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Recent advances and applications of artificial intelligence (AI) have increased the opportunities for students to interact with AI in their learning tasks. Although various fields of scholarly research have investigated human-AI collaboration, the underlying processes of how students collaborate with AI in a student-AI teaming scenario have been scarcely investigated. To develop effective AI applications in education, it is necessary to understand differences in the student-AI interaction (SAI) process depending on students' characteristics. The present study attempts to fill this gap by exploring the differences in the SAI process amongst students with varying drawing proficiencies and attitudes towards AI in performing a public advertisement drawing task. Based on the empirical evidence obtained from the think-aloud protocols of 20 Korean undergraduate students, the study first conducted a lag sequential analysis to identify statistically significant linear patterns of each group and then chronologically incorporated them into the SAI duration via coded activity alignment series to distinguish the overall SAI process of each group. The study revealed the distinctive differences in SAI processes of students with different attitudes towards AI and drawing skills. To better facilitate student-AI teams for learning, a range of implications of educational AI development and instructional design is discussed.

We investigated how the opportunity to learn (OTL) with different types of mathematics tasks are related to mathematical literacy and the role of perceived control in the relationship between OTL and mathematical literacy. The structural equation modeling was applied to the data of 1,649 Korean students from the PISA 2012 database. OTL with the four different types of tasks -- algebraic word problems, procedural tasks, pure mathematics reasoning, and applied mathematics reasoning -- were measured via student survey on how often they have encountered each type of task in their mathematics lessons and tests. The results showed that OTL with the procedural tasks was likely to increase mathematical literacy directly and indirectly through internal perceived control. Engaging in the applied reasoning tasks is positively related to external perceived control, but negatively to mathematical literacy.

This study evaluated a life skill training program on school violence given to elementary school children. A quasi-experimental study was conducted, and a 12-week intervention was implemented targeting 70 students aged between 10 and 11 years. The instruments included peer competency, attitudes toward school violence, experience of school violence, and the Self-Control Rating Scale. The data were analyzed using repeated measure analysis of variance. A significant difference was observed between the groups over time on peer competency (F = 4.17, p = 0.020), attitudes toward school violence (F = 6.02, p = 0.004), and violence experience as a victim (F = 3.49, p = 0.036) and as a perpetrator (F = 3.87, p = 0.026). In the experimental group, the mean scores for peer competency increased compared to the control group, whereas school violence experience decreased at the posttests. A 12-week program of life skill training offered to children was effective in promoting peer competency and attitudes toward school violence, while decreasing the experience of school violence.

The purpose of this study is to identify trends of integrative approach in South Korean technology education. A literature review was completed from 131 selected research journal papers published in South Korean academic databases from 2010 to 2018. The review identified four trends. First, research on technology education within STEAM education has steadily increased since 2010, with student-targeted studies comprising the largest share. Second, program development and implementation type was the most frequent regarding the research types. Third, the analysis of school subjects integrated with technology for integrative approach in South Korean technology education showed the most links to science. Fourth, invention was the most common focus in analysis of the content area of technology education, while creation constituted the most common core concept of the new Korean national curriculum. The results of this study shed light on the place of technology education within STEAM education in South Korea and has implications for research and practice for integrative STEAM education in future Korean technology education.

This research aims to scrutinize the moderating effect of teacher interaction on the relationships between students' self-efficacy and achievement in mathematics in three countries, Korea, Singapore, and the USA. We analyzed the Trends in International Mathematics and Science Study (TIMSS) 2015 data with hierarchical linear modeling. The findings show that in each country, different types of teacher interaction moderate the relationships between students' self-efficacy and achievement in mathematics. Also, when moderated relationships are found, Korean students with lower self-efficacy are likely to have higher achievement when teachers interact with each other very often. Singaporean students across all self-efficacy levels are expected to have advantages of high achievement from teachers interacting with other teachers. However, US students have similar achievement although teachers have frequent interaction with other teachers. We suggest several implications: To improve educational systems, it is necessary to consider which type of teacher interaction is common in that specific context as well as to examine how teacher interaction moderates the relationships between students' self-efficacy and achievement in mathematics.

This study examines the possibility that certain schools may benefit more from culturally responsive leadership than others. We conceptualize culturally responsive leadership as a special form of leadership for uncertainty management. Acknowledging that student diversity usually adds additional complexity to the already difficult task of teaching, we hypothesize that the desired effect of principals' culturally responsive leadership is more pronounced in schools in which alternative social mechanisms for pedagogical uncertainty management are less well-developed. Our data from the Korea Multicultural Education Survey 2017 give credence to this postulation. The results indicate that the effect of principals' culturally responsive leadership tends to be larger in schools characterized by lower levels of teacher collegiality and/or school-community partnership. Considering that these two organizational features are characteristic of effective social mechanisms for pedagogical uncertainty management, schools with these features less clearly discernable would likely be in greater need of culturally responsive leadership.

Background Epigenetic modifications, such as DNA methylation, contribute to the pathophysiology of major depressive disorder (MDD). This study aimed to identify novel MDD-associated epigenetic loci using DNA methylation profiles and explore the correlations between epigenetic loci and cortical thickness changes in patients with MDD. Methods A total of 350 patients with MDD and 161 healthy controls (HCs) were included in the epigenome-wide association studies (EWAS). We analyzed methylation, copy number alteration (CNA), and gene network profiles in the MDD group. A total of 234 patients with MDD and 135 HCs were included in neuroimaging methylation analysis. Pearson's partial correlation analysis was used to estimate the correlation between cortical thickness of brain regions and DNA methylation levels of the loci. Results In total, 2018 differentially methylated probes (DMPs) and 351 differentially methylated regions (DMRs) were identified. DMP-related genes were enriched in two networks involved in the central nervous system. In neuroimaging analysis, patients with MDD showed cortical thinning in the prefrontal regions and cortical thickening in several occipital regions. Cortical thickness of the left ventrolateral prefrontal cortex (VLPFC, i.e. pars triangularis) was negatively correlated with eight DMPs associated with six genes (EML6 , ZFP64 , CLSTN3 , KCNMA1 , TAOK2 , and NT5E). Conclusion Through combining DNA methylation and neuroimaging analyses, negative correlations were identified between the cortical thickness of the left VLPFC and DNA methylation levels of eight DMPs. Our findings could improve our understanding of the pathophysiology of MDD. [ABSTRACT FROM AUTHOR]

This study aimed to examine the serial multiple mediating effects of play teaching efficacy and support competence on the relationship between early childhood teachers' teaching creativity and teacher-child interactions. A survey was conducted among 333 early childhood teachers working in Seoul and Gyeonggi-do, South Korea. Data were analyzed using PROCESS macro (Model=6). Results revealed the following points. First, play teaching efficacy and play support competence fully mediated the relationship between early childhood teachers' teaching creativity and teacher-child interactions. Second, play teaching efficacy and play support competence had serial multiple mediating effects on the relationship between early childhood teachers' teaching creativity and teacher-child interactions. These findings provide a basis for improving the quality of early childhood teachers' teaching creativity, teacher-child interactions, play teaching efficacy, and play support competence, which may have meaningful practical implications for the implementation of the 2019 revised Nuri curriculum of Korea. [ABSTRACT FROM AUTHOR]

