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Item type: Publication , Access status: Metadata only , Reconciling extragalactic star formation efficiencies with theory: Insights from PHANGS(2025-08-01) Meidt, Sharon E.; Glover, Simon C.O.; Klessen, Ralf S.; Leroy, Adam K.; Sun, Jiayi; Agertz, Oscar; Emsellem, Eric; Henshaw, Jonathan D.; Neumann, Lukas; Rosolowsky, Erik; Schinnerer, Eva; Utomo, Dyas; Van Der Wel, Arjen; Bigiel, Frank; Colombo, Dario; Gleis, Damian R.; Grasha, Kathryn; Gensior, Jindra; Gnedin, Oleg Y.; Hughes, Annie; Murphy, Eric J.; Querejeta, Miguel; Smith, Rowan J.; Williams, Thomas G.; Usero, AntonioNew extragalactic measurements of the cloud population-averaged star formation efficiency per free-fall time, Ïμff, from PHANGS show little sign of a theoretically predicted dependence on the gas virial level and weak variation with cloud-scale gas velocity dispersion. We explore ways to bring theory into consistency with the observations, particularly by highlighting systematic variations in internal density structure that must accompany an increase in virial parameter typically found toward denser galaxy centers. To introduce these variations into conventional turbulence-regulated star formation models, we adopted three adjustments, all motivated by the expectation that the background host galaxy has an influence on the cloud scale: (1) We incorporate self-gravity and an internal density distribution that contains a broad power-law (PL) component and resembles the structure observed in local resolved clouds; (2) We allow the internal gas kinematics to include motion in the background potential and let this regulate the onset of self-gravitation; (3) We assume that the distribution of gas densities is in a steady state for only a fraction of a cloud free-fall time. In practice, these changes significantly reduce the efficiencies predicted in multi-free-fall (MFF) scenarios compared to purely lognormal probability density functions (PDFs) and tie efficiency variations to variations in the slope of the PL α. We fit the model to PHANGS measurements of Ïμff to identify the PL slopes that yield an optimal match. These slopes vary systematically with galactic environment in the sense that gas that sits furthest from virial balance contains fractionally more gas at high density. We relate this to the equilibrium response of gas in the presence of the galactic gravitational potential, which forces more gas to high density than characteristic of fully self-gravitating clouds. Viewing the efficiency variations as originating with time evolution in the PL slope, our findings would alternatively imply coordination of the cloud evolutionary stage within environment. With this galaxy regulation behavior included, our preferred self-gravitating multi-freefall sgMFF models function similarly to the original, roughly virialized cloud single-free-fall models. However, outside the environment of disks with their characteristic regulation, the flexible MFF models may be better suited.Item type: Publication , Access status: Metadata only , Classifying Stillbirths and Neonatal Deaths to Inform Prevention Strategies(2026) Flenady, Vicki J.; Wojcieszek, Aleena M.; Astell, Chrissie; Dahlstrom, Jane E.; Gordon, AdrienneAccurate and consistent classification – at the global level – of causes and contributing factors to stillbirths and neonatal deaths (perinatal mortality) is essential to inform policy and programmatic change, and counsel bereaved parents. However, a globally acceptable classification system remains elusive. The World Health Organization’s International Classification of Diseases for Perinatal Mortality (WHO ICD-PM) is recommended as a global solution for the accurate classification of perinatal deaths, but deficiencies in this system remain. The International Stillbirth Alliance proposes a system for use across data-rich settings, which will also serve low-resource settings through a purposeful mapping to the ICD-PM.Item type: Publication , Access status: Metadata only , The Position of Tomoip in the Oceanic Family(2025) Barlow, Russell; Ross, MalcolmTomoip is an Oceanic language spoken on the island of New Britain in the Bismarck Archipelago of Papua New Guinea. Although previously thought by some to be a non-Austronesian language, Tomoip is undeniably a member of the Oceanic branch of the Austronesian family. However, its precise classification has remained a challenge, largely because its lexicon seemingly contains a high percentage of non-Austronesian content and its Austronesian forms exhibit several complex sound correspondences. This paper provides a historical phonology of Tomoip, detailing the sound changes that have led from Proto-Oceanic to contemporary Tomoip. Based on these sound changes and morphological evidence, we propose that Tomoip is most closely related to the New Ireland subgroup of the Meso-Melanesian cluster. We further hypothesize that Tomoip and Proto-New Ireland are coordinate branches of a single proto-language, which we call Proto-Tomoip–New Ireland.Item type: Publication , Access status: Metadata only , Cattle chill events in northern Australia: observations and predictions(2026) Taylor, Rachel; Cowan, Tim; Hinds, Emily; Marshall, AndrewExtended periods of cold, wet and windy conditions, known as 'chill events', rapidly increase potential heat loss in livestock. Such events pose substantial risks to cattle, particularly breeds in northern Australia, that are acclimatised and bred for warmer conditions. Yet due to their rarity, very little is known about chill events in tropical climates, particularly during the dry season (May to October). This study provides an observational analysis of two multi-day chill events over Australia's Northern Territory in June 2007 and September 2021; combined, these events caused the deaths of over 700 cattle at two pastoral stations. Here we investigate the meteorological evolution and biometeorological severity of each event using livestock-specific thermal stress indices: the Cattle Comfort Index (CCI) and Livestock Chill Index (LCI). In both events, unusual warmth gave way to extremely cold conditions (CCI < the long-term 1st percentile), including high to very high LCI values despite the events occurring during the May to October dry season. We find that established LCI absolute thresholds developed for southern sheep do not adequately reflect chill severity in northern cattle systems, underscoring the need for locally derived percentile-based measures. We also present an illustrative example of the early-warning signals for the September 2021 event that could have been produced using the Bureau of Meteorology's operational numerical weather prediction system ACCESS-G. Several forecast initialisations indicated a shift towards markedly colder conditions up to 8-10 days in advance. Our results highlight the benefit of integrating agriclimatic indices into forecast products and the need to develop region-and species-appropriate chill thresholds for northern Australia livestock.Item type: Publication , Access status: Metadata only , Operationalizing social justice theory in transport resource allocation(2026) Qiu, Esta; Rey, David; Waller, TravisOperationalizing social justice is challenged by the absence of a universal equity definition and inherent policy trade-offs. This study bridges theoretical social justice principles with operational decision-making by integrating four commonly discussed distributive justice theories—Utilitarianism, Rawls’ Egalitarianism, Prioritarianism, and Capabilitarian Sufficiency—into a bilevel bus frequency optimization model. It introduces linearized equity-oriented formulations to reflect the distinct distributive principles of these theories and proposes justice theory-driven equity metrics to evaluate distributive impacts using different ethical criteria. Using cumulative opportunity as a unit of distribution, the proposed frameworks and metrics are applied to Canberra's southern suburbs. The results demonstrate that the choice of justice framework is not a neutral modelling decision but a normative one, with each framework producing distinct redistributive patterns and community-level trade-offs. This highlights the importance of aligning equity frameworks with policy objectives and governance contexts, as these choices ultimately shape public perception, political feasibility, and the long-term societal goals of transport investment.