• Research in Plant Disease
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• v.10 no.4
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• pp.217-226
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• 2004

One hundred isolates of Magnaporthe grisea from Korea and China were characterized for pathogenicity using eight Korean differential varieties(KDV), six Chinese differential varieties(CDV) and six near isogenic lines(NILs) developed in China. The restriction length polymorphism of M. grisea isolates from each country also was analyzed using MGR586 as a probe. One hundred Korean isolates classified into 17 races on KDV were grouped into 29 pathotypes on Chinese near isogenic lines(NILs). Virulence of 46% of Korean isolates against all the six Chinese NILs indicated that the current six Chinese NILs alone was not enough to be used as differential varieties in Korea. Especially, susceptibility of the BL1 carrying resistance gene Pi-b to 70% of tested Korean isolates suggested that BL1(Pi-b) may not be a useful resistance source to Korean blast. Based on the virulence assays of M. grisea populations from each country were divided into two groups. About 50% of Chinese isolates showed similarity to the 30% of the Korean isolates. Especially, the isolates from northern part of China, where Japonica rice cultivars were grown, showed high similarity to the Korean isolates, while isolates from southern part of China, where Indica rice were mainly grown, showed low similarity to Korean isolates. The genome RFLPs of Korean isolates were quite different from those of southern part of China using MGR586 as a probe. These data indicated that the physiological and genetical characteristics of M. grisea population might be determined by strong interaction with cultivated rice.

• Progress in Medical Physics
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• v.15 no.2
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• pp.100-104
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• 2004

The detector size effect due to the spatial response of detectors is a critical source of inaccuracy in clinical dosimetry that has been the subject of numerous studies. Conventionally, the detector response kernel contains all the information about the influence that the detector size has on the measured beam profile. Various analytical models for this kernel have been proposed and studied in theoretical and experimental works. Herein, a method to simply determine the detector response kernel using the Monte Carlo simulation and convolution theory has been proposed. Based on this numerical method, the detector response kernel for a Farmer type ion chamber embedded in a water phantom has been obtained. The obtained kernel shows characteristics of both the pre-existing parabolic model proposed by Sibata et al. and the Gaussian model used by Garcia-Vicente et al. From this kernel and deconvolution technique, the detector size effect can be removed from measurements for 6MV, 10${\times}$10 $\textrm{cm}^2$ and 0.5${\times}$10 $\textrm{cm}^2$photon beams. The deconvolved beam profiles are in good agreements with the measurements performed by the film and pin-point ion chamber, with the exception of in the tail legion.

• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.960-968
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• 2003

A bacterial isolate showing a strong endochitosanase activity was isolated from soil and then characterized. The isolate was identified and designated as Bacillus cereus P16, based on morphological and biochemical properties, assimilation tests, cellular fatty acids pattern, along with 16S rRNA gene sequence. The optimized medium for producing extracellular chitosanase in a batch culture contained 1% tryptone, 0.5% chitosan, and 1% NaCl (pH 7.0). Powder chitosan and tryptone served the best as carbon and nitrogen sources, respectively, for the chitosanase production. Chitosanase activity was the highest when culture was completed at $37^{\circ}C$ among various temperatures ($20-42^{\circ}C$) tested in a shaking incubator (200 rpm). The levels of chitosanase activity in the culture fluid were 2.0 U/ml and 3.8 U/ml, respectively, when incubated in a flask for 60 h and in a jar fermenter for 24 h. The culture supernatant showed a strong liquefying activity on the soluble chitosan. The viscosity of 1% chitosan solution, that was incubated with the culture supernatant, was rapidly decreased, suggesting the secretion of endochitosanolytic enzymes by P16. The culture fluid revealed six endo-type chitosanase isozymes, two major (38 and 45 kD), and four minor (54, 65, 82, and 96 kD) forms by staining profile. The crude enzymes were very stable, and full activity was maintained for 4 weeks at $4^{\circ}C\;or\;-20^{\circ}C$ in the culture supernatant, suggesting a highly desirable stability rate for making an industrial application of the crude enzymes. The supernatant also cleaved the insoluble chitosan powder, but the hydrolysis rate was much lower. The enzymic degradation products of chitosan contained $(GlcN)_n$ (n=2-8). The concentration of chitosan in the reaction mixture of the crude enzyme affected the chitooligosaccharides composition of the hydrolysis products. When the higher concentration of chitosan was used, the higher degree of polymerized chitooligosaccharides were produced. By comparison with other commercial chitosanase preparations, P16 was indeed found to be a valuable enzyme source for industrial production of chitooligosaccharides from chitosan.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.3
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• pp.205-216
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• 2017

