A total of 73 patients with baseline CD4⁺ cell counts ⩾350 cells/mm³ who were receiving combination antiretroviral therapy (ART) were randomized to receive subcutaneous interleukin-2 (IL-2; n = 36) ...in addition to ART or to continue ART alone (n = 37). Subcutaneous IL-2 was delivered at 1 of 3 doses (1.5 million international units MIU, 4.5 MIU, and 7.5 MIU per dose) by twice-daily injection for 5 consecutive days every 8 weeks. After 24 weeks, the time-weighted mean change from baseline CD4⁺ cell count was 210 cells/mm³ for recipients of subcutaneous IL-2, compared with 29 cells/mm³ for recipients of ART alone (P <.001). There were no significant differences between treatment groups for measures of plasma human immunodeficiency virus RNA (P = .851). Subcutaneous IL-2 delivered at doses of 4.5 MIU and 7.5 MIU resulted in significant increases in CD4⁺ cell count (P = .006 and P <.001, respectively), compared with that seen in control patients. These changes were not significant in the 1.5 MIU dose group compared with that in the control patients (P = .105). Side effects that occurred from subcutaneous IL-2 administration were generally low grade, of short duration, and readily managed in an outpatient environment.
We use the angular Two Point Correlation Function (TPCF) to investigate the hierarchical distribution of young star clusters in 12 local (3--18 Mpc) star-forming galaxies using star cluster ...catalogues obtained with the \textit{Hubble Space Telescope} (\textit{HST}) as part of the Treasury Program LEGUS (Legacy ExtraGalactic UV Survey). The sample spans a range of different morphological types, allowing us to infer how the physical properties of the galaxy affect the spatial distribution of the clusters. We also prepare a range of physically motivated toy models to compare with and interpret the observed features in the TPCFs. We find that, conforming to earlier studies, young clusters (\(T \la 10\, \mathrm{Myr}\)) have power-law TPCFs that are characteristic of fractal distributions with a fractal dimension \(D_2\), and this scale-free nature extends out to a maximum scale \(l_{\mathrm{corr}}\) beyond which the distribution becomes Poissonian. However, \(l_{\mathrm{corr}}\), and \(D_2\) vary significantly across the sample, and are correlated with a number of host galaxy physical properties, suggesting that there are physical differences in the underlying star cluster distributions. We also find that hierarchical structuring weakens with age, evidenced by flatter TPCFs for older clusters (\(T \ga 10\, \mathrm{Myr}\)), that eventually converges to the residual correlation expected from a completely random large-scale radial distribution of clusters in the galaxy in \(\sim 100 \, \mathrm{Myr}\). Our study demonstrates that the hierarchical distribution of star clusters evolves with age, and is strongly dependent on the properties of the host galaxy environment.
K2-19b and c were among the first planets discovered by NASA's K2 mission and together stand in stark contrast with the physical and orbital properties of the solar system planets. The planets are ...between the size of Uranus and Saturn at 7.0\(\pm\)0.2 R_E and 4.1\(\pm\)0.2 R_E, respectively, and reside a mere 0.1% outside the nominal 3:2 mean-motion resonance. They represent a different outcome of the planet formation process than the solar system, as well as the vast majority of known exoplanets. We measured the physical and orbital properties of these planets using photometry from K2, Spitzer, and ground-based telescopes, along with radial velocities from Keck/HIRES. Through a joint photodynamical model, we found that the planets have moderate eccentricities of \(e \approx0.20\) and well-aligned apsides \(\Delta \varpi \approx 0\) deg. The planets occupy a strictly non-resonant configuration: the resonant angles circulate rather than librate. This defies the predictions of standard formation pathways that invoke convergent or divergent migration, both of which predict \(\Delta \varpi \approx 180\) deg and eccentricities of a few percent or less. We measured masses of \(M_{p,b}\) = 32.4\(\pm\)1.7 M_E and \(M_{p,c}\) = 10.8\(\pm\)0.6 M_E. Our measurements, with 5% fractional uncertainties, are among the most precise of any sub-Jovian exoplanet. Mass and size reflect a planet's core/envelope structure. Despite having a relatively massive core of \(M_{core} \approx15\) \(M_E\), K2-19b is envelope-rich, with an envelope mass fraction of roughly 50%. This planet poses a challenge to standard models core-nucleated accretion, which predict that cores \(\gtrsim 10\) \(M_E\) will quickly accrete gas and trigger runaway accretion when the envelope mass exceeds that of the core.
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