• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.262-270
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• 2017

Yersinia enterocolitica is a well-known foodborne pathogen causing gastrointestinal infections worldwide. The strain Y. enterocolitica FORC_002 was isolated from the gill of flatfish (plaice) and its genome was sequenced. The genomic DNA consists of 4,837,317 bp with a GC content of 47.1%, and is predicted to contain 4,221 open reading frames, 81 tRNA genes, and 26 rRNA genes. Interestingly, genomic analysis revealed pathogenesis and host immune evasion-associated genes encoding guanylate cyclase (Yst), invasin (Ail and Inv), outer membrane protein (Yops), autotransporter adhesin A (YadA), RTX-like toxins, and a type III secretion system. In particular, guanylate cyclase is a heat-stable enterotoxin causing Yersinia-associated diarrhea, and RTX-like toxins are responsible for attachment to integrin on the target cell for cytotoxic action. This genome can be used to identify virulence factors that can be applied for the development of novel biomarkers for the rapid detection of this pathogen in foods.

• Proceedings of the Korean Society of Toxicology Conference
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• 1998.10a
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• pp.8-13
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• 1998

Polyoma Virus Enhancer core Binding Protein (PEBP2)는 유전자의 전사를 조절하는 hetero-dimeric transcription factor로서 $\alpha$와 $\beta$ subunit으로 구성되어 있다. $\alpha$ subunit을 coding 하는 유전자중 하나인 PEBP2aB는 급성백혈병과 관련되어있는 t(8;21) 또는 t(12;21)에 의하여 변형됨으로서 백혈병 발병의 원인이 되고 있다 (Miyoshi et al., 1993; .Romana et al., 1995). $\beta$ subunit을 coding 하는 PEBP2$\beta$도 inv(16)에 의하여 변형됨으로서 백혈병을 유도하는 주요 원인이 되고 있다 (Liu et al., 1993). 이 유전자들의 생물학적 활성을 밝히기 위한 연구가 gene targeting에 의한 knockout mouse 생산 방법으로 수행되었다. 그 결과 PEBP2$\alpha$B와 PEBP2$\beta$ 유전자가 definitive hematopoiesis에 있어서 결정적으로 중요한 역할을 하고 있음이 관찰되었다 (Okuda et al., 1996, Wang et al., 1996a, 1996b), 이는 이들 유전자가 bematopoietic master switch 유전자임을 밝힌 중요한 결과로서 이로부터 혈액학 연구 분야의 새로운 장이 열리게 되었다. 또한 이러한 연구 결과들은 PEBP2 family에 속하는 다른 유전자의 생물학적 활성의 연구를 촉진하는 계기가 되었다. 최근 PEBP2$\alpha$A 유전자가 결손된 마우스가 생산되었는데 이 유전자의 경우에는 모든 종류의 뼈의 생성이 완전히 결손됨이 관찰되었다 (Komori et al., 1997). 이는 PEBP2$\alpha$A 유전자가 뼈의 생성을 지배하는 master switch 유전자임을 보여주는 중요한 관찰로서 bone biologist 들의 큰 관심을 모으고 있다. 본 연구팀은 PEBP2 family 유전자 중 유일하게 아직 생물학적 활성이 규명되지 않은 PEBP2$\alpha$C 유전자의 활성을 knockout 마우스를 생산하는 방법에 의하여 분석하였으며 소화기관의 형성에 중요한 역할을 하고 있음을 확인하였다.

