1,721,018 research outputs found
Cell-Based Assays to Assess Neuroprotective Activity
No full textThe most common neurodegenerative diseases (NDDs), i.e. Alzheimer’s disease (AD), Parkinson’s disease (PD) and Amyotrophic Lateral Sclerosis (ALS), share common features both at molecular and cellular level: at molecular level, all these disorders are characterized by conformational changes of specific proteins leading to aggregates formation and mitochondrial dysfunctions together with impairment in ubiquitin-proteasome system and autophagy to this pathogenic mechanism; at cellular level, NDDs affect all brain cell types, leading to their dysfunction, which contributes to neurodegeneration. In fact, at early stages, all NDDs are characterized by degeneration and death of neurons in specific brain areas, often related to neural precursors cells (NPCs) proliferation/differentiation dysfunctions, making difficult the replacement of degenerated neurons. In the meanwhile, activation of microglia occurs, which initially acts to protect neurons and to support neuroregeneration, but, when activation is wide and/or prolonged, it contributes to neurodegeneration, to neurogenesis impairment and, together with astrocytes, to neuroinflammation. Finally, at later stages, most of NDDs are also characterized by white matter dysfunction, as a consequence of defects in oligodendrocytes functions or precursors cells (OPCs) proliferation/differentiation processes. Therefore, considering the cellular mechanisms involved in the complex process of neurodegeneration, to exactly characterize the neuroprotective potential of candidate molecules for central nervous system (CNS) drug discovery there is a need to use different brain cells-based assays.
To this aim, here we describe the drug screening pipeline that we have developed in more than 10 years of research and that involves the use of different in vitro brain cell models. First, rat primary cultures of cerebellar granule neurons (CGNs) are used to evaluate the potential dose-dependent toxicity of all molecules to be tested; then, the potential neuroprotective effect of selected, non-toxic molecules is evaluated on specific in vitro models of neurodegeneration (age-related, AD, PD or ALS). Then, the use of neurospheres isolated from the sub-ventricular zone (SVZ) of adult mice allows to investigate the potential neuroregenerative effects of selected molecules of interest.
Cultures of rat primary microglial cells or microglial cell lines (murine N9 or human HMC3), previously activated by commonly-used inflammatory stimuli (LPS or INFγ), are then set up, together with murine astrocytes cell line (IMA 2.1) or primary rat astrocytes, to assess immunomodulation, i.e. the shift from neurotoxic to neuroprotective phenotypes, of further selected compounds. In parallel, proliferation and differentiation mechanisms need to be analyzed in immortalized murine oligodendrocytes precursor cells (Oli-Neu cells) to evaluate effects on remyelination processes. Finally, to confirm the specific neuroprotective, neuroregenerative and immunomodulatory effects of selected molecules, different brain cells derived by human induced pluripotent stem cells (hiPSCs) from healthy donors or of patients with specific NDDs can be used to confirm the translational potential of the interesting candidates, as well as a strategy for the identification of more personalized and effective treatments for neuroprotection
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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