• Journal of Animal Science and Technology
• /
• v.63 no.1
• /
• pp.125-136
• /
• 2021

Bovine coronavirus (BCoV) is associated with severe diarrhea, dehydration, and depression, which result in significant economic damages in the dairy and beef cattle industries worldwide. However, differences in the gut microbiota structure and their correlations with differing physiological parameters between BCoV-infected calves with diarrhea and recovered calves are not well understood. In this study, fecal specimens were collected from 10 post-weaned calves, before and after 2 months of fluid therapy, and the samples were used for microbiota analysis. Following recovery, the alpha-diversity profiles (observed operational taxonomic units [OTUs], and Chao1, Shannon, and Simpson indices) changed significantly when compared with those of calves with diarrhea. Beta-diversity analysis exhibited significant differences in gut microbiota compositions between calves with diarrhea and those in the recovered state. The abundances of eight phyla and thirteen genera in feces changed markedly after restoration of BCoV diarrhea. In addition, our correlation study clearly revealed that increased abundances of the genera Caproiciproducens, Pseudoflavonifractor, and Oscillibacter negatively correlated with serum glucose, and phosphorus levels, but positively correlated with serum chloride in calves with diarrhea, whereas increased abundances of the genera Peptostreptococcaceae;Clostridium (Clostridium cluster XI), Intestinibacter, Cellulosilyticum, Ruminococcus, Romboutsia, Paeniclostridium, Clostridiaceae;Clostridium and Turicibacter in recovered calves showed the opposite pattern. These results suggest that structural changes of the gut microbiota after recovery from BCoV infection correlate with changes in physiological parameters. In conclusion, our data provide evidence of gut microbiota-composition changes and their correlations with the physical profiles of post-weaned calves, before and after fluid therapy for BCoV-related diarrhea.

• Progress in Superconductivity
• /
• v.13 no.3
• /
• pp.169-177
• /
• 2012

Distribution of the local properties in GdBCO and YBCO coated conductors was investigated using Low-temperature Scanning Laser and Hall Probe Microscopy (LTSLHPM). We prepared GdBCO and YBCO coated conductors to study the spatial distribution of the current density in a single bridge. Inhomogeneity of the ${T_c}^{max}$ in the bridge was analyzed from experimental results of Scanning Laser Microscopy (SLM) near the superconducting transition. The local transport and screening current in the bridge were also investigated using Scanning Hall Probe Microscopy (SHPM). A series of line scans of SLM of the GdBCO and YBCO sample showed that lines with more inhomogeneous distributions of ${\delta}V$ had more inhomogeneous distributions of ${T_c}^{max}$. The defect of the superconducting layer of the GdBCO sample caused by damage to the substrate affected the current flow. And we could analyze the redistribution of the current density using SLM and SHPM.

• Korean Journal of Veterinary Research
• /
• v.63 no.4
• /
• pp.37.1-37.7
• /
• 2023

Canine respiratory coronavirus (CRCoV) is a significant pathogen that causes respiratory diseases in dogs, collectively known as a canine infectious respiratory disease. The virus is highly contagious and exhibits high seroprevalence worldwide. Currently, bovine coronavirus (BCoV) enzyme-linked immunosorbent assay (ELISA) kits are used to detect CRCoV antibodies. However, BCoV-ELISA kits cannot differentiate between infections caused by BCoV and those caused by CRCoV. In this study, we evaluated the hemagglutination inhibition (HI) test for CRCoV by comparing it with the virus neutralization (VN) test. Subsequently, we evaluated the seroprevalence of CRCoV in 383 dog serum samples collected from South Korea utilizing the HI test. The HI test for CRCoV showed a strong correlation with the VN test (R = 0.83, p < 0.001). The analysis of seroprevalence revealed that 52.2% (95% confidence interval [CI], 47.2%-57.1%) of the Korean dog serum samples were positive. The seroprevalence exhibited varied with age, with a positivity rate of 43.9% in dogs under 1 year of age and 66.7% in dogs aged 3 to 5 years (odds ratio, 2.54; 95% CI, 1.43-4.59). In conclusion, the HI test to monitor CRCoV antibody proved to be closely related to the VN test. Furthermore, over half of the dogs in Korea tested positive for CRCoV antibodies. These findings contribute to a better understanding of the sero-epidemiology of CRCoV.

