• Korean Journal of Poultry Science
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• v.46 no.3
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• pp.161-171
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• 2019

Four-week-old male Korean native chicks (KNC) were assigned to 3 groups with 6 replicates (8 birds/replicate) in each group: a basal diet (CON, 100 ppm of Zn), basal diet fortified with 50 ppm of Zn with zinc oxide (ZnO), or basal diet fortified with 50 ppm of Zn with Zn-methionine (ZnM). Immediately after a 4-week-feeding trial, 6 birds per group were used to evaluate the effects of zinc supplements on antioxidant indicators and the mRNA expression of zinc transport genes. The nitrogen components, lipid peroxidation, and total antioxidant status in blood were not influenced by Zn fortified diets. However, the ZnM group showed a significant (P<0.05) increase in uric acid levels than those in the ZnO group. In the small intestine, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities, and malondialdehyde (MDA) level were unaffected by zinc supplements. The activity of glutathione S-transferase (GST) was significantly (P<0.05) enhanced by Zn-methionine supplementation. In the liver, the activity of GST was significantly (P<0.05) increased by Zn-methionine supplement without affecting SOD, GPX, and MDA levels. With respect to the mRNA expression of zinc transport genes, the ZnM group displayed a strong tendency for increases in intestinal ZnT-1 (P=0.09) and ZnT-5 (P=0.06) levels, compared to those in the CON group. Moreover, the ZnM group showed a tendency (P=0.10) for up-regulation of hepatic metallothionein mRNA as compared with the CON group. In conclusion, the Zn-fortified diet with 50 ppm of Zn-methionine helped to improve GST activity and Zn transport gene expression in the small intestine or liver of KNC.

• Korean Journal of Heritage: History & Science
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• v.38
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• pp.129-156
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• 2005

Increasing discovery cases of underground storage facilities made of earth, wood, or stone are being reported from the recent excavation survey of the Baekje relics. Accordingly, the purpose of this study is to examine the structure and function of the underground storage facilities of Baekje following a classification made by the type and building method as follows: plask shape, wooden box shape, and stone box shape. The plask shape storage is the most representative underground storage of Baekje that has been found in numerous relics more than 600 sets around Hangang(Han River) and Geumgang(Geum River) from the Hansung period to Sabi period in Baekje Dynasty. It is a historical artefact as a part of the unique storage culture of Baekje around Hangang and Geumgang from the 3rd to 7th Century. Considering its structure and the example of Chinese one, it might had been used for a long-term storage of grains and various other items including earth wares. The storage facility in wooden box shape and stone box shape are found mostly in the relics Of Sabi period. Thus it might had taken some functions of the storage in traditional pouch shape which had decreased after the 6th Century. In particular, the wooden box shape and stone box shape storage required enormous labor force to build owing to their structure and building method. Thus, they were considered to had been used for official purposes in province fortress and citadel artefact. The wooden box shape storage facility is classified into flat rectangular type and square type based on the structure, and into Gagu type(架構式) and Juheol type(柱穴式) based on the building method. It might had been decided according to the geography and geological feature of the place where the storage was to be built. Considering the examples of Gwanbuk-ri relics and Weolpyong-dong relics, the wooden box shape storage facility might had been used for various items depending on the needs, including foods such as fruits and essential provisions at the military base. Considering the long-term food storage, the examples in Japan, and the functional characteristics of the underground storage facility, there is a possibility that the wooden and stone box shape storage facilities had been built so as to safely store important items in case of fire. This study is only a rudimentary examination for the storage facility in Baekje. Thus further studies are to be made specifically and comprehensively on the comparison with other regions, distribution pattern, discovered relics and artefacts, and functions.

• Journal of Plant Biotechnology
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• v.46 no.3
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• pp.189-204
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• 2019

In this study, we analyzed the changes in glucosinolate content and gene expression in TO1000DH3 and Early big seedling upon methyl jasmonate (MeJA) treatment. Analysis of glucosinolate contents after MeJA treatment at $200{\mu}M$ concentration showed that the total glucosinolate content increased by 1.3-1.5 fold in TO1000DH3 and 1.3-3.8 fold in Early big compared to those before treatment. Aliphatic glucosinolates, progoitrin and gluconapin, were detected only in TO1000DH3, and the changes in the content of neoglucobrassicin were the greatest at 48 hours after MeJA treatment in TO1000DH3 and Early big. The transcriptomic analysis showed that transcripts involved in stress or defense reactions, or those related to growth were specifically expressed in TO1000DH3, while transcripts related to nucleosides or ATP biosynthesis were specifically expressed in Early big. GO analysis on transcripts with more than two-fold change in expression upon MeJA treatment, corresponding to 12,020 transcripts in TO1000DH3 and 13,510 transcripts in Early big, showed that the expression of transcripts that react to stimulus and chemical increased in TO1000DH3 and Early big, while those related to single-organism and ribosome synthesis decreased. In particular, the expression increased for all transcripts related to indole glucosinolate biosynthesis, which is associated with increase in glucobrassicin and neoglucobrassicin contents. Upon MeJA treatment, the expression of AOP3 (Bo9g006220, Bo9g006240), TGG1 (Bo14804s010) increased only in TO1000DH3, while the expression of Dof1.1 (Bo5g008360), UGT74C1 (Bo4g177540), and GSL-OH (Bo4g173560, Bo4g173550, Bo4g173530) increased specifically in Early big.

