• Title/Summary/Keyword: host factors

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Molecular Characterization of Survival and Toxigenesis of Vibrio vulnificus

  • Choi Sang Ho
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2002.10a
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    • pp.56-58
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    • 2002
  • Understanding the molecular pathogenesis of the multifaceted host-pathogen interaction is critical in the development of improved treatment and prevention, as well as elucidating how certain bacteria can circumvent host defenses, multiply in the host, and cause such extensive damage. Disease caused by infection with V. vulnificus is remarkable for the invasive nature of the infection, ensuing severe tissue damage, and rapidly fulminating course. The characterization of somatic as well as secreted products of V. vulnificus has yielded a large list of putative virulence attributes, whose known functions are easily imagined to explain the pathology of disease. These putative virulence factors include a carbohydrate capsule, lipopolysaccharide, a cytolysin/hemolysin, elastolytic metalloprotease, iron sequestering systems, lipase, and pili. However, only few among the putative virulence factors has been confirmed to be essential for virulence by the use of molecular Koch's postulates. This presentation describes molecular biological characterization of the virulence factors contributing to survival as well as to toxigenesis of V. vulnificus.

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Interaction Study of Soybean mosaic virus Proteins with Soybean Proteins using the Yeast-Two Hybrid System

  • Seo, Jang-Kyun;Hwang, Sung-Hyun;Kang, Sung-Hwan;Choi, Hong-Soo;Lee, Su-Heon;Sohn, Seong-Han;Kim, Kook-Hyung
    • The Plant Pathology Journal
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    • v.23 no.4
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    • pp.281-286
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    • 2007
  • Interactions between viral proteins and host proteins are essential for virus replication. Especially, translation of viral genes completely depends on the host machinery. In potyviruses, interactions of genome-linked viral protein (VPg) with host translation factors including eIF4E, eIF(iso)4E, and poly(A)-binding protein (PABP) has previously been characterized. In this study, we investigated interactions between Soybean mosaic virus (SMV) viral proteins and host translation factors by yeast two-hybrid system. SMV VPg interacted with eIF4E, eIF(iso)4E, and PABP in yeast two-hybrid system, while SMV helper component proteinase (HC-pro) interacted with neither of those proteins. The interaction between SMV NIb and PABP was also detected. These results are consistent with those reported previously in other potyviruses. Interestingly, we found reproducible and specific interactions between SMV coat protein (CP) and PABP. Deletion analysis showed that the region of CP comprising amino acids 116 to 206 and the region of PABP comprising amino acids 520 to 580 are involved in CP/PABP interactions. Soybean library screening with SMV NIb by yeast two-hybrid assay also identified several soybean proteins including chlorophyll a/b binding preprotein, photo-system I-N subunit, ribulose 1,5-biphosphate carboxylase, ST-LSI protein, translation initiation factor 1, TIR-NBS type R protein, RNA binding protein, ubiquitin, and LRR protein kinase. Altogether, these results suggest that potyviral replicase may comprise a multi-protein complex with PABP, CP, and other host factors.

Factors Affecting the Intention to Provide and Use Accommodation Sharing Economy Service (숙박 공유경제 서비스의 제공 및 사용 의도에 대한 영향 요인)

  • Lee, Hyun Jin;Park, Hyun Jung
    • The Journal of the Korea Contents Association
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    • v.19 no.5
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    • pp.205-216
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    • 2019
  • The sharing economy, which maximizes the value of resources by sharing, is appearing in various sectors today and is gradually expanding with the development of ICT. This study identified factors affecting the intention to use the services of the sharing economy with a focus on the sharing accommodation platform services. As the intention to use the sharing economy service is divided into the intention to use as a taker(guest) and a provider(host), those influencing factors were analyzed respectively. Results showed that collaborative norm, economic benefit and honorary compensation affected the intention to use as a guest. Openness to experience, economic benefit, and honorary compensation increased the intention to use as a host. Economic benefit made a greater impact on the intention to use as a guest, while honorary compensation enhanced the intention to use as a host.

