• Korean Journal of Audiology
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• v.25 no.2
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• pp.65-71
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• 2021

Background and Objectives: In masking level difference (MLD), the masked detection threshold for a signal is determined as a function of the relative interaural differences between the signal and the masker. Study 1 analyzed the results of school-aged children with good school performance in the MLD test, and study 2 compared their results with those of a group of children with poor academic performance. Subjects and Methods: Study 1 was conducted with 47 school-aged children with good academic performance (GI) and study 2 was carried out with 32 school-aged children with poor academic performance (GII). The inclusion criteria adopted for both studies were hearing thresholds within normal limits in basic audiological evaluation. Study 1 also considered normal performance in the central auditory processing test battery and absence of auditory complaints and/or of attention, language or speech issues. The MLD test was administered with a pure pulsatile tone of 500 Hz, in a binaural mode and intensity of 50 dBSL, using a CD player and audiometer. Results: In study 1, no significant correlation was observed, considering the influence of the variables age and sex in relation to the results obtained in homophase (SoNo), antiphase (SπNo) and MLD threshold conditions. The final mean MLD threshold was 13.66 dB. In study 2, the variables did not influence the test performance either. There was a significant difference between test results in SπNo conditions of the two groups, while no differences were found both in SoNo conditions and the final result of MLD. Conclusions: In study 1, the cut-off criterion of school-aged children in the MLD test was 9.3 dB. The variables (sex and age) did not interfere with the MLD results. In study 2, school performance did not differ in the MLD results. GII group showed inferior results than GI group, only in SπNo condition.

• Journal of Information Technology Applications and Management
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• v.29 no.1
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• pp.47-57
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• 2022

The purpose of this study is to analyze the current status of augmented reality picture books, which have been steadily developed since 2010, as a genre of electronic picture books, and to reveal how children's immersion in augmented reality picture books differs from paper picture books. To this end, 30 augmented reality picture books on the market were analyzed according to genre, life theme, implementation method, and augmented reality scene ratio. As a result of the study, it was found that the genre of picture books was in the order of information fairy tales, daily fairy tales, and historical fairy tales, and there were no traditional or fantasy fairy tales. Animals and plants accounted for about half of the life topics, and in some cases, there were only a few or no other life topics. In the augmented reality implementation scene, it consisted of only one page in the early days, but all pages are now possible to implement augmented reality due to technology development, production cost reduction, and improved hardware performance of smartphones. It was found that the augmented reality implementation method used CD-ROM in the early days, but gradually became possible to implement using only mobile phones and tablets that were easy for readers to access. In addition, after presenting four picture books to eight 5-year-old infants, the immersion time was measured and the immersion behavior was observed. As a result, augmented reality picture books showed higher immersion[immersion time, immersion behavior] than paper picture books, but compared by literature genre, life fairy tales were higher in paper picture books and natural fairy tales in augmented reality picture books. It was higher when presenting augmented reality picture books after presenting paper picture books according to the order of presentation of picture book types. The results of this study suggest that more diverse life topics and augmented reality picture books in the genre of children's literature should be developed to increase the utilization of augmented reality picture books. In addition, considering that there are differences in immersion between types, literary genres, and reading experience [presentation order], it is expected to increase the educational effect by using picture books complementarily.

• Journal of Animal Environmental Science
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• v.10 no.3
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• pp.163-168
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• 2004

This research was carried out to investigate the moisture evaporation and property change depenging on the composting temperature for the escalator reversing composting system. The system was supported by the Y livestock cooperative composting factory. According to the test, the composting remperature eas varied in the range of $65\~80^{\circ}C$. The water content was de-creased to $75\%$ and became about $60\%$ at the end of the phase. Total nitrogen became $0.58\%$, total phosphoric acid $1.47\%$ and potashium $0.49\%$ at the end of the phase.

• BMB Reports
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• v.47 no.2
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• pp.86-91
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• 2014

Tissue-specific gene expression is regulated by epigenetic modification involving trans-acting factors. Here, we identified that the human MAGEB16 gene and its mouse homolog, Mageb16, are only expressed in the testis. To investigate the mechanism governing their expression, the promoter methylation status of these genes was examined in different samples. Two CpG islands (CGIs) in the 5' upstream region of MAGEB16 were highly demethylated in human testes, whereas they were methylated in cells without MAGEB16 expression. Similarly, the CGI in Mageb16 was hypomethylated in mouse testes but hypermethylated in other tissues and cells without Mageb16 expression. Additionally, the expression of these genes could be activated by treatment with the demethylation agent 5'-aza-2'-deoxycytidine (5'-aza-CdR). Luciferase assays revealed that both gene promoter activities were inhibited by methylation of the CGI regions. Therefore, we propose that the testis-specific expression of MAGEB16 and Mageb16 is regulated by the methylation status of their promoter regions.

