We experimentally investigate the structure and evolution of planar, inertia-dominated intrusions from a constant source into linearly stratified ambients that are either quiescent or uniformly flowing. The source is either a negatively buoyant plume or a diffuser at the level of neutral buoyancy. The intrusions generated by plumes in a quiescent ambient form self-similar wedges, with constant thickness at the source $(2.5\pm 0.3)\sqrt {Q/N}$ and the wedge lengthening in time $t$ as $(0.32\pm 0.03)\sqrt {\textit{NQ}}\,t$, where $N$ is the buoyancy frequency, and $Q$ is the areal supply rate. In a flowing ambient, the intrusions remain self-similar with the same functional dependence on parameters. However, they become increasingly asymmetric as the ambient flow speed increases, and for speeds greater than approximately $0.3\sqrt {\textit{NQ}}$, there is no upstream propagation. Intrusions generated by diffusers are structurally different and not clearly self-similar. Immediately adjacent to the source, they thicken significantly through a turbulent, entraining hydraulic jump. Beyond this is a gently thinning region that lengthens over time. Ahead of this is a more rapidly tapering nose. Both the area of these intrusions and the front positions increase as power laws in time, with exponents between $0.6$ and $0.7$. With an ambient flow, this overall structure persists with asymmetry. We compare our experimental observations for plume-generated intrusions with predictions from the intrusive shallow-water model of Ungarish (2005, J. Fluid Mech., vol. 535, pp. 287–323). The model explains some of the observed behaviours, but does not provide an accurate description of the thickness profiles.

For any integer k and any positive integer n, let $\sigma _k(n)=\sum _{d\mid n}d^k$. For any prime p and any positive integer m, let $\nu _p(m)$ be the largest integer $\alpha $ such that $p^\alpha \mid m$ and let $\lceil x\rceil $ denote the least integer not less than x. In 2021, Amdeberhan et al. [‘Arithmetic properties of the sum of divisors’, J. Number Theory 223 (2021), 325–349] proved that $\nu _2(\sigma _1(n))\le \lceil \log _2n\rceil $ for any positive integer n and that $\nu _p(\sigma _1(n))\le \lceil \log _pn\rceil $ for any odd prime p if n satisfies some conditions. Recently, Zhao and Chen [‘p-adic valuation of the sum of divisors’, Front. Math. 20(4) (2025), 795–827] proved this unconditionally. We generalise these results to all k: for any prime p, any n and any $k\ge 2$, $\nu _p(\sigma _k(n))\le \lceil k\log _p n\rceil .$ Let $p^\star $ be an odd prime. We also prove that there are an integer $k\ge 2$ and a prime q satisfying $\nu _{p^\star }(\sigma _k(q))=\lceil k\log _{p^\star }q\rceil $ if and only if $p^\star $ is a Fermat prime.

There are multiple intersecting crises afflicting society, from environmental devastation to the collapse of democracy, from economic exploitation to gratuitous violence, in the so-called “metacrisis.” Universities have both contributed to these crises in various ways, but have also tried to prevent them In this paper, we consider our responses to the metacrisis from our various disciplinary perspectives as four university educators from different scholarly traditions in one institution in Aotearoa New Zealand, We draw from our teaching experiences and our theoretical perspectives to engage in a reflective conversation with each other about how we may address the challenges of the metacrisis. Our conversation illustrates the potential benefits that such reflections, amongst colleagues who are intimately connected to a range of crises, may have to elucidate knowledge, power and performativity, and considers how humility, in a variety of forms, may be important to navigate the metacrisis.

Society faces an urgent need to move agriculture toward more environmentally sustainable practices to reduce greenhouse gas emissions, biodiversity loss, and water pollution. Mandatory policy tools, such as regulations, are unpopular with farmers, notoriously difficult to enforce, and politically challenging in the United States. Instead, social norms—descriptive, dynamic, and injunctive—may be critical levers for scaling up conservation practices. In this study, we analyze the predictive power of social norms on three practices, two of which benefit conservation (no-till and cover crops) and one that is likely harmful to conservation (fall nitrogen fertilizer application). Farmers (N = 585) in four U.S. states (Illinois, Indiana, Maryland, and Pennsylvania) completed a survey indicating perceived social norms and adoption of each practice. Logit models of practice adoption demonstrate that different types of social norms predict each of the three practices. We find that social norms are correlated with practices that are both helpful and harmful to conservation outcomes. Descriptive norms are associated with no-till adoption, while dynamic norms are associated with the use of cover crops. Both descriptive and injunctive norms are associated with fall nitrogen fertilizer application. In line with previous work, we also find that self-efficacy, response efficacy, farm size, and farm income are statistically significant predictors of the adoption of each practice. Future research would benefit from examining the role of different types of social norms in more contextually specific areas of farm management and at different junctures in the prevalence of management practices within a farming community, whether emerging, well-established, or declining in use.

