Investigation of potential antioxidant effects of sulfated polysaccharides from Sargassum thumbergii

YuJin Roh,Hyo-Geun Lee,Fengqi Yang,H.H.A.C.K Jayawardhana,You-Jin Jeon 한국수산과학회 양식분과 2023 한국수산과학회 양식분과 학술대회 Vol.2023 No.6

Brachybacterium kimchii sp. nov. and Brachybacterium halotolerans subsp. kimchii subsp. nov., isolated from the Korean fermented vegetables, kimchi, and description of Brachybacterium halotolerans subsp. halotolerans subsp. nov.

Yujin Kim,Yeon Bee Kim,Juseok Kim,Joon Yong Kim,Tae Woong Whon,Won-Hyong Chung,Eun-Ji Song,Young-Do Nam,Se Hee Lee,Seong Woon Roh 한국미생물학회 2022 The journal of microbiology Vol.60 No.7

Two Gram-stain-positive, oxidase-negative, catalase-positive, and coccus-shaped bacterial strains, designated CBA3104T and CBA3105T, were isolated from kimchi. Strain CBA3104T and CBA3105T grew at 10–35°C (optimum, 25°C and 30°C, respectively), at pH 6.0–8.5 (optimum, pH 6.5), and in the presence of 0–15% (w/v) NaCl (optimum, 5%). A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CBA3104T formed a distinct phylogenetic lineage within the genus Brachybacterium whereas strain CBA3105T was closely positioned with Brachybacterium halotolerans MASK1Z-5T. The 16S rRNA gene sequence similarity between strains CBA3104T and CBA3105T was 99.9%, but ANI and dDDH values between strains CBA3104T and CBA3105T were 93.61% and 51.5%, respectively. Strain CBA3104T showed lower ANI and dDDH values than species delineation against three closely related strains and type species of the genus Brachybacterium, however, strain CBA3105T showed 96.63% ANI value and 69.6% dDDH value with Brachybacterium halotolerans MASK1Z-5T. Among biochemical analysis results, strain CBA3104T could uniquely utilize bromo-succinic acid whereas only strain CBA3105T was positive for alkaline phosphatase and α-fucosidase among two novel strains, closely related strains, and type species of the genus Brachybacterium. Compared with strain CBA3105T and Brachybacterium halotolerans JCM 34339T, strain CBA3105T was differentially positive for acid production of D-arabinose, D-adonitol, and potassium 5-ketogluconate and enzyme activity of β-glucuronidase. Both strains contained menaquinone-7 as the dominant quinone. The cell-wall peptidoglycan of two novel strains contained meso-diaminopimelic acid. The major fatty acids of strains CBA3104T and CBA3105T were anteiso-C15:0, anteiso-C17:0, and iso-C16:0. The major polar lipids of both strains were phosphatidylglycerol and diphosphatidylglycerol. Strain CBA3104T possessed a uniquely higher abundance of tRNA (97 tRNAs) than four Brachybacterium strains used for comparative taxonomic analysis (54–62 tRNAs). Both the CBA3104T and CBA3105T strain harbored various oxidoreductase, transferase, hydrolase, and lyase as strain-specific functional genes compared to closely related strains and Brachybacterium type species. The results of biochemical/physiological, chemotaxonomic, and genomic analyses demonstrated that strains CBA3104T and CBA3105T represent a novel species of the genus Brachybacterium and a novel subspecies of B. halotolerans, respectively, for which the names Brachybacterium kimchii sp. nov. and B. halotolerans subsp. kimchii subsp. nov. are proposed. The type strains of the novel species and the novel subspecies are CBA3104T (= KCCM 43417T = JCM 34759T) and CBA3105T (= KCCM 43418T = JCM 34760T), respectively.

