1,720,978 research outputs found
Influence of process parameters on three-dimensional surface coloring
No full text학위논문(석사) - 한국과학기술원 : 기계공학전공, 2005.2, [ x, 88 p. ]산업에서 시작품의 실감재현을 위한 3차원 칼라링 기술이 필요하다. 그러나 기존의 3차원 표면에 칼라를 재현하는 기술은 다른 시작품에 채색할 수 없으며 시간과 비용이 많이 소요된다. 본 연구에서는 잉크젯 헤드를 이용하여 3차원 표면에 채색을 하는 새로운 공정을 제안한다. 공정 개발을 위해 잉크젯 헤드와 기울어진 면사이의 거리와 각도에 따른 인쇄 특성에 대한 실험을 수행하였다. 실험 결과 공정 변수에 따라 인쇄 오차를 최소화할 수 있는 보정 행렬을 제안하고 검증하였다. 곡면에 대한 프린트 특성을 알아보기 위해 선곡면에 대한 실험을 수행하였으며 3차원 곡면 인쇄를 위해 곡률에 따른 단속 거리와 각도를 제안하였다. 이러한 개념은 곡면에서 오차 범위내에 드는 몇 개의 단속적인 분할을 수행하여 분할 곡면을 기울어진 면으로 근사하여 보정 행렬에 따라 이미지를 왜곡하는 것이다. 최종적으로 헬멧 표면에 일반적인 이미지 프린팅 실험을 수행하여 본 연구의 실용성 검증할 수 있었다.한국과학기술원 : 기계공학전공
Control of APC-Cdc20 by the tumor suppressor RASSF1A
No full textThe tumor suppressor gene RASSF1A is frequently hypermethylated in various tumors. However, how RASSF1A functions in tumor suppression was unknown. Our study shows that RASSF1A regulates the stability of mitotic cyclins and the timing of mitotic progression by inhibiting APC-Cdc20. RASSF1A appears to work in early pro-metaphase, after Emi1 destruction and before activation of the Mad2-dependent spindle checkpoint. Loss of RASSF1A expression induces premature APC activation, thereby resulting in acceleration of mitotic cyclin degradation and mitotic progression as well as induction of mitotic abnormalities. Thus, RASSF1A plays a critical role in mitotic progression and tumor suppression by controlling APC-Cdc20 activity
Aurora B-Mediated Phosphorylation of RASSF1A Maintains Proper Cytokinesis by Recruiting Syntaxin16 to the Midzone and Midbody
No full textAurora B is critically involved in ensuring proper cytokinesis and maintaining genomic stability. The tumor suppressor RASSF1A regulates cell cycle progression by regulating mitotic progression, G(1)-S transition, and microtubute stability. We previously reported that both Aurora A and Aurora B phosphorylate RASSF1A, and showed that phosphorylation of RASSF1A by Aurora A blocks the inhibitory function of RASSF1A toward anaphase-promoting complex-Cdc20. However, the role of Aurora B-mediated RASSF1A phosphorylation remains unknown. Here, we show that phosphorylation of RASSF1A on Ser203 by Aurora B during late mitosis has a critical role in regulating cytokinesis. Notably, RASSF1A interacts with Syntaxin16, a member of the t-SNARE family at the midzone and midbody during late mitosis. Aurora B is required for this interaction and for the subsequent recruitment of Syntaxin16 to the midzone and midbody, a prerequisite for the successful completion of cytokinesis. Furthermore, Aurora B depletion results in a failure of Syntaxin16 to properly localize to the midzone and midbody, a mislocalization that was prevented by overexpression of the phosphomimetic RASSF1A (S203D) mutant. Finally, either depletion of Syntaxin]6 or expression of the nonphosphorylatable RASSF1A (S203A) mutant results in cytokinesis defects. Our findings implicate Aurora B-mediated phosphorylation of RASSF1A in the regulation of cytokinesis. [Cancer Res 2009;69(22):8540-4]This work was supported by 21st Century Frontier Functional Human Genome Project and the Korea National Cancer Center Control Program
The centrosomal protein RABP1 regulates mitotic by recruiting RASSF1A to spindle poles
No full textThe protein RAS association domain family protein 1A (RASSF1A), which is encoded by a gene that is frequently silenced in many types of sporadic tumor, functions in mitosis as a regulator of the anaphase-promoting complex (APC). With the use of a yeast two-hybrid screen, we identified a human protein, previously designated C19ORF5, that interacts with RASSF1A. This protein, here redesignated RASSF1A-binding protein 1 (RABP1), contains two microtubule-associated protein domains, and its association with RASSF1A was confirmed in mammalian cells by immunoprecipitation and immunofluorescence analyses. RABP1 was found to be localized to the centrosome throughout