• Parasites, Hosts and Diseases
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• 제30권4호
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• pp.259-262
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• 1992

국내 마우스에서 분리하여 계대중인 Cryptosporidium parvum 원충이 송아지에 감염되는지 알아보기 위하여 25일령의 한우 송아지에 1×106개의 오오시스트를 감염시킨 결과 점종 후 4일 째부터 분변 내에 오오시스트를 배출하였다. 오오시스트의 배설은 8일간 지속되었고, 그 수는 인충 점종 후 6일째에 가장 많았다(분변 gram당 4.9×105개 오오시스트). 감염된 송아지의 분변 내로 오오시스트가 배출되는 동안 분변의 성상은 정상이었다. 이상의 결과로 볼 때 국내 마우스에서 분리된 C. parvum은 송아지에게도 교차감염이 이루어져 숙주특이성이 없음을 알 수 있었다.

• 한국학교보건학회지
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• 제14권1호
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• pp.83-93
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• 2001

Objectives: The purpose of this study is to develop a health-promoting program centered on the university-health center and to provide a developed program for students and faculties. Methods: A survey was conducted of 719 female students and 238 faculties concerning their health-promoting programs. Based on the results of the survey, we developed programs that could be applied to students and faculties. After operating the programs, we developed further models by evaluating the effectiveness and satisfaction. Conclusions: We selected a comprehensive health-promoting program that included weight control, preventive inoculation, sex education and control of disease based on repsective needs. We also applied programs developed through collaboration with other departments from September 1998 to August, 1999. Users of the preventive inoculation-program increased by one point five during the year. Also, participants were generally satisfied with the weight control program and succeeded in reducing weight. We hope that we can set up this program and expand it by developing various other projects in Korea.

• 한국토양비료학회지
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• 제51권1호
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• pp.28-34
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• 2018

Yuzu (Citrus junos) gummosis disease, caused by Phytophthora nicotianae, was first reported in 1997. As known in citrus, Phytophthora is the most fastidious soil-borne pathogen to control. In order to minimize its damage to Citrus spp., integrated pest management (IPM) approach, including fungicide chemicals and resistant cultivars, is necessary. Therefore, in this study we tried to evaluate tolerance of yuzu cultivars and its related species against yuzu Phytophthora. Trifoliate orange was evaluated as a susceptible host to yuzu Phytophthora by both mycelial growth onto extract media and immature fruit inoculation. However, in zoospores spray-inoculation on 2-year-old cuttings tree, trifoliate orange appeared to have a resistant property as showing less than 6% diseased leaf rate. Among yuzu cultivars only 'Namhae No. 1' appeared resistant property against both P. nicotianae and P. citrophthora. The 'Namhae No. 1' showed 5.7% and 10.6% diseased leaf ratio by P. nicotianae and P. citrophthora, respectively. Clearly, in order to reduce damages caused by two yuzu Phytophthora, we suggest that growers may utilize a trifoliate orange as a rootstock and 'Namhae No. 1' as a scion for fruit production.

• Journal of Oral Medicine and Pain
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• 제15권1호
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• pp.125-132
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• 1991

We have previously reported that simulated snuff dipping in conjunction with type I herpes simplex virus (HSV-1) induced oral malignant changes in hamsters. Present study was designed to investigate the carcinogenic effect of tobacco specific-N-nitrosamines (TSNAs) and HSV-1, alone or in combination, in hamsters. Hamsters were divided into 6 groups and the right buccal pouch mucosa were treated as follows: Grp 1, Control (Mock inoculation) [MI]+Topical Application [TA] of mineral oil[MO] : Grp 2, TA of 1% n'- nitrosonornicotine [NNN] + IM: Grp3, TA of 1% 4-N-nitrosomethylamino-1- (3-pyridyl)-1-butanone [NNK] + MI: Grp 4, HSV-1 inoculation [HI]+TA of MO : Grp 5, TA of 1% N-nitrosonornicotine [NNN] + HI: Grp 6, TA of 1% NNK + HI. TA of MO or TSNAs was initiated 1 day after the MI or HI and given 3 times per week for 20 consecutive weeks. At the buccal pouches were fixed for light microscope examination. No animal s developed tumors or malignant histopathologic changes in the mucosa of the buccal pouches. These data indicate that individual TSNAs, alone or in conjunction with HSV-1 infection, do not develop malignant changes in hamster buccal pouches.

• International Journal of Industrial Entomology and Biomaterials
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• 제6권2호
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• pp.179-181
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• 2003

$F(ab`)_2$-ELISA and direct antigen coating-ELISA (DAC-ELISA) were evaluated in the detection of purified Bombyx mori nuclear polyhedrosis virus (BmNPV) and nuclear polyhedrosis virus infection in silkworm larvae inoculated with BmNPV polyhedra. Although nanogram levels of BmNPV was detected in both DAC- and $F(ab`)_2$-ELISA, similar concentrations of antigen was detected in case of F(ab’)$_2$-ELISA even at higher dilution of antibody (up to 1 : 20 K). One hundred percent nuclear polyhedrosis infection was detected 6 hrs after inoculation in BmNPV infected silkworm larvae by $F(ab`)_2$-ELISA. On the other hand, detection of 100% infection was observed only three days after inoculation in DAC-ELISA. In this study, it was observed $F(ab`)_2$-ELISA was more sensitive than DAC-ELISA in the detection of purified BmNPV as well as nuclear polyhedrosis infection in silkworm larvae.

