Phosphatidylinositol 4,5-bisphosphate is important for stomatal opening

Lee, Yuree,Kim, Yong-Woo,Jeon, Byeon Wook,Park, Ki-Youb,Suh, Su Jeoung,Seo, Jiyoung,Kwak, June M.,Martinoia, Enrico,Hwang, Inhwan,Lee, Youngsook Blackwell Scientific Publishers and BIOS Scientifi 2007 The Plant journal Vol.52 No.5

<P>Summary</P><P>Previously, we demonstrated that a protein that binds phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P<SUB>2</SUB>] inhibits both light-induced stomatal opening and ABA-induced stomatal closing. The latter effect is due to a reduction in free PtdIns(4,5)P<SUB>2</SUB>, decreasing production of inositol 1,4,5-trisphosphate and phosphatidic acid by phospholipases C and D. However, it is less clear how PtdIns(4,5)P<SUB>2</SUB> modulates stomatal opening. We found that in response to white light irradiation, the PtdIns(4,5)P<SUB>2</SUB>-binding domain GFP:PLC&dgr;1PH translocated from the cytosol into the plasma membrane. This suggests that the level of PtdIns(4,5)P<SUB>2</SUB> increases at the plasma membrane upon illumination. Exogenously administered PtdIns(4,5)P<SUB>2</SUB> substituted for light stimuli, inducing stomatal opening and swelling of guard cell protoplasts. To identify PtdIns(4,5)P<SUB>2</SUB> targets we performed patch-clamp experiments, and found that anion channel activity was inhibited by PtdIns(4,5)P<SUB>2</SUB>. Genetic analyses using an Arabidopsis <I>PIP5K4</I> mutant further supported the role of PtdIns(4,5)P<SUB>2</SUB> in stomatal opening. The reduced stomatal opening movements exhibited by a mutant of Arabidopsis <I>PIP5K4</I> (<I>At3g56960</I>) was countered by exogenous application of PtdIns(4,5)P<SUB>2</SUB>. The phenotype of reduced stomatal opening in the <I>pip5k4</I> mutant was recovered in lines complemented with the full-length <I>PIP5K4</I>. Together, these data suggest that PIP5K4 produces PtdIns(4,5)P<SUB>2</SUB> in irradiated guard cells, inhibiting anion channels to allow full stomatal opening.</P>

Effects of Vocabulary Size on Anticipatory Sentence Processing in Korean Learners of English

Yuree Noh,Miseon Lee 한국언어학회 2016 언어 Vol.41 No.3

Noh Yuree & Lee Miseon. 2016. Effects of vocabulary size on anticipatory sentence processing in Korean learners of English. Korean Journal of Linguistics, 41-3. 359-378. The present study investigates whether and the extent to which nonnative speakers of English exhibit anticipatory processing of English sentences in comparison to native speakers (Borovsky et al., 2012), using a looking-while-listening paradigm. We also examine the relationship between the anticipatory behavior and vocabulary knowledge of English as a second language. College students with high-intermediate English proficiency participated in an eye-tracking experiment and an offline measurement of vocabulary knowledge. The results revealed that the participants anticipate upcoming words, thereby incrementally processing English sentences as native speakers do. In doing so, they also actively make use of combinatory information of semantic cues and real-world knowledge, having advantage of a larger L2 vocabulary size. (Hanyang University)

Roles of phosphoinositides in regulation of stomatal movements.

Lee, Yuree,Lee, Youngsook Landes Bioscience 2008 Plant signaling & behavior Vol.3 No.4

<P>Guard cells sense various environmental and internal stimuli and, in response, modulate the stomatal aperture to a size optimal for growth and adaptation. Among the many factors involved in the fine regulation of stomata, we have focused our studies on the role of phosphoinositides. Our recent study published in the Plant Journal (52:803-16) provides evidence for an important role for phosphatidylinositol 4,5-bis-phosphate (PtdIns(4,5)P(2)) in inducing stomatal opening. Light induces translocation of a PtdIns(4,5)P(2)-binding protein from the cytosol to the plasma membrane and treatments that increase the intracellular PtdIns(4,5)P(2) level induce stomatal opening in the absence of light irradiation. Inhibition of anion channel activity, a negative regulator for stomatal opening, was suggested as a mechanism of PtdIns(4,5)P(2)-induced stomatal opening. We also reported that phosphatidylinositol 3-phosphate (PtdIns(3)P) and phosphatidylinositol 4-phosphate (PtdIns(4)P) regulate actin dynamics in guard cells. The effects of the phosphoinositides were specific, and were not induced by other lipids with similar structures. The roles of different interacting partners are likely to be important for these lipids to produce specific changes in guard cell activity.</P>

