Data-driven design of well-behaved nonlinear structures:a case study on the von Mises truss

Well-behaved nonlinear structures, which exploit elastic instabilities for functionality, have garnered increasing interest for rapid shape shifting and energy dissipation applications. One of the current bottlenecks during design is the large computational cost associated with nonlinear solvers when targeting a specific function through inverse design. Advances in machine learning (ML) tools have enabled a more efficient inverse design process. However, generating sufficient data efficiently to train the ML models still remains a challenge. This paper presents a novel computational toolbox that automates the generation of nonlinear finite element models, submission of analyses, monitoring of ongoing analyses, termination of analyses upon meeting specified criteria, and post-processing of results. With this computational toolbox, we develop three types of ML models: two forward models that classify and characterise nonlinear equilibrium paths based on the structure’s properties (material and geometry), and one backward model for predicting the structure’s properties from key features of the nonlinear equilibrium path. We evaluate various ML algorithms for each model type, provide recommendations, and explore algorithmic modifications to enhance prediction accuracy. To illustrate the effectiveness of the proposed tools, we present two case studies where the von Mises truss plays a key role: a) a recoverable energy dissipating mechanical metamaterial and (b) a vibro-impact capsule robot. Our findings highlight the potential of data-driven approaches to efficiently enable the design of high-performance nonlinear structures that harness instabilities for targeted functionalities

TRANSFER::ThReatened preterm birth, assessment of the need for in-utero tranSFER between 22 + 0-23 + 6 weeks' gestation, a multicentre prospective service evaluation across the United Kingdom.

TRANSFER was established following updated guidance from British Association of Perinatal Medicine, suggesting offering survival focussed care from 22 + 0 weeks’ gestation. The number of women presenting with threatened preterm birth at this gestation is unknown; essential data to facilitate adequate service provision and planning for UK perinatal services. Objectives: To identify women presenting with threatened preterm birth between 22 + 0–23 + 6 weeks’ gestation across the UK and determine the number presenting ou + tside an obstetric unit with a Level 3 NICU. Record the number of in-utero transfers of women presenting between 22 + 0––23 + 6 weeks’ gestation and determine the number of women who deliver prior to 24 weeks’ gestation in units without a Level 3 NICU. Design: Multicentre prospective service evaluation. Setting: 90 UK maternity units. Patients: Women presenting with threatened preterm birth between 22 + 0–23 + 6 weeks’ gestation between 17/ 5/21–30/6/22. Main outcome measures: Number of women presenting in each geographical region, need for in utero transfer, length of antenatal hospital stay and use of biomarkers to predict preterm birth. Results: Between 22 + 0–23 + 6 weeks’ gestation:1. 511 women presented with threatened preterm birth to UK obstetric units. 2. 286 (56%) women presented to obstetric units without level 3 NICU. 3. 217 (76%) women required transfer. 4. 41 (8%) women delivered in a unit without a Level 3 NICU (10 (24%) opted for survival focussed care).Conclusions: Women presenting with threatened preterm birth between 22 + 0–23 + 6 weeks gestation is higher than anticipated and is likely to be an under-representation of actual number of presentations

Community estimate of global glacier mass changes from 2000 to 2023

Glaciers are indicators of ongoing anthropogenic climate change1. Their melting leads to increased local geohazards2, and impacts marine3 and terrestrial4,5 ecosystems, regional freshwater resources6, and both global water and energy cycles7,8. Together with the Greenland and Antarctic ice sheets, glaciers are essential drivers of present9,10 and future11, 12–13 sea-level rise. Previous assessments of global glacier mass changes have been hampered by spatial and temporal limitations and the heterogeneity of existing data series14, 15–16. Here we show in an intercomparison exercise that glaciers worldwide lost 273 ± 16 gigatonnes in mass annually from 2000 to 2023, with an increase of 36 ± 10% from the first (2000–2011) to the second (2012–2023) half of the period. Since 2000, glaciers have lost between 2% and 39% of their ice regionally and about 5% globally. Glacier mass loss is about 18% larger than the loss from the Greenland Ice Sheet and more than twice that from the Antarctic Ice Sheet17. Our results arise from a scientific community effort to collect, homogenize, combine and analyse glacier mass changes from in situ and remote-sensing observations. Although our estimates are in agreement with findings from previous assessments14, 15–16 at a global scale, we found some large regional deviations owing to systematic differences among observation methods. Our results provide a refined baseline for better understanding observational differences and for calibrating model ensembles12,16,18, which will help to narrow projection uncertainty for the twenty-first century11,12,18.</p

