Royal Society Open Science

Gendered divisions of labor are a feature of every known contemporary hunter-gatherer (forager) society. While gender roles are certainly flexible, and prominent and well-studied cases of female hunting do exist, it is more often men who hunt. A new study (Anderson et al., 2023) surveyed ethnographically known foragers and found that women hunt in 79% of foraging societies, with big-game hunting occurring in 33%. Based on this single type of labor, which is one among dozens performed in foraging societies, the authors question the existence of gendered division of labor altogether. As a diverse group of hunter-gatherer experts, we find that claims that foraging societies lack or have weak gendered divisions of labor are contradicted by empirical evidence. We conducted an in-depth examination of Anderson et al. (2023) data and methods, finding evidence of sample selection bias and numerous coding errors undermining the papers conclusions. Anderson et al. (2023) have started a useful dialogue to ameliorate the popular misconception that women never hunt. However, their analysis does not contradict the wide body of empirical evidence for gendered divisions of labor in foraging societies. Furthermore, a myopic focus on hunting diminishes the value of contributions that take different forms and downplays the trade-offs foragers of both sexes routinely face. We caution against ethnographic revisionism that projects Westernized conceptions of labor and its value onto foraging societies.

The structural complexity of cold-water corals is threatened by ocean acidification. Increased porosity and weakening of structurally critical parts of the reef framework may lead to rapid physical collapse on an ecosystem scale, reducing their potential for biodiversity support. We can use computational models to describe the mechanisms leading to reef-crumbling. How-ever, the implementation of such models into an efficient predictive tool that allows us to determine risk and timescales of reef collapse is missing. Here, we identified possible surrogate models to represent the branching architecture of the cold-water coral species Lophelia pertusa. For length scales greater than 13 cm, a continuum finite element mechanical approach can be used to analyse mechanical competence whereas at smaller length scales, mechanical surrogate models need to explicitly account for the statistical differences in the structure. We showed large morphological variations between L. pertusa colonies and branches, as well as dead and live skeletal structures, which need to be considered for the development of rapid monitoring tools for predicting risk of cold-water coral reefs crumbling. This will allow us to investigate timescales of changes, including the impact of exposure times to acidified waters on reef-crumbling.

Extended acoustic interactions with a humpback whale (Megaptera novaeangliae) were captured via human-initiated playbacks of the purported humpback "throp" social call and hydrophone recordings of the animals vocalized responses during August 2021 in Frederick Sound, Southeast Alaska. Multivariate statistical analyses performed after the event, that adapted the Wasserstein metric to spectrograms, strongly imply that the played back call was from the same animal, which had been recorded the previous day and initially selected for its clarity. This suggests these interactive playback studies may have formed a probe of time-delayed self-recognition. Fluke photographs taken that previous day and during the interactions revealed that the animal had been identified 38 years earlier, now known as the female humpback named Twain 14 years ago. This exciting and to our knowledge unique series of interactive vocalization events, while hopeful, poses more questions than answers. Most basically, did the half-hour long series of acoustic exchanges constitute an interspecies conversation? We argue that analysis tools available to infer the implied causality of interaction--statistical dependency, multivariate information theory, and machine learning--leave the question open. That said, and perhaps more importantly, the extended interaction broaches questions whose answers bear directly on future interspecies communication and, more generally, the human appreciation of nonhuman intelligence. The reported human-humpback interactions will facilitate exploring these issues at new depths.

