We examine the energy distribution of the fast radio burst (FRB) population using a well-defined sample of 63 FRBs from the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope, 28 of which are localised to a host galaxy. We apply the luminosity-volume ($V/V_{\mathrm{max}}$) test to examine the distribution of these transient sources, accounting for cosmological and instrumental effects, and determine the energy distribution for the sampled population over the redshift range $0.01 \lesssim z \lesssim 1.02$. We find the distribution between $10^{23}$ and $10^{26}$ J Hz$^{-1}$ to be consistent with both a pure power-law with differential slope $\gamma=-1.96 \pm 0.15$, and a Schechter function with $\gamma = -1.82 \pm 0.12$ and downturn energy $E_\mathrm{max} \sim 6.3 \, \times 10^{25}$ J Hz$^{-1}$. We identify systematic effects which currently limit our ability to probe the luminosity function outside this range and give a prescription for their treatment. Finally, we find that with the current dataset, we are unable to distinguish between the evolutionary and spectral models considered in this work.

Fast radio bursts (FRBs) are short-duration radio transients that occur at random times in host galaxies distributed all over the sky. Large field of view instruments can play a critical role in the blind search for rare FRBs. We present a concept for an all-sky FRB monitor using a compact all-sky phased array (CASPA), which can efficiently achieve an extremely large field of view of $\sim10^4$ square degrees. Such a system would allow us to conduct a continuous, blind FRB search covering the entire southern sky. Using the measured FRB luminosity function, we investigate the detection rate for this all-sky phased array and compare the result to a number of other proposed large field-of-view instruments. We predict a rate of a few FRB detections per week and determine the dispersion measure and redshift distributions of these detectable FRBs. This instrument is optimal for detecting FRBs in the nearby Universe and for extending the high-end of the FRB luminosity function through finding ultraluminous events. Additionally, this instrument can be used to shadow the new gravitational-wave observing runs, detect high-energy events triggered from Galactic magnetars and search for other bright, but currently unknown transient signals.

Sub-glacial canyon features up to 580 m deep between flat terraces were identified beneath Devon Ice Cap during a 2023 radar echo sounding (RES) survey. The largest canyon connects a hypothesized brine network near the Devon Ice Cap summit with the marine-terminating Sverdrup outlet glacier. This canyon represents a probable drainage route for the hypothesized water system. Radar bed reflectivity is consistently 30 dB lower along the canyon floor than on the terraces, contradicting the signature expected for sub-glacial water. We compare these data with backscattering simulations to demonstrate that the reflectivity pattern may be topographically induced. Our simulated results indicated a 10 m wide canal-like water feature is unlikely along the canyon floor, but smaller features may be difficult to detect via RES. We calculated basal temperature profiles using a 2D finite difference method and found the floor may be up to 18°C warmer than the terraces. However, temperatures remain below the pressure melting point, and there is limited evidence that the canyon floor supports a connected drainage system between the DIC summit and Sverdrup Glacier. The terrain beneath Devon Ice Cap demonstrates limitations for RES. Future studies should evaluate additional correction methods near complex terrain, such as RES simulation as we demonstrate here.

This study examines the use of graph centrality to identify critical components in assembly models, a method typically dominated by computationally intense analyses. By applying centrality measures to simulated assembly graphs, components were ranked to assess their criticality. These rankings were compared against Monte Carlo sensitivity analysis results. Preliminary findings indicate a promising correlation, suggesting graph centrality as a valuable tool in assembly analysis, enhancing efficiency and insight in critical component identification.

This article presents an fNIRS experiment investigating cognitive differences between physical and digital prototyping methods in designers (N=25) engaged in open and constrained design tasks. Initial results suggest that physical prototyping yields increased hemodynamic response (i.e., brain activity) compared to digital design, and that constrained design yields increased hemodynamic response compared to open design, in the prefrontal cortex. Further work will seek to triangulate results by investigating potential correlations to design processes and design outputs.

