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.

In April 2023, eighteen scholars from nine different subjects representing the humanities, natural and social sciences came together for a one-day workshop at St John’s College, Durham. Despite our differences, all had one aim: the study of past environmental change and its effects on human societies. Talking across disciplinary divides, we discussed what environmental history is, how it may or may not contribute to tackling the climate crisis, and the problems of sources, scale and temporality. This article collects select conversations into a roundtable format split into four areas: scale, time and space, interdisciplinarity, and the future of environmental history. We argue that environmental history is more usefully understood not as a distinct sub-field of history, but as an interdisciplinary meeting place for innovative collaboration. This also presents a model for future research aimed at tackling the climate crisis at higher education institutions.

We recently reported that cultural group membership may be a predictor of the likelihood that an individual will detect a faked accent in a recording. Here, we present follow-up data to our original study using a larger data set comprised of responses from the across the world. Our findings are in line with our previous work and suggest that native listeners perform better at this task than do non-native listeners overall, although with some between-group variation. We discuss our findings within the context of signals of trustworthiness and suggest future avenues of research.

Distinguishing early domesticates from their wild progenitors presents a significant obstacle for understanding human-mediated effects in the past. The origin of dogs is particularly controversial because potential early dog remains often lack corroborating evidence that can provide secure links between proposed dog remains and human activity. The Tumat Puppies, two permafrost-preserved Late Pleistocene canids, have been hypothesized to have been littermates and early domesticates due to a physical association with putatively butchered mammoth bones. Through a combination of osteometry, stable isotope analysis, plant macrofossil analysis, and genomic and metagenomic analyses, this study exploits the unique properties of the naturally mummified Tumat Puppies to examine their familial relationship and to determine whether dietary information links them to human activities. The multifaceted analysis reveals that the 14,965–14,046 cal yr BP Tumat Puppies were littermates who inhabited a dry and relatively mild environment with heterogeneous vegetation and consumed a diverse diet, including woolly rhinoceros in their final days. However, because there is no evidence of mammoth consumption, these data do not establish a link between the canids and ancient humans.

Previous observational studies suggested that vitamin D may control the absorption of iron (Fe) by inhibition of hepcidin, but the causal relevance of these associations is uncertain. Using placebo-controlled randomisation, we assessed the effects of supplementation with vitamin D on biochemical markers of Fe status and erythropoiesis in community-dwelling older people living in the UK. The BEST-D trial, designed to establish the optimum dose of vitamin D3 for future trials, had 305 participants, aged 65 years or older, randomly allocated to 4000 IU vitamin D3 (n 102), 2000 IU vitamin D3 (n 102) or matching placebo (n 101). We estimated the effect of vitamin D allocation on plasma levels of hepcidin, soluble transferrin receptor (sTfR), ferritin, Fe, transferrin, saturated transferrin (TSAT%) and the sTfR–ferritin index. Despite increases in 25-hydroxy-vitamin D, neither dose had significant effects on biochemical markers of Fe status or erythropoiesis. Geometric mean concentrations were similar in vitamin D3 arms v. placebo for hepcidin (20·7 [se 0·90] v. 20·5 [1·21] ng/ml), sTfR (0·69 [0·010] v. 0·70 [0·015] µg/ml), ferritin (97·1 [2·81] v. 97·8 [4·10] µg/l) and sTfR–ferritin ratio (0·36 [0·006] v. 0·36 [0·009]), respectively, while arithmetic mean levels were similar for Fe (16·7 [0·38] v. 17·3 [0·54] µmol/l), transferrin (2·56 [0·014] v. 2·60 [0·021] g/dl) and TSAT% (26·5 [0·60] v. 27·5 [0·85]). The proportions of participants with ferritin < 15 µg/l and TSAT < 16 % were unaltered by vitamin D3 suggesting that 12 months of daily supplementation with moderately high doses of vitamin D3 are unlikely to alter the Fe status of older adults.

