (YOnsei Nearby Supernovae Evolution Investigation) project to measure central velocity dispersion and Lick/IDS absorption indices. By using the Evolutionary Population Synthesis (EPS) models, luminosity-weighted mean age and metallicity of host galaxies were determined from $H{\beta}$ and absorption lines. Here we will discuss the correlation between the velocity dispersion, which indicates the mass of galaxies, and mean age of stellar population in our sample of early-type host galaxies.

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High efficiency deep blue phosphorescent organic light emitting diodes using a phenylcarbazole type phosphine oxide as a host material

  • Jeon, Soon-Ok;Yook, Kyoung-Soo;Lee, Jun-Yeob
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.188-191
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    • 2009
  • A high efficiency deep blue phosphorescent organic light-emitting diode (PHOLED) was developed using a new wide triplet bandgap host material (PPO1) with a phenylcarbazole and a phosphine oxide unit. The wide triplet bandgap host material was synthesized by a phosphornation reaction of 2-bromo-Nphenylcarbazole with chlorodiphenylphosphine. A deep blue emitting phosphorescent dopant, tris((3,5-difluoro-4-cyanophenyl)pyridine)iridium (FCNIr), was doped into the PPO1 host and a high quantum efficiency of 17.1 % and a current efficiency of 19.5 cd/A with a color coordinate of (0.14,0.15) were achieved in the blue PHOLED. The quantum efficiency of the deep blue PHOLED was better than any other quantum efficiency value reported up to now.

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Influence of green phosphorescent organic light-emitting devices of host by hole transport layer

  • Yoon, Do-Yeol;Lee, Chan-Jae;Moon, Dae-Gyu;Lee, Jeong-No
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.814-816
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    • 2009
  • We have investigated the effect of host on the device charactistics of green phosphorescent organic light emitting devices consising of mCP, CBP and TPBi. Electrons were confined within the device by inserting hole transport layer between the electro transport and the emitting layer. When the appropriate interlayers were added, the device with TPBI host layer performances were found to be dramatically enhanced, with current efficiency and lifetime of 18cd/A and 18hour.

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Highly efficient deep-blue electroluminescence using doped PCVtPh with a new host material

  • Park, Jeong-Keun;Lee, Kum-Hee;Kim, Seul-Ong;Park, Jung-Sun;Seo, Ji-Hoon;Kim, Young-Kwan;Yoon, Seung-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.775-778
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    • 2009
  • Novel blue host material, 4,4'-(dinaphthalen-2-yl)-1,1'-binaphthyl (DNBN), was designed and synthesized for OLEDs. In order to test the electroluminescent properties of DNBN, DNBN was used as the host materials for a blue emitter, PCVtPh. The device exhibited deep-blue emission with the CIEx,y coordinates (x=0.15, y=0.08) at 8.0 V, a luminous efficiency of 1.66 cd/A, a power efficiency of 0.77 lm/W and an external quantum efficiency of 2.30 % at 20 mA/$cm^2$, respectively.

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벼물바구미의 가해식물 (Feeding Plants of Rice Water Weevil)

  • 김용헌;임경섭
    • 한국응용곤충학회지
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    • 제31권2호
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    • pp.139-143
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    • 1992
  • 벼멸바구미의 성충과 유충가해식물을 조사하였다. 성충 가해식물은 18과 116종의 조사대상 식물중 13과 104종의 식물이 확인되었으며, 이 중 74종은 성충기주식물로 처음 확인되었다. 주요 성충가해식물은 개밀, 새, 띠, 꿩의밥 등 20종이었다. 이들은 대부분이 화본과와 사초과에 속하는 것이었다. 한편, 유충가해 잡초는 너도방동사니, 올방게, 올미, 벗풀 등 9종이 확인되었다.