Carbonaceous aerosols such as the equivalent black carbon (eBC), the elemental carbon (EC) and the organic carbon (OC) were monitored at the Seoul Olympic Park site ($37.521^{\circ}N$, $127.124^{\circ}E$) during the KORUS-AQ 2016 campaign using a Multi Angle Absorption Photometer (MAAP) and an OCEC Analyzer. Averaged mass concentrations of eBC, EC and OC were presented as $2.46{\pm}1.52{\mu}g/m^3$, $1.01{\pm}0.60{\mu}g/m^3$ and $4.85{\pm}2.60{\mu}g/m^3$, respectively. OC/EC ratio and mass absorption cross-section (MAC) of light absorbing aerosols were calculated as 2.32 and $14.8m^2/g$, respectively. Diesel OC concentrations were estimated from a source profile of diesel vehicles as well. eBC mass concentrations measured from May $26^{th}$ to May $27^{th}$, 2016 showed 40% higher than averaged eBC mass concentrations during campaign period. $PM_{2.5}$ concentrations measured in this period were also higher than average $PM_{2.5}$ concentrations. High eBC concentrations were observed from May $29^{th}$ to May $31^{st}$, 2016 and from June $9^{th}$ to June $11^{th}$, 2016, possibly due to morning rush hour and the effect of temperature inversion at night. Diurnal variations of eBC, EC and Diesel OC showed a typical pattern of metropolitan area. In the weekend, however, diurnal variations of eBC, EC and Diesel OC mass concentrations were different from those measured in the weekday. It is expected that this study can help to understand the relationship between carbonaceous aerosols in a metropolitan area.

• Journal of Food Hygiene and Safety
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• v.18 no.2
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• pp.61-66
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• 2003

This study was conducted to produce the egg yolk Imunoglobulin (IgY) on Vibrio parahaemolyticus from immunized hen with lipopolysaccharide (LPS). Vibrio parahaemolyticus is considered as a potentially pathogenic bacteria, the causative agents of the gastroenteritis. According as the LPS antigens were injected into laying hens in order to produce antibodies against Vibrio parahaemolyticus in egg yolk. After chickens were immunized four times in 2 weeks interval and three times booster in 2 weeks interval, the profile of antibody Production was examined by ELISA. The Production of antibody in egg yolk was started in 1 week after the first immunization, reached peak in 7 weeks and maintained until 13 weeks later. The antibody titre in serum showed similar tendency as IgY. No significant difference in antibody titre when the titre compared to water diluted IgY and commercial IgY kit. Purified IgY reacted with only Vibrio parahaemolyticus, but other Vibrio species and food-borne pathogenic bacteria. In conclusion, we showed that it is possible to obtain a high antibody titre in chicken with quite low amounts of LPS antigen. These results suggested that egg yolk antibodies could be a good source for production of specific antibodies to pathogenic bacteria inducing epidemic gastroenteritis.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.283-288
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• 2007

