• Journal of Elementary Mathematics Education in Korea
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• v.12 no.2
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• pp.149-163
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• 2008

The purpose of this study was to investigate research trends of the articles in Math-Educational journals between 1998 and 2006 in a bid to discuss whether the articles evenly dealt with different fields and whether studies on elementary mathematics education were in line with the 7th national curricula. It's basically meant to determine some of the right directions for future research on elementary mathematics education. The articles included in Math-Educational journals during the selected period were analyzed to find out the theme, area, method and subjects of the studies and when the studies were conducted. After checking National Assembly Digital Library by inputting a keyword 'elementary mathematics', 235 articles were found, and a content analysis was carried out, and statistical data on percentage were obtained. The results of this study were as follows: First, there had been steady research efforts about elementary mathematics education, as 20 or 30 studies had been conducted on a yearly basis. Second, as for theme of research, the most common themes were instructional design and method(25.5%), and an analysis of curricula and textbook(15.3%) was the second most dominant theme. Third, regarding the area of study, the most widely investigated area was number and operation (30.0%), followed by character/expression(27.8%), figure (23.9%), regularity/function (8.9%), probability/statistics(5.6%), and measurement (3.9%). Fourth, concerning the method of research, didactical analysis(43.8%) was most prevalent, followed by quantitative research(29.8%), qualitative research(16.6%) and a combination of qualitative and quantitative approaches(9.8%). Fifth, as to subjects, many of the studies(21.7%) investigated upper graders. In conclusion, it has to be accomplished the impartial researches for the whole area in order to develop elementary mathematics education and attain the objects of the 7th national curricula.

• BMB Reports
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• v.40 no.5
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• pp.625-635
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• 2007

The enzyme squalene synthase (EC 2.5.1.21) catalyzes a reductive dimerization of two farnesyl diphosphate (FPP) molecules into squalene, a key precursor for the sterol and triterpene biosynthesis. A full-length cDNA encoding squalene synthase (designated as TcSqS) was isolated from Taxus cuspidata, a kind of important medicinal plants producing potent anti-cancer drug, taxol. The full-length cDNA of TcSqS was 1765 bp and contained a 1230 bp open reading frame (ORF) encoding a polypeptide of 409 amino acids. Bioinformatic analysis revealed that the deduced TcSqS protein had high similarity with other plant squalene synthases and a predicted crystal structure similar to other class I isoprenoid biosynthetic enzymes. Southern blot analysis revealed that there was one copy of TcSqS gene in the genome of T. cuspidata. Semi-quantitative RT-PCR analysis and northern blotting analysis showed that TcSqS expressed constitutively in all tested tissues, with the highest expression in roots. The promoter region of TcSqS was also isolated by genomic walking and analysis showed that several cis-acting elements were present in the promoter region. The results of treatment experiments by different signaling components including methyl-jasmonate, salicylic acid and gibberellin revealed that the TcSqS expression level of treated cells had a prominent diversity to that of control, which was consistent with the prediction results of TcSqS promoter region in the PlantCARE database.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.2
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• pp.141-150
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• 2019

Despite increased evidence of bio-activity following far-infrared (FIR) radiation, susceptibility of cell signaling to FIR radiation-induced homeostasis is poorly understood. To observe the effects of FIR radiation, FIR-radiated materials-coated fabric was put on experimental rats or applied to L6 cells, and microarray analysis, quantitative real-time polymerase chain reaction, and wound healing assays were performed. Microarray analysis revealed that messenger RNA expressions of rat muscle were stimulated by FIR radiation in a dose-dependent manner in amount of 10% and 30% materials-coated. In 30% group, 1,473 differentially expressed genes were identified (fold change [FC] > 1.5), and 218 genes were significantly regulated (FC > 1.5 and p < 0.05). Microarray analysis showed that extracellular matrix (ECM)-receptor interaction, focal adhesion, and cell migration-related pathways were significantly stimulated in rat muscle. ECM and platelet-derived growth factor (PDGF)-mediated cell migration-related genes were increased. And, results showed that the relative gene expression of actin beta was increased. FIR radiation also stimulated actin subunit and actin-related genes. We observed that wound healing was certainly promoted by FIR radiation over 48 h in L6 cells. Therefore, we suggest that FIR radiation can penetrate the body and stimulate PDGF-mediated cell migration through ECM-integrin signaling in rats.

