A shared accretion instability for black holes and neutron stars.

Accretion disks around compact objects are expected to enter an unstable phase at high luminosity. One instability may occur when the radiation pressure generated by accretion modifies the disk viscosity, resulting in the cyclic depletion and refilling of the inner disk on short timescales. Such a scenario, however, has only been quantitatively verified for a single stellar-mass black hole.

A rapidly changing jet orientation in the stellar-mass black-hole system V404 Cygni.

Powerful relativistic jets are one of the main ways in which accreting black holes provide kinetic feedback to their surroundings. Jets launched from or redirected by the accretion flow that powers them are expected to be affected by the dynamics of the flow, which for accreting stellar-mass black holes has shown evidence for precession due to frame-dragging effects that occur when the black-hole spin axis is misaligned with the orbital plane of its companion star. Recently, theoretical simulations have suggested that the jets can exert an additional torque on the accretion flow, although the interplay between the dynamics of the accretion flow and the launching of the jets is not yet understood.

Point-of-care testing for HCV infection: recent advances and implications for alternative screening.

Over the last few years, hepatitis C virus (HCV) infection has emerged as one of the most significant causes of chronic liver disease worldwide, with an estimated prevalence ranging from 2.2 to 3.0%.

Cross-sectional study of community serostatus to highlight undiagnosed HIV infections with oral fluid HIV-1/2 rapid test in non-conventional settings.

The submerged portion of undiagnosed HIV infection in Italy is about 30% of subjects found seropositive. This fact represents one of the most important public health problems hindering the control of infection progression. This means we need to fight unawareness and social stigma and promote easy and friendly access to HIV test.

Stellar-mass black holes and ultraluminous x-ray sources.

We review the likely population, observational properties, and broad implications of stellar-mass black holes and ultraluminous x-ray sources. We focus on the clear empirical rules connecting accretion and outflow that have been established for stellar-mass black holes in binary systems in the past decade and a half. These patterns of behavior are probably the keys that will allow us to understand black hole feedback on the largest scales over cosmological time scales.