3 research outputs found
A new model of population dynamics of HIV-1 in vivo
Using a simple model of HIV-1 viral load and infected CD4+ count, with easily measurable
coe cients, valid on time scales of approximately a month, we nd that HIV-1 is understood
by sequential outburst of viral populations with delay between populations. AIDS is
characterised by shorter delays between viral populations and HAART is characterised by
longer delays between viral populations, as evidenced in observed viral blips. Infected CD4+
dynamics is understood by sequential outburst with overlap of CD4+ populations. We argue
that viral load and CD4+ counts must be in phase and present a model in di erential
equations that supports this conclusion and is consistent with decay rates discovered by the
outburst model
An investigation of data compression techniques for hyperspectral core imager data
We investigate algorithms for tractable analysis of real hyperspectral image data from core samples provided by AngloGold Ashanti. In particular, we investigate feature extraction, non-linear dimension reduction using diffusion maps and wavelet approximation methods on our data
ECOSTRESS: NASA's next generation mission to measure evapotranspiration from the International Space Station
The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station ECOSTRESS) was launched to the International Space Station on June 29, 2018. The primary science focus of ECOSTRESS is centered on evapotranspiration (ET), which is produced as levelâ3 (L3) latent heat flux (LE) data products. These data are generated from the levelâ2 land surface temperature and emissivity product (L2_LSTE), in conjunction with ancillary surface and atmospheric data. Here, we provide the first validation (Stage 1, preliminary) of the global ECOSTRESS clearâsky ET product (L3_ET_PTâJPL, version 6.0) against LE measurements at 82 eddy covariance sites around the world. Overall, the ECOSTRESS ET product performs well against the site measurements (clearâsky instantaneous/time of overpass: r2 = 0.88; overall bias = 8%; normalized RMSE = 6%). ET uncertainty was generally consistent across climate zones, biome types, and times of day (ECOSTRESS samples the diurnal cycle), though temperate sites are overârepresented. The 70 m high spatial resolution of ECOSTRESS improved correlations by 85%, and RMSE by 62%, relative to 1 km pixels. This paper serves as a reference for the ECOSTRESS L3 ET accuracy and Stage 1 validation status for subsequent science that follows using these data