1,720,970 research outputs found
A Bipartite Activation Domain Is Responsible For the Activity of Transcription Factor Hnf1/lfb1 In Cells of Hepatic and Nonhepatic Origin
No full textHNF1/LFB1 is a transcription factor that controls the expression of several liver-specific genes. Previous in vitro experiments allowed us to identify two different regions in the carboxy-terminal portion of the protein responsible for most of the transcription activation potential: the first, ADI, between amino acids 546 and 628 and the second, ADII, between amino acids 281 and 318. To characterize the molecular anatomy of HNF1/LFB1 better, we have analyzed its trans-activating properties in vivo. Several HNF1/LFB1 deletion mutants were tested for their ability to induce transcription from HNF1/LFB1-dependent synthetic promoters in cells of hepatic and nonhepatic origin. These last recipient cells provide an HNF1/LFB1-deficient environment that is useful for a precise quantification of the recombinant protein. Our results confirm the importance of ADI and indicate that no activating property can be assigned to ADII in vivo. Moreover, a novel glutamine/proline-rich activation domain (ADIII) has been identified between amino acids 440 and 506. These findings are confirmed by domain-swapping experiments, carried out with the heterologous GAL4 DNA-binding domain, which also show that the activity of each individual activation domain is influenced by combining adjacent HNF1/LFB1 sequences. The data presented indicate that HNF1/LFB1 transcription activating potential relies on a complex structure and also provide important clues to understanding the different fucntions exerted by transcription factors of this family
Synergistic Transactivation of the Human C-reactive Protein Promoter By Transcription Factor Hnf-1 Binding At 2 Distinct Sites
No full textThe promoter region of the human C-reactive protein (CPR) gene comprises two distinct regions (APREs, for Acute Phase Responsive Elements) each one containing information necessary and sufficient for liver specific and IL-6 inducible expression in human hepatoma Hep3B cells. In this paper we show that both APREs contain a low affinity binding site for the liver specific transcription factor HNF-1/LF-B1. The two sites are separated by approximately 80 bp. Mutations in either of the two sites abolish inducible expression. The same effect is specifically obtained in cotransfection competition experiments when the human albumin HNF-1 site is used as competitor. However, HNF-1 is not the intranuclear mediator of IL-6 because synthetic promoters formed by multimerized copies of different HNF-1 binding sites are not transcriptionally activated by this cytokine. An expression vector encoding full length HNF-1 is capable of trans-activating transcription from the wild-type CPR promoter but not from mutants which have lost the ability to bind HNF-1. Moreover, the level of trans-activation observed with the natural promoter containing both HNF-1 binding sites is far greater than the level of mutated variants containing only one of the two sites. This result strongly suggests that two HNF-1 molecules bound simultaneously to sites distant from each other can act synergistically to activate gene expression
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
Laparoscopia ed endometriosi: le localizzazioni extragenitali
No full textvengono descritti tre casi di endometriosi vescicale, due casi di endometriosi intestinale ed uno della parete addominale appartenenti alla casistica della clinica ginecologica dell'Università di Veron
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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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