• Ecology and Resilient Infrastructure
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• v.4 no.2
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• pp.93-96
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• 2017

Spatial variations of physicochemical and microbiological variables were examined to understand spatial heterogeneity of those variables in intertidal flat. Variograms were constructed for understanding spatial autocorrelations of variables by a geostatistical analysis and spatial correlations between two variables were evaluated by applications of a Cross-Mantel test with a Monte Carlo procedure (with 999 permutations). Water content, organic matter content, pH, nitrate, sulfate, chloride, dissolved organic carbon (DOC), four extracellular enzyme activities (${\beta}-glucosidase$, N-acetyl-glucosaminidase, phosphatase, arylsulfatase), and bacterial diversity in soil were measured along a transect perpendicular to shore line. Most variables showed strong spatial autocorrelation or no spatial structure except for DOC. It was suggested that complex interactions between physicochemical and microbiological properties in sediment might controls DOC. Intertidal flat sediment appeared to be spatially heterogeneous. Bacterial diversity was found to be spatially correlated with enzyme activities. Chloride and sulfate were spatially correlated with microbial properties indicating that salinity in coastal environment would influence spatial distributions of decomposition capacities mediated by microorganisms. Overall, it was suggested that considerations on the spatial distributions of physicochemical and microbiological properties in intertidal flat sediment should be included when sampling scheme is designed for decomposition processes in intertidal flat sediment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.3
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• pp.260-267
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• 1992

In this paper, the performance of frequency hopped(FH) M-ary frequency shift keyed(MFSK)system is analyzed with the fading channel and the multione famming. In general, the performance degradation of FH/MFSK system is due to the Rayleigh fading and the multitone jamming environment. In order to improve the system performance. the time diversity is used. When the time diversity is applied to the Rayleigh fading and the mulitone jamming, we get around 18dB and 19dB improvements. respectively. And when it is applied to both the Rayleigh fading and the multitone jamming, we get around 4 dB improvement.

• The Plant Pathology Journal
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• v.22 no.4
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• pp.369-374
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• 2006

To characterize benzimidazole-resistant and -sensitive Monilinia fructicola populations, the fungal isolates were obtained from peach plants showing brown rot and bloosom blight. Benzimidazole-sensitive isolates did not grow on potato dextrose agar(PDA) amended with $\geq1.0{\mu}g$ active ingredient(a.i.)/ml of the fungicides. However, benzimidazole-resistant isolates grew on PDA regardless of the tested concentrations of fungicides. Benzimidazole-resistant isolates did not grow on diethofencarb-PDA, but sensitive isolates grew on the same PDA. In the nucleotide sequences of $\beta$-tubulin gene, only codon 198(GAG: glutamic acid), a target site for benzimidazole, was replaced with GCG(alanine) in all of the resistant isolates, and this substitution seems to play an important role in the development of resistance. Other interesting codons such as 165(GCT), 200(TTC), and 241(GCT) were not changed among the isolates. Benzimidazole-resistant and -sensitive isolates were clustered clearly in random amplified polymerphic DNA analyses and the results revealed that low levels of genetic diversity between benzimidazole-sensitive and -resistant isolates of M. fructicola in the investigated regions.

• Journal of Microbiology and Biotechnology
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• v.14 no.1
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• pp.205-211
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• 2004

A 16S rDNA clone library was generated to investigate the bacterial diversity in tidal flat sediment in Ganghwa Island, Republic of Korea. A total of 103 clones were sequenced and analyzed by comprehensive phylogenetic analyses. No clones were identical to any of known 16S rRNA sequences in public databases. Sequenced clones fell into thirteen lineages of the domain Bacteria: the alpha, beta, gamma, delta, and epsilon Proteobacteria, Actinobacteria, CFB group, Chloroflexi, Acidobacteria, Planctomycetes, Verrucomicrobia, and known uncultured candidate divisions (OP11, BRC1, KSB1, and WS1). Two clones were not associated with any known bacterial divisions. The majority of clones belonged to the gamma and delta Proteobacteria (46.7%). Clones of Actinobacteria were distantly related to known taxa. It is evident from 16S rDNA-based community analysis that the bacterial community in tidal flat sediment is remarkably diverse and unique among other marine environments examined so far.

• Journal of Microbiology and Biotechnology
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• v.17 no.9
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• pp.1407-1429
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• 2007

The Burkholderia genus consists of over 40 Gram-negative, ${\beta}$-proteobacteria species that occupy remarkably diverse ecological niches. This genus contains species pathogenic to human, animals, and plants, as well as species involved in promoting plant growth and biodegradation of pollutants. This is largely explained by the extraordinary versatility of Burkholderia, as reflected by the remarkable diversity of extracellular products released by these bacteria. We exhaustively surveyed the extracellular enzymes, siderophores, toxins, antimicrobials, and other secondary metabolites produced by the members of this very diverse genus. Available information on regulation, especially quorum sensing mechanisms, and secretion is highlighted.