• The korean journal of orthodontics
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• v.49 no.5
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• pp.299-309
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• 2019

Objective: This study aimed to investigate the effect of pre-applied orthodontic force on the regeneration of periodontal ligament (PDL) tissues and the underlying mechanisms in tooth replantation. Methods: Orthodontic force (50 cN) was applied to the left maxillary first molars of 7-week-old male Sprague-Dawley rats (n = 32); the right maxillary first molars were left untreated to serve as the control group. After 7 days, the first molars on both sides were fully luxated and were immediately replanted in their original sockets. To verify the effects of the pre-applied orthodontic force, we assessed gene expression by using microarray analysis and real-time reverse transcription polymerase chain reaction (RT-PCR), cell proliferation by using proliferating cell nuclear antigen (PCNA) immunofluorescence staining, and morphological changes by using histological analysis. Results: Application of orthodontic force for 7 days led to the proliferation of PDL tissues, as verified on microarray analysis and PCNA staining. Histological analysis after replantation revealed less root resorption, a better arrangement of PDL fibers, and earlier regeneration of periodontal tissues in the experimental group than in the control group. For the key genes involved in periodontal tissue remodeling, including CXCL2, CCL4, CCL7, MMP3, PCNA, OPG, and RUNX2, quantitative RT-PCR confirmed that messenger RNA levels were higher at 1 or 2 weeks in the experimental group. Conclusions: These results suggest that the application of orthodontic force prior to tooth replantation enhanced the proliferation and activities of PDL cells and may lead to higher success rates with fewer complications.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.281-281
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• 2022

Rice is a staple crop used by more than 50% of the world's population. However, in rapidly changing climates such as abnormal high temperatures and typhoons, the food security of rice is greatly threatened. Plant factories have the advantage of being able to grow crops regardless of climate change, so they can be a response to climate change. However, in plant factories, crops are grown by placing the culture bed vertically, so shorter crops are more efficient. Therefore, in order to search for genes related to the height of rice, QTL analysis was performed by investigating the plant height of Cheongcheong/Nagdong doubled haploids from 2017 to 2021. Plant height of rice investigated for five years showed a normal distribution, meaning that genes related to rice height are quantitative traits. As a result of QTL analysis, a total of 12 QTLs were detected, and QTLs overlapped for 5 years in RM12285-RM212 on chromosome 1. Also, The QTLs of plant height detected in 2019 has a LOD score of 17.64 in RM12285-RM212 region of chromosome 1. As a result of QTL analysis, 44 height-related genes were searched from the detected chromosomes, and among them, Os01g0757200 in RM 12285-RM212 on chromosome 1 region, named OsGA2ox3q1, were selected as genes related to the height of rice. The relative gene expression level of OsGA2ox3q1 was highly expressed in cultivar with short culm lines, and was low expressed in cultivar with long culm lines. OsGA2ox3q1 can be used to breed semi-dwarf cultivar in rice more efficiently.

• 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 fish pathology
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• v.24 no.2
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• pp.53-64
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• 2011

In quantitative studies of clinical signs, rock bream of adults and juveniles infected with Megalocytivirus IVS-1 isolated from rock bream (Oplegnathus fasciatus) in Korea showed average $4.49{\pm}1.13$ and $4.85{\pm}1.06$ of spleen index respectively. In challenge experiments, Megalocytivirus IVS-1 induced 100% cumulative mortality in both adult and juvenile rock bream. However we found 60% cumulative mortality in juvenile red sea bream (Pagrus major) even after 30 days of injection, which contradicted with the results of other laboratories. Interestingly, IVS-1 infected red sea bream of the same juvenile size with rock bream showed lower spleen index compared to that of rock bream. In real-time PCR, there was continuous increasing of the numbers of viral copies ($2.03{\times}10^7$ copies/mg) in the spleen of juvenile rock bream infected, which were different from those in adult rock bream showing plateau level after reaching to the peak level. Moreover, enlarged cell numbers in the infected spleen were also increased continuously in the juvenile but not in adult of rock bream, even decreased after reaching to peak level. Consequently, significant differences in clinical signs: cumulative mortality. spleen index and viral copy number were found between rock bream and red sea bream, but not between adult and juvenile rock bream. Certainly quantitative expression of clinical sign as in this study may be a way to compare the progression of megalocitiviral disease more accurately in different species or physiological conditions.

