1,721,023 research outputs found
UNCOUPLING PROTEIN-3 (UCP3) IS INVOLVEDIN METABOLIC ADAPTATION INDUCED BY TRIIODOTHYRONINE
No full textThe classical Lenz vector and the two-dimensional quantum harmonic oscillator
Full text linkBoth the two-dimensional harmonic oscillator and the Newton potential allow particular solutions for the orbits which are ellipses with center of attraction in the center, in the !rst case, and in one focus, in the second. The same complex map which allows to go from Kepler’s to Hooke’s orbits, and back, is used to transform the Lenz vector, de!ned for the Kepler orbit, into two conserved quantities for the harmonic motion. Upon quantization, the resulting operators, together with the angular momentum Lz , are found to correspond to the generators of the SU(2) internal symmetry of the two-dimensional quantum oscillator and the connection to the Schwinger model of angular momentum is made apparent. We give a self-contained new look on this topic
Absence of uncoupling protein-3 (UCP3) affects mice metabolic parameters and the metabolic adaptation induced by the administration of triiodothyronine to hypothyroid rats
No full text
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
Charge density response in layered metals: retardation effects, generalized plasma waves and their spectroscopic signatures
Full text linkTransverse plasma polaritons and longitudinal plasmons describe the
propagation of light-matter modes in an isotropic metal. However, in a layered
metal the anisotropy of the bare electromagnetic response mixes the
longitudinal and transverse excitations, making the distinction between
polariton and plasmon blurred at small wavevectors, where retardation effects
of the electromagnetic interactions become quantitatively relevant. In the
usual Kubo approach for the linear response, this effect appears as a mixing
between the density and the transverse current fluctuations, that requires to
revise the standard RPA approach for density correlations where only the
instantaneous Coulomb potential is included. In this paper we derive the
general expression for the density and current correlation functions at long
wavelength in a layered metal, showing that below a crossover scale set by the
anisotropy of the plasma frequencies retardation effects make the dispersion of
the generalized plasma modes different from the standard RPA result. In
addition, the mixed longitudinal and transverse nature of these excitations
reflects in a double-peak structure for the density response, that can be
eventually accessed by means of high-momentum resolution electron-energy-loss
or X-rays spectroscopies.Comment: 22 pages, 3 figure
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