Background: Ark clams, a seafood abundant in various nutrients, are widely consumed worldwide. This study aimed to investigate the protective benefits of two common ark clams in Korea, Scapharca subcrenata (SS) and Tegillarca granosa (TG), on gut health in d‐galactose (d‐gal)‐induced aging rats. Results: Thirty‐two Wistar rats (11 weeks old) were randomly allocated into four groups: a CON group (normal diet + saline intraperitoneal (i.p.) injection), a CD group (normal diet + d‐gal i.p. injection), an SS group (normal diet with 5% SS supplementation + d‐gal i.p. injection), and a TG group (normal diet with 5% TG supplementation + d‐gal i.p. injection). After 12 weeks of treatment, histopathological results showed that gut barrier damage was alleviated in rats of the SS and TG groups, as evidenced by increases in mucus layer thickness and goblet cell numbers. Meanwhile, the two groups supplemented with ark clams showed an evident reduction in oxidative stress biomarkers (malondialdehyde and protein carbonyl content levels in the colon) and an increase in the immune‐related factor (immunoglobulin A level in the plasma) in rats. The 16S ribosomal RNA analysis revealed that SS and TG ark clams significantly increased the proliferations of Bacteroidetes at the phylum level and Parabacteroides at the genus level. Additionally, the levels of the three main short‐chain fatty acids in the cecal contents were also significantly increased in the SS and TG groups. Conclusion: Our results indicated a potent preventive effect of SS and TG ark clams on d‐gal‐induced gut injury, suggesting that ark clams may be a promising dietary component for intervening in aging. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The purpose of the current study was to investigate a two-stage model in which parent-related stress and hopelessness each served as mediators of the relationship between perceived parental bonding and South Korean adolescent peer victimization. This study also examined whether the mediating relationships differed by the gender of parents and adolescents. A casual chain with three links and four sets of variables were analyzed using structural equation modeling. Data were collected from 800 adolescents attending 10 middle schools in the Busan region of South Korea. Results indicated that both maternal and paternal parental bonding were negatively associated with stress, stress was positively associated with hopelessness, and hopelessness was positively associated with South Korean adolescent peer victimization. Most importantly, the significant negative associations between both maternal and paternal parental bonding and peer victimization were mediated by both stress and hopelessness. Furthermore, gender differences in these relationships existed for both parents and adolescents. Limitations and implications to practice were discussed.

This study examines teacher collaboration across three Asia-Pacific countries (Australia, Malaysia, and South Korea), focusing on the possibility that principal-teacher perceptual disagreement regarding principal instructional leadership performance may impede progress toward a school organizational condition conducive to collaborative teacher interactions. Data for this study were taken from the OECD Teaching and Learning International Survey 2008. Overall, the results from a series of hierarchical linear modelling analyses appear to give credence to the hypothesis that the degree to which a principal's self-evaluation of her/his instructional leadership diverges from teachers' perception of the leadership is likely to negatively influence teachers' engagement in collaborative activities and collegial interactions; in other words, teachers become more likely to establish collegial relationships with other teachers in a situation where there is little principal-teacher disagreement regarding principal leadership performance. The significant effect of principal-teacher perceptual disagreement found in this study was fairly consistent across all three countries examined despite the substantial differences among the countries in terms of socio-cultural background. This finding sheds light on the need for paying close analytic attention to principal-teacher perceptual agreement as it may constitute an important aspect of school capacity.

The purpose of this study was to examine the possible effects of the simultaneous inclusion of self and other ratings of principal instructional leadership on teachers' self-efficacy beliefs. Special attention was given to the case where principal and teacher ratings were incongruent and exhibited a self-other rating disagreement regarding the principals' effectiveness in instructional leadership. The data used in the analyses were taken from the Organisation for Economic Co-operation and Development's (OECD's) Teaching and Learning International Survey (TALIS) conducted in 2008 and involved information from 672 principals and 11,323 teachers in four OECD countries located in the broader Asia-Pacific region. The study tested a set of hypotheses based on a multi-source assessment framework for the analysis of leadership performance. Results indicated that principal-teacher incongruence regarding principal instructional leadership was significantly and negatively associated with teacher self-efficacy across all four countries. The findings suggest that multi-source assessment can provide unique performance-relevant information about leadership that would not be captured by traditional single-source ratings alone.

This study investigates the influence of principal instructional leadership on teachers' effort to employ instructional strategies for nurturing student autonomy in learning. Nationally representative multi-level data for 7,879 teachers in 479 middle schools in Australia, Malaysia, and South Korea were analyzed in this study. In all three countries analyzed, principal instructional leadership was significantly positively associated with teachers' use of autonomy-supportive instruction. This significant association persisted even when a range of other variables was simultaneously taken into account. This result gives credence to the hypothesis that teachers, who work in a school where the principal effectively demonstrates greater instructional leadership, tend more likely to actively integrate elements of teaching for learner autonomy into their instructional practice.

Calling is one of the unique amphibian characteristics that facilitates social communication and shows individuality; however, it also makes them vulnerable to predators. Researchers use amphibian call properties to study their population status, ecology, and behavior. This research scope has recently broadened to species identification and taxonomy. Dryophytes flaviventris has been separated from the endangered anuran species, D. suweonensis, based on small variations in genetic, morphometric, and temporal call properties observed in South Korea. The Chilgap Mountain (CM) was considered as the potential geographic barrier for the speciation. However, it initiated taxonomic debates as CM has been hardly used and is considered a potential barrier for other species. The calls of populations from both sides are also apparently similar. Thus, to verify the differences in call properties among populations of D. suweonensis sensu lato (s.l.; both of the species), we sampled and analyzed call data from five localities covering its distribution range, including the southern (S) and northern (N) parts of CM. We found significant differences in many call properties among populations; however, no specific pattern was observed. Some geographically close populations, such as Iksan (S), Wanju (S), and Gunsan (S), had significant differences, whereas many distant populations, such as Pyeongtaek (N) and Wanju (S), had no significant differences. Considering the goal of this study was only to observe the call properties, we cautiously conclude that the differences are at the population level rather than the species level. Our study indicates the necessity of further investigation into the specific status of D. flaviventris using robust integrated taxonomic approaches, including genetic and morphological parameters from a broader array of localities. [ABSTRACT FROM AUTHOR]

Salt, one of the most commonly consumed food additives worldwide, is produced in many countries. The chemical composition of edible salts is essential information for quality assessment and origin distinction. In this work, a simple laser-induced breakdown spectroscopy instrument was assembled with a diode-pumped solid-state laser and a miniature spectrometer. Its performances in analyzing Mg and Ca in six popular edible sea salts consumed in South Korea and classification of the products were investigated. Each salt was dissolved in water and a tiny amount of the solution was dropped and dried on the hydrophilicity-enhanced silicon wafer substrate, providing homogeneous distribution of salt crystals. Strong Mg II and Ca II emissions were chosen for both quantification and classification. Calibration curves could be constructed with limits-of-detection of 87 mg/kg for Mg and 45 mg/kg for Ca. Also, the Mg II and Ca II emission peak intensities were used in a k-nearest neighbors model providing 98.6% classification accuracy. In both quantification and classification, intensity normalization using a Na I emission line as a reference signal was effective. A concept of interclass distance was introduced, and the increase in the classification accuracy due to the intensity normalization was rationalized based on it. Our methodology will be useful for analyzing major mineral nutrients in various food materials in liquid phase or soluble in water, including salts. [ABSTRACT FROM AUTHOR]

