Post-asymptotic giant branch (post-AGB) binary stars are evolved systems that host circumbinary discs formed through mass loss during late stage binary interactions. Their structural, morphological, kinematic, and chemical similarities to planet-forming discs suggest that these systems may act as sites of ‘second-generation’ planet formation. In this study, we assess whether the disc instability mechanism – a proposed pathway for rapid, giant planet formation in some protoplanetary discs - can operate in post-AGB discs; motivated by their short lifetimes ($10^{4-5}$ yr). Using the Toomre criterion under well motivated assumptions for disc structure and size, mass, and thermal properties, we assess the conditions for gravitational instability. We first benchmark our analytical framework using well studied protoplanetary disc systems (including HL Tauri, Elias 2-27, GQ Lupi) before applying the same analysis to observed post-AGB discs. We find that post-AGB discs are generally gravitationally stable at present, due primarily to their low masses. Using viscous disc theory, we find that the discs were stable against collapse even in the past, when their masses were potentially higher. In contrast, several protoplanetary discs analysed in the same way show that they likely experienced gravitationally unstable phases early on. We also find that higher viscosity parameters ($\alpha \sim 10^{-2}$) are better aligned with expected post-AGB disc lifetimes. Finally, we revisit the planet formation scenario proposed for the post-common envelope system NN Ser, first carried out by Schleicher and Dreizler, and we show that gravitational instability could be feasible under specific, high disc mass assumptions. Overall, our results provide the first systematic theoretical assessment of gravitational instability in post-AGB discs, demonstrating that this mechanism is unlikely to dominate second-generation planet formation in these systems and underscoring the need to explore alternative pathways – such as core accretion – in future studies.

In recent years, there has been growing interest regarding the impact of human movement quality on health. However, assessing movement quality outside of laboratories or clinics remains challenging. This study aimed to evaluate the capabilities of consumer-grade wearables to assess movement quality and to consider optimal sensor locations. Twenty-two participants wore Polar Verity Sense magnetic, angular rate, and gravity (MARG) sensors on their chest and both wrists, thighs, and ankles, while performing repeated bodyweight movements. The Madgwick sensor-fusion algorithm was utilized to obtain three-dimensional orientations. Concurrent validity, quantified using the root-mean-square-error (RMSE), was established against a Vicon optical motion capture system following time-synchronization and coordinate-system alignment. The chest sensors demonstrated the highest accuracies overall, with mean RMSE ($ {\mathrm{RMSE}}_{\mathrm{mean}} $) less than 9.0° across all movements. In contrast, the wrist sensors varied considerably ($ 5.5\hskip-2pt {}^{\circ}\le {\mathrm{RMSE}}_{\mathrm{mean}}\le 139.1\hskip-2pt {}^{\circ} $). Ankle and thigh sensors yielded mixed results, with the $ {\mathrm{RMSE}}_{\mathrm{mean}} $ ranging from 2.0° to 40.0°. Notably, yaw angles consistently demonstrated higher discrepancies overall, while pitch and roll were relatively more stable. This study highlights the potential of consumer-grade MARG sensors to increase the real-world applicability and accessibility of complex biomechanical models. It also accentuates the requirement for strategic sensor placement and refined calibration and postprocessing methods to ensure accuracy.

