• Korean journal of applied entomology
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• v.22 no.4 s.57
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• pp.277-282
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• 1983

Number and percentage of diseased area of leaf blast lesions formed on different leaf location were mostly distributed from the flag leaf(n-1) to the 3rd leaf from the top(n-3) in Tongil line rice varieties and on the 2nd leaf from the top(n-2) in Japonica type rice varieties. Especially leaf lesions of Nopung which was more susceptible to leaf blast among Ton1 line rice varieties were mostly distributed on flag leaf. Relation between the degree of lesion distribution and level of fertilizer was more clear with an increase of fertilizer quantity. Leaf blast lesions of rice varieties were generally distributed from the flag leaf to the with leaf from the top but mainly those at flag leaf and the 2nd leaf from the top were found to be most responsible for inoculum source of panicle blast after booting stage. Increase of the conidia formation was resulted from fluctuation of temperature$(24^{\circ}C\~16^{\circ}C)$ in low temperature range after booting stage and many inoculum sources were supplied on panicles until the end of September without impeding dispersal from leaf blast lesions as an inoculum source of panicle blast.

• Weed & Turfgrass Science
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• v.4 no.4
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• pp.376-382
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• 2015

Dollar spot, caused by Sclerotinia homoeocarpa, is the major disease in cool-season turfgrasses. Understanding the distribution of this pathogen in soil and thatch is important to developing disease control strategies. In this study, toothpicks were used to detect S. homoeocarpa in the turfgrass canopy, thatch, and soil at different distances from dollar spot infection centers. The effect of penetrant and contact fungicide applications with different water volumes on distribution of S. homoeocarpa was also investigated. S. homoeocarpa was detected in 100% of samples taken from the leaf canopy, 83.3% in thatch area, and 0% in the soil from within the infection center. S. homoeocarpa was isolated in 100% of samples taken from the edge of the infection center, but was only detected in 13% of the samples taken at 1.5 cm away from the infection center edge. S. homoeocarpa was isolated at a higher frequency in the propiconazole treated plots than those treated with chlorothalonil and was not detected in leaf canopy samples when either fungicides was applied with 6.78 L of water. In conclusion, the toothpick-aided detection technique has improved our understanding of S. homoeocarpa epidemiology and could be used as a diagnostic tool to detect for fungicide resistance on golf courses.

• Journal of Preventive Medicine and Public Health
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• v.10 no.1
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• pp.86-93
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• 1977

An epidemiological study was conducted, from April 28 to June 3, 1975, to investigate source and course of infection of typhoid fever occurred in Munhyeon Dong, Nam Gu, Busan. The obtained results were as follows: 1. The entity of unknown febrile disease was identified as Salmonella typhi, D group and it's symptoms were abdominal pain, diarrhea, hepatomegaly, nausea and vomiting, aplenomegaly, rose spots, tenderness of ileocecal region etc., in that order. 2. The average duration from onset to recovery was 25.2 days and incidence rate was 39.5 per 1,000 population. 3. The source of infection was presumed a charity patient. 4. By the duration of report on the cases from onset, 10-19 days group was the highest. 5. The positive rate of initial stool culture was 38.9% and secondary was 5.6%. 6. Distribution of the cases by age and sex showed that 5-9 years old group was the highest as 30.5%, and male was higher than female. 7. Distribution of the cases by education level, under primary school as 66.6% was the highest. By the living standard, the highest was low income earner group as 77.8%. 8. Utilization rate of medical facilites was drug store (41.7%), herbal drug (8.3%), clinic (5.6%) in that order.

• Research in Plant Disease
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• v.10 no.4
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• pp.231-240
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• 2004

In the year of 2002 annual nationwide survey of virus diseases occurring in the pepper fields and greenhouses in Korea, the distribution and the incidence of viral diseases was investigated. The pepper samples from both greenhouses (155 samples) and open fields (227 samples) were collected and further analyzed to detect eleven different viruses by RT-PCR. The results indicate that no sample collected from both greenhouse and open field seems to be infected by TMV, RMV, PVY, AMV, and TSWV. On the other hand, CMV, BBWV2, PepMoV, PMMoV, TMGMV and ToMV are readily identified from greenhouse and open field samples by RT-PCR. The infection rates of the collected samples between greenhouse and open field are largely different. Comparing with 10% of virus-infected pepper samples grown in greenhouse, approximately one third of pepper samples collected from open field are infected. The mixed-infection rates in the virus-infected greenhouse and open field samples are 16% and 61%, respectively. The dominant virus occuring in greenhouse is PMMoV, indicating that virus-infected seed stocks and infected plant debris in the growing area may be important sources of inocula. On the other hand, both CMV and BBWV2 are dominant viruses in open field. This may indicate that the migration of viruliferous insect vectors into pepper fields may be the most important source of inoculum. Also, the survey shows that BBWV2 is newly immerging virus to be controlled in Korea. The discrepancies on the distribution and the occurrence of viral diseases between field and greenhouse may provide a fact that the accumulation and distribution of inoculum by successive cultivation and the migration of viruliferous vectors into growing areas are likely to be important factors to determine the incidence of viral diseases. Therefore, the further studies on epidemiology and the consideration of new breeding program of pepper are essential to minimize virus diseases.

