• Title/Summary/Keyword: RhoA

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A Small GTPase RHO2 Plays an Important Role in Pre-infection Development in the Rice Blast Pathogen Magnaporthe oryzae

  • Fu, Teng;Kim, Joon-Oh;Han, Joon-Hee;Gumilang, Adiyantara;Lee, Yong-Hwan;Kim, Kyoung Su
    • The Plant Pathology Journal
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    • v.34 no.6
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    • pp.470-479
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    • 2018
  • The rice blast pathogen Magnaporthe oryzae is a global threat to rice production. Here we characterized RHO2 gene (MGG_02457) that belongs to the Rho GTPase family, using a deletion mutant. This mutant ${\Delta}Morho2$ exhibited no defects in conidiation and germination but developed only 6% of appressoria in response to a hydrophobic surface when compared to the wild-type progenitor. This result indicates that MoRHO2 plays a role in appressorium development. Furthermore, exogenous cAMP treatment on the mutant led to appressoria that exhibited abnormal morphology on both hydrophobic and hydrophilic surfaces. These outcomes suggested the involvement of MoRHO2 in cAMP-mediated appressorium development. ${\Delta}Morho2$ mutation also delayed the development of appressorium-like structures (ALS) at hyphal tips on hydrophobic surface, which were also abnormally shaped. These results suggested that MoRHO2 is involved in morphological development of appressoria and ALS from conidia and hyphae, respectively. As expected, ${\Delta}Morho2$ mutant was defective in plant penetration, but was still able to cause lesions, albeit at a reduced rate on wounded plants. These results implied that MoRHO2 plays a role in M. oryzae virulence as well.

HOMOTOPY FIXED POINT SET $FOR \rho-COMPACT$ TORAL GROUP

  • Lee, Hyang-Sook
    • Bulletin of the Korean Mathematical Society
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    • v.38 no.1
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    • pp.143-148
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    • 2001
  • First, we show the finiteness property of the homotopy fixed point set of p-discrete toral group. Let $G_\infty$ be a p-discrete toral group and X be a finite complex with an action of $G_\infty such that X^K$ is nilpotent for each finit p-subgroup K of $G_\infty$. Assume X is $F_\rho-complete$. Then X(sup)hG$\infty$ is F(sub)p-finite. Using this result, we give the condition so that X$^{hG}$ is $F_\rho-finite for \rho-compact$ toral group G.

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SHARP FUNCTION AND WEIGHTED $L^p$ ESTIMATE FOR PSEUDO DIFFERENTIAL OPERATORS WITH REDUCED SYMBOLS

  • Kim, H.S.;Shin, S.S.
    • East Asian mathematical journal
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    • v.6 no.2
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    • pp.133-144
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    • 1990
  • In 1982, N. Miller [5] showed a weighted $L^p$ boundedness theorem for pseudo differential operators with symbols $S^0_{1.0}$. In this paper, we shall prove the pointwise estimates, in terms of the Fefferman, Stein sharp function and Hardy Littlewood maximal function, for pseudo differential operators with reduced symbols and show a weighted $L^p$-boundedness for pseudo differential operators with symbol in $S^m_{\rho,\delta}$, 0{$\leq}{\delta}{\leq}{\rho}{\leq}1$, ${\delta}{\neq}1$, ${\rho}{\neq}0$ and $m=(n+1)(\rho-1)$.

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Effect of the Injection Parameters on Diesel Spray Characteristics

  • Song Kyu Keun;Sim Sang Cherl;Jung Byong Koog;Kim Hyung Gon;Kim Jang Heon
    • Journal of Mechanical Science and Technology
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    • v.19 no.6
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    • pp.1321-1328
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    • 2005
  • The characteristics of the diesel spray have affected certain aspects of engine performance, such as the power, fuel consumption, and emissions. Therefore, this study was performed to investigate the effects of various injection parameters. In order to obtain the effect of injection parameters on diesel spray characteristics, the experiment is performed by using a high temperature and pressure chamber. The behaviors of the spray are visualized by using a high speed video camera, spray angle, penetration, and various other things. The results of the experiment are summarized as follows. (1) The correlation of the spray penetration can be expressed as follows. $$0< t $$t_{b} (2) The correlation of the spray angle can be expressed as follows $$T_a=293K\;tan({\theta}/2)=0.59({\rho}a/{\rho}f)^{0.437}$$ $$T_a=473K\;tan({\theta}/2)=0.588({\rho}a/{\rho}f)^{0.404}$$ (3) The measured macro characteristics that include the spray tip penetration and spray angle corresponded with the established correlations.

