• Korean Journal of Community Nutrition
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• v.29 no.2
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• pp.97-113
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• 2024

Objectives: Since the enactment of the School Nutrition Act in 1981, school lunch programs in South Korea have grown quantitatively and qualitatively with a current student participation rate of 99.8%. Nonetheless, educational materials are needed to reduce misunderstanding and ignorance about school lunch programs. This study aimed to develop 3 educational videos that help students of various ages (kindergarteners/lower-grade elementary, upper-grade elementary, and secondary school, respectively), understand the school lunch program. Methods: A scenario was created, was made, and the opinions on the scenario from experts in foodservice sectors were collected. A survey was conducted to students and parents to determine topics they wanted to know about school foodservice. The final videos were produced using this information and the expert opinions. The data were analyzed using SPSS 27.0 for Mac (IBM Corp., Armonk, NY, USA); a P-value of < 0.05 was considered significant. Results: Three videos on school foodservice were developed for various age levels of students: kindergarten/lower-grade elementary, upper-grade elementary, and secondary school. Additionally, English subtitles were included for the multicultural student population. These videos, each lasting about 7 minutes, cover topics such as nutrition, hygiene, and the cultural significance of the school lunch program. The survey results showed that parents and students wanted to know the following topics about the school lunch program: "nutritionally balanced diet" (11.9%), "purchasing safe food ingredients" (10.9%), and "healthy eating habits" (9.9%). Conclusions: The developed videos will serve as valuable educational resources on school foodservice, foster a deeper understanding of the school lunch program in parents and students, and potentially address their inquiries regarding production processes, nutrition, hygiene, cultural heritage, and health.

• Animal Bioscience
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• v.37 no.3
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• pp.522-535
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• 2024

Objective: Transition period is considered from 3 weeks prepartum to 3 weeks postpartum, characterized with dramatic events (endocrine, metabolic, and physiological) leading to occurrence of production diseases (negative energy balance/ketosis, milk fever etc). The objectives of our study were to analyze the periodic concentration of serum beta-hydroxy butyric acid (BHBA), glucose and oxidative markers along with identification, and validation of the putative markers of negative energy balance in buffaloes using in-silico and quantitative real time-polymerase chain reaction (qRT-PCR) assay. Methods: Out of 20 potential markers of ketosis identified by in-silico analysis, two were selected and analyzed by qRT-PCR technique (upregulated; acetyl serotonin o-methyl transferase like and down regulated; guanylate cyclase activator 1B). Additional two sets of genes (carnitine palmotyl transferase A; upregulated and Insulin growth factor; downregulated) that have a role of hepatic fatty acid oxidation to maintain energy demands via gluconeogenesis were also validated. Extracted cDNA (complementary deoxyribonucleic acid) from the blood of the buffaloes were used for validation of selected genes via qRTPCR. Concentrations of BHBA, glucose and oxidative stress markers were identified with their respective optimized protocols. Results: The analysis of qRT-PCR gave similar trends as shown by in-silico analysis throughout the transition period. Significant changes (p<0.05) in the levels of BHBA, glucose and oxidative stress markers throughout this period were observed. This study provides validation from in-silico and qRT-PCR assays for potential markers to be used for earliest diagnosis of negative energy balance in buffaloes. Conclusion: Apart from conventional diagnostic methods, this study improves the understanding of putative biomarkers at the molecular level which helps to unfold their role in normal immune function, fat synthesis/metabolism and oxidative stress pathways. Therefore, provides an opportunity to discover more accurate and sensitive diagnostic aids.

• Journal of The Korean Association For Science Education
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• v.26 no.2
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• pp.246-257
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• 2006

TIMSS (Trends in International Mathematics and Science Study) aims to produce reliable and internationally comparable indicators of student achievement. The TIMSS science achievement scale summarizes student performance on test items designed to measure a wide range of student knowledge and proficiency. This study analyzed Korean middle school students' science achievement at the advanced and high international benchmarks of the four benchmark levels of the benchmarks classified in TIMSS 2003 in light of science content areas (physics, chemistry, biology, earth science, and environmental science) and item characteristics. The average percent correct on items at the advanced benchmark by Korean students was highest in physics followed by earth science, biology, chemistry, and environmental science, whereas internationally the order was earth science, chemistry, biology, physics and lastly environmental science. Korean students performed relatively better in physics yet somewhat worse in chemistry than other top-performing countries. According to item analysis, Korean students reaching the advanced international benchmark understood some fundamentals of scientific investigation, but demonstrated weakness in written explanations of scientific principles, abstract science concept comprehension, and application of scientific concepts to solve quantitative problems. In addition, Korean students reaching the high international benchmark demonstrated relative weak conceptual understanding of ecology compared with other countries.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.2
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• pp.118-126
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• 2009