Performance Study of Composite Air Filters Using Heterogeneous Fibers

Lee, Ji Soo,Oh, Yuree,Kim, Heejin,Park, Hyun-Seol,Yoon, Sam S.,Lee, Min Wook The Korean Society for Composite Materials 2022 Composites research Vol.35 No.3

Recently, the worldwide demand for disposable masks has increased due to COVID-19 infections and severe air pollution. Personal masks should reduce breathe resistance while maintaining filtering performance. In this study, a solution blowing process is used to produce composite nanofiber filters to co-spin two polymers at once. The manufacture process of the various fiber diameter filter was designed, and the filtration performance and differential pressure of the prepared filter was investigated. Poly vinylidene fluoride-hexafluoropropylene (PVDF-HFP) and Polylactic acid (PLA) fibers were chosen to be entangled together in a layer with a diameter of 1.05 ㎛ and 0.33 ㎛. Composite nanofilters showed up to 87% filtration efficiency and 32 Pa differential pressure.

A Lignin Molecular Brace Controls Precision Processing of Cell Walls Critical for Surface Integrity in <i>Arabidopsis</i>

Lee, Yuree,Yoon, Taek Han,Lee, Jiyoun,Jeon, So Yeon,Lee, Jae Ho,Lee, Mi Kyoung,Chen, Huize,Yun, Ju,Oh, Se Yun,Wen, Xiaohong,Cho, Hui Kyung,Mang, Hyunggon,Kwak, June M. Elsevier 2018 Cell Vol.173 No.6

<P><B>Summary</B></P> <P>The cell wall, a defining feature of plants, provides a rigid structure critical for bonding cells together. To overcome this physical constraint, plants must process cell wall linkages during growth and development. However, little is known about the mechanism guiding cell-cell detachment and cell wall remodeling. Here, we identify two neighboring cell types in <I>Arabidopsis</I> that coordinate their activities to control cell wall processing, thereby ensuring precise abscission to discard organs. One cell type produces a honeycomb structure of lignin, which acts as a mechanical “brace” to localize cell wall breakdown and spatially limit abscising cells. The second cell type undergoes transdifferentiation into epidermal cells, forming protective cuticle, demonstrating <I>de novo</I> specification of epidermal cells, previously thought to be restricted to embryogenesis. Loss of the lignin brace leads to inadequate cuticle formation, resulting in surface barrier defects and susceptible to infection. Together, we show how plants precisely accomplish abscission.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Two neighboring cell types coordinate cellular activities for organ separation </LI> <LI> A honeycomb structure of lignin acts as a “molecular brace” </LI> <LI> The lignin brace spatially restricts cell wall breakdown </LI> <LI> Lignin deposition ensures surface integrity of transdifferentiated epidermal cells </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

