South Korea Research Articles

Genome-based classification of Halobellus rubicundus sp. nov., a novel extremely halophilic archaeon isolated from a Korean solar saltern.

A novel extremely halophilic archaeon designated, MBLA0158T, was isolated from a solar saltern in Sorae, Republic of Korea. The colonies are red-pigmented, Gram-stain-negative, pleomorphic, non-motile, and lysed in distilled water. The strain grows at 25-45°C (optimum, 37°C), in 15-30% (w/v) NaCl (optimum, 20%) and 0.1-1.0M Mg2+ (optimum, 0.2-0.3M) at pH 6.0-10.0 (optimum, 7.0-8.0). Comparative analysis based on the 16S rRNA gene sequence revealed that this strain is most closely related to the Halobellus inordinatus YC20T with a sequence identity of 96.0%. Strain MBLA0158T contained phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester as major polar lipids. The genome size is 3.29Mb and the DNA G + C content is 66.9mol%. Phylogenomic analysis confirmed that strain MBLA0158T is distinct from previously reported type strains of the genus Halobellus. Pan-genome analysis showed that strain MBLA0158T contains 419 genes that are not present in other type strains of the genus Halobellus. Based on overall analyses, strain MBLA0158T is considered to represent a new species of the genus Halobellus, for which the name Halobellus rubicundus sp. nov. is proposed. The type strain is MBLA0158T (= KCTC 4318T = JCM 36642T).

New realities of economic cooperation between Russia and Mongolia

The article examines the development of the Mongolian vector of foreign economic policy, the strategy of Russia’s turn to the East, within which it seeks global multipolarity and a reduction in opportunities for U.S. domination. In Russia’s confrontation with the United States and its allies after the reunification of Crimea in 2014 and especially after the start of the Russian Special military operation in February 2022 of particular importance is the development of Russian-Mongolian economic and political cooperation in the Russia-Mongolia-China triangle and in regional associations (EAEU, SCO, ASEAN, etc.). The article shows that Mongolia, which sticks to political neutrality, is actively developing economic ties with both neighboring countries – Russia and China – and (within the framework of the “third neighbor” concept) with the United States, the EU, Japan, South Korea and other developed countries, in competition with which Russia now has to renew the economic partnership with Mongolia once lost after the collapse of the USSR. The result of the study is the conclusion that currently Russia’s foreign economic interests in Mongolia are mainly built on the economic and infrastructure projects of the Chinese Initiative “One Belt, One Road”, thereby strengthening the Chinese factor in the bilateral Russian-Mongolian economic partnership, which in the future may lead to new risks to national economic security.

Impact of pandemic-driven online education on student evaluation scores: A comparative study in natural sciences

ABSTRACT The COVID-19 pandemic necessitated the adoption of online systems by educational institutions for infection control. The widespread implementation of online systems presented an opportunity to assess the impact of online education. However, research into the perceptions of students who directly experienced these changes remained relatively underexplored. This study conducted a comparative analysis of student evaluation of teaching scores (SET) before and after the pandemic to examine the impact of accelerated online system adoption on student satisfaction. This study employed a quantitative research design, utilising Ordinary Least Squares regression for the analysis. The analysis utilised SET data from 49,201 students enrolled in the College of Natural Sciences of a top-ranking university in South Korea from 2018 to 2020. The results showed that theory courses that emphasised information delivery demonstrated minimal changes in evaluation scores. By contrast, laboratory courses requiring direct student engagement and controlled environments demonstrated decreased scores. Notably, mathematics, with a conducive online learning environment for laboratory courses, exhibited improved post-pandemic evaluations. Furthermore, the student evaluation of teaching scores decreased in chemistry classes that require restricted laboratory settings. These findings highlight the importance of considering instructional characteristics when integrating modern technologies into educational systems to effectively replace traditional lectures.

