• The Plant Pathology Journal
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• v.38 no.5
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• pp.541-549
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• 2022

Potato late blight caused by Phytophthora infestans is a destructive disease in Korea. To elucidate the genomic variation of the mitochondrial (mt) genome, we assembled its complete mt genome and compared its sequence among different haplotypes. The mt genome sequences of four Korean P. infestans isolates were revealed by Illumina HiSeq. The size of the circular mt genome of the four major genotypes, KR_1_A1, KR_2_A2, SIB-1, and US-11, was 39,872, 39,836, 39,872, and 39,840 bp, respectively. All genotypes contained the same 61 genes in the same order, comprising two RNA-encoding genes, 16 ribosomal genes, 25 transfer RNA, 17 genes encoding electron transport and ATP synthesis, 11 open reading frames of unknown function, and one protein import-related gene, tatC. The coding region comprised 91% of the genome, and GC content was 22.3%. The haplotypes were further analyzed based on sequence polymorphism at two hypervariable regions (HVRi), carrying a 2 kb insertion/deletion sequence, and HVRii, carrying 36 bp variable number tandem repeats (VNTRs). All four genotypes carried the 2 kb insertion/deletion sequence in HVRi, whereas HVRii had two VNTRs in KR_1_A1 and SIB-1 but three VNTRs in US-11 and KR_2_A2. Minimal spanning network and phylogenetic analysis based on 5,814 bp of mtDNA sequences from five loci, KR_1_A1 and SIB-1 were classified as IIa-6 haplotype, and isolates KR_1_A2 and US-11 as haplotypes IIa-5 and IIb-2, respectively. mtDNA sequences of KR_1_A1 and SIB-1 shared 100% sequence identity, and both were 99.9% similar to those of KR_2_A2 and US-11.

• Journal of Practical Agriculture & Fisheries Research
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• v.17 no.1
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• pp.57-71
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• 2015

This study was conducted to develop the fertigation system with a peristaltic hose pump and brushless DC motor. The fertigation system was consisted of sensor, main controller, motor control unit, peristaltic pump, water supply pump, control panel, and filter. The peristaltic pump discharges liquid by squeezing the tube with rollers. Rollers attached to the external circumference of the rotor compresses the flexible tube. The fluid is contained within a flexible tube fitted inside a circular pump casing. The developed fertigation system has no mixing tank but instead injects directly a concentrated nutrient solution into a water supply pipe. The revolution speed of the peristaltic pump is controlled by PWM (Pulse width modulation) method. When the revolution speed of the peristaltic pump was 300rpm, the flow rate of the 3.2, 4.8, 6.3mm diameter tube was 202, 530, 857mL/min, respectively. As increasing revolution speed, the flow rate of the peristaltic pump linearly increased. As the inner diameter of a tube larger, a slope of graph is more steep. Flow rate of three roller was more than that of four roller. Flow rate of a norprene tube with good restoring force was more than that of a pharmed tube. As EC sensor probe was installed in direct piping in comparison with bypass piping showed good performance. After starting the system, it took 16~17 seconds to stabilize EC. The maximum value of EC was 1.44~1.7dS/m at a setting value of 1.4dS/m. The developed fertigation system showed ±0.06dS/m deviation from the setting value of EC. In field test, Cucumber plants generally showed good growth. From these findings, this fertigation system can be appropriately suitable for fertigation culture for crops.

• Current Research on Agriculture and Life Sciences
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• v.5
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• pp.52-58
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• 1987

The yeast S. cerevisiae DBY747 was transformed with E. C - S. C shuttle vector YIp5, YEp13 and YRp7 by the method of spheroplast. The transformation frequency of YEp13 and YRp7 in S. cerevisiae DBY747 was $1.2{\times}10^3$ and $1.0{\times}10^2$ per $10{\mu}g$ of DNA, respectively. The transformants with YIp5 plasmid incapable of autonomous replication in S. cerevisiae were not detected in the condition of this experiment, but YIpS plasmid expressed the gene carried on it when cotransformed with a helper plasmid such as YEp13 or YRp7 : autonomously replicating plasmid. When plasmids were used in covalently closed circular form, cotransformation frequency of Ylp5-YEpl3 and Ylp5-YRp7 was 210 and 95 per $10{\mu}g$ of DNA, respectively. In cotransformation of linear plasmids, transformation frequency of the same cohesive ends was similar to that of noncomplementary cohesive ends. Transformants by the cotransformation with circular plasmids have been shown much higher frequency than with linear plasmids in S. cerevisiae DBY 747. The mitotic segregation stability test suggested that the cotransformant of YIpS-YEp13 was more stable than that of YIpS-YRp7.

