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        검색결과 302

        101.
        2017.04 구독 인증기관·개인회원 무료
        Plant essential oils have been reported to show repellent, insecticidal and growth-reducing effect on many insect herbivores. Recently, it has been reported that plants synthesize secondary metabolites regulating insect juvenile hormone (JH) receptor complex as a part of their defense mechanisms. We tested 180 plant essential oil compounds using a yeast two-hybrid system transformed with the Aedes aegypti JH receptor as a reporter system. Among them, we identified 17 compounds that showing high JH agonist (JHA) or antagonist (JHAN) activities. They were grouped into 4 groups by their structural similarity and their insecticidal activity was tested against larvae of Aedes albopictus, Plutella xylostella, Plodia interpunctella and Laodelphax striatellus. These results could provide insights on the plant-insect coevolution and may be useful for the development of insect specific and safe pesticides.
        102.
        2017.04 구독 인증기관·개인회원 무료
        RNA interference (RNAi) is an universal gene-knockdown mechanism in eukaryotic organisms including insects. RNAi has been considered as an alternative strategy to control agricultural pests whereby double-stranded RNA triggers a potent and specific inhibition of its homologous mRNA. Bacillus thuringiensis (Bt) is a spore-forming bacterium that produces a copious amount of crystal proteins δ-endotoxins under the control of sporulation-dependent promoter. In order to develop dsRNA mass-production platform utilizing recombinant Bt, the pHT1K-EGFP which expresses dsRNA against EGFP under the control of Cyt1-Aa sporulation-dependent promoter was constructed and the expression level of transgene (EGFP) was confirmed by qPCR analysis. These results suggested that Bt’s potential of becoming a new platform in dsRNA production.
        103.
        2017.04 구독 인증기관·개인회원 무료
        Insect growth regulators (IGRs) are insecticides that disrupt the normal development of target insects by inducing symptoms such as premature molting or supernumerary larval stages. Juvenile hormone (JH)-based IGRs are of particular interest because they simulate or interfere with the formation of juvenile hormone receptor complex. Insect larvae generally have been poorly susceptible to JH agonists (JHAs) because endogenous JH titer is already high in the larval stage. In contrast, JH antagonists (JHANs) might be more effective for control of target pests in larval stages through interference in the status quo action of JHs. In this study, we tested 2,354 chemical compounds using the yeast-two hybrid system to identify JHANs. Among them, K265674 sample was selected and its insecticidal activity was evaluated against Aedes albopictus larvae. These results may be useful for development of novel IGR insecticide.
        104.
        2017.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi have been widely studied for their potential as the effective biological control agents. They produce variety of secondary metabolites with insecticidal activities, and it is reasonable to assume that entomopathogenic fungi might produce secondary metabolites modulating juvenile hormone for their survival against defense mechanisms of host insect. In this study, acetone extract of the Lecanicillium spp. cultured on unpolished rice medium showed juvenile hormone antagonist (JHAN) activity in the yeast-two hybrid β-galactosidase assay and high insecticidal activity against Aedes albopictus and Plutella xylostella. In addition, to compare bioactivities of secondary metabolites from solid and liquid culture, the Lecaniciilium spp. strain cultured on unpolished rice medium or PDB medium were serially extracted with acetone and ethyl acetate respectively. Both extracts showed JHAN activity and high insecticidal activity against A.albopictus. Theses results suggested that secondary metabolites of entomopathogenic fungi could be useful for development of novel IGR insecticides.
        105.
        2017.04 구독 인증기관·개인회원 무료
        Rice stripe virus (RSV) is one of the serious plant pathogenic viruses for rice transmitted by small brown planthopper (SBPH), Laodalphax striatellus. RNA interference (RNAi) was recently suggested as a promising strategy for controlling insect pests, including those that serve as important vectors for plant pathogens. To disturb transmission of the RSV in SBPH using RNAi pathway, we chose nine genes highly expressed in RSV-viruliferous SBPH by transcriptome sequencing. These SBPH-derived dsRNAs were applied to the insects indirectly through xylem of rice leaves by irrigation. qPCR result demonstrated that five out of nine SBPH-derived dsRNAs successfully reduced the replication of RSV in viruliferous SBPH in dose-dependent manner, suggesting that these five dsRNAs could suppress replication of RSV and provide a new tool for RSV control strategy.