Moderators of the Association Between Contact Frequency With Non-Cohabitating Adult Children and Depressive Symptoms Among Community-Dwelling Older Adults

Rho Yujin,Kim Minji,Beon Jungeun,Kim Yeojin,Yoon Sunwoo,Nam You Jin,Hong Sunhwa,Cho Yong Hyuk,Son Sang Joon,Hong Chang Hyung,Roh Hyun Woong 대한신경정신의학회 2023 PSYCHIATRY INVESTIGATION Vol.20 No.8

Objective Contact frequency with adult children plays a critical role in late-life depression. However, evidence on possible moderators of this association remains limited. Moreover, considering alterations in contact modes after the coronavirus disease-2019 pandemic, there is a need to investigate this association post-pandemic to develop effective therapeutic interventions.Methods This study included 7,573 older adults who completed the Living Profiles of the Older People Survey in Korea. Participants’ contact frequency and depressive symptoms were analyzed. Regression analysis was performed after adjusting for covariates. The moderating effects of variables were verified using a process macro.Results Multivariable logistic regression analysis revealed that infrequent face-to-face (odd ratio [OR]=1.86, 95% confidence interval [CI]=1.55–2.22) and non-face-to-face contact (OR=1.23, 95% CI=1.04–1.45) in the non-cohabitating adult children group was associated with a higher risk of late-life depression compared to that in the frequent contact group. Linear regression analysis indicated consistent results for face-to-face and non-face-to-face contact (estimate=0.458, standard error [SE]=0.090, p<0.001 and estimate=0.236, SE= 0.074, p=0.001, respectively). Moderation analysis revealed that the association between late-life depression and frequency of face-toface contact was moderated by age, household income quartiles, number of chronic diseases, physical activity frequency, presence of spouse, nutritional status, and whether the effect of frequency of non-face-to-face contact on late-life depression was increased by participation in social activity, frequent physical activity, and good cognitive function (p for interaction<0.05).Conclusion Frequent contact with non-cohabitating children lowers the risk of depression later in life. Several variables were identified as significant moderators of contact frequency and depression symptoms.

세종학당의 한국어 초급 콘텐츠 재정비 및 활용 방안 연구 -온라인 세종학당 ‘사이버 한국어 초급’과 누리-세종학당 한국어 초급 콘텐츠를 중심으로-

노채환 ( Roh Chaehwan ),박기선 ( Park Keeseon ),안유진 ( An Yujin ) 이중언어학회 2021 이중언어학 Vol.85 No.-

The purpose of this study is to prepare contents reorganization plan and linkage utilization plan by analyzing the ‘Cyber Korean Beginner’ of the online King Sejong Institute developed in 2019 and the previously developed contents of Nuri-King Sejong Institute. To this end, reorganization of contents plan was established, and the contents were reviewed by selecting target contents based on the learners demand. Afterwards, meta-analysis and tagging of the 160 contents was conducted. Based on this analysis, it was proposed to find a way to maximize the linkage between contents and information sharing through micro-contentization, segmentation, re-editing, and strengthening of search functions. In addition, a method for linking and utilizing online contents for beginners through contents reorganization was proposed. (Cyber Hankuk University of Foreign Studies·Cyber Hankuk University of Foreign Studies·University of Niigata Prefecture)

와류 저감을 위해 설계한 라온하제의 수치적 연구

노나현(Nahyeon Roh),김아람(Aram Kim),박민지(Minji Park),박민혜(Minhye Park),전예진(Yejin Jeon),김가은(Kaeun Kim),백유진(Yujin Baek),오은미(Eunmi Oh),오세종(Sejong Oh) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11

In this study, numerical study is conducted to suggest wing which reduce the vortex strength generated by the leading aircraft. The wing with 3 holes is suggested, which is named as Raon-hajae. Computational grid is created by using pointwise. ANSYS Fluent is employed with the incompressible assumption and RSM turbulence model. As a result of this study, it is confirmed that decrement of lift coefficient is 2.1% and increment of drag coefficient is 11.8%. Nevertheless penalty of aerodynamic performance, reduction of vortex strength is confirmed up to 63%.

