본 연구는 콘크리트 교량의 지진취약도 곡선을 개발함에 있어 성능 스펙트럼 기법(Capacity Spectrum Method)에 대한 고찰을 통해 가장 적절한 해석방법을 제시하는데 그 목적이 있다. 원래 성능 스펙트럼 기법은 빌딩 구조물을 위한 간략화된 정적 비선형 해석의 일환으로 개발되었는 바, 본 연구에서는 이 기법을 교량의 지진취약도 곡선을 개발하는데 응용하였다. 서로 다른 네가지의 방법으로 성능 스펙트럼 기법을 통해 구해진 취약도 곡선들을 비선형 시간이력해석 방법에 의해 구해진 취약도 곡선과 비교하였다. 취약도 곡선은 두 개의 변수를 가진 lognormal 분포를 따르는 것으로 가정하였으며 PGA(Peak Ground Acceleration)의 함수로 나타내어졌다. FEMA(Federal Emergency Management Agency) SAC(SEAOC-ATC-CUREe) steel 프로젝트에 의해 개발된 로스앤젤레스 지역 60개의 지진이 교량해석을 위해 사용되었다. 성능 스펙트럼 기법과 시간이력해석에 따라 만들어진 교량의 지진취약도 곡선들을 비교 검토한 바, 이 중 하나의 방법이 부합되는 결과를 보여주었다. 요구 스펙트럼 작성시 본 논문에서 제시된 지침을 따르면 비선형 시간이력 해석시와 유사한 결과를 얻을 수 있을 것으로 사료된다. 다만 지진과 교량이 지닌 특수성으로 인해 본 연구의 결과가 항상 적용되는지는 더 심도있는 연구를 통해 검증되어야 할 것이다.

We present (U-B) and (U-V) radial color distributions of 103 galaxies based on the UBV multiaperture photometry compiled by Longo, de Vaucouleurs, and Corwin (1983). About half of the galaxies show radial negative color gradients (i. e., bluer at the outer parts of the galaxies). E and SO galaxies have similar color gradients. and there appears to be no correlation between the size of color gradients in these galaxies and their luminosity, but the luminous spiral galaxies tend to have steeper color gradients. The metallicity gradients of elliptical galaxies derived from the (U-V) color gradients agree with those from the magnesium gradients within the errors.

Citrus canker caused by Xanthomonas citri is a notorious disease affecting a decrease in fruit productivity and quality. Citrus export to USA is also prohibited by the disease. Therefore, development of citrus canker resistant variety is essential and exploitation of markers for molecular breeding is urgent. To develop DNA molecular markers, we performed whole genome resequencing for 8 varieties: 4 citrus canker resistant varieties including C. hybrid ‘Kioymi’ and 4 citrus canker susceptible varieties including C. iyo ‘Miyauchiiyokan’. In total, 642 polymorphic SNPs were detected between resistant and susceptible varieties. Of the 642 SNPs, 50 SNPs were preferably selected based on integrative genomics viewer. To apply the markers in a broad range of citrus variety, we performed genotyping with 6 other varieties very well known as citrus canker resistant and susceptible varieties in addition to previous mentioned 8 varieties. Three of the 50 SNPs were identified as a marker to distinguish citrus canker resistant varieties from susceptible varieties. Secondly, we developed molecular markers to apply for F1 lines crossed by ‘Kiyomi’ and ‘Miyauchiiyokan’. Of the 50 SNPs, we identified 2 SNP markers to distinguish between F1 resistant and susceptible lines. One of them is a resistance gene that plays a role in plant defense mechanism. In this study, we developed 5 molecular marker candidates possible to apply for molecular breeding to develop citrus canker resistant variety. We are working on development of candidate markers related to citrus canker.

