• Journal of Ecology and Environment
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• 제35권4호
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• pp.359-365
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• 2012

We investigated leaf disease intensity of Kalopanax septemlobus (prickly castor oil tree) caused by the parasitic fungus Mycosphaerella acanthopanacis, in thirty natural host populations in the Japanese Archipelago. The disease intensity observed for individual trees were analyzed using a generalized additive model as a function of tree size, tree density, climatic terms and spatial trend surface. Individual tree size and conspecific tree density were shown to have significant negative and positive effects on disease intensity, respectively. The findings suggest that the probability of disease infection is partly determined by dispersal of infection agents (ascospores) from the fallen leaves on the ground, which can be enhanced by aggregation of host trees in a forest stand. Regional-scale spatial bias was also present in disease intensity; the populations in northern Japan and southern Kyushu were more severely infected by the fungus than those in southwestern Honshu and Shikoku. Regional variation of disease intensity was explained by both climatic factors and a trend surface term, with a latitudinal cline detected, which increases towards the north. Further research should be conducted in order to understand all of the factors generating the latitudinal cline detected in this study.

• 한국식물병리학회지
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• 제14권5호
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• pp.413-417
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• 1998

Magnaporthe grisea, the casual agent of rice blast, requires formation of an appressorium, a dome-shaped and well melanized infection structure, to penetrate its host. Environmental cues that induce appressorium formation include hydrophobicity and hardness of contact surface and chemicals from its host. Artificial surfaces are widely used to induce appressorium formation, but frequencies of appressorium induction are not always consistent. To understand variable induction of appressorium formation in M. grisea, several factors were tested on GelBond. High levels of appressorium formation were induced over a wide range of temperature (20~3$0^{\circ}C$) and pH (4~7). spore age up to 3-week-old did not significantly affect appressorium formation, but only a few apressoria on GelBond. However, adenosine specifically inhibited appressorium formation. Adenosine inhibition of appressorium formation was restored by exogenous addition of cAMP. Germ tube tips of M. grisea maintained the ability to differentiate appressoria by chemical inducers on GelBond at least up to 16 h after conidia germination. These results suggest that environmental factors have little effect on the variable induction of appressorium formation on the artificial surface in M. grisea.

• 마케팅과학연구
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• 제19권2호
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• pp.5-16
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• 2009

Against the backdrop of the increasing trend towards economic globalisation, many international firms are indicating that decisions on how to enter foreign markets remains one of the key strategic challenges confronting them. Despite the rich body of literature on the topic, the fact that these challenges have continued to dominate global marketing strategy discourses point to someevident lacunae. Accordingly, this paper considers the variables, categorised in terms of firm contexts (standardisation, market research, competition, structure, competitive advantage) and host country-contexts (economic development, cultural differences, regulation and political risk), which influence the degree of involvement of UK companies in overseas markets. Following hypotheses were drawn from literature review: H1: The greater the level of competition, the higher the degree of involvement in the overseas market. H2: The more centralised the firm's organisation structure, the higher the degree of involvement in the overseas market. H3a: The adoption of a low cost-approach to competitive advantage will lead to a higher degree of involvement. H3b: The adoption of an innovation-approach to competitive advantage will lead to a higher degree of involvement. H3c: The adoption of a market research approach to competitive advantages will lead to a higher degree of involvement. H3d: The adoption of a breadth of strategic target-approach to competitive advantage will lead to a lower degree of involvement. H4: The higher the degree of standardisation of the international marketing mix the higher the degree of involvement. H5: The greater the degree of economic development in the host market, the higher the degree of involvement. H6: The greater the cultural differences between home and host countries, the lower the degree of involvement. H7: The greater the difference in regulations between the home country and the host country, the lower the degree of involvement. H8: The higher the political risk in the host country, the lower the degree of involvement. A questionnaire instrument was constructed using, wherever possible, validated measures of the concepts to serve the aims of this study. Following two sets of mailings, 112 usable completed questionnaires were returned. Correlation analysis and multiple regression analysis were used to analyze data. Statistically, the paper suggests that factors relating to the level of competition, competitive advantages and economic development are strong in influencing foreign market involvements. On the other hand, unexpectedly, cultural factors (especially individualism/collectivism and low and high power distance dimensions) proved to have weak moderating effects. The reason for this, in part, is due to the pervading forces of globalisation and the attendant effect on global marketing. This paper has contributed to the general literature in a way that point to two mainimplications. First, with respect to research on national systems, the study may hold out some important lessons especially for developing nations. Most of these nations are known to be actively seeking to understand what it takes to attract foreign direct investment, expand domestic market and move their economies from the margin to the mainstream global economy. Second, it should be realised that competitive conditions remain in constant flux (even in mature industries and mature economies). This implies that a range of home country factors may be as important as host country factors in explaining firms' strategic moves and the degree of foreign market involvement. Further research can consider the impact of the home country environment on foreign market involvement decisions. Such an investigation will potentially provide further perspectives not only on the influence of national origin but also how home country effects are confounded with industry effects.