• Korean Journal of Remote Sensing
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• v.35 no.6_1
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• pp.933-944
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• 2019

This study analyzes the tide deformation of land boundary regions on the east (Region A) and west (Region B) sides of the Ross Ice Shelf in Antarctica using Double-Differential Interferometric Synthetic Aperture Radar (DDInSAR). A total of seven Sentinel-1A SAR images acquired in 2015-2016 were used to estimate the accuracy of tide prediction model and Young's modulus of ice shelf. First, we compared the Ross Sea Height-based Tidal Inverse (Ross_Inv) model, which is a representative tide prediction model for the Antarctic Ross Sea, with the tide deformation of the ice shelf extracted from the DDInSAR image. The accuracy was analyzed as 3.86 cm in the east region of Ross Ice Shelf and it was confirmed that the inverse barometric pressure effect must be corrected in the tide model. However, in the east, it is confirmed that the tide model may be inaccurate because a large error occurs even after correction of the atmospheric effect. In addition, the Young's modulus of the ice was calculated on the basis of the one-dimensional elastic beam model showing the correlation between the width of the hinge zone where the tide strain occurs and the ice thickness. For this purpose, the grounding line is defined as the line where the displacement caused by the tide appears in the DDInSAR image, and the hinge line is defined as the line to have the local maximum/minimum deformation, and the hinge zone as the area between the two lines. According to the one-dimensional elastic beam model assuming a semi-infinite plane, the width of the hinge region is directly proportional to the 0.75 power of the ice thickness. The width of the hinge zone was measured in the area where the ground line and the hinge line were close to the straight line shown in DDInSAR. The linear regression analysis with the 0.75 power of BEDMAP2 ice thickness estimated the Young's modulus of 1.77±0.73 GPa in the east and west of the Ross Ice Shelf. In this way, more accurate Young's modulus can be estimated by accumulating Sentinel-1 images in the future.

• Korean Journal of Optics and Photonics
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• v.11 no.6
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• pp.452-456
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• 2000

A measurement unit and signal processing algorithm have been developed for predicting arterial oxygen saturation noninvasively. The measurement set-up was composed of a probe including light source and photodetector, optical signal processing section, LED driving circuit, PC interface software for data acquisition and data processing software. Light from the LED's was irradiated onto the finger nail bed and transmitted light was measured at different wavelengths. An effective baseline correction method was developed and measured data were analyzed by using various data processing methods and prediction algOlithms. For performance evaluation, a pulse oximeter simulator (Bio- Tek Instrument Inc.) was used as reference. The best performance in terms of the correlation coefficient and the standard deviation was obtained under the following conditions; when the arterial signals were computed in terms of area rather than peak-valley difference, and when the algorithm calculating by $In(I_p/I_v)/I_{avr}$ value for pulsation waveform was used. In in vivo test, prediction was improved when the developed baseline correction method was used. In addition, wavelengths of 660 nm and 940 nm provided better linearity and precision than wavelengths of 660 nm and 805 nm. 05 nm.

• Journal of The Korean Astronomical Society
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• v.46 no.5
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• pp.191-200
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• 2013

Full-disk solar images are provided by many solar telescopes around the world. However, the observed images show Non-Radial Variation (NRV) over the disk. In this paper, we propose algorithms for detecting distortions and restoring these images. For detecting NRV, the cross-correlation coefficients matrix of radial profiles is calculated and the minimum value in the matrix is defined as the Index of Non-radial Variation (INV). This index has been utilized to evaluate the H images of GONG, and systemic variations of different instruments are obtained. For obtaining the NRV's image, a Multi-level Morphological Filter (MMF) is designed to eliminate structures produced by solar activities over the solar surface. Comparing with the median filter, the proposed filter is a better choice. The experimental results show that the effect of our automatic detection and restoration methods is significant for getting a flat and high contrast full-disk image. For investigating the effect of our method on solar features, structural similarity (SSIM) index is utilized. The high SSIM indices (close to 1) of solar features show that the details of the structures remain after NRV restoring.