Ramie (Boehmeria nivea L.) is a hardy perennial herbaceous plant of the Urticaceae family and has been grown as a fiber crop in several countries including Korea for many centuries. Ramie leaves also have been traditionally used as a major ingredient of a type of rice cake called ‘Song-pyun’ in the Southwest area of Korea, especially Yeong-Gwang province. Despite its economic importance, the molecular genetics of ramie have not been studied in detail yet. Genetic resources of ramie were widely collected from domestic local sites by Bioenergy Crop Research Center (RDA) and Yeong-Gwang Agricultural Technology Center. For the systematic and efficient management of the genetic resources, we developed SSR (simple sequence repeat) markers of ramie. To do this, we generated microsatellite-enriched genomic DNA libraries using magnetic bead hybridization selection method. 247 non-redundant contigs containing SSR motif were generated using nucleotide sequences of 376 clones from the libraries. Primer sets were designed from the flanking sequences of the repeat motif. Finally, we selected 10 SSR markers, possibly showing polymorphism among the genetic resources. Results on the genotype analysis of the ramie genetic resources using the SSR markers will be presented.

Livestock wastewater has high potential as one of energy resources because this wastewater is including high organic matter. Therefore the studies attempting to bio-gasification and bio-electricity generation using livestock wastewater is being tried. The pre-treatment system used in this study was the purpose to control the ammonia nitrogen in conjunction with the system and the microbial fuel cell. Because ammonia nitrogen is to inhibit the electricity generation efficiency of microbial fuel cell. These studies were to ascertain the effect of oxidants on the nitrogen removal in the pre-treatment system using catalyst and microbubbles to treat the ammonia nitrogen. The three kinds of oxidant such as air, oxygen (O2), and hydrogen peroxide (H2O2) were used to know the ammonia and nitrate nitrogen removal. This system was operated with four kinds of conditions. First method is O2 gas with 100 mL/min with 1ml of 30% H2O2 was supplied to the wastewater. A second method, the O2, with 400 and 1,000 mL/min was supplied through the flow meter before livestock wastewater was flow in the reactor. The last method, air was supplied 800 mL/min. The nitrate removal had no significant difference all conditions except the air supply. On the other hand, the ammonia and nitrate nitrogen removal when oxygen was supplied with 1000 mL O2/min was higher than that of the other conditions. The removal rate when air was supplied 800 mL/min was similar to the value in the supplied with 400 ml O2/min. This result showed that oxidant was important factor to improve the ammonia nitrogen removal rate.

Citrus canker caused by Xanthomonas citri pv. citri is one of economically important diseases in the citrus industry. The devastating bacterial disease results in unattractive quality and a significant reduction in fruit production. Citrus growers and industry in Korea has been struggling with the serious disease causing the prohibition of export market. Korea also became the top import market for oranges. The development of markers linked to citrus canker resistance is strongly needed. In this study, we investigated molecular markers between ‘Kiyomi’ (Citrus unshiu ｘ C. sinensis), a resistant cultivar, and Natsudaidai (C. natsudaidai), a susceptible cultivar. To develop markers, we focused on structural variation (copy number variation, CNV, and presence/absence variation, PAV). It has been well documented that CNV and PAV of defense-related genes are associated with resistant cultivars. Using a read depth approach following next-generation sequencing, we performed genome-wide analysis of CNV and PAV in two varieties. As a result, 633 genes showing at least two times difference between the mapping reads from two varieties and 61 genes showing presence of the mapping reads in only either one of them were screened. Visual inspection using the Integrative Genomics Viewer (IGV) was performed and experimental validation is being investigated. Interestingly, one of PAV candidates showed polymorphism in ‘Kiyomi’ and ‘Natsudaidai’ as well as other resistant and susceptible cultivars. Our results suggest a necessity for the detection of structural variation and indicate that the candidates may be useful for molecular breeding for citrus canker resistance and understanding disease resistance mechanism.

