1,720,980 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
CARDIOPROTEZIONE ED ANESTESIA EPIDURALE TORACICA: UN CASO DI ISCHEMIA MIOCARDICA POSTOPERATORIA
No full textObiettivo. Analisi dell’effetto cardioprotettivo perioperatorio dell’anestesia peridurale toracica (TEA) in un paziente car- diopatico sottoposto a chirurgia non cardiaca.
Materiali e metodi. Paziente di 59 anni affetto da patologia neoplastica, BPCO severa, insufficienza renale cronica e car- diopatia ipertensiva (ASA IV), viene sottoposto ad intervento chirurgico di cistectomia radicale e resezione duodeno-digiu- nale. In fase preoperatoria si posiziona un catetere epidurale (T10) e si somministra un bolo di Levobupivacaina (75 mg) e Fentanest (0,05 mg). Si procede a monitoraggio intraoperato- rio con CardioQ che evidenzia uno stato ipotensivo iniziale con bassa portata e basse resistenze. Trascorsi 150 minuti si somministra un bolo peridurale con Levobupivacaina (25 mg) e Fentanest (0,005 mg). Al termine della chirurgia si procede alla somministrazione mediante pompa infusionale di Levo- bupivacaina (1.25 mg/ml) e Morfina (0,05 mg/ml) alla veloci- ta di 5 ml/h; Il paziente si trasferisce in UTI dove si continua l’infusione peridurale per le successive 24h. Ridotta la velocitàdi infusione si sospende la stessa e dopo 4 h si assiste a com- parsa di dolore toracico con sottoslivellamento del tratto ST- T in sede antero-laterale e relativa diagnosi di angina instabi- le.
Risultati. Dall’analisi del monitoraggio intraoperatorio e postoperatorio (Tabelle I, II) non si rileva alcuna alterazione dei parametri emodinamici ed elettrocardiografici suggestiva di un evento ischemico. I suddetti parametri si sono mantenu- ti nel range di valori fisiologici per tutta la durata dell’infusio- ne peridurale, e successivamente in seguito alla sospensione della stessa si è verificata la comparsa dell’evento ischemico, correlato all’aumento delle resistenze vascolari periferiche come documentato dal PRAM.
Discussione. La TEA, attraverso il controllo del dolore perio- peratorio e della risposta simpatico-adrenergica, determina una vasodilatazione delle arterie coronarie stenotiche e una riduzione degli episodi di ischemia miocardica 1,2. Dall’analisi della letteratura 3 e dai dati obiettivi emersi si ipotizza che la sospensione del protocollo anestesiologico attraverso la TEA abbia indotto una riduzione della cardioprotezione e di con- seguenza un incremento del rischio potenziale di malattia coronarica acuta
Accidental poisoning with Aconitum: Case report and review of the literature
Full text linkAconitine intoxication by ingestion of Aconitum roots can lead to ventricular tachycardia and cardiac arrest and provides an example of the potential effect of self-medication. Educational campaigns should be implemented to contain acute intoxications caused by herbal-derived products
A New Configuration for Helmet Continuous Positive Airway Pressure Allowing Tidal Volume Monitoring
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