We present an interdisciplinary analysis of finds from the Trypillia settlement of Kosenivka, Ukraine (ca. 3700-3600 BCE, Trypillia C1), that links information on human, faunal, and botanical remains with archaeological data to provide exceptionally detailed insights into life and death at a Trypillia mega-site. We obtained osteological, palaeopathological, and histotaphonomic data from human bone fragments; performed carbon and nitrogen stable isotopic analysis of human and animal bone to calculate food webs with the software FRUITS; and modelled newly generated radiocarbon dates to refine the sites chronology. The biological profile of seven identified individuals, some of whom suffered from disease symptoms common in the Chalcolithic, represents a demographic cross-section of the population. The analysis of perimortem cranial trauma suffered by two individuals suggest cases of interpersonal conflict. Food web calculations demonstrate the large contribution of cereals to the protein component of the human diet, which is supported by dental observations, and we suggest that livestock were a major manure producer for crop cultivation. The most probable scenario for the formation of the Kosenivka find assemblage is a deathly fire event. This makes the site a rare example where the archaeological and osteological results can be used to reconstruct a minimum number of house inhabitants. Following a literature review, we contextualise our analysis by discussing the general lack of human remains from Early and Middle Trypillia sites. The individuals from Kosenivka form part of the less than 0.05% of the total estimated Trypillia population that is represented skeletally; its members were deposited within settlements in the Middle Trypillia stage (until C1), preceding the shift to extramural burials in its late phase (C2). Our detailed results indicate the huge explanatory potential that has yet to be unlocked in the rare and often poorly preserved bioarchaeological archives of the Cucuteni-Trypillia phenomenon.

OBJECTIVETo explore the nature of genetic and environmental susceptibility to multiple sclerosis (MS) and to define the limits of this nature based on the statistical uncertainties regarding the various epidemiological observations that have been made. BACKGROUNDCertain parameters of MS-epidemiology are directly observable (e.g., the risk of MS-recurrence in siblings and twins of an MS proband, the proportion of women among MS patients, the population-prevalence of MS, and the time-dependent changes in the female-to-male (F:M) sex-ratio. By contrast, other parameters can only be inferred from observed parameters (e.g., the proportion of the population that is genetically susceptible, the proportion of women among susceptible individuals, the probability that a susceptible individual will experience an environment sufficient to cause MS given their genotype, and if they do, the probability that they will develop the disease). DESIGN/METHODSThe "genetically-susceptible" subset (G) of the population (Z) is defined to include everyone with any non-zero life-time chance of developing MS under some environmental conditions. For the observed parameters, acceptable ranges are assigned values such that they always include their 95% confidence intervals. By contrast, for the non-observed parameters, the acceptable ranges are assigned such that they cover the entire "plausible" range for each parameter. Using both a Cross-sectional Model and a Longitudinal Model, together with established parameter relationships, we explore, iteratively, trillions of potential parameter combinations and determine those combinations (i.e., solutions) that fall within the acceptable range for the observed and non-observed parameters. RESULTSBoth Models and all analyses are consistent and converge to demonstrate that genetic-susceptibitly is limited to 52% or less of the population and to 30% or less of women. Consequently, most individuals (particularly women) have no chance whatsoever of developing MS, regardless of their environmental exposure. Also, currently, the penetrance of MS in susceptible women is greater than it is in men. Moreover, as expected, the probability that susceptible individuals will develop MS increases with an increased likelihood of these individuals experiencing an environment sufficient to cause MS, given their genotype. Nevertheless, although it is conceivable that these response-curves plateau at 100% for both women and men, this possibility requires extreme conditions and seems remote. Rather, at least men, seem to plateau well below this level and, if so, it is this difference, rather than any differences in the genetic and environmental determinants of disease, that primarily accounts both for the difference in penetrance between women and men and for the increasing proportion of women among of MS patients worldwide. CONCLUSIONSThe development of MS (in an individual) requires both that they have an appropriate genotype (which is uncommon in the population) and that they have an environmental exposure sufficient to cause MS given their individual genotype. Nevertheless, even when the necessary genetic and environmental factors, sufficient for MS pathogenesis, co-occur for an individual, this still insufficient for that person to develop MS. Thus, disease pathogenesis, even in this circumstance, seems not to be deterministic but, rather, to involve an important element of chance. Author SummaryCertain parameters of MS-epidemiology can be directly observed. These parameters include the risk of MS recurrence in siblings and twins of an MS proband, the proportion of women among MS patients, the population-prevalence of MS, and the time-dependent changes in the female-to-male (F:M) sex-ratio. By contrast, there are other parameters of MS-epidemiology, which cant be observed, but which must be inferred based on the values of the observable parameters. These parameters include the proportion of the general population (Z) that is genetically susceptible to MS, the proportion of women among susceptible individuals, the probability that a susceptible individual will experience an environment sufficient to cause MS, and if they do, the likelihood that they will, in fact, develop the MS. We define the subset (G) - i.e., the genetically-susceptible subset - to include everyone in (Z) who has any non-zero chance of developing MS over their life-time, under some environmental circumstances. For the observed parameters, plausible ranges are assigned acceptable values such that they always include their 95% confidence interval. By contrast, for the non-observed parameters, the acceptable ranges are assigned such that they cover the entire "plausible" range for each parameter. Then, using both a Cross-sectional Model and a Longitudinal Model, together with established parameter relationships, we explore iteratively trillions of potential parameter combinations and determine those combinations (i.e., solutions) that are allowed by the observed and non-observed parameter ranges. The Cross-sectional Model makes two assumptions, commonly made in studies of monozygotic twins, to establish certain relationships between the observed and non-observed parameters. By contrast, the Longitudinal Model makes neither of these assumptions but, rather, this Model utilizes the observed changes in the female-to-male (F:M) sex-ratio and the disease prevalence, which have taken place over the past 4-5 decades, to determine the response curves for susceptible individuals, relating their probability of developing MS to their probability of experiencing an environment sufficient to cause MS. Both Models and all analyses are consistent with each other and converge to demonstrate that genetic-susceptibitly is limited to 52% or less of the population and 30% or less of women. Consequently, most individuals have no chance whatsoever of developing MS, regardless of their environmental experiences. Thus, MS is a genetic disease in the sense that, if an individual does not have the correct genetic makeup, they cant develop the disease. However, the probability that susceptible individuals will develop MS increases with an increased likelihood of these individuals experiencing an environment sufficient to cause MS, given their genotype. Thus, MS is also and environmental disease in the sense that the development of MS (in an individual), in addition to their having an appropriate genotype, requires that they experience an environmental exposure sufficient to cause MS given their individual genotype. Nevertheless, there must be another factor involved in disease pathogenesis because, although it is conceivable that these response-curves plateau at 100% for both women and men, this possibility requires extreme conditions and seems remote. Rather, at least men, seem to plateau well below this and, if so, it is this difference, rather than differences in the genetic and environmental determinants of disease, that primarily accounts both for the difference in penetrance between women and men and for the increasing proportion of women among of MS patients worldwide. Consequently, even when the necessary genetic and environmental factors, sufficient for MS pathogenesis, co-occur for an individual, this still seems to be insufficient for that person to develop MS. Thus, disease pathogenesis, even in this circumstance, seems not to be deterministic but, rather, to involve an important element of chance.

