검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 183

        62.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to evaluate antimicrobial resistance of food-borne pathogens isolated from retail meat in Korea. A total of 157 samples of beef, pork, and chicken were collected and analyzed for E. coli, Salmonella, Campylobacter. Resistances to tetracycline were declined in accord with reduced usage of tetracycline in live stock production. E. coli stains from chicken meat had higher multi-drug resistance ratio than strains from other meat. One extended spectrum beta lactamase (ESBL) producing E. coli and two ESBL producing Salmonella were identified in this study. ESBL producing Salmonella strains were confirmed to carry CTX-M-1 type genes.
        4,000원
        63.
        2013.04 구독 인증기관·개인회원 무료
        To substitute for bluebottle fly, Chrysomyia megacephala which is being used for pollinator in mango fruit, and improve the pollinating effect of mango fruit which is also being increased as high value added crop recently in Jeju island of korea, 2 kinds of pollinator were used in analyzing and surveying of foraging activities on mango fruit in Seogwipo province. This study was conducted using 3 species of pollinator, Apis mellifera, Bombus terrestris and Chrysomyia megacephala with 3 treatment in vinyl-house condition respectively. Species of mango fruit, Irwin, was used in this experiment. A number of foraging activity of Apis mellifera and Bombus terrestris in hive showed highest 11 AM, and showed normal foraging activity in high temperature condition(28℃). Pollinating ratio of Bombus terrestris was shown 100% and over 95% in case of Apis mellifera. This ratio suggest that the 2 species of insects is effective as pollinator on mango fruit compared with bluebottle fly. Daily pollinating activity of Apis mellifera and Bombus terrestris was shown peak in 11 AM, but showed even activity from 9 AM to 3 PM in case of Chrysomyia megacephala. The pollinating characteristics of 3 species depends on illuminance but temperature, especially in case of Bombus terrestris was more affected by change of illuminance. Visiting time of Bombus terrestris and Apis mellifera on this flower was shown 2.8 and 3.4 seconds respectively. But Chrysomyia megacephala showed longer 10 times with 32.5 seconds than other insects. This results suppose that Chrysomyia megacephala showed as resting behavior for almost time on the flower not foraging activity to pollinate.
        65.
        2012.10 구독 인증기관·개인회원 무료
        Lepidopteran pests monitoring in adult stage was generally performed using delta or corn typed trap including rubber septa impregnated sex pheromone (lure). Sometimes, unfortunately trapped samples were severly damaged because of biotic and/or abiotic environments such as micro-organism, predator and rain, sticky material, respectively. In our case, we monitored potato tuber moth, PTM, Phthorimaea operculella distribution during 2009~2012 in Korea. However, we encountered unexpected problem, another species can be trapped in species specific sex pheromone trap. Therefore, species confirmation was needed in trapped samples. Here we developed confirmation method by direct PCR (without DNA extraction) or sequencing methods which trapped samples that cannot identified by morphologically. We designed multi-plex PCR universal primers and species specific primers in rRNA region because to check the success of PCR and species identification. This direct PCR method can be applied in other species confirmation which monitored using pheromone trap.
        66.
        2012.10 구독 인증기관·개인회원 무료
        The green peach aphid, Myzus persicae (Sulzer), is one of the most serious pests in cabbage cultivation. Field survey was carried out to know the insecticide resistance levels and to develop the applicable insecticide resistant markers in five main cabbage cultivation regions (Pyeong-chang, Hong-cheon, Bong-wha, Mu-ju and Je-ju) during 2009 to 2011. M. persicae can resist a wide range of insecticides in five surveyed local populations. Therefore multi resistant (MR) strain was selected from these five local populations and esterase over-expression, modified AChE (MACE) and mutation(s) in para-type sodium channel were analyzed using native IEF and quantitative sequencing with five local populations. Esterase over-expression and MACE (StoF mutation) were observed in all populations including MR strain. LtoF mutation is well known as a kdr mutation in para-type sodium channel. However, even though LC50 values of MR strain noted over 2,000 times higher than that of susceptible strain against bifenthrin, LtoF mutation was not detected in para type sodium channel and also local populations. We found another mutation (MtoL) in para and that mutation highly correlated between mutation ratio and bioassay data. For preliminary resistance monitoring, we developed quantitative sequencing (QS) to detect the frequencies of point mutation as a population genotyping. These methods can apply to manage M. persicae resistant populations in field.
