Functional genomics by integrated analysis of transcriptome of sweet potato (Ipomoea batatas (L.) Lam.) during root formation

Sujung Kim,Hualin Nie,Byungki Jun,Jiseong Kim,Jeongeun Lee,Seungill Kim,Ekyune Kim,Sunhyung Kim 한국유전학회 2020 Genes & Genomics Vol.42 No.5

Background Sweet potato is easily propagated by cuttings. But the molecular biological mechanism of adventitious root formation are not yet clear. Objective To understand the molecular mechanisms of adventitious root formation from stem cuttings in sweet potato. Methods RNA-seq analysis was performed using un-rooted stem (0 day) and rooted stem (3 days). Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, comparison with Arabidopsis transcription factors (TFs) of DEGs were conducted to investigate the characteristics of genes and TFs involved in root formation. In addition, qRT-PCR analysis using roots at 0, 3, 6, 9, and 12 days after planting was performed to confirm RNA-seq reliability and related genes expression. Results 42,459 representative transcripts and 2092 DEGs were obtained through the RNA-seq analysis. The DEGs indicated the GO terms related to the single-organism metabolic process and cell periphery, and involved in the biosynthesis of secondary metabolites, and phenylpropanoid biosynthesis in KEGG pathways. The comparison with Arabidopsis thaliana TF database showed that 3 TFs (WRKY, NAC, bHLH) involved in root formation of sweet potato. qRT-PCR analysis, which was conducted to confirm the reliability of RNA-seq analysis, indicated that some metabolisms including oxidative stress and wounding, transport, hormone may be involved in adventitious root formation. Conclusions The detected genes related to secondary metabolism, some hormone (auxin, gibberellin), transports, etc. and 3 TFs (WRKY, NAC, bHLH) may have functions in adventitious roots formation. This results provide valuable resources for future research on the adventitious root formation of sweet potato.

Is the Activeness of ETFs Beneficial to Investors? Evidence from Korean Domestic Stock ETFs

Sujung Choi 한국자료분석학회 2022 Journal of the Korean Data Analysis Society Vol.24 No.1

ETF Activeness is defined as a standard deviation of return difference between ETF market price-based returns and a market portfolio’s returns. This study investigates the Activeness of domestic stock ETFs listed in the Korean market from 2010Q1 to 2020Q4. ETF Activeness strongly predicts fund performance in the following quarter and is positively associated with fees and fund classes. However, Activeness does not show a statistically significant relationship with fund sizes although fund sizes are negatively related to fund performance. As for all domestic stock ETFs, if contemporaneous (lagged) Activeness increases by one standard deviation (i.e., approximately +0.5), the annualized return of ETFs will change by -12.5% (23.5%) a year on average over the sample period. This effect is strengthened in recent years over the period from 2018Q1 to 2020Q4 relative to the earlier period from 2010Q1 to 2017Q4. The magnitudes are also economically significant in the perspective of investors even after netting fees because the highest fee is 0.690% a year for domestic stock ETFs in our sample.

Quality of Life in Korean Patients with Tuberculosis: A Longitudinal Study

Sujung Park,Ja Yun Choi 한국간호과학회 2019 한국간호과학회 학술대회 Vol.2019 No.10

Metapragmatic Approach to Impoliteness in Korean and English

Sujung Min 한국영어어문교육학회 2022 영어어문교육 Vol.28 No.1

This study aimed to investigate how impoliteness is conceptualized in Korean and American female students to reveal the discursive nature of impoliteness by comparing judgements of impoliteness based on metapragmatic data analysis. The data consisted of responses to a questionnaire filled by one hundred female students (fifty from each group). The results show that there are similarities as well as differences. Both groups of participants provided a wide range of impoliteness related concepts, revealing the variability of semantic domains that lay people associate with impoliteness. Among the various concepts, ‘rudeness’ and ‘verbal agression’ are mainly judged as impoliteness by both groups of participants. A significant difference between the two groups was that the American participants associated impoliteness with public contexts involving strangers while the Korean participants related impoliteness to both public and private settings involving friends and acquaintances. Findings from the contrastive study appear to be in line with the relational approach to impoliteness which views impoliteness as relational and proposes a discursive understanding of social norms of inappropriateness that underlie the judgements.

