• Title/Summary/Keyword: initial infection date

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Development of a Model to Predict the Primary Infection Date of Bacterial Spot (Xanthomonas campestris pv. vesicatoria) on Hot Pepper

  • Kim, Ji-Hoon;Kang, Wee-Soo;Yun, Sung-Chul
    • The Plant Pathology Journal
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    • v.30 no.2
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    • pp.125-135
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    • 2014
  • A population model of bacterial spot caused by Xanthomonas campestris pv. vesicatoria on hot pepper was developed to predict the primary disease infection date. The model estimated the pathogen population on the surface and within the leaf of the host based on the wetness period and temperature. For successful infection, at least 5,000 cells/ml of the bacterial population were required. Also, wind and rain were necessary according to regression analyses of the monitored data. Bacterial spot on the model is initiated when the pathogen population exceeds $10^{15}cells/g$ within the leaf. The developed model was validated using 94 assessed samples from 2000 to 2007 obtained from monitored fields. Based on the validation study, the predicted initial infection dates varied based on the year rather than the location. Differences in initial infection dates between the model predictions and the monitored data in the field were minimal. For example, predicted infection dates for 7 locations were within the same month as the actual infection dates, 11 locations were within 1 month of the actual infection, and only 3 locations were more than 2 months apart from the actual infection. The predicted infection dates were mapped from 2009 to 2012; 2011 was the most severe year. Although the model was not sensitive enough to predict disease severity of less than 0.1% in the field, our model predicted bacterial spot severity of 1% or more. Therefore, this model can be applied in the field to determine when bacterial spot control is required.

Effect of Barley Yellow Mosaic Virus (BaYMV)- Infested Soil on the Agronomic Characters of Three Different Barley Varieties

  • Hyun, Jong-Nae;Hong, Yeon-Kyu;Lim, Sea-Gyu;Kim, Yang-Gil;Kim, Mi-Jung;Lee, Mi-Ja;Lee, Key-Woon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.53 no.4
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    • pp.427-433
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    • 2008
  • Barley Yellow Mosaic Virus (BaYMV) caused significant reduction in barley yield and is difficult to control due to alive parasitic soil-borne fungus, Palmyra gamines that transmits the, virus. Previous studies have indicated that a virus-free soil could be infested by using virus-contaminated farming machineneries and implements. For the further confirmation of this finding, different proportions of BaYMV-infested soil were mixed into virus free soil. Three barley varieties (Hordum vulgarae, cv "Olbori", "Baegdong" and "Sacheon 6") were sown in pots treated with different rate of P. graminis-infested soil ranging from 0% to 100% in October 20, 2001. Results showed that BaYMV infection increased as the rate of infested soil increased. Initial symptoms were observed in a pots treated with 10% infested soil in all the 3 varieties of barley. "Olbori" had about 5% infection in 20% infested soil and about 10% infection in 40% or 50% infested soil and about 20% infection in 60% infested soil. In "Baegdong", the trend of BYMV occurrence was similar with "Olbori" but the time of severe infection was earlier than "Olbori". BaYMV infection in "Sacheon 6" was even earlier than "Baegdong" with much more severe symptoms than "Baegdong". The growth rate of barley was affected by about 19-22% when grown in 20% infested soil. As the rate of BaYMV infested soil increased the heading date was delayed but the maturing date was early in "Olbori" and "Sacheon 6". Also, reduction rate of culm length in 3 varieties increased with increase of infested soil content. However, "Olbori" showed the highest reduction. "Sacheon 6", have been characterized with long spike length, however was significantly reduced as the infested soil increased. On the other hand, spike length of "Olbori" was not significantly affected despite of increased of infested soil. The reduction rate of 1000 kernel weight was higher in large kernel size cultivar "Sacheon 6" and "Olbori" than small kernel size "Baegdong" as increase of BaYMV-infested soil content.

Development of a Forecasting Model for Bacterial Wilt in Hot Pepper (고추 풋마름병 예찰 모형 개발)

  • Kim, Ji-Hoon;Kim, Sung-Taek;Yun, Sung-Chul
    • Research in Plant Disease
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    • v.18 no.4
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    • pp.361-369
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    • 2012
  • A population density model for bacterial wilt, which is caused by Ralstonia solanacearum, in hot pepper was developed to estimate the primary infection date after overwintering in the field. We developed the model mechansitically to predict reproduction of the pathogen and pathogensis on seedlings of the host. The model estimates the pathogen's populations both in the soil and in the host. In order to quantify environmental infection factors, various temperatures and initial population densities were determined for wilt symptoms on the seedlings of hot pepper in a chamber. Once, the pathogens living in soil multiply up to 400 cells/g of soil, they can infect successfully in the host. Primary infection in a host was supposed to be started when the population of the pathogen were over $10^9$ cells/g of root tissue. The estimated primary infection dates of bacterial wilt in 2011 in Korea were mostly mid-July or late-July which were 10-15 days earlier than those in 2010. Two kinds of meterological data, synoptic observation and field measurements from paddy field and orchard in Kyunggi, were operated the model for comparing the result dates. About 1-3 days were earlier from field data than from synoptic observation.