Background: Cholesterol plays important roles in β-amyloid (Aβ) metabolism and atherosclerosis. However, the relationships of plasma cholesterol levels with Aβ and cerebral small vessel disease (CSVD) burdens are not fully understood in Asians. Herein, we investigated the relationships between plasma cholesterol profile components and Aβ and CSVD burdens in a large, non-demented Korean cohort. Methods: We enrolled 1,175 non-demented participants (456 with unimpaired cognition [CU] and 719 with mild cognitive impairment [MCI]) aged ≥ 45 years who underwent Aβ PET at the Samsung Medical Center in Korea. We performed linear regression analyses with each cholesterol (low-density lipoprotein cholesterol [LDL-c], high-density lipoprotein cholesterol [HDL-c], and triglyceride) level as a predictor and each image marker (Aβ uptake on PET, white matter hyperintensity [WMH] volume, and hippocampal volume) as an outcome after controlling for potential confounders. Results: Increased LDL-c levels (β = 0.014 to 0.115, p = 0.013) were associated with greater Aβ uptake, independent of the APOE e4 allele genotype and lipid-lowering medication. Decreased HDL-c levels (β = − 0.133 to − 0.006, p = 0.032) were predictive of higher WMH volumes. Increased LDL-c levels were also associated with decreased hippocampal volume (direct effect β = − 0.053, p = 0.040), which was partially mediated by Aβ uptake (indirect effect β = − 0.018, p = 0.006). Conclusions: Our findings highlight that increased LDL-c and decreased HDL-c levels are important risk factors for Aβ and CSVD burdens, respectively. Furthermore, considering that plasma cholesterol profile components are potentially modified by diet, exercise, and pharmacological agents, our results provide evidence that regulating LDL-c and HDL-c levels is a potential strategy to prevent dementia. [ABSTRACT FROM AUTHOR]

Amyloid-beta (Aβ) is a pathological hallmark of Alzheimer's disease (AD). We aimed to identify genes related to Aβ uptake in the Korean population and investigate the effects of these novel genes on clinical outcomes, including neurodegeneration and cognitive impairments. We recruited a total of 759 Korean participants who underwent neuropsychological tests, brain magnetic resonance imaging, 18F-flutemetamol positron emission tomography, and microarray genotyping data. We performed gene-based association analysis, and also performed expression quantitative trait loci and network analysis. In genome-wide association studies, no single nucleotide polymorphism (SNP) passed the genome-wide significance threshold. In gene-based association analysis, six genes (LCMT1, SCRN2, LRRC46, MRPL10, SP6, and OSBPL7) were significantly associated with Aβ standardised uptake value ratio in the brain. The three most significant SNPs (rs4787307, rs9903904, and rs11079797) on these genes are associated with the regulation of the LCMT1, OSBPL7, and SCRN2 genes, respectively. These SNPs are involved in decreasing hippocampal volume and cognitive scores by mediating Aβ uptake. The 19 enriched gene sets identified by pathway analysis included axon and chemokine activity. Our findings suggest novel susceptibility genes associated with the uptake of Aβ, which in turn leads to worse clinical outcomes. Our findings might lead to the discovery of new AD treatment targets. [ABSTRACT FROM AUTHOR]

The purpose of the study was to identify the economic differences in familial, physiological, psychological, and lifestyle characteristics associated with overweight and obese children in South Korea. A total of 407 overweight and obese children participated in the study. The obesity rate was 69.0% and the prevalence of metabolic syndrome (MS) was 33.3% in the low-income bracket, and the prevalence of MS was 27.2% for the population. The children in the low-income group were more prone to have poor eating behavior and more likely to spend more than 2 hr viewing television. They also were more likely to have lower self-esteem and more depressive symptoms. School nurses should understand that risk factors for childhood obesity are more prevalent in low-income groups, which will eventually aggravate health disparities between socioeconomic status groups. Therefore, prevention programs for childhood obesity, which target high-risk groups of such children need to be developed and prioritized.

The purpose of this study was to investigate the association of sociodemographic, psychosocial, and behavioral characteristics with screen time among school-age children in Korea. This study employed a nonexperimental, cross-sectional study design. A total of 370 children attending four elementary schools participated in the study. Self-report method was used, and instruments included screen time (time spent on TV/video/computer/video games), sleep duration, eating behavior, pros and cons of exercise, and exercise self-efficacy. According to the results, 45.7% of the children had screen time of 1-2.9 hr/day and 8.9% had 3 or more hr/day. Increased screen time showed an association with gender (boy), higher body mass index, fast food consumption, higher cons of exercise, having a working mother, and attendance at a school in an inner city area (p < 0.05). Understanding the factors associated with screen time may provide useful information in the development of health promotion programs aimed at decreasing sedentary behaviors.

The study investigated perceived effectiveness and perceived barriers to health education curriculum targeting school nurses as health teachers in Korea. A total of 741 health teachers participated. The questionnaire included perceived effectiveness and perceived barriers to health education curriculum, future roles of health teachers, and needs for in-service training programs. The most frequently selected perceived barrier was a lack of personnel to serve in the health clinic when the nurse was teaching, although 60.9-61.7% wanted to continue both duties of health education and school health services. Perceived effectiveness of health education was positively associated with duration of teaching career (p less than 0.05). Elementary school health teachers had higher perceived effectiveness than those in middle and high schools, while those with bachelor’s degrees had lower perceived effectiveness than those with master’s degrees (p less than 0.05). In-service training and efforts to decrease the perceived barriers would help to offer effective health education. (Contains 5 tables.)

The global immigration of people has increased the call by governments for multicultural education. Across the globe, in country after country, multicultural education have come to represent the theory and practice to teach majority and minority citizens and immigrants and to explore issues of policy and practice as it relates to: ethnicity, religion, gender, immigration, language and race. This article is concerned with the approach to multicultural education that the South Korean government has employed to meet the needs of its people and those of immigrants and South Korean citizens. Using framework of "politics of difference" and five different approaches of multicultural education discussed by Grant and Sleeter, the article examines how South Korea's multicultural education policy treats new comers as "different." This article argues the significance of movement from a discourse about cultural difference to multicultural social justice education that challenge oppression and structural inequality and illuminate the politics of difference.

