• The Journal of the Korean dental association
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• v.11 no.1
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• pp.59-66
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• 1973

• Information Systems Review
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• v.3 no.2
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• pp.337-347
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• 2001

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1998.10a
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• pp.201-202
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• 1998

• Annals of Clinical Neurophysiology
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• v.12 no.1
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• pp.32-34
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• 2010

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.617-623
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• 2001

To predict the seasonal variation of dissolved oxygen (DO) in Hakata bay, Japan, possible 20 time-series of different hourly-solar-radiation intensities were generated based on stochastically changing solar radiation intensity, and a numerical simulation on dissolved oxygen (DO) was carried out for each time series by using the Sediment-Water Ecological Model (SWEM). The model, consisting of two sub-models with hydrodynamic and biological models, simulates the circulation process of nutrient between water column and sediment, such as nutrient regeneration from sediments as well as ecological structures on the growth of phytoplankton and zooplankton, The results of the model calibration followed the seasonal variation of observed water quality well, and generated cumulative-frequency-distribution (CFD) curves of daily solar radiation agreed well with observed ones, The simulation results indicated that the exchange of sea water would have a great influence on the DO concentration, and that the concentration could change more than 1 mg/L in a day. This prediction method seems to be an effective way to examine a solution to minimize fishery damage when DO is depleted.

• The Korean Journal of Mycology
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• v.46 no.4
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• pp.415-425
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• 2018

To study the characteristics of yeasts, 433 strains of the genus Aureobasidium were isolated from the flowers collected from Jeolla-do in Korea, and the diversity of the strains was confirmed through molecular phylogenetic and morphological analyses. Based on phylogenetic analysis of LSU rDNA seguences, the Aureobasidium strains from the Jeolla-do province were classified into six groups. The dominant species of flower-derived yeasts were Groups A and D. Since Groups B, E, and F were found only in Jeollanam-do, we can infer that the Aureobasidium is distributed more widely in Jeollanam-do than in the Jeollabuk-do province. Through LSU and ITS rDNA sequence analyses, Group A was identified as A. pullulans, Group B as A. melanogenum, and Group F as a putative new species of Aureobasidium. Groups C, D, and E do not completely match with A. leucospermi, A. namibiae, or A. subglaciale by LSU or ITS rDNA analysis but are closely related to those species. Comparisons of colony morphology are likely to be more helpful in distinguishing Groups C and D. The results of this study can provide useful characteristics for future studies of the genus Aureobasidium.

• Language and Information
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• v.20 no.1
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• pp.51-71
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• 2016

The status of the Korean morphological marker '-e ci' has been controversial whether it is a passive marker, an anticausative marker, or a passive/anticausative marker. However, the previous approaches that tried to classify '-e ci' constructions based on the syntactic verb classes (i.e. intransitive or transitive) were short of explaining the properties of the constructions. In this study, the '-e ci' constructions were distinguished based on agentivity, following Levin & Rappaport Hovav (1995) and Alexiadou et al. (2006). Moreover, how the verbal root meaning is associated with the passive/anticausative construction was investigated by means of Distributed Morphology (DM) (Embick 2010; Marantz 1997). I argued that the morphological marker '-e ci' is the instantiation of the absence of external arguments. With respect to the behavior of the Korean '-e ci' constructions with the semantics of each verbal root class, I found out that the '-e ci' constructions can form passives with the verbal roots that require the external arguments; whereas, the anticausatives cannot be formed with the roots that necessarily require the agentive arguments. However, contrary to the previous arguments that '-e ci' passives can be only formed with transitive verbs, it is discovered that non-agentive transitive roots do form anticausatives. Moreover, I argued that there are two types of the anticausatives - zero and '-e ci' anticausatives. Since the valency reduction is marked by the non-active voice morphology, the zero anticausatives appear only with the roots that do not require external arguments. The different '-e ci' constructions (passives, '-e ci', and zero anticausatives) are represented by the distinct syntactic structures. I proposed that the morphological similarity between the passives and the '-e ci' anticausatives is due to the presence of VoiceP, which introduces the external arguments. Moreover, the lack of the voice morphology in the zero anticausatives is explained by the absence of the VoiceP.

