• Journal of Microbiology and Biotechnology
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• 제33권2호
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• pp.180-187
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• 2023

The skin is a dynamic ecosystem on which diverse microbes reside. The interkingdom interaction between microbial species in the skin microbiota is thought to influence the health and disease of the skin although the roles of the intra- and interkingdom interactions remain to be elucidated. In this context, the interactions between Malassezia and Staphylococcus, the most dominant microorganisms in the skin microbiota, have gained attention. This study investigated how the interaction between Malassezia and Staphylococcus affected the antifungal susceptibility of the fungus to the azole antifungal drug ketoconazole. The susceptibility was significantly decreased when Malassezia was co-cultured with Staphylococcus. We found that acidification of the environment by organic acids produced by Staphylococcus influenced the decrease of the ketoconazole susceptibility of M. restricta in the co-culturing condition. Furthermore, our data demonstrated that the significant increased ergosterol content and cell membrane and wall thickness of the M. restricta cells grown in the acidic environment may be the main cause of the altered azole susceptibility of the fungus. Overall, our study suggests that the interaction between Malassezia and Staphylococcus influences the antifungal susceptibility of the fungus and that pH has a critical role in the polymicrobial interaction in the skin environment.

• Ocean and Polar Research
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• 제37권2호
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• pp.161-177
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• 2015

This study analyzes the stock assessment of yellow croaker caught mainly by the Korean stow net and gill net fisheries focusing on single species and multiple fisheries. This study standardizes fishing efforts for the two fisheries using the general linear model and uses a surplus production model based on the exponential growth model. The Clarke Yoshimoto Pooley model estimates a maximum sustainable yield(MSY), an allowable biological catch(ABC), fishing efforts for MSY($E_{MSY}$) and for ABC($E_{ABC}$). The bio-economic model is used to estimate the maximum economic yield(MEY) and fishing efforts for MEY($E_{MSY}$). Also, the study employs an economic analysis to estimate the economic interaction between stow net and gill net fisheries. The economic analysis shows the profit accruing to the two fisheries from estimated ABC. Finally, the study compares TACs based on single species and single fishery to TAC based on single species and multiple fisheries. The study proposes that the TAC assessment is necessary for single species and multiple fisheries in order to preserve resources.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3429-3432
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• 2011

Distribution diagram of $FeCl_2$ in HCl solution indicated that $FeCl^+$ was a predominant species in strong HCl solution up to 10 M. Solvent extraction of $FeCl_2$ has been performed in the HCl concentration range from 5 to 9 M by using Alamine336 as an extractant. Interaction parameter of $FeCl^+$ for Bromley equation was estimated from our solvent extraction data. This parameter thus obtained in our study can be employed in calculating the activity coefficient of $FeCl^+$ in high concentration of HCl.

• 대한기계학회논문집
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• 제10권2호
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• pp.232-240
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• 1986

본 연구에서는 대향류 유동장에서 두 예혼합화염의 후류 상호작용을 Fig.1 과 같은 계를 이용하여 일반적인 Lewis수에 대하여 접합 점근 전개 방법으로 해석하 여, 강한 상호작용을 나타내는 구간의 변화가 확산선호도의 영향임을 규명하고, 화염 스트레치가 상호 작용하는 예혼합화염의 소화특성에 미치는 영향을 파악하였다.

• Bulletin of the Korean Chemical Society
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• 제12권2호
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• pp.138-143
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• 1991

Laser Raman spectroscopy has been used to study the interaction of $MoO_3$ with $TiO_2$. The bulk molybdenum oxide appeared to spread on the surface of titania under the submonolayer coverage. The surface polymolybdate was observed to be very stable with respect to the repeated treatment of reduction and subsequent calcination. Owing to the interaction of molybdate and titania, the phase transformation of $TiO_2$ seemed to be strongly retarded. The additives such as Co and Ni reacted readily with $MoO_3$ to form the corresponding molybdate salts. Nevertheless, the polymolybdate species appeared to be more stable on the titania surface than the molybdate salts.

