This longitudinal study used data from the Busan Educational Longitudinal Study (BELS) to identify growth profiles of English class self-efficacy (ECS) over three years and their associations with English class comprehension, engagement, and achievement. A middle school student sample from 2016 to 2018 BELS comprised 3,038 students (1,394 females and 1,644 males) from 56 middle schools in South Korea. Using a personcentered approach with Mplus 8.4, a higher-order growth mixture modeling (GMM) yielded three distinct growth trajectories of ECS: 82.8% of initially high and slowly decreasing (HSD) group, 9.7% of intermediate high and decreasing (IHD) group, and 7.5% of low but increasing (LI) group growth profiles. Results indicated that English class comprehension, engagement, and achievement showed statistically significant mean differences across each growth profile of ECS. The identified ECS growth profiles can be used to tailor intervention measures. Empirical findings are discussed in terms of pedagogical implications in applied language learning and teaching practices and further research.

Uranium-contaminated soil can be effectively decontaminated through acid leaching; however, this process process generates significant amounts of radioactive wastewater. Therefore, developing efficient methods to remove uranium from wastewater is essential to minimize radioactive waste generation. This study investigates the applicability of various precipitation methods for uranium removal from acidic wastewater produced during soil-washing processes. Three methods were evaluated: metal hydroxide (M–OHx) co-precipitation, uranium peroxide (UO4) precipitation, and uranium phosphate (KUO2PO4) precipitation. The M–OHx precipitation method removes uranium by precipitating excess metal ions in wastewater by adjusting the pH. This method is easy to use and has a high removal efficiency. The UO4 and KUO2PO4 precipitation methods involve adding reagents to precipitate uranium in the mineral phase. They enable selective uranium separation and further volume reduction. In the results, M–OHx and KUO2PO4 precipitation methods remove uranium to less than 1 mg∙L−1 within 2 h, demonstrating superior capabilities compared to UO4 precipitation. The optimal method is different depended on the management strategy for the recovered uranium. The M–OHx precipitation method was suitable for permanent disposal, whereas KUO2PO4 could be recycled. Based on these findings, guidelines for the effective treatment of wastewater containing uranium from the soil-washing process can be established.

Writing conferences are one-on-one feedback sessions that enable teachers and students to engage in constructive interactions to improve students’ writing. While interacting individually, a teacher can use various feedback strategies to improve the quality of a student’s writing. This study examined how a secondary English teacher elicited students’ self-correction of writing issues during EFL writing conferences conducted in Korean (L1) as part of an after-school English program at a Korean high school. One English teacher and five first-year students participated in writing classes for two weeks during the winter vacation. Their conversations were video-recorded and analyzed using Conversation Analysis. Findings revealed that the teacher elicited the student’s selfcorrection through four key strategies: (1) metalinguistic clues, (2) building on initial corrections, (3) leveraging morphological knowledge, and (4) guiding students through a stepwise construction of sentence elements. This study can enhance our understanding of corrective feedback in secondary EFL writing conferences and offer insights for improving teacher-student feedback interactions.

Sodium sulfate, as a commonly used early strengthening agent, has been widely used in different areas. Because of its sulfonic acid group, sodium sulfate is also used as a cement capillary crystal waterproof material. However, temperature has a significant effect on concrete mixed with sodium sulfate. The effect of sodium sulfate on the early hydration rate at different temperatures was studied by conducting a time and hydration thermal analysis. The effects of sodium sulfate on the mechanical properties of concrete at different temperatures were studied through compressive strength experiments. Impermeability at different temperatures was studied by testing resistance to chloride ion penetration and resistance to water penetration. The effect of resistance to sulfate attack was also experimentally. The hydration products were analyzed by electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The experimental results showed that at low temperature, sodium sulfate can accelerate the early hydration reaction rate, and the effect becomes weaker with increasing temperature. At low temperature, the addition of sodium sulfate can effectively improve the degree of hydration, and enhance the permeability resistance and ion erosion resistance of the matrix.

During an investigation of indigenous prokaryotic species in the Republic of Korea, 17 bacterial strains belonging to the phylum Bacteroidota and 4 strains belonging to the phylum Bacillota were isolated from freshwater environments. These isolated bacterial strains formed a robust phylogenetic clade with type strains of the closest related bacterial species, with 16S rRNA gene sequences sharing similarities of higher than 98.7%. To date, there have been no official report of these 21 isolates in the Republic of Korea. At the genus level, these unreported species were affiliated with Mucilaginibacter and Pedobacter of class Sphingobacteriia, Flavobacterium and Gillisia of class Flavobacteriia, Hymenobacter of class Cytophagia, and Paenibacillus and Planococcus of class Bacilli. These species were further examined by performing Gram staining, analyzing their colonies and cell morphologies, and determining their basic biochemical characteristics and phylogenetic positions. Detailed descriptions of the 21 previously unreported species are provided.