Through compositional inclusion or exclusion, the photograph can assert and communicate what belongs in a picture, in a landscape, in an ecosystem. It can illuminate what we deem conservation-worthy, or, on a larger scale, which extinctions are attention-worthy. Photographic practice helps to illuminate the active nature of extinction, and our choices as actors and witnesses within that process. Here, researchers from the University of Leeds’ Extinction Studies Doctoral Training Programme present individual reflections on interdisciplinary practice-led research in the Scottish Small Isles. We consider how photography, as a form of praxis, can generate new forms of knowledge surrounding extinction: its meanings, representations, and legacies, particularly through visual representation. We offer seven perspectives on contemporary image-making, from disciplines including philosophy, conservation biology, literature, sociology, geology, cultural anthropology, and palaeontology. Researchers gathered experiential, ethical, even biological meanings from considering what to include or exclude in images: from the micro to the macro, the visible to the invisible, the aesthetic to the ecological. We draw conclusions around meaning-making through the process of photography itself, and the tensions encountered through framing and decision-making in a time of mass ecological decline.

This paper uses log-linear models with latent variables (Hagenaars, in Loglinear Models with Latent Variables, 1993) to define a family of cognitive diagnosis models. In doing so, the relationship between many common models is explicitly defined and discussed. In addition, because the log-linear model with latent variables is a general model for cognitive diagnosis, new alternatives to modeling the functional relationship between attribute mastery and the probability of a correct response are discussed.

We present a re-discovery of G278.94+1.35a as possibly one of the largest known Galactic supernova remnants (SNRs) – that we name Diprotodon. While previously established as a Galactic SNR, Diprotodon is visible in our new Evolutionary Map of the Universe (EMU) and GaLactic and Extragalactic All-sky MWA (GLEAM) radio continuum images at an angular size of $3{{{{.\!^\circ}}}}33\times3{{{{.\!^\circ}}}}23$, much larger than previously measured. At the previously suggested distance of 2.7 kpc, this implies a diameter of 157$\times$152 pc. This size would qualify Diprotodon as the largest known SNR and pushes our estimates of SNR sizes to the upper limits. We investigate the environment in which the SNR is located and examine various scenarios that might explain such a large and relatively bright SNR appearance. We find that Diprotodon is most likely at a much closer distance of $\sim$1 kpc, implying its diameter is 58$\times$56 pc and it is in the radiative evolutionary phase. We also present a new Fermi-LAT data analysis that confirms the angular extent of the SNR in gamma rays. The origin of the high-energy emission remains somewhat puzzling, and the scenarios we explore reveal new puzzles, given this unexpected and unique observation of a seemingly evolved SNR having a hard GeV spectrum with no breaks. We explore both leptonic and hadronic scenarios, as well as the possibility that the high-energy emission arises from the leftover particle population of a historic pulsar wind nebula.

Previous research in the evolutionary and psychological sciences has suggested that markers or tags of ethnic or group membership may help to solve cooperation and coordination problems. Cheating remains, however, a problem for these views, insofar as it is possible to fake the tag. While evolutionary psychologists have suggested that humans evolved the propensity to overcome this free rider problem, it is unclear how this module might manifest at the group level. In this study, we investigate the degree to which native and non-native speakers of accents – which are candidates for tags of group membership – spoken in the UK and Ireland can detect mimicry. We find that people are, overall, better than chance at detecting mimicry, and secondly we find substantial inter-group heterogeneity, suggesting that cultural evolutionary processes drive the manifestations of cheater detection. We discuss alternative explanations and suggest avenues of further inquiry.

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.

Studies of extinction typically focus on unintended losses of biodiversity and culture. This study, however, examines an attempt to induce extinction of a parasite: human hookworm (Necator americanus and Ancylostoma duodenale). Our interdisciplinary approach integrates medical history and epidemiology using records created by the Jamaica Hookworm Commission of 1919–1936. We show that the attempt to induce the extinction of hookworms was driven by its perceived effects on labour productivity and consequent status as an ideological and economic threat. We use spatial epidemiology to describe the relationships between parasites, environments and the working conditions of plantation labourers. Using data from 330 locations across Jamaica in which 169,380 individuals were tested for hookworm infection we show that the prevalence of hookworm infection was higher in districts surrounding plantations. Prevalence decreased with the temperature of the coldest month, increased with the amount of rainfall in the driest month, and increased with vegetation quantity (normalised difference vegetation index). Worm burden (and thus pathology) varied greatly between individuals, even those living together; hookworm infection varied between environments, socioeconomic conditions and individuals. Nevertheless, the conditions of labour shaped the distribution of hookworms. Plantations both spread and problematised hookworms, driving efforts to bring it to extinction.