On September 1, 2019, Hurricane Dorian made landfall as a category 5 hurricane on Great Abaco Island, Bahamas. Hurricane Dorian matched the “Labor Day” hurricane of 1935 as the strongest recorded Atlantic hurricane to make landfall with maximum sustained winds of 185 miles/h.1 At the request of the Government of the Bahamas, Team Rubicon activated a World Health Organization Type 1 Mobile Emergency Medical Team and responded to Great Abaco Island. The team provided medical care and reconnaissance of medical clinics on the island and surrounding cays…

In this essay, I argue that the role for exclusionary reasons in a sound account of practical rationality is, at most, much more circumscribed than proponents of exclusionary reasons might suppose. Specifically, I argue that an attractive account of moral motivation is in tension with the idea that moral reasons can be excluded. Limiting ourselves to the tools of first order moral reasons—including such relations as outweighing, and disabling—allows us to preserve a more attractive account of the relationship between what there is strongest reason to do, what one is motivated to do, and that for which one is praiseworthy or blameworthy. In closing, I argue that we can capture the normativity associated with legal decision-making using only the resources of the first-order model.

We present a multi-frequency study of the intermediate spiral SAB(r)bc type galaxy NGC 6744, using available data from the Chandra X-Ray telescope, radio continuum data from the Australia Telescope Compact Array and Murchison Widefield Array, and Wide-field Infrared Survey Explorer infrared observations. We identify 117 X-ray sources and 280 radio sources. Of these, we find nine sources in common between the X-ray and radio catalogues, one of which is a faint central black hole with a bolometric radio luminosity similar to the Milky Way’s central black hole. We classify 5 objects as supernova remnant (SNR) candidates, 2 objects as likely SNRs, 17 as H ii regions, 1 source as an AGN; the remaining 255 radio sources are categorised as background objects and one X-ray source is classified as a foreground star. We find the star-formation rate (SFR) of NGC 6744 to be in the range 2.8–4.7 M⊙~yr − 1 signifying the galaxy is still actively forming stars. The specific SFR of NGC 6744 is greater than that of late-type spirals such as the Milky Way, but considerably less that that of a typical starburst galaxy.

We explore the two-dimensional flow around a circular cylinder with the aim of elucidating the changes in the topology of the vorticity field that lead to the formation of the Kármán vortex street. Specifically, we analyse the formation and disappearance of extremal points of vorticity, which we consider to be feature points for vortices. The basic vortex creation mechanism is shown to be a topological cusp bifurcation in the vorticity field, where a saddle and an extremum of the vorticity are created simultaneously. We demonstrate that vortices are first created approximately 100 diameters downstream of the cylinder, at a Reynolds number, $Re_{K}$ , which is slightly larger than the critical Reynolds number, $Re_{crit}\approx 46$ , at which the flow becomes time periodic. For $Re$ slightly above $Re_{K}$ , the newly created vortices disappear again a short distance further downstream. As $Re$ is further increased, the points of creation and disappearance move rapidly upstream and downstream, respectively, and the Kármán vortex street persists over increasingly large streamwise distances.