• Journal of Microbiology and Biotechnology
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• v.32 no.12
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• pp.1605-1614
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• 2022

The strains associated with foodborne Salmonella enterica Thompson outbreaks in Korea have not been identified. Therefore, we characterized S. Thompson strains isolated from chocolate cakes linked to foodborne outbreaks in Korea. A total of 56 strains were isolated from preserved cake products, products in the supply chain distribution, the manufacturer's apparatus, and egg white liquid products used for cream preparation. Subsequently, serological typing, pathogenic gene-targeted polymerase chain reaction (PCR), pulsed-field gel electrophoresis (PFGE), and whole-genome multi-locus sequence typing (wgMLST) were performed to characterize these isolates. The antigen formula of all isolates was 7:k:1,5, namely Salmonella enterica subsp. enterica Serovar Thompson. All 56 isolates harbored invA, his, hin, and stn, and were negative for sefA and spvC based on gene-targeted PCR analyses. Based on PFGE results, these isolates were classified into one group based on the same SP6X01.011 pattern with 100% similarity. We selected 19 strains based on the region and sample type, which were subjected to wgMLST. Although the examined strains showed 100% similarity, they were classified into seven clusters based on allelic differences. According to our findings, the cause of these outbreaks was chocolate cake manufactured with egg white liquid contaminated with the same Salmonella Thompson. Additionally, comparative analysis of wgMLST on domestic isolates of S. Thompson from the three outbreaks showed genetic similarities of over 99.6%. Based on the results, the PFGE and wgMLST combination can provide highly resolved phylogeny and reliable evidence during Salmonella outbreak investigations.

• Journal of Veterinary Science
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• v.25 no.3
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• pp.39.1-39.11
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• 2024

Importance: Salmonella outbreaks linked to poultry meat have been reported continuously worldwide. Therefore, Salmonella contamination of poultry meats in slaughterhouses is one of the critical control points for reducing disease outbreaks in humans. Objective: This study examined the carry-over contamination of Salmonella species through the entire slaughtering process in South Korea. Methods: From 2018 to 2019, 1,097 samples were collected from the nine slaughterhouses distributed nationwide. One hundred and seventeen isolates of Salmonella species were identified using the invA gene-specific polymerase chain reaction, as described previously. The serotype, phylogeny, and antimicrobial resistance of isolates were examined. Results: Among the 117 isolates, 93 were serotyped into Salmonella Mbandaka (n = 36 isolates, 30.8%), Salmonella Thompson (n = 33, 28.2%), and Salmonella Infantis (n = 24, 20.5%). Interestingly, allelic profiling showed that all S. Mbandaka isolates belonged to the lineage of the sequence type (ST) 413, whereas all S. Thompson isolates were ST292. Moreover, almost all S. Thompson isolates (97.0%, 32/33 isolates) belonging to ST292 were multidrug-resistant and possessed the major virulence genes whose products are required for full virulence. Both serotypes were distributed widely throughout the slaughtering process. Pulsed-field gel electrophoretic analysis demonstrated that seven S. Infantis showed 100% identities in their phylogenetic relatedness, indicating that they were sequentially transmitted along the slaughtering processes. Conclusions and Relevance: This study provides more evidence of the carry-over transmission of Salmonella species during the slaughtering processes. ST292 S. Thompson is a potential pathogenic clone of Salmonella species possibly associated with foodborne outbreaks in South Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.334-339
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• 1995

Removal of apical ear after silking is a method to increase seed production in corn inbreds. Due to the phenomenon of apical dominance, the subapical ear would develope and produce seeds following the removal of the apical ear. This experiment was conducted to investigate the varietal difference in subapical ear development and seed production. Days to silking of subapical ears were delayed by about 4 days compared to normal apical ears. Cob length and filled ear length of subapical ears across seven inbreds tested were reduced by 21% and 36%, respectively. Those of inbred INV302 decreased less and subapical ear of inbred NC246 were barren, which incicated the varietal defferences. Number of kernel rows, kernels per row, and total kernels per ear also decreased. The mean reduction rates for those characters were 28%, 37%, and 47%, respectively. Weights of ears and kernels were reduced and showed different response among inbred lines. Coefficients of variations for cob and filled ear lengths, number of kernel rows and kernels were greater in subapical ears than in apical ears. Seed production of subapical ears was 40 ~ 80% of apical ears, depending on inbred lines when the apical ear is removed immediately after silking.

