• Title/Summary/Keyword: biogeography

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Intron sequence diversity of the asian cavity-nesting honey bee, Apis cerana (Hymenoptera: Apidae)

  • Wang, Ah Rha;Jeong, Su Yeon;Jeong, Jun Seong;Kim, Seong Ryul;Choi, Yong Soo;Kim, Iksoo
    • International Journal of Industrial Entomology and Biomaterials
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    • v.31 no.2
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    • pp.62-69
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    • 2015
  • The Asian cavity-nesting honeybee, Apis cerana (Hymenoptera: Apidae), has been extensively studied for its biogeography and genetic diversity, but the molecules utilized in past studies were mainly ~90 bp long mitochondrial non-coding sequences, located between $tRNA^{Leu}$ and COII. Thus, additional molecular markers may enrich our understanding of the biogeography and genetic diversity of this valuable bee species. In this study, we reviewed the public genome database to find introns of cDNA sequences, with the assumption that these introns may have less evolutionary constraints. The six introns selected were subjected to preliminary tests. Thereafter, two introns, titled White gene and MRJP9 gene, were selected. Sequencing of 552 clones from 184 individual bees showed a total of 222 and 141 sequence types in the White gene and MRJP9 gene introns, respectively. The sequence divergence ranged from 0.6% to 7.9% and from 0.26% to 17.6% in the White gene and the MRJP9 introns, respectively, indicating higher sequence divergence in both introns. Analysis of population genetic diversity for 16 populations originating from Korea, China, Vietnam, and Thailand shows that nucleotide diversity (π) ranges from 0.003117 to 0.025837 and from 0.016541 to 0.052468 in the White gene and MRJP9 introns, respectively. The highest π was found in a Vietnamese population for both intron sequences, whereas the nine Korean populations showed moderate to low sequence divergence. Considering the variability and diversity, these intron sequences can be useful as non-mitochondrial DNA-based molecular markers for future studies of population genetics.

The Basic Theories for Restoration of Fragmented Habitats (파편화된 서식처 복원을 위한 기초이론 고찰)

  • Kim, Myoung-Soo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.4 no.2
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    • pp.52-61
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    • 2001
  • At least, there are intense pressures on the natural habitats from various disturbance, including urbanization, extension of industrial area, and road construction. These human land use result in fragmentation of landscape and natural habitat. The ecological consequences of habitat fragmentation include the direct effects of habitat loss and the indirect effects of reduced inter-patch dispersal. The decline of biological diversity has been rapidly declined by the habitat loss and fragmentation. Conservation strategists should consider not only the habitat amount of that must be preserved, but also the spatial configuration of habitat across the landscape. But, the paucity of available data for most species forces landscape ecologists to develop the concept, model, and theory. The developed theories are often misused in academic papers and practical applications. The development history, presumption of concept, model, theory is ignored. This tendency have leaded to failure of landscape restoration and the use of theory in conservation practice have come under increasing attacks. This paper will highlight the ecological theory that have proven the most influential in landscape ecology, restoration and conservation : the theory of island biogeography, the theory of nested subset analysis, minimum viable population(MVP), the theory of metapopulation dynamics. And, it find the problem and usefulness of four theory in application to real world. Consequently, the understanding of theoretical implication about landscape ecological theory is required. We must carefully apply the theory after examining the problem and availability of various theory because of no existence of only one general theory.

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Sulzbacheromyces sinensis, an Unexpected Basidiolichen, was Newly Discovered from Korean Peninsula and Philippines, with a Phylogenetic Reconstruction of Genus Sulzbacheromyces

  • Liu, Dong;Wang, Xin Yu;Wang, Li Song;Maekawa, Nitaro;Hur, Jae-Seoun
    • Mycobiology
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    • v.47 no.2
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    • pp.191-199
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    • 2019
  • Most of lichens are formed by Ascomycota, less than 1% are lichenized Basidiomycota. The flora investigation of lichenized Ascomycota of South Korea has been well studied in the past three decades; however, prior to this study, none of basidiolichens was discovered. During the recent excursion, an unexpected clavarioid basidiolichen, Sulzbacheromyces sinensis was collected. Morphology and ecology has been recorded in detail. DNA was extracted, and ITS, 18S, 28S nuclear rDNA were generated. In order to further confirm the systematic position of the Korean specimens, maximum likelihood and Bayesian inference analysis including all the species of the order Lepidostromatales were conducted based on the ITS. As a result, the phylogenetic tree of the order Lepidostromatales was reconstructed, which differed from the previous studies. The inferred phylogenetic tree showed that species of Sulzbacheromyces in three different continents (Asia, South Africa and South America) were separated into three clades with support. In this study, the species worldwide distribution map of Lepidostromatales was illustrated, and S. sinensis had a widest distribution range (paleotropical extend to the Sino-Japanese) than other species (paleotropical or neotropical). Prior to this study, the range of distribution, southernmost and northernmost points and the fruiting time of S. sinensis were recorded, and the genus Sulzbacheromyces was firstly reported from Korean peninsula and Philippines.

