• Title/Summary/Keyword: isolation forest

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Characterization of NAD-Dependent Formate Dehydrogenase from Trametes versicolor Using a Cell-Free Protein Expression System

  • LEE, Su-Yeon;JANG, Seokyoon;LEE, Soo-Min
    • Journal of the Korean Wood Science and Technology
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    • v.50 no.3
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    • pp.159-166
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    • 2022
  • CO2 emissions are the primary reason for global warming; hence, biological and chemical technologies for converting CO2 into useful compounds are being actively studied. Biological methods using enzymes can convert CO2 under mild conditions. Formate dehydrogenase (FDH) is a representative CO2 conversion enzyme. Its function was revealed after isolation from bacteria, yeast, and plants. In this study, we evaluated the CO2 conversion potential of FDH isolated from wood-rotting fungi. After isolating the FDH gene (TvFDH) from Trametes versicolor, we cloned the full-length FDH from T. versicolor and expressed it in a cell-free expression system. The gene encoding TvFDH was identified as 1,200 bp open reading frame (ORF) and the expected molecular weight of the protein was approximately 42 kDa. Overexpression of the recombinant crude protein including TvFDH was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Enzyme activities and metabolite analyses confirmed the efficiency of TvFDH for CO2 reduction.

Qualitative Assessment of Experience on Urban Forest Therapy Program for Preventing Dementia of the Elderly Living Alone in Low-Income Class

  • Lee, Hyun Jin;Son, Sung Ae
    • Journal of People, Plants, and Environment
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    • v.21 no.6
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    • pp.565-574
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    • 2018
  • Previous studies have shown that forest therapy program can help prevent dementia. However, few studies have focused on low-income elderly people living alone. The current study examined the meanings that the elderly living alone receiving medical care assigned to the urban forest therapy program, as a way to understand the pathways that nature-based intervention affect preventing dementia. Twenty-one participants were recruited and they participated in a five-week urban forest therapy program. Semi-structured interviews were carried out with 21 participants who experienced the urban forest therapy program, and analyzed qualitative data using thematic analysis. Results showed that all themes identified were related to connectedness with oneself, neighbors and nature. Awarenesses of change were consisted of positive and negative themes. The themes of positive awareness were improvements of mental and emotional condition, feelings of isolation and loneliness, and health-related lifestyle. The negative themes were terminations of short-term programs and inconvenient access to the urban forest. Based on these data, we suggest an urban green welfare framework for future research and interventions for preventing dementia of underprivileged elderly group.

Studies on Factors Affecting Isolation and Fusion of Protoplasts of Quercus Species (참나무류(類)의 원형질체(原形質體) 분리(分離) 및 융합(融合)에 영향(影響)을 끼치는 요인(要因)에 관한 연구(硏究))

  • Hyun, Jung Oh;Kim, Jae Hun;Chang, Suk So
    • Journal of Korean Society of Forest Science
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    • v.71 no.1
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    • pp.66-73
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    • 1985
  • Factors affecting isolation and fusion of protoplasts of three Quercus species were investigated and procedures for isolation, purification and fusion of protoplasts of the three species were also established. Unhardened leaves and rapidly growing callus cultures were good source of viable protoplasts. The optimum composition of enzyme mixture for rapid isolation of protoplasts from leaf mesophyll tissues and calli was Cellulase Onozuka R-10 (20g/l, Macerozyme R-10(10g/l), Pectinase(250 units/l, $CaCl_2$, $2H_2O$(14mM), $MgSO_4{\cdot}7H_2O$(1.8mM), $KNO_3$(1.0mM), $H_3BO_3$(1.0mM), $KH_2PO_4$(0.2mM), KI($1.0{\mu}M$), 1,4-dithiothreitol (0.1mM) and mannitol (0.6M). Optimum density of protoplasts for maximum fusion was $2{\times}10^5/ml$ which was the highest protoplast density given in this study. Optimum concentration and duration of PEG 1450 treatment for inducing fusion appeared to be 29%(W/V) final PEG 1450 concentration and 5-10 minutes, respectively.