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Growth Characteristics of Rhizophagus clarus Strains and Their Effects on the Growth of Host Plants

  • Lee, Eun-Hwa;Eom, Ahn-Heum
    • Mycobiology
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    • 제43권4호
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    • pp.444-449
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    • 2015
  • Arbuscular mycorrhizal fungi (AMF) are ubiquitous in the rhizosphere and form symbiotic relationships with most terrestrial plant roots. In this study, four strains of Rhizophagus clarus were cultured and variations in their growth characteristics owing to functional diversity and resultant effects on host plant were investigated. Growth characteristics of the studied R. clarus strains varied significantly, suggesting that AMF retain high genetic variability at the intraspecies level despite asexual lineage. Furthermore, host plant growth response to the R. clarus strains showed that genetic variability in AMF could cause significant differences in the growth of the host plant, which prefers particular genetic types of fungal strains. These results suggest that the intraspecific genetic diversity of AMF could be result of similar selective pressure and may be expressed at a functional level.

도마도 암종내 Agrobacterium tumefaciens의 동태에 대하여 (Electron microscope study on Agrobacterium tumefaciens in tomato tumor)

  • 윤권상;이민재;하영칠
    • 미생물학회지
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    • 제10권1호
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    • pp.41-50
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    • 1972
  • The tomato plant, Lycopersicon esculentum Mill, was inoculated with tumor inducing strain, $A_6K_1$, of Agrobacterium tumefaciens and its produced tumors were examined with the electron microscope. A number of bacteria are usually detected in the intercellular region of the host plant, and it is observed that the host cytoplasm is readily destroyed in the region where the bacterial invasion occurred. Some of the bacteria in the host tissues are enclosed with the single unit membranes, in other locations lots of bacteroids were examined and the bacterial lysis is generally observed in those bacteroids. The bacterial movement in the tumor tissue and some peculiar relationships between the pathogens and the host plant are discussed.

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Influence of Host Age on Development and Morphological Parameters of the Parasitoid Nesolynx thymus Girault (Hymenoptera: Eulophidae), An Ecto-Pupal Parasitoid of the Uzi Fly, Exorista bombycis (Louis) (Diptera: Tachinidae)

  • Aruna A.S.;Manjunath D.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제12권1호
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    • pp.45-49
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    • 2006
  • The present investigation was conducted to know the effects of host age on development and morphological characteristics of Nesolynx thymus, a gregarious ectopupal parasitoid of the uzi fly, Exorista bombycis, a serious en do-larval parasitoid of the silkworm, Bombyx mori L. For experimentation, 3 - 11 day-old pupae of E. bombycis were exposed to 2 day-old adults of N. thymus at $25{\pm}2^{\circ}C\;and\;60{\pm}10%$ RH. A highly significant negative correlation between host age and the following development and morphological characteristics of the parasitoid was observed: number of pupae parasitised, total adult recovery, sex ratio and recovery, longevity, body length, wing span, abdomen length, and abdomen width of females. The findings of the present study clearly demonstrate that various development and morphological parameters of N. thymus are influenced by the age of E. bombycis pupae.

Effect of rearing season, host plants and their interaction on economical traits of tropical tasar silkworm, Antheraea mylitta Drury- an overview

  • Bhatia, Narendra Kumar;Yousuf, Mohammad
    • International Journal of Industrial Entomology and Biomaterials
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    • 제29권1호
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    • pp.93-119
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    • 2014
  • Tropical tasar silkworm, Antheraea mylitta (Lepidoptera: Saturniidae) is a polyphagous silk producing forest silkworm of commercial importance in India. Forest dependent people rear its larvae on different forestry host plants twice or thrice in a year for small household income. Larvae of A. mylitta feeds on many forest tree species, but always show a great degree of selectivity as a function of its behavioural responses to physical structure and chemical features of the host plants. Cocoon crop of A. mylitta is influenced by heterogeneity of tasar food plants and climatic conditions of the habitat. The role of host plants, temperature, humidity, rainfall, photoperiod and climatic variables on the growth and development of insects have clearly been demonstrated. This article entails an in-depth analysis on ecological and nutritional aspects of A. mylitta, which may provide selective information to researcher and forest managers, who are particularly associated with livelihood improvement of the poor people in forested area through location specific forest insect industry.