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        검색결과 211

        81.
        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.
        82.
        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
        84.
        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
        85.
        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.
        86.
        2011.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the influence of the static pelvic inclination and declination in the static standing position on weight bearing rate and gait elements. Fourteen healthy adults in their twenties were participated. Two groups of healthy adults were allocated in this study: above and below the average of pelvic tilt. The correlation between the pelvic inclination, weight bearing rate and gait elements were measured. There was a statistical correlation between the pelvic tilt and step. Also, there was a statistical difference when we compared anterior declination with swing period and posterior declination with step. There was an asymmetric correlation between pelvic tilt and step. However, there was no statistical difference between the groups above and below the average of pelvic tilt. This result indicates that dipper pelvic inclination doesn't affect the asymmetry of step.
        4,000원
        87.
        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
        89.
        2009.10 구독 인증기관·개인회원 무료
        In organic agriculture, various cover-crops have been used to control weeds. In this study, we have investigated the effect of Vicia tetrasperma (L.) Schred. (Eolchigiwandu) which is native to on major insect pests of pepper. Redpepper seedlings at 8 leaves stage were transplanted in 20th May 2009 into experimental field located in the farm of the department of agricultural biology, Suwon, Korea. A cover-crop cultivation plot was compared with a control plot mulched by black plastic-film. Density of aphids and damaged fruits by oriental tobacco budworm, Helicoverpa assulta, were surveyed ten times from 21 days after transplanting (DAT) to 82 DAT. Fifty and forty pepper plants were sampled to count the density of aphids and damaged fruits by oriental tobacco budworm per a plant, respectively. In current study, three aphid species namely, cotton aphid, Aphis gossypii, green peach aphid, Myzus persicae, potato aphid, Macrosiphum euphorbiae were collected. Overally, the density of aphids on pepper in the control plot was higher than the cover-crop plot. Especially, aphid density increased up to 67.44±26.8 in early stage of control plot, whereas aphid was not found in cover-crop plot. The rate of fruit damage by oriental tobacco budworm was significantly higher in the cover-crop plot than the control plot in early stage of pepper, however damaged fruit rate of pepper in the control plot was significantly higher since the middle of July.
        90.
        2009.10 구독 인증기관·개인회원 무료
        The devastating insect pests of the tomato (Lycopersicon esculentum) were surveyed in environmentally friendly (no-pesticide and organic) greenhouses located in the provinces of Gyeonggi, Gyeongsang, Gangwon, Chungcheong and Jeju. Whitefly, leaf miner, aphid and moth were recorded as the major pests in these surveys. Among them, whitefly was the most serious pest of greenhouse cultivated tomato and major species was Trialeurodes vaporariorum. The population densities of T. vaporariorum was 0~36 nymph per leaf. Population of moths Spodoptera litura were the highest in summer season. Population of the whitefly was considered to be influenced by the previous cultural methods. Farmers in organic cultivation, used insect natural enemy, commercial EFAM (Environment Friendly Agricultural Material), yellow sticky trap or home made pesticides. Commercial microbial pesticides were applied to evaluate their insecticidal activities against whitefly. The results revealed that microbial pesticides exhibited 65.3 to 100% whitefly nymph mortality. Further, pesticidal activities of Cooking Oil and Yolk (COY), plant extracts and neem oil were evaluated against other tomato pests as well.
        92.
        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.
        93.
        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.
        96.
        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
        98.
        2004.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        4,800원
        99.
        2003.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        강진을 고려한 지진설계 규준은 약진지역에서는 불필요한 경제적 손실을 가져을 수 있고, 지반-구조물 상호작용을 고려한 성능기준 설계가 합리적인 지진설계를 위해서 중요하다는 것이 인식되었다. 이 연구에서는 연약지반 위에 놓인 단자유도계의 탄성, 비탄성 지진응답 해석을 지반의 비선형성을 고려하여 최대지진가속도를 0.07g와 0.11g로 조정한 11개 약진에 대해 수행하였다. 지진응답해석은 지반-구조물체계에 대해 유사 3차원 동적해석 프로그램으로 암반에 지진기록을 입력하여 한 단계에 일괄적으로 수행하였다. 연구 결과에 의하면 고정지반이나 선형지반을 가정한 지진응답 스펙트럼은 구조물-지반체계의 실제적인 거동을 보여주지 못하는 것으로 나타났으며, 합리적인 지진설계를 위해서는 지진규준에 정해진 일상적인 설계절차에 다라서 수행하는 것보다 다른 성질을 가진 여러 지반에 대해서 성능기준 지진설계를 수행하는 것이 필요하다. 약진을 받는 연약지반의 비선형성도 입력지진동을 증폭시켜 탄성, 비탄성 지진응답 스펙트럼에 심하게 영향을 미쳤으며, 그 현상은 특히 탄성 응답스펙트럼에서 두드러졌다.
        4,000원
        100.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        5,100원
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