Background and purpose: The association between Parkinson's disease (PD) and age‐related macular degeneration (AMD) has been shown in previous reports. However, the association between the severity of AMD and PD development is unknown. The aim was to evaluate the association of AMD with/without visual disability (VD) with the risk of PD occurrence using the National Health Insurance data in South Korea. Methods: A total of 4,205,520 individuals, 50 years or older and without a previous diagnosis of PD, participated in the Korean National Health Screening Program in 2009. AMD was verified using diagnostic codes, and participants with VD were defined as those with loss of vision or visual field defect as certified by the Korean Government. The participants were followed up until 31 December 2019, and incident cases of PD were identified using registered diagnostic codes. The hazard ratio was calculated for groups (control and AMD with/without VD) using multivariable adjusted Cox regression analysis. Results: In total, 37,507 participants (0.89%) were diagnosed with PD. Amongst individuals with AMD, the risk of PD development was higher in individuals with VD (adjusted hazard ratio [aHR] 1.35, 95% confidence interval [CI] 1.09–1.67) than in those without (aHR 1.22, 95% CI 1.15–1.30) compared with controls. Additionally, an increased risk of PD was observed in individuals with AMD compared with controls, regardless of the presence of VD (aHR 1.23, 95% CI 1.16–1.31). Conclusions: Visual disability in AMD was associated with the development of PD. This suggests that neurodegeneration in PD and AMD may have common pathways. [ABSTRACT FROM AUTHOR]

Background: Gastrointestinal (GI) infections, caused by various pathogens such as bacteria, viruses, protozoa, and parasites, are the second most common infectious diseases. Molecular diagnostics that can simultaneously detect these pathogens are commonly used in syndromic approaches. The authors aimed to identify the causative pathogens of GI infections to provide clinically useful information. Methods: This retrospective study used molecular diagnostic methods to determine the incidence and distribution of GI pathogens according to gender, age, and season and analyze their co-infection from August 2020 to December 2022. Results: The overall incidence of at least one GI pathogen was 40.1% (991/2, 471). The positivity rates for bacteria and viruses were 33.1% (817/2, 471) and 9.2% (227/2,471), respectively; the positivity rate for bacteria was significantly higher than that for viruses (p < 0.001). The incidence of GI pathogens according to age group was highest in group 3 (59.9%), followed by group 4 (57.0%). The most common bacterial pathogen associated with GI infections was C. difficile, followed by diarrheagenic E. coli, Campylobacter spp., and Salmonella spp. Enteropathogenic E. coli accounted for a large percentage of diarrheagenic E. coli (63.6%, 157/247). Among the viral pathogens, norovirus GI/GII was the most commonly detected virus, followed by adenovirus F40/41 and rotavirus A. For bacterial- or viral-positive cases, the distribution of GI pathogens according to age group showed the highest proportion of C. difficile in all groups, except for group 2. In group 2, rotavirus A accounted for the highest percentage (61.1%, 22/36). The incidence of GI pathogens was the highest in summer (36.1%), followed by autumn (32.7%), and winter (18.0%). The co-infection rate with two or more pathogens was 16.9% (167/991). The rates of co-infection with two or more bacteria, bacteria and viruses, and two viruses were 58.1%, 31.7%, and 10.2%, respectively. Conclusions: Information on the incidence and distribution of GI pathogens might be clinically useful; however, unlike the distribution of other infectious pathogens, it is necessary to consider that microorganisms identified through molecular diagnostics can be detected even in healthy people without clinical symptoms. [ABSTRACT FROM AUTHOR]

Simple Summary: In clinical settings, patients receiving immune checkpoint inhibitors (ICIs) have different treatment criteria than those enrolled in clinical trials. There are concerns regarding the efficacy of ICIs in older adults due to age-associated decline in the immune system, and no study has directly compared the efficacy of different ICIs for the elderly in a real-world setting. We aimed to analyze ICIs' use and treatment outcomes in Korean veterans with stage IV non-small-cell lung cancer (NSCLC). Three cohort groups were derived based on the ICI type (pembrolizumab, nivolumab, and atezolizumab treatment groups), and their clinical characteristics and survival outcomes were compared. There was no difference in the overall survival (OS) rate among the groups, no treatment-specific OS benefit was observed relative to the tumor PD-L1 expression, and bone metastasis was a poor prognostic factor for OS. Our study demonstrates that all three agents may be appropriate treatment options for elderly patients. Purpose: To provide a comprehensive analysis of ICI usage and treatment outcomes in elderly Korean veterans with stage IV NSCLC. Methods: Patients diagnosed with stage IV NSCLC between 2016 and 2021 were included, and three cohorts were derived according to the type of ICI received. Thereafter, the clinical characteristics and survival outcomes were compared. Results: Of the 180 patients with NSCLC (median age, 76 years) included in this study, 49 (27.7%), 61 (33.9%), and 70 (38.9%) received pembrolizumab, nivolumab, and atezolizumab, respectively, and 19.4%, 36.1%, and 34.4% had PD-L1 expressions < 1%, 1–49%, and ≥50%, respectively. The pembrolizumab, nivolumab, and atezolizumab groups, the objective response rates (ORR), and the disease control rates (DCR) were 22.4%, 8.2%, and 4.3% (p = 0.004), and 59.2, 55.7%, and 30.0% (p = 0.001), respectively. However, no difference in the overall survival (OS) rate was noted among the groups (12.6 months vs. 8.4 months vs. 7.7 months, p = 0.334). Similarly, there was no treatment specific OS benefit with respect to the tumor PD-L1 expression status. Interestingly, multivariate analysis identified bone metastasis as a significant poor prognostic factor for OS (HR = 2.75 [95% CI, 1.31–5.76], p = 0.007). Conclusion: Pembrolizumab and nivolumab showed stronger associations with increases in ORR and DCR than atezolizumab, but no statistically significant differences were observed with respect to OS. [ABSTRACT FROM AUTHOR]

Current research highlights the use of natural products or phytochemicals as drugs and functional additives to treat obesity with few side effects. Sargassum horneri (SH) and Ulva australis (UA) are marine waste resources on Jeju Island, Republic of Korea. In this study, we analyzed their antioxidant and anti-obesity efficacies to confirm their potential as functional additives. We prepared SH and UA extracts using 80% ethanol and observed that free radical scavenging activity and total phenol content were high in SH extracts, and total flavonoid content was elevated in UA extracts. Additionally, 3T3-L1 cells were treated with SH and UA extracts, and the ability of the extracts to inhibit adipocyte differentiation was examined using Oil Red O staining and analysis of neutral fat content. We confirmed that the mRNA expression of the C/EBPα, PPARγ, and SREBP1c genes that act on adipocyte differentiation, and of FAS, a fatty acid synthase, was suppressed. Experiments in a mouse model of obesity showed that 12-week administration of a high-fat diet with 1% extract added to drinking water resulted in lower weight gain compared to the high-fat diet alone. These results suggest that SH and UA extracts have antioxidant properties and are effective in obesity prevention. Therefore, the two marine waste resources are potential functional additive candidates for preventing obesity. [ABSTRACT FROM AUTHOR]

