SUMMARY The 2013-2015 Ebola virus disease (EVD) epidemic is caused by the Makona variant of Ebola virus (EBOV). Early in the epidemic, genome sequencing provided insights into virus evolution and transmission, and offered important information for outbreak response. Here we analyze sequences from 232 patients sampled over 7 months in Sierra Leone, along with 86 previously released genomes from earlier in the epidemic. We confirm sustained human-to-human transmission within Sierra Leone and find no evidence for import or export of EBOV across national borders after its initial introduction. Using high-depth replicate sequencing, we observe both host-to-host transmission and recurrent emergence of intrahost genetic variants. We trace the increasing impact of purifying selection in suppressing the accumulation of nonsynonymous mutations over time. Finally, we note changes in the mucin-like domain of EBOV glycoprotein that merit further investigation. These findings clarify the movement of EBOV within the region and describe viral evolution during prolonged human-to-human transmission.
This report is aimed at answering the following question: “why do real metals oppose the flow of current?” The simple answer is “because electrons can’t be accelerated indefinitely by an external field without loosing energy”. I aim at discussing this question in the framework of Fermi Liquids – however, a large part of the argument only depends on weakly interacting charge carriers, irrespective of them being Landau quasiparticles. The main elements that make Landau quasiparticles unique in the context of conductivity is the fact that they have an intrinsic decay time. As we’ll see, this phenomenon leads to both a T² temperature dependence of the resistivity and a form of magnetoresistance.