Uranium-contaminated soil can be cleaned using an acid washing process. However, high-concentration acid washing generates substantial amounts of radioactive waste, making it essential to develop a treatment process using low-concentration acid. This study evaluated the effectiveness of low-concentration sulfuric acid washing for uranium removal from contaminated soil. Experiments were conducted with a 0.05 M sulfuric acid solution. With a mixing ratio of soil to acid solution at 1:5, three consecutive washes were sufficient to remove uranium from contaminated soil to clearance level. During the acid washing process, real-time pH monitoring was performed to analyze the correlation between uranium leaching and pH changes. This led to the establishment of a monitoring-based process control strategy. In conclusion, we identified an effective method for removing uranium from soil under low acid concentration conditions. Consequently, significant reductions in radioactive waste generation are anticipated.

This study was conducted to investigate the effects of feeding DDGS and full-fat soybean in the finishing diet on the performance, carcass characteristics and unsaturated fatty acid composition of Hanwoo steers. Thirty Hanwoo steers (average age, 26.4 months; weight, 756.69 kg) were assigned into Control (no additive), DS (DDGS supplemented) and FS (full-fat soybean supplemented). The feeding rate of DDGS and full-fat soybean was set at 10% and 5% in the finishing diet, respectively, and the in vivo trial was conducted for 122 days. The final body weight was 779.81, 774.20 and 791.95 kg for Control, DS and FS, respectively, and the average daily gain was not different among treatments. The feed conversion ratio was lower in FS compared to Control. Carcass cold carcass weight, backfat thickness, M. longissimus dorsi area and marbling scores were not different among treatments, and moisture, crude protein, and crude fat content in carcass were not different. The melting point of sirloin ranged from 25 to 26℃ among treatments. The saturated fatty acid, C18:0, was lower in the FS than in Control. C18:1, the main unsaturated fatty acid (UFA) in carcasses, did not show any difference among treatments, but C18:2 was higher in DS than in Control. Total UFAs were higher in the FS than in Control. Based on the above results, DDGS feeding was effective in improving feed conversion ratio and C18:2 content, and full-fat soybean feeding was effective in improving feed conversion ratio and increasing UFA content.

This study assessed the effects of fescue toxicosis on ruminal metabolism and physiology in steers. Twelve ruminally cannulated Angus steers [body weight (BW) = 547 ± 9 kg] were blocked by BW and randomly assigned to six blocks. The steers were fed alfalfa cubes (1.5× NEm) and dosed (1 kg/d) with either endophyte-infected tall fescue seed (E+) or endophyte-free tall fescue seed (E-) via rumen cannula for 21 days. Ruminal dry matter (DM) content was tended to have a higher (p=0.052) in steers in E+ than in E- group. Total volatile fatty acid (VFA), acetate concentrations, as well as the acetate:propionate ratio, were higher (p=0.084, 0.095, and <0.001, respectively) in the E+ group, while propionate was lower (p<0.001). Ruminal pH and temperature were similar between treatment groups (p=0.62 and 0.95, respectively), but ruminal pressure was higher (p<0.001) in E-. Additionally, serum prolactin levels was lower (p<0.001) in the E+ group. These findings suggest that consumption of endophyte-infected tall fescue seed may impair ruminal VFA absorption, potentially due to changes in ruminal motility.

Freshwater environments serve as crucial habitats for diverse microorganisms, playing essential roles alongside plants and animals within the ecosystem. Bacteria in these environments are particularly important for maintaining ecosystem functions. Among them, members of the phylum Pseudomonadota are known to be involved in processes such as nitrogen fixation, ammonia oxidation, and biofilm formation. Pseudomonadota comprises six classes: Acidithiobacillia, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Hydrogenophilia, and Zetaproteobacteria. This study reports 43 previously unrecorded species belonging to the phylum Pseudomonadota. They were isolated from various freshwater habitats in Republic of Korea. These strains were isolated and cultured using nine different standard media, with classification based on Gram staining, cell morphology, and biochemical characteristics. Species identity was determined using 16S rRNA gene sequencing, with a similarity threshold of 98.7% for designation as unreported species. Phylogenetic analysis revealed that these 43 strains were distributed across three classes, 13 orders, 28 families, and 39 genera. This research emphasizes microbial diversity in freshwater ecosystems and provides valuable insights into ecological roles and potential novel functions of unreported bacterial species in Korea.

