• Journal of Plant Biology
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• 제38권3호
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• pp.275-280
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• 1995

The formation of osmiophilic globules related to the granal lysis has been investigated with a shade plant ginseng (Panax ginseng C. A. Meyer) exposed to full sunlight. The changes of chloroplast were examined as a function of time over 9 days under full sunlight exposure. The ultrastructure of ginseng leaf showed swelling of the granal thylakoid during an early stage of the light exposure. The thylakoid membrane faded and small electron-opaque dots were aggregated on the edges of the granal thylakoid membrane when the exposure time was increased over 1 day. Then, the sahpe of the grana changed into round. After the exposure over 3 days, there appeared many osmiophilic globules with multi-lamellated concentric structure. The globules at this stage were partly accumulated with osmiophilic substances. The outermost membrane of these multi-lamellated osmiophilic globules was attached to the stromal thylakoid membrane connecting to the deforming grana. The osmiophilic globules were elongated after 9 days. In this stage, the multi-lamellated structure was difficult to identify due to severe accumulation of osmiophilic substances. The number of the osmiophilic globules also increased along with the full sunlight exposure time. This observation leads us to believe that the multi-lamellated osmiophilic globules came from the deformation of grana.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.52-56
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• 2009

In this study a dynamic modeling scheme is presented to derive the probabilistic structure of soil water and plant water stress when subject to stochastic precipitation conditions. The newly developed model has the form of the Fokker-Planck equation, and its applicability as a model for the probabilistic evolution of the soil water and plant water stress is investigated under climate change scenarios. This model is based on the cumulant expansion theory, and has the advantage of providing the probabilistic solution in the form of probability distribution function (PDF), from which one can obtain the ensemble average behavior of the dynamics. The simulation result of soil water confirms that the proposed soil water model can properly reproduce the results obtained from observations, and it also proves that the soil water behaves with consistent cycle based on the precipitation pattern. The plant water stress simulation, also, shows two different PDF patterns according to the precipitation. Moreover, with all the simulation results with climate change scenarios, it can be concluded that the future soil water and plant water stress dynamics will differently behave with different climate change scenarios.

• 한국해양공학회지
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• 제34권3호
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• pp.217-226
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• 2020

An offshore plant is an offshore platform that can process oil and gas resources in rough seas with a poor working environment. Moreover, it is a complex structure with different types of offshore facilities and a large amount of outfitting that connects different offshore installations. In particular, an enormous amount of various piping materials is installed in a relatively narrow space, and thus, the difficulty of working is relatively high compared to working in ships or ground plants. Generally, when the 3D detailed design is completed, an offshore plant piping process is carried out at the shipyard with ISO 2D fabrication drawings and ISO 2D installation drawings. If a worker wants to understand the three-dimensional piping composition in the working area, he can only use three-dimensional viewers that provide limited functionality. As offshore plant construction progresses, correlating work with predecessors becomes more complicated and rework occurs because of frequent design changes. This viewer function makes it difficult to identify the 3D piping structure of the urgently needed part. This study deals with the process support method based on a system using a 3D simulator to improve the efficiency of the piping process. The 3D simulator is based on the Unity3D engine and can be simulated by considering the classification and priority of 3D models by the piping process in the system. Further, it makes it possible to visualize progress information of the process. In addition, the punch content can be displayed on the 3D model after the pipe inspection. Finally, in supporting the data in relation to the piping process, it is considered that 3D-simulator-supported piping installing could improve the work efficiency by more than 99% compared to the existing method.

• Interdisciplinary Bio Central
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• 제3권4호
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• pp.15.1-15.11
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• 2011

Background: Histone deacetylase (HDAC) 8 is one of its family members catalyzes the removal of acetyl groups from N-terminal lysine residues of histone proteins thereby restricts transcription factors from being expressed. Inhibition of HDAC8 has become an emerging and effective anti-cancer therapy for various cancers. Application computational methodologies may result in identifying the key components that can be used in developing future potent HDAC8 inhibitors. Results: Facilitating the discovery of novel and potential chemical scaffolds as starting points in the future HDAC8 inhibitor design, quantitative structure-activity relationship models were generated with 30 training set compounds using genetic function approximation (GFA) and Bayesian algorithms. Six GFA models were selected based on the significant statistical parameters calculated during model development. A Bayesian model using fingerprints was developed with a receiver operating characteristic curve cross-validation value of 0.902. An external test set of 54 diverse compounds was used in validating the models. Conclusions: Finally two out of six models based on their predictive ability over the test set compounds were selected as final GFA models. The Bayesian model has displayed a high classifying ability with the same test set compounds and the positively and negatively contributing molecular fingerprints were also unveiled by the model. The effectively contributing physicochemical properties and molecular fingerprints from a set of known HDAC8 inhibitors were identified and can be used in designing future HDAC8 inhibitors.

• The Plant Pathology Journal
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• 제38권5호
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• pp.432-448
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• 2022

Planthopper infestation in rice causes direct and indirect damage through feeding and viral transmission. Host microbes and small RNAs (sRNAs) play essential roles in regulating biological processes, such as metabolism, development, immunity, and stress responses in eukaryotic organisms, including plants and insects. Recently, advanced metagenomic approaches have facilitated investigations on microbial diversity and its function in insects and plants, highlighting the significance of microbiota in sustaining host life and regulating their interactions with the environment. Recent research has also suggested significant roles for sRNA-regulated genes during rice-planthopper interactions. The response and behavior of the rice plant to planthopper feeding are determined by changes in the host transcriptome, which might be regulated by sRNAs. In addition, the roles of microbial symbionts and sRNAs in the host response to viral infection are complex and involve defense-related changes in the host transcriptomic profile. This review reviews the structure and potential functions of microbes and sRNAs in rice and the associated planthopper species. In addition, the involvement of the microbiota and sRNAs in the rice-planthopper-virus interactions during planthopper infestation and viral infection are discussed.

