• Title/Summary/Keyword: Mechanisms

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Multi-omics integration strategies for animal epigenetic studies - A review

  • Kim, Do-Young;Kim, Jun-Mo
    • Animal Bioscience
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    • v.34 no.8
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    • pp.1271-1282
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    • 2021
  • Genome-wide studies provide considerable insights into the genetic background of animals; however, the inheritance of several heritable factors cannot be elucidated. Epigenetics explains these heritabilities, including those of genes influenced by environmental factors. Knowledge of the mechanisms underlying epigenetics enables understanding the processes of gene regulation through interactions with the environment. Recently developed next-generation sequencing (NGS) technologies help understand the interactional changes in epigenetic mechanisms. There are large sets of NGS data available; however, the integrative data analysis approaches still have limitations with regard to reliably interpreting the epigenetic changes. This review focuses on the epigenetic mechanisms and profiling methods and multi-omics integration methods that can provide comprehensive biological insights in animal genetic studies.

Comparative Proteomic Analysis for a Putative Pyridoxal Phosphate-Dependent Aminotransferase Required for Virulence in Acidovorax citrulli

  • Lee, Jongchan;Heo, Lynn;Han, Sang-Wook
    • The Plant Pathology Journal
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    • v.37 no.6
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    • pp.673-680
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    • 2021
  • Acidovorax citrulli (Ac) is the causative agent of bacterial fruit blotch disease in watermelon. Since resistant cultivars have not yet been developed, the virulence factors/mechanisms of Ac need to be characterized. This study reports the functions of a putative pyridoxal phosphate-dependent aminotransferase (PpdaAc) that transfers amino groups to its substrates and uses pyridoxal phosphate as a coenzyme. It was observed that a ppdaAc knockout mutant had a significantly reduced virulence in watermelon when introduced via germinated-seed inoculation as well as leaf infiltration. Comparative proteomic analysis predicted the cellular mechanisms related to PpdaAc. Apart from causing virulence, the PpdaAc may have significant roles in energy production, cell membrane, motility, chemotaxis, post-translational modifications, and iron-related mechanisms. Therefore, it is postulated that PpdaAc may possess pleiotropic effects. These results provide new insights into the functions of a previously unidentified PpdaAc in Ac.

Co-creation and Personalization as Incentive Mechanisms of Utilizing External Innovation Sources: Which Performs Better?

  • Lee, Sangjic;Nishiyama, Kohei;Kimita, Koji;Nishino, Nariaki
    • Asian Journal of Innovation and Policy
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    • v.10 no.3
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    • pp.274-293
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    • 2021
  • Utilizing outside knowledge for innovation is an important task for companies in the competitive economy. Due to the rapid advance in the internet communication technology, the number and quality of innovation sourcing methods are increasing. We select co-creation, personalization and in-house R&D as the representative forms of innovation sourcing and suggest a game theory model that enables the comparative analysis between them. The decision and surplus outcome of the innovation mechanisms are compared under various settings of the input parameters of the model. The stakeholders voluntarily participate into all mechanisms when the product price is moderately high and the participation cost is low, while co-creation is the only feasible one when the product quality is niche. When the participation cost is relatively high, personalization outperforms co-creation.

Comparative Analysis of the Achievements and Limitations of Projects that Support Local Businesses in an Area Undergoing Gentrification: A case study on Brixton

  • Park, Youngseo;Ham, Sungil
    • Architectural research
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    • v.24 no.1
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    • pp.13-20
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    • 2022
  • This research has been conducted to find answers to the questions of how projects that support local businesses work in areas undergoing gentrification and what are the achievements and limitations of these projects, based on the case studies of Brixton Pound and Pop Brixton supporting local businesses in Brixton in the London borough of Lambeth. To this end, this study collected data through interviews with local businesses belonging to each project and analysed them based on prior research on the projects, evaluation reports, and articles in the media. It began by investigating the supporting mechanisms of projects that support local businesses in the area, and then analysed and evaluated the projects' contribution to local businesses and the impact on the local community according to these mechanisms. The two projects in the case study showed contrasts in their support mechanisms, governance, and the role of Lambeth Council, and the local businesses' evaluations of the projects' support differed depending not only on the support mechanism of each project but also on business type and perceptions of the impact of gentrification.

