• Journal of Animal Science and Technology
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• v.54 no.3
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• pp.219-226
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• 2012

Gender specificity in muscle growth and development is well known. Genesis of muscle is dependent on proliferation and differentiation potential of resident myogenic satellite cells (MSCs) present in muscle fibers. Multipotential capacity of forming myocyte, osteocyte, and adipocyte like cell makes MSCs a unique stem cell. To understand the molecular mechanism involved in determination of muscle quality due to difference in hormone concentration of different gender of animals, MSCs were isolated from bovine skeletal muscle and cultured in male, female, and castrated serum supplemented media. DNA microarray used consisted of 24,000 spots with 70 mer oligo in each spot. A total of 88 genes were up-regulated and 551 genes were down-regulated by more than two fold. Among up-regulated gene, 33, 34, and 21 genes were found up-regulated in cells grown in male, female, and castrated serum, respectively. Interestingly, male serum showed 4, female 11 and castrated male showed 4 genes expressed highly in each gender. Further study on the highly up-regulated gene may unfold the mystery of gender specificity found in muscle development. Also, the identification of differentially expressed genes in gender-specific serum will add information on infrastructure of bovine genome research.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.367-394
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• 1994

The purpose of this study was to evaluate self perception of occlusal status and recognition for orthodontic treatment as well as the prevalence of orthodontic treatment need objectively and subjectively. 3979 (male 2107, female 1872) school students of age 7~18 were analyzed by questionnaire and clinical examination and the results were as follows, 1. Perception of occlusal status on one's own was more generous than that of orthodontist's and it was affected by the factors such as age, patterns of malocclusion. 2. Recogniuon of subjective need for orthodontic treatment was more generous than that of objective need for the treatment, and factors such as age and sex of patient, parents' age and rate of education, income, occupation, classification of malocclusion and regional discrepancy were influenced. 3. Negative aspect of orthodontic treatment was influenced by the environmental factors. 4. A survey of want for orthodontic treatment showed one's alteration in recognition of the occlusal status with age and esthetic component was much more emphasized than functional component. 5. The multivariate discriminanat analysis for orthodontic treatment group showed that mother's rate of education, classification of malocclusion, demographic characteristics were critical in the determination of treatment group. 6. Test of inter-examiner reliability showed moderate coincidence.

• Imaging Science in Dentistry
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• v.52 no.1
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• pp.83-91
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• 2022

Purpose: This study assessed the associations between chronological age, dental maturation (DM), cervical vertebrae maturation (CVM), and hand-wrist maturation (HWM) in individuals aged 9-19 years. In addition, this study aimed to derive practical methods to evaluate the skeletal age using DM, CVM, or HWM for orthodontic, medical, and forensic purposes and to compare which of these 3 developmental parameters is more accurate for estimating the age of individuals in a Turkish population. Materials and Methods: Panoramic, lateral cephalometric, and hand-wrist radiographs of 284 patients aged 9-19 years were used in this study. The DM, CVM, and HWM stages were determined. The Kolmogorov-Smirnov, kappa, Wilcoxon, Kruskal-Wallis, chi-square, and Spearman correlation tests and simple linear regression analysis were used for statistical analysis. The significance level was 0.05. Results: Statistically significant differences were found between chronological age and DM, chronological age and CVM, and chronological age and HWM in both sexes (P<0.05). DM did not show statistically significant differences according to sex (P>0.05), but CVM and HWM were statistically different between males and females (P<0.05). The DM-estimated age yielded more accurate values than the other methods. Conclusion: All correlations between skeletal and dental stages were statistically significant. Our results showed that there was no statistically significant difference between chronological age and DM-estimated age. Therefore, it can be concluded that DM stages have the potential to be used for legal purposes.

