• Title, Summary, Keyword: RhoA

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Cauchy problem for the Euler equations of a nonhomogeneous ideal incompressible fluid

  • Itoh, Shigeharu
    • Journal of the Korean Mathematical Society
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    • v.31 no.3
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    • pp.367-373
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    • 1994
  • Let us consider the Cauchy problem $$ {\rho_t + \upsilon \cdot \nabla\rho = 0 {\rho[\upsilon_t + (\upsilon \cdot \nabla)\upsilon] + \nabla p + \rho f {div \upsilon = 0 (1.1) {\rho$\mid$_t = 0 = \rho_0(x) {\upsilon$\mid$_t = 0 = \upsilon_0(x) $$ in $Q_T = R^3 \times [0,T]$, where $f(x,t), \rho_0(x) and \upsilon_0(x)$ are given, while the density $\rho(x,t)$, the velocity vector $\upsilon(x,t) = (\upsilon^1(x,t),\upsilon^2(x,t),\upsilon^3(x,t))$ and the pressure p(x,t) are unknowns. The equations $(1.1)_1 - (1.1)_3$ describe the motion of a nonhomogeneous ideal incompressible fluid.

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Analysis of the Korean peninsula precipitation using inverse statistics methodology (역통계 방법론을 이용한 한반도의 강수 특성 분석)

  • Min, Seungsik
    • The Korean Journal of Applied Statistics
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    • v.29 no.3
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    • pp.425-435
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    • 2016
  • In this paper, we analyze the inverse statistics of rainfall for 12 regions from 1973 to 2014. We obtain a probability density function f(x) of daily rainfall x, and $f({\tau}_{\rho})$ of the first passage time ${\tau}_{\rho}$ for a given ${\rho}$. Lastly, we derive the relation between ${\rho}$ and ${\tau}_{mean}({\rho})$, i.e., the averaged value of ${\tau}_{\rho}$. The analyses result in the x and ${\tau}_{\rho}$ have stretched exponential distributions. Also, ${\tau}_{mean}({\rho})$ has the form of a stretched exponential function. We derive the shape parameter ${\beta}$ of the distribution, and analyze the characteristics of 12 regional rainfalls.

Role of Rho A and F-actin for uropod formation in T lymphocytes (T 세포의 Uropod 형성에 있어 Rho A와 F-actin의 역할)

  • Lee, Jong-Hwan
    • Journal of Life Science
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    • v.17 no.2
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    • pp.192-197
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    • 2007
  • Two distinct morphological features, leading edge and uropod, in mobile T lymphocyte are crucial for efficient directional movement. The uropod is a unique rear protrusion in migrating lymphocytes, in which several proteins, including CD44, ERM (ezrin/radixin/moesin), and F-actin cytoskeleton are concentrated and concerted. F-actin cytoskeleton is a basic mold for the shape maintenance. Rho A small GTPase acts as cytoskeleton organizer, So far, various pathways potentially can induce the Rho activation. PDZ domain is able to increase active Rho A form (Rho-GTP) level, reorganize F-actin cytoskeleton, disrupts the uropod structure and cell migration was diminished, suggesting that signaling pathways between Rho and F-artin cytoskeleton are related to uropod formation.

Presteady State Kinetics of ATP Hydrolysis by Escherichia coli Rho Protein Monitors the Initiation Process

  • Jeong, Yong-Ju;Kim, Dong-Eun
    • Bulletin of the Korean Chemical Society
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    • v.27 no.2
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    • pp.224-230
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    • 2006
  • Escherichia coli transcription termination factor Rho catalyzes the unwinding of RNA/DNA duplex in reactions that are coupled to ATP binding and hydrolysis. We report here the kinetic mechanism of presteady state ATP binding and hydrolysis by the Rho-RNA complex. Presteady state chemical quenched-flow technique under multiple turnover condition was used to probe the kinetics of ATP binding and hydrolysis by the Rho-RNA complex. The quenched-flow presteady state kinetics of ATP hydrolysis studies show that three ATPs are bound to the Rho-RNA complex with a rate of $4.4\;{\times}\;10^5M^{-1}s^{-1}$, which are subsequently hydrolyzed at a rate of $88s^{-1}$ and released during the initiation process. Global fit of the presteady state ATP hydrolysis kinetic data suggests that a rapid-equilibrium binding of ATP to Rho-RNA complex occurs prior to the first turnover and the chemistry step is not reversible. The initial burst of three ATPs hydrolysis was proposed to be involved in the initialization step that accompanies proper complex formation of Rho-RNA. Based on these results a kinetic model for initiation process for Rho-RNA complex was proposed relating the mechanism of ATP binding and hydrolysis by Rho to the structural transitions of Rho-RNA complex to reach the steady state phase, which is implicated during translocation along the RNA.

