1,720,980 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
Aggregates of cAMP-dependent kinase isoforms characterize different areas in the developing central nervous system of the chicken, Gallus gallus.
No full textThe intracellular second messenger adenosine 3',5'-cyclic monophosphate (cAMP) acts mainly through cAMP-dependent protein kinases (PKA). In mammals and reptiles, the PKA regulatory isoforms (RI and RII) are differentially distributed among the various brain areas and cell types, according to the age of the animal. Since PKA distribution may be an additional marker for homologous areas, PKA regulatory subunit types RI and RII were examined in the chicken brain, a species not yet investigated. Chicken brains were examined from prehatching to adult age, by means of immunohistochemistry and biochemical characterization. Most PKA regulatory subunits were segregated in discrete non-soluble clusters that contained either RI or RII. While RII aggregates were present also in non-neuronal cells, RI aggregates were detected only in neurons of some brain areas that are mainly related to the telencephalon. They appeared later than RII aggregates; their presence and location varied during development. RI aggregates were detected first in the olfactory bulb, around embryonic day 14; within 3 days they appeared in the hyperpallium and nidopallium, where the most intense labeling was observed in the perihatching period. Fainter RI aggregates persisted up to 3 years in the olfactory bulb and nidopallium caudale. Less intense RI aggregates were present for a shorter time, from 2 weeks to 3 months, in the septal nuclei, thalamic medial nuclei, periventricular hypothalamus, optic tectum periventricular area, brainstem reticular formation and spinal cord substantia gelatinosa. RI aggregates were not detected in many brain areas including the arcopallium, striatum and cranial nerve nuclei. RII distribution showed less variation during development. From embryonic day 12, some insoluble RII aggregates were detected in the brain; however, only minor modifications were observed in positive structures once they started to harbor insoluble RII aggregates. The present results suggest that the distribution of PKA aggregates may assist in characterizing phylogenetically homologous structures of the vertebrate central nervous system and may also unravel biochemical differences among areas considered homologous
Protein kinase A in cancer.
Full text linkIn the past, many chromosomal and genetic alterations have been examined as
possible causes of cancer. However, some tumors do not display a clear molecular and/or
genetic signature. Therefore, other cellular processes may be involved in carcinogenesis.
Genetic alterations of proteins involved in signal transduction have been extensively
studied, for example oncogenes, while modifications in intracellular compartmentalization
of these molecules, or changes in the expression of unmodified genes have received less
attention. Yet, epigenetic modulation of second messenger systems can deeply modify
cellular functioning and in the end may cause instability of many processes, including cell
mitosis. It is important to understand the functional meaning of modifications in second
messenger intracellular pathways and unravel the role of downstream proteins in the
initiation and growth of tumors. Within this framework, the cAMP system has been
examined. cAMP is a second messenger involved in regulation of a variety of cellular
functions. It acts mainly through its binding to cAMP-activated protein kinases (PKA), that
were suggested to participate in the onset and progression of various tumors. PKA may
represent a biomarker for tumor detection, identification and staging, and may be a
potential target for pharmacological treatment of tumors
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
Indagine sperimentale del campo di moto in un canale di raffreddamento per il bordo d'uscita di pale rotoriche di tubina a gas
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