1,721,047 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
Outcomes of critically ill patients who received cardiopulmonary resuscitation
No full textRATIONALE: Studies examining survival outcomes after in-hospital cardiopulmonary arrest (CPA) among intensive care unit (ICU) patients requiring medications for hemodynamic support are limited. OBJECTIVES: To examine outcomes of ICU patients who received cardiopulmonary resusitation. METHODS: We identified 49,656 adult patients with a first CPA occurring in an ICU between January 1, 2000 and August 26, 2008 within the National Registry of Cardiopulmonary Resuscitation. Survival outcomes of patients requiring hemodynamic support immediately before CPA were compared with those of patients who did not receive hemodynamic support (pressors), using multivariable logistic regression analyses to adjust for differences in demographics and clinical characteristics. Pressor medications included epinephrine, norepinephrine, phenylephrine, dopamine, dobutamine, and vasopressin. MEASUREMENTS AND MAIN RESULTS: The overall rate of survival to hospital discharge was 15.9%. Patients taking pressors before CPA were less likely to survive to discharge (9.3 vs. 21.2%; P \u3c 0.0001). After multivariable adjustment, patients taking pressors before pulseless CPA were 55% less likely to survive to discharge (adjusted odds ratio [OR], 0.45; 95% confidence interval [CI], 0.42-0.48). Age equal to or greater than 65 years (adjusted OR, 0.77; 95% CI, 0.73-0.82), nonwhite race (adjusted OR, 0.58; 95% CI, 0.54-0.62), and mechanical ventilation (adjusted OR, 0.60; 95% CI, 0.56-0.63) were also variables that could be identified before CPA that were independently associated with lower survival. More than half of survivors were discharged to rehabilitation or extended care facilities. Only 3.9% of patients who had CPA despite pressors were discharged home from the hospital, as compared with 8.5% of patients with a CPA and not taking pressors (adjusted OR, 0.53; 95% CI, 0.49-0.59). CONCLUSIONS: Although overall survival of ICU patients was 15.9%, patients requiring pressors and who experienced a CPA in an ICU were half as likely to survive to discharge and to be discharged home than patients not taking pressors. This study provides robust estimates of CPR outcomes of critically ill patients, and may assist clinicians to inform consent for this procedure
In adult cardiac arrest (prehospital or in-hospital) (P), initially with a non-shockable rhythm but who develop a shockable rhythm (prehospital or in-hospital) (P), does any specific alteration in treatment algorithm (I) as opposed to standard care (accor
No full textTime to invasive airway placement and resuscitation outcomes after inhospital cardiopulmonary arrest
No full textBACKGROUND: Clinicians often place high priority on invasive airway placement during cardiopulmonary resuscitation. The benefit of early vs. later invasive airway placement remains unknown. In this study we examined the association between time to invasive airway (TTIA) placement and patient outcomes after inhospital cardiopulmonary arrest (CPA). METHODS: We analyzed data from the National Registry of Cardiopulmonary Resuscitation (NRCPR). We included hospitalized adult patients receiving attempted invasive airway placement (endotracheal intubation, laryngeal mask airway, tracheostomy, and cricothyrotomy) after the onset of CPA. We excluded cases in which airway insertion was attempted after return of spontaneous circulation (ROSC). We defined TTIA as the elapsed time from CPA recognition to accomplishment of an invasive airway. The primary outcomes were ROSC, 24-h survival, and survival to hospital discharge. We used multivariable logistic regression to evaluate the association between the patient outcome and early (\u3c5 min) vs. later (\u3e or =5 min) TTIA, adjusted for hospital location, patient age and gender, first documented pulseless ECG rhythm, precipitating etiology and witnessed arrest. RESULTS: Of 82,649 CPA events, we studied the 25,006 cases in which TTIA was recorded and the inclusion criteria were met. Observations were most commonly excluded for not having an invasive airway emergently placed during resuscitation. The mean time to invasive airway placement was 5.9 min (95% CI: 5.8-6.0). Patient outcomes were: ROSC 50.3% (49.7-51.0%), 24-h survival 33.7% (33.1-34.3%), survival to discharge 15.3% (14.9-15.8%). Early TTIA was not associated with ROSC (adjusted OR: 0.96, 0.91-1.01) but was associated with better odds of 24-h survival (adjusted OR: 0.94, 0.89-0.99). The relationships between TTIA and survival to discharge could not be determined. CONCLUSIONS: Early invasive airway insertion was not associated with ROSC but was associated with slightly improved 24-h survival. Early invasive airway management may or may not improve inhospital cardiopulmonary resuscitation outcomes. Copyright 2009 Elsevier Ireland Ltd. All rights reserved
Impact of resuscitation system errors on survival from in-hospital cardiac arrest
No full textBACKGROUND: An estimated 350,000-750,000 adult, in-hospital cardiac arrest (IHCA) events occur annually in the United States. The impact of resuscitation system errors on survival during IHCA resuscitation has not been evaluated. The purpose of this paper was to evaluate the impact of resuscitation system errors on survival to hospital discharge after IHCA. METHODS AND RESULTS: We evaluated subjective and objective errors in 118,387 consecutive, adult, index IHCA cases entered into the Get with the Guidelines National Registry of Cardiopulmonary Resuscitation database from January 1, 2000 through August 26, 2008. Cox regression analysis was used to determine the relationship between reported resuscitation system errors and other important clinical variables and the hazard ratio for death prior to hospital discharge. Of the 108,636 patients whose initial IHCA rhythm was recorded, resuscitation system errors were committed in 9,894/24,467 (40.4%) of those with an initial rhythm of ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT) and in 22,599/84,169 (26.8%) of those with non-VF/pVT. The most frequent system errors related to delay in medication administration (\u3e5 min time from event recognition to first dose of a vasoconstrictor), defibrillation, airway management, and chest compression performance errors. The presence of documented resuscitation system errors on an IHCA event was associated with decreased rates of return of spontaneous circulation, survival to 24h, and survival to hospital discharge. The relative risk of death prior to hospital discharge based on hazard ratio analysis was 9.9% (95% CI 7.8, 12.0) more likely for patients whose initial documented rhythm was non-VF/pVT when resuscitation system errors were reported compared to when no errors were reported. It was 34.2% (95% CI 29.5, 39.1) more likely for those with VF/pVT. CONCLUSIONS: The presence of resuscitation system errors that are evident from review of the resuscitation record is associated with decreased survival from IHCA in adults. Hospitals should target the training of first responders and code team personnel to emphasize the importance of early defibrillation, early use of vasoconstrictor medication, and compliance with ACLS protocols. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved
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