• Title/Summary/Keyword: frequency re-growth

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Prevention of Oak Wilt by Tree Injection of Culture Suspension of an Antifungal Microorganism, Streptomyces blastmyceticus against Oak Wilt Fungus, Raffaelea quercus-mongolicae

  • Lee, Jin Heung;Hong, A Reum;Yun, Ji Ho;Seo, Sang Tae;Lee, Jong Kyu
    • Journal of Forest and Environmental Science
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    • v.34 no.5
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    • pp.376-381
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    • 2018
  • For the control of oak wilt caused by Raffaelea quercus-mongolicae, an antifungal microorganism, Streptomyces blastmyceticus, was used as a potential agent. Culture suspension of S. blastmyceticus was injected into Quercus mongolicae in the research forest of Kangwon National University by $ChemJet^{(R)}$ trunk injection and Macro-infusion at root flare injection. $Alamo^{(R)}$ (a.i., propiconazole 14.5%), a fungicide currently used for the control of oak wilt in USA, was also treated by both methods to compare the efficacy. For preventive efficacy, culture suspension of the pathogen was inoculated at 1 month after injection of either agent. Tested trees were cut at 3 months after treatment, stained with 1% Fuchsin acid, and then non-conductive area (NCA) and re-isolation frequency (RIF) of oak wilt fungus were compared among treatments. While NCA was the highest as 47.3% in pathogen only treatment, it was the lowest as 16.0% in sterilized water treatment by Macro-infusion. NCAs of Alamo treatment by Macro-infusion and ChemJet injection were 25.3% and 32.1%, respectively. NCA of S.blastmyceticus treatment by ChemJet injection was 32.3%, similar with Alamo treatment's by ChemJet injection. All treatments by either injection method showed significantly lower NCA compared to the pathogen only treatment. These results indicate that S. blastmyceticus injection shows the preventive efficacy against oak wilt disease by suppressing the growth of pathogen injected. NCA of Macro-infusion injection of sterilized water was lower as 16.0%, compared to 21.3% of ChemJet injection. It means that Macro-infusion is more effective in translocation of sterilized water than ChemJet injection by even distribution. RIF from wood discs of treated trees showed high in pathogen only treatment, but relatively low in S. blastmyceticus treatment. RIF results were correlated with NCA results. From the above results, it was confirmed that S. blastmyceticus showed preventive efficacy against oak wilt disease by ChemJet trunk or Macro-infusion at root flare injection.

Nutritional Education Status and Recognition of the Importance of Elementary School Dietitians in the Gyeongnam Area (경남지역 초등학교 영양사의 영양교육 실시현황 및 인식조사 - 공동관리 여부와 경력을 중심으로 -)

  • 허은실;양한라;윤현숙;이경혜
    • Korean Journal of Community Nutrition
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    • v.7 no.6
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    • pp.781-793
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    • 2002
  • This study was carried out to investigate the nutritional education status and the recognition of the importance of elementary school dietitians (N=183) in the Gyeongnam area. The results are summarized as follows. All subjects took part in nutritional education program, but the educational methods were passive, as in the case of “home correspondence”(80.8%) and “bulletin board poster”(16.4%), and the education frequency was very low as in “one time/month”(90.2%). The subjects thought “as an independent subject”(41.5%) and “as a related subjects”(35.1%) were suitable teaching venues for the nutritional education. They were very low in individual counseling (4.5%) for school children because of “lack of opportunity”(42.2%) and “heavy work load”(24.1%). However, most of the subjects wished that nutritional counseling could offered in the future (95.5%). The parents' experience of nutritional education was also low (34.3%). Information sources for nutritional education were mainly the “internet”(53.1%) and “re-educational materials” (25.0%). The available instructional materials included “printed materials”(96.7%), “exhibition bulletin materials” (70.3%) and “electronic materials”(46.4%). The preferred education materials were “exhibitionㆍbulletin materials”(32.2%), “printed materials”(29.2%), and “electronic materials”(27.7%). However, materials they wished to purchase were “electronic materials”(54.5%) and “cubic materials”(26.0%). These results show a difference between the preferred materials and the possessed materials. Most school dietitians (98.4%) recognized the necessity of nutritional education with respect to “good table manners”(42.0%), “correction of food prejudices”(30.3%), and “proper nutrition for growth”(21.0%) Although they had a great interest in nutritional education, they had difficulty in cutting their teaming into practice because of “heavy work load”(30.9%), “lack of a systematic curriculum”(25.2%), and “lack of a educational opportunity”(22.8%). Ninety five percent of subjects wished to have nutrition education taught as an independent subject. They pointed out “kindergarten”(60.0%) and “lower grades in elementary school”(33.9%) as the optimal starting times for nutritional education and “school dietitians”(91.3%) as suitable teachers for these programs. The required topics chosen by the subjects for nutritional education for children were “proper eating habits”(54.2%) and “nutritional problem”(31.5%). The dietitians thought “food prejudices”(44.7%), “rat too much processed and instant foods”(36.5%), and “obesity”(11.8%) were the most common nutritional problems among elementary school children. These results suggest the necessity of solving the nutritional problems in children by developing a nutritional education program. Along with this program, if dietitian assisted programs for parents were developed, the effects of nutritional education could definitely be increased.

