• Title/Summary/Keyword: interaction sites

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Cellular and Molecular Pathology of Fungi on Plants Studied by Modern Electron Microscopy

  • Sanwald, Sigrun-Hippe
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 1995.06b
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    • pp.27-53
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    • 1995
  • In plant pathology there is an increasing necessity for improved cytological techniques as basis for the localization of cellular substances within the dynamic fine structure of the host-(plant)-pathogen-interaction. Low temperature (LT) preparation techniques (shock freezing, freeze substitution, LT embedding) are now successfully applied in plant pathology. They are regarded as important tools to stabilize the dynamic plant-pathogen-interaction as it exists under physiological conditions. - The main advantage of LT techniques versus conventional chemical fixation is seen in the maintenance of the hydration shell of molecules and macromolecular structures. This results in an improved fine structural preservation and in a superior retention of the antigenicity of proteins. - A well defined ultrastructure of small, fungal organisms and large biological samples such as plant material and as well as the plant-pathogen (fungus) infection sites are presented. The mesophyll tissue of Arabidopsis thaliana is characterized by homogeneously structured cytoplasm closely attached to the cell wall. From analyses of the compatible interaction between Erysiphe graminis f. sp. hordei on barley (Hordeum vulgare), various steps in the infection sequence can be identified. Infection sites of powdery mildew on primary leaves of barley are analysed with regard to the fine structural preservation of the haustoria. The presentation s focussed on the ultrastructure of the extrahaustorial matrix and the extrahaustorial membrane. - The integration of improved cellular preservation with a molecular analysis of the infected host cell is achieved by the application of secondary probing techniques, i.e. immunocytochemistry. Recent data on the characterization of freeze substituted powdery mildew and urst infected plant tissue by immunogold methodology are described with special emphasis on the localization of THRGP-like (threonine-hydrxyproline-rich glycoprotein) epitopes. Infection sites of powdery mildew on barley, stem rust as well as leaf rust (Puccinia recondita) on primary leaves of wheat were probed with a polyclonal antiserum to maize THRGP. Cross-reactivity with the anti-THRGP antiserum was observed over the extrahaustorial matrix of the both compatible and incompatible plant-pathogen interactions. The highly localized accumulation of THRGP-like epitopes at the extrahaustorial host-pathogen interface suggests the involvement of structural, interfacial proteins during the infection of monocotyledonous plants by obligate, biotrophic fungi.

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Distribution of Co Ions in Ferromagnetic Zn (1-x) Co (x)O Films

  • Park, Chang-In;Seo, Su-Yeong;Kim, Jeong-Ran;Han, Sang-Uk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.166-166
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    • 2012
  • We examined the distribution of Co ions of ferromagnetic n-type Zn(1-x)Co(x)O semiconducting films with the Co concentrations of 0.03~0.07 using x-ray absorption fine structure (XAFS) measurements at the Co and Zn K edges. Extended XAFS (EXAFS) revealed that Co ions mainly occupied the zinc sites of the films. X-ray absorption near edge structure (XANES) spectra demonstrated that the pre-edge peak of the Co K edge was substantially affected by the second neighboring Co ions at the zinc sites due to hybridizing of the Co 4p conduction electrons with the Co 3d bounded electrons. From XANES and EXAFS analysis using ab initio calculations, we found that Co ions uniformly occupied the zinc sites of the Zn (0.93) Co (0.07)O film, whereas the Co ions of the Zn (0.97) Co (0.03)O and Zn (0.95) Co (0.05)O films were substituted at localized zinc sites. The ferromagnetic properties of the Zn (0.93) Co(0.07)O film could be induced by direct interaction between the magnetic dipoles of the Co ions with a mean distance of 4.3 A or by Co 4p electron mediation.

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A Study Regarding the Effects of Direction of Comments about Online Reviews and Credibility of Web Sites on Brand Attitudes Toward Services : Comparison between Korean and Chinese Cases (댓글의 방향성과 웹사이트의 신뢰성이 서비스 브랜드 태도와 구매의도에 미치는 영향 : 한국과 중국비교)

  • Cho, Chun-Han;Ahn, Seung-Ho;Son, Young-Don
    • Journal of Information Technology Services
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    • v.11 no.2
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    • pp.69-91
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    • 2012
  • The purpose of the study is to investigate the effects of direction of comments about online reviews and the credibility of web sites on brand attitudes toward restaurants. Also, the study compared two study results using Korean and Chinese on-line users to assess the feasibility of the application of on-line marketing developed in Korea to Chinese internet user contexts. The results show that the credibility of web sites and the direction of comments influence the brand attitude as hypothesized. Overall, the results from two country consumer groups are similar. However, there are unique results including the significant interaction effects between the direction of comments and the credibility of web sites only for Chinese on-line users on the brand evaluation tasks and for Korean on-line users on the purchase intention. The cultural value might cause these different results across the nations.