Bush-crickets exhibit remarkable auditory diversity, having the ears in the forelegs, where the tympana could be exposed or covered by cuticular flaps known as auditory pinnae. These tympanic membranes receive sound either directly or internally via an acoustic tracheal tube. Despite extensive research on auditory tuning, the relationships between tympanal structure, body size, and acoustic traits remain unclear. In this study, {micro}CT reconstructions with AI-assisted segmentation and phylogenetically informed regressions across 18 bush-cricket species were used to investigate how tympanal surface area and mean cross-sectional thickness relate to body size, carrier frequency, and the presence of auditory pinnae. Tympanal surface area scaled positively with body size, whereas thickness was independent of size. Carrier frequency decreased with increasing body size but showed no direct association with tympanal properties. Among 14 species with auditory pinnae, tympanal dimensions showed no correlation with peak cavity resonance frequency, indicating semi-independent evolution of pinna cavity and tympanal traits. Across species, pinnae did not alter tympanal surface area, although unilateral pinnae were linked to thicker tympana. Within these unilateral species, the pinna-covered tympanum remained consistently larger in area but thinner than the exposed side. Overall, these findings indicate that tympanal evolution reflects a balance of scaling constraints and localised effects of auditory pinnae. Summary StatementThe tympanal morphology in bush-crickets reflects a balance of scaling and pinna effects. Surface area scales with body size and unilateral pinnae generate consistent asymmetries.