The effects of Ge-Geol radish powder on the physical and sensory properties of wet noodles were investigated by adding 4-16% Ge-Geol radish powder based on the flour source. The Ge-Geol radish powder additions significantly increased the redness of the uncooked and cooked noodles. For the texture profile analysis (TPA) of the wet noodles with added Ge-Geol radish powder, hardness, adhesiveness and resilience decreased, whereas chewiness increased. Changes in the volume and weight of the cooked noodles were not significantly different according to Ge-Geol radish powder concentration, but the turbidities of the soup increased. In sensory test, overall acceptability was significantly higher for the noodles with added Ge-Geol radish powder of concentrations between 4-8%. These samples had similar sensory texture properties as the control and had peculiar hot and cool tastes of the radish. Therefore, adding Ge-Geol radish powder at concentrations below 8% was good for making noodles that maintained a natural texture, and also gave an characteristic radish-like flavor to the noodles.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.11
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• pp.1547-1554
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• 2009

This study was carried out to evaluate the effects of dietary supplementation of different sources of chromium on growth performance, blood profile and carcass trait in growing-finishing pigs. A total of 200 growing pigs (Landrace${\times}$Yorkshire)${\times}$Duroc, average initial weight 8.5 kg) were allotted to 5 treatments with 4 replicates per treatment and 10 pigs per replicate. Five treatments were designated as follows according to the source of chromium. i) Control (No chromium): corn-soybean meal based basal diet, ii) $CrCl_{3}$: control diet+200 ppb Cr as $CrCl_{3}$, iii) CrPic: control diet+200 ppb Cr as Cr picolinate, iv) CrMet-1: control diet+100 ppb Cr as Cr methionine, and v) CrMet-2: control diet+200 ppb Cr as Cr methionine. After the feeding trial, three pigs per replicate (12 pigs per treatment) were slaughtered for the evaluation of carcass traits. Average daily gain (ADG), average daily feed intake (ADFI), and feed: gain ratio (F/G) were not different (p>0.05) among dietary Cr sources. However, whole-period ADG of pigs fed CrPic, CrMet-1 and CrMet-2 diets was higher (p<0.05) than for the control diet. Nutrient digestibility was not different (p>0.05) among dietary Cr sources, but the nutrient digestibility of pigs fed CrPic, CrMet-1 and CrMet-2 diets was higher (p<0.05) than for the control diet. BUN level decreased with more magnitude (p<0.05) in pigs fed Cr during the 20 to 50 kg period. Although both serum cholesterol and triglyceride were different (p<0.05) among treatments, there was no consistent response that could be related to the dietary Cr sources regardless of growth phase. However, the overall data suggested that serum cholesterol level increased as BW of pigs increased. Blood total protein (TP) increased (p<0.05) in pigs fed Cr only during the 90-110 kg phase, and blood creatinine (Creat) level was higher in $CrCl_{3}$ and CrPic treatments than in the control only during the 90-110 kg phase. Backfat thickness was thinner (p<0.05) in pigs fed CrMet-2 than in the control treatment. Therefore, lean percentage was higher (p<0.05) in CrMet-2 than in control pigs. However, dressing percentage and Longissimus muscle area (LMA) were not different (p>0.05) among treatments. In conclusion, dietary supplementation of 200 ppb Cr, via either CrPic or CrMet, improved pig growth performance and nutrient digestibility. Moreover, dietary CrMet supplementation for the growing-finishing pig is evidently remarkable for improving both lean percentage of the carcass and backfat thickness.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.1
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• pp.6-10
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• 2003