• 한국응용곤충학회지
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• 제5_6권
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• pp.39-46
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• 1968

본시험은 5개 기주식물(뽕나무$\cdot$버즘나무$\cdot$미류나무$\cdot$네군도나무 및 사과나무)의 Nitrogen$\cdot$Phosphorus$\cdot$Potassium 및 Sugar함량이 흰불나방의(Hyphantria cunea DRURY) 유충기간$\cdot$용기간$\cdot$용체중$\cdot$자아의 포난수 및 $\gamma-BHC$에 대한 감응도에 미치는 영향을 조사연구하기 위해 시행되었다. 그 시험결과는 다음과 같다. (1) 공시 기주식물엽의 Nitrogen$\cdot$Phosphorus$\cdot$Potassiuln 및 Sugar함양은 기주의 종류와 화기(1화기와 2화기)에 따라 각각 상이한 차가 있었다(표 1). (2) 1, 2화기 유충기간과 용기간은 비교적 N의 함량이 많은 뽕나무에서 짧았고 그렇지 않은 사과나무에서 가장 긴 경향이었으며, 1화기보다 2화기에서 더 짧아졌다. 이들은 기주의 N함량과 유의성은 인정할 수 없었으나(1화기 유충기간은 제외), 비교적 높은 부의 상관을 나타낸 것으로 보아 P·K 및 Sugar에 비하여 크게 관여한 것 같았다. (3) 용체중과 포난수에 있어서도 (2)의 경우와 마찬가지로 기주의 종류, 자웅의 성 및 화기에 따라 현저한 차이가 있었다(표 3). 용체중은 N의 함량이 많은 뽕나무에서 역시 가장 높았고 그렇지 않은 사과나무에서 가장 낮았으며, 자아당 평균 포란수에 있어서도 용체중의 경향과 비슷하였다. 용체중이나 포난수의 경우나 영양과의 관계는 유의한 상관을 인정할 수 없었으나 크게 관여한 것은 N의 함량으로 생각되었다. (4) $\gamma-BHC$에 대한 천불나방유충의 내약력은 기주의 종류에 따라 현저한 차가 있었으며, 그 감응도는 네군도나무$\cdot$미류나무$\cdot$버즘나무$\cdot$사과나무$\cdot$뽕나무 순으로 강하였다(표 6). 역시 유의한 상관을 인정할 수는 없었으나 N·P 및 Sugar보다 K의 함량이 많은 기주 일수록 $\gamma-BHC$에 대한 유충의 내약력이 강한 경향을 나타내었다.

• 한국정보과학회논문지:시스템및이론
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• 제32권6호
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• pp.296-305
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• 2005

기존의 컴퓨터 시스템에서는 인터넷의 대표적인 프로토콜인 TCP/IP가 호스트 CPU에서 처리되는데, 이는 호스트 CPU에 많은 부하(load)를 발생시켜 전체 시스템의 성능을 저하시키는 문제를 야기한다. 최근 이러한 문제점을 해결하는 방안으로서 네트워크 어댑터에서 TCP/IP를 처리하는 TCP/IP Offload Engine(TOE)에 대한 연구가 활발히 진행되고 있다. 본 논문에서는 Linux 운영체제에 내장된 TCP/IP 프로토콜 스택의 구조를 분석하고, 통신을 수행할 때 프로토콜 스택의 각 함수에서 소모되는 시간을 측정하여 호스트 CPU에 부하를 발생시키는 주 요인을 분석하였다. 이러한 분석을 바탕으로 CPU에 많은 부하를 발생시키는 기능은 하드웨어로 구현하고 나머지 기능들은 소프트웨어로 구현하는 Hybrid TOE 구조를 제안한다.

