715 research outputs found
Experimental study of Tc 100 β decay with total absorption γ -ray spectroscopy
The β decay of Tc100 has been studied by using the total absorption γ-ray spectroscopy technique at the Ion Guide Isotope Separator On-Line facility in Jyväskylä. In this work the new Decay Total Absorption γ-ray Spectrometer in coincidence with a cylindrical plastic β detector has been employed. The β intensity to the ground state obtained from the analysis is in good agreement with previous high-resolution measurements. However, differences in the feeding to the first-excited state as well as weak feeding to a new level at high excitation energy have been deduced from this experiment. Theoretical calculations performed in the quasiparticle random-phase approximation framework are also reported. Comparison of these calculations with our measurement serves as a benchmark for calculations of the double β decay of Mo100. © 2017 American Physical Society
Tissue-specific modulation of gene expression in response to lowered insulin signalling in Drosophila
Reduced activity of the insulin/IGF signalling network increases health during ageing in multiple species. Diverse and tissue-specific mechanisms drive the health improvement. Here, we performed tissue-specific transcriptional and proteomic profiling of long-lived Drosophila dilp2-3,5 mutants, and identified tissue-specific regulation of >3600 transcripts and >3700 proteins. Most expression changes were regulated post-transcriptionally in the fat body, and only in mutants infected with the endosymbiotic bacteria, Wolbachia pipientis, which increases their lifespan. Bioinformatic analysis identified reduced co-translational ER targeting of secreted and membrane-associated proteins and increased DNA damage/repair response proteins. Accordingly, age-related DNA damage and genome instability were lower in fat body of the mutant, and overexpression of a minichromosome maintenance protein subunit extended lifespan. Proteins involved in carbohydrate metabolism showed altered expression in the mutant intestine, and gut-specific overexpression of a lysosomal mannosidase increased autophagy, gut homeostasis, and lifespan. These processes are candidates for combatting ageing-related decline in other organisms
Improving Fission-product Decay Data for Reactor Applications: Part I -- Decay Heat
Effort has been expended to assess the relative merits of undertaking further
decay-data measurements of the main fission-product contributors to the decay
heat of neutron-irradiated fissile fuel and related actinides by means of Total
Absorption Gamma-ray Spectroscopy (TAGS/TAS) and Discrete Gamma-ray
Spectroscopy (DGS). This review has been carried out following similar work
performed under the auspices of OECD/WPEC-Subgroup 25 (2005-2007) and the
International Atomic Energy Agency (2010, 2014), and various highly relevant
TAGS measurements completed as a consequence of such assessments. We present
our recommendations for new decay-data evaluations, along with possible
requirements for total absorption and discrete high-resolution gamma-ray
spectroscopy studies that cover approximately 120 fission products and various
isomeric states.Comment: Submitted to European Physical Journal
Shapes of the Pb ground states from beta decay studies using the total absorption technique
The beta decay of Pb has been studied using the total absorption
technique at the ISOLDE(CERN) facility. The beta-decay strength deduced from
the measurements, combined with QRPA theoretical calculations, allow us to
infer that the ground states of the Pb isotopes are spherical.
These results represent the first application of the shape determination method
using the total absorption technique for heavy nuclei and in a region where
there is considerable interest in nuclear shapes and shape effects
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