1,721,005 research outputs found
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
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
Molecular characterization and expression of a N-acetylneuraminate lyase gene from Trichomonas vaginalis.
No full textBy screening a Trichomonas vaginalis gt11 cDNA library with anti-serum raised against a purified preparation of T. vaginalis cell-detaching factor (CDF), two clones were identified. Molecular analysis of the cDNA sequences indicated that the clones were distinct and could potentially represent two unique T. vaginalis genes. Further characterization of the CDF anti-serum used in the initial library screening indicated that the serum possessed reactivity to CDF and a variety of other T. vaginalis proteins. The multiple specificities of the anti-serum are likely to have contributed to the identification of the two distinct cDNA clones. While the relationship between the weaker of the two immunoreactive cDNA sequences (CDF-2) and the CDF protein was unclear, the results of Northern hybridization and sequence analysis suggested that the strongly reactive CDF-1 clone did not contain sequences representing a CDF gene. Since the CDF-1 cDNA clone contained an almost complete coding sequence and because the encoded polypeptide exhibited significant protein sequence similarity to bacterial N-acetylneuraminate (Neu5Ac) lyases, this T. vaginalis sequence was further analyzed. Using the cDNA sequence and cloned segments of overlapping genomic DNA, the complete coding and flanking regions of this T. vaginalis gene, designated TvnanA, were determined. TvnanA is a single copy gene that lacks introns and contains a 954 bp open-reading frame that is predicted to encode a 318 amino acid polypeptide with a calculated molecular mass of 35 kDa. The gene is transcribed as a single 1.1 kb polyadenylated mRNA with short 5\sp\prime (17-18 nt) and 3\sp\prime (28 nt) untranslated regions. A sequence resembling the T. vaginalis initiator element was identified in the region surrounding the transcriptional initiation site, however this Inr-like element did not direct accurate gene transcription. The TvnanA encoded polypeptide shows 35% identity and 53% similarity to the Neu5Ac lyase of Escherichia coli, and 73% identity to a predicted Neu5Ac lyase of Haemophilus influenzae. The homology includes significant similarity within a region corresponding to the putative active site pocket of the E. coli enzyme. A complete copy of the TvnanA gene was assembled and the gene product was expressed in E. coli as a glutathione S-transferase fusion protein. In the absence of detergents required for efficient solubilization, the T. vaginalis gene product exhibited Neu5Ac lyase activity that was 30 times greater than background activity in controls. Lyase activity was increased a further 5-fold by deletion of the N-terminal hydrophobic region of the T. vaginalis protein. While fusion proteins exhibited Neu5Ac lyase activity, they did not appear to be capable of producing cell-detaching activity when incubated in the presence of eukaryotic cell monolayers. Preliminary experiments to determine the size and location of the T. vaginalis Neu5Ac lyase suggests that the enzyme is present as an intracellular 35 kDa species. While questions remain concerning the regulation of the TvnanA gene and the role of the N-terminal region in the encoded polypeptide, this is the first reported characterization of a T. vaginalis gene product involved in sialic acid metabolism. The presence of this enzyme combined with the reports of a T. vaginalis neuraminidase suggests that the parasite may utilize host sialic acid as a nutrient source
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
Vaccination of BALB/c Mice with an Alhydrogel Adjuvanted Whole Cell Trichomonas vaginalis Formulation
No full textA human safe, Alhydrogel adjuvanted whole cell Trichomonas vaginalis vaccine was tested for efficacy in a BALB/c mouse model of vaginal infection. Additionally, the systemic and local immune response were measured. Vaccination reduced incidence and increased clearance of infection, and induced both systemic and local humoral immune responses. CD4+ cells were detected in vaginal tissues following intravaginal challenge with T. vaginalis, but were not seen in uninfected mice. CD4+ cells were detected more often, earlier, and in greater numbers in vaccinated vaginal tissues compared to unvaccinated controls. Presence of CD4+ T cells following infection can have significant implications of increasing HIV susceptibility and transmission. These data suggest that the vaccine induces local and systemic immune responses, and confers significantly greater protection against vaginal challenge than unvaccinated vaginal challenge. These data support the potential for a human vaccine against T. vaginalis infection that could also impact the incidence of HIV infections
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