천연물 기반의 에센셜 오일은 합성 살충제의 대체제로 주목받고 있는데, 그 구성 성분인 단일 화합물들은 훈증활성과 더불어 다양한 생리활성 을 통해 해충 방제에 효과를 나타낸다. 본 연구에서는 페닐프로파노이드 계열의 대표 화합물들인 trans-cinnamaldehyde와 trans-anethole의 반복 노출에 따른 초파리 성충(Drosophila melanogaster)에 대한 저항성비, 해독 효소 활성, fitness cost 변화를 분석하였다. 국소처리법을 통해 선택압을 부여한 결과, trans-anethole 처리군에서는 10세대 동안 RR값이 1 수준으로 유지된 반면, trans-cinnamaldehyde의 LD50 농도 처리 계통에서는 RR값이 최대 2.51까지 증가하였다. 이는 기존 합성 살충제에 비해 매우 낮은 수준이지만, 단일 천연물에 의해서도 일정 수준의 저항성 발달이 가능 함을 시사한다. 해독 효소 분석 결과, 계통별로 esterase 및 GST 활성이 상이하게 변화하였으며, 이는 처리 물질의 구조적 차이뿐만 아니라 노출 농 도에 따른 생리적 반응 차이로 해석될 수 있다. 본 연구는 천연물 유래 단일성분의 반복 사용이 해충에서 저항성 발달을 유도할 수 있음을 실험실 조 건에서 확인하였으며, 단일물질보다는 혼합물 형태의 활용이 저항성 지연에 효과적일 수 있음을 제안한다.
This study was conducted to explore ways to improve the operation of NCS-based curricula, focusing on vocational education programs. The purpose is to design and establish an effective NCS-based vocational education curriculum and to apply it in educational settings. For the purpose of improving the operation of NCS-based curricula, this study first reviewed the relevant information and system operations presented on the National Competency Standards (NCS) website (http://www.ncs.go.kr/). This is because effective vocational education can only be achieved when accurate information regarding the curriculum and educational content is properly delivered. In conclusion, it is required to identify the problems in the design, composition, and operation of vocational education curricula, and to establish curriculum design strategies that can enhance the overall efficiency of vocational education programs. Based on the results of this study, the research examined the competency unit “Inspection of Aircraft Reciprocating Engine Fuel Systems” under the NCS categories — Major Category [15. Machinery], Subcategory [09. Aircraft Manufacturing], Minor Category [03. Aircraft Maintenance], and Detailed Category [03. Aircraft Reciprocating Engine Maintenance] — and designed the learning content for the NCS learning module “Inspecting the Boost Pump.” The designed practical training plan has the following characteristics: First, by incorporating additional content from the NCS competency unit, it was structured to be applicable in actual workplaces that operate aircraft equipped with reciprocating engines. Second, it aims to enhance troubleshooting skills required for the maintenance of aircraft reciprocating engines. Third, the contents were designed to align with the practical training environments of educational institutions while ensuring applicability to real-world work settings. Fourth, it was designed to allow learners to simultaneously practice content related to obtaining aviation-related certifications. This study is significant in that it designed a vocational education curriculum and proposed effective strategies for improving vocational education. However, there are certain limitations. The study did not include an empirical implementation or analysis of the results based on the designed instructional program. In addition, it did not develop curricula that reflect the specific characteristics of individual subjects within the field of NCS-based aircraft maintenance through the design of diverse course modules.
