• Journal of Life Science
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• v.19 no.6
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• pp.793-798
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• 2009

This study was undertaken to reveal the relationship between genetic variations and inheritance patterns and the development of a systemic white coat color frequently observed in Jeju horses. It was determined that the white coat color occurred in all basic coat colored (black, bay and chestnut) horses by combining the phenotype and MC1R genotypes. There were no polymorphisms found in Jeju horses tested for mutational loci in the KIT gene, which were previously reported as potential mutations of the congenital dominant white coat color in other horse breeds in heterogeneity. The horses that had the 4.6-kb duplication in the STX17 intron 6 specifically showed the depigmented white coat color. Based on observation and STX17 genotypes, this depigmented whitening is defined as 'Chongma' (whitening, progressive graying with age-Gray) in Jeju horses. Pedigrees showed that this is an autosomal dominant inheritance pattern distinct from the bovine albinism caused by an autosomal recessive passion eye color. Because the gray phenotype is generally not completely expressed early in Jeju horses, it often makes them indistinguishable from other horses. Further studies are recommended for classification between the gray coat color and its similar phenotypes, such as the roan with its mixed hair colors appearing since neonatal period, acquired white hairs on wounded skin by veterinary treatment, and vitiligo-like skin pigmentation. However, study results revealing the relationship between the gray phenotype and genetic background suggested that useful information may be provided in regards to molecular breeding of Jeju horses.

• 해운
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• no.2 s.13
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• pp.10-17
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• 2005

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.183-188
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• 2015

This study analyzed the coat color-related genes of MC1R, ASIP, ECA3-inversion, and STX17 of 1,462 Jeju horses administered by the Jeju Special Self-Governing Province. This was done to investigate the distributional characteristics of coat color-related genes in the Jeju horse group and the changes of its coat color-related genes by generation. The genotype frequency of the MC1R gene of $E^+/E^+$ and $E^+/E^e$ related to black coat color was 0.122 and 0.447, respectively, while $E^e/E^e$ of the chestnut genotype was 0.429. The genotype frequency of the ASIP gene of $A^A/A^A$, $A^A/A^a$, and $A^a/A^a$ was 0.46, 0.448, and 0.091, respectively, where the genotype frequency of $A^a/A^a$ turned out to be relatively low. The To/To and +/To genotype that manifests the Tobiano shape was 0.001 and 0.119, respectively, with the share of Tobiano shape around 12%. The genotype frequency of G/G and G/g of STX17 related to grey coat color was 0.002 and 0.680, respectively, with the share of grey horses among the Jeju horse group at 68.2%. As for the change of coat color genes by generation, no large changes were observed in the MC1R and ASIP genes. In ECA3-inversion, the To allele that manifests Tobiano significantly decreased following the generational change (p<0.05), while the STX17 G allele related to grey coat color significantly increased following the generational change (p<0.05). It will be necessary to examine the coat color genes when selecting breeding horses so that the diversity of coat colors among the Jeju horse group can be maintained.

• Microbiology and Biotechnology Letters
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• v.48 no.2
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• pp.121-128
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• 2020

Diarrhea is a major public health concern associated with pathogenic Escherichia coli infections. Food-borne pathogenic E. coli can lead to large diarrheal outbreaks and hence, there is a need to estimate the frequency of pathogenic E. coli load in the various types of meat available in markets. In the present study, we classified and characterized diarrheagenic E. coli isolates collected from 399 raw meat samples from retail sources in Korea. Shiga toxin-producing E. coli (STEC) were detected in 11 (9.7%) samples, including nine strains (8.0%) in beef and two strains (1.8%) in chicken. The frequency of the detected virulence markers were as follows: astA, 28.3%; escV,18.6%; eaeA,17.7%; ent, 7.0%; EHEC-hly, 4.4%; stx1, 3.5%; and stx2, 3.5%. We did not observe any typical EPEC, EIEC, or ETEC virulence determinants in any of the samples. The STEC serotype O26 was detected in one sample, but no other serogroups (O91, O103, O128, O157, O145, O111, and O121) were found. Further research is needed to better understand the virulence mechanism of STEC serotypes, their ecology, and prevalence in animals, food, and the environment. These results will help improve risk assessment and predict the sources of food poisoning outbreaks.