The present study investigated peripheral plasma immunoreactive inhibin (ir-inhibin) concentrations in relation to the stage of oestrous cycle and progesterone concentrations in cycling Sahiwal cattle (Bos indicus) and Murrah buffaloes (Bubalus bubalis). Blood samples were collected once daily for thirty-two consecutive days from cattle and buffaloes (5 each) during winter months of January and February. Mean (${\pm}$S.E.M.) plasma ir-inhibin concentrations ranged from $0.40{\pm}0.01$ to $0.59{\pm}0.03ng/ml$ in cattle and from $0.29{\pm}0.03$ to $0.52{\pm}0.05ng/ml$ in buffaloes. In cattle, ir-inhibin concentrations increased from $0.47{\pm}0.07ng/ml$ on day -4 (day 0=day of oestrus) to reach a maximum value of $0.59{\pm}0.03ng/ml$ on day -2. Thereafter, ir-inhibin concentrations showed a decline to reach a low of $0.40{\pm}0.01ng/ml$ on day 11 of the oestrous cycle. In buffaloes, ir-inhibin concentrations increased from $0.38{\pm}0.04 ng/ml$ on day -4 to reach a maximum concentration of $0.52{\pm}0.05ng/ml$ on day -2. Ir-inhibin concentrations then declined to reach a low of $0.29{\pm}0.03ng/ml on day 9 of the cycle. In both cattle and buffaloes, ir-inhibin concentrations which were lowest ($0.43{\pm}0.02$ and $0.34{\pm}0.02ng/ml$, respectively) during the mid-luteal phase of the oestrous cycle increased (p<0.05) to $0.52{\pm}0.03$ and $0.44{\pm}0.04ng/ml$, respectively, during the late luteal phase, and then further to the highest value of $0.53{\pm}0.02$ and $0.49{\pm}0.04ng/ml$, respectively, during the perioestrus phase, following which these declined to $0.50{\pm}0.02$ and $0.39{\pm}0.03ng/ml$, respectively, during the early luteal phase. The variations in peripheral plasma ir-inhibin profile in both the species appear to be related to the changes in characteristics of follicular populations during the oestrous cycle. Peripheral plasma ir-inhibin concentrations were negatively correlated with progesterone concentrations in cattle (r=-0.51, p<0.01) and buffaloes (r=-0.30, p<0.01) indicating that the corpus luteum is not a source of peripheral ir-inhibin in these species.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.15-20
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• 2005

Defects of dam body which can be induced in seepage or leakage procedure can directly affect dam safety. Therefore, a proper inspection method should be carried out in the first place to find out their positions and sizes, After that, some reinforcement works such as grouting and the corresponding assessment could be taken in a proper way. The dam(center core type earth dam) issued in this study has been in need for intensive diagnosis and reinforcement work, because a lot of slumps similar to cracks, seepage and some boggy area have been observed on the downstream slope. High resolution seismic reflection method was performed on the crest profile twice before and after grouting work(Aug. 2001 and Nov. 2004) aimed at the dam inspection and the assessment of grouting efficiency as well. To enhance the data resolution, P-beam energy radiation technique which can reduce the surface waves and hence to reinforce the reflection events was used. Strong reflection events were recognized in the stack section before grouting work, It seems that the events would be caused by e.g. horizontal cracks with a considerable aperture, Meanwhile such strong reflection events were not observed in the section after grouting. That is, the grouting work was dear able to reinforce the defects of dam body. Hence, the section showed an well arranged picture of dam inner structure. In this sense, seismic reflection method will be a desirable technique for dam inspection and for monitoring dam inner structure as well.

• Korean Journal of Microbiology
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• v.51 no.4
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• pp.440-443
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• 2015

The widespread emergence of antibiotic resistant microorganisms in clinics and natural environments has attracted public concern. Especially, microorganisms inhabiting natural environment is considered as a source responsible for increasing the abundance of antibiotic resistant genes in ecosystem. In this study, the diversity of culturable bacteria resistant to ampicillin was investigated with water samples collected from seven locations in Korea. The genera belonging to Aeromonas and Acidovorax were dominant among the isolated 498 strains. The 66% of isolates showed multi-drug resistance against more than six antibiotics among tested fourteen ones and isolates resistant to seven antibiotics were the most prevalent with 19.7% abundance. Using the antibiotics susceptibility results, the intrinsic resistance profile was suggested for the most dominant genera, Aeromonas, Acidovorax, Pseudomonas, and Elizabethkingia.