Paleontology provides insights into the history of the planet, from the origins of life billions of years ago to the biotic changes of the Recent. The scope of paleontological research is as vast as it is varied, and the field is constantly evolving. In an effort to identify “Big Questions” in paleontology, experts from around the world came together to build a list of priority questions the field can address in the years ahead. The 89 questions presented herein (grouped within 11 themes) represent contributions from nearly 200 international scientists. These questions touch on common themes including biodiversity drivers and patterns, integrating data types across spatiotemporal scales, applying paleontological data to contemporary biodiversity and climate issues, and effectively utilizing innovative methods and technology for new paleontological insights. In addition to these theoretical questions, discussions touch upon structural concerns within the field, advocating for an increased valuation of specimen-based research, protection of natural heritage sites, and the importance of collections infrastructure, along with a stronger emphasis on human diversity, equity, and inclusion. These questions offer a starting point—an initial nucleus of consensus that paleontologists can expand on—for engaging in discussions, securing funding, advocating for museums, and fostering continued growth in shared research directions.

These guidelines update the 2013 “Updated US Public Health Service (PHS) Guidelines for the Management of Occupational Exposures to Human Immunodeficiency Virus and Recommendations for Postexposure Prophylaxis,” hereafter referred to as the 2013 PHS Guidelines.1,2 The availability of new medication options, new information on the window of detection for different human immunodeficiency virus (HIV) tests, and the risk of transmission from people with undetectable viral loads prompted this update. The primary intended audience for these recommendations remains anyone involved in the provision of HIV post-exposure management to healthcare personnel (HCP).

The U.S. Centers for Disease Control and Prevention assembled a working group of representatives from federal agencies in the U.S. Department of Health and Human Services (HHS) who identified the priority topics for update and conducted systematic literature reviews to formulate recommendations (see Appendix). All recommendations were reviewed by the Healthcare Infection Control Practices Advisory Committee (HICPAC) at public meetings, and by a non-consensus forming panel of external experts. New evidence-based recommendations are developed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework and classified according to the HICPAC recommendation scheme when evidence supported recommendation development.3,4 Other recommendations in this document are classified as good practice statements according to the criteria set forth by GRADE.5 The working group solicited additional feedback on recommendations from relevant agencies, subject-matter experts, and the public.

Recommendations that have changed since the 2013 PHS guidelines include:

• new antiretroviral drug regimens for post-exposure prophylaxis (PEP);

• a shortened duration of post-exposure follow-up HIV testing;

• elimination of routine laboratory tests for antiretroviral drug toxicity; and

• considerations for PEP for HCP with exposures to source patients with undetectable viral loads.

Important strategies in the principles of exposure management remain: primary prevention strategies; the prompt reporting and management of occupational exposures; adherence to recommended HIV PEP regimens when indicated; the role of expert consultation in management of exposures; and follow-up of exposed HCP.

Complex machines are increasingly expensive to develop and build, which causes many to be maintained in service for longer than initially designed, as they still effectively perform valuable tasks. Longlasting, effective service lives of centuries rather than decades are a valuable characteristic for certain machines in several industries, whether for continual service, extended storage, or extremely remote deployment, such as in military service, agriculture and space exploration. Although there are various archival publications that focus on longevity, we seek to identify product architecture decisions which impact a machine’s longevity and can then be extrapolated out for timescales greater than 100 years. We refer to this as hyper-longevity. This paper seeks to find patterns in the literature that can identify causes linked to longevity effects, their frequency in the literature, and the types of impacts they have in facilitating longevity.

Some of us recently discussed the problems existing in describing the channels that permit interventricular shunting. We offered suggestions for improvement, particularly when assessing the channel that is found when both arterial trunks arise from the morphologically right ventricle. Our proposals engendered significant debate, with several criticisms appearing in an editorial commentary. The commentator now accepts that not all of the criticisms were justified. In an attempt to seek further consensus, we have now joined with additional colleagues so as to clarify the aspects of our initial work that created potential confusion. Having reviewed the aspects producing the misconceptions, we again provide an overview of the evidence relevant to deficient ventricular septation now provided by knowledge of cardiac development. We show how remodelling of the primary interventricular communication involves the provision of an inlet for the developing right ventricle and an outlet for the developing right ventricle. During this process, the secondary interventricular foramen, which is a subaortic-left ventricular communication when the outflow tract remains supported exclusively by the right ventricle, becomes the outflow tract for the left ventricle, with a subaortic-right ventricular communication then being closed to complete ventricular septation. We show how knowledge of these processes, coupled with an appreciation of the mechanism of formation of the muscular ventricular septum and the separate formation of an embryonic muscular outlet septum, which with normal development becomes the subpulmonary infundibulum, provides the basis for understanding the various phenotypic lesions that permit interventricular shunting in the postnatal heart.

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.