• International Journal of Industrial Entomology and Biomaterials
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• 제29권1호
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• pp.135-144
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• 2014

Rearing of tropical tasar silkworm, Antheraea mylitta Drury is mainly conducted in outdoor on Terminalia tomentosa W. & A. a nature grown primary host plant available in forest and also on raised primary host plant Terminalia arjuna Bedd. Temperature, relative humidity and rainfall are the main environmental factors for occurrence of pests (parasites and predators) of tasar silkworm during I, II and III crop rearing in the tropical tasar producing zones. The present study was aimed to study the influence of abiotic factors on prevalence of tasar silkworm pests. The study was conducted at different agro-climatic regions viz., Central Tasar Research &Training Institute, Ranchi, Jharkhand, Regional Extension Centre, Katghora, Chattisgarh and Regional Extension Centre, Hatgamaria during 2010-13 covering 3 seed crop and 6 commercial crops. Data on incidence of tropical tasar silkworm endo-parasitoids like Uzi Fly, Blepharipa zebina Walker and Ichneumon fly (Yellow Fly), Xathopimpla pedator, Fabricius and Predators such as Stink bug (Eocanthecona furcellata Wolf), Reduviid bug (Sycanus collaris Fabricius) and Wasp (Vespa orientalis Linnaeus) was recorded Weekly. The meteorological data was collected daily. Data was collected from 4 different agro-climatic zones of tasar growing areas. Analysis of the data revealed a significant negative correlation between abiotic factors and incidence of ichneumon fly and uzi fly. Based on the 3 years data on prevalence of pests region-wise pest calendars and prediction models were developed.

• 한국가금학회지
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• 제48권2호
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• pp.81-90
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• 2021

조류 인플루엔자 바이러스는 다양한 숙주 단백질을 이용해야만 증식이 가능하다. 포유류 (사람, 쥐) Fragile X mental retardation protein (FMRP)는 최근 인플루엔자 A 바이러스 viral RNP (vRNP)의 조립을 돕고, 이를 핵에서 세포질로 운반시켜 바이러스 증식에 도움을 준다. 하지만, 조류 인플루엔자 바이러스의 주요 숙주인 닭에서는 FMRP translational regulator 1 (FMR1) 유전자의 기능이 규명되지 않았다. 본 연구는 CRISPR/Cas9 (Clustered regularly interspaced short palindromic repeats/Cas9) 유전자 가위를 이용해 정확히 닭 FMR1 유전자를 제거하여 닭 FMR1 유전자가 조류 인플루엔자 바이러스 증식에 어떤 영향을 끼치는지 연구하였다. 닭 FMR1 유전자는 닭 배아섬유아세포 (DF1세포)에서 초기 조류 인플루엔자 바이러스의 유전자 발현을 촉진하나, 감염 후 24시간 뒤에는 바이러스 생산 및 바이러스 중합효소 (Polymerase)의 활성에 영향을 끼치지 않았다. 또한, 야생형 닭 FMR1 유전자를 과발현 함에도 불구하고, 조류 인플루엔자 바이러스의 생산량에는 변화가 없었다. 위 결과들은 닭 FMR1은 포유류 FMR1 유전자에 비해 조류 인플루엔자 바이러스의 증식에 큰 영향을 주지 못하는 숙주인자임을 시사한다. 또한, 닭 FMR1처럼 기존에 포유류에서 알려진 숙주 인자를 목표로 하는 조류 인플루엔자 바이러스 저항성 치료제 및 형질전환 동물을 생산할 때, 조류 시스템에서 위 숙주 인자의 기능이 보존돼 있는지 고찰할 필요가 있다고 사료된다.

