• Title/Summary/Keyword: exogenous strategy

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Exogenous Bio-Based 2,3-Butanediols Enhanced Abiotic Stress Tolerance of Tomato and Turfgrass under Drought or Chilling Stress

  • Park, Ae Ran;Kim, Jongmun;Kim, Bora;Ha, Areum;Son, Ji-Yeon;Song, Chan Woo;Song, Hyohak;Kim, Jin-Cheol
    • Journal of Microbiology and Biotechnology
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    • v.32 no.5
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    • pp.582-593
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    • 2022
  • Among abiotic stresses in plants, drought and chilling stresses reduce the supply of moisture to plant tissues, inhibit photosynthesis, and severely reduce plant growth and yield. Thus, the application of water stress-tolerant agents can be a useful strategy to maintain plant growth under abiotic stresses. This study assessed the effect of exogenous bio-based 2,3-butanediol (BDO) application on drought and chilling response in tomato and turfgrass, and expression levels of several plant signaling pathway-related gene transcripts. Bio-based 2,3-BDOs were formulated to levo-2,3-BDO 0.9% soluble concentrate (levo 0.9% SL) and meso-2,3-BDO 9% SL (meso 9% SL). Under drought and chilling stress conditions, the application of levo 0.9% SL in creeping bentgrass and meso 9% SL in tomato plants significantly reduced the deleterious effects of abiotic stresses. Interestingly, pretreatment with levo-2,3-BDO in creeping bentgrass and meso-2,3-BDO in tomato plants enhanced JA and SA signaling pathway-related gene transcript expression levels in different ways. In addition, all tomato plants treated with acibenzolar-S-methyl (as a positive control) withered completely under chilling stress, whereas 2,3-BDO-treated tomato plants exhibited excellent cold tolerance. According to our findings, bio-based 2,3-BDO isomers as sustainable water stress-tolerant agents, levo- and meso-2,3-BDOs, could enhance tolerance to drought and/or chilling stresses in various plants through somewhat different molecular activities without any side effects.

Dynamic Interactive Relationships among Advertising Cost and Customer Types of Social Network Game (소셜네트워크게임에서 광고비와 고객 유형 변수간 동적 상호관계)

  • Lee, Hee-Tae
    • Journal of Distribution Science
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    • v.14 no.4
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    • pp.47-53
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    • 2016
  • Purpose - The objective of this study is to investigate the dynamic relationships among Advertising Cost (AD), Newly Registered Users(NRU), and Buying Users(BU) of Social Network Game(SNG). SNG is getting pervasive mainly due to the rapid growth of mobile game and Social Network Service(SNS). It would be helpful for marketing researchers interested in SNG and related practitioners to understand the changes in AD, NRU, and BU with time as well as the effects on one another in mutual and dynamic way. Research Design, Data, and Methodology - Necessary data were collected from Social Network Game(SNG) company. AD, NRU, and BU are endogenous variables, but new event such as launching (event) and holidays(holiday) are exogenous dummy variables. Vector Auto regression (VAR) model is generally used to examine and capture the dynamic relationships among endogenous variables. VAR model can easily capture dynamic and endogenous relationships among time-series variables. Vector Auto regression with Exogenous variables(VARX) is a model in which exogenous variables are added to VAR. To investigate this study, VARX is applied. Result - By estimating the VARX model, the author finds that the past periods' NRU affect negatively and significantly the present AD, and past periods' BU have a positive and significant impact on the increase of AD. In addition, the author shows that the past periods' AD and BU have a positive and significant effect on the increase of NRU, and the past periods' AD affect positively and significantly BU. While the impact of AD on NRU happens after 3 or 4 days (carryover effect), that of AD on BU comes about within just 1 or 2 days (immediate effect). The effect of BU on NRU can be considered as word of mouth (WOM effect). Therefore, SNG companies can obtain not only the growth of revenue but also the increase of NRU by increasing BU. Through those results, the author can also find that there are significant interactions between endogenous variables. Conclusion - This study intends to investigate endogenous and dynamic relationships between AD, NRU, and BU. They also give managerial implications to practitioners for SNS and SNG firms. Through this study, it is found that there exist significant interactions and dynamic relationships between those three endogenous variables. The results of this study can have meaningful implications for practitioners and researchers of SNG. This research is unique in that it deals with "actual" field data and intend to find "actual" relationships among variables unlike other related existing studies which intend to investigate psychological factors affecting the intention of game usage and the intention of purchasing game items. This study is also meaningful by showing that the increase of BU can be a good strategy for "killing birds with one stone" (i.e., revenue growth and NRU increase). Although there are some limitations related with future research topics, this research contributes to the current research on SNG marketing in the above mentioned ways.

