Quarrying is a significant, locally dominant glacial erosion process. For settings where glaciers cut into partially intact bedrock, prior work has hypothesized that it occurs when glaciers impose spatially concentrated loads to drive fracture growth in the underlying rock, linking pre-existing fractures to complete dislodgment. This prior work, however, has not rigorously explained how most of this process occurs or whether it can leave the bed with a form susceptible to subsequent quarrying. We use a numerical model that combines finite element and discrete element capabilities to calculate the co-evolution of stress, elastic deformation, and fracturing in a granite and a weak sandstone containing discontinuous prior fractures. We find that quarrying is achievable in situations with rapid glacier sliding, as expected from prior work, but only if additional factors contribute. These include, especially, transient episodes when loading increasingly concentrates on the lips of bedrock steps, imposition of shear traction by friction between entrained clasts and the bed, and exploitation of anisotropic structural weaknesses in the bedrock. Hydraulic fracturing can significantly reduce the loads needed for quarrying if low hydraulic transmissivity allows for large water pressure differences between saturated fractures and the adjacent subglacial water system.

A theory of the spectral ‘zebra’ pattern of the Crab pulsar’s high-frequency interpulse (HFIP) radio emission is developed. The observed emission bands are interference maxima caused by multiple ray propagation through the pulsar magnetosphere. The high-contrast interference pattern is the combined effect of gravitational lensing and plasma de-lensing of light rays. The model enables space-resolved tomography of the pulsar magnetosphere, yielding a radial plasma density profile of $n_{e}\propto r^{-3}$, which agrees with theoretical insights. We predict the zebra pattern trend to change at a higher frequency when the ray separation becomes smaller than the pulsar size. This frequency is predicted to be in the range between 42 and 650 GHz, which is within the reach of existing facilities like ALMA and SMA. These observations hold significant importance and would contribute to our understanding of the magnetosphere. Furthermore, they offer the potential to investigate gravity in the strong field regime near the star’s surface.

Poko (Skou, Papua New Guinea) displays a complex tone system, with three contrastive levels, toneless syllables and floating tones. Lexical tone is characterised by robust patterns of anti-alignment, wherein high (H) tones may not be initial and low (L) tones may not be final (McPherson & Dryer 2021; McPherson 2022). This article analyses the postlexical realisation of tone, especially the behaviour of floating tones, rising tones and toneless syllables. The Poko tone system shows unique twists on cross-linguistic patterns, such as the OCP, tone raising before L and the avoidance of non-final rising tones. We demonstrate that the behaviour of floating tones cannot be accounted for in a constraint-based theory with global evaluation, as in traditional Optimality Theory or Harmonic Grammar. Instead, the data motivate the use of directional Harmonic Serialism (Lamont 2022b), wherein changes are made incrementally and directionally, thus avoiding the creation of ties among otherwise similar candidates.

When do laws and policies that do not explicitly treat people differently on the basis of legally protected traits like race and sex nonetheless constitute disparate treatment on these bases? According to U.S. constitutional law, they do so when “facially neutral” laws are both enacted for impermissible reasons and also produce a discriminatory effect. To date, the first element of this claim – impermissible intention – has attracted significant attention. However, its second element – discriminatory effect – has been largely ignored. Yet it is critical that we better understand what discriminatory effect requires, as competing tests animate debates in Circuit court cases and the issue has recently been flagged by Justice Alito. This Article takes up the task. It explores the normative disagreement that underlies the controversy regarding how to assess whether discriminatory effect is present and diagnoses the genuine moral conflict that any test for discriminatory harm must navigate.

Multiscale differentials arise as limits of holomorphic differentials with prescribed zero orders on nodal curves. In this paper, we address the conjecture concerning Gorenstein contractions of multiscale differentials, originally proposed by Ranganathan and Wise and further developed by Battistella and Bozlee. Specifically, in the case of a one-parameter degeneration, we show that multiscale differentials can be contracted to Gorenstein singularities, level by level, from the top down. At each level, these differentials descend to generators of the dualizing bundle at the resulting singularities. Moreover, the global residue condition, which governs the smoothability of multiscale differentials, appears as a special case of the residue condition for descent differentials.