Dynamic environment but no temperature change since the late Paleogene at Lühe Basin (Yunnan, China)

The complex tectonic evolution in the Tibetan region has impacted climate, the Asian monsoon system, and the development of major biodiversity hotspots, especially since the onset of the India-Eurasia continental collision during the early Paleogene. Untangling the links between the geologic, climatic, and ecological history of the broader region provides insights into key Earth system mechanisms, relevant for understanding our rapidly changing planet. Notably around this time, the Eocene-Oligocene transition (EOT; ∼34 million years ago, Ma) marked a critical shift from a greenhouse to an icehouse climate. Whereas temperatures derived from benthic marine records show ubiquitous global cooling of 4 °C, there is an emerging picture that sea surface temperatures and the terrestrial realm experienced a heterogenous response across this interval. Here, we reconstruct a terrestrial temperature record from ∼35–27 Ma at a tectonically unresolved location at the margins of the Tibetan Plateau, Lühe Basin (Yunnan, China). Our multi-proxy organic geochemistry approach across a 340-m long section, complemented by sedimentological interpretations, climate model results, and palaeobotany-based estimates at a nearby site, shows that Lühe Basin hosted a dynamic fluvial environment that maintained relatively stable average temperatures across this 8-million-year interval. The lack of cooling at Lühe Basin supports evidence that sea surface temperatures and terrestrial sections had a complex and heterogenous response across the EOT despite the ubiquitous 4 °C cooling trends seen in the benthic marine record. Furthermore, these palaeotemperature estimates match present-day values at this location, suggesting that this area has not undergone significant temperature change – and possibly no significant uplift – since the late Paleogene.</p

Impact of the rollout of the national social prescribing link worker programme on population outcomes:evidence from a repeated cross-sectional survey

Background: Social prescribing link workers have been rolled out nationally through the Additional Roles Reimbursement Scheme. Link workers connect people to advice and support to address the non-medical and social issues affecting their health and well-being. Aim: To determine whether the rollout of social prescribing link workers through primary care networks improved population outcomes. Design and Setting: 4,132,676 respondents from repeated cross-sections of the General Practice Patient Survey (2018 to 2023) combined with administrative workforce data. Method: We used logistic regression models to relate the number of full-time equivalent social prescribing link workers per 50,000 patients to five population outcomes. Results: An additional full-time equivalent link worker per 50,000 patients was associated with higher probabilities of respondents with long-term conditions having confidence in managing long-term condition(s) (Odds Ratio (OR)=1.006; 95% confidence interval (CI)= 1.001 to 1.010) and having enough support from local services (OR=1.005; 95%CI=1.001 to 1.008). For all respondents, the same size increase in link workers was associated with a higher probability of having a good experience at their general practice (OR=1.015; 95%CI=1.004 to 1.027). For respondents with mental health needs, this increase in link workers was associated with a higher probability of having their needs understood (OR=1.012; 95%CI=1.003 to 1.021). Conclusions: The rollout of link workers was associated with small improvements in patient experience and slightly better outcomes for population groups specifically targeted for social prescribing. Future work is required to determine whether the scheme is financially sustainable and to ensure it does not widen existing health inequalities.<br/

‘Before They Sent Us to Civilise Them, Now They Send Us to Defend Them from Civilisation’:Missionary Theopolitics at the Margins of the State

This article examines the involvement of Catholic missionaries in mediating the socioenvironmental conflicts arising from oil extraction in the Northern Ecuadorian Amazon.Drawing on a 13-month ethnographic study and archival research, it investigates how missionaries navigate marginality areas where state practices are both constructed and deconstructed through informal and illegal practices. The analysis foregrounds the mediatory role of missionaries between local communities, the state, and oil corporations, dwelling on the theological drivers of their interventions in political arenas. Using the conceptual lens of theopolitics, my analysis of practices of missionisation argues for a de secularisation of politics, highlighting the co-constitution of missionisation and state governance in marginal and contested regions

How to assess similarities and differences between mantle circulation models and Earth using disparate independent observations