An Intercultural Pragmatic Study of Speech Act of Correction in Korean EFL Context

Sujung Min 한국영어어문교육학회 2020 영어어문교육 Vol.26 No.2

Taking an intercultural pragmatic approach, the present study compared native English speakers and Korean L2 learners performance of the speech act of correction and how it is realized with status unequals. The difference in status here is not necessarily socio-economic, but rather a matter of the power structure within the classroom context. By focusing on correction, this study looked at situations where one person knows the other has had a factual errors. The study attempted to find out whether there is pragmatic transfer from Korean (L1) among L2 learners of English in the strategies used to realize the speech act of correction. The correction speech act classified as an expressive is one of face-threatening speech acts and therefore have received much attention because of their potential for causing cross-cultural miscommunication. The participants included 20 Korean university students and 10 native English speakers. The data consisted of responses to four items of written discourse completion test per participant to elicit the speech act of correction. All the responses were analyzed as consisting of a sequence of semantic formulas (Cohen & Olshtain, 1981). Findings indicated the cultural background and L1 effects on the use of correction strategies.

Combination of Hydrophobic Filtration and Enrichment Methods for Detecting Bacillus cereus in Fresh-Cut Cabbage

Sujung Lee,Yukyung Choi,Heeyoung Lee,Sejeong Kim,Jeeyeon Lee,Jimyeong Ha,Hyemin Oh,Yewon Lee,Yujin Kim,Yohan Yoon,Soomin Lee 한국식품위생안전성학회 2018 한국식품위생안전성학회지 Vol.33 No.5

본 연구에서는 신선편이 양배추 내 Bacillus cereus의 최 적 증균 온도를 선정하고 증균배양액에 소수성필터를 적용하여 multiplex PCR의 검출률을 확인하였다. B. cereus 증균온도는 B. cereus 균주 5 개를 혼합하여 1 Log CFU/ mL이 되도록 증균배지에 접종하고 30oC, 37oC, 42oC에서 증균한 뒤 3시간 간격으로 MYP agar에 도말한 후 계수하여 선정하였다. 소수성필터 미적용 그룹은 B. cereus 균 주 5 개를 혼합하여 신선편이 양배추에 접종한 뒤 최적 증균온도에서 증균하였으며, 증균배양액을 가열하여 DNA 를 추출한 뒤 multiplex PCR을 진행하였다. 소수성필터 적용 그룹은 증균배양액을 소수성 필터에 적용하고 필터에 있는 균을 멸균증류수로 현탁한 뒤 가열하여 추출된 DNA 로 multiplex PCR을 진행하였다. 증균온도 확인 결과, 6시간 증균 시 42oC에서 증균된 샘플(5.4 ± 0.3 Log CFU/mL) 과 30oC에서 증균된 샘플(4.6 ± 0.6 Log CFU/mL) 간 유의 차가 확인되었다(p < 0.05). 소수성필터 적용 유무에 따른 multiplex PCR 결과, 1 Log CFU/g 접종된 샘플의 검출률이 소수성 필터 적용 전 60%(3/5)에서 100%(5/5)로 향상 되었다. 2 Log CFU/g 접종 샘플은 소수성필터 적용 전 80%(4/5)에서 소수성 필터 적용 후 100%(5/5)로 검출률이 증가하였으나, 3 Log CFU/g 접종 샘플은 소수성 필터 적용 전후 모두 100%(5/5)로 확인되었다. 이상의 결과를 통해 신선편이 양배추 내 B. cereus 검출 시 증균배양액에 소수성필터를 적용하고 multiplex PCR을 적용했을 때 신속하고 효율적인 검출이 가능할 것으로 판단된다. This study developed a rapid detection method for Bacillus cereus in fresh-cut cabbages. Fresh-cut cabbage samples were inoculated at 1-, 2- and 3-Log CFU/g, and pathogens were enriched in tryptic soy broth containing 0.15% polymyxin B at 30oC, 37oC, and 42oC to determine the detection limit and appropriate enrichment temperature for multiplex PCR detection. Enriched bacterial cells in enrichment broth were collected in a hydrophobic filter prior to DNA extraction for multiplex PCR. Filters were resuspended in distilled water, and DNA was extracted from the suspension. DNA samples were further analyzed by multiplex PCR. Detection limit of multiplex PCR was 5-Log CFU/mL. B. cereus cell counts were higher (P < 0.05) at 42oC than other temperatures. Detection rate of 1-, 2-, and 3-Log CFU/g inoculated samples were 60%, 80%, and 100% after enrichment respectively. However, when enriched samples were filtered with hydrophobic membrane filter, detection rates became 100%, regardless of inoculation level. Results indicate a combination of enrichment with hydrophobic filtration improves rapid detection efficiency of B. cereus in fresh-cut cabbage by multiplex PCR.

