1,721,127 research outputs found
Physico-chemical characterization of the interaction between thyroid transcription factor 1 (TTF-1) and DNA
No full textThe thyroid transcription factor 1 (TTF-1) is a tissue-specific transcription factor involved in the development of thyroid and lung. It is a protein of 371 amino acids that possesses two independent transcriptional activation domains, one located in the N-terminal region of homeodomain and the other in the C-terminal region. The homeodomain is a highly conserved DNA-binding motif that is found in numerous transcription factors throughout a large variety of species from yeasts to human. These gene-specific transcription factors play critical roles in development and adult homeostasis, and therefore, any germline mutations associated with these proteins can lead to a number of congenital abnormalities. Remarkable features of structural and functional conservation have been observed within homeodomain family members. This high degree of conservation between the sequence and structure makes the homeodomain an ideal model for studying protein-DNA interactions and gene regulation. In this PhD thesis, the study on the conformational stability and DNA binding energetics of the rat thyroid transcription factor 1 homeodomain (TTF-1HD) is reported. Furthermore, to gain a molecular-level understanding of the interactions determining the association of TTF-1HD to the target DNA sequence, Some key point mutants (W48, Q50 and Y54) and a deletion mutant (desTTF-1HD), lacking five residues from the N-terminal region have been produced and studied. Since it has been demonstrated that N-terminal region of TTF-1 also interact with Pax-8 (transcription factor belonging to the PAX genes superfamily) in the regulation of thyroid-specific gene expression, the study of the thermal stability and DNA binding energetics of a fusion protein, containing the N-terminal region and the homeodomain of TTF-1 (TTF-1NH2HD), and a recombinant protein containing C-terminal region of Pax-8 (Pax-8 Prd) has been reported
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
Multimodal Deep Learning and Fast Retrieval for Recommendation
No full textWe propose a retrieval architecture in the context of
recommender systems for e-commerce applications, based on a multi-modal representation of the items
of interest (textual description and images of the products), paired with a
locality-sensitive hashing (LSH) indexing scheme for the fast retrieval of the
potential recommendations.
In particular, we learn a latent multimodal representation
of the items through
the use of CLIP architecture, combining text and images
in a contrastive way. The item embeddings thus generated
are then searched by means of different types of LSH.
We report on the experiments we performed on two real-world datasets from e-commerce sites, containing both images and textual descriptions of the products
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
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