• The Bulletin of The Korean Astronomical Society
• /
• v.41 no.1
• /
• pp.37.3-38
• /
• 2016

Recent studies suggest that faint active galactic nuclei may be responsible for the reionization of the universe. Confirmation of this scenario requires spectroscopic identification of faint quasars ($M_{1450}$ > -24 mag) at z > 6, but only a very small number of such quasars have been spectroscopically identified so far. Here, we report the discovery of a faint quasar IMS J220417.92+011144.8 at z ~ 6 in a $12.5deg^2$ region of the SA22 field of the Infrared Medium-deep Survey (IMS). The spectrum of the quasar shows a sharp break at ${\sim}8443{\AA}$, with emission lines redshifted to $z=5.944{\pm}0.002$ and rest-frame ultraviolet continuum magnitude $M_{1450}=-23.59{\pm}0.10$ AB mag. The discovery of IMS J220417.92+011144.8 is consistent with the expected number of quasars at z ~6 estimated from quasar luminosity functions based on previous observations of spectroscopically identified low-luminosity quasars. This suggest that the number of $M_{1450}$ ~ -23 mag quasars at z ~ 6 may not be high enough to fully account for the reionization of the universe. In addition, our study demonstrates that faint quasars in the early universe can be identified effectively with a moderately wide and deep near-infrared survey such as the IMS.

• Korean Journal of Veterinary Research
• /
• v.21 no.2
• /
• pp.99-104
• /
• 1981

A total of 251 clinical isolates (human origin, 43 strains and bovine udder origin 208 strains) of the Staphylococcus that fermented mannitol aerobically were tested for their ability to produce coagulase, DNase, and thermostable nuclease. Of these, 158 isolates coagulated human or bovine plasma, produced DNase, and thermostable, nuclease and were identified as St. aureous, 146 of which produced a 1+ to 3+ clot. The remaining 12 isolated produced a -clot in citrate treated plasma but produced 1+ to 3+ clot in ethylenedi-aminetetraacetic acid (EDTA) treated plasma. It was found that 7 coagulase positive isolates failed to produced thermostable nuclease. In these organisms, we found out of the clot formation is not by coagulase activity but utilization of citrate, because EDTA treated plasma is not coagulated. Among 93 isolates which did not coagulate citrate-or EDTA treated plasma and thermostable nuclease negative, 28 strains produced DNase were identified as St. epidermidis, and other strains were not identification further. It was found that thermostable nuclese production appears to be a consistent property of St. aureus and the test is easy to perform, is rapid became quite distinct within 2 to 4 hour, and is not influenced by as many factors and variations as the coagulase test.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.3
• /
• pp.464-471
• /
• 2013

This paper proposes a hybrid searching algorithm based on parameter identification for power system load models. Hybrid searching was performed by the combination of particle swarm optimization (PSO) and a complex method, which enhances the convergence of solutions closer to minima and takes advantage of global searching with PSO. In this paper, the load model of interest is composed of a ZIP model and a third-order model for induction motors for stability analysis, and parameter sets are obtained that best-fit the output measurement data using the hybrid search. The origin of the hybrid method is to further apply the complex method as a local search for finding better solutions using the selected particles from the performed PSO procedure.

• Korean Journal of Oriental Medicine
• /
• v.9 no.1
• /
• pp.113-122
• /
• 2003

In the present paper, morphological characteristic and PCR analysis were carried not to identify the medicinal origins of Peucedanum decursivum and Anthriscus sylvestris. Some samples in Korean. markets were Peucedanum decursivum misused with rhizomes of Anthriscus sylvestris. The main. origin of Peucedanum decursivum producted was quite different from those of Anthriscus sylvestris in the morphological characteristics. And PCR analysis, the three primer has developed into anew tool for identification of Peucedanum decursivum and Anthriscus sylvestris.

• Korean Journal of Veterinary Research
• /
• v.34 no.2
• /
• pp.315-320
• /
• 1994

The API STAPH-IDENT system was evaluated as a means for identifying Staphylococcus hyicus subsp hyicus straints isolated from swine and poultry. Of 80 strains from swine, 68 (85%) were correctly identified by the API STAPH-IDENT system alone after 5 h of incubation. When results were determined after 24 h of incubation, the accuracy of this system alone was 93.8%. By additional tests in conjunction with the API STAPH-IDENT system, however, all 80 strains could be correctly identified. Of 120 strains from poultry, 87 (72.5%) required additional testing to achieve a correct identification, and 33 (27.5%) were incorrectly identified by this system after 5 h of incubation. After 24 h of incubation, 99 of 120 (82.5%) avian strains were incorrectly identified as Staph epidermidis owing to false-negative mannose and trehalose utilizations. Seventy-seven (96.3%) of swine strains were positive for ${\beta}-glucuronidase$, whereas all 120 strains recovered tram poultry were negative for it.