Lexical Bundles in the Spoken Discourse of Native and Nonnative Speakers of English

Sujung Woo 한국언어연구학회 2019 언어학연구 Vol.24 No.3

The present study explores the lexical bundles in the spoken discourse of native and Korean learners of English to examine how they are similar and different in structural and functional distribution. The results show that only a few lexical bundles are in common between the two groups, and the frequency distribution of the common bundles is significantly different. Moreover, it is found that there are three major characteristics in the use of lexical bundles in the Korean learners’ spoken discourse. First of all, the Korean learners tend to overuse certain bundles such as I think it is, I agree with the, and bundles with particular connectors such as and, and so. Second, they rely heavily on a small set of lexical bundles which indicates that they possess limited repertoire of lexical bundles. Lastly, the Korean learners’ lexical bundles are more formal than those in the native speakers’ spoken discourse. It is attributed to exposure of formal expressions through textbooks rather than colloquial expressions. The results of the present study also support the idea that the lexical bundles should be underlined in the second and foreign language education.

The Speech Act of Complaint by Korean L2 Learners of English in an Intercultural Perspective

Sujung Min 한국언어과학회 2020 언어과학 Vol.27 No.3

Taking an intercultural approach, this study investigates the L2 speech act of complaint produced by Korean L2 learners and the effect of L2 proficiency by comparing complaint speech act produced by Korean L2 learners of English with native speakers’ act. Thirty-two subjects participated in the study and were divided into three groups: one consisting of native English speakers and two groups of Korean L2 learners of different English proficiency levels. The effect of L2 proficiency on the complaint speech act was examined accordingly. The data were collected using a discourse completion task. A questionnaire containing six complaint situations were given to the subjects. Their responses were coded using the taxonomy of complaint proposed by Oshtain and Weinbach(1987). The results show that there are some discrepancies between native speakers and Korean L2 learners in making complaints and L2 proficiency influenced the overall production of complaints. The findings suggest the cultural background and L1 effects on the production of complaints by Korean L2 learners of English.

A study on the efficiency improvement of plastic scintillators using nanomaterials

Sujung Min,Bumkyung Seo,Changhyun Roh,Sangbum Hong,Jaehak Jeong 대한방사선방어학회 2021 대한방사선방어학회 학술발표회 논문요약집 Vol.2021 No.11

7-Diethylamino-4-methylcoumarin based liquid scintillator and performance evaluation of gamma and neutron detection

SuJung Min,YongDae Park,ChangHyun Roh,SangBum Hong,BumKyung Seo,JaeHak Cheong 대한방사선방어학회 2022 대한방사선방어학회 학술발표회 논문요약집 Vol.2022 No.11