Benthic diatoms are very important primary producers in understanding estuary ecosystems and their productions are largely varied by their photo-physiological characteristics. The short-term effects of increased temperature on the photosynthetic and photo-physiological characteristics of cultured different species of benthic diatoms (Navicula sp., Nitzschia sp., Cylindrotheca closterium, and Pleurosigma elongatum) were investigated by measuring their PSII-fluorescence kinetics using a Diving-PAM. Photosynthesis versus irradiance curves were measured every two hours at six different temperatures (10, 15, 20, 25, 30, and $35^{\circ}C$) for twenty-four hour. The effective quantum yield of PSII ($\Phi_{PSII}$) for most of the species showed a decreasing trend with increased temperature. The relative maximum electron transport rate (rETRmax) was significantly increased up to the optimum temperature level and then sharply decreased. Relative to the values of other parameters, the maximum light use coefficient ($\alpha$) was not substantially changed at lower temperature levels (<$30^{\circ}C$) but significantly decreased only at higher temperatures (30 and $35^{\circ}C$). The light saturation coefficient ($E_K$) mirrored the rETRmax temperature response. In regards to the temperature acclimation abilities of the four species with time, Navicula sp. and C. closterium acclimated to short-term changes in temperature through their photo-physiological adjustments.

• Journal of The Korean Association For Science Education
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• v.26 no.6
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• pp.743-752
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• 2006

The purpose of this study is to gain an understanding of scientifically gifted students' views on the nature of science. A multiple-choice format questionnaire was administered to 237 Korean 10th, 11th and 12th graders at the Korea Science Academy. The differences and similarities by gender and experience of R&E program on the students' views of the nature of science were investigated. The questionnaire developed by Lim(2004) was implemented for this investigation. We found that the majority of scientifically gifted students had highly possessed the tentativeness of scientific knowledge. The students who experienced R&E program have relatively high apprehension of scientists' motivation for researches and activities in social context compared to the students who did not experience an R&E program. Scientifically gifted students had relatively high apprehension that government should not control researches of scientists and relatively low apprehension of social responsibilities of scientists comparing to general high school students. The experience on R&E program was identified as a factor to effect changes in the students' views on the nature of science. The study has implications for the development of gifted program and curriculum such as running and assessing R&E program, and also the pre-service preparation of science teacher, teacher education reformat in both the practical and the policy levels.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.530-538
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• 2023

This study conducted an investigation into the effects of fruit type and cultivation practices (organic and conventional) on soil characteristics and soil arthropod communities within apple, blueberry, grape, peach, and pear orchards. The collection of soil arthropod communities was achieved through the utilization of pitfall traps, with concurrent measurements taken for soil moisture content, electrical conductivity, and temperature. The findings of this study unveiled substantial impacts attributed to fruit type and cultivation practices on soil characteristics. Specifically, within organic apple orchards, discernibly higher levels of soil moisture content, electrical conductivity, and temperature were observed when compared to their conventional counterparts. The investigation into soil arthropod communities yielded a total of 1,527 individuals, classified in to five phyla and 15 orders. The range of abundance, species richness, and diversity indices varied across conventional and organic orchards. Cultivation practices were found not to exert a significant influence on soil arthropod community characteristics. However, Non-metric Multidimensional Scaling (NMDS) analysis indicated a significant differentiation in soil arthropod community structure based on cultivation practices. This study underscores the importance of considering vegetation structure and environmental characteristics that may influence soil arthropod communities comprehensively when assessing the impact of cultivation practices on soil arthropods. Furthermore, it emphasizes the need to account for both the characteristics and structure of soil arthropod communities in understanding the implications of cultivation practices on these organisms.

• The Journal of the Acoustical Society of Korea
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• v.43 no.4
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• pp.400-405
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• 2024

When cavitation noise occurs in ship propellers, the level of underwater radiated noise abruptly increases, which can be a critical threat factor as it increases the probability of detection, particularly in the case of naval vessels. Therefore, accurately and promptly assessing cavitation signals is crucial for improving the survivability of submarines. Traditionally, techniques for determining cavitation occurrence have mainly relied on assessing acoustic/vibration levels measured by sensors above a certain threshold, or using the Detection of Envelop Modulation On Noise (DEMON) method. However, technologies related to this rely on a physical understanding of cavitation phenomena and subjective criteria based on user experience, involving multiple procedures, thus necessitating the development of techniques for early automatic recognition of cavitation signals. In this paper, we propose an algorithm that automatically detects cavitation occurrence based on simple statistical features reflecting cavitation characteristics extracted from acoustic signals measured by sensors attached to the hull. The performance of the proposed technique is evaluated depending on the number of sensors and model test conditions. It was confirmed that by sufficiently training the characteristics of cavitation reflected in signals measured by a single sensor, the occurrence of cavitation signals can be determined.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.386-399
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• 2023

