There is an enduring debate about whether, to what extent, and along which fault lines citizens’ policy preferences are ideologically structured. Some scholars maintain that public opinion is largely unstructured, with individuals adopting inconsistent and idiosyncratic positions – for instance, holding a ‘left’ stance on issue A does not necessarily imply a ‘left’ stance on issue B. Others argue that citizens’ views are shaped by coherent ideological constraints, such that a ‘left’ position on one issue is systematically accompanied by ‘left’ positions on others. This paper contributes new evidence to this debate by leveraging unprecedented big data. We draw on original data from Belgium’s widely used Voting Advice Application (VAA), known as the Vote Test, which was completed more than six million times in the run-up to the June 2024 elections. Our analysis is based on the actual log files of the application, encompassing millions of observations. The Vote Test consisted of twelve distinct VAAs designed for the seven concurrent elections held in Belgium in 2024 – including simultaneous federal, regional, and European contests across the country’s three regions – yielding millions of responses to hundreds of policy statements. Using these exceptional data, we examine the correlations among citizens’ answers and assess the dimensionality of the opinion landscape. We further compare the structure of mass opinion with that of political elites, who responded to the identical set of policy statements. Our findings reveal minimal, if any, ideological structuring among voters, especially when contrasted with the more consistent patterns observed among elites.

The present paper originates from the need to understand nonlinear wave behaviour in dusty plasmas, aiming to explore stable envelope wave propagation and interactions beyond traditional theoretical models. By using nonlinear Schrödinger equation (NLSE) analysis and molecular dynamics (MD) simulations, the study verifies the existence and stable propagation of non-standard envelope waves. It demonstrates elastic like collisions, introduces tuneable parameters for wave shaping and quantifies error trends with nonlinearity. A key breakthrough is confirming that even analytically invalid waveforms remain stable, challenging NLSE constraints. Present results enhance nonlinear wave theory and support precise, tuneable signal transmission in plasma diagnostics and microgravity experiments.

We introduce and begin the study of quasi-BPS categories for K3 surfaces, which are a categorical version of the BPS cohomologies for K3 surfaces.

We construct semiorthogonal decompositions of derived categories of coherent sheaves on moduli stacks of semistable objects on K3 surfaces, where each summand is a categorical Hall product of quasi-BPS categories. We also prove the wall-crossing equivalence of quasi-BPS categories, which generalizes Halpern-Leistner’s wall-crossing equivalence of moduli spaces of stable objects for primitive Mukai vectors on K3 surfaces.

We also introduce and study a reduced quasi-BPS category. When the weight is coprime to the Mukai vector, the reduced quasi-BPS category is proper, smooth, and its Serre functor is a shift functor étale locally on the good moduli space. Moreover we prove that its topological K-theory recovers the BPS invariants of K3 surfaces, which are known to be equal to the Euler characteristics of Hilbert schemes of points on K3 surfaces. We regard reduced quasi-BPS categories as noncommutative hyperkähler varieties which are categorical versions of crepant resolutions of singular symplectic moduli spaces of semistable objects on K3 surfaces.

Unbeknownst to many in the fields of African history and archaeology, the South African archaeologist A. J. H. Goodwin conducted important research in Nigeria during the last decade of his life, from 1953 to 1957. Following work at the Yoruba town of Ile-Ife, Goodwin led the first systematic excavations in Benin City in 1954–55 and 1956–57. With little of this material ever published, this article outlines, analyzes, and discusses Goodwin’s archives at the University of Cape Town that pertain to his research at Benin City, which contain important unpublished information in reports, sketch maps, photographs, and correspondence. Using this material, the article reconstructs important dimensions of the town’s old palace landscape – including the locations and organization of compounds and shrines associated with past kings – and Goodwin and others’ excavations within it, situating this novel spatial and archaeological information within the larger landscape of the city.

Too often, conflict-related detainees are ill-treated or killed, go missing, or are held in inhumane conditions of detention. Detention occurs in all armed conflicts, including those that involve Muslim-majority States and Islamic non-State armed groups. In 2024, a substantial percentage of the International Committee of the Red Cross’s visits to detention/internment places were in Muslim-majority contexts.

While the humane treatment of detainees is the responsibility of the detaining authorities, third actors, including humanitarian organizations, can and should work with those authorities with a view to making sure that they respect their obligations. To facilitate such dialogue, this article analyzes the protection of detainees under international humanitarian law (IHL) and Islamic law. As the vast majority of today’s armed conflicts are non-international in nature, the article focuses on IHL rules applicable in non-international armed conflicts (NIACs), discussing key rules of IHL and Islamic law on the protection of detainees. The selection of rules presented in this article reflects IHL rules applicable in NIACs, based on Article 3 common to the four Geneva Conventions, Additional Protocol II to the Geneva Conventions, and customary IHL rules. The article provides an issue-by-issue analysis that allows the reader to easily understand how IHL and Islamic law address specific issues on the protection of detainees in NIACs.

The history of the KwaZulu-Natal region in the period under study has mostly been written round the evolution of a series of polities seen as more or less firmly bounded territorial “states.” This approach goes hand in hand with readings of recorded oral source materials as “oral traditions.” In this article, we reread the materials not simply as relayed historical accounts but as evidence of past discursive practices geared towards the navigation of change. This allows us to argue that a fundamental feature of the political order at this time was a degree of mobility and political flexibility that earlier studies hardly engage with.