Hybrid solar photovoltaic-wind turbine system for on-site hydrogen production: A techno-economic feasibility analysis of hydrogen refueling Station in South Korea's climatic conditions

The South Korean government has an ambitious policy to roll out hydrogen-powered vehicles across the country with 2000 hydrogen refueling stations (HRSs) infrastructure by 2050. However, the country currently lacks sufficient HRS infrastructure. In this context, this study proposes and investigates the technoeconomic feasibility and performance assessment of an optimal hybrid renewable energy system integrated with a vanadium redox flow battery for on-site hydrogen production. The system is designed to refuel a fleet of 20 fuel cell electric vehicles at seven South Korean locations with distinct climates. Based on the typical daily hydrogen and electric load profile of the HRS, the capital expenditure, net present cost, operation expenditure, levelized cost of hydrogen and levelized cost of energy were estimated to be, $5.95 - $13.2 M, $8.93 - $19.4 M, 82,670–202,184 $/yr, 8.77–19.1 $/kg and 2.1–4.58 $kWh, respectively.

Improving seed germination: effect of stratification and dormancy-release priming in Lonicera insularis Nakai

Lonicera insularis Nakai is endemic plant predominantly distributed along the coastlines of Ulleung-do and Dok-do in South Korea, and is significant for medicinal and ornamental uses. However, previous studies reported that L. insularis seeds exhibit morphological dormancy (MD), causing them to germinate only at specific temperatures. Therefore, this study aimed to classify the dormancy type of L. insularis seeds, expand the germination temperature range, and confirm the industrial applicability through dormancy-release (DR) priming. The seeds of L. insularis exhibited no inhibition of water absorption by the seed coat, with 85.0% germination observed at 15°C, similar to the viability (84.0%). Initially, the initial seeds of L. insularis exhibited an embryo-to-seed (E:S) ratio of 0.24 during dispersal, which increased to 0.81 by day 18 at 15°C, indicating that the seeds exhibit MD with underdeveloped embryos. Treatments with GA3 and GA4 + 7 to overcome MD and expand the germination temperature range did not significantly enhance germination. However, seeds that grew embryos through stratification for 2 weeks at 15°C effectively expanded the germination temperature range. Additionally, DR-primed seeds maintained the expanded germination temperature range even after redrying, confirming the commercial potential of DR-primed seeds. Therefore, this study represents the first application of a novel approach to alleviate dormancy in L. insularis seeds through the integration of stratification and priming techniques, termed dormancy-release priming. This approach resulted in a significant increase in germination and expanded the effective temperature range for seed germination. These findings suggest that dormancy-release priming could be a valuable method for producing non-dormant seeds, enhancing the potential for L. insularis distribution and industrial applications.

“Cute saves the world!”: animal Internet Celebrities’ cute activism in the #adoptdon’tshop animal rescue campaign on social media

ABSTRACT This paper examines everyday media practices and seamless work in animal advocacy by various actors with different levels of internet celebrity status, who curate their media personas around ‘cute’ animal images, including established pet Influencers and animal internet celebrities. Through a case study of the most prominent (hashtag) campaign and movement against the pet trade industry and culture in South Korea, #AdoptDon’tShop [#사지말고입양하세요, sajimalgo-ipyanghaseyo], I explore animal internet celebrities’ media practices and immaterial labor that are understated but rigorously performed out of compassion and care for animals. Taking up scholarship on cuteness and Influencer culture, I introduce the concept of cute activism, a novel iteration of social movements adapted into visual social media cultures, pivoting on the performative potential of cuteness and its inherent competency in navigating increasingly-visualized, attention-seeking social media environments. While the instinctive affective appeal of cuteness serves as a driving force and primary modality of cute activism, effectively attracting more people to be tuned into messages, events, and ultimately movements, the very appeal may come into being as a burden for activists, inducing them into continuous immaterial labor.

Accessing long-term care social insurance benefits in South Korea and its correlates

Accessing long-term care social insurance benefits in South Korea and its correlates

Analysis of the incidence of influenza before and after the COVID-19 pandemic in South Korea.