Cultural traditions shape how animals approach and solve problems. Previously, Ugandan chimpanzees (Pan trogodytes schweinfurthii), have engaged with the honey-trap experiment, an apparatus designed to mimic a beehive and provide ecological opportunities for tool use, relying on their cultural knowledge. Here, we presented chimpanzees from the Mwera South community, a newly habituated community in Bugoma Forest, with variations of the honey-trap experiment and compared their engagement to other Ugandan chimpanzee communities to investigate various aspects of cultural behaviour in animals. First, we wanted to test whether communities varied in cultural attitude towards a given food, and whether this attitude correlated with particular instrumental components of their cultural knowledge. Second, we were interested in analyzing individual variation across individuals within the same culture. Comparing individuals from Bugomas Mwera South (N=15), Budongos Sonso (N=34), and Kibales Kanyawara (N=14) communities, we found that the latter both exhibited higher engagement with the honey-trap, and a dedicated instrumental method, stick use, to obtain the honey. In contrast, Sonso and Mwera South chimpanzees appeared similar in lacking a cultural attitude towards honey, with no attached tool technique overall. Nevertheless, there were also strong inter-individual differences. Notably, some Mwera South chimpanzees displayed undescribed behavioural flexibility, using a range of tool behaviours including both stick and leaf tool use --a pattern never before documented in over a decade of honey-trap experiments. These results demonstrate that cultural attitudes toward resources constitute an additional layer to culture in addition to instrumental knowledge, and that the latter two coexist with individual motivational traits in influencing the realization of cultural behaviour.

Scleractinian (stony) corals build reef frameworks through calcium carbonate deposition, yet all methods for assessing skeletal growth - staining, SEM, or ex vivo {micro}CT - are limited to endpoint measurements on dead specimens. Here, we utilise in vivo X-ray computed microtomography ({micro}CT) to non-destructively quantify skeletal growth in the reef-building coral Stylophora pistillata for the first time. Our in vivo {micro}CT approach applied to one individual over 16 days revealed a volume increase from [~]630 to [~]700 mm3 that can be partitioned into external vertical extension and internal lateral thickening, generating high-resolution 4D reconstructions of the evolving skeletal architecture. These measurements were consistent with established approaches but provide additional unique insights into internal growth dynamics. We demonstrate that in vivo CT enables micron-scale monitoring of calcification processes of living stony corals, thereby representing a powerful new tool to probe coral growth dynamics in the face of rapidly changing environmental conditions.

Animal colouration is fundamentally important for social communication within conspecifics to advertising threat to competitors or fitness to possible mates. Social status and animal colouration are covarying traits that are plastic in response to dynamic environments. In the African cichlid, Astatotilapia burtoni, body colouration and behaviour have been extensively reported to vary with social rank. However, the nature of the interaction between these two traits is poorly understood. We hypothesise that pigmentation patterns could be linked to the behavioural repertoires underlying social status and can be resolved to regions on the cichlid body plan. To test this hypothesis, we generated Territorial (T) and Non-territorial (NT) males and employed computer vision tools to quantify and visualise patterns/colour enrichment associated with stereotyped T/NT male behaviour. We report colour-behaviour interactions localised in specific areas of the body and face for two colour morphs illustrating a more nuanced view of social behaviour and pigmentation. Since behavioural and morphological variation are key drivers of selection in the East African Great Rift Lakes, we surmise our data may be translatable to other cichlid lineages and underline the importance of trait covariance in sexual selection and male competition.

In the search for universals shaping acoustic communication across species, we increasingly look for patterns known from human languages and music in non-human animals. These parallels are often explored separately and with limited ecological context. Here, we take a deep dive into the temporal structure of a complex call used by the little auk (Alle alle), a pelagic seabird with elaborate vocal behaviour and socially complex colonial life. Based on syllable durations, intervals and silences, we examine its conformance to linguistic laws, rhythmic structure and information content. This reveals intricate problems of temporal organisation: while the calls conform not only to linguistic laws of brevity but also to the initial and final lengthening known from human prosody, these effects interact with the internal structure of the call and information carried within it. To our knowledge, this is the first time that conformance to multiple linguistic laws, exceeding simple vocal efficiency, has been described for a non-human, non-vocal learning animal. The calls rhythmic structure shows a progressive rallentando -- a systematic slowing driven by changes in syllable and silence durations and the intervals between syllable onsets. The exact patterns of this rallentando are indicative of the callers sex and individually specific. These results reveal how seabird communication is shaped not only by efficiency universals, but also the specific pressures of colonial life. Our work highlights the temporal structure as an important axis of communication evolution, but also serves as a reminder to consider the species ecological reality and the function, not only presence, of temporal organisation. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=127 SRC="FIGDIR/small/713940v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@13de3a8org.highwire.dtl.DTLVardef@2d64adorg.highwire.dtl.DTLVardef@2ca53aorg.highwire.dtl.DTLVardef@113c38d_HPS_FORMAT_FIGEXP M_FIG C_FIG