A Study on Organizational Forms in Foreign Expansion of Korean Banks

  • CHOI, Jeong-Yoon;KIM, So-Hyung
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.7
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    • pp.343-348
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    • 2020
  • So far, research into multinational bank' overseas expansion has focused on foreign direct investment in the financial services industry. However, this study focused its existing theories on multinational banks on decision-making related to the type of overseas advancement of local financial institutions. For research, four environmental factors were considered: the scale of foreign direct investment, the scope of financial services that can be provided according to the rules of the host country, the corporate tax rate of the host country, and the level of development of the host country's banking industry. Through Kotra, data on the total amount of claims from 2010 to 2014 and the regulatory status for the country's financial industries were obtained. Hypothesis are built around theories and survey factors and has been demonstrated through regression analysis. Results show that Korean financial institutions tend to expand as legally independent subsidiaries where the corporate tax rate of the host country is relatively low. Contrary to the previous studies based on the U.S. banking corporates, results show that Korean banks tend to expand in forms of branches to the host countries with high level of banking system development.

Ecological Factors Influencing Severity of Cashew Fusarium Wilt Disease in Tanzania

  • Lilai, Stanslaus A.;Kapinga, Fortunus A.;Nene, Wilson A.;Mbasa, William V.;Tibuhwa, Donatha D.
    • Research in Plant Disease
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    • v.27 no.2
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    • pp.49-60
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    • 2021
  • Cashew (Anacardium occidentale L.) is an important cash crop in Tanzania as a source of income to cashew growers and provides foreign exchange for the country. Despite its significance, the crop is threatened by fast spreading disease known as cashew Fusarium wilt caused by Fusarium oxysporum. Field assessment and laboratory tests were conducted to determine incidences of the disease, severity, ecological factors that influence them and explored the pathogen host specificity in six cashew growing districts. The results revealed significant (P<0.001) variation of disease incidences and severity among the studied districts. The results further revealed that there is both positive and negative correlation between the incidence and severity of the disease versus the evaluated ecological factors. The soil pH, soil temperature, air temperature, and relative humidity depicted positive correlation of disease incidence and severity versus ecological factors at ρ=0.50 and ρ=0.60, ρ=0.20 and ρ=0.94, ρ=0.11 and ρ=0.812, ρ=0.05 and ρ=0.771 respectively while nitrogen, phosphorus, and carbon depicted negative correlations at ρ=-0.22 and ρ=-0.58, ρ=-0.15 and ρ=-0.94, ρ=-0.19 and ρ=-0.12 respectively. In terms of host range, none of the weed species was found to be a carrier of Fusarium pathogen implying that it is host specific or semi selective. The results revealed that the tested ecological parameters favor the growth and development of Fusarium pathogen. Thus, management of the disease requires nutrients replenishment and soil shading as essential components in developing appropriate strategies for the control and prevention of further spread of the disease.

Bcl-2 Knockdown Accelerates T Cell Receptor-Triggered Activation-Induced Cell Death in Jurkat T Cells

  • Lee, Yun-Jung;Won, Tae Joon;Hyung, Kyeong Eun;Lee, Mi Ji;Moon, Young-Hye;Lee, Ik Hee;Go, Byung Sung;Hwang, Kwang Woo
    • The Korean Journal of Physiology and Pharmacology
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    • v.18 no.1
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    • pp.73-78
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    • 2014
  • Cell death and survival are tightly controlled through the highly coordinated activation/inhibition of diverse signal transduction pathways to insure normal development and physiology. Imbalance between cell death and survival often leads to autoimmune diseases and cancer. Death receptors sense extracellular signals to induce caspase-mediated apoptosis. Acting upstream of CED-3 family proteases, such as caspase-3, Bcl-2 prevents apoptosis. Using short hairpin RNAs (shRNAs), we suppressed Bcl-2 expression in Jurkat T cells, and this increased TCR-triggered AICD and enhanced TNFR gene expression. Also, knockdown of Bcl-2 in Jurkat T cells suppressed the gene expression of FLIP, TNF receptor-associated factors 3 (TRAF3) and TRAF4. Furthermore, suppressed Bcl-2 expression increased caspase-3 and diminished nuclear factor kappa B (NF-${\kappa}B$) translocation.

An Empirical Analysis on MNC's Investment Performances in a Host Country through Market Orientation Mediation Effects (현지시장지향성의 매개변수 효과를 통한 다국적기업의 해외시장 투자성과에 대한 실증연구)

  • Lim, Sung-Hoon
    • Korea Trade Review
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    • v.44 no.2
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    • pp.221-237
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    • 2019
  • Multinational corporations (MNCs) usually face indigenous business environments in host countries which are different from a home country's. In this circumstance, MNCs would accomplish low-investing performance if they pursuit the same as the home oriented business strategy in the host country. The more different kinds of specialized environments a host countries have, the more pressure of modifying the international strategy needed for MNCs. This paper examines that how a different market environment between a home country and a host country, through MNC's local responsive managements, can influence investing performance in a host country. This paper conducts structural equation analyses with collected empirical data focusing upon a MNC's market orientation efforts and the realization of management localization (i.e., increasing local sourcing intensity or local sales intensity) as mediators between the specialized environment in a host country and the MNC's investing performance. This paper has several contributions in developing the prior approaches: first, the market orientation variables are regarded not as normal independent factors but mediators; second, two step mediation model is examined to make link between host market's heterogeneity and MNC's performance.

