• 한국미생물·생명공학회지
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• 제47권3호
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• pp.423-433
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• 2019

Midgut microbiota is known to play a fundamental role in the biology and physiology of the agricultural pest, Spodoptera litura. This study reports the difference in the larval midgut microbiota of field-caught and laboratory-reared populations of S. litura by performing 16S rDNA amplicon pyrosequencing. Field populations for the study were collected from castor crops, whereas laboratory-reared larvae were fed on a regular chickpea based diet. In total, 23 bacterial phylotypes were observed from both laboratory-reared and field-caught caterpillars. Fisher's exact test with Storey's FDR multiple test correction demonstrated that bacterial genus, Clostridium was significantly abundant (p < 0.05) in field-caught larvae of S. litura as compared to that in the laboratory-reared larvae. Similarly, bacterial genera, such as Bradyrhizobium, Burkholderia, and Fibrisoma were identified (p < 0.05) predominantly in the laboratory-reared population. The Bray-Curtis dissimilarity matrix depicted a value of 0.986, which exhibited the maximum deviation between the midgut microbiota of the laboratory-reared and field-caught populations. No significant yeast diversity was seen in the laboratory-reared caterpillars. However, two yeast strains, namely Candida rugosa and Cyberlindnera fabianii were identified by PCR amplification and molecular cloning of the internal transcribed space region in the field-caught caterpillars. These results emphasize the differential colonization of gut residents based on environmental factors and diet.

• Journal of Microbiology and Biotechnology
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• 제32권10호
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• pp.1275-1283
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• 2022

Understanding soil microbial community structure in the Arctic is essential for predicting the impact of climate change on interactions between organisms living in polar environments. The hypothesis of the present study was that soil microbial communities and soil chemical characteristics would vary depending on their associated plant species and local environments in Arctic mature soils. We analyzed soil bacterial communities and soil chemical characteristics from soil without vegetation (bare soil) and rhizosphere soil of three Arctic plants (Cassiope tetragona [L.] D. Don, Dryas octopetala L. and Silene acaulis [L.] Jacq.) in different local environments (coal-mined site and seashore-adjacent site). We did not observe any clear differences in microbial community structure in samples belonging to different plant rhizospheres; however, samples from different environmental sites had distinct microbial community structure. The samples from coal-mined site had a relatively higher abundance of Bacteroidetes and Firmicutes. On the other hand, Acidobacteria was more prevalent in seashore-adjacent samples. The relative abundance of Proteobacteria and Acidobacteria decreased toward higher soil pH, whereas that of Bacteroidetes and Firmicutes was positively correlated with soil pH. Our results suggest that soil bacterial community dissimilarity can be driven by spatial heterogeneity in deglaciated mature soil. Furthermore, these results indicate that soil microbial composition and relative abundance are more affected by soil pH, an abiotic factor, than plant species, a biotic factor.

• 수산해양기술연구
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• 제59권1호
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• pp.9-18
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• 2023

Fish samples were collected by a set net from April to December 2020 at the coastal waters off Tongyeong, Korea to determine fish species composition and seasonal variation. A total of 330,675 fish (1,032,578 g) representing 56 species belonging to 39 families were collected during the sampling period. The dominant species were Engraulis japonicus, Trachurus japonicus and Trichiurus japonicus, which accounted for 98.1% of the total number of individuals and 87.5% of the total biomass collected. E. japonicus and Chelidonichthys spinosus appeared every month off the coast of the Tongyeong. Cluster analysis based on the number of individuals of fish were classified into two groups at the dissimilarity level of 57%, and the results of ANOSIM analysis revealed significant differences in community structure among the two groups.

• The Korean Journal of Ecology
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• 제19권1호
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• pp.93-104
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• 1996

Ecological approach to conservation of Korea's National Parks (KNP) was reviewed. Four hundred twenty five reports on 15 national parks for 80 years (1915~1994) were analyzed in consideration of phytocoenotic information such as flora, plant community and landscape. Total species was recorded as 157 familles, 752 genera, and 2,369 species (64.3% of Korean flora), in which is included only 75 species of the protected plant species designated by the Ministry of EnvironMent. Occurrence patterns of plant species in national parks were quite similar to one another, but those of plant community were rather unique. Seventy-four of 97 plant communities were reported in only one of 15 national parks, which might be regarded as an endemic or local vegetetation type. These facts are far different from actual status of the KNP＇s ecosystem, which indicate that not only original data in previous reports are less informative, but also tools of investigation and description are too subjective, and thus these can never afford to monitor the ecosystem. From the correlation analysis between 10 ecological characteristics, the following results were obtained: (1) the species richness was positively associated with the area of national park, (2) the number of visitors was related to landscape diversity, (3) occurrence of the designated species was closely related to the vegetation diversity. Numerical analysis (cluster analysis and ordination) using dissimilarity ratio by ecological characteristics divided 15 national parks into 4 groups. The first group, composed of national parks of Chirisan, $S\v{o}laksan$, Sokrisan, Hallasan, $T\v{o}kyusan$, Odaesan, and Sobaeksan, is recognized as the best national parks in terms of ecological conservation values. Nevertheless, they have been faced with the threat of visitor stress. This study will contribute to the establishment of strategy for appropriate conservation and sustainable use of KNP.