• The Korean Journal of Franchise Management
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• v.5 no.1
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• pp.85-108
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• 2014

This study provides the information about size, financial structure, profitability and growth of franchisors using financial data(asset, liability, equity, sales volume, operating income and net income) in uniform franchise offering circular of fair trade commission. The data were collected from 1,050 franchisors in various business fields: fast food, family restaurant, bakery, agriculture & fishery and liquor shop in the uniform franchise offering circular in 2012 and 2011. Results of this study are as follows: For company size, median of total assets was KRW 675 million and the accumulated median assets rate was 0.48%, but the accumulated median company numbers were 49.9%, which showed small size. For financial structure, 525 companies were below 200% debt ratio, while 314 (29.9%) companies were in over 200% debt, and 211 (20.1%) companies were impaired in capital. These also showed financial structure was vulunerable. For profitability, median of ROA for total companies were only 4.72%, which showed low profitability. For growth, median of growth rate for sales were 7.57% per year, which showed mature industry. In overall, the results showed franchisors should improve their financial status.

• Korean journal of applied entomology
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• v.16 no.1 s.30
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• pp.21-31
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• 1977

The study has been carried out to compare the pathogenicity, physiological characteristics and genetic reliability between rough colony type strain and smooth colony type strains of Pseudomonas mori (Boyer et Lambert) Stevens which were isolated from diseased plant parts in 5 different areas throughout country. The results are summarized as follow. 1. The rough colony type strain showed more agressive reactions to tested host plant varieties than smooth colony type strains though there was no differences in the appearence of lesion types caused by both strains. 2. Both colony types were differentiated morphologically in that the rough colony type strain was having more than 200r long filamentous body without flagella where as the smooth colony type strains have short rods with one or several polar flagella. 3. The colony of smooth type strains was circular, entire, smooth and opaque, while the rough type strain shelved endulated, irregular margin, rough and wrinkled colony on nutrient agar media. 4. There were no differences between both colony types in the physiological and serological test. 5. Both of smooth and rough colony type strains showed genetic reliability through more than 100 succeeding cultures on the media, and were stable to various chemicals such as 1 to 3 percent of NaCl, 5 kinds of organic acid and 4 kinds of antibiotics.

• Food Science of Animal Resources
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• v.37 no.1
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• pp.123-133
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• 2017

The development of a new manufacturing process, a two-step temperature treatment, to modulate the physicochemical properties of nanoparticles including the size is critical. This is because its physicochemical properties can be key factors affecting the cellular uptake and the bioavailability of bioactive compounds encapsulated in nanoparticles. The aims of this study were to produce (beta-lactoglobulin) ${\beta}-lg$ nanoparticles and to understand how two-step temperature treatment could affect the formation and physicochemical properties of ${\beta}-lg$ nanoparticles. The morphological and physicochemical properties of ${\beta}-lg$ nanoparticles were determined using atomic force microscopy and a particle size analyzer, respectively. Circular dichroism spectroscopy was used to investigate the secondary structure of ${\beta}-lg$. The surface hydrophobicity and free thiol groups of ${\beta}-lg$ were increased with a decrease in sub-ambient temperature and an increase in mild heat temperature. As sub-ambient temperature was decreased, a decrease in ${\alpha}-helical$ content and an increase in ${\beta}-sheet$ content were observed. The two-step temperature treatment firstly involved a sub-ambient temperature treatment from 5 to $20^{\circ}C$ for 30 min, followed secondly by a mild heat temperature treatment from 55 to $75^{\circ}C$ for 10 min. This resulted in the production of spherically-shaped particles with a size ranging from 61 to 214 nm. Two-way ANOVA exhibited the finding that both sub-ambient and mild heat temperature significantly (p<0.0001) affected the size of nanoparticles. Zeta-potential values of ${\beta}-lg$ nanoparticles were reduced with increasing mild heat temperature. In conclusion, two-step temperature treatment was shown to play an important role in the manufacturing process - both due to its inducement of the conformational changes of ${\beta}-lg$ during nanoparticle formation, and due to its modulation of the physicochemical properties of ${\beta}-lg$ nanoparticles.