• Parasites, Hosts and Diseases
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• v.55 no.3
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• pp.337-340
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• 2017

Leishmaniasis is a neglected and endemic disease that affects poorest population mainly in developing countries. A lack of adequate and definitive chemotherapeutic agents to fight against this infection has led to the investigation of numerous compounds. The aim of this study was to investigate in vitro activity of boldine against Leishmania amazonensis murine cell infection. Boldine ((S)-2,9-dihydroxy-1,10-dimethoxy-aporphine) is an aporphine alkaloid found abundantly in the leaves/bark of boldo (Peumus boldus Molina), a widely distributed tree native to Chile. The in vitro system consisted of murine macrophage infection with amastigotes of L. amazonensis treated with different concentrations from 50 to $600{\mu}g/ml$ of boldine for 24 hr. Intracellular parasite destruction was assessed by morphological examination and boldine cytotoxicity to macrophages was tested by the MTT viability assay. When cells were treated with $100{\mu}g/ml$ of boldine the reduction of parasite infection was 81% compared with untreated cultures cells. Interestingly, boldine-treatment caused a concentration-dependent decrease of macrophage infection that culminated with 96% of reduction when cells were submitted to $600{\mu}g/ml$ of boldine. Cell cultures exposed to $100{\mu}g/ml$ of boldine and $300{\mu}g/ml$ of $Glucantime^{(R)}$ during 24 hr showed a significant reduction of 50% in parasitized cells compared with cell cultures exposed just to $Glucantime^{(R)}$. The study showed that treatment with boldine produces a better effect than treatment with the reference antimonial drug, glucantime, in L. amazonensis infected macrophage. Our results suggest that boldine is a potentially useful agent for the treatment of leishmaniasis.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.643-649
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• 2010

Evaluation of the primary etiologic agents that cause aseptic meningitis outbreaks may provide valuable information regarding the prevention and management of aseptic meningitis. In Korea, an outbreak of aseptic meningitis caused by echovirus type 30 (E30) occurred from May to October in 2008. In order to determine the etiologic agent, CSF and/or stool specimens from 140 children hospitalized for aseptic meningitis at Soonchunhyang University Cheonan Hospital between June and October of 2008 were tested for virus isolation and identification. E30 accounted for 61.7% (37 cases) and echovirus 6 accounted for 21.7% (13 cases) of all the human enteroviruses (HEVs) isolates (60 cases in total). For the molecular characterization of the isolates, the VP1 gene sequence of 18 Korean E30 isolates was compared pairwise using the MegAlign with 34 reference strains from the GenBank database. The pairwise comparison of the nucleotide sequences of the VP1 genes demonstrated that the sequences of the Korean strains differed from those of lineage groups A, B, C, D, E, F, and G. Reconstruction of the phylogenetic tree based on the complete VP1 nucleotide sequences resulted in a monophyletic tree, with eight clustered lineage groups. All Korean isolates were segregated from other lineage groups, thus suggesting that the Korean strains were a distinct lineage of E30, and a probable cause of this outbreak. This manuscript is the first report, to the best of our knowledge, of the molecular characteristics of E30 strains associated with an aseptic meningitis outbreak in Korea, and their respective phylogenetic relationships.

• IMMUNE NETWORK
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• v.13 no.5
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• pp.213-217
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• 2013

Enterotoxigenic Bacteroides fragilis (ETBF) is a human gut commensal bacteria that causes inflammatory diarrhea and colitis. ETBF also promotes colorectal tumorigenesis in the Min mouse model. The key virulence factor is a secreted metalloprotease called B. fragilis toxin (BFT). BFT induces E-cadherin cleavage, cell rounding, activation of the ${\beta}$-catenin pathway and secretion of IL-8 in colonic epithelial cells. However, the precise mechanism by which these processes occur and how these processes are interrelated is still unclear. E-cadherin form homophilic interactions which tethers adjacent cells. Loss of E-cadherin results in detachment of adjacent cells. Prior studies have suggested that BFT induces IL-8 expression by inducing E-cadherin cleavage; cells that do not express E-cadherin do not secrete IL-8 in response to BFT. In the current study, we found that HT29/C1cells treated with dilute trypsin solution induced E-cadherin degradation and IL-8 secretion, consistent with the hypothesis that E-cadherin cleavage causes IL-8 secretion. However, physical damage to the cell monolayer did not induce IL-8 secretion. We also show that EDTA-mediated disruption of E-cadherin interactions without E-cadherin degradation was sufficient to induce IL-8 secretion. Finally, we determined that HT29/C1 cells treated with LiCl (${\beta}$-catenin activator) induced IL-8 secretion in a dose-dependent and time-dependent manner. Taken together, our results suggest that BFT induced IL-8 secretion may occur by the following process: E-cadherin cleavage, disruption of cellular interactions, activation of the ${\beta}$-catenin pathway and IL-8 expression. However, we further propose that E-cadherin cleavage per se may not be required for BFT induced IL-8 secretion.