1,721,023 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
Novel investigational drugs for gastric cancer
No full textBACKGROUND: Gastric cancer still represents a leading cause of death worldwide. Several cytotoxic agents have demonstrated activity and combination regimens improve progression-free survival, overall survival and quality of life. Nevertheless, now there is no standard therapy for advanced gastric cancer patients.
OBJECTIVE: To evaluate the role of new investigational agents.
METHODS: We analysed Phase I, II and III studies that evaluated tailored drugs directed against the epidermal growth factor receptor (EGFR), the c-erbB2, the vascular endothelial growth factor (VEGF), the vascular endothelial growth factor receptor (VEGFR), the matrix metalloproteinases (MMP) and the mammalian target of rapamycin (mTOR).
CONCLUSION: Data from Phase II trials indicate the potential of improved efficacy of chemotherapy when administered in combination with bevacizumab and cetuximab. Trastuzumab results are ongoing, while marimastat has not obtained clinical developments even if it has demonstrated to be an active drug in this setting of patients
Ammonia decomposition over commercial Ru/Al2O3 catalyst: An experimental evaluation at different operative pressures and temperatures
No full textThe ammonia decomposition process for hydrogen production was studied experimentally in a fixed bed tubular micro-reactor (I.D. = 1 cm and h = 20 cm) filled with 15 ml of ACTA Hypermec 10010 Ru catalyst. With the aim of pointing out the best process conditions, experiments were carried out varying the reaction temperature between 400 and 500 C, the feeding gas pressure between 1 and 10 bar and the GHSV (Gas Hourly Space Velocity) between 300 and 2400 h -1. To maintain the temperature as uniform as possible along the reactor axis, a 3 zone heater was used and each zone was controlled independently. An acid H2SO4 trap was used downstream the reactor to remove by neutralization the residual ammonia from the product gas. Moreover, the residual ammonia amount in the gas and thus the NH3 dissociation were evaluated for the catalyst in different operative conditions by measuring the PH of the trap and its changing rate over time. Dissociations close to the chemical equilibrium were obtained for every GHSV and temperature we tested with a pressures of 1 and 5 bar in the reactor. In particular, the dissociation was always higher than 99% at 1 bar, while at 5 bar it varied from 96% at 400 °C to 99% at 500 °C. At 10 bar the chemical equilibrium was reached for all GHSVs only at 450 °C and 500 °C with dissociations equal to 95.5% and 97.2%. At 400 °C a dissociation close to the chemical equilibrium (92%) was reached only for a GHSV of 300 h-1 while for the remaining GHSVs the dissociation was always lower, down to 80.8% for a GHSV equal to 2400 h-1. The kinetic parameters of the Temkin-Pyzhev model were evaluated for the ACTA Hypermec 10010 catalyst starting from the literature data on Ru catalyst. The results of this analysis showed that a pre-exponential factor of 1.5 × 10-9 mol m-3 s-1, an activation energy of 117 kJ mol-1 and a reaction order of 0.27 can be adopted for numerical simulations. Copyright © 2013, Hydrogen Energy Publications, LLC
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