From Island to Ecotone: Nature Recognition as Boundary Crossed and Ecocritical Implication (섬에서 에코톤으로-경계중첩지대로서의 자연인식과 생태비평적 함의)

  • Shin, Dooho
    • Journal of English Language & Literature
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    • v.57 no.2
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    • pp.237-264
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    • 2011
  • Based on its geophysical feature, the island has long been recognized as a separate and self-sustaining space independent of neighboring continent or other islands. Literary tradition has used the island as a metaphor for a utopian alternative to mundane human society with its various kinds of wrongdoings. Recent nature writings have taken up this island metaphor to emphasize the wholeness of the ecosystem in specifically designated natural community or landscapes such as national parks or wilderness preservation areas. Human-nature relations as border-divided area is also recognized as the island. Modern island biogeography, however, has disproved such a concept of islands as autonomous, revealing the contrasting fact that the richness of species on an undisturbed island is determined largely by species immigration from and emigration to a source of colonists. This scientific finding has posited the island as the interconnected nature, but the public and metaphoric use of it still resorts to the old concept of it as isolated and autonomous nature, because this image has been ingrained deeply in our consciousness and culture. Considering the negative consequences from the recognition of nature and nature-humans as isolated space, we need a new nature metaphor that embodies interconnectedness in nature and of human-nature relations. Such feature of interconnectedness is best embedded in the concept of ecotone. Some ecotones are created and maintained through human participation in nature, and this human induced nature of ecotone denotes the possibilities of a constructive relation between them. The substitution of the island with the ecotone as the concept of nature and the image of human-nature relations is expected to correct ecocritical practices of reading of nature writing, which has been predominantly interpreted within the orientation of nature itself and nature-human relations as an isolated and self-autonomous island. Adopting the ecotone in literary study enables ecocriticism to dig out cultural elements embedded in nature writing and reveal socio-political, ideological factors hidden behind the writers' portrayal of nature as islands.

A taxonomic and distributional study of the rhodolith-forming species Lithothamnion muelleri (Corallinales, Rhodophyta) in the Eastern Pacific Ocean

  • Robinson, Nestor M.;Hansen, G.I.;Fernandez-Garcia, C.;Riosmena-Rodriguez, R.
    • ALGAE
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    • v.28 no.1
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    • pp.63-71
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    • 2013
  • Lithothamnion muelleri is reported for the first time as one of the main components of rhodolith beds along the Eastern Pacific Ocean based on samples from Washington State (USA), Pacific Baja California (M$\acute{e}$xico), southern Nicaragua, and Costa Rica. Individual rhodoliths ranged from fruticose to lumpy in morphology, and bi-sporangial, tetrasporangial, and gametangial plants were similar to those described from Australia and Brazil. Our study revealed a surprisingly wide latitudinal distribution of this species along the American continent. Its documentation in the Eastern Pacific will facilitate a more accurate interpretation of the ecology, biology, and biogeography of rhodolith beds worldwide.

Graphis yunnanensis (Ostropales, Graphidaceae), a New Lichen Species from China

  • Joshi, Santosh;Upreti, Dalip Kumar;Wang, Xin Yu;Hur, Jae-Seoun
    • Mycobiology
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    • v.43 no.2
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    • pp.118-121
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    • 2015
  • Graphis yunnanensis is described here as a new species. It is taxonomically well characterized by entire labia, slit-like disc, lateral thalline margin, completely carbonized proper exciple, inspersed hymenium, 8-spored asci, muriform $25{\sim}45{\times}8{\sim}12{\mu}m$ ascospores, and the presence of norstictic and stictic acids. The separation of the new species from other somewhat similar Graphis species is discussed. In addition, the study includes Graphis tenoriensis and Phlyctis karnatakana reported for the first time from China.

