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        검색결과 1,206

        264.
        2019.04 구독 인증기관·개인회원 무료
        270.
        2019.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The use of non-therapeutic antibiotics as animal feed additives has raised public health concerns due to the increasing resistance of pathogens to antibiotics. It is therefore required to develop safe and effective alternative feed additives to replace non-therapeutic antibiotics. The aim of this study was to assess the effects of the multiherbal compound, KIOM-C, on growth performance and immune response of growing-to-finishing pigs under farm conditions. The experimental trials were performed in a Korean commercial swine growing-to-finishing complex, and a total of 70-day-old 160 pigs were selected. Eighty pigs were treated with KIOM-C at the level of 2 kg/tonne until slaughter age (KT group), while another 80 pigs were not treated with KIOM-C (NT group). All animals were vaccinated against foot-and-mouth disease (FMD) at 60 and 110 days of age. During the trial period, average daily weight gain (ADWG), average daily feed intake (ADFI), feed conversion ratio (FCR), survival rates, and average slaughter ages were measured. The serum concentrations of tumor necrosis factor-a (TNF-α), interferon-γ (IFN-γ), and IgA were also evaluated. In order to evaluate specific humoral immune responses, the foot-and-mouth disease virus (FMDV) serotype O-specific antibody was measured. The ADWG, ADFI, and FCR of the KT group were significantly greater than those of the NT group (p<0.05). Serum concentrations of IgA in the KT group was statistically higher than the NT group. The antibody levels of the KT group against FMDV serotype O was higher than the NT group, and 86.67% of the KT group tested positive for anti-FMDV antibodies. Overall, these findings suggest that KIOM-C improves growth performance and immune response of pigs under growing-to-finishing farm conditions, and implies that the herbal compound may be used as a suitable alternative feed additive.
        4,000원
        271.
        2019.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In argumentative writing, writers are expected to use hedged expressions and stance devices through specific linguistic expressions to convince their proposition effectively. Yet little research attention has been paid to whether the inclusion of such devices is related to the overall quality of second or foreign language learners’ argumentative writing. In this study, hedges and stance devices that are included in 28 advanced Korean EFL writers’ argumentative writing were analyzed to identify their potential relation to the overall writing quality. Analyses demonstrated that although hedges and stance devices were related to argumentative writing quality in general, the specific linguistic forms that predicted two different aspects of writing quality – formal and content quality – were different. Specifically, hedges played a significant positive role in only content quality of writing, and the specific stance devices that significantly predicted formal quality did not contribute to the content quality, and vice versa. The findings from this study provides important pedagogical implications for EFL writing instruction.
        5,700원
        272.
        2019.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Acoustics are increasingly regarded as a remote-sensing tool that provides the basis for classifying and mapping ocean resources including seabed classification. It has long been understood that details about the character of the seabed (roughness, sediment type, grain-size distribution, porosity, and material density) are embedded in the acoustical echoes from the seabed. This study developed a sophisticated yet easy-to-use technique to discriminate seabed characteristics using a split beam echosounder. Acoustic survey was conducted in Tongyeong waters, South Korea in June 2018, and the verification of acoustic seabed classification was made by the Van Veen grab sampler. The acoustic scattering signals extracted the seabed hardness and roughness components as well as various seabed features. The seabed features were selected using the principal component analysis, and the seabed classification was performed by the K-means clustering. As a result, three seabed types such as sand, mud, and shell were discriminated. This preliminary study presented feasible application of a sounder to classify the seabed substrates. It can be further developed for characterizing marine habitats on a variety of spatial scales and studying the ecological characteristic of fishes near the habitats.
        4,200원
        273.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pigs are considered as optimal donor animal for the successful xenotransplantation. To increase the possibility of clinical application, genetic modification to increase compatibility with human is an important and essential process. Genetic modification technique has been developed and improved to produce genetically modified pigs rapidly. CRISPR/Cas9 system is widely used in various fields including the production of transgenic animals and also can be enable multiple gene modifications. In this study, we developed new gene targeting vector and enrichment system for the rapid and efficient selection of genetically modified cells. We conducted co-transfection with two targeting vectors for simultaneous inactivation of two genes and enrichment of the genetically modified cells using MACS. After this efficient enrichment, genotypic analysis of each colony showed that colonies which have genetic modifications on both genes were confirmed with high efficiency. Somatic cell nuclear transfer was conducted with established donor cells and genetically modified pigs were successfully produced. Genotypic and phenotypic analysis of generated pigs showed identical genotypes with donor cells and no surface expression of α-Gal and HD antigens. Furthermore, functional analysis using pooled human serum revealed dramatically reduction of human natural antibody (IgG and IgM) binding level and natural antibody-mediated cytotoxicity. In conclusion, the constructed vector and enrichment system using MACS used in this study is efficient and useful to generate genetically modified donor cells with multiple genetic alterations and lead to an efficient production of genetically modified pigs.
        4,000원
        274.