        106.
        2017.04 구독 인증기관·개인회원 무료
        Dermanyssus gallinae is parasitic to chicken, and they cause many damages such as disturbing sleep reducing for body weight and egg production by blood-sucking. To develop acaricide against D. gallinae, The acaricidal activity of 40 species plant extract were examined. Cnidium officinale extracted by Me-OH showed 82.0% acaricidal activity after treated 48 hrs at 4,000 ppm. The hexane fraction showed 92.4% mortality against D. gallinae at 48 hrs at 2,000 ppm. Purification of the biologically active constituents from the hexane extraction with acaricidal activity was done using silica gel open column chromatography and HPLC. H1122 fraction gave 80.9% mortality to D. gallinae at 400 ppm after treated 48 hrs. H1122 fraction was analyzed by GC-MS and NMR.
        107.
        2016.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        고준위방사성폐기물 심층처분에서 처분안전성의 신뢰도를 향상시킬 수 있는 방안으로 그리고 처분 프로그램 개발 및 인허가를 위해 많은 나라들에서 자국에 적합한 safety case를 개발하고 있다. 본 연구에서는 방사성폐기물 처분을 위한 safety case 의 의의, 필요성, 개발과정들을 정리하고 소개하였다. 그리고 처분안전성을 safety case의 다양한 측면에서 논의하였다. 아울러 스위스, 일본, 미국, 스웨덴, 핀란드 등 해외의 safety case 개발 현황과 현재 KAERI에서 개발 중인 safety case의 개발 전략을 간략히 소개하였다. 고준위방사성폐기물 처분안전성의 신뢰도 향상을 위해 safety case 기반 하에서 어떤 노력들이 필요한지를 분석하였다. 그리고 국내 상황을 반영하여 신뢰할 수 있는 정보자료의 구축, 안전성 관련 과정들의 이해, 안전성 평가의 불확실성 저감, 이해당사자와의 의사소통, 공정성과 투명성 확보 등의 실행 방안을 제안하고 논의하였다. 본 논문에 제시된 내용들은 심층처분 safety case를 이해하고, 국내에서 개발하고 있는 고준위방사성폐기물 처분 safety case 개발을 통한 처분안전성 신뢰도 향상에 기여할 수 있을 것으로 기대한다.
        5,200원
        110.
        2016.10 구독 인증기관·개인회원 무료
        Varroa destructor is a devastating ectoparasitic mite which attacks Honeybee, Apis mellifera. V. destructor feeds on honeybee hemolymph, and often harbors small RNA viruses such as the deformed wing virus to transmit these viruses in the infested bee hive. To survey the genes of V. destructor, total RNA was subjected to high-throughput transcriptome sequencing to construct in silico cDNA library by using the Illumina HiSeq 2000 platform. Total of 2×107,748,792 paired-end short reads were obtained and quality filtered reads were subjected to Trinity de novo assembler followed by TransDecoder, and CD-HIT program to make a V. destructor reference cDNA library containing 28,023 of clustered contigs with protein coding capacity. These cDNA sequences will help us to understand the molecular biology of V. destructor.
        111.
        2016.10 구독 인증기관·개인회원 무료
        The small brown planthopper (SBPH), Laodelphax striatellus, is one of the most serious pest insects of rice plants because it can transmit the rice stripe virus (RSV) which often causes significant reduction of yield in the field. Buprofezine is an effective insect growth regular (IGR) pesticide to control planthoppers, however, since the use of buprofezine for more than a decade, it has caused a certain resistance of SBPH. To survey the responses of SBPH to buprofezine, we exposed 4th instar SBPH to 200 ppm buprofezine by dipping method, and extracted total RNA for RNA-seq by Illumina platform. The quality filtered raw reads of cDNA obtained from experimental and control SBPH were subjected to Bowtie2 followed by eXpress computer program to compare the differential gene expression which will be important information for pest control methods using RNAi.