• 한국자기공명학회논문지
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• 제11권2호
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• pp.95-109
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• 2007

Vanadium-incorporated aluminophosphate microporous molecular sieve VH-SAPO-42 has been studied by electron spin resonance(ESR) and electron spin-echo modulation (ESEM) spectroscopies to determine the vanadium location and interaction with various adsorbate molecules. The results are interpreted in terms of V(IV) ion location and coordination geometry. Assynthesized VH-SAPO-42 contains only vanadyl species with distorted octahedral or trigonal bipyramidal coordination. Vanadium incorporated into H-SAPO-42 occupied extra-framework site. After calcinations in $O_2$ and exposure to moisture, only species A is observed with reduced intensities. Species A is identified as a $VO(H_2O)_2^{2+}$ complex coordinated to three framework oxygen atoms bonded to aluminum. When hydrated VH-SAPO-42 is dehydrated at elevated temperature by calcination, species A loses its water ligand and transforms to $VO^{2+}$ ions coordinated to three framework oxygens (species B). Species B reduces its intensities significantly after treatment with $O_2$ at high temperature, thus suggesting oxidation of $V^{4+}$ to $V^{5+}$. When dehydrated VH-SAPO-42 makes contact with $D_2O$ at room temperature, the ESR signal of species A is regained. The species is assumed as a $VO(O_f)_3(D_2O)_2$ by considering three framework oxygens. Adsorption of deuterated methanol on dehydrated VH-SAPO-42 results in another new vanadium species D, which is identified as a $VO(CD_3OH)_2$ complex. When deuterated ethylene is adsorbed on dehydrated VH-SAPO-42, another new vanadium species E identified as a $VO(C_2D_4)^{2+}$, is observed. Possible coordination geometries of these various complexes are discussed.

• 대한수학회논문집
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• 제21권4호
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• pp.701-717
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• 2006

The positive coexistence of a simple food chain model with ratio-dependent functional response and cross-diffusion is discussed. Especially, when a cross-diffusion is small enough, the existence of positive solutions of the system concerned can be expected. The extinction conditions for all three interacting species and for one or two of three species are studied. Moreover, when a cross-diffusion is sufficiently large, the extinction of prey species with cross-diffusion interaction to predator occurs. The method employed is the comparison argument for elliptic problem and fixed point theory in a positive cone on a Banach space.

• 한국안전학회지
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• 제25권1호
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• pp.9-16
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• 2010

Flame structure of diffusion flame interacting with a single vortex was investigated with direct numerical simulation (DNS). A well-known counterflow diffusion flame was used as an initial flat flame and single vortices were made by issuing a high-velocity jet abruptly in fuel- and air-side. The variations in the maximum concentration of major species (CO and $CO_2$) and NOx (NO and $NO_2$) with the stoichiometric scalar dissipation rate were investigated. Unsteady effects in the species concentration variation of the flame interacting with a vortex were identified by comparing with that of steady flame. $NO_2$ formation characteristics of the flame interacting with a vortex were well understood by investigating the $HO_2$ formation. To enhance the prediction performance in the fire simulation, current turbulent combustion modelings are needed to be modified by adopting the unsteady effects in the species concentrations of diffusion flame interacting with a vortex.

• Preventive Nutrition and Food Science
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• 제4권1호
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• pp.75-78
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• 1999

Acetylcarnitine, a metabilite of carnitine, has been porven to be a potent inhibitor of ethanol oxidation in hepatocytes. It inhibits the activity of alcohol dehydrognase (ADH), but not the microsomal ethanol oxidizing system. which was significatly inhibited by acetylcarnitine at NAD ; acetylcarnitine $\leq$1. the main objectives of his study were to ascertain the interaction between acetylcarnitine and NAD on ADH activity and to elucidate whether different species have different effects. Tehpost-mocrosomal supernatant (PMS) was prepared from normal rat, guinea pig, mouse and broilers by differential centrifugation . Horse and yeast ADH were purchased from the Sigma Chemical Co. Prepared and purchased ADH are used for determination of ADH activity in the presence or absence of carnitine and acetylcar- nitine. Binding studies showed that acetylcarnitine did bind to ADH in a dose realted manner when low NAD ; acetylcar- nitine ratio was provided. It was found that the inhibitionof ADH activity occurred only when NAD concentration was less than the inhibitor concentration . Crystalline and crude ADH preparation from different vertebrate species wer inhibited by acetylcarnitine, whereas the yeast ADH was not affected by acetylcarnitine.

• 농촌계획
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• 제14권1호
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• pp.23-32
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• 2008

Landscape structure is important to understand a complex patterns and interaction with adjacent habitat in rural area. The aim of this study is to analyze relationship between landscape structure and insect spatial distribution in rural area to suggest applicable possibility of landscape structure as biological indicator. For this purpose, first, four landscape structure criteria such as distance from the forest; density of farmland-forest ecotone; landscape continuity; and field size are selected. Secondly, these criteria are applied to Gangsang-myeon, Yangpyeong-gun where mosaic feature are conserved at various spatial scale. Thirdly, application of landscape structure criteria is verified using correlation with species number, species diversity, and species richness of insect. As a result, it could be suggested that the landscape structure criteria are useful for explaining insect spatial distribution.