Hosking & Schekochihin (Phys. Rev. X, 2021, vol. 11, 041005) have proposed that statistically isotropic decaying magnetohydrodynamic turbulence without net magnetic helicity conserves the mean square fluctuation level of magnetic helicity in large volumes – or, equivalently, the integral over space of the two-point correlation function of the magnetic-helicity density, denoted $I_{\!H}$. Formally, the conservation and gauge invariance of $I_{\!H}$ require the vanishing of certain boundary terms related to the strength of long-range spatial correlations. These boundary terms represent the ability (or otherwise) of the turbulence to organise fluxes over arbitrarily large distances to deplete or enhance fluctuations of magnetic helicity. In this work, we present a theory of these boundary terms, employing a methodology analogous to that of Batchelor & Proudman (Philos. Trans. R. Soc. A, 1956, vol. 248, p. 369) to determine the relevant asymptotic forms of correlation functions. We find that long-range correlations of sufficient strength to violate the conservation of $I_{\!H}$ cannot develop dynamically if the evolution equation for the magnetic vector potential is chosen to be local in space. Likewise, we find that such correlations cannot develop for a wide class of gauge choices that make this equation non-local (including the Coulomb gauge). Nonetheless, we also identify a class of non-local gauge choices for which correlations that are sufficiently strong to violate the conservation of $I_{\!H}$ do appear possible. We verify our theoretical predictions for the case of the Coulomb gauge with measurements of correlation functions in a high-resolution numerical simulation.

This paper tells the story of the Kensington Food Forest, an urban ecological oasis where food production, forest growth, and grassroots activism intersect. Set within the Kensington Public Housing estates on Wurundjeri Country in Naarm/Melbourne, Victoria (Australia), it stands as a site of local regeneration against and beyond industrialised food and waste systems. Conducted with the Kensington Circular Economy Precinct Community Group, this research foregrounds the often-overlooked impact of grassroots initiatives within circular transitions by co-creating indicators that capture the ecological, social, and pedagogical values these spaces (re)generate. Together, the community and researchers position regenerative circularity not as a technological fix, but as an embodied, relational, and pedagogical praxis. By tracing the social-material flows and knowledge generation within this landscape, we show how communities learn with place, each other, and more-than-human worlds, revealing how Food Forest Pedagogies of Praxis can make circularity truly regenerative through practices of emancipation.

This paper examines two-dimensional liquid curtains ejected from a narrow horizontal outlet at an angle to the vertical. Curtains are characterised by the Froude number ${\textit{Fr}}=U/ ( gH ) ^{1/2}$, Reynolds number ${\textit{Re}}=UH/\nu$ and Weber number ${\textit{We}}=\rho U^{2}H/\sigma$, where $U$ is the ejection velocity, $g$ the gravity, $H$ the outlet’s half-width, $\nu$ the kinematic viscosity and $\sigma$ the surface tension. It is assumed that ${\textit{Fr}}\gg 1$ (so that the radius of the curtain’s curvature due to gravity exceeds $H$), ${\textit{Re}}\ll 1$ (viscosity is strong) and ${\textit{We}}\sim 1$ (surface tension is on par with inertia). It is shown that steady oblique curtains exist only subject to a constraint of the form ${\textit{We}}\gt f({\textit{Fr}}^{2}{\textit{Re}})$, which is more restrictive than the previously known constraint ${\textit{We}}\gt 1$. Thus, sufficiently strong viscosity and/or surface tension eliminate the steady regime and make the curtain evolve – typically, rotate around the outlet, eventually producing the teapot effect.

A series of laboratory experiments was conducted to evaluate the germination ecology of buttongrass [Dactyloctenium radulans (R. Br.) P. Beauv.] for designing weed management practices in eastern Australia. Two populations (BG3 and BG4) were evaluated under varying temperature, light, salinity, water stress, residue cover, and burial depth conditions. Germination was completely inhibited at 15/5 C (alternating day/night temperature regime) but increased at high temperature regimes, reaching 90–92% at 30/20 C and remaining high (72–88%) at 35/25 C, indicating strong adaptation to warm climates. Both populations germinated well in light (12 h)/dark (12 h) conditions (87–93%), while BG3 showed a reduction (80%) in complete darkness (24 h) compared with light/dark conditions, suggesting weak positive photoblastic behaviour. Germination decreased progressively with increasing sodium chloride (NaCl) concentrations, with 50% inhibition at 40 mM NaCl, indicating moderate salt tolerance. Germination was reduced by 50% at osmotic potentials of -0.30 MPa and -0.25 MPa for BG3 and BG4 populations, respectively. Seedling emergence declined with increasing sorghum residue loads, dropping by >80% at >6 Mg ha-1, and was completely inhibited at 8 cm burial depth. These results demonstrate that D. radulans is a thermophilic, light-responsive, shallow-emerging grass capable of germinating under moderate salinity and water stress conditions, enabling persistence in semi-arid and reduced-tillage systems. High residue retention and deep burial of seeds (≥8 cm) could significantly suppress emergence, providing ecologically sustainable management options. Future studies should quantify population-level physiological variations and integrate temperature, moisture, and residue interactions into predictive emergence models to guide region-specific weed management under changing climatic conditions.