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Estrellas variables en NGC 5286
Get PDFNGC 5286 es un cúmulo globular pobre en metales y por consiguiente rico en estrellas variables RR Lyrae (L. Rosino, 1972). Los autores han descubierto en este cúmulo 13 estrellas variables, de las cuales, 6 se han estudiado en el presente trabajo en forma preliminar ya que las observaciones son escasas.Asociación Argentina de Astronomí
Metallicità dell'ammasso globulare NGC 5286
Get PDFQuesto lavoro di tesi presenta la rianalisi di un campione di 7 stelle giganti nell’ammasso globulare NGC 5286, osservate con lo spettrografo UVES-FLAMES al Very Large Telescope. Lo stesso dataset era stato analizzato da Marino et al. (2015), che hanno evidenziato una distribuzione bimodale dell’abbondanza di ferro con due gruppi di stelle separati in [Fe/H] di ∼0.2 dex. Gli spettri sono stati rianalizzati utilizzando diversi metodi per stimare temperatura e gravità delle stelle. I parametri derivati spettroscopicamente confermano la presenza di due popolazioni con diversi valori di [Fe/H]. Tuttavia, le gravità derivate spettroscopicamente corrispondono a delle masse stellari irrealisticamente basse per quasi tutte le stelle analizzate (0.3-0.5 Msun). Se invece si considera un valore ragionevole per le masse stellari, le gravità spettroscopiche implicano che le stelle a più bassa metallicità dovrebbero essere più brillanti di quasi una magnitudine rispetto alle magnitudini osservate. I parametri spettroscopici risultano quindi non affidabili. Se invece si adottano temperature e gravità derivate dalla fotometria non si rileva alcuna dispersione intrinseca di ferro. Questa analisi dimostra quindi che, come la stragrande maggioranza (se non la totalità) degli ammassi globulari, anche NGC 5286 è monometallico, ovvero non è stato in grado di trattenere il materiale espulso dalle supernovae all’interno della sua buca di potenziale
The globular cluster NGC 5286
Get PDFNGC 5286 is a very interesting globular cluster of the southern hemisphere because of its photometric and spectroscopic characteristics. The cluster is located in the direction of the galactic centre rather than in the anticentre (1" = 311°, 57; b" = +10°,58) and at a small altitude over tha galactic plane. The cluster is seen through the Sagitarius Arm of our Galaxy and therefore the stellar field studied shows a strong component of Population I. The reddening of the cluster is E(B-V)=0.47 magnitudes and its distance is of about 6982 pc while the Population I stars projected into the field are located at about 1600 pc which agrees quite well with the Sagitarius arm in this direction (1"= 311°,57). The color-magnitude diagram of NGC 5286 imitates the diagram of clusters with very low metallic content formed in the Halo of our Galaxy. There is a marked predominance of blue stars in the horizontal branch. These stars are located at large projects distances from the cluster center.Asociación Argentina de Astronomí
Corrigendum : A recurrent p. Arg92Trp variant in steroidogenic factor-1 (NR5A1) can act as a molecular switch in human sex development [Human Molecular Genetics, 25, 23, (2016) (5286-5286)] DOI: 10.1093/hmg/ddw186
No full textPublisher Copyright: © The Author 2016. Published by Oxford University Press. All rights reserved.The author Marie-Charlotte Dumargne should have been included in the author list of the above article. This has been corrected above and in the original article (doi:10.1093/hmg/ddw186)
THE GLOBULAR CLUSTER NGC 5286. I. A NEW CCD <i>BV</i> COLOR-MAGNITUDE DIAGRAM
No full textWe present BV photometry of the Galactic globular cluster NGC 5286, based on 128 V frames and 133 B frames, and covering the entire face of the cluster. Our photometry reaches almost two magnitudes below the turn-off level, and is accordingly suitable for age analysis. Field stars were removed statistically from the cluster's color-magnitude diagram (CMD), and a differential reddening correction applied, thus allowing a precise ridgeline to be calculated. Using the latter, a metallicity of [Fe/H] = - 1.70 +/- 0.05 in the Zinn & West scale, and [Fe/H] = - 1.47 +/- 0.02 in the Carretta & Gratton scale, was derived on the basis of several parameters measured from the red giant branch, in good agreement with the value provided in the Harris catalog. Comparing the NGC 5286 CMD with the latest photometry for M3 by P. B. Stetson, and using VandenBerg isochrones for a suitable chemical composition, we find evidence that NGC 5286 is around 1.7 +/- 0.9 Gyr older than M3. This goes in the right sense to help account for the blue horizontal branch of NGC 5286, for which we provide a measurement of several morphological indicators. If NGC 5286 is a bona fide member of the Canis Major dwarf spheroidal galaxy, as previously suggested, our results imply that the latter's oldest components may be at least as old as the oldest Milky Way globular clusters
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
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
A bulk tank milk survey of Ostertagia ostertagi antibodies in dairy herds in Prince Edward Island and their relationship with herd management factors and milk yield
No full textThe objective of this study was to quantify the relationship of the levels of antibodies to Ostertagia ostertagi in bulk-tank milk samples from Prince Edward Island (PEI) dairy farms to milk production and to herd-management practices potentially related to gastrointestinal nematode infections. The milk samples were obtained from 289 to 322 dairy farms during 2000; production and management data were available from 197 and 200 farms, respectively. Cow exposure to pasture and whole-herd anthelmintic treatment were the only herd management variables significantly associated with antibody levels in the fall of 2000. An increase in antibody levels from the observed 25th percentile to the 75th percentile (interquartile range) was associated with a drop in milk production of 1.2 kg/cow/day. The results of this study indicate that the enzyme-linked immunosorbent assay for O. ostertagi antibody is a potentially useful technique to measure parasite exposure in adult dairy cows and that parasite burdens in lactating cattle in PEI have an important impact on milk production..RE: 18 ref.; SC: 0D; 0I; 0H; 0V; ZA; VE; HE; CA; BE; PA; ZDSource type: Electronic(1) http://upei-resolver.asin-risa.ca?sid=SP:CABI&id=pmid:&id=&issn=0008-5286&isbn=&volume=43&issue=6&spage=454&pages=454-459&date=2002&title=Canadian%20Veterinary%20Journal&atitle=A%20bulk%20tank%20milk%20survey%20of%20Ostertagia%20ostertagi%20antibodies%20in%20dairy%20herds%20in%20Prince%20Edward%20Island%20and%20their%20relationship%20with%20herd%20management%20factors%20and%20milk%20yield.&aulast=Sanchez&pid=%3Cauthor%3ESanchez%2c%20J%3bDohoo%2c%20I%3C%2Fauthor%3E%3CAN%3E20023095979%3C%2FAN%3E%3CDT%3EJournal%20article%3C%2FDT%3
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
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