Reconfigurable Selective Harmonic Elimination Technique for Wide Range Operations in Asymmetric Cascaded Multilevel Inverter

  • Kavitha, R;Rani, Thottungal
    • Journal of Power Electronics
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    • v.18 no.4
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    • pp.1037-1050
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    • 2018
  • This paper presents a novel reconfigurable selective harmonic elimination technique to control harmonics over a wide range of Modulation Indexes (MI) in Multi-Level Inverter (MLI). In the proposed method, the region of the MI is divided into various sectors and expressions are formulated with different switching patterns for each of the sectors. A memetic BBO-MAS (Biogeography Based Optimization - Mesh Adaptive direct Search) optimization algorithm is proposed for solving the Selective Harmonic Elimination - Pulse Width Modulation (SHE-PWM) technique. An experimental prototype is developed using a Field Programmable Gate Array (FPGA) and their FFT spectrums are analyzed over a wide range of MI using a fluke power logger. Simulation and experimental results have validated the performance of the proposed optimization algorithms and the reconfigurable SHE-PWM technique. Further, the sensitivity of the harmonics has been analyzed considering non-integer variations in the magnitude of the input DC sources.

Marine Molluscan Fauna of Jindo Island

  • Lee, Yucheol;Choe, Yeongjae;Shin, Youngheon;Kim, Taeho;Park, Jina;Park, Joong-Ki
    • Animal Systematics, Evolution and Diversity
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    • no.spc9
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    • pp.30-36
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    • 2016
  • As a part of the commemorative joint faunal survey for the 30th anniversary of the Korean Society of Systematic Zoology, the molluscan fauna of Jindo Island was investigated based on sample collection from 6 localities from the 6 to the 8 of Jul 2016. A total of 114 molluscan species from 47 families were collected and identified. Among these, 42 species from 11 families are newly reported from Jindo Island and combining the previous records with the present study totals 157 species from 57 families. Distribution of species records indicates that marine biogeography of Jindo Island represent an overlapping zone for marine organisms which dwell in the Yellow sea and the southern sea areas of Korean waters.

Report on Bivalve Mollusks from Beach Death Assemblages in Gangwon and Gyeongsangbuk Provinces, Korea (East Sea)

  • Konstantin A. Lutaen;Je, Jong-Geel;Shin, Sang-Ho
    • The Korean Journal of Malacology
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    • v.18 no.1
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    • pp.27-40
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    • 2002
  • Beach death assemblages of bivalve mollusks were studied with respect to their species composition in six localities along the eastern coast of Korea (Gangneung, Jumunjin, Daejin, Gallam, Jukbyeon, Hupo and Chooksan). In all, thirty-nine species belonging to 30 genera and 19 families were recorded, and species diversity between the sampling sites varied from 5 to 21. Biogeographical analysis showed that studied fauna has warm-water character with the predominance of subtropical and subtropical-lowboreal species and the presence of tropical-subtropical species (in total, 77 %), and only 23 % of mollusks found are cold-water and temperate species. The most abundant species were Septifer virgatus (Wiegmann, 1837), Mytilus galloprovinciallis Lamarck, 1819, Gomphina melanaegis Romer, 1861, Ruditapes philippinarum (Adams et Reeve, 1850), Mactra chinensis Philippi, 1847 and Spisula sachalinensis (Schrenck, 1862).

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Bivalve mollusks in Ulsan Bay (Korea)

  • Lutaenko, Konstantin A.
    • The Korean Journal of Malacology
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    • v.30 no.1
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    • pp.57-77
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    • 2014
  • The bivalve molluscan fauna of Ulsan Bay, East Sea coast of Korea, is summarized, based on original and literature data. The fauna consists of 61 species belonging to 20 families. Seven species are identified only to genus level. Two species (Carditellopsis toneana (Yokoyama, 1922), Carditidae and Fulvia hungerfordi (G.B. Sowerby III, 1901), Cardiidae) are new records for the East Sea coast of Korea, and one species (Crenella decussata (Montagu, 1808), Mytilidae) is a new record for Korea. Biogeographically, Ulsan Bay's bivalve fauna is subtropical with a predominance of tropical-subtropical species, 21 species, or 39% of the total species number, subtropical, 14 species, or 26%, and subtropical-boreal (mostly subtropical-lowboreal), 11 species, 21%, totalling 86%. A remarkable feature of the Ulsan Bay fauna is the presence of tropical-subtropical species not found in Yeongil Bay but common in tidal flats and shallow waters of the Yellow Sea and the southern part of Korea. A cold water mass appearing off the southeast coast of Korea near Ulsan in summer seems responsible for the presence of boreal-arctic species in this area.