Background: Although the detection of respiratory viruses other than severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was significantly reduced because of quarantine due to the coronavirus disease (COVID-19) pandemic, an epidemic of several viruses was reported unexpectedly. We also detected a change in the pattern of human metapneumovirus (HMPV) outbreak compared to that before the COVID-19 pandemic. Therefore, the authors intended to identify the incidence and altered distribution pattern of the HMPV outbreak and provide useful information for clinical practice. Methods: This retrospective study investigated the incidence and distribution of HMPV from March 2020 to December 2022 during the COVID-19 pandemic. Detection of respiratory microorganisms was performed by multiplex polymerase chain reaction using a commercial kit and FilmArray assay. Results: The overall incidence of at least one respiratory microorganism was 50.3% (1,152/2,290). HMPV was not detected between March 2020 and June 2022. However, it was suddenly detected in July 2022 and continued for approximately five months until November 2022. In particular, the detection rate of HMPV was high in September and October 2022, accounting for approximately 76.1% (51/67) of the total HMPV-positive cases. Seasonally, 92.5% (62/67) of HMPV cases were detected in autumn, while the rest of the cases were detected in summer. The HMPV detection rate, according to the age group, was highest in group 4 (3 - 6 years) at 7.4% (27/367), followed by group 3 (4 months to 2 years) at 3.6% (31/861). In HMPV-positive cases, the rate of more than two respiratory pathogens was 46.3% (31/67). An analysis of co-infecting pathogens showed that HMPV with rhinovirus A/B/C/enteroviruses accounted for the highest percentage (51.6%), followed by HMPV with respiratory syncytial virus (48.4%). Conclusions: The COVID-19 pandemic has caused several changes in our lives. This study confirmed that the seasonal distribution of HMPV was different from that before the COVID-19 pandemic. Therefore, it can be assumed that the distribution of other respiratory microorganisms could have changed and it appears that changes could occur in previously known viral epidemiology. Clinicians should therefore be alert to this possibility. [ABSTRACT FROM AUTHOR]

The spread of the COVID-19 disease has had significant social and economic impacts all over the world. Numerous measures such as school closures, social distancing, and travel restrictions were implemented during the COVID-19 pandemic outbreak. Currently, as we move into the post-COVID-19 world, we must be prepared for another pandemic outbreak in the future. Having experienced the COVID-19 pandemic, it is imperative to ascertain the conclusion of the pandemic to return to normalcy and plan for the future. One of the beneficial features for deciding the termination of the pandemic disease is the small value of the case fatality rate (CFR) of coronavirus disease 2019 (COVID-19). There is a tendency of gradually decreasing CFR after several increases in CFR during the COVID-19 pandemic outbreak. However, it is difficult to capture the time-dependent CFR of a pandemic outbreak using a single exponential coefficient because it contains multiple exponential decays, i.e., fast and slow decays. Therefore, in this study, we develop a mathematical model for estimating and predicting the multiply exponentially decaying CFRs of the COVID-19 pandemic in different nations: the Republic of Korea, the USA, Japan, and the UK. We perform numerical experiments to validate the proposed method with COVID-19 data from the above-mentioned four nations. [ABSTRACT FROM AUTHOR]

We explored academic socialization experiences of nine mothers in South Korea. Academic socialization has been defined as parents' practices that transfer their educational expectations, values, and aspirations to their children (Hill, 2001). Adopting Giorgi's phenomenological research method (1997), we interviewed nine mothers who had recently prepared their children to get into college. The interviews were focused on the ways in which they intervened in the academic process when their children were in high school. The data analysis proceeded along the four steps suggested by Giorgi (1997). The analysis resulted in the 12 constituents, which are the themes underlying the essential structure of the academic socialization experiences. The findings showed that during the academic socialization process, all participating mothers set high academic standards for their children. The mothers actively engaged in supporting their children through shadow education (i.e., supplementary private education) to strengthen their academic competitiveness. Further, the mothers found themselves competing with other mothers regarding the academic achievement of their children. The mothers rather than their children took initiatives for decision makings of academic matters. Some of their practices were noticed to have compromised the autonomy of their children. The mothers appeared to fulfill their needs that prove their self-worth by raising their children to be competent. The significance and implications of these results were discussed. Highlights: Mothers' practices of academic socialization in South Korea unfold under the cultural and societal contexts of educational zeal, competitive educational climate, and shadow education dependency. During the academic socialization process, mothers take initiatives to improve the academic rankings of their children and compromise their autonomy. Mothers frequently engage in competitions with other mothers regarding the academic performance of their children. Mothers believe that the essence of their role is providing best shadow education programs or tutors. [ABSTRACT FROM AUTHOR]

In an effort to understand how collaborative teacher interaction is contingent upon teacher characteristics and school-organizational contexts, this study conducts a series of hierarchical generalized linear modeling analyses based on a nationally representative sample of about 2,500 teachers across 149 middle schools in South Korea. The data are from the OECD Teaching and Learning International Survey 2008. The result from this study suggests that teacher collegiality may be understood largely as teachers' collective effort to deal with uncertainties that arise from their approach to teaching as a constructivist endeavor to engage students in meaningful inquiry-based learning. This result is very robust as it holds after a range of other factors such as principal instructional leadership and teacher efficacy are simultaneously taken into account.

As a comparative analysis of teacher preparation in its sociohistorical contexts, this study examines the official educational aims and curricula of 49 mathematics teacher preparation programs in South Korea and the United States, where substantial differences have been observed in both student achievement and teacher knowledge. Overall, the findings from this study suggest that transnational commonalities and national differences exist simultaneously in social expectations for teacher knowledge. The authors argue that attending to both "culturally contextualized" and "semantically decontextualized" dimensions helps us have a more balanced comparative perspective from which we can better assess current conditions of teacher education. Constructive international dialogue can be facilitated by such a balanced perspective that may further enrich teacher education without ignoring either profound differences in sociohistorical contexts or important commonalities in epistemic models of teacher education across countries. (Contains 2 notes, 4 tables, and 1 figure.)

The purpose of this study is to evaluate the educational value of teaching practicum in secondary schools. For this purpose, on the basis of literature review and interviews, three evaluation criteria for measuring educational value of teaching practicum are constructed as follows: (1) practical teaching competence, (2) readiness for teacher, and (3) maturity in character. A total of 29 pre-service teachers in the College of Education at Seoul National University in South Korea participated voluntarily in this study, and their practical teaching competence, readiness for teacher, and maturity in character were measured twice before and after teaching practicum. As a result, the teaching practicum had significantly improved pre-service teachers' practical teaching competence, readiness for teacher, and maturity in character. In other words, teaching practicum increases the educational value. This study provides a conceptual framework and three instruments for measuring the educational value of many other teaching practicums.

