• 제목/요약/키워드: HOST

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망혼용단말 탐지방법에 대한 연구 및 자동탐지시스템 구현 (A Study on Detection Method of Multi-Homed Host and Implementation of Automatic Detection System for Multi-Homed Host)

  • 이미화;윤지원
    • 정보보호학회논문지
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    • 제28권2호
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    • pp.457-469
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    • 2018
  • 본 연구에서는 망혼용단말(Multi-homed host)이 사라지지 않는 근본원인과 위험성을 알아보았다. 또한, 지금까지 연구 개발된 망혼용단말 탐지방법에 대해 비교 분석하여 개선사항을 도출하였다. 도출한 개선사항을 반영하여 망혼용단말을 효과적으로 탐지할 수 있는 자동 탐지시스템 모델을 제안하고 구현하였다. 아울러, 개발한 탐지시스템을 실제 망분리 기관과 유사한 가상실험환경에 설치한 후, 망혼용단말을 유형별로 발생시켜가며 탐지시스템의 기능과 성능을 측정하였다. 본 연구 범위에서는 오탐과 미탐 없이 정상 작동됨을 확인하였다. 제안한 탐지시스템은 에이전트(Agent) 기반 방식 중, 망혼용단말 탐지를 목표로한 최초의 학술 연구이다.

At Death's Door: Alternaria Pathogenicity Mechanisms

  • Lawrence, Christopher B.;Mitchell, Thomas K.;Craven, Kelly D.;Cho, Yang-Rae;Cramer, Robert A.;Kim, Kwang-Hyung
    • The Plant Pathology Journal
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    • 제24권2호
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    • pp.101-111
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    • 2008
  • The fungal genus Alternaria is comprised of many saprophytic and endophytic species, but is most well known as containing many notoriously destructive plant pathogens. There are over 4,000 Alternaria/host associations recorded in the USDA Fungal Host Index ranking the genus 10th among nearly 2,000 fungal genera based on the total number of host records. While few Alternaria species appear to have a sexual stage to their life cycles, the majority lack sexuality altogether. Many pathogenic species of Alternaria are prolific toxin producers, which facilitates their necrotrophic lifestyle. Necrotrophs must kill host cells prior to colonization, and thus these toxins are secreted to facilitate host cell death often by triggering genetically programmed apoptotic pathways or by directly causing cell damage resulting in necrosis. While many species of Alternaria produce toxins with rather broad host ranges, a closely-related group of agronomically important Alternaria species produce selective toxins with a very narrow range often to the cultivar level. Genes that code for and direct the biosynthesis of these host-specific toxins for the Alternaria alternata sensu lato lineages are often contained on small, mostly conditionally dispensable, chromosomes. Besides the role of toxins in Alternaria pathogenesis, relatively few genes and/or gene products have been identified that contribute to or are required for pathogenicity. Recently, the completion of the A. brassicicola genome sequencing project has facilitated the examination of a substantial subset of genes for their role in pathogenicity. In this review, we will highlight the role of toxins in Alternaria pathogenesis and the use of A. brassicicola as a model representative for basic virulence studies for the genus as a whole. The current status of these research efforts will be discussed.

숙주범위가 넓어진 재조합 Baculoviruses의 특성 및 병원성 검정

  • 김혜성;우수동;김우진;최재영;진병래;오현우;이윤형;강석권
    • 한국미생물·생명공학회지
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    • 제25권4호
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    • pp.359-366
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    • 1997
  • The usefulness of host range expanded recombinant viruses for economical viral insecticide and expression vector system has been studied. Host range expanded recombinant viruses, RecS-B6 and RecB-8, constructed by cotransfection of Bombyx mori nuclear polyhedrosis virus (BmNPV) and Autographa californica NPV (AcNPV), and a host range expanded AcNPV recombinant, Ac-BH, constructed by substitution of the 0.6Kb fragment of the BmNPV helicase gene were compared. The restriction enzyme digestion patterns showed that RecS-B6 and RecB-8 had expanded host ranges by genomic recombination and were more similar to genome of AcNPV than that of BmNPV. SDS-PAGE and PCR analysis showed that the polyhedrin gene of RecS-B6 and RecB-8 was derived from BmNPV genomic DNA. The morphology of polyhedra of recombinant viruses showed a slight difference between the two host cells, Sf and BmN cells, indicating that the morphology of polyhedra was influenced by host cells. The bioassay data for insect larvae showed that Ac-BH, compared to wild type viruses, had superior pathogenicity against Bombyx mori larvae but inferior pathogenicity against Spodoptera exigua larvae. Although the pathogenicity was lower than that of wild type viruses in both larvae, RecS-B6 showed the pathogenicity in both larvae. These results suggested that Ac-BH was a less useful economical insecticide than random genomic recombinant virus RecS-B6.

