Motivated by recent breathtaking progress in the synthetic study of Lorentzian geometry, we investigate the local concavity of time separation functions on Finsler spacetimes as a Lorentzian counterpart to Busemann’s convexity in metric geometry. We show that a Berwald spacetime is locally concave if and only if its flag curvature is nonnegative in timelike directions. We also give another characterization of nonnegative flag curvature by the convexity of future (or past) capsules, inspired by Kristály–Kozma’s result in the positive definite case. These characterizations are new even for Lorentzian manifolds.

Free Steiner triple systems (STSs) are infinite structures that are naturally characterised by a universal property. We consider the class of free STSs from a model-theoretic viewpoint. We show that free STSs on any number of generators are elementarily equivalent. We axiomatise their theory and show that it is stable.

The Chancellor of the Exchequer, Rachel Reeves, has described the UK economy as being in its worst state since 1945. Unlike the Labour Government of 1945, Reeves has rejected Beveridge-style public investment, in part because of claims of public support for fiscal restraint. We report findings of innovative, iterative mixed-methods survey (1) n = 693; 2) n = 10; 3) n = 2200) analysis of a programme for progressive tax reform designed to achieve comparable post-war outcomes conducted between November 2023 and January 2024 of adult UK residents. We analyse the findings of survey 3 to assess public support for the policy, impact of narratives and associations with demographic, socio-economic and health data. We find high levels of support for tax and spend, particularly where burdens are placed on wealth and business; significant impact of four narratives to persuade initial opponents to support the policy thematically organised around absolute gains, relative gains, security and environmental benefit; and clear associations between risk of destitution and various other socio-economic characteristics, health status and levels of support. We present structural equation modelling (SEM) of these associations and find moderately strong positive correlations with levels of support for key infrastructural policies. This suggests high levels of support for progressive taxation.

Readings of the history of penal expertise trace its rise to the late nineteenth century and its decline to the late twentieth century, with the crumbling of the welfare state. Despite stark differences along Whiggish and Foucauldian lines in evaluations of that history, a consensus has emerged that the penal-welfare complex peaked around mid-century, dependent on correctional experts. Most studies of that phenomenon have focused on the institutionalization and “treatment” of “problem” populations while neglecting the role of penal expertise in critiques of capital punishment. When Britain and Canada undertook major inquiries into the death penalty in the 1950s, they turned to the world’s foremost expert on the subject: sociologist Thorsten Sellin. Yet, these government-appointed studies devalued his academic capital in favor of the lived expertise of police. By examining the contestation of Sellin’s sources, methods, and conclusions, this paper puts the chronology of penal welfarism and its experts into question. Not simply a case of ill-informed opinion prevailing over criminological evidence, the dismissive treatment of this penal expert highlights the need to apply a more capacious understanding of contending forms of expertise at numerous points in penal history, rather than setting the devaluation of penal expertise in the recent past.

Although conditional cash transfers are a cornerstone of Latin American welfare states, little is known about the public opinion dynamics that sustain or challenge their long-term viability. Drawing on original, nationally representative surveys conducted in 2022 in seven Latin American democracies (Argentina, Chile, Colombia, Costa Rica, Guatemala, Mexico, and Peru), this article examines public support for cash transfers toward children across three dimensions: existence (yes/no), breadth (who should receive them) and adequacy (benefit levels). Across all countries, we find widespread support for such transfers, challenging the notion that only universal policies can create broad social support. However, preferences for expansion vary significantly across countries, with only partial alignment with existing coverage: support is highest in countries with extensive and minimal program coverage. Logistic regression models reveal that gender and household composition (living with children and being of reproductive age) are strong predictors of individual preferences, in addition to ideology and income. These findings contribute to existing scholarship by highlighting the role of gender and household composition in shaping social policy preferences.

This paper explores how unrecognised separatist entities in Eurasia – de facto regimes such as Transnistria, South Ossetia, Abkhazia, Nagorno-Karabakh, and the Donetsk and Luhansk People’s Republics – engage with international law. It examines whether, and to what extent, these regimes comply with international law, analysing court decisions and legislation to move beyond simplistic views of non-recognition or assumed legality. The findings reveal that de facto regimes tend to mirror the international law approaches of the states they are most closely connected to – whether the territorial state (e.g. Ukraine) or an outside state exercising effective control over the entity (e.g. Russia or Armenia). This pattern is explained by the theory of “acculturation to statehood”: through sustained legal and institutional interaction, these regimes internalise and replicate the legal systems of their reference states. The study contributes to a more nuanced understanding of the role of de facto regimes in the international legal order.