Influenza outbreaks of varying size occur every year, but during the COVID-19 pandemic, many countries experienced influenza at lower levels. However, following the relaxation of COVID-19 prevention measures in 2022, the incidence of influenza began to increase gradually. Thus, this study compared the occurrence of influenza from week 36 of 2017, before the COVID-19 outbreak, until 2023. The analysis was conducted using influenza-like illness occurrence data available from the Korea Disease Control and Prevention Agency infectious disease website. Additionally, to examine the changes in COVID-19 and influenza occurrence during the pandemic, COVID-19 incidence data from 20 January 2020 to 31 August 2023 were obtained from the KDCA Coronavirus Disease 19 homepage. During the COVID-19 pandemic, which corresponds to the 2020/2021 and 2021/2022 influenza seasons, there was no seasonal influenza epidemic, and the incidence rates were below the usual outbreak levels. However, in the 2022/2023 season, when the spread of COVID-19 had eased, a seasonal pattern similar to that observed before the COVID-19 pandemic was noted. Furthermore, correlation analysis between the rates of influenza-like illness and COVID-19 incidence showed no significant correlation during the entire period. However, a significant correlation emerged in 2023 (r = 0.393, p <0.05). These results suggest that influenza was suppressed during the COVID-19 pandemic but returned to typical seasonal patterns after the COVID-19 prevention policies were eased. The positive correlation observed between the incidences of COVID-19 and influenza in 2023 indicates that COVID-19, no longer a novel pandemic-causing infectious disease, may have transitioned to an endemic pattern similar to seasonal influenza.

Exploring the Psychological Mechanism of How the Multidimensional Service Quality of Fitness Centers Affects Consumer Satisfaction and Loyalty Depending on the Level of Exercise Involvement

This study aimed to examine the influence of core services and the physical servicescape and social servicescape on consumer satisfaction and loyalty via perceived price fairness, flow experience, and rapport in fitness centers. Additionally, the present study explored how exercise involvement moderates the relationship between perceived price fairness, flow experience, rapport, and consumer satisfaction. For these purposes, targeting adults using fitness centers in South Korea, a total of 763 participants were sampled based on a cross-sectional design and used for data analyses involving confirmatory factor analysis for measurement validation and latent moderated structural equation modeling for hypothesis testing. The results showed that the core services, physical servicescape, and social servicescape enhance perceived price fairness, flow experiences, and rapport between staff and consumers, respectively. The study findings also indicated that exercise involvement significantly moderates the effect of price fairness and flow experience on satisfaction but not rapport. These insights offer practical and theoretical implications for fitness center management, emphasizing the importance of tailored service strategies in retaining loyal customers.

The predetermined future: tackling South Korea's total fertility rate crisis.

The predetermined future: tackling South Korea's total fertility rate crisis.

Machine Learning-Based Prediction for Incident Hypertension Based on Regular Health Checkup Data: Derivation and Validation in 2 Independent Nationwide Cohorts in South Korea and Japan.

Worldwide, cardiovascular diseases are the primary cause of death, with hypertension as a key contributor. In 2019, cardiovascular diseases led to 17.9 million deaths, predicted to reach 23 million by 2030. This study presents a new method to predict hypertension using demographic data, using 6 machine learning models for enhanced reliability and applicability. The goal is to harness artificial intelligence for early and accurate hypertension diagnosis across diverse populations. Data from 2 national cohort studies, National Health Insurance Service-National Sample Cohort (South Korea, n=244,814), conducted between 2002 and 2013 were used to train and test machine learning models designed to anticipate incident hypertension within 5 years of a health checkup involving those aged ≥20 years, and Japanese Medical Data Center cohort (Japan, n=1,296,649) were used for extra validation. An ensemble from 6 diverse machine learning models was used to identify the 5 most salient features contributing to hypertension by presenting a feature importance analysis to confirm the contribution of each future. The Adaptive Boosting and logistic regression ensemble showed superior balanced accuracy (0.812, sensitivity 0.806, specificity 0.818, and area under the receiver operating characteristic curve 0.901). The 5 key hypertension indicators were age, diastolic blood pressure, BMI, systolic blood pressure, and fasting blood glucose. The Japanese Medical Data Center cohort dataset (extra validation set) corroborated these findings (balanced accuracy 0.741 and area under the receiver operating characteristic curve 0.824). The ensemble model was integrated into a public web portal for predicting hypertension onset based on health checkup data. Comparative evaluation of our machine learning models against classical statistical models across 2 distinct studies emphasized the former's enhanced stability, generalizability, and reproducibility in predicting hypertension onset.

Highly Pathogenic Avian Influenza A(H5N1) Virus Infection in Cats, South Korea, 2023.