Ramie (Boehmeria nivea L. Gaudich.) is a hardy perennial herbaceous plant of the Urticaceae family and has been grown as a fiber crop in several countries including Korea for many centuries. Ramie leaves also have been traditionally used as a major ingredient of a type of rice cake called ‘Song-pyun’ in the Southwest area of Korea, especially Yeong-Gwang province. Despite its economic importance, the molecular genetics of ramie have not been studied in detail yet. Genetic resources of ramie were widely collected from domestic local sites by Bioenergy Crop Research Center (RDA) and Yeong-Gwang Agricultural Technology Center. For the systematic and efficient management of the genetic resources, we developed microsatellite molecular markers of ramie. To do this, we generated microsatellite-enriched genomic DNA libraries using magnetic bead hybridization selection method. 216 contigs containing microsatellite repeat motif were generated using nucleotide sequences of 376 clones from the libraries. Primer sets were designed from the flanking sequences of the repeat motif. Finally, we selected 26 microsatellite markers, possibly showing polymorphism among the genetic resources. Results on the genotype analysis of the ramie genetic resources using the microsatellite markers will be presented.

To determine the expression levels of genes related to the salt stress response in rice, gene expression profiles were investigated through microarray analysis using the rice mutant line Till-II-877. There were no significant changes in physiological response under salt stress of the mutant increased less than that in the WT. The intensity of gene expression was analyzed and compared between the wild type and mutant lines using a microarray. Among the most significantly affected pathways, α-linolenic acid metabolism and linoleic acid metabolism (in lipid metabolism), fructose and mannose metabolism and glycolysis-gluconeogenesis (in carbohydrate metabolism), cysteine and methionine metabolism (in amino acid metabolism), and carbon fixation (in the energy metabolism of photosynthetic organisms) showed changes in gene expression levels under salt stress. These results further our understanding of the effects of salt stress in rice and may aid in the development of salt-tolerant rice cultivars.

Soluble sugar content in soybean seed is an important quality attribute for soyfood and feed. Usually, soluble sugars comprise 6 to 17% of total dry wt. in mature soybean seeds. In this study, 414 soybean mutant lines induced by gamma-ray were screened by colormetric assay, FACE (Fluorophore-assisted carbohydrate electrophoresis), and GC-MS to identify the change of soluble sugar contents. Among 414 soybean mutant lines, 12 mutant lines derived from three different soybean cultivars (Hwanggum, Paldal, and Bangsa) showed higher level of soluble sugar content compared to their original cultivars. However, 5 mutant lines derived from soybean landrace KAS 636-15 showed lower level in the colormetric assay. In FACE, 17 soybean mutant lines selected by colormetric assay also showed different band intensity compared with their original cultivars. However, there were no different soluble sugar patterns between soybean original cultivars and mutant lines. Finally, the variations of soluble sugar content in 17 soybean mutant lines were confirmed by using GC-MS. These mutant lines will be used for genetic study to find mutations of genes related soluble sugar biosynthesis.

밀가루와 면대 색이 밝은 품종의 육종효율을 증진하기 위하여 PPO 활성과 연관된 sequence-tagged site(STS) 분자표지인 PPO-05, PPO-16, PPO-18, PPO-30과 PPO-43을 이용하여 국내의 밀 품종의 PPO활성 수준과 유전자형 간의 관계를 분석하였다. Ppo-A1에 연관된 PPO-18이 국내 밀 품종의 PPO 활성 판별과 선발에 유용한 분자표지로 확인되었다. PPO 활성은 Ppo-A1b 유전자형 품종(0.446)이 P

밀가루 및 국수 면대의 색깔 변화에 영향을 미치는 요인을 분석하여 소비자가 선호하는 밝은 색택의 밀가루 및 국수 제조에 적합한 품종의 육성에 유용한 간편 분석법을 확립하고자 본 연구를 수행하였다. 국산밀 25 품종을 이용하여 종실 및 밀가루 특성과 저장기간 동안 국수 면대의 밝기 변화를 조사하였다. 종실의 PPO 활성은 천립중이 낮을수록, 종실 회분과 단백질 함량이 낮을수록 낮은 경향을 나타내었다. 종실의 PPO 활성은 총폴리페놀 함량(r=0.609**