• Molecules and Cells
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• v.19 no.1
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• pp.104-113
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• 2005

Large inversions are well characterized in the chloroplast genomes of land plants. In contrast, reports of small inversions are rare and involve limited plant groups. In this study, we report the widespread occurrence of small inversions ranging from 5 to 50 bp in fully and partially sequenced chloroplast genomes of both monocots and dicots. We found that small inversions were much more common than large inversions. The small inversions were scattered over the chloroplast genome including the IR, SSC, and LSC regions. Several small inversions were uncovered in chloroplast genomes even though they shared the same overall gene order. The majority of these small inversions were located within 100 bp downstream of the 3' ends of genes. All had inverted repeat sequences, ranging from 11 to 24 bp, at their ends. Such small inversions form stem-loop hairpin structures that usually have the function of stabilizing the corresponding mRNA molecules. Intra-molecular recombination between the inverted sequences in the stem-forming regions are responsible for generating flip-flop orientations of the loops. The presence of two different orientations of the stem-loop in the trnL-F noncoding region of a single species of Jasminum elegans suggests that a short inversion can be generated within a short period of time. Small inversions of non-coding sequences may influence sequence alignment and character interpretation in phylogeny reconstructions, as shown in nine species of Jasminum. Many small inversions may have been generated by parallel or back mutation events during chloroplast genome evolution. Our data indicate that caution is needed when using chloroplast non-coding sequences for phylogenetic analysis.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.1
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• pp.46-61
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• 2002

Among the many phases involved in software development, requirements analysis phase in generally considered to play a crucial role in determining the overall software quality. Therefore, many software development companies manages the phase as one of the important phase. Especially, safety assurance through requirements analysis for safety-critical systems is quite demanding, and national and international bodies routinely require safety demonstration. Among various approaches, inspection and formal methods are generally shown to be effective. In this paper, we propose a formal verification procedure for SCR(Software Cost Reduction)-style SRS(Software Requirements Specification) using the PVS specification and verification procedure and applied this procedure to an industrial system such that a shutdown system for Wolsung nuclear power plant. This system had been verified through inspection not formal verification. The application of formal methods is rare in Korea, so it is very important to experiment about formal verification to industrial systems.

• Journal of Microbiology and Biotechnology
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• v.32 no.7
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• pp.892-901
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• 2022

The rising demand for carotenoids can be met by microbial biosynthesis as a promising alternative to chemical synthesis and plant extraction. Several species of lactic acid bacteria (LAB) specifically produce C₃₀ carotenoids and offer the added probiotic benefit of improved gut health and protection against chronic conditions. In this study, the recently characterized Lactiplantibacillus plantarum subsp. plantarum KCCP11226^T produced the rare C₃₀ carotenoid, 4,4'-diaponeurosporene, and its yield was optimized for industrial production. The one-factor-at-a-time (OFAT) method was used to screen carbon and nitrogen sources, while the abiotic stresses of temperature, pH, and salinity, were evaluated for their effects on 4,4'-diaponeurosporene production. Lactose and beef extract were ideal for optimal carotenoid production at 25℃ incubation in pH 7.0 medium with no salt. The main factors influencing 4,4'-diaponeurosporene yields, namely lactose level, beef extract concentration and initial pH, were enhanced using the Box-Behnken design under response surface methodology (RSM). Compared to commercial MRS medium, there was a 3.3-fold increase in carotenoid production in the optimized conditions of 15% lactose, 8.3% beef extract and initial pH of 6.9, producing a 4,4'-diaponeurosporene concentration of 0.033 A₄₇₀/ml. To substantiate upscaling for industrial application, the optimal aeration rate in a 5 L fermentor was 0.3 vvm. This resulted in a further 3.8-fold increase in 4,4'-diaponeurosporene production, with a concentration of 0.042 A₄₇₀/ml, compared to the flask-scale cultivation in commercial MRS medium. The present work confirms the optimization and scale-up feasibility of enhanced 4,4'-diaponeurosporene production by L. plantarum subsp. plantarum KCCP11226^T.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2418-2425
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• 2021

Monazite is a phosphate mineral that contains thorium (Th) and rare earth elements. The Th concentration in monazite can be as high as 500 ppm, and it has the potential to be used as fuel in the nuclear power system. Therefore, this study aimed to conduct the techno-economic analysis (TEA) of Th extraction in the form of thorium oxide (ThO₂) from monazite. Th can be extracted from monazite through an alkaline fusion method. The TEA of ThO₂ production studied parameters, including raw materials, equipment costs, total plant direct and indirect costs, and direct fixed capital cost. These parameters were calculated for the production of 0.5, 1, and 10 ton ThO₂ per batch. The TEA study revealed that the highest production cost was ascribed to installed equipment. Furthermore, the highest return on investment (ROI) of 21.92% was achieved for extraction of 1 ton/batch of ThO₂, with a payback time of 4.56 years. With further increase in ThO₂ production to 10 ton/batch, the ROI was decreased to 5.37%. This is mainly due to a significant increase in the total capital investment with increasing ThO₂ production scale. The minimum unit production cost was achieved for 1 ton ThO₂/batch equal to 335.79 $/Kg ThO₂.

