• 한국환경과학회지
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• 제21권11호
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• pp.1361-1369
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• 2012

A biological assessments of fish community structure were carried out in the lower reach of Seomjin River from May 2009 to November 2010. The collected fish from the six surveyed sites were 63 species belonging to 24 families, and 10 orders. Although species was different depending on sites, the numbers of individuals were not shown significance on sites. Locational dominant species were different. For example, the dominant species on May were Zacco platypus at W-1, Zacco temminckii at W-2, Acanthogobius flavimanus at W-3 and W-4, and Leiognathus nuchalis at W-5 and W-6. There is no seasonal differences in species. Species diversity was the best up to 2.64 on May at W-1 from 1.33 on November at W-6. As a result of an analysis about environmental factors for the numbers of fish species and individuals in each surveyed sites, the most effective groups were DO, BOD, and COD. The proportional difference was high on May than November between transient and asymptotic projections for population size and population growth rate for simulations starting at the current or theoretical stage distribution.

• Journal of Forest and Environmental Science
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• 제28권2호
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• pp.75-83
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• 2012

An explanatory survey was conducted to assess preference and consumption pattern of horticultural species, their sources, location-wise planting preferences and diversity of these species in the rural homestead forest of the offshore island of Bangladesh. Assessment was done through multistage random sampling. Based on homestead size respondents were categorized into small (<0.05 ha), medium (0.05-0.25 ha) and large (>0.25 ha) and twenty from each category were selected randomly for the study. The study revealed that most of the farmer (75.5%) preferred to plant fruit tree species for future plantation followed by timber species (62.2%). But fruit-bearing plants were being gradually replaced by some exotic timber species such as Swietenia mahagoni, Acacia auriculiformis, Tectona grandis, Eucalyptus spp., etc. Diversity and abundance of fruit species was found higher in almost all homestead. A total of 41 horticultural species were identified and seven horticultural species among them were recognized as the most preferred ones in the study area. Consumption pattern was chiefly to meet the nutritional demand and to gain a quick monetary benefit. Average annual income from horticultural species was 7,183.33 Taka (US$102).

• ALGAE
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• 제31권3호
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• pp.219-230
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• 2016

The Euglena deses group are common freshwater species composed of E. adhaerens, E. carterae, E. deses, E. mutabilis, and E. satelles. These species are characterized by elongated cylindrical worm-like cell bodies and numerous discoid chloroplasts with a naked pyrenoid. To understand the cryptic diversity, species delimitation and phylogenetic relationships among members of the group, we analyzed morphological data (light and scanning electron microscopy) and molecular data (nuclear small subunit [SSU] and large subunit [LSU] rDNAs and plastid SSU and LSU rDNAs). Bayesian and maximum likelihood analyses based on the combined four-gene dataset resulted in a tree consisting of two major clades within the group. The first clade was composed of two subclades: the E. mutabilis subclade, and the E. satelles, E. carterae, and E. adhaerens subclade. The E. mutabilis subclade was characterized by a lateral canal opening at the anterior end and a single pellicular stria, whereas the E. satelles, E. carterae, and E. adhaerens subclade was characterized by an apical canal opening at the anterior end of the cell and double pellicular striae. The second clade consisted of 20 strains of E. deses, characterizing by a subapical canal opening at the anterior end and double pellicular striae, but they showed cell size variation and high genetic diversity. Species boundaries were tested using a Bayesian multi-locus species delimitation method, resulting in the recognition of five cryptic species within E. deses clade.

• Asian-Australasian Journal of Animal Sciences
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• 제21권9호
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• pp.1238-1243
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• 2008

Domestic buffalo and cattle are two extremely important livestock species in worldwide agricultural production. In this paper, to investigate genetic diversity and divergence among swamp buffalo, river buffalo and cattle, 30 microsatellite markers were screened on 168 individuals sampled from five populations. Substantial differences were observed among the three groups of animals with respect to allele frequency distribution, allele size and polymorphism. The cattle sample (Mongolian) showed significantly higher genetic variability (0.674 of gene diversity, p<0.01), and the swamp and river buffalo samples displayed similar degree of genetic variation (0.536 in swamp and 0.546 in river, p = 0.92). Results of both phylogenetic tree and multivariate analysis could distinguish three groups of animals, suggesting their deep evolutionary divergence. Additionally, using $({\delta}{\mu})^2$ genetic distance, we estimated a divergence time of 1.7 million years between swamp and river buffalo that strongly supported distinct genetic origins for the two buffalo types.

• 환경영향평가
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• 제19권6호
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• pp.547-552
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• 2010

The theory of island biogeography has influenced strongly on the conservation and management issues of species diversity in the islands. The theory has not limited to islands in the ocean, but expanded to isolated and fragmented areas in the forests and urban. This study has a rare opportunity to explore the species diversity and abundance of birds in the islands of Korea. A total of 151 islands in the west and south areas in the Korean peninsula were examined. The number of species and the area of islands were highly significant (P<0.000) and the number of species and the distance from the mainland showed not so strong relationship. This indicated that bird species diversity has more influenced by the size of the islands not the distance. This can be from the study species of birds that can fly long distance, and also natural characteristics of migratory and resident status. Species-area curve showed that the z-value was 0.21 indicating the area and the bird species are strongly correlated. The long-term monitoring of bird species presence in the islands should be followed for a proper management plan.

