1,720,986 research outputs found
Safety and efficacy of everolimus initiation from the first month after liver transplantation: A systematic review and meta‐analysis
Get PDFIntroductionEverolimus, a selective inhibitor of mamalian target of rapamycin (mTORi), is considered to be an alternative immunosuppressive regimen in the liver transplantation (LT) setting. However, most of the transplant centers avoid its early use (i.e., during the first month) after LT mainly due to safety issues. MethodsWe searched for all articles published between 01/2010 and 7/2022 to evaluate the effectiveness and safety of initial/early administration of everolimus after LT. ResultsSeven studies (three randomized controlled trials and four prospective cohort studies) were included: initial/early everolimus-including therapy (group 1) was used in 512 (51%) and calcineurin inhibitor (CNI) based therapy (group 2) in 494 (49%) patients. No significant difference was found between group 1 and group 2 patients regarding the rates of biopsy-proven acute rejection episodes (Odds Ratio [OR]: 1.27, 95% CI: .67-2.41, p = .465) and hepatic artery thrombosis (OR: .43, 95% CI: .09-2.02, p = .289). Everolimus was associated with higher rates of dyslipidemia (14.2% vs. 6.8%, p = .005) and incisional hernia (29.2% vs. 10.1%, p < .001). Finally, no difference was found between the two groups regarding recurrence of hepatocellular carcinoma (Risk Rates [RR]: 1.22 95%CI: .66-2.29, p = .524) and mortality (RR: .85 95%CI: .48-1.50, p = .570). ConclusionUse of initial/early everolimus seems to be effective with a satisfactory safety profile, making its administration a reasonable therapeutic option in the LT setting
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Μοντέλα αιτιότητας και εφαρμογή τους για την εκτίμηση της επίδρασης της θεραπείας της χρόνιας ηπατίτιδας Β
No full textClassic statistical analysis methods examine whether observed relationships are due to chance and provide us with inference concerning non-circumstantial associations between variables, that may however be non-causally interpreted. Unfortunately, it has been shown that in the context of a longitudinal observational study, when a covariate affected by past exposure is both a predictor of the future exposure and the outcome, i.e there exists time-dependent confounding, standard analysis approaches for the estimation of the exposure’s effect, may produce biased estimates. The g-methods are a class of methods introduced to estimate causal effects. The most recent of them is the Inverse Probability of Treatment Weighting (IPTW), which is applied to estimate the parameters of the Marginal Structural Models (MSMs). The aim of this thesis was to assess the performance of the MSMs in situations often met in longitudinal observational studies with survival endpoints. Following an exact simulation method, we explored two classes of scenarios: a) missed visits, which resembles clinical cohort studies; b) missing confounder’s values that corresponds to interval cohort studies. In the first class, data were analyzed initially without any correction and subsequently using either weights’ truncation or normalization. In the second class, data were analyzed either filling-in the missing values with the Last Observation Carried Forward (LOCF), or after imputing them by Multiple Imputation (MI) or accounting for missingness through additional weighting with the Inverse Probability of Missingness (IPMW).Furthermore, we analysed data from the HEPNET.Greece study for viral hepatitis B, in order to evaluate the effect of treatment and the treatment type (Interferon (IFN) +/- Nucleos(t)ide (NA) vs. NA) to the occurrence of a clinical event in CHB patients. Results of this thesis suggest that data from observational studies can provide us with useful inference, given that they are analyzed appropriately. Even in the presence of problems related to missing confounding data or irregular observational plans that are often met in observational studies, sophisticated approaches to account for potential bias can be incorporated into the MSM.