1,720,972 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
Analysis of prognostic factors for the indication of central lymphadenectomy in papillary thyroid carcinomas.
No full textBACKGROUND: In this study we examined whether it was possible following preoperative parameters statistically significant correlation with the presence of metastatic lymph nodes in the papillary thyroid carcinoma. We conducted a retrospective study in a group of patients with a preoperative diagnosis of papillary carcinoma who underwent total thyroidectomy associated with routine lymphadenectomy of the central compartment (level VI). PATIENTS AND METHODS: The study group consisted of patients whose definitive histological lymph node examination was positive for metastasis (N1), and the control group comprised patients found negative for metastasis (N0). RESULTS: Tumour diameter had a significance at 10% level [Pr(>|z|): 0.056], thus indicating that increased tumour size results in a higher probability of being in group N1. The logistic regression revealed that variables with a significance at 5% level for the presence of metastatic lymph nodes in the central compartment (N1) were: sex [Pr(>|z|): 0.019], overall patient age [Pr(>|z|): 0.012] and age >45 [Pr(>|z|): 0.022]. We performed a statistical analysis with the association of three preoperative variables (presence of ultrasound-revealed microcalcifications, presence of solid hypoechogenic nodule and type III vascularisation on echocolour-Doppler); this was found to result in a highly significant probability of entering into group N1. CONCLUSIONS: We found variables statistically significant for the presence of metastatic central compartment lymph nodes, including female sex, age >45 yrs and tumour diameter >1.5 cm. The association of papillary carcinoma with microcalcifications, solid hypoechogenic nodule structure and type III vascularisation on echocolour-Doppler also resulted in a statistically significant increase in the probability of positive level VI lymph nodes
Right Colectomy for Cancer. A Matched Comparison of Three Different Surgical Approaches
No full textPURPOSE: The standard approach to right colon cancer resection is still a matter of debate and includes laparoscopy, open midline incision, or open transverse incision. We aimed this study to compare the short- and long-term results of laparoscopic right-colectomy with those provided by the open approaches.
METHODS: Of the 176 patients who underwent right-colectomy at our Department for nonmetastatic colon cancer, 40 patients treated by laparoscopy, 40 treated by transverse incisions, and 40 treated by midline incisions were selected and matched using the propensity score method. Short-term results included: operating time, morbidity rate, number of lymph-nodes harvested (LNH), patients' recovery features, and costs. Long-term results included: disease-specific survivals and the rate of incisional hernias. The sub-groups were compared using t-test and Chi-square tests, whereas the Kaplan-Meier method was used to assess survivals.
RESULTS: Laparoscopies were the longer procedures, providing similar morbidity rates and LNH in comparison with the open approaches. Laparoscopy provided a faster return to oral intake and a shorter use of analgesics comparing with the midline approach; however, it showed only a minor consumption of analgesics in comparison with transverse laparotomy. There were no differences in the hospital stay and the long-term results were comparable between sub-groups. Costs analysis documented minor but not significant surgical expenses for the transverse approach.
CONCLUSIONS: Laparoscopy was documented safe, with similar morbidity rates and long-term results comparing with open surgery. Laparoscopy provided better functional short-term results comparing with the midline approach, but only small differences with respect to the transverse incision approach
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