1,721,072 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
Examining the impact of psychological distress on short-term postoperative outcomes after elective endovascular aneurysm repair (EVAR)
Purpose: preoperative psychological factors have an impact on postoperative outcomes and there is a paucity of research in vascular surgery. The objective of this study was to examine the impact of preoperative psychological factors on short-term postoperative outcomes in an infrarenal endovascular aneurysm repair (EVAR) cohort. Methods: a prospective, multi-centre observational study was conducted across three vascular units in England. English-speaking participants who were older than 18 years, able to provide informed consent and awaiting an elective standard infrarenal EVAR were eligible for the study. A total of 46 patients undergoing elective infrarenal AAA repair were assessed preoperatively with the State Trait Anxiety Inventory (STAI), Beck's Depression Inventory (BDI-II) and Life Orientation Test-Revised (LOT-R). Data on five short-term postoperative outcomes was collected and analysed using Spearman's rank correlations. Results: higher preoperative anxiety levels (ρ = 0.38, p = 0.01), and depression scores (ρ = 0.36, p = 0.02) were moderately correlated with an increased length of postoperative critical care stay. Higher levels of preoperative depression were moderately correlated with greater postoperative opioid analgesia use (ρ = 0.34, p = 0.02). No correlation was witnessed between optimism scores and postoperative outcomes. No correlation was witnessed with respect to total length of stay, number of complications, or time to mobilisation. Conclusions: here is a potential link between preoperative psychological well-being and short-term postoperative outcomes in an EVAR cohort. Further work is necessary to validate this link and examine the role of preoperative interventions in optimising the psychological well-being of patients undergoing EVAR.</p
Dispelling the Myths Behind First-author Citation Counts
We 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
We 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
Neurophysiological effects of ischaemia
Spinal cord injury (SCI) and paralysis remains a tragic complication of thoraco-abdominal aortic aneurysm (TAAA) surgery, despite advances in surgical and medical management. A survey of vascular anaesthetists showed availability of intra-operative spinal cord monitoring to detect an injury and subsequently guide remedial interventions, is variable across the United Kingdom and Ireland, despite clear evidence of its benefit. This research sought to explore the potential benefits of transcranial magnetic stimulation (TMS) and near infrared spectroscopy (NIRS) as alternative, more accessible monitors of ischaemic SCI.
TAAA surgery has several nuances that required greater investigation if TMS was to be utilised in theatre. Firstly, the motor evoked potentials (MEPs) of peripheral vascular disease (PVD) patients were characterised. PVD is the primary pathology underlying TAAA and the MEPs of this cohort of patients showed no difference beyond that which would accountable by aging compared to healthy, younger controls. Also, it was demonstrated that over an hour of repeated single-pulse TMS, a time-frame similar to when the spinal cord is at greatest risk intra-operatively and a need for intense monitoring, the variability of the MEPs was no different to controls.
A second feature of TAAA surgery is the need to render the surgical field bloodless, thus providing a clear operative space for the surgeons to work in. This is achieved using arterial clamps, the unintended consequence of which is an ischaemic nerve block (INB). An INB has been used as a research tool to initiate changes in cortical excitability. Deafferentation of distal limb structures and subsequent disinhibition of the motor cortical output to non-ischaemic muscles ipsilateral to the INB, manifested as increased MEPs. Through the use of a novel, low pressure INB applied to the lower limb, an increase in MEP amplitude in muscles proximal to the INB occurred. It was further shown that this increase in cortical excitability extended to the contralateral legs muscles and to arm muscles. Simultaneous recordings of somatosensory evoked potentials (SSEP) from stimulation of the tibial nerve, also distal to the INB, demonstrated a reduction in SSEP amplitude but not a complete deafferentation as previously assumed.
Investigations into the mechanisms underlying these finding was then performed. Using quantitative sensory testing whilst an INB was performed, the loss of Aβ and Aδ indicated the deafferentation required to initiate changes in motor cortical excitability. The preservation of C-fibre function could account for the unexpected finding where participants with exaggerated punctate sensation had greater increases in MEPs and possible cortical excitability. Paired-pulse TMS paradigms explored the potential neuronal networks responsible for the increase in MEPs of the contralateral muscles. A reduction in interhemispheric inhibition was seen from the deafferented motor cortex to the intact motor cortex, whilst no change in intrahemispheric pathways was seen.
The final chapter of this thesis explores the use of TMS and NIRS under surgical conditions. Despite numerous obstacles to patient recruitment, not withstanding a pandemic, a case series is presented with meaningful data which can be used to guide future study. Under the correct anaesthetic regimen, TMS induced MEPs can be recorded. The limited sample size was unable to determine if changes in cortical excitability occur in these conditions during surgery utilising a thigh INB however. In the second clinical investigation, NIRS was used to measure paraspinal muscle oxygen saturations levels (rO2), believed to correlate with intra-spinal oxygenation. This was performed alongside traditional intraoperative neuromonitoring of spinal cord with transcranial electrical stimulation (TES) MEPs. Paraspinal rO2 appeared to follow changes in the haemodynamic status of the patients, where a low rO2 would reflect a low blood pressure. One patient experienced a paraparesis, with a recoverable reduction in MEP amplitude and paraspinal rO2. Another patient who later died without clinical confirmation of paralysis, had a precipitous and permanent reduction in both MEPs and rO2, likely reflecting a SCI. A third patient where a decrease in MEPs and paraspinal rO2 was seen had remedial interventions initiated to prevent a possible SCI, which resulted in a return of both measures close to baseline.
Future work should look to explore the changes in cortical excitability secondary to iatrogenic limb ischaemic during TAAA surgery and how this impacts TMS-induced MEP characteristics and their interpretation in detecting a SCI. It should also explore their use alongside NIRS to detect both intra-operative and post-operative SCI and to guide their management.Open Acces
Author-wise bibliometric analysis based on entropy.
Author-wise bibliometric analysis based on entropy.</p
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