We have conducted a widefield, wideband, snapshot survey using the Australian SKA Pathfinder (ASKAP) referred to as the Rapid ASKAP Continuum Survey (RACS). RACS covers ≈ 90% of the sky, with multiple observing epochs in three frequency bands sampling the ASKAP frequency range of 700–1 800 MHz. This paper describes the third major epoch at 1 655.5 MHz, RACS-high, and the subsequent imaging and catalogue data release. The RACS-high observations at 1 655.5MHz are otherwise similar to the previously released RACS-mid (at 1367.5 MHz), and were calibrated and imaged with minimal changes. From the 1 493 images covering the sky up to declination ≈ +48°, we present a catalogue of 2 677 509 radio sources. The catalogue is constructed from images with a median root-mean-square noise of ≈ 195 μJy PSF−1 (point-spread function) and a median angular resolution of 11″. 8 × 8″. 1. The overall reliability of the catalogue is estimated to be 99.18 %, and we find a decrease in reliability as angular resolution improves. We estimate the brightness scale to be accurate to 10 %, and the astrometric accuracy to be within ≈ 0″. 6 in right ascension and ≈ 0″. 7 in declination after correction of a systematic declination-dependent offset. All data products from RACS-high, including calibrated visibility datasets, images from individual observations, full-sensitivity mosaics, and the all-sky catalogue are available at the CSIRO ASKAP Science Data Archive.

The bright radio source, GLEAM J091734$-$001243 (hereafter GLEAM J0917$-$0012), was previously selected as a candidate ultra-high redshift ($z \gt 5$) radio galaxy due to its compact radio size and faint magnitude ($K(\mathrm{AB})=22.7$). Its redshift was not conclusively determined from follow-up millimetre and near-infrared spectroscopy. Here we present new HST WFC3 G141 grism observations which reveal several emission lines including [NeIII]$\lambda$3867, [NeV]$\lambda$3426 and an extended ($\approx 4.8\,$kpc), [OII]$\lambda$3727 line which confirm a redshift of $3.004\pm0.001$. The extended component of the [OII]$\lambda$3727 line is co-spatial with one of two components seen at 2.276 GHz in high resolution ($60\times 20\,$mas) Long Baseline Array data, reminiscent of the alignments seen in local compact radio galaxies. The BEAGLE stellar mass ($\approx 2\times 10^{11}\,\textit{M}_\odot$) and radio luminosity ($L_{\mathrm{500MHz}}\approx 10^{28}\,$W Hz$^{-1}$) put GLEAM J0917$-$0012 within the distribution of the brightest high-redshift radio galaxies at similar redshifts. However, it is more compact than all of them. Modelling of the radio jet demonstrates that this is a young, $\approx 50\,$kyr old, but powerful, $\approx 10^{39}\,$W, compact steep spectrum radio source. The weak constraint on the active galactic nucleus bolometric luminosity from the [NeV]$\lambda$3426 line combined with the modelled jet power tentatively implies a large black hole mass, $\ge 10^9\,\textit{M}_\odot$, and a low, advection-dominated accretion rate, i.e. an Eddington ratio $\le 0.03$. The [NeV]$\lambda$3426/[NeIII]$\lambda$3867 vs [OII]$\lambda$3727/[NeIII]$\lambda$3867 line ratios are most easily explained by radiative shock models with precursor photoionisation. Hence, we infer that the line emission is directly caused by the shocks from the jet and that this radio source is one of the youngest and most powerful known at cosmic noon. We speculate that the star-formation in GLEAM J0917$-$0012 could be on its way to becoming quenched by the jet.

The increased severity and frequency of bushfires accompanying human-induced global warming have dire implications for biodiversity conservation. Here we investigate the response of a cryptic, cool-climate elapid, the mustard-bellied snake Drysdalia rhodogaster, to the extensive Black Summer fires of 2019/2020 in south-eastern Australia. The species is categorized as Least Concern on the IUCN Red List (last assessed in 2017), but because a large part of its range was burnt during the Black Summer and little was known about its ecology, D. rhodogaster was identified as a priority species for post-fire impact assessment. We evaluated three lines of evidence to assess the impact of the Black Summer fires on D. rhodogaster. Habitat suitability modelling indicated that c. 46% of the predicted range of the species was affected by bushfire. Field surveys conducted 9–36 months post-fire and collation of records from public databases submitted 0–24 months post-fire indicated that D. rhodogaster persisted in burnt landscapes. Fire severity and proportion of the landscape that was burnt within a 1,000-m radius of survey sites were poor predictors of site occupancy by D. rhodogaster. Although conclusions regarding the effects of fire on D. rhodogaster are limited because of the lack of baseline data, it is evident that the species has persisted across the landscape in the wake of extensive bushfires. Our work highlights the need for baseline knowledge on cryptic species even when they are categorized as Least Concern, as otherwise assessments of the impacts of catastrophic events will be constrained.

Community involvement in research is key to translating science into practice, and new approaches to engaging community members in research design and implementation are needed. The Community Scientist Program, established at the MD Anderson Cancer Center in Houston in 2018 and expanded to two other Texas institutions in 2021, provides researchers with rapid feedback from community members on study feasibility and design, cultural appropriateness, participant recruitment, and research implementation. This paper aims to describe the Community Scientist Program and assess Community Scientists' and researchers' satisfaction with the program. We present the analysis of the data collected from 116 Community Scientists and 64 researchers who attended 100 feedback sessions, across three regions of Texas including Northeast Texas, Houston, and Rio Grande Valley between June 2018 and December 2022. Community Scientists stated that the feedback sessions increased their knowledge and changed their perception of research. All researchers (100%) were satisfied with the feedback and reported that it influenced their current and future research methods. Our evaluation demonstrates that the key features of the Community Scientist Program such as follow-up evaluations, effective bi-directional communication, and fair compensation transform how research is conducted and contribute to reducing health disparities.

