Expression of the common heat-shock protein receptor CD91 is increased on monocytes of exposed yet HIV-1-seronegative subjects.

The significantly higher surface expression of the surface heat-shock protein receptor CD91 on monocytes of human immunodeficiency virus type-1 (HIV-1)-infected, long-term nonprogressors suggests that HIV-1 antigen uptake and cross-presentation mediated by CD91 may contribute to host anti-HIV-1 defenses and play a role in protection against HIV-1 infection. To investigate this further, we performed phenotypic analysis to compare CD91 surface expression on CD14+ monocytes derived from a cohort of HIV-1-exposed seronegative (ESN) subjects, their seropositive (SP) partners, and healthy HIV-1-unexposed seronegative (USN) subjects. The median fluorescent intensity (MFI) of CD91 on CD14+ monocytes was significantly higher in ESN compared with SP (P=0.028) or USN (P=0.007), as well as in SP compared with USN subjects (P=0.018). CD91 MFI was not normalized in SP subjects on highly active antiretroviral therapy (HAART) despite sustainable, undetectable plasma viraemia. Data in three SP subjects experiencing viral rebounds following interruption of HAART showed low CD91 MFI comparable with levels in USN subjects. There was a significant positive correlation between CD91 MFI and CD8+ T cell counts in HAART-naïve SP subjects (r=0.7, P=0.015). Increased surface expression of CD91 on CD14+ monocytes is associated with the apparent HIV-1 resistance that is observed in ESN subjects.

Alfvén Waves in the Lower Solar Atmosphere

The flow of energy through the solar atmosphere and the heating of the Sun's outer regions are still not understood. Here, we report the detection of oscillatory phenomena associated with a large bright-point group that is 430,000 square kilometers in area and located near the solar disk center. Wavelet analysis reveals full-width half-maximum oscillations with periodicities ranging from 126 to 700 seconds originating above the bright point and significance levels exceeding 99%. These oscillations, 2.6 kilometers per second in amplitude, are coupled with chromospheric line-of-sight Doppler velocities with an average blue shift of 23 kilometers per second. A lack of cospatial intensity oscillations and transversal displacements rules out the presence of magneto-acoustic wave modes. The oscillations are a signature of Alfvén waves produced by a torsional twist of ±22 degrees. A phase shift of 180 degrees across the diameter of the bright point suggests that these torsional Alfvén oscillations are induced globally throughout the entire brightening. The energy flux associated with this wave mode is sufficient to heat the solar corona.

GALEX AND PAN-STARRS1 DISCOVERY OF SN IIP 2010aq: THE FIRST FEW DAYS AFTER SHOCK BREAKOUT IN A RED SUPERGIANT STAR

We present the early UV and optical light curve of Type IIP supernova (SN) 2010aq at z = 0.0862, and compare it to analytical models for thermal emission following SN shock breakout in a red supergiant star. SN 2010aq was discovered in joint monitoring between the Galaxy Evolution Explorer (GALEX) Time Domain Survey (TDS) in the NUV and the Pan-STARRS1 Medium Deep Survey (PS1 MDS) in the g, r, i, and z bands. The GALEX and Pan-STARRS1 observations detect the SN less than 1 day after the shock breakout, measure a diluted blackbody temperature of 31,000 +/- 6000 K 1 day later, and follow the rise in the UV/optical light curve over the next 2 days caused by the expansion and cooling of the SN ejecta. The high signal-to-noise ratio of the simultaneous UV and optical photometry allows us to fit for a progenitor star radius of 700 +/- 200R(circle dot), the size of a red supergiant star. An excess in UV emission two weeks after shock breakout compared with SNe well fitted by model atmosphere-code synthetic spectra with solar metallicity is best explained by suppressed line blanketing due to a lower metallicity progenitor star in SN 2010aq. Continued monitoring of PS1 MDS fields by the GALEX TDS will increase the sample of early UV detections of Type II SNe by an order of magnitude and probe the diversity of SN progenitor star properties.