The Korean Development Strategy: Trajectories of the Korean Economic Development, 1961~2010 (한국의 발전 전략: 한국 경제발전 궤적(1961~2010))

  • Jung, Sung-Hoon
    • Journal of the Economic Geographical Society of Korea
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    • v.14 no.4
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    • pp.453-466
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    • 2011
  • The main aim of this paper is to explore the Korean development strategy in the context of trajectories of the economic development from 1961 to 2010. The fast and high growth in the period of 1961 and 2010 resulted from the 'export-oriented industrialization' through a combination of 'mass production-mass exports' and '(relatively) high productivity-low wages' up to the late 1980s, a mixture of 'mass production-mass exports' and '(relatively) high productivity-high wages' to the late 1990s, and a combination of the reformation of public and private sectors for overcoming the Korean financial crisis and the gradual improvement of the marketization and social safety net since 2000. With respect to this model of development, the global and national modes of regulation were established. Along with the formation of endogenous forces (as the national mode of regulation), that of exogenous forces (as the global mode of regulation) are the important rules of the game at the global level, which lead and stabilize the process of accumulation by the export-led industrialization in Korea. In this respect, the establishment of global modes of regulation is led by exogenous forces such as trade regulations, exchange rates, global-Korean industrial relations, and global regulations of loans to developing countries. On the other hand, the national modes of regulation are formed by endogenous forces such as the triangular relationship of the state, capital and labor.

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Structural Equation Modeling of Health Promotion Behavior on Migrant Workers: A Multi-Group Analysis Based on the Period of Residence (외국인 근로자의 건강증진행위 구조모형: 거주기간별 다중집단분석)

  • Jeong, Hanna;Kim, Youngsuk
    • Journal of Korean Academy of Nursing
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    • v.54 no.1
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    • pp.73-92
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    • 2024
  • Purpose: This study developed and tested a hypothetical model of health promotion behavior on migrant workers based on the Health Promotion Model and the Health Literacy Skills Framework. Methods: Data were collected from 298 migrant workers in 9 regions across the country from December 2020 to March 2021. The exogenous variables were e-health literacy, occupational stress, acculturation, and social support. The endogenous variables were perceived benefits of action, self-efficacy, and health promotion behavior. Data were analyzed using SPSS/WIN 25.0, AMOS 20.0, and R-4.0.3 program. Results: The model fit was appropriate. Social support had the most significant direct impact on the health promotion behavior of migrant workers. Perceived benefits of action and self-efficacy played a mediating role in the relationship among e-health literacy, social support, and health promotion behavior. Based on multi-group analysis, the migrant worker group with less than 5 years of residency had a more statistically significant effect on the relationship between perceived benefits of action and health promotion behavior than those with over 5 years. Conclusion: Providing social support as a critical administrative strategy to enhance the health promotion behavior of migrant workers is necessary. Furthermore, when developing an intervention program utilizing the internal mechanism between social support and health promotion behavior, a self-efficacy-enhancing strategy is considered to be more effective. Additionally, educating migrant workers with short-term residence of less than 5 years about the benefits of health behaviors is essential.

