Although THA is routinely offered to patients age 85 years and older, surgeons might hesitate to operate on patients deemed "too young." This study tests whether such hesitancy reflects a consistent standard. (1) How much utility (net benefit) can be expected from THA, as a function of patient age and operation-related clinical variables? (2) What relative cost must be attributed to revision of a THA such that the imposition of this penalty renders the expected utility of the operation too low to justify it in younger people? A calculator was programmed using a state-transition Markov model to estimate the expected lifetime benefit of THA as a function of patient age and other user-specified parameters. A novel unit of benefit, the joint-adequate life year (JALY), was defined. One JALY is earned in each postoperative year that the patient has an intact prosthesis and adequate clinical outcome. JALYs can also be forfeited when a patient enters a revision state. Thus, previously accumulated JALYs may be partially or completely offset, resulting in a net lifetime total that is lower than the total years of an adequate outcome. Users of the calculator specify patient sex and age at the time of THA (we modeled sex rather than gender in order to be able to derive life expectancy from sex-specific life tables published by the Social Security Administration), the anticipated fraction of patients expected to have a clinically adequate outcome (termed here the "satisfaction fraction"), prosthetic life expectancy, the expected annual risk of revision attributed to catastrophic events such as fracture or infection, and a discount rate, which is used to convert future gains and losses to their net present value. The prosthetic life expectancy parameter was used to calculate an annual risk of needing revision for wear. Users also assign a negative value to the revision state, representing the number of JALYs that a patient would be willing to forgo to avoid that state. This penalty was applied in the first instance the failure state was encountered, and a value 1.5 times this penalty was applied for any subsequent encounter. The model was then interrogated to provide the expected JALYs earned as a function of failure-state penalties ranging from 0 to 40 JALYs. For this calculation, prosthetic life expectancy was set to 15 years, the anticipated satisfaction fraction was set to 90%, the annual rate of catastrophic failure was set to 0.5%, and no temporal discounting was applied. Sensitivity analyses were then performed for different values of prosthetic life expectancy, satisfaction fraction, catastrophic failure rate, second-revision penalty ratio, and with 2% and 10% temporal discounting applied. Based on the common use of THA in 85-year-old patients (a group with a life expectancy of about 6 years after THA), a benchmark of six JALYs was established, as logically no patient can have more "adequate joint years" than total years of life. We then determined the penalty that must be assigned to the revision state, such that a 45-year-old male's expected benefit would fall below this six-JALY benchmark. A cohort of 45-year-old males can be expected to earn 25 lifetime JALYs under the base case assumptions and a revision penalty of five JALYs. Lifetime JALYs for this cohort do not drop below the threshold of six until the revision penalty reaches 25 JALYs. Sensitivity analysis demonstrated that this finding was robust across wide variation in clinically plausible values for prosthetic life expectancy, satisfaction, failure rates, and discounting. Hesitation to offer THA to 45-year-old patients with impairing hip disease is logically inconsistent with the procedure's broad acceptance in 85-year-old patients. This is because under plausible assumptions of the clinical parameters, 45-year-old patients stand to accrue considerably more lifetime benefit. Indeed, even accounting for the inevitable failures younger patients may encounter (and the penalties these failures impose), such patients can expect to accrue more than six JALYs across their lifetimes unless implausibly large failure penalties are assumed. Level II, Economic and Decision Analyses.

Objectives Prone positioning improves oxygenation and survival in patients with severe acute respiratory distress syndrome (ARDS). Transport of intubated patients in the prone position is considered high risk, particularly during air medical transport, where patient access is limited. Evidence on prolonged helicopter transport in the prone position remains limited. We aimed to describe helicopter transport of intubated patients with severe ARDS in the prone position in North Norway. Methods We conducted an observational, retrospective case series of six consecutive adult patients with severe ARDS who were transported intubated in the prone position by helicopter within mainland North Norway from community hospitals to tertiary referral intensive care units between June 2020 and February 2025. Data were extracted from transport charts and hospital medical records and included transport characteristics, ventilatory parameters, adverse events, and clinical outcomes. Results Six intubated patients with severe ARDS were transported by helicopter in the prone position. Five patients were transported in a true prone position and one in a modified semi-prone position because of aircraft constraints. In four transports, the patient was transferred together with the hospital mattress onto the transport stretcher, minimizing repositioning and preserving the established prone position. All patients had severe ARDS with pre-transport PaO₂/FiO₂ (P/F) ratios below 100 mmHg and required vasoactive support. Median transport time was 73 min (range 45–135 min). No catastrophic transport-related events occurred. One patient developed clinically significant hypotension, and one had worsening oxygenation requiring ventilator adjustment. The P/F ratio improved after arrival in five of six patients. Three patients survived to hospital discharge. Conclusions In remote regions with long transport distances, prone helicopter transport may be a feasible option for selected intubated patients with severe hypoxemic respiratory failure. Our observations suggest that successful execution depends on careful preparation, appropriate transport resources, experienced air medical teams, and a pragmatic approach aimed at minimizing unnecessary patient handling.