A Study on Content Characteristics, Consumer Behavior and Economic Value According to the Degree of Consideration of Graphic Content (그래픽 콘텐츠 고려 정도에 따른 콘텐츠 특성, 소비자 행동, 경제적 가치에 관한 연구)

  • Lee, Sangho;Cho, Kwangmoon
    • Journal of Internet of Things and Convergence
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    • v.7 no.4
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    • pp.85-94
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    • 2021
  • This study verified what differences in screen golf content characteristics, intention to reuse, customer satisfaction and economic value experienced by consumers according to the image feeling, expression method, and image color provided by screen golf graphic content. In addition, the purpose of this study was to analyze what kind of influence the content characteristics of screen golf have on the economic value and what kind of influence the intention to reuse and customer satisfaction have in this process. From September 1, 2021 to September 30, 2021, a survey of 225 copies of consumers using the screen golf course was conducted. For data processing, frequency analysis, factor analysis, reliability analysis, cluster analysis, chi-square analysis and 3-step mediated regression analysis were performed. The research results are as follows. First, the preferred image feeling showed a high level of clean and sophisticated feeling and the preferred expression method showed a high realistic image. In addition, the preferred image color showed a high level of green color. Second, there were differences in competitiveness, ease of use, sense of solidarity and realism according to the degree of consideration of graphic content and differences in consumer's intention to reuse, customer satisfaction, and economic value. Third, in the relationship between screen golf content characteristics and economic value, customer satisfaction and re-use intention had a mediating effect. Through this study, by providing basic data to derive the graphic design model of screen golf, the operating entity suggested a way to improve economic benefits and tried to contribute to the growth of the screen golf industry.

Evaluation of Grassland Grade by Grassland Vegetation Ratio (초지식생비율에 의한 초지등급평가 연구)

  • Lee, Bae Hun;Kim, Ji Yung;Park, Hyung Soo;Sung, Kyung Il;Kim, Byong Wan
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.40 no.1
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    • pp.29-36
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    • 2020
  • This study was conducted to suggest the new grassland grade system on evaluating the grassland status. The grassland status has been evaluated based on the forage yield (good, fair and poor) by municipal authorities. The grassland grades by current system were 19 good, 11 fair and 11 poor among the 41 grassland farms from 6 provinces. This evaluation result differed greatly from the result of actual measurement of forage yields which showed all poor. The big difference was resulted from failing the reflection of the various characteristics, such as different seasonal growth and harvest frequency. Furthermore, the lack of consistent examining date and method added the inaccuracy of current grassland grade system. The new grassland grade system based on the grassland vegetation ratio (grass, weed and bare soil) was initially designed into 6-grade system (1st; 100~80%, 2nd; 79~60%, 3rd; 59~40%, 4th; 39~20%; 5th; 19~1% and 6th; 0% on the basis of grasses proportion), but later was changed into 4-grade system (1st, 2nd, 3rd, and 4th grades are 70% or more, 50% or more, 50% or less, and 0% of forage proportion, respectively) after reflecting the opinion of grassland farms and municipal authorities. Re-evaluation on the grassland status using the 4-grade system resulted in the total 80% consisted of 2nd, 3rd and 4th grade which means most grasslands needs the partial reseeding or the rehabilitation of entire grassland. Pictures and schematic diagrams depicting the 4-grade system were presented to improve the objectivity of evaluation. The optimal time for assessing grassland status is fall when plant height 20~30 cm. Conclusively, the 4-grade system is an efficient method for all non-professionals including grassland farms or municipal authorities in assessing the grassland status. To apply this system to the field, the institutional arrangements such as amendment of grassland act should take place in advance.

Application of a New Conjugation Method to Fish Pathogenic Bacteria Containing R Plasmid for the Analysis of Drug-Resistant Status in Aquaculture (새로운 conjugation 방법을 응용한 R plasmid 함유 어병세균의 분리와 양식장 내성균의 현황 분석)

  • Yoo Min Ho;Jeong Joon Beom;Kim Eun Heui;Lee Hyoung Ho;Jeong Hun Do
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.2
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    • pp.115-121
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    • 2002
  • To develop a new method of conjugation and to determine the distribution of R plasimds, we isolated multi-drug resistant strains from fish pathogenic bacteria in the farms of south and east seacoasts of Korea. Out of the 134 isolates examined, 10 showed resistance to chloramphenicol, tetracycline, streptomycin, ampicillin, colistin, nalidixic acid, oxolinic acid and kanamycin. One out of 10 multi-drug resistance bacteria, Vibfio damsela JE1 (V. damsela JE1), contained transferable R plasmid of chlorarnphenicol- tetracycline resistance genes and other nucleic acids encoding ampicillin and kanamycin resistance. The presence of the R plasmid was confirmed by conjugation using the chromocult medium (CC) as a selective and differential medium for transconiugants with identification based on the growth or colors of the colonies. The frequency of R plasmid transfer with filter mating method was come out much higher than that of broth mating method and appeared to be dependent upon the mating time and temperature. The optimum conditions for filter mating method were found to be 30$^{\circ}C$ and 24hrs as mating temperature and period, respectively, Moreover, donor cells with R plasmid, both isolate and standard bacteria, were shown to have an ability to transfer the plasmid against Escherichia coli K-12 HB101 (E. coli HB101) and Edwardsiella tarda (E. tarda) RE14 at fairly high frequencies, finally, we isolated 3 isolates of Sphingomonas sp., carrying R plasmid from 12 multi-drug resistant bacteria in normal microflora of the flounder (Paralichthys olivaceus) group used for the isolation of V emsela JE1 four months before. The same size and gene transfer chayateristics of R plasimds with those of V damsela JE1 confirmed that normal microflora have the reservoir activity for R plasmid in natural aquatic environment.