        112.
        2016.10 구독 인증기관·개인회원 무료
        Bacillus thuringiensis (Bt) produces a variety of insecticidal crystal proteins and widely used as one of the most successful biological control agents. Recently, studies that introduce cry genes into crops to create pest resistance have made much progress, and the total area of land planted with Bt crops has increased substantially. In this study, pest resistance of 8 transgenic Bt rice events with a synthetic cry1Ac gene linked to rice rbcS-tp sequence were assessed under laboratory conditions. Bioassays were performed against Cnaphalocrocis medinalis, which is a significant pest of rice in Asia. C. medinalis larvae were shown to be susceptible to all eight events, even though there were differences between the causes of death. The results differed between developmental stages of the larvae, despite the fact that all 8 events led to high mortalities. These results may be a significant foundation for the evaluation of improved transgenic Bt rice.
        113.
        2016.10 구독 인증기관·개인회원 무료
        Insect growth regulators (IGRs) are attractive pest control agents due to their high target specificity and relative safety to the environment. Recently, plants have been shown to synthesize IGRs that affect the insect juvenile hormone (JH) as a part of their defense mechanisms. We identified several JH agonists (JHAs) and antagonists (JHANs) from plant essential oil compounds using a yeast two-hybrid system transformed with the Aedes aegypti JH receptor as a reporter system. They showed high mosquitocidal activities with relatively low LC50 values and caused retardation of ovarian development in female mosquitoes. While the JHAs increased the expression of JH-induced gene, the JHANs caused reduction in the expression of the same gene. The compounds identified in this study could provide insights on the plant-insect interactions and may be useful for the development of novel IGR insecticides.
        114.
        2016.10 구독 인증기관·개인회원 무료
        Streptomyces is the largest genus of Actinobacteria that forms fungus-like branched networks of hyphae. Streptomyces has been clinically important because they produce various secondary metabolites with antibacterial, antifungal, and nematocidal activities. In order to explore novel insecticidal compounds, extracts from 363 strains of Actinobacteria were screened for their juvenoid and anti-juvenoid activities using yeast-two hybrid system. Among them, extract of Streptomyces spp. showed high anti-juvenoid activity. This extract also showed high level of insecticidal activities against larvae of Aedes albopictus, Laodelphax striatellus, and Ostrinia furnacalis. These results suggested that the secondary metabolites of Streptomyces could be natural sources of novel insecticidal compounds.
        115.
        2016.10 구독 인증기관·개인회원 무료
        Entomopathogenic fungi have been widely studied for their potential as the effective biological control agents. They produce variety of secondary metabolites with insecticidal activities, and it is reasonable to assume that entomopathogenic fungi might produce secondary metabolites modulating juvenile hormone for their survival against defense mechanisms of host insect. In this study, Beauveria spp. and Lecanicillium spp. strains cultured on unpolished rice medium were extracted with acetone. Both extracts showed juvenile hormone antagonist (JHAN) activities in the yeast-two hybrid β-galactosidase assay. In addition, they showed high insecticidal activities against Aedes albopictus, Plutella xylostella, and Ostrinia furnacalis. These results suggested that secondary metabolites of entomopathogenic fungi could be useful for development of novel IGR insecticides.
        116.
        2016.10 구독 인증기관·개인회원 무료
        Insect growth regulators (IGRs) are insecticides that disrupt the normal development of target insects by inducing symptoms such as premature molting or supernumerary larval stages. IGRs are categorized into three types based on their mode of action. One of the them is classified as juvenile hormone agonists (JHAs). In recent studies, we identified juvenile hormone antagonists (JHANs) from plant extracts. In order to identify a novel juvenile hormone agonists and antagonists, we tested 2,354 chemical compounds using the yeast-two hybrid system. Among them, 2 JHAs and 4 JHANs were selected and their insecticidal activities were evaluated against Aedes albopictus larvae. These results may be useful for development of novel IGR insecticides.