This study examines the effect of a means-tested COVID-19 stimulus payment, which was provided by the Seoul Metropolitan Government in South Korea, on consumer spending. The Seoul government issued a one-off payment in the spring of 2020 for residents in the city living below the national median income. We use daily card transaction data aggregated by users' age, income and location of residence, and apply a difference-in-differences approach to assess the effect of the stimulus payment. We compare consumption for the treatment (eligible for the payment) and control (ineligible but with a similar level of income) groups before and after the implementation of the payment. The results show that the payment increased consumer spending for the treatment group by about 12%. Recipients of the means-tested payment have a marginal propensity of consumption at no less than 59%, larger than that found for a universal emergency payment made by the Korean government and similar stimulus checks in other countries. [ABSTRACT FROM AUTHOR]

Container terminals are at the center of global logistics, and are highly dependent on the schedule of vessels arriving. Conventional ETA records from ships, utilized for terminal berth planning, lack sufficient accuracy for effective plan implementation. Thus, there is a pressing need for improved ETA prediction methods. In this research, we propose a novel approach that leverages past voyage route patterns to predict the ETA of container vessels arriving at a container terminal at Busan New Port, South Korea. By modeling representative paths based on previous ports of call, the method employs real-time position and speed data from the Automatic Identification System (AIS) to predict vessel arrival times. By inputting AIS data into segmented representative routes, optimal parameters yielding minimal ETA errors for each vessel are determined. The algorithm's performance evaluation during the modeling period demonstrates its effectiveness, achieving an average Mean Absolute Error (MAE) of approximately 3 h and 14 min. These results surpass the accuracy of existing ETA data, such as ETA in the Terminal Operating System and ETA in the AIS of a vessel, indicating the algorithm's superiority in ETA estimation. Furthermore, the algorithm consistently outperforms the existing ETA benchmarks during the evaluation period, confirming its enhanced accuracy. [ABSTRACT FROM AUTHOR]

Nuclear Data Production System (NDPS), a fast neutron facility for nuclear science and applications, was constructed at the Rare Isotope Accelerator complex for ON-line experiments (RAON) in Korea. NDPS is designed to provide both white and quasi-monoenergetic neutrons using 98 MeV deuteron and 20 – 83 MeV proton beams with thick graphite and thin lithium targets, respectively. Neutron energy is determined by employing the Time-Of-Flight (TOF) technique, along with a pulsed deuteron (or proton) beam with a repetition rate of less than 200 kHz. Fast neutrons are produced in the target room and are guided to the TOF room through a 4 m long neutron collimator consisting of iron and 5% borated polyethylene. The neutron beam is monitored using a parallel plate avalanche counter (PPAC) and a micro-mesh gaseous (MICROMEGAS) detector installed in the TOF room, so as to measure the energy and the position of neutrons. [ABSTRACT FROM AUTHOR]

Rare isotope Accelerator complex for ON-line experiments (RAON), which is being constructed in Korea, will provide both rare isotope and stable ion beams for various nuclear physics experiments as well as other applications, at a wide energy range up to a few hundreds of MeV/nucleon. The ion beams will be provided to low-energy experimental facilities at RAON such as Korea Broad Acceptance Recoil spectrometer and Apparatus (KoBRA) and Nuclear Data Production System (NDPS). Since the bunch length of some ion beams becomes unsuitably long at the targets of these facilities, a re-bunching system has been designed and developed. Besides, a pre-bunching system based on a fast chopper and a Double Gap Buncher (DGB) has been developed and installed upstream of the Radio-Frequency Quadrupole (RFQ) to lower the repetition rate for the time-of-flight measurements of secondary particles at KoBRA and NDPS. We present the status of the pre-bunching and re-bunching systems for the RAON low-energy experimental facilities. [ABSTRACT FROM AUTHOR]

The microstructure of diatom frustules found in mud sediments along the coast of Boryeong- city, South Korea, was observed using a scanning electron microscopy (SEM), and the constituent elements of diatoms were analyzed using energy-dispersive X-ray spectroscopy (EDS). Diatom frustules and clay minerals were present in the SEM images of the mud powder. High-magnification SEM images revealed that the surface of the frustules contained identically shaped circular pores, measuring 1 μm in diameter, arranged at regular intervals. This study revealed that the diatom shell fragments in the mud powder ranged in size from 3 to 30 μm, with an average thickness of approximately 2.5 μm. The elements Si, Al, Fe, K, Na, Mg, and Ti were detected while analyzing the frustule constituents, with Si being the primary component with the highest content. [ABSTRACT FROM AUTHOR]

Background: The incidence of respiratory viral diseases including parainfluenza virus (PIV) infection has decreased noticeably due to strict quarantine measures during the COVID-19 pandemic. However, the recent outbreak of PIV in children occurred unexpectedly and the distribution pattern showed prominent differences from before the COVID-19 pandemic. PIV is one of the major viral pathogens related to acute lower respiratory infection in young children and the elderly. Accordingly, the authors intended to identify the incidence and distribution pattern of PIV outbreaks and to contribute to public health by providing information on it. Methods: This study was conducted retrospectively to investigate the incidence and distribution of PIV according to age group, gender, month, and season, and to analyze the co-infections from March 2020 to February 2022. The detection for respiratory microorganisms was performed through FilmArray assay. Results: The overall incidence for at least one respiratory pathogen was 45.9% (665/1,450). PIV was not detected at all from March 2020 to August 2021. However, it was first detected in September 2021 and the rate in the month that followed, October, accounted for 60% (114/190) of the total PIV infections during the entire study period. It also accounted for 44.9% (190/423) of patients with respiratory pathogens from September 2021 to February 2022. It reached the highest proportion at 90.5% (114/126) in October 2021. As for the distribution according to the age groups, group 3 (58.4%) accounted for the highest percentage, followed by group 4 (21.1%). In the PIV positive cases, the overall rate of more than two respiratory pathogens was 32.6% (62/190). The most common pattern of co-infection was PIV3 with rhinovirus/enterovirus (67.7%), followed by PIV3 with adenovirus (8.1%) and PIV3 with rhinovirus/enterovirus and adenovirus (8.1%). Conclusions: The COVID-19 pandemic has brought about many changes in our daily lives. It has been confirmed that the seasonal distribution of PIV was distinctly different from before the COVID-19 pandemic. It is anticipated that this phenomenon will affect the incidence or distribution of other respiratory pathogens and viral epidemiology. Therefore, clinicians should pay attention to these changes in terms of public health. [ABSTRACT FROM AUTHOR]

Although conserving native pig breeds is important in Korea, research on the genomic aspects to identify breed-specific variations in native pig breeds is uncommon. Single nucleotide polymorphisms (SNPs) can be a powerful source for identifying breed-specific variants. We used whole genome sequencing data, including Jeju Native Pig (JNP), Korean Native Pig (KNP), Korean Wild Boar (KWB), and other western commercial pig breeds to determine native pig breed-specific SNPs. Furthermore, the goal was not only to determine the genomic specificity of native pig breeds but also to identify SNPs that carry breed-specific information (breed-informative SNPs) that can be related to breed characteristics. The representative characteristics of native pigs are their unique meat quality and disease resistance. We surveyed the gene ontology (GO) of native pigs with breed-specific SNPs. Examining the genes associated with GO may contribute to revealing the reasons for the unique characteristics of native pig breeds. The enriched GOs terms were neuron projection development, cell surface receptor signaling pathway, ion homeostasis in JNP, cell adhesion and wound healing in KNP, and DNA repair and reproduction in KWB. We expect that this study of breed-specific SNPs will enable us to gain a deeper understanding of native pigs in Korea. [ABSTRACT FROM AUTHOR]