This study reveals the mineralogy and origin of unusual silica-carbonate bodies (listvenite) associated with tectonized serpentinites and Permian–Triassic phyllites from the Tokat region in northern Turkey. The listvenite includes green-coloured opaline silica intersected by saddle dolomite and minor sulfide mineralization (pyrite, cobaltite and enargite). It also hosts abundant chalcedonic bodies, i.e. agate of bluish to bluish-white colour. Listvenite-hosted opaline silica has been recognized as lussatite, a fibrous birefringent opal-CT variety, with a dominantly ‘tridymitic’ structure. The green colouration results from discrete, but widely disseminated, Cr-bearing smectite-group minerals, such as volkonskoite and/or Cr-montmorillonite. Chromium, the main colouring agent as determined by element-distribution mapping and visible-light spectroscopy, was probably derived from spinel-group minerals (e.g. chromite), the relics of which mark the presence of an ultramafic protolith. In contrast, the vein agate is composed of length-fast chalcedony, with subordinate quartzine and minor opaline silica, followed by drusy quartz. Its bluish colour appears to be related to scattering effects enhanced by elevated moganite contents (up to 46 wt.%). The observed mineral paragenesis suggests at least a two-stage evolution: (1) early listvenitization marked by carbonate-silica alteration of the host serpentinite together with concomitant sulfide precipitation; and (2) subsequent silicification producing chalcedony (agate) veins under low-temperature conditions, followed by possible dissolution of the earlier saddle dolomite. This evolution reflects complex fluid–rock interactions involving CO2-rich, Ca-bearing and later Si-rich fluids under fluctuating redox and pH conditions. Hence, the proposed crystallization sequence of the associated mineral assemblage is: sulfides (cobaltite+pyrite+enargite) → saddle dolomite → opal (lussatite) + Cr-smectite → chalcedony (agate). These data provide new insights into the genesis, colouration mechanisms and structural state of Cr-bearing opaline and chalcedonic silica in altered ultramafic terrains.

This article proposes a local projection (LP) residual bootstrap method to construct confidence intervals for impulse response coefficients of AR(1) models. Our bootstrap method is based on the LP approach and involves a residual bootstrap procedure applied to AR(1) models. We present theoretical results for our bootstrap method and proposed confidence intervals. First, we prove the uniform consistency of the LP-residual bootstrap over a large class of AR(1) models that allow for a unit root, conditional heteroskedasticity of unknown form, and martingale difference shocks. Then, we prove the asymptotic validity of our confidence intervals over the same class of AR(1) models. Finally, we show that the LP-residual bootstrap provides asymptotic refinements for confidence intervals on a restricted class of AR(1) models relative to those required for the uniform consistency of our bootstrap.

The rational allocation of authority across government levels is crucial for the effective provision of environmental public goods. Based on China’s environmental policy texts (1973–2023) and case studies, this paper analyzes the division and adjustment of environmental governance powers. The findings reveal selective decentralization under the trend of centralization over the past fifty years in China’s environmental governance: (1) Legislative power has been conditionally devolved, to encourage distinctive local environmental legislation that is non-contradictory to central legislation; (2) Administrative power has transitioned from an ambiguous two-tier system to a three-category framework with attempts to quantify shared authorities. This recentralization aligns with the principle that national public goods are provided by the central government, while regional ones are supplied jointly; (3) Supervisory power has transitioned from local to vertical management, and its oversight has been elevated to a national initiative, receiving strong political endorsement.

In 1963, Martin Luther King, Jr. wrote Letter from Birmingham Jail in response to white clergy members who had urged him to cease demonstrating against segregation laws, follow the standards of law and order, and pursue change through official governmental channels. These remonstrations mirror arguments invoked to delegitimize dissent and provide support for legal but immoral governmental policies such as American slavery, Nazi atrocities, and apartheid. At the heart of religious justifications for such arguments is Romans 13:1–7, which endorses human government as God ordained but can be interpreted to require unqualified obedience to law. It is also the go to passage used by Christians to describe the role and authority of police officers in their law enforcement capacity. The way Romans 13 has often been interpreted and applied, however, is exegetically and theologically problematic. Most importantly, the passage is not describing the role of individual police officers as is often argued, but rather the operation of human government as an institution. This flawed starting point has led to a cascade of other interpretive errors, which include describing police officers as agents of God’s wrath and delegitimizing dissent against unjust laws. It also promotes some of the most pernicious features of American law enforcement, including the alienating idea of police as the thin blue line, the we-they mentality that demeans those being policed, the use of warrior to describe the policing role, the militarization of law enforcement, and the systemic racism that plagues U.S. policing. In this article, the author offers a more exegetically and theologically accurate reading of Romans 13, with very different implications for role of law enforcement, and gestures toward a much-needed Christian theology of policing.

