• Title/Summary/Keyword: 매개화

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Wolbachia-mediated Reproductive Alterations in Arthropod Hosts and its use for Biocontrol Program (볼바키아 세균에 의한 절지동물 기주의 생식적 변화와 생물적방제 프로그램에 이용 방안)

  • Rostami, Elahe;Madadi, Hossein;Abbasipour, Habib;Sivaramakrishnan, Shiva
    • Korean journal of applied entomology
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    • v.55 no.2
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    • pp.177-188
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    • 2016
  • The alpha-proteobacterium Wolbachia is one of the most important intracellular symbionts of arthropods. This Gram-negative bacterium is involved in many biological processes and is currently considered as a potential tool for biological control. Wolbachia is a cytoplasmic bacterium, maternally transferred through generations, and to facilitate its success, it has evolved several strategies that manipulate its host reproductive system to increase the number of infected individuals in the host population. The variety of Wolbachia was first recognized using genes wsp, 16S rRNA, ftsZ, gltA and groEL as molecular markers while strain genotypes of Wolbachia are determined of Multilocus sequence typing (MLST) and sequence of amino acid in region, hyper variable regions (HVRs) in protein WSP. Possible uses of the bacteria and their predominant phenotypes in control programs for agricultural pests and human disease vectors have been considered. Phenotypes are known to induce cytoplasmic incompatibility (CI), parthenogenesis induction (PI), feminization (F) and male killing (MK). Finally, applications of the bacterium in control programs of agricultural and medical insect pests have been discussed.

A study on antecedents of relationship strength in a B2B environment: Focusing on export manufacturing corporations (B2B 관계강화에 영향을 미치는 선행요인에 관한 연구: 수출 제조기업을 중심으로)

  • Choi, Jong-Hwa;Lee, Hyun Ju;Kang, Gi-Du
    • International Commerce and Information Review
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    • v.16 no.4
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    • pp.3-34
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    • 2014
  • Nowadays to thrive on the intensively competitive environments based on drastic and rapid technical evolutions, exporting manufacturing companies need to keep very stable relationship with suppliers. Thus, analyzing key factors of strengthening relationship with suppliers in a B2B environment is important. In this regard, this study develops a research model to deeply understand key antecedents of relationship strength between B2B companies. Relationship quality was considered as the key factor affecting to the relationship strength. This study considers relationship satisfaction, trust, and relationship commitment as the factors of relationship quality. Moreover, technical service quality and relational service quality were considered to be the antecedents of relationship satisfaction, while communication and information exchange, relationship policies and practices, and opportunistic behavior were regarded as the antecedents of trust. The PLS method was applied for the empirical analysis of 107 companies data. The results indicated that the relationship commitment has a significant impact on relationship strength. Moreover, relationship satisfaction and trust had indirectly impact on relationship strength through relationship commitment. Although the quality of technical service quality had a significant impact on relationship satisfaction, relational service quality did not have a significant impact. While communication and information exchange, relationship policies, and practices had positively significant impacts, opportunistic behavior had a negative impact.

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Surface Modification Using Spiropyran-Derivative and Its Analysis of Surface Potential Induced by UV (스파이로파이란에 의한 표면 개질 및 자외선에 의해 유도된 표면 전위에 대한 분석)

  • Lee, Bong-Soo;Han, Dong-Keun;Son, Tae-Il;Jung, Young-Hwan
    • Journal of the Korean Chemical Society
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    • v.55 no.3
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    • pp.478-485
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    • 2011
  • Merocyanine derivatives transformed from spiropyran-containing compounds by irradiating the light of ultraviolet (UV) include zwitterion of phenolate anion and amine cation. Complexation of this phenolate anion on merocyaninemodified surface and Ni ion among metal ions led to a change of surface charge and it was measured with kelvin prove force microscopy (KFM). We found that the resultant surface potential decreased linearly as UV-exposed time increased, and finally were saturated. Also it was analyzed through XPS the immobilized amount of Ni ions was increased according to increase of UV-exposed time. It is considered that these properties could be applied for detection and a quantitative control of different metal ions. Further research is to aim construct specific scaffold/matrix which enable high selective, high sensitive and, especially, a quantitative immobilization of metal ions-binding biomaterials such as proteins and cells.

