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        검색결과 952

        305.
        2016.10 구독 인증기관·개인회원 무료
        Unlike somatic cells mitosis, germ cell meiosis consists of two consecutive rounds of divisions that segregate homologous chromosomes and sister chromatids, respectively. The meiotic oocyte is characterized by an absence of centrioles and asymmetric divisions. Centriolin is a relatively novel centriolar protein that functions in mitotic cell cycle progression and cytokinesis. Here, we explored the function of centriolin in meiosis and showed that it was localized to meiotic spindles, and concentrated at the spindle poles and midbody during oocyte meiotic maturation. Unexpectedly, knockdown of centriolin in oocytes with either siRNA or Morpholino micro-injection, did not affect meiotic spindle organization, cell cycle progression, or cytokinesis (as indicated by polar body emission), but led to a failure of peripheral meiotic spindle migration; and symmetric division or large polar body emission. These data suggest that, unlike in mitotic cells, the centriolar protein centriolin does not regulate cytokinesis, but plays an important role in regulating asymmetric division of meiotic oocytes.
        306.
        2016.10 구독 인증기관·개인회원 무료
        CDK2 inhibition plays a central role in DNA damage–induced cell cycle arrest and DNA repair. However, whether CDK2 also influences early porcine embryo development is unknown. In this study, we examined whether CDK2 is involved in the regulation of oocyte meiosis and early embryonic development of porcine. We found that disrupting CDK2 activity with RNAi or an inhibitor did not affect meiotic resumption or MII arrest. However, CDK2 inhibitor-treated embryos showed delayed cleavage and ceased development before the blastocyst stage. Disrupting CDK2 activity is able to induce sustained DNA damage as demonstrated by the formation of distinct γH2AX foci in nuclei of day 3- and day 5-embryos. Inhibiting CDK2 triggers a DNA damage checkpoint by activating of the ATM-P53-P21 pathway. However, the mRNA expression of genes involved in non-homologous end-joining (NHEJ) or homologous recombination (HR) pathways for double strand break (DSB) repair reduced after administering CDK2 inhibitor to 5-day-old embryos. Furthermore, CDK2 inhibition caused apoptosis in day 7 blastocysts. Thus, our results indicate that an ATM-P53-P21 DNA damage checkpoint is intact in the absence of CDK2; however, CDK2 is important for proper repair of the damaged DNA by either directly or indirectly influencing DNA repair-related gene expression.
        307.
        2016.10 구독 인증기관·개인회원 무료
        We investigated pollination and foraging activities of honeybee (Apis mellifera L.) and bumblebee (Bombus terrestris L.) during flowering season of the asian pear (Pyrus pyrifolia N.) under different weather conditions. There was no significant statistical difference about the pollination activities of two species. However, the pollination activities of bumblebee were more active than those of honeybee under low temperature and rainfall period. The activities of honeybee and bumblebee were more influenced by temperature than other factors (i.e. illumination and wind velocity). Honeybee was more sensitive to temperature and illumination than bumblebee. At low temperatures (<20℃) on cloudy days (<30,000 lux) with a certain wind velocity (>4.0 m/s), the pollination activity of the honeybee was lower twice than that of bumblebee.
        308.
        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.
        309.
        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.
        310.
        2016.10 구독 인증기관·개인회원 무료
        Beauveria bassiana JEF-007 with strong virulence against Riptortus pedestiris was selected for the Agrobacerium tumefaciens-mediated transformation(AtMT). AtMT generated two transformants, B1-06 and C1-49, showed significantly reduced virulence against R. pedestris. To identify the virulence-related genes, thermal asymmetric interlaced(TAIL) PCR and flanking region analysis were performed. From the analysis, two genes, Complex I intermediated-associated protein 30(CIA30) and Autophagy protein 22(Atg22), possibly related virulence in B. bassiana JEF-007. For the analysis of two putative virulence-related genes in JEF-007, hairpin RNA interference (hpRNAi) is under consideration. This work can provide the functional roles of the virulence-related genes in B. bassiana JEF-007.