대학의 플립드러닝에 요구되는 학습자 역량 진단 도구 개발 및 타당화 연구

이유리(Lee, YuRee),이소영(Lee, So Young) 한국교육학회 2020 敎育學硏究 Vol.58 No.3

최근 대학교육 현장에서는 학습자의 능동적 참여를 수반하는 플립드러닝이 주목받고 있다. 플립드러닝은 사전 학습부터 사후 학습까지 맥락적 연계와 다양한 자료원 및 수업활동이 요구되므로 수업설계에서 학습자에 대한 정보가 필요하다. 이에 본 연구에서는 대학 수업환경에서 플립드러닝을 위한 대학생용 학습자 역량 진단 도구를 개발함으로써 교수자에게 플립드러닝 수업 설계에 필요한 학습자 정보를 제공하고자 한다. 먼저 대학의 플립드러닝 수업에서 수업 목표를 성공적으로 달성하는데 기여하는 구인을 선정하고전문가 집단의 검토를 바탕으로 34개의 설문 문항을 구성하였다. 플립드러닝 수업의 수강생 203명에게 설문조사를 실시하고 그 결과를 토대로 탐색적 요인분석을 실시하여 설명력이 낮은 문항을 제거하였다. 최종 선정된 19개 문항에 대해서는 신뢰도와 탐색적 요인분석 및 확인적 요인분석을 통해 신뢰도 및 구인타당도를 확인하였다. 타당화된 대학생용 플립드러닝에 대한 학습자 역량 진단 도구는 수업설계를 위한 기초자료로 활용되어 플립드러닝을 수강하는 대학생이 성공적인 결과에 도달하는데 도움이 될 것으로 기대된다. Recently higher education has paid attention to flipped learning, which required the active participation of learners. Because the pre-class should be related to the post-class, instructors’ competency and role are essential in the flipped learning instructional design. Therefore by developing a measurement tool for university learners‘ competency about flip learning, we want to provide the instructor with learner information needed for designing a flipped class. The constructs which are to achieve class goals in the university’s flipped class successfully were selected, and 34 questionnaire items were constructed based on expert group review. A survey was conducted with 203 students in the flipped class. In addition, through exploratory factor analysis, items with low eigenvalue were removed, and 19 items were finally selected. Afterward, reliability analysis and confirmatory factor analysis were conducted on the final item to validate the test tool. In the reliability, convergence validity, and discriminant validity, the learners’ competency measurement tool’s validation was secured. It is expected that the validated flipped learning learner measurement tool for the university will be used as a means of providing primary data in instructional design, which will help learners who take flipped classes in university to conduct the learning objective successfully.

블렌디드 러닝에서 대학생의 학습활동이 역량 및 전공수업 만족도에 미치는 영향

이유리(YuRee Lee) 학습자중심교과교육학회 2022 학습자중심교과교육연구 Vol.22 No.22

목적 본 연구에서는 대학의 교수⋅학습성과에 해당하는 역량 향상과 전공수업만족도에 영향을 미치는 학생의 적극적인 수업관련 활동의 영향력을 비교하고 관계를 분석하였다. 방법 이를 위해 비수도권인 부산지역 4년제 A대학의 블렌디드 러닝 수강생을 대상으로 수업관련 활동이라는 과정이 교수⋅학습성과로 도출되는 관계를 구조방정식모형으로 분석하였다. 수업관련 활동으로 수업 전 활동과 팀 기반 수업방법, 적극적 학습 참여를 설정하였고 교수⋅학습성과로 역량 향상과 전공수업만족도를 설정하였다. 결과 분석 결과에서 역량 향상에 대한 영향력은 도전적학습활동의 직접효과가 능동적학습활동의 직접효과보다 더 크게 나타났다. 전공수업 만족도에 대한 긍적적인 영향력은 도전적학습활동의 총효과가 가장 컸으며, 수업준비의 직접효과와 도전적학습경험의 직접효과, 협력학습활동의 직접효과, 역량향상을 매개한 도전적학습활동의 간접효과 순으로 작게 나타났다. 결론 이를 토대로 블렌디드 러닝에서 의미있는 교육경험을 통해 역량 향상을 유도하고 전공수업 만족도를 증진시키기 위해서는 수업준비가 가능한 수업설계를 고려하고, 능동적학습활동과 도전적학습활동, 협력학습활동에 대한 경험을 확대할 필요가 있다. Objectives In this study, the university's teaching and learning outcomes are viewed as competency improvement and major class satisfaction. Since these are influenced by students' active class-related activities, this study compared the influence of students' active class-related activities and analyzed the relationship. Methods To this end, the relationship between class-related activities derived as outcomes was analyzed with a structural equation model for blended learning students at a University in Busan, a non-metropolitan area. Pre-class activities, team-based teaching methods, and active learning participation were set as class-related activities, and competency improvement and major class satisfaction were set as teaching and learning outcomes. Results In the analysis results, the direct effect of challenging learning activities on competency improvement was greater than that of active learning activities. The positive influence on major class satisfaction was the largest in the total effect of challenging learning activities, followed by the direct effect of class preparation, the direct effect of challenging learning experiences, and the indirect effect of challenging learning activities that mediated competency improvement. Conclusions Based on the results, it is necessary to consider class design capable of class preparation and expand experience in active learning activities, challenging learning activities, and cooperative learning activities to induce competency improvement through meaningful educational experience in blended learning.