In July 2023, cases of highly pathogenic avian influenza (HPAI) were reported at 2 shelters for stray cats in Seoul, South Korea. The cause of infection was suspected to be improperly sterilized raw food made from domestic duck meat, which was manufactured in South Korea. All viruses isolated from cats at the shelters and from the raw food belonged to HPAI A(H5N1) clade 2.3.4.4b. The gene constellation of all viruses was most similar to that of viruses isolated in Korea in November 2022. Of note, the viruses isolated from infected cats harbored mutations E627K or D701N in polymerase basic 2, which are indicative of adaptation to mammals. Postmortem examination revealed systemic pathologic lesions and the presence of widespread virus in different tissues. Thus, consumption of raw duck meat contaminated with HPAI virus likely caused systemic symptoms and death in cats, indicating the introduction of mammal-adapted mutations of the virus.

Cave morphology and moonmilk deposits of Ryongmun Cavern, Democratic People’s Republic of Korea: A Study for the Conservation of Natural Heritage

The Ryongmun Cavern, registered on the World Heritage Tentative List, is the largest and most beautiful karst cave on the Korean peninsula. The characteristics of the cave morphology and moonmilk deposits in the Ryongmun Cavern were studied. A cross section of the main direction of the cave shows that the Ryongmun Cavern is made up mainly of four strata and this caused 4 stages of decline in underground waterline in the course of cave formation. The cave is mainly characterized by NW–SE-trending, NWW–SEE-trending and NNE– SSW-trending passages. The horizontal passages usually have large and wide spaces, whereas the inclined ones are relatively small and narrow. The cave minerals in the Ryongmun Cavern are mainly calcite and aragonite. In the cave, stalactites, stalagmites, limestone columns, cave pearls, etc. Are calcite; and, anthodites are aragonite. In the cave, speleothems display a wonderful underground landscape in harmony with the cave bedrock and groundwater (streams, waterfalls and ponds). The main scenes of the underground karst landscape in the cave are stalactites, stalagmites, limestone columns, stone waterfalls anthodites, underground waterfalls, and underground ponds.The deposits that have been formed recently on the surface of speleothems and walls in the cave are mainly moonmilk composed of hydromagnesite (Mg5(CO3)4(OH)2•4H2O) with an average particle size of 0.55 μm and chemical composition of MgO–29.43% and CaO–6.28%. The moonmilk is present in a white, fine powder form, a hand-rubbed smooth, and a moisture content of 42.0%. Also, the pH is 10.09, which is alkaline. In the Ryongmun Cavern, moonmilk was formed at sites with very low supply of karst water and relatively high wind speeds. The unique underground karst features provide sufficient evidence for geoheritage value of the cave and the characteristics of moonmilk provide a significant implication for management and preservation of the cave environment.

3D Printed Orthodontic Aligners—A Scoping Review

This scoping review aims to provide a comprehensive summary of the current literature on 3D-printed orthodontic aligners. It was conducted following the Preferred Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. An electronic literature search was conducted across the PubMed, Embase, and Web of Science databases. After applying the inclusion criteria, a total of 46 eligible studies published until September 2024 were selected for qualitative synthesis. To date, scientific evidence is primarily available for Tera Harz TC (Graphy, Seoul, Republic of Korea), which is the only studied material approved for orthodontic tooth movements. Although additional materials were identified during the literature search, there is a lack of scientific studies regarding their characteristics and clinical use. This review highlights that while material properties and biocompatibility are of critical importance, the clinical efficacy and long-term safety of 3D-printed aligners require further investigation. Many studies exhibit significant variability in testing methodologies, making substantiated comparisons challenging. Moreover, the existing literature primarily comprises in vitro studies, with limited clinical trials assessing the effectiveness of 3D-printed aligners. Given the current gaps in knowledge and the evolving nature of this field, further well-designed controlled clinical studies are necessary to evaluate the clinical performance and safety of 3D-printed aligners. The findings underscore the need for standardized protocols and comprehensive reporting to enhance the reliability of future research in this area.