Exogenous D-ala Enhances the Accumulation of $\rho-Coumaroylamino$ Acids in Ephedra distachya Cultures

  • Song, Kyung-Sik
    • Archives of Pharmacal Research
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    • v.18 no.5
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    • pp.336-339
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    • 1995
  • Ephedra distachya cultures have been known to accumulate two major $\rho-coumaroylamino$ acids (p-coumaroylgicine and $\rho-coumaroylamino$ -D-alanine) by D-Ala treament. When D-Ala was added together with serial concentrations of yeast-derived elicitor, the accumulation of $\rho-coumaroylamino$ -D-Ala $(\rho-CDA)$ was geatly increased in an additive manner. In feeding experiments, $[1-^14C]$-D-Ala was incorporated into $\rho-CDA$at a rate of 2.2% or 2.3% of added radioactivity, indicating that exogenous D-Ala served as a precursor of the conjugate. $[1-^14C]$-L-Ala wasalso incorporated into p-CDA (0.23%) in the elicitor treated cultures. This fact suggested that at least a part of $(\rho-CDA)$ was produced from active conversion of L-Ala by the elecitation. In order to investigate a possible role of D-Ala as an elicitor of $\rpo-coumaroylamino$ acids $(\rpo-CAA)$, cold D-Ala was added together with labeled L-Ala. Although L-Ala seemed to be incorporated into $\rho-CDA$ by this treatment, the incorporation ratio was too small (0.054%) to draw a clear conclusion. However, the amount of $\rpo-coumaroylglycine$, which did not use D-Ala as a substrate, was also sightly increased by D-Ala treatment irrespective of the presence of elicitor, suggesting that exogenous D-Ala might act as an elicitor of$\rpo-CAA$ as well as a precusor substrate of $\rho-CDA$.

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Structure-Reactivity Relationship of Benzyl Benzenesulfonates. Part 4. Application of Correlation Interaction Coefficients

  • 여수동;정덕영;박종환;김성홍;황규탁
    • Bulletin of the Korean Chemical Society
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    • v.19 no.4
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    • pp.434-436
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    • 1998
  • The mechanism of nucleophilic displacement was studied by using three variable systems of ${\rho}_X,\; {\rho}_Y,\; and {\rho}_Z$ obtained from the change of substituent X, Y, and Z for the reaction of (Z)-substituted benzyl (X)-benzensulfonates with (Y)-substituted thiobenzamides in acetone at 45 ℃. The results ${\rho}_Z$<0 and ${\rho}_YZ$>${\rho}_XZ$ indicate that this reaction series proceeded via a dissociative $S_N2$ mechanism. The prediction of the movement of TS by using the sign of ${\rho}_XZ{\cdot}{\rho}_{YZ}$ accorded with the Hammond postulate.

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Rhodanthpyrone A and B play an anti-inflammatory role by suppressing the nuclear factor-κB pathway in macrophages

  • Kim, Kyeong Su;Han, Chang Yeob;Han, Young Taek;Bae, Eun Ju
    • The Korean Journal of Physiology and Pharmacology
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    • v.23 no.6
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    • pp.493-499
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    • 2019
  • Macrophage-associated inflammation is crucial for the pathogenesis of diverse diseases including metabolic disorders. Rhodanthpyrone (Rho) is an active component of Gentiana rhodantha, which has been used in traditional Chinese medicine to treat inflammation. Although synthesis procedures of RhoA and RhoB were reported, the biological effects of the specific compounds have never been explored. In this study, the anti-inflammatory activity and mechanisms of action of RhoA and RhoB were studied in lipopolysaccharide (LPS)-stimulated macrophages. Pretreatment with RhoA and RhoB decreased inducible nitric oxide synthase and cyclooxygenase-2 expressions in RAW 264.7 cells and in thioglycollate-elicited mouse peritoneal macrophages. In addition, it downregulated transcript levels of several inflammatory genes in LPS-stimulated RAW 264.7 cells, including inflammatory cytokines/chemokines (Tnfa, Il6, and Ccl2) and inflammatory mediators (Nos2 and Ptgs2). Macrophage chemotaxis was also inhibited by treatment with the compounds. Mechanistic studies revealed that RhoA and RhoB suppressed the nuclear factor $(NF)-{\kappa}B$ pathway, but not the canonical mitogen activated protein kinase pathway, in LPS-stimulated condition. Moreover, the inhibitory effect of RhoA and RhoB on inflammatory gene expressions was attenuated by treatment with an $NF-{\kappa}B$ inhibitor. Our findings suggest that RhoA and RhoB play an anti-inflammatory role at least in part by suppressing the $NF-{\kappa}B$ pathway during macrophage-mediated inflammation.