Mantle circulation in the Earth acts to remove heat from its interior and is thus a critical driver of our planet’s internal and surface evolution. Numerical mantle circulation models (MCMs)driven by plate motion history allow us to model relevant physical and chemical processes and help answer questions related to mantle properties and circulation. Predictions from MCM scan be tested using a variety of observations. Here, we illustrate how the combination of many disparate observations leads to constraints on mantle circulation across space and time. We present this approach by first describing the setup of the example test MCM, including the parameterisation of melting, and the methodology used to obtain elastic Earth models. We subsequently describe different constraints, that either provide information about present-day mantle (e.g. seismic velocity structure and surface deflection) or its temporal evolution (e.g. geomagnetic reversal frequency, geochemical isotope ratios and temperature of upper mantle sampled by lavas).We illustrate the information that each observation provides by applying it to a single MCM. In future work, we will apply these observational constraints to a large number of MCMs, which will allow us to address questions related to Earth-like mantle circulation

Understanding Measurement of Postural Hypotension (UMPH):a nationwide survey of general practice in England

Background Postural hypotension (PH) is associated with excess mortality, falls and cognitive decline. PH is poorly recorded in routine general practice (practice) records. Few practice studies have explored measurement and diagnosis of PH. Aim To understand how PH is measured, diagnosed and managed in practice. Design and setting Online survey of practice staff in England. Method Clinical Research Networks distributed the survey to practices, seeking individual responses from any clinical staff involved in routine blood pressure (BP) measurement. Responses were analysed according to role and demographic data using descriptive statistics. Multivariable modelling of undertaking postural BP measurements was performed. Results 703 responses were received from 243 practices (mean practice-level response rate 17%). Half (362; 51%) of respondents were doctors, 196 (28%) practice nurses and 77 (11%) healthcare assistants (HCAs). Eight percent did not routinely check for PH, usually citing time constraints. For the remaining 92%, postural symptoms were the predominant reason for checking (97% respondents); only 24% cited any other guideline indication for PH testing. 77% used sit-to-stand BP measurements; only 25% measured standing BP for more than one minute. On regression modelling, other professionals tested less for PH than doctors (Odds ratios: nurses 0.323 (95% confidence interval 0.117 to 0.894), HCAs 0.102 (0.032 to 0.325), pharmacists 0.986 (0.024 to 0.412)). Conclusion Awareness of reasons, besides symptoms, and adherence to guidelines for PH testing, are low. Time is the key barrier to improved testing for PH. Clarity on pragmatic methods of measuring PH in practice would also facilitate measurement uptake

Worldwide Soundscapes:A Synthesis of Passive Acoustic Monitoring Across Realms

AimThe urgency for remote, reliable and scalable biodiversity monitoring amidst mounting human pressures on ecosystems has sparked worldwide interest in Passive Acoustic Monitoring (PAM), which can track life underwater and on land. However, we lack a unified methodology to report this sampling effort and a comprehensive overview of PAM coverage to gauge its potential as a global research and monitoring tool. To address this gap, we created the Worldwide Soundscapes project, a collaborative network and growing database comprising metadata from 416 datasets across all realms (terrestrial, marine, freshwater and subterranean).LocationWorldwide, 12,343 sites, all ecosystem types.Time Period1991 to present.Major Taxa StudiedAll soniferous taxa.MethodsWe synthesise sampling coverage across spatial, temporal and ecological scales using metadata describing sampling locations, deployment schedules, focal taxa and audio recording parameters. We explore global trends in biological, anthropogenic and geophysical sounds based on 168 selected recordings from 12 ecosystems across all realms.ResultsTerrestrial sampling is spatially denser (46 sites per million square kilometre—Mkm2) than aquatic sampling (0.3 and 1.8 sites/Mkm2 in oceans and fresh water) with only two subterranean datasets. Although diel and lunar cycles are well sampled across realms, only marine datasets (55%) comprehensively sample all seasons. Across the 12 ecosystems selected for exploring global acoustic trends, biological sounds showed contrasting diel patterns across ecosystems, declined with distance from the Equator, and were negatively correlated with anthropogenic sounds.Main ConclusionsPAM can inform macroecological studies as well as global conservation and phenology syntheses, but representation can be improved by expanding terrestrial taxonomic scope, sampling coverage in the high seas and subterranean ecosystems, and spatio-temporal replication in freshwater habitats. Overall, this worldwide PAM network holds promise to support cross-realm biodiversity research and monitoring efforts