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        검색결과 399

        61.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Antibiotic Detection Kit (Combination I), a lateral flow immunoassay (LFIA) developed for detecting antibiotic residues in milk, was utilized for the analysis of antibiotic residues in the muscle tissue of olive flounder. After 5-h treatment of samples by placing them in water dosed with sulfadimethoxine (SDM; 200 g/ton water), the residue depletion of SDM was investigated in 25 cultured olive flounders (Paralichthys olivaceus). Muscles from fish were sampled before treatment and on the 1st, 2nd, 3rd, 4th and 5th days after treatment. The concentration of SDM in the muscle was then determined by LFIA. The absorbance ratio of the sample to the control blank (Bs/Bo) was employed as an index to determine the residue in olive flounder muscle. To investigate the recovery rate, standard solutions were added to muscle samples to obtain final concentrations of 25 and 50 ng/mL in the muscle. The recovery rates of all spiked samples were >96.6% of the spiked value. SDM was detectable in the muscle of fish treated with the drug until the 1st day of the withdrawal period. The present study shows that the LFIA can be easily adopted to detect SDM residues in the tissue of farmed fish.
        4,000원
        62.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Xenotransplantation of pig islet regarded as a good alternative to allotransplantation. However, cellular death mediated by hypoxia-reoxygenation injury after transplantation disturb success of this technique. In the present study, we produce transgenic pig expressing human heme oxygenase 1 (HO1) genes to overcome cellular death for improving efficiency of islet xenotransplantation. Particularly, Korean miniature pig breed, Micro-Pig, was used in the present study. Somatic cell nuclear transfer (SCNT) technique was used to produce the HO1 transgenic pig. Six alive transgenic piglets were produced and all the transgenic pigs were founded to have transgene in their genomic DNA and the gene was expressed in all tested organs. Also, in vitro cultured fibroblasts derived from the HO1 transgenic pig showed low reactive oxygen species level, improved cell viability and reduced apoptosis level
        4,000원
        63.
        2015.12 구독 인증기관 무료, 개인회원 유료
        Nitric Oxide (NO) is an important signaling molecule in the nociceptive process. Our previous study suggested that high concentrations of sodium nitroprusside (SNP), a NO donor, induce a membrane hyperpolarization and outward current through large conductances calcium-activated potassium (BKca) channels in substantia gelatinosa (SG) neurons. In this study, patch clamp recording in spinal slices was used to investigate the sources of Ca²+ that induces Ca²+-activated potassium currents. Application of SNP induced a membrane hyperpolarization, which was significantly inhibited by hemoglobin and 2-(4-carboxyphenyl) -4,4,5,5- tetramethylimidazoline-1-oxyl-3-oxide potassium salt (c-PTIO), NO scavengers. SNP-induced hyperpolarization was decreased in the presence of charybdotoxin, a selective BKCa channel blocker. In addition, SNP-induced response was significantly blocked by pretreatment of thapsigargin which can remove Ca²+ in endoplasmic reticulum, and decreased by pretreatment of dentrolene, a ryanodine receptors (RyR) blocker. These data suggested that NO induces a membrane hyperpolarization through BKca channels, which are activated by intracellular Ca²+ increase via activation of RyR of Ca²+ stores.
        4,000원
        69.
        2015.06 구독 인증기관 무료, 개인회원 유료
        Growing evidence suggests that mitochondrial reactive oxygen species (ROS) are involved in various pain states. This study was performed to investigate whether ROS-induced changes in neuronal excitability in trigeminal subnucleus caudalis are related to ROS generation in mitochondria. Confocal scanning laser microscopy was used to measure ROS-induced fluorescence intensity in live rat trigeminal caudalis slices. The ROS level increased during the perfusion of malate, a mitochondrial substrate, after loading of 2′,7′-dichlorofluorescin diacetate (H2DCF-DA), an indicator of the intracellular ROS; the ROS level recovered to the control condition after washout. When pre-treated with phenyl N-tert-butylnitrone (PBN) and 4-hydroxy-2,2,6,6-tetramethylpiperidene-1-oxyl (TEMPOL), malate-induced increase of ROS level was suppressed. To identify the direct relation between elevated ROS levels and mitochondria, we applied the malate after double-loading of H2DCF-DA and chloromethyl-X-rosamine (CMXRos; MitoTracker Red), which is a mitochondria- specific fluorescent probe. As a result, increase of both intracellular ROS and mitochondrial ROS were observed simultaneously. This study demonstrated that elevated ROS in trigeminal subnucleus caudalis neuron can be induced through mitochondrial-ROS pathway, primarily by the leakage of ROS from the mitochondrial electron transport chain.