Drug Discovery Perspectives of Antisense Oligonucleotides

  • Yeonjoon Kim
    • Biomolecules & Therapeutics
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    • v.31 no.3
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    • pp.241-252
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    • 2023
  • The era of innovative RNA therapies using antisense oligonucleotides (ASOs), siRNAs, and mRNAs is beginning. Since the emergence of the concept of ASOs in 1978, it took more than 20 years before they were developed into drugs for commercial use. Nine ASO drugs have been approved to date. However, they target only rare genetic diseases, and the number of chemistries and mechanisms of action of ASOs are limited. Nevertheless, ASOs are accepted as a powerful modality for next-generation medicines as they can theoretically target all disease-related RNAs, including (undruggable) protein-coding RNAs and non-coding RNAs. In addition, ASOs can not only downregulate but also upregulate gene expression through diverse mechanisms of action. This review summarizes the achievements in medicinal chemistry that enabled the translation of the ASO concept into real drugs, the molecular mechanisms of action of ASOs, the structure-activity relationship of ASO-protein binding, and the pharmacology, pharmacokinetics, and toxicology of ASOs. In addition, it discusses recent advances in medicinal chemistry in improving the therapeutic potential of ASOs by reducing their toxicity and enhancing their cellular uptake.

NewHorizon: On the Quenching Mechanisms of the Dwarf Galaxies

  • Kim, Seonwoo;Rhee, Jinsu;Han, San;Choi, Hoseung;Yi, Sukyoung K.
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.1
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    • pp.53.1-53.1
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    • 2021
  • Dwarf galaxies are the most abundant objects in the universe. Hence, understanding the dwarfs is important but relatively little is known due to the lack of computing power and limitations in the telescope resolution. We thus use the state-of-the-art NewHorizon simulation, which is a set of cosmological hydrodynamical simulations, to dissect the quenching mechanism working on dwarf galaxies by inspecting the star formation and mass history of individual galaxies. It is known that internal (AGN, SN, stellar feedback) and external (major and minor mergers, ram pressure stripping, strangulation) mechanisms affect the quenching of dwarfs. Because of the combination of these mechanisms, periodicity in the star formation history of the dwarf galaxies is expected. To check for their periodicity, Fourier transform was performed on the star formation history. By comparing the physical timescales and the periodicity, we determine the dominant effect working on the dwarfs. Then, we compare the dominant effects working on the galaxies according to their varying properties.

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Immunologic Basis of Type 2 Biologics for Severe Asthma

  • Soyoon Sim;Youngwoo Choi;Hae-Sim Park
    • IMMUNE NETWORK
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    • v.22 no.6
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    • pp.45.1-45.15
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    • 2022
  • Asthma is a chronic airway inflammatory disease characterized by reversible airway obstruction and airway hyperreactivity to various environmental stimuli, leading to recurrent cough, dyspnea, and wheezing episodes. Regarding inflammatory mechanisms, type 2/eosinophilic inflammation along with activated mast cells is the major one; however, diverse mechanisms, including structural cells-derived and non-type 2/neutrophilic inflammations are involved, presenting heterogenous phenotypes. Although most asthmatic patients could be properly controlled by the guided treatment, patients with severe asthma (SA; classified as a treatment-refractory group) suffer from uncontrolled symptoms with frequent asthma exacerbations even on regular anti-inflammatory medications, raising needs for additional controllers, including biologics that target specific molecules found in asthmatic airway, and achieving the precision medicine for asthma. This review summarizes the immunologic basis of airway inflammatory mechanisms and current biologics for SA in order to address unmet needs for future targets.

Down-regulation of Protease-activated Receptor 4 in Lung Adenocarcinoma is Associated with a More Aggressive Phenotype

  • Jiang, Ping;Yu, Guo-Yu;Zhang, Yong;Xiang, Yang;Hua, Hai-Rong;Bian, Li;Wang, Chun-Yan;Lee, Wen-Hui;Zhang, Yun
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.6
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    • pp.3793-3798
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    • 2013
  • The role of protease-activated receptors (PARs) in lung tumors is controversial. Although PAR4 is preferentially expressed in human lung tissues, its possible significance in lung cancer has not been defined. The studies reported herein used a combination of clinical observations and molecular methods. Surgically resected lung adenocarcinomas and associated adjacent normal lung tissues were collected and BEAS-2B and NCI-H157 cell lines were grown in tissue culture. PAR4 expression was evaluated by RT-PCR, RT-qPCR, Western blotting and immunohistochemistry analysis. The results showed that PAR4 mRNA expression was generally decreased in lung adenocarcinoma tissues as compared with matched noncancerous tissues (67.7%) and was associated with poor differentiation (p=0.017) and metastasis (p=0.04). Western blotting and immunohistochemical analysis also showed that PAR4 protein levels were mostly decreased in lung adenocarcinoma tissues (61.3%), and were also associated with poor differentiation (p=0.035) and clinical stage (p=0.027). Moreover, PAR4 expression was decreased in NCI-H157 cells as compared with BEAS-2B cells. In conclusion, PAR4 expression is significantly decreased in lung adenocarcinoma, and down-regulation of PAR4 is associated with a more clinically aggressive phenotype. PAR4 may acts as a tumor suppressor in lung adenocarcinoma.