• Journal of Environmental Health Sciences
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• v.47 no.3
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• pp.245-258
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• 2021

Objectives: In many previous studies, endocrine disruptors (EDCs) have been found to affect delays in puberty. Various EDCs have been reported on, but there have been only limited epidemiologic studies on the effects of exposure to environmental heavy metals and pyrethroid pesticides on puberty delay. Therefore, the aim of this study was to investigate the association of exposure to environmental mercury, cadmium, and pyrethroid pesticides with delayed puberty in children based on national survey data that represents Korean children. Methods: We selected 450 children at the ages of 9-11 years old from the third Korean National Environmental Health Survey (3rd KoNEHS). The relations of urinary Hg, Cd, and 3-PBA with pubertal development were evaluated using multiple logistic regression analyses. Results: Urinary Hg levels were significantly associated with delayed puberty in boys [testicle development: OR=0.41 (95% CI: 0.20, 0.84); genitalia development: OR=0.35 (95% CI: 0.15, 0.81)]. Girls with higher Hg levels were more likely to experience delayed menarche [OR=0.23 (95% CI: 0.06, 0.90)]. We observed a significant 49% reduction in odds for menarche per increasing unit of urinary cadmium levels [OR=0.51 (95% CI: 0.24, 1.01)]. In addition, urinary 3-PBA showed a negative association with genitalia development in boys and menarche in girls [genitalia development: OR=0.73 (95% CI: 0.55, 0.96); menarche: OR=0.56 (95% CI: 0.32, 1.00)]. Conclusions: The results of this study support the hypothesis that exposure to environmental mercury, cadmium and pyrethroid pesticides may affect puberty delays. Additional evidence needs to be obtained through further prospective studies.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.393-398
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• 2012

We investigated the changes in chemical properties of paddy field soils at 300 different sampling sites containing 4 topography in Jeonbuk province, Korea. The soil samples were collected 43.0% from local valley and fans, 39.3% from fluvio-marine deposits, 15.0% from alluvial plains, and 2.7% from diluvium sites. The optimal values of soil properties in the total soil samples were as follows: 65.3% of total samples in soil pH value, 48.3% of total samples in cation exchange capacity (CEC) value, and 22.3% of total samples in available phosphorus content, whereas the deficient values of soil properties were 63.3% of total samples in soil organic matter (SOM) content, 75.7% of total samples in available silicate content, and 61.3%, 51.0%, and 59.3% of total samples in exchangeable $K^+$, $Ca^{2+}$, and $Mg^{2+}$ concentrations, respectively. There were different soil types in the paddy fields: that is, 34.4% immature paddy and 33.6% sandy paddy in the local valley and fans, 57.8% sandy paddy in the alluvial plains, 47.4% normal paddy in the fluvio-marine deposits, and 75.7% immature paddy in the diluvium. Soil textures were also different: 53.5% loam in the local valley and fans, 37.8% sandy loam in the alluvial plains, and 55.1% silty loam in the fluvio-marine deposits. Soil pH and SOM contents were not different among the different topographical sampling sites. However, the mean value of available phosphorus content, 224 mg $kg^{-1}$, was exceeded optimal values in the diluvium. The contents of exchangeable cations were optimal in all the sites, except exchangeable $Ca^{2+}$ contents in the local valley and fans. The contents of available silicate ranged between 112 and 127 mg $kg^{-1}$ in all the sites, which were lower than optimal value. In addition, soil pH values were proportionally correlated to the order of available silicate, exchangeable $Ca^{2+}$, $Mg^{2+}$, $Na^+$, CEC, and exchangeable $K^+$. The contents of SOM were proportionally correlated to the order of CEC, available $P_2O_5$, exchangeable $Ca^{2+}$, and available silicate. The contents of heavy metals, Cd, Cr, Cu, Ni, Pb, and Zn, were only 10% of the threshold levels of the metals, and As content was about 20 to 30% of the threshold level.

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.694-706
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• 2012

The purpose of this study was to offer the raw data for conservation and restoration of aquatic ecosystem by surveying and analysing a water quality, sediment, benthic macroinvertebrate, fish and hydrophyte in Junam reservoir. In the result of analysing the water quality, pH was 8.2~8.4, 6.0~7.5mg/${\ell}$ in COD, 10.0~10.3mg/${\ell}$ in SS, 8.3~11.5mg/${\ell}$ in DO, 0.1mg/${\ell}$ in T-P and 1.2~1.3mg/${\ell}$ in T-N. In case of the sediments, Cd was 0.47~0.52mg/kg, 7.08~7.43mg/kg in Cu, 0.22~0.32mg/kg in As, 0.02~0.03mg/kg in Hg, 6.20~7.45mg/kg in Pb, 32.80~39.70mg/kg in Ni, 513.0~543.0mg/kg in F and 137.0~140.0mg/kg in Zn. $Cr^{6+}$ was not detected. The benthic macroinvertebrates were 432 individuals including 3 phyla, 5 classes, 9 orders, 26 families, 33 genera and 39 species, and the ecological score of benthic macroinvertebrate community(ESB) was 25. The fishes were 8 families and 14 species, and the invasive alien species were 2 taxa including Micropterus salmoids and Lepomis macrochirus. The hydrophytes were 63 taxa including 28 families, 42 genera, 56 species, 1 subspecies and 6 varieties. The emergent plants were 38 taxa(60.3%), 5 taxa(7.9%) in floating-leaved plants and each 10 taxa(15.9%) in free-floating plants and submerged plants.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.1
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• pp.41-53
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• 1997

