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First Report of Pink Rot of Potato (Solanum tuberosum) Caused by Phytophthora erythroseptica in Korea (Phytophthora erythroseptica에 의한 감자 홍색부패병 발생)

  • Ryu, Kyoung-Yul;Kim, Jeom-Soon;Kim, Jong-Tae;Hahm, Young-Il
    • Research in Plant Disease
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    • v.9 no.1
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    • pp.32-35
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    • 2003
  • Pink rot of potato (Solanum tuberosum L.) occurred at Pyeongchang in Gangwon and at Bosung in Junnam province since 1999. The disease incidence in the surveyed areas was about 5% of harvested potatoes in 2002. Affected tubers showed a dull brown appearance and the lenticels and eyes on tubers turned dark brown. The cut surface of the diseased tuber colored faint pink and the entire surface of the diseased tuber becomes deep salmon pink within 30 min. The pathogen isolated from the diseased tubers was identified as Phytophthora erythroseptica based on morphological and cultural characteristics. Mycelial mat was fairly fluffy, rosette or stellate patterns and rounded or angular hyphal swellings were farmed in water, Temperature for mycelial growth was ranged from 5 to 3$0^{\circ}C$ and optimal temperature was $25^{\circ}C$. Non-papillate sporangia were persistent on stalk and ellipsoid, ovoid, obpyriform or distorted in shape, often with a constriction distal in the middle. Size of sporangia was 41.3~69.6$\times$26.8~47.4 (av, 55.5$\times$37.1) ${\mu}{\textrm}{m}$. Sexuality of Phytophthora erythroseptica was homothallic. Oogonia were 30~46 ${\mu}{\textrm}{m}$ in diameter and oospores were 28~35 ${\mu}{\textrm}{m}$ in diameter, Elongated or cyclindrical antheridia were all amphigynous. This is the first report on potato pink rot caused by Phytophthora erythroseptica in Korea.

Optimal Management of Patent Ductus Arterisus in Premature (미숙아 동맥관개존증의 효과적 치료)

  • 전태국;박표원
    • Journal of Chest Surgery
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    • v.30 no.6
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    • pp.585-590
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    • 1997
  • Between December 1994 and October 1996, 57 premature infants with evidence of a hemodynamically significant PDA associated with cardiopulmonary compromise underwent indomethcin therapy(Group I, n=48) or surgical ligation(Group II, n=9) because of indomethacin failure. The gestational alee(29.6$\pm$ 3.1weeks vs. 28.1 $\pm$ 1.6weeks) and birth weight(1,413 $\pm$ 580gm, ,098 $\pm$ 235gm) showed no significant differences between the two groups. Medical management included fluid restriction, diuretics, and indomethacin therapy(one or two cycles). Surgical libation was done at the neonatal intensive care unit(NICU) without moving the patient to the operation room. There was no complication associated with the operation. There were 9 deaths in Group I(19%, 9/48) and 2 deaths in Group II(22% , 219). The main causes of deaths were persistent bronchopulmonary dysplasia with sepsis(n=8) and intrapulmonary hemorrhage(n=3). The rate of medical treatment failure including death and complication in premature infants whose body weights were less than 1500gm was higher(41%, 15/38) than in premature infants whose body weights were more than 1500gm(16%, 3/19). Early surgical ligation of PDA may be applicable in the premature infant with a large size, low birth weight(<1500 gm), or associated intracardiac anomalies. Perfoming the operation in the NICU may be safe in s ead of moving the patient to the operating room.

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Assessing Biosecurity Practices on Commercial Pig Farms across Korea and Risk Factors for Porcine Circovirus Type 2 Infection (국내 양돈장의 차단방역 수준 평가 및 돼지써코바이러스 2형 감염의 위험요인에 관한 연구)