• Journal of Food Hygiene and Safety
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• v.32 no.2
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• pp.129-134
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• 2017

Diarrheagenic Escherichia coli is now recognized as an important cause of diarrhea, hemorrhagic colitis and hemolytic-uremic syndrome (HUS) worldwide. E. coli were isolated from 80 of 356 (22.5%) chicken and chilled chicken products in Korea. Fifteen virulence genes specific for pathogenic E. coli, including Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC) and enteroaggregative E. coli (EAEC), were examined by multiplex PCR. STEC virulence markers were detected for eaeA (20.0%), escV (21.3%), stx1 (3.8%), ent (2.5%), EHEC-hly (1.3%), stx2 (1.3%), EAEC virulence marker (astA) was detected in 32.5%. ETEC and EIEC were not detected. STEC serotypes O152, O1, O116, O26, O25, O119 and O153 were found in chicken samples. This suggests the importance of diarrheagenic Escherichia coli control in raw chicken and chilled chicken food for food safety.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.97-97
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• 2009

The use of thin plate increases due to the need for light weight in large ship. Thin plate is easily distorted and has residual stress by welding heat. Therefore, the thin plate should be carefully joined to minimize the welding deformation which costs time and money for repair. For one effort to reduce welding deformation, it is very useful to predict welding deformation before welding execution. There are two methods to analyze welding deformation. One is simple linear analysis. The other is nonlinear analysis. The simple linear analysis is elastic analysis using the equivalent load method or inherent strain method from welding experiments. The nonlinear analysis is thermo-elastic analysis which gives consideration to the nonlinearity of material dependent on temperature and time, welding current, voltage, speed, sequence and constraint. In this study, the welding deformation is analyzed by using thermo-elastic method for PCTC(Pure Car and Truck Carrier) which carries cars and trucks. PCTC uses thin plates of 6mm thickness which is susceptible to welding heat. The analysis dimension is 19,200mm(length) * 13,825mm(width) * 376mm(height). MARC and MENTAT are used as pre and post processor and solver. The boundary conditions are based on the real situation in shipyard. The simulations contain convection and gravity. The material of the thin block is mild steel with $235N/mm^2$ yield strength. Its nonlinearity of conductivity, specific heat, Young's modulus and yield strength is applied in simulations. Welding is done in two pass. First pass lasts 2,100 second, then it rests for 900 second, then second pass lasts 2,100 second and then it rests for 20,000 second. The displacement at 0 sec is caused by its own weight. It is maximum 19mm at the free side. The welding line expands, shrinks during welding and finally experiences shrinkage. It results in angular distortion of thin block. Final maximum displacement, 17mm occurs around welding line. The maximum residual stress happens at the welding line, where the stress is above the yield strength. Also, the maximum equivalent plastic strain occurs at the welding line. The plastic strain of first pass is more than that of second pass. The flatness of plate in longitudinal direction is calculated in parallel with the direction of girder and compared with deformation standard of ${\pm}15mm$. Calculated value is within the standard range. The flatness of plate in transverse direction is calculated in perpendicular to the direction of girder and compared with deformation standard of ${\pm}6mm$. It satisfies the standard. Buckle of plate is calculated between each longitudinal and compared with the deformation standard. All buckle value is within the standard range of ${\pm}6mm$.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.128-128
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• 2003

The annually outbreak of paralytic shellfish poisoning (PSP) were caused by toxic dinolagellate A. tamarense and A. catenella in Korea. The purpose of this study were to investigate the distribution of PSP-causative organisms, A. tamarense and A. catenella and their species classification. Sediment (Saemangeum, the south open sea) and water samples (southeastern coast) were sampled to establish clonal isolates in 2003. After isolation and purification, strains were cultured under $17^{\circ}C$, f/2 media, 14:10=L:D cycle. PST analysis and species identification were performed by HPLC-FD method and specific DNA probe, respectively. Thirty-ons strains were isolated from the Saemangeum reclamation, southeastern coast including Jinhae Bay and south open sea. PSTs were detected in all cultured strains. In eight strains from south offshore, major toxin components are GTX5, C1/2 and minors are GTX3/4, dcGTX3, neoSTX. Sixteen strains from south coastal area have GTX1/4, neoSTX, C1/2 as major toxin components and GTX2/3 as minors. Seven strains from the Saemangeum reclamation have GTX5, C1/2 as major toxin components and GTX1/2/3/4 as minors. Thus, among eight south offshore isolates, four A. tamarense have more toxic (38.31~l19.16 fmol.$cell^{-1}$) than A. catenella (3.78~13.13 fmol.$cell^{-1}$). With the previous results of different toxin composition, toxin components and toxin contents, .it is toxin profile that could used to diagnosis of regional toxic population and geographical distribution of both A. tamarense and A. catenella and their toxigenic strains.