• Imaging Science in Dentistry
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• v.53 no.2
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• pp.91-99
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• 2023

Purpose: This systematic review aimed to investigate the correlation between chronological age and dental pulp volume in cone-beam computed tomography (CBCT). Materials and Methods: The literature was searched in 4 databases(PubMed, Scopus, Web of Science, and Google Scholar). Within each study, the outcome of interest was the correlation (r) between chronological age and pulp volume. A random-effect meta-analysis was conducted. Subgroup analysis was carried out according to sex and tooth type. Results: Of 5,693 identified studies, 27 fulfilled the inclusion criteria and were selected for meta-analysis. These articles focused on single-rooted teeth (n=21), multi-rooted teeth (n=6), maxillary teeth (n=14), mandibular teeth (n=6), and maxillary and mandibular teeth (n=12). The relationship between chronological age and dental pulp volume was examined in the entire population (r= -0.67), men (r= -0.75), and women (r= -0.77) in single- and multi-rooted teeth. The results of the total population analysis showed a relatively strong negative relationship between age and pulp volume. Conclusion: This study suggested that CBCT is a reliable and repeatable tool for dental age estimation. A strong inverse relationship was observed between pulp chamber volume and age. Further studies on the correlation between chronological age and pulp volume of multi-rooted teeth may be beneficial.

• Korean Journal of Poultry Science
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• v.49 no.4
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• pp.229-237
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• 2022

This study investigated the growth characteristics of four strains of newly developed synthetic Korean native commercial chickens (KNCs). We investigated a suitable growth curve model in KNCs and estimated the number of days to reach a 2 kg market weight. Body weight was measured at 2-week intervals from birth to 12 weeks of age. The growth curves were estimated using von Berteralanffy, Gompertz, and logistic functions. The results showed that males were significantly heavier than females at all ages, but there were no significant differences in body weight between strains, except at birth and 2 and 6 weeks of age. The coefficients of determination and adjusted determination of growth function had high goodness-of-fit (97.4~99.7). Of the growth curve parameters, the mature weight and growth ratio were higher in males than in females, but the maturity rate was similar in males and females. The inflection point occurred at approximately 7 weeks of age for females and 8 to 9 weeks of age for males. The weights estimated from the growth curve functions almost agreed with the actual weights, except for male weights estimated using the von Bertalanffy function. The coefficients of determination of the regression equations for weight to age were 0.9583 to 0.9746. The 8- and 10-week-old body weights estimated using the regression equation, and the 12-week-old weight estimated using the logistic function were most similar to the actual weight. Using these models, the estimated age of KNCs to reach 2 kg was 62.0~64.6 days for males and 74.9~78.6 days for females.

• Journal of Genetic Medicine
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• v.8 no.1
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• pp.1-16
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• 2011

Owing to the risk of fetal loss associated with prenatal diagnostic procedures (amniocentesis, chorionic villus sampling), noninvasive prenatal diagnosis (NIPD) is ultimate goal of prenatal diagnosis. The discovery of circulating cell-free fetal DNA (cffDNA) in maternal plasma in 1997 has opened up new probabilities for NIPD by Dr. Lo et al. The last decade has seen great development in NIPD. Fetal sex and fetal RhD status determination by cffDNA analysis is already in clinical use in certain countries. For routine use, this test is limited by the amount of cell-free maternal DNA in blood sample, the lack of universal fetal markers, and appropriate reference materials. To improve the accuracy of detection of fetal specific sequences in maternal plasma, internal positive controls to confirm to presence of fetal DNA should be analyzed. We have developed strategies for noninvasive determination of fetal gender, and fetal RhD genotyping using cffDNA in maternal plasma, using real-time quantitative polymerase chain reaction (RT-PCR) including RASSF1A epigenetic fetal DNA marker (gender-independent) as internal positive controls, which is to be first successful study of this kind in Korea. In our study, accurate detection of fetal gender through gestational age, and fetal RhD genotyping in RhD-negative pregnant women was achieved. In this assay, we show that the assay is sensitive, easy, fast, and reliable. These developments improve the reliability of the applications of circulating fetal DNA when used in clinical practice to manage sex-linked disorders (e.g., hemophilia, Duchenne muscular dystrophy), congenital adrenal hyperplasia (CAH), RhD incompatibility, and the other noninvasive pregnant diagnostic tests on the coming soon. The study was the first successful case in Korea using cffDNA in maternal plasma, which has created a new avenue for clinical applications of NIPD.

