• Title/Summary/Keyword: endogenous development

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PIF4 Integrates Multiple Environmental and Hormonal Signals for Plant Growth Regulation in Arabidopsis

  • Choi, Hyunmo;Oh, Eunkyoo
    • Molecules and Cells
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    • v.39 no.8
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    • pp.587-593
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    • 2016
  • As sessile organisms, plants must be able to adapt to the environment. Plants respond to the environment by adjusting their growth and development, which is mediated by sophisticated signaling networks that integrate multiple environmental and endogenous signals. Recently, increasing evidence has shown that a bHLH transcription factor PIF4 plays a major role in the multiple signal integration for plant growth regulation. PIF4 is a positive regulator in cell elongation and its activity is regulated by various environmental signals, including light and temperature, and hormonal signals, including auxin, gibberellic acid and brassinosteroid, both transcriptionally and post-translationally. Moreover, recent studies have shown that the circadian clock and metabolic status regulate endogenous PIF4 level. The PIF4 transcription factor cooperatively regulates the target genes involved in cell elongation with hormone-regulated transcription factors. Therefore, PIF4 is a key integrator of multiple signaling pathways, which optimizes growth in the environment. This review will discuss our current understanding of the PIF4-mediated signaling networks that control plant growth.

Studies on Mechanism of Antidiuretic Action of N$_G$ Nitro-L-Arginine, Nitric Oxide Synthase Inhibitor, in Dog (Nitric Oxide의 합성 억제제인 N$_G$-Nitro-L-Arginine의 항이뇨작용 기전에 관한 연구)

  • 고석태;유강준
    • Biomolecules & Therapeutics
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    • v.6 no.3
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    • pp.225-231
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    • 1998
  • This studies were performed for investigation of mechanism on central antidiuretic action of L$_{G}$-Nitro-L-arginine (L-NOARG), nitic oxide systhase inhibitor, in dog. Antidiuretic action of L-NOARG infused into the carotid artery was not affected by renal denervation but inhibited by pretreatment with arginine, NO Precusor. Furthermore, L-NOARG inhibited the diuretic action of dopamine induced by hemodynamic development. Above results suggest that antidiuretic actions of L-NOARG mediated by endogenous substances not associated with renal nerve. Therefore, it is demonstrated that those endogenous substances might be associated with NO which mediate the diuretic action of dopamine.e.

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Crosstalk between RNA silencing and RNA quality control in plants

  • Yun Ju Kim
    • BMB Reports
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    • v.56 no.6
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    • pp.321-325
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    • 2023
  • RNAs are pivotal molecules acting as messengers of genetic information and regulatory molecules for cellular development and survival. From birth to death, RNAs face constant cellular decision for the precise control of cellular function and activity. Most eukaryotic cells employ conserved machineries for RNA decay including RNA silencing and RNA quality control (RQC). In plants, RQC monitors endogenous RNAs and degrades aberrant and dysfunctional species, whereas RNA silencing promotes RNA degradation to repress the expression of selected endogenous RNAs or exogenous RNA derived from transgenes and virus. Interestingly, emerging evidences have indicated that RQC and RNA silencing interact with each by sharing target RNAs and regulatory components. Such interaction should be tightly organized for proper cellular survival. However, it is still elusive that how each machinery specifically recognizes target RNAs. In this review, we summarize recent advances on RNA silencing and RQC pathway and discuss potential mechanisms underlying the interaction between the two machineries.

Can the Evolutionary Economics Solve the Walras' Trap? (진화주의 기술경제학과 '왈라스 함정')

  • Kim, Tae-Eok
    • Journal of Technology Innovation
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    • v.13 no.1
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    • pp.213-246
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    • 2005
  • Despite of the impressive progress made in the Evolutionary techno-economics during the last two decades, there have been very little, if not at all, theoretical advancement in explaining an endogenous mechanism of transforming a technological paradigm within self-perpetuatingstructural dynamics. The question poorly attempted was raised by Schumpeter a century ago in his effort to overcome the well-known 'Walras' trap'. Although there have been increasing number of researchers recently tackling the issue quite seriously from within the Evolutionary school, I see it that radical reconstruction of the basic principle of Evolutionary research framework is urgently needed to solve the century long fundamental question, from evolutionary approach to transformational approach. In the paper, I will show the theoretical feasibility of explaining an endogenous mechanism of paradigm transformation, relying upon the concept of localized dynamics and the concept of morphogenetic structuration. It should be emphasized that there must be aendogenous process of deepening structural Instability generated in the process of economic coordination to secure efficient circular flow. The concept of development bottleneck initiated by the Baumol's cost disease could be regarded as one of the important source of such mechanism. Unfortunately, however, it is a brief conceptual description presented in the paper rather than a comprehensive analytical model, due to the space limitation imposed.