  • Choi, Sung-Hyun;Pak, Son-Il
    • Journal of Veterinary Clinics
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    • v.32 no.4
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    • pp.324-329
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    • 2015
  • The primary aim of this study was to investigate biosecurity practices in pig farms and to determine the major risk factors associated with PCV2 infection for a sampled swine population in Korea. To this end, we analyzed data from a cross-sectional study of 296 farrow-to-finish farms, which was conducted between March and September 2014 to explore the prevalence of swine disease at farm level. Face-to-face interviews by on-site visit of trained veterinarians were conducted with the farm owners or managers using a standardized questionnaires with information about basic demographical data and management practices. Farms were classified as negative or positive through the use of infection profiles that combined data on serological testing including PCR antigen test result, antibody titer and sero-conversion pattern at each age category taking into account vaccination status. Data were analyzed using multivariate ordinal logistic regression. Results from this study indicated that biosecurity level of the farms was considered not good given low compliance of the biosecurity programs and facilities in the farm: off-site removal of dead stocks (7%), off-site location of storage facility for incoming feeds (12.6%), off-site pick-up location for finishers (19.3%), restrictions on feed supplier vehicles for farm entrance (19.6%), restriction of finisher trucks entering the farm (22.4%), and restriction on manure disposal trucks entering the farm (26.4%). In the final model (n = 255), allowance of finisher truck driver to the pig unit had increased risk of infection (OR = 2.4, 95% CI 1.22-4.67) whereas farms with a sign forbidding the entrance had decreased risk of infection (OR = 0.19, 95% CI 0.10-0.58). Further comprehensive research with larger sample size is required to better understand the multifactorial characteristic that some predisposing risk factors that were not available in this study. To the best knowledge of the authors, this was the first study to use empirical data to report risk factors associated with PCV2 infection in the Korean pig farms. Results from the current study could be used to decide optimal biosecurity measures to reduce the impact of PCV2 infection to farmers and policy makers.

Synthesis of Na-A type Zeolite From Melting Slag (소각재 용융슬래그를 이용한 제올라이트 Na-A의 합성)

  • Jang Young-Nam;Chae Soo-Chuu;Bae In-Kook;Ryou Kyung-Won
    • Journal of the Mineralogical Society of Korea
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    • v.18 no.1
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    • pp.11-17
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    • 2005
  • Na-A zeolite were synthesized from melting slag of the incinerated ash by the alkaline activation processes. The experiments were performed in stainless steel vessels, with continuous stirring during the reaction periods. The silica-rich solution, a starting material, which was the waste of crystal growth factory, contains 5.7 wt% SiO₂ and 3.2 wt% Na₂O. And NaAlO₂ was made by the reaction of aluminium dross and NaOH solution and its molar ratios were Na₂O/Al₂O₃= 1.2 and H₂O/Na₂O=9. During the residence time of 7∼8 h at 80℃, the mixing of the silica-rich solution, NaAlO₂ and melting slag yields the production of homogeneous Na-A zeolite. The optimal reactant composition in molar ratio of Na₂O:Al₂O₃:SiO₂ was 1.3∼l.4 : 0.8∼0.9 : 2 and mixing ratio of solution and slag was 1/7∼10 (g/cc). Synthesized Na-A zeolite has cubic form uniformly and its size ranges about 1 ㎛. Ca/sup 2+/ ion exchange capacity of the Na-A was about 180∼210 meq/100g, corresponding approximately 80% to the commercial detergent builder.

Role of Korean Society of Pediatric Infectious Disease during the Middle East Respiratory Syndrome (MERS) Outbreak in Korea, 2015 (2015년 우리나라에서 발생한 중동호흡기증후군과 대한소아감염학회의 역할)

  • Kim, Kyung-Hyo
    • Pediatric Infection and Vaccine
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    • v.22 no.3
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    • pp.136-142
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    • 2015
  • The Korean Society of Pediatric Infectious Diseases (KSPID) has participated in the task force team consisting of government authorities as well as civil medical experts and facilities to block the spread of Middle East Respiratory Syndrome in 2015. KSPID posted the "Middle East Respiratory Syndrome (MERS) Pop-up" in the homepage of The Korean Pediatric Society and The Korean Society of Pediatric Infectious Diseases. KSPID also released the "Guidelines for testing for MERS in children and adolescents" and the "Instructions for the Operation of National Safe Hospital" for children and adolescents in a timely manner. Such actions were aimed to prevent unnecessary anxieties, studies and isolation of pediatric patients with respiratory symptoms and signs caused by other common microbial etiologies as being suspected for MERS patients. This strategy relieved the doctors and parents from unnecessary fear and prevented the loss of unnecessary health care costs, and has proven to be a well-judged guideline and management protocol as evaluated after the final end of MERS outbreak. KSPID and its members should support the presence of pediatric infectious disease (PID) specialists in every medium size hospitals in Korea by developing the need for consultation fees for PID consultation in the hospital based practice and promoting the potential for cost savings related to prevention of health care associated infections and optimal prescription of antimicrobial agents. KSPID and its members need to approach and develop a communication plan to political decision makers to demonstrate and convince them of the importance of a PID specialist service.