A Case of Herpes Zoster in a 9-month-old Infant (9개월 영아에서 발생한 대상포진 1례)

  • Keun, Seung On;Lee, Soo Young;Kim, Sun Mi;Jeong, Dae Chul;Chung, Seung Yun;Kang, Jin-Han
    • Pediatric Infection and Vaccine
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    • v.9 no.2
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    • pp.230-235
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    • 2002
  • We experienced a case of herpes zoster in a 9-months aged infant as followings; The patient had no history of chickenpox or varicella vaccination. Also, her mother had no history of varicella infection and no contact history with varicella during pregnancy. The patient had only a history of exposure to chickenpox patient at 7th days after birth, but fortunately chickenpox was not developed. Sequentially, symptoms of cough with fever and tachypnea were developed on admission date(7 days had passed already after development of the initial skin lesion). On physical examination, multiple grouped painless erythematous papulovesicles with small crusts were observed on the right lower back, flank and abdomen along the T11 dermatome. Coarse breathing sound was osculated, and increased linear infiltrations on both parahilar areas were seen on chest radiography. Liver enzymes were slightly elevated. Tzanck test was negative. The initial titers of anti-VZV IgM and IgG on admission were negative, but the following titers of anti-VZV IgM and IgG were positive. The patient received treatment of acyclovir for 7 days, and healed completely without sequelae. We report this case with brief review of related literatures.

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Immediate Replacement of Bone Fragments in Compound Comminuted Depressed Skull Fractures (개방성 분쇄 함몰 두개골절의 즉각 골편 복위술)

  • Cho, Yong Jun;Kim, Young Ock;Song, Joon Ho;Hwang, Jang Hoi;Kim, Sung Min;Ahn, Myung Soo;Oh, Sae Moon;Ahn, Moo Eob
    • Journal of Korean Neurosurgical Society
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    • v.29 no.5
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    • pp.668-674
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    • 2000
  • Objective : The classic and accepted surgical method of compound comminuted depressed skull fractures (FCCD) involves total resection of all the contaminated bone and fragments at the fracture site. A second operation for cranioplasty is then performed at a later date. However, we have believed that primary repair of these bony defects can be achieved by the replacement of bone fragments at the time of the initial debridement, and this can be accomplished without danger to patient. The authors retrospectively reviewed the surgical results to assess the advantages and disadvantages, and also propose the selection criteria of replacement of fractured bone fragments as a primary procedure in FCCD. Materials and Methods : The authors analyzed the data extracted from medical records, and radiological findings in 22 of 71 patients with FCCD, who underwent immediate replacement of fractured bone fragments between April 1993 and October 1998. The mean follow-up period was 13.7 months. The selection criteria for the operation included the patients with mild to moderate severity, regardless of the degree of contamination or dural violation, which presented in hospital within 24 hours of injury. Results : The ages of the patients varied from 4 to 63 years, and there were 20 males and 2 females. Seventeen of 22 patients were fully conscious on admission and the others also had relatively good Glasgow coma scales. Sixteen fractures were located in the frontal area, 9 with involvement of the frontal sinuses, and 6 in the parietal and temporoparietal areas. Of the 22 patients, 8(36.3%) had dural lacerations with 3 of these requiring patching with pericranium, and 12(54.5%) had intracranial hematoma requiring wide craniotomy. The degree of wound contamination was also variable. Fifteen patients had relatively clean wounds, while seven(31.8%) had seriously contaminated wounds with soil, sand, hair, and wood. Only one patient(4.5%) developed infection, and the bone fragments were removed. All wounds healed primarily without pulsatile defect, the skull has remained solid, and no complications have occurred, except the infected case. Conclusion : It is proposed that bone fragments removal for FCCD, regardless of the degree of contamination or dural violation, is not necessary and that primary bone fragments replacement avoids a second operation for cranioplasty.

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A Clinical Study of Facial Paralysis (안명신경 손상 환자의 임상적 고찰)

  • Huh, Choon-Bok;Suh, Tae-Soo
    • Journal of Korean Physical Therapy Science
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    • v.5 no.3
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    • pp.643-650
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    • 1998
  • Facial nerve is subject to injury at any point in the course from the cerebral cortex to the motor end plate in the face, so many etiologic varieties of facial paralysis may be encountered, including trauma, viral infection and the idiopathic. Authors have studied 39 cases of facial paralysis which had experienced of treatment in our department from March, 1996 to March, 1997 at Dong San Medical Center. The results obtained are as follows : 1) The highest age incidence showed 10 cases(24.6%) in 3rd decade 2) Among the total of 39 cases, male were 21 cases(53.8%) and female were 18cases(46.2%). 3) At the involved side, left side were 19 cases(48.7%) and right side were 18 cases(46.2%). 4) The causes of facial paralysis were; idiopathic (Bell's palsy) in 19 cases(48.7%) infectious in 6 cases(15.4%) neoplastic in 6 cases(15.4%) traumatic in 5 cases(12.9%) metabolic in 2 cases(5.1%) congenital in 1 cases(2.6%) 5) In time interval between onset of symptom and treated initial date, 26 cases(66.7%) in below 10 days and 8 cases(20.5%) in 11-20 days 6) Correlation of recovery rate according to the treated duration did not differ significantly 7)Result after treatment were satisfactory

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