ON A FUZZY BANACH SPACE

  • Rhie, G.S.;Hwang, I.A.
    • Journal of the Chungcheong Mathematical Society
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    • v.13 no.1
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    • pp.71-78
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    • 2000
  • The main goal of this paper is to prove the following theorem ; Let (X, ${\rho}_1$) be a fuzzy normed linear space over K and (Y, ${\rho}_2$) be a fuzzy Banach space over K. If ${\chi}_{B_{{\parallel}{\cdot}{\parallel}}}{\supseteq}{\rho}*$, then (CF(X,Y), ${\rho}*$) is a fuzzy Banach space, where ${\rho}*(f)={\vee}{\lbrace}{\theta}{\wedge}\frac{1}{t({\theta},f)}\;{\mid}\;{\theta}{\in}(0,1){\rbrace}$, $f{\in}CF(X,Y)$, $B_{{\parallel}{\cdot}{\parallel}}$ is the closed unit ball on (CF(X, Y), ${\parallel}{\cdot}{\parallel}$ and ${\parallel}f{\parallel}={\vee}{\lbrace}P^2_{{\alpha}^-}(f(x))\;{\mid}\;P^1_{{\alpha}^-}(x)=1,\;x{\in}X{\rbrace}$, $f{\in}CF(X,Y)$, ${\alpha}{\in}(0,1)$.

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FOLIATIONS ASSOCIATED WITH PFAFFIAN SYSTEMS

  • Han, Chong-Kyu
    • Bulletin of the Korean Mathematical Society
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    • v.46 no.5
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    • pp.931-940
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    • 2009
  • Given a system of smooth 1-forms $\theta$ = ($\theta^1$,...,$\theta^s$) on a smooth manifold $M^m$, we give a necessary and sufficient condition for M to be foliated by integral manifolds of dimension n, n $\leq$ p := m - s, and construct an integrable supersystem ($\theta,\eta$) by finding additional 1-forms $\eta$ = ($\eta^1$,...,$\eta^{p-n}$). We also give a necessary and sufficient condition for M to be foliated by reduced submanifolds of dimension n, n $\geq$ p, and construct an integrable subsystem ($d\rho^1$,...,$d\rho^{m-n}$) by finding a system of first integrals $\rho=(\rho^1$,...,$\rho^{m-n})$. The special case n = p is the Frobenius theorem on involutivity.

Hall effect of K-doped $BaFe_2As_2$ superconducting thin films

  • Son, Eunseon;Lee, Nam Hoon;Hwang, Tae-Jong;Kim, Dong Ho;Kang, Won Nam
    • Progress in Superconductivity and Cryogenics
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    • v.15 no.3
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    • pp.5-8
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    • 2013
  • We have studied Hall effect for potassium (K)-doped $BaFe_2As_2$ superconducting thin films by analyzing the relation between the longitudinal resistivity (${\rho}_{xx}$) and the Hall resistivity (${\rho}_{xy}$). The thin films used in this study were fabricated on $Al_2O_3$ (000l) substrates by using an ex-situ pulsed laser deposition (PLD) technique under a high-vacuum condition of ~$10^{-6}$ Torr. The samples showed the high superconducting transition temperatures ($T_c$) of ~ 40 K. The ${\rho}_{xx}$ and the ${\rho}_{xy}$ for K-doped $BaFe_2As_2$ thin films were measured by using a physical property measurement system (PPMS) with a temperature sweep (T-sweep) mode at an applied current density of $100A/cm^2$ and at magnetic fields from 0 up to 9 T. We report the T-sweep results of the ${\rho}_{xx}$and the ${\rho}_{xy}$ to investigate Hall scaling behavior on the basis of the relation of ${\rho}_{xy}={A{\rho}_{xx}}^{\beta}$. The ${\beta}$ values are $3.0{\pm}0.2$ in the c-axis-oriented K-doped $BaFe_2As_2$ thin films, whereas the thin films with various oriented-directions like a polycrystal showed slightly lower ${\beta}$ than that of c-axis-oriented thin films. Interestingly, the ${\beta}$ value is decreased with increasing magnetic fields.

