• Title/Summary/Keyword: Symbiotic activities

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High Resolution Spectroscopy of Raman Features in Symbiotic Stars and Young Planetary Nebulae Using the BOES

  • Lee, Hee-Won
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.59.4-60
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    • 2016
  • One important aspect of the late stage stellar evolution is the mass loss processes, where a significant amount of stellar material will be returned to the interstellar space to be used for stars of the next generation. Raman scattered O VI and He II by atomic hydrogen in symbiotic stars and young planetary nebulae are found to be excellent tools to investigate the mass loss processes and estimate the mass loss rate. These features appear near hydrogen Balmer emission lines due to the huge cross section in the vicinity of Lyman resonance transitions. With the capability of high spectral resolution and broad spectral coverage, BOES is an ideal instrument to perform Raman spectroscopy of these objects. In this talk, a cursory overview of our research activities on Raman spectroscopy of symbiotics and PNe using the BOES is presented.

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Isolation and Synthesis of Tryptamine Derivatives from a Symbiotic Bacterium Xenorhabdus nematophilus PC

  • Paik, Seung-Uk;Park, Myung-Kwang;Jhun, Seong-Hoon;Park, Heai-Ku;Lee, Chun-Soo;Cho, Bum-Rae;Byun, Hong-Sik;Choe, Seok-Burm;Suh, Seong-Il
    • Bulletin of the Korean Chemical Society
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    • v.24 no.5
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    • pp.623-626
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    • 2003
  • Nematophin and its analog incorporating tryptamine unit have been isolated and characterized from strain XRPC of a symbiotic bacterium Xenorhabdus nematophilus, which was newly isolated from Korean entomopathogenic nematodes. The stereoselective synthesis of these compounds was accomplished, and the relative configurations were determined. Nematophin exhibited potent antibacterial activities over several strains of methicillin-resistant S. aureus (MRSA) comparable to those of vancomycin.

Pharmacognostical Studies on Orchidaceae Plants (난과식물의 생약학적 연구)

  • Toh, Chung-Ae
    • Korean Journal of Pharmacognosy
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    • v.25 no.3
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    • pp.293-304
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    • 1994
  • In order to estimate accurate originality of the important crude drugs, Gastrodia, Dendrobium, Bletilla and Cremastra spp. were investigated comparing their morphological, anatomical and physicochemical characteristics and antibacterial, antifungal activities. The results of the studies as follows: 1. In morphological and anatomical studies, Korean Gastrodia contained more mucilage duct and symbiotic fungi than imported Gastrodia. Korean Dendrobium contained starch grains but without starch grains in the imported Dendrobium from China enclosed with thicken silicified wall. The corm of Cremasta appendiculata contained raphides of bundles with mucilage while the bulbs of Tulipa edulis contained several various starch grains form. 2. In physiological and TLC analysis, crude drugs in Orchidaceae contained common constituents with fluorescence and much mucilage. 3. The EtOH extracts of Gastrodia, Dendrobium, Bletilla, Cremastra showed antibacterial activities against B. subtilis and E. coli (Dendrobium>Gastrodia>Bletilla>Cremastra). But, no antifungal activities against C. albicans, A. niger were observed.

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The Effect and Satisfaction Level of After-school Cooking Activities for the Children of Multicultural Families (다문화 가정 아동을 위한 방과후 요리활동 프로그램의 만족도 및 효과)

  • Yoon, Sun Hye;Park, Shin Jin;Jin, So-Yeon
    • Journal of the Korean Society of Food Culture
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    • v.30 no.5
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    • pp.491-501
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    • 2015
  • This study examined the satisfaction level and effects of after-school program cooking activities in children of multicultural families. A total of 135 children of general and multicultural families from 3th to 6th grades and their 11 teachers were surveyed, and 75 multicultural family children underwent a cooking activity program. Children of multicultural families showed higher participation in cooking activities than other Korean children. Children of multicultural families wanted to be involved in cooking activity programs after school more than other Korean children. These children also showed a higher rate of wanting to cook Korean foods compared to children of general families. Regarding reasons for participating in cooking activities, 'I think I'm glad to be served delicious food' response was the most common. Children of multicultural families showed higher participation in cooking activities than children of general families. Regarding school life changes, children of multicultural families were found to be less picky of foods in general as well as kimchi and vegetables. In conclusion, cooking activity programs for children of multicultural family showed beneficial effects on diet and understanding of Korean culture.

