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A complete classification of unimodular valuations on the set of lattice polygons with values in the spaces of polynomials and formal power series, respectively, is established. The valuations are classified in terms of their behavior with respect to dilation using extensions to unbounded polyhedra and basic invariant theory.
In this article, I argue that public political theorists need to adopt a different attitude and audience. If they are to help their fellow citizens learn collectively to engage critically with their future to take care of it, they must write and talk not only to their fellow theorists but also to their fellow citizens. To do this, they would need to focus on the opposite of the strictures of their specialised academic discipline that rewards internal debate, arcane language, and abstract theorising. They must provide a clear, persuasive understanding and critique of contemporary social, economic, and political narratives and structures of power. What matters is persuasion, not exclusive expertise; a change of attitude, not method; and a plurality of approaches. Perhaps most importantly, what they teach, write, and say must be comprehensively open to all, not beholden to corporate interests and canons, and they must act as “gadflies” in their society—public critics in battles over ideas, values, and power relations. While history is vital for this future-oriented craft, to bow down before predecessors is to miss the radical imaginative potential of thinking (and teaching) collectively in the present to provide for a better future: to change the world by changing oneself and thus one’s fellow travellers in improving how we live and love together. This would also make public political theory genuinely political.
Conservative parties and politicians are often caught in a dilemma regarding immigration policies. Business interest groups and xenophobic populist forces both support conservative political parties but expect fundamentally different immigration policies. Japan is a rare case among advanced democracies that has experienced neither large-scale immigration nor the emergence of xenophobic populism. Yet, Japan’s conservative government, facing the reality of a rapidly aging and declining population, has begun to loosen immigration policy. We analyze the ruling party politicians’ policy positions on foreign worker intake and demonstrate that their views have shifted in a pro-foreign-worker direction, especially among legislators representing rural areas that have seen a sharp increase in foreign residents.
Lorsque des locuteurs produisent des néologismes à l’écrit, ils peuvent utiliser des marqueurs typographiques ou linguistiques pour mettre en saillance ces derniers. Cette étude, centrée sur des néologismes dénominaux suffixés en -ien, -ique et -esque, combine une analyse de corpus et une étude expérimentale de type questionnaire en ligne afin d’examiner, d’une part, le type et la proportion de ces marqueurs et, d’autre part, leur influence sur les jugements de néologicité. En production, les locuteurs marquent environ 23 % des néologismes, principalement avec des guillemets, puis avec des motifs syntaxiques et enfin avec des commentaires. En réception, la présence de ces marqueurs (guillemets et commentaires) augmente les taux de détection des néologismes. L’identification des néologismes est influencée par le cotexte. De plus, d’autres éléments semblent expliquer les variations des jugements de néologicité, tels que le suffixe du néologisme lorsque ce dernier est morphologiquement dérivé, et l’âge des locuteurs.
In recent years, the emergence of both the spatial and spectral turns has meant a more intense focus on the importance of space in supernatural narratives, especially within modern, industrialized cities. Less has been said, however, about the importance of understanding the affective resonances of space in early modern tales. This article examines tales of ghost sightings in London and Southwark that appeared in print. It argues that these hauntings created affective topographies that had both individual and communal resonances. In turn, the article explores how these emotional responses contributed to conceptions of space, community and neighbourhood in early modern London. As such, it demonstrates how paying attention to supernatural narratives can reveal a hidden geography of the city, one that is shaped by supernatural storytelling, emotions and close conceptions of community.
Cock-tailed Tyrant Alectrurus tricolor (Vieillot, 1816), a Vulnerable South American grassland specialist, is facing substantial habitat loss due to land-use change by agricultural and forestry expansion. This study aims to assess the current distribution and suitable habitat availability for Cock-tailed Tyrant using species distribution modelling (SDM) and recent distributional data from the Global Biodiversity Information Facility (GBIF). Occurrence data from 1,583 records, mapped by season and habitat type, were used to generate a MaxEnt model with a high predictive accuracy (AUC = 0.974). Results revealed three main distributional clusters: one in Brazil, another spanning Mato Grosso do Sul, Paraguay and north-eastern Argentina, and a separate group in the Bolivian lowlands. Seasonal analysis found no significant distributional shifts, supporting previous findings of the species’ non-migratory behaviour. Key environmental contributors to habitat suitability included ecoregion type, precipitation, and vapour pressure. The predicted suitable habitat covers approximately 177,753 km². These findings underscore the urgent need for conservation efforts focusing on critical grassland habitats, particularly within the Cerrado, Southern Cone Mesopotamian grasslands, and Beni savanna biomes. Sustainable land-use practices, grassland restoration, and periodic habitat reassessments are essential to preserve Cock-tailed Tyrant populations and support the biodiversity of South American grasslands.
