We present the serendipitous radio-continuum discovery of a likely Galactic supernova remnant (SNR) G305.4–2.2. This object displays a remarkable circular symmetry in shape, making it one of the most circular Galactic SNRs known. Nicknamed Teleios due to its symmetry, it was detected in the new Australian Square Kilometre Array Pathfinder (ASKAP) Evolutionary Map of the Universe (EMU) radio–continuum images with an angular size of 1 320$^{\prime\prime}$$\times$1 260$^{\prime\prime}$ and PA = 0$^\circ$. While there is a hint of possible H$\alpha$ and gamma-ray emission, Teleios is exclusively seen at radio–continuum frequencies. Interestingly, Teleios is not only almost perfectly symmetric, but it also has one of the lowest surface brightnesses discovered among Galactic SNRs and a steep spectral index of $\alpha$=–0.6$\pm$0.3. Our best estimates from Hi studies and the $\Sigma$–D relation place Teleios as a type Ia SNR at a distance of either $\sim$2.2 kpc (near-side) or $\sim$7.7 kpc (far-side). This indicates two possible scenarios, either a young (under 1 000 yr) or a somewhat older SNR (over 10 000 yr). With a corresponding diameter of 14/48 pc, our evolutionary studies place Teleios at the either early or late Sedov phase, depending on the distance/diameter estimate. However, our modelling also predicts X-ray emission, which we do not see in the present generation of eROSITA images. We also explored a type Iax explosion scenario that would point to a much closer distance of $\lt$1 kpc and Teleios size of only $\sim$3.3 pc, which would be similar to the only known type Iax remnant SN1181. Unfortunately, all examined scenarios have their challenges, and no definitive Supernova (SN) origin type can be established at this stage. Remarkably, Teleios has retained its symmetrical shape as it aged even to such a diameter, suggesting expansion into a rarefied and isotropic ambient medium. The low radio surface brightness and the lack of pronounced polarisation can be explained by a high level of ambient rotation measure (RM), with the largest RM being observed at Teleios’s centre.

Background: Location-specific hematoma volume thresholds are associated with poor outcomes and can inform surgical trial inclusion criteria and clinical decision rules for hematoma evacuation. Methods: We performed a secondary analysis of the ATACH-2 and INTERACT2 clinical trials. We evaluated the associations between intraparenchymal location-specific hematoma volume cutoffs (basal ganglia, thalamus and lobar) and poor outcome (modified Rankin Scale 4-6). Using 24-hour CT scans, we calculated Youden’s index for each hematoma location to determine the optimal location-specific volume thresholds that predict outcomes. We calculated odds ratios (OR) of poor outcome through multivariable logistic regression models for each location. Results: Out of 1691 patients, 919, 551 and 221 were diagnosed with basal ganglia, thalamus and lobar intracerebral hemorrhage (ICH), respectively. Location-specific hematoma volume cutoffs most predictive of a poor outcome (mRS 4-6) were 22.24 mL for basal ganglia ICH (OR 4.82, 95% CI 3.19-7.27), 8.13 mL for thalamus ICH (OR 2.73, 95% CI 1.62-4.59) and 21.99 mL for lobar ICH (OR 6.31, 95% CI 2.53-15.74). Conclusions: Hematoma volumes associated with poor outcomes vary by location, supporting the idea that location-specific “hematoma volume tolerances” exist. Our results provide important data on location-specific hematoma volume tolerances to inform clinical trials in ICH management.