• 전자공학회논문지SC
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• 제42권5호
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• pp.51-58
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• 2005

본 논문에서는 유방 초음파 볼륨영상에서 진단하고자 하는 종양 영역을 율왜곡 기반(rate-distortion based) 시드영역 확장 법으로 분할하는 알고리듬을 제안한다. 제안된 분할법에서는 율은 윤곽의 거친 정도를 나타내고 왜곡은 영역의 동질성 정도를 나타내는데, 흉부 종양 볼륨으로부터 획득한 2차원 단면 영상에서 설정된 초기 시드영역에서 시작하여 이러한 율과 왜곡을 동시에 최소화하는 주위영역 중 하나씩 시드영역으로 병합한다. 이러한 병합은 시드영역의 윤곽 화소당 평균 율왜곡 비용이 최대가 될 때까지 반복적으로 수행한다. 이렇게 함으로써 최종 시드영역은 동질성이 잘 유지되고 부드러운 윤곽을 갖게 된다. 마지막으로 모든 단면 영상에 있는 최종 시드영역의 윤곽들을 이용하여 3차원 흉부 종양을 추출한다. 실험 결과, 제안한 방법이 초음파 데이터에 대하여 평균 에러율이 약 4% 미만으로 나타났다.

• 한국약용작물학회지
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• 제13권5호
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• pp.249-253
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• 2005

This study was carried out to develop convenient and reproducible methods for identifying the genetic relationship among germplasms of Panax species based on molecular genetics. Using random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) analyses, genetic polymorphism of the Panax species was investigated with following cultivars and accessions, such as Chunpoong, Yunpoong, Kopoong, Sunpoong, and Kumpoong in domestic cultivars, Hwangsuk, Jakyung and Suckju in domestic accessions, and Panax quinquefolius L. and Panax japonicus C.A. Meyer in foreign introduced accessions, respectively. Specific DNA fragments ranging from 200 to 3,000 base pairs in size could be obtained with various ISSR and RAPD primers under the optimized PCR conditions. The dissimilarity coefficients among the genetic polymorphisms of ginseng cultivars and accessions were calculated from 0.26 to 0.90 in RAPD and from 0.12 to 0.89 in ISSR analysis, respectively. Eleven plant samples were grouped siblings together with cultivars and parents based on cluster analysis of genetic distance depending on genetic property such as origin of the species. In results, both RAPD and ISSR analyses were useful for identifying the genetic relationship among cultivars and accessions of Panax species at DNA level.

• 환경생물
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• 제29권4호
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• pp.379-387
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• 2011

Copepod nauplii plays an important role as a linker between the microbial food web and classical food chain in marine ecosystem and is an essential food source for early stage of many larval fishes. Study on the influencing factors on the growth of copepod naupliar stages has been rarely carried out in despite of these ecological significances. Many studies have shown that food availability and temperature are major factors to influence copepod growth. However, due to the complicated environment parameters in coastal ecosystem, the relationships between growth of copepods and influencing factors are still unclear under the natural condition. Growth rates of the copepod $Acartia$ $hongi$ nauplii were measured in Kyeonggi Bay from February to December 2001. $Acartia$ $hongi$ is numerically abundant and widespread predominant species in the coastal regions of the Yellow Sea and occurs continuously throughout the year, with a maximum peak in late spring. The naupliar growth rates of $Acartia$ $hongi$ by the artificial cohort method varied from 0.03 to 0.18 $day^{-1}$, with a mean of 0.09 $day^{-1}$. The overall naupliar growth rates showed a significantly positive relationship with the variation in water temperature. However, Previous study reported that the growth rates of adult $Acartia$ $hongi$ were primarily influenced by the variation in chlorophyll-$a$. Therefore, these differences demonstrated that the influencing factors of growth did not correspond with the developmental stages. The results of this study suggest that the dissimilarity of growth between nauplius and adult female resulted from the size-dependant difference in food availability and the growth of older developmental stages containing adults are more food-dependent than juveniles.