The flow in and around a pair of plumes from sources that are vertically and horizontally offset is investigated. An analytical potential flow model is developed using an adapted version of the Milne–Thomson circle theorem to represent the flow due to adjacent circular and point sinks. This approximates the horizontal section through offset plumes, which have differing radii at the same vertical position. The predictions of this model are compared against Reynolds-averaged Navier–Stokes (RANS) simulations of the same system. These yield time-averaged results and so are particularly suitable for investigating the relatively weak entrainment field. Single and double plume results from RANS are also presented to compare with known results. Good agreement is found between the features in the analytical model and in the numerical solutions including the location of the stagnation point between the two plumes.

Spectral variability offers a new technique to identify small scale structures from scintillation, as well as determining the absorption mechanism for peaked-spectrum (PS) radio sources. In this paper, we present very long baseline interferometry (VLBI) imaging using the long baseline array (LBA) of two PS sources, MRC 0225–065 and PMN J0322–4820, identified as spectrally variable from observations with the Murchison Widefield Array (MWA). We compare expected milliarcsecond structures based on the detected spectral variability with direct LBA imaging. We find MRC 0225–065 is resolved into three components, a bright core and two fainter lobes, roughly 430 pc projected separation. A comprehensive analysis of the magnetic field, host galaxy properties, and spectral analysis implies that MRC 0225–065 is a young radio source with recent jet activity over the last $10^2$–$10^3$ yr. We find PMN J0322–4820 is unresolved on milliarcsecond scales. We conclude PMN J0322–4820 is a blazar with flaring activity detected in 2014 with the MWA. We use spectral variability to predict morphology and find these predictions consistent with the structures revealed by our LBA images.

Recent higher-order explicit Runge–Kutta methods are compared with the classic fourth-order (RK4) method in long-term integration of both energy-conserving and lossy systems. By comparing quantity of function evaluations against accuracy for systems with and without known solutions, optimal methods are proposed. For a conservative system, we consider positional accuracy for Newtonian systems of two or three bodies and total angular momentum for a simplified Solar System model, over moderate astronomical timescales (tens of millions of years). For a nonconservative system, we investigate a relativistic two-body problem with gravitational wave emission. We find that methods of tenth and twelfth order consistently outperform lower-order methods for the systems considered here.

We describe a new low-frequency wideband radio survey of the southern sky. Observations covering 72–231 MHz and Declinations south of $+30^\circ$ have been performed with the Murchison Widefield Array “extended” Phase II configuration over 2018–2020 and will be processed to form data products including continuum and polarisation images and mosaics, multi-frequency catalogues, transient search data, and ionospheric measurements. From a pilot field described in this work, we publish an initial data release covering 1,447 $\mathrm{deg}^2$ over $4\,\mathrm{h}\leq \mathrm{RA}\leq 13\,\mathrm{h}$ , $-32.7^\circ \leq \mathrm{Dec} \leq -20.7^\circ$ . We process twenty frequency bands sampling 72–231 MHz, with a resolution of 2′–45′′, and produce a wideband source-finding image across 170–231 MHz with a root mean square noise of $1.27\pm0.15\,\mathrm{mJy\,beam}^{-1}$ . Source-finding yields 78,967 components, of which 71,320 are fitted spectrally. The catalogue has a completeness of 98% at ${{\sim}}50\,\mathrm{mJy}$ , and a reliability of 98.2% at $5\sigma$ rising to 99.7% at $7\sigma$ . A catalogue is available from Vizier; images are made available via the PASA datastore, AAO Data Central, and SkyView. This is the first in a series of data releases from the GLEAM-X survey.

OBJECTIVES/GOALS: An increasing number of hospitals and provider groups are consolidating into larger health systems, which hold potential to improve access to and quality of surgical cancer care through clinical integration across sites. In order to study clinical integration, we sought to develop: METHODS/STUDY POPULATION: Hospital data from the American Hospital Association were merged with data from the Agency for Healthcare Research and Quality’s Compendium of United States Health Systems. For each health system with more than one acute care hospital, the hospital with the highest surgical volume (inpatient and outpatient) was categorized as the hub hospital while all other hospitals were categorized as spokes. We evaluated the concentration of case volumes at hub versus spoke hospitals and compared characteristics of these hospitals and their surrounding communities using univariate and multivariable logistic regression analyses. RESULTS/ANTICIPATED RESULTS: Within 624 health systems containing 3,554 hospitals, 355 hospitals were characterized as hub hospitals and had 2,645 affiliated spoke hospitals (median 17 spokes per hub, range 2-151). Hub hospitals performed a median of 68% of all surgical cases (25th-75th percentile 44-87%) and were concentrated in metropolitan (88.5%) and urban areas (11.5%) with none in rural areas; spoke hospitals were located in metropolitan (67%), urban (28%) and rural (5%) areas. On multivariable analysis, spoke hospitals were more often located in rural and small urban counties (OR 9.49, CI 4.57-19.70) and took care of a higher percentage of patients with less than high school education (OR 1.06 for each 1% increase, CI 1.03-1.10) but with lower poverty rates (OR 0.90 for each 1% increase in % poverty, CI 0.86-0.95). DISCUSSION/SIGNIFICANCE: For integrated health systems with multiple acute care hospitals, surgical volume is highest at a single hub hospital, supporting use of a hub-spoke taxonomy. Patient populations in counties with hub versus spoke hospitals differ in urban-rural location, poverty rates, and education level, which may impact access to quality care.