• Korean Journal of Veterinary Service
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• v.28 no.1
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• pp.71-79
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• 2005

In this study, a total of 2,119 samples was taken from bovine feces and carcass from March 2002 to December 2003. And those were examined for the presence of enterohemorrhagic E coli O157:H7. The properties of the isolates were characterized for biochemical features, serotypes, virulence genes and antimicrobial susceptibility. Forty five strains($3.7\%$) of E coli O157:H7 were isolated from 1,208 fecal samples and were not detected in carcass using immunomagnetic separation technique and selective media. In multiplex PCR using stx1, stx2, eaeA and hlyA primers, the amplified bands at 180 bp, 255bp, 384bp and 534bp were observed, respectively. In antimicrobial susceptibility test, all isolates were susceptible to amoxicillin/clavulanic acid and cefazolin. The isolates were most resistant to sulfisoxazole($24.4\%$), followed by streptomycin($22.2\%$), tetracycline($20.0\%$). Eight strains($17.8\%$) of 45 isolates showed the multi-resistant patterns with over 3 drugs.

• Korean Journal of Veterinary Service
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• v.42 no.2
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• pp.93-112
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• 2019

Calf diarrhea is a common disease in young claves and is still a major cause of productivity and economic loss in livestock farms. Fecal samples from Korean native cattle (n=100) with diarrhea from 64 farms in Gwangju area, Korea from september 2017 to December 2018 were examined for shedding of important protozoan parasitic, viral and bacterial pathogens using culture, rapid test kit and PCR methods. Of 57 (89.1%) of the 64 Korean native cattle farms examined had samples infected with at least one of the investigated pathogens. Among 100 fecal samples, 88 samples were positive for at least one the twelve pathogens and 51 samples were simultaneously positive for two or more pathogens by culture and PCR assay. Bovine group A rotavirus (BRV) was the most common pathogen, found in 43/100 (43.0%) samples on 32/64 (50.0%) farms. Subsequently, kobuvirus (30.0%), pathogenic E. coli (29.0%), bovine parvovirus (17.0%), Giardia spp. (13.0%), Eimeria spp. (10.0%), Clostridium perfringens type A (8.0%), bovine torovirus (8.0%), bovine viral diarrhea virus (6.0%), bovine coronavirus (5.0%), bovine norovirus (2.0%) and Cryptosporidium spp. (2.0%) were detected. Nebovirus, kırklareli virus, bovine adenovirus, Salmonella spp. and intestinal parasites were not detected. Of the 72 calves sampled in this age group, 64 (88.9%) samples were positive for at least one enteropathogen. BRV was identified in 34/72 (47.2%) samples from 27/48 (56.3%) farms. Subsequently, pathogenic E. coli (30.6%), kobuvirus (29.2%), BPaV (22.2%), Giardia spp. (15.3%), Eimeria spp. (9.7%), BVDV (6.9%), Cl. perfringens type A (6.9%), BCoV (4.6%) and Cryptosporidium spp. (2.8%) were detected in fecal samples. A total of ninety-six strains of E. coli were isolated from one hundred fecal samples collected from Korean native cattle with diarrhea. The presence of stx1, stx2, eaeA, LT, STa, STb, ehxA, saa, F4, F5(K99), F6, F17, F18 and F41 genes in the isolates was investigated by PCR. Out of ninety-six E. coli isolates screened for specific genes, 30 strains E. coli were identified to harbor shiga toxin-producing E. coli (STEC) 7 (7.3%), enterohemorrhagic E. coli (EHEC) 8 (8.3%), enteropathogenic E. coli (EPEC) 6 (6.3%), enterotoxigenic E. coli (ETEC) 2 (2.1%) and STEC/ETEC hybrid 7 (7.3%). This study provides epidemiological estimates of the prevalence of Korean native cattle's enteropathogens in Gwangju area, Korea, which would be used for cattle farmers and veterinarians to select appropriate therapeutic method.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.481-487
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• 2023

In this study, we analyzed the incidence of side effects of photoneutron dose according to the number of beams during intensity-modulated radiotherapy of prostate cancer using 15 MV. The radiation treatment plan design for intensity-modulated radiation therapy for prostate cancer was established with a prescription dose of 220 cGy per dose and a total of 7260 cGy for 33 treatments. The linear accelerator used in the experiment is Varian's True Beam STx (Varian, USA). Photoneutron dose was generated by using 15 MV energy in the planning target volume (PTV). The treatment plan was designed with IMRT 5, 7, and 9 portals using the Eclipse System (Varian Ver 10.0, USA). An optically stimulated luminescence albedo neutron dosimeter (Landauer Inc., USA) was used to measure photoneutron dose. IMRT 5 portals, 1.7 per 1,000, 7 portals, 1.8 per 1,000, 9 portals, 2.0 per 1,000 were calculated as the probability of experiencing side effects on the thyroid gland due to photoneutron dose. This study studies the risk of secondary radiation exposure dose that can occur during intensity-modulated radiation therapy, and it is considered that it will be used as useful data in relation to stochastic effects in the future.