Chromoanagenesis in Myelodysplastic Syndromes Is Associated With Highly Complex Karyotype, TP53 Disruption and Dismal Prognosis.

Evolution of dispersal in a spatially heterogeneous population with finite patch sizes and catastrophes.

In emergencies, the quick response capability of gas pipeline network dispatch is critical for maintaining flow equilibrium. For moderate disruptions, operators can sustain system balance through flow redistribution or reserve utilisation. However, in catastrophic events—marked by high uncertainty in supply restoration timelines and magnitudes—demand prioritisation and curtailment based on user heterogeneity become imperative, posing new challenges to conventional time-window constrained hierarchical dispatch. This paper proposes a user classification mechanism based on demand elasticity. Under tight resource limits, we study hierarchical scheduling to unlock demand flexibility, fill emergency flow allocation gaps, and boost system resilience. Thus, the emergency scheduling process is modelled as a priority-driven Markov Decision Process. Departing from proximity-based allocation, the model prioritises differential urgency in user demand profiles instead. A case study of China’s gas pipelines validates the model, showing interruptible users buffer shocks via demand elasticity. Moreover, gas reserve effectiveness is limited by pipeline capacity—releasing stored gas in severe disruptions may create bottlenecks, hindering efficient delivery. This approach provides an integrated emergency allocation system and theoretical foundations for priority-based flow management.

Mass extinctions and land plant evolution.

Light beams carrying orbital angular momentum (OAM) possess an unbounded set of orthogonal modes, offering significant potential for optical communication and security. However, exploiting OAM beams in space has been hindered by the lack of a versatile design toolkit. Here, we demonstrate a strategy to tailor OAM across multiple transverse planes by shaping optical caustics leveraging on catastrophe theory. With 3D-printed metasurfaces fabricated using two-photon polymerization lithography, we construct these caustics to steer Poynting vectors and achieve arbitrary shapes of OAM beams. Interestingly, we further realize "hidden" OAM along the propagation trajectory, where the intensity of the beam is spread out thus avoiding detection. By exploiting this intrinsic nature of OAM, we demonstrate the detection of encoded information in optical encryption. Our approach provides a unique framework for dynamic control of OAM in space, with promising applications in optical trapping and sensing, high-capacity data storage, and optical information security.

IntroductionHysteroscopy is a common gynecologic procedure increasingly performed in outpatient settings, yet in Canada cases still occur in operating rooms. As care transitions to ambulatory suites, processes for managing complications remain poorly defined. This educational initiative aimed to design in-situ simulation scenarios to enhance patient safety during outpatient hysteroscopy by strengthening team preparedness and identifying system gaps.MethodsA needs assessment was conducted via literature review and interviews with local staff. Findings informed the creation of 4 simulation scenarios targeting the most common and catastrophic adverse events in the outpatient setting: intravenous sedation overdose, hemorrhage, local anesthetic toxicity, and vasovagal reaction. Physicians and nurses working in the outpatient suite were invited to participate. Surveys assessing self-efficacy components on a 5-point Likert scale were administered pre- and postsimulation.ResultsExisting literature revealed minimal simulation-based training for outpatient hysteroscopy. Twelve participants (8 physicians, 4 nurses), with experience ranging from 6 months to 23 years, engaged in 4 simulation sessions. Across all measured domains, participants reported improved confidence in managing complications.DiscussionSimulation effectively prepares teams for rare, high-acuity events but remains underutilized in ambulatory gynecology. These scenarios can be deployed in simulation centers to enhance crisis resource management or in-situ to uncover latent safety threats and test system readiness. They offer a structured approach to support the safe establishment of outpatient hysteroscopy services and can serve as a continuing quality assurance tool. Implementing standardized, team-based simulation may help close safety gaps as outpatient hysteroscopy becomes the preferred standard of care.

