• Title/Summary/Keyword: Spatial genetic structure

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A Study on the Grid Land Subdivision of Ancient Local City in Korea (고대 한국 지방도시 격자형 토지구획의 형태특성에 관한 연구)

  • Lee, Kyung-Chan
    • Journal of architectural history
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    • v.11 no.4 s.32
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    • pp.45-69
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    • 2002
  • This study aims to find out the genetic characteristics of gridded subdivision area which has its origin from ancient local administrative city-Sangju, Jeonju, Namwon, Kwangju, Chungju. The spatial structure, based on the inter-relationship among gridded subdivision area, city wall, and topographic condition, and the morphological characteristics of gridded subdivision area are analyzed. The points of analysis on morphological characteristics of gridded subdivision area consist of the size of unit block, the organization system of unit block, the orientation of subdivision line. As a result of the analysis, three main characteristics are found. Firstly there can be found no same land subdivision rule among study areas. Secondly, the morphological features of study area were the products of cumulative process of different subdivision areas which were developed in different periods. Thirdly, the original regular gridded land subdivision seems to have been carried out in the object of a farm-land cultivation around 7th century. And there was a change of land-use from farm land to urban land-use during the later 7th century and 8th century.

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Comparison of Spatial Optimization Techniques for Solving Visibility Location Problem (가시권 문제를 위한 공간최적화 기법 비교 연구)

  • Kim, Young-Hoon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.3
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    • pp.156-170
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    • 2006
  • Determining the best visibility positions on terrain surface has been one of the frequently used analytical issues in GIS visibility analysis and the search for a solution has been carried out effectively using spatial search techniques. However, the spatial search process provides operational and methodological challenges for finding computational algorithms suitable for solving the best visibility site problem. For this problem, current GIS visibility analysis has not been successful due to limited algorithmic structure and operational performance. To meet these challenges, this paper suggests four algorithms explored robust search techniques: an extensive iterative search technique; a conventional solution based on the Tornqvist algorithm; genetic algorithm; and simulated annealing technique. The solution performance of these algorithms is compared on a set of visibility location problems and the experiment results demonstrate the useful feasibility. Finally, this paper presents the potential applicability of the new spatial search techniques for GIS visibility analysis by which the new search algorithms are of particular useful for tackling extensive visibility optimization problems as the next GIS analysis tool.

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Reproduction Strategies of Clonal Plants of Potentilla conferta in Uzbekistan and Mongol

  • Huh, Man-Kyu;Lee, Byeong-Ryong
    • Journal of Environmental Science International
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    • v.21 no.11
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    • pp.1297-1305
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    • 2012
  • Clonal plants combine sexual and clonal reproduction, which contribute differently to plant fitness. Reproductive analyses have highlighted the importance of clonal growth in shaping the spatial genetic structure in Potentilla conferta Bunge, a herbaceous rhizomatic clonal distributed in hot sand dunes. We investigated the reproduction system of P. conferta at two populations in Mongol and three natural populations in Uzbekistan. The measurements of 19 quantitative or qualitative morphological characters were taken on each of total individuals directly from their natural habitats. Some morphological characteristics between Mongolia and Uzbekistan populations showed a slight heterogeneity of variance. Especially, the length of internodes (LFI and LSI) and characteristics of root (LLR and NOR) were shown a significant difference between two countries (P<0.05). P. conferta of Uzbekistan has most ramets at short distance intervals 30~100 cm. In light conditions, P. conferta of Uzbekistan was significantly less resilience than P. conferta of Mogol. In drought conditions, although there was not shown significant difference, P. conferta in Uzbekistan was less resilience than that in Mogol. The core analysis indicates that P. conferta in Uzbekistan is the more resistant than that of Mongol and seems to do by sexual reproduction strategy during several strong environmental disadvantages such as drought events.

Molecular Analysis of Archaea, Bacteria and Eucarya Communities in the Rumen - Review-

  • White, B.A.;Cann, I.K.O.;Kocherginskaya, S.A.;Aminov, R.I.;Thill, L.A.;Mackie, R.I.;Onodera, R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.1
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    • pp.129-138
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    • 1999
  • If rumen bacteria can be manipulated to utilize nutrients (i.e., ammonia and plant cell wall carbohydrates) more completely and efficiently, the need for protein supplementation can be reduced or eliminated and the digestion of fiber in forage or agricultural residue-based diets could be enhanced. However, these approaches require a complete and accurate description of the rumen community, as well as methods for the rapid and accurate detection of microbial density, diversity, phylogeny, and gene expression. Molecular ecology techniques based on small subunit (SSU) rRNA sequences, nucleic acid probes and the polymerase chain reaction (PCR) can potentially provide a complete description of the microbial ecology of the rumen of ruminant animals. The development of these molecular tools will result in greater insights into community structure and activity of gut microbial ecosystems in relation to functional interactions between different bacteria, spatial and temporal relationships between different microorganisms and between microorganisms and reed panicles. Molecular approaches based on SSU rRNA serve to evaluate the presence of specific sequences in the community and provide a link between knowledge obtained from pure cultures and the microbial populations they represent in the rumen. The successful development and application of these methods promises to provide opportunities to link distribution and identity of gastrointestinal microbes in their natural environment with their genetic potential and in situ activities. The use of approaches for assessing pupulation dynamics as well as for assessing community functionality will result in an increased understanding and a complete description of the gastrointestinal communities of production animals fed under different dietary regimes, and lead to new strategies for improving animal growth.

