• Journal of the Korean Geographical Society
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• v.48 no.2
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• pp.303-319
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• 2013

The purpose of this paper in the case of elementary and middle schools in Hwaseong city is that clarify spatial structure by seasonal changes of supply region of school meal foods and changes in food mileage. This paper used account registers of school meal foods of the subject schools as data for this analysis. And this paper analyzed data in March, June, September, and December in order to understand seasonal changes of school meal foods. The spatial structure of school meal foods in elementary and middle schools in Hwaseong city take four with private contracts, limited competition, and bidding quotation by suppliers. With the crops in Hwaseong city, they consist of eco-friendly vegetables in Gyeonggi-do, domestic eco-friendly vegetables and fruits, general vegetables and fruits, and imported processed foods and agricultural products. In case of food mileage, around Hwaseong city, there are spatial structure with about 17 $ton{\cdot}km$, 26 $ton{\cdot}km$, and 11,000 $ton{\cdot}km$ respectively. The spatial structure of school meal foods supplies was determined by difference in feed rate of crops, eco-friendly agricultural products, imported processed foods, and imported agricultural products.

• The Journal of the Petrological Society of Korea
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• v.22 no.2
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• pp.117-135
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• 2013

Orbicular granite gneisses occur as a xenolith within two-mica leucogranites, together with early Paleoproterozoic metasedimentary xenoliths, in Wangjeong-ri, Muju area. The whole-rock chemistries and SHRIMP zircon Pb/U ages of the leucogranites indicate that they are S-type granitoids formed in the continental tectonic setting at $1875{\pm}75$ Ma. The SHRIMP age of monazites from the orbicular granite gneiss gives $1867{\pm}4$ Ma as a metamorphic age which is similar to the intrusion age of the two-mica leucogranite within the error range. The similar ages between zircons and monazites represent that the orbicular granite gneisses formed by metamorphism during the intrusion of the two-mica leucogranite; the metasedimetary xenoliths which sank within the parent magma of leucogranites were metamorphosed into orbicular granite gneisses by thermal metamorphism ($650-740^{\circ}C$, 4-6.5 kbar) due to the heat supplied from surrounding magma. During the thermal metamorphism, the core of orbicular granite gneiss mainly consisting of cordierite formed, and in some orbicular granitic gneisses, the leucocratic melt formed by melting of quartz and plagioclase in the core, squeezed out from core and crystallized around the core forming outer rim. The hydrothermal fluid at the late stage of magma differentiation penetrated into the orbicular granite gneisses resulting pinitization of cordierite into chlorite and sericite. As Muju orbicula granite gneiss was formed from sedimentary rocks, it is more appropriate to be called Muju orbicula granitic gneiss.

• The Korean Journal of Ecology
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• v.28 no.6
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• pp.375-382
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• 2005

The American bullfrog, Rana catesbeiana was imported from Japan for farming for the human consumption in 1970's and introduced populations were a great threat to native habitats in the pond and lake ecosystem. However, it is thought that the population of bullfrog has rapidly declined for past years in Korea. In this study, we investigated the intra-genetic diversity of R. catesbeiana habitated in Korea. The nucleotide sequences of 1,215bp mitochondrial ND1/tRNA region in bullfrogs sampled from 5 sites in Jeollanamdo were analyzed and compared to the original sequence of R. catesbeiara reported in Genbank. The nucleotide similarity between Korean and North American bullfrog was ranged from 98.7% to 100% based on kimura-2-parameter distance. In addition, bullfrogs analyzed in this study were clustered into two groups with one including Jangheung and the other including Gwangju populations in the neighbor-joining tree. North American R. catesbeiana was grouped in Jangheung cluster, indicating that there is the very low genetic difference between Korean and North American populations. The maximum parsimony tree in which North American R. catesbeiana was set as an outgroup suggests that Jangheung group represents the introduced population to Korea. Taken together, the results indicate that the population of R. catesbeiana in Korea has not segregated geographically yet, after the introduction.

