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        검색결과 20

        1.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study describes the national program of year-round surveillance and monitoring for avian influenza (AI). The validity of the epidemiologically-based surveillance scheme was assessed. Korea’s current surveillance program is aimed at detecting subclinical infection of either the highly pathogenic avian influenza (HPAI) virus or the low pathogenic avian influenza virus, types H5 and H7, both of which carry risk of converting to HPAI. The current AI surveillance program has demonstrated that implementing a surveillance strategy is plausible. Farmer and livestock related professional support is the critical step of specimen collection to discover hidden infection. Early detection of AI virus infection can achieve best by the combined efforts of farmers, animal health authorities, and other related industries.
        4,000원
        2.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Foot-and-mouth disease (FMD) has great potential for causing huge economic loss and was the first disease identified by the World Organisation for Animal Health (OIE) in its official list of free countries and zones. This study examined the governmental expenditures for five FMD epidemics that occurred in the Republic of Korea between 2000 and 2011. The costs of an epidemic ranged from 26 billion Korean won (KRW, approximately 23.6 million US dollars, ) to a maximum of 2,044 billion KRW (US 1.9 billion). For two epidemics in which vaccinations were implemented, the costs were higher than those epidemics without vaccination. The mean cost for an outbreak ranged from 0.5 billion KRW (US 4.5 million) for the 2010/2011 epidemic to 18.2 billion KRW (US 16.5 million) for the 2000 epidemic. Mean costs per infected premises were 7.0 billion KRW for cattle farms (95% CI: 4.72∼9.28), 1.38 billion KRW for pig farms (0.88∼1.87), 0.11 billion KRW for deer farms (0.08∼0.14), and 0.10 billion KRW for goat farms (0.07∼0.13). The highest cost for an outbreak in cattle seemed associated with the number of outbreak cattle farms in two epidemics in which vaccination was implemented.
        4,000원
        3.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study presents a smartphone application, named「Vepi Tools」. This stand-alone type application is aiming at supporting on-site decision-making for animal health professionals. It provides basic calculations of epidemiology including estimating disease frequency, measuring associations using two-by-two table, calculating sample sizes to detect disease, and to estimate a mean or prevalence. Rationale and examples are available for each function. This study shows some use cases with this「Vepi Tools」application.
        3,000원
        4.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Veterinary Epidemiology Division of The Animal, Plant, and Fisheries Quarantine and Inspection Agency (QIA) was established in 2002. It is the first governmental organization in the Republic of Korea to be charged with the epidemiological task of managing veterinary public health. In commemorating the previous efforts of this organization, this paper describes the brief history, concept, tools, and approaches of veterinary epidemiology. The mission of veterinary epidemiology, as a leader of 'One Health', to improve the public health status of human and animal is also discussed.
        4,000원
        5.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Over the past decade, the magnitude and variety of modelling work in the realm of veterinary services has shown a significant increase. Accordingly, the need for enhancement of communication and cooperation among modellers (those who develop models), users (those who run models), policy makers (those who use model outputs in decision making on control policy) and coordinators (those who connect modellers with policy makers) has also shown a notable increase. In this paper, terms used in epidemiological models are listed alphabetically and explained. It is expected that development of this lexicon will help to boost communication and collaboration among those concerned with modelling work and its utilization.
        4,500원
        6.
        2015.07 서비스 종료(열람 제한)
        The complete chloroplast (cp) genomes of two Miscanthus species, M. sinensis and M. sacchariflorus, were sequenced and investigated for genes, genome size variation, and polymorphisms. There are 154 genes in both cp genomes, consisting of 122 coding genes, 40 tRNA genes, and 8 rRNA genes. The cp genome contains two inverted repeat (IR) regions, separated by large single copy (LSC) region and small single copy (SSC) region. 112bp indels in M. sinensis and 152bp in M. sacchariflorus were found mainly in LSC and SSC, which are responsible for 40 bp-difference in cp genome size in two species. Likewise, out of 94bp of SNPs, 88bp were found in LSC and SSC regions. Although gene number and sequence structure were quite well conserved, indel distribution and size were different in these two Miscanthus species.
