• Journal of the Korean earth science society
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• 제44권6호
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• pp.643-654
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• 2023

The West Philippine Basin, an oceanic basin half the size of the Philippine Sea Plate, lies in the western part of the plate and south of the Korean Peninsula on the Eurasian Plate. It subducts beneath the Eurasian Plate and the Philippine Islands bordering the Ryukyu Trench and the Philippine Trench with 25-50% of this basin already consumed. However, the history of the opening of the basin's southern region has been a topic of debate. The non-transform discontinuity formed during the seafloor spreading is similar to the transform fault boundaries normally perpendicular to mid-ocean ridge axes; however, it was created irregularly due to ridge propagations caused by variations of mantle convection attributable to magma supply changes. By analyzing high-resolution multi-beam echo-sounding data, we confirmed that the non-transform discontinuity due to the propagating rift evolved in the entire basin and that the abyssal hill strike direction changed from E-W to NNW-SSE from the fossil spreading center. In the early stage of basin extension, the Amami-Sankaku Basin was rotated 90 degrees clockwise from its current orientation, and it bordered the Palau Basin along the Mindanao Fracture Zone. The Amami-Sankaku Basin separated from the Palau Basin while the spreading of the West Philippine Basin began with a counter-clockwise rotation. This indicates that the non-transform discontinuities formed by a sudden change in magma supply due to the drift of the Philippine Sea Plate and simultaneously with the rapid changes in the spreading direction from ENE-WSW to N-S. The Palau Basin was considered to be the sub-south of the West Philippine Basin, but recent studies have shown that it extends into an independent system. Evidence from sediment layers and crustal thickness hints at the possibility of its existence before the West Philippine Basin opened, although its evolution continues to be debated. We performed a combined analysis using high-resolution multi-beam bathymetry and satellite gravity data to uncover new insights into the evolution of the West Philippine Basin. This information illuminates the complex plate interactions and provides a crucial contribution toward understanding the opening history of the basin and the Philippine Sea Plate.

• Korean Journal of Heritage: History & Science
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• 제56권3호
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• pp.214-232
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• 2023

Stromatolite at the Daegu Catholic University, Gyeongsan was designated as a natural monument in December 2009 because it was very excellent in terms of rarity, accessibility, preservation and scale. From the time of designation, the necessity of confirming the lateral extension of the stromatolite beds with the excavation of the surrounding area, and preparing a preservation plan was raised. Accordingly, the Cultural Heritage Administration conducted an investigation of the scale, production pattern, and weathering state of stromatolites with an excavation from April to December 2022, and based on this, suggested natural heritage values and conservation and use plans. The excavation was carried out in a 1,186m² area surrounding the exposed hemispherical stromatolite (approximately 30m2). Stromatolites are continuously distributed over the entire excavation area, and hemispherical stromatolites predominate in the eastern region, and the distribution and size of hemispherical domes tend to decrease toward the west. These characteristics are interpreted as a result of long-term growth in large-scale lakes, where stratiform or small columnar domes continued to grow and connect with each other, finally forming large domes. Consequently, large and small domes were distributed on the bedding plane in clusters like coral reefs. The growth of plants and lichens, as well as small-scale faults and joints developed on the stromatolite bedding surface, is the main cause of accelerated weathering. However, preservation treatment with chemicals as with dinosaur footprints or dinosaur egg fossil sites is not suitable due to the characteristics of stromatolites, and preservation with the installation of closed protection facilities should be considered. This excavation confirmed that the distribution, size and value of stromatolites are much larger and higher than at the time of designation as a natural monument. Therefore, additional excavation of areas by experts that could not be excavated due to the discovery of buried cultural properties (stone chamber tombs) and reexamination of the expansion designation of natural monuments are required.