Early recognition and management of acute deterioration is essential to reduce the risk of patients experiencing catastrophic events, such as cardiac arrest, and to prevent potentially avoidable deaths. Common signs and symptoms of acute deterioration include increased respiratory rate, alteration in skin temperature, increased heart rate, hypotension, reduced urine output and acute onset confusion. Nurses undertake clinical monitoring and observation of patients in acute care settings and are therefore ideally placed to recognise and act on these signs and symptoms. This article explores the pathophysiology of common signs and symptoms of acute deterioration in relation to body systems, aligned with the airway, breathing, circulation, disability and exposure (ABCDE) approach and with reference to the National Early Warning Score (NEWS) 2 'track and trigger' tool. The author also considers the contribution of clinical intuition, clinical judgement and effective communication in the management of the deteriorating patient.

Emerging economies suffer a huge economic burdens from environmental damage because most of the time we measure environmental damage using conventional emissions-based metrics. This study addresses this gap by introducing environmental cost (EC) as a novel measure that quantifies the economic burden of environmental degradation. The need for the new measurement stems from the requirement to examine the non-linear and asymmetric behaviors of the relationship between the environment and the economy in rapidly developing economies such as the BRICS countries in their transition from fossil fuels, their drive for new types of innovation, and their increased susceptibility to sudden changes in the cost of degradation due to energy transition, innovation-related pressures, and vulnerability to sudden changes. Therefore, stabilizing mechanisms such as Energy Transition, Innovation, Environmental Adaptability, and Trade in Low-carbon Technologies (TLCT) will reduce the possibility of experiencing high levels of Environmental Cost, while Environmental Vulnerability (EV) will heighten the probability of experiencing catastrophic regime shifts to high-cost, unstable states with sudden and extreme changes in costs. To accomplish this objective of validating the Cusp-Logit framework, a balanced panel data consisting of the BRICS countries (Brazil, Russia, India and South Africa) for the years 2015 to 2024 is used. The hybrid model of the Cusp-Logit framework consists of the geometrical layout of the Cusp Catastrophe model and a stochastic Logit transition mechanism that will capture the nonlinear regimes of the Cusp Catastrophe model and the dynamic persistence of costs associated with environmental degradation. Although empirical evidence points to the stabilizing effects of energy transition, innovation, environmental adaptability and TLCT on flattening the potential surface and reducing the possible occurrence & duration of high-cost regimes; EV creates a systemic tilt which increases the likelihood of a shift to an unstable/high-EC state. The cross-national analysis demonstrates that while China & India have stable innovation-based environments; Brazil, Russia & South Africa are much more susceptible to instability due to a limited ability to adapt to & utilize technology. Given that there is currently no comprehensive framework for understanding environmental performance in terms of costs; this work develops a new methodology for modeling the dynamic behaviors of asymmetrical regimes as well as understanding the transition probabilities between them. This provides an early warning system, which will assist BRICS policymakers to manage their exposure to environmental risks while moving towards developing sustainable pathways with low cost. Unlike conventional emission-based and linear approaches, the proposed framework captures nonlinear regime shifts, transition probabilities, and persistence of environmental cost dynamics, offering a scalable tool for policy design under uncertainty.

ABSTRACT Rapid urbanization and climate change contribute to the increased vulnerability of informal urbanisation, making informal dwellers more prone to natural disasters. Nevertheless, informal communities show inbuilt resilience in coping with such catastrophic events. This research seeks to map and characterize vulnerability to natural hazards in informal settlements in South Africa. By combining drone imagery with collaborative mapping, this pilot study proposes a novel approach to enhance community resilience and co-design practical strategies for disaster management in informal settlements. The proposed approach seeks to stimulate a community-led response to risks, focusing on implementing early warning systems and using low-cost moisture and fire sensors, while showing how vulnerable communities can actively participate as co-researchers in disaster management planning. Findings show the value of participatory workshops, the establishment of community disaster committees, and the use of accessible communication channels to strengthen disaster risk education and awareness. This research highlighted the critical role of leadership and capacity building in informal communities as a key strategy for fostering community resilience and self-reliance, and advancing community-led approaches to risk management. By combining local and Indigenous knowledge with technical tools and community-driven approaches, this study presents a framework for inclusive disaster risk reduction in vulnerable settings.