We prove that the spectrum of Van Douwen families is closed under singular limits. For any maximal eventually different family Raghavan defined in [10] an associated ideal which measures how far the family is from being Van Douwen. Under CH we prove that every ideal containing $\mathrm {Fin}$ is realized as the associated ideal of some maximal eventually different family. Finally, we construct maximal eventually different families with Sacks-indestructible associated ideals to prove that in the iterated Sacks-model every $\aleph _1$-generated ideal containing $\text {Fin}$ is realized.

Redo cardiac surgery is often needed for right ventricular outflow tract complications after tetralogy of Fallot repair. Common approaches include redo sternotomy or anterior thoracotomy. We report a case of pulmonary valve replacement performed via vertical left axillary thoracotomy, which effectively minimises cardiac injury risk during reentry and offers a safe, cosmetic alternative to conventional thoracotomy approaches.

Terrestrial isopods (Isopoda: Oniscidea), also known as sowbugs or woodlice, are one of the few groups of crustaceans with fully terrestrial members. Sowbugs are readily transported by human activity, with many species having been introduced worldwide. Although nonnative sowbugs have been present in Canada for more than 150 years, the study of sowbugs in Canada has been largely overlooked, especially in the Prairie Provinces. We conducted the first survey of sowbug species in Alberta, with additional collections from British Columbia, Saskatchewan, Ontario, and Newfoundland. We compiled an updated Canadian species checklist of 32 species from 12 families, including seven new species records for Canada since the previous 2001 checklist. Species with older records tend to occupy more provinces than species recorded more recently. Nine sowbug species occur in Alberta: all are nonnative and originate from Europe or Asia. Our collection of Nagurus cristatus (Dollfus, 1899) (Trachelipodidae) from Edmonton represents the first record from Canada. We support our identifications with molecular data (cytochrome c oxidase subunit 1 barcode region). Further surveys of sowbugs in the Prairie Provinces may uncover additional species; we encourage reporting of sowbug bycatch from arthropod surveys and note the utility of community science platforms for conducting sowbug surveys.

The 1891 International Gymnastics Festival, Sweden’s first international sports event and five years before the first modern Olympic Games, was hugely controversial. Many people argued that hosting the festival threatened the survival of Sweden’s own “Ling gymnastics” and even Swedish culture itself. These critics feared that hosting the competition, which would be shaped by outside influence, in turn would disadvantage Ling gymnastics and reduce confidence in a system that Swedes had believed to be the best in the world. The episode illustrates the complications arising from the emergence of international athletic competition and the underlying tension between nationalist and internationalist considerations.

British bioprospecting in the last decades of imperial China was propelled not merely by natural history and commerce, but significantly by China’s evolving foreign relations under international treaties. This article unravels the legal dimension of British naturalists’ collecting activities in late Qing China, challenging indiscriminate associations of their presence with imperialist or illicit plunder of natural resources. While the Sino-British treaties did not explicitly address plant collecting, they authorized British naturalists, as travelers, to move from Guangzhou to treaty ports and subsequently, under passports, into the interior. In practice, their expeditions encompassed both licit travel and illicit transgressions; and plant collecting was either officially acquiesced to or incorporated into the general regulation of travel for pleasure, coupled with lax inspection of plant outflow. From 1863, initially under British influence, Qing authorities even legalized international trade in tea seeds and plants, thus diminishing their control of a species economically vital to China. However, an international legal consensus on sovereign resource rights remained absent. The evolving legal environment for the botanical connection between the British Empire and late Qing China preceded the integration of natural resources into the agenda of international law, nuancing understanding of the politics of nature.

Twisted arrow $\infty$-categories of $(\infty ,1)$-categories were introduced by Lurie, and they have various applications in higher category theory. Abellán García and Stern gave a generalization to twisted arrow $\infty$-categories of $(\infty ,2)$-categories. In this paper, we introduce another simple model for twisted arrow $\infty$-categories of $(\infty ,2)$-categories.

This article studies the stability of the $L_p$ torsional measure in dimension $n \geq 3$. We show that the ball is the unique domain for the solution to the related overdetermined boundary value problem. Two concepts of relative asymmetry distance and $L^c$-distance have been used to estimate the stability of the $L_p$ torsional measure, based on different stability results of the $L_p$-width functionals. The result has been uniformly given via relative asymmetry distance for all $1<p \neq n+2$. In terms of $L^c$-distance, the result has been split into two cases: $p\in (1,n)$, and $n< p\neq n+2$.