• Korean Journal of Agricultural and Forest Meteorology
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• 제25권3호
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• pp.142-150
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• 2023

As global warming continues, the time of invasion of Spodoptera frugiperda has been advanced and the inflow rate has been increasing, leading to great increases in damage to crops. In this study, in order to minimize crop damage caused by S. frugiperda, the control period was set for corn fields through control thresholds, and the control effects according to the chemical spraying methods were investigated in forage corn filed. Even under the condition of 4% injury level during the corn silking stage, the damage rate of ear was 70%, showing an aspect of extensive damage. The economic injury level of S. frugiperda second instar larvae was shown to be 0.7 larvae per stalk, and the control threshold level was shown to be 0.6 larvae. The income was calculated by applying the corn wholesale unit price, and according to the result, even under the condition of injury level of 4%, there was a loss of KRW 895,221/10a, and the higher the injury level, the greater the decrease in income. To control S. frugiperda, the insecticidal effects of 10 single formulations registered for S. frugiperda were tested, and according to the results, four types(emamectin benzoate, chlorantraniliprole, indoxacarb, and spinetoram) showed high insecticidal activity not lower than 93.3%, and three types (chloran- traniliprole, spinetoram, and indoxacarb) were considered to be effective in controlling S. frugiperda as they showed high residual effects through insecticidal effect persistence tests. Therefore, conventional control and aerial control were conducted twice at 7-day intervals with indoxacarb SC and chlorantraniliprol WP, which show high activity against S. frugiperda, respectively, prior to the silking of forage corn. As a result, conventional control showed higher control values, 46.3%p in the case of indoxacarb SC and 21.7%p in the case of chlorantraniliprol WP, than aerial control through the primary control. In the secondary control too, higher control values of 26.7%p in the case of indoxacarb SC and 40.4%p in the case of chlorantraniliprol WP were found in conventional control than in aerial control. Therefore, it is considered necessary to prepare measures to improve the control effects in the recent situation where alternative methods for manpower control are widely used.

• Korean Journal of Culture and Social Issue
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• 제10권2호
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• pp.103-137
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• 2004

This study examines the basis of trust in relationships by adolescents and their parents using the indigenous psychological approach. Using the indigenous methodology, adolescents were asked the reasons why they trusted their mother, father, friends, and teachers. Parents were asked why they trusted their children, spouse and their children's teachers. A total of 1,737 participants completed an open-ended survey: 579 adolescents (274 middle school and 305 high school students) and their parents (579 fathers) and (579 mothers). The results indicate that adolescents trust their parents because of their sacrifice, followed by consanguinity (i.e., blood relationship), respect, their trust in me, dependability, and their advice and counseling. The reasons why adolescents trust their teachers is because of the academic guidance they provide, unconditional trust of teachers, their concern and care, respect for teachers, advice and counseling they provide, they are like parents, and because of their sacrifice for the students. The reasons for trusting their friends are as follows: Dependability, closeness, unconditional trust of friends, their understanding of me, and their emotional support. The reasons why parents trust their children are: Children's sincerity, honesty, consanguinity, parents' expectation and communication with the children, children's obedience, and since they are diligent in their schoolwork. The reasons for trusting one's spouse are reported to be sincerity, their sacrifice for the family, honesty, unconditional trust of a spouse, and because of mutual support. The reasons why parents trust their children's teachers are reported as follows: Unconditional trust of teachers, their sacrifice for the students, and their sincerity. There were no significant differences across the type of school and academic grades in terms of trust of parents. However, middle school students are more likely to trust their teachers, and high school students are more likely trust their friends. The male students rather than female students and those students with higher academic grades are more likely to trust their parents, friends, and teachers. For parents, there were no significant differences across age, sex, and educational status concerning the trust of their children, spouse, and children's teachers. There was a positive correlations between parents' trust of their spouse and children and their children's trust of their parents. There was also a positive correlations of mothers' trust of children's teachers and the children's trust of their teachers.