This study conducted to investigate potential differences in the activity of genes involved in volatile fatty acid (VFA) absorption, pH regulation, and energy metabolism in epithelial cells of forestomach administered either endophyte-infected (E+; 4.45 mg ergovaline/kg) or endophyte-free (E−) tall fescue seed. Twelve steers [body weight (BW) = 547 ± 9 kg] were fed alfalfa cubes at 1.5 × NEm and dosed 1 kg of ground tall fescue seed daily via rumen cannula for 21 days. On day 22, steers were slaughtered, and tissue samples were collected from the rumen, reticulum, omasum, and abomasum. Gene expression analysis revealed that monocarboxylate transporters (MCT), isoform 1 and MCT4 expression levels were significantly lower (p<0.05) in the rumen epithelium of steers dosed with E+ seed, while MCT2 expression remained unchanged. Similarly, sodium hydrogen exchanger (NHE), isoform 2 expression was significantly reduced (p<0.05) in the E+ seed, whereas NHE1 and NHE3 were unaffected by the seed treatment. Additionally, expression levels of down regulated in adenoma (DRA) and anion exchanger (AE), isoform 2 were lower (p<0.05) in the rumen epithelium of E+ steers, while putative anion transporter 1, sodium bicarbonate cotransporter, isoform 1, 3-hydroxy 3-methylglutaryl coenzyme A synthase, isoform 2, and sodium potassium ATPase pump, isoform 1 expression levels were not influenced by the seed treatment. Notably, gene expression in the reticulum, omasum, and abomasum epithelia was unaffected (p>0.05) by seed exposure. These findings suggest that endophyte-infected tall fescue seed may impair ruminal VFA absorption in its dissociated state (pH > 5.8) by downregulating MCT1 and MCT4, along with suppressing NHE2, DRA, and AE2. Therefore, this mechanism may partially explain the reduced weight gain associated with fescue toxicosis in cattle.

A 13-year-old female lion underwent a simple mastectomy for a rapidly growing abdominal mass, confirmed as mammary adenocarcinoma after histopathological examination. Mammary tumors are common in domestic cats but less frequently reported in African lions. This report presents the first documented case of mammary adenocarcinoma in an African lion in South Korea. The mass was successfully excised through stable anesthesia and surgery. This report adds to the limited literature on mammary tumors in large felids and discusses the need for tailored management strategies.

Acid-washed solutions containing various ions, including uranium, are produced by washing uranium-bearing soil or minerals with H2SO4. Conventional extraction processes are complex, as they involve multiple steps and generate significant amounts of radioactive organic waste, posing environmental risks. Therefore, it is necessary to develop a simplified process that can selectively extract uranium while minimizing radioactive waste production. In this study, thermodynamic equilibrium calculations were performed to investigate the selective extraction of uranium through its reaction with H2O2. A basic additive was introduced to facilitate this reaction. The calculation results indicated that uranium in acid-leached solutions could be selectively extracted through a single-step precipitation process, which was experimentally validated. These findings can be utilized to design an efficient process for obtaining high-purity uranium from uranium-bearing soil or minerals.

최근 국내에서는 온라인 거래를 통한 화훼류의 판매가 증가 하고 있다. 온라인 플랫폼의 종류에 따라서 각기 다양한 운송 시스템과 포장 방법을 이용하고 있지만, 품질과 관련된 정보가 부족한 실정이다. 특히, 일반 택배 배송을 이용하는 직거래 방식 은 다양한 외부 환경에 노출되기 때문에 품질에 문제가 발생할 수 있다. 절화장미는 외부의 환경에 노출되는 통기 구멍이 있는 포장 박스와 외부의 환경과 단절된 밀폐된 포장 박스가 사용되 고 있다. 포장 박스의 종류에 따른 절화장미의 품질을 조사한 결과 통기구가 있는 포장 박스를 이용하여 택배 운송한 절화장 미는 운송 중의 낮은 습도로 인해 생체중 감소가 높아 품질이 하락하였다. 밀폐된 포장 박스를 이용해서 운송한 절화장미는 통기 구멍이 있는 포장 박스를 이용해 운송한 절화장미보다 생 체중 감소는 작았지만, 포장 박스 내부의 온도가 높아져 품질이 하락하였다. 내부가 코팅된 밀폐형 포장박스 내부에 절화장미와 함께 냉매를 동봉하여 포장 후 운송하면, 운송 중 포장박스 내부 의 온도를 경감하고 품질을 보존하는 효과가 있었다.