본 연구에서는 TMD 설계 방법에 따른 배관의 지진응답 감소효과를 분석하였다. 구체적으로, 실제 원전 배관에 대한 진동대 시험 결과를 바탕으로 수치 배관 모델을 수립하고 검증하였다. 검증된 배관 모델을 바탕으로 TMD 설치 위치를 결정하고, 여러 가지 방법을 사용하여 TMD 설계값을 도출하였다. 더불어, 본 연구에서는 기존 설계식들을 기하평균한 값을 TMD 설계값으로 활용하였다. 최종적으로, 기존 배관을 기반으로 설계된 TMD가 지진의 무작위성과 지진 및 대상물질의 불확실성 아래에서도 효용성을 검증하였다. 또한, 연구에서 제안한 기하평균 모델을 기반으로 설계된 TMD의 작동성을 확인하였다. 결과적으로, TMD 설계 공식 및 방법에 따른 성능 차이를 비교한 결과, 기하평균 모델의 경우, 기존 설계식들의 특징을 포괄하는 양상이 보였다. 이러한 기하평균 모델은 추후 반복 적인 수치해석을 수행할 때 초기값으로 사용될 수 있을 것으로 보인다. 더불어, 이러한 분석 결과는 향후 원전 배관 계통의 TMD 설계 를 통해 내진 성능을 개선하는 데 유용한 자료로 활용될 것으로 기대된다.
Desmidiales (Conjugatophyceae, Charophyta) are commonly found in freshwater ecosystems and exhibit high species diversity, particularly in acidic wetlands, lakes, swamps, and peat bogs. They possess a distinctive morphology characterized by symmetrical semicells, and their wide variation in cell shape and size presents challenges in species identification due to high morphological plasticity. Although 832 species of Desmidiales have been reported in Korea, phylogenetic studies have been limited to only a few taxonomic groups. This study focused on investigating species-level relationships among Desmidiales using strains from the Freshwater Bioresources Culture Collection (FBCC), integrating morphological characteristics, ecological data, and original species descriptions. A total of 352 new plastid gene sequences were generated for phylogenetic analyses, including accD (30), atpA (42), atpB (22), ndhH (37), petA (37), psaA (32), psbA (44), psbC (1), psbD (39), rbcL (40), rpl2 (19), and rpoB (9). Among the 12 plastid genes analyzed, psbA showed the highest proportion of conserved sites (83.9%), while petA exhibited the highest proportion of variable sites (38.7%). Based on the combined phylogenetic analysis, Desmidiales were grouped into five major clades: Cosmarium Clade-1: Cosmarium punctulatum, Cosmarium sp. 1, Cosmarium Clade-2: C. blyttii, C. botrytis, C. costatum, C. ochthodes, C. pachydermum, C. subcostatum, C. subcrenatum, C. subprotumidum, C. trilobulatum, Cosmarium Clade-3: C. angulosum, C. formosulum, C. granatum, C. impressulum, C. norimbergense, C. regnellii, C. subtumidum, Cosmarium sp. 2, Staurastrum Clade-1: Staurastrum avicula var. lunatum, Staurastrum Clade-2: S. boreale, S. dispar, S. kouwetsii, S. margaritaceum, S. punctulatum. The newly generated sequence data from FBCC strains will serve as a valuable resource for accurate species identification and for exploring the molecular ecology of Desmidiales in freshwater ecosystems. This phylogenetic framework improves our understanding of Desmidiales species diversity in Korea and aids in achieving a more comprehensive taxonomic resolution within this algal order.
본 연구는 선박 기관 냉각수 계통의 부식 관리를 해양사고 예방 관점에서 분석하였다. 해양사고 재결서 분석을 통해 관련 주요 사고 원인을 도출하고, 부식 억제제 농도 변화가 부식 거동에 미치는 영향을 실험적으로 평가하였다. 중앙해양안전심판원 재결서 950건을 텍스트 마이닝과 대규모 언어모델로 분석한 결과, 기관손상 사고 중 냉각수 계통 관련 사례의 비중이 가장 높았으며 주된 원인은 관리 소 홀과 점검 미흡 등 인적 요인으로 확인되었다. 이 분석을 토대로 선박 냉각수 관리의 핵심 요소인 부식 억제제의 첨가와 농도 유지가 부 식 거동에 미치는 영향을 구상흑연주철(FCD-500)을 대상으로 평가하였다. 아질산염 기반 억제제 농도를 0에서 19,000 ppm 범위로 설정하 고, 침적시험과 전기화학 기법을 적용하여 부식 특성을 비교하였다. 권장 농도 13,000 ppm에서는 균일부식과 국부부식이 모두 효과적으로 억제되었고 3000에서 7000 ppm의 저농도 구간에서는 국부부식으로 인한 설비 손상 위험이 증가하였다.
