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Resolución UNRN N° 428/2009. Contratación Directa N° 15/2009.
No full textFil: Universidad Nacional de Río Negro (U). Universidad Nacional de Río Negro. Río Negro, ArgentinaResolución UNRN N° 428/2009. Contratación Directa N° 15/2009.fals
Bulletin No. 428 - Some Common Internal Parasites of Sheep in Wyoming
No full textBulletin No. 428 - Some Common Internal Parasites of Sheep in Wyomin
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Revealing the True Nature of Hen 2-428
No full textThe nucleus of Hen 2-428 is a short orbital period (4.2 h) spectroscopic binary, whose status as potential supernovae type Ia progenitor has raised some controversy in the literature. We present preliminary results of a thorough analysis of this interesting system, which combines quantitative non-local thermodynamic (non-LTE) equilibrium spectral modelling, radial velocity analysis, multi-band light curve fitting, and state-of-the art stellar evolutionary calculations. Importantly, we find that the dynamical system mass that is derived by using all available He II lines does not exceed the Chandrasekhar mass limit. Furthermore, the individual masses of the two central stars are too small to lead to an SN Ia in case of a dynamical explosion during the merger process
Variations on the Author
Get PDF“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
An in-depth reanalysis of the alleged type Ia supernova progenitor Henize 2-428
No full textContext. The nucleus of the planetary nebula Hen 2-428 is a short orbital-period (4.2 h), double-lined spectroscopic binary, whosestatus as a potential supernova type Ia progenitor has raised some controversy in the literature.Aims. With the aim of resolving this debate, we carried out an in-depth reanalysis of the system.Methods. Our approach combines a refined wavelength calibration, thorough line-identifications, improved radial-velocity measurements, non-LTE spectral modeling, as well as multi-band light-curve fitting. Our results are then discussed in view of state-of-the-artstellar evolutionary models.Results. Besides systematic zero-point shifts in the wavelength calibration of the OSIRIS spectra which were also used in the previous analysis of the system, we found that the spectra are contaminated with diffuse interstellar bands. Our Voigt-profile radialvelocity fitting method, which considers the additional absorption of these diffuse interstellar bands, reveals significantly lower masses(M1 = 0.66 ± 0.11 M? and M2 = 0.42 ± 0.07 M?) than previously reported and a mass ratio that is clearly below unity. Our spectraland light curve analyses lead to consistent results, however, we find higher effective temperatures and smaller radii than previouslyreported. Moreover, we find that the red-excess that was reported before to prove to be a mere artifact of an outdated reddening lawthat was applied.Conclusions. Our work shows that blends of He ii λ 5412 Å with diffuse interstellar bands have led to an overestimation of thepreviously reported dynamical masses of Hen 2−428. The merging event of Hen 2−428 will not be recognised as a supernova typeIa, but most likely leads to the formation of a H-deficient star. We suggest that the system was formed via a first stable mass transferepisode, followed by common envelope evolution, and it is now composed of a post-early asymptotic giant branch star and a reheatedHe-core white dwarf.</div
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Band 3, 428 (Sammlung Friedlaender)
No full textBAND 3, 428 (SAMMLUNG FRIEDLAENDER)
Band 3, 428 (Sammlung Friedlaender) (Public Domain) (1
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