• Title/Summary/Keyword: Instability

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A Novel Reciprocal Crosstalk between RNF168 and PARP1 to Regulate DNA Repair Processes

  • Kim, Jae Jin;Lee, Seo Yun;Kim, Soyeon;Chung, Jee Min;Kwon, Mira;Yoon, Jung Hyun;Park, Sangwook;Hwang, Yiseul;Park, Dongsun;Lee, Jong-Soo;Kang, Ho Chul
    • Molecules and Cells
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    • v.41 no.8
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    • pp.799-807
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    • 2018
  • Emerging evidence has suggested that cellular crosstalk between RNF168 and poly(ADP-ribose) polymerase 1 (PARP1) contributes to the precise control of the DNA damage response (DDR). However, the direct and reciprocal functional link between them remains unclear. In this report, we identified that RNF168 ubiquitinates PARP1 via direct interaction and accelerates PARP1 degradation in the presence of poly (ADP-ribose) (PAR) chains, metabolites of activated PARP1. Through mass spectrometric analysis, we revealed that RNF168 ubiquitinated multiple lysine residues on PARP1 via K48-linked ubiquitin chain formation. Consistent with this, micro-irradiation-induced PARP1 accumulation at damaged chromatin was significantly increased by knockdown of endogenous RNF168. In addition, it was confirmed that abnormal changes of HR and HNEJ due to knockdown of RNF168 were restored by overexpression of WT RNF168 but not by reintroduction of mutants lacking E3 ligase activity or PAR binding ability. The comet assay also revealed that both PAR-binding and ubiquitin-conjugation activities are indispensable for the RNF168-mediated DNA repair process. Taken together, our results suggest that RNF168 acts as a counterpart of PARP1 in DDR and regulates the HR/NHEJ repair processes through the ubiquitination of PARP1.

Effects of Gluteus Medius Strengthening Training Using Sling on Ankle Instability, Muscle Strength, Balance in Adults in Their 20s with Chronic Ankle Instability (슬링을 이용한 중간볼기근 강화훈련이 만성 발목 불안정성을 가진 20대 성인의 발목 불안정성, 균형, 근력에 미치는 영향)

  • Jeong, Jong-Hyo;Kim, Ho;Shin, Won-Seob
    • Journal of The Korean Society of Integrative Medicine
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    • v.10 no.4
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    • pp.57-69
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    • 2022
  • Purpose : The purpose of this study was to investigate the effect of ankle strengthening exercise combined with sling-assisted gluteus medius strengthening on ankle instability score, and static and dynamic balance ability, muscle strength in adults in their 20s with chronic ankle instability. Methods : Twenty-eight adults in their 20s with chronic ankle instability were recruited. After screening test, they were randomized through R studio program as an experimental group (n=14) to apply an ankle strengthening exercise combined with sling-assisted gluteus medius strengthening and a control group (n=14) to apply ankle strengthening exercise. The intervention lasted two times a week for 6 weeks. To compare the intervention effects, the Cumberland ankle instability tool (CAIT) score, static and dynamic balance ability, and muscle strength of lower extremities were measured. Results : The experimental group showed a significant increase in pre and post-intervention Cumberland ankle instability tool (CAIT) score, static and dynamic balance ability, and muscle strengt (p<.05). The control group showed a significant increase in pre and post-intervention CAIT score, dynamic balance ability, and muscle strength (p<.05). The experimental group showed a significant increase in CAIT score, dynamic balance ability, and muscle strength compared to the control group (p<.05), and showed a high effect size. Conclusions : The results of this study confirmed that ankle strengthening exercise combined with sling-assisted gluteus medius strengthening on people with chronic ankle instability the possibility that it could be effective in improving ankle instability and improving dynamic balance ability, and strength by movement. Although additional research is needed to increase the number of participants due to the small sample size, it is hoped that this study will be an optimistic clinical protocol for people with chronic ankle instability.