        4,000원
        70.
        2015.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study intends to analyze the fit of directly-imported American casual pants for Korean female college students in terms of appearance and comfortableness. The authors carried out a wearing test with sample pants from 3 brands (DKNY: A, Gap: B, Pol C) that had the most market share and that were mostly preferred by Korean female college students. Results showed that pants A had insufficient ease in the crotch, as the depth of the crotch was short. The hip girth received a low assessment in terms of appearance. Moreover, the hem widths were wide while the pants length was long. Pants B were expected to be most appropriate for Korean women’s bodies, as they had the longest crotch depth among the three brands. However, the pants appeared to pull downward due to the narrow thigh and the knee girth and hem width. Moreover, the crotch girth and hip girth received a poor appearance assessment. Pants C were rated as satisfactory for their thigh girth, knee girth, and hem width. However, the crotch was uncomfortable, as it had a short crotch depth. The hip girth received a low appearance assessment. This study suggests that a pattern adjustment is required for directly-imported American pants to provide a better fit for the bodies of Korean women. The crotch depths should be approximately 17.5 cm. The hem widths should be approximately 20 cm. We also suggest a leg length of 75 cm, a waist girth of 86 cm, and a hip girth of 97 cm.
        4,000원
        71.
        2015.04 구독 인증기관·개인회원 무료
        Vollenhovia emeryi (Hymenoptera: Myrmicinae) is dimorphic in its wing morphology of alate females: the long-winged and the short-winged. In our previous study, we found that the long-winged is ancestral and the short-winged is derived. Intriguingly, the former is infected with the intracellular symbiotic Wolbachia bacterium and the derived is void of the bacterium indicating that the latter somehow evolved resistance to the bacterium. This may be one of few cases in which transition from susceptibility to the bacterium can be traceable via the divergence estimation. As a consequence, we inferred that the two morphs diverged approximately quarter million years ago; a remarkably recent event in evolutionary perspective. In this presentation, we will further discuss genetic orchestration in the host insect and future research directions.
        76.
        2014.10 구독 인증기관·개인회원 무료
        The Wolbachia bacterium is one of the best studied reproductive manipulators found in variuos invertebrate taxa. Theoretically it infects two thirds of invertebrates. It is thought to have a huge impact on its hosts’ evolution. The ant is a very successful organism in terrestrial ecosystems especially with its charicteristic sociality. However, the influence of Wolbachia on the animal remains to be paid more attention. This study is to examine Wolbachia infection frequency in some ant species in Korea. The result shows that 9 out of 12 ant species harbor the bacterium. Furthermore, at least two species show polymorphism in their infection status at the colony level. This will be used as a foundation of further study on the interactions between the bacterium and ant species.
        77.
        2014.10 구독 인증기관·개인회원 무료
        Recently, researches of molecular biology for the identification of root-knot nematode (RKN) species have been reported in plant quarantine. In this study, applicable and reproducible method to extract high quality genomic DNA from single nematode (Meloidogyne spp.) was developed. Also, the modified method was verified by DNA manipulation techniques such as PCR amplification and cloning. Single juvenile was floated in a drop of water and digested with proteinase K for 24 h. After that, DNA was extracted by using distilled water as extraction buffer. PCR amplification was carried out with universal primers spanning the internal transcribed spacer (ITS) region to distinguish species. When using the existing DNA detection method, quantification results showed that 42.86% of the deposited DNA was extracted. Whereas the modified DNA extraction method was increased to 100%. When PCR products test the direct sequencing using the ITS rDNA primers, it was also identified as M. javanica, M. incognita, and M. hispanica. Based on the studies conducted, the application of this modified method would be useful and efficient on plant parasitic nematode molecular assay.
        78.
        2014.10 구독 인증기관·개인회원 무료
        The study was to examine the variation and pattern of colony components of Vollenhovia emeryi. The total of 38 colonies was collected from 10 locations, including 35 colonies from 9 locations in South Korea and 3 colonies from 1 location in USA. To know colony components variation, we studied the approximate colony size, the approximate number of reproductives: queens, gyne and male, the approximate number of brood during 7 months. The observation period was from September 2012 to March 2013 over the breeding season from July to August. As a result, the study has found that colony components of the 38 colonies are not constant. This also indicates that gynes and males appear during non-breeding season at least in the laboratory condition. There are 4 types of gynes and males emergence: both(31.6%), only gynes(2.6%), only males(28.9%), absence(28.9%). The number of gynes and males of each colony also shows variance. It indicates that Vollenhovia emeryi may show colony components continuum. In this species, fertilized eggs become worker females and males; worker females are diploid but males are haplid because of maternal genomic elimination. Unfertilized eggs become queens which are diploid by clonal reproduction. Therefore, each individual of the sex can exceptionally transfer its own genes. This unique haplodiploid sex determination may create the conflict between queen and male and cause colony components continuum.