        7.
        2015.07 서비스 종료(열람 제한)
        More than 300 Miscanthus accessions as a potential bioenergy crop were collected in Korea and their morphological traits were investigated at various growth stages. Among morphological traits, stem growth habit, the presence of awn in spikelet, and autumn new shoot are the most important key traits enabling to cluster Miscanthus accessions into M. sinensis and M. sacchariflorus groups. Miscanthus sinensis has bunch stem growth habit and awn in spikelet, and produces autumn new shoot, while M. sacchariflorus has scattering stem growth habit with no awn in spikelet and does not produce autumn new shoot. Interestingly, we found several Miscanthus accessions showing intermediate morphological traits. 7 M. sinensis accessions showed morphological traits similar to M. sacchariflorus and 17 M. sacchariflorus accessions showed morphological traits similar to M. sinensis. Flow cytometry and chromosome counting finally revealed 5 Miscanthus hybrids, suggesting that they are resulted from natural hybridization between M. sinensis and M. sacchariflorus. Therefore, these Miscanthus hybrids can be used to understand genetic recombination between these two Miscanthus species and our understanding may support future efforts for breeding new Miscanthus variety with high biomass productivity and environmental adaptability.
        8.
        2014.07 서비스 종료(열람 제한)
        It is assumed that air temperature and light intensity may influence thermal image of plants but little effort has been made to these environmental factors. We conducted this study to investigate the effects of these environmental factors on the thermal image of rice and thus to optimize the condition for thermal image acquisition for high-throughput screening of salt-tolerant rice. Rice (Oryza sativa cv. Chucheong-byeo) seedlings at the four-leaf stage were treated with 0, 50, and 100 mM of NaCl for salt stress. Thermal images (T420, FLIR, Sweden) were taken at 1 and 2 days after salt treatment under 4 different air temperatures and 3 light intensities. Thermal images were analyzed using FLIR Tools 3.1 (FLIR systems Inc., USA) and MATLAB 8.1 (The MathWorks Inc., USA). Rice leaf temperature increased significantly with increasing air temperature and light intensity, resulting in greater discrimination between salt-stressed and unstressed rice plants. Our results thus conclude that environmental conditions such as air temperature and light intensity affect rice thermal image and their optimization is essential for better image acquisition and high-throughput screening system based on thermal image analysis
        9.
        2014.07 서비스 종료(열람 제한)
        The purpose of this study was to establish a system for plant fluorescence image acquisition and to verify the possibility of plant fluorescence image analysis as a non-destructive method to screen the salt tolerance of soybean (Glycine max). Two-weeks-old seedlings of soybean at the V1 growth stage were treated with 0, 50, and 100 mM of NaCl for salt stress and plant fluorescence images were taken by CCD camera (EOS-600D, Canon, Japan) equipped with band pass filter (XNiteBPB, LPD LLC, USA) at 0, 15, 30, 60, 120 and 240 second after blue light exposure at 1 day after treatment. Red color intensity was extracted using MatLab 8.1 (The MathWorks Inc., USA) for estimation of plant fluorescence intensity. Red color intensity of soybean image decreased 0 (F0-10) to 240 (F240-250) second after blue light exposure irrespective of NaCl concentration, while F0-10/F240-250 decreased with NaCl concentration, resulting in significant relationship with plant fluorescence (Fv/Fm) and salt stress intensity. Therefore, our results suggest that our plant fluorescence image acquisition and analysis methods can be a part of high-throughput screening system for salt tolerance of soybean varieties
        10.