• Korean Journal of Microbiology
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• v.47 no.4
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• pp.281-288
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• 2011

To screen downstream genes of Aspergillus nidulans MsnA showing amino acid sequence similarity to the zinc finger region of Msn2/4 stress response transcription factors in Saccharomyces cerevisiae, differentially expressed genes (DEG) in MsnA overexpressed or msnA null mutant strains compared to wild type have been isolated. The cognate gene IDs were identified by DNA sequencing of the selected DEGs. Among those, DEG6 was known as mstB encoding a putative monosaccharide transporter. Expression level of mstB mRNA was increased in MsnA overproducing strains and MsnA bound directly to the promoter region of mstB in vitro. MstB containing twelve transmembrane domains exhibited 80% of amino acid sequence identities to A. niger MstA a high-affinity monosaccharide transporter. A null mutant of mstB was phenotypically undistinguishable to wild type. On the other hand, forced overexpression of MstB caused the increased formation of sexual structure cleistothecia in 0.1% glucose condition where wild type showed almost no cleistothecia. This result implies that mstB is involved in transport of monosaccharide required for sexual differentiation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3389-3404
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• 2012

Based on the case study methods, the study analyzes emergence and ensuing typology of global ebook platforms such as Google eBook, Amazon Kindle, iBooks Store. Global ebook platforms show adaptation process responding to rapidly changing digital technological envirment and it's fitness landscape. The critical elements in its emerging process are the distinct selection criteria, the degree of resource abundance and the search process based on open innovation. Based on these critical elements, the global platforms show speciation process, so called niche creation and are evolving into a variety of the typology based on the initial condition of key resource which makes the platform emerge and grow. Each global ebook platforms is evolving into open platform, hybrid platform, closed platform. Google eBook has openness and extensibility due to a variety of devices based on Android and a direct involvement of actors. Amazon Kindle has developed from a online bookstore and into the hybrid platform which have not only closed quality but also openness with ebook devices and mobile network. iBooks Store has developed into the closed platform through the agency model based on competitive hardwares and closed quality with iphone and ipad.

• Journal of agriculture & life science
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• v.44 no.5
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• pp.23-27
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• 2010

The control of stem length is most important external quality aspect in cut chrysanthemum. The present work in conducted in growth chamber and aims at investigating the effect of light intensity on the photosynthesis capacity and stem elongation in cut chrysanthemum. To evaluate the effect, different level of assimilation lighting (LEDs) was given to canopy level 60, 100, 140, and $180mol{\cdot}m^{-2}{\cdot}s^{-1}$, individually, under short-day conditions, and the light treatments were initiated from 7days after planting. There was a positive linear-regression relationship between the light intensity and the net assimilation rate. On the other hand, there was not significant difference in flower buds induction. The growth of stem length, leaf area, and dry weight was increased by increasing the light intensity, whereas the plants grown under 140 and $180mol{\cdot}m^{-2}{\cdot}s^{-1}$ was not differences in those of growth. It indicates that the increased net assimilation rate is not continually coincided with the maximized growth in cut chrysanthemum. It might be considered that the optimal light intensity for stem elongation of cut chrysanthemum is $140mol{\cdot}m^{-2}{\cdot}s^{-1}$ under short-day condition.

• Research in Plant Disease
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• v.29 no.3
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• pp.258-267
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• 2023

Fusarium wilt, caused by Fusarium oxysporum f. sp. niveum (Fon) is a serious disease in watermelon cultivation. Most of commercialized watermelon cultivars to Fusarium wilt are susceptible in Korea. Fon isolates were divided into four races (races 0, 1, 2, and 3), based on pathogenicity in four watermelon differentials including 'Sugar baby', 'Charleston gray', 'Calhoun gray' and 'PI-296341-FR'. We obtained 7 isolates of Fon and tested to determine race of the fungal strains. Fon KACC 40902 and Fon HA were race 0 and Fon NW1, Fon NW2, Fon CW and Fon KACC 40901 were race 1. And Fon KACC 40905 was race 2, but race 3 isolate of Fon was not founded. We also tested virulence of seven Fon isolates on three-susceptible cultivars of watermelon. The isolates showed different virulence on the cultivars. In addition, to study the resistance characteristics of watermelon to Fon, we selected three moderately or highly resistant cultivars of watermelon and occurrence of Fusarium wilt in seedlings of the cultivars by seven Fon isolates was investigated. Among them, 'Calhoun gray' is highly resistant to six Fon isolates except Fon KACC 40905. On the other two cultivars, disease severity of Fusarium wilt caused by each isolate was positively correlated with the virulence of the Fon isolates. The results suggest that resistance of the watermelon cultivars to Fon isolates is likely affected by the virulence of the pathogen.

