1,721,112 research outputs found
An innovative “geo-carpet” system as a countermeasure against local scour at bridge piers: small-scale test results
No full textLocal scour around bridge piers is one of the most diffused causes of failure for river bridges since it considerably modifies the geometry of the riverbed around the foundation. Countermeasures have been proposed in terms of both bed armoring and flowaltering devices. In this field, the use of Geosynthetics can provide innovative solutions, with environmental, economic and technological benefits compared to more traditional approaches. In the paper some flume experiments, run in clear-water flow conditions on a circular pier in a homogeneous granular riverbed, are described. The tests included four runs where the area around the pier was covered with innovative “Geo-carpet” systems made by plastic nets with different mesh size, and one reference test on an unprotected pier. The results, at least for a single hydro-dynamic condition, showed the efficiency of the Geo-carpets on the reduction of the scour depth and volume, and pave the way to future experiments investigating different geometries and flow conditions (including live-bed scour)
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
Comparison of PR3-ANCA specific assay performance for the diagnosis of granulomatosis with polyangiitis (Wegener's)
No full textBackground: PR3-ANCA, the serological marker of granulomatosis with polyangiitis (GPA), is usually detected by immunometric assays, with purified PR3 directly coated onto the solid-phase. Novel methods for PR3-ANCA detection have been developed to improve the performance of traditional PR3-ANCA specific assays, but little is known about their diagnostic performance in real-life clinical settings. This study aimed to compare the performance of nine different commercial PR3-ANCA specific assays, including traditional and newer ones, for the diagnosis of GPA. Methods: The evaluated assays for PR3-ANCA detection were representative of the first, second, and third generation tests (direct, capture and anchor assays, respectively). A third-generation assay employing both human and recombinant PR3 was also evaluated. The study population consisted of 55 GPA patients, 175 disease controls (representing most diseases in differential diagnosis with primary small-vessel vasculitis) including 52 with microscopic polyangiitis, and 20 healthy subjects. We performed the primary evaluation of test sensitivity using cut-off points which provided adequate and identical specificity for each test. Results: Although specificity and area under the ROC curve did not differ significantly between the different assays, substantial differences in sensitivity at 98%-specificity were found in some instances (p<0.001). Compared to first generation direct PR3-ANCA specific assays, some of the second and third generation tests increased the positive predictive value (PPV) for GPA diagnosis. Conclusions: Some of the newer PR3-ANCA specific assays have better PPV than traditional ones
Propagation of aggrading sediment fronts in a laboratory flume
No full textChannel bed aggradation due to sediment overloading was studied experimentally. A series of aggradation tests, with uniform lightweight sediment, were performed to observe the hydro-morphologic response of a laboratory flume to bed-load sediment transport and nonequilibrium upstream sediment feeding. The hydro-dynamic and the sediment feeding rates were kept constant in time. The temporal evolution of the longitudinal profiles of the stream bed and of the water surface was measured by imaging methods. The experimental data were used to (i) provide a phenomenological description of the aggradation process, recognizing different morphologic features superimposed on one another and (ii) characterize the height and velocity of propagation of aggrading sediment fronts. The front heights increased with increasing sediment supply, while the front celerity decreased. The celerity values were compared to a few predictors available in the literature. The literature formulae return celerity values scattered over almost two orders of magnitude, and present conflicting trends (a predicted celerity may either increase or decrease for increasing sediment feeding rate), thus stimulating further research on the topic
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