        2018.12 구독 인증기관 무료, 개인회원 유료
        There have long been debated whether Jeju king cherry in Korea and Punus x yedoensis (Yoshino cherry) in Japan are the same or not and its originality. Recent genomic approach among P. yedoensis and closed related varieties from Korea, Japan and USA confirms that P. yedoensis is F1 hybrid. The results also show that there are two types of Jeju king cherry in Mt. Halla, Jeju, Korea and one type is clearly different and the other type is the same grouping to Yoshino cherry in Japan and USA and the maternal texa of the two types in Jeju is the same of P. pendula. The search of paternal texa of the same type and further molecular genetic analysis and classification among newly found hundreds of Jeju King Trees in natural habitats of Mt. Halla including a 265 year-old tree along with previous findings would reveal the hypothesis that two independent F1 hybrid of P. yedoensis are evolved in Mt. Halla where is the only natural birth place of P. yedoensis in the world. Furthermore, policy agenda of king cherry tree eco-exploration among six countries including two divided Korea proposed. In terms of bio-diplomacy, it was amazing fact that Jeju King Cherry trees were sent USA under Japanese colony in 1912. In 1943, USA Congressman John Rankin of Mississippi confirms that they were Korean Cherry Trees. The first four of these trees were presented to the American University in 1943 by the Korean Women’s Relief Society of Honolulu according to notice of AU’s School authority. As Jeju NAtional University students and teachers confirmed the fact in April 2018, they suggest Jeju King Cherry Trees Eco- Exploration between the two universities at university level, hoping to extend a warming program of planting Jeju King Cherry trees at the Dalma tourism complex in Wonsan city of North Korea in April of 2020.
        4,000원
        275.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        농촌진흥청 국립원예특작과학원에서 육성된 formolongi-Asiatic(FA)종간잡종 나리 ‘Bonanza’, ‘Coral Candy’, ‘Purple Crystal’의 특성검정 및 FISH 분석을 통한 염색체 검경을 수행하였다. ‘Bonanza’, ‘Coral Candy’, ‘Purple Crystal’의 개화시기는 6월 중하순, 중순, 상순으로 각각 중만생종, 중생종, 조생종에 해당한다. 개화방향은 3품종 모두 상향이며 약간의 향기를 가지고 있다. 절화장은 101.0cm(‘Purple Crystal’)에서부터 142.3cm(‘Bonanza’)로 초장 신장성이 우수하여 절화로서의 개발이 가능하다. 화폭은 ‘Bonanza’와 ‘Coral Candy’가 17,1cm, 16.9cm로 관찰되어 대형화로 분류되며 ‘Purple Crystal’은 12.3cm으로 좁으나 화폭이 4cm 이상으로 화폭이 안정적이다. 잎의 길이는 ‘Bonanza’는 15.7cm, ‘Coral Candy’는 19.7cm, ‘Purple Crystal’은 11.1cm로 관찰되었다. 염색체 분석 결과, 3품종 모두 3배체(2n=3x=36)로 관찰되었다. FISH 분석 결과, ‘Bonanza’, ‘Coral Candy’, ‘Purple Crystal’의 5S/45S rDNA가 각각 4/11 loci, 4/12 loci, 4/11 loci로 관찰되었다. 3번 염색체를 제외하고 나머지 염색체에서 관찰되는 rDNA의 패턴이 달라 FISH 분석에 대한 결과는 품종을 구별하는 마커로 유용하게 이용 될 수 있을 것으로 기대할 수 있다.
        4,000원
        276.
        2018.12 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to determine if natural extracts could be used as an additive in oral health food made with Weissella cibaria CMU (oraCMU). Natural extracts of green tea, mulberry leaf, licorice, and propolis, which are reported to have antimicrobial activities, were selected and used in this study. The minimum inhibitory concentrations (MIC) of extracts on periodontal pathogens such as Fusobacterium nucleatum and Porphyromonas gingivalis and their synergy effects with oraCMU by the fractional inhibitory concentrations methods were measured. From the results obtained, all the extracts showed no effect on the growth of oraCMU. Green tea extract showed the best antibacterial activity with MIC of 1.8 mg/ml against both F. nucleatum and P. gingivalis. In addition, green tea extract had a synergistic effect with oraCMU against F. nucleatum. Therefore, these results suggested that green tea extract is available as an additive in oral health food made with oraCMU.
        4,000원
        277.
        2018.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Galaxy clusters are known to host many active galaxies (AGNs) with radio jets, which could expand to form radio bubbles with relativistic electrons in the intracluster medium (ICM). It has been suggested that fossil relativistic electrons contained in remnant bubbles from extinct radio galaxies can be re-accelerated to radio-emitting energies by merger-driven shocks via diffusive shock acceleration (DSA), leading to the birth of radio relics detected in clusters. In this study we assume that such bubble consist primarily of thermal gas entrained from the surrounding medium and dynamically-insignificant amounts of relativistic electrons. We also consider several realistic models for magnetic fields in the cluster outskirts, including the ICM field that scales with the gas density as BICM ∝ n0.5 ICM. Then we perform time-dependent DSA simulations of a spherical shock that runs into a lower-density but higher-temperature bubble with the ratio nb/nICM ≈ TICM/Tb ≈ 0.5. We find that inside the bubble the shock speed increases by about 20 %, but the Mach number decreases by about 15% in the case under consideration. In this re-acceleration model, the observed properties of a radio relic such as radio flux, spectral index, and integrated spectrum would be governed mainly by the presence of seed relativistic electrons and the magnetic field profile as well as shock dynamics. Thus it is crucial to understand how fossil electrons are deposited by AGNs in the ICM and how the downstream magnetic field evolves behind the shock in detailed modeling of radio relics.