Background: An aberrant neural connectivity has been known to be associated with bipolar disorder (BD). Local gyrification may reflect the early neural development of cortical connectivity and has been studied as a possible endophenotype of psychiatric disorders. This study aimed to investigate differences in the local gyrification index (LGI) in each cortical region between patients with BD and healthy controls (HCs). Methods: LGI values, as measured using FreeSurfer software, were compared between 61 patients with BD and 183 HCs. The values were also compared between patients with BD type I and type II as a sub-group analysis. Furthermore, we evaluated whether there was a correlation between LGI values and illness duration or depressive symptom severity in patients with BD. Results: Patients with BD showed significant hypogyria in various cortical regions, including the left inferior frontal gyrus (pars opercularis), precentral gyrus, postcentral gyrus, superior temporal cortex, insula, right entorhinal cortex, and both transverse temporal cortices, compared to HCs after the Bonferroni correction (p < 0.05/66, 0.000758). LGI was not associated with clinical factors such as illness duration, depressive symptom severity, and lithium treatment. No significant differences in cortical gyrification according to the BD subtype were found. Conclusions: BD appears to be characterized by a significant regionally localized hypogyria, in various cortical areas. This abnormality may be a structural and developmental endophenotype marking the risk for BD, and it might help to clarify the etiology of BD. [ABSTRACT FROM AUTHOR]

Background: Group B Streptococcus (GBS) colonization in pregnant women is a risk factor for causing infection in neonates; therefore, GBS screening tests are performed on them. Culture methods and molecular diagnostics are mainly performed for GBS detection; however, culture methods differ in the detection rate for GBS depending on the procedure of culture. The authors intended to confirm the difference in GBS colonization rate in the conventional culture method, enrichment culture method, and molecular genetic test as screening tests for GBS. Methods: Duplicate vagino-rectal swabs were collected from 371 pregnant women between the 35th and 37th week of gestation; one was used for conventional culture method and the other was frozen at -80°, followed by enrichment culture method and molecular genetic test. Results: The prevalence of GBS colonization identified by conventional culture, enrichment culture, and molecular genetic test was 4.35% (17/391), 8.95% (35/391), and 22.25% (87/391), respectively. The detection rate by enrichment culture method was 2.06 times higher (17/391 vs. 35/391) than that by conventional culture method. It was identified that there was a significant difference in the detection rates of GBS between the two methods (p < 0.001). The detection rate identified in molecular genetic test was much higher at 22.25% (87/391). The concordance rate of the results from three detection methods for GBS was 80.05% (313/391). All pregnant women colonized with GBS were given intrapartum antibiotic prophylaxis using cefazolin and their neonates were confirmed not to be infected with GBS. Conclusions: Prevalence of GBS colonization in pregnant women is shown to vary depending on detection method. Particularly, it differs greatly depending on the use of enrichment media in the culture method. Therefore, it is necessary that the microbiological laboratory implements the culture method with supplementary procedures such as selective or enrichment media in order to improve the detection rate of GBS. [ABSTRACT FROM AUTHOR]

The damage caused by disasters is increasing worldwide, with hundreds of thousands of deaths due to the occurrence of complex large-scale disasters such as the 2010 Haiti earthquake and the 2004 Indian tsunami. South Korea has also experienced human casualties and damage to property caused by large-scale disasters in the past 10 years. Accordingly, a disaster-appropriate response measure is needed. Thus, we conducted this study to present a measure of utilizing spatial database and image information to improve the efficiency of disaster management that is operated based on the country's existing national disaster management system. We present an efficient disaster response measure that differs from the existing collection-, reporting-, and propagation-oriented operating methods of disaster information through the use of spatial database and image-based information that can be combined with mandatory information with regard to nuclear power plant accidents. Thus, this study contributes to deriving a system that could collect and provide information rapidly at the time of disaster by defining the attribute and spatial information required at the time of disaster during nuclear power plant accidents and by deriving available systems and providing institutions. [ABSTRACT FROM AUTHOR]

In South Korea, the Advance Notice Legislation (ANL) system requires by law that a public announcement be issued on any proposed bill that is likely to affect the fundamental rights, duties, and/or daily life of the general public. By investigating the effects of public dissent submitted via the online ANL system in South Korea, this study attempts to address the critical issue of how to increase citizen participation in the political process and to offer a possible strategy that modern democratic governments can employ in this regard. The findings suggest that citizens will actively participate in the political process to make their voices heard when an appropriate participatory mechanism is available, but they will be more active if the administration encourages citizen participation with various policies and institutions. In other words, formal and informal institutions actively interact to affect the behavior of actors both within and outside the political arena. [ABSTRACT FROM AUTHOR]

In large projects such as dams, embankments, and seawalls, it is sometimes important to determine the compressive properties of a mixture containing soil and gravel with particle sizes exceeding 75 mm. The Saemangeum Renewable Energy Vision Proclamation Ceremony, held in October 2018 in Korea, confirmed and promulgated the plan to build a total of 4.0 GW of renewable energy power generation complex in the Saemangeum area. The project will be carried out on an area of 31.95 km2, and a 1.0 GW offshore wind power development plan is in progress. Since most of the Saemangeum area has a soft ground layer that has been reclaimed, a key research institute is absolutely necessary to lead in the stabilization of the supporting structures for power generation facilities and to achieve the renewable energy 3020 policy in extreme environments. Hence, it is meaningful to investigate the effect of gravel content (P) on the ground strength characteristics. However, such investigation cannot be routinely performed due to the limited size of the equipment available. Several equations have been proposed in the literature to modify the compaction properties of gravel-mixed soils containing coarse aggregates. Among these is the proposed equation by Walker and Holtz, which has widely been used. However, the use of this equation in the case of high gravel content is not appropriate because the physical meaning of this equation is not clear and does not apply to materials with gravel content exceeding 40%. Therefore, a better quantitative evaluation method in determining material characteristics according to gravel content must be established through laboratory tests on samples of acceptable particle size for the experimental equipment. To obtain the compressive properties of decomposed granite soil (D-G-S), in this study, the results from large-scale one-dimensional compression tests on samples compacted at various gravel concentrations, constant compaction energy, and constant water content were analyzed. To quantitatively evaluate the properties of D-G-S according to the gravel content, a modified formula based on the two-phase mixing theory was utilized. It was shown that the degree of mixing between the gravel and sand for the conditions of D-G-S used in the experiments was high, at 0.85. To estimate the compression curves of D-G-S at various gravel content, the compression curves of purely sand (P = 0%) and purely gravel (P = 100%) materials, and the value of Rm = 0.85 were utilized, and it was shown that the compression index and swelling index curves estimated using the method presented in this study were in good agreement with the experimental results. To confirm the engineering applicability of the presented method, finite element analysis was performed, and as a result, it was revealed that it can be sufficiently applied in the simulation of embankment settlement. In order to obtain more reliable results in the future, verification using various samples is required. [ABSTRACT FROM AUTHOR]

