• Animal cells and systems
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• v.1 no.2
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• pp.363-370
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• 1997

RNase MRP is a ribonucleoprotein complex with a site-specific endonuclease activity. Its original substrate for cleavage is the small mitochondrial RNA near the mitochondrial DNA replication origin, thus it was proposed to generate the primer for mtDNA replication. Recently, it has been shown to have another substrate in the nucleus, such as pre-S.8S ribosomal RNA in nucleolus. The gene for the RNA component of RNase MRP (MRP RNA) was found to be encoded by the nucleus genome, suggesting an interesting intracellular trafficking of MRP RNA to both mitochondria and nucleolus after transcription in nucleus. In this study, genomic DNA encoding MRP RNA was microinjected into the nucleus of Xenopus oocytes, to analyze promoter regions involved in the transcription. It showed that the proximal sequence element and TATA box are important for basal level transcription; octamer motif and Sp1 binding sites are for elevated level transcription. Most of Xenopus MRP RNA was exported out to the cytoplasm following transcription in the nucleus. Utilizing various hybrid constructs, export of MRP RNA was found to be regulated by the promoter and the 5' half of the coding region of the gene. Interestingly, the transcription in nucleus seems to be coupled to the export of MRP RNA to cytoplasm. Intracellular transport of injected MRP RNA can be easily visualized by whole-mount in situ hybridization following microinjection; it also shows possible intra-nuclear sites for transcription and export of MRP RNA.

• Ocean Science Journal
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• v.43 no.1
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• pp.39-48
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• 2008

Tritium ($^3H$ or T) has been produced mostly by atmospheric nuclear weapon tests, and entered the ocean in the form of water (HTO). As tritium exists as water itself, it has been regarded as an ideal tool to study the transport of water masses. In April 2001 we collected water samples in the western Japan Basin (WJB) for tritium and helium measurement. The timely sampling provided direct evidence of the bottom water formation, resulting in the drastic increase in tritium concentration from 0.3 TU in 2000 to 0.67 TU in 2001. Considering that the new bottom waters were found mostly in the WJB, it implies that maximum 1% of the whole bottom layer below 2600 m should be replaced with the surface water during the severely cold winter 2000 2001. $^3H-^3He$ age, showing the elapsed time since the water left from the surface, can be used to calculate oxygen utilization rate by dividing AOU by the age. Under the condition of 90% oxygen saturation in the surface water, the integration of OUR in the water column below 200 m yields net oxygen consumption of 12 mol $(O_2)m^{-2}yr^{-1}$, which corresponds to the export production of $99\;g\;C\;m^{-2}yr^{-1}$. This estimate is comparable to a previous estimate based on satellite data and implies that the ratio of export to primary production(f-ratio) is as high as 0.5 in the WJB.

• BMB Reports
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• v.56 no.9
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• pp.514-519
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• 2023

Methyltransferase-like 3 (METTL3), a key component of the m⁶A methyltransferase complex, regulates the splicing, nuclear transport, stability, and translation of its target genes. However, the mechanism underlying the regulation of METTL3 expression by alternative splicing (AS) remains unknown. We analyzed the expression pattern of METTL3 after AS in human tissues and confirmed the expression of an isoform retaining introns 8 and 9 (METTL3-IR). We confirmed the different intracellular localizations of METTL3-IR and METTL3 proteins using immunofluorescence microscopy. Furthermore, the endogenous expression of METTL3-IR at the protein level was different from that at the mRNA level. We found that 3'-UTR generation by intron retention (IR) inhibited the export of METTL3-IR mRNA to the cytoplasm, which in turn suppressed protein expression. To the best of our knowledge, this is the first study to confirm the regulation of METTL3 gene expression by AS, providing evidence that the suppression of METTL3 protein expression by IR is an integral part of the mechanism by which 3'-UTR generation regulates protein expression via inhibition of RNA export to the cytoplasm.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.50
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• pp.215-250
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• 2011