Acquiring Vitellogenic Competence in the Rice Pest Nilaparvata lugens Stal: Effects of a Juvenile Hormone Analogue, Hydroprene

  • Pradeep A. R.;Nair V. S. K.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.10 no.2
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    • pp.137-141
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    • 2005
  • Though many insecticides are commercially available, development of resistance, pest resurgence and effects on non-target organisms led to the search for alternate insect pest management (IPM) strategy based on larval growth and reproductive fitness. Reproductive potential of insects depends on its acquiring of vitellogenic competence which is under hormonal control. Exogenous application of analogues of JR (JHAs) and ecdysterone could derail normal development and reproduction in insects by manipulating an array of physiological processes. In the rice pest, brown planthopper, Nilaparvata lugens, JHA, hydroprene induced metathetely from the fifth (final) instar nymphs in an age-dependent manner. Day 0 of the final instar showed highest sensitivity to induce this abnormal development. Adults emerged from treated day 3 nymphs looked normal. Both the morphotypes were reproductively incompetent and showed partial to complete sterility. Pre-adult exposure of the ovarian tissue to hydroprene suppressed mitotic division of germinal cells and induced abnormalities in the later s1ages of growth and differentiation of ovary in N. lugens. More over the nymphal exposure to hydroprene inhibited patency changes of follicular epithelium and affected competence of the follicles for yolk sequestration. In the absence of ovarian growth and oocyte differentiation, germarium found disintegrated, trophic core regressed and terminal oocytes resorbed. Hydroprene exposure to newly ecdysed brachypterous females did not affect ovarian development and egg production. Proper larval-adult transition appeared as a. prerequisite for vitellogenic competence in N. lugens for which the ovarian tissues must be exposed to ecdysterone in the internal milieu devoid of JH.

Genetic Transformation of Geobacillus kaustophilus HTA426 by Conjugative Transfer of Host-Mimicking Plasmids

  • Suzuki, Hirokazu;Yoshida, Ken-Ichi
    • Journal of Microbiology and Biotechnology
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    • v.22 no.9
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    • pp.1279-1287
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    • 2012
  • We established an efficient transformation method for thermophile Geobacillus kaustophilus HTA426 using conjugative transfer from Escherichia coli of host-mimicking plasmids that imitate DNA methylation of strain HTA426 to circumvent its DNA restriction barriers. Two conjugative plasmids, pSTE33T and pUCG18T, capable of shuttling between E. coli and Geobacillus spp., were constructed. The plasmids were first introduced into E. coli BR408, which expressed one inherent DNA methylase gene (dam) and two heterologous methylase genes from strain HTA426 (GK1380-GK1381 and GK0343-GK0344). The plasmids were then directly transferred from E. coli cells to strain HTA426 by conjugative transfer using pUB307 or pRK2013 as a helper plasmid. pUCG18T was introduced very efficiently (transfer efficiency, $10^{-5}-10^{-3}\;recipient^{-1}$). pSTE33T showed lower efficiency ($10^{-7}-10^{-6}\;recipient^{-1}$) but had a high copy number and high segregational stability. Methylase genes in the donor substantially affected the transfer efficiency, demonstrating that the host-mimicking strategy contributes to efficient transformation. The transformation method, along with the two distinguishing plasmids, increases the potential of G. kaustophilus HTA426 as a thermophilic host to be used in various applications and as a model for biological studies of this genus. Our results also demonstrate that conjugative transfer is a promising approach for introducing exogenous DNA into thermophiles.

An Empirical Study of the Factors Influencing the Task Performances of SaaS Users

  • Park, Sung Bum;Lee, Sangwon;Chae, Seong Wook;Zo, Hangjung
    • Asia pacific journal of information systems
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    • v.25 no.2
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    • pp.265-288
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    • 2015
  • IT convergence services, as the main stream of the digital age, are currently on their way to include the concept of Software as a Service (SaaS), where IT products and services are integrated as one. In particular, the recently introduced web-service-based SaaS is expected to be a more developed SaaS model. This new model provides greater influence on clients' job performances than its previous models, such as application service providers and the web-native phase. However, the effects of technology maturity on task performance have been overlooked in adoption and performance studies. Accordingly, this study introduces SaaS technology maturity as the exogenous technological characteristic influencing job performance. This study also examines the relationships among various SaaS-related performances according to the different levels of SaaS maturity. Results suggest that applying innovative technologies (such as SaaS), particularly when the technology reaches a certain level of maturity, is more helpful for managers in improving task-technology fit and job performance. This study makes an academic contribution by establishing and validating a performance model empirically with SaaS technology maturity perspectives.