Hygrothermal effects on dynamic instability of a laminated plate under an arbitrary pulsating load

  • Wang, Hai;Chen, Chun-Sheng;Fung, Chin-Ping
    • Structural Engineering and Mechanics
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    • v.48 no.1
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    • pp.103-124
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    • 2013
  • This paper studies the static and dynamic characteristics of composite plates subjected to an arbitrary periodic load in hygrothermal environments. The material properties of composite plates are depended on the temperature and moisture. The governing equations of motion of Mathieu-type are established by using the Galerkin method with reduced eigenfunction transforms. A periodic load is taken to be a combination of axial pulsating load and bending stress in the example problem. The regions of dynamic instability of laminated composite plates are determined by solving the eigenvalue problems based on Bolotin's method. The effects of temperature rise and moisture concentration on the dynamic instability of laminated composite plates are investigated and discussed. The influences of various parameters on the instability region and dynamic instability index are also investigated. The numerical results reveal that the influences of hygrothermal effect on the dynamic instability of laminated plates are significant.

Diagnosis and Comorbidity of Chronic Ankle Instability (만성 족관절 불안정성의 진단 및 동반 질환)

  • Ha, Dongjun;Kim, Duckhee;Gwak, Heuichul
    • Journal of Korean Foot and Ankle Society
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    • v.22 no.2
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    • pp.49-54
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    • 2018
  • Ankle sprains are among the most common injuries sustained during athletic activities and daily life. Acute ankle sprain is usually managed conservatively with functional rehabilitation but the failure of conservative treatment leads to the development of chronic ankle instability. The development of repetitive ankle sprains and persistent symptoms after injury has been termed chronic ankle instability. Acute ankle sprains and chronic ankle instability require a careful evaluation to detect other comorbidities, such as subtalar instability, osteochondral defect, peroneal tendinopathy, tarsal coalition, os trigonum, flexor hallucis longus tendinitis, calcaneus anterior process fracture, and neural injuries. For the successful treatment of acute ankle sprains and chronic ankle instability, the treatment of comorbidity lesions should be performed first.

Turing, Turing Instability, Computational Biology and Combustion (Turing, Turing 불안정성 그리고 수리생물학과 연소)

  • Kim, J.S.
    • Journal of the Korean Society of Combustion
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    • v.8 no.1
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    • pp.46-56
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    • 2003
  • The present paper is concerned with the development of the computational biology in the past half century and its relationship with combustion. The modem computational biology is considered to be initiated by the work of Alan Turing on the morphogenesis in 1952. This paper first touches the life and scientific achievement of Alan Turing and his theory on the morphogenesis based on the reactive-diffusive instability, called the Turing instability. The theory of Turing instability was later extended to the nonlinear realm of the reactive-diffusive systems, which is discussed in the framework of the excitable media by using the Oregonator model. Then, combustion analogies of the Turing instability and excitable media are discussed for the cellular instability, pattern forming combustion phenomena and flame edge. Finally, the recent efforts on numerical simulations of biological systems, employing the detailed bio-chemical knietic mechanism is discussed along with the possibility of applying the numerical combustion techniques to the computational cell biology.

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Dynamic Instability of Lattice-Dome Structures by Lyapunov Concept

  • Han, Sang-Eul;Hou, Xiao-Wu
    • Architectural research
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    • v.10 no.1
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    • pp.25-32
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    • 2008
  • Stability is a very important part which we must consider in structural design. In this paper, we take advantage of finite element method to study parametrical instability of lattice dome structures, which is subjected to harmonically pulsating load. We consider elastic stiffness and geometrical stiffness simultaneously during the calculation of stiffness matrix, and adopt consistent mass matrix to make the solution more correct. In order to obtain instability regions, we represent displacements and accelerations in dynamic equation by trigonometric series expansions, and then obtain Hill's infinite determinants. After first order approximation, we can get first and second order dynamic instability regions eventually. Finally, we take 24-bar star dome and 90-bar lamella dome as examples to investigate dynamic instability phenomena.

