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    Determining the stellar masses of submillimetre galaxies: the critical importance of star formation histories

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    Submillimetre (submm) galaxies are among the most rapidly star-forming and most massive high-redshift galaxies; thus, their properties provide important constraints on galaxy evolution models. However, there is still a debate about their stellar masses and their nature in the context of the general galaxy population. To test the reliability of their stellar mass determinations, we used a sample of simulated submm galaxies for which we derived stellar masses via spectral energy distribution (SED) modelling (with Grasil, Magphys, Hyperz and LePhare) adopting various star formation histories (SFHs). We found that the assumption of SFHs with two independent components leads to the most accurate stellar masses. Exponentially declining SFHs (tau) lead to lower masses (albeit still consistent with the true values), while the assumption of single-burst SFHs results in a significant mass underestimation. Thus, we conclude that studies based on the higher masses inferred from fitting the SEDs of real submm galaxies with double SFHs are most likely to be correct, implying that submm galaxies lie on the high-mass end of the main sequence of star-forming galaxies. This conclusion appears robust to assumptions of whether or not submm galaxies are driven by major mergers, since the suite of simulated galaxies modelled here contains examples of both merging and isolated galaxies. We identified discrepancies between the true and inferred stellar ages (rather than the dust attenuation) as the primary determinant of the success/failure of the mass recovery. Regardless of the choice of SFH, the SED-derived stellar masses exhibit a factor of ~2 scatter around the true value; this scatter is an inherent limitation of the SED modelling due to simplified assumptions. Finally, we found that the contribution of active galactic nuclei does not have any significant impact on the derived stellar masses.Comment: Accepted to A&A. 11 pages, 9 figures, 1 table. V2 main changes: 1) discussion of the stellar age as the main parameter influencing the success of an SED model (Fig. 4, 5, 7); 2) discussion of the age-dust degeneracy (Fig 9); 3) the comparison of real and simulated submm galaxies (Fig 1

    Fenomenología y sabiduría popular

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    Ser y estar. Dos horizontes para definir la cultura

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    Association of the exon 9 single nucleotide polymorphism of CAPN1 with beef tenderness

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    The document attached has been archived with permission from the Association for the Advancement of Animal Breeding and Genetics.Initial data analysis from both the University of Adelaide’s Davies Cattle Gene Mapping and the New Zealand AgResearch Cattle Gene Mapping Projects showed a tenderness quantitative trait locus (QTL) on BTA29. Based on its function and location, the gene for micromolar calcium-activated neutral protease or calpain gene (CAPN1) was considered to be a strong positional candidate for the observed QTL effects. The objective of this study was to assess the association of a previously reported single nucleotide polymorphism (SNP) in Exon 9 of CAPN1 with the tenderness of M. longissimus dorsi (LD) and M. semitendinosus (ST) muscles in Bos taurus. The SNP (base 5709) causes the amino acid substitution of alanine for glycine316 [superscript] in the μ-calpain enzyme. Results demonstrated that the Exon 9 SNP was significantly associated with tenderness of both ST and LD muscles (P<0.01). Animals with the GG genotype showed higher (P<0.01) shear force values compared with CC genotypes (15% and 11% on day 1 and 14% and 11% on day 26 in LD and ST, respectively). The paternal allele encoding glycine at position 316 was associated with decreased meat tenderness relative to the allele encoding alanine at position 316. The equivalent maternal allele for CAPN1 Exon 9 was significantly associated with decreased tenderness of LD at four cook times and ST at day 1

    Additive effects of two growth QTL on cattle chromosome 14

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    The document attached has been archived with permission from the World Congress on Genetics Applied to Livestock Production.DNA-marker technology has the potential to assist seed-stock beef producers with genetic improvement of traits that are difficult to measure, and to assist research workers in identifying chromosomal regions containing quantitative trait loci (QTL), and eventually genes, which control animal performance traits. A collaborative study was established in 1995 between AgResearch in New Zealand (NZ) and Adelaide University in Australia to search for DNA markers significantly linked to production, carcass and meat quality traits in beef cattle. The present paper reports on a sub-set of that data, namely evidence from microsatellite markers on chromosome (Chr) 14 of significant linkage to growth traits and hot carcass weight (HSCW) at a standard level of trim

    Schottky mass measurements of heavy neutron-rich nuclides in the element range 70\leZ \le79 at the ESR

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    Storage-ring mass spectrometry was applied to neutron-rich 197^{197}Au projectile fragments. Masses of 181,183^{181,183}Lu, 185,186^{185,186}Hf, 187,188^{187,188}Ta, 191^{191}W, and 192,193^{192,193}Re nuclei were measured for the first time. The uncertainty of previously known masses of 189,190^{189,190}W and 195^{195}Os nuclei was improved. Observed irregularities on the smooth two-neutron separation energies for Hf and W isotopes are linked to the collectivity phenomena in the corresponding nuclei.Comment: 10 pages, 9 figures, 2 table
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