1,721,134 research outputs found
Alzheimer's disease: an update of the roles of receptors, astrocytes and primary cilia
No full textThe pathophysiological mechanisms underlying the onset and inexorable progression of the late-onset form of Alzheimer's disease (AD) are still the object of controversy. This review takes stock of some most recent advancements of this field concerning the complex roles played by the amyloid-β (Aβ)-binding p75 neurotrophin receptor (p75NTR) and calcium-sensing receptor (CaSR) and by the primary cilia in AD. Apart from their physiological roles, p75NTR is more intensely expressed in the hippocampus of human AD brains and Aβ-bound p75NTR triggers cell death, whereas Aβ-bound CaSR signalling induces the de novo synthesis and release of nitric oxide (NO), vascular endothelial growth factor (VEGF)-A and Aβ peptides (Aβs), particularly on the part of normal adult human astrocytes. The latter effect could significantly increase the pool of Aβ-and NO-producing nerve cells favouring the progressive spread of a self-sustaining and self-reinforcing 'infectious' mechanism of neural and vascular (i.e. blood-brain barrier) cell damage. Interestingly, primary cilia concentrate p75NTR receptors in their membranes and are abnormally structured/damaged in transgenic (Tg) AD-model mice, which could impact on the adult neurogenesis occurring in the dentate gyrus's subgranular zone (SGZ) that is necessary for new memory encoding, thereby favouring typical AD cognitive decline. Altogether, these findings may pave the way to novel therapeutic approaches to AD, particularly in its mild cognitive impairment (MCI) and pre-MCI stages of development
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
Is Alzheimer’s Disease at Least Partly a Ciliopathy?
Full text linkThe uninterrupted generation throughout life of the dentate gyrus [DGY] granule cells [GCs] (one site of adult neurogenesis), which initiate the encoding of novel memories, is driven by signals from the DGy GC precursors tiny, non-motile primary cilia. The hypothesis is surmised that the damage of such primary cilia be responsible of the crippling decline of memory formation in Alzheimer's Disease [AD]. Were human DGy CGs ciliated like their rodent counterparts, part of the AD cases might be indeed based upon a ciliopathy
Leptin, Sonic Hedgehogs, and Neurogenesis--A Primary Cilium's Tale
Full text linkLeptin-induced signals from from Leptin receptor (R)-b stationed in the cell membrane could stimulate the primary cilium-dependent proliferation of transit amplifying cells [TANs] generated by radial glial neuronal stem cells [RG-NSCs] in the dentate gyrus of the adult hippocampal formation
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