1,720,984 research outputs found
CHRONIC MILD STRESS OCCLUDES DOPAMINE-DEPENDENT SYNAPTIC PLASTICITY IN THE MEDIAL PFC AND ALTERS PFC TO BASOLATERAL AMYGDALA SYNAPTIC DRIVE
No full textMajor depressive disorder (MDD) is a difficult to treat condition of epidemic proportions all over the world. In preclinical models, the depressive-like phenotype induced by chronic stress exposure is partly mediated by a down-regulation of dopamine (DA) transmission, likely to affect synaptic plasticity in the medial prefrontal cortex (mPFC) and related limbic circuits. Recently, the potential efficacy of ketamine as a fast-acting antidepressant has been reported, but we still lack sufficient knowledge about its mechanism of action. Here, male Sprague-Dawley rats were subjected to a chronic mild stress (CMS) protocol lasting 3-5 weeks, inducing anhedonia in a subset of ‘vulnerable’ rats, contrary to resilient ones, tested using a sucrose preference test (SPT; CMS-R vs CMS-V, p<10-3). We obtained electrophysiological recordings of DA-dependent long-term potentiation (DA-LTP) and depression (DA-LTD) on acute slices of the mPFC from control, CMS-R and CMS-V rats. DA-LTP was reliably induced in control and CMS-R rats while this was strongly occluded in vulnerable rats (CMS-R vs CMS-V: p < 0.01). On the contrary, DA-LTD induction was unaffected by CMS. Later, we tested the effects of sub-anesthetic ketamine (10 mg/kg) showing that this treatment seems to prevent DA-LTP occlusion (CMS-R w/KET vs CMS-V w/KET: n.s.). We then tested changes in the synaptic drive of two major pathways connecting mPFC to the basolateral amygdala (BLA), thought to mediate top-down control of emotion regulation. To this aim, we applied our recently developed approach SynaptoZip (SZ). Our analysis indicates that CMS increases prelimbic (PL) while reduces infralimbic (IL) to BLA synaptic drive, so that the overall PL/IL ratio is augmented. Interestingly, rats treated with ketamine (10 mg/kg) for 90 minutes display a rescue of the physiological PL/IL balance in our experiments. Financial support provided by the NARSAD YIG 2017 (ID: 26414; PI: J.L.)
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
Extracellular Vesicles of Mesenchymal Stem Cells: Therapeutic Properties Discovered with Extraordinary Success
No full textMesenchymal stem cells (MSCs), the cells distributed in the stromas of the body, are known for various properties including replication, the potential of various differentiations, the immune-related processes including inflammation. About two decades ago, these cells were shown to play relevant roles in the therapy of numerous diseases, dependent on their immune regulation and their release of cytokines and growth factors, with ensuing activation of favorable enzymes and processes. Such discovery induced great increase of their investigation. Soon thereafter, however, it became clear that therapeutic actions of MSCs are risky, accompanied by serious drawbacks and defects. MSC therapy has been therefore reduced to a few diseases, replaced for the others by their extracellular vesicles, the MSC-EVs. The latter vesicles recapitulate most therapeutic actions of MSCs, with equal or even better efficacies and without the serious drawbacks of the parent cells. In addition, MSC-EVs are characterized by many advantages, among which are their heterogeneities dependent on the stromas of origin, the alleviation of cell aging, the regulation of immune responses and inflammation. Here we illustrate the MSC-EV therapeutic effects, largely mediated by specific miRNAs, covering various diseases and pathological processes occurring in the bones, heart and vessels, kidney, and brain. MSC-EVs operate also on the development of cancers and on COVID-19, where they alleviate the organ lesions induced by the virus. Therapy by MSC-EVs can be improved by combination of their innate potential to engineering processes inducing precise targeting and transfer of drugs. The unique properties of MSC-EVs explain their intense studies, carried out with extraordinary success. Although not yet developed to clinical practice, the perspectives for proximal future are encouraging
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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