        2013.07 서비스 종료(열람 제한)
        This study was conducted to provide basic data for high-throughput screening (HTS) system construction based on phenomics. Rice (Oryza sativa cv. Chucheongbyeo) seedlings in vegetative growth stage were grown in the glass house and treated with 0, 3.75, 7.5, 15, and 30% (w/v) of polyethylene glycol (PEG) to give osmotic stress. Three days after PEG treatment, hyper-spectral reflectance images were obtained and analyzed after removing background image in several steps. The reflectance of rice seedlings treated with 15 and 30% of PEG solutions were significantly different at 680 nm, where differences in the chlorophyll reflectance spectrum and visual symptoms were not observed. These results thus indicate that hyper-spectral reflectance observed at 680 nm can be used to screen drought tolerant rice lines. A HTS system equipped with this hyper-spectral reflectance system may play an important role of future rice breeding program.
        11.
        2013.07 서비스 종료(열람 제한)
        This study was conducted to investigate plant body temperature response of soybean (Glycine max) to saline stress. Two-weeks-old seedlings of soybean in V1 growth stage were treated with 0, 10, 20, 40, 80 and 160 mM of NaCl for salt stress. Thermal images acquired using Flir T-420 (US) were obtained at 4 days after treatment. Soybean leaf temperature increased with increasing NaCl concentration, resulting in significant positive correlation between soybean leaf temperature and stress intensity (P < 0.01). Leaf temperature of soybean was significantly different at 160 mM of NaCl, where no visual symptom was observed. Therefore, soybean leaf temperature can be used for evaluating the response of soybean to salt stress as a non-destructive and phenomic parameter. Non-destructive diagnosis of soybean leaf temperature may be a key parameter in a high throughput screening (HTS) system in breeding program for salt stress tolerance soybean cultivars.
        12.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        Global warming means not only increase in average air temperature but also increase in frequency of extreme weathers such as extremely high temperature over 45oC. Crops are generally sensitive to high temperature during their reproductive growth stage. This experiment was thus conducted to investgate physiological responses of rice (Oryza sativa cv. Chucheong) and soybean (Glycine max cv. Sinpaldal) to high temperature (HT) stress at their reproductive stage. Rice and soybean were exposed to different degrees of high temperature stress by keeping them in a growth cabinet deisnged to maintain air temperature up to 45oC for at least 5 hours in a day for different durations, 0, 1, 2, 3, and 4 days. HT stress treatment delayed heading and flowering of rice and increased the sterility of its' main panicle with increasing duration of HT treatment; 19.7 43.4, 68.1, 81.5 and 91.1% at 0, 1, 2, 3 and 4 days HT treatment, respectively. Increasing sterility due to HT treatment thus resulted in significant rice yield loss; 5.07 4.27, 4.32, 4.51 and 3.62 g/plant at 0, 1, 2, 3 and 4 days of HT treatment, respectively. Soybean was also significantly affected by HT stress in its pod formation and sterility, particularly along the vertical stem. Increasing pod sterility with increasing HT treatemnt thus resulted in significant soybean yield loss.
        13.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        Over the past few decades Miscanthus has been studied as a potential bioenergy crop in Europe but not much been studied in Korea although Korea has many native Miscanthus species and genetic resources. Because of their features, such as low demands of fertilizers and other agrochemicals, high water use efficiency and high productivity, Miscanthus can be cultivated in marginal lands. However, it is not known how Miscanthus can survive in saline soil and what extent Miscanthus can tolerate salt stress, one of main abiotic stresses in reclaimed lands or dry climates. Therefore, this study was conducted to investigate physiological response of Miscanthus species to salt stress and thus to establish a salt stress threshold. Miscanthus sinensis and M. sacchariflorus showed similar responses to salt stress. Chlorophyll contents, photosynthesis and plant growth were all significantly affected by salt stress. Both species were completely killed at > 100 mM NaCl. The GR50 values estimated by non-linear regression analysis with the logistic model were 116.2 mM and 63.1 mM for M. sinensis and M. sacchariflorus, respectively. These GR50 values can be used as their thresholds of salt stress. Further studies will be conducted to screen salt-tolerant Miscanthus genotypes.
