• BMB Reports
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• v.40 no.4
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• pp.475-485
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• 2007

Methamphetamine is an illicit drug that is often abused and can cause neuropsychiatric and neurotoxic damage. Repeated administration of psychostimulants such as methamphetamine induces a behavioral sensitization. According to a previous study, Bax was involved in neurotoxicity by methamphetamine, but the function of Bax in rewarding effect has not yet been elucidated. Therefore, we have studied the function of Bax in a rewarding effect model. In the present study, we treated chronic methamphetamine exposure in a Bax-deficient mouse model and examined behavioral change using a conditioned place preference (CPP) test. The CPP score in Bax knockout mice was decreased compared to that of wild-type mice. Therefore, we screened for Bax-related genes that are involved in rewarding effect using microarray technology. In order to confirm microarray data, we applied the RT-PCR method to observe relative changes of Bcl2, a pro-apoptotic family gene. As a result, using our experiment microarray, we selected genes that were associated with Bax in microarray data, and eventually selected the Tgfbr2 gene. Expression of the Tgfbr2 gene was decreased by methamphetamine in Bax knockout mice, and the gene was overexpressed in Bax wild-type mice. Additionally, we confirmed that Creb, FosB, and c-Fos were related to rewarding effect and Bax using immunohistochemistry.

• Molecules and Cells
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• v.26 no.2
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• pp.121-130
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• 2008

Methamphetamine, a commonly used addictive drug, is a powerful addictive stimulant that dramatically affects the CNS. Repeated METH administration leads to a rewarding effect in a state of addiction that includes sensitization, dependence, and other phenomena. It is well known that susceptibility to the development of addiction is influenced by sources of reinforcement, variable neuroadaptive mechanisms, and neurochemical changes that together lead to altered homeostasis of the brain reward system. These behavioral abnormalities reflect neuroadaptive changes in signal transduction function and cellular gene expression produced by repeated drug exposure. To provide a better understanding of addiction and the mechanism of the rewarding effect, it is important to identify related genes. In the present study, we performed gene expression profiling using microarray analysis in a reward effect animal model. We also investigated gene expression in four important regions of the brain, the nucleus accumbens, striatum, hippocampus, and cingulated cortex, and analyzed the data by two clustering methods. Genes related to signaling pathways including G-protein-coupled receptor-related pathways predominated among the identified genes. The genes identified in our study may contribute to the development of a gene modeling network for methamphetamine addiction.

• Journal of the Korea Society of Computer and Information
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• v.22 no.11
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• pp.151-160
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• 2017

IIn this paper, I investigate the effect of special education teachers' self-leadership on job-satisfaction. The data was collected from 141 special education teachers to analyze the correlations between self-leadership, job and life satisfaction. In addition, another purpose is to analyze how self-leadership influence on job satisfaction (human relationship, assigned tasks) and life satisfaction. The results are shown as follows. First, self-expectation and goal setting, self-expectation and human relationship, human relationship and assigned tasks have meaningful correlation. Second, self-expectation and self-rewarding are sub-factors of self-leadership that have great influence on human relationship which is a subordinate factor of job satisfaction and assigned tasks. Third, self-expectation and self-rewarding are factors of self-leadership that have a great influence on life satisfaction. Finally, it shows that self-leadership has an effect on life satisfaction through assigned task, which is a factor of job satisfaction. However, through human relationship, self-leadership does not have a meaningful effect on life satisfaction. This study is significant by finding sub-factors which influence special education teacher's self leadership, job satisfaction and life satisfaction by using Bootstrap method.

• Biomolecules & Therapeutics
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• v.18 no.2
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• pp.125-134
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• 2010

Bisphenol A (BPA) is one of the most common endocrine disrupters. In the last decade, the number of studies concerning the effects of chronic treatment with BPA on the development of the central nervous system (CNS) has increased. However, little is known about the effects of chronic exposure to BPA on higher brain functions such as memory or psychomotor functions. Here, we report our following findings: (1) Prenatal and neonatal exposure to BPA enhances psychostimulant-induced rewarding effects, results in the up- or downregulation of dopamine receptors, causes memory impairment, and decreases choline acetyltransferase (ChAT) activity. (2) BPA activates astrocytes in vivo and in vitro. These findings suggest that prenatal and neonatal exposure to BPA affects the development of the CNS.

• Proceedings of the PSK Conference
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• 2003.10a
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• pp.112-112
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• 2003

Morphine is a potent analgesic and addictive substance. Morphine produces neurotoxicity such as rewarding effect, analgesic tolerance and physical dependence. It has been restricted to the use of morphine in patients because of these problems. The present study was investigated the effect of berberine on the neurotoxicity of morphine. Repeated administration of morphine produced conditioned place prefernece (CPP) and behavioral sensitization in mice. (omitted)

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.226-229
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• 2001

Owing to handset subsidies, large growth in the Korean mobile telephony subscribers has occurred. While most of firms create artificial switching costs by rewarding customers for repeated purchases to retain their customers, mobile telephone carriers discriminate against loyal customers through handset subsidies. This article examines the effect of switching cost on the prices and profits in a two-period, differentiated product duopoly model.

