21,045 research outputs found
GeMs/GSAOI observations of La Serena 94: an old and far open cluster inside the solar circle
Physical properties were derived for the candidate open cluster La Serena 94,
recently unveiled by the VVV collaboration. Thanks to the exquisite angular
resolution provided by GeMS/GSAOI, we could characterize this system in detail,
for the first time, with deep photometry in JHK - bands. Decontaminated
JHK diagrams reach about 5 mag below the cluster turnoff in H. The locus
of red clump giants in the colour - colour diagram, together with an extinction
law, was used to obtain an average extinction of . The
same stars were considered as standard - candles to derive the cluster
distance, kpc. Isochrones were matched to the cluster colour -
magnitude diagrams to determine its age, , and
metallicity, . A core radius of pc was
found by fitting King models to the radial density profile. By adding up the
visible stellar mass to an extrapolated mass function, the cluster mass was
estimated as M, consistent with an
integrated magnitude of and a tidal radius of
pc. The overall characteristics of La Serena 94 confirm that
it is an old open cluster located in the Crux spiral arm towards the fourth
Galactic quadrant and distant kpc from the Galactic centre. The
cluster distorted structure, mass segregation and age indicate that it is a
dynamically evolved stellar system.Comment: 16 pages, 24 figures, 2 Tables, accepted by MNRAS; corrected typo
Um grande surto de Legionella ausente do debate público
The Legionnaires’ disease outbreak that hit Portugal in November 2014 was the third largest worldwide and was declared a “great public health emergency”. Nonetheless, the Portuguese outbreak, despite killing 12 people and infecting 375 others did not promote extensive media coverage, nor did it make it into the political debate. We conducted a quantitative analysis of 83 news pieces on Legionella published in four national newspapers, and interviewed the journalists who covered this outbreak. The communication process was controlled by a small group of official sources and the outbreak was pushed away from news lineups due to two political scandals. The production of another news wave made the outbreak’s news wave to break prematurely.O surto de Legionella que atingiu Portugal em novembro de 2014 foi o terceiro maior em nível mundial, constituindo “uma grande emergência de saúde pública”. Ainda assim, o surto português não promoveu uma longa cobertura mediática, apesar das 12 mortes e 375 pessoas infetadas. Nem entrou no debate político. Fizemos uma análise quantitativa das 83 notícias sobre Legionella publicadas em quatro jornais nacionais, e conduzimos entrevistas com os jornalistas que cobriram este surto. O processo comunicativo foi controlado por um pequeno grupo de fontes oficiais, e o surto foi rapidamente afastado dos alinhamentos noticiosos, sendo substituído por dois escândalos políticos. A produção de outra onda noticiosa fez com que a onda noticiosa do surto de Legionella se quebrasse prematuramente.(undefined)info:eu-repo/semantics/publishedVersio
Instanton Corrected Non-Supersymmetric Attractors
We discuss non-supersymmetric attractors with an instanton correction in Type
IIA string theory compactified on a Calabi-Yau three-fold at large volume. For
a stable non-supersymmetric black hole, the attractor point must minimize the
effective black hole potential. We study the supersymmetric as well as
non-supersymmetric attractors for the D0-D4 system with instanton corrections.
We show that in simple models, like the STU model, the flat directions of the
mass matrix can be lifted by a suitable choice of the instanton parameters.Comment: Minor modifications, Corrected typos, 38 pages, 1 figur
Genomic wide-selection for tick resistance in Hereford and Braford cattle via reaction norm model.
The objective of this study was to compare a conventional genomic model (GBLUP) and its extension to a linear reaction norm model (GLRNM) specifying genotype by environment interaction (G*E) for tick resistance in Brazilian cattle. Tick counts (TC) from 4,363 Hereford and Braford cattle from 146 contemporary groups (CG) were available of which 3,591 animals had BovineSNP50 Illumina v2 BeadChip genotypes. The reaction norm covariate was based on CG estimates of TC from a first-step model. Analysis was conducted based on adapting the single step GBLUP/REML procedure. Fivefold cross validation based on K-means and random partitioning was used to compare the fit of the two models. Cross validation correlations were strong and not significantly different between models for either partitioning strategy. Nevertheless, it seems apparent that G*E for tick infestation exists and can captured by GLRNM models
Genotype by environment interaction for tick resistance of Hereford and Braford beef cattle using reaction norm model.
The cattle tick is a parasite that adversely affects livestock performance in tropical areas. Although countries such as Australia and Brazil have developed genetic evaluations for tick resistance, these evaluations have not considered genotype by environment (G*E) interactions. Genetic gains could be adversely affected, since breed-stock comparisons are environmentally dependent on the presence of G*E interactions, particularly if residual vari-ability is also heterogeneous across environments. The objective of this study was to infer upon the existence of G*E interactions for tick resistance of cattle based on various models with different assumptions of genetic and residual variability.Article 3
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