the cell cycle in a manner dependent on its microtubule-associated protein domains. Ectopic expression of RABP1 induced both stabilization of mitotic cyclins and mitotic arrest at prometaphase in a RASSF1A-dependent manner. It also increased the extent of association between RASSF1A and Cdc20. Conversely depletion of RABP1 by RNA interference prevented both the localization of RASSF1A to the spindle poles as well as its binding to Cdc20, resulting in premature destruction of mitotic cyclins and acceleration of mitotic progression. These findings indicate that RABP1 is required for the recruitment of RASSF1A to the spindle poles and for its inhibition of APC-Cdc20 activity during mitosis
The centrosomal protein RAS association domain family protein 1A (RASSF1A)-binding protein 1 regulates mitotic progression by recruiting RASSF1A to spindle poles
No full textThe protein RAS association domain family protein 1A (RASSF1A), which is encoded by a gene that is frequently silenced in many types of sporadic tumor, functions in mitosis as a regulator of the anaphase-promoting complex (APC). With the use of a yeast two-hybrid screen, we identified a human protein, previously designated C19ORF5, that interacts with RASSF1A. This protein, here redesignated RASSF1A-binding protein 1 (RABP1), contains two microtubule-associated protein domains, and its association with RASSF1A was confirmed in mammalian cells by immunoprecipitation and immunofluorescence analyses. RABP1 was found to be localized to the centrosome throughout the cell cycle in a manner dependent on its microtubule-associated protein domains. Ectopic expression of RABP1 induced both stabilization of mitotic cyclins and mitotic arrest at prometaphase in a RASSF1A-dependent manner. It also increased the extent of association between RASSF1A and Cdc20. Conversely depletion of RABP1 by RNA interference prevented both the localization of RASSF1A to the spindle poles as well as its binding to Cdc20, resulting in premature destruction of mitotic cyclins and acceleration of mitotic progression. These findings indicate that RABP1 is required for the recruitment of RASSF1A to the spindle poles and for its inhibition of APC-Cdc20 activity during mitosis.Supported by a grant from the 21st Century Frontier Functional
Human Genome Project of Korea Institute of Science & Technology
Evaluation and Planning (Ministry of Science and Technology of Korea)
Association of hepatitis B virus polymerase with promyelocytic leukemia nuclear bodies mediated by the S100 family protein p11
No full textHepatitis B virus (HBV) polymerase (Pol) interacts with cellular chaperone proteins and thereby performs multiple functions necessary for viral replication. Yeast two-hybrid analysis was applied to identify additional cellular targets required for HBV Pol function. HBV Pol interacted with S100A10 (p11), a Ca2+-modulated protein previously shown to bind to annexin II. The interaction between HBV Pol and p11 was confirmed by co-immunoprecipitation of the two proteins synthesized either in vitro or in transfected cells and by inhibition of the DNA polymerase activity of HBV Pol by p11. Immunofluorescence analysis of transfected human cell lines revealed that, although most HBV Pol and p11 was restricted to the cytoplasm, a small proportion of each protein colocalized as nuclear speckles; HBV Pol was not detected in the nucleus in the absence of p11. The HBV Pol-p11 nuclear speckles coincided with nuclear bodies containing the promyelocytic leukemia protein PML. Furthermore, the association of HBV Pol-p11 with PML was increased by exposure of cells to EGTA and inhibited by valinomycin. These results suggest a role for p11 n modulation of HBV Pol function and implicate PML nuclear bodies and intracellular Ca2+ in viral replication. (C) 2003 Elsevier Science (USA). All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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