        14.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        Miscanthus, a perennial rhizomatous C4 grass, is a potential biomass crop, mainly because of its high yield potential and low demand for inputs. But, overwintering is the biggest problem for establishment of Miscanthus in the first year after planting rhizomes, particularly in East Nothern Asia, where winter is very cold. In this study, overwintering and freezing tests with Miscanthus rhizomes were conducted in the field (Experimental Farm Station of Seoul National University, Suwon, Korea) and the freezer maintained at -18℃, respectively. For overwintering test, rhizomes of Miscanthus sinensis, M. sacchariflorus and M. x giganteus were buried at 1, 3, 6, and 9 cm soil depths in the field in December 2009 and transplanted in a plastic pot containing sandy loam soil in March 2010. The pot was then placed in the incubation room maintained at 35/25℃ for assessing seedling establishment and early growth. For freezing test, Miscanthus rhizomes planted at 3 cm soil depth in a plastic pot containing sandy loam soil were kept in the freezer for different durations and then transfer to the incubation room for assessing seedling establishment and early growth. Rhizomes buried at 1 cm showed the least seedling establishment, while those buried at 6 cm showed the best seedling establishment, suggesting that rhizomes need to be planted at 6 cm for their successful overwintering. When rhizomes were exposed to freezing temperature down to -18℃, their survival decreased with increasing the duration of freezing exposure. From 12 hours of exposure their survival rate decreased significantly and finally reached to zero at longer than 24 hours of exposure. Further studies will be conducted to screen cold tolerant genotypes.
        15.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        Miscanthus, a perennial rhizomatous C4 grass, is a potential biomass crop. Its propagation can be made by seed, rhizome and cultured tissue. Propagation by rhizomes or cultured tissues is expensive, while seed propagation is rather simple and cheaper. However, little effort has been made to investigate seed germination, particularly in relation with exogeneous chemicals including plant growth regulators to improve germination. This study was conducted to improve the seed germination of Miscanthus with GA3, NaClO, KNO3 and procloraz. iscanthus sacchariflorus and Miscanthus sinesis seeds were treated with the above chemicals at different concentrations. Decoated seeds were soaked in GA3, NaClO, KNO3, and procloraz solutions. Pretreated 20 Miscanthus seeds were then sown in each petri dish covered with a single layer of Watman filter paper and maintained in the incubation chamber at 33℃/25℃ (day/night). Seed germination were measured every 8 hours. As a result, the best germination was obtained at 250 mg/L GA3, 0.3% NaClO, 1 mM KNO3 and 1 mL/L procloraz solutions.
        16.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        Early diagnosis of crop growth at various growth stages will help to make an optimum fertilization. If we can diagnose crop growth at around the time of topdressing of N fertilizer, N fertilization can be made based on crop growth and target crop yield, which may provide economic and environmental benefits as compared with fixed rate fertilization. In this study we devised methods to diagnose rice growth non-destructively at panicle initiation stage and to determine N topdressing rate. SPAD-502, Field Scout CM1000 and Green Seeker GNDVI were used to diagnose the growth status of rice grown at different soil N fertilities. The values measured by the diagnostic equipments at rice panicle initiation stage were then regressed to rice grain yield. It was found that CM1000 and GNDVI were more efficient than SPAD to diagnose rice growth. Therefore, a multivariate model with CM1000 and GNDVI values was developed to make a decision of N fertilization at rice panicle initiation stage. In a subsequent field study, N fertilization determined by non-destructive growth diagnose by CM1000 and GNDVI, and the multivariate model could minimize N fertilizer use to achieve our target yield, resulted in significant reduction of N fertilizer as compared with fixed rate N fertilization.