Οι κλασικές μέθοδοι στατιστικής ανάλυσης εξετάζουν αν οι παρατηρούμενες σχέσεις είναι αποτέλεσμα τύχης και να μας δώσουν συμπεράσματα σχετικά με μη περιστασιακές σχέσεις μεταξύ μεταβλητών, οι οποίες όμως ενδέχεται να μην έχουν αιτιολογική ερμηνεία. Δυστυχώς, έχει αποδειχθεί ότι στο πλαίσιο μιας διαχρονικής μελέτης παρατήρησης, όταν μια μεταβλητή που επηρεάζεται από προηγούμενη έκθεση είναι ταυτόχρονα προγνωστικός παράγοντας α. μελλοντικής έκθεσης και β. της έκβασης, υπάρχει δηλαδή συγχυτικός παράγοντας εξαρτώμενος από το χρόνο, οι κλασικές προσεγγίσεις ανάλυσης για την εκτίμηση της επίδρασης της έκθεσης μπορεί να είναι μεροληπτικές. Οι g- μέθοδοι είναι μια κατηγορία των μεθόδων που εισήχθησαν για την εκτίμηση των αιτιακών επιδράσεων. Η πιο πρόσφατη εξ αυτών είναι η μέθοδος της στάθμισης με την αντίστροφη πιθανότητα θεραπείας (Inverse Probability of Treatment Weighting; IPTW), η οποία εφαρμόζεται για την εκτίμηση των παραμέτρων των περιθωριακών δομικών μοντέλων (Marginal Structural Models; MSMs). Ο σκοπός αυτής της εργασίας ήταν να αξιολογήσει τις επιδόσεις των MSM σε καταστάσεις που συχνά συναντώνται σε διαχρονικές μελέτες παρατήρησης με έκβαση την επιβίωση. Χρησιμοποιώντας μια ακριβή μέθοδο προσομοίωσης, διερευνήσαμε δύο κατηγορίες σεναρίων: α)Απουσία από προγραμματισμένες επισκέψεις, όπως συμβαίνει κατά την παρακολούθηση μιας κλινικής κοόρτης (clinic cohort) και β) μη καταγραφή των τιμών του συγχυτικού παράγοντα, που θα μπορούσε να προκύψει ακόμα και όταν οι επισκέψεις γίνονται ανά συγκεκριμένα χρονικά διαστήματα. Στην πρώτη περίπτωση, τα δεδομένα αναλύθηκαν αρχικά χωρίς καμία διόρθωση και στη συνέχεια χρησιμοποιήθηκε είτε περικοπή είτε κανονικοποίηση των βαρών/σταθμών. Στη δεύτερη περίπτωση, τα δεδομένα αναλύθηκαν είτε συμπληρώνοντας τις ελλείπουσες τιμές με την τελευταία παρατηρηθήσα τιμή τους (Last Observation Carried Forward; LOCF), είτε συμπληρώνοντας τις ελλείπουσες τιμές με τη μέθοδο των πολλαπλών υποκαταστάσεων (Mutliple Imputation; MI) είτε εφαρμόζοντας πρόσθετη στάθμιση με την αντίστροφη πιθανότητα του να είναι μια τιμή μη παρατηρηθήσα (ελλείπουσα) (Inverse Probability of Missingness Weighting; IPMW).Επιπλέον, αναλύσαμε δεδομένα από τη μελέτη HEPNET.Greece για την χρόνια ηπατίτιδα Β (Chronic Hepatitis B; CHB), προκειμένου να αξιολογηθεί η επίδραση της θεραπείας και του τύπου θεραπείας (Ιντερφερόνη +/- Νουκλεο(τ)ιδικό Ανάλογο (NA) έναντι μόνο Νουκλεο(τ)ιδικό Ανάλογο) στην εμφάνισηκλινικού συμβάντος σε ασθενείς με CHB.Τα αποτελέσματα αυτής της εργασίας δείχνουν ότι τα δεδομένα από τις μελέτες παρατήρησης μπορούν να παρέχουν χρήσιμα αποτελέσματα, εφόσον αναλυθούν με την κατάλληλη μέθοδο. Ακόμα και όταν υπάρχουν ελλείπουσες τιμές στο συγχυτικό παράγοντα ή σε περιπτώσεις παρακολούθησης ανά τυχαία/μη προκαθορισμένα χρονικά διαστήματα, όπως συμβαίνει συχνά σε μελέτες παρατήρησης, υπάρχουν εξειδικευμένες προσεγγίσεις για την αντιμετώπιση της πιθανής μεροληψίας οι οποίες μπορούν να ενσωματωθούν στα MSM
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
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