Antipredator response of Korean clawed salamander (Onychodactylus koreanus) larvae to odors of potential predators (Chinese minnow, Rhynchocypris oxycephalus and Korean freshwater crayfish, Cambaroides similis)

Jiyeon Cheon,Jongsun Kim,Hyerim Kwon,Jiho Park,Daesik Park The Ecological Society of Korea 2024 Journal of Ecology and Environment Vol.48 No.1

Background: To identify and avoid predators, amphibians rely on chemical cues. Onychodactylus koreanus undergo two to three years of the larval stage in mountainous streams, where they encounter various predators. We aimed to identify the potential predators of O. koreanus larvae based on their antipredator responses to predator odors. Additionally, we examined whether the response was innate or can be strengthened by predator olfactory learning. Results: In Experiment 1, O. koreanus larvae exhibited a substantial antipredator response to Chinese minnow (Rhynchocypris oxycephalus) odor but not to Korean freshwater crayfish (Cambaroides similis) odor. In Experiment 2, O. koreanus larvae, who did not previously expose to R. oxycephalus odor, demonstrated a substantial antipredator response to it. Experiment 3 indicated that predator olfactory learning of R. oxycephalus did not enhance the antipredator response of the larvae. Conclusions: Rhynchocypris oxycephalus could prey on O. koreanus larvae, whose antipredator response to R. oxycephalus odor is innate and not enhanced by olfactory learning. Further investigation into the olfactory system of this species may provide insights into the life cycle of O. koreanus, uncovering hidden underground breeding sites and unknown breeding periods.

Antipredator behavior to the chemical cue of potential predators in Korean clawed salamander larvae (Onychodactylus koreanus)

Jiyeon Cheon,Jongsun Kim,Hyerim Kwon,Jiho Park,Daesik Park 한국양서ㆍ파충류학회 2023 한국양서·파충류학회 학술대회 Vol.2023 No.07

Korean clawed salamander larvae (Onychodactylus koreanus) mainly inhabit mountain valleys, unlike other Hynobius salamanders. This study aimed to reveal if predation pressure affects the distribution of O. koreanus larvae in the valleys through olfactory antipredator behavior tests. In summer, the larvae move downstream that increasing the chance of encountering potential fish predators. So, we wanted to know if antipredator behavior is acquired while first experiencing the predators or innate. First, we investigated the response of O. koreanus larvae to chemical cues (100%, 50%, 25%, and 0%) of crayfishes (Cambaroides similis) and minnows (Rhynchocypris oxycephalus). Second, after learning twice by mixing the target species and potential predators' chemical cues, we tested if antipredator behavior is shifted. Onychondactylus koreanus showed significant antipredator response to minow odors by reducing moved time and distance, but not to crayfish odors. In the second test, the larvae showed significant antipredator behavior regardless of whether they had learned about the predator or not. Our results demonstrate that minnows are potential predator of O. koreanus larvae and potentially affect the restriction of distribution of the larvae in the valleys. In addition, the second result suggests that antipredator response of O. koreanus to minow odors is innate.

관상동맥질환자의 D유형 성격과 치료지시이행의 관계에 미치는 극복력의 매개효과

천미영(Cheon, Mi Young),강지연(Kang, Jiyeon) 한국성인간호학회 2016 성인간호학회지 Vol.28 No.1

The Role of Ethnic Socialization, Ethnic Identity and Self-Esteem: Implications for Bi-ethnic Adolescents’ School Adjustment

Lee, Jiyeon,Cheon, Yuen Mi,Wei, Xinying,Chung, Grace H. Springer-Verlag 2018 Journal of child and family studies Vol.27 No.12

실시간 용접데이터를 이용한 Tandem GMW 용접부 비드 형상 예측 모델 개발

심지연(Jiyeon Shim),천현필(Heonpil Cheon) 한국자동차공학회 2023 한국자동차공학회 학술대회 및 전시회 Vol.2023 No.11

20대 소비자에게 벼룩시장 및 중고품의 의미는 무엇인가?