• KSBB Journal
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• v.20 no.5 s.94
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• pp.363-370
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• 2005

Neural stem cells (NSCs) of the central nervous system (CNS) have raised a great interest not only for their importance in basic neural development but also for their therapeutic potentials in neurologically degenerative diseases such as Parkinson's, Alzheimer and stroke. During the CNS development, two molecular cascades determine specification of midbrain dopamine system. In one pathway, FGF-8, sonic hedgehog and transcription factor Nurr1 specify dopamine neurotransmitter phenotype. In the other, transcription factors $Lm{\times}lb\;and\;Pt{\times}3$ are required for induction of dopaminergic neurons. In Nurr1 knockout mouse, tyrosine hydroxylase (TH) positive cells fail to appear in substantia nigra, indicating that Nurr1 is essential in specification of dopaminergic cell phenotype. In this study, we used the immortalized human NSCs retrovirally transduced with Nurr1 gene to probe the Nurr1 mediated mechanism to induce dopamine phenotype. While Nurr1 over-expression alone did not generate dopamine phenotype in NSCs, applications of retinoid and forskolin induced expression of TH and AADC mRNAs. In addition, co-cultures of Nurr1 expressing NSCs with human astrocytes induced a marked increase of TH expression. In this co-culture system, the addition of retinoid and forskolin dramatically increased expression of TH. These results indicate that the immortalized human NSCs with Nurr1 gene could have a clinical utility for cell replacement for the Parkinson patients.

• The Journal of the Petrological Society of Korea
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• v.14 no.1
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• pp.12-23
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• 2005

Cretaceous granitic rocks in the Waryongsan area occur as a stock and show compositional changes with altitude. They include mafic microgranular enclaves (MME) with various sizes and types. The MMEs present clear evidence of magma mingling such as supercooling zone, mantling texture and back veining. The granitic rocks are divided into porphyritic granite, porphyritic granodiorite and fined-grained granite by their petrographic characteristics and modal compositions. The MMEs are discriminated to quartzdioritie, quartzmonzodiorite and tonalite. They have varying areal proportions in each granitic rock-type: 10∼l5% in the porphyritic granite, about 50% in the porphyritic granodiorite, and about 20% in the fined-grained granite. SiO₂ contents shows compositional change of 61.2∼72.0wt.%. Mean SiO₂ contents have 61.7wt.% in the porphyritic granodiorite, 68.6wt.% in the porphyritic granite. and 71.9wt.% in the fined-grained granite, respectively. Major oxide contents of the granitic rocks linearly vary with SiO₂ contents from the porphyiritic granodiorite to the fine-grained granite on Harker diagrams. Linear compositional variations seem to have been caused by differential degrees of mingling between mafic magma and host granite. Where larger amount of mafic magma was injected into the host granitic magma, the two magmas reached to thermal equilibrium more quickly and eventually chemical mixing occurred to produce the composition of the porphyritic granodiorite. On the other hand. less amount of injected mafic magma would have been responsible for mechanical mixing to produce the compositions of the porphyritic granite and the fined-grained granite. Therefore, it is considered that the granitic rocks in the Waryongsan area experienced magmas mingling resulting from the injection of more mafic magma into differentiating granitic magma, and that the compositional changes of the granitic rocks were ascribed to the degree of mingling between the two magmas.

• Journal of Life Science
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• v.25 no.6
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• pp.703-708
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• 2015

Hox genes encode a highly conserved family of homeodomain-containing transcription factors controlling vertebrate pattern formation along the anteroposterior body axis during embryogenesis. Retinoic acid (RA) is a key morphogen in embryogenesis and a critical regulator of both adult and embryonic cellular activity. Specifically, RA regulates Hox gene expression in mouse- or human-derived embryonic carcinoma (EC) cells. Histone modification has been reported to play a pivotal role in the process of RA-induced gene expression and cell differentiation. As histone modification is thought to play an essential role in RA-induced Hox gene expression, we examined RA-induced initiation of collinear expression of Hox genes and the corresponding histone modifications in F9 murine embryonic teratocarcinoma (EC) cells. Hox expression patterns and histone modifications were analyzed by semiquantitative RT-PCR, RNA-sequencing, and chromatin immuno-precipitation (ChIP)-PCR analyses. The Hoxc4 gene (D0) was initiated earlier than the Hoxc5 to –c10 genes (D3) upon RA treatment (day 0 [D0], day 1 [D1], and day 3 [D3]). The Hox nonexpressing D0 sample had a strong repressive marker, H3K27me3, than the D1 and D3 samples. In the D1 and D3 samples, reduced enrichment of the H3K27me3 marker was observed in the whole cluster. The active H3K4me3 marker was closely associated with the collinear expression of Hoxc genes. Thus, the Hoxc4 gene (D1) and all Hoxc genes (D3) expressed H3K4me3 upon transcription activation. In conclusion, these data indicated that removing H3K27me3 and acquiring H3K4me3 regulated RA-induced Hoxc gene collinearity in F9 cells.