The Relationship between the Distance and Kinematical Parameters of Javelin in Korean Male Javelin Throwers (한국 남자 창던지기 선수들의 창의 운동학적 요인과 기록과의 관계)

  • Kim, Woo-Jin
    • Korean Journal of Sport Biomechanics
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    • v.24 no.3
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    • pp.217-227
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    • 2014
  • The purpose of this study was to investigate the relationship between distance and factors of javelin in korean male's javelin throwing. To accomplish this purpose, the analyzed trail selected total 29 trails (subjects 9) recorded more than 65 m in the 93rd National Sports Festival. The Kwon3D 3.1 version was used to obtain the three dimensional coordinates about the top, grip, end of javelin. And the kinematic data such as projection factors and direction angle of javelin calculated using Matlab2009a program. The statical analysis on the records (n=29) were used to Pearson's product moment correlation coefficient. There was a statistically positive relationship between the records and horizontal velocity (r=.866, ${\rho}$<.01), height (r=.541, ${\rho}$ <.001), height rate (r=.373, ${\rho}$ <.05) and horizontal displacement of javelin (r=.749, ${\rho}$ <.01), but the medial/lateral velocity showed a negative relationship to r=-.663 (${\rho}$ <.01). The attack and yaw angle showed not a significant relationship between the records, but the medial-lateral tilt (E1:r =-.557 [p<.01)] E2:r=-.629 [${\rho}$<.01], E3:r=-.528 [${\rho}$ <.01]) and attitude angle (E2:r=-.629 [[${\rho}$<.01], E3:r=-.619 [${\rho}$ <.01]) of javelin showed a negative relationship between the records, as well as the projection angle of javelin (r=-.419, ${\rho}$ <.05) showed a negative relationship between the records.

Structure direct agent-assisted hydrothermal synthesis and small gases adsorption behavior of pure RHO zeolite (구조유도물질 18-crown-6 ether를 이용한 순수한 RHO 제올라이트 수열합성과 작은 가스 흡착 거동)

  • Kim, Beom-Ju;Sharma, Pankaj;Han, Moon-Hee;Cho, Churl-Hee
    • Journal of Energy Engineering
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    • v.23 no.4
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    • pp.141-149
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    • 2014
  • In the present study, pure RHO zeolite was hydrothermally synthesized by using 18-crown-6 ether as a structure directing agent(SDA), and the small gases adsorption was investigated. Synthesized RHO zeolite was a cube shape particle of which average edge length was around $1.2{\mu}m$ and composed of primary crystallites having a diameter of around 100 to 200 nm. RHO zeolite structure was stable under 3h calcination at $600^{\circ}C$. Water adsorption data announced that RHO zeolite has a specific surface area of 483.32 m2/g and its micropore diameter was about 4 A. Gas adsorption was studied in the pressure range of 50 to 500 kPa for $CO_2$, $N_2$, $O_2$ and $H_2$. It was evident that RHO zeolite showed a strong $CO_2$ adsorption behavior. Especially, RHO zeolite showed a transient $CO_2$ adsorption behavior. The 3h $CO_2$ up-take at 50 kPa and 500 kPa was 1.283 and 3.357 mmol/g, respectively. The $CO_2/H_2$ selectivity was around 16 at 500 kPa. Compared with gas adsorption data for some representative microporous adsorbents, it was certain that RHO zeolite is a beneficial adsorbent for $CO_2/H_2$ separation.

ADDITIVE ρ-FUNCTIONAL EQUATIONS IN NON-ARCHIMEDEAN BANACH SPACE

  • Paokanta, Siriluk;Shim, Eon Hwa
    • The Pure and Applied Mathematics
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    • v.25 no.3
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    • pp.219-227
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    • 2018
  • In this paper, we solve the additive ${\rho}$-functional equations $$(0.1)\;f(x+y)+f(x-y)-2f(x)={\rho}\left(2f\left({\frac{x+y}{2}}\right)+f(x-y)-2f(x)\right)$$, where ${\rho}$ is a fixed non-Archimedean number with ${\mid}{\rho}{\mid}$ < 1, and $$(0.2)\;2f\left({\frac{x+y}{2}}\right)+f(x-y)-2f(x)={\rho}(f(x+y)+f(x-y)-2f(x))$$, where ${\rho}$ is a fixed non-Archimedean number with ${\mid}{\rho}{\mid}$ < |2|. Furthermore, we prove the Hyers-Ulam stability of the additive ${\rho}$-functional equations (0.1) and (0.2) in non-Archimedean Banach spaces.