        79.
        2014.07 구독 인증기관 무료, 개인회원 유료
        Introduction Driven by the rapidly evolving media landscape, firms extensively use social media to engage with their customers (Avery et al., 2010). Today, social media is an integral part of an individual’s daily life, which makes a vital venue through which companies connect with customers (Men & Tsai, 2011; Utz, 2009). Given the increased use of social media, recent studies have investigated how social media cultivates customer relationships with celebrities and/or media personalities (e.g., Smith, 2010). In light of the effectiveness of social media as a marketing tool, it is noteworthy to analyze the source power of celebrities and social relationships and consider how to take advantage of the power. The parasocial relationship is founded upon the communication process, which is an important factor in understanding the relationship between media and users. Parasocial relationships differ according to the motives for using social network service (SNS), while connection and attachment to celebrities, such as having empathy for a particular celebrity, is affected by celebrity source credibility. (Ohanian, 1990). The purpose of this study is to clarify the relation between parasocial relationships and customer equity in the social media context. The study investigates effects of motivations to use SNS and source credibility on parasocial relationships, as well as the effects of parasocial relationships on attitude and customer equity, and customer lifetime value. Theoretical Frameworks In this study, parasocial relationship refers to a virtual intimacy between a media personality and the media users, in other words, it is a psychological, interpersonal relationship unilaterally formed by users based on proximity, similarity, and attraction to the media personalities (Rubin & Step, 2000). When a parasocial relationship is formed, the media consumer appreciates the values and motives of the media character, often viewing him or her as a counselor, comforter, and model (Horton & Wohl, 1956). When using an SNS, users’ communication habits and their selection of social network services vary according to their motives, which in turn affect the parasocial relationships with celebrities via SNS. Motives for using SNS, specifically, information seeking, entertainment, and social connection may have a positive relationship with parasocial relationships. Source credibility, the positive characteristics of a communicator that affect the receiver’s acceptance of a message, positively influences parasocial relationships (Ohanian, 1990; McCracken, 1989) based on expertise, trustworthiness, and attractiveness of the media celebrities. In the social media context, a parasocial relationship has positive influence on attitude toward using an SNS. Social media users engage in finding people with whom they have an offline connection (Ellison, Steinfield, & Lampe, 2007). Social media enables individuals to connect with others all around the world easily, it is not surprising that parasocial relationships influence users’ attitude toward using social media, offering environments to enhance connections (Byod & Ellison, 2008). Further, it is worthwhile to note that parasocial relationships may have a positive influence on customer equity. The key to customer equity lies in understanding the customer lifetime value concept, which refers to the net present value of a customer’s profit stream (Rust, Lemon, & Zeithaml, 2004). Parasocial relationships positively influence brand, value and relationship equity, with the emergence of brands as one of the key organizational assets (Gummesson, 2004). Parasocial relationships explain relationships between individuals and brands, product, symbols, objects, and corporate identities. Such relationships allow individuals to have bonds with brands, trademarks and other symbols, politicians, sportsmen or even actors (Gummesson, 2004). Thus, they positively influence customer equity including brand equity, value equity, and relationship equity. Focused on effects of motivations to use SNS and source credibility on parasocial relationship as well as the effects of parasocial relationship on attitude, customer equity, and customer lifetime value, this study tests the following hypotheses: H1: Motivations to use SNS will have a positive influence on parasocial relationship. H2: Source credibility will have a positive influence on parasocial relationship. H3: Parasocial relationship will have a positive influence on attitude toward using SNS. H4: Attitude toward using SNS will have a positive influence on customer equity. H5: Parasocial relationship will have a positive influence on customer equity. Methods This study used a survey to investigate key questions about the associations between parasocial relationships and customer equity. A total of 350 social media users recruited from Hong Kong and Macau in China participated in the survey. Of the 350 participants, 129 were men (36.9%) and 221 were women (63.1%), with ages ranging from 21 and 35 years old (mean = 25.6 years). This study measured motivations for using SNS on a five-point Likert scale (1 = strongly disagree; 7 = strongly agree), which was adapted from an existing motivation scale (Leung, 2009; Leung & Wei, 1998; Sheldon 2008). To measure source credibility, this study used a five-point Likert scale, which was also adapted from an existing source credibility scale (Eisend & Langner, 