• Journal of Wetlands Research
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• v.26 no.1
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• pp.92-113
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• 2024

The Purpose of this study were to present the basic data for conservation and management of wetland ecosystem by surveying the characteristics of vascular plants distributed in Hwapocheon wetland protected area. The results are as follows. The numbers of vascular plants were summrized as 339 taxa including 81 familices, 221 genera, 315 species, 9 subspecies and 12 varieties and 2 forms. The rare plants were 7 taxa including Aristolochia contorta, Hydrocharis dubia and so on. The floristic target species were 32 taxa including 17 taxa of grade I, 7 taxa of grade II, 4 taxa of grade III, 2 taxa of grade IV and 2 taxa of grade V. The invasive alien plants were 66 Rumex crispus, Oenothera biennis, Veronica arvensis and so on. The ecosystem disturbing species were 11 taxa including Humulus scandens, Ambrosia artemisiifolia, Ambrosia trifida, Lactuca seriola, Symphyotrichum pilosum and so on. The hydrophytes were 29 taxa including 16 taxa of emergent plants, 3 taxa of submerged plants, 4 taxon of free-floating plant 6 taxa of floation-leaved plants.

• Korean Journal of Environment and Ecology
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• v.23 no.2
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• pp.177-186
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• 2009

In the flora of the whole area of Jakeundang at Byeonsanbando National Park, a total of 105 taxa were identified including 50 families, 88 genera, 98 species, 6 varieties and 1 form. These were again divided into 31 taxa (29.5%) of woody plants and 74 taxa (70.5%) of herbaceous plants. In addition, 4 taxa of the Korea Forest Service, designated rare plants in the flora were identified to grow there including Phacelurus latifolius (Preservation priority order: No. 194), Aristolochia contorta (No. 151), Koelreuteria paniculata (No. 115), and Glehnia littoralis (No. 203). Indigofera koreana, Viola seoulensis that are on the list of Korean endemic plants were also identified and the plants approved for export were identified similarly to rare plants. In addition, among the floral region-based specific plants, the plant group belonging to class V, class IV and II didn't appear and a total of 16 taxa 3 taxa including Elymus mollis, Salsola collina and Koelreuteria paniculata in class III, and 13 taxa including Ischaemum anthephephoroides, Phacelurus latifolius, Asparagus cochinchinensis, Melandryum oldhamianum for. roseum, Calystegia soldanella, Messerschmidia sibirica, Scutellaria strigillosa and Aster spathulifolius, etc. in class I were identified. Among the naturalized plants in the surveyed sites, 6 families, 10 genera, and 10 taxa were identified to grow, such as Bromus unioloides, Phytolacca americana, Lepidium apetalum, Robinia pseudoacacia, Oenothera biennis and Xanthium canadense, etc. and the naturalization rate was analyzed to be 9.5% of all 105 taxa of vascular plants. This research analyzed the coverage ratio and importance value by dividing the community into a sand dunes and back swamp and divided the sand dune area into Vitex rotundifolia community and the back swamp into Phacelurus latifolius community. Jakeundang is designated as a sand dune plants observation area and managed by the office of Byeonsanbando National Park. To preserve this place, it is desirable to take a systematic management measure, such as a visit to this place on a subscription basis or education and publicity on sand dune plants.

• Korean Journal of Environment and Ecology
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• v.32 no.5
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• pp.445-468
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• 2018

The purpose of this study was to investigate the distribution of vascular plants growing at the Mt. Daedun provincial park area in the boundary between Nonsan-si, Geumsan-gun, Chungcheongnam-do and Wanju-gun, Jeollabuk-do, Korea. We collected the vascular plants 9 times from May 2016 to July 2017. The flora of Mt. Daedun was classified as a total of 434 taxa comprising of 95 families, 278 genera, 388 species, 3 subspecies, 38 varieties and 5 forma. Among them, the endemic plants in Korea that the investigation found were 11 taxa including Broussonetia kazinoki Siebold, Clematis trichotoma Nakai, Thalictrum actaefolium var. brevistylum Nakai, etc. It also found rare plant species, as designated by the Korea Forest Service were 6 taxa including 5 grade LC taxa such as Eranthis stellata Maxim., Viola albida Palib., and Scopolia japonica Maxim. and 1 grade DD taxa, Scrophularia koraiensis Nakai. The special floristic plants were a total of 35 taxa such as 9 taxa in degree III (Eranthis stellata Maxim., Stewartia pseudocamellia Maxim., Acer palmatum Thunb., etc.), 7 taxa in degree II (Equisetum hyemale L., Potentilla dickinsii Franch.&Sav., Viola orientalis (Maxim.) W. Becker, etc.) and 19 taxa in degree I (Dryopteris crassirhizoma Nakai, Cephalotaxus koreana Nakai, Ulmus parvifolia Jacq., etc.) to provide basic data. No taxa in grade V or IV were found. The naturalized plants were 34 taxa including Rumex acetosella L., Phytolacca americana L. and Chenopodium album L., and the percentage of urbanization index was 10.6% while the naturalized plant index was 7.7%.