• Korean Journal of Ecology and Environment
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• v.52 no.2
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• pp.71-80
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• 2019

Effects of environmental factors on phytoplankton succession and community structure were studied in Lake Chuncheon located in Bukhan River, South Korea. The data were sampled at three sites such as CC1 (lower side), CC2 (middle side), and CC3 (upper side of Lake Chuncheon) from 2014 to 2017. The annual average precipitation in Lake Chuncheon was 992 mm during the study period (2014~2017), and the annual precipitation was lower than 800 mm in 2014 and 2015. The annual average water temperature, total phosphorus (TP), and total nitrogen (TN) ranged from 17.0 to $21.1^{\circ}C$, 0.012 to $0.019mg\;L^{-1}$, and 1.272 to $1.922mg\;L^{-1}$, respectively. The TN concentration was relatively high in 2015 compared with the other study years, as a drought continued from 2014 to 2015. When comparing the correlation between precipitation and environmental factors, water temperature (p<0.01) and TP(p<0.05) showed positive correlations with rainfall. The average numbers of phytoplankton cells by branch were 2,094, 2,182, and $3,108cells\;mL^{-1}$ in CC1, CC2, and CC3, respectively. CC3 is considered advantageous for phytoplankton growth, even in small pollution sources due to low water depth. As a result of analyzing the relationship between precipitation and phytoplankton, the correlation between the two was shown to be high for 2016 (p<0.01) and 2017 (p<0.05), which is when precipitation was high. However, the correlation was not clear to 2014 and 2015. The relationship between water temperature and phytoplankton indicated a negative correlation with diatoms (p<0.01), yet positive correlations with green algae (p<0.01) and cyanobacteria (p<0.01). Diatoms increased in spring and autumn, which are characterized by low water temperature, and green algae and cyanobacteria increased in summer, when the water temperature is high. Our findings provide a scientific basis for characteristics of phytoplankton and water quality and management at the Lake Chuncheon.

• Korean Journal of Poultry Science
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• v.46 no.2
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• pp.117-125
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• 2019

The aim of the study was to investigate the effects of dietary supplementation of zinc (Zn) sources (zinc oxide and Zn-methionine) on performance, organ weights, blood biochemical profiles, and digestive enzymes of the pancreas and small intestine in Korean native chicks (KNC). A total of 144 KNC (n=6) were fed a basal diet (CON, 100 ppm of Zn), a basal diet supplemented with 50 ppm of Zn with ZnO (ZNO), or a basal diet supplemented with 50 ppm of Zn with Zn-methionine (ZMT) for 28 days. There was no significant difference in body weight, gain, feed intake, and feed conversion ratio among the three groups. The relative weights of the liver, spleen, and intestinal mucosa were unaffected by the dietary source of Zn, whereas pancreas weight in the ZNO group decreased (P<0.05) compared with that in the CON and ZMT groups. Blood biochemical components including aspartate aminotransferase, and alanine aminotransferase were unaffected by dietary Zn supplementation. Pancreatic trypsin activity in the ZNO and ZMT groups was significantly (P<0.05) enhanced compared with that in the CON group. However, the activities of ${\alpha}$-amylase and carboxypeptidase A were not altered by dietary Zn supplementation. The activities of maltase and sucrase were unchanged, whereas the activity of leucine aminopeptidase tended (P=0.08) to be increased by dietary Zn supplementation. In conclusion, the supplementation with 50 ppm of ZnO or Zn-methionine resulted in an activation of protein digestive enzymes in the pancreas and small intestine without affecting animal performance in KNC.

• Korean Journal of Poultry Science
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• v.46 no.2
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• pp.105-115
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• 2019

In this study, viability, growth performance and egg production performance were investigated to determine the productive characteristics of 12 Korean domestic chicken varieties which have been collected and conserved for over 25 years in National Institute of Animal Science, Rural Development Administration, Korea. The 1,134 hens were tested and their production traits including survival rate, body weight, age at first egg laying, hen-day and hen-housed egg production, egg weight, and egg quality were measured. Survival rate was the highest in Korean Rhode-D and Korean Native Chicken (KNC) White and the lowest in Korean Cornish Brown (92.2% and 54.3%, respectively). Body weights from 4 to 50 wks were consistently high in the order of Korean Cornish, Korean Rhode, KNC, Korean Ogye, and Korean Leghorn breeds. There was no significant difference in weight between varieties within a breed. Age at first egg laying was the shortest in Korean Leghorn, while it was the longest in Korean Cornish. The hen-day egg production from $1^{st}$ egg to 57 wks was the highest in Korean Leghorn-K, and the lowest in Korean Cornish Brown. Egg weight was the heaviest in Korean Leghorn-F and the lightest in KNC White. The Haugh unit was the highest in Korean Rhode-C and the lowest in Korean Ogye. Taken together, these results suggest that it is desirable that the Korean Cornish variety is improved as the Korean meat breed because of its excellent growth ability, the Korean Leghorn variety is improved as the Korean layer breed because of its good laying performance, and the Korean Rhode and KNC varieties are improved as strong viable breeds because of their good survival rate.