A Study on Critical Failure Factors of a Mega-Event by the Host Community's Lifestyle - Centered on Changwon F3 Car Racing - (지역주민의 라이프스타일에 따른 메가 이벤트 도입저해 요인에 대한 연구 - 창원 F3 자동차 경주를 중심으로 -)

  • Cho, Sang-Hee;Oh, Chang-Gyu
    • Journal of Global Scholars of Marketing Science
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    • v.15 no.2
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    • pp.123-140
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    • 2005
  • Recently, one of the issues that are significantly considered is to keep Changwon F3 car racing. In most existing studies, however, there is shortage of opinions for understanding the reactions of the host community. The question addressed in this paper is what are the underlying factors that affect which inhibitors are likely to be discussed by the host community for car racing. Survey collected from 299 participants in Changwon city were analyzed to test their reactions. Through the empirical study, several research findings emerged. The results indicate that (1) the event seeker, the drive seeker, and the hard internal seeker were significant discriminant factors to separate inhibitors from the host community, (2) the significant differences between the recognition of demographic characteristics and that of negative effects, (3) the significant level between cluster groups(overcontrolled, resilient, undercontrolled) and negative effects is found. The findings also provide implications for practice on several fronts, which is to understand the reaction of the host community to F3 car racing, and for the event planner to reduce complaints.

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Immune Responses against Marek's Disease Virus Infection (마렉병 바이러스 감염에 대한 면역 반응)

  • Jang, H.K.;Park, Y.M.;Cha, S.Y.;Park, J.B.
    • Korean Journal of Poultry Science
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    • v.35 no.3
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    • pp.225-240
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    • 2008
  • Marek's disease virus(MDV) is a highly cell-associated, lymphotropic $\alpha$-herpesvirus that causes paralysis and neoplastic disease in chickens. The disease has been controlled by vaccination which was provided the first evidence for a malignant cancer being controlled by an antiviral vaccine. Marek's disease pathogenesis is complex, involving cytolytic and latent infection of lymphoid cells and oncogenic transformation of $CD4^+$ T cells in susceptible chickens. MDV targets a number of different cell types during its life cycle. Lymphocytes play an essential role, although within them virus production is restricted and only virion are produced. Innate and adaptive immune responses develop in response to infection, but infection of lymphocytes results in immunosuppressive effects. Hence in MDV-infected birds, MDV makes its host more vulnerable to tumour development as well as to other pathogens. All chickens are susceptible to MDV infection, and vaccination is essential to protect the susceptible host from developing clinical disease. Nevertheless, MDV infects and replicates in vaccinated chickens, with the challenge virus being shed from the feather-follicle epithelium. The outcome of infection with MDV depends on a complex interplay of factors involving the MDV pathotype and the host genotype. Host factors that influence the course of MD are predominantly the responses of the innate and adaptive immune systems, and these are modulated by: age at infection and maturity of the immune system; vaccination status; the sex of the host; and various physiological factors.

A Study on the Validity of Host Call Service in the Family Restaurant using Fishbein Model (Fishbein 모델을 이용한 패밀리 레스토랑의 호스트 호명제 서비스 타당성에 대한 연구)

  • Seo Kwang-Kyu;Ahn Beum-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.4
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    • pp.753-758
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    • 2006
  • The recent drastic increase of imported foreign restaurants provided the importance of service quality and the customer satisfaction is considered as the most important factors for the business activity. In order to identify the important factors for the customer satisfaction of the family restaurant in Korea, we attempt to test the validity of host call service as a significant variable in the family restaurant using Fishbein behaviour model. Based on literature review, the empirical study was conducted using the questionnaires for customers of the family restaurant in Seoul. Descriptive statistics, t-test, F-test and regression analysis were made of the gathered questionnaires using SPSS programs. The results shows that four hypotheses established in this study were significant. Therefore, host call service in the family restaurant should be introduced to increase the customer satisfaction. In conclusion, it proved that host call service in the family were the important factors that could satisfy the customers and the family restaurants will have to make a great effort to develop the differentiated service so as to enhance their competitiveness.

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