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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
폐전이성 MDA-MB-231 세포주에서 Ras-ERK 신호전달이 세포골격구조, 이동성 및 암전이 마커에 미치는 영향
No full text학위논문(박사) - 한국과학기술원 : 생명과학과, 2015.2
,[78p :]MDA-MB-231 LM2 는 MDA-MB-231 세포들 중 쥐에서 폐 조직으로 전이가 잘 이루어지는 세포들을 따로 분리하여 확립한 세포주이다. 본 연구에서 LM2 세포주의 세포 특성인 액틴 세포골격구조, 이동성 및 폐전이 특이적인 유전발현 (lung metastasis signature genes)을 유도하는 세포신호과정에 대해 중점적으로 연구하였다. LM2 세포주의 경우 Parental 세포에 비해 K-Ras 단백질의 양이 증가되어 있었으며, downstream pathway 인 MEK과 ERK의 인산화 정도가 높은 정도와 일치되는 점을 보여주고 있었다. K-Ras 단백질의 발현을 siRNA를 이용하여 저해하거나 MEK의 활성을 저해하는 약물인 UO126를 처리하였을 때 LM2 세포주의 경우 세포골격구조가 활성화되고 폐 전이 특이적 유전발현 인자들이 감소하였음을 관찰할 수 있었다. 그러나 세포의 이동성의 경우 큰 변화는 관찰할 수 없었는데 그 이유는 Ras-ERK pathway를 저해할 경우 또 다른 oncogenic signaling 중의 하나인 PI3K가 활성화되기 때문으로 이해된다. 왜냐하면 MEK를 저해하는 약물인 UO126와 PI3K를 저해하는 LY294002를 같이 처리할 경우 세포의 이동성이 급격하게 저해되는 것을 관찰할 수 있었기 때문이다. 또한 Ras-ERK pathway를 저해할 경우 integrin β1, MLCK and Myosin IIA 단백질이 PI3K/AKT 활성화에 관여하고 있음을 밝혔다. 더불어 Ras-ERK pathway의 저해가 결과적으로 fibronectin의 발현과 assembly에 영향을 미치며 그리고 mTORC1 pathway와 함께 PI3K/AKT의 활성화에 필요하다. 본 연구는 MEK 저해제와 저항성을 보이는 암세포에서 integrin β1, MLCK and Myosin IIA 단백질이 필수적인 요소로서 작용할 수 있음을 보여준다. 또한 이러한 단백질을 Ras-ERK pathway 저해와 함께 동시에 저해한다면 좀더 효율적인 치료효과를 보이는 의료기술을 발전하는데 필요할 것으로 생각된다.한국과학기술원 :생명과학과
MLCK의 발현감소가 유방상피세포의 이동성 및 침윤성에 미치는 영향
No full text학위논문(박사) - 한국과학기술원 : 생명과학과, 2016.2
,[vi, 65 p. :]Myosin light chain kinase (MLCK) expression is down-regulated in breast cancer, including invasive ductal carcinoma compared with ductal breast carcinoma in situ and metastatic breast tumors. However, little is known about how loss of MLCK expression contributes to tumor progression. MLCK is a component of the actin cytoskeleton and its known role is the phosphorylation of the regulatory light chains of myosin II. To gain insights into the role of MLCK in breast cancer, we perturbed its function using siRNA or pharmacological inhibition in untransformed breast epithelial cells (MCF10A). Loss of MLCK by siRNAs led to increased cell migration and invasion, disruption of cell-cell adhesions and enhanced formation of focal adhesions at the leading edge of migratory cells. In addition, down-regulation of MLCK cooperated with HER2 in MCF10A cells to promote cell migration and invasion and low levels of MLCK is associated with a poor prognosis in HER2 positive breast cancer patients. Associated with these altered migratory behaviors were increased expression of EGFR and activation of ERK and JNK signaling pathways in MLCK down-regulated MCF10A epithelial cells. By contrast, inhibition of the kinase function of MLCK using pharmacological agents inhibited cell migration and invasion, and did not affect cellular adhesions. Our results demonstrate loss of MLCK contributes to the migratory properties of epithelial cells resulting from changes in cell-cell and cell-matrix adhesions, and increased EGFR signaling. These findings suggest that decreased expression of MLCK might play a critical role during tumor progression by facilitating the metastatic potential of tumor cells.한국과학기술원 :생명과학과
An investigation of tropomyosin 4 in the regulation of invadopodia and motility in MDA-MB-231
No full text학위논문(석사) - 한국과학기술원 : 나노과학기술학과, 2013.8, [ iii, 28 p. ]Tropomyosins are α-helical coiled coil proteins that bind actin filaments. Four genes encode the tropomyosin family of proteins that includes about 40 members. Studies of tropomyosins revealed a functional diversity between different isoforms. TPM4 gene encodes 2 isoforms: tropomyosin 4 low molecular weight (TM4 LMW) and tropomyosin 4 high molecular weight (TM4 HMW). TM4 LMW has been reported to regulate resorptive capacity of osteoclasts. However, the role of TM4 in facilitating degradation and motility in cancer cells has not been investigated yet. In this research, I used siRNAs to TM4 LMW and TM4 HMW and performed degradation and migration assays in MDA-MB-231 breast cancer cells to study the role of both isoforms. I found that degradation is regulated by TM4 LMW, but not TM4 HMW. This is first evidence that TM4 might regulate invadopodia dynamics in tumor cells. In addition, this result might indicate that TM4 isoforms don’t possess a redundant function. Further research should focus on mechanism underlying the observed effect by TM4 LMW. In conclusion, this study contributes to our knowledge regarding invadopodia and the role of cytoskeletal proteins in the regulation of these structures.한국과학기술원 : 나노과학기술학과
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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