Expansion of an invasive species, Ailanthus altissima, at a regional scale in Japan

  • Chuman, Misaki;Kurokochi, Hiroyuki;Saito, Yoko;Ide, Yuji
    • Journal of Ecology and Environment
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    • v.38 no.1
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    • pp.47-56
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    • 2015
  • Ailanthus altissima, which is recognized as an invasive tree in the Western world, has been widely observed in Japan. To investigate how A. altissima expanded within-population and to new populations within a region, 446 A. altissima trees were sampled from three separate sites (A, B, and C) including 35 distantly positioned patches, with three chloroplast DNA markers and nine nuclear microsatellite markers. We detected 2, 2, and 3 chloroplast haplotypes in sites A, B, and C, respectively. In addition, 271, 40, and 41 nuclear genotypes were detected in sites A, B, and C, respectively. The clonal richness value was 0.85, 0.78, and 0.53 in sites A, B, and C, respectively. Most trees with the same genotypes were distributed in the same patch, indicating that range expansion by asexual reproduction was limited to a maximum of 45 meters. According to autocorrelation analysis, the extent of nonrandom spatial genetic structure was approximately 0-2 km in sites A and C. KINGROUP analyses showed that 812, 74, and 111 nuclear genotype pairs were detected to have kinship in sites A, B, and C, respectively. Most nuclear genotype pairs were detected within the same patches or sites. These results indicate that the number of A. altissima trees gradually increased from seeds, some of which were produced by trees within sites, meaning that this species could regenerate naturally. This shows the need for the future management of A. altissima as an invasive species in Japan.

The Occurrence and Origin of a Syn-collisional Mélange in Timor (티모르섬 충돌 동시성 멜란지의 산상 및 기원)

  • Park, Seung-Ik;Koh, Hee Jae;Kim, Sung Won;Kihm, You Hong
    • Economic and Environmental Geology
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    • v.47 no.1
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    • pp.1-15
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    • 2014
  • The Bobonaro m$\acute{e}$lange is one of the youngest syn-collisional m$\acute{e}$langes, located between the Indo-Australian and Eurasian plates. The m$\acute{e}$lange has formed in association with a collision between the Australian continental margin and the Banda arc initiated in Neogene. The Suai area at the southern part of Timor is a good place to examine the genetic relationship between the m$\acute{e}$lange and other rock sequences because various tectonostratigraphic units coexist in the area. In this study, we present the structural characteristics and spatial distribution of the Bobonaro m$\acute{e}$lange investigated as a part of 1:25K scale geologic mapping in the area, and discuss on the origin of the m$\acute{e}$lange. The Bobonaro m$\acute{e}$lange in the Suai area is composed of unmetamorphosed clay matrix and blocks of various lithologies. The clay matrix mainly is reddish brown or greenish gray in colour, and has scaly texture. Most blocks are allochthonous, but mostly derived from nearby formations. Based on the internal structure and relationship with surrounding rocks, the Bobonaro m$\acute{e}$lange is genetically classified into 1) diapiric m$\acute{e}$lange; 2) tectonic m$\acute{e}$lange; and 3) broken formation. The spatial distribution of the Bobonaro m$\acute{e}$lange indicates that it intruded all pre-collisional units including the lower Australian continental margin unit(Gondwana megasequence) and the Banda arc unit. Taking the field evidences and previous genetic models into consideration, the Bobonaro m$\acute{e}$lange is interpreted to be mainly formed as a diapiric m$\acute{e}$lange originated from Gondwana megasequence, consistently effected by faulting events. This study reflects that diapiric m$\acute{e}$lange is a significant component in recent accretionay-collision belts. It suggests that diapiric process should be considered as a main genetic factor even in ancient m$\acute{e}$lange.