Mesoscale wind field patterns play important roles in episodes of high particulate matter (PM 2.5). Previous studies have reported the main synoptic meteorological features associated with high-PM 2.5 days with two primary modes: long-range transport (LRT) and stagnation or local contribution (STL). However, due to the lack of more small-scale analyses spanning across multiple administrative regions, statistical quantification of representative mesoscale wind patterns with elevated PM 2.5 episodes is needed to explore region-specific emissions reduction strategies in South Korea. This study applied k -means clustering to NCEP FNL reanalysis data from 2016 to 2020 to identify mesoscale wind field patterns associated with high-PM 2.5 episodes across all 17 administrative regions of South Korea. Our statistical approach yielded region-specific wind fields for 17 individual administrative regions, and also empirically yielded a total of eight representative patterns, four patterns each for both LRT and STL modes, which were applicable across all regions. The eight patterns were consistent with most previous studies. In addition, we quantified the LTP and STL modes in all 17 regions, and showed that they were more prevalent in the western and southeastern administrative regions of South Korea, respectively. Our results serve as a reference for region-specific mitigation strategies in all administrative regions of South Korea, and will also be useful for analyzing relations between meteorology and high-PM 2.5 episodes in the SIJAQ and ASIA-AQ studies. • Mesoscale wind patterns for high PM 2.5 episodes in South Korea are presented. • Mesoscale wind patterns well compared between local and transported patterns. • Dominant wind patterns correlated with geographical locations in Korea. • Patterns can be a reference for aircraft-based campaign studies over Korea. [ABSTRACT FROM AUTHOR]

As the pet industry continues to grow worldwide, reptile species have become increasingly popular, which has increased the trade of these species. However, as various species are bred, some are discovered in the wild after being lost or abandoned, which can result in ecosystem disturbances. Accordingly, in this study, we report a black-headed python (Aspidites melanocephalus) that was found in the wild for the first time, in the Republic of Korea. At the time of discovery, the deceased python was ascertained to be roadkill, and it appeared to have been killed a few days prior to discovery. The reptile was identified as a black-headed python through its appearance (head color, body stripes, etc.) and DNA analysis. It is suspected that the snake was a lost or abandoned pet. The occurrence of exotic reptiles in the wild may disturb Korean ecosystems. Thus, it is necessary to evaluate the current status of potentially exotic reptiles and improve the management of abandoned animals, especially reptiles. [ABSTRACT FROM AUTHOR]

Plant growth-promoting rhizobacteria are known to enhance the growth and antioxidant activity of several plants. However, the effects of such rhizobacteria on Geum aleppicum, a plant with pharmacological potential in Korea are unknown. In this study, we investigated the effects of Pseudarthrobacter sp. NIBRBAC000502770 treatment (100 mL/pot, every two weeks for 55 days), in the form of culture medium, 100−fold diluted culture, culture supernatant, and pelleted cells resuspended in water, on the growth, antibacterial activity and flavonoid content of G. aleppicum. The NIBRBAC000502770 strain showed high indole-3-acetic acid (IAA) content of 461.81 μg∙mL−1. The dry weight of the roots was significantly higher in the supernatant, diluted culture, and pellet-treated plants compared to that in the control plants. Additionally, the plant height, root length, leaf length, leaf width, chlorophyll content, biomass, and dry weight of the shoot were highest in the pellet-treated plants. Further, methanol extracts of pellet-treated plants showed significantly high flavonoid content compared to that in the control plants (28 mg∙g−1 vs. 7.5 mg∙g−1) and exhibited strong antibacterial activity against Gram-positive and negative bacteria. These results demonstrate the beneficial effects of Pseudarthrobacter sp. NIBRBAC000502770 on the growth and flavonoid content of G. aleppicum. [ABSTRACT FROM AUTHOR]

Simple Summary: Age determination is very important for observing life history traits, evaluating vulnerable life stages, and setting proper management and conservation strategies. Age determination in animals has always been tricky. Among other approaches, skeletochronology, an age determination method that involves counting the lines of arrested growth (LAGs) produced during inactive periods, similar to plant year rings, is well-practiced in many animal groups. However, the applicability of this method remains questioned for many species, including amphibians, because of concerns around the scarcity of information on confirmed numbers of annual LAGs (e.g., once or twice in a year), chances of the disappearance of LAGs over time, and which lines exactly to count. Herein, we tested its applicability to Kaloula borealis, a class II endangered amphibian in South Korea, by rearing juveniles in the laboratory for more than one year and comparing the results with the wild population at Lake Sihwa. This study confirmed the formation of one LAG each year and no disappearance of LAGs over time in this species. Furthermore, we were also able to determine the age structure of this wild population accurately. Hence, our study validates using skeletochronology in this species and recommends it for others that show similar growth patterns. Despite having some limitations, the use of skeletochronology—age determination by counting lines of arrested growth (LAGs)—in amphibians is increasing. The main limitation of using skeletochronology is identifying the innermost visible line (IVL) and counting the exact number of LAGs. Thus, we tested its applicability to Kaloula borealis, a class II endangered amphibian in South Korea. We reared juveniles in the lab to investigate the process of bone formation. This confirmed the development of one LAG each year. Hence, our study validates skeletochronology for the age determination of this species and recommends it for others that show similar growth patterns. Furthermore, the comparison of threshold diameters with the IVL of wild individuals confirmed no LAG1 resorption. The average age of males and females in this population was 2.75 ± 1.05 and 3.64 ± 3 years, respectively. We estimated sexual maturity at 2 years with rapid growth up to that stage in both sexes. We found a female-dominated sexual size dimorphism. This study offers accurate information on the life history traits and age structure of K. borealis that may help to evaluate population dynamics in other areas, identify vulnerable life stages and sites, assess the causes of population decline, and set conservation priorities. [ABSTRACT FROM AUTHOR]

Background: Given the increasing incidence of Clostridioides difficile infections in Korea, there has been an increase in inappropriate testing for C. difficile, which has rendered overdiagnosis of asymptomatic colonisers common. We aimed to investigate the appropriateness of C. difficile testing and the related factors. Methods: We retrospectively reviewed the medical records of patients who were admitted to a 1300-bed tertiary-care teaching hospital in Korea and were tested for C. difficile infection from September 2019 to November 2019. We performed logistic regression analysis to investigate factors related to inappropriate testing. Further, a survey was conducted on physicians to assess the knowledge and ordering patterns of C. difficile testing. Results: We included 715 tests from 520 patients in the analysis. Testing was classified as hospital-onset and community-onset and subclassified as appropriate and inappropriate following an algorithmic method. Among the 715 tests, 576 (80.6%) and 139 (19.6%) tests were classified as hospital-onset and community-onset, respectively. Among the hospital-onset tests, 297 (52%) were considered inappropriate. The risk of inappropriate testing increased when C. difficile tests were conducted in the emergency room (OR 24.96; 95% CI 3.12–199.98) but decreased in intensive care units (OR 0.36, 95% CI 0.19–0.67). The survey was conducted on 61 physicians. Internal medicine physicians had significantly higher scores than non-internal medicine physicians (7.1 vs. 5.7, p = 0.001). The most frequently ordered combination of tests was toxin + glutamate dehydrogenase (47.5%), which was consistent with the ordered tests. Conclusion: Almost half of the C. difficile tests were performed inappropriately. The patient being located in the emergency room and intensive care unit increased and decreased the risk of inappropriate testing, respectively. In a questionnaire survey, we showed that internal medicine physicians were more knowledgeable about C. difficile testing than non-internal medicine physicians. There is a need to implement the diagnostic stewardship for C. difficile, especially through educational interventions for emergency room and non-internal medicine physicians. [ABSTRACT FROM AUTHOR]