Suicide disproportionately burdens low- and middle-income countries. In Uganda, attempt survivors encounter intense stigma, minimal mental-health services and social exclusion, elevating their risk of future attempts. Rural African data on post-attempt experiences are scarce. From June to August 2023, we conducted semi-structured, in-depth interviews in Buyende District with 18 attempt survivors, 17 relatives, 10 healthcare workers and 9 community health workers. Transcripts were translated into English and thematically analyzed using the framework method within a phenomenologically informed qualitative design. Three interlinked themes emerged. (1) Stigma-shaped immediate responses: cultural, religious and legal norms fostered moral judgment, social distancing, bureaucratic delays and occasionally police involvement. (2) Informal, uneven support: survivors relied on family aid, religious counseling and ad-hoc community advocacy; effectiveness varied widely. (3) Conditional reintegration: sustained practical help, employment and communal acceptance promoted recovery, whereas their absence perpetuated economic hardship and marginalization. Post-attempt trajectories in rural Uganda are governed by multilevel stigma and fragile support systems. Priority actions include provider training, family-community psychoeducation, stigma-reduction initiatives, structured follow-up care and decriminalization of suicide to foster compassionate responses and reduce repeat attempts.

The circumpolar Arctic region has undergone a major geopolitical transformation because of two external forces altering regional security: climate change and increasing great power competition, notably due to the Russian war against Ukraine. Underscored by the de facto suspension of pan-Arctic cooperation after Russia’s expanded invasion in February 2022, the circumpolar Arctic has fragmented into two distinct blocs: the Russian Federation and the Arctic 7 (A7) group of allied democracies. These blocs are informed not just by different security policies between Russia and its polar neighbours but by differing Arctic security public opinion among their populations. Drawing on an original dataset of 164 polls and surveys from all eight Arctic states taken between 2007 and 2024, we outline sub-regional patterns in security public opinion that demonstrate different attitudes between Russia and the A7 with respect to the two defining issues in Arctic regional security: climate change and great power competition between Russia, China, and USA. We find that climate change is universally considered the most serious security issue in the Arctic; Russia is widely seen as a threat to other Arctic states; China is not seen as a major threat nor as particularly relevant to Arctic security; and USA is strongly supported in all Arctic states but Russia. We also conclude that sub-regional analysis may offer clearer insights into Arctic security public opinion than pan-Arctic analyses.

Organizations don’t have a mind and can’t have goals if we follow a microstructural approach that builds on methodological individualism. Yet, paradoxically, the existence of a normatively binding, shared organizational goal is typically a definitional criterion of what makes a group of individuals an organization. Building on the recent philosophy of social ontology, I answer this puzzle by demonstrating how agents within an organization believing in a shared goal make such a shared goal epistemologically independent, while ontologically emergent and dependent on individual beliefs. Through this collective belief, organizational goals become functionally real and normatively binding, and part of the most predictive theories to explain how individual agents behave in an organization. I also analyze how the deontic duties and rights of within-organizational roles aim to ensure that every member is either inspired, obliged, or channeled to engage in activities serving those goals, while also determining how much each member can influence the shared goals. This helps to bridge the micro-macro gap in organizational research by providing an account of the normative microfoundations for how individual agents come to adhere to organizational goals and together form a “group agent” capable of having goals and being morally responsible for them.

In this work, we develop a unified framework for establishing sharp threshold results for various Ramsey properties. To achieve this, we view such properties as noncolourability of auxiliary hypergraphs. Our main technical result gives sufficient conditions on a sequence of such hypergraphs that guarantee that this noncolourability property has a sharp threshold in subhypergraphs induced by random subsets of the vertices.

Furthermore, we verify these conditions in several cases of interest. In the classical setting of Ramsey theory for graphs, we show that the property of being Ramsey for a graph H in r colours has a sharp threshold in $G_{n,p}$, for all $r \geqslant 2$ and all H in a class of graphs that includes all cliques and cycles. In the arithmetic setting, we establish sharpness of thresholds for the properties corresponding to van der Waerden’s theorem and Schur’s theorem, also in any number of colours.

In a socio-interactive context, bilinguals effortlessly plan their language appropriately. This study explores how high-literate and low-literate bilinguals plan their language when interacting with interlocutors with varied second language (L2) proficiency presented in an interactive context. Participants named objects in the presence of interlocutors with varying proficiency, which were presented in the background as visual-world stimuli. Results indicate that bilingual participants’ language choices and proportion of fixations were modulated by their level of literacy and the interlocutors’ language profiles. High-literate bilinguals chose to name in L2, and while doing so, they looked at high-L2-proficient interlocutors. Meanwhile, low-literate bilinguals looked at low-L2-proficient interlocutors and named in first language (L1) more often times than in L2. This indicates that bilinguals’ literacy level is not determined solely by their language choice but also by their sociolinguistic processing when interacting with interlocutors with varied L2 proficiencies.