        67.
        2012.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We investigate non-LTE effects on the H+ 3 level populations to help the analysis of the observed 2 and 3.5 micron H+ 3 emissions from the Jovian ionosphere. We begin by constructing a simple three- level model, in order to compute the intensity ratio of the R(3,4) line in the hot band to the Q(1,0) line in the fundamental band, which have been observed in the Jovian auroral regions. We find that non-LTE effects produce only small changes in the intensity ratios for ambient H2 densities less than or equal to 5×1011 cm−3. We then construct two comprehensive models by including all the collisional and radiative transitions between pairs of more than a thousand known H3+ rovibrational levels with energies less than 10000 cm−1. By employing these models, we find that the intensity ratios of the lines in the hot and fundamental bands are affected greatly by non-LTE effects, but the details depend sensitively on the number of collisional and radiative transitions included in the models. Non-LTE effects on the rovibrational population become evident at about the same ambient H2 densities in the comprehensive models as in the three-level model. However, the models show that rotational temperatures derived from the intensities of rotational lines in the 2 and 22 bands may differ significantly from the ambient temperatures in the non-LTE regime. We find that significant non-LTE effects appear near and above the H3+ peak, and that the kinetic temperatures in the Jovian thermospheric temperatures derived from the observed line ratios in the 2 and 3.5 micron H3+ emissions are highly model dependent.
        4,000원
        69.
        2012.04 구독 인증기관 무료, 개인회원 유료
        1990년대 후반 IMO 해양사고 조사 결과(A.21/884-9)에 따르면 해양사고 중 75% 이상이 Human Elements와 인과관계를 가지는 것으로 보고된다. 또한 2010 마닐라 회의에서 결의된 문서, STCW Code 개정안에 따르면 안전항해 당직 유지를 위하여 항해사의 선교자원관리(BRM, Bridge Resource Management) 지식 및 자격에 관한 요건에 관한 내용을 강화하고 있다. 본 연구는 인적 요인에 의한 해양사고
        3,000원
        70.
        2011.11 구독 인증기관·개인회원 무료
        Beauveria bassiana is one of universal insect pathogenic fungi that have been used for biocontrol agent against insect pests. This fungus has also been studied for medicinal use. To meet for commercial use, the artificial production of the fruit body of this fungus has been established by the Mushtech Co in Korea. This study was carried out to define the morphological features of the fruit body of B. bassiana developed through artificial cultivation. For the observation of mycelia growth, B. bassiana was cultured on the Sabouraud Dextrose agar plus Yeast Extract(SDAY), nut-supplemented medium, and Fe ion-supplemented SDAY at 25℃ for 15 days. The variation of colony color was observed between the different media. Strong pigmentation was observed on Fe ion-supplemented SDAY. To investigate morphological characteristics of fruit body, geminating ascospores and vegetative hyphae were observed though light microscopy and scanning microscope. During seven weeks of cultivation period, the development process of apical fertile part of stromata can be separated by the development stage of perithecia. To understand the developing process of fruit body at the transcript level, investigating process of distinct gene expression according to cultural condition and developmental stage was discussed.
        71.
        2011.10 구독 인증기관·개인회원 무료
        To increase the fruit quality and productivity of the apricot, 2 species of insects, Apis mellifer, and Bombus terrestris were used for pollination in apricot field in Yeongcheon province. This study was conducted using 3 kinds of methods for pollination effect, natural condition, net-house treatment and control method. Also this experiment carried out in 2 places, vinyl-house and field condition. In case of field treatment of Apis mellifera, heating lamp experiment was added in net-house to find out the reason for harmful efficacy of low temperature early in the spring. Species of apricot, Mangum, was used in this experiment. A number of foraging activity of Apis mellifera and Bombus terrestris in vinyl-house showed higher than in field condition. But after stoping heating, showed low efficacy after showing peak in 1 PM. In field, Apis mellifera showed peak of foraging activity from 1 to 3PM, heating lamp experiment of field condition showed peak in 3 PM and then lowest tendency to evening suddenly. The fruit set rate of Apis mellifera and Bombus terrestris in vinyl-house showed higher with 92% and 89% respectively than control with 83%. In field, heating lamp treatment of Apis melliferawas was highest with 28% compared to Bombus terrestris with 25% and control with 15%. This results suppose that apricot in field was to be harmed by low temperature and frost in blooming time early in spring
        74.
