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.

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.

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.

Optimal vaccination and treatment in the SIR epidemic model

Gul Zaman,Yong Han Kang,Il Hyo Jung 한국산업응용수학회 2007 한국산업응용수학회 학술대회 논문집 Vol.3 No.2

Mathematical epidemiological models for the dynamics of infections that induce lifelong immunity have been extensively developed. In this work, we consider a nonlinear SIR model given by a nonlinear system describing the dynamics of the interaction between susceptible and infective individuals in population. We analyze the dynamical behavior of the nonlinear system and then use two types of control vaccination and treatment to reduce the susceptible and infective individuals and increase the number of recovered individuals. The optimality system is derived and then solved numerically using an iterative method with Runge-Kutta fourth order scheme.

Clinical Research Article : The optimal volume of 0.2% ropivacaine required for an ultrasound-guided stellate ganglion block

( Gul Jung ),( Bum Soo Kim ),( Kyung Bae Shin ),( Ki Bum Park ),( Sae Yeon Kim ),( Sun Ok Song ) 대한마취과학회 2011 Korean Journal of Anesthesiology Vol.60 No.3

Background: This study was performed to find the optimal volume of local anesthetics needed for a successful ultrasound-guided stellate ganglion block (SGB) to treat head and neck pathology. Methods: Fifteen female and fourteen male sensory-neural hearing loss patients received 4 times SGBs with 0.2% ropivacaine in volumes of 6, 4, 3 and 2 ml at 1 to 3 day intervals. Using the transverse short-axis view of the neck that showed Chassaignac`s tubercle at the C6 level, a 25-gauge, and 4 cm needle was inserted via the lateral paracarotid approach with out-of-plane targeting between the prevertebral fascia and the ventral surface of longus colli muscle (subfascial injection). A successful block was confirmed with the onset of ptosis (Horner`s syndrome). Results: There were no significant statistical differences between the presence of Horner`s syndrome and the volume of local anesthetics given. However, Horner`s syndrome was present in all trials for the 4 ml and 6 ml groups. Six (20.7%) and three out (10.4%) of twenty-nine trials in the 2 ml and 3 ml groups, respectively, failed to elicit Horner`s syndrome. The duration of action was significantly different in the 2 ml group compared to that of the 6 ml group, but there was no significant difference between the other groups, including the 4 ml vs. 6 ml groups. The side effects were not different between the groups. Conclusions: This data suggests that the optimal volume of 0.2% ropivacaine for ultrasound-guided SGB to treat the head and neck pathology in daily practice is 4 ml. (Korean J Anesthesiol 2011; 60: 179-184)

First Principles Calculations of Mn₂As

Gul Rahman,Sungle Cho,Soon Cheol Hong 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Biodegradation of Evercion Blue P-GR and Ostazin Black H-GRN in synthetic textile wastewater by membrane bioreactor system using Trametes versicolor

Gul, Ulkuye D.,Acikgoz, Caglayan,Ozan, Kadir Techno-Press 2020 Advances in environmental research Vol.9 No.2

In this study, the decolorization of Evercion Blue P-GR (EBP) and Ostazin Black H-GRN (OBH) was investigated using white-rot fungi named as Trametes versicolor (T. versicolor) by Membrane Bioreactor (MBR) system. This study involved experiments employing synthetic textile wastewater in Membrane Bioreactor (MBR) system (170 ml), initially inoculated with a pure culture of fungi, but operated, other than controlling pH (4.5±0.2) and temperature (25±1℃), under non-sterile conditions. The effect of dye concentrations on fungal biodegradation was also investigated. The decolorization efficiencies were 98%, 90%, and 87% respectively, for EBP when the initial dye concentration of 50, 100, and 200 mg L^-1 were used. However, the decolorization percentages for OBH dye were obtained 95% for 50 mg L^-1 dye solution in 2 days and 66% for 100 mg L^-1 dye solution in 5 days. Possible interactions between dye molecules and the fungal surface were confirmed by SEM, EDX, and FTIR analyses.

On the Design of a WiFi Direct 802.11ac WLAN under a TGn MIMO Multipath Fading Channel

( Gul Zameen Khan ),( Ruben Gonzalez ),( Eun-chan Park ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.3

WiFi Direct (WD) is a state of the art technology for a Device-to-Device (D2D) communication in 802.11 networks. The performance of the WD system can be significantly affected by some key factors such as the type of application, specifications of MAC and PHY layer parameters, and surrounding environment etc. It is, therefore, important to develop a system model that takes these factors into account. In this paper, we focus on investigating the design parameters of the PHY layer that could maximize the efficiency of the WD 802.11 system. For this purpose, a basic theoretical model is formulated for a WD network under a 2x2 Multiple In Multiple Out (MIMO) TGn channel B model. The design level parameters such as input symbol rate and antenna spacing, as well as the effects of the environment, are thoroughly examined in terms of path gain, spectral density, outage probability and Packet Error Rate (PER). Thereafter, a novel adaptive algorithm is proposed to choose optimal parameters in accordance with the Quality of Experience (QoE) for a targeted application. The simulation results show that the proposed method outperforms the standard method thereby achieving an optimal performance in an adaptive manner.