22 research outputs found

    GRB 171010A/SN 2017htp: a GRB-SN at z = 0.33

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    The number of supernovae known to be connected with long-duration gamma-ray bursts (GRBs) is increasing and the link between these events is no longer exclusively found at low redshift (z â‰Č 0.3) but is well established also at larger distances. We present a new case of such a liaison at z = 0.33 between GRB 171010A and SN 2017htp. It is the second closest GRB with an associated supernova of only three events detected by Fermi-LAT. The supernova is one of the few higher redshift cases where spectroscopic observations were possible and shows spectral similarities with the well-studied SN 1998bw, having produced a similar Ni mass (⁠ M Ni =0.33±0.02 M ⊙ MNi=0.33±0.02 M⊙ ⁠) with slightly lower ejected mass (⁠ M ej =4.1±0.7 M ⊙ Mej=4.1±0.7 M⊙ ⁠) and kinetic energy (⁠ E K =8.1±2.5× 10 51 erg EK=8.1±2.5×1051 erg ⁠). The host-galaxy is bigger in size than typical GRB host galaxies, but the analysis of the region hosting the GRB revealed spectral properties typically observed in GRB hosts and showed that the progenitor of this event was located in a very bright H ii region of its face-on host galaxy, at a projected distance of ∌ 10 kpc from its galactic centre. The star-formation rate (SFRGRB ∌ 0.2 M⊙ yr−1) and metallicity (12 + log(O/H) ∌8.15 ± 0.10) of the GRB star-forming region are consistent with those of the host galaxies of previously studied GRB–SN systems

    Differences in serum cytokine levels between wild type mice and mice with a targeted mutation suggests necessity of using control littermates

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    To enhance protection from pathogens, housing conditions have been improved constantly. We wanted to test whether various environmental conditions and caging systems affect serum cytokine levels of immunodeficient mice differently than they affect immunocompetent control animals. We compared serum cytokine levels of immunodeficient and immunocompetent mice kept in three different environments: a specific pathogen free (SPF) breeding barrier with open cages. An SPF experimental unit with individually ventilated cages. An experimental semi-barrier with open cages. Serum from Rag1(-/-), {mu}MT(-/-), IFN-{gamma}R(-/-), IFN-{gamma}(-/-), IL-4(-/-), the heterozygous controls and wild type C57BL/6 or BALB/c mice was analyzed for the presence of 10 cytokines (IL-1{alpha}, IL-2, IL-4, IL-5, IL-6, IL-10, IL-17, IFN-{gamma}, TNF-{alpha} and GM-CSF). No major changes in cytokine levels were detected in mice exposed to different housing conditions. However, irrespective of immunodeficiency at 4 weeks of age a number of mice from the breeding colonies with a targeted mutation (TM), both -/- and +/- mice, showed a statistically significant elevation of some cytokines (primarily IL-1{alpha}, IL-5) when compared to wild type BALB/c and C57BL/6 mice. We conclude that under SPF conditions, immunodeficient mice can be kept either in open caging or IVC systems without affecting serum cytokine levels. The more important conclusion, however, stems from the observation that there is a significant difference in serum cytokine levels between wild type and mice carrying either one or two alleles of a targeted mutation (either -/- and +/- mice). This suggests an altered base-line inflammatory responsiveness in the TM-breeding colonies
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