Drawing from an interpretivist framework, this paper proposes Black Embodied Political Subjectivity (BEPS) as a conceptual framework that foregrounds the body, affect, and historical memory as critical to political subjectivity. BEPS draws on Black political thought to challenge dominant epistemologies that prioritize disembodied rationality and abstract ideological commitments over lived, felt, and corporeal political experiences. Rather than treating the body as an inert vessel or secondary site of politics, BEPS argues that the body is central to the ways Black people negotiate, contest, and reconstitute power in lived political contexts.

The present account describes a new species of alpheid shrimp, Alpheus madhusoodanai sp. nov., belonging to the brevirostris group, collected from the Cochin estuary, the south west coast of India. This represents the first species of alpheid shrimps described from the estuary. The morphological and molecular characteristics of the new species are compared with those of its closely related congeners. The newly described species is separated from its morphological congener A. rapax, by its wider major chela and longer merus of the first cheliped. Molecular data also confirmed the delimitation of A. rapax with A. madhusoodanai sp. nov. Habitat and distribution details are also discussed, highlighting the potential for further taxonomic exploration in the Cochin estuary and the importance in uncovering its hidden biodiversity.

This article prefaces our Special Issue on “AI and the Decision to Go to War.” We begin by introducing the prospect of artificial intelligence (AI)-enabled systems increasingly infiltrating state-level decision making on the resort to force, clarifying that our focus is on existing technologies, and outlining the two general ways that this can conceivably occur: through automated self-defense and AI-enabled decision-support systems. We then highlight recent, on-going developments that create a backdrop of rapid change and global uncertainty against which AI-enabled systems will inform such deliberations: (i) the widespread tendency to misperceive the latest AI-enabled technologies as increasingly “human”; (ii) the changing role of “Big Tech” in the global competition over military applications of AI; (iii) a conspicuous blind spot in current discussions surrounding international regulation; and (iv) the emerging reality of an AI-nuclear weapons nexus. We suggest that each factor will affect the trajectory of AI-informed war initiation and must be addressed as scholars and policymakers determine how best to prepare for, direct, and respond to this anticipated change. Finally, turning to the pressing legal, ethical, sociotechnical, political, and geopolitical challenges that will accompany this transformation, we revisit four “complications” that have framed the broader project from which this Special Issue has emerged. Within this framework, we preview the other 13 multidisciplinary research articles that make up this collection. Together, these articles explore the risks and opportunities that will follow AI into the war-room.

This article explores the use of composition as a methodological tool in ethnomusicology. By reflecting on the creation, rehearsal, and performance of the Suíte Afro-Brasileira—an original piece blending a big band with choir, capoeira, samba, and Candomblé ensembles—the author contends that the knowledge gained through composition parallels that acquired through bi-musicality, the established ethnomusicological practice of learning to perform music for research purposes. The multiple musicalities developed by composer-researchers in cross-cultural projects such as the Suíte Afro-Brasileira result in a form of compositional poly-musicality. This application of composition, however, intensifies the ethical issues of bi-musicality, forcing composer-researchers to rethink representational issues.

Clinical work with people who are seriously unwell and overwhelmed by psychotic functioning can be profoundly rewarding yet uniquely demanding. Beyond visible symptoms lie powerful unconscious forces that affect all involved. Drawing on psychoanalytic theory from Bion, Money-Kyrle, Menzies Lyth and Lucas, this article explores how psychotic processes such as splitting, projection, denial and rationalisation are transmitted to those providing care. Recognising and working with these dynamics not only deepens clinical understanding, enabling meaning to be found in apparently chaotic presentations, but also enhances the capacity to engage therapeutically with distress. Reflective practice, supervision and organisational containment are identified as essential clinical interventions to help clinicians understand the unconscious impact of psychotic processes and to preserve their capacity for thought and compassion.