• Journal of Veterinary Clinics
• /
• v.29 no.5
• /
• pp.377-383
• /
• 2012

Bovine diarrhea is a major economical burden to the bovine industry in Korea. Since multiple infectious agents can be involved in bovine diarrhea, differential diagnosis is essential for effective treatment. Therefore, a panel of two multiplex real-time PCR assays which can simultaneously detect six major bovine enteric pathogens [i.e., bovine viral diarrhea virus (BVDV), bovine coronavirus (BCoV), group A bovine rotavirus (BRV), Salmonella spp., Escherichia coli (E. coli) $K99^+$, and Cryptosporidium parvum] was developed and applied to test 97 fecal samples collected from cattle farms in Korea. In addition, microscopic examination was also preformed on the samples to detect Coccidium oocyst. The estimated sensitivity of the multiplex PCR was 0.1 $TCID_{50}$ for BVDV, BCoV and group A BRV, 5 and 0.5 CFU for E. coli $K99^+$ and Salmonella, respectively, and 50 oocysts for Cryptosporidium. The amplification efficiency of the multiplex PCR ranged between 0.97 and 0.99 for each pathogen. Among 97 samples, 36 samples were positive for at least one of the 6 major pathogens and 6 samples were simultaneously positive for 2 pathogens by the multiplex PCR assay. Coccidium oocysts were also detected in 48 samples, which were all collected from over 1 month old calves. In conclusion, the multiplex real-time PCR panel can be a useful tool for fast and accurate diagnosis of calf diarrhea associated with BVDV, BCoV, group A BRV, E. coli $K99^+$, Salmonella, and/or Cryptosporidium and Coccidium may be an important target which needs to be included in the multiplex PCR panel in the future.

• Progress in Superconductivity and Cryogenics
• /
• v.9 no.4
• /
• pp.19-23
• /
• 2007

The superconducting properties of several HTS coated conductors (CC), which had different tape structures, fabricated by KERI, X and Y institutes were compared. We have fabricated the $high-J_c$ SmBCO CC, which has 273.5 A/cm, $1.2MA/cm^2$ and 93.5 K for $I_C,\;J_C\;and\;T_{c-zero}$, respectively, using the EDDC (Evaporation using Drum in Dual Chambers) process. Both X and Y institutes CCs, however, were purchased. The n-values of KERI, X and Y institutes CCs are 58.5, 40.7 and 31.5 in $V=1{\sim}10{\mu}V$ criterion, respectively. The in-field properties of $I_C$ at 77K were investigated and the $J_C(B)/J_C(0G)$ at 0.5 T with $B{\perp}$ ab-plane are 0.31, 0.19 and 0.24 for KERI, X and Y institutes CCs, respectively. From the $I_C-{\theta}-B$ measurement, we observed that the ab-plane of ReBCO phase was tilted for the ab-plane of substrate in the KERI and X institutes CCs. The tilted angle is about 5 degree. We confirmed that the peak shift (as an inclined texture) was observed by X-ray (102) pole figures of the SmBCO for the KERI CC.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.2
• /
• pp.145-150
• /
• 2001

A marine bacterium having a high oil-degrading activity was isolated from the coastal water of Yosu, Korea, identified as Pseudomonas sp. and named Pseudomonas sp. BCK-1. The optimal temperature, pH and NaCl concentration for cell growth was $30^{\circ}C$, 7.0 and $3\%$ (w/v), respectively. After cultivation at $30^{\circ}C$, 180 rpm in 250 mL erlenmeyer flask for 72 and 168 hours, $2\%$ (w/v) arabian light crude oil (ACO) and bunker C oil (BCO) which are considered to be hardly biodegradable compounds were degraded $92\%$ (w/w) and $72\%$ (w/w), respectively.