Interdependence of Corporate Control Mechanisms and Firm Performance in Korea (기업지배구조의 상호관계 및 기업성과에 관한 연구)

  • Cho, Sungbin
    • KDI Journal of Economic Policy
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    • v.28 no.2
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    • pp.131-177
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    • 2006
  • This paper examines a simultaneous determination of corporate control mechanisms, and its effects on firm performance. The corporate control mechanisms considered include the following; insider shareholding, institutional shareholding, the board of directors, dividend policy, and capital structure. This paper applies a simultaneous equation methodology and investigates the interdependence among the corporate control mechanisms. In the first part, the paper finds that firm-level variations of control mechanisms are large across time although average variations are relatively small. These variations are related to one another, which is confirmed by Granger causality test based on dynamic panel autoregression model. More specifically insider shareholding, institutional shareholding and outside director ratio cause each other. With regard to interdependence among the control mechanisms, 2SLS(two stage least squares) regression results show that insider shareholding and institutional shareholding are substitutes while institutional shareholding acts as complements to the ratio of outside members in the board of directors. Then in the second part, the paper examines the relationship between firm performance and corporate governance. Firm performance, measured by Tobin's Q, has a positive association with leverage ratio while that has a negative relation to outside director ratio. This suggests that there may be a room for reforming corporate governance in Korea. Specifically it is necessary to enhance the independence of the outside directors.

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Exploratory Study on Developing Model for Smoking Cessation Process (금연 과정의 모델 개발을 위한 탐색적 연구)

  • 오현수;김영란
    • Journal of Korean Academy of Nursing
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    • v.27 no.1
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    • pp.71-82
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    • 1997
  • In this paper, the study model, which presents the patterns of how the changing mechanisms are adopted to the changing stages of smoking cessation, was developed by modifying the integrative model of Prochaska et al. (1983) with including seven changing mechanisms which were identified by Oh and Kim(1996). Then the developed study model was exploratively tested with 155 University student between 20 and 29 years of age as subjects. According to the study results. among the five mechanisms. which are significant in explaining the differences between stages. DUNCAN post-comparison showed that the least applied ones were Stimulus Control, Self Determinism, Cognitive Restructuring in the precomplation stage, and Reinforcement and Dramatic Relief. in the relapsed stage. In the comtemplation stage. it was observed that Dramatic Relief is used most frequently and that the other two mechanisms, Information Management and Cognitive Restructuring, showed different results from those inferred in the study hypothesis. In the case of Information Management, it was excluded from the analysis it was not included in explaining significant difference among changing stages, but Cognitive Reconstruction turns out to be a more frequently used mechanism in the action stage rather than in the comtemplation stage. Helping Relationship was also excluded in the post-comparison analysis since it was not included in explaining significant difference among changing stages and Reinforcement was a more frequently used mechanisms in the comtemplation stage. Stimulus Control turns out to be the connecting mechanism which was most frequently used in both the contemplation and action stages. Self Determination was most frequently used in the action stage rather than in both the comtemplation stage and action stage, differing from the presumption of the model. Lastly, subjects in the relapsed stage were utilizing Stimulus Control and Self Determination at the same level as subjects in the precontemplation stage. and the utilization of both Reinformcement and Dramatic Relief was lower than that of the precomtemplation stage, that is, at the lowest level. Only Cognitive Restructuring was used of the same level as the comtemplation stage. The relapsed stage in this study did not represent the preparation for action stage as presumed in the model of Prochaska et. al. (1983) but did show a pattern similar to the initial stage of smoking cessation. However, since this interpretation about the relapser was based on only a small number of relapsers(n=5), this conclusion may not be reliable.

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