1,721,003 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
Long-term outcome of a patient with Transcobalamin deficiency caused by the homozygous c.1115_1116delCA mutation in TCN2 gene. a case report
Full text linkBackground: Transcobalamin deficiency is a rare autosomal recessive inborn error of cobalamin transport (prevalence: < 1/1000000) which clinically manifests in early infancy. Case presentation: We describe the case of a 31 years old woman who at the age of 30 days presented with the classical clinical and laboratory signs of an inborn error of vitamin B12 metabolism. Family history revealed a sister who died at the age of 3 months with a similar clinical syndrome and with pancytopenia. She was started on empirical intramuscular (IM) cobalamin supplements (injections of hydroxocobalamin 1 mg/day for 1 week and then 1 mg twice a week) and several transfusions of washed and concentrated red blood cells. With these treatments a clear improvement in symptoms was observed, with the disappearance of vomiting, diarrhea and normalization of the full blood count. At 8 years of age injections were stopped for about two and a half months causing the appearance of pancytopenia. IM hydroxocobalamin was then restarted sine die. The definitive diagnosis could only be established at 29 years of age when a genetic evaluation revealed the homozygous c.1115_1116delCA mutation of TCN2 gene (p.Q373GfsX38). Currently she is healthy and she is taking 1 mg of IM hydroxocobalamin once a week. Conclusions: Our case report highlights that early detection of TC deficiency and early initiation of aggressive IM treatment is likely associated with disease control and an overall favorable outcome
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
Strain analysis of cardiac tissues from 3D ultrasound images through speckle tracking
No full textIn this paper we are presenting a method for achieving strain analysis of cardiac tissues from 3D ultrasound images. First of all, the left ventricle was segmented by an iterative snake algorithm which exploits the gradient vector flow field estimated from the 3D images. Once the ventricle was segmented, a set of points located on the external surface of the ventricle was selected. The movement of all these points along the entire cardiac cycle was calculated by using speckle tracking techniques based on the minimization of a Sum of Absolute Differences. The strain of all the segments connecting two of the considered points was computed, together with the rotation of the points along the long axis of the ventricle. The method was tested on images acquired from 10 patients: 3 with heart pathologies, 5 healthy subjects, and 2 patients with mild hypertrophy. The segmentation of the left ventricle with iterative methods demonstrated to be able to delineate the external surface of the ventricle in a consistent way. Preliminary results showed the feasibility of characterizing healthy subjects and patients with well-defined heart pathologies by using the outcomes achieved with the strain analysis
On the strain–line patterns in a real human left ventricle
No full textWe present and discuss a method to infer non invasively information on the fiber architecture in real LV walls. The method post–processes the echocardiographic data acquired by three–dimensional Speckle Tracking Echocardiography (3DSTE) through a MatLab–based protocol, already presented, discussed and val- idated in [5]. Our results reveals the difference between the role of endocardial and epicardial principal strain lines, at the systolic peak, and set the bases for possible future investigations aimed to analyze the onset of specific cardiac diseases through noninvasive analysis of LV fiber architectur
Dual vs. triple antithrombotic treatment after percutaneous coronary intervention in patients with non-valvular atrial fibrillation. a meta-analysis on current evidence
No full textObjective: Combination and duration of antithrombotic therapy in order to prevent both stent thrombosis and thromboembolic complications after coronary artery stenting (PCI) in non-valvular atrial fibrillation (AF) is still debated. This uncertainty can be attributed mainly to the fact that the reference trials were open-label and not adequately powered in order to reach a definitive conclusion on ischemic endpoints (i.e., stent thrombosis). On these grounds, data from real-life studies could support evidence on dual antithrombotic treatment (DAT) safety (bleeding risk) and efficacy (stent thrombosis prevention). The aim of the meta-analysis is to investigate in both randomized controlled trials (RCTs) and observational studies (Obs) the risks and/or benefits related to DAT vs. triple antithrombotic treatment (TAT) regimens in patients affected by AF undergoing PCI. Materials and methods: RCTs and Obs were retrieved through PubMed database. The risk ratio with 95% confidence interval was used to compare the primary and the safety endpoints. Results: Meta-analysis demonstrated no significant differences between DAT vs. TAT for mortality. However, a two-fold higher mortality rate was registered in Obs than in RCTs. The Obs did not confirm the expected significant reduction in bleeding risk shown by the RCTs; however, the bleeding rates in Obs were more than three-fold those of RCTs. In Obs, a significant greater risk for stent thrombosis was observed in DAT than in TAT. Conclusions: The safety and efficacy outcomes observed in RCTs are unrealistic with respect to the current clinical practice. So, more evidence is needed to have more exhaustive guidelines based on RCTs with homogeneous designs and protocols that should mimic real-life population and practice
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
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