• Research in Plant Disease
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• 제30권2호
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• pp.139-147
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• 2024

Erwinia amylovora is a gram-negative plant pathogen that causes fire blight in apple and pear trees, resulting in significant damage worldwide. In this study, we monitored the emergence of fire blight from 2019 to 2023 to determine the emergence patterns and the factors affecting the outbreak of the disease. As a result of the 5-year survey on the emergence of fire blight, a total of 2,029 cases have emerged, mostly in apple trees of 1,378 cases (67.9%) followed by 645 cases (31.8%) in pear trees, and from quince, hawthorn, and mountain ash trees. Fire blight appeared in specific areas of Gyeonggi, Chungnam, Gangwon, and Chungbuk provinces in 2019, but spread to Andong and Yesan in 2021, Muju and Bonghwa in 2023. In 2020 and 2021, there were 744 and 618 cases of fire blight outbreaks, respectively, compared to other years (188-245 cases/year). Notably, 914 of these cases were observed in apple trees from May to July, with 667 cases reported in Chungju and Jecheon. The incidence of fire blight was positively correlated with the daily maximum temperatures and rainy days in January and February, as well as the rainy days in May and June. The average age of the diseased pear trees was 25 years, higher than the 10-year average age of the apple trees. This study provides fundamental information to understand the status and factors affecting the fire blight emergence in Korea. Prevention measures should be established through continuous analysis of the status of fire blight.

• Food Science and Preservation
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• 제30권6호
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• pp.1095-1106
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• 2023

This study investigated the anti-oxidative and anti-inflammatory effects of Aster glehni (AG) extract in RAW 264.7 cells and Caenorhabditis elegans. The total polyphenol and flavonoid contents were higher in the ethanol extracts than in the hot water extracts. As a result of measuring the moisture contents (%) and extraction yields (%) of AG and drying A. glehni for processing (DAG), 70% ethanol, which has the highest percentage of extraction yield, was selected as the final solvent. DPPH radical scavenging activity showed higher antioxidant activity of ethanol extracts of DAG than AG. The cytotoxicity assay of the AG or DAG ethanol extracts was treated at different concentrations (25, 50, and 100 ㎍/mL), and cell viability rates were higher than 80% at all concentrations. The LPS-stimulated nitric oxide (NO) production in RAW 264.7 was significantly reduced at all concentrations of AG and DAG groups. As a result of measuring the gene expression of iNOS, which induces NO production, the AG or DAG group decreased by 33% and 32%, compared with the phosphate buffer saline (PBS) group. Under inflammatory stress conditions, the survival rate of C. elegans treated with AG or DAG ethanol extract with LPS showed concentration-dependent improvement in survival rate compared with the PBS group. Considering these results, AG could potentially be developed as an antioxidant and anti-inflammatory functional food material.

• Journal of Korean Dental Hygiene Science
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• 제1권1호
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• pp.23-36
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• 2018

This research has been conducted from June 1, 2017 to August 25, 2017 for the dental hygienists working in Busan and Gyeongnam area, to provide necessary basic data for the purpose of revision of the relating laws from the analysis of their understanding and perspective on such laws through 262 subjects' questionnaire. Its analysis of their perspectives are as follows. 1. The common characteristics of the subjects are that 40.1% of them are under 25, and their working period was under three years with the 38.9%, and as for their marital status, 70.2% were single, the final education of 80.2% were associated degrees. Their working areas are centered in Gyeongsangnam-do province with 91.2%, the workplace type is for the dental clinic with 80.2%. 2. The comparison of the view point of the medical(technician) law according to the characteristics of the research subjects differed only whether or not the completion of the education, and as a result of the comparison according to the characteristics of those subjects understanding the details of the medical(technician) law, there was a significant difference saying "the current law has clear job description" depending on the working area or "the job duty is definite" depending on the job experience and job details. As for those saying "the job duty is definite", there was also significant difference depending upon marital status, final education and work details. There was no significant difference in all characteristics from findings of the necessity of legal system according to the subjects not understanding the medical(technician) law. 3. As a result of comparing the necessity of the medical(technician) law according to the characteristics of the research subjects, it was found that all the subjects accepted the necessity of the medical law revision including the dental hygienist in the medical person. The "necessity of the professional dental hygienist system" showed a significant difference depending upon the final education and medical institution type. Among the triggering factors in its amendment, there showed significant difference in the "cooperation of other organizations" and "solution of medical law problems" only in the final education. 4. As a result of comparison of the needs of the medical(technician) law revision according to the characteristics of the research subjects, it was found that the significant traits related to the age and job details showed "Legal responsibility would be increased" when the medical law is revised, in case that "it will help broaden the job extension", there showed a significant difference in career, final education, and working institution, and job details. "Legal protection is possible" showed significant difference except the age group and working area, and "it help the system settlement" showed in the final education. There was a significant difference in career, final education, and job details that "I can regulate the education and field practice", and the same in "my status will be improved" depending upon the final education, work area, and job details. Accordingly, in this research, for the establishment of more professional and comprehensive dental health service as suggested from the demand and necessity toward the medical(technician) Law by the dental hygienists.