브루나이 열대우림 내 주요 3개 수종 고사목의 초기 질량 감소율과 탄질율 변화

노유진,장민주,손요환,Roh, Yujin,Jang, Minju,Son, Yowhan 한국환경생물학회 2021 환경생물 : 환경생물학회지 Vol.39 No.2

본 연구에서는 열대우림인 브루나이 MDF와 PSF의 주요 수종(D. aromatic, D. rappa, C. arborescens)을 대상으로 초기 분해 단계의 수종별 질량 감소율과 탄질율의 변화를 파악하였다. 2019년 5월에 총 48개의 고사목 시료(15 cm ×4.8 cm ×5 cm)를 산림 지표면에 배치하고 16개월 후 수거하였다. 분해 전 수종별 고사목의 밀도(g cm^-3)는 0.64±0.01 (D. aromatic), 0.60±0.00 (D. rappa), 0.44±0.02 (C. arborescens) 등이었으며, 16개월 동안 수종별 연간 질량 감소율(%)은 6.37 (D. aromatic), 8.17 (D. rappa), 18.53 (C. arborescens) 등으로 나타났다. 부후등급은 C. arborescens에서 III등급이 약 25%로 높았으며 흰개미의 분해 흔적이 나타났다. 한편, 16개월 후 탄질율은 D. aromatic과 D. rappa에서 통계적으로 유의하게 감소하였으나, C. arborescens에서는 감소하는 경향이 유의하지 않았다. 이러한 연구 결과는 열대우림 내 고사목의 초기 분해는 밀도와 같은 수종의 물리적 특성에 따라 차이가 나타날 수 있으며, 주요 분해자의 유형에 따라 탄질율의 변화에도 상대적으로 차이가 있을 수 있음을 시사하는 것이다. This study was conducted to determine the mass-loss rates and the changes in carbon/nitrogen (C/N) ratio of dead woods, which were of following species: Dryobalanops aromatic, D. rappa, and Cratoxylum arborescens. These were dominant tree species in mixed Dipterocarp forests (MDF) and peat swamp forests (PSF) in Brunei Darussalam. In May, 2019, 48 dead wood samples (15 cm×4.8 cm×5 cm) were placed in MDF and PSF sites, and all the samples were collected after 16 months. The effects of species on mass loss were statistically significant (p<0.05); however, no difference was observed in the mass loss obtained from the two forest types (p>0.05). The initial density (g·cm^-3) of the dead woods D. aromatic, D. rappa, and C. arborescens, was 0.64±0.02, 0.60±0.00, and 0.44±0.01, respectively. Also the annual mass loss rate (%) was estimated to be 6.37, 8.17, and 18.53 for D. aromatic, D. rappa, and C. arborescens, respectively. The proportion of dead woods in decay class III was only 25% of C. arborescens samples, which were attacked by wood-feeding invertebrates, such as termites. The C/N ratio decreased significantly in D. aromatic and D. rappa, but the decreasing trend of C/N ratio was not statistically significant in C. arborescens. The results indicate that physical traits of dead woods, such as density, could be one of the main factors causing the decomposition of dead woods initially, as invertebrates such as termites are one of the key decomposers of dead wood in tropical rainforests. In the samples of C. arborescens, which was attacked by invertebrates, nitrogen immobilization occurred to lesser extent as compared to that observed in D. aromatic and D. rappa.

편심률에 따른 수평 비정형 건물의 비선형 해석

주보근(Ju, Bogeun),노지은(Roh, Ji-Eun),황유진(Hwang, Yujin),이상현(Lee, Sang-Huyn) 한국콘크리트학회 2019 한국콘크리트학회 학술대회 논문집 Vol.31 No.1

YOLOv5를 이용한 매장 방문자 인식 방법에 대한 연구

정수진(Sujin Jeong),정유진(Yujin Jeong),노학균(Hakgyun Roh),정관수(Kwansoo Jung) 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.6

Forest structure and carbon dynamics of an intact lowland mixed dipterocarp forest in Brunei Darussalam

Lee, Sohye,Lee, Jongyeol,Kim, Seongjun,Roh, Yujin,Salim, Kamariah Abu,Lee, Woo-Kyun,Son, Yowhan Springer-Verlag 2018 JOURNAL OF FORESTRY RESEARCH Vol.29 No.1