천혜정(Hyejung Cheon),이지연(Jiyeon Lee) 한국유통학회 2015 流通硏究 Vol.20 No.3

본 연구에서는 중노년의 장소로 알려진 황학동/동묘 벼룩시장을 20대 소비자가 왜 찾으며 이 시장에서 어떠한 경험을 하는지, 그리고 20대 소비자에게 벼룩시장 및 중고품의 의미는 무엇인지를 살펴보고자 한다. 이를 위해 황학동/동묘 벼룩시장을 방문, 중고품을 구매하는 20대 소비자 8명과의 개인면접을 실시하였다. 연구결과 20대 소비자는 황학동/동묘 벼룩시장에서 자신이 어렸을 때 가지고 놀거나 사용하던 물건이지만 이제는 현대화된 시장에서 쉽게 발견할 수 없는 물건들을 통해 과거를 추억하는데, 이들에게 추억 ‘돋는’ 물건은 도스형 컴퓨터, 디스켓, 게임팩, 장난감, 워크맨, 비디오테이프등으로 다양하였다. 그런데 이들이 시장의 물건을 보며 느끼는 기억은 과거에 의존하고 있지만 기억을 통해 상기되는 과거의 것들은 현재의 상태를 지시하고 있었다. 즉 한국사회의 20대로서 자신들이 직면한 불안한 현실보다 위협적이지 않고 편안했던 과거를 돌아볼 수 있는 곳으로 황학동/동묘 벼룩시장을 경험하며 승자독식의 현대사회에서 시골생활의 낭만을 느낄 수 있는 힐링의 장소로 황학동/동묘 벼룩시장에 대한 가치를 부여하고 있었다. 또한 마구잡이로 쌓여있는 물건들, 갈 때마다 바뀌는 물건들, 허를 찌르는 물건들에 대한 호기심을 이야기하는 등 ‘탐험가’로서의 소비자의 모습을 띠고 있었으며 자신이 원하는 물건을 저렴하게 구매하는 이른바 ‘득템’의 즐거움을 경험한다. 이들은 중고품에 대한 거부감을 전혀가지지 않으며, 오히려 보물찾기, 빈티지 등의 용어를 사용하며 세월의 흔적을 느낄 수 있는 중고품에 매력을 느낀다고 하였다. 현대화된 백화점과 쇼핑몰, 합리화/대형화된 유통점과 편의점 등에 보다 익숙한 20대 소비자들이 오히려 허름하고 낡은 벼룩시장의 날 것 그대로의 모습에 의미를 부여하고 있다는 것은 매우 흥미로운 지점이다. 결국 중고품과 벼룩시장에서의 소비경험을 이해하기 위해서는 중고품과 벼룩시장이 가지는 기본적인 경제적 기능 이외 사회문화적 가치까지 재고할 필요가 있음을 보여주고 있었다.

Compressive Properties of Nanoporous Gold Through Nanoindentation: An Analytical Approach Based on the Expanding Cavity Model

Oh Min Kwon,Jiyeon Kim,Jinwoo Lee,Jong‑hyoung Kim,Hee‑Jun Ahn,Ju‑Young Kim,Young‑Cheon Kim,Dongil Kwon 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.10

We investigated the analytic relation between hardness and compressive yield stress using an expanding cavity model (ECM)for nanoporous gold (np-Au). We prepared three np-Au samples with ligament sizes 30.61, 59.36 and 116.33 nm by freecorrosiondealloying and post heat treatment. The indentation contact morphology was examined to estimate the hardnessaccurately from the nanoindentation load-depth curve. Unlike conventional dense metals, the deformation was confined to theprojected contact area, and the center of the residual impression was dominated by densification. The projected contact areaestimated by the Oliver–Pharr method was overestimated, so that a new contact area function was proposed that consideredthe indentation contact morphology of np-Au. It was confirmed that a hardness value taking into account the indentationcontact morphology of np-Au matches well with the hardness derived by direct measurement of the residual impression. We modeled the ratio of hardness to compressive yield stress for np-Au using an ECM. The scaling factors, which representthe extra strain-hardening in the core in the ECM, were analyzed for np-Au and dense metals. An ECM that better matchesnp-Au is suggested based on the scaling factor resulting from densification beneath the indenter.

Fungal Diversity in Nam River and Their Biodegradative Activities

Yeon Jae Choi,Hyerang Eom,Jiyeon Park,Jelyn Park,Seoyoung Cheon,Hyeon-Su Ro 한국균학회 2024 Mycobiology Vol.52 No.1