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A Research Trend on Utilization of the Byproducts(Lignin) from Bioethanol Production Process with Lignocellulosic Biomass: A Literature Review (목질바이오매스 에너지 부산물(리그닌)이용에 관한 연구 동향)

  • Kim, Yeong-Suk
    • Journal of Forest and Environmental Science
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    • v.27 no.3
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    • pp.183-194
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    • 2011
  • This study reviewed on the research trend of sources and utilization of the byproducts(Lignin) from bioethanol production process with lignocellulosic biomass such as wood, agri-processing by-products(corn fiber, sugarcane bagasse etc.) and energy crops(switch grass, poplar, Miscanthus etc.). During biochemical conversion process, only Cellulose and hemicellulosic fractions are converted into fermentable sugar, but lignin which represents the third largest fraction of lignocellulosic biomass is not convertible into fermentable sugars. It is therefore extremely important to recover and convert biomass-derived Lignin into high-value products to maintain economic competitiveness of cellulosic ethanol processes. It was introduced that lignin types and characteristics were different from various isolation methods and biomass sources. Also utilization and potentiality for market of those were discussed.

Land cover change and forest fragmentation analysis for Naypyidaw, Myanmar (미얀마 네피도 지역의 도시개발로 인한 토지피복변화 탐지 및 산림파편화 분석)

  • Kong, In-Hye;Baek, Gyoung-Hye;Lee, Dong-Kun
    • Journal of Environmental Impact Assessment
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    • v.22 no.2
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    • pp.147-156
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    • 2013
  • Myanmar(Burma) has been preserved valuable environmental resources because of its political isolation. But recently, Myanmar has moved a capital city(Naypyidaw) at central forest area and it has been urbanized radically since 2005. In this paper, we built multi-temporal land cover map from Landsat images of 1970s to 2012 with ENVI 4.5 software. For a broad approach, administrative district Yamethin which includes Naypyidaw is classified into 3 classes and with only Naypyidaw region is classified with 4-5 classes to analyse specific changes. And with forest cover extracted by Object Oriented Classification, we evaluated forest fragmentation before and after the development using Patch Analyst(FRAGSTATs 3.3) at Yamethin area. For Yamethin area, there were significant forest cover change, 51% in 1999 to 48% in 2012, and for Naypyidaw area, 67% in 1999 to 57% in 2012 respectively. Also landscape indices resulted from Patch Analyst concluded that the total edge, edge density and mean shaped index of forest patches increased and total core area is decreased. It is attributed from land cover change with urbanization and agricultural land expansion.

Actual Vegetation and Vegetation Structure of Tongyoung District in Hallyo-Haesang National Park (한려해상국립공원 통영지구의 현존식생 및 식생구조)

  • 오구균;추갑철;지용기
    • Korean Journal of Environment and Ecology
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    • v.12 no.4
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    • pp.317-330
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    • 1999
  • To study the actual vegetation and vegetation structure of Tongyoung district and Yokjido (Island) in Hallyo-Haesang National Park, thirty seven plots were surveyed in July,1998. The vegetation structure of the surveyed plots were dissimilar in virtue of geographical isolation and artificial disturbance. The actual vegetation were classified into five group: Pinus thunbergii forest, P. thunbergii-P. densiflora- deciduous broad-leaved forest, deciduous broad-leaved forest, P. thunbergii-P. densiflora-evergreen broad-leaved forest, evergreen broad-leaved forest. P. thunbergii forest was a major vegetaion type of the surveyed area and evergreen broad-leaved forests were distributed at Ch'ubongdo, Yongch'odo, Pijindo, Yokjido and Youjado as a small patch. Successional sere shall be assumed from Pinus thunbergii, Pinus densiflora, and deciduous broad leaved trees to Neolitsea sericea, Cinnamomum japonicum and Persea thunbergii via Castanopsis sieboldii.