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Salen-Aluminum Complexes as Host Materials for Red Phosphorescent Organic Light-Emitting Diodes

  • Bae, Hye-Jin;Hwang, Kyu-Young;Lee, Min-Hyung;Do, Young-Kyu
    • Bulletin of the Korean Chemical Society
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    • 제32권9호
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    • pp.3290-3294
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    • 2011
  • The properties of monomeric and dimeric salen-aluminum complexes, [salen(3,5-$^tBu)_2$Al(OR)], R = $OC_6H_4-p-C_6H_6$ (H1) and R = [salen(3,5-$^tBu$)AlOPh]C$(CH_3)_2$ (H2) (salen = N,N'-bis-(salicylidene)-ethylenediamine) as host layer materials in red phosphorescent organic light-emitting diodes (PhOLEDs) were investigated. H1 and H2 exhibit high thermal stability with decomposition temperature of 330 and $370^{\circ}C$. DSC analyses showed that the complexes form amorphous glasses upon cooling of melt samples with glass transition temperatures of 112 and $172^{\circ}C$. The HOMO (ca. -5.2~-5.3 eV) and LUMO (ca. -2.3~-2.4 eV) levels with a triplet energy of ca. 1.92 eV suggest that H1 and H2 are suitable for a host material for red emitters. The PhOLED devices based on H1 and H2 doped with a red emitter, $Ir(btp)_2$(acac) (btp = bis(2-(2'-benzothienyl)-pyridinato-N,$C^3$; acac = acetylacetonate) were fabricated by vacuum-deposition and solution process, respectively. The device based on vacuum-deposited H1 host displays high device performances in terms of brightness, luminous and quantum efficiencies comparable to those of the device based on a CBP (4,4'-bis(Ncarbazolyl) biphenyl) host while the solution-processed device with H2 host shows poor performance.

시설 중증장애아동의 결연가정체험 프로그램을 통한 적응행동과 자기관리기술 효과성 연구 (A Study on the Effectiveness of a Host Family Experience Program on the Adaptive Behavior and Self-Management Skills of Children with Severe Disabilities at a Facility)

  • 오혜경;황성혜
    • 가정과삶의질연구
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    • 제27권1호
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    • pp.165-179
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    • 2009
  • The purpose of this study is to analyze the effectiveness of a host family experience program on the adaptive behavior and self-management skills of children with severe disabilities and to suggest its applicability into clinical practice. The investigators developed a host family experience program and researched the pre-test and post-test designs with nonequivalent groups. The experiment and comparison groups were comprised of 34 children with severe disabilities that lived at S, a care facility for the severely disabled. They were examined for the program's effects on them before and after the application. After analyzing 17 cases for differences in the subjects' quantitative scores, a qualitative analysis was carried out on one representative case. The quantitative analysis results reveal that the experiment group showed a significant increase in their scores of adaptive behavior and self-management skills compared to the comparison group. Positive changes were also observed among the former group in the qualitative analysis. Thus the host family experience program was effective in improving the adaptive behavior and self-management skills of the children with severe disabilities at the facility. These findings indicate that the host family experience program played a positive role in enhancing the adaptive behavior and self-management skills of the children with severe disabilities at the facility and that such host family experience programs should be applied and reinforced in the field of social welfare practice.

High-throughput Gene Expression Analysis to Investigate Host-pathogen Interaction in Avian Coccidiosis

  • Lillehoj Hyun, S.
    • 한국가금학회지
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    • 제34권1호
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    • pp.77-83
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    • 2007
  • Poultry products including meat and eggs constitute a major protein source in the American diet and disease-causing pathogens represent major challenges to the poultry industry. More than 95% of pathogens enter the host through the mucosal surfaces of the respiratory, digestive and reproductive tracts and over the past few decades, the two main mechanisms used to control diseases have been the use of vaccines and antibiotics. However, in the poultry industry, there are mounting concerns over the ability of current vaccines to adequately protect against emerging hyper-virulent strains of pathogens and a lack of suitable, cost effective adjuvants. Thorough investigation of the immunogenetic responses involved in host-pathogen interactions will lead to the development of new and effective strategies for improving poultry health, food safety and the economic viability of the US poultry industry. In this paper, I describe the development of immunogenomic and proteomic tools to fundamentally determine and characterize the immunological mechanisms of the avian host to economically significant mucosal pathogens such as Eimeria. Recent completion of poultry genome sequencing and the development of several tissue-specific cDNA libraries in chickens are facilitating the rapid application of functional immunogenomics in the poultry disease research. Furthermore, research involving functional genomics, immunology and bioinformatics is providing novel insights into the processes of disease and immunity to microbial pathogens at mucosal surfaces. In this presentation, a new strategy of global gene expression using avian macrophage (AMM) to characterize the multiple pathways related to the variable immune responses of the host to Eimeria is described. This functional immunogenomics approach will increase current understanding of how mucosal immunity to infectious agents operates, and how it may be enhanced to enable the rational development of new and effective strategies against coccidiosis and other mucosal pathogens.

