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Background Rapid antiretroviral therapy (ART) is the recommended treatment strategy for patients newly diagnosed with HIV, but the literature supporting this strategy has focused on short-term outcomes. We examined both long-term outcomes and predictors of rapid ART among patients newly diagnosed with HIV within an integrated health care system in Northern California. Methods This observational cohort study included adults newly diagnosed with HIV between January 2015 and December 2020 at Kaiser Permanente Northern California. Rapid ART was defined as ART initiation within 7 days of HIV diagnosis. We collected demographic and clinical data to determine short-term and long-term outcomes, including viral suppression, care retention, medication adherence, and cumulative viral burden. Logistic regression models were used to identify predictors of rapid ART initiation. Results We enrolled 1409 adults; 34.1% initiated rapid ART. The rapid ART group achieved viral suppression faster (48 vs 77 days; P <.001) and experienced lower cumulative viral burden (log10 viremia copy-years, 3.63 vs 3.82; P <.01) but had slightly reduced medication adherence (74.8% vs 75.2%; P <.01). There was no improvement in long-term viral suppression and care retention in the rapid group during follow-up. Patients were more likely to initiate rapid ART after 2017 and were less likely if they required an interpreter. Conclusions Patients who received rapid ART had an improved cumulative HIV burden but no long-term improvement in care retention and viral suppression. Our findings suggest that rapid ART should be offered but additional interventions may be needed for patients newly diagnosed with HIV. [ABSTRACT FROM AUTHOR]

The coronavirus disease 2019 (COVID-19) pandemic disrupted health systems. For patients newly diagnosed with human immunodeficiency virus, starting immediate antiretroviral therapy (ART) is recommended. For periods before and during the COVID-19 pandemic, Kaiser Permanente Northern California found similar rates of rapid ART initiation and time to viral suppression, concurrent with an increase in telemedicine. [ABSTRACT FROM AUTHOR]

Plants moved onto land ∼450 million years ago and faced their biggest challenge: living in a dry environment. Over the millennia plants have become masters of regulating water flow and the toolkit they have developed has been co-opted to effect rapid movements. Since plants are rooted, these fast movements are used to disperse reproductive propagules including spores, pollen, and seeds. We compare five plants to demonstrate three ways, used alone or in combination, that water powers rapid movements: the direct capture of the kinetic energy of a falling raindrop propels gemmae from the splash cups of the liverwort, Marchantia ; the loss of water powers the explosive dispersal of the spores of Sphagnum moss; the alternate loss and gain of water in the bilayer of the elaters of Equisetum drive the walk, jump, and glide of spores; the gain of water in the inner layer of the arils of Oxalis drive the eversion of the aril that jettisons seeds from the capsule; and the buildup of turgor pressure in the petals and stamens of bunchberry dogwood (Cornus canadensis) explosively propels pollen. Each method is accompanied by morphological features, which facilitate water movement as a power source. The urn shaped splash cups of Marchantia allow dispersal of gemmae by multiple splashes. The air gun design of Sphagnum capsules results in a symmetrical impulse creating a vortex ring of spores. The elaters of Equisetum can unfurl while they are dropping from the plant, so that they capture updrafts and glide to new sites. The arils of Oxalis are designed like miniature toy "poppers." Finally, in bunchberry, the softening of stamen filament tissue where it attaches to the anther allows them to function as miniature hinged catapults or trebuchets. [ABSTRACT FROM AUTHOR]

The diffuse plasma that fills galaxy groups and clusters (the intracluster medium) is a by-product of galaxy formation. The present thermal state of this gas results from a competition between gas cooling and heating. The heating comes from two distinct sources: gravitational heating associated with the collapse of the dark matter halo and additional thermal input from the formation of galaxies and their black holes. A long-term goal of this research is to decode the observed temperature, density and entropy profiles of clusters and to understand the relative roles of these processes. However, a long-standing problem has been that cosmological simulations based on smoothed particle hydrodynamics (SPH) and Eulerian mesh-based codes predict different results even when cooling and galaxy/black hole heating are switched off. Clusters formed in SPH simulations show near power-law entropy profiles, while those formed in Eulerian simulations develop a core and do not allow gas to reach such low entropies. Since the cooling rate is closely connected to the minimum entropy of the gas distribution, the differences are of potentially key importance. In this paper, we investigate the origin of this discrepancy. By comparing simulations run using theGADGET-2 SPH code and theFLASH adaptive Eulerian mesh code, we show that the discrepancy arises during the idealized merger of two clusters and that the differences are not the result of the lower effective resolution of Eulerian cosmological simulations. The difference is not sensitive to the minimum mesh size (in Eulerian codes) or the number of particles used (in SPH codes). We investigate whether the difference is the result of the different gravity solvers, the Galilean non-invariance of the mesh code or an effect of unsuitable artificial viscosity in the SPH code. Instead, we find that the difference is inherent to the treatment of vortices in the two codes. Particles in the SPH simulations retain a close connection to their initial entropy, while this connection is much weaker in the mesh simulations. The origin of this difference lies in the treatment of eddies and fluid instabilities. These are suppressed in the SPH simulations, while the cluster mergers generate strong vortices in the Eulerian simulations that very efficiently mix the fluid and erase the low-entropy gas. We discuss the potentially profound implications of these results. [ABSTRACT FROM AUTHOR]

We use a large suite of carefully controlled full hydrodynamic simulations to study the ram pressure stripping of the hot gaseous haloes of galaxies as they fall into massive groups and clusters. The sensitivity of the results to the orbit, total galaxy mass, and galaxy structural properties is explored. For typical structural and orbital parameters, we find that ∼30 per cent of the initial hot galactic halo gas can remain in place after 10 Gyr. We propose a physically simple analytic model that describes the stripping seen in the simulations remarkably well. The model is analogous to the original formulation of Gunn & Gott, except that it is appropriate for the case of a spherical (hot) gas distribution (as opposed to a face-on cold disc) and takes into account that stripping is not instantaneous but occurs on a characteristic time-scale. The model reproduces the results of the simulations to within ≈10 per cent at almost all times for all the orbits, mass ratios, and galaxy structural properties we have explored. The one exception involves unlikely systems where the orbit of the galaxy is highly non-radial and its mass exceeds about 10 per cent of the group or cluster into which it is falling (in which case the model underpredicts the stripping following pericentric passage). The proposed model has several interesting applications, including modelling the ram pressure stripping of both observed and cosmologically simulated galaxies and as a way to improve present semi-analytic models of galaxy formation. One immediate consequence is that the colours and morphologies of satellite galaxies in groups and clusters will differ significantly from those predicted with the standard assumption of complete stripping of the hot coronae. [ABSTRACT FROM AUTHOR]

We report observations of an unpredicted fine structure in the activity profile of the Leonid meteor storm of 1999 November 18. Our observations were obtained at three widely separated sites (on the Iberian peninsula, in Germany, and in northern Sweden) and with two totally different techniques (video cameras and meteor radars). The observations clearly show quasi-periodic variations of the meteor rate with temporal separations of individual maxima in the 6- to 9-min range. These temporal variations translate into spatial variations within the dust trail with scales between 10 000 and 30 000 km, depending in which reference frame or direction one chooses to compare. The times for the central three maxima as observed at the three sites agree within 2 min of each other after application of the appropriate topocentric time corrections. We consider a number of potential causes for the observed density variations within the meteor stream. [ABSTRACT FROM AUTHOR]