Current Status of Korean Lichen Research -Beginning and Prospect

  • Hur Jae-Seoun;Koh Young Jin
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2003.05a
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    • pp.16-18
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    • 2003
  • Lichen is one of the most widely distributed eucaryotic organisms in the world. Lichen is the result of a symbiotic association between two unrelated organisms - a fungus and an alga (or cyanobacterium). Researches in Korean lichens were mainly focused on investigation of Korean lichen flora and most of them were primitive and short-term based projects until 1990's. In this communication, current status and prospect of Korean lichen research are briefly discussed with emphasis of KoLRI (Korean Lichen Research Institute) activities and roles in national research projects on bioresource development in Korea.

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Screening on Receptor Tyrosine Kinase Inhibitory Activity of Marine Algae-Derived Symbiotic Microorganisms (해조류 공생미생물의 Receptor Tyrosine Kinase 억제효능 검색)

  • Yun, Keum-Ja;Yang, Guohua;Feng, Zhile;Nenkep, Viviane N.;Xavier, Siwe-Noundou;Leutou, Alain S.;Kim, Gun-Do;Cho, Hee-Yeong;Choi, Hong-Dae;Son, Byeng-Wha
    • Korean Journal of Pharmacognosy
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    • v.41 no.1
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    • pp.43-47
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    • 2010
  • In order to screen new receptor tyrosine kinase inhibitor which is expected to be anticancer drug lead, we have investigated receptor tyrosine kinase inhibitory activity on the marine alga-derived symbiotic microorganisms (500 strains). The significant activities (over 70% inhibition at $10\;{\mu}g/ml$) were observed in the extracts of ten strains (Strain No.: MFA018, 019, 206, 242, 325, 335, 343, 344, 354, 356), isolated from marine red algae, five strains (Strain No.: MFA030, 126, 213, 324, 339), isolated from the brown algae, and one strain (Strain No.: MFA272), isolated from the marine green algae, respectively. Among the active strains, MFA019 and 356 showed strong receptor tyrosine kinase inhibitory activity with $IC_{50}$ values of 0.6 and $0.9\;{\mu}g/ml$, respectively.

THE SPECTROSCOPIC CHARATERISTICS OF 23 SYMBIOTICS (23개 공생별의 분광학적 특성)

  • KIM YEOJEONG;HYUNG SIEK;ALLER LAWRENCE H.
    • Publications of The Korean Astronomical Society
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    • v.15 no.spc1
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    • pp.133-145
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    • 2000
  • Symbiotic stars are known as binary systems with both cool and hot components with enshrounding nebulous gas. The cool component, M-type giant, is presumably loosing its mass into a hot white or main sequence companion star through the inner Lagrangian point. The lines emit from the ionized nebulous region around the hot star while the mass loss or accretion activity is believed to be the main cause of sudden variation of the continuum and line fluxes. We selected 17 symbiotics for which the emission line fluxes were measured from the IUE SWP, LWR data, to find variability of spectrum. We also investigated the periodic variation of emissions or eclipsing effect from the IUE lines. All of our symbiotics show very high electron densities in the emission regions. For other optical symbiotics, the observations had been carried in 1999 with BOAO mid-resolution spectrometer. We classified symbiotics based on their outburst activities, or emission line characteristics, i.e., $OVI{\lambda}6830.\;The\;OVI{\lambda}6830$ emission lines are also found in S-type symbiotics, which have been known as charateristics of D-types.