• The Plant Pathology Journal
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• 제27권2호
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• pp.128-137
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• 2011

Fifty two Macrophomina phaseolina isolates were recovered from 24 host plant species through the 14 Iranian provinces. All isolates were confirmed to species using species-specific primers. The colony characteristics of each isolate were recorded, including chlorate phenotype, relative growth rate at $30^{\circ}C$ and $37^{\circ}C$, average size of microsclerotia, and time to microsclerotia formation. The feathery colony phenotype was the most common (63.7%) on the chlorate selective medium and represented the chlorate sensitive phenotype of the Iranian Macrophomina phaseolina population. Meantime, inter simple sequence repeats (ISSR) Markers were used to assess the genetic diversity of the fungus. Unweighted pair-group method using arithmetic means (UPGMA) clustering of data showed that isolates did not clearly differentiate to the specific group according to the host or geographical origins, however, usually the isolates from the same host or the same geographic origin tend to group nearly. Our results did not show a correlation between the genetic diversity based on the ISSR and phenotypic characteristics. Similar to the M. phaseolina populations in the other countries, the Iranian isolates were highly diverse based on the phenotypic and the genotypic characteristics investigated and needs more studies using neutral molecular tools to get a deeper insight into this complex species.

• Journal of Species Research
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• 제1권2호
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• pp.224-231
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• 2012

To assess the genetic diversity of Aconitum coreanum (Ranunculaceae) populations in Korea, we have amplified and sequenced eight organellar marker regions, and developed and analyzed microsatellite markers. No sequence variation was detected from the eight organellar markers. Ten microsatellites were developed using Next Generation Sequencing and two microsatellite markers, AK_CA03 and AK_CT07, were identified polymorphic and applied for 143 individuals of twelve A. coreanum populations. Four and five alleles were detected for the two microsatellite loci, respectively, and number of migrants ($N_m$) was estimated as 1.12586. Two microsatellite marker loci showed $F_{ST}$ of 0.205 and 0.275, respectively. The heterozygosity deficit, low level of among-population differentiation, small size of gene flow, and lack of sequence variation of the organellar markers suggest that A. coreanum is reproductively isolated from other Aconitum species and there has been continuous gene flow among the populations of A. coreanum or it has dispersed relatively recently after speciation. Though population pairwise $F_{ST}$'s presented significant geographic structure, further sampling and study will be necessary to confirm this.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.369-379
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• 2021

This paper investigated the relationship between corporate governance mechanisms and firm performance in Vietnam. Based on a dataset of 101 HOSE-listed manufacturing firms, the results showed that CEOs' knowledge capability, gender diversity, and board size are positively associated with firm performance, whereas firm age is negatively associated. These findings suggested that firms should consider enlarging the boardrooms, but to a certain extent to avoid an inverse-U-shaped decline of performance; furthermore, firms should promote women executives' presence in a boardroom for it brings greater cultural-diversity benefits and inhibits information asymmetry. Contrary, the aging process impedes firms' growth. It depreciates their values in terms of total assets, so managers must review their assets' net value after each working year to avoid such a hardship. However, the thesis constrains itself since it did not treat the TMTs' knowledge capability equally as the CEOs' and completely excluded their treatment. Besides, it did not regard the effect of external governance mechanisms such as the supply-demand relationship, customer behavior, market imperfections, and market concentration due to data unavailability. Based on the main findings, several suggestions are set forth for firms and managers to enhance performance and minimize a poor governance mechanism's adverse consequence.

• Journal of Ecology and Environment
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• 제45권4호
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• pp.218-227
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• 2021

Background: Artificial light at night has recently been identified as a major factor adversely affecting global insect diversity. Here, we compared the insect diversity in Gwangneung Forest Biosphere Reserve, specifically in the Korea National Arboretum (with no artificial light at night), with that of three nearby urban sites with a gradient of artificial light at night (five locations at each site). We analyzed the effects of the artificial night lighting index, mean annual temperature, and field light intensity (lux) at night on the insect community structure. Results: The urban sites generally exhibited higher species richness and abundance as well as clear indicator species compared with the control site. The size distribution of the collected insects markedly differed between the control and the three urban sites. The abundance of herbivorous and omnivorous insects increased and decreased, respectively, with the increase in light intensity. Species richness of herbivorous and omnivorous insects was likely correlated with the field light intensity at night and artificial night lighting index, respectively. Conclusions: This study demonstrates the association between nighttime environment and marked changes in insect community structure and revealed consequent transition of ecosystem services by changes in trophic group composition.

• Journal of Forest and Environmental Science
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• 제26권1호
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• pp.9-15
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• 2010

This paper analyzes data on the plant species diversity and their contribution to the livelihoods of rural people in five villages of Domar upazila, Nilphamari district, Bangladesh. Assessment was done by means of multistage random sampling. Information collected from a total of 40 households ranging from small, medium and large categories. A total of 52 plant species belonging to 34 families were identified as being important to local livelihoods. Fruits (37%), timber (23%) and medicinal (17%) species were the most important plant use categories. Determination of the relative density of the different species revealed that Areca catechu constitutes 19.17% of homestead vegetation of the area followed by Artocarpus heterophyllus, which occupies 10.34%. Margalef index showed that there is no major difference (5.11 for large, 5.49 for medium, 4.73 for small) across the different size classes and Shannon-Weiner Index of the study area varies from 2.75 to 2.98. Results show that the average annual homestead income varied from US$108.69 to US$291.67 and contribute 6.63% of the household income.