        17.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        Miscanthus is a rhizomatous perennial C4 grass and has been studied as a lignocellulosic biomass energy crop in Europe and USA. Although Korea has many native Miscanthus species, however, Miscanthus has never been considered as a potential bioenergy crop and not much studied. Therefore, we collected Miscanthus spp (M. sinensis and M. sacchariflorus) in Korea and overseas and conducted a field experiment during 2008-2010 to investigate their agronomic characteristics related to biomass yield and thus to select genotypes with a high biomass yield potential. The agronomic characteristics assessed are plant height, leaf area, stem thickness, stem density, flowering time, dry weight and so on. Some Korean genotypes particularly collected in Jeju and Gyeonggi showed very high biomass yield, suggesting that they can be used for breeding a new Miscanthus cultivar for biomass production. Correlation analyses showed that plant height, stem thickness and density are closely related with biomass yield. Flowering times vary with genotypes and their collection sites. Phenotypic information of Korean Miscanthus we present herein may be useful for further studies on Miscanthus as a bioenergy crop.
        18.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        Acid rain due to air pollution has been believed to be harmful to vegetation and crops, either by direct deposition on the foliage or by indirect leaching of nutrients from the soil. This study was conducted to investigate physiological response and damage of soybean caused by acid rain in the glasshouse at the experimental station of Seoul National University. Soybean (Glycine max L.) cv. Sinpaldal was subjected to simulated acid rain (SAR) two times a week from R2 stage until its maturity. The pH values of SAR treatments were ranged from 2 to 5 together with tap water treatment (pH 7±0.2) as a control. The SAR was composed of H2SO4 and HNO3 at the ratio of 2:1 (v/v). SAR treatment at pH 2 caused clear visual damage on leaves and pods with severe chlorosis and necrosis even after the first SAR was applied, while those at pH greater than 3 showed no clear visual damage. Chlorophyll content (expressed as SPAD value) tended to decrease with decreasing pH with significant reduction at pH 2 as compared with pH values greater than 3. Photosynthesis also showed decrease with decreasing pH with significant reduction at pH 3 and 2. Soybean yield and its components were also affected by SAR treatment, particularly significant at pH 2.
        19.
        2006.09 KCI 등재 서비스 종료(열람 제한)
        A pot experiment was conducted to investigate the effects of soil burial depth on seedling emergences of rice (Oryza sativa) and Echinochloa spp. and to model such effects for mathematical prediction of seedling emergences. When the Gompertz curve was fitted at each soil depth, the parameter C decreased in a logistic form with increasing soil depth, while the parameter M increased in an exponential form and the parameter B appeared to be constant. The Gompertz curve was combined by incorporating the logistic model for the parameter C, the exponential model for the parameter M, and the constant for the parameter B. This combined model well described seedling emergence of rice and Echinochloa species as influenced by soil burial depth and predicted seedling emergence at a given time after sowing and a soil burial depth. Thus, the combined model can be used to simulate seedling emergence of crop sown in different soil depths and weeds present in various soil depths.
        20.
        2006.09 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to investigate the influence of drought stress during the pod developing and seed filling stage on source-sink relationships of soybean (Glycine max). Drought treatments were imposed by withholding water at the full-pod stage, 19 days after flowering, and then limited watering was relieved at 15 days after the initiation of drought treatment. Soybean seed yield was reduced by 39% mainly due to decreased pod number under drought stress, but the 100-seed weight was relatively less reduced. In spite of the 15-day drought during the full-pod stage, soybean produced good seeds showing similar l00-seed weight, protein, starch and soluble sugar content to those from the well-watered. Although drought during the full-pod stage caused source limitations; i.e. accelerated leaf senescence and reduced leaf soluble sugars, it did not cause limitations of other source characteristics such as SGR and leaf starch level. This is because the reduction in size of sinks, such as pod and seed abortions compensated for source limitations, resulting in balanced source-sink as expressed by LAR and the ratio of leaf area to seed dry weight. Drought stress during the pod developing and seed filling stage did not disrupt the source-sink balance