The Effect of Marital Interaction on the Marital Instability of Foreign Wives in Gyeongnam (경남지역 여성결혼이민자의 부부 상호작용이 결혼불안정성에 미치는 영향에 관한 연구)

  • Kim, Eun-Kyung
    • Journal of Families and Better Life
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    • v.28 no.3
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    • pp.1-12
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    • 2010
  • This study identifies how marital interaction influences the marital instability of foreign wives. Data for the study were based on a snowball sampling of 101 foreign wives married to Korean husbands in Gyeongnam, Korea. The respondents reported higher levels of perceived spousal support, marital satisfaction, and sexual satisfaction, but reported lower levels of spousal hostility. A hierarchical regression analysis was conducted to identify the variables that affect marital instability. Independent variables included in the study were years married, religion, monthly income, educational level, perceived husband support, sexual satisfaction, marital satisfaction, and perceived husband hostility. While religion, educational level, sexual satisfaction, marital satisfaction, and perceived husband hostility had a strong effects on the marital instability of foreign wives, years of marriage, monthly income, and perceived husband support did not show significant effect on marital instability. Marital satisfaction had the strongest effect on marital instability.

A CFD Study on Thermo-Acoustic Instability of Methane/Air Flames in Gas Turbine Combustor

  • Sohn, Chae-Hoon;Cho, Han-Chang
    • Journal of Mechanical Science and Technology
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    • v.19 no.9
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    • pp.1811-1820
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    • 2005
  • Thermo-acoustic instability of methane/ air flames in an industrial gas-turbine combustor is numerically investigated adopting CFD analysis. The combustor has 37 EV burners through which methane and air are mixed and then injected into the chamber. First, steady fuel! air mixing and flow characteristics established by the burner are investigated by numerical analysis with single burner. And then, based on information on the flow data, the burners are modeled numerically via equivalent swirlers, which facilitates the numerical analysis with the whole combustion system including the chamber and numerous burners. Finally, reactive flow fields within the chamber are investigated numerically by unsteady analysis and thereby, spontaneous instability is simulated. Based on the numerical results, scaling analysis is conducted to find out the instability mechanism in the combustor and the passive control method to suppress the instability is proposed and verified numerically.

Performances of non-dissipative structure-dependent integration methods

  • Chang, Shuenn-Yih
    • Structural Engineering and Mechanics
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    • v.65 no.1
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    • pp.91-98
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    • 2018
  • Three structure-dependent integration methods with no numerical dissipation have been successfully developed for time integration. Although these three integration methods generally have the same numerical properties, such as unconditional stability, second-order accuracy, explicit formulation, no overshoot and no numerical damping, there still exist some different numerical properties. It is found that TLM can only have unconditional stability for linear elastic and stiffness softening systems for zero viscous damping while for nonzero viscous damping it only has unconditional stability for linear elastic systems. Whereas, both CEM and CRM can have unconditional stability for linear elastic and stiffness softening systems for both zero and nonzero viscous damping. However, the most significantly different property among the three integration methods is a weak instability. In fact, both CRM and TLM have a weak instability, which will lead to an adverse overshoot or even a numerical instability in the high frequency responses to nonzero initial conditions. Whereas, CEM possesses no such an adverse weak instability. As a result, the performance of CEM is much better than for CRM and TLM. Notice that a weak instability property of CRM and TLM might severely limit its practical applications.

Heavy Rainfall prediction using convective instability index (대류성 불안정 지수를 이용한 집중호우 예측)

  • Kim, Young-Chul;Ham, Sook-Jung
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.17 no.1
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    • pp.17-23
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    • 2009
  • The purpose of this study is possibility of the heavy rainfall prediction using instability index. The convective instability index using this study is Convective Available Potential Energy(CAPE) concerned the growth energy of the storm, Bulk Richardson Number(BRN) concerned the type and strength of the storm, and Sotrm Relative Helicity(SRH) concerned maintenance of the storm. To verify the instability index, the simulation of heavy rainfall case experiment by Numerical Weather Prediction(NWP) model(MM5) are designed. The results of this study summarized that the heavy rainfall related to the high instability index and the proper combination of one more instability index made the higher heavy rainfall prediction.

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