Darwinian clonal evolution provides a necessary framework for understanding tumour progression, yet emerging evidence shows that some cancers depart from a strictly gradualist tempo through episodic "macroevolutionary" leaps. We propose a unifying Burst-Drift-Control (BDC) model in which short-lived genomic reconfigurations ("bursts") that transiently alter heritable genomic states ("reactive heredity") precede longer intervals of constrained expansion, creating time-bounded vulnerabilities that clinicians may strategically steer ("control"). In this usage, the Drift component refers specifically to a drift-dominated or weak-selection interval after any initial post-burst sorting, not to the selective sweep itself. In the Burst phase, single catastrophic events, such as extrachromosomal DNA amplifications, chromothripsis, chromoplexy or whole-genome doubling, can generate major shifts in genotype and phenotype. These bursts produce new genetic configurations and can increase evolvability, for example when ecDNA circles permit oncogene dose tuning and non-Mendelian inheritance. During the drift-dominated interval, tumours may enter longer periods of constrained or near-neutral expansion in which spatial structure, clonal interference and weak or unresolved selection allow multiple lineages to persist, although the prevalence of such dynamics varies substantially by tumour type and treatment context. BDC does not assume that selective advantage is higher immediately after a burst than at later time points; later therapy or microenvironmental change can also impose strong selection. Finally, in the Control phase, if therapy is timed to exploit ecological dependencies and the fitness costs of resistance, cancer growth may be restrained as a stable, polyclonal "oligopoly" rather than progressing rapidly to an aggressive monoclonal takeover. We discuss supporting evidence, counterexamples and practical limitations, and argue that the main value of BDC lies in linking punctuated genome change to testable windows for evolutionary steering.

Reliability-constrained maintenance optimization for safety-critical wind turbine bearings with distribution-free predictive uncertainty

ABSTRACT This study examines why nuclear power in Taiwan remains persistently contested yet only partially stigmatised. Combining topic modelling with qualitative analysis of over 10,000 newspaper articles published between 2005 and 2021, we show that technological stigmatisation is continually reproduced through recurring framing contests rather than gradually resolved. Political turnovers, referendums, and catastrophic events such as the Fukushima nuclear accident generate event stigmas that interact with pre-existing core stigmas associated with nuclear technology. The repeated mobilisation of these event stigmas can crystallise into enduring symbolic imprints that shape collective memory and subsequent debates. Pro- and anti-nuclear actors draw on shared frames—particularly governance, well-being, and politics—but deploy them in incompatible and politicised ways, while distinct frames such as risk and democracy further intensify contestation. We contribute by theorising how the interaction of core and event stigmas sustains long-term framing contests and embeds energy debates within broader struggles over political legitimacy.

Coronary stent implantation has revolutionised percutaneous coronary intervention (PCI), preventing vessel closure and reducing restenosis. Nonetheless, the permanent presence of an intracoronary endoprosthesis introduces two intrinsic major limitations: restenosis and stent thrombosis (ST). Although ST incidence has declined with last-generation drug-eluting stents, improved implantation technique and antiplatelet regimens, it remains a catastrophic event, typically presenting as ST-elevation myocardial infarction or sudden cardiac death, with persistently high early and late mortality. Standardised definitions classify ST by diagnostic certainty and timing from implantation, reflecting distinct underlying mechanisms across intraprocedural, early, late and very late phases. Early ST is most often driven by correctable procedural and pharmacological determinants, including underexpansion and malapposition, high thrombotic burden in acute coronary syndromes and premature discontinuation or inadequate effect, of dual antiplatelet therapy (DAPT). Late and very late ST are frequently related to delayed healing with uncovered struts, late-acquired malapposition and intrastent neoatherosclerosis or may involve hypersensitivity to stent components or allergy to external factors (Kounis syndrome type III). Intravascular imaging, particularly optical coherence tomography, complemented by intravascular ultrasound, is pivotal to identify the dominant mechanism and guide targeted therapy. Acute management relies on rapid reperfusion with PCI, mechanical optimisation and potent antithrombotic strategies; drug-coated balloon angioplasty is emerging as a mechanistically attractive option in selected late presentations to avoid additional metal. Prevention relies on imaging-guided implantation, individualised DAPT and strict risk-factor control. This narrative review summarises current definitions, epidemiology, mechanisms, diagnostic pathways and contemporary therapeutic and preventive strategies, integrating recent consensus recommendations.

