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        검색결과 29

        21.
        2014.04 구독 인증기관·개인회원 무료
        Integrin is a cell surface protein that is composed of α and β heterodimer and mediates cell interaction with extracellular matrix or other cells including microbial pathogens. A full length cDNA sequence (2,517 bp) of a integrin subunit β1 (HaITGβ1) was cloned from the oriental tobacco budworm, Helicoverpa assulta. Phylogenetic analysis showed that HaITGβ1 was clustered with other insect β integrin subunits with the highest amino acid sequence identity (61%) to β1 of other Noctuidae such as Spodoptera exigua and S. litura. Structural analysis of the HaITGβ1 possessed all functional domains known in other insect β1 integrins. RT-PCR analysis showed that HaITGβ1 was expressed in all developmental stages and all tested tissues of H. assulta. Injection of double-stranded HaITGβ1 RNA (dsHaITGβ1) into third instar of H. assulta suppressed HaITGβ1 expression and resulted in significant delay from last larval stage to pupal stage. The dsHaITGβ1 injection significantly impaired nodule formation of H. assulta in response to bacterial challenge and hemocyte adherence. These results suggest that HaITGβ1 plays crucial roles in cellular immune responses as well as development in H. assulta.
        22.
        2013.10 구독 인증기관·개인회원 무료
        Glycerol is a polyol that is responsible for the cold hardiness of insects. Glycerol kinase gene, which is an important key enzyme for glycerol biosynthesis, was predicted from whole genome sequencing data from the diamondback moth, Plutella xylostella. Four of P. xylostella glycerol kinase genes (PxGKs) were determined as a functional glycerol kinase through in silico study. Pre-exposure of P. xylostella larvae to 4°C for 7 h significantly enhanced survival (rapid cold hardiness: RCH) under a freezing temperature (-10°C) and increased glycerol titers. To determination of functional GK gene, expressions of all GK genes were measured by RT-PCR analysis. All GK genes were expressed in all larval stage and tissues (gut, hemocyte, and fat body). Expressions of all GK genes were suppressed by its specific dsRNA treatment into 4 th instar larva. Each 150 ng of dsRNA PxGK2 treatment significantly decreased glycerol amount in hemolymph by HPLC analysis. Larval treated by dsRNA PxGK2 also significantly lost the RCH under -10°C exposure. These results indicate that glycerol is a crucial RCH agent and its synthesis is regulated by a specific PxGK2 gene among GK gene isoforms in P. xylostella. In addition, the beet armyworm, Spodpotera exigua, encodes RCHassociated SeGK1, which has been functionally identified by RNA interference.
        23.
        2013.10 구독 인증기관·개인회원 무료
        Environmental changes such as land-use change including reclamation cause effects on the ecosystem seriously. Present study investigated community structure of hemipterans in several reclaimed lands from western coast of South Korea in 2010, because among arthropods, hemipterans are more influenced by land-use change which caused the change of dominant plants. Six reclaimed lands were selected for our study based on the ages of reclaimed land (0, 5, 12, 16, 20, and 31 years). Dominant plant species of reclaimed lands were belonging to Poaceae, Phragmites communis and Oryza sativa in Yeongsangan II, Sabkyocheon, Geumgan I and Gyehwado, Secale cereale in Seokmun, and Imperata cylindrica and Calamagrostis epigeios in Sihwa. A total of 31 species in 10 families were identified from 4475 collected hemipterans. In Sihwa, Shannon’s diversity was very low compared to other 5 reclaimed lands due to dominance of Paromius exiguus. Because I. cylindrica and C. epigeios were 1st and 2nd host plants of P. exiguus (2824 individuals only collected from Sihwa). In multivariate analysis, 6 reclaimed lands grouped into 2 major groups showing 49.8% in Bray-Curtis similarity between 2 groups. From these results, land-use change such as reclamation project may cause the outbreak of insect pests by destruction of ecosystem functions and simplification of plant community, although community structure of hemipterans may be stable over age of land reclamation.
        24.
        2013.10 구독 인증기관·개인회원 무료
        Putative cadherin genes, which are a receptor of the Bacillus thuringinesis toxins, were predicted from a whole genome sequencing data from the diamondback moth, Plutella xylostella. After the sequence and expression analysis, a Bt receptor cadherin gene was selected. The P. xylostella cadherin gene (PxCad1, GenBank Accession no. GU901158.1) encodes 11 cadherin repeats and a transmembrane domain. The PxCad1 gene was expressed in all developmental stage specifically in gut tissue by RT-PCR analysis. Expression of PxCad1 gene was suppressed by feeding of its specific dsRNA PxCad1 in 4th instar larval stage. The suppression of PxCad1 expression did not significantly feeding of its specific dsRNA PxCad1 in 4th instar larval stage. The suppression of PxCad1 expression did not significantly influence on pupal and adult development of P. xylostella. However, the larval treated with dsRNA PeCad1 (150 ng/larva) significantly reduced susceptibility to B. thuringiensis Cry1Ac (4.83 μg/ml). By contrast, the dsRNA PxCad1 -treated larvae did not show any change in susceptibility to B. thuringiensis Cry1Ca (0.24 μg/ml). These results suggest that PxCad1 is a specific receptor of Cry1Ac toxin from B. thuringiensis in P. xylostella.
        25.