        2009.05 구독 인증기관·개인회원 무료
        Root knot nematode species, such as Meloidogyne hapla, M. incognita, M. arenaria and M. javanica are economically most notorious nematode pests, causing serious damage to the various crops throughout world. In this study, DNA sequence analyses of the D1-D3 expansion segments of the 28S gene in the ribosomal DNA were conducted to characterize genetic variation of the four Meloidogyne species obtained from Korea and United States. PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism), SCAR (Sequence Characterized Amplified Region) marker and RAPD (Random Amplification of Polymorphic DNA) also were used to develop the methods for exact and rapid species identification. In the sequence analysis of the D1-D3 expansion segments, only a few nucleotide sequence variation were detected among M. incognita, M. arenaria, and M. javanica, except for M. hapla. The PCR-RFLP analysis that involves amplification of the mitochondrial COII and lrRNA region yielded one distinct amplicon for M. hapla at 500 bp, enabling us to distinguish M. hapla from M. incognita, M. arenaria, M. javanica reproduced by obligate mitotic parthenogenesis. SCAR markers successfully identified the four root knot nematode species tested. We are under development of RAPD primers specific to the three root knot nematodes found in Korea.
        75.
        2008.10 구독 인증기관·개인회원 무료
        Cryptic mealybug (CMB), Pseudococcus cryptus, is a serious scale pest on citrus, especially grown in plastic greenhouse on Jeju island, Korea. Binomial sampling plan was developed using the relationship between infested proportion of twig with less than T scales (pT) and mean density per twig (m) according to the empirical model ln(m)=α+βln(-ln(1-pT)). T was defined as tally threshold and set to 1, 2, 3, 4 and 5 scales per twig in this study. T=3 was the best tally threshold for estimating densities of CMB based on the precision of the model. Binomial model with T=3 provided reliable predictions of mean densities of CMB observed on commercial citrus orchards. The obtaining model was evaluated by resampling validation of Wald's sequential binomial plan and by fit at 95% confidence intervals for independent collected data sets. Binomial sampling program for decision-making of CMB population level was obtained at the action threshold 0.10, proportion of twig infested with more than 3 scales.
        78.
        2005.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A new ion transport code for planetary ionospheric studies has been developed with consideration of velocity differences among ion species involving ion-ion collision. Most of previous planetary ionosphere models assumed that ions diffuse through non-moving ion and neutral background in order to consolidate continuity and momentum equations for ions into a simple set of diffusion equations. The simplification may result in unreliable density profiles of ions at high altitudes where ion velocities are fast and their velocity differences are significant enough to cause inaccuracy when computing ion-ion collision. A new code solves explicitly one-dimensional continuity and momentum equations for ion densities and velocities by utilizing divided Jacobian matrices in matrix inversion necessary to the Newton iteration procedure. The code has been applied to Martian nightside ionosphere models, as an example computation. The computed density profiles of O+, OH+, and HCO+ differ by more than a factor of 2 at altitudes higher than 200 km from a simple diffusion model, whereas the density profile of the dominant ion, O2+, changes little. Especially, the density profile of HCO+ is reduced by a factor of about 10 and its peak altitude is lowered by about 40 km relative to a simple diffusion model in which HCO+ ions are assumed to diffuse through non-moving ion background, O2+. The computed effects of the new code on the Martian nightside models are explained readily in terms of ion velocities that were solved together with ion densities, which were not available from diffusion models. The new code should thus be expected as a significantly improved tool for planetary ionosphere modelling.
        4,000원
        80.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        5,100원
        1 2 3 4 5