2010; Priester & Petty 2003). Parasocial relationships were measured on the basis of user responses to 17 items on an existing five-point scale that assessed parasocial relationships (Koeppel et al., 1993). This study measured attitude toward using SNS through an existing scale (Venkatesh, Morris, Davis, & Davis, 2003). Customer equity was measured using an existing five-point scale (Keller, 2003; Rust et al., 2004) that elicited user responses to 13 items. Customer lifetime value (CLV) was calculated only for the customers in the sample, and CLVs were calculated separately before the average was taken by using the equation below: The CLVij of customer i to brand j, is given as: Tij= Frequency of purchases by customer i for a specific period of time dj= The rate of discount offered by company j fi= Annual average frequency of purchases by customer i for a certain period of time Vijt= The amount of purchase of brand j by customer i for a period of time t πijt= Expected profits by purchase unit of brand j by customer i for a period of time t Bijt= Probability that customer i buys brand j in purchase t Results The overall goodness-of-fit for this measurement model was acceptable (Chi-square = 8.218, df = 5, p = 0.145, GFI = 0.992, CFI = 0.991, RMR = 0.095, RMSEA = 0.043). The reliability coefficients of all 20 motivation measures were 0.885, and they were based on three factors of information seeking, entertainment, and building relationships. The reliability coefficients of all 16 source credibility measures were 0.924 with three factors of attractiveness, expertise, and trustworthiness. The reliability coefficients of all 17 parasocial relationship measures were 0.866 with three factors: proximity, similarity, and attachments. The reliability coefficients of all 13 customer equity measures were 0.838 with three factors of value equity, brand equity, and relationship equity. Cronbach’s alpha for attitude was 0.792. The coefficients indicate the acceptable reliability of the measures. Motivations to use SNS showed statistically positive effects on parasocial relationship (β = 0.151, p < 0.001). Specifically, entertainment (β = 0.148, p < 0.01) and building relationships (β = 0.093, p < 0.05) motivations showed significant positive effects on parasocial relationships while information seeking motivation did not show significant effects on parasocial relationships (β = 0.074). Source credibility showed statistically positive effects on parasocial relationship (β = 0.316, p < 0.001). Thus, the results supported H1 and H2. Parasocial relationships showed statistically positive effects on attitude (β = 0.295, p < 0.001) and customer equity (β = 0.272, p < 0.001). Attitude showed statistically positive effects on customer equity (β = 0.172, p < 0.001). Thus, the results supported H3 and H4. Customer equity showed statistically positive effects on customer lifetime value (β = 3.452, p < 0.001). Thus, the results supported H5 (see Table 1, Figure 1). Discussion This study contributes to clarifying parasocial relationships in the social media context and determining the relationships between parasocial relationship and customer equity. This study contributes to the theoretical foundation and implications of parasocial relationships and customer equity. Specifically, motivations to use SNS and source credibility positively influence parasocial relationship. Parasocial relationships have positive effects on attitude and customer equity. Customer equity, in turn, has positive effects on customer lifetime value. The study is the first of its kind on the effects of parasocial relationships on customer equity in the social media context. The study finds that motivations and source credibility are important antecedents of consumers’ parasocial relationships formed via social media. Parasocial relationships have a positive effect on attitude and customer equity, and customer equity leads to increased customer lifetime value. This study suggests that parasocial relationship is one of the strong influential variables on customer equity as it improves customer lifetime value. Thus, marketers should definitely consider parasocial relationship management in the social media context while tailoring their brand communications to their most profitable customers and enhance their customer lifetime value.
        4,000원
        80.
        2014.04 구독 인증기관·개인회원 무료
        Radopholus similis belong to the plant parasitic nematode family, Pratylenchidae and was recognized that injure the plant. R. similis was generally identified from bananas and plantain in the tropics. However, the occurrence of infection of R. similis on new host plant was confirmed recently. The aim of this study was to report the determination of new host plant for R. similis on Staurogyne sp. The species identification was evaluated the morphological and molecular characteristics of nine R. similis. Molecular assay was designed from the internal transcribed spacer region (ITS) of ribosomal DNA to distinguish species. Nematodes from Staurogyne sp. showed almost similar morphological and morphometric characteristics in general R. similis, but some variation in tail shape was confirmed. Also, male was not detectable. Molecular assay showed a high level (97%) of similarity in the TW81-AB28 and 18S-28S sequences (ITS region) with corresponding NCBI sequence. The quarantine should be more intensely to detect the prohibited nematode.
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