1,720,956 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
Social enrichment affects and reverses changes of emotional state and HPA sensitivity induced by early postweaning social isolation
No full textAdverse stress events during the adolescence period may have long-term effects on developing and emotional/behavioral state inducing deep, and sometimes irreversible, changes in the adulthood. It is well known that environmental enrichment has an heavy impact in the development brain networks as well as neuroendocrine system in the lifespan. Long-lasting stress experiences such as social isolation lead to profound neuronal and behavioral changes, increasing anxiety state, reduction in neurogenesis and dendritic arborization as well as an alteration of HPA axis function related to an abnormal hormones pattern fluctuation. We used a mild chronic stress model in rats in order to study the long-lasting effect of environmental enrichment in the future outcomes in the offspring previously socially isolated (SI). We evaluated the potential role of environmental conditions in rats deprived of social contact experience for long time (4-8 weeks) starting from weaning (21PND). Socially isolated rats usually show biochemical and behavioral alterations that persist into adult life if they live in this condition. Moreover, this kind of stress condition changes both hormones pattern and also the responsiveness to novel acute stress stimuli suggesting a greater HPA axis sensitivity. Environmental enrichment is able to revert some neuronal and behavior deficits switching the rearing social isolation. Here, we focused our attention on the effects of rat reintegration in group after 4 weeks of social isolation on different stress-related parameters such as anxiety, HPA hormones pattern and responsiveness to acute stress. We found that eight weeks of social isolation induced a decrease of plasmatic corticosterone and allopregnanolone content that in socially isolated-joined group (SI-J) were subsequently restored to levels observed in group housed animals. Similar effect was found in foot-shock-induced changes in corticosterone content and in several behavioral test such as Vogel, elevated plus maze and motility test. Our results further support that, in rats, the positive impact of environmental conditions reverts the plastic neuronal and behavioral responses to long-lasting stress
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
Immunohistochemical markers of stem/progenitor cells in the developing human cerebellum
Full text linkThe aim of this study was to identify the stem/progenitor cell markers, by immunohistochemistry, in order to highlight the cortical neurogenesis niches during the different gestational ages. To this end, the following stem/progenitor cell markers have been utilized: Sox2, Pax6, Pax2, WT1, Nestin, Vimentin and Calretinin. The expression of these markers have been compared with the expression of those markers of mature neurons and glial markers including Neurofilament (NF), neuron specific enolase (NSE), Synaptophysin (Syn), Glial fibrillary acid protein (GFAP) and S100β.
Evaluating both stem/progenitor and mature cell markers lead to the identification of multiple stages of differentiation of neuronal and glial progenitors during gestation, in order to better understand the development of human cerebellar cortex
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
La separazione materna riduce gli effetti indotti sulla sensibilità dell’asse iis dall’isolamento sociale durante l’adolescenza
No full textLe cure materne che i neonati ricevono dopo la nascita stanno alla base del loro equilibrio
emotivo, interpersonale e sociale. Nella prima infanzia, infatti, uno degli eventi più stressanti può essere
rappresentato dalla ripetuta e protratta separazione materna (MS) la quale innesca una serie di
modificazioni molecolari, comportamentali e ormonali. Un altra importante tappa, della crescita nella vita
dei mammiferi, è il periodo post-svezzamento, infatti, quando si verificano eventi stressanti come
l'isolamento sociale (IS), questo provoca diversi cambiamenti nello sviluppo del cervello e del
comportamento. La nostra ipotesi è che gli effetti indotti da un ambiente sfavorevole come l’isolamento
sociale possano essere influenzati da precedenti stress come quello post-natale con un effetto risultante
diverso da quello osservato nei singoli eventi stressori. Tre ore di separazione materna (3°-15° giorno post
natale) riduce gli effetti indotti dall’isolamento sociale sui livelli allopregnanolone e corticosterone e
modifica inoltre la risposta al foot-shock stress, suggerendo che il protocollo separazione materna potrebbe
aiutare gli animali in età adulta ad essere meno sensibili agli stimoli stressanti. Questo effetto è mostrato
anche nella misurazione del fattore neurotrofico BDNF, infatti la le variazione di espressione di BDNF
osservata negli animali sottoposti a separazione materna e successivamente a isolamento sociale è simile a
quello misurato nel gruppo sottoposto a sola separazione materna ma significativamente più alto degli
animali socialmente isolati. I nostri risultati suggeriscono che nei ratti una breve separazione giornaliera
dalla madre durante la prima settimana di vita, che di per sé non altera sostanzialmente la funzionalità e
reattività dell'asse HPA nell’età adulta, aumenta la resilienza a protratte esperienze stressanti come
l’isolamento sociale
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