• Journal of Korean Society of Transportation
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• v.26 no.6
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• pp.49-60
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• 2008

The aim of this study was to evaluate the variability of the blood.breath ratio (BBR) value and to rationalize the determination of ethanol in breath for evidential sobriety testing. In the experiment forty eight healthy persons, 24 men and 24 women, took part. The experiment included the experimental condition such as sex(2),the type of alcoholic beverage(2; soju, whisky), the type of food(2;kimchi stew, pork belly) and the amount of ethanol consumed(2; 0.35g/kg, 0.70g/kg, based on body weight ) according to 24 factorial design by orthogonal arrays. Breath and blood sample were taken each 8 times and 5 times after the end of drinking. The blood and breath alcohol measurements were highly correlated (r = 0.973). The Results of four way analyses of variance revealed a significant 'the type of food' effect for maximum BrAC (F (1, 43) =5.1, pp<.029), but no significant effect in the type of alcoholic beverage and sex. The overall blood/breath ratio (${\pm}$ SD) was 2295${\pm}$403 and the 95% confidence interval were 1489 and 3101. In spite of these variations, at this time, it seems to be reasonable that apply 2100:1 conversion factor to breathalyzers, because most of the subjects showed the blood.breath ratio of over 2100:1 at least 30 minutes or more passed from the time of drinking as shown in this study.

• Journal of Life Science
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• v.31 no.6
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• pp.537-542
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• 2021

Schisandra nigra Max., a dioecious plant native to Jeju Island in Korea, is cultivated on a small scale for fruit production. As fruit-producing female individuals are generally considered to be more valuable than male, early identification of plant sex at the seedling stage is important. In this study, a sequence-characterized amplified region (SCAR) marker associated with a female-specific region in the genome of S. nigra was investigated. Of 120 randomly amplified polymorphic DNA (RAPD) primers, one primer (OPB-03) consistently amplified a 749 bp band in female plants. The female-specific PCR product was isolated and cloned, and the nucleotide sequences were then determined. Southern hybridization performed using the female-specific fragment as a probe produced positive signals only in genomic DNA from the female plants. This result revealed that the 749 bp segment of DNA was present in the genome of female plants but absent in the genome of male plants. A SCAR primer pair was designed based on the RAPD marker to amplify a 436 bp fragment in the genomic DNA of female plants. This primer pair amplified the expected size of DNA fragment in female plants and four monoecious individuals collected from a natural population. The SCAR marker identified in this study can be used to distinguish female-flowering individuals at the seedling stage.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.423-432
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• 2022

The mass-rearing system for Neodryinus typhlocybae as a biological control agent of Metcalfa pruinosa was established. Depending on the density of host nymphs and plants, the average number of cocoons produced by the parasitoids was 5-8 and 70-150 cocoons per leaf and sapling of mulberry, respectively. There is a significant difference in cocoon length between females (6.10-6.46mm) and males (4.20-4.62mm). Sex determination of cocoons before emergence will be helpful for efficiently releasing this parasitoid in fields. The parasitic rate of N. typhlocybae at the semi-field condition was on average 13-17%. The release number of this parasitoid did not affect parasitism. Nevertheless, the population growth rate of M. pruinosa was reduced by increasing the release number of N. typhlocybae. The parasitoid offspring's sex and bivoltine were influenced by the host age. On young host nymphs, the bivoltine portion of parasitoid increased. When parasitized on 4^th or 5^th nymphs, the offspring's female ratio of N. typhlocybae increased. This result may be useful for potentially controlling mass rearing production of parasitoid.

• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.65-75
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• 2015

This paper analyzes the determinants of wage for the college and university graduates utilizing both individual-level and industry-level variables. We note that wage determination has multi-level structure in the sense that individual wage is influenced by individual-level variables (level-1) and industry-level (level-2) variables. Then, the assumption that individual wage is independent in the classical regression is violated. Therefore, this paper utilizes the hierarchical linear model (HLM). The major results are the followings. First, the multiple correspondence analysis including level-1 and 2 variables reveals that both level 1 and level 2 variables affects individual wages judging from the fact that the values of level 1 and level 2 variables differ across the different level of individual wage groups. Second, the decision tree analysis including level-1 and 2 variables shows that the most influential variable in wage determination is industry-level wage and the next is industry-level working hour, ages and sex in the decling order in. This suggests that the utilization of the HLM is appropriate since the characteristics of industry is important in determining the individual wage. Third, it is shown that the HLM model is the best compared to the other models which do not take level-1 and level-2 variables simultaneously into account.