• Journal of Species Research
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• v.13 no.3
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• pp.318-325
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• 2024

Bacterial communities residing on islands have a significant impact on the functioning and establishment of a unique isolated ecosystem. Notwithstanding, systematic research on the indigenous microbial resources of domestic islands has been lacking. In order to understand the biodiversity and potential bioresources, we conducted sampling in 2023 from coastal waters from various islands off the west coast of the Korean Peninsula, including Baengnyeongdo, Daebudo, Deokjeokdo, Jangbongdo, Yeonpyeongdo Islands, along with Somaemuldo Island along the south coast. The coastal seawater samples were used to unearth microbial resources through the standard dilution plating. In total, approximately 1,600 bacterial strains were isolated from the samples as single colonies and identified using 16S rRNA gene sequence analyses. Eighteen strains, exhibiting ≥98.7% 16S rRNA gene sequence similarity to bacterial species with validly published names but not previously reported in Korea, were categorized as unrecorded bacterial species in Korea. These unrecorded bacterial strains displayed phylogenetic diversity, representing three phyla, four classes, 9 orders, 13 families, and 18 genera. The unrecorded species were assigned to the classes Alphaproteobacteria (Aliiroseovarius, Kiloniella, Maritalea, Palleronia, and Roseobacter), Gammaproteobacteria (Aliamphritea, Aliivibrio, Enterovibrio, Francisella, Leucothrix, Pseudoalteromonas, Psychrobium, Shewanella, and Vibrio), Flavobacteriia (Aquimarina, Pseudofulvibacter, and Tenacibaculum), and Verrucomicrobiae (Roseibacillus). This study presents comprehensive descriptions of the taxonomic attributes of these unrecorded species, covering morphology, biochemistry, and phylogenetic position.

• Journal of Communications and Networks
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• v.5 no.4
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• pp.354-364
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• 2003

A general method for the evaluation of the symbol error probability (SER) of ultra wideband (UWB) systems with various kind of modulation schemes (N-PAM, M-PPM, Bi-Orthogonal), in presence of multipath channel, multiuser and strong narrowband interference, is presented. This method is shown to be able to include all the principal multiaccess techniques proposed so far for UWB, time hopping (TH), direct sequence (DS) and optical orthogonal codes (OOC). A comparison between the performance of these multiple access and modulation techniques is given, for both ideal Rake receiver and minimum mean square error (MMSE) equalizer. It is shown that for all the analyzed multiple access schemes, a Rake receiver exhibits a high error floor in presence of narrowband interference (NBI) and that the value of the error floor is in-fluenced by the spectral characteristics of the spreading code. As expected, an MMSE receiver offers better performance, representing a promising candidate for UWB systems. When the multiuser interference is dominant, all multiple access techniques exhibit similar performance under high-load conditions. If the number of users is significantly lower than the spreading factor, then DS outperforms both TH and OOC. Finally 2PPM is shown to offer better performance than the other modulation schemes in presence of multiuser interference; increasing the spreading factor is proposed as a more effective strategy for SER reduction than the use of time diversity.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.2
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• pp.157-162
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• 2013

The use of Korean native chicken is increasing, and the discovery of new genetic resources is very important from both economic and genetic conservation points of view. In this study, mtDNA D-loop sequences from 272 privately-owned Korean native chickens from a Hyunin farm were investigated. Seventeen nucleotide substitutions were identified from the sequence analysis and they were classified as 6 haplotypes. Previously investigated haplotypes in five Korean native chicken populations have been compared with the Hyunin chicken population. The results indicated that two haplotypes, H10 and H15, in the Hyunin chicken population were not previously identified in other Korean native chicken populations, representing 33.09% (90/272) and 1.1% (3/272) of the Hyunin population, respectively. On the other hand, four other haplotypes were identical to those of a previous study of Korean native chicken populations. This result is indicative of conservation strategies of Hyunin chicken populations for expanding the genetic diversity in the Korean native chicken population.

• Corrosion Science and Technology
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• v.7 no.2
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• pp.99-111
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• 2008

Copper was exposed unsheltered and sheltered in four humid tropical sites, representing urban, urban-industrial, urban-marine and rural environments. The corrosion rates and the sequence of corrosion product formation are presented and discussed in relation with climatic and atmospheric pollution parameters. Chemical compositions of corrosion products were found to depend on environments and duration of exposure. In all environments, cuprite was the predominating corrosion product that formed first and continuously increased during the exposure. Among the sulphur-containing corrosion products, posnjakite and brochantite were more frequently found and the first formed earlier. Nantokite was the most common chlorine-containing products for most cases, except the high-chloride environment, where atacamite was detected instead. The corrosion rate of copper was well indicated by the colour of patina. The red-purple colour corresponded to the high corrosion rate and the greenish grey colour corresponded to the low corrosion rate. Corrosion rate of sheltered copper in urban-marine environment increased with the exposure time.

• Journal of Korean Academy of Nursing
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• v.37 no.6
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• pp.976-985
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• 2007

Purpose: The aim of this study was to identify the present situation of hospital infection and route of infection by clarifying the transmission aspect of methicillin-resistant Staphylococcus aureus(MRSA) in a Neurosurgical Intensive Care Unit by analysing genotype. Methods: MRSA was cultured from twenty five patients with a tracheostomy, twenty five health care workers, and environments in the Neurosurgical Intensive Care Unit of one hospital in D city. Data was collected from December 21, 2004 to November 5, 2005. MRSA isolates representing each genotype were analyzed by spaA typing and a multiplex PCR method capable of identifying the structural type of the staphylococcal cassette chromosome mec(SCCmec) carried by the bacteria. Results: As the same genotype and gene sequence were found among health care workers, patients, and environments, it was assumed that there was cross transmission among them. Conclusion: This study suggests that first, as the hospital infection by MRSA between health care workers and patients in the Neurosurgical Intensive Care Unit was due to result of cross transmission and the relevance of transmission between them was verified, it is necessary to take preventive measures and conduct education. Secondly, development of nursing interventions and study of infection are needed. Thirdly, consistent investment in prevention against hospital infections and environmental renovation is needed.

