The persistent pool of HIV-1-infected cells is formed episodically during untreated infection.

Previous studies have shown that the majority of long-lived cells harboring persistent HIV-1 proviral genomes originates from viruses circulating in the year prior to antiretroviral therapy (ART) initiation, but a smaller proportion originates from viruses circulating much earlier in untreated infection. These observations suggest that discrete biological factors influence the entry and persistence of viruses into the persistent proviral pool, and there may be periods earlier in untreated infection with increased seeding. Therefore, we examined the timing of formation of the long-lived pool of infected cells that persists during ART in seven women (after a median of 5.

The role of Nef in the long-term persistence of the replication-competent HIV reservoir in South African women.

HIV-1 Nef mediates immune evasion and viral pathogenesis in part through downregulation of cell surface cluster of differentiation 4 (CD4) and major histocompatibility complex class I (MHC-I) on infected cells. While Nef function of circulating viral populations found early in infection has been associated with reservoir size in early-treated cohorts, there is limited research on how its activity impacts reservoir size in people initiating treatment during chronic infection. In addition, there is little research on its role in persistence of viral variants during long-term antiretroviral therapy (ART).

The Graphene Squeeze-Film Microphone.

Most microphones detect sound-pressure-induced motion of a membrane. In contrast, we introduce a microphone that operates by monitoring sound-pressure-induced modulation of the air compressibility. By driving a graphene membrane at resonance, the gas, that is trapped in a squeeze-film beneath it, is compressed at high frequency.

The timing of HIV-1 infection of cells that persist on therapy is not strongly influenced by replication competency or cellular tropism of the provirus.

People with HIV-1 (PWH) on antiretroviral therapy (ART) can maintain undetectable virus levels, but a small pool of infected cells persists. This pool is largely comprised of defective proviruses that may produce HIV-1 proteins but are incapable of making infectious virus, with only a fraction (~10%) of these cells harboring intact viral genomes, some of which produce infectious virus following ex vivo stimulation (i.e.

The oldest fossil bird-like footprints from the upper Triassic of southern Africa.

Footprint morphology reflects the anatomy of the trackmaker's foot and is direct evidence for the animal's behaviour. Consequently, fossil tracks can be used to infer ancient diversity, ethology, and evolutionary trends. This is particularly useful for deep-time intervals during which the early history of an animal group is reliant upon limited fossil skeletal material.