Gentamicin is an aminoglycoside antibiotic effective against aerobic gram-negative bacteria and is also used in veterinary medicine, particularly in the swine and bovine industries. However, no gentamicin product is currently approved for treating equine diseases in Korea. The present study aims to examine the time-dependent residue of gentamicin in horses after intravenous injection (IV) via jugular vein. The test product was injected at 6.6 mg/kg BW via jugular vein in nine horses. Blood was collected from the horse's jugular vein at 15 minutes, 30 minutes, 1, 4, 8, 12, 24 and 48 hours after injection. To purify the gentamicin in serum, 100μL of 20 mM HFBA in DW, 100 μL of 30% trichloroacetic acid and 300 μL of 20 mM heptafluorobutyric acid (HFBA) in acetonitrile (ACN) were added to 500 μL of serum and supernatant was applied to LC-MS/MS after centrifugation. LC-MS/MS-8050 analyzed the level of gentamicin in serum with Electrospray ionization (ESI) and multiple reaction monitoring (MRM) positive mode. Gentamicin C1 was 478 m/z and product ions were 322, 157 m/z. Precursor ion of Gentamicin C1a was 450 m/z and product ions were 322, 160 m/z. Precursor ion of Gentamicin C2 and C2a was 464 m/z and product ions were 322, 160 m/z. The LC column was a C18 and mobile phase composed of 20 mM HFBA in 5% ACN and 20 mM HFBA in 50% ACN. The amount of gentamicin was calculated by adding four components of gentamicin (C1, C1a, C2 and C2a). The pharmacokinetic parameters of gentamicin were calculated by the WinNonlin program. The Cmax of gentamicin in horse serum was 93 ± 17 μg/kg and the Tmax was 0.25 ± 0 hours. The T1/2 was 6.41 ± 2.32 hours and the CLt was 0.05 ± 0.01L/hr/kg. The Vd was shown as 0.44 ± 0.13 L/kg and the MRT was 1.98 ± 0.55 hours. In conclusion, our data provides useful pharmacokinetic parameters for gentamicin in horses following IV injection.

This study explored factors affecting variability in second language (L2) learning motivation among Korean university students and how they appraised their L2 learning experience. In this study, 85 undergraduate students majoring in English or English education from three universities in Seoul, South Korea, reflected on their past English learning experience. They drew a motigraph and wrote a retrospective reflection essay covering their English learning that spanned over ten years. Researchers divided participants into two groups: a high variability (HV) group and a low variability (LV) group. Data were analyzed using open, axial, and selective coding. Findings suggest thncontextual factors such as the learning method, atmosphere, and situation were main (de)motivational factors for the HV group. In contrast, the LV group was (de)motivated by intrapersonal factors, including the learning context appraisal. These results imply that visualizing long and short-term goals and positive appraisal of the L2 learning experience can help L2 learners maintain a stable pattern in L2 learning motivation.

산마늘(Allium microdictyon)과 울릉산마늘(A. ulleungense) 은 수선화과(Amaryllidaceae) 부추속(Allium)에 속하는 다년 초 식물로 산마늘은 우리나라에서는 지리산, 오대산 등의 고산 지대, 울릉산마늘은 울릉도에 분포하고 있다. 본 연구는 산마늘 과 울릉산마늘의 휴면과 발아특성을 조사하여 효과적인 대량증 식법을 위한 기초자료를 제공하고자 수행하였다. 실험은 2021 년 7월에 강원도 정선에서 재배한 산마늘 종자와 2021년 8월에 울릉도에서 채종한 종자를 사용하였다. 수분흡수 실험결과, 산 마늘과 울릉산마늘 모두 수분흡수 3시간 만에 20% 이상의 수분 흡수율을 보여 물리적 휴면이 없는 것으로 판단하였다. 온도 처리(25/15, 20/10, 15/6, 5℃) 실험에서 패트리디쉬에 종자 를 치상 후 30일 이전에 5℃를 제외한 나머지 온도 처리에서 모두 발아가 나타났으며, 산마늘과 울릉산마늘 종자의 발아 적 온은 20~25℃인 것으로 확인되었다. 저온층적(0, 4, 8, 12주)처 리 결과, 산마늘과 울릉산마늘 종자 모두 발아율 향상에는 큰 효과가 없었지만, 저온층적처리 기간이 길어질수록 발아세가 증가하는 양상을 보였다. GA3 처리 결과, 산마늘 종자는 처리 농도 간 유의성이 나타나지 않았지만, 울릉산마늘 종자는 처리 농도가 높아질수록 평균발아일수 및 발아균일도에서 유의적인 차이를 나타냈다. 이러한 결과를 통하여 산마늘과 울릉산마늘 종자는 non-deep PD 유형인 것으로 판단된다.

