A model is proposed for the one-dimensional spectrum and streamwise Reynolds stress in pipe flow for arbitrarily large Reynolds numbers. Constructed in wavenumber space, the model comprises four principal contributions to the spectrum: streaks, large-scale motions, very-large-scale motions and incoherent turbulence. It accounts for the broad and overlapping spectral content of these contributions from different eddy types. The model reproduces well the broad structure of the premultiplied one-dimensional spectrum of the streamwise velocity, although the bimodal shape that has been observed at certain wall-normal locations, and the $-5/3$ slope of the inertial subrange, are not captured effectively because of the simplifications made within the model. Regardless, the Reynolds stress distribution is well reproduced, even within the near-wall region, including key features of wall-bounded flows such as the Reynolds number dependence of the inner peak, the formation of a logarithmic region, and the formation of an outer peak. These findings suggest that many of these features arise from the overlap of energy content produced by both inner- and outer-scaled eddy structures combined with the viscous-scaled influence of the wall. The model is also used to compare with canonical turbulent boundary layer and channel flows, and despite some differences being apparent, we speculate that with only minor modifications to its coefficients, the model can be adapted to these flows as well.

The article addresses the question of the distinction between voluntary and involuntary immobility under emigration restrictions. Based on semi-structured in-depth interviews with people whose family members intended to emigrate from the Polish People’s Republic and the Russian Soviet Federative Socialist Republic but who have not fulfilled their intentions, it examines the role of the would-be migrant’s agency in driving the immobility outcome under the narrow opportunity structure for international mobility. The analysis of reasons for the emigration intentions of formerly aspiring migrants having remained unfulfilled demonstrates that the boundary between voluntary and involuntary immobility – similar to that of voluntary versus forced migration – is often blurred. The studied cases suggest it is more justified to view immobility through the lens of a continuum of (in)voluntariness rather than as a voluntary-involuntary binary. Moreover, the study shows how the blurriness of the boundary between voluntary and involuntary immobility may be understood through changes over time in the reasons for the non-realization of one’s migration intentions.

Understanding the stock structure of a commercial species is essential for sustainable management. Failure to do so can lead to the depletion of regional sub-populations, erosion of genetic diversity, and ecosystem services loss. Plaice, Pleuronectes platessa, is a commercially exploited species inhabiting the continental shelf around Iceland. Despite a tagging study providing support for strong spawning site and feeding ground fidelity, and otolith microstructure analysis revealing local population structure, plaice is managed as a single stock in Icelandic waters. Here, we describe and quantify the parasite fauna of plaice and assess the potential of parasites as biological tags for stock identification of plaice in Icelandic waters. A total of 82 plaice were sampled from different geographical locations (north and south) and seasons (summer and winter) in Iceland. Our sampling identified 11 parasites, five of which are new parasite records for plaice in Icelandic waters: the trematodes Zoogonoides viviparus (adults) and Rhipidocotyle sp. (metacercariae), and the nematodes Contracaecum osculatum (larvae), Dichelyne sp. (adults), and Hysterothylacium aduncum (larvae and adults). Additionally, we recovered metacercariae of the trematode genus Apatemon, which has not been recorded previously from plaice. Two parasites were identified as potential biological tags for stock identification – namely, the nematode Anisakis simplex and the trematode Z. viviparus. Our findings support a complex stock structure for plaice in Icelandic waters and the need for an integrative strategy to stock identification to provide fine spatial scale data required to inform fisheries managers.

This article investigates the rules that were put into the mouth of the Buddha by Indian Buddhist jurists in order to differentiate monks from non-Buddhist (particularly Jaina and Ājīvika) ascetics as observed in extant Vinaya literature. It demonstrates that the Buddhist jurists were fully aware of Jaina and Ājīvika modes of asceticism, and that they consciously used legislation as a tool to construct Buddhist identity, particularly through legally differentiating the physical appearance, customs, practices, and even social status of monks from those of their śramaṇic rivals. The Buddha’s prescription of a rule to make monks distinguishable from non-Buddhist ascetics often occurs as an immediate response to the laity’s criticism or misunderstanding. This arrangement indicates that the monastic jurists were concerned not only with differentiating Buddhist and non-Buddhist renunciants, but also with protecting the public image of the Buddhist monastic institution and ultimately with maintaining the laity’s trust and support.

Many young people feel distressed about climate change, and pessimistic about what the future holds. Gaps in education about climate change contribute to limited understanding of opportunities for climate mitigation and adaptation, and to a pervasive “discourse of doom.” Here we describe a “game for change” co-designed by climate and education researchers and young people, that aims to shift narratives about climate changed futures toward an active, adaptation-oriented focus.

The Heat Is On is designed to be played by high school classes. Set in 2050, the game takes place on a fictional island called “Adaptania.” Teams of students play the role of town councillors in communities facing the same challenges that Australian towns are experiencing as the climate heats up, including flooding, heatwaves, bushfires, inequality, health issues and economic challenges. By focussing on decision-making for adaptation and resilience, The Heat Is On enables participants to envision climate-changed futures in which communities can thrive. Students learn how to plan and collaborate to prepare for diverse and cascading impacts of climate hazards. We explore the potential for games in climate education, focussing on The Heat Is On as a case study, and share initial learnings from its development and implementation in schools.

