1,721,011 research outputs found
High precision flavour physics
Full text linkFlavour Physics is a very powerful tool to test the Standard Model and quantify the effects of New Physics by exploring possible departures from the model. It is necessary, however, to increase the level of precision of the experimental measurements and of the theoretical predictions in order to be sensitive to possible deviations. In this thesis we address this issue by providing theoretical improvements for both non-perturbative and perturbative calculations of some relevant flavour observables. On the one hand, we present a new strategy to renormalize lattice operators in QCD+QED in the RI-MOM scheme, fully including the non perturbative dynamics of QCD, and QED at O(αem). We show how to keep systematically into account all contributions not separable between the two interactions, thus overcoming the factorization approximation in which the mixed effects are neglected. A numerical analysis in the electro-quenched approximation is carried out for quark bilinear operators and for the case of the matrix elements relevant for Kl2 and πl2 processes and for semileptonic decays like Kl3. A detailed discussion of the calculation of the leading isospin breaking corrections to the leptonic decay rates Γ(Kμ2) and Γ(πμ2) is presented. On the other hand, we compute for the first time the anomalous dimension matrices of quark bilinear and weak four-fermions semileptonic operators at O(αs αem), thus improving the evolution and matching of the matrix elements related to such operators in Effective Field Theories
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
SYNTHESIS OF BETA-LACTAM DERIVATIVES OF 1,5-BENZOXAZEPINES AND 1,5-BENZOTHIAZEPINES
No full textCondensed beta-lactam derivatives of 1,5 benzoxazepines (2a-i) and of 1,5 benzothiazepines (2j-r) have been synthesized by the reaction of quino (2,3-b)(1,5) benzoxazepines (1a-c) or the corresponding benzothiazepines (1d-f) with some acyl chlorides in the presence of triethylamine.The formyl chloroacetamido derivatives (4a,b) were instead obtained by treating 1a,d with chloroacetyl chloride in the absence of the base. The mechanism of the reactions is discussed. No antibacterial activity was shown by the title compounds (2a-r) in the test experimental conditions
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
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
Modelling spatially-averaged wind profiles at the neighbourhood scale
No full textThis paper deals with the modelling of the flow in the urban canopy layer. It
critically reviews a well-known formula for the spatially-averaged wind profile, originally
proposed by Cionco in 1965, and provides a new interpretation for it. This opens up a number
of new applications for modelling mean wind flow over the neighbourhood scale. The
model is based on a balance equation between the obstacle drag force and the local shear
stress as proposed by Cionco for a vegetative canopy. The buildings within the canopy are
represented as a canopy element drag formulated in terms of morphological parameters such
as λf and λp (the ratios of plan area and frontal area of buildings to the lot area). These
parameters can be obtained from the analysis of urban digital elevation models. The shear
stress is parameterised using a mixing length approach. Spatially-averaged velocity profiles
for different values of building packing density corresponding to different flow regimes are
obtained and analysed. The computed solutions are compared with published data from windtunnel
and water-tunnel experiments over arrays of cubes. The model is used to estimate the
spatially-averaged velocity profile within and above neighbourhood areas of real cities by
using vertical profiles of λf
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