Effects of Rudbeckia laciniata Extract on Phagocytosis of Serum-Opsonized Zymosan Particles in Macrophages (대식세포의 혈청으로 식균된 자이모잔의 탐식능에 대한 삼잎국화 추출물의 효과)

  • Kim, Jun-Sub
    • The Korean Journal of Food And Nutrition
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    • v.29 no.3
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    • pp.341-346
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    • 2016
  • Phagocytosis is a primary and an essential step of host defense, and is triggered by the interaction of particles with specific receptor of macrophages. In this study, we investigated the effect of extracts of Rudbeckia laciniata (RLE) on the phagocytic activity of macrophage, by monitoring the phagocytosis-associated signal transduction. RLE markedly increased phagocytosis of serum-opsonized zymosan particles (SOZ), while phagocytosis of IgG-opsonized zymosan particles (IOZ) or none-opsonized zymosan particles (NOZ) remained unaffected. However, RLE did not affect the binding of opsonized zymosan particles (OZ) with the cell surface of macrophage. This suggests that RLE may regulate SOZ-induced intracellular signaling during phagocytosis of macrophage. To confirm this hypothesis, we investigated whether RLE was involved in the RhoA-mediated signal transduction during phagocytosis of SOZ. Inhibitors of the RhoA-mediated signaling pathway, such as Y-27632 (for ROCK), ML-7 (for MLCK), and Tat-C3 (for RhoA), totally blocked phagocytosis of SOZ enhanced by RLE, as well as phagocytosis of SOZ. Additionally, RhoA activity was markedly increased when cells were treated with RLE, suggesting that RLE could increase the phagocytic activity of macrophage via RhoA-ROCK/MLCK signal pathway. Thus, RLE may be used to develop functional foods for immunity.

Effect of Injection Parameters on Diesel Spray Characteristics (디젤분무 특성에 미치는 분사인자의 영향)

  • Sim Song-Cheol;Jung Byung-Kook;Ahn Byoung-Kyu;Kim Jang-Hein;Jung Jae-Yeon;Song Kyu-Keun
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.1
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    • pp.17-24
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    • 2005
  • The characteristics of diesel spray have effect on the engine Performance such as power. fuel consumption and emissions. Therefore, This study was Performed to investigate the effect of various injection parameters. In this study. the experiment is performed by using the high temperature and high pressure chamber. Spray behaviors are visualized by using the high speed camera and spray angle. Penetration etc. are measured. Experimental results are summarized as follows ; 1) Correlations of spray Penetration is expressed as follows $$0 $$t_b 2) Correlations of spray Angle is expressed as follows $$T_a=293K \;;\; tan({\theta}/2)=0.59({\rho}_a/{\rho}_f)^{0.437}$$ $$T_a=473K\;;\; tan({\theta}/2)=0.588({\rho}_a/{\rho}_f)^{0.404}$$ 3) The measured macro characteristics - spray tip penetration and spray angle agreed well with established correlations.

$^{13}C-NMR$ Study of the Applicaton of the “ Tools of Increasing Electron Demand ” to the 8-Aryl-tricyclo $[3.2.1.0^{2,7}]$oct-8-yl Cations

  • Gweon-Young Ryu;Jung-Hyu Shin
    • Bulletin of the Korean Chemical Society
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    • v.12 no.2
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    • pp.193-196
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    • 1991
  • The $^{13}C-NMR$ shifts of a series of para-substituted $8-aryl-tricyclo[3.2.1.0^{2,7}]oct-8-yl$ and $9-aryl-tricyclo[3.3.1.0^{2,8}]-non-9-yl$ cations were measured in $FSO_3H/SO_2ClF\ at\-90^{\circ}$ in order to examine whether the ${\rho}^{C^+}$ values can be used as a measure of the geometric influence on the charge delocalization resulting from ${\rho}$ conjugation in rigid tricyclopropylcarbinyl cations. Plot of the ${\Delta}{\delta}^{C+} shifts against the ${\sigma}^{C+}$ constants revealed excellent linear correlation. The 8-aryl tricyclooctyl systems yielded a ${\rho}^{C+}$ value of -5.00 with r = 0.9962. Previous investigation of the 9-aryl-tricyclononyl systems gave a correlation coefficient of r = 0.9948 with a slope of ${\rho}^{C+}$ = -4.95. A fair parallelism exists between the results of $^{19}F-NMR $ studies and the change of ${\rho}^{C+}$ value in these cations. Consequently, it is established that the ${\rho}^{C+}$ value can be used to explain the mechanism of charge stabilization of the rigid cyclopropylcarbinyl cation such as tricyclo $[3.2.1.0^{2,7}]oct-8-yl$ cation.