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An Effect of CSR Engagement on Brand Image in the Food Service Industry (푸드서비스 산업에서 CSR의 참여 효과가 브랜드 이미지에 미치는 영향)

  • Xue, Jiyu;Kim, Changsik;Ham, Sunny
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.15 no.1
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    • pp.157-172
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    • 2019
  • The purpose of this study was to explore the moderating effect of food safety scandals on the relationship between food company's Corporate Social Responsibility(CSR) engagement at different levels and brand image in the Chinese dairy company context. In addition, this study also examined the mediating effect of brand image on CSR engagement and consumer loyalty. The study adopted a $2{\times}2$ between-subjects experimental design using scenarios. Four scenarios provided a mixed combination of yes or no cases for food safety scandal, and high or low cases for a dairy company's CSR engagement. In this study, survey was used to collect data from Chinese consumers. Of these, 377 valid data were collected from a sample of average Chinese consumers over the age of 20, collected through the internet. The results show that CSR engagement at different levels has a significant effect on brand image and food safety scandal has a significant moderating effect on the relationship between the two. This study expanded the previous study on the sensitivity of consumers to CSR activities in eastern China. At the same time, according to the results of the study, different CSR engagement of food enterprises does have a significant impact on brand image and consumer loyalty. In particular, high CSR engagement reduces negative impact on brand image through the moderating effect of food safety scandals. Therefore, for food business managers, actively participate in CSR activities, and actively enhance the engagement has a significant influence on the management of brand image.

Studies on Symbiotic Nitrogen Fixation in Soybean -I. Methods of Measurement and Amounts of Symbiotic N2 Fixation in Soybean Root Nodules (대두근류균(大豆根瘤菌)의 질소고정(窒素固定)에 관(關)한 연구 -I. 대두(大豆) 근류균(根瘤菌)의 질소고정력(窒素固定力) 측정방법(測定方法) 및 질소고정량(窒素固定量))

  • Ryu, Jin-Chang;Lee, Sang-Kyu;Lee, Hyuk-Ho;Hong, Chong-Woon;Cho, Moo-Je
    • Korean Journal of Soil Science and Fertilizer
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    • v.15 no.4
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    • pp.277-283
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    • 1982
  • A series of experiments were conducted on procedures of $N_2$ fixation measurements with soybean (Glycine max. L.) root nodules by acetylene reducing assay and estimation of amounts of $N_2$ fixed by soybean root nodules grown in the pot. The results are summarized as follows; 1. In case of nitrogen fixing activities were determined by means of acetylene reducing method, more appropriates results were obtained with direct determination of root nodules which was adhering from root under 2 hours after incubation, while more fluctuated data was obtained with root nodules determined under separated conditions. 2. The weight of soybean nodules was linearly increased from 17 days to 55 days after planting, whereas, the amounts of $N_2$ fixation from soybean nodules were Peaked at 38 days after planting, and declined thereafter. 3. When calculated upon the basis of the amounts of $N_2$ fixed as measured by acetylene reducing activities in single soybean plant, it was found that the average amount of symbiotic $N_2$ fixation falls in the range of 80 kg N per ha.

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Studies on streptomycin resistant mutant strains of rhizobium trifolii (Rhizobium trifolii의 스트렙토마이신 내성 돌연변이주의 특성)

  • 신종희;허연주;이영록
    • Korean Journal of Microbiology
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    • v.25 no.4
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    • pp.290-296
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    • 1987
  • Some streptomycin resistant strains of Rhizobium trifolii having nodulation ability were selected, and their nitrogenase activities, symbiotic effects on plant growth, and nodule electronmicroscope were compared with those of the wild type. After NTG treatment, as a mutagen, at the concentration exhibiting 99.7% lethal rate, 5 strains of streptomycin resistant mutant having nodulating ability were selected. Among these nodulating mutant strains, 3 strains produced more nodules and 2 strains showed less nodules than wild type. But their nitrogenase activities were decreased significantly, and nodule formation time was also delay compared with those of the wild type, and there was no remarkable difference in effects on plant growth. Microstructure of nodules by electronmicroscopy had mant distinctive differences between red clover nodules inoculated with wild type and mutants.

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