• The Plant Pathology Journal
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• 제25권2호
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• pp.113-120
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• 2009

Microscopic study of chili pepper (Capsicum annuum L.) infected with Phytophthora capsici, causing Phytophthora blight of chili pepper, was conducted to compare histological and cytological characteristics in the root and stem of susceptible (C. annuum cv. Bugang) and resistant (C. annuum cv. CM334) pepper cultivars. The susceptible pepper roots and stems were extensively penetrated and invaded by the pathogen initially into epidermal cells and later cortical and vascular cells. Host cell walls adjacent to and invaded by the infecting hyphae were partially dissolved and structurally loosened with fine fibrillar materials probably by cell wall-degrading enzymes of the pathogen. In the resistant pepper, the pathogen remained on root epidermal surface at one day after inoculation, embedded and captured in root exudation materials composed of proteins and polysaccharides. Also the pathogen appeared to be blocked in its progression at the early infection stages by thickened middle lamellae. At 3 days after inoculation, the oomycete hyphae were still confined to epidermal cells of the root and at most outer peripheral cortical cells of the stem, resulting from their invasion blocked by wound periderms formed underneath the infection sites and/or cell wall appositions bounding the hyphal protrusions. All of these aspects suggest that limitation of disease development in the resistant pepper may be due to the inhibition of the pathogen penetration, infection, invasion, and colonization by the defense structures such as root exudation materials, thickened middle lamellae, wound peridems and cell wall appositions.

• The Plant Pathology Journal
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• 제15권3호
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• pp.144-151
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• 1999

Chitinase activities from Shumard oak tissues were determined to study changes in chitinase activities related to water stress. The enzyme extracted in sodium acetate buffer (0.1M, pH 4.5) was assayed by a colorimetric method. In addition, the fungal hyphae of Hypoxylon atropunctatum in xylem tissues of oak were observed through scanning electron microscopy. The enzyme in oak tissues was mainly endochitinase, and optimum pH for enzyme activity was 5. Specific chitinase activities from both of stems held under high relative humidity (ranges of 0.63-1.11 pKatal/$\mu\textrm{g}$ of protein) and stems held under low relative humidity (ranges of 0.41-0.99 pKatal/$\mu\textrm{g}$ of protein) were significantly increased following fungal inoculation with H. atropunctatum. However, there was no significant difference in chitinase activities between tissues held under high and low humidities, which might be due to fungal chitinase. Scanning electron microscopy showed holes in fungal hyphae in the xylem tissues of stems held under high humidity but not in the stems held under ow humidity, suggesting that hyphae might be hydrolyzed by plant hydolases such as chitinase.

• The Plant Pathology Journal
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• 제30권1호
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• pp.90-95
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• 2014

This study was conducted to evaluate the resistance of 212 accessions of lettuce germplasm to gray mold disease caused by Botrytis cinerea. The lettuce germplasm were composed of five species: Lactuca sativa (193 accessions), L. sativa var. longifolia (2 accessions), L. sativa var. crispa (2 accessions), L. saligna (2 accessions), and L. serriola (1 accession); majority of these originated from Korea, Netherlands, USA, Russia, and Bulgaria. After 35 days of spray inoculation with conidial suspension ($3{\times}10^7$ conidia/ml) of B. cinerea on the surface of lettuce leaves, tested lettuce germplasm showed severe symptoms of gray mold disease. There were 208 susceptible accessions to B. cinerea counted with 100% of disease incidence and four resistant accessions, IT908801, K000598, K000599, and K021055. Two moderately resistant accessions of L. sativa, K021055 and IT908801, showed 20% of disease incidence of gray mold disease at 45 days after inoculation; and two accessions of L. saligna, K000598 and K000599, which are wild relatives of lettuce germplasm with loose-leaf type, showed complete resistance to B. cinerea. These four accessions are candidates for breeding lettuce cultivars resistant to gray mold disease.

• Asian-Australasian Journal of Animal Sciences
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• 제5권1호
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• pp.159-164
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• 1992

The present study was done to examine whether inoculated and established bacteria in the digestive tract of germ-free (GF) chickens affect growth performance, energy availability, nitrogen utilization and neutral detergent fibre (NDF) digestibility of the host bird fed a high-fibre diet. Gnotobiotic (GB) chicks were made from GF birds by co-inoculating with Ruminococcus albus, and Staphylococcus warneri, only the latter of which was established in the chicken gut. No difference was detected among conventional (CV), GF and GB birds in body weight gain, food intake or food efficiency from 7 to 21 d of age. The amount of nitrogen retained was larger in CV than in GF and GB chicks. DE and ME values of the diet and NDF digestibility were higher in CV birds than in GF and GB counterparts. It was concluded, therefore, that the established bacterium S. warneri did not give any beneficial effects on the host bird as judged by growth performance, energy availability, nitrogen utilization, and NDF digestibility.

• The Plant Pathology Journal
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• 제29권1호
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• pp.87-92
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• 2013

This study was conducted to determine the Phytophthora rot resistance of 514 accessions of watermelon germplasm, Citrullus lanatus var lanatus. About 46% of the 514 accessions tested were collections from Uzbekistan, Turkey, China, U.S.A., and Ukraine. Phytophthora capsici was inoculated to 45-day-old watermelon seedlings by drenching with 5 ml of sporangial suspension ($10^6$ sporangia/ml). At 7 days after inoculation, 21 accessions showed no disease symptoms while 291 accessions of susceptible watermelon germplasm showed more than 60.1% disease severity. A total of 510 accessions of watermelon germplasm showed significant disease symptoms and were rated as susceptible to highly susceptible 35 days after inoculation. The highly susceptible watermelon germplasm exhibited white fungal hyphae on the lesion or damping off with water-soaked and browning symptoms. One accession (IT032840) showed moderate resistance and two accessions (IT185446 and IT187904) were resistant to P. capsici. Results suggest that these two resistant germplasm can be used as a rootstock and as a source of resistance in breeding resistant watermelon varieties against Phytophthora.