Effects of Website Characteristics and Delivery Service Quality on Repurchase Intention

  • Dai, Wenqian;Lee, Jong-Ho
    • The Journal of Industrial Distribution & Business
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    • v.9 no.5
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    • pp.17-24
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    • 2018
  • Purpose - Through the analysis of the characteristics of overseas direct purchase websites and the relevant empirical analysis of the quality of service delivery, the activated theory/strategy and significance of the overseas direct purchase are sorted out. Research design, data, and methodology - In the process, to make more effective analysis, several analysis tools and analysis programmes are used, IBM SPSS Statistics 23.0 and IBM SPSS AMOS 23.0. Results - Among the characteristics of the overseas direct purchase website, the security, convenience and information provided by the overseas direct purchase have already had a positive impact on the satisfaction. The quality of the delivery service is composed of four factors: rapidity, reliability, intimacy and correctness. The research results indicate that the satisfaction level has a positive impact on the re-purchase intention. Conclusions - The significance of this study has the characteristics of overseas direct purchase sites which have confirmed that security convenience and intelligence availability have a positive impact on satisfaction and re-purchase intent. It is important to have a safe and reliable access to shopping sites on overseas direct purchase sites. In the characteristics of overseas direct purchase sites, the interaction have no positive effect on satisfaction and re-purchase intention.

Evaluation of linear measurements of implant sites based on head orientation during acquisition: An ex vivo study using cone-beam computed tomography

  • Sabban, Hanadi;Mahdian, Mina;Dhingra, Ajay;Lurie, Alan G.;Tadinada, Aditya
    • Imaging Science in Dentistry
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    • v.45 no.2
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    • pp.73-80
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    • 2015
  • Purpose: This study evaluated the effect of various head orientations during cone-beam computed tomography (CBCT) image acquisition on linear measurements of potential implant sites. Materials and Methods: Six dry human skulls with a total of 28 implant sites were evaluated for seven different head orientations. The scans were acquired using a Hitachi CB-MercuRay CBCT machine. The scanned volumes were reconstructed. Horizontal and vertical measurements were made and were compared to measurements made after simulating the head position to corrected head angulations. Data was analyzed using a two-way ANOVA test. Results: Statistical analysis revealed a significant interaction between the mean errors in vertical measurements with a marked difference observed at the extension head position (P<0.05). Statistical analysis failed to yield any significant interaction between the mean errors in horizontal measurements at various head positions. Conclusion: Head orientation could significantly affect the vertical measurements in CBCT scans. The main head position influencing the measurements is extension.

Ginsentology III;Identifications of Ginsenoside Interaction Sites for Ion Channel Regulation

  • Choi, Sun-Hye;Shin, Tae-Joon;Lee, Byung-Hwan;Lee, Jun-Ho;Hwang, Sung-Hee;Pyo, Mi-Kyung;Nah, Seung-Yeol
    • Journal of Ginseng Research
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    • v.32 no.2
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    • pp.99-106
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    • 2008
  • A ligand - whether an endogenous hormone, neurotransmitter, exogenous toxin or synthetic drug - binds to plasma membrane proteins (e.g., ion channels, receptors or other functional proteins) to exert its physiological or pharmacological effects. Ligands can also have functional groups, showing stereospecificity for interaction sites on their counterpart plasma membrane proteins. Previous reports have shown that the ginsenoside Rg$_3$, a bioactive ginsenoside, meets these criteria in that: 1) an aliphatic side chain of $Rg_3$ plays a role as a functional group, 2) Rg$_3$ regulates voltage- and ligand-gated ion channels in a stereospecific manner with respect to carbon-20, and 3) $Rg_3$ regulates subsets of ligand-gated and voltage-gated ion channels through specific interactions with identified amino acid residues inside the channel pore, in the outer pore entryway, or in toxin binding sites. Rg$_3$, therefore, could be a candidate for a novel ginseng-derived glycosidic ligand regulating ion channels and receptors. This review will examine how Rg$_3$ regulates voltage-gated and ligand-gated ion channels through interactions with its target proteins in the plasma membrane. Hopefully, this review will advance understanding of ginseng pharmacology at the cellular and molecular levels.

