• Title/Summary/Keyword: growth of population

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Competitive Growth and Attachment of Listeria monocytogenes and Lactococcus lactis ssp. lactis ATCC 11454

  • Lee, Shin-Ho;Frank, Joseph-F.
    • Journal of Microbiology and Biotechnology
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    • v.2 no.2
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    • pp.73-77
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    • 1992
  • The effect of a nisin-producing Lactococcus lactis spp. lactis (L. lactis) on the growth and attachment of Listeria monocytogenes Scott A and Brie 1 on stainless steel and their growth in Brain Heart Infusion broth was determined. Viable cells of Listeria decreased rapidly after 9~12 hr of incubation at $21^{\circ}C$ and after 6~9 hr of incubation at $32^{\circ}C$ in the presence of L. lactis. The number of L. monocytogenes Scott A attached to stainless steel in pure culture was $2.5{\times}10^3/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}2.3{\times}10^3/\textrm{cm}^2{\;}at{\;}32^{\circ}C$ after 48 hr of incubation, but was only $10/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}1.1{\times}10/\textrm{cm}^2{\;}at{\;}32^{\circ}C$ in the presence of L. lactis. Results from L. monocytogenes strain Brie 1 were similar to those from strain Scott A. The population of L. monocytogenes Scott A which attached to stainless steel with previously adherent L. lactis was $1.8{\times}10^2/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}8.2{\times}10^2/\textrm{cm}^2{\;}at{\;}32^{\circ}C$, whereas the population attached to sterile stainless steel was $1.2{\times}10^3/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}2.1{\times}10^2/\textrm{cm}^2{\;}at{\;}32^{\circ}C$. For L. monocytogenes Brie 1, the attached population of the control was $1.6{\times}10^4/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}3.2{\times}10^2/\textrm{cm}^2{\;}at{\;}32^{\circ}C$, and on stainless steel with adherent L. lactis, it was $1.1{\times}10/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}6.9{\times}10/\textrm{cm}^2{\;}at{\;}32^{\circ}C$. Surface adherent L. lactis was less inhibitory to attachment of L. monocytogenes on stainless steel than a liquid culture inoculum. Listeria attached to stainless steel survived dry storage for 20 days both in the presence and absence of adherent lactococci.

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Diseases of Ginseng: Environmental and host effect on disease outbreak and growth of pathogens. (인삼의 환경 및 기주조건과 발병과의 관계)

  • 오승환
    • Journal of Ginseng Research
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    • v.5 no.1
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    • pp.73-84
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    • 1981
  • Effect of environmental factors and host on the growth and outbreak of various ginseng diseases was reviewed Environmental lectors included hydrogen ion concentration, moisture content, temperature, nutrition, and microbiol populations. Age of the ginseng plants in relation to several ginseng disease occurrence was also included in order to formulate the effective control measure for ginseng diseases. Damping-off caused by Rhizoctonia, Pythium, and Phytophthora, greymold by Botrytis, sclerotinia by Scleretinia, and phytophthora blight caused by Phytophthora were usually prevalent during the early growing season of ginseng when temperature is below 20$^{\circ}C$, while anthrac se caused by Colletotrichum, alternaria blight by Alternaria, and bacterial soft rot by Erwinia were so during the latter growing season when temperature is above 25$^{\circ}C$. However, the root rot incited by Fnarium and Cylindrocarpon caused severe damages throughout the growing season. Growth range of the temperature for a pathogen was highly related to the corresponding disease outbreak. Hydrogen ion concentration was highly related to the outbreak of sclerotinia, root rot, and red rot. Most severe outbreak of those diseases where the soil acidity was pH 4.7, pH 6.5- 7.5, and pH6.0-6.5, respectively. Nitrogen content in the soil was also related to outbreak of root rot and red rot. More red rot occurred where NH,-nitrogen is above 30 ppm and more root rot obtained when excessive nitrogen fertilizer applied. Yellow necrosis apparently was related to magnesium especially its ratio with potassium or calcium content in a soil. Fusarium Population showed significant .relations to missing rate of ginseng Plants in a Implanting ginseng field, while that of total bacteria showed similar relations in all ginseng field, However, in six year old ginseng fields, the more the Streptomyces population was, the less the Fusarium obtained. Consequently, less missing rate observed in a field where Streptomyces population was high. Damping-off, root rot, Rhytophthor a blight were mose severe on the nursery and on 2-3 years old ginseng plants, whereas sclerotinia, and grey cod, alteraria blight, anthracnose were severe on 4-6 years old ginseng plants. Root rot caused by Fusarium and Erwinia, however, was also severe regardless of the age of the plants when the roots were injured. Therefore, for the effective control of ginseng root rot most careful control of the disease during the early year should be rendered.