• Journal of Embryo Transfer
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• v.19 no.3
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• pp.291-299
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• 2004

Characterization of quantitative trait loci (QTL) was investigated in the experimental cross population between Berkshire and Yorkshire breed. A total of 512 F$_2$ offspring from 65 matting of F$_1$ parents were phenotyped the carcass traits included average daily gain (ADG), average backfat thickness (ABF), tenth rip backfat thickness (TRF), loin eye area (LEA), and last rip backfat thickness (LRF). All animals were genotyped for 125 markers across the genome. Marker linkage maps were derived and used in QTL analysis based on line cross least squares regression interval mapping. A decision tree to identify QTL with imprinting effects was developed based on tests against the Mendelian mode of QTL expression. To set the evidence of QTL presence, empirical significance thresholds were derived at chromosome-wise and genome-wise levels using specialized permutation strategies. Significance thresholds derived by the permutation test were validated in the data set based on simulation of a pedigree and data structure similar to the Berkshire-Yorkshire population. Genome scan revealed significant evidences for 13 imprinted QTLs affecting growth and body compositions of which nine were identified to be QTL with paternally expressed inheritance mode. Four of QTLs in the loin eye area (LEA), and tenth rip backfat thickness (TRF), a maternally expressed QTL were found on chromosome 10 and 12. These results support the useful statistical models to analyse the imprinting far the QTLs related carcass trait.

• Animal Bioscience
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• v.35 no.1
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• pp.115-125
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• 2022

Objective: Intramuscular fat (IMF) is a critical economic indicator of pork quality. Studies on IMF among different pig breeds have been performed via high-throughput sequencing, but comparisons within the same pig breed remain unreported. Methods: This study was performed to explore the gene profile and identify candidate long noncoding RNA (lncRNAs) and mRNAs associated with IMF deposition among Laiwu pigs with different IMF contents. Based on the longissimus dorsi muscle IMF content, eight pigs from the same breed and management were selected and divided into two groups: a high IMF (>12%, H) and low IMF group (<5%, L). Whole-transcriptome sequencing was performed to explore the differentially expressed (DE) genes between these two groups. Results: The IMF content varied greatly among Laiwu pig individuals (2.17% to 13.93%). Seventeen DE lncRNAs (11 upregulated and 6 downregulated) and 180 mRNAs (112 upregulated and 68 downregulated) were found. Gene Ontology analysis indicated that the following biological processes played an important role in IMF deposition: fatty acid and lipid biosynthetic processes; the extracellular signal-regulated kinase cascade; and white fat cell differentiation. In addition, the peroxisome proliferator-activated receptor, phosphatidylinositol-3-kinase-protein kinase B, and mammalian target of rapamycin pathways were enriched in the pathway analysis. Intersection analysis of the target genes of DE lncRNAs and mRNAs revealed seven candidate genes associated with IMF accumulation. Five DE lncRNAs and 20 DE mRNAs based on the pig quantitative trait locus database were identified and shown to be related to fat deposition. The expression of five DE lncRNAs and mRNAs was verified by quantitative real time polymerase chain reaction (qRT-PCR). The results of qRT-PCR and RNA-sequencing were consistent. Conclusion: These results demonstrated that the different IMF contents among pig individuals may be due to the DE lncRNAs and mRNAs associated with lipid droplets and fat deposition.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.27.1-27.9
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• 2016

Background: The objective of this study was to place bone graft materials in cranial defects in a rabbit model and compare their bone regenerating ability according to the size and density of demineralized dentin matrix (DDM). Methods: We selected nine healthy male rabbits that were raised under the same conditions and that weighed about 3 kg. Two circular defects 8 mm in diameter were created in each side of the cranium. The defects were grafted with DDM using four different particle sizes and densities: 0.1 mL of 0.25- to 1.0-mm particles (group 1); 0. 2 mL of 0.25- to 1.0-mm particles (group 2); 0.1 mL of 1.0- to 2.0-mm particles (group 3); and 0.2 mL of 1.0- to 2. 0-mm particles (group 4). After 2, 4, and 8 weeks, the rabbits were sacrificed, and bone samples were evaluated by means of histologic, histomorphometric, and quantitative RT-PCR analysis. Results: In group 1, osteoblast activity and bone formation were greater than in the other three groups on histological examination. In groups 2, 3, and 4, dense connective tissue was seen around original bone even after 8 weeks. Histomorphometric analysis of representative sections in group 1 showed a higher rate of new bone formation, but the difference from the other groups was not statistically significant. RT-PCR analysis indicated a correlation between bone formation and protein (osteonectin and osteopontin) expression. Conclusions: DDM with a space between particles of $200{\mu}m$ was effective in bone formation, suggesting that materials with a small particle size could reasonably be used for bone grafting.