This study explores the potential of applying machine learning (ML) methods to identify and predict areas at risk of food insufficiency using a parsimonious set of publicly available data sources. We combine household survey data that captures monthly reported food insufficiency with remotely sensed measures of factors influencing crop production and maize price observations at the census enumeration area (EA) in Malawi. We consider three machine-learning models of different levels of complexity suitable for tabular data (TabNet, random forests, and LASSO) and classical logistic regression and examine their performance against the historical occurrence of food insufficiency. We find that the models achieve similar accuracy levels with differential performance in terms of precision and recall. The Shapley additive explanation decomposition applied to the models reveals that price information is the leading contributor to model fits. A possible explanation for the accuracy of simple predictors is the high spatiotemporal path dependency in our dataset, as the same areas of the country are repeatedly affected by food crises. Recurrent events suggest that immediate and longer-term responses to food crises, rather than predicting them, may be the bigger challenge, particularly in low-resource settings. Nonetheless, ML methods could be useful in filling important data gaps in food crises prediction, if followed by measures to strengthen food systems affected by climate change. Hence, we discuss the tradeoffs in training these models and their use by policymakers and practitioners.

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.

Global food security worsened during the COVID-19 pandemic. In Nigeria, food security indicators increased in the first months of the pandemic and then decreased slightly but never returned to their pre-pandemic levels. We assess if savings groups provided household coping mechanisms during COVID-19 in Nigeria by combining the in-person LSMS-ISA/GHS-2018/19 with four rounds of the Nigerian Longitudinal Phone Survey collected during the first year of the pandemic. A quasi-difference-in-differences analysis setup leveraging the panel nature of the data indicates that savings group membership reduces the likelihood of skipping a meal but finds no statistically significant effect on the likelihood of running out of food or eating fewer kinds of food. Given theoretical priors and other literature positing a relationship, we also implement an OLS regression analysis controlling for baseline values finding that having at least one female household member in a savings group is associated with a 5–15% reduction in the likelihood of reporting skipping meals, running out of food, and eating fewer kinds of food. This analysis is not able to establish causality, however, and may in fact overestimate the effects. Together, the results indicate that savings group membership is positively associated with food security after COVID-19, but the causal effect is statistically significant for only one of the three food security indicators. To conclude, considering the interest in savings groups and expectations of continued food security shocks, the importance of collecting better gender-disaggregated longitudinal household data combined with experimental designs and institutional data on savings groups.

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.

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 elusive southern river otter (Lontra provocax; huillín in Spanish) is critically endangered in the Argentine portion of Tierra del Fuego, and low social awareness may be one of the major threats to its conservation. Our survey of local residents’ knowledge and valuation of the huillín showed that only 14% recognized photographs of the species, almost half did not know that it is endangered and most erroneously thought it was an introduced species. Greater knowledge about the huillín was related to higher respondent education levels. Younger and more knowledgeable residents valued the species more for ecological and relational reasons; its instrumental value was considered least important. More communication should be targeted at older people and groups not directly interacting with nature via informal education methods, including combining positive messages about the huillín and other native species with ongoing outreach efforts warning about biological invasions. Understanding perceptions and valuations of biodiversity can make conservation efforts more effective and inclusive.

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.

Sudden cardiac death poses a significant risk in patients with surgically repaired tetralogy of Fallot. Despite extensive research, risk stratification practices vary. This study surveyed the Pediatric and Adult Congenital Electrophysiology Society to identify these differences. Results showed diverse practices in indications, methods, and interpretation of electrophysiology studies, highlighting a need for standardised algorithms to improve patient outcomes.

A Monte Carlo approach was employed to investigate the interpretability of improper solutions caused by sampling error in maximum likelihood confirmatory factor analysis. Four models were studied with two sample sizes. Of the overall goodness-of-fit indices provided by the LISREL VI program significant differences between improper and proper solutions were found only for the root mean square residual. As expected, indicators of the factor on which the negative uniqueness estimate occurred had biased loadings, and the correlations of its factor with other factors were also biased. In contrast, the loadings of indicators on other factors and those factor intercorrelations did not have any bias of practical significance. For initial solutions with one negative uniqueness estimate, three respecifications were studied: Fix the uniqueness at .00, fix it at .20, or constrain the domain of the solution to be proper. For alternate, respecified solutions that were converged and proper, the constrained solutions and uniqueness fixed at .00 solutions were equivalent. The mean goodness-of-fit and pattern coefficient values for the original improper solutions were not meaningfully different from those obtained under the constrained and uniqueness fixed at .00 respecifications.

A Monte Carlo study assessed the effect of sampling error and model characteristics on the occurrence of nonconvergent solutions, improper solutions and the distribution of goodness-of-fit indices in maximum likelihood confirmatory factor analysis. Nonconvergent and improper solutions occurred more frequently for smaller sample sizes and for models with fewer indicators of each factor. Effects of practical significance due to sample size, the number of indicators per factor and the number of factors were found for GFI, AGFI, and RMR, whereas no practical effects were found for the probability values associated with the chi-square likelihood ratio test.