<P>Tropical forests play a critical role in mitigating climate change because they account for large amount of terrestrial carbon storage and productivity. However, there are many uncertainties associated with the estimation of carbon dynamics. We estimated forest structure and carbon dynamics along a slope (17.3A degrees-42.8A degrees) and to assess the relations between forest structures, carbon dynamics, and slopes in an intact lowland mixed dipterocarp forest, in Kuala Belalong, Brunei Darussalam. Living biomass, basal area, stand density, crown properties, and tree family composition were measured for forest structure. Growth rate, litter production, and litter decomposition rates were also measured for carbon dynamics. The crown form index and the crown position index were used to assess crown properties, which we categorized into five stages, from very poor to perfect. The living biomass, basal area and stand density were 261.5-940.7 Mg ha(-1), 43.6-63.6 m(2) ha(-1) and 6,675-8400 tree ha(-1), respectively. The average crown form and position index were 4, which means that the crown are mostly symmetrical and sufficiently exposed for photosynthesis. The mean biomass growth rate, litter production, litter decomposition rate were estimated as 11.9, 11.6 Mg ha(-1) a(-1), and 7.2 g a(-1), respectively. Biomass growth rate was significantly correlated with living biomass, basal area, and crown form. Crown form appeared to strongly influence living biomass, basal area and biomass growth rate in terms of light acquisition. However, basal area, stand density, crown properties, and biomass growth rate did not vary by slope or tree family composition. The results indicate that carbon accumulation by tree growth in an intact lowland mixed dipterocarp forest depends on crown properties. Absence of any effect of tree family composition on carbon accumulation suggests that the main driver of biomass accumulation in old-growth forests of Borneo is not species-specific characteristics of tree species.</P>

브루나이 열대우림의 산림 유형별 지상부 바이오매스 추정

장민주,노유진,김형섭,이정민,손요환,Jang, Minju,Roh, Yujin,Kim, Hyung-sub,Lee, Jeongmin,Son, Yowhan 한국환경생물학회 2021 환경생물 : 환경생물학회지 Vol.39 No.3

본 연구의 목적은 동남아시아 열대우림의 대표 산림 유형인 MDF, PSF 그리고 HF에서 지상부 바이오매스를 추정하는 것이다. 브루나이에서 MDF, PSF 그리고 HF를 대상으로 각각 3개 지역을 선정하여 20 m×20 m 조사구를 지역마다 9개씩 설치하고 흉고직경 10 cm 이상인 임목의 흉고직경을 측정하였다. 지상부 바이오매스는 측정된 흉고직경과 바이오매스 상대생장식을 활용하여 추정되었다. 지상부 바이오매스는 MDF, PSF 그리고 HF에서 각각 603.3±159.9, 305.9±23.4 그리고 284.3±19.3 Mg ha^-1 순으로 나타났다. 산림 유형에 따라 지상부 바이오매스는 유의하게 차이가 있었으며, MDF에서 가장 높게 나타났다. 이는 흉고직경이 70 cm 이상인 거대목이 MDF에서 집중되어 출현했기 때문이다. 이러한 연구 결과는 산림 유형에 따라 거대목의 출현빈도가 다르며, 나아가 거대목의 출현이 지상부 바이오매스 추정에 영향을 주는 요인 중 하나라는 의미를 가진다. The aboveground biomass (AGB) was estimated in mixed dipterocarp forests (MDF), peat swamp forests (PSF), and heath forests (HF) in Brunei Darussalam. A total of 81 (20 m×20 m) plots were established for MDF, PSF, and HF in three regions. The diameter at breast height(DBH) of all live trees (DBH≥10 cm) was measured within the plots. The AGB was calculated using an allometric equation with the measured DBH. The AGB(Mg ha^-1) for MDF, PSF, and HF was 603.3±159.9, 305.9±23.4, and 284.3±19.3, respectively, and was significantly different among the forest types (p<0.05). The greater AGB in MDF than those in PSF and HF was due to the presence of emergent trees in MDF. The results showed that the number of emergent trees varied by forest type. Consequently, the appearance of the emergent trees could be one of the main factors affecting AGB in Southeast Asia's tropical rain forests.