The Australian SKA Pathfinder (ASKAP) offers powerful new capabilities for studying the polarised and magnetised Universe at radio wavelengths. In this paper, we introduce the Polarisation Sky Survey of the Universe’s Magnetism (POSSUM), a groundbreaking survey with three primary objectives: (1) to create a comprehensive Faraday rotation measure (RM) grid of up to one million compact extragalactic sources across the southern $\sim50$% of the sky (20,630 deg$^2$); (2) to map the intrinsic polarisation and RM properties of a wide range of discrete extragalactic and Galactic objects over the same area; and (3) to contribute interferometric data with excellent surface brightness sensitivity, which can be combined with single-dish data to study the diffuse Galactic interstellar medium. Observations for the full POSSUM survey commenced in May 2023 and are expected to conclude by mid-2028. POSSUM will achieve an RM grid density of around 30–50 RMs per square degree with a median measurement uncertainty of $\sim$1 rad m$^{-2}$. The survey operates primarily over a frequency range of 800–1088 MHz, with an angular resolution of 20” and a typical RMS sensitivity in Stokes Q or U of 18 $\mu$Jy beam$^{-1}$. Additionally, the survey will be supplemented by similar observations covering 1296–1440 MHz over 38% of the sky. POSSUM will enable the discovery and detailed investigation of magnetised phenomena in a wide range of cosmic environments, including the intergalactic medium and cosmic web, galaxy clusters and groups, active galactic nuclei and radio galaxies, the Magellanic System and other nearby galaxies, galaxy halos and the circumgalactic medium, and the magnetic structure of the Milky Way across a very wide range of scales, as well as the interplay between these components. This paper reviews the current science case developed by the POSSUM Collaboration and provides an overview of POSSUM’s observations, data processing, outputs, and its complementarity with other radio and multi-wavelength surveys, including future work with the SKA.

Prospective and early-career paleontologists deserve an accurate assessment of employment opportunities in their chosen field of study. Drawing on a wide range of sources, we have produced an admittedly incomplete analysis of the current status and recent trends of permanent academic employment in the discipline. Obtaining more complete longitudinal data on employment trends is a major difficulty; this is a challenge that needs to be addressed. The number of job seekers is far in excess of available positions. There has been a clear erosion in the number of academic paleontologists in the United States, a trend exacerbated in recent years. The decline, in constant dollars, of federal funding for paleontological research has potential strong negative impacts on future hiring. The loss of paleontology positions has also had a deleterious effect on our professional societies, which have seen a loss of regular (professional) membership, although student membership remains strong. These trends also potentially negatively impact efforts to diversify the field. Professional societies need to better coordinate their efforts to address these serious issues. Individual paleontologists also must become more effective advocates for the importance and relevance of our science.

We provide an assessment of the Infinity Two fusion pilot plant (FPP) baseline plasma physics design. Infinity Two is a four-field period, aspect ratio $A = 10$, quasi-isodynamic stellarator with improved confinement appealing to a max-$J$ approach, elevated plasma density and high magnetic fields ($ \langle B\rangle = 9$ T). Here $J$ denotes the second adiabatic invariant. At the envisioned operating point ($800$ MW deuterium-tritium (DT) fusion), the configuration has robust magnetic surfaces based on magnetohydrodynamic (MHD) equilibrium calculations and is stable to both local and global MHD instabilities. The configuration has excellent confinement properties with small neoclassical transport and low bootstrap current ($|I_{bootstrap}| \sim 2$ kA). Calculations of collisional alpha-particle confinement in a DT FPP scenario show small energy losses to the first wall (${\lt}1.5 \,\%$) and stable energetic particle/Alfvén eigenmodes at high ion density. Low turbulent transport is produced using a combination of density profile control consistent with pellet fueling and reduced stiffness to turbulent transport via three-dimensional shaping. Transport simulations with the T3D-GX-SFINCS code suite with self-consistent turbulent and neoclassical transport predict that the DT fusion power$P_{{fus}}=800$ MW operating point is attainable with high fusion gain ($Q=40$) at volume-averaged electron densities $n_e\approx 2 \times 10^{20}$ m$^{-3}$, below the Sudo density limit. Additional transport calculations show that an ignited ($Q=\infty$) solution is available at slightly higher density ($2.2 \times 10^{20}$ m$^{-3}$) with $P_{{fus}}=1.5$ GW. The magnetic configuration is defined by a magnetic coil set with sufficient room for an island divertor, shielding and blanket solutions with tritium breeding ratios (TBR) above unity. An optimistic estimate for the gas-cooled solid breeder designed helium-cooled pebble bed is TBR $\sim 1.3$. Infinity Two satisfies the physics requirements of a stellarator fusion pilot plant.