• Korean Journal of Veterinary Service
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• v.32 no.3
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• pp.227-239
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• 2009

At the present study, it was aimed to detect virulence genes and antimicrobial resistance genes among 102 strains of 12 Salmonella serotypes isolated from pigs and cattle. In polymerase chain reaction (PCR), invA was detected from all strains of Salmonella spp., spvC was detected from Salmonella enterica serotype Enteritidis (S. Enteritidis) (100%), S. Bradenburg (75%), and S. Typhimurium (20.4%). Drug resistance related genes of 12 types were detected from all strains. TEM ($bla_{TEM}$) gene was detected from 51 (92.7%) of 55 $\beta$-lactams (54 ampicillin or 1 amoxicillin) resistance strains. 55 (100%) of 55 chloramphenicol resistance strains, 3 (100%) of 3 gentamicin resistance strains and 5 (100%) of 5 kanamycin resistance strains did contain cml, aadB, and aphA1-Iab, respectively. strB (89.9%), strA (88.4%), aadA2 (84.1%) and aadA1 (72.5%) were detected from 69 streptomycin resistance strains. sulII and dhfrXII were detected from 49 (100%) of 49 sulfamethoxazole/trimethoprim resistance strains, but sulI was not detected. tetA (97.9%) and tetB (21.6%) were detected from 97 tetracycline resistance strains. int gene was detected from 58 (56.9%) of 102 strains. 54 S. Typhimurium of 102 Salmonella spp. were attempted to detect drug resistance genes. TEM was detected from 44 (95.7%) of 46 $\beta$-lactams (45 ampicillin or 1 amoxicillin) resistance strains. cmlA was detected from 51 (100%) of 51 chloramphenicol resistance strains. aadA2 (100%), strA (100%), strB (100%), and aadA1 (79.6%) were detected from 54 streptomycin resistance strains. sulII (100%) and dhfrXII (100%) were detected from 49 sulfamethoxazole/trimethoprim resistance strains. tetA was detected from 54 (100%) of 54 tetracycline resistance strains. int gene was detected from 54 (100%) of 54 strains. The major drug resistance pattern and resistance gene profile were ampicillin, chloramphenicol, streptomycin, sulfamethoxazole/trimethoprim and tetracycline (ACSSuT) and TEM, cmlA, aadA1, aadA2, strA, strB, sulII, dhfrXII, tetA and int, respectively.

• Korean Journal of Veterinary Service
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• v.41 no.3
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• pp.157-163
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• 2018

In order for monitoring of pathogenic bacterial contamination in the freshly slaughtered poultry meats produced in Gyeong-Nam province, we first isolated 4 strains of Salmonella spp. and 32 strains of Enterococcus faecalis from the total 164 samples, then we analyzed potential virulence gene profiles of the bacterial isolates by PCR using species-specific primer. The potential virulence genes we selected in this study were stn, invA, fimA, spvR, and spvC for the isolates of Salmonella spp. and those of esp, cylM, cylA, cylB, gelE, fsrA, fsrB, and fsrC were for the isolates of E. faecalis. The PCR results showed that all 5 virulence genes were detected simultaneously in the all isolates of Salmonella spp. However, there was a diverse occurrence pattern of the virulence genes in the case of E. faecalis. The gene for enterococcal surface protein (esp) was not detected among the isolates (0/32), and the haemolysin gene prevalence rate of cylA, cylB, and cylM were 3.1% (1/32), 9.3% (3/32), and 9.3% (3/32), respectively. Moreover, the genes of gelE, fsrA, fsrB, and fsrC that associated with gelatinase activity were detected in the rate of 53.1% (17/32), 53.1% (17/32), 53.1% (17/32), and 53.1% (17/32), respectively. In conclusion, in the isolates of Salmonella spp., all possessed 5 virulence genes tested, suggesting that they are all related with each other clonally. However, in the case of E. faecalis isolates, the occurrence of the haemolysin genes (cylM, cylA, cylB) and the gelatinase genes (gelE, fsrABC) was highly variable among the isolates.