• Research in Plant Disease
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• v.11 no.1
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• pp.16-20
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• 2005

Several time-course experiments were carried out to understand seasonal development of melanose on yuzu trees at koehung area, Jeonnam province, during May to October. The occurrence of dead twigs, known as a source of infection, was much more in older trees, and from June to August, mostly in July. In the experiment of pycnidia development on dead twigs seasonally collected, the number of developed pycnidia was highest on July-collected dead twigs especially with the diameter of 1.1~1.5 cm. In the collection survey of disseminated pycnidiospores, although the collected number of pycnidiospores was affected with amount of precipitation, the number of observed pycnidiospores in rainwater was relatively high from June to August, with highest in early August in 1997 and late July in 1998. In the inoculation tests on 3-year-old trees and fruits in natural condition, disease occurrences were mostly affected on twigs by inocula treatment in June, and on fruits by inocula treatment in July, respectively.

• Korean Journal Plant Pathology
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• v.13 no.3
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• pp.184-190
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• 1997

Lesion enlargement of ginger rhizome rot was most rapid at 35~40 C, but delayed greatly as temperature decreased. Time needed for a killing a ginger plant, 22~25 cm long, was about 5 days at 35~40 C, but was 15 days at 15 C in a growth chamber test. Higher RH above 90%, higher soil moisture level above 80% of maximum soil moisture capacity, and deeper planting below 4cm enhanced the lesion development on ginger stems and rhizomes. Pythium myriotylum existed in field soil as forms of hyphal portion, hyphal swelling body, or oospore- or zoospore-like bodies, and served as the origin of its colonization. Inocula of P. myriotylum was randomly distributed in soil surface around ginger plants, but its density was decreased as increasing soil depth with the highest density at 0~10 cm soil depth. Population density of P. myriotylum did not vary significantly between the rhizoplane and the rhizosphere soil of a ginger plant, but differed greatly between the disessed and healthy plants with several to several hundreds times higher population in the diseased plants. A positive curvilinear relationship was found between P. myriotylum density and ginger rhizome rot severity.

• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.79-82
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• 2000

This study was carried out to investigate the effect of seed disinfectant on leaf blight and smut in adlay. Leaf blight and smut disease in adlay are known to be seed borne. Bjpolan's cojds, pathogen causing leaf blight in adlay, was detected from 32. 7 to 45. 7 % on seeds collected from adlay cultivated farms in Yonchon province. Periods of seed infestation are $0{\sim}7$ days on the variety 'yulmu 1' and $0{\sim}20$ days on 'Yonchon jaerae'. Distribution ratio of seed disinfestation periods was that no disinfestation, $1{\sim}5$days, $6{\sim}10$days and more 11days were 20%, 20%, 45% and 15%, respectively. Frudioxonil W. S. treatment was effective on inhibition of leaf blight and smut disease when treated with infested seeds ; that is, disease control values of the fungicide are 97 and 93.4 percentage, repectively.

• Food Industry And Nutrition
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• v.11 no.3
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• pp.6-11
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• 2006