Interventions to mitigate the spread of infectious diseases, while succeeding in their goal, have economic and social costs associated with them. These limit the duration and intensity of the interventions. We study a class of interventions which reduce the reproduction number and find the optimal strength of the intervention which minimises the final epidemic size for an immunity inducing infection. The intervention works by eliminating the overshoot part of an epidemic, and avoids a second-wave of infections. We extend the framework by considering a heterogeneous population and find that the optimal intervention can pose an ethical dilemma for decision and policy makers. This ethical dilemma is shown to be analogous to the trolley problem. We apply this optimisation strategy to real world contact data and case fatality rates from three pandemics to underline the importance of this ethical dilemma in real world scenarios.

Using tools to access hard-to-reach and high-quality resources, such as termites, honey, and nuts, initiated a fundamental adaptive shift in human and nonhuman primate cognitive and behavioural evolution. Variation in the efficiency of extracting calorie-rich and nutrient-dense resources directly impacts energy expenditure, and potentially has significant repercussions for cultural transmission where model selection biases are employed during skill acquisition. Assessing variation in efficiency is key to understanding the evolution of complex behavioural traits in primates. Yet, individual-level differences beyond age- and sex-class in primate extractive foraging efficiency have never been investigated. Here, we used 25 years (1992- 2017) of video data of the Bossou chimpanzee community (Guinea), to investigate whether individual differences in nut-cracking efficiency exist across the life span of chimpanzees aged [≥] 6 years. Data from 3,882 oil-palm nut-cracking bouts from over 800 hours of observation were collected. We found long-term stable and reliable individual differences in four (out of five) measures of efficiency. We found no sex effect, challenging previous research on a female bias in chimpanzee tool use. These life-long differences in extractive foraging impacts daily energy budgets, which potentially have significant individual fitness and life history consequences. Additionally, the establishment of long-term individual variation in chimpanzee stone tool use has implications for interpreting archaeological records of hominins. Our findings highlight the importance of longitudinal data from long-term field sites when investigating underlying cognitive and behavioural diversity across individual lifespans and between populations.

The long-term dynamics of predator populations may be driven by fluctuations in resource availability and reflect ecosystem changes such as those induced by climate change. The Icelandic Arctic fox (Vulpes lagopus) population has known major fluctuations in size since the 1950s. Using stable isotopes analysis of bone collagen over a long-time series (1979-2018), we aimed at identifying the main resources used by Icelandic Arctic foxes during periods of growth and decline to assess if the variations in their population size are linked to fluctuations in the availability of resources. We hypothesized that (1) the decline in Seabirds abundance was responsible for the decrease in the fox population; and (2) that the growth in the fox population combined to fluctuations in main resources would lead to an increase in intra-specific competition, ultimately leading to variations in their isotopic niches at the population scale. The isotopic signatures of Arctic foxes as well as their temporal trends differed clearly between inland and coast. Inland foxes showed an overall shift towards more terrestrial preys, whereas coastal foxes displayed a relatively stable use of marine resources over the years. Stable isotopes mixing models suggested that marine resources and rock ptarmigans were the most important food source and highlighted a rather stable diet in coastal habitats compared to inland habitats where more fluctuations in dietary composition were observed. Coastal foxes had a broader niche than inland foxes, and there was more variation in niche size in the inland habitat. Our results are in agreement with a general decline in seabird populations driving the decline in Arctic foxes, especially in coastal habitats. For the inland foxes, our results suggest that the lack of marine resources might have led to an increased use of ptarmigans as well as other terrestrial resources such as geese and waders, especially during the most recent period.