Italian ryegrass (Lolium multiflorum L.) is an annual forage crop widely cultivated across the globe for its excellent nutritional value and high productivity. Despite its importance, studies on differentially expressed genes (DEGs) involved in its morphogenesis remain limited. In this study, we employed a high-yielding mutant line developed through radiation mutagenesis to identify candidate genes associated with morphogenesis, focusing on Expansins (EXPs), GRFs (Growth regulating factors), GIFs (GRF-interacting factors), and growth hormone-related genes. RT-qPCR primers were designed, and differential gene expression analysis was performed. Gene expression was assessed in the leaves of seedlings at one to three weeks of age, comparing the control cultivar 'Kowinearly' with the mutant line. Expression patterns fell into four distinct categories: (1) genes consistently exhibiting lower expression in the mutant line across all developmental stages; (2) genes showing persistently low expression in the mutant, while the control displayed a sharp increase at early stages followed by a decline; (3) genes with low expression in the control but a marked early-stage increase in the mutant; and (4) genes with decreasing expression over time in the mutant, contrasting with gradually increasing expression in the control. These expression profiles highlight Actin and GRF6 as Group 1 genes, AXR1 (Auxin-resistant protein 1) and EXPB6 (c) as Group 2 genes, PEVMPP1 (Pyrophosphate-energized vacuolar membrane proton pump 1) as a Group 3 gene, and EF1A (Elongation factor 1-alpha) as a Group 4 gene, all of which are key candidate genes for the development of high-yielding Italian ryegrass cultivars.
Natural populations of numerous species have decreased sharply in recent years, and a number of mammalian species are also now at elevated risk of extinction globally. The long-tailed goral Naemorhedus caudatus, a vulnerable and protected species designated by IUCN (International Union for Conservation of Nature) and CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora), is distributed in Northeast Asia including the Korean Peninsula. In South Korea, the Seoraksan National Park is known as the largest core habitat for the long-tailed goral population. In this study, phylogenetic relationships and population genetic features of the Seoraksan goral population were analyzed using fecal samples with both mitochondrial DNA and microsatellite markers. We found that Seoraksan gorals were the most closely related to Russian population, and also found that a unique Seoraksan lineage evolved there. In addition, the Seoraksan goral population showed higher genetic diversity than other South Korean populations, suggesting that this population might represent the most ecologically and evolutionarily important remnants of the long-tailed goral in South Korea. The Seoraksan goral population had a low level of genetic differentiation and a rather single genetic structure, suggesting that non-negligible levels of gene flow might have occurred across populations. Moreover, microsatellite genotype-based individual identification estimated that the population size was ≥81 in the Seoraksan National Park. Findings of our study suggest that effective conservation and restoration actions are needed for long-term conservation of N. caudatus in this protected area.
초당옥수수는 고당도 옥수수 품종으로, 식단 트렌드 변화와 천연 당류에 대한 관심 증가로 인해 수요가 증가하면서 재배가 확대되고 있다. 초당옥수수는 높은 당도로 매우 달고 맛이 좋지만, 전분 함량이 낮아 일반 옥수수에 비해 발아율이 낮은 특징이 있다. 본 연구는 초당옥수수 계통의 전분 함량과 발아율의 상관관계를 조사하여, 우수한 생장과 발아율을 갖춘 고품질 계통을 선발하는 것을 목표로 하였다. 본 연구에서는 10개의 초당옥수수 계통을 대상으로 발아율과 식물체 생장 특성을 평가하였다. 모든 계통이 80% 이상의 발아율을 보였으며, KH51 계통이 53일로 가장 출사일이 빨랐고, KH29W 계통이 148cm로 간장이 가장 크게 나타났다. 고당도 계통을 선발하기 위해 수정 후 20일째에 이삭을 수확하여 유리당 함량을 측정하였다. KH28W 계통이 가장 높은 당 함량(23.3%)을 보였으며, KH45 계통이 가장 낮은 당 함량(8.1%)을 나타냈다. 또한, 전분 함량이 유리당과 비례하여 축적되는지를 확인하기 위해 수분 후 40일째에 이삭을 수확하여 분석한 결과, KH47 계통이 가장 높은 전분 함량(30.1%)을, KH28W 계통이 가장 낮은 전분 함량(23.6%)을 보였다. 전분 함량이 발아에 미치는 영향을 평가하기 위해 발아와 관련된 효소 및 유전자들을 분석하여, 발아 과정에서의 효소 활성 및 유전자 발현 수준을 측정하였다. 낮은 전분 함량은 발아 초기에 효소 활성과 유전자 발현을 저하시켜 발아 지연 및 불균일성을 초래하였으나, 발아 후 생장에는 큰 영향을 미치지 않았다. 이는 초당옥수수 종자의 초기 발아 과정이 유리당과 전분 함량에 의해 영향을 받을 수 있음을 시사한다.