        2013.10 구독 인증기관·개인회원 무료
        Cold tolerance of the palm thrips, Thrips palmi Karny, was investigated to predict its survival in field during winter. Supercooling temperatures of T. palmi ranged from -26.4 to -18.4°C. However, exposure to subzero temperatures (from -5°C to -15°C) gave significant mortality to all developmental stages of T. palmi. Thus, T. palmi was determined to be a freeze-susceptible and suffered with cold injury. A brief pre-exposure to a low temperature (4°C) for 7 h significantly increase the cold tolerance of all stages of T. palmi with respect to survival at -10°C and supercooling capacity. A pre-exposure of T. palmi at 4°C significantly increased the survival rate on all developmental stages at -10°C. The rapid cold hardiness (RCH) was dependent on the duration of the pre-exposure period at 4°C in adult stage. Cryoprotectant analysis using an HPLC showed that the pre-exposure treatment increased the adult to synthesize glycerol, trehalose, mannitol, and mannose, at which trehalose represented the highest content. This study suggests that all stages of T. palmi are able to become cold-hardy by RCH, in which several polyols may play crucial roles as cryoprotectant.
        26.
        2013.04 구독 인증기관·개인회원 무료
        Cadherin gene, which is a receptor of the Bacillus thuringiensis toxins, was predicted from 454 pyrosequencing transcripts from fifth instar larvae of the beet armyworm, Spodoptera exigua. The S. exigua cadherin gene (SeCad1) encodes 9 cadherin repeats and a tranmembrane domain. The SeCad1 gene was expressed in all developmental stage specifically in gut tissue by RT-PCR analysis. Expression of SeCad1 gene was suppressed by both injection and feeding of its specific dsRNASeCad1 in 5th instar larval stage. The suppression of SeCad1 expression did not significantly influence on pupal and adult development of S. exigua. However, the larval treated with dsRNASeCad1 (100 ng/larva) significantly reduced susceptibility to B. thuringiensis ssp. aizawai (3 × 106 CFU/larva). By contrast, the dsRNASeCad1-treated larvae did not show any change in susceptibility to B. thuringiensis ssp. krustaki (4 × 107 CFU/larva). These results suggest that SeCad1 is a specific receptor of Cry1A toxin from B. thuringiensis in S. exigua, but not Cry1C toxin.
        27.
        2013.04 구독 인증기관·개인회원 무료
        The beet armyworm, Spodoptera exigua, is a freeze-susceptible species and overwinters without diapause in temperate zone. Depression of supercooling point (SCP) and rapid cold hardiness (RCH) allow S. exigua to survive at low temperatures. This study reports a polyol which is responsible for the cold hardiness of S. exigua. Pre-exposure of S. exigua larvae to 4°C for 6 h significantly enhanced survival under a freezing temperature (-10°C). This pre-exposure treatment also significantly depressed larval SCPs. Analysis of polyols indicated that glycerol titers significantly increase with increase of pre-exposure time. Glycerol kinase (GK) and glycerol-3-phosphate dehydrogenase (GPDH) are involved in glycolysis pathway of insect. The S. exigua GK (SeGK1) and G3PDH (SeG3PDH1) genes were predicted from 454 pyrosequencing transcripts from fifth instar larvae of the beet armyworm, S. exigua. The SeGK1 and SeG3PDH1 genes both were expressed in all larval stage by RT-PCR analysis. Expression of SeGK1 and SeG3PDH1 genes were suppressed by its specific dsRNASeGK1 or dsRNASeG3PDH1 injection into hemocoel of 5th instar larva. Each 200 ng of dsRNASeGK1 or dsRNASeG3PDH1 injection also significantly decreased glycerol amount in hemolymph. Larval treated by either dsRNASeGK1 or dsRNASeG3PDH1 significantly lost the RCH under -10°C exposure. These results indicate that glycerol is a crucial RCH agent and its synthesis is regulated by SeGK1 and SeG3PDH1 genes in S. exigua.
        28.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The corporate R&D(Research and Development) has a primary role of new product development and its potential is the most crucial factor to estimate corporate future value. However, its systemic inadequacies and inefficiencies, the shorten product life-cycl
        4,000원
        29.
        2019.08 KCI 등재 서비스 종료(열람 제한)
        본 연구의 목적은 시간 분해능이 향상된 비지역적 평균 (fast non local means, FNLM) 노이즈 제거 알고리 즘을 모델링하여 광학 현미경 영상에서의 적용 가능성을 확인하는 것이다. 이를 위해 실제 흰쥐 (mouse)의 첫째어금니 치아를 사용하여 영상을 획득한 후 기존에 널리 사용되고 있는 노이즈 제거 알고리즘과 제안 하는 FNLM 알고리즘을 각각 적용하여 비교하였다. 정량적 평가는 대조도 대 잡음비 (contrast to noise ratio, CNR), 변동계수 (coefficient of variation, COV), 그리고 최근에 개발된 no reference 기반의 방법인 natural ima ge quality evaluator (NIQE)와 Blind/referenceless image spatial quality evaluator (BRISQUE)를 사용하였다. 결과적으로 모든 정량적 평가 인자에서 제안하는 FNLM 노이즈 제거 알고리즘이 가장 우수한 값을 나타내었다. 특히나 치아의 전체적인 형태학적 영상을 분석할 수 있는 NIQE와 BRISQUE 인자는 원본영상에 비하여 각각 1.14와 1.12배 향상됨을 확인할 수 있었다. 결론적으로 소동물 치아 광학 현미경 영상에서의 FNLM 노이즈 제거 알고리즘의 유용성 및 가능성을 증명하였다.
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