1,720,971 research outputs found
NPY augments the proliferative effect of FGF2 and increases the expression of FGFR1 on nestin positive postnatal hippocampal precursor cells, via the Y1 receptor
No full textWe have shown that neuropeptide Y (NPY), a peptide neurotransmitter released by hippocampal interneurons, is proliferative for hippocampal neural stem progenitor cells (NSPCs) via the Y1 receptor. Fibroblast growth factor 2 (FGF2), released predominantly by astrocytes, is also a powerful mitogen for postnatal and adult NSPCs, via the FGFR1 receptor. Knockout studies show that NPY and FGF2 are individually necessary, but not sufficient, for seizure-induced neurogenesis, suggesting a possible interaction. Here we examined for interactions between NPY and FGF2 on NSPCs from the postnatal hippocampus and report that the combination of NPY and FGF2 significantly shortens the cell cycle time of nestin positive NSPCs, more than either factor alone. This augmentation of proliferation rate is NPY Y1 receptor mediated, and Y1 receptor activation increases both FGFR1 mRNA and protein in NSPC cultures. NSPCs immunostain for both Y1 and FGFR1 receptors and the interaction is specific for dentate NSPCs.This is the first report of a proliferative factor that augments the proliferative effect of FGF2 and is the first evidence of a positive proliferative interaction between a glial growth factor and a neuronal transmitter, identifying a novel neural activity driven mechanism for modulating the proliferation of hippocampal NSPCs
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
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
Carriage of streptococcus pneumoniae in adults hospitalised with community-acquired pneumonia
Full text linkOBJECTIVES: We aimed to determine the prevalence of and risk factors for nasopharyngeal and oral pneumococcal carriage in adults with community-acquired pneumonia (CAP), and the relationship between carried and disease-causing serotypes., METHODS: Between 2016 and 2018, nasopharyngeal swabs, oral-fluid, and urine were collected from hospitalised adults recruited into a prospective cohort study of CAP. Pneumococcal carriage was detected by semi-quantitative real-time PCR of direct and culture-enriched nasopharyngeal swabs and culture-enriched oral-fluid. LytA and piaB positive/indeterminate samples underwent semi-quantitative serotype/serogroup-specific real-time-PCR. Serotypes in urine were identified using a 24-valent serotype-specific urinary-antigen assay., RESULTS: We included 465 CAP patients. Nasopharyngeal carriage was detected in 34/103 (33.0%) swabbed pneumococcal pneumonia patients and oral carriage in 18/155 (12%) of sampled pneumococcal pneumonia patients. Concordance between nasopharyngeal/urine serotypes and oral/urine serotypes was 70.6% and 50% respectively. Serotypes 3 (26%, 22.2%), 8 (19.7%, 19.4%), non-typeable (11.6%, 13.9%) and 19A/F (7.5%, 8.3%) were most prevalent in urine and nasopharyngeal swabs respectively, with non-typeable (35%) and 15A/F (17%) most prevalent in oral-fluid. Pneumococcal carriage was significantly associated with pneumococcal pneumonia (nasopharyngeal adjusted odds ratio aOR] 8.1, 95% confidence interval CI] 3.8-17.2; oral aOR 5.5, 95% CI 2.1-13.3). All-cause CAP patients >=65 years had lower odds of nasopharyngeal carriage (aOR 0.47, 95% CI 0.24-0.91) and current smokers had higher odds of oral carriage (aOR 2.69, 95% CI 1.10-6.60)., CONCLUSIONS: The association between nasopharyngeal carriage and pneumococcal CAP was strong. Adult carriage and disease from serotypes 8 and 19A may support direct protection of adults with PCV vaccines. Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.https://doi.org/10.1016/j.jinf.2024.10627
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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