Asymmetries and anisotropies are widespread in biological systems, including in the structure and dynamics of cilia and eukaryotic flagella. These microscopic, hair-like appendages exhibit asymmetric beating patterns that break time-reversal symmetry needed to facilitate fluid transport at the cellular level. The intrinsic anisotropies in ciliary structure can promote preferential beating directions, further influencing their dynamics. In this study, we employ numerical simulation and bifurcation analysis of a mathematical model of a filament driven by a follower force at its tip to explore how intrinsic curvature and direction-dependent bending stiffnesses impact filament dynamics. Our results show that while intrinsic curvature is indeed able to induce asymmetric beating patterns when filament motion is restricted to a plane, this beating is unstable to out-of-plane perturbations. Furthermore, we find that a three-dimensional whirling state seen for isotropic filament dynamics can be suppressed when sufficient asymmetry or anisotropy are introduced. Finally, for bending stiffness ratios as low as 2, we demonstrate that combining structural anisotropy with intrinsic curvature can stabilise asymmetric beating patterns, highlighting the crucial role of anisotropy in ciliary dynamics.
Luminescence dating and profiling are important analytical methods for providing chronological constraints and reconstructing depositional histories from sediment cores. However, sediment cores have often been exposed to ionising radiation sources during geophysical analyses, which potentially contaminates natural luminescence signals and may compromise the accuracy and reliability of luminescence analyses. Variable water content down-core is another potential issue for the rapid analysis of sediments, as water attenuates luminescence and may limit the comparability of samples. Here, we use a portable optically stimulated luminescence reader to test the influence of two common geophysical analyses—X-radiography and gamma-ray logging—on the luminescence properties of sediments in marine cores. We demonstrate that both techniques cause negligible changes to luminescence signals with doses <100 mGy. We test the effect of variable water content on luminescence and show that net signals are reduced by up to 70% at 30% moisture, relative to dry sediments. Accurate and reliable luminescence signals can be obtained from sediment cores despite prior exposure to ionising radiation from geophysical loggers or variable water content. However, the accuracy of luminescence measurements does require taking appropriate steps before analysis, like assessing the doses given by geophysical instruments at specific laboratories or drying samples.
Identity is a permanent integral feature of archaeological research. Even when it seems marginal to the current archaeological agenda, identity is brought back into the discussion by the urgency to engage with—often homogenizing—identity-based policies in contemporary politics. Lately, the emphasis placed on difference, fluidity and multivocality within archaeology has sensibly advanced the debate. Nevertheless, immutable identities continue to arise in studies of antiquity, replicating essentialist assumptions on the human past built around binary structures and simplistic equations of culture-historical reminiscence between material culture/practices and identities. The contributors to this special issue show how informing archaeological discourse with a semiotic methodology enhances the visibility of social dynamism, cultural complexities, among ancient human groups. This is particularly true for the communities silenced by history. These papers push the ontological and epistemological boundaries of archaeology by envisaging the archaeological record as a set of interconnected signs, whose cognitive potential overcomes the material space they occupy so that they become meaningful to different individuals and communities in diverse ways. Their stance maintains that semiotics holds the largely unexplored potential to enhance our understanding of the complexity of the past, ultimately offering a compelling standpoint to engage with contemporary identity-centred political debates.
Herein we respond to a recent call by Kay & Dzierzewski1 for works describing the importance of sleep and circadian rhythms in psychological functioning. The premise of this paper is to emphasize the need to enhance medical education by addressing the interplay between sleep health, cognitive functioning, and patient care among medical residents. We focus on three key areas: first, the physiological basis of sleep and circadian rhythms; second, the impact of sleep deprivation on cognitive functioning in medical residents; and third, practical implications and policy recommendations for schedule management with optimization for sleep sufficiency and circadian alignment in medical residents (Fig. 1). Context on typical resident work schedules and international policy models, including the European Working Time Directive, highlights the global scope of this issue. The outcomes are intended to inform improvements in physician training and have broader implications for patient care and support the need for institutional change to enhance residents’ well-being and performance.
The motionless conducting state of liquid-metal convection with an applied vertical magnetic field confined in a vessel with insulating sidewalls becomes linearly unstable to wall modes through a supercritical pitchfork bifurcation. Nevertheless, we show that the transition proceeds subcritically, with stable finite-amplitude solutions with different symmetries existing at parameter values beneath this linear stability threshold. Under increased thermal driving, the branch born from the linear instability becomes unstable and solutions are attracted to the most subcritical branch, which follows a quasiperiodic route to chaos. Thus, we show that the transition to turbulence is controlled by this subcritical branch and hence turbulent solutions have no connection to the initial linear instability. This is further quantified by observing that the subcritical equilibrium solution sets the spatial symmetry of the turbulent mean flow and thus organises large-scale structures in the turbulent regime.
