A chloroplast-localized DEAD-box RNA helicaseAtRH3 is essential for intron splicing and plays an important role in the growth and stress response in Arabidopsis thaliana

Gu, L.,Xu, T.,Lee, K.,Lee, K.H.,Kang, H. Gauthier-Villars ; Elsevier Science Ltd 2014 Vol. No.

Although many DEAD-box RNA helicases (RHs) are targeted to chloroplasts, the functional roles of the majority of RHs are still unknown. Recently, the chloroplast-localized Arabidopsis thaliana AtRH3 has been demonstrated to play important roles in intron splicing, ribosome biogenesis, and seedling growth. To further understand the functional role of AtRH3 in intron splicing and growth and the stress response in Arabidopsis, the newly-generated artificial microRNA-mediated knockdown plants as well as the previously characterized T-DNA tagged rh3-4 mutant were analyzed under normal and stress conditions. The rh3 mutants displayed retarded growth and pale-green phenotypes, and the growth of mutant plants was inhibited severely under salt or cold stress but marginally under dehydration stress conditions. Splicing of several intron-containing chloroplast genes was defective in the mutant plants. Importantly, splicing of ndhA and ndhB genes was severely inhibited in the mutant plants compared with the wild-type plants under salt or cold stress but not under dehydration stress conditions. Moreover, AtRH3 complemented the growth-defect phenotype of the RNA chaperone-deficient Escherichia coli mutant and had the ability to disrupt RNA and DNA base pairs, indicating that AtRH3 possesses RNA chaperone activity. Taken together, these results demonstrate that AtRH3 plays a prominent role in the growth and stress response of Arabidopsis, and suggest that proper splicing of introns governed by RNA chaperone activity of AtRH3 is crucial for chloroplast function and the growth and stress response of plants.

An RRM-containing mei2-like MCT1 plays a negative role in the seed germination and seedling growth of Arabidopsis thaliana in the presence of ABA

Gu, L.,Jung, H.J.,Kwak, K.J.,Dinh, S.N.,Kim, Y.O.,Kang, H. Gauthier-Villars ; Elsevier Science Ltd 2016 Vol. No.

<P>Despite an increasing understanding of the essential role of the Mei2 gene encoding an RNA-binding protein (RBP) in premeiotic DNA synthesis and meiosis in yeasts and animals, the functional roles of the mei2-like genes in plant growth and development are largely unknown. Contrary to other mei2-like RBPs that contain three RNA-recognition motifs (RRMs), the mei2 C-terminal RRM only (MCF) is unique in that it harbors only the last C-terminal RRM. Although MCTs have been implicated to play important roles in plants, their functional roles in stress responses as well as plant growth and development are still unknown. Here, we investigated the expression and functional role of MCT1 (At1g37140) in plant response to abscisic acid (ABA). Confocal analysis of MCT1-GFP-expressing plants revealed that MCT1 is localized to the nucleus. The transcript level of MCT1 was markedly increased upon ABA treatment. Analysis of MCT1-overexpressing transgenic Arabidopsis plants and artificial miRNA-mediated mct1 knockdown mutants demonstrated that Mal inhibited seed germination and cotyledon greening of Arabidopsis plants under ABA. The transcript levels of ABA signaling-related genes, such as ABI3, ABI4, and ABI5, were markedly increased in the MCT1-overexpressing transgenic plant. Collectively, these results suggest that ABA-upregulated MCT1 plays a negative role in Arabidopsis seed germination and seedling growth under ABA by modulating the expression of ABA signaling-related genes. (C) 2016 Elsevier Masson SAS. All rights reserved.</P>

선인장 양심실 보조장치의 설계 및 임상적용을 위한 평가

민병구,박찬영,최재순,이혁수,황창모,김삼성,윤걸중,김종원,선경,이경갑,정종태,김원곤 제주대학교 인공심장이식연구소 2001 인공심장 연구 Vol.2 No.1