• Asian Journal of Innovation and Policy
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• v.11 no.3
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• pp.363-396
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• 2022

This study focuses on the happiness of the generation MZ of innovative enterprises, which are evaluated as the driving force of economic growth at a time when the value of happiness is emerging. Happiness is related to the prosperity and performance of the organization. However, MZ generation office workers, who account for 45% of the economically active population, are considered unhappy at work. Therefore, this study attempted to explore the preceding factors (organizational factors, relationship and communication factors, and personal factors) of happiness for the generation MZ of innovative enterprises and to examine the effect of happiness on employee engagement. For the study, 300 usable responses were collected from generation MZ working in innovative enterprises through an online survey. Research hypotheses and research questions were verified using SPSS 26.0 and AMOS 23.0. As a result, it was confirmed that procedural justice among the organizational factors, rewarding co-worker/supervisor relationship among the relationship/communication factors, and personal factors (meaningfulness of work, personal accomplishment) positively affected the MZ generation's workplace happiness. In particular, the meaningfulness of work, which corresponds to personal factors, exerted the most significant influence. In addition, in the case of happiness at the workplace, there was a positive effect on employee engagement, which was stronger in organizational engagement than in job engagement. As a result of examining the structural relationship between variables used in the study, it was found that procedural justice, rewarding co-worker/supervisor relationships, the meaningfulness of work, and personal accomplishment positively affected employee engagement through happiness. Through research, the importance of happiness at the workplace was suggested by systematically reviewing the preceding variables of happiness at the workplace and grasping the positive effects of happiness. In addition, the management measure of generation MZ employees of innovative enterprises was discussed, the necessity of research on happiness at the workplace was emphasized, and follow-up studies were proposed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48
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• pp.65-71
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• 2003

Sesame seed are one of the oldest oil-bearing crops known to man. Not only are they nutritious, they are physicologically beneficial. Because of these properties, the promotion of sesame as a crop is set to increase from now on. The lignan component of sesame, which has an antioxidative function, varies considerably. In addition, the seeds remain viable for longer than other crops. At low temperature, it has been reported that the seed remain viable for up to thirty years. This is due to the lignan content of the seeds. In the last twenty years, the mysteries of the natural chemistry of sesame seeds have been unravelled one by one. Up to now, the lignan component has been found to have an $\alpha$-tocopherol synergist effect, an anti-aging effect, a cancer suppressing effect, a hypertension reduction effect, an effect on the promotion of liver function, an effect on the control of the ration of unsaturated fat, and an effect on the synthesis of unsaturated fatty acids. The lignan component of sesame does not simply have an anti-oxidant function, but has diverse recently discovered physiological uses which make the study of lignan highly rewarding.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.197-208
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• 2016

The study showed that directional Shared Leadership and transformational Shared Leadership positively influences the relationship between Shared Leadership and interpersonal relationships in the view of organizational wellbeing. In addition, in the relationship between Shared Leadership and rewarding job experience of organizational wellbeing, three leadership types excluding directional Shared Leadership had positive effects. In addition, transformational Shared Leadership and empowering Shared Leadership had a positive impact on the relationship between Shared Leadership and organizational mood of organizational wellbeing. In the relationship between Shared Leadership and a sense of fulfillment in the view of organizational wellbeing, transformational Shared Leadership only had a positive effect. As is the case with the sense of fulfillment, the transformational Shared Leadership, of and itself, positively influenced the relationship between Shared Leadership and leisure of life of organizational wellbeing. A analysis of the study showed that transformational Shared Leadership has an impact on both organizational wellbeing and personal wellbeing. Transformational Shared Leadership helps set up mutual vision or strategies, or to challenge each other to enhance existing processes and procedures. On the other hand, directional Shared Leadership influences the interpersonal relations only, whereas transactional Shared Leadership impacts rewarding job experience only. Presenting clearer ideas on what to do to each other and sharing the reward for performance implies that the members of an organization can feel much more rewarded through job engagement.

• Journal of Pharmacopuncture
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• v.23 no.1
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• pp.1-7
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• 2020

Nicotine, primary component of tobaco produces craving and withdrawal effect both in humans and animals. Nicotine shows a close resemblance to other addictive drugs in molecular, neuroanatomical and pharmacological, particularly the drugs which enhances the cognitive functions. Nicotine mainly shows its action through specific nicotinic acetylcholine receptors located in brain. It stimulates presynaptic acetylcholine receptors thereby enhancing Ach release and metabolism. Dopaminergic system is also stimulated by it, thus increasing the concentration of dopamine in nuclear accumbens. This property of nicotine according to various researchers is responsible for reinforcing behavioral change and dependence of nicotine. Various researchers have also depicted that some non dopaminergic systems are also involved for rewarding effect of nicotinic withdrawal. Neurological systems such as GABAergic, serotonergic, noradrenergic, and brain stem cholinergic may also be involved to mediate the actions of nicotine. Further, the neurobiological pathway to nicotine dependence might perhaps be appropriate to the attachment of nicotine to nicotinic acetylcholine receptors, peruse by stimulation of dopaminergic system and activation of general pharmacological changes that might be responsible for nicotine addiction. It is also suggested that MAO A and B both are restrained by nicotine. This enzyme helps in degradation dopamine, which is mainly responsible for nicotinic actions and dependence. Various questions remain uninsurable to nicotine mechanism and require more research. Also, various genetic methods united with modern instrumental analysis might result for more authentic information for nicotine addiction.