        117.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As a replacement for activated carbon, biochar was synthesized and used for the adsorptive removal of formaldehyde and nitrogen oxide. Biochar was produced from the fast pyrolysis of the red marine macro alga, Pyropia tenera. The P. tenera char was then activated with steam, ammonia and KOH to alter its characteristics. The adsorption of formaldehyde, which is one of the main indoor air pollutants, onto the seaweed char was performed using 1-ppm formaldehyde and the char was activated using a range of methods. The char activated with both the KOH and ammonia treatments showed the highest adsorptive removal efficiency, followed by KOH-treated char, ammonia-treated char, steam-treated char, and non-activated char. The removal of 1000-ppm NO over untreated char, KOH-treated char, and activated carbon was also tested. While the untreated char exhibited little activity, the KOH-treated char removed 80% of the NO at 50°C, which was an even higher NO removal efficiency than that achieved by activated carbon.
        4,000원
        118.
        2016.07 구독 인증기관·개인회원 무료
        The combination of sports and the IT industry has reached a variety of fields, especially in the area of broadcasting technology. Due to diverse preference of viewer and the rising number of channels, broadcasting companies provide differentiated contents to reach a dominant position. Therefore, each broadcasting company has their own strategy to produce contents through special technology skills to hold a top position amongst other companies. According to Eric Rothenbuhler's ‘media niche theory’, when there exists numerous media device with identical resources, the competition to survive between the devices become intense and soon draws a line between the superior and inferior devices which results in eliminating the less viewed media devices out of the race. To secure the uniqueness of the media broadcasting market like the ecosystem, the object is to verify the effectiveness of the convergence of sport broadcasting technology skills and IT technology. Therefore, the media devices and the newly developed technology for video production method were the independent variables. Additionally, the dependent variable was the media effect. Concretely, the media device technology variable set as 3DTV, video production method was set as the variable for FreePointView(FPV) and media effect was separated into arousal and presence level. Recent technology is developed three-dimensionally so that the viewers can feel as close to reality as possible and the most current
        119.
        2016.07 구독 인증기관·개인회원 무료
        In 2015, the movie “Northern Limit Line” which based on the naval battle of South and North Korea occurred in 2002 was premiered (Los Angeles Times, 2016). This movie made a significant contribution to improve the image of the R.O.K Navy. Brand Placement (BPL) was used to promote the R.O.K Navy in this movie (Karrh, 1994; Van Reijmersdal, Neijens & Smit, 2007). The R.O.K. Navy is trying to build powerful naval forces with the slogan called “The Ocean Navy”. It is essential to acquire the elite military forces who can help the Korean Navy to accomplish its strategic goal and heighten the competitiveness. The acquired elite military forces are expected to demonstrate their own ability while they serve the R.O.K. Navy. They will have positive influences to the local communities as the supporters of the R.O.K. Navy after they are discharged. This research analyzed BPL effect in terms the recruitment of workforce. This research identified the relationship among BPL, organization image, organization reputation, employment brand equity and intention to pursue job opportunity in R.O.K Navy. In previous researches, the effect of image can be applied to corporate brands, product, individual brands, geographical areas, events and people (Balmer, 1997). The image of organization can remind people of the particular organization (Cable & Yu, 2006). The reputation is a dynamic interaction construct with the image, and defined as a subjective judgment based on the reliability and integrity about the organization in long term (Clardy, 2012). Employment brand equity is defined as outcome of applicant’s decision choices attributable to job seeker’s beliefs about the organization as employer(Han & Collins, 2002). Marketing literatures on employment brand equity can be useful in helping to understand how job seeker develops beliefs about organization as employer. Although many researches studied BPL, organization image and reputation, employment brand equity, etc., little researches have been conducted to integrate the variables mentioned above in public sector such as the military forces. Samples of this research consist of people who watched the movie called “Northern Limit Line”. SPSS and AMOS package programs are employed to analyze the data. Marketing strategy for a public sector such as Korean Navy based upon the results of the findings from this study is expected to position Korean Navy as more efficient and effective organization to recruit better quality human resources.
