1,721,020 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
Post-operative spondylodiscitis
No full textPostoperative spine infections (PSIs) are a frequent and dreaded complication of spine surgery. Although different studies have been published, the prevalence of PSIs is thought to be about 5% for most spine surgical procedures. Different risk factors have been identified for PSIs. Among the others, extensive soft tissue dissection, longer operative time, soft tissue devitalization, and use of surgical instrumentation have been associated with higher risks of infection. Direct inoculation during surgery is the common infection route for PSIs. Gram-positive cocci (such as Staphylococcus aureus, Staphylococcus epidermidis and beta-hemolytic streptococci) are the most common pathogens. Gram-negative bacteria also play a role in PSIs and may be associated with systemic illness and multisystem organ failure. A high level of suspicion is of paramount importance in early diagnosis of PSIs. Clinical symptoms of PSIs may be subtle and the infection may become apparent only in its late stages. Early diagnosis is the most important prognostic factor for PSIs. Although blood tests (i.e. ESR, CRP, and white blood cell count) and imaging studies (most commonly MRI) can be useful, it must be clear to the clinician that diagnostic modalities, either tissue biopsy or blood cultures, are of the utmost importance for diagnosing PSIs and devising a correct antibiotic therapy. Antibiotic therapy with early bracing (or bed rest) is the most commonly used treatment method for PSIs. Nevertheless, a more aggressive surgical treatment may be required in some patients. The goals of surgical treatment are to help the eradication of the infection, provide an adequate wound closure, and maintain spine column mechanical stability
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
Surgical treatment of tuberculous spondylodiscitis
No full textBACKGROUND: Most patients affected by spinal tuberculosis can be successfully treated conservatively with chemotherapy, external bracing and prolonged rest. Nevertheless, kyphotic deformity, spinal instability and neurological deficit remain a common complication associated with conservative approach.
AIM: To illustrate different indications and treatment modalities for tuberculous spondylodiscitis, focusing on the role of surgery as an adjuvant of effective chemotherapy in the management of selected patients.
MATERIALS AND METHODS: Various early and late surgical procedures are recommended to treat spinal tuberculosis. The Authors analyzed surgical indications, approaches, complications and outcomes comparing their experience with available Literature.
RESULTS: Conservative management is preferable in patients without vertebral instability and deformity; in presence of abscesses, invasive radiological techniques in combination with abscess drainage and chemotherapy are recommended. In patients with vertebral collapse, kyphotic deformity or abscess formation, vertebral instability or neurological deficits, anterior radical debridement, anterior strut grafting and anterior instrumentation is an optimal standardized procedure. In patients with involvement of more than two vertebral levels or lumbosacral junction and in those whose sagittal alignment is markedly deformed with segmental kyphosis, and in patients who have difficulty in undergoing anterior instrumentation, posterior instrumentation is recommended in combination with anterior radical debridement and anterior strut grafting in one or two staged procedures.
CONCLUSIONS: Since surgery for spinal tuberculosis is demanding, it should be performed only after taking into account the risks and benefits in operable patients. Various surgical procedures are recommended to treat spinal tuberculosis but the common goals are to eradicate the infection and to prevent or to treat neurologic deficits or spinal deformity
CFD 3D Analysis of Charge Motion and Combustion in a Spark-Ignition Internal Combustion Engine under Close-to-Idle Condition
No full textThe increasingly stringent limitations on noxious missions of transport sector highly affect the development of new engines. The operating conditions of the engine at low-load and idle play a relevant role along the regulatory homologation cycles, contributing to overall emissions. In this work, the effectiveness of some solutions to improve the behaviour under close-to-idle operation of a Spark-Ignition motorcycle engine are compared by 3D CFD analyses. Specifically, the effects of two designs of the intake port and of the opening direction of the throttle valve, either clockwise or counterclockwise, are investigated. Multi-cycle simulations are carried out, under motored and fired conditions, for a single close-to-idle operating point. The various designs are compared in terms of capability to generate a stable tumble vortex during the intake phase and to produce an adequate turbulence level at the beginning of the combustion process. The analyses revealed that a clockwise throttle opening can produce enhanced turbulence levels at the end of the compression stroke, especially in a close-to-spark region (increase of about 5% and 27 % at the TDC at a global and local level, respectively, compared to the base configuration). Additional limited improvements are obtained with the high tumbling design, where, however, a penalty on the maximum power output could emerge. The flow and turbulence motion differences among the tested geometries reflect on combustion development in its early stage, and on its degree of completeness at the exhaust valve opening. A clockwise opening of the throttle valve leads to an increase of the mass fraction burned of 5 percent points, compared to the base configuration
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
- …
