Phospholipase A2β mediates light-induced stomatal opening in Arabidopsis

Phospholipase A2 (PLA2) catalyses the hydrolysis of phospholipids into lysophospholipids and free fatty acids. Physiological studies have indicated that PLA2 is involved in stomatal movement. However, genetic evidence of a role of PLA2 in guard cell signalling has not yet been reported. To identify PLA2 gene(s) that is (are) involved in light-induced stomatal opening, stomatal movement was examined in Arabidopsis thaliana plants in which the expression of PLA2 isoforms was reduced or knocked-out. Light-induced stomatal opening in PLA2α knockout plants did not differ from wild-type plants. Plants in which PLA2β was silenced by RNA interference exhibited delayed light-induced stomatal opening, and this phenotype was reversed by exogenous lysophospholipids, which are products of PLA2. Stomatal opening in transgenic plants that over-expressed PLA2β was faster than wild-type plants. The expression of PLA2β 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 PLA2β. Collectively, these results provide evidence that PLA2β is involved in light-induced stomatal opening in Arabidopsis

A Case Report of Familial Benign Hypocalciuric Hypercalcemia: A Mutation in the Calcium-Sensing Receptor Gene

Familial benign hypocalciuric hypercalcemia (FBHH) is an autosomal dominant trait with high penetrance, clinically manifestating a relatively benign, lifelong, persistent hypercalcemia and hypocalciuria without hypercalcemic related complications. The calcium-sensing receptor (CaSR) plays an important role in the regulation of PTH secretion and calcium metabolism. Here we present a family with FBHH of an autosomal dominant inheritance. A heterozygous mutation of E297K (GAG→AAG, exon 4) of CaSR gene was found in 3 family members. To our knowledge, it is the first confirmed case of FBHH with CaSR gene mutation in Korea

In situ electrochemically synthesized Pt-MoO3-x nanostructure catalysts for efficient hydrogen evolution reaction

Designing and preparing highly active and stable nanostructured Pt-based catalysts with ultralow Pt loading are still challenging for electrochemical applications such as water electrolysis and fuel cells. Here we report for the first time an in situ electrochemical process to synthesize Pt-MoO3-x nanoflakes (NFs) overgrown on commercial bulk MoS2 by employing a facile and simple electrochemical method without using any expensive precious metal salts. The overgrowth of Pt-MoO3-x NFs on the bulk MoS2 surface is conducted by applying electrical energy to the bulkMoS(2) and using Pt counter electrode dissolution in an acidic solution. In spite of their 10 times lower Pt loadings compared to commercial Pt black (Alfa Aesar), the synthesized Pt-MoO3-x NFs demonstrate excellent catalytic performance with a Ptmass activity of 2.83 A/mg(Pt) at the overpotential of 100 mV for electrochemical hydrogen evolution reaction (HER), an approximately 4 times higher value than the value of 0.76 A/mg(Pt) at the overpotential of 100 mVfor commercial Pt black. We hypothesize that the outstanding HER characteristics of Pt-MoO3-x NFs are related to the existence and increase of Pt-MoO3 interfacial sites and oxygen vacancy sites such as Mo5+ in the Pt-MoO3-x NF structures. In addition, our density functional theory (DFT) calculations demonstrate that Pt and O sites at Pt and MoO3 interfaces and O sites at defective MoO3-x in the Pt-MoO3-x NFs contribute to accelerate the HER. (C) 2019 Elsevier Inc. All rights reserved

Factors in Evaluating Online Learning in Higher Education in the Era of a New Normal Derived from an Analytic Hierarchy Process (AHP) Based Survey in South Korea

Before COVID-19, online learning in higher education was more of a choice than a requirement. The majority of universities in South Korea are currently not utilizing an evaluation index tailored specifically to online courses and are instead using the traditional in-person class evaluation standards. The study, hence, examines the factors that could be used to evaluate the quality of online learning in higher education taking place due to the COVID-19 pandemic from the point of views of the main subjects of online education: e-learning system administrators, instructors, and students. The analytical hierarchy process (AHP) method was used to determine the relative importance of factors in evaluating online learning. The conclusions derived from this research can be used as foundational material for evaluation factors of online learning in higher education