Termite mounds exhibit highly heterogeneous porous architectures that support efficient ventilation and thermoregulation under variable environmental conditions. Despite considerable interest, particularly in the context of bio-inspired design, the structural properties governing these processes remain only partially understood. In this study, we combine X-ray tomography and numerical simulations to investigate the relationship between structure and climatic properties in non-fungus farming termite mounds built by Trinervitermes geminatus, Cubitermes sp., Apicotermes sp., and Thoracotermes sp. Our results reveal substantial variation in airflow, diffusive transport, and thermal behaviour within mound interiors, driven by differences in internal architecture. At the scale of the whole mound, transport is strongly constrained by the outer walls, which act as the primary resistance to flow and diffusion, thereby largely determining overall permeability and CO2 diffusivity. At the microscale, wall microporosity plays a key role in regulating both CO2 diffusion and thermal conductivity, with increased microporosity enhancing gas exchange while reducing heat transfer. Within the mound interior, however, structural properties, such as macroporosity, connectivity, and tortuosity, govern transport. Together, these findings demonstrate that transport in termite mounds is inherently multiscale, with microscale wall properties exerting a strong influence on macroscale behaviour. This work advances understanding of the mechanisms underlying passive ventilation and thermoregulation in termite mounds and offers potential guidance for the design of energy efficient, bio-inspired systems.

IntroductionPSA screening for prostate cancer detection is highly debated due to the challenging balance between its potential benefits and risks, regarding overdiagnosis and overtreatment. This study applies a preference epidemiology approach to understand how individuals evaluate these trade-offs, aiming to identify the thresholds at which people find screening acceptable or burdensome. By examining both personal and societal perspectives on PSA screening, this preference epidemiology study provides insights into how values, preferences, and psychosocial factors influence health-related decision-making. MethodsA survey of Swiss men aged 55+ examined their awareness of PSA screening, their screening history, and their willingness to participate in future screenings. Hypothetical scenarios illustrating different trade-offs between overdiagnosis and lives saved by PSA screening were presented to the participants. Data were analyzed using Chi-square tests, MANOVA, and thematic analysis. Results425 participants were included in the study. Most respondents significantly overestimated PSA screenings life-saving potential, with a median estimate of 50 deaths prevented versus the current figure of 3 deaths prevented per 1000 persons screened reported in the literature. Over half of the participants supported the use of PSA screening even in a hypothetical scenario where no lives were saved. Personal and family cancer history were associated with increased support for PSA screening. Discussion and conclusionProviding factual information about the risks and benefits of PSA screening alone may not ensure fully informed, autonomous decision-making. A systematic understanding of how personal evaluations of the risks and benefits are conducted is essential for the assessment of screening programs, which could inform key policy decisions, such as the integration of screenings into mandatory health insurance packages. These findings highlight the importance for both policy decisions and health communication to go beyond fact-sharing and incorporate systematic evidence from nuanced, value-sensitive evaluations to better support informed and autonomous decision-making.

Early vaccination of the general population is a very crucial aspect in the successful mitigation of highly infectious diseases, as it is the case of the SARS-CoV-2 pandemic. The perception of possible side-effects from early batches of vaccines, presumably under-tested, is often a hindering factor for people not in high-risk categories to optin for early vaccination. In this work, early vaccination is formulated under a game-theoretic view with preference ranking and expectation maximization, in order to explore the constraints and conditions under which individuals are keen to opt-in for getting vaccinated. Although simple preference ranking leads to purely non-cooperative / non-altruistic Nash equilibrium, stable cooperative strategies can emerge under simple constraints on the payoffs, specifically the individual cost from possible side-effects versus the collective gain for the community ( herd) when endorsing vaccination by default. Significance StatementO_LIIf the collective gain from community-scale vaccination is deemed even marginally greater than each individuals cost of possible side-effects, then the best strategy is to cooperate, i.e., every individual to opt-in for getting vaccinated. C_LIO_LIThis condition is independent from the probabilities of getting infected, with or without vaccination, and it is sufficient to lead to a stable cooperative Nash equilibrium. C_LIO_LIIn any lethal infectious disease like SARS-CoV-2 and less-than-lethal possible side-effects from the vaccine, for anyone that is susceptible plus one more in his/her own close environment, vaccination is the optimal strategy for all. C_LI