• BMB Reports
• /
• v.51 no.10
• /
• pp.481-483
• /
• 2018

Glioblastoma (GBM) is the most common and aggressive form of human adult brain malignancy. The identification of the cell of origin harboring cancer-driver mutations is the fundamental issue for understanding the nature of GBM and developing the effective therapeutic target. It has been a long-term hypothesis that neural stem cells in the subventricular zone (SVZ) might be the origin-of-cells in human glioblastoma since they are known to have life-long proliferative activity and acquire somatic mutations. However, the cell of origin for GBM remains controversial due to lack of direct evidence thereof in human GBM. Our recent study using various sequencing techniques in triple matched samples such as tumor-free SVZ, tumor, and normal tissues from human patients identified the clonal relationship of driver mutations between GBM and tumor-free SVZ harboring neural stem cells (NSCs). Tumor-free SVZ tissue away from the tumor contained low-level GBM driver mutations (as low as 1% allelic frequency) that were found in the dominant clones in its matching tumors. Moreover, via single-cell sequencing and microdissection, it was discovered that astrocyte-like NSCs accumulating driver mutations evolved into GBM with clonal expansion. Furthermore, mutagenesis of cancer-driving genes of NSCs in mice leads to migration of mutant cells from SVZ to distant brain and development of high-grade glioma through the aberrant growth of oligodendrocyte precursor lineage. Altogether, the present study provides the first direct evidence that NSCs in human SVZ is the cell of origin that develops the driver mutations of GBM.

• Korean Journal of Organic Agriculture
• /
• v.12 no.4
• /
• pp.451-461
• /
• 2004

In an animals, identification system has been widely used by ear tag with dummy code and blood typing for parernity. Also, genotyping methods were using for useful mean of individual identification for live animals. In the case of genotyping estimation of gene in population of korean native chicken. In this study, we tested for development of genetic markers used it possible to determination of individual identification system. The candidate genetic markers were used already bow 10 of microstalite DNA sequence information in chromosome No. 1 and 14. Result of analysis for genotyping, the number of alleles of those microstatelites DNA was shown minimal 3 to 12 and the heterozygote expression frequency range was shown from 0.617 to 0.862. In our result, effective number of allele for each microsatellites DNA was shown 3~7, and the accuracy of individual identification was shown nearly 100%, when used with 6 genetic marker. This study was about genotyping method for identification used specific genetic marker form microsatellite DNA in the brand marketing of korean native chicken. Our results suggest that genotyping method used specific genetic marker from microsatellite DNA might be very useful for determination of individual identification.

• Clinical and Experimental Pediatrics
• /
• v.52 no.8
• /
• pp.862-868
• /
• 2009

Since its identification in April 2009, a swine-origin H1N1 influenza A virus (S-OIV) which is a reassortment of gene segments from both North American triple-reassortant and Eurasian swine influenza has been widely spread among humans in unexpected rapidity. To date, each gene segment of the 2009 influenza A (H1N1) outbreak viruses have shown high (99.9%) neucleotide sequence identity. As of July 6, 94,512 people have been infected in 122 countries, of whom 429 have died with an overall case-fatality rate of <0.5%. Most confirmed cases of S-OIV infection have been characterized by self-limited, uncomplicated febrile respiratory illness and 38% of cases have also included vomiting or diarrhea. Standard plus droplet precautions should be adhered to at all times. Tests on S-OIV have indicated that current new H1N1 viruses are sensitive to neuraminidase inhibitors (oseltamivir). However, current less virulent S-OIV may evolve into a pathogenic strain or acquire antiviral resistance, potentially with more severe clinical consequences. Efforts to control these outbreaks would be based on our understanding of novel S-OIV and previous influenza pandemics.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2003.03a
• /
• pp.3-11
• /
• 2003

We analysed phases recorded by the M$_{L}$ 3.6 Cheolwon, Korea, earthquake occurred on the 10th of December, 2002 and computed source parameters such as hypocenter, origin time, earthquake magnitude and focal solutions. We used PmP and SmS phases to increase the accuracy in determinations of the hypocenter and origin time in addition to the phases such as Pg, Pn, Sg and Sn which are generally used in routine processes. The epicenter, depth, and origin time of the Cheolwon earthquake determined based on data of 11 stations within 200 km from the epicenter are 38.8108$^{\circ}$N, N, 127.2214'E, 11.955 km, and on 7:42:51.436. The earthquake magnitude obtained from all the stations is 3.6 M$_{L}$. The fault plane solution calculated based on data from 19 stations indicates slip process of a normal fault including strike-slip motion. The direction of compressional stress field has a large vertical component and a ESE-WNW direction of horizontal component, which is different from the mainly horizontal direction of main compressional stress field in the Korean Peninsula (ENE-WSW) obtained by previous studies.ies.s.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.04a
• /
• pp.289-292
• /
• 2004

In order to identify the origin and nature of the spilled oil in the potential source, we analyzed the pattern of alkyi PAM(Polynuclear Aromatic Hydrocarbons) in fuel standard and environmental samples. Alkyl PAM patterns are used for fuel-type identification in weathered environmental samples. Detection of alkyl PAH was achieved by operation CC/MS in the SIM mode. We chose ions of naphthalene(m/z 128), C1-naphthalene(m/z 142), C2-naphthalene(m/z 156), C3-naphthalene(m/z 170), C4-naphthalene(m/z 184) for the comparison of this pattern according to the type of fuel. We analyzed tile pattern of alkyl PAH in neat gasoline, kerosene, diesel, and JP-8, and in groundwater samples which were collected in monitoring wells. The distribution map of alkyl-naphthalene shows different patterns among four different fuel types (gasoline, kerosene, diesel, and JP-8). Particularly, tile distribution map of kerosene and JP-8 is found to be of value in identifying fuel type in that the difference is clear. Therefore distribution patterns of alkyl-PAH compounds provide another useful tool for fuel-type identification of petroleum fuels.