Fighting Hate and Hate Speech: Raising Anti-Hate Awareness through Critical Analysis of Popular Cultural Texts on an Undergraduate Course

Central to the understanding of hate is an apprehension of the complexities of various hate-motivated social attitudes, which include Othering and the production of social, economic, and political hierarchies of domination. While hate speech is endemic both online and offline in contemporary society, Korean youths have difficulties recognizing its structural forces. The present study aims to offer an instructional model of a college-level course for identifying and countering hate in everyday life. As participants in this course, students read popular cultural texts thematizing hate, wrote critical reviews, and held group discussions to develop anti-hate critical thinking and raise awareness about online hate speech and hate-motivated social behavior. They showed significant progress in the surveys, which measured anti-hate critical thinking, as well as during the course, as they proceeded from observing and identifying hate speech to formulating and articulating proactive strategies to challenge it. This study provided an opportunity for college students to develop good citizenship in reading hate speech and representations of hate in popular cultural texts with a critical eye, and to reflect on the problem of hate in society

Factors in Evaluating Online Learning in Higher Education in the Era of a New Normal Derived from an Analytic Hierarchy Process (AHP) Based Survey in South Korea

Before COVID-19, online learning in higher education was more of a choice than a requirement. The majority of universities in South Korea are currently not utilizing an evaluation index tailored specifically to online courses and are instead using the traditional in-person class evaluation standards. The study, hence, examines the factors that could be used to evaluate the quality of online learning in higher education taking place due to the COVID-19 pandemic from the point of views of the main subjects of online education: e-learning system administrators, instructors, and students. The analytical hierarchy process (AHP) method was used to determine the relative importance of factors in evaluating online learning. The conclusions derived from this research can be used as foundational material for evaluation factors of online learning in higher education

Comparison between Korean and foreign authors concerning the citation impact of Korean journals indexed in Scopus

Purpose An aim of this study is to analyze the citation impact of articles and reviews that were published in engineering, materials science, and medical journals in Korea over the 5-year period from 2012 to 2016 based on authors’ countries. These three subject areas were selected to provide insights regarding citation impact because they are better represented than other subjects among the 248 Korean journals indexed by Scopus. Methods We classified authors’ as Korean and foreign to assess and compare the citation impact of articles and reviews according to the authors’ countries and evaluated whether bibliometric indicators, such as the number of authors and the view count, were associated with a higher citation impact. Results We found that the citations count and publications in the top 10 citation percentile in these three subject areas were higher for reviews than for articles; further, the citation impact of articles and reviews by foreign authors was higher than that of articles and reviews by Korean authors. The number of authors had a weak relationship with citation impact based on the subject area, and the number of authors per review by foreign authors in materials science and medicine was negatively associated with citation impact. Moreover, the views count was found to be positively associated with the citation impact of publications in these three subject areas. Conclusion Considering these findings, future research should explore more bibliometric indicators, subject areas, and countries in order to develop practical applications. The results of this study provide insights and statistical evidence indicating that journal publishers and editors in Korea should attempt to attract more publications by foreign authors and promote their publications to increase their visibility and likelihood of being cited

Anti-Thermal Skin Aging Activity of Aqueous Extracts Derived from Apple Mint (Mentha suaveolens Ehrh.) in Human Dermal Fibroblasts

Thermal skin aging refers to skin aging induced by heat shock treatment. Apple mint (Mentha suaveolens Ehrh.) has been used as a folk medicine to treat various diseases. However, the activity of apple mint in thermal skin aging has yet to be investigated. In this study, we conducted various biological assays to demonstrate the anti-thermal skin aging activity of extracts of apple mint leaves (ALE). As a result, ALE showed significant antioxidant activities and inhibited the production of reactive oxygen species (ROS), matrix metalloproteinases (MMPs), and interleukin-8 (IL-8) as well as suppressed mitogen-activated proteins kinases (MAPKs) such as extracellular signal regulated kinases (ERK), c-Jun N terminal kinases (JNK), and p38 MAPK triggered by heat shock treatment in human dermal fibroblasts (HDFs). Consequently, ALE could be used as attractive cosmetic materials with anti-thermal skin aging activity