Support Vector Machine and Regression Analysis of Blood Glucose Regulation in Male Workers with Type 2 Diabetes: Insights from a Nationwide Survey in South Korea

Support Vector Machine and Regression Analysis of Blood Glucose Regulation in Male Workers with Type 2 Diabetes: Insights from a Nationwide Survey in South Korea

Correction to: Reducing Worker Exploitation in Time-Limited, Low-Wage Visa Schemes: Lessons from South Korea and Thailand

Correction to: Reducing Worker Exploitation in Time-Limited, Low-Wage Visa Schemes: Lessons from South Korea and Thailand

Research on the Training Mode of Compound Talents in "International Trade and Economics + Korean" in the Context of “The Belt and Road Initiative”

Since the establishment of diplomatic ties between China and South Korea 32 years ago, the economic and trade cooperation between the two countries has continued to deepen, and both the investment and trade exchanges have shown a trend of steady growth. Under the background of increasing trade volume between China and South Korea，the demand for versatile talents who understand both "international economics and trade" and Korean is increasing. Therefore, the cultivation of this kind to talents has become more and more important. This paper aims to explore how to cultivate "cross-border interdisciplinary" talents who can promote transnational communication and enhance the comprehensive strength of the country under the framework of the "Belt and Road". At the same time, China's higher education system needs to seize opportunities, face challenges, and strive to cultivate "cross-border compound talents" for the country.

Red blood cell transfusion for critically ill patients admitted through the emergency department in South Korea

Red blood cell transfusion for critically ill patients admitted through the emergency department in South Korea

Barefoot Walking (Earthing) Craze and Policy Support Among Community-Dwelling Older Adults in South Korea: A Grounded Theory Analysis

Barefoot walking is currently a craze in South Korean communities. In particular, the elderly are participating in barefoot walking (earthing) to improve their physical and mental health due to their increasing desire for a healthy life. The purpose of this study was to analyze causes, processes, and consequences of the barefoot walking craze among the elderly in Korean society. The research method used was the grounded theory method. Thirty-five elderly people participating in barefoot walking were selected as participants. Data were analyzed according to open coding, axial coding, and selective coding proposed by Strauss and Corbin. First, an open coding phase yielded 61 concepts, 18 subcategories, and 7 categories through continuous questioning and comparative analysis. Second, in the axial coding stage, causal, contextual, and mediating conditions, action/interaction strategies, and consequences were presented, centering on the phenomenon. Causal conditions and contextual conditions contributing to the phenomenon of barefoot walking were identified as “motivation to participate” and “barefoot walking environment,” respectively. “Participating in barefoot walking” was identified as a phenomenon in the axial coding paradigm. The intervening condition was analyzed as “information about barefoot walking.” The action/interaction strategy was analyzed as “spreading the value of barefoot walking.” In the axial coding paradigm, consequences that emerged through the action/interaction strategy were “restoring physical and mental health” and “community spread and nuisance.” Third, in the selective coding stage, “barefoot walking as a daily routine” was derived as the core category, and the narrative outline was presented. To create a sustainable barefoot walking environment in Korea, it is necessary to have a healthy civic consciousness that coexists and harmonizes with nature.

High-dose denosumab (Xgeva®) Associated Medication-Related Osteonecrosis of the Jaws (MRONJ): incidence and clinical characteristics in a retrospective analysis of 1278 patients.

High-dose denosumab (Xgeva®) is increasingly used for treating bone metastasis and various malignant diseases but carries the risk of medication-related osteonecrosis of the jaw (MRONJ). This study aimed to evaluate the incidence, risk factors, and clinical outcomes of MRONJ in patients treated with high-dose denosumab. A retrospective review was performed on 1278 patients who received high-dose denosumab at Severance Hospital, Seoul, South Korea, from September 2014 to February 2023. Data on the incidence of MRONJ, patient demographics, primary diseases, and treatment outcomes were analyzed. Among the 1278 patients (average age 64.72years; 728 males and 550 females) treated, 34 developed MRONJ, with a 2.66% incidence rate. The average age of those with MRONJ was 68.32years, and they received more Xgeva® injections on average (13.62) compared to the overall cohort. Factors such as age and the frequency of injections were significantly associated with the risk of MRONJ. Notably, the incidence of MRONJ did not significantly differ between those who underwent oral surgery and those with spontaneous MRONJ, especially if oral surgery occurred within 1month of injection. Surgical interventions have shown higher recovery rates in advanced MRONJ stages. This study confirmed a significant MRONJ incidence of 2.66% among high-dose denosumab recipients, highlighting the importance of careful patient selection, monitoring, and education, particularly in older and long-term treatment patients, to mitigate the risk of MRONJ.