Isogeometric Shape Design Optimization of Structures Subjected to Design-dependent Loads (설계 의존형 하중 조건을 갖는 구조물의 아이소-지오메트릭 형상 최적설계)

  • Yoon, Min-Ho;Koo, Bon-Yong;Ha, Seung-Hyun;Cho, Seon-Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.1
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    • pp.1-7
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    • 2011
  • In this paper, based on an isogeometric approach, we have developed a shape design optimization method for plane elasticity problems subjected to design-dependent loads. The conventional shape optimization using the finite element method has some difficulties in the parameterization of geometry. In an isogeometric analysis, however, the geometric properties are already embedded in the B-spline basis functions and control points so that it has potential capability to overcome the aforementioned difficulties. The solution space for the response analysis can be represented in terms of the same NURBS basis functions to represent the geometry, which yields a precise analysis model that exactly represents the normal and curvature depending on the applied loads. A continuum-based isogeometric adjoint sensitivity is extensively derived for the plane elasticity problems under the design-dependent loads. Through some numerical examples, the developed isogeometric sensitivity analysis method is verified to show excellent agreement with finite difference sensitivity.

Experiment on Chloride Adsorption by Calcium Aluminate Phases in Cement (시멘트내 칼슘 알루미네이트 상에 의한 염소이온의 흡착반응 연구)

  • Yoon, In-Seok
    • Journal of the Korea Concrete Institute
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    • v.29 no.4
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    • pp.389-397
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    • 2017
  • Friedel's salt is an important product of chemical adsorption between cement hydrate and chloride ions because it contains chlorine in its structure. When cement reacts with water in the presence of chloride ions, the $C_3A$ phase, and $C_4AF$ phase react with chloride to produce Friedel's salt. If chloride ions penetrate into concrete from external environments, many calcium aluminate hydrates, including AFm, can bind chloride ions. It is very important, therefore, to investigate the chloride binding isotherm of $C_3A$ phase, $C_4AF$ phase, and AFm phase to gain a better understanding of chloride binding in cementitious materials. Meanwhile, the adsorption isotherm can provide us with the fundamental information for the understanding of adsorption process. The experimental results of the isotherm can supply not only the quantitative knowledge of the cement-Friedel's salt system, but also the mechanism of adsorption and the properties of their interactions. The purpose of this study is to explore the time dependant behaviors of chloride ions adsorption with $C_3A$, $C_4AF$ and AFm phases. The chloride adsorption isotherm was depicted with Langmuir isotherm and the adsorption capacity was low in terms of the stoichiometric point of view. However, the chloride adsorption of AFm phase was depicted with Freundlich isotherm and the value was very low. Since the amount of the adsorption was governed by temperature, the affecting parameters of isotherm were expressed as a function of temperature.

Korean Teachers' Conceptions of Models and Modeling in Science and Science Teaching (과학 탐구와 과학 교수학습에서의 모델과 모델링에 대한 교사들의 인식)

  • Kang, Nam-Hwa
    • Journal of The Korean Association For Science Education
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    • v.37 no.1
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    • pp.143-154
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    • 2017
  • Science inquiry has long been emphasized in Korean science education. Scientific modeling is one of key practices in science inquiry with a potential to provide students with opportunities to develop their own explanations and knowledge thereafter. The purpose of this study is to investigate teacher's understanding of models in science and science teaching. A professional development program on Models (PDM) was developed and refined through three times of implementation while teachers' conceptions of models and modeling were examined. A total of 29 elementary and secondary teachers participated in this study. A survey based on model use of scientists in the history of science was developed and used to collect data and audio recordings of discussions among teachers and artifacts produced by the teachers during PDM were also collected. Three ways of ontological and two ways of epistemological understanding of models and modeling were found in teachers' ideas. After PDM, a quarter of the teachers changed their ontological understanding whereas very few changed their epistemological understanding. In contrast, more than two thirds of the teachers deepened and extended their ideas about using models and modeling in teaching. There were no clear relationships between teachers' understanding of models and ways and ideas about using models in science teaching. However, teachers' perceptions of school conditions were found to mediate their intention to use models in science teaching. The findings indicate possible approaches to professional development program content design and further research.

Histone Modifications and It's Relation with Functional Aspects (히스톤의 변이와 이와 관련된 기능적 측면)

  • Kang, Han-Chul;Kim, Jong-Bum;Roh, Kyung Hee;Kim, Hyun-UK;Lee, Kyung-Ryeol;Kim, Sun Hee
    • Journal of Applied Biological Chemistry
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    • v.57 no.4
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    • pp.379-386
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    • 2014
  • Chromatin is an instructive DNA structure that can widely respond to external signals. An important change of chromatin is the modifications of histone for this regulation. There are accumulating lists of these modifications and the complexity of their action is gradually understood. It is evident that histone modifications play important roles in most biological processes that are involved in the expression or repression of DNA. The surface of nucleosomes is susceptible to multiplicity of modifications. Chromatin modifications can play either by eliminating chromatin contacts or by recruiting non-histone proteins to chromatin. Many of these regulations seem to be epigenetically inherited. Thus, histone modifications are closely correlated with many fundamental biological processes in animal, plant and microbial kingdoms. Failures of histone modification lead, in general, to defective chromosome condensation or decondensation, impeding many biological functions including development, maturation, and protection against various diseases.