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An Analysis of Urban Green Network using Nearest Features Model in Korean Metropolitan Cities (최근린사상법을 활용한 6대 광역시 녹지네트워크 경향 분석)

  • Oh, Jeong-Hak;Jang, Gab-Sue;Kim, Yong-Bum
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.5
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    • pp.135-145
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    • 2010
  • This study was carried out to investigate the current urban forest network and future plan of forest framework using nearest features program where stepping stones within 5km from the core forest were selected in the program. We found several conclusions as follows: First, we found that cities in inland area including Daegu, Dajeon and Gwangju have quite different types of forest network with comparing to the cities nearby coastline including Busan, Incheon and Ulsan. The cities in inland area have large mountain patch around each city. However they have small and lower number of island forests within their urban area. Otherwise, cities nearby coastline have more forest patches than in the cities in inland area, and Busan and Incheon especially have strong forest network using various size of forest patches. Second, Daegu and Daejeon have much smaller forest patches distributed in each urban area. So additional forest patches should be added to have highly strong forest network within urban area. Third, Ulsan and Gwangju have most stepping-stone forests close to the large mountain patches in suburban area, which are not able to connect to the forest patches in the central area of each city So additional forest patches are needed to be added in the central area of each city for reinforcing the effect of stepping stone in the central area. Though there should be an addition approach except for forest size and its isolation to construct the ecological network in an urban area, this indices can be a good method to check an environmental and ecological status in an urban area.

Genetic diversity and structure of natural populations of Picea jezoensis in South Korea

  • Lee, Seok Woo;Yang, Byeong Hoon;Hur, Seong Doo;Lee, Jung Joo;Song, Jeong Ho;Moriguchi, Yoshinari
    • Journal of Korean Society of Forest Science
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    • v.97 no.2
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    • pp.187-195
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    • 2008
  • Picea jezoensis (Sieb. et Zucc.) Carriere is one of the major and widespread components of the cold-temperate and boreal forests in Russian Far East, northeast China, Korea, and Japan. However, it is restricted to a highly fragmented range in South Korea with small populations. Mean expected heterozygosity $(H_e)$ based on 22 loci in 11 isozyme systems was 0.077 for four sampled populations that covered the whole distribution range of P. jezoensis in South Korea. This value is within the range reported for conifers, but it is very low compared to that of other spruce species as well as that of P. jezoensis populations in Russian Far East. Most populations had a slight excess of heterozygotes and the Wright's $F_{IS}$ (-0.019) was comparable to that previously reported for other spruce species. In all of the four populations, the Wilcoxon sign-rank test indicated no greater heterozygosity than that expected for populations at mutation-drift equilibrium, suggesting that the populations have not been bottlenecked recently. Despite a fragmented range and isolated populations, population differentiation was not high $(F_{ST}=0.047)$ and the number of migrants per generation was 5.09. Nei's genetic distances were also small $({\bar{D}}=0.005)$ but strongly related to geographic distances between populations, suggesting an Isolation by Distance. The northernmost isolate, Mt. Gyebang population was genetically distinct from the other three populations. Implications for the conservation of genetic variation of P. jezoensis in South Korea were discussed.

A Preliminary Population Genetic Study of an Overlooked Endemic ash, Fraxinus chiisanensis in Korea Using Allozyme Variation

  • Lee, Heung Soo;Chang, Chin-Sung;Kim, Hui;Choi, Do Yeol
    • Journal of Korean Society of Forest Science
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    • v.98 no.5
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    • pp.531-538
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    • 2009
  • We used enzyme electrophoresis to evaluate genetic diversity in five populations of endemic ash, Fraxinus chiisanensis in Korea. Of 15 putative allozyme loci examined 26.7% were polymorphic and expected heterozygosity for the species was low (0.082). Within the range, population were highly differentiated ($F_{ST}$=0.356) and little genetic variation was explained by geography. The pattern of distribution of variation showed low genetic variation within populations and pronounced divergence among populations, which was consistent with the prediction for the effects of limited gene flow and local genetic erosion. Although the frequencies of male plants were dominant ranging from 79.3% to 89.4%, most mating events seems to be inevitable mating between relatives in small populations based on heterozygote deficiency of this species. Small effective population size and the limited dispersal contributed to the low rates of gene flow within as well as between populations.