Simultaneous Analysis Method for Polar and Non-polar Ginsenosides in Cultivated Wild Ginseng by Reversed-phase HPLC-CAD (HPLC-CAD에 의한 산양삼의 극성 및 비극성 ginsenoside 동시 분석)

  • Ok, Seon;Kang, Jae Seon;Kim, Kang Min
    • Journal of Life Science
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    • v.26 no.2
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    • pp.247-252
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    • 2016
  • Cultivated wild ginseng is a widely used dietary supplement and medicinal herb. The aim of this study was to optimize the ginseng using high performance liquid chromatography (HPLC)- charged aerosol detection (CAD) for ginsenoside analysis. CAD measures the physical property of an analyte and responds to almost all non-volatile species, independent of their nature, spectral properties, or particle size. It has become widely employed in pharmaceutical analysis. The cultivated wild ginseng extracts were analyzed for compositions of ginsenosides Rb1, Rd, Rg1, Rf, Re, and Rh1. The optimal analysis condition was set up from an experiment using a gradient. Ten grams of cultivated wild ginseng were extracted with 95% EtOH 100 ml for 24 hr at 80℃. The contents of the 6six major ginsenosides in the cultivated wild ginseng extract were Rb1 (5.48±0.12 mg/g), Rd (5.33±0.14 mg/g), Rg1 (12.80± 0.05 mg/g), Rf (19.08±0.68 mg/g), Re (19.87±0.05 mg/g), and Rh1 (16.47±0.16 mg/g), respectively. HPLC showed that the protopanaxatriol group (Rg1, Rf, Re, Rh1) had more content than the protopanaxadiol group (Rb1, Rd) in cultivated wild ginseng extract. In summary, the ginsenosides were identified with HPLC-CAD analysis, and their presence and quantity imply the importance of quality control, as well as the pharmacological activity of the ginseng root.

Enzymatic Characterization of a Thermostable 4-α-Glucanotransferase from Thermotoga neapolitana (Thermotoga neapolitana 유래 내열성 4-알파-글루칸전이효소의 효소적 특성)

  • Choi, Kyoung-Hwa;Seo, Ja-Yeong;Kim, Ji-Eun;Cha, Jae-Ho
    • Journal of Life Science
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    • v.21 no.2
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    • pp.221-226
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    • 2011
  • The gene encoding 4-$\alpha$-glucanotransferase (mgtA) from Thermotoga neapolitana was cloned and expressed in Escherichia coli in order to investigate whether this enzyme was capable of producing cycloamylose for industrial applications. MgtA was purified to homogeneity by HiTrap Q HP and Sephacryl S-200 HR column chromatographies. The size of the enzyme as determined by SDS-PAGE was about 52 kDa, which was in good agreement with its deduced molecular mass of 51.9 kDa. The optimal temperature and pH for the activity of the 4-$\alpha$-glucanotransferase was found to be $85^{\circ}C$ and 6.5, respectively. The enzyme hydrolyzed the 1,4-$\alpha$-glucosidic bonds in oligomeric 1,4-$\alpha$-glucans and transferred oligosaccharides (maltotriose being the shortest one) to acceptor maltodextrins. However, the enzymes had no activity against pullulan, glycogen, and other di- or trioligosaccharides with rare types of $\alpha$-bond. MgtA is distinguished from 4-$\alpha$-glucanotransferase from Thermotoga maritima in that it can convert maltotriose into maltooligosaccharides. The treatment of glucoamylase after the reaction of MgtA with maltotriose, maltotetraose, maltopentaose, or maltohexaose as sole substrate revealed that MgtA yielded linear maltooligosaccharides instead of cycloamylose.