Species Identification and Genetic Structure of Octopus minor from Korea and China on the Basis of Partial Sequences of Mitochondrial Cytochrome Oxidase I (미토콘드리아 Cytochrome Oxidase I 유전자 마커에 의한 한국.중국 낙지의 종판별 및 집단분석)

  • Kang, Jung-Ha;Yu, Ki-Hwan;Kim, Sang-Kyu;Park, Jung-Yeon;Kim, Bong-Seok;An, Chel-Min
    • The Korean Journal of Malacology
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    • v.26 no.4
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    • pp.285-290
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    • 2010
  • The nucleotide sequences of the mitochondrial cytochrome oxidase subunit 1 (CO1) gene of octopus groups collected from Muan, Taean, Yesu, Jeju in Korea and Youngsung, Daeryen in China were analyzed for the identification of species and populations. Six haplotypes were identified from the analyzed 60 individuals. All of the individuals (N = 10) from Jeju showed the A haplotype which was not observed from other groups, and could be classified as a distinct group. The analyzed groups could form two separate clade in MEGA4 analysis. The individuals from Muan, Taean, Yesu in Korea and Daeryen in China form a clase and the others from Jeju in Korea and Youngsung in China formed the other clade. The analysis of relationship among the groups showed the same results. Individuals belong to the group A (Muan, Taean, Yesu and Daeryen) showed closer relationship than individuals belong to the group B (Jeju and Youngsung). Although the CO1 universal primers used in this study was useful as a marker for species identification among Octopus, analysis of population was limited because of few variations in the partial sequences of CO1 analyzed in this study. However, it was possible to show the limited gene flow among the groups which is resulted from the spatial separation and differences in their habitats.

Vegetation Composition and Structure of Sogwang-ri Forest Genetic Resources Reserve in Uljin-gun, Korea (울진 소광리 산림유전자원보호구역 산림식생의 조성 및 구조)

  • Kim, Hak-Yun;Cho, Hyun-Je
    • Korean Journal of Environment and Ecology
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    • v.31 no.2
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    • pp.188-201
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    • 2017
  • Based on a total of 272 vegetation data collected by the ZM school phytosociological study method, the composition and structural characteristics of the forest vegetation in the Sogwang-ri forest genetic resource reservoir located in Uljin-gun, Gyeongsangbuk-do were compared using the table comparison method and the TWINSPAN method, And their ecological characteristics were analyzed. The types of forest vegetation were classified into 7 types, and it was divided into two major groups, 'Slope and Ridge type', which characterized by Quercus mongolica, Pinus densiflora for. erecta, Lespedeza bicolor etc. and 'valley and concave slope', which characterized by Cornus controversa, Fraxinus mandshurica, Morus bombycis, Hydrangea serrata for. acuminata etc. The hierarchy of the vegetation unit was 2 community groups, 4 communities, and 6 subcommunities. The structural characteristics such as the total percent cover, species importance value, species diversity of the constituent species per unit area($/100m^2$) of each type of forest vegetation were also identified. In order to understand the spatial distribution of forest vegetation, 1/5,000 large-scale physiognomic vegetation map was created by the uppermost dominant species. The composition and structural characteristics of Geumgang pine(P. densiflora for. erecta) forest, which is a core community of protected area by natural and anthropogenic influences, appear as a subtype of Quercus mongolica forest, which is a potential natural vegetation, Appropriate maintenance measures seemed urgently needed.

Availability of the metapopulation theory in research of biological invasion: Focusing on the invasion success (침입생물 연구에 대한 메타개체군 이론의 활용 가능성: 침입 성공을 중심으로)

  • Jaejun Song;Jinsol Hong;Kijong Cho
    • Korean Journal of Environmental Biology
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    • v.40 no.4
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    • pp.525-549
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    • 2022
  • The process of biological invasion is led by the dynamics of a population as a demographic and evolutionary unit. Spatial structure can affect the population dynamics, and it is worth being considered in research on biological invasion which is always accompanied by dispersal. Metapopulation theory is a representative approach to spatially structured populations, which is chiefly applied in the field of ecology and evolutionary biology despite the controversy about its definition. In this study, metapopulation was considered as a spatially structured population that includes at least one subpopulation with significant extinction probability. The early phase of the invasion is suitable to be analyzed in aspects of the metapopulation concept because the introduced population usually has a high extinction probability, and their ecological·genetic traits determining the invasiveness can be affected by the metapopulation structure. Although it is important in the explanation of the prediction of the invasion probability, the metapopulation concept is rarely used in ecological research about biological invasion in Korea. It is expected that applying the metapopulation theory can supply a more detailed investigation of the invasion process at the population level, which is relatively inadequate in Korea. In this study, a framework dividing the invasive metapopulation into long- and middle-distance scales by the relative distance of movement to the natural dispersal range of species is proposed to easily analyze the effect of a metapopulation in real cases. Increased understanding of the mechanisms underlying invasions and improved prediction of future invasion risk are expected with the metapopulation concept and this framework.