Geochemical data of soil and water samples were presented in order to assess the environmental impart for drinking water sites. Microscopic observation of rock samples and physical and chemical analysis of soil and water samples were undertaken. The geology of study areas are classified into three groups such as granitic rocks, meta-sedimentary rocks and sedimentary rocks. Enrichment of heavy metals derived from those rocks is not found in this study areas. Soils were analyzed for Cu, Pb, Zn, Cd and Cr using AAS extracted by HNO$_3$+HClO$_4$ and 0.1 N HCl. Heavy metal concentrations in soils are within the range of those in uncontaminated soils. In comparison of metal contents extracted by 0.1 N HCl and HNO$_3$+HC1O$_4$, less than 10% of the heavy metals are present in the exchangeable fraction. In particular, an pollution index has been proposed to assess the degree of soil contamination. Pollution index in soils are between 0.03 and 0.47 therefore, soils are not polluted with heavy metals. Deep groundwaters within granitic rocks have been evolved into Na$\^$＋/-HCO$_3$$\^$-/ type, whereas other deep groundwaters evolved into Ca$\^$2＋/-HCO$_3$$\^$-/ type. The predominance of Na$\^$＋/ over Ca$\^$2＋/ in deep groundwaters within granitic rocks is a result of dissolution of plagioclase, but for sedimentary and meta-sedimentary rocks, dissolution of calcite is a dominant factor for their hydrogeochemistry. The pH, conductivity and contents of the most dissolved ions in the water increase with depth. Shallow groundwaters, however, are highly susceptible to pollution owing to agricultural activities, considering the fact that high contents of nitrate, chloride and potassium, and high K/Na ratio are observed in some shallow groundwaters. In a thermodynamic approach, most natural water samples are plotted within the stability fields of kaolinite and smectite. Therefore, microcline and other feldspars will alter to form clay minerals, such as kaolinite and smectite. From the modelling for water-rock interactions based on mass balance equation, models accord well with behavior of the ions and results of thermodynamic studies are derived.

• Tuberculosis and Respiratory Diseases
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• v.48 no.5
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• pp.757-765
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• 2000

Background : Angiogenesis plays a critical role in human tumor growth and metastasis. Microvessel count as a measure of tumor angiogenesis, has been significantly correlated with invasive and metastatic patterns in breast. prostate and cutaneous carcinomas. Materials and Methods : Fifty patients with curatively resected non-small cell lung cancer were evaluated. Tumor tissues embedded in paraffin block were stained by anti CD 31 (PECAM, platelet endothelial cellular adhesion molecule) using immunohistochemical method to assess microvessel count. Microvessels were counted in the most active areas of neovascularization(microscopy, 200$\times$). Results: 1) Mean microvessel count was 47.1$\pm$17.7(per 200$\times$field) in total 50 cases. 2) Mean microvessel count of adenocarcinoma (54.4$\pm$19.9) was significantly higher than that of squamous cancer (43.9$\pm$16.2) (p<0.05), but there were no relationship between microvessel count and TNM stages. 3) Median survival time, 2-year and 5-year survival rates of the low microvascular group (microvessel count<45, 22 cases) were 61 months, 80% and 40%, respectively, and those of the high microvascular group(microvessel count$\geq$45, 28 cases) were 46 months, 75% and 12%, respectively. As results, prognosis of low microvascular group is statistically significantly superior to that of the high microvascular group (p=0.0162, Kaplan-Meier, log-rank). Conclusion : Angiogenesis assessed by microvessel count can be used as one of the significant prognostic factors in non-small cell lung cancer.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.123-136
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• 2010

In order to remediate heavy metal contaminated Nong island, Maehyang-ri shooting range soils through the batch reactor scale washing were evaluated. The experiment texture soil of N3 in the Nong island at north side incline was (g)mS containing 12.9% gravel, 47.0% sand, 35.1% silt and 5.0% clay. And the N3 soil area was contaminated with Cd($22.5\pm1.9$ ppm), Cu($35.5\pm4.0$ ppm), Pb($1,279.0\pm5.1$ ppm) and Zn($403.4\pm9.8$ ppm). The EDTA(ethylene diamine tetra acetic acid, $C_{10}H_{16}N_2O_8$) in the N3 soil was observed as most effective extractants among the 5 extractants(citric acid, EDTA, phosphoric acid, potassium phosphate and oxalic acid) tested. And chemical partitioning of heavy metals after washing N3 soil with EDTA was evaluated. Removal efficiency of residual fractions was higher than that of non-residual fractions. To choose EDTA extractant which is the most effective in soil washing technology using batch reactor process cleaning Pb and Zn contaminated sits; Pb and Zn removal rates were investigated 92.4%, 94.0% removal(1,000 mM, soil:solution=5, $20^{\circ}C$, 24 hour shaking, pH=2, 200 RPM), respectively. The results of the batch test showed that the removal efficiency curve was logarithmic in soil was removal. Thus, EDTA washing process can be applied to remediate the Pb and Zn contaminated soil used in this study.