OBJECTIVES/GOALS: To assess barriers and recommendations for improving delivery of care for chronic obstructive pulmonary disease (COPD) in rural clinics, we assessed COPD care metrics and obtained perspectives of primary care providers (PCPs) who practice in rural clinics. METHODS/STUDY POPULATION: Quantitative retrospective analysis of patients with COPD using VA data. We included patients whose primary care clinic is located in a rural VA Midwest Health Care Network (HCN) facility and quantified binary measures for receipt of: spirometry, pulmonary specialty care, and optimal inhaler therapy (regimen with LAMA or LABA monotherapy) Qualitative semi-structured individual interviews of PCPs (physicians, nurse practitioners, and physician assistants) whose clinics are located in a rural VA Midwest HCN facility. We elicited perceived barriers to and recommendations for receiving spirometry, pulmonary specialty care, and optimal inhaler therapy from PCPs. RESULTS/ANTICIPATED RESULTS: 6,350 rural patients had a new diagnosis of COPD in 2016-2019. 48.4% had spirometry, 14.4% had pulmonary encounters, and among patients who were prescribed long-acting inhaler therapy, 48.8% received optimal inhaler regimens. Rural PCPs (n=14) highlighted lack of access to spirometry, pulmonary specialty care, and clinic staff support in local clinics and suggested: 1) leveraging the expertise of pharmacists in COPD management and 2) improving access to resources, including use of telehealth technologies. DISCUSSION/SIGNIFICANCE: Less than 50% of rural COPD patients received recommended diagnostic testing and therapy. Resource limitations in rural clinics were the main barrier. The main recommendation was to leverage pharmacists’ expertise in COPD care. These findings provide a pathway forward to improving rural COPD care.

In response to Timothy Darvill's article, ‘Mythical rings?’ (this issue), which argues for an alternative interpretation of Waun Mawn circle and its relationship with Stonehenge, Parker Pearson and colleagues report new evidence from the Welsh site and elaborate on aspects of their original argument. The discovery of a hearth at the centre of the circle, as well as further features around its circumference, reinforces the authors’ original interpretation. The authors explore the evidence for the construction sequence, which was abandoned before the completion of the monument. Contesting Darvill's argument that the Aubrey Holes at Stonehenge originally held posts, the authors reassert their interpretation of this circle of cut features as Bluestone settings.

The cosmological constant problem stems from treating quantum field theory and general relativity as an effective field theory (EFT). We argue that the problem is a reduction ad absurdum and that one should reject the assumption that general relativity can generically be treated as an EFT. This marks a failure of naturalness and provides an internal signal that EFT methods do not apply in all spacetime domains. We then take an external view, showing that the assumptions for using EFTs are violated in general relativistic domains where Λ is relevant. We highlight some ways forward that do not depend on naturalness.

The Chronos 14Carbon-Cycle Facility is a new radiocarbon laboratory at the University of New South Wales, Australia. Built around an Ionplus 200 kV MIni-CArbon DAting System (MICADAS) Accelerator Mass Spectrometer (AMS) installed in October 2019, the facility was established to address major challenges in the Earth, Environmental and Archaeological sciences. Here we report an overview of the Chronos facility, the pretreatment methods currently employed (bones, carbonates, peat, pollen, charcoal, and wood) and results of radiocarbon and stable isotope measurements undertaken on a wide range of sample types. Measurements on international standards, known-age and blank samples demonstrate the facility is capable of measuring 14C samples from the Anthropocene back to nearly 50,000 years ago. Future work will focus on improving our understanding of the Earth system and managing resources in a future warmer world.