Occurrence mechanism of recent large earthquake ground motions at nuclear power plant sites in Japan under soil-structure interaction

  • Kamagata, Shuichi;Takeqaki, Izuru
    • Earthquakes and Structures
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    • v.4 no.5
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    • pp.557-585
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    • 2013
  • The recent huge earthquake ground motion records in Japan result in the reconsideration of seismic design forces for nuclear power stations from the view point of seismological research. In addition, the seismic design force should be defined also from the view point of structural engineering. In this paper it is shown that one of the occurrence mechanisms of such large acceleration in recent seismic records (recorded in or near massive structures and not free-field ground motions) is due to the interaction between a massive building and its surrounding soil which induces amplification of local mode in the surface soil. Furthermore on-site investigation after earthquakes in the nuclear power stations reveals some damages of soil around the building (cracks, settlement and sand boiling). The influence of plastic behavior of soil is investigated in the context of interaction between the structure and the surrounding soil. Moreover the amplification property of the surface soil is investigated from the seismic records of the Suruga-gulf earthquake in 2009 and the 2011 off the Pacific coast of Tohoku earthquake in 2011. Two methods are introduced for the analysis of the non-stationary process of ground motions. It is shown that the non-stationary Fourier spectra can detect the temporal change of frequency contents of ground motions and the displacement profile integrated from its acceleration profile is useful to evaluate the seismic behavior of the building and the surrounding soil.

Spry2 does not directly modulate Raf-1 kinase activity in v-Ha-ras-transformed NIH 3T3 fibroblasts

  • Ahn, Jun-Ho;Eum, Ki-Hwan;Lee, Michael
    • BMB Reports
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    • v.43 no.3
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    • pp.205-211
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    • 2010
  • Sprouty (Spry) proteins have previously been suggested as negative regulators of the MAPK pathway through interaction with Raf-1. However, the molecular basis of this inhibition has not been elucidated. In this study, we used cells expressing FLAGtagged Raf-1 with point mutations at known phosphorylation sites to reveal that activation of Raf-1 mutants does not correlate with their degree of interaction with Spry2. The association of Raf-1 with Spry2 in intact cells was further corroborated by immunofluorescence colocalization. Additionally, there was no significant change observed in the strength of interaction between Raf-1 mutants and Spry2 after paclitaxel treatment despite differences in the activation levels of these mutants. Thus, our study provides the evidence that Spry2 does not directly regulate Raf-1 kinase activity, but instead acts as a scaffolding protein that assists interactions between Raf-1 kinase and its direct regulators.

Web-Based Computational System for Protein-Protein Interaction Inference

  • Kim, Ki-Bong
    • Journal of Information Processing Systems
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    • v.8 no.3
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    • pp.459-470
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    • 2012
  • Recently, high-throughput technologies such as the two-hybrid system, protein chip, Mass Spectrometry, and the phage display have furnished a lot of data on protein-protein interactions (PPIs), but the data has not been accurate so far and the quantity has also been limited. In this respect, computational techniques for the prediction and validation of PPIs have been developed. However, existing computational methods do not take into account the fact that a PPI is actually originated from the interactions of domains that each protein contains. So, in this work, the information on domain modules of individual proteins has been employed in order to find out the protein interaction relationship. The system developed here, WASPI (Web-based Assistant System for Protein-protein interaction Inference), has been implemented to provide many functional insights into the protein interactions and their domains. To achieve those objectives, several preprocessing steps have been taken. First, the domain module information of interacting proteins was extracted by taking advantage of the InterPro database, which includes protein families, domains, and functional sites. The InterProScan program was used in this preprocess. Second, the homology comparison with the GO (Gene Ontology) and COG (Clusters of Orthologous Groups) with an E-value of $10^{-5}$, $10^{-3}$ respectively, was employed to obtain the information on the function and annotation of each interacting protein of a secondary PPI database in the WASPI. The BLAST program was utilized for the homology comparison.

An Empirical Study on Web Site User-Interface Evaluation For Service Information Management (서비스정보관리자를 위한 웹사이트 인터페이스 평가요인에 관한 연구)

  • 김명옥
    • The Journal of Society for e-Business Studies
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    • v.7 no.1
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    • pp.19-34
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    • 2002
  • The main objective of this research is to find out whether there exist any user interface factors that influence service information management professionals(SIMP)'s business activities on the web. The result of this study shows that there exists a significant level of difference between two groups of office Professionals: SIMP and general office management professionals on user interface factors. We analyzed the past and current research results and focused on four major evaluation categories: (1) web design, (2) structure, (3) navigation, and (4) interaction and identified 26 evaluation items in those categories. The study has been initiated by an intuition that there might be a significant difference in sets of user interface factors that influence SIMP and general office professionals. From the list of Best 100 Web Sites the best 30 information-providing web sites and the best 30 service-providing web sites were carefully chosen by a panel of 10 members for each group. To evaluate 60 web sites, another panel was formed by 30 professionals from each group, and they conducted evaluation in their own work settings. Reliability analysis on user interface factors and T-test to find out any influencing factors on SIMP were performed. As a result of this study, we have recognized that clarity, formation, consciseness, economics, and robustness are the most influencing user interface factors for web designers to concern when they develop web sites for SIMP. The study result can be improved by enhancing reliability of choosing target web sites In investigate and panel members. Also, in the future study it is recommended to investigate influencing factors for office professionals in terms of. age, sex, experience, academic background, etc.

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