• Korean Journal of Environment and Ecology
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• v.37 no.3
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• pp.182-191
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• 2023

This study was carried out to identify the distribution and growth characteristics and evaluate the conservation status of the Michelia compressa Maxim., a rare and endangered wild plant II, in the habitats in Korea. A total of 314 individuals were found in the natural habitats of Heuksan Island and Jeju Island and were divided into four populations. About 45.9% (144 individuals) were distributed in the range of 401m~500m above sea level. The average height of trees was 2.7(±4.8)m, the diameter at breast height was 12.6(±13.9)cm, and the number of branches was 1.0(±0.5) on average. 54.3% of the sapling individuals of M. compressa were distributed within a radius of 30 m from the mother tree, 25.8% were distributed between 31 m through 40 m, and most (90.1%) were distributed within a radius of 60 m. The fact that sapling individuals of M. compressa are not identified even around some mature individuals and appear only in extremely limited areas is estimated to be closely related to the growth conditions as well as the environment of the natural habitats. The dispersal of M. compressa is presumed to be related to the birds and natural seedlings because water puddles, a resting place for birds beyond the range of natural seedlings, characterize its habitats. The IUCN Red List evaluation criteria at the regional and national level of M. compressa corresponds to the Critically Endangered category, and the domestic population under the category of "CR B2ab(v); C2a(i); D."

• Korean Journal of Plant Resources
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• v.22 no.1
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• pp.31-36
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• 2009

The aim of this study was to examine geographic variation to support a genetic resource conservation plan of rare endemic Picea jezoensis (Siebold & Zucc.) Carriere. Three populations of P. jezoensis were analysed using multivariate analysis for 7 characteristics of needle morphology. In the morphological characters, seven characters of needle were 15.11 mm (needle length), 1.43 mm (needle width), 0.42 mm (needle thickness), 10.9 (length / width of needle), 3.6 (width / thickness of needle), 0.47 mm (Distance between resin duct and vascular), 17.4 ea. (number of stomata row), respectively. Nested analysis showed that were statistically significant differences among populations as well as among individuals within populations in 6 quantitative characters. In 5 of 7 characters, variance components among populations were higher than those among individuals within populations. Cluster analysis using complete linkage method showed two groups (Mt. Gyebang populations was genetically distinct from the other two populations) to Euclidean distance 0.4. Among principal components, primary 2 principal components appeared to be major variables because of the loading contribution of 100%.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.27-27
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• 2018

본 연구는 강원지역에 분포하는 희귀 특산식물 5종 광릉요강꽃(CR), 개느삼(EN), 모데미풀(EN), 금강봄맞이(EN), 난장이붓꽃(EN)을 대상으로 고정조사구($5{\times}5m$, $2{\times}2m$, $1{\times}1m$)를 설치한 뒤, 2014년부터 2017년까지 4년간의 개화 및 결실 특성을 조사하여 자생지와 식물종의 보전을 위한 기초자료를 제공하기 위해 수행하였다. 그 결과, 광릉요강꽃의 개화율은 2014년 총 개체수 6개 중 100%(6개체), 2015년 6개 중 66.7%(4개체), 2016년 3개 중 33.3%(1개체), 2017년 7개 중 14.3%(1개체)으로 나타났고, 결실율은 2014년 0%(0개체), 2015년 33.3%(2개체), 2016년 0%(0개체), 2017년 0%(0개체)으로 각각 나타났다. 개느삼의 개화율은 2014년 총 개체수 83개 중 0%(0개체), 2015년 83개 중 1.2%(1개체), 2016년 83개 중 7.2%(6개체), 2017년 76개 중 0%(0개체)으로 나타났고, 2014년부터 2017년까지의 결실은 이루어지지 않은 것으로 조사되었다. 모데미풀의 개화율은 2014년 총 개체수 6개 중 33.3%(2개체), 2015년 23개 중 91.3%(21개체), 2016년 30개 중 50%(15개체), 2017년 16개 중 100%(16개체)으로 나타났고, 결실율은 2014년 33.3%(2개체), 2015년 52.2%(12개체), 2016년 36.7%(11개체), 2017년 37.5%(6개체)으로 각각 나타났다. 금강봄맞이의 개화율은 2014년 총 개체수 20개 중 50%(10개체), 2015년 27개 중 59.3%(16개체), 2016년 47개 중 34%(16개체), 2017년 58개 중 31%(18개체)으로 나타났고, 결실율은 2014년 50%(10개체), 2015년 29.6%(8개체), 2016년 4.3%(2개체), 2017년 10.3%(6개체)으로 각각 나타났다. 난장이붓꽃의 개화율은 2014년 총 개체수 28개 중 0%(0개체), 2015년 15개 중 100%(15개체), 2016년 28개 중 21.4%(6개체), 2017년 35개 중 62.9%(22개체)으로 나타났고, 2014년부터 2017년까지의 결실은 이루어지지 않은 것으로 조사되었다.