Phospholipase A ₂ β mediates light-induced stomatal opening in <i>Arabidopsis</i>

Seo, Jiyoung,Lee, Hyoung Yool,Choi, Hyunju,Choi, Yunjung,Lee, Yuree,Kim, Yong-Woo,Ryu, Stephen Beungtae,Lee, Youngsook Oxford University Press 2008 Journal of experimental botany Vol.59 No.13

<P>Phospholipase A<SUB>2</SUB> (PLA<SUB>2</SUB>) catalyses the hydrolysis of phospholipids into lysophospholipids and free fatty acids. Physiological studies have indicated that PLA<SUB>2</SUB> is involved in stomatal movement. However, genetic evidence of a role of PLA<SUB>2</SUB> in guard cell signalling has not yet been reported. To identify <I>PLA</I><SUB>2</SUB> gene(s) that is (are) involved in light-induced stomatal opening, stomatal movement was examined in <I>Arabidopsis thaliana</I> plants in which the expression of <I>PLA</I><SUB>2</SUB> isoforms was reduced or knocked-out. Light-induced stomatal opening in <I>PLA</I><SUB>2</SUB><I>α</I> knockout plants did not differ from wild-type plants. Plants in which <I>PLA</I><SUB>2</SUB><I>β</I> was silenced by RNA interference exhibited delayed light-induced stomatal opening, and this phenotype was reversed by exogenous lysophospholipids, which are products of PLA<SUB>2</SUB>. Stomatal opening in transgenic plants that over-expressed PLA<SUB>2</SUB>β was faster than wild-type plants. The expression of <I>PLA</I><SUB>2</SUB><I>β</I> was localized to the endoplasmic reticulum of guard cells, and increased in response to light in the mature leaf. Aristolochic acid, which inhibits light-induced stomatal opening, inhibited the activity of purified PLA<SUB>2</SUB>β. Collectively, these results provide evidence that PLA<SUB>2</SUB>β is involved in light-induced stomatal opening in <I>Arabidopsis.</I></P>

Facile fluorescent labeling of a polyacrylamide-based hydrogel film <i>via</i> radical initiation enables selective and reversible detection of Al³⁺

Lee, Kyoung Min,Oh, Yuree,Chang, Ji Young,Kim, Hyungwoo Royal Society of Chemistry 2018 Journal of Materials Chemistry B Vol. No.

<P>Stimuli-responsive hydrogels have attracted significant attention for their promising characteristics and have been used in diverse platforms developed for practical applications. When processed as films, these hydrogels show enhanced properties, including faster responses and higher loading capacities, and enhanced interfacial interactions. In this study, we prepared a functional polyacrylamide hydrogel film containing a rhodamine-based probe. The probe plays two fundamental roles: in the fabrication of the film <I>via</I> redox-initiated radical polymerization and in providing a fluorescence response to Al<SUP>3+</SUP>. The amine-containing probe initiated the polymerization reaction at room temperature; the resulting film synthesized through the one-step reaction was transparent and stretchable, elongating by more than five times under tensile tension. The fluorogenic probe in the film showed a sensitive, selective response to Al<SUP>3+</SUP> with a detection limit of 1.5 μM. Furthermore, after detection, the addition of ethylenediaminetetraacetic acid (EDTA) to the film turned off the fluorescence from the probe; this facilitated reversible fluorescence sensing when the film was repeatedly exposed to Al<SUP>3+</SUP>, as expected. The facile preparation method can be expanded to incorporate other multi-functional amine probes that can impart hydrogel films with autonomous, responsive systems.</P>

The Impact of Inhibitory Controls on Anticipatory Sentence Processing in L2

( Yuree Noh ),( Miseon Lee ) 서울대학교 인지과학연구소 2017 Journal of Cognitive Science Vol.18 No.1

This study investigates the relationship between anticipatory behaviors and inhibitory controls in L2 learners using a visual world paradigm. Thirty-four college students with high-intermediate English proficiency participated in an eye-tracking experiment and a flanker task. The eye-tracking results show that the participants predict upcoming words, thereby incrementally processing English sentences in a similar manner to L1 speakers. The eye-movement patterns indicate that they actively made use of combinatory information extracted from subject and verb and real-world knowledge. The results from a flanker task, as a measurement of inhibitory controls, reveal that the flanker effect of accuracy, but not the flanker effect of RT, is significantly correlated with anticipatory processing. That is, the participants who responded to the flankers more accurately were better and faster in predicting the target object. In short, our study supports the constraint-based accounts for sentence processing in L2 suggesting that inhibitory controls as an index of cognitive functions can be another constraint on predictive sentence processing.