1,721,164 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
Investigation of the neurochemical, molecular and behavioural properties of the putative lithium-mimetic, ebselen
Full text linkLithium is the first choice drug for the treatment of bipolar disorder and it is also used as supplementary therapy for treatment-resistant depression. A leading candidate target of lithium is inositol monophosphatase (IMPase) which is critically involved in signalling via the phosphoinositide cycle (PI). Ebselen, first developed as an anti-inflammatory and anti-oxidant drug, has recently been shown to inhibit IMPase and therefore is a putative lithium-mimetic. This project aimed to investigate the neuropharmacological effects of ebselen in mouse models relevant to depression. Initial studies examined the function of 5-HT2A and 5-HT2C receptors, which signal through PI cycle. Ebselen attenuated the responses of systemically administered 5-HT2A agonists at the behavioural and molecular level; specifically the induction of head twitches and ear scratches and increased immediate early gene (IEG) expression. Lithium produced similar effects to ebselen in the same experiments. In addition, an IMPase inhibitor but not a GSK-3 inhibitor mimicked the effect of ebselen at the behavioural model of 5-HT2A receptor function. Ebselen also reduced 5-HT2C receptor function, as assessed using IEG expression, and lithium had a similar effect. Ebselen was also found to increase 5-HT synthesis in mouse brain regions as previously reported for lithium. In microdialysis studies, ebselen tended to enhance the increase in extracellular 5-HT levels induced by the SSRI citalopram in hippocampus. This finding was consistent with the observation that ebselen and citalopram increased IEG-expression when administered together but not when administered separately. Lastly, ebselen when administered repeatedly increased the abundance of a variety of gene markers of neuronal plasticity in mouse brain regions. Lithium also increased the abundance of markers of neuronal plasticity. Overall, the present study found that ebselen attenuated 5-HT2 receptor function and partially augmented the effects of citalopram, while it increased markers of neuronal plasticity. These effects of ebselen were largely mimicked by lithium. These findings show that ebselen has similar neuropharmacological effects to lithium across a range of mouse models relevant to depression. The antidepressant potential of ebselen is discussed
Evidence for a 5-HT6 receptor-mediated control of midbrain 5-HT neurons
Full text linkThe dorsal raphe nucleus (DRN) contains the majority of 5-hydroxytryptamine (5-HT)-producing neurons, whose firing is influenced by homeostatic feedback pathways. Dysfunction of 5-HT neurons is implicated in the pathophysiology of diseases such as depression. Thus, pathways regulating 5-HT neuron activity represent potential therapeutic targets. Negative feedback pathways influencing 5-HT neurons include 5-HT1A autoreceptors located in the DRN, and feedback from 5-HT1A, 5-HT2A and 5-HT2C receptors on postsynaptic neurons in forebrain regions. One pathway, mediated by 5-HT4 receptors on medial prefrontal cortex (mPFC) neurons, positively regulates 5-HT neuron activity. Preliminary findings in the Sharp Laboratory suggested that 5-HT6 receptors may also positively regulate 5-HT neuron activity. Using in vivo electrophysiological recordings in combination with drug tools, this thesis investigated the 5-HT6 receptor control of 5-HT neurons, a proportion of which were identified as 5-HT-containing using a juxtacellular labelling technique.
Electrophysiological recordings in anaesthetised rats found that 5-HT6 receptor agonists WAY-181187 and WAY-208466 increased 5-HT neuron firing to 58% and 47% above pre-drug firing, respectively. By contrast 5-HT6 receptor antagonist SB-399886 reduced 5-HT neuron firing to 56% below pre-drug firing. Four other 5-HT6 ligands, agonist ST-1936, and antagonists AE-58054, SB-258585, and SB-271046, had no significant effect on 5-HT neuron firing. Simultaneous electroencephalogram (EEG) recordings found that WAY-181187 and WAY-208466 reduced frontal cortex slow wave (SW) oscillation power to 62% and 60% below pre-drug values, respectively. It was considered that the frontal cortex may be involved in the effect of these agonists on 5-HT neuron firing. Subsequent experiments investigated the influence of 5-HT6 receptors over mPFC neural activity.
WAY-181187 reduced mPFC SW oscillation power maximally to 54% below pre-drug values. This occurred in a putatively 5-HT6 receptor-dependent manner since the effect was blocked by SB-399885 and AE-58054. WAY-181187 also modulated the firing of mPFC pyramidal neurons, including those projecting to the DRN. Specifically, one population of neurons was excited by WAY-181187, with a maximum increase in firing of 161% above pre-drug firing, whereas another population was inhibited by WAY-181187, with a maximum decrease to 73% below pre-drug firing.
In a final set of experiments neurotoxic mPFC lesion attenuated the excitatory effect of WAY-181187 on 5-HT neuron firing. Thus the effect of WAY-181187 at 2mg/kg was significantly reduced in lesioned rats compared to sham controls.
Experiments in this thesis provide evidence to support a role of 5-HT6 receptor-mediated excitatory control of DRN 5-HT neurons via an mPFC-dependent mechanism. This control may act with previously reported feedback mechanisms to balance inhibitory and excitatory input to 5-HT neurons. Finally, 5-HT6 receptor-mediated feedback may be a useful target for modulating the 5-HT-system, such as in depression therapy.</p
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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