• The Korean Journal of Financial Management
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• v.23 no.2
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• pp.85-107
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• 2006

This paper investigates whether the futures market responds to the news more sensitively and uses more diverse information than the spot market. The sensitivity to the news is measured by the coefficients of the model which regresses the daily changes in the futures prices to the daily changes in the theoretical prices computed from spot prices using the spot-futures parity. The diversity of news is measured by the mean range differences ($\overline{RD}$), mean hi-price differences($\overline{HD}$) and mean low-price differences. The data in this paper is the closing prices of the nearest-to-maturity and the second-nearest-to-maturity contracts of the KOSPI 200 index futures. As the estimates of the relative sensitivity of the futures prices($^{\beta}$) for the whole-period sample are not significantly different from 1, the sensitivity of two markets to the news are not different. However, $\hat{\beta}$ of the most recent period(Nov. 2002 to Dec. 2005) are strongly different from 1. And, in the most recent period, the futures price changes for the good news, which is defined as the price increase of KOSPI of more than 1.5% in a day, show additional sensitivity. Since the mean range different which measures the relative diversity of information used, are not significantly different from 0 for the whole-period and subperiod samples, and this can be interpreted that the futures market does not use more diverse information than the spot market. However, the mean high-price difference, which measures the relative diversity of good news, are significantly different from 0 for the nearest-maturity contracts in the whole-period and subperiod samples. This evidence supports that the futures prices reflects more diverse good news which brings price increase in the market.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.115.1-115
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• 2003

Post-harvest decay, caused by Penicillium spp. is a serious problem of fruits worldwide. Morphological characteristics and molecular markers were used to characterize 22 Penicillium isolates from apples, 18 isolates from pears, 60 from oranges and 18 from grapes and 23reference isolates representing related Penicillium spp. to assess their diversity and resolve their taxonomy. Based on morphological and physiological characteristics, the isolates were grouped as identical or very similar to P. digitatum, P. italicum, P. ulaiense or very similar to P. crustosum, P. expansum, P. solitum and unidentified Penicillium spp. Based on sequence comparisons of ITS region, variable site were presented within and among the species, but there variation were not correlated with the species. Cluster analyses of AP-PCR fragment patterns using UP and L45 primer and the -tubulin gene sequence, the Penicillium species were segregated into distinct groups. Particularly. the -tubulin partial sequence data provided support for species concepts based on morphological and physiological characteristics.

• Biomedical Science Letters
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• v.25 no.3
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• pp.275-281
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• 2019

This study was performed to characterize the chromosomal metallo-${\beta}$-lactamases (MBLs) of Chryseobacterium indologenes isolated from Korea and to propose a clustering method of IND MBLs based on their amino acid similarities. Chromosomal MBL genes were amplified by PCR from 31 clinical isolates of E. indologenes. Nucleotide sequencing was performed by the dideoxy chain termination method using these PCR products. Antimicrobial susceptibilities were determined by the agar dilution method. PCR experiments showed that all 31 E. indologenes isolates contained all $bla_{IND}$ genes. DNA sequence analysis revealed that E. indologenes isolates possessed ten types of $bla_{IND}$ gene, including seven novel variants ($bla_{IND-8}$ to $bla_{IND-14}$). The most common combination of MBL was IND-2 (n = 18). Minimum inhibitory concentrations of imipenem and meropenem for the isolates harboring novel IND MBLs were ${\geq}16{\mu}g/mL$. IND MBLs were grouped in three clusters, based on amino acid similarities.

• Microbiology and Biotechnology Letters
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• v.51 no.1
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• pp.124-127
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• 2023

Among certain animals, gut microbiomes demonstrate species-specific patterns of beta diversity. This host-specificity is a potent driver of exogenous microbial exclusion. To overcome persistent translational limitations, translational microbiome research and therapeutic development must account for host-specific patterns of microbial engraftment. This commentary seeks to highlight the important implications of host-specificity for microbial ecology, Fecal Microbiota Transplantation (FMT), next-generation probiotics, and translational microbiota research.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.1
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• pp.19-25
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• 2013

In this paper, we proposed an enhanced monopulse MIMO radar system for the tactical scenario where the ground receivers are connected wireless backhaul and closely spaced. By applying the ${\alpha}{\beta}$ filter to the conventional monopulse MIMO radar, we show that the localization performance can be improved significantly. We also propose an efficient localization algorithm for a system with lower rate feedback. Using numerical simulations, we demonstrate that the proposed scheme can improve the localization performance while reducing the feedback over conventional scheme.