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Differential Selection by Nematodes of an Introduced Biocontrol Fungus vs. Indigenous Fungi in Nonsterile Soil

  • Kim, Tae Gwan;Knudsen, Guy R.
    • Journal of Microbiology and Biotechnology
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    • v.28 no.5
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    • pp.831-838
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    • 2018
  • Trophic interactions of introduced biocontrol fungi with soil animals can be a key determinant in the fungal proliferation and activity. This study investigated the trophic interaction of an introduced biocontrol fungus with soil nematodes. The biocontrol fungus Trichoderma harzianum ThzID1-M3 and the fungivorous nematode Aphelenchoides sp. (10 per gram of soil) were added to nonsterile soil, and microbial populations were monitored for 40 days. Similar results were obtained when the experiment was duplicated. ThzID1-M3 stimulated the population growth of indigenous nematodes (p < 0.05), regardless of whether Aphelenchoides sp. was added. Without ThzID1-M3, indigenous nematodes did not increase in number and the added Aphelenchoides sp. nematodes almost disappeared by day 10. With ThzID1-M3, population growth of nematodes was rapid between 5 and 10 days after treatment. ThzID1-M3 biomass peaked on day 5, dropped at day 10, and then almost disappeared at day 20, which was not influenced by the addition of nematodes. In contrast, a large quantity of ThzID1-M3 hyphae were present in a heat-treated soil in which nematodes were eliminated. Total fungal biomass in all treatments peaked on day 5 and subsequently decreased. Addition of nematodes increased the total fungal biomass (p < 0.05), but ThzID1-M3 addition did not affect the fungal biomass. Hyphae of total fungi when homogenously distributed did not support the nematode population growth; however, hyphae of the introduced fungus did when densely localized. The results suggest that soil fungivorous nematodes are an important constraint on the hyphal proliferation of fungal agents introduced into natural soils.

Investigation of Urban Sprawl and Interregional Interaction by Demographic and Commuting Data - The Case of Seoul Metropolitan Area - (인구 및 통근자 자료 분석을 통한 도시확산현상 및 지역 간 상호작용 검증 - 서울 대도시권을 중심으로 -)

  • Park, Jane;Choi, Nak-Hoon;Chang, Hoon
    • Journal of Korean Society for Geospatial Information Science
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    • v.14 no.2 s.36
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    • pp.77-88
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    • 2006
  • Overpopulation has been one of the most serious problem of the Seoul Metropolitan Area (SMA), which consists of the City of Seoul, Incheon, and the whole of Gyeonggi Province. People have been still moving into SMA, especially being concentrated into the fringe of Seoul. This study examines the inner city decline phenomenon of SMA which can be easily found in large cities over the world, based on the demographic data of these area. In addition, this study monitors the imbalance in growing of SMA by analyzing RMI (Rank Mobility Index), and the inverse relation between the self sufficiency of the adjacent area and the commuting rate to Seoul by analyzing commuting data. Even though the total population has been unchanged, the internal change of population was substantial. The growth of Seoul Metro region was placed near the city of Seoul, especially commuter data reassured the population concentrations. The results will be useful in urban planning and growth management.

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Employment Growth and Industrial Change in Cheongju, 1985-2005: An Analysis Using a Shift-Share Model (청주의 고용 성장과 산업 변화, 1985-2005: 변이할당모형에 의한 분석)

  • Kim, Hak-Hoon
    • Journal of the Economic Geographical Society of Korea
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    • v.14 no.3
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    • pp.325-341
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    • 2011
  • The population and employment of Cheongju have increased rapidly since the 1970s. This study examines the industrial employment change of Cheongju City and performs a shift-share analysis for the employment growth. The data used in this study are mainly from the 1985, 2000 and 2005 Census of Population and Housing. This study first explained the population change and industrial structure of Cheongju, then reviewed the development of shift-share models. Location quotients and specialization coefficients resulted from this study revealed the diversifying tendency in the urban industrial structure. Shift-share analysis employing the modified Arcelus model elucidated the favorable industrial mix and the competitiveness of industrial sectors. As a whole, Cheongju has advantageous industrial structure in comparison with that of the nation. All sectors of Cheongju except several services sectors grew faster than those of the nation and showed positive competitive effects. It is suggested to utilize more disaggregated industrial data in more fractured subperiod in order to pinpoint the competitive industries.

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Growth Factors Affecting to Kalosaponins Contents of Kalopanax pictus Nakai (한국산 음나무의 Kalosaponins 함량과 이에 영향하는 몇 가지 생장요인)

  • Lee, Cheol-Ho;Jo, Dong-Kwang;Lee, Kap-Yeon;Kwon, Ki-Won;Choi, Myung-Suk
    • Journal of Plant Biotechnology
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    • v.29 no.3
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    • pp.209-215
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    • 2002
  • Four kinds of kalosaponins from inner bark of Kalopanax pictus Nakai as a medicinal and edible timber tree species growing in Korea was analyzed by HPLC. A considerable range of variation in the contents was observed among population. The kalosaponins contents in inner bark from each population were the highest in the Mt. Barwang (30.37 mg/g on the dry weight basis) followed by Mt. Gariwang, Hanra II, Mangun, Paltan, and Hanra II population. Growth factors that might have influenced the contents of the kalosaponins were also examined. As both analysis results of partial correlation and multiple regression, the weight of inner bark and tree age were influenced the kalosaponin O contents. The kalosaponin B contents was influenced by both the weight of inner layer bark and annual mean DBH increment. The contents of kalosaponins appeared to be closely related to the inner bark characteristics.

