1,721,009 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
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
Implication des cellules gliales dans la modulation de l’activité synaptique à la jonction neuromusculaire sénescente
Full text linkL’affaiblissement musculaire est un processus inévitable du vieillissement qui peut sévèrement affecter la mobilité des personnes âgées, en plus d’accroître le risque de chute avec blessure. Un candidat important pouvant sous-tendre ce déclin moteur est la dégénérescence de la jonction neuromusculaire (JNM), la connexion synaptique entre le motoneurone et le muscle. Parmi les évènements survenant à la JNM sénescente, la dénervation fréquente de la terminaison axonale du motoneurone couplée à des mécanismes compensatoires altérés compromettent la fonction et l’intégrité de la JNM. En plus des altérations synaptiques, des changements ont aussi été observés dans les propriétés des cellules de Schwann périsynaptiques (CSPs), les cellules gliales de cette synapse. Ces changements gliaux peuvent être d’une grande importance puisque les CSPs sont reconnues pour jouer un rôle crucial à la JNM adulte en régulant la fonction, le maintien et la plasticité synaptique. Dès lors, nous avons émis l’hypothèse que les altérations fonctionnelles observées à la JNM sénescente sont en partie causées par des altérations dans la régulation gliale. Dans cette veine, nous avons d’abord caractérisé, à l’aide d’enregistrements électrophysiologiques, les propriétés fonctionnelles des JNMs du muscle levator auris longus provenant de souris CD1 adultes (3 mois), âgées (24 mois) et très âgées (30 mois). Nous avons observé une préservation avec l’âge des propriétés de la transmission synaptique, toutefois accompagnée de profondes altérations dans la plasticité synaptique suivant des trains de stimulation à haute fréquence de l’axone moteur. Particulièrement, nous avons montré que la plasticité synaptique à long-terme est de polarité inversée autant pour les animaux âgés que très âgés, passant d’une potentialisation à une dépression synaptique avec l’âge. Pour investiguer l’implication des CSPs dans cette altération synaptique, nous avons adapté une stratégie impliquant la méthode d’électroporation de cellule unique afin de manipuler sélectivement l’activité calcique gliale tout en réalisant simultanément des enregistrements électrophysiologiques pour les souris 3 mois et 24 mois. Cette stratégie a permis de révéler que les altérations de la plasticité à long-terme semblent être médiées de manière calcium-dépendante par les CSPs. En utilisant une approche pharmacologique spécifique, nous avons montré que ces phénomènes de plasticité synaptique à long-terme sont aussi dépendants de l’activation des récepteurs à l’adénosine, qui sont des effecteurs présynaptiques de la plasticité gliale dépendante. Mis ensemble, ces résultats suggèrent qu’une dysrégulation par les CSPs semble médier de manière purine-dépendante l’affaiblissement de la JNM sénescente. Ainsi, notre étude soulève une possible implication des CSPs dans la dégénération de la JNM sénescente et met en lumière ces cellules gliales comme une cible thérapeutique potentielle pour prévenir l’affaiblissement musculaire qui touche les personnes âgées.Age-related muscle weakness is simply unavoidable, and it can severely compromise physical autonomy for elderlies in addition to increase the risk of fall-related injuries. One element underlying this motor decline is the degeneration of the neuromuscular junction (NMJ), the synaptic connection between motor neuron and muscle. Amongst other age-related events, frequent denervation of the motor axon terminal coupled with impaired compensatory mechanisms compromise NMJ function and integrity. Beside the synaptic alterations, properties changes have also been observed for Perisynaptic Schwann cells (PSCs), glial cells at this synapse. These glial changes could play key role in the degenerative events happening at the senescent NMJ, since PSCs are well known to be crucial at the mature NMJ by regulating synaptic function, maintenance and plasticity. Therefore, we hypothesized that impaired NMJ function may arise in part from age-related glial dysfunction. Using electrophysiological recordings, we characterized NMJs functionals properties of levator auris longus muscle from adult (3 months) CD1 mice, old (24 months) and very old (30 months). We observed preserved synaptic transmission properties with aging, along with profound synaptic plasticity alterations following high-frequency nerve stimulation. Particularly, we showed long-term synaptic plasticity is reversed in terms of polarity for both old and very old animals, going from synaptic potentiation to depression with age. To investigate PSCs contribution to this synaptic alteration, we adapted a strategy implicating single-cell electroporation to manipulate selectively glial calcium activity while simultaneously realizing electrophysiological recordings for 3 months and 24 months mice. This strategy revealed long-term synaptic plasticity alterations seem to be mediated in a Ca2+-dependent manner by PSCs. Using a specific pharmacological approach, we then showed long-term synaptic plasticity events are also dependents upon adenosine receptors activation, which are presynaptic effectors of glial-dependent plasticity. Altogether, these results suggest PSCs dysregulation seems to mediate in a purine-dependent manner age-related NMJ weakness. Thus, our study raises the possible implication of PSCs in NMJ’s age-related degeneration and it brings to light glial cells as a potential therapeutic target to prevent muscle weakness for elderlies
Interactions synapse-glie à la jonction neuromusculaire de mammifère
Full text linkMémoire numérisé par la Direction des bibliothèques de l'Université de Montréal
- …