• Korean journal of applied entomology
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• v.24 no.3 s.64
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• pp.141-149
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• 1985

Embryonic developmental rates of the Oriental tobacco budworm, Heliothis assulta Guenee, were compared at various constant temperatures and 16 hours of light, and detailed embryogenesis was also studied at $25^{\circ}C$. The egg was nearly globular in form and had an average equatorial diameter of 0.53mm. A single micropyle was in the center of the circular area at the anterior pole of the egg. Durations of embryogenesis at 20, 25, 30, and $35^{\circ}C$ were 147, 81, 61, and 67hrs, respectively. Embryonic death was especially higher at $35^{\circ}C$ than any other temperatures investigated. Embryogenesis progressed with changes in color and pattern, which are quite characteristic at each developmental stage of the embryo. At $25^{\circ}C$, organogenesis began in 14hrs after oviposition, formation of gut completed in 44hrs and eclosion occurred in 80hrs. The embryo formed along the long axis at early developmental stage, moved towards the equatorial plane in 24hrs, and made a half-turn on the plane in 36hrs. In 40hrs, head was oriented to the anterior pole of the egg until eclosion.

• Journal of Biosystems Engineering
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• v.32 no.5
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• pp.339-347
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• 2007

A hexapod walking robot had been developed for gathering information in the field. The developed robot was $260{\times}260{\times}130$ ($W{\times}L{\times}H$, mm) in size and 14.7 N in weight. The legs had nineteen degrees of freedom. A leg has three rotational joints actuated by small servomotors. Two servomotors placed at ankle and knee played the roles of vertical joint for up and down motions of the leg and the other one placed at coxa played the role of horizontal joint for forward and backward motions. In addition, a servomotor placed at thorax between the front legs and the middle legs played the role of vertical joint for pumping the two front legs to climb stair or inclination. Walking motion of the robot was executed by tripod gait. The robot was controlled by manual remote-controller communicated by an infrared ray. Two controllers were equipped to control the walking of the robot. The sub-controller using PIC microcomputer (Microchips, PIC16F84A) received the 16 bit command signal from the manual remote controller, decoded it to 8bit and transmitted it to the main microcomputer (RENESAS, SH2/7045), which controlled the 19 servomotors using the PWM command signals. Walking speeds were controlled by adjusting the period of command cycle and the stride. Forward walking speed were within 100 cm/min to 300 cm/min. However, experimental walking speed had the error of 4-40 cm/min to compare with the theoretical one, because of slippage of the leg and the circular arc motion of servomotor of coxa.

• Korean Journal Plant Pathology
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• v.13 no.4
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• pp.195-199
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• 1997

Anthracnose symptoms were observed on the commercially cultivating ultivating cyclamen in Chonbuk province in 1995. The symptoms of infected flowers were small, circular and dark brown ring-spots or water-soaked lesions and gradually changed to lack blight. Mycelial colony of the isolates was light or whitish gray to dark gray on potato dextrose agar. Conidia were straight cylindrical and obtuse at the apex and measured 8.3~15.0${\times}$2.5~6.3 ${\mu}m$ in size. Appressoria were brown to dark brown and clavate, but most of them were irregular. Acervuli on lesions were brown, rounded and measured 50~140${\times}$32.5~90 ${\mu}m$ in size. The optimum temperatures for mycelial growth and conidial sporulation were ranged from 25 to 30$^{\circ}C$. Thus, based on mycological characteristics of the fungus, the causal agent of cyclamen anthracnose was identified as Colletotrichum gloeosporioides Penz.

• Korean Journal of Veterinary Research
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• v.14 no.1
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• pp.77-90
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• 1974

Hemolytic reaction of normal fresh chicken serum on sheep erythrocytes was studied and the following experimental results were obtained and summarized. 1. Chicken sera, 258 (78%) out of 344 samples showed hemolytic activity on sheep erythrocytes. 2. Distribution of a different hemolytic titer of chicken sera was not dependent to sex and age difference of test chicken. 3. Hemolytic activity of serum component obtained from normal fresh chicken was heat inactivated at $56^{\circ}C$. 30 minutes heating. 4. The most enhanced hemolytic activity of chicken serum on sheep erythrocytes was observed at the incubation temperature of $46^{\circ}C$. 5. The most effective pH for the hemolytic reaction of chicken serum on sheep erythrocytes was observed at 7.0, and pH 6.0 or 8.5 resulted less or no hemolysis. 6. Hemolytic reaction of chicken serum and sheep erythrocytes required Mg⧻ and Ca⧻ ions as, co-factor, and the former was required more compared to the latter. 7. Hemolytic activity of chicken serum was observed in ChC 2, 4 fraction but not in ChC 1, 3, ChC 3, 4, ChC 1, 2, 4 and ChC 1, 2, 3 fractions. 8. In electron micrography, morphological changes of sheep erythrocyte membrane by normal chicken serum was similar to that of immune hemolysis: that was, the hemolytic hole was circular and it was surrounded with a white ring. 9. Electron micrography of morphological changes on sheep erythrocyte membrane indicated that the size of hemolytic hole and white ring were functional to the chicken serum concentration used and reaction time.