Brief, low-intensity interventions may hold untapped promise for bolstering maternal health in low-resource contexts. The current study used propensity score matching (PSM) to evaluate uptake and differential effectiveness of two low-intensity digital perinatal health (PH) support programs in Lima, Peru. Pregnant women (N = 251) were assigned to one of two conditions (PH vs. trauma-focused PH [TF-PH]) and received weekly psychoeducational content via WhatsApp from a lay paraprofessional for 5 weeks. Conditions were not randomly assigned; PSM was used to improve causal inference of the condition. Women were interviewed before participation (T1), immediately following treatment (T2) and at 3 (T3) and 12 months postpartum (T4). Intimate partner violence had strong negative effects on women’s mental health, multisystem resilience and parenting, and single mothers reported higher levels of depression and posttraumatic stress symptoms than did partnered women. Intervention uptake was high, with 77% of women participating in all sessions. There were no significant differences between treatment groups over time, but effect sizes indicated a slight advantage of the TF-PH condition in addressing depression symptoms (dr = −0.29) and multisystem resilience (dr = 0.39). Study findings suggest that brief interventions may be well-received and that trauma-focused supports may also confer additional benefits for addressing depression and resilience.

“Cultures of Power” tells the story of the electrification of greater Los Angeles from the first introduction of electric light in 1882 through 1969. Whereas scholars have previously examined how electrification has either preceded urbanization or amended pre-existing urban forms, in Southern California these two processes took place simultaneously, with each indelibly shaping the other. The result was not only a new model of American urbanism, but also a transformative approach to electric system development that shaped that industry’s growth worldwide. Greater Los Angeles and its electric systems, I argue, emerged from a decades-long process of co-creation fueled by differing perceptions of local landscapes, regional political conflict, and an emerging local mass culture fixated on electric symbols and products. I use this decades-long arc to illustrate how electricity’s social prominence shifted in response not merely to the passage of time and the growing familiarity of electric technologies, but rather as a consequence of choices made by Angeleno institutions and individuals.

Today, there is a tendency within the field of environmental education to argue that the current global metacrisis is intrinsically linked to idealist traditions in philosophy and culture. The underlying intuition appears to be that idealism ultimately relies on a Cartesian distinction between mind and body: that it privileges the mind while neglecting the body, thereby enabling a view of materiality – or “nature” – as something to be used or exploited. A similar assumption can be identified in the call for papers for this issue, where modern idealism is linked to neoliberal politics and economics. In contrast, the aim of our paper is not to reject idealism entirely but to argue that the real issue lies in particular ideas and worldviews associated with specific understandings of reality. To open up space for alternative ideas and imaginaries, we propose that educational theory and practice must engage with a process we term mundification: the initiation of individuals – though education and other cultural practices – into what it means for there to be something at all, that is; a world.

With the growing number of gravitational wave detections, achieving a competitive measurement of $H_0$ with dark sirens is becoming increasingly feasible. The expansion of the LIGO-Virgo-KAGRA Collaboration into a four detector network will reduce both the localisation area and the luminosity distance uncertainty associated with each gravitational wave event. It is therefore essential to identify and mitigate other major sources of error that could increase the uncertainty in $H_0$. In this work, we explore three scenarios relevant to the dark siren method in future observing runs. First, we demonstrate that there is a precision gain offered by a catalogue of spectroscopic-like redshifts compared to photometric-like redshifts, with the greatest improvements observed in smaller localisation areas. Second, we show that redshift outliers (as occur in realistic photometric redshift catalogues), do not introduce bias into the measurement of $H_0$. Finally, we find that uniformly sub-sampling spectroscopic-like redshift catalogues increases the uncertainty in $H_0$ as the completeness fraction is decreased; at a completeness of 50% the benefit of spectroscopic redshift precision is outweighed by the degradation from incompleteness. In all three scenarios, we obtain unbiased estimates of $H_0$. We conclude that a competitive measurement of $H_0$ using the dark siren method will require a hybrid catalogue of both photometric and spectroscopic redshifts, at least until highly complete spectroscopic catalogues become available. This, however, will come at the cost of a more complex selection function.