        120.
        2016.07 구독 인증기관·개인회원 무료
        Multisided platforms (e.g. eBay, Airbnb, Facebook, Apple’s iOS etc.) are marketplaces to facilitate direct interactions between two or more customer or participant groups and enable the value to customers on one side of a platform typically to increase with the number of participating customers on another side (Hagiu, 2014). Platform is a business model to have the more knowledge of its customers and become more networked (Weill & Woerner, 2015). Collaborative consumption platforms (CCPs) are marketplaces to facilitate sharing activities such as the form of renting, lending, trading, bartering and swapping of goods or services based on Möhlmann’s (2015) definition. The rise of information and communications technology (ICT) such as the internet or mobile apps enables an easy access on CCP, which facilitates peers to trade and decrease transaction costs (Möhlmann, 2015). Although CCPs can create better customer experience than traditional business model, there is asymmetric information among peers, which results in lemons. Boudreau and Hagiu (2008) suggested that platforms owners should reduce lemons problems by establishing technical standards and interfaces, rules and procedures, defining the division of tasks, providing support and documentation and sharing information as non-priced instruments. Some attempts have been made in order to demonstrate online service failure or lemons on the web (Holloway & Beatty, 2003). In the Holloway and Beatty’s study (2003), the typology of online service failures has been provided and demonstrated how online retailers could manage their online service failures effectively. The solution to reduce information problems is signaling of trust about quality such as price, adverting, and warranties (Boulding & Kirmani, 1993). Trust in CCPS is to trust in other peers within the platform to share (Möhlmann, 2015). If a CCP cannot control opportunistic behaviors of peers, the peers participating in the CCP can be harmed as well as the CCP will fail to encourage more peers to participate and thus the social value of the CCP may decrease. It is important to understand decision making process of peers in CCPs and consider the motivations to use CCPs and the contexts at the same time. Enjoyment and economic benefits have a direct impact on behavioral intention to participate in CC in the motivation model by Hamari and his colleagues (2015). We suggest the motivatio ns such as enjoyment or economic benefits can be fit by the specific signals of peers in CCPs. The consumers with different motivations to use CCPs can perceive signals for trust differen tly. The more people pursue hedonic value for CCP, the more they tend to make a decision de pending on heuristics rather than elaborate cognitive process. The more people pursue utilitar ian value for CCP, the more they tend to make a decision depending on elaborate cognitive pr ocessing. We conduct two experiments to examine the fit between motivations and signals of CCPs. The interaction effect between motivations to use CCPs and types of signals is investigated through ANOVA test. People to use CCPs for enjoyment have more usage intention when they are exposed by more reviews rather and CCP with low governance power. On the other hand, People to use CCPs for convenience have more usage intention when they are exposed by high review quality and CCP with strong governance power rather than low governance. Social marketers and public policy makers seek to spread CC for the sake of fostering sustainable consumption behavior and promoting public sharing events (Möhlmann, 2015). Sharing and collaborative consumption can be solutions against global warming, rising fuel and raw material prices, growing pollution, and other anticipatable trends (Belk, 2014). CCPs strive to make people participate to create value of their CCPs based external crosseffect by providing various signals for peers with different motivations. Thus public policy makers should foster CCPs rather than encourage people directly to participate. In addition, public policy makers should give CCPs self-regulation that can decide the types of governance and policies to reduce lemons market problems. Our research contributes to the literature on market failures in CCPs by highlighting the importance of the fit between the motivations to use CCPs and signals. Although people have motivation to participate in CC, they are not willing to participate in CCPs without trust of other peers or goods and services. Thus CCPs need to provide peers with proper signals.