• Animal Systematics, Evolution and Diversity
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• v.24 no.3
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• pp.327-332
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• 2008

Soft coral Dendronephthya gigantea (Verrill, 1864) is a conspicuous species dominating shallow sea waters of Jejudo Island, Korea. Recently its whole mitochondrial genome sequencing was completed by us and the sequence information provided an opportunity to test the age of Octocorallia and time of evolutionary separation between some representative orders of the subclass Octocorallia. Molecular phylogenetic analyses based on 13 mitochondrial protein encoding genes revealed a polyphyletic relationship among octocorallians representing two orders (Alcyonacea and Gorgonacea) and four families (Alcyoniidae, Nephtheidae, Briareidae, and Gorgoniidae). Estimates of divergence times among octocorallians indicate that the first splitting might occur around end of or after Cretaceous period (50-79 million years ago (Ma)). The age is relatively young compared to the long history of stony sea corals (>240 Ma). Taken together our result suggests a possible relatively recent radiating evolution at least in the order Alcyonacea and Gorgonacea. Molecular dating and phylogenetic analysis based on much broader taxon sampling and many genes might give an insight into this interesting hypothesis.

• Journal of the Korea Computer Graphics Society
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• v.5 no.2
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• pp.43-52
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• 1999

In this paper, we present an animation toolkit based on motion mapping technique in a graphics user interface that can represent data structures necessary for generating character motions. The motion mapping means that an animation sequence generated once can be mapped to another object directly according a data structure in the graphics user interface. Users can generate animation sequences interactively using a mouse. These are obtained automatically by modifying motion data structures interactively. Compared with other conventional tools, the toolkit has different features that two hierarchical structures necessary for representing modeling and animation data are managed independently each other, and that animations generated can be applied to any other characters by connecting the two hierarchical structures in the user interface.

• The Plant Pathology Journal
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• v.24 no.4
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• pp.384-391
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• 2008

Rice blast disease, caused by the pathogenic fungus Magnaporthe grisea, is a serious issue in rice (Oryza sativa L.) growing regions of the world. Transcript profiling in rice inoculated with the fungus has been investigated using the transcriptomics technology, serial analysis of gene expression (SAGE). Short sequence tags containing sufficient information which are ten base-pairs representing the unique transcripts were identified by SAGE technology. We identified a total of 910 tag sequences via the GenBank database, and the resulting genes were shown to be up-regulated in all functional categories under the fungal biotic stress. Compared to the compatible interaction, the stress and defense genes in the incompatible interaction appear to be more up-regulated. Particularly, thaumatin-like gene (TLP) was investigated in determining the gene and protein expression level utilizing Northern and Western blotting analyses, resulting in an increase in both the gene and the protein expression level which arose earlier in the incompatible interaction than in the compatible interaction.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.10
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• pp.1478-1484
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• 2007

To determine the origin and genetic diversity of Red Chittagong (RC) cattle in Bangladesh, we analyzed mitochondrial DNA displacement loop (D-loop) sequences of 48 samples along with 22 previously published sequences from Bos indicus and Bos taurus breeds. Twenty five haplotypes were identified in RC cattle that were defined by 44 polymorphic sites and nucleotide diversity was $0.0055{\pm}0.0026$. The estimated sequence divergence times between RC and other zebu cattle breeds studied ranged between 22,700-26,900 years before present (YBP) which, it is suggested, predate domestication of RC cattle. Furthermore, it is assumed that introgressions have occurred in this breed mainly from Indian zebu breeds in the recent millennia. The phylogenetic studies showed RC cattle clustered with Bos indicus lineage with two distinct haplogroups representing high genetic variability of this breed. These findings can be used for designing proper breeding and conservation strategies for RC cattle in Bangladesh.

• The Plant Pathology Journal
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• v.34 no.3
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• pp.218-235
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• 2018

Plant growth promoting rhizobacteria and endophytic bacteria were isolated from different varieties of turmeric (Curcuma longa L.) from South India. Totally 50 strains representing, 30 PGPR and 20 endophytic bacteria were identified based on biochemical assays and 16S rDNA sequence analysis. The isolates were screened for antagonistic activity against Pythium aphanidermatum (Edson) Fitzp., and Rhizoctonia solani Kuhn., causing rhizome rot and leaf blight diseases in turmeric, by dual culture and liquid culture assays. Results revealed that only five isolates of PGPR and four endophytic bacteria showed more than 70% suppression of test pathogens in both assays. The SEM studies of interaction zone showed significant ultrastructural changes of the hyphae like shriveling, breakage and desication of the pathogens by PGPR B. cereus (RBacDOB-S24) and endophyte P. aeruginosa (BacDOB-E19). Selected isolates showed multiple Plant growth promoting traits. The rhizome bacterization followed by soil application of B. cereus (RBacDOB-S24) showed lowest Percent Disease Incidence (PDI) of rhizome rot and leaf blight, 16.4% and 15.5% respectively. Similarly, P. aeruginosa (BacDOB-E19) recorded PDI of rhizome rot (17.5%) and leaf blight (17.7%). The treatment of these promising isolates exhibited significant increase in plant height and fresh rhizome yield/plant in comparison with untreated control under greenhouse condition. Thereby, these isolates can be exploited as a potential biocontrol agent for suppressing rhizome rot and leaf blight diseases in turmeric.