• Animal cells and systems
• /
• v.5 no.4
• /
• pp.283-290
• /
• 2001

Phylogenetic relationships among the Korean taxa of the genus Allium subgenus Rhizirideum and some related taxa were assessed on the basis of in sequences of nuclear ribosomal DNA. Twenty-eight accessions of the genus Allium L. consisting of subgenera Rhizirideum (19 taxa), Allium (5 taxa) and Amerallium (one taxon) were analyzed. The variation in the ITS region was informative at the levels of section except for sect. Reticulato- bulbosa which is known to be of multiple origin. The ITS 2 region was longer than the ITS 1 region, and all of the investigated Allium taxa were the same in length in the 5.8S region except for A. monanthum. Allium cyaneum var. cyaneum was the shortest (635 bp) and A. victorialis the longest (646 bp) among the investigated Korean taxa. The three morphologically similar taxa, A. thunbergii, A. sacculiferum that has been included in A. thunbergii, and A. deltoid- fistulosum, had the same ITS lengths of 641 bp, but were clearly distinguished in the phylogenetic analysis of their ITS sequences.

• Journal of Life Science
• /
• v.26 no.11
• /
• pp.1341-1344
• /
• 2016

Dendropanax morbifera is an endemic tree species of Korea, it is restricted to the southern parts of Korea. The internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA) for Dendropanax morbifera grown at Bogil-do, Korea was determined. We investigated the sequence-based phylogenetic relationships of plants related and clarified its taxonomical position. The determined sequences consisted of 689 residues. ITS1 was 222 bp long while ITS2 was 233 bp long. The 5.8S rDNA was 160 bp long. The ITS region sequences of the Dendropanax species included in this study were obtained from GenBank. Oreopanax polycephalus was used as the outgroup. A pairwise alignment was calculated using the Clustal X program. A phylogenetic tree was constructed by the neighbor-joining method using the Tree view program. Sequence similarities among species including D. morbifera Bogil-do isolate showed the range 92.6 to 99.7% in sequence-based phylogenetic analysis using total 615 base pairs of ITS1, 5.8S rDNA and ITS2. D. morbifera Bogil-do isolate exhibited the highest degree of relatedness to D. chevalieri, sharing 99.7% ITS region similarity. D. morbifera Bogil-do isolate also showed to D. trifidus, sharing 99.4% ITS region similarity.

• The Korean Journal of Mycology
• /
• v.32 no.2
• /
• pp.148-151
• /
• 2004

This study was carried out to elucidate phylogenetic relationship of a yellow lump, Phellinus linteus by comparing the nuclear ribosomal intergenic spacer (IGS) I region with that of other genera of basidiomycetes retrieved from Genbank. IGS I region of Phellinus linteus was 730 bp long and sequence homology was conserved in the 5' region, in particular $1{\sim}280\;bp$, and decreased in the direction toward the 3' end. ITS region was widely studied in phylogenies related to basidiomycetes, but IGS region was not well understood yet. Our study indicated that IGS region can be a good tool in phylogenetic study of basidiomycetes.

• Korean Journal of Veterinary Service
• /
• v.42 no.3
• /
• pp.161-167
• /
• 2019

The poultry red mite (PRM), Dermanyssus gallinae, causes great economic losses to poultry industries in Korea. The molecular epidemiological characterization of PRM has been investigated in some countries, but those analysis has been not conducted yet in Korea. The aim of this study is to determine the genetic diversity of PRMs in Korea compared with those from other countries. Here, 13 PRM samples collected from Korea were analyzed with a part of the mitochondrial cytochrome oxidase subunit I (COI) gene and nuclear internal transcribed spacers (ITS) region. All the samples showed an identical COI sequence, which has also been reported in European countries and Japan. Phylogenetic diversity analysis showed that the mites from Korea were genetically related to those in other countries. The nuclear ITS region sequences were classified into three sequence types. Additionally, one of the ITS sequences was an intermediate type, implying that a hybridization event occurred among the mite populations in Korea. These findings suggested PRMs from Korea showed low genetic diversity with respect to mitochondrial COI gene, but three different populations inhabited in Korea with respect to nuclear ITS region sequences.

• Journal of Radiation Protection and Research
• /
• v.41 no.2
• /
• pp.155-159
• /
• 2016

Background: Nuclear reactors produce a great number of antielectron neutrinos mainly from beta-decay chains of fission products. Such neutrinos have energies mostly in MeV range. We are interested in neutrinos in a region of keV, since they may take part in special weak interactions. We calculate reactor antineutrino spectra especially in the low energy region. In this work we present neutrino spectrum from a typical pressurized water reactor (PWR) reactor core. Materials and Methods: To calculate neutrino spectra, we need information about all generated nuclides that emit neutrinos. They are mainly fission fragments, reaction products and trans-uranium nuclides that undergo negative beta decay. Information in relation to trans-uranium nuclide compositions and its evolution in time (burn-up process) were provided by a reactor code MVP-BURN. We used typical PWR parameter input for MVP-BURN code and assumed the reactor to be operated continuously for 1 year (12 months) in a steady thermal power (3.4 GWth). The PWR has three fuel compositions of 2.0, 3.5 and 4.1 wt% $^{235}U$ contents. For preliminary calculation we adopted a standard burn-up chain model provided by MVP-BURN. The chain model treated 21 heavy nuclides and 50 fission products. The MVB-BURN code utilized JENDL 3.3 as nuclear data library. Results and Discussion: We confirm that the antielectron neutrino flux in the low energy region increases with burn-up of nuclear fuel. The antielectron-neutrino spectrum in low energy region is influenced by beta emitter nuclides with low Q value in beta decay (e.g. $^{241}Pu$) which is influenced by burp-up level: Low energy antielectron-neutrino spectra or emission rates increase when beta emitters with low Q value in beta decay accumulate Conclusion: Our result shows the flux of low energy reactor neutrinos increases with burn-up of nuclear fuel.