        311.
        2016.10 구독 인증기관·개인회원 무료
        Myeloid differentiation factor 88 (MyD88) is an intracellular adaptor protein involved in Toll pathway. In this study, we monitored the response of 4 key genes of the insect immune system against Beauveria bassiana JEF-007 in Tenebrio molitor using RT-PCR. To better understand the roles of Toll pathway in mealworm immune system, TmGPR and TmMyD88 was knocked down by RNAi silencing. Target gene expressions were decreased at 6 days post-dsRNA injection. Therefore, mealworms were compromised by B. bassiana JEF-007 at 6 days post-dsRNA injection. Silencing of the TmMyD88 and TmGPR resulted in reducing the resistance of the host to fungal infection. However, only dsTmMyD88 showed significant difference with dsEGFP by statistical analysis, which may be due to partial gene knock down of dsGPR. These results indicate that TmMyD88 is required in mealworms for survival against B. bassiana JEF-007.
        312.
        2016.10 구독 인증기관·개인회원 무료
        A viral genome was assembled de novo from next-generation sequencing (NGS) data from bean bugs, Riptortus pedestris, infected with an entomopathogenic fungus, Beauveria bassiana (Bb), and was further confirmed via the RACE method. Based on the phylogenetic analysis of the RdRp sequences, RiPV-1 was clustered in the unassigned insect RNA viruses with two other viruses, APV and KFV. These three viruses were suggested to constitute a new group of insect RNA viruses. Interestingly, RiPV-1 replication was increased dramatically in bean bugs 2 to 6 days after fungal infection. In conclusion, a novel insect RNA virus was found by NGS data assembly. This virus can provide further insight into the interaction between virus, fungus and the host.
        313.
        2016.10 구독 인증기관·개인회원 무료
        White rice with grains is a nutritious meal that richly contains fiber, vitamin and mineral, but it is difficult for elderly people to masticate some grains and beans due to its hardness. This study was aimed to find the optimal mixing ratio of rice with texture modified grains and beans by comparing rheological properties. Beans were soaked in tap water for 24 hr at 20°C, cooked under pressure (1hr at 121°C), frozen for 24 hr at -18°C, and thawed in water bath for three hr at 30°C. The samples were submerged in macerating enzyme solution, left under vacuum at 60 mmHg for 5 min to infuse the enzyme into the intercellular spaces of samples, and rapidly returned to the atmospheric pressure. The samples were removed from enzyme solution, sealed in plastic bag, placed at 70°C for 20 min for enzyme activation and inactivated at 95°C for 15 min. The grains and texture modified beans were added to white rice with different ratio, soaked for one hr in enzyme solution under warming condition at 70°C, and steamed with electric pressure cooker. Cooked meals were rapidly cooled at -18°C for one hr, placed at 20°C for another one hr, and then rheological properties were measured with texture analyzer. The hardness of texture modified rice with grains was reduced to 2.3 ~ 4.1 × 104 N/m2 and the hardness of rice with beans was reduced to 3.8 ~ 4.8 × 104 N/m2 depending on mixing ratio. The cohesiveness was reduced by 1/3 ~ 2/3 respectively, while adhesiveness was not changed significantly, compared to those of cooked rice. These results suggest that cooked rice mixed with 30 ~ 40% of grain and 6 ~ 10% of bean would be appropriate for elderly people to consume without chewing difficulty.
        316.