Microplastics and nanoplastics (NMPs) are considered one of hazardous contaminants in marine ecosystems due to their toxic effects, such as reproduction disorder and oxidative stress, on marine organisms. Although water temperature is rising due to global climate change, little information on the toxicological interaction between NMPs and temperature is available. Therefore, in this study, we confirmed the toxicity of NMPs (polystyrene [PS] beads; 0.05- and 6-㎛) on brackish water fleas (Diaphanosoma celebensis) depending on increased temperature (30℃ and 35℃) at individual and molecular levels. In the chronic toxicity test, the group exposed to high temperatures showed an earlier first reproduction time compared to the normal temperatures group, but it was delayed by co-exposure to NMPs at 35℃. Notably, the total reproduction decreased significantly only after 0.05-㎛ PS beads exposure at 30℃. Interaction analysis showed that first reproduction time, modulation of the antioxidant-related gene (GSTS1), heat shock gene (Hsp70), and ecdysteroid pathway-related genes (EcR_A, EcR_B, and CYP314A1) were closely related to temperature and PS beads size. These results indicate that microplastics have size-dependent toxicity, and their toxicity can be enhanced at high temperatures. In addition, higher temperatures and PS beads exposure may have negative effects on reproduction. This study suggests that various factors such as water temperature should be considered when evaluating the toxicity of microplastics in marine ecosystems, and provides an understanding of the complex toxic interaction between water temperature and microplastics for marine zooplankton.

• Journal of The Korean Association For Science Education
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• v.31 no.8
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• pp.1158-1174
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• 2011

In this study, we examined the compositions, basic principles, and the area of the National Higher Education Entrance Examination (GaoKao) in 2009, we also analyzed the categories and characteristics of items. Also, the GaoKao was analyzed in terms of test specifications, the number of items, item patterns, difficulty levels, and implications of the College Scholastic Ability Test(CSAT) were explored. Results show Natural Science section of the National Test 1, 2 are 300 points per 150 min, and Natural Science, and Chemistry of Shanghai is 150 points each per 120 min. Also, the GaoKao contained multiple choice and fill in the blanks questions, and the description items are composed of experiments of various types. The GaoKao Natural Science section is composed of physics, chemistry, biology but not earth science, which is different from the CSAT. GaoKao requires basic understanding or the observation ability to reasoning, the complex thinking ability, especially emphasized on the experiment ability. The range of possible questions is in the examination outline, not the curriculum, and the ratio of questions from the University level is high. In the analysis of the behavioral domain, the ratios of the understanding and application items is higher than the CSAT, and inquiry items is lower, but the inquiry items are deeper. In case of the ratio of the expected correct answer, National Test 1 and National Test 2 is similar, but the difficult items or about 20~39% of the test is 4~5 times to that of the CSAT, making the GaoKao very difficult. The peculiar characteristics of GaoKao is the emphasis on the experiment, and even though the practical items is of lower ratio, they are very useful in life.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.4
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• pp.295-305
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• 2001

Protein kinase C (PKC) is known to play a pivotal role in neoplastic transformation cells and its high expression is often found in a variety of types of tumors including oral cancer. While PKC is associated with the altered signal transduction pathway of the tumor cells, it is still unclear which isoform is involved in the carcinogenesis process. Since the cellular distributions and the roles of PKC are isoform-specific, it is very important to identify the specific target molecules to improve our understanding of the carcinogenesis processes. Thus, the present study attempted to perform chemical carcinogen-induced neoplastic transformation of human epithelial cells and analyze the specific isoform of PKCs involved in the cellular transformation. The study analyzed overall PKC responses upon MNNG(N-Methyl-N'-nitro-N-nitroso guanidine) exposure with [$^3H$] PDBu binding assay. PKC translocation was observed at high doses of MNNG treatment in the presence of extracellular calcium. Such effects were not observed in the absence of extracellular calcium. Translocational effects with exposure of MNNG was further enhanced in the presence of hydrocortisone. The result suggests that the type of PKC involved may be $Ca^{2+}$-dependent classical isoform and steroid hormone enhances PKC activation. Among cPKC isoforms examined, only $PKC-{\alpha}$ and r showed significant translocation of protein levels from cytosolic fraction to membrane fraction, as analyzed by immunoblot. $PKC-{\varepsilon}$ in nPKC class showed an inch·eased translocation, but other forms in this class did not show the effect. None of isoforms in aPKC class was affected by MNNG treatment. The study demonstrated that there was a certain specificity in the patterns of isoform induction follwong chemical carcinogen exposure and helped identify all the types of PKC isoforms expressed in human epithelial cells. It was revealed that PKC isoforms were activated in an early resonse to chemical carcinogen, suggesting that PKC be associated with carcinogenesis process from an early stage in this particular cell system. The study will contribute to improving our understanding of chemical-induced carcinogenesis in human cells and may provide a scientific basis to introduce the specific PKC inhibitors as an anticancer drug of epithelial cell-origin cancers including oral cancer.