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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
Thoracoscopic parietal pleural argon beam coagulation versus pleural abrasion in the treatment of primary spontaneous pneumothorax.
No full textOBJECTIVE: The obliteration of pleural space is useful to prevent recurrences of spontaneous pneumothorax. We retrospectively compared the results of pleural argon beam coagulation versus pleural abrasion in the treatment of primary spontaneous pneumothorax.
METHODS: Between 1996 and 2004, 136 patients underwent surgery for primary spontaneous pneumothorax, with 143 surgical procedures, all performed by VATS. Indications were recurrent pneumothorax in 107 patients, a complicated first episode in 29 and occupational activity in 7. Six patients were excluded because of postoperative histopathological diagnosis other than pulmonary emphysema. In 70 cases pleurodesis was performed with argon beam coagulation and in 67 by Marlex degrees mesh abrasion. These techniques were employed during two different periods. Median follow-up was 68 months in the Marlex degrees group and 41 in the argon group. The two groups resulted as being homogeneous for gender, age, smoking attitude and surgical indication. Statistical analysis was done with chi2 and Fisher's test.
RESULTS: No postoperative mortality was observed. Mean recovery time was 5 days. There were three patients with postoperative bleeding who underwent re-operation. There were nine cases of prolonged air-leak, one needing surgical exploration. Nine recurrences were noted, all requiring surgery. Two recurrences were observed in the group treated by pleural abrasion (3.4%) and seven in the group treated by argon coagulation (10.7%). The Fisher's test failed to demonstrate a statistical significance between the two procedures in terms of recurrence rate (p=0.18). Multivariate analysis yielded no risk factors for recurrences. Postoperative complications resulted as being equally distributed in both groups.
CONCLUSION: After primary spontaneous pneumothorax, pleurodesis induced by argon beam parietal pleural coagulation resulted as being no better than that obtained by pleural abrasion in the prevention of recurrences. No benefits in terms of postoperative complications resulted by use argon beam coagulation
Postoperative outcome of patients undergoing lung resection presenting with new-onset atrial fibrillation managed by amiodarone or diltiazem
No full textOBJECTIVE: Atrial fibrillation (AF) is a common complication after thoracic surgery. The objective of the study was to prospectively evaluate the postoperative outcome of patients undergoing lung resection and presenting with new onset of AF. The postoperative course of AF was also evaluated in relation to either amiodarone or diltiazem employed as anti-arrhythmic agents.
METHODS: A prospective observational study during a 3-year period was designed to evaluate all patients presenting AF as a complication of anatomic lung resections. The absence of a history of heart rhythm disease was an inclusion criterion. Amiodarone was employed as the anti-arrhythmic drug during the first 18 months, and diltiazem in the second half of the study. Anti-arrhythmic drugs were started intravenously; when rhythm was restored or after 48h of treatment, they were administered orally. AF duration, recurrences and the postoperative outcome of patients were recorded.
RESULTS: Thirty patients fulfilled inclusion criteria. No deaths occurred; median hospital stay was 10 days (range 6-37). AF presented as a solitary complication in 17 patients; in 10 patients it was associated with a respiratory complication and in the last three patients in one case each with pulmonary embolism, acute renal failure and chylothorax respectively. AF occurred on median post-operative day 2 (range: 1-9). Sinus rhythm restoration within the first 24h was observed in 11 (70%) out of the 15 patients receiving diltiazem and in 10 (67%) out of the 15 receiving amiodarone. After 48h, in 80% of patients in both groups cardioversion was achieved. AF recurrence occurred in 11 patients (37%). In 10 out of these 11 patients iterative intravenous treatment was attempted and in all a permanent cardioversion was achieved. Fisher's exact test indicated AF recurrence as being significantly correlated to the presence of a respiratory complication (p=0.02).
CONCLUSION: Postoperative outcome of patients undergoing lung surgery with new onset of AF resulted as being significantly complicated by AF recurrence in the case of an associated respiratory complication. The pharmacological strategies tested during this pilot study led to no differences in the postoperative course of AF
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
Prophylactic Use of Helmet-CPAP After Pulmonary Lobectomy: A Prospective Randomized Controlled Study.
No full text
Management of post intubation membraneous tracheal rupture.
No full textBACKGROUND: Postintubation tracheobronchial laceration is a rare complication of general anesthesia. A renewed interest in this disorder induced us to review our experience on its treatment, focusing on the evolution of the surgical approach, and describing a technical variation of the transcervical approach.
METHODS: From January 1994 to December 2002 we treated 13 patients with diagnosis of postintubation tracheobronchial laceration. The treatment was nonsurgical in 3 patients (1-cm-long tear) and surgical in the other cases. Two lesions extending to the main bronchi were repaired through a right thoracotomy as well as four lesions limited to the trachea observed before January 2001. After this date we used the transcervical approach for entirely intratracheal lesions: in three cases we performed an anterior transverse tracheotomy and in one case a transverse and midline vertical incision (T tracheotomy).
RESULTS: Both conservative and surgical therapy were successful in all the cases. Two patients in the thoracotomy group had a transient right vocal cord palsy. No morbidity was observed with the cervical approach. Normal healing of the sutures was evidenced by an endoscopic follow-up 30 days later.
CONCLUSIONS: In our experience nonsurgical treatment is advisable in small (length < 2 cm) uncomplicated tears. Concerning surgery, thoracotomy is indicated in tracheal lacerations extending to the main bronchi, whereas the transcervical approach is preferred for intratracheal tears because of its efficacy in reaching and suturing the lesions extending to the carina and for its limited invasiveness
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