1,720,955 research outputs found
Cervical spinal degenerative disease in multiple sclerosis
No full textBackground and purpose: root and cord irritation from cervical spinal degenerative disease (SDD) may share clinical features with progressive multiple sclerosis (MS), so diagnostic overshadowing may occur. We hypothesized that cervical stenotic SDD is commoner in people with progressive MS, compared to controls.Methods: a retrospective case-control study of 111 cases (56 with progressive MS and 55 age- and sex-matched controls) was conducted. Five types of cervical SDD (disc degeneration, posterior disc protrusion, endplate changes, canal stenosis and foraminal stenosis) were assessed objectively on magnetic resonance imaging using published scales. Multivariable regression analysis was performed.Results: moderate-to-severe cervical spinal degeneration occurred more frequently in progressive MS, compared to controls. In multivariable regression, foraminal stenosis was three times more likely in progressive MS (odds ratio 3.20, 95% confidence interval 1.27, 8.09; p = 0.014), and was more severe (p = 0.009). This finding was confirmed on retrospective evaluation of clinical radiology reports in the same population. Foraminal stenosis was twice as likely in progressive MS, compared to relapsing-remitting MS.Conclusions: people with progressive MS are susceptible to foraminal stenosis. A higher index of suspicion for cervical SDD is required when appropriate neurological symptoms occur in the setting of progressive MS, to guide appropriate treatment or monitoring
CRP (C-reactive protein) in outcome prediction after subarachnoid haemorrhage and the role of machine learning
No full textBackground and Purpose: Outcome prediction after aneurysmal subarachnoid hemorrhage (aSAH) is challenging. CRP (C-reactive protein) has been reported to be associated with outcome, but it is unclear if this is independent of other predictors and applies to aSAH of all grades. Therefore, the role of CRP in aSAH outcome prediction models is unknown. The purpose of this study is to assess if CRP is an independent predictor of outcome after aSAH, develop new prognostic models incorporating CRP, and test whether these can be improved by application of machine learning.Methods: This was an individual patient-level analysis of data from patients within 72 hours of aSAH from 2 prior studies. A panel of statistical learning methods including logistic regression, random forest, and support vector machines were used to assess the relationship between CRP and modified Rankin Scale. Models were compared with the full Subarachnoid Hemmorhage International Trialists’ (SAHIT) prediction tool of outcome after aSAH and internally validated using cross-validation.Results: One thousand and seventeen patients were included for analysis. CRP on the first day after ictus was an independent predictor of outcome. The full SAHIT model achieved an area under the receiver operator characteristics curve (AUC) of 0.831. Addition of CRP to the predictors of the full SAHIT model improved model performance (AUC, 0.846, P=0.01). This improvement was not enhanced when learning was performed using a random forest (AUC, 0.807), but was with a support vector machine (AUC of 0.960, P <0.001).Conclusions: CRP is an independent predictor of outcome after aSAH. Its inclusion in prognostic models improves performance, although the magnitude of improvement is probably insufficient to be relevant clinically on an individual patient level, and of more relevance in research. Greater improvements in model performance are seen with support vector machines but these models have the highest classification error rate on internal validation and require external validation and calibration.</p
Changes in outcome prediction during the first week after subarachnoid hemorrhage
No full textBACKGROUND: Prediction of long-term outcome based on initial neurological condition after aneurysmal subarachnoid hemorrhage varies with time. To date, studies have been limited to early time points and have reported that prognostication is best after resuscitation.OBJECTIVE: To describe how prediction of outcome varies from ictus through the first week of admission.METHODS: A retrospective analysis of patients with a diagnosis of aneurysmal subarachnoid hemorrhage recruited to a prospective database. Neurological condition was recorded on each day of the inpatient stay, up to day 7, using World Federation of Neurological Societies score (WFNS). Poor outcome was defined by modified Rankin scale of 3-6 at 3 months. Outcome prediction was assessed using area under the curve (AUC) after binary logistic regression.RESULTS: Of 645 patients, 55(14%) patients with WFNS 1&2 and 77(45%) patients with WFNS 4&5 on day 0 had a poor outcome. 30(8%) patients with WFNS 1&2 and 54(81%) patients with WFNS 4&5 on day 7 had a poor outcome. Prognostication using WFNS improved from day 0 to day 7 (AUC = 70.1%, CI 65.0%–75.1% vs AUC = 81.9%, CI 77.4%–86.0%) with an incremental improvement with each day in between, and the largest increases early around the time of resuscitation.CONCLUSION: Prediction of outcome improves beyond the initial resuscitation, up to day 7 of admission, with no evidence of any deterioration around the time of treatment or delayed complications like delayed cerebral ischemia. This is important when prognosticating for clinical purposes and emphasizes the importance of standardization of timing of WFNS in research
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
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