현재 개발되고 있는 맥동형 이식형 인공심장은 완전이식형 인공심장과 좌심실보조장치 뿐이다. 좌심실보조장치를 장착한 환자의 10~15%가 우심실의 보조를 필요로하고 완전이식형 인공심장의 장착을 위해서는 자연심장을 제거해야하는 상황에서 이식형 양심실보조장치에 대한 필요성이 대두되고 있다. 본 연구진은 완전이식형 인공심장으로 개발된 한국형 인공심장을 개선하여 양심 실 보조장치를 개발하였다. 양심실보조장치는 이동형 작동기식 미케니즘을 이용하고 있으며 에너지 변환장치와 감속기로 구성된 작동기와 혈액주머니, 그리고 내장형 제어기로 구성되어 있다. 선인장 펌프로 명명된 KAH350은 캐뉼라의 연결을 위한 커넥터를 포함하여 길이 177mm, 폭 164mm, 높이 67 이고 무게 780g이며 최대 심박출량은 5L/min 이다. 양심실보조장치로 개발된 선인장펌프는 좌심실보조장치로도 응용이 가능하다. 이식적합성과 생체적합성을 평가하기 위하여 좌심실보조장치로 5회, 양싱실보조장치로 6회의 동물실험을 수행하였다. 각각 최장 28일간 생존하였으며 11회의 동물실험중 장치의 결함에 의한 것이 3회 있었는데 이들은 모두 전자장치의 결함과 방수처리문제였다. 현재 이식적합성과 일박출량을 향상시킨 KAH400모델이 개발중이다. The types of pulsatile implantable artificial hearts that are on the way of development and have been developed are totally implantable artificial heart and implantable left ventricular assist device (LVAD). Approximately 10% to 15% of all patients Implanted with wearable VADs have required right heart support with another device. And it is reluctant to patient who should remove his or her own heart to be implanted with total artificial heart. These situations drive the development of implantable bi-ventricular assist device (BVAD). The Korean BVAD was develophed by modifying the moving actuator type Korean artificial heart. This electro-mechanical BVAD comprises actuator including energy converter and reduction gear train, blood sacs, and internal motor and energy controllers. The KAH350 which is named as 'Cactus Pump' is 177mm in length, 164mm in width, and 67mm in thickness including connectors and nuts. The weight and maximum cardiac output of Cactus Pump is 780g and 5L/min, respectively. The Cactus Pump that was developed as BVAD could be used as LVAD by attaching compliance caps on the 2 ports of one ventricle. The animal experiments were undergone 5 times for LVAD, and 6 times for BVAD. The best records were 28 days survival in both applications. There were 3 times of device failure and they were all associated with electrical connection and hermetic sealing. The KAH400 that has improved anatomical fitting characterisitcs and stroke volume is on development.

Magnetism of Zinc-Blende Fe Chalcogenides (FeY, Y = S, Se and Te): First-Principles Calculations

Gul Rahman,Sunglae Cho,Soon Cheol Hong 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.1

Within the framework of density functional theory (DFT) in the generalized gradient approximation (GGA) using the full potential linearized augmented plane wave (FLAPW) method, we study the magnetism and the electronic properties of zinc-blende (ZB) Fe chalcogenides. The theoretical calculations show that the magnetic ground states of all of the ZB FeS, FeSe and FeTe considered in this study are antiferromagnetic (AFM). The calculated equilibrium lattice constant of ZB Fe chalcogenides in the AFM states varies linearly with the ionic radius of anion. The calculated density of states shows that these Fe chalcogenides are metals.

Ab-initio Study on Magnetism of Al Impurity in bcc Fe

Gul Rahman,In Gee Kim 한국자기학회 2010 한국자기학회 학술연구발표회 논문개요집 Vol.2010 No.12

STABILITY AND THE EFFECT OF HARVESTING IN A BUDWORM POPULATION MODEL

GUL ZAMAN,YONG HAN KANG,IL HYO JUNG 한국산업응용수학회 2010 Journal of the Korean Society for Industrial and A Vol.14 No.3

In this work, we consider a nonlinear budworm model by a system of three ordinary differential equations originally created by Ludwig et al. in 1978. The nonlinear system describes the dynamics of the interaction between a budworm and a fir forest. We introduce stability techniques to analyze the dynamical behavior of this nonlinear system. Then we use constant effort harvesting techniques to control the budworm population. We also give numerical simulations of the population model with harvest and without harvest.

Structural monitoring of movable bridge mechanical components for maintenance decision-making

Gul, Mustafa,Dumlupinar, Taha,Hattori, Hiroshi,Catbas, Necati Techno-Press 2014 Structural monitoring and maintenance Vol.1 No.3

This paper presents a unique study of Structural Health Monitoring (SHM) for the maintenance decision making about a real life movable bridge. The mechanical components of movable bridges are maintained on a scheduled basis. However, it is desired to have a condition-based maintenance by taking advantage of SHM. The main objective is to track the operation of a gearbox and a rack-pinion/open gear assembly, which are critical parts of bascule type movable bridges. Maintenance needs that may lead to major damage to these components needs to be identified and diagnosed timely since an early detection of faults may help avoid unexpected bridge closures or costly repairs. The fault prediction of the gearbox and rack-pinion/open gear is carried out using two types of Artificial Neural Networks (ANNs): 1) Multi-Layer Perceptron Neural Networks (MLP-NNs) and 2) Fuzzy Neural Networks (FNNs). Monitoring data is collected during regular opening and closing of the bridge as well as during artificially induced reversible damage conditions. Several statistical parameters are extracted from the time-domain vibration signals as characteristic features to be fed to the ANNs for constructing the MLP-NNs and FNNs independently. The required training and testing sets are obtained by processing the acceleration data for both damaged and undamaged condition of the aforementioned mechanical components. The performances of the developed ANNs are first evaluated using unseen test sets. Second, the selected networks are used for long-term condition evaluation of the rack-pinion/open gear of the movable bridge. It is shown that the vibration monitoring data with selected statistical parameters and particular network architectures give successful results to predict the undamaged and damaged condition of the bridge. It is also observed that the MLP-NNs performed better than the FNNs in the presented case. The successful results indicate that ANNs are promising tools for maintenance monitoring of movable bridge components and it is also shown that the ANN results can be employed in simple approach for day-to-day operation and maintenance of movable bridges.

