7 research outputs found
A lower bound on the local extragalactic magnetic field
Assuming that the hard gamma-ray emission of Cen A is a result of synchrotron
radiation of ultra-relativistic electrons, we derive a lower bound on the local
extragalactic magnetic field, G. This result is consistent with
(and close to) upper bounds on magnetic fields derived from consideration of
cosmic microwave background distortions and Faraday rotation measurements.Comment: Includes extensive discussion of particle acceleration above 10^20 eV
in the hot spot-like region of Cen
Genomics of 1 million parent lifespans implicates novel pathways and common diseases and distinguishes survival chances
We use a genome-wide association of 1 million parental lifespans of genotyped subjects and data on mortality risk factors to validate previously unreplicated findings near CDKN2B-AS1, ATXN2/BRAP, FURIN/FES, ZW10, PSORS1C3, and 13q21.31, and identify and replicate novel findings near ABO, ZC3HC1, and IGF2R. We also validate previous findings near 5q33.3/EBF1 and FOXO3, whilst finding contradictory evidence at other loci. Gene set and cell-specific analyses show that expression in foetal brain cells and adult dorsolateral prefrontal cortex is enriched for lifespan variation, as are gene pathways involving lipid proteins and homeostasis, vesicle-mediated transport, and synaptic function. Individual genetic variants that increase dementia, cardiovascular disease, and lung cancer - but not other cancers - explain the most variance. Resulting polygenic scores show a mean lifespan difference of around five years of life across the deciles.Peer reviewe
Generation of magnetic field fluctuations in relativistic electron-positron magnetoplasmas
It is shown that magnetic field aligned equilibrium relativistic plasmas flows can excite electromagnetic fluctuations in a magnetized electron–positron (e–p) plasma. For this purpose, a new dispersion relation is derived by using a relativistic two-fluid model and the Maxwell equations. The dispersion relation admits purely growing instabilities of electromagnetic perturbations across the ambient magnetic field direction. The results have relevance for understanding the origin of magnetic field fluctuations in cosmological and laser-produced plasmas