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A Critique of Conventional Nonmarket Valuation - Attitudes and Action - (비시장 가치평가에 대한 비판적 고찰 - 선택행동과 심리변수에 대해서 -)

  • Choi, Andy Sungnok;Bennett, Jeff
    • Environmental and Resource Economics Review
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    • v.15 no.5
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    • pp.885-919
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    • 2006
  • This paper revisits two conventional beliefs of environmental nonmarket valuation and examines their weaknesses and a new opportunity. The two beliefs are that willingness to pay (WTP) is an appropriate measure of nonmarket behaviour and that exogenous variables are relevant predictors of WTP whilst endogenous variables are not. The contemporary literature in psychology and economics is reviewed to demonstrate departures from these two beliefs. Tackling heterogeneity in stated preferences, both socio-demographic and psychological variables should be measured simultaneously to explain and predict choice behaviours more accurately.

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Molecular Signalling Mechanisms Involved in the Development of Fertilizing Capacity by Mammalian Spermatozoa

  • Jones, Roy
    • Korean Journal of Animal Reproduction
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    • v.23 no.4
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    • pp.353-358
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    • 1999
  • Four important attributes for successful fertilization by a spermatozoon are (ⅰ) correct morphology, (ⅱ) correct presentation of egg recognition and fusion molecules, (ⅲ) progressive motility and (ⅳ), correct transfer of signalling molecules from sperm to egg for activation of development. In this presentation, these topics will be described and illustrated with emphasis on the endogenous control mechanisms that enable spermatozoa to respond to external signals. (omitted)

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Can Religion Save Our Health?: Quasi-Experimental Evidence from the U.S.

  • PARK, YOON SOO
    • KDI Journal of Economic Policy
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    • v.40 no.1
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    • pp.31-43
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    • 2018
  • There is a large amount of empirical literature reporting that people who regularly attend religious services tend to have better health outcomes. However, it remains an unanswered question as to whether the observed correlation reflects any causality. Exploiting exogenous changes in church attendance driven by law changes in 21 states of the U.S., I find tentative but suggestive evidence that the observed strong correlation between religious participation and health is likely to be driven by endogenous selection.

Issues and Methodological Status of System Dynamics (시스템다이내믹스의 발전과 방법론적 위상)

  • 문태훈
    • Korean System Dynamics Review
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    • v.3 no.1
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    • pp.61-77
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    • 2002
  • This paper reviews issues and methodological status of system dynamics and suggest some research agenda for its development in Korea. After reviewing some characteristics of system dynamics approach, including dynamic feedback perspective and endogenous point of view, the paper pointed out methodological characteristics of system dynamics. It seems to be the most notable characteristics of System Dynamics that it use both quantitative and qualitative approach in explaining and modelling reality. Besides, System Dynamicists rely more heavily on refutationism than instrumentalism and this allows System Dynamicists follow more strict way of scientific inquiry. For the development of System Dynamics in Korean academic circle, developing training program and curriculum, networking scattered System Dynamicist all over the country, would be the most important task.

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Regulation of Notch1/NICD and Hes1 Expressions by GSK-3α/β

  • Jin, Yun Hye;Kim, Hangun;Oh, Minsoo;Ki, Hyunkyung;Kim, Kwonseop
    • Molecules and Cells
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    • v.27 no.1
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    • pp.15-19
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    • 2009
  • Notch signaling is controlled at multiple levels. In particular, stabilized Notch receptor activation directly affects the transcriptional activations of Notch target genes. Although some progress has been made in terms of defining the regulatory mechanism that alters Notch stability, it has not been determined whether Notch1/NICD stability is regulated by $GSK-3{\alpha}$. Here, we show that Notch1/NICD levels are significantly regulated by $GSK-3{\beta}$ and by $GSK-3{\alpha}$. Treatment with LiCl (a specific GSK-3 inhibitor) or the overexpression of the kinase-inactive forms of $GSK-3{\alpha}/{\beta}$ significantly increased Notch1/NICD levels. Endogenous NICD levels were also increased by either $GSK-3{\alpha}/{\beta}$- or $GSK-3{\alpha}$-specific siRNA. Furthermore, it was found that $GSK-3{\alpha}$ binds to Notch1. Deletion analysis showed that at least three Thr residues in Notch1 (Thr-1851, 2123, and 2125) are critical for its response to LiCl, which increased not only the transcriptional activity of endogenous NICD but also Hes1 mRNA levels. Taken together, our results indicate that $GSK-3{\alpha}$ is a negative regulator of Notch1/NICD.