바이러스성 식중독은 장염을 일으키는 원인 병원체 중 노로바이러스에 의해 흔히 발생하며 이외에도 아스트로바이러스나 로타바이러스에 의한 집단 설사 사례가 국내에서 보고된 바 있다. 노로바이러스는 식중독과 관련하여 특히 오염된 식수와 굴 등 어패류의 생식을 통한 감염 사례가 많이 보고되어 있으나 사람 간 전파도 흔히 일어나는 전염력이 매우 높은 바이러스이다. 국내에서는 1999년 이후 보고가 되고 있으며 최근 집단 급식과 관련된 대형 식중독 사례들이 보고되면서 학교급식이 사회적인 이슈로 대두되고 있다. 2000년 이후 질병관리본부는 바이러스성 설사의 국내 발생현황을 파악하기 위하여 전국의 17개 시도보건환경 연구원과 노로바이러스를 포함한 4종의 바이러스성 장염원인 병원체에 대한 전국적인 실험실 감시체계를 운영한 결과 바이러스성 병원체가 확인된 사례의 약 18%에서 노로바이러스가 검출되었고, 집단설사 사례에서는 대부분 노로바이러스가 원인병원체로 확인되었다. 또한 노로바이러스의 조기 검출을 위해 질병관리본부는 2004년 중 노로바이러스 유전자 검출 kit를 자체적으로 제작하여 이를 전국의 시도 보건환경연구원을 연계한 감시체계에서 적극 활용함으로써 노로바이러스 집단설사사례의 조기 검출이 가능하게 되었고 지역내 노로바이러스 검출율을 높이는데 기여하였다. 국립보건연구원은 2003년과 2006년에 발생한 대규모 노로바이러스 식중독 사례 이외에도 산발적으로 지속적으로 발생하는 사례들을 조기에 탐지하고 국내에서 검출되는 설사바이러스 유전형 분포양상과 새로운 유전자형이나 변이주를 조기에 검출하고자 전국적인 노로바이러스 실험실 감시망을 강화하여 운영하고 있으며, 집단설사 발생시 각 사례의 연관성을 신속하게 분석할 수 있는 실시간 분자역학적 유전자 분석체계를 단계적으로 도입하고 있다. 실험실 감시체계 운영과 함께 집단 식중독 유발 병원체의 효율적인 관리를 위해 질병관리본부는 노로바이러스를 포함한 설사 유발 병원체를 신고대상 병원체로 지정(2006.06.12)하여 병원체 검출시 보고하도록 하고 관련 지침을 마련하였다. 노로바이러스가 지정전염병 병원체로 추가로 지정됨에 따라 집단 사례 및 실험실 감시사업을 통해 검출되는 병원체에 대한 보고가 강화되고 전파 방지와 2차 감염 사례 감소에도 기여할 수 있을 것으로 사료되며 전국의 실험실 감시망을 연결하는 국가 차원의 노로바이러스 실시간 분자역학적 분석체계 도입을 통해 노로바이러스 2차 감염을 줄이고 대규모 집단발병 및 유행의 조기 차단 효과를 가져올 수 있을 것이다.

• Pediatric Infection and Vaccine
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• v.10 no.1
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• pp.87-94
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• 2003

Purpose : Respiratory viruses are one of the most infectious agent in human. Acute lower respiratory tract infection(ALRTIs) is associated with significant morbidity and mortality in children. This study is performed to investigate the etiologic organism, age and sex distribution, clinical manifestations and seasonal occurrence of ALRTIs in children. Methods : Viral agent was evaluated with nasopharyngeal aspirates, rhinorrhea and saliva collected from 568 patients. We confirmed viral agents in 54 patients who were younger than 15 year old. They had visited Maryknoll Hospital, Busan in Korea from January, 2002 to December, 2002 for ALRTIs. Results : The viral pathogens identified were Influenza A virus(59.3%), Enterovirus(33.3%), Adenovirus(5.6%), and Influenza B virus(1.9%). Parainfluenza virus and Respiratory syncytial virus were not detected. The occurrence of acute lower respiratory infections was high between 3 & 6 years old. The clinical patterns include pneumonia(51.9%), bronchitis(31.5%), croup(9.3%), bronchiolitis(7.4%). The respiratory viral agents had their characteristic seasonal patterns. Conclusion : Influenza A virus was the most common cause of acute lower respiratory tract infections in Busan area during the 2002. ALRTIs had high occurrence between 3 to 6 years old. And the most common clinical patterns were pneumonia and bronchitis.

• Pediatric Infection and Vaccine
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• v.9 no.2
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• pp.201-207
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• 2002

Purpose : We analyzed clinical features and causal viruses of acute lower respiratory tract infections(LRTIs) in order to improve the management of these infections. Methods : From end of April to early May 2001, amongst 30 children at a local institute for children's adoption and welfare, 13 were admitted to the hospital with the diagnostic impression of acute LRTIs. Nasopharyngeal aspirates were sent in Seoul National University Hospital for viral culture of respiratory syncytial virus(RSV), adenovirus, parainfluenza virus. Results : One or more viral agents were identified in 4 cases(30.7%) : were RSV(15.4%), adenovirus(7.7%), and a mix of these two viruses(7.7%). Initial symptoms were fever(69%), cough(100%), tachypnea(54%), chest retraction(69%), rale(85%) and wheezing(15%). Leukocytosis was noted in 23%, CRP increased more than 10 mg/L in 46%. Chest X-ray abnormalities were 69%. Conclusion : Although viruses were identified in 30.7%, further studies should be made for prevention and treatment of acute viral LRTIs.