• Nuclear Engineering and Technology
• /
• v.44 no.1
• /
• pp.33-42
• /
• 2012

In the present study, CFD is employed to investigate phenomena occurring during a process of thermal stratification in U-bent pipes at transitional Reynolds number. URANS evaluation had been chosen for its low computational costs during transient analysis and for the evaluation of modeling performance in these conditions. Application of CFD at transitional Reynolds number and buoyancy driven flows indeed contains deeper uncertainties in relation to the range of applicability for hydrodynamic and thermal models. The methodology applied in the work points out, through validations with the basic problems constituting the complex stratified phenomenon, the applicability of the current turbulence modeling. Accurate predictions have been found in relation to transitional Reynolds number in bent pipes and region of stability induced by the gravitational field. On the other hand the defects introduced in the unstable region of the U bent pipe, are discussed in relation to the adopted modeling.

• Nuclear Engineering and Technology
• /
• v.51 no.4
• /
• pp.1081-1090
• /
• 2019

Detailed pulse shape analysis of a Geiger-$M{\ddot{u}}ller$ counter is performed to understand the pulse shape dependence on operating voltage. New data is presented to demonstrate that not all pulses generated in a GM counter are identical. In fact, there is a strong correlation between the operating voltage and the pulse shape. Similar to detector deadtime, pulse shapes fall in three distinct regions. For low voltage region, where deadtime was reported to reduce with increasing voltage, pulse generated in this region was observed to have a fixed pulse width with a variable tail. The pulse width and fall time of the tail was observed to be a function of applied voltage; exponentially reducing with increasing voltage with an exponent of negative 6E-04 and 2E-03 respectively. The second region showed a pulse without any significant tail. During this time the detector deadtime was earlier reported to be at its minimum. The highest voltage region demonstrated a different deadtime mechanism where the second pulse was reduced in width. During this time the deadtime seemed to be increasing with increasing voltage. This data allows us to gain some unique insight into the phenomenon of GM detector deadtime not reported thus far.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.4
• /
• pp.816-821
• /
• 2004

A reliable molecular phylogenetic method to identify Hericium erinaceum, the most industrially valuable species in the Hericium genus, was established. Sequencing and phylogenetic analyses of the PCR-amplified ITS and 5.8S rDNA from Hericium fungi, including 6 species and 23 isolates, showed that variation in nucleotide sequences and size exists in both ITS1 and ITS2 regions, but not in the 5.8S region. These two ITS regions provided different levels of information on the relationship of H. erinaceum to other Hericium species. Based on the ITS1 sequence, both the parsimony and neighbor joining trees clearly distinguished Asian H. erinaceum isolates from other Hericium species and isolates. The intraspecific divergence of the ITS2 region was suitable to dissect the Asian H. erinaceum isolates into a few groups.

• Clinical and Experimental Reproductive Medicine
• /
• v.40 no.1
• /
• pp.1-6
• /
• 2013

Objective: Oocyte-specific homeobox 4 (Obox4) is preferentially expressed in oocytes and plays an important role in the completion of meiosis of oocytes. However, the Obox4 expression pattern has not been reported yet. In this study, we investigated the subcellular localization of Obox4 using a green fluorescent protein (GFP) fusion expression system. Methods: Three regions of Obox4 were divided and fused to the GFP expression vector. The partly deleted homeodomain (HD) regions of Obox4 were also fused to the GFP expression vector. The recombinant vectors were transfected into HEK-293T cells plated onto coated glass coverslips. The transfected cells were stained with 4',6-diamidino-2-phenylindol and photographed using a fluorescence microscope. Results: Mutants containing the HD region as well as full-length Obox4 were clearly localized to the nucleus. In contrast, the other mutants of either the N-terminal or C-terminal region without HD had impaired nuclear localization. We also found that the N-terminal and C-terminal of the Obox HD contributed to nuclear localization and the entire HD was necessary for nuclear localization of Obox4. Conclusion: Based on the results of the present study, we demonstrated that the intact HD region of Obox4 is responsible for the nuclear localization of Obox4 protein in cells.

• Nuclear Engineering and Technology
• /
• v.45 no.7
• /
• pp.961-968
• /
• 2013

The Arabian Gulf region has one of the highest ocean temperatures, reaching above 35 degrees and ambient temperatures over 50 degrees in the summer. Two nuclear power plants (NPP) are being introduced in the region for the first time, one at Bushehr (1,000 MWe PWR plant from Russia), and a much larger one at Barakah (4X1,400 MWe PWR from Korea). Both plants take seawater from the Gulf for condenser cooling, having to modify the secondary/tertiary side cooling systems design by increasing the heat transfer surface area from the country of origin. This paper analyses the secondary side of a typical PWR plant operating under the Rankine cycle with a simplified thermal-hydraulic model. Parametric study of ocean cooling temperatures is conducted to estimate thermal efficiency variations and its associated design changes for the secondary side. Operational safety is reviewed to deliver rated power output with acceptable safety margins in line with technical specifications, mainly in the auxiliary systems together with the cooling water temperature. Impact on the Gulf seawater as the ultimate heat sink is considered negligible, affecting only the adjacent water near the NPP site, when compared to the solar radiation on the sea surface.