Biodiversity encompasses species diversity, which includes species richness and species evenness. High species diversity is known to contribute to community stability and the potential for maintaining healthy ecosystem functioning. However, the most commonly used species diversity indices have some limitations, as they require species-specific abundance data for each community. In contrast, phylogenetic diversity measures the evolutionary distances between species within a community, reflecting ecological and/or evolutionary divergences and niche differences, without requiring abundance data. This study assessed biodiversity by calculating phylogenetic diversity indices for freshwater fishes (19 species) and aquatic insects (49 species) at three sites within Seoraksan and Odaesan National Parks. The aquatic insects studied belong to the EPT group (Ephemeroptera, Plecoptera, and Trichoptera), which are widely used as bioindicators of aquatic ecosystems. Two mitochondrial DNA genes were used as molecular markers: COI and cyt b for fish, and COI and 16S rRNA for the EPT - group. Overall, Odaesan National Park exhibited higher phylogenetic diversity in both fishes and aquatic insects compared to Seoraksan National Park, although this difference was not statistically significant. The highest phylogenetic and species diversity were observed for fish at the OD2 site (Woljeong District) and for the EPT group at the OD1 (Gyebangsan) and SA2 (Jangsudae) sites. Correlation analysis revealed that phylogenetic diversity indices were more positively associated with species richness than species diversity indices. This study serves as a pilot project for establishing standardized methods for assessing biodiversity in national park habitats using phylogenetic diversity. It also aims to inform various policies, such as the development of biodiversity assessment systems and the prioritization of protected areas within national parks.
The Grifola frondosa cultivar KMCC03118 was used to isolate monokaryotic strains via spore separation, resulting in the successful crossbreeding of strains KMCC03118-11 and KMCC03118-23, which produced F1 hybrids. These F1 hybrids were then further crossed with various monokaryotic strains to generate F2 progeny. In evaluating the effects of different medium compositions on fruit body development, it was found that a substrate consisting of wheat bran and dried sawdust, with a carbon-to-nitrogen (C/N) ratio of 66-68, provided the most favorable conditions for mycelial growth. Among the strains tested, KMCC03137 and GF-18-50 demonstrated superior characteristics, including a larger fruit body diameter, thicker pileus, and greater stipe thickness, with the highest productivity observed at 143.6 ± 13.3 g and 144.7 ± 15.2 g, respectively. Furthermore, the color of the caps (L: 29.7 ± 7.1, a: 2.6 ± 0.7, b: 8.2 ± 1.8) remained consistent, indicating stable high-quality production. Based on these results, the optimal substrate composition for enhancing both the quality and productivity of the fruit bodies was determined to be 42% Quercus sp. sawdust, 42% Quercus sp. fermented sawdust, 6% wheat bran, and 10% dried tofu residue. This study provides a crucial foundation for the commercial cultivation and breeding improvement of Grifola frondosa, offering valuable insights into its genetic enhancement, and providing essential data for future research aimed at increasing the species' genetic diversity and productivity.