1,720,988 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
The surgical management of Peyronie’s Disease
No full textPeyronie's disease (PD) is an acquired benign connective tissue disorder that involves the tunica albuginea of the penis and can cause penile deformity and shortening. Because this condition is frequently associated with cardiovascular risk factors, a degree of erectile dysfunction is frequently present. The surgical management of PD should be offered once the acute phase of the disease has settled and the deformity is stable
Rare earth element speciation in volcanic groundwater: the Mount Vulture aquifer (Southern Italy).
No full textGranite- and andesite-hosted thermal water: geochemistry and environmental issues in northern Sardinia, Italy
No full textGroundwater quality can be compromised by its interaction with deep thermal waters. In northern Sardinia, two different deep thermal-water-flow systems have recently been recognized on the basis of thermal and isotopic features. One system (GW) is hosted in deep, mainly granitic, fractured reservoirs with water temperatures of 30–45 °C and Cl–Na hydrofacies. These waters have high fluoride contents owing to their alkalinity and water–rock interactions during long residence times in the reservoirs. Their bulk chemistry indicates chemistry by concentrating elements of environmental concern through adsorption, such as first-row transition metals and some chalcophile elements. The other system (AW) involves volcano-sedimentary rocks with water temperatures of 20–30 °C. These waters have neutral pH and are categorized as bicarbonate-alkaline and alkaline-earth hydrofacies. Their relatively high contents of chalcophile elements are consistent with their high dissolved CO2 contents; major elements are in equilibrium with kaolinite, which has a low cationic exchange capacity. In both of these flow systems, B speciation depends on pH. Furthermore, Mn and Fe occur as Mn2+ and Fe2+ species, respectively, depending on Eh–pH conditions. High Mn and Fe concentrations are derived from the reduction of Fe oxyhydroxides, releasing adsorbed Mn2+. The direct reduction of Mn4+ phases of Tertiary volcanic rocks also produces high Mn2+ concentrations. Fe oxyhydroxide reduction, at near-neutral pH, can also promote mobilization of As as HAsO42− or, with increasing pH, as H2AsO4− species. Trace-element analyses and speciation modeling indicate marked differences between GW and AW thermal-water systems, but neither contains metal concentrations at sufficient levels to cause health concerns via water consumption
Rare earth element distribution in groundwater of Mount Vulture volcanic aquifer (southern Italy).
No full text
Boron isotopes as a tool for the assessment of groundwater quality in the Mt. Vulture volcanic area (southern Italy).
No full textVariations 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
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