Korean won overseas construction projects worth 71.6 billion US Dollars in 2010, which exceeded that of 2009 by 45.6%. An overseas construction project is a transaction of large scale, long term project, many parties participating, deferred payment, and of high-technology. It contributes to foreign currency earning, and also leads the nation's export restructuring work towards high value-added one. There are various kinds of risks towards the relevant parties respectively, which are key elements in successfully performing the overseas construction project. There are completion risk, financing risk, operating risk, revenue risk etc, in an employer's place. A contractor may be confronted with payment risk, issuance risk of performance bond, financing risk, performance risk of sub-contractors, and exchange rate risk. In lenders place there are repayment risk, completion risk, and political risk in the host country. In order to mitigate risks, the parties shall take relevant measures or require relevant securities. A contractor needs to evaluate the credibility of an employer in respect of payment risk, and can also request export insurance cover by the Korea Trade Insurance Corporation(the former 'Korea Export Insurance Corporation"). An employer can require a contractor to provide performance bond in respect of completion risk, and employ a well-known first class bank as a mandated arranger to arrange financing with regard to completion risk. Lenders needs to evaluate the credibility of an employer and accomplish feasibility study of the project. Lenders can request insurance cover from export credit agency. Once the parties assess the respective risks and obtain relevant securities, the project will be successfully completed. The success of the project will be sure to bring the parties involved enormous profits and another opportunity to participate in overseas construction project afterwards.

• Korean Journal of Microbiology
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• v.51 no.4
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• pp.435-439
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• 2015

THO/TREX complex plays an important role in transcriptional elongation, mRNA processing, nuclear RNA export, and genome stability. A fission yeast, Schizosaccharomyces pombe, SPBC577.04 gene encoding the ortholog of THOC5, a component of THO/TREX complex, was identified and characterized. The S. pombe thoc5 (spthoc5) is not essential for both growth and mRNA export, but deletion of the spthoc5 gene caused growth defect and slight accumulation of $poly(A)^+$ RNA in the nucleus. And the functional spThoc5-GFP protein is localized mainly in the nucleus. Co-immunoprecipitation analysis showed that the Hpr1(THOC1) protein, an evolutionally well-conserved component of THO/TREX complex, interacted with spThoc5 as well as Tho2(THOC2), another subunit of THO complex. These results suggest that S. pombe Thoc5 as a component of THO/TREX complex is also involved in mRNA export from the nucleus.

• Journal of Technology Innovation
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• v.12 no.1
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• pp.271-285
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• 2004

The purpose of this paper is an application of AHP in the problem of exportable nuclear technology selection based on data gathered from nuclear experts. In this paper, the decision criteria for evaluating export competitiveness of nuclear technologies are identified and the hierarchical structure of decision making process is developed systematically. Subsequently the values of weights for relative importance among decision criteria are derived using AHP methodology, and the score of importance of nuclear technologies with respect to each criterion is evaluated. Finally the score indicating exportability of each nuclear technology is quantified in order to prioritize then. We discuss implications of our results with a viewpoint of national nuclear technology policy.

• Journal of Life Science
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• v.7 no.3
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• pp.161-166
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• 1997

HIV-1 Rev protein plays an important role in regulating the expression of viral structural proteins. It allows the nuclear export and accumulation of unspliced and partially spliced viral mRNA in the cytoplasm. The Rev-responsive element RNA, present in the env gene, forms a higly ordered RNA secondary structure and is required for the Rev-mediated mRNA export. For this process to complete factor(s) are strongly suggested. From our experiments of electrophoretic mobility shift, UV-crosslinking and SDS/PAGE, RRE RNA was found to be recognized to several nuclear factors such as 36/37, 56, 41. 76, 150 kD proteins in the order of reactivity. Among them, 36/37 and 56 kD proteins are more reactive upon a brief UV treatment (5 min) and more persistent in the presence of high amount of nonspecific competitor, heparin. Certain nuclear protein9s) seemed to recognize the RRE RNA structure in competition with Rev to gel mobility shift assay.