Blood components are a perishable resource that play a crucial role in clinical medicine. The blood component inventory is managed by transfusion services, who ultimately aim to balance supply with demand so as to ensure availability whilst minimising waste. Whilst the blood component inventory problem has been the focus of theoretical approaches for over 50 years, evidence for the direct utilisation of existing models in the day-to-day management of blood stocks in clinical settings is limited. In this study we formulate a discrete mathematical model that describes the main processes in the management of a single population of red blood cells in a clinical setting: ageing, supply and demand. After time averaging the discrete model, a time-delayed integro-partial differential equation model is derived. Steady state analysis yields expressions for: a range of clinically relevant quantities (i.e. age distributions, total stock levels, wastage rates, age of transfused units); key performance indicators; and simple formulae that identify optimal restock thresholds in terms of parameters that are readily available in clinical settings. The approach is validated by testing predictions using data from a Scottish district general hospital. It is envisaged that the proposed methodology can ultimately be used to aid in situ rule-of-thumb decision making in clinical laboratory settings.

NHS waiting lists currently sit at record lengths due to a combination of the immediate impact of the pandemic and, as well as, long-run pressures requiring investment on NHS resources. These factors have left managers and clinicians with increasingly complex decisions when scheduling elective operations. It is imperative that managers understand the basic dynamics, tradeoffs, and pressures when managing waiting lists. Queueing theory is a key part of operational research, extensively used throughout manufacturing, retail, information technology and other sectors. This article provides an exposition of the theory of queues within the context of the current NHS backlog. With this information a manager will be able understand the demand, queue size, waiting times, capacity requirements and trade-offs for different waiting lists. We describe the metrics and a reporting system developed to understand waiting list pressures in a large NHS trust. Our aim is to enable managers to better understand their waiting lists, to achieve targets and improve health outcomes.

In this simulation study, we adopt the comprehensive neurocomputational approach of Active Inference (AIF) to illustrate some key concepts of Material Engagement Theory (MET) [1]. MET posits that craftwork does not require, or rely on, rich internal pre-planning, i.e., complex and highly detailed representations that occur mainly in the makers head. Instead, the maker engages materiality through thinging, where the human agent (the maker) is guided by and leverages the materiality of the artefact (such as a spinning of clay or a chunk of marble). MET assigns a crucial co-participatory role to materiality, attributing agency to it. We investigate METs claims through the widely adopted theory of AIF [2]. Our first aim is to simulate the plausibility of the (creative) thinging, adopting a simple modelling scenario. Then, we also discuss its applicability to other, more complex cases, which seem to require greater levels of pre-thinking (e.g., planning, imagining and conceptualising outcomes). We highlight how these cases, too, align with the general principle of thinging. With our AIF neurocomputational understanding, we explain that even in these situations, the predictive brains involved in the creative process attempt to minimise the complexity of their internal model. The upshot of this is that, always and everywhere, our human minds engage the materiality to make the most of the characteristic dynamics of the world surrounding us - things and processes alike.

Butterfly wing patterns exhibit notable differences between the dorsal and ventral surfaces, and morphological analyses of them have provided insights into the ecological and behavioural characteristics of wing colour patterns. Conventional methods for dorsoventral comparisons are constrained by the need for homologous patches or shared features between two surfaces, limiting their applicability across species. We used a convolutional neural network (CNN)-based analysis, which can compare images of the dorsal and ventral surfaces without focusing on homologous patches or features, to detect dorsoventral bias in intraspecific polymorphisms such as sexual dimorphism (SD) and female-limited mimetic polymorphism (FMP). Using specimen images of 29 butterfly species from the Yaeyama Islands, Japan, we first showed that the level of SD calculated by CNN-based analysis corresponded well with traditional assessments of SD, demonstrating the validity of the method. Dorsoventral biases were widely detected, particularly in SD, which tended to bias dorsally. This supports the conventional hypothesis that sexual selection acts more strongly on the dorsal surface. In contrast, the FMP analysis showed no significant bias. Our findings highlight CNN-based analysis as a versatile technique for dorsoventral comparisons, suggesting that broader species sampling could reveal general patterns of selection acting differentially on the two surfaces.