Anti-inflammatory effects of the Rubus occidentalis seed extracts on UV-B induced inflammation in HaCat cells (각질형성세포에서 UV-B와 사이토카인에 의하여 유도되는 염증 반응에 대한 복분자 씨앗 추출물의 항염증 효과)

  • Kim, Dong-Hee;Park, Tae-Soon;Son, Jun-Ho
    • Journal of Applied Biological Chemistry
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    • v.59 no.3
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    • pp.247-253
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    • 2016
  • It confirmed the applicability as an anti-inflammatory material from Rubus occidentalis seed (RSE) extract. In HaCaT cells to evaluate the anti-inflammatory potential as a material RSE extract on the activity of the inflammatory factors caused by UVB and $IFN-{\gamma}/TNF-{\alpha}$. We measured the activity of ROS, interleukin-$1{\beta}$ ($IL-1{\beta}$), interleukin-6 (IL-6) and interleukin-8 (IL-8) by ROS-Glo $H_2O_2$ assay and ELISA kit. Our results showed that the RSE extracts inhibit the UVB and $IFN-{\gamma}/TNF-{\alpha}$-induced ROS activities and expression of $IL-1{\beta}$, IL-6 and IL-8 in a dose-dependent manner. Also it was found that inflammatory mediators of the expression of cyclooxygenase-2 (COX-2) inhibition were also brought, the expression of which is increased $PGE_2$ by COX-2 also inhibited. Finally RSE extracts measure the seed expression of filaggrin in the skin barrier, the main factor of the extract could be confirmed to increase the expression of the filaggrin damaged as a result of this concentration-dependent manner. Through this, it was able to confirm that the efficacy RSE extract to protect the inflammation by restoring the damaged layers of the epidermis. Results from more than RSE extract was able to confirm that the extract that has anti-inflammatory effects by improving the inflammation being produced from UVB.

Estimates of Regional Flood Frequency in Korea (우리나라의 빈도홍수량의 추정)

  • Kim, Nam-Won;Won, Yoo-Seung
    • Journal of Korea Water Resources Association
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    • v.37 no.12
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    • pp.1019-1032
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    • 2004
  • Flood frequency estimate is an essential index for determining the scale of small and middle hydraulic structure. However, this flood quantity could not be estimated directly for practical design purpose due to the lack of available flood data, and indirect method like design rainfall-runoff method have been used for the estimation of design flood. To give the good explain for design flood estimates, regional flood frequency analysis was performed by flood index method in this study. First, annual maximum series were constructed by using the collected data which covers from Japanese imperialism period to 1999. Wakeby distribution recommended by WMO(1989) was used for regional flood frequency analysis and L-moment method by Hosking (1990) was used for parameter estimation. For the homogeneity of region, the discordance and heterogeneity test by Hosking and Wallis(1993) was carried for 4 major watersheds in Korea. Physical independent variable correlated with index flood was watershed area. The relationship between specific discharge and watershed area showed a type of power function, i.e. the specific discharge decreases as watershed area increases. So flood quantity according to watershed area and return period was presented for each watershed(Han rivet, Nakdong river, Geum river and Youngsan/Seomjin river) by using this relation type. This result was also compared with the result of point frequency analysis and its regionalization. It was shown that the dam construction couldn't largely affect the variation of peak flood. The property of this study was also examined by comparison with previous studies.

Neoliberal Urbanization and Projects of Entrepreneurial City (신자유주의적 도시화와 기업주의 도시 프로젝트)

  • Choe, Byeong-Doo
    • Journal of the Economic Geographical Society of Korea
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    • v.14 no.3
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    • pp.263-285
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    • 2011
  • Despite the process of neoliberalization has made a decisive influence on our society as a whole, there seems little interests in neoliberal urbanization and entrepreneurial urban projects promoting it. This study is to see relationships between neolibealization process and recent urbanization and urban policies in terms of entrepreneurial city mediating them. In particular, this paper tries to reconceptualize entrepreneurial city as corresponding to privatization and commodification, financialization, state redistribution, and management and manipulation of crises which Harvey(2005) suggests as four main features of neoliberalization process in general and 'accumulation by dispossession' in particular, and to characterize it in terms of 'creative destruction' and of 'entrepreneurial governance'. As examined in the later part of this paper, recent cases of these entrepreneurial urban projects in S. Korea include volatility of land and housing price in the Capital region and urban regeneration and newtown projects, project for free economic zones construction in Incheon and other 5 regions, project for SOC construction heavily relying on private investment, in particular project financing pursued nationwidely including Daegu, and project of urban cultural marketing to promote capital inflow tacitly as well as to enhance urban imagine explicitly.

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