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The most efficient energy sources known in the Universe are accretion disks. Those around black holes convert 5-40 per cent of rest-mass energy to radiation. Like water circling a drain, inflowing mass must lose angular momentum, presumably by vigorous turbulence in disks, which are essentially inviscid. The origin of the turbulence is unclear. Hot disks of electrically conducting plasma can become turbulent by way of the linear magnetorotational instability. Cool disks, such as the planet-forming disks of protostars, may be too poorly ionized for the magnetorotational instability to occur, and therefore essentially unmagnetized and linearly stable. Nonlinear hydrodynamic instability often occurs in linearly stable flows (for example, pipe flows) at sufficiently large Reynolds numbers. Although planet-forming disks have extreme Reynolds numbers, keplerian rotation enhances their linear hydrodynamic stability, so the question of whether they can be turbulent and thereby transport angular momentum effectively is controversial. Here we report a laboratory experiment, demonstrating that non-magnetic quasi-keplerian flows at Reynolds numbers up to millions are essentially steady. Scaled to accretion disks, rates of angular momentum transport lie far below astrophysical requirements. By ruling out purely hydrodynamic turbulence, our results indirectly support the magnetorotational instability as the likely cause of turbulence, even in cool disks.

The summit of Mauna Kea in Hawaii, the area near Cerro Chajnantor in Chile, and the South Pole are sites of large millimeter‐ or submillimeter‐wavelength telescopes. We have placed 860 GHz sky brightness monitors at all three sites and present a comparative study of the measured submillimeter brightness due to atmospheric thermal emission. We report the stability of that quantity at each site.

The first observation of fast and slow magnetocoriolis (MC) waves in a laboratory experiment is reported. Rotating nonaxisymmetric modes arising from a magnetized turbulent Taylor-Couette flow of liquid metal are identified as the fast and slow MC waves by the dependence of the rotation frequency on the applied field strength. The observed slow MC wave is damped but the observation provides a means for predicting the onset of the Magnetorotational Instability.

Objective: Retrospective, real-world study to evaluate visual acuity (VA), anti-vascular endothelial growth factor (anti-VEGF) injection intervals, and central macular thickness (CMT) in neovascular age-related macular degeneration (nAMD) eyes switched to brolucizumab only or to brolucizumab alternating with another anti-VEGF. Methods: The overall study population comprised eyes that were given [greater than or equal to] 1 brolucizumab injection between 1 October 2019 and 30 November 2021. The brolucizumab-only (BRO) cohort consisted of prior anti-VEGF-treated eyes treated exclusively with [greater than or equal to] 3 brolucizumab injections over [greater than or equal to] 12 or [greater than or equal to] 18 months; the alternating brolucizumab (ALT) cohort comprised prior anti-VEGF-treated eyes treated with [greater than or equal to] 2 brolucizumab injections and [greater than or equal to] 1 other anti-VEGF over [greater than or equal to] 12 or [greater than or equal to] 18 months. Results: A total of 482 eyes received[greater than or equal to] >1 brolucizumab injection during the study period. Mean VA changes from baseline were -1.1 [+ or -] 15.1 letters (BRO cohort; n = 174) and 1.3 [+ or -] 13.0 letters (ALT cohort; n = 47) at Month 12, and 0.0 [+ or -] 13.5 letters (BRO cohort; n = 95) and -7.3 [+ or -] 17.2 letters (ALT cohort; n = 29) at Month 18. Mean changes in injection intervals were +26.9 [+ or -] 48.1 days (BRO cohort) and +11.1 [+ or -] 17.3 days (ALT cohort) at Month 12 and +36.3 [+ or -] 52.3 days (BRO cohort) and +14.0 [+ or -] 19.9 days (ALT cohort) at Month 18. Mean changes in CMT were -35.2 [+ or -] 108.1 pm (BRO cohort) and -31.5 [+ or -] 91.2 [ILLUSTRATION OMITTED] m (ALT cohort) at Month 12 and -38.9 [+ or -] 75.0 [micro]m (BRO cohort) and -9.0 [+ or -] 59.9 [micro]m (ALT cohort) at Month 18. Intraocular inflammation-related adverse events were recorded in 22/482 (4.6%) eyes. Conclusion: Treatment with either brolucizumab alone or brolucizumab alternating with another anti-VEGF can preserve vision, reduce CMT, and extend anti-VEGF injection intervals in patients with nAMD. Keywords: alternating anti-VEGF treatments, brolucizumab, neovascular age-related macular degeneration, wet age-related macular degeneration, 12-month outcomes, 18-month outcomes

The summit of Mauna Kea in Hawaii, the area near Cerro Chajnantor in Chile, and the South Pole are sites of large millimeter or submillimeter wavelength telescopes. We have placed 860 GHz sky brightness monitors at all three sites and present a comparative study of the measured submillimeter brightness due to atmospheric thermal emission. We report the stability of that quantity at each site.

We describe the instrumentation, experiment design and data reduction for the first season of observations with the Degree Angular Scale Interferometer (DASI), a compact microwave interferometer designed to measure anisotropy in the Cosmic Microwave Background (CMB) on degree and sub-degree scales (l=100--900). The telescope was deployed at the Amundsen-Scott South Pole research station during the 1999--2000 austral summer and conducted observations of the CMB throughout the following austral winter. In its first season of observations, DASI has mapped CMB fluctuations in 32 fields, each 3.4 deg across, with high sensitivity.