1,721,010 research outputs found
Massive neutrinos and dark halos around galaxies
No full textIn this paper we investigate the hypothesis that hot massive neutrinos can be the main dark matter component of galactic halos. The consistency of the cosmological nu's phase space density with the properties of the dark matter halos of dwarf galaxies sets an upper limit to the neutrino mass m(nu) (Tremaine & Gunn 1973; TG). Here we apply the TG argument to a very large sample (1100 objects) of high quality rotation curves of normal spirals, and calculate reliable upper limits to the neutrino mass. Unlike previous works, our estimate is distance independent and holds for different Hubble Types and for the whole luminosity range. We find that, in order to be clustered on galaxy halo scales, nu's should be so massive as to violate the cosmological constraint <Omega(nu) less than or equal to 1. Thus, we conclude that hot neutrinos do not play a relevant role on galactic scales
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
Anisotropic fluorescence emission and photobleaching at the surface of one-dimensional photonic crystals sustaining bloch surface waves. II. experiments
No full textPhotonic crystal (PC)-enhanced fluorescence has been proposed as a novel tool for early disease detection in liquid biopsy. Photobleaching of the emitters has never been deeply investigated, although its cross section is expected to increase because of the large field intensity enhancement in PC. Herein, we report on the experimental investigation of the anisotropic effects arising when fluorescence excitation and emission are coupled to differently polarized modes of the same PC structure. In particular, we experimentally characterized the anisotropic photobleaching taking place during the operation of one-dimensional PC (1DPC) biosensors sustaining Bloch surface waves (BSW) at their truncation edge. The experimental results are compared to the description provided by our theoretical model reported in a twin article. We demonstrate experimentally that photobleaching affects the response of a cancer biomarkers' detection assay and propose a procedure to compensate for it. Moreover, we describe the experimental use of BSW-coupled fluorescence and of the strong localization of the BSW at the 1DPC surface to selectively probe the rotational diffusion kinetics of proteins bound at the 1DPC surface with high spatial resolution and for different binding strengths
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
Bloch Surface Wave Based Biosensing
No full textAn integrated biosensing platform exploiting the properties of Bloch surface waves on all-dielectric thin film stacks is described. It combines label-free sensing based on angular resonance tracking with surface wave enhanced fluorescence excitation and detection. Detailed design considerations reveal a system with defined attenuation to improve resolution limits in both modes
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
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