The naming of cityscapes has never been a disinterested or straightforward affair. This article, which introduces the special issue on multifunctional urban toponymy in the Romanov Empire, opens by providing an overview of recent developments in critical place-name studies and bringing this field into dialogue with the historiography of the empire. It then delineates the main waves of toponymic changes in the empire from the eighteenth to the early twentieth century, and proposes a typology of the main categories of imperial toponyms used for (re)naming. Our main argument is that place names performed a wider array of functions, beyond just orientational and ideological, and were also used to gain socio-economic capital and enhance the social desirability and economic value of urban areas. Having introduced the contributions to the special issue, the article then outlines several avenues for future research.
This study investigates second language (L2) phonetic categorization and phonological encoding of L2 words (hereafter, phonolexical encoding1) with phonemic and allophonic cross-linguistic mismatches. We focus on the acquisition of Spanish /ɾ/-/l/ and /ɾ/-/t/ contrasts among Spanish learners with American English (AE) and Mandarin Chinese (hereafter, Chinese) as first languages (L1s). [ɾ] and [t] are positional allophones in AE but separate phonemes in Spanish. The phoneme /ɾ/ is absent in Chinese. AE learners showed nativelike phonetic categorization and little between-contrast difference in phonolexical encoding, suggesting that L1 positional allophony does not necessarily impede L2 contrast acquisition. Chinese learners showed persistent perceptual difficulties with both contrasts due to perceptual similarity. Phonetic categorization significantly predicted phonolexical encoding for /ɾ/-/t/ contrasts for Chinese learners bidirectionally, while AE learners showed this relationship only when /t/ was incorrectly replaced by /ɾ/ in Spanish words. This asymmetry can be driven by the fact that [t] is the dominant allophone of /t/ in AE, while [ɾ] is a positional allophone. It suggests L1 allophonic knowledge heightens perceptual monitoring when evaluating substitutions that conflict with L1 phonological expectations. This study calls for more nuanced treatment of L1 influence in L2 phonological acquisition models, especially at the allophonic level.
This paper presents the development of a graph autoencoder architecture capable of performing projection-based model-order reduction (PMOR) using a nonlinear manifold least-squares Petrov–Galerkin (LSPG) projection scheme. The architecture is particularly useful for advection-dominated flows modeled by unstructured meshes, as it provides a robust nonlinear mapping that can be leveraged in a PMOR setting. The presented graph autoencoder is constructed with a two-part process that consists of (1) generating a hierarchy of reduced graphs to emulate the compressive abilities of convolutional neural networks (CNNs) and (2) training a message passing operation at each step in the hierarchy of reduced graphs to emulate the filtering process of a CNN. The resulting framework provides improved flexibility over traditional CNN-based autoencoders because it is readily extendable to unstructured meshes. We provide an analysis of the interpretability of the graph autoencoder’s latent state variables, where we find that the Jacobian of the decoder for the proposed graph autoencoder provides interpretable mode shapes akin to traditional proper orthogonal decomposition modes. To highlight the capabilities of the proposed framework, which is named geometric deep least-squares Petrov–Galerkin (GD-LSPG), we benchmark the method on a one-dimensional Burgers’ model with a structured mesh and demonstrate the flexibility of GD-LSPG by deploying it on two test cases for two-dimensional Euler equations that use an unstructured mesh. The proposed framework is more flexible than using a traditional CNN-based autoencoder and provides considerable improvement in accuracy for very low-dimensional latent spaces in comparison with traditional affine projections.
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 (104−5years). 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 disk 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 (α ∼ 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.
Internal waves in a two-layer fluid with rotation are considered within the framework of Helfrich’s $f$-plane extension of the Miyata–Maltseva–Choi–Camassa model. We develop simultaneous asymptotic expansions for the evolving mean fields and deviations from them to describe a large class of uni-directional waves via the Ostrovsky equation, which fully decouples from mean-field variations. The latter generate additive inertial oscillations in the shear and in the phase of both the interfacial displacement and shear. Unlike conventional derivations leading to the Ostrovsky equation, our formulation does not impose the zero-mean constraints on the initial conditions of any variable. Using the constructed solutions, we model the evolution of quasi-periodic initial conditions close to the cnoidal wave solutions of the Korteweg–de Vries (KdV) equation but with local defects, both with and without rotation. We show that rotation leads to the emergence of bursts of internal waves and shear currents, qualitatively similar to the wavepackets generated from solitons and modulated cnoidal waves in earlier studies, but emerging much faster. We also show that cnoidal waves with expansion defects discussed in this work are generalised travelling waves of the KdV equation: they satisfy all conservation laws of the KdV equation (appropriately understood), as well as the Weirstrass–Erdmann corner condition for broken extremals of the associated variational problem and a natural weak formulation. Being smoothed in numerical simulations, they behave, in the absence of rotation, as long-lived states with no visible evolution, while rotation leads to the emergence of strong bursts.
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.