As part of the 2024 research initiative, “Investigation and Discovery of Prokaryotes in Freshwater Systems,” samples were collected from diverse freshwater habitats, including both water and soil environments. Approximately 2,000 bacterial strains were isolated as single colonies and identified through 16S rRNA gene sequence analysis. Among these, 38 strains shared ≥98.7% 16S rRNA gene sequence similarities with those of known bacterial species not previously reported in Korea. These strains were thus categorized as newly recorded bacterial species in Korea. These 38 bacterial strains displayed significant phylogenetic diversities, spanning 2 phyla, 4 classes, 15 orders, 24 families, and 34 genera. These unrecorded species were classified into the following classes: Actinomycetia (with genera including Microcella, Conyzicola, Curtobacterium, Leucobacter, Microbacterium, Frigoribacterium, Lysinibacter, Streptomyces, Nonomuraea, Actinocorallia, Ruania, and Actinoplanes), Alphaproteobacteria (Paracoccus, Youngimonas, Loktanella, Corticibacterium, Neorhizobium, Onobrychidicola, Ferranicluibacter, Aureimonas, Asticcacaulis, and Novosphingobium), Betaproteobacteria (Rhodoferax, Rugamonas, and Cupriavidus), and Gammaproteobacteria (Rheinheimera, Shewanella, Kosakonia, Leclercia, Hafnia, Yersinia, Pseudomonas, Lysobacter, and Acinetobacter ). Further characterization included assessment of Gram reaction, colony and cell morphology, biochemical properties, and phylogenetic relationships. This report presents detailed phylogenetic and phenotypic characteristics of these bacterial species.

Periodontitis is a chronic inflammatory disease characterized by the progressive destruction of periodontal tissue and alveolar bone loss. To develop effective treatment strategies, a model that mimics this disease must be implemented. From this perspective, animal models can be used to investigate its mechanisms by reproducing disease progression and providing insights into host-microbe interactions, immune responses, and bone remodeling. In addition, periodontitis-associated bone loss fundamentally differs from systemic bone loss. Targeted treatments require distinguishing periodontitis-induced and systemic bone loss mechanisms. This review examines the rationale for using animal models in periodontal research and evaluates various experimental approaches, such as bacterial inoculation, ligature-induced periodontitis, and chemically induced inflammation. These models have advanced our understanding of periodontal disease but have limitations in replicating the chronic nature of periodontitis and human immune responses. However, current models cannot fully replicate chronic disease progression and human immune responses. Recent developments have focused on improving animal models to more accurately simulate disease progression and host responses, which has led to the elucidation of the immunomodulatory mechanisms of periodontitis and their relevance to the human dental environment. Moreover, new approaches, such as developing age-related periodontitis models and improving ligature techniques, could enhance experimental reproducibility and translational potential. Future studies are needed to reflect these improvements and enhance the clinical relevance of periodontitis models.

Mauremys reevesii (Reeves’ turtle) is an endemic freshwater turtle species found throughout East Asia. Due to a rapid population decline, the International Union for Conservation of Nature (IUCN) and the Korean government have classified this species as Endangered (EN). The reported largest population size of M. reevesii in the Republic of Korea was previously estimated to be approximately 20-30 individuals. Our study assessed the population size and structure of M. reevesii at Geumho Reservoir, Republic of Korea, using a capture-recapture data. A total of 433 M. reevesii were incidentally captured during a 35-week trapping process conducted from March to October 2023. The sex ratio of the captured population exhibited a male bias of 1.3 : 1. Sexual size dimorphism was observed only in body weight. Individuals were recaptured up to 11 times during the study period, with males and females being recaptured at an average of 2.1±2.0 times and 1.5±0.9 times, respectively. The estimated population size of M. reevesii in Geumho Reservoir was approximately 891 turtles. The absence of notable sexual size dimorphism and significant sex ratio differences suggests that the population in this area may have been established relatively recently. Compared to previous records, the population in Geumho Reservoir represents the largest single population of M. reevesii, both within the Republic of Korea and globally.