The magnetohydrodynamic (MHD) equilibrium and stability properties of the Infinity Two fusion pilot plant baseline plasma physics design are presented. The configuration is a four-field period, aspect ratio $A = 10$ quasi-isodynamic stellarator optimised for excellent confinement at elevated density and high magnetic field $B = 9\,T$. Magnetic surfaces exist in the plasma core in vacuum and retain good equilibrium surface integrity from vacuum to an operational $\beta = 1.6 \,\%$, the ratio of the volume average of the plasma and magnetic pressures, corresponding to $800\ \textrm{MW}$ deuterium–tritium fusion operation. Neoclassical calculations show that a self-consistent bootstrap current of the order of ${\sim} 1\ \textrm{kA}$ slightly increases the rotational transform profile by less than 0.001. The configuration has a magnetic well across its entire radius. From vacuum to the operating point, the configuration exhibits good ballooning stability characteristics, exhibits good Mercier stability across most of its minor radius and it is stable against global low-n MHD instabilities up to $\beta = 3.2\,\%$.

Several non-experimental studies claim that heterogeneity among individuals reduces trust. A few experimental studies have examined the effects of naturally-occurring differences among subjects on trusting behavior, and in contrast, most have not supported these claims. We adopt a novel approach by inducing heterogeneity among subjects in a canonical trust experiment. We accomplish this by varying the show-up payments given to subjects for participating in the experiment. We find that this induced inequality does not consistently affect first- or second-mover behavior in the classic trust game in the manner predicted by either previous theoretical work or empirical studies of survey-based measures of trust. Further, the effect of inequality on trust, in terms of both sign and significance, depends on whether show-up payments are awarded publicly or privately.

Pigmentation and colouration are important to animal fitness. Colourations convey important information and impact predation risk, thermoregulation and mate selection. There are many cases of hypopigmentation across the animal kingdom, and leucism is a common form. We observed a Weddell seal (Leptonychotes weddellii) pup with cream-coloured fur, light skin and white nails multiple times in 2022 in Erebus Bay, Antarctica. The pup was observed 1 year later as a generally healthy yearling. This is the first documentation of a leucistic seal within this well-studied population and the second documentation of such colouration in this species. This seal offers a potential opportunity to observe the effects of hypopigmentation in Antarctic true seals.

We present the first results from a new backend on the Australian Square Kilometre Array Pathfinder, the Commensal Realtime ASKAP Fast Transient COherent (CRACO) upgrade. CRACO records millisecond time resolution visibility data, and searches for dispersed fast transient signals including fast radio bursts (FRB), pulsars, and ultra-long period objects (ULPO). With the visibility data, CRACO can localise the transient events to arcsecond-level precision after the detection. Here, we describe the CRACO system and report the result from a sky survey carried out by CRACO at 110-ms resolution during its commissioning phase. During the survey, CRACO detected two FRBs (including one discovered solely with CRACO, FRB 20231027A), reported more precise localisations for four pulsars, discovered two new RRATs, and detected one known ULPO, GPM J1839 $-$10, through its sub-pulse structure. We present a sensitivity calibration of CRACO, finding that it achieves the expected sensitivity of 11.6 Jy ms to bursts of 110 ms duration or less. CRACO is currently running at a 13.8 ms time resolution and aims at a 1.7 ms time resolution before the end of 2024. The planned CRACO has an expected sensitivity of 1.5 Jy ms to bursts of 1.7 ms duration or less and can detect $10\times$ more FRBs than the current CRAFT incoherent sum system (i.e. 0.5 $-$2 localised FRBs per day), enabling us to better constrain the models for FRBs and use them as cosmological probes.