• Journal of Korean Society of Forest Science
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• v.108 no.1
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• pp.67-76
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• 2019

With an increasing demand of timber production, the use of heavy machinery in forest management has significantly increased, causing the changes of soil physical properties and the decline of long-term site productivity. This study was conducted to evaluate the effects of logging slash (non-slash, slash $7.3kg/m^2$, and slash $11.5kg/m^2$) and machine passes(harvester 1 pass and forwarder 1 to 10 passes) on soil physical properties at 10 cm, 20 cm and 30 cm soil depths in harvester and forwarder operations and also to estimate the degree of soil surface disturbance. The results indicated that soil bulk density in the non-slash treatment site increased 10 %~29 % (25~139 % in soil penetration resistance) at all soil depths, compared with the slash treatment site(slash $11.5kg/m^2$). Therefore, the creation of a slash mat could be an effective way to minimize the changes of soil physical properties. In addition, 92 % of total soil compaction in slash treatment site was created within harvester 1 pass and forwarder 5 passes. In non-slash treatment site, 84 % of total soil compaction was created within first harvester and forwarder passes. The results showed that slash treatment was effective to reduce soil compaction caused by machine passes and also it is necessary to create designed forwarding trails for minimizing soil compaction area at timber harvesting sites.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.242-250
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• 2019

An analytical method was developed for the determination of fenquinotrione, a triketone herbicide, in agricultural products. Fenquinotrione was metabolized to KIH-3653-M-2 in plants. Analyte extraction was conducted using 2% formic acid in acetonitrile and cleaned up using a hydrophillic-lipophillic balance (HLB) cartridge. The limits of detection (LOD) and quantification (LOQ) were 0.004 and 0.01 mg/kg, respectively. Matrix-matched calibration curves were linear over the calibration ranges ($0.001{\sim}0.1{\mu}g/mL$) into a blank extract with $r^2>0.99$. The recovery results for fenquinotrione and KIH-3653-M-2 ranged between 81.1 to 116.2% and 78.0 to 110.0% at different concentration levels (LOQ, $10{\times}LOQ$, $50{\times}LOQ$) with relative standard deviation (RSD) less than 4.6%. All values were corresponded with the criteria ranges requested in both the Codex (CAC/GL 40-1993, 2003) and MFDS guidelines (2016). Therefore, the proposed method can be used as an official analytical method for determination of fenquinotrione in the Republic of Korea.

• Phonetics and Speech Sciences
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• v.11 no.1
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• pp.9-18
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• 2019

The purpose of this study is to determine whether the mean fundamental frequency (F0) changes depending on language, task, or language proficiency for Korean-English bilinguals. A total of forty-eight Korean-English speakers (28 balanced bilinguals and 20 Korean dominant bilinguals) participated in the study. Participants were asked to read aloud two types of tasks in English and Korean. For statistical analyses, the language ${\times}$ task two-way repeated ANOVAs were conducted within the balanced bilingual group first, and then group ${\times}$ language two-way mixed ANOVAs. The results showed that the females in both bilingual groups changed their mean F0 depending on the language they used and the tasks (p<.05), whereas no significant results were found in the males in either group under any conditions. The mean fundamental frequency in the Korean reading task was significantly higher than that in the English reading task for females in both balanced and Korean dominant bilingual groups. Thus, changes in mean F0 depending on language and context may reflect gender-specific characteristics, and females seem to be more sensitive to the socio-cultural standards that are imposed on them.

• Management & Information Systems Review
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• v.37 no.4
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• pp.1-20
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• 2018

This study aimed to examine earnings quality of firms selected as Global Champs project which has been promoted by the government since 2013 to support small and medium sized enterprises, for the screening year(t-1) and selected year(t). Earing quality is measured as the value of discretionary accruals estimated by Dechow et al.(1995) adjusted Jones model and Kothari et al.(2005) model, respectively. I analyze the differences of earning quality between the Global Champ firms and the paired firms selected through criteria of the similar total assets and the same industry in the screening year and the selected year. This study is motivated by the needs of measurement of the performance of the Project from the accounting transparent point of view. As the results of this study, major findings are summarized as follows. Firstly the earnings quality of the selected firms was lower than that of the paired firms. This can be explained as a result of motivation of earnings management by companies eager to meet the requirements to be selected for the Project. Secondly, in the selected year, the earnings quality was proved to improve, comparing to the screening year. This can be explained by the efforts of companies to reinforce management innovation and transparent management, which in turn led to positive effects on the earnings quality. These findings were found to be consistent in the additional analyses, where the earning quality of the reconstructed sample with only selected companies was compared for the screening year and the selected year, based on the year before the screening year(t-2).