• Journal of Intelligence and Information Systems
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• v.20 no.3
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• pp.109-131
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• 2014

As the demand of nuclear power plant equipment is continuously growing worldwide, the importance of handling nuclear strategic materials is also increasing. While the number of cases submitted for the exports of nuclear-power commodity and technology is dramatically increasing, preadjudication (or prescreening to be simple) of strategic materials has been done so far by experts of a long-time experience and extensive field knowledge. However, there is severe shortage of experts in this domain, not to mention that it takes a long time to develop an expert. Because human experts must manually evaluate all the documents submitted for export permission, the current practice of nuclear material export is neither time-efficient nor cost-effective. Toward alleviating the problem of relying on costly human experts only, our research proposes a new system designed to help field experts make their decisions more effectively and efficiently. The proposed system is built upon case-based reasoning, which in essence extracts key features from the existing cases, compares the features with the features of a new case, and derives a solution for the new case by referencing similar cases and their solutions. Our research proposes a framework of case-based reasoning system, designs a case-based reasoning system for the control of nuclear material exports, and evaluates the performance of alternative keyword extraction methods (full automatic, full manual, and semi-automatic). A keyword extraction method is an essential component of the case-based reasoning system as it is used to extract key features of the cases. The full automatic method was conducted using TF-IDF, which is a widely used de facto standard method for representative keyword extraction in text mining. TF (Term Frequency) is based on the frequency count of the term within a document, showing how important the term is within a document while IDF (Inverted Document Frequency) is based on the infrequency of the term within a document set, showing how uniquely the term represents the document. The results show that the semi-automatic approach, which is based on the collaboration of machine and human, is the most effective solution regardless of whether the human is a field expert or a student who majors in nuclear engineering. Moreover, we propose a new approach of computing nuclear document similarity along with a new framework of document analysis. The proposed algorithm of nuclear document similarity considers both document-to-document similarity (${\alpha}$) and document-to-nuclear system similarity (${\beta}$), in order to derive the final score (${\gamma}$) for the decision of whether the presented case is of strategic material or not. The final score (${\gamma}$) represents a document similarity between the past cases and the new case. The score is induced by not only exploiting conventional TF-IDF, but utilizing a nuclear system similarity score, which takes the context of nuclear system domain into account. Finally, the system retrieves top-3 documents stored in the case base that are considered as the most similar cases with regard to the new case, and provides them with the degree of credibility. With this final score and the credibility score, it becomes easier for a user to see which documents in the case base are more worthy of looking up so that the user can make a proper decision with relatively lower cost. The evaluation of the system has been conducted by developing a prototype and testing with field data. The system workflows and outcomes have been verified by the field experts. This research is expected to contribute the growth of knowledge service industry by proposing a new system that can effectively reduce the burden of relying on costly human experts for the export control of nuclear materials and that can be considered as a meaningful example of knowledge service application.

• Nuclear industry
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• v.37 no.8
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• pp.21-23
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• 2017

최근까지 건실한 내수 시장 구축을 구축하고 수출 시장 일선에서 성과를 거둔 원자력산업의 성공 신화는 대한민국의 자부심이었다. 하지만 문재인 대통령의 탈원전 정책은 대한민국 원자력산업계의 전망을 어둡게 하고 있다. 이러한 정책은 대한민국 원자력산업계의 신뢰성와 역량, 그리고 가능성을 해치며 원전 기술 수출 가능성을 낮출 것이다. 탈원전 정책은 신고리 5,6호기 건설 중단에서 드러났듯이 대한민국 정부와 원전 사업자 간 혼란을 야기할 수 있다. 이러한 조건에서 러시아와 중국을 비롯한 강력한 경쟁자를 상대로 기존의 'Team Korea'가 보여주었던 탁월한 협력이 가능할지 의문이 들 수밖에 없다.

• Journal of the Korean Institute of Intelligent Systems
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• v.7 no.1
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• pp.27-33
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• 1997

This project is dedicated to the elaboration of a man-machine system for monitoring the non spread of nuclear weapons, technologies, raw materials. The main purpose of such a system depends on the customer requirements and may be : - control of non proliferation of nuclear technologies, especially those that can be used to manufacture a nuclear explosive device; - the appraisal of the possibility of production of nuclear weapons by a certain country on the basic of its intellectual and scientific-technical potential, its raw material resources, its export-import potential and other parameters.