• 한국해양공학회지
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• 제26권1호
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• pp.70-77
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• 2012

In this study, a numerical analysis of offshore installation using a floating crane with heave compensator is carried out in time domain. The motion analysis of crane vessels is based on floating body dynamics using convolution integral and the crane wire is treated as simple spring. The lifted structure is assumed as a rigid body with 3 degree-of-freedom translational motion. The heave compensator is numerically modelled by the generalized spring-damper system. Firstly, forced motion simulations of crane wire system are carried out to figure out the basic principle of heave compensator. The transfer function of crane wire system is obtained and effective wave period of heave compensator are found. Then, coupled analysis of crane vessel, crane wire, and lifted structure are performed in regular and irregular sea conditions. Two different crane vessels and two lifted structures (suction pile and manifold) are considered in this study. Through a series of numerical calculations, the effective zone of heave compensator is investigated with respect to wave period and crane wire length.

• Nuclear Engineering and Technology
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• 제53권9호
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• pp.3100-3111
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• 2021

Numerical modeling for the safety-related equipment used in a nuclear power plant (i.e., cabinet facilities) plays an essential role in seismic risk assessment. A full finite element model is often time-consuming for nonlinear time history analysis due to its computational modeling complexity. Thus, this study aims to generate a simplified model that can capture the nonlinear behavior of the electrical cabinet. Accordingly, the distributed plasticity approach was utilized to examine the stiffness-degradation effect caused by the local buckling of the structure. The inherent dynamic characteristics of the numerical model were validated against the experimental test. The outcomes indicate that the proposed model can adequately represent the significant behavior of the structure, and it is preferred in practice to perform the nonlinear analysis of the cabinet. Further investigations were carried out to evaluate the seismic behavior of the cabinet under the influence of the constitutive law of material models. Three available models in OpenSees (i.e., linear, bilinear, and Giuffre-Menegotto-Pinto (GMP) model) were considered to provide an enhanced understating of the seismic responses of the cabinet. It was found that the material nonlinearity, which is the function of its smoothness, is the most effective parameter for the structural analysis of the cabinet. Also, it showed that implementing nonlinear models reduces the seismic response of the cabinet considerably in comparison with the linear model.

• Journal of Microbiology and Biotechnology
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• 제16권9호
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• pp.1441-1447
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• 2006

The light perception and phototransformation of phytochromes are the first process of the phytochrome-mediated light signal transduction. The chromophore ligation and its photochromism of various site-specific and deletion mutants of pea phytochrome A and bacterial phytochrome-like protein (Cph1) were analyzed in vitro. Serial truncation mutants from the N-terminus and C-terminus indicated that the minimal N-terminal domain for the chromophore ligation spans from the residue 78 to 399 of pea phytochrome A. Site-specific mutants indicated that several residues are critical for the chromophore ligation and/or photochromism. Histidine-324 appears to serve as an anchimeric residue for photochromism through its H-bonding function. Isoleucine-80 and arginine-383 playa critical role for the chromophore ligation and photochromism. Arginine-383 is presumably involved in the stabilization of the Pfr form of pea phytochrome A. Apparently, the amphiphilic ${\alpha}$-helix centered around the residue-391 is in the chromophore pocket and critical for the chromophore ligation.

• Journal of Plant Biology
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• 제25권3호
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• pp.123-133
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• 1982

The tropic structure and the function of a small pone ecosystem under the tree stand were studied in terms of energy flow. About 28% of total solar radiation was intercepted by the tree canopy over the pond. Primary producers converted 1.1%(3,382 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$) of solar radiation (320,000 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$) into gross primary production. The amount of energy availble to the pond snail was 1,683 kcal.m-2.y-1 of the net production by primary producers and 1,033 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$ of the litter fallen into the pond. The amount of gross secondary production by the pond snail was 245 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$. Judging from these, supply of both net primary production and the litter was indispensable for the maintenance of the pond ecosystem. The total amont of energy as gross primary production plus litter was 4,415 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$(100%). Since the total respiration loss was calculated to be 1,917 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$(43.4%), the rate of energy accumulation in the pond estimated to 56.6%.

• 한국지반공학회논문집
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• 제26권10호
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• pp.49-60
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• 2010

지반의 투수특성은 다양한 지반구조물의 설계 및 해석에서 중요한 지반물성이다. 특히 불포화 상태에서 모관흡수력의 영향을 받으며 모판흡수력 증가에 따라 감소하는 경향은 함수특성 변화와 유사하다. 불포화 투수계수는 실내실험을 통해 직접적으로 구하거나 함수특성곡선으로부터 유추된 이론식을 통해 간접적으로 얻을 수 있다. 본 논문에서는 국내 7개 지역에 대한 시료를 대상으로 함수특성실험과 본 연구에서 개발한 불포화 투수실험 장비를 이용하여 불포화 투수실험을 실시하였다. 지반의 함수상태를 나타내는 함수특성곡선이 불포화 투수계수와 밀접한 관련이 있으므로 함수특성곡선으로부터 불포화 투수곡선을 유추하는 여러 모텔 결과와 실험결과를 비교하였다. 그러나 기존의 추정방법은 국내지반의 투수특성을 잘 표현하지 못하고 있다. 따라서 국내 풍화토의 불포화 투수곡선을 정확히 유추하기 위하여 보정계수를 적용하여 FXK-M 투수모델을 제시하였고 보정계수를 함수특성곡선의 공기함입치로부터 산정할 수 있는 수식을 제안하였다.