Single-step genomic evaluation for growth traits in a Mexican Braunvieh cattle population

  • Jonathan Emanuel Valerio-Hernandez;Agustin Ruiz-Flores;Mohammad Ali Nilforooshan;Paulino Perez-Rodriguez
    • Animal Bioscience
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    • v.36 no.7
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    • pp.1003-1009
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    • 2023
  • Objective: The objective was to compare (pedigree-based) best linear unbiased prediction (BLUP), genomic BLUP (GBLUP), and single-step GBLUP (ssGBLUP) methods for genomic evaluation of growth traits in a Mexican Braunvieh cattle population. Methods: Birth (BW), weaning (WW), and yearling weight (YW) data of a Mexican Braunvieh cattle population were analyzed with BLUP, GBLUP, and ssGBLUP methods. These methods are differentiated by the additive genetic relationship matrix included in the model and the animals under evaluation. The predictive ability of the model was evaluated using random partitions of the data in training and testing sets, consistently predicting about 20% of genotyped animals on all occasions. For each partition, the Pearson correlation coefficient between adjusted phenotypes for fixed effects and non-genetic random effects and the estimated breeding values (EBV) were computed. Results: The random contemporary group (CG) effect explained about 50%, 45%, and 35% of the phenotypic variance in BW, WW, and YW, respectively. For the three methods, the CG effect explained the highest proportion of the phenotypic variances (except for YW-GBLUP). The heritability estimate obtained with GBLUP was the lowest for BW, while the highest heritability was obtained with BLUP. For WW, the highest heritability estimate was obtained with BLUP, the estimates obtained with GBLUP and ssGBLUP were similar. For YW, the heritability estimates obtained with GBLUP and BLUP were similar, and the lowest heritability was obtained with ssGBLUP. Pearson correlation coefficients between adjusted phenotypes for non-genetic effects and EBVs were the highest for BLUP, followed by ssBLUP and GBLUP. Conclusion: The successful implementation of genetic evaluations that include genotyped and non-genotyped animals in our study indicate a promising method for use in genetic improvement programs of Braunvieh cattle. Our findings showed that simultaneous evaluation of genotyped and non-genotyped animals improved prediction accuracy for growth traits even with a limited number of genotyped animals.

Structural Change and Green Growth in Korea, 1980~2020 (한국의 구조적 변화와 녹색성장)

  • Kim, Yong Jin
    • KDI Journal of Economic Policy
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    • v.34 no.4
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    • pp.1-26
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    • 2012
  • Greenhouse gas emission policy in Korea and elsewhere is based on emissions projections, a key element of which is the projected path of structural change from high productivity growth to low productivity growth economic sectors given sector specific labor productivity growth, emissions abatement across sectors and population growth. Thus, it is important to model the source of the structural change to forecast emissions correctly. Using data for the Korean economy, this study constructs and quantitatively evaluates a model of structural change and green growth to generate policy implications for Korea and the international greenhouse gas debate.

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Variation of Growth Characteristics in Natural crossed Population of Paeonia lactiflora Pallas (자연교잡 실생작약 집단의 생육특성 변이)

  • Kim, Se-Jong;Kim, Jeong-Hye;Park, Jun-Hong;Park, So-Deuk;Choi, Boo-Sull
    • Korean Journal of Medicinal Crop Science
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    • v.7 no.3
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    • pp.177-184
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    • 1999
  • This study was carried out to find growth characters and distribution of above and underground in natural crossed population of Paeonia lactiflora Pallas. Sprouting time was 1 April to 15 April, and distribution of stem length ranged from 21 to 80cm, and 3 to 18 in stem number. Distribution of root length ranged from 12 to 59cm, root number per plant was 73 to 4, root yield per plant was highly varied by 37 to 882g, and larger root above 750g was occupied by 7.1%. Paeoniflorin content was 1.9 to 10.29% and plants containing higher paeoniflorin was 14.3%. Root length and yield had highly positive correlation. Root diameter and stem length was also positively correlated.

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Transport Infrastructure Investment and Its Impacts on Rural Development : Exploratory Analysis for Policy Evaluation (교통 인프라 투자와 농촌지역 발전에 미치는 영향 - 정책평가를 위한 탐색적 분석 -)

  • Lee, Wonho
    • Journal of the Korean association of regional geographers
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    • v.21 no.3
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    • pp.503-514
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    • 2015
  • This study aims to analyze the relationship between transport infrastructure investment and rural development in Korea in a more systematic and empirical way. To do so, we formulate research framework to examine the multi-faceted relationship through extensive literature review and carry out a descriptive study on the spatial patterns of road investment and rural development in Korea. Finally, using the structural equation model, this study carries out the exploratory empirical analysis on the direct and indirect relationship between transport infrastructure investment and rural development. The study finds that the transport infrastructure investment in rural Korea impacts clearly on both the population base promotion and production and income growth through better accessibility. In addition, the investment has an indirect effects on the production and income growth through its influence on the population base promotion. This implies that the transport infrastructure investment in rural Korea so far exerts both long-term and short-term influences on rural development through various channels of impacts.

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