• Reproductive and Developmental Biology
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• 제31권2호
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• pp.121-126
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• 2007

The objective of this study was to establish the optimal conditions for hypoosmotic swelling (HOS) test to assess the functional integrity of the membranes of boar fresh or frozen/thawed spermatozoa. When pooled semen sample was incubated for 30 min at $37^{\circ}C$ with different test solution of varied osmolarity, the highest percentage of HOS positive spermatozoa was observed in a 150 mOsmol fructose/Na-citrate solution (33.6%). Incubation time did not affect significantly the score of HOS positive spermatozoa observed in a 150 mOsmol fructose/Na-citrate solution at $37^{\circ}C$, but the osmolarity affected the score of HOS positive spermatozoa under the same condition above. Fresh semen was significantly better than frozen/thawed semen in semen parameters evaluated such as motility, viability, membrane integrity and lipid peroxidation (p<005). In the relationships of sperm parameters, motility vs viability, motility vs membrane integrity and viability vs membrane integrity were positively correlated ($0.82{\sim}0.94$) but lipid peroxidation vs other estimated factors was negatively correlated ($- 0.90{\sim}- 0.98$). Among the evaluation methods, motility vs Viability, motility vs membrane integrity and lipid peroxidation vs other estimated factors were significantly correlated (p<0.05). These results of this. study indicate that the optimal condition of HOST in boar spermatozoa is a 150 mOsmol fructose/Na-citrate solution for 30 min incubation at $37^{\circ}C$ and HOST can substitute the examination of motility, viability and lipid peroxidation.

• Molecules and Cells
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• 제39권4호
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• pp.286-291
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• 2016

Epstein-Barr virus (EBV) is the prototypical ${\gamma}$-herpesvirus and an obligate human pathogen that infects mainly epithelial cells and B cells, which can result in malignancies. EBV infects these target cells by fusing with the viral and cellular lipid bilayer membranes using multiple viral factors and host receptor(s) thus exhibiting a unique complexity in its entry machinery. To enter epithelial cells, EBV requires minimally the conserved core fusion machinery comprised of the glycoproteins gH/gL acting as the receptor-binding complex and gB as the fusogen. EBV can enter B cells using gp42, which binds tightly to gH/gL and interacts with host HLA class II, activating fusion. Previously, we published the individual crystal structures of EBV entry factors, such as gH/gL and gp42, the EBV/host receptor complex, gp42/HLA-DR1, and the fusion protein EBV gB in a postfusion conformation, which allowed us to identify structural determinants and regions critical for receptor-binding and membrane fusion. Recently, we reported different low resolution models of the EBV B cell entry triggering complex (gHgL/gp42/HLA class II) in "open" and "closed" states based on negative-stain single particle electron microscopy, which provide further mechanistic insights. This review summarizes the current knowledge of these key players in EBV entry and how their structures impact receptor-binding and the triggering of gB-mediated fusion.

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 2005년도 제36차 추계학술대회 및 제4회 HVEM 이용자 워크샵
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• pp.127-129
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• 2005

Bacterial lipopolysaccharide(LPS) is can stimulate the most LPS-responsive cells in the mammalian host. The macrophage response to LPS can protect the host from infection but high levels, contribute to systemic inflammatory response syndrome and destruction of host itself, The previously study, secretory leukocyte pretense inhibitor (SLPI) was known LPS-induced product of macrophage and had the function that antagonizes their LPS-induced activation of pro-inflammation signaling factors. Purpose of this study was to identify the expression of SLPI involving the infection in various cell lines including odontoblast cell line. Therefore, we conducted in vitro researches, which treated the LPS to the MDPC-23, and compared to NIH3T3, RAW264.7. To investigate the expressionof SLPI in mRNA level, the methods was used RT-PCR and western blotting for protein expression of SLPI. Moreover, we performed the scanning electron microscopic (SEM) observation for the morphological change. This work was supported by Korea Science and Engineering Foundation.