145 fungal isolates were obtained from three sampling sites situated within the Nam Riverbasin, located in the southern region of South Korea. Through ITS sequence analysis, thefungal isolates were identified to comprise 55 species of ascomycetes and 11 species ofbasidiomycetes. The 55 species of ascomycetes exclusively belong to the phylumPezizomycotina, comprising 33 species of Dothideomycetes, 6 species of Eurotiomycetes, and16 species of Sordariomycetes. Regarding their plant pathogenicity, an investigation into thefungi’s ability to penetrate solid media revealed Nigrospora chinensis as displaying the highestgrowth, followed by Pseudopestalotiopsis theae, various Curvularia species, Diaporthe species,and Alternaria alternata. Further research associating this penetration ability with fungalpathogenicity is deemed necessary. Among the 10 fungal species exhibiting penetrationabilities, an examination of their capability to degrade biological polymers revealed that twostrains of D. phaseolorum displayed exceptional polymer degradation. These strains exhibitedremarkable abilities in decomposing malachite green and crystal violet, both recalcitrant dyes. This study underscores the potential utilization of fungal diversity in freshwater environmentsas a foundational approach to address freshwater pollution issues.

Fungal Diversity in Nam River and Their Biodegradative Activities

Yeon Jae Choi,Hyerang Eom,Jiyeon Park,Jelyn Park,Seoyoung Cheon,Hyeon-Su Ro The Korean Society of Mycology 2024 Mycobiology Vol.52 No.2

145 fungal isolates were obtained from three sampling sites situated within the Nam River basin, located in the southern region of South Korea. Through ITS sequence analysis, the fungal isolates were identified to comprise 55 species of ascomycetes and 11 species of basidiomycetes. The 55 species of ascomycetes exclusively belong to the phylum Pezizomycotina, comprising 33 species of Dothideomycetes, 6 species of Eurotiomycetes, and 16 species of Sordariomycetes. Regarding their plant pathogenicity, an investigation into the fungi's ability to penetrate solid media revealed Nigrospora chinensis as displaying the highest growth, followed by Pseudopestalotiopsis theae, various Curvularia species, Diaporthe species, and Alternaria alternata. Further research associating this penetration ability with fungal pathogenicity is deemed necessary. Among the 10 fungal species exhibiting penetration abilities, an examination of their capability to degrade biological polymers revealed that two strains of D. phaseolorum displayed exceptional polymer degradation. These strains exhibited remarkable abilities in decomposing malachite green and crystal violet, both recalcitrant dyes. This study underscores the potential utilization of fungal diversity in freshwater environments as a foundational approach to address freshwater pollution issues.

OB-40 : Isolation and Characterization of Chorionic Mesenchymal Stromal Cells from Human Full Term Placenta

( Hye Jung Yun ),( Ju Young Cheon ),( Narinay Kim ),( In Yang Park ),( Bo Kyung Koo ),( Jiyeon Kim ),( Ji Hyun Kim ),( Ahlm Kwon,),( Myungshin Kim ),( Yonggoo Kim ),( Jong Chul Shin ),( Jong Hoon Kim 대한산부인과학회 2014 대한산부인과학회 학술대회 Vol.100 No.-

목적: Adult stem cells are considered as an excellent source for research because they pose few ethical problems and limitations in terms of availability. Although many types of stem cells are available, the sources of the stem cells selected for clinical use should possess the ability to renew, be easily isolated and be pluripotent. These properties can be satisfied with human term placental-derived stromal cells. It is essential to understand the expansion capability and potency of isolated stem cells. 방법: This study focused on the characterization of mesenchymal stromal cells (MSCs) from the chorion of human full term placenta from 15 donors.We characterized the surface markers and multilineage differentiation (adipogenic, osteogenic and chondrogenic induction) ability of cultured chorionic MSCs. We also present our findings regarding their growth rate and gene expressions. 결과: Chorionic MSCs revealed homologous fibroblast-like morphology and expressed CD73, CD29, CD105, and CD90. The hematopoietic stem cell markers including HLA DR, CD11b, CD34, CD79a, and CD45 were not expressed. The growth kinetics of their serial passage was steady at the later passages (passage 10). The multilineage capability of chorionic MSCs was demonstrated by successful adipogenic, osteogenic and chondrogenic differentiation and associated gene expression. Chorionic MSCs expressed genes associated with undifferentiated cells (NANOG, OCT4, REX1) and cardiogenic or neurogenic markers such as SOX2, FGF4, NES, MAP2, and NF. TERT was negative in all the samples. 결론: A low HLA DR expression suggests that chorionic MSCs may serve as a great source of stem cells for transplantation because of their immune- privileged status and their immunosuppressive effect. Based on these unique properties, it is concluded that chorionic MSCs are pluripotent stem cells that are probably less differentiated than BM-MSCs, and they have considerable potential for use in cell-based therapies.