• Title/Summary/Keyword: Environmental Studies

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Population Dynamics of Phage-Host System of Microlunatus phosphovorus Indigenous in Activated Sludge

  • Lee, Sang-Hyon;Otawa, Kenichi;Onuki, Motoharu;Satoh, Hiroyasu;Mino, Takashi
    • Journal of Microbiology and Biotechnology
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    • v.17 no.10
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    • pp.1704-1707
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    • 2007
  • Monitoring of the phage-host system of Microlunatus phosphovorus indigenous in activated sludge was attempted. A laboratory-scale activated sludge process was operated for 5 weeks with synthetic wastewater. The phage-host system population in the process was monitored by plaque assay and FISH methods at every 3 days. During the process operation, the phage-host system populations were more or less steady, except for 1 week in the middle of the operation. In that period, initially M. phosphovorus decreased significantly and its lytic bacteriophages increased, and then M. phosphovorus increased back to its original level while its lytic bacteriophages decreased. This observation suggests that lytic bacteriophages should be considered as one of the biological factors affecting the bacterial population dynamics in activated sludge processes.

Plant growth promoting rhizobacteria that decrease chromium toxicity in Brassica juncea

  • M. Rajkumar;Lee, Kui-Jae;Lee, Wang-Hyu;R. Nagendran
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2003.10b
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    • pp.14-14
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    • 2003
  • The aim of the present study isto assess the importance of siderophore producing rhizosphere bacteria on the growth of Brassica junceaunder chromium stress. Pseudomonassp. (A4) produced an iron chelating substance siderophores in iron deficient medium. Under chromium stress condition Pseudomonassp. (A4) markedly increased the root and shoot length and also biomass of Brassica juncea as compared to Pseudomonas sp. (A3). This plant growth promotion has been related to the microbial production of siderophore.

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Growth of Phaseolus mungounder chromium stress - influence of chromate reducing bacteria

  • M. Rajkumar;Lee, Kui-Jae;Seo, Jae-Hwan;Lee, Wang-Hui
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2003.10b
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    • pp.57-57
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    • 2003
  • The plant growth promoting rhizobacteria (PGPR), Pseudomonas sp. (A3) and Bacillus sp. (AT33) were isolated from the rhizosphere of Amaranthus blitum collected from soil contaminated with chromium. Bothbacterial strains quantitatively reduced hexavalent chromium to trivalent chromium. Pseudomonas sp. broughter greater conversion of Cr6+ in the medium (100%) as compared to Bacillus sp.(62%). Phaseolus mungo seeds inoculated with Pseudomonas sp. or Bacillus sp. were grown under different concentration of chromium. The monitoredparameters included elongation of shoot and root, fresh weight, dry weight and concentration of chromium in the shoot and root systems. As compared to non inoculated seedlings those inoculated with A3 and AT33 exhibited better growth.

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Effect of UV -B radiation on seedlings of two Solidago virgaurea populations from the Mt. Hakusan area of Japan

  • Nakajima, Nobuyoshi;Takahashi, Shinya;Tamaoki, Masanori;Kubo, Akihiro;Aono, Mitsuko;Saji, Hikaru
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.400-402
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    • 2002
  • We collected seeds of Solidago virgaurea plants growing at different altitudes on the Mt Hakusan area in Japan and cultivated them in a naturally-lit green house. Three-week-old seedlings were irradiated with supplemental UV-B for 12 h each day for 1 and 2 weeks. After a week of itradiation the seedlings of the population collected from the higher altitude at Oh-nanjiho (ON) had accumulated more anthocyanins than those from the lower altitude at Bettoh-deai (BD). Levels of anthocyanins in the ON seedlings were highly correlated with the dose of UV-B radiation and the correlation was also observed after 2 weeks. The growth of the third leaves was retarded by UV-B radiation in both populations. The extent of growth retardation in the third leaves was correlated with the dose of UV -B radiation in both populations. However, no significant difference in the extent of leaf area growth was observed between the ON and BD populations. The increase in plant fresh weight was extensively inhibited in the ON seedlings after 1 week of UV-B radiation. The inhibition was recovered to those in the BD population by 2 weeks irradiation. These results indicate that these populations respond differentially to supplementary UV -B radiation during the first week. Because flavonoids such as anthocyanins play an important role in protection against UV-B radiation in many plants, populations growing at higher altitude may be better able to adapt to increased global levels of UV-B radiation.

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CEP-CFP Relationship and Its Moderators : A Meta-analysis (환경성과와 재무성과 간의 관련성과 조절요인에 관한 메타분석)

  • Yook, Keun-Hyo
    • Journal of Environmental Policy
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    • v.13 no.1
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    • pp.25-47
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    • 2014
  • We examined the heterogeneity in the financial -environmental performance nexus, carrying out a meta-analysis of 48 outcomes from 26 empirical studies. Multiple correspondence analysis (MCA) was performed in this study to facilitate the analysis of the structural relationship among an array of study characteristics. As expected, the results of analyzing the multiple studies of the general corporate environmental performance and financial performance link suggested a significant positive relationship. Some of the results of the moderator analysis suggest that empirical studies using self-reporting measurement and structural equation method benefited from environmental performance as much as or more than the archival and regression method.

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Ecological land cover classification of the Korean peninsula Ecological land cover classification of the Korean peninsula

  • Kim, Won-Joo;Lee, Seung-Gu;Kim, Sang-Wook;Park, Chong-Hwa
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.679-681
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    • 2003
  • The objectives of this research are as follows. First, to investigate methods for a national-scale land cover map based on multi-temporal classification of MODIS data and multi-spectral classification of Landsat TM data. Second, to investigate methods to p roduce ecological zone maps of Korea based on vegetation, climate, and topographic characteristics. The results of this research can be summarized as follows. First, NDVI and EVI of MODIS can be used to ecological mapping of the country by using monthly phenological characteris tics. Second, it was found that EVI is better than NDVI in terms of atmospheric correction and vegetation mapping of dense forests of the country. Third, several ecological zones of the country can be identified from the VI maps, but exact labeling requires much field works, and sufficient field data and macro-environmental data of the country. Finally, relationship between land cover types and natural environmental factors such as temperature, precipitation, elevation, and slope could be identified.

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