Recovery Pattern and Seasonal Dynamics of Kelp Species, Ecklonia cava Population Formed Following the Large-scale Disturbance (대규모 교란현상 후 형성된 대형갈조류 감태(Ecklonia cava) 개체군의 계절적 변동 및 회복 양상)

  • KIM, SANGIL;KANG, YUN HEE;KIM, TAE-HOON;PARK, SANG RUL
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.21 no.3
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    • pp.103-111
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    • 2016
  • Seasonal dynamics of kelp forest-forming algae, Ecklonia cava population formed following the large-scale disturbance by Typhoon 'Bolaven' in August 2012 were investigated in Jeju Island, Korea. Morphological characteristics, recruits density, mortality rate, total density and biomass were monitored bimonthly from June 2013 to June 2015. Total and longest blade lengths, and individual weight of E. cava showed distinct seasonal trends. Stipe length increased from winter to spring, but did not show increase or reduced from summer to autumn. This indicates that morphological characteristics of E. cava are mainly affected by the change of blades. The optimal temperature for E. cava growth was about $15-18^{\circ}C$ during winter to spring while the growths were inhibited at the water temperature above $20^{\circ}C$ during summer. E. cava exhibited very low recruitment during spring-summer. However, high recruitment was observed on April 2015 when canopy cover was very low due to low density. This indicates that recruitment of E. cava was controlled not by seasonal effects but by physical factors such as canopy and space. The mortality rate of juvenile plants was highest due to their unstable settlement. By June 2015, 34 months after the disturbances, E. cava was almost recovered to the pre-disturbance population size structure. These results suggest that recovery of kelp forest following the large-scale disturbance requires a considerable period of time (more than three years). This study should provide valuable ecological information on management, restoration and protection of kelp species.

Natural Dyeing of Rayon Fabric using Loess (황토를 이용한 인견직물의 천연염색)

  • Jung, Yang-Sook;Bae, Do-Gyu
    • Current Research on Agriculture and Life Sciences
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    • v.31 no.3
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    • pp.193-199
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    • 2013
  • This study dyed rayon fabric using loess as a natural colorant. To obtain the optimal dyeing conditions, various dyeing conditions were examined (temperature, pH, time, and concentration). The color fastness was evaluated using standard washing and rubbing fastness tests. The results were as follows: The loess powder particle size ranged from 0.4 to $1.7{\mu}m$ with a distribution range of 1.1 to $1.4{\mu}m$, representing a fine and uniform manufactured loess powder. The loess component analysis showed a large amount of silicon dioxide and aluminum oxide. TheFT-IR spectra showed that the ammonium group in the rayon fabric produced N-H banding at $1,540cm^{-1}$. The highest K/S value for the rayon fabric was obtained when the pH was 8.0, and this value increased rapidly with a longer dyeing time and when increasing the loess concentration to 30% (w/v). Pre-treatment with a soybean solution produced the highest K/S value for the rayon fabric with a loess concentration of 30% (w/v). The SEM analysis showed a higher amount of loess adhered to the rayon fabric surface when increasing the loess concentration. However, pre-treatment with a cationic agent and soybean solution resulted in a much higher attachment of loess to the fabric surface. Thus, the experimental results showed that using a cationized fabric and pre-treatment with a soybean solution are more effective when dyeing rayon fabric with loess than when using only loess.

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Population growth of a tropical tintinnid, Metacylis tropica on different temperature, salinity and diet (수온, 염분 및 먹이에 따른 열대 유종류, Metacylis tropica의 성장)

  • Lee, Kyun-Woo;Choi, Young-Ung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.9
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    • pp.322-328
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    • 2016
  • This study investigated the effects of temperature, salinity, and algal diet to find the optimal conditions for 5 days for the mass culture of the tropical tintinnid, Metacylis tropica. This tintinnid had a small, hyaline, and ovoid lorica. The oral diameter, length, and maximum width of the lorica were $36.7{\mu}m$, $49.5{\mu}m$, and $44.5{\mu}m$, respectively. In the temperature experiments, the highest maximum density and population growth rate were observed at $30^{\circ}C$ with 340.7 cells/mL and 1.1/day, respectively. Lower salinities adversely affected the population growth of M. tropica. The maximum density was observed at 33 ppt (840 cells/mL). In the diet experiments, M. tropica fed Isochrysis galbana showed the highest density (413 cells/mL) and population growth rate (1.2/day). As a result, M. tropica is appropriate as a potential prey organism for early fish larvae with smaller mouths because the tintinnid has a relatively small size compared to the rotifer. In addition, the conditions of $30^{\circ}C$, 33 ppt and supplying I. galbana would be effective in the cultivation of M. tropica.