ABSTRACT IMPACT: Our research focuses on determining rural-urban disparities in chronic obstructive pulmonary disease (COPD) management to improve COPD health outcomes in rural areas. OBJECTIVES/GOALS: Several methods exist to distinguish rural from urban areas, but it is not clear which method relates most directly to rural-urban health care disparities. To address this, we compared different measures of rurality to measures of chronic obstructive pulmonary disease (COPD) processes of care among a national sample of veterans. METHODS/STUDY POPULATION: Retrospective analysis of patients with COPD (2016-2019 by ICD-10 codes) using national Veterans Affairs (VA) data. We assessed rurality by: 1) patient’s residential address, 2) assigned primary care clinic address, and 3) drive time from the patient’s residence to closest primary care clinic. Rurality designations of the residential address and primary care clinic address into urban, rural, and highly rural areas are based on the Rural Urban Commuting Area (RUCA) codes. The dependent variables were binary outcomes of: 1) documentation of a pulmonary clinic encounter and 2) evidence of spirometry to confirm the diagnosis of COPD. RESULTS/ANTICIPATED RESULTS: Of 6,765,951 veterans, 1,157,002 (17%) had COPD (Table 1). Although approximately 40% of patients with COPD reside in addresses that are rural and highly rural, a large majority are assigned to primary care clinics in urban areas (82.8%) and reside within 30 minutes to the closest primary care clinic (76.7%) (Table 2). Compared to defining rurality based on patient’s residential address or drive time to closest primary care, defining rurality based on the assigned primary care clinic address was associated with a larger disparity in rates of pulmonary encounter. In contrast, the drive time from the patient’s residence to the closest primary care was the strongest predictor of receipt of spirometry (Figure 1 and Table 3). DISCUSSION/SIGNIFICANCE OF FINDINGS: Estimates of the severity of rural-urban disparities varied based on the definition of rurality used. For two process measures, definitions of rurality based on where the patient received primary care generated more evidence of disparities than definitions based solely on the patient’s residential address.

The impacts of the COVID-19 pandemic extend to global biodiversity and its conservation. Although short-term beneficial or adverse impacts on biodiversity have been widely discussed, there is less attention to the likely political and economic responses to the crisis and their implications for conservation. Here we describe four possible alternative future policy responses: (1) restoration of the previous economy, (2) removal of obstacles to economic growth, (3) green recovery and (4) transformative economic reconstruction. Each alternative offers opportunities and risks for conservation. They differ in the agents they emphasize to mobilize change (e.g. markets or states) and in the extent to which they prioritize or downplay the protection of nature. We analyse the advantages and disadvantages of these four options from a conservation perspective. We argue that the choice of post-COVID-19 recovery strategy has huge significance for the future of biodiversity, and that conservationists of all persuasions must not shrink from engagement in the debates to come.

The Rapid ASKAP Continuum Survey (RACS) is the first large-area survey to be conducted with the full 36-antenna Australian Square Kilometre Array Pathfinder (ASKAP) telescope. RACS will provide a shallow model of the ASKAP sky that will aid the calibration of future deep ASKAP surveys. RACS will cover the whole sky visible from the ASKAP site in Western Australia and will cover the full ASKAP band of 700–1800 MHz. The RACS images are generally deeper than the existing NRAO VLA Sky Survey and Sydney University Molonglo Sky Survey radio surveys and have better spatial resolution. All RACS survey products will be public, including radio images (with $\sim$ 15 arcsec resolution) and catalogues of about three million source components with spectral index and polarisation information. In this paper, we present a description of the RACS survey and the first data release of 903 images covering the sky south of declination $+41^\circ$ made over a 288-MHz band centred at 887.5 MHz.

In recent work, Peter Hanks and Scott Soames argue for the type view, according to which propositions are types whose tokens are acts, states, or events. Hanks and Soames think that one of the virtues of the type view is that it allows them to explain why propositions have semantic properties. But, in this paper, we argue that their explanations aren't satisfactory.

Geologists and archaeologists have long known that the bluestones of Stonehenge came from the Preseli Hills of west Wales, 230km away, but only recently have some of their exact geological sources been identified. Two of these quarries—Carn Goedog and Craig Rhos-y-felin—have now been excavated to reveal evidence of megalith quarrying around 3000 BC—the same period as the first stage of the construction of Stonehenge. The authors present evidence for the extraction of the stone pillars and consider how they were transported, including the possibility that they were erected in a temporary monument close to the quarries, before completing their journey to Stonehenge.