Recent research has shown that adult learners can rapidly acquire novel words of a foreign language by tracking cross-situational statistics, but learning is substantially reduced when the target words are phonologically similar and contain non-native contrasts. We expand on this research by investigating whether perceptual discrimination training on non-native target contrasts facilitates cross-situational learning of new words (CSWL). Our design combines perceptual training and CSWL to test the transfer of perceptual gains to lexical learning—an approach that integrates methods from L2 speech and statistical learning. In two studies, we tested English-native and Portuguese-native speakers’ learning of 24 Portuguese pseudowords via a CSWL task. In Study 1, we examined baseline learning in both language groups without prior training. In Study 2, English-native speakers were assigned to one of three conditions: phonetic training with an AX discrimination task, phonetic training with an oddity discrimination task, or no phonetic training prior to the CSWL task. Results confirmed that adults can learn non-native words from cross-situational statistics, and that phonological overlap between words decreases learning. Perceptual training improved the discrimination of target contrasts, but this did not transfer to statistical learning of words that contain these contrasts. These findings suggest that phonetic training alone may not be sufficient for vocabulary acquisition, suggesting the need for instructional approaches that integrate phonetic training with more explicit teaching methods or meaning-based practice.

The stewardship of wahi kūpuna (Hawaiian ancestral places and resources and the knowledge systems and practices inherently tied to them.) requires an interdisciplinary approach that weaves together Hawaiian and Western knowledge systems. However, for the past century, those not native to Hawaiʻi have held the authority to “manage” Hawaiian heritage. To transform and restore this unbalanced system, there remains a critical need to increase opportunities for Native Hawaiians to care for our own cultural heritage. In 2010, the Native Hawaiian-led non-profit organization, Huliauapa‘a, established the Wahi Kūpuna Internship Program (WKIP). The primary goal of the WKIP is to develop leaders and advocates in Hawaiʻi’s cultural heritage fields by training the next generation of stewards in both Indigenous and Western knowledge systems, so they have a strong cultural foundation, elevate their roles and responsibilities to our lands and communities, obtain higher education degrees, and gain professional career-ready skillsets. The Internship takes a progressive approach that recognizes the constraints of a conventional indoor learning environment, and instead creates an authentic experience for students outside the classroom, on the land, and in the community. Our goal is to re-establish our connections to and care of these ancestral places in order to re-invigorate our cultural practices as a key element of perpetuating our Hawaiian identity and self determination.

Literature reviews are core parts of the research process with most conducted in the early research stages. The way a literature review is done can differ depending on the type of research, its aims and goals. This means some view literature reviews as best being done through a systematic approach that has set stages and ways to analyse the literature. This editorial article discusses the main reasons for literature reviews in terms of being helpful, educative and progressive. This is useful in furthering the way researchers collect, interpret and analyse data. As more business management researchers and practitioners utilise review articles it is important to remain vigilant about their purpose and usefulness to business practices.

Oats (Avena sativa L.) are cultivated worldwide for food and feed. Recently, there has been a growing interest in oats in South Korea owing to their nutritional and feed value. To support efficient breeding and genetic resource management, this study evaluated seven agronomic traits of 506 Avena accessions collected globally with two Korean oat varieties as standards. Seven agronomic traits – days to heading (DTH), plant height (PH), plant type, dehulling characteristics, 1,000-grain weight (TGW), seed length, and seed width (SW) – were evaluated over two to three years under Korean spring conditions. An augmented design was employed due to a lack of seeds and the field, and environmental bias was adjusted using Best Linear Unbiased Predictions. Statistical analyses revealed a strong positive correlation between TGW and SW and a moderate positive correlation between PH and DTH. Principal component analysis (PCA) identified that the first two principal components (PCs) explained 66.88% of the total variance, and that PC1 and PC2 were highly correlated with grain characteristics. K-prototype clustering analysis classified the 506 oat genetic resources into four distinct clusters based on the results of PCA, rather than their geographical origins. Cluster analysis indicated that Clusters 1 and 3 have potential for forage oat breeding, particularly in fodder use, whereas Clusters 2 and 4 may be valuable for grain-use oat breeding in South Korea. This study provides a comprehensive phenotypic assessment of oat germplasm obtained globally under Korean spring conditions and provides a useful foundation for germplasm management, cultivar development, and future genetic research.