• Journal of Life Science
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• 제34권5호
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• pp.313-319
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• 2024

Cultivars or genetic resources with a black seed coat and green cotyledons are rich in lutein, which can promote eye health, and anthocyanin, known for its numerous health benefits. However, mature seeds also contain P34, 7S α' subunit, and lectin proteins, which are allergenic and degrade quality. Here, we report the breeding of a new soybean line with a black seed coat, green cotyledon, and free of P34, 7S α' subunit, and lectin proteins. A total of 157 F₂ seeds with black seed coats and green cotyledons were selected by crossing a female parent with a brown seed coat, green cotyledon, and lacking the 7S α' subunit and lectin proteins with a male parent with a black seed coat, green cotyledon, and lacking the P34 and lectin proteins. The P34 and 7S α' subunit proteins were consistent with a ratio of 9:3:3:1, indicating that they are independent of each other. From 14 F₂ seeds that were recessive (cgy1cgy1p34p34) for both proteins, one individual F₂ plant (F₃ seeds) with the desired traits-black seed coat, green cotyledon, and lacking P34, 7S α' subunit, and lectin proteins- was finally selected. The triple null genotype (absence for P34, 7S α' subunit, and lectin proteins) was confirmed in random F₃ seeds. The selected line has a black seed coat and green cotyledons, and when sown on June 14 in the greenhouse, the maturity date was approximately October 3, the height was about 68 cm, and the 100-seed weight was about 26.5 g.

• Korean Journal of Radiology
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• 제22권12호
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• pp.2094-2123
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• 2021

Incidental thyroid nodules are commonly detected on ultrasonography (US). This has contributed to the rapidly rising incidence of low-risk papillary thyroid carcinoma over the last 20 years. The appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors in small (1-2 cm) thyroid nodules. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.

• Korean Journal of Agricultural and Forest Meteorology
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• 제26권2호
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• pp.127-139
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• 2024

Climate change has increased extreme weather events likewise heatwaves, heavy rain, and drought. Unlike other natural disaster, drought is a slowly developing phenomenon and thus drought damage increases as the drought continues. Therefore, it is necessary to understand the characteristics and mechanism of drought occurrence. Agricultural drought occurs when the water supply needed by crops becomes insufficient due to lack of soil water. Therefore, soil water is used as a key variable affecting agricultural drought. In this study, we examined the spatio-temporal distribution and trends of drought across the Korean Peninsula by determining the soil available water content (SAWC) through a model that integrated soil, meteorological, and crop data. Moreover, an investigation into the correlation between meteorological variables and the SAWC was conducted to assess how meteorological characteristics influence the nature of drought occurrences. During the soybean cultivation period, the average SAWC was lowest in 2018 at 88.6% and highest in 2021 at 103.2%. Analysis of the spatial distribution of SAWC by growth stage revealed that the lowest SAWC occurred during the flowering stage (S3) in 2018, during the leaf extension stage (S2) in 2019, during the seedling stage (S1) in 2020, again during the flowering stage (S3) in 2021, and during the seedling stage (S1) in 2022. Based on the average SAWC across different growth stages, the frequency of upland drought was the highest at 22 times during the S3 in 2018. The lowest SAWC was primarily influenced by a significant negative correlation with rainfall and evapotranspiration, whereas the highest SAWC showed a significant positive correlation with rainfall and relative humidity, and a significant negative correlation with reference evapotranspiration.