Quantitative Detection of Residual E. coli Host Cell DNA by Real-Time PCR

  • Lee, Dong-Hyuck;Bae, Jung-Eun;Lee, Jung-Hee;Shin, Jeong-Sup;Kim, In-Seop
    • Journal of Microbiology and Biotechnology
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    • 제20권10호
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    • pp.1463-1470
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    • 2010
  • E. coli has long been widely used as a host system for the manufacture of recombinant proteins intended for human therapeutic use. When considering the impurities to be eliminated during the downstream process, residual host cell DNA is a major safety concern. The presence of residual E. coli host cell DNA in the final products is typically determined using a conventional slot blot hybridization assay or total DNA Threshold assay. However, both the former and latter methods are time consuming, expensive, and relatively insensitive. This study thus attempted to develop a more sensitive real-time PCR assay for the specific detection of residual E. coli DNA. This novel method was then compared with the slot blot hybridization assay and total DNA Threshold assay in order to determine its effectiveness and overall capabilities. The novel approach involved the selection of a specific primer pair for amplification of the E. coli 16S rRNA gene in an effort to improve sensitivity, whereas the E. coli host cell DNA quantification took place through the use of SYBR Green I. The detection limit of the real-time PCR assay, under these optimized conditions, was calculated to be 0.042 pg genomic DNA, which was much higher than those of both the slot blot hybridization assay and total DNA Threshold assay, where the detection limits were 2.42 and 3.73 pg genomic DNA, respectively. Hence, the real-time PCR assay can be said to be more reproducible, more accurate, and more precise than either the slot blot hybridization assay or total DNA Threshold assay. The real-time PCR assay may thus be a promising new tool for the quantitative detection and clearance validation of residual E. coli host cell DNA during the manufacturingprocess for recombinant therapeutics.

먹이식물·흡밀식물·식생이 나비 군집에 미치는 영향 (Effects of Host plant, Nectar plant and Vegetation types on Butterfly Communities)

  • 김도성;조영복;정종철
    • 한국응용곤충학회지
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    • 제51권4호
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    • pp.331-342
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    • 2012
  • 본 연구는 먹이식물과 흡밀식물의 수 그리고 식생이 나비의 개체수 및 다양성에 미치는 영향을 조사하기 위하여 2008-09년까지 충북 보은군 속리산 법주사 지역을 4개 구간으로 나누어 모니터링을 실시하였으며 이를 단순회귀분석 및 다중회귀분석하였다. 그 결과 나비 개체수와 식물종수, 흡밀식물 그리고 먹이식물 수를 다중회귀분석 한 결과에서 상관관계를 보였으며, 서식지 면적이 클수록 개체수는 많아지는 것으로 나타났다. 그러나 단순회귀 분석 시 나비의 종수와 다양도지수는 먹이식물 수 및 구간면적과 각각 낮은 상관관계를 나타냈다. 또한 보다 다양한 식생을 보이는 구간에서 나비 종수가 증가하였다. 나비의 다양성과 개체군 보전을 위해서는 다양한 수종의 식물과 함께 나비의 먹이식물과 흡밀식물이 복합적으로 분포하고, 식생은 각각의 요소들이 서로 보완관계를 유지할 수 있도록 다른 형태로 존재하는 것이 필요함을 시사한다.

Detailed Abundance Analysis for Plant Host Stars

  • 강원석;이상각;김강민
    • 천문학회보
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    • 제36권1호
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    • pp.27.1-27.1
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    • 2011
  • We obtained the spectra of 93 Planet host stars and 73 normal field stars in F, G, K type using BOES at BOAO. We measured the equivalent width of Fe and 25 elements lines using the automatic EW measurement program, TAME(Tools for Automatic Measurement of Equivalent-widths) and estimated the elemental abundances by synth and abfind driver of MOOG code. Since the absence of planets in the normal field stars cannot be "completely" proved, this work focused on the chemical abundances and planet properties of planet host stars, which have the massive planets close to the parent star relatively. We carried out an investigation for the difference of abundances between stars with "Hot Jupiter" and normal field stars with no known planets. We examined the chemical composition of 25 elements, such as C, N, O, S, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd, and Eu by EW measurements, and the S abundances were estimated using synthetic spectrum. We have found that [Mg/Fe] and [Al/Fe] for planet host stars have lower limit comparing with those of comparison stars, and [Ca/Fe] of host star with Neptunian planets is relatively lower than the other host stars with massive planets. We have performed the Kolmogorov-Smirnov test, and examined the ratio of planet host stars to all stars for each bin of [X/H]. As a result, we noted that the O, Si, and Ca abfor undances are strongly related with the presence of planets.

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