        4,200원
        278.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ranunculus asiaticus characterizes colorful and attractive flower shapes that are related with the ornamental value of bulbous plants. Improving ornamental value of bulbous flowers has been the general goal of floricultural market. Gibberellic acid (GA3) and benzyladenine (BA) play an important role in growth and developmental processes in floriculture. Combinational treatments of these two hormones have been used in floriculture to improve flower quality. We assessed the effects of combined GA3 and BA, as well as the individual effects of each hormone, on growth characteristics using soil drench application to eight R. asiaticus cultivars, ‘Giallo Millepetali’, ‘Bianco Millepetali’, ‘Arancio Millepetali’, ‘Rosa SC’, ‘Arancio Pratolino’, ‘Giallo Pratolino’, ‘Bianco Pratolino’, and ‘Rosa Ch Pratolino’. GA3 treatments increased plant height and first flower size of R. asiaticus cultivars. Moreover, about 5 to 9 days to flowering were averagely shortened by GA3 treatments compared to controls. On the other hand, the opposites, including first flower size and days to flowering, were observed for cultivars treated with BA, compared with controls. Treatments of GA3 + BA generally affected growth traits, such as plant height, flower size, and the timing of flowering on some R. asiaticus cultivars. In particular, about 5 to 6 days to flowering were reduced on average by Treatments of GA3 + BA. Our results showed positive growth effects, including plant height, days to flowering, first flower height, number of flowers from the application of individual and combined hormones to R. asiaticus cultivars and demonstrate a role for these hormones in future bulbous floriculture.
        4,000원
        279.
        2018.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This study examined EFL college-level learners’ perception toward the contentbased instruction (CBI) by focusing on their participation in and expectation on the courses practiced in a strong form of CBI. Having analyzed the data collected from a questionnaire, observation and interview, the study found that the participants, 39 students who enrolled in two different CBI courses at a university in South Korea, put top priority on the enhancement of content-knowledge considering their CBI course as a content-course, not as a language-course. Second, the participants seemed to prefer participation opportunities induced by a required and prepared speaking task such as presentation through which they can practice a formal speech appropriate for their education experience and cognitive maturity. They also seemed to favor instructor-initiated interaction rather than being put into pair- or group-discussion between and among themselves. Third, the lack of participation was mainly attributed to the lack of understanding contents rather than lack of language skills. Based on the research findings, the study made suggestions on how to offer CBI courses more effectively for a particular group of EFL college-level learners who already earned basic interpersonal communication skills (BICS), yet to reach cognitive academic language proficiency (CALP).
        8,100원
        280.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 노인 스스로가 관리 운영하는 여가복지시설 경로당의 기능을 조사 ․ 분석하여, 지역노인들이 건강한 노년을 보낼 수 있도록 기여하고자 하는데 있다. 경로당은 2017년 12월 기준 서울시 전역에 3,369개소, 1개동에는 7.8개꼴로 있으며, 전국에는 약 68,000개소가 있어 접근성이 가장 뛰어난 노인의 여가복지시설이다. 뿐만 아니라 전통미풍양속과 문화의 전달자 역할을 수행하며 훌륭한 노인복지전달체계로서의 사회간접자본이라 말할 수 있다. 본 연구는 2016. 4. 1~2016. 6. 30까지 서울시내 3,369개 경로당 회장을 대상으로 설문조사를 실시하여 유효샘플 3,100개를 분석하였다. 자료 분석은 SPSS/WIN 21.0프로그램을 이용하였다. 본 연구결과에서 서울 경로당별 등록 회원수는 21~50명 미만이 70.7%로 가장 많았고, 51~100명 미만도 14.7%에 달했다. 경로당의 주요 기능인 중식 관련 도우미 지원금은 20만원 이하가 46.2%로 열악함을 보여주었다. 프로그램 만족도는 매우 만족이 67%로 높았으며, 치매예방과 검진, 건강걷기, 힐링도시농업 등이 70% 안팎의 높은 만족을 나타냈다. 경로당 연면적 규모는 30평 미만이 64.7%로 비좁아 프로그램 진행에 한계로 작용하고 있는것으로 드러났다. 경로당 시설기준 보완과 맞춤형 프로그램 제공, 회장?총무의 리더십 등이 활성화의 주요 요인으로 나타났다. 경로당 기능 개선을 통하여 효율적인 운영역량을 확보하고 경로당의 질관리 및 강화에 보탬이 되고자 한다.
        6,600원