• Progress in Superconductivity
• /
• v.3 no.2
• /
• pp.241-246
• /
• 2002

We have performed the current and voltage loading tests of resistive superconducting fault current limiters (SFCLS) based on $YBa_2$$Cu_3$$O_{7}$(YBCO) films with the diameter of 2 inch. The SFCL consists of meander-type YBCO stripes covered with 200 nm Au layer grown in situ for current shunt and heat dispersion at hot spots. The minimum quench current of an SFCL unit was about 25 Apeak. Seven SFCL units were connected in parallel fur the current load ing tests at power source of 100 $V_{rms}$ $/2,000A_{rms}$. This SFCL units had maximum limiting current of 170 Apeak during the fault instant and then successfully controlled the fault current below 100 Apeak within 1~2 msec after short circuit. Increased short current also reduced the quench completion time with little change of current limiting characterization. We connected six SFCL units in series fur the voltage loading tests at power source of $1,200 V_{rms}$/170 $A_{rms}$ at this time. The shunt resistors were inserted into each SFCL unit to eliminate power imbalance originated from serial connection of SFCL units. Each SFCL unit was quenched simultaneously during the fault condition. The current increased up to 40 $A_{peak}$ and decreased to 14 $A_{peak}$ after 3 cycles. Quench was completed within 1 msec after the fault. We confirmed operating characteristics of 140 kVA($120 A_{rms}$ $\times$ 1,200 $V_{rms}$) SFCL and presented the manufacturing possibility of 3.3 kV SFCL using 4 inch YBCO films.BCO films.lms.

• Progress in Superconductivity and Cryogenics
• /
• v.21 no.4
• /
• pp.29-33
• /
• 2019

2G HTS wire with high engineering current density is desired for applications where compact, high power density superconducting equipment is important. We have succeeded in enhancing engineering current density of commercial SuperOx 2G HTS wire based on GdBCO by increasing the HTS layer thickness without fast degradation of the HTS film microstructure. This was possible after improving the temperature uniformity along the HTS film deposition zone. In particular, the wire engineering current density was increased from 700-770 A/㎟ (for a 65 ㎛-thick wire without stabilisation) or 430-480 A/㎟ (for a 105 ㎛-thick stabilised wire) at the beginning of this study to almost 1200 A/㎟ (for a 67 ㎛-thick wire without stabilisation) or 770 A/㎟ (for a 107 ㎛-thick stabilised wire) at completion of this study.

• Korean Journal of Veterinary Service
• /
• v.46 no.1
• /
• pp.47-58
• /
• 2023

Between February 2020 and September 2021, 378 calves with diarrhea were investigated across 96 cattle breeding farms in Korea, using a rapid diagnostic kit. The study examined the infection rates of major pathogens causing diarrhea in calves, which were categorized by season, age, birth month, and region. Additionally, logistic regression analysis was conducted to investigate the factors affecting the infection rate. The study found that the five representative pathogens causing calf diarrhea exhibited differences in infection rates based on season, region, age, and birth month. Bovine rotavirus, bovine coronavirus, Cryptosporidium, and Giardia commonly exhibited varying risks of infection based on season and age. Furthermore, in addition to these risk factors, bovine rotavirus and Cryptosporidium were found to impact the infection risk of each pathogen by region, while Giardia was found to be affected by birth month.

• Progress in Superconductivity and Cryogenics
• /
• v.17 no.1
• /
• pp.21-24
• /
• 2015

New results of dependence of magnetic field, trapped by a stack of HTS tapes, on amount of tapes in a stack are reported. Commercial GdBCO tape 12 mm width and without Cu layer was used for the research. Tape was divided in square pieces $12{\times}12mm^2$ from which stacks were formed. Filling factor of the tape was about 1.4%. Measurements were carried out for stacks with height from 5 to 250 pieces and at wide temperature range from liquid helium to liquid nitrogen. Both FC (field cooling) and ZFC (zero field cooling) cooling methods were used in the research. These two methods show matching results with good accuracy. As a result dependences of trapped magnetic flux on amount of tapes for different temperatures were received. Research shows, that with increasing height of the stack trapped magnetic field value reach saturation at about 60 tapes in a stack for low temperatures. From 60 to 100 tapes increase of magnet flux is only 5%. Thus increase amount of tapes in a stack is not profitable. Also investigation of trapped magnet field relaxation was carried out. Relaxation speed decreases with increasing amount of elements. It means that the higher the stack is, the longer trapped flux will be held in cause of the same temperature.