Purpose Natural disasters are increasing in frequency and severity, intensifying the communication demands placed on school leaders. This article examines how Australian school leaders communicated during catastrophic wildfire events, with attention to how communication supported trust, ensured safety, and fostered operational continuity. Design/methodology/approach An interpretivist collective case study was conducted with six school leaders in New South Wales, Australia. Data comprised open ended interviews, supplemented by relevant school/system documents and social media captures. Interviews were professionally transcribed and analysed using reflexive thematic analysis, with iterative, inductive coding and analytic dialogue between researchers. Findings Leaders mobilised a set of crisis-communication practices spanning immediate threat response and longer-term recovery. These included emotionally attuned communication; rapid, adaptive multi-channel messaging; values-based care; ethical advocacy and boundary-setting; risk-informed proactive decisions; coordinated engagement of frontline staff; receptive listening to lived experience; trust-building transparency; decisive messaging under uncertainty; and equitable communication oriented to the collective rather than the most vocal. Research limitations/implications Findings are based on a small group of participants in one Australian state with retrospective accounts of crises. Transferability to other crisis types and systems warrant further research. Practical implications The typology and reflective questions provide a practical framework for preparedness planning, distributed communication roles, and equity-oriented stakeholder engagement. Social implications Strengthening crisis communication capacity can support community trust, safety and resilience as climate-related disasters increasingly disrupt schooling. Originality/value The study contributes a typology of crisis communication grounded in leaders' wildfire experiences and offers a reflective self-assessment tool for leadership preparation and team learning. It extends crisis-leadership scholarship by specifying communication as a situated, relational practice that underpins trust, safety and continuity in high-stakes contexts.

ABSTRACT Taking the tragic shooting at Sandy Hook Elementary School in Newtown, Connecticut as a case study, this paper examines the connection that exists between materiality and mourning and how that connection can be effectively mobilised to help manage community grief following catastrophic events. In the wake of social traumas like the one under consideration, it is common to focus immediate attention on abstract social issues aimed at preventing future tragedies. This paper emphasises that attention must, at the same time, be turned towards the social wound that traumatic events inflict on the communities in which they occur. In this work, the material world matters. The process of healing can be greatly facilitated by the thoughtful management of the material remnants associated with traumatic events. The purpose of this inquiry is to emphasise the power that material has both to bind us to tragedy and to heal us from it, and to provide an example where this power was both recognised and utilised effectively by those managing a community’s response to an unthinkable event. Through the use of both additive and subtractive strategies, the material world became a critical tool in the work of mourning in Newtown, Connecticut.

Catastrophic events, such as epidemics and natural disasters, can dramatically affect the mental health of individuals, making it crucial to investigate the psychological effects of these events. This study aims to explore the associations between social support, death obsession, hope, and resilience among individuals affected by the February 6, 2023, earthquake in Türkiye, one of the most catastrophic earthquakes of this century. A total of 470 Turkish adults participated in the research. Structural equation modeling was employed to examine the mediating roles of hope and resilience in the relationship between social support and death obsession. The model revealed that resilience and hope serially fully mediated the relationship between social support and death obsession in earthquake-affected individuals (χ2 (57, N = 470) = 131.702, p < 0.001; RFI = 0.92; NFI = 0.94; TLI = 0.95; IFI = 0.97; GFI = 0.96; CFI = 0.97; RMSEA = 0.053; SRMR = 0.066). These findings contribute to our comprehension of the interplay between social support, death obsession, hope, and resilience in the context of earthquakes and are expected to inform future research in this area.

The persistent failure of linear, plan-driven models to effect lasting organisational transformation necessitates a paradigm shift. Contemporary organisations, particularly in high-stakes environments such as healthcare, do not function as predictable machines but as Complex Adaptive Systems (CAS), in which change is inherently non-linear and emergent. This longitudinal, mixed-methods study investigates the central premise that micro-changes in leadership behaviour, such as subtle, sustained adjustments in daily practice, can act as a critical catalyst, precipitating significant and often discontinuous shifts in organisational culture and performance. Designed as a 24-month longitudinal mixed-methods study within a Malaysian healthcare organisation, this research will synthesise CAS theory, transformational leadership, and organisational culture theory to track the co-evolution of leadership and culture. A key methodological innovation will be the application of Cusp Catastrophe Modelling to formally test for threshold-based, non-linear transitions. Quantitative and qualitative data will be collected in parallel across four waves (Baseline, Month 8, Month 16, and Month 24) to map broad trends and probe lived experiences and mechanisms of change. The study is designed to address contemporary calls for rigour in microfoundations and in embedding research. The findings aim to advance theory by empirically modelling cultural emergence as a dynamic system and provide practitioners with a nuanced, evidence-based framework for fostering genuine adaptability in complex environments.

Mechanistic and topological insights into the Curtius rearrangement of N,N-dimethylcarbamoyl azide: A quantum chemical study.