• 디자인학연구
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• 제13권4호
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• pp.195-201
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• 2000

본 연구에서는 멀티미디어라는 기술적 속성에 기반한 정보 전달매체로서의 활용 방법에 관한 연구 내용들의 고찰을 통해 커뮤니케이션 효과에 영향을 미치는 매체의 작용을 알고, 통합적 심볼 시스템의 멀티미디어가 갖는 효과와 이에 따른 디자인 문제 및 인테페이스 디자인의 매체 선택을 위한 접근방향을 모색하였다. 내용전달의 인지적 효과에서 나타나는 서로 다른 매체들간의 차이는 매체의 여러 수준별 속성들로부터 이해될 수 있는데, 지각 단계에서의 물리적 특성에서부터 심볼 시스템에 의한 보다 지적인 작용 결과까지를 포함한다. 멀티미디어 정보는 통합적 매체 활용과 상호작용의 특성으로부터 가능한 정보 전달상의 여러 장점과 함께 인지적 과부하와 혼란 등의 부정적 측면을 가짐으로써 이에 대한 체계적 접근을 요구한다. 본 연구에서는 이 같은 맥락에서 매체 선택의 주요 요소를 파악하고 인터페이스 구성 요소와의 연관성을 모색하였다. 주어진 요구나 상황에 보다 적합한 매체의 선택을 위해서는 사용자 요소로서 ${\circled1}$배경적 요인 ${\circled2}$내용영역.시스템에 대한 지식/사용빈도/전문성, 내용 요소로서 ${\circled1}$과제 특성 ${\circled2}$목표.지식유형, 매체 요소로서 ${\circled1}$표현형식 ${\circled2}$상호작용형식 등을 고려해야 한다. 그리고 매체 요소는 각종 표현 요소들이 결정됨으로써 인터페이스 디자인의 구체적 특질을 결정하게 된다.

• 원예과학기술지
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• 제17권3호
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• pp.352-354
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• 1999

꽃도라지(Eustoma grandiflorum) 조직배양시 발생한 5개의 변이체와 모본을 이용하여 PCR 반응으로 나타난 RAPDs 밴드 형태로 유전적인 변이 유무를 확인하려고 하였다. 6개의 분류군은 엽수, 옆모양, 줄기직경, 초장 그리고 옆면적과 같은 형태적인 특징이 달랐다. 실험한 20개의 임의 primers 중에서 모본과 변이체에서 모두 밴드를 나타낸 5개 PCR 반응에서 증폭밴드는 총 34개였으며 64.7%의 다형성을 나타냈다. 밴드의 유무를 코드화하여 NTSYS-PC (ver. 1.5)분석으로 나타난 변이체들의 유전적인 거리값의 차이가 변이체인 5개체와 정상 식물체간 비유사성 계수는 0.72에서 0.91로 밀접한 유사성을 나타냈으며 거리값이 0.79에서 두 그룹으로 나뉘어졌기 때문에 변이체의 형태적인 차이와 거의 일치되는 유전적인 차이를 나타냈다.

• 원예과학기술지
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• 제34권2호
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• pp.294-304
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• 2016

Members of the genus Brassica, which are known as oil crops or cruciferous vegetables, are widely cultivated in Canada, Australia, Asian and Europe. Because Brassica species have high yields, are well adapted to their environments, and are self-incompatible, the germplasm is abundant. Previous studies have reported abundant genetic diversity even within Brassica subspecies. In Korea, fresh cabbage leaves are eaten with roast meat, and to meet the current popular demand, new varieties are being increasingly bred. To determine the genetic diversity and relationships among the cabbage vegetables in Korea, we evaluated the genetic variation of 18 accessions based on 5S and 18S ribosomal RNA (rRNA) gene sequences. We detected many variable nucleotide sites, especially in the 5S rRNA gene sequences. Because the length of the 18S rRNA gene might influence the dissimilarity rate statistics, we used both the 5S and 18S sequences to analyze the phylogenetic relationships. S7 (B. oleracea) showed the most distant phylogenetic relationship with the other Brassica species. Interestingly, B2 (B. oleracea), B15, and B18 (B. campestris) have three different types of leaf profiles, and were divided into one group, and the other Brassica species formed another group. Statistical analysis of interspecies and intraspecies genetic distances revealed that B. campestris L. showed higher genetic diversity than B. oleracea L. This work provides additional data that facilitates the evaluation of the genetic variation and relationships among Brassica species. The results could be used in functional plant breeding programs to improve Brassica crops.