A Predictive Model of Quality of Life for Stomach Cancer Patients with Gastrectomy (위암수술 환자의 삶의 질 예측모형 구축)

  • Kim, Young Suk;Tae, Young Sook
    • Korean Journal of Adult Nursing
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    • v.27 no.6
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    • pp.613-623
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    • 2015
  • Purpose: This study was designed to construct a predictive model to explain quality of life of stomach cancer patients with gastrectomy. Methods: Data were collected from July 10 to August 30, 2013 through survey using self-reported questionnaires. A total of 218 patients with gastrectomy was recruited from three different hospitals. Outcome variables were exogenous ones (self efficacy and social support) and endogenous ones (depression, perceived health status, self care behavior, and quality of life). Results: Goodness-of-fit of the hypothetical model was $x^2=143.37$, RMSEA=.07 CFI=.95, TLI=.93 SRMR=.05. Self care behavior, depression and perceived health status had significant direct effects on quality of life. Self efficacy and social support were affected quality of life indirectly. These variables explained 67.9% of total variance of quality of life, and self-care behavior was the most influential factor for quality of life. Conclusion: The findings of this study suggested that self care behavior must be considered as an intervention strategy to improve quality of life. Also a development of a specific intervention program to promote self efficacy and control depression for patients with gastrectomy is essential to facilitate their self care behaviors.

Orientation of Youth towards Social Entrepreneurship: An Empirical Study from Pakistan

  • ZUBAIR, Syed Sohaib;AYOOB, Ifrah;ALI, Kashif;KHAN, Mukaram Ali;AZAD, Muhammad;ZEESHAN, Muhammad
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.9
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    • pp.67-77
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    • 2021
  • The importance of Entrepreneurship has been widely acknowledged by researchers and practitioners worldwide, however, the idea of Social Entrepreneurship is still considered to be an emerging area. Entrepreneurship is vital not only because of its economic impacts but also because it helps to address issues of poverty and welfare, where it can act as a catalyst for change. The importance of social entrepreneurship is that it serves to turn a profit and find success while helping others throughout the world. They know the power of social enterprise and are eager to serve the societal and economic benefits. This study aims to identify the level of orientation of youth towards social entrepreneurship in Pakistan. The study identifies the role of various factors that affect Social Entrepreneurial Orientation and is conducted following a quantitative research strategy and survey research design where data is collected from 302 individuals. Structural Equation Modelling was used to analyze the data and to test the hypotheses. The main finding of this research is that there is an increasing trend in the orientation towards social entrepreneurship. The exogenous variables namely Perceived Educational Support, Perceived Structural Support, and Perceived Relational Support were found to have positive and significant effects on the endogenous construct of Social Entrepreneurial Orientation.

A Study on Resolutions of Manpower shortage problems in Small and Mid-Sized Manufacturing Firms -Focused on the Era of Incheon and Siheung- (중소제조업의 인력 부족 해소방안을 위한 연구 -인천과시흥지역을 중심으로-)

  • Choi, Byung Woo;Yoon, Do Youl
    • Journal of Industrial Convergence
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    • v.1 no.1
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    • pp.159-169
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    • 2003
  • In the 21st century, a time for smaller companies is fast approaching. A lot of people believe that the small and mid-sized companies will be a main force for industry. However, this concept could only be possible after we find some solutions for the general, labor shortage problem. Specifically, the majority of these challenges stem from improper distribution of labor within each company's divisions. These labor shortages have been influenced by a variety of exogenous (human) variables. The sources of the most serious problems come from the lack of appropriate labor and their fair wages. The work environment is also a contributing factor. These items are considered to be serious challenges to the development of smaller enterprises. The purpose of this study is to explore these difficulties. For solving the labor shortage, enterprises and government should offer employees supportive benefits. Enterprise companies should make an effort to improve their work environments. Companies should also use innovative strategies to raise labor compensation. With this in mind, smaller firms should struggle to retain their employees for an extended period of time and commit to an organizational business strategy. Governments should try to develop a higher recognition of smaller enterprises. They should create human power recruitment, development, and recourse policies as needed. Furthermore, they should manipulate existing policies to support human resource development that aids these companies to be more competitive with larger ones. Additionally, it is necessary to develop new, creative programs to help with the social recognition of smaller enterprises.

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