        2016.07 구독 인증기관 무료, 개인회원 유료
        Crowdfunding has recently emerged as a novel way for people to collect monetary donation from large numbers of internet users. Since 2009, the volume of crowdfunding has increased exponentially, reaching 16.2 billion in 2014. A growing number of literature starts to investigate social influence in crowdfunding that occurs when former backers, who make contribution to fund a project at an earlier stage of fund-raising period, make influences of the contribution decision of latter backers. Crowdfunding can be classified into four categories, namely, lending-based, equity-based, reward-based, and donation-based. The primary goal of lending-based and equity-based crowdfunding is to raise capital and borrow money from a number of investors or lenders in exchange for interest payment or equity share of a company. In contrast, reward-based crowdfunding or donation-based crowdfunding requires a project initiator to create a project, which raise fund to develop a new product (e.g., private good) or enhance the public interest (e.g., public good). In this study, we focus on the two most popular crowdfunding type: reward-based and donation-based crowdfunding projects. In reward-based crowdfunding, backers (or contributors) give a small amount of money in return for a reward such as a copy of creative work or pre-sell products. In donation-based crowdfunding, backers donate to projects for gratitude and the pleasure of giving and expect no compensation in exchange
        3,000원
        317.
        2016.07 구독 인증기관·개인회원 무료
        This study aims to examine the impact of endorser ethnicity and portrayal on consumers’ attitude toward luxury ad and brand. In addition, the moderating role of individual’s appearance self-esteem is examined. In the ads of luxury brands in China, it is common to have two types of endorser ethnicity (i.e., international vs. local) and two types of endorser portrayal (i.e., sexy vs. smart). Endorser ethnicity in an ad may influence consumers’ self-referencing behavior which refers to an individual’s tendency to encode communication information differently depending on the level on which the self is implicated in the information (Rogers et al., 1997). Asian consumers’ self-reference level is found to be higher when they are exposed to ads featuring an Asian model than a Western model (Martin et al., 2004). In other words, if an international luxury brand adopts a localization advertising strategy in China by using a Chinese endorser, the local consumers are more likely to generate a higher level of self-reference.
        318.
        2016.07 구독 인증기관·개인회원 무료
        There has been an increasing trend of using code-switching to enhance ad persuasion among local and global brands. Ads that include two or more languages are referred to as code-switched ads (Luna and Peracchio 2005a; 2005b). It is noted that previous studies investigating code-switched ad effectiveness have focused on bilinguals, not monolinguals. Due to the emerging use of code-switching in ads in monolingual markets, more research efforts are required to understand its effectiveness and boundaries among the monolinguals. The purpose of this study is to investigate the moderating role of consumer local-global identity in the effectiveness of code-switched ads among monolinguals. Two experiments were conducted and the results confirmed our hypothesis that consumer local-global identity moderates the effect of code-switched ads. The results indicated that congruence between consumer local-global identity and code-switching enhanced persuasiveness. In addition, the mediating effect of ad involvement was identified. These findings provide managerial implications for marketers.
        319.
        2016.07 구독 인증기관 무료, 개인회원 유료
        The expertise, trustworthiness and attractiveness of the information source all positively influence information recipients’ eWOM (Electronic Word-of-Mouth), acceptance of CSR messages, as well as their attitudes to the company.
        4,000원
        320.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon source, an essential nutrient for plant growth, mainly includes exogenous sugar and CO2 of the environment in vitro. Therefore, the exogenous sugar and CO2 of the environment make the important roles in tissue culture. The aim of this study is to investigate the effects of different sugar concentrations (0, 10, 15 and 30 g·L-1) on the growth of colored Zantedeschia in vitro under certain CO2 concentration and explore the optimal sugar concentration. The plantlets in vitro of colored Zantedeschia had the largest root number, root weight, and root vigor under 0 g·L-1 (sugar-free culture) treatment. And they had the largest plant height, leaf length and leaf chlorophyll content, but p oor r oot v igor under 3 0 g·L-1 sugar. This study indicated that the optimal condition for proliferation and seedling culture of colored Zantedeschia plantlets in vitro was MS medium with 30 g·L-1 sugar, and the suitable medium for rooting culture and transplanting of colored Zantedeschia was MS medium with sugar-free culture under CO2 enrichment condition.
        4,000원