The Nexus Between Intellectual Capital and Financial Performance: An Econometric Analysis from Pakistan

GUL, Raazia,AL-FARYAR, Mamdouh Abdulaziz Saleh,ELLAHI, Nazima Korea Distribution Science Association 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.7

Intellectual Capital, a valuable intangible organizational asset, is primarily linked to a company's financial performance and is divided into three categories: human, structural, and relational capital. This paper investigates the impact of intellectual capital on the financial performance of selected Pakistani companies in the Information and Communication sector, as this sector is heavily reliant on intellectual capital. The data for 11 firms was gathered from the State Bank's Financial Statements Analysis of Companies Listed on the Pakistan Stock Exchange from 2015 to 2020. Pulić's (2004) Value Added Intellectual Coefficient (VAICTM) has been used to assess a company's IC efficiency. VAIC^TM and its components, the efficiency of intellectual capital, and the efficiency of capital employed are calculated. Financial performance is measured through return on assets, return on capital employed, and asset turnover ratio. Multiple regression, fixed-effect, and random-effect Panel Data estimation are used in the empirical study. The findings suggest that intellectual capital efficiency has a large impact on major profitability metrics, but little effect on company productivity. It can be inferred from the results that the companies must invest in advanced technology, the latest machinery, and well-equipped offices to improve financial performance and productivity and gain a competitive advantage.

Serum N-Desmethylcitalopram Concentrations are Associated with the Clinical Response to Citalopram of Patients with Major Depression

Gul Ozbey,Berna Yucel,Nurdan Eren Bodur,Serap Erdogan Taycan,Tayyibe Arslan,Nazan Cerit,Nevzat Yuksel,Ismail Cuneyt Guzey,Canan Uluoglu 대한신경정신의학회 2018 PSYCHIATRY INVESTIGATION Vol.15 No.3

Objective-Citalopram (CITA) is a widely used and well-tolerated selective serotonin reuptake inhibitor. The aim of the study was to evaluate the possible influences of serum concentrations of CITA and its major metabolite n-desmethylcitalopram (NDCITA) on the efficacy and tolerability of CITA in patients with major depressive disorder. Methods-The study included 46 outpatients with major depressive disorder who received CITA. The efficacy and tolerability were assessed for 6 weeks. Serum CITA and NDCITA levels were measured at the 4th week. Results-The HDRS17 total scores of the patients with high NDCITA and CITA & NDCITA concentrations showed a more significant reduction compared to the patients with expected and low serum NDCITA and CITA & NDCITA concentrations. However, we did not observe a correlation between the serum concentrations and the side effects of CITA, NDCITA, and CITA & NDCITA. Conclusion-Our results suggested the potential contribution of NDCITA to the antidepressant effect of CITA. Further studies involving larger clinical samples are required to confirm the impact of serum NDCITA concentrations on the efficacy of CITA.

The influence of kinematics of blades on the flow structure in deep dynamic stall

Gul Chang,Hamid Reza Karbasian,Shujun Zhang,Yao Yan,Binqi Chen,Kyung Chun Kim 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.7

This study considers the effect of kinematics on the aerodynamic loads and flow structure around moving blades of micro air vehicles (MAVs) in deep dynamic stall. The transversal (pure heaving) and rotational (pure pitching) motions are considered distinctly to investigate the dynamic stall. An equivalent effective angle of the attack profile is given to both motions. This method helps to figure out the influence of kinematics on flow structures when all boundary conditions and effective angles of attack profiles are the same. An experiment is conducted in fully turbulent flow at Re = 1.5×10 4 to avoid any transition regime in the boundary layer, and make the results relatively independent of the flow characteristics. A NACA 0012 airfoil is chosen at high reduced frequencies (k = 0.25 and 0.375) and high angles of attack to reach deep dynamic stall conditions. Additionally, time-resolved particle image velocimetry (PIV) and post-processing are used to compute the aerodynamic loads using a control-volume approach. The flow field is also reconstructed using proper orthogonal decomposition (POD) to separate the flow structures in different modes. It is shown that the kinematics can significantly influence the flow structure and aerodynamic loads. In the pre-stall region, the pure pitching motion usually produces higher lift force, while the pure heaving motion has a higher lift peak. However, in the post-stall region, the pure heaving motion usually has higher lift than the pure pitching motion. The pure heaving motion produced lower drag force than the pure pitching motion. For pure heaving motion, the POD analysis reveals there is a high-energy mode in the flow structure that helps to make the vortices more stable compared to pure pitching motion. Furthermore, the pure heaving motion adds extra kinetic energy to the boundary layer, which decelerates the reversal flow and the transfer of the separation point on suction side of the airfoil.