This paper explores the transformative potential of artificial intelligence (AI), particularly generative AI (GenAI), in supporting the teaching, learning, and assessment of second language (L2) listening and speaking. It examines how AI technologies, such as spoken dialogue systems and intelligent personal assistants, can refine existing practices, offer innovative solutions, and address challenges related to spoken language competencies, as well as drawbacks they present. It highlights the role of GenAI, explores its capabilities and limitations, and offers insights into the evolving role of GenAI in language education. This paper discusses actionable insights for educators and researchers, outlining practical considerations and future research directions for optimizing GenAI integration in the learning and assessment of listening and speaking.

Yaw control can effectively enhance wind farm power output, but the vorticity distribution and coherent structures in yawed turbine wakes remain poorly understood. We propose a physical model capable of accurately predicting tip vortex dynamics from their generation to destabilisation. This model integrates a point vortex framework with advanced blade element momentum theory and vortex cylinder theory for yawed turbines. Comparisons with large eddy simulations demonstrate that the model effectively predicts the vorticity distribution of tip vortices and the wake profile of yawed turbines. Finally, we employ sparsity-promoting dynamic mode decomposition to analyse the dynamics of the far wake. Our analysis reveals four primary mode types: (i) the averaged mode; (ii) shear modes; (iii) harmonic modes; and (iv) merging modes. Under yawed conditions, these modes become asymmetric, leading to interactions between the tip and root vortex modes. This direct interaction plays a critical role during the formation process of the counter-rotating vortex pair observed in yawed wakes.

Past research alerts to the increasingly unpleasant climate surrounding public debate on social media. Female politicians, in particular, are reporting serious attacks targeted at them. Yet, research offers inconclusive insights regarding the gender gap in online incivility. This paper aims to address this gap by comparing politicians with varying levels of prominence and public status in different institutional contexts. Using a machine learning approach for analyzing over 23 million tweets addressed to politicians in Germany, Spain, the United Kingdom, and the United States, we find little consistent evidence of a gender gap in the proportion of incivility. However, more prominent politicians are considerably and consistently more likely than others to receive uncivil attacks. While prominence influences US male and female politicians’ probability to receive uncivil tweets the same way, women in our European sample receive incivility regardless of their status. Most importantly, the incivility varies in quality and across contexts, with women, especially in more plurality contexts, receiving more identity-based attacks than other politicians.

Exchangeable partitions of the integers and their corresponding mass partitions on $\mathcal{P}_{\infty} = \{\mathbf{s} = (s_{1},s_{2},\ldots)\colon s_{1} \geq s_{2} \geq \cdots \geq 0$ and $\sum_{k=1}^{\infty}s_{k} = 1\}$ play a vital role in combinatorial stochastic processes and their applications. In this work, we continue our focus on the class of Gibbs partitions of the integers and the corresponding stable Poisson–Kingman-distributed mass partitions generated by the normalized jumps of a stable subordinator with an index $\alpha \in (0,1)$, subject to further mixing. This remarkable class of infinitely exchangeable random partitions is characterized by probabilities that have Gibbs (product) form. These partitions have practical applications in combinatorial stochastic processes, random tree/graph growth models, and Bayesian statistics. The most notable class consists of random partitions generated from the two-parameter Poisson–Dirichlet distribution $\mathrm{PD}(\alpha,\theta)$. While the utility of Gibbs partitions is recognized, there is limited understanding of the broader class. Here, as a continuation of our work, we address this gap by extending the dual coagulation/fragmentation results of Pitman (1999), developed for the Poisson–Dirichlet family, to all Gibbs models and their corresponding Poisson–Kingman mass partitions, creating nested families of Gibbs partitions and mass partitions. We focus primarily on fragmentation operations, identifying which classes correspond to these operations and providing significant calculations for the resulting Gibbs partitions. Furthermore, for completion, we provide definitive results for dual coagulation operations using dependent processes. We demonstrate the applicability of our results by establishing new findings for Brownian excursion partitions, Mittag-Leffler, and size-biased generalized gamma models.

Linear hydroelastic waves propagating in a frozen channel are investigated. The channel has a rectangular cross-section, finite depth and infinite length. The liquid in the channel is an inviscid, incompressible liquid and covered with ice. The ice is modelled as a thin elastic plate of variable thickness clamped to the channel walls. The thickness is constant along the channel length and varying across it. The flow induced by ice deflections is potential. The problem reduced to a problem of wave profiles across the channel and was solved using a piecewise linear approximation of a shape of the thickness. Normal modes are calculated to ensure continuous deflections, slopes, bending stresses and shear forces in the ice plate. Two thickness distributions are studied: in Case I, the thickness is constant at a middle segment and linearly increases at edge segments over the channel’s width; in Case II, the thickness linearly decreases at the edge segments. In Case I, there is one segment with the thin part of the ice cover where, as expected, the oscillations of the ice plate will be concentrated. In Case II, there are two such areas, separated by the middle segment with the thick part of the ice cover. Dispersion relations, phase and group velocities, wave profiles and strain distributions in the ice plate are studied. Results show that the properties of periodic hydroelastic waves are significantly influenced by the ice thickness distribution across the channel.

Take two positions, both of which we take to be popular ways of thinking about law. First, some norm N is part of the law only if, and in virtue of, N being ultimately recognized or validated by the rule of recognition. Call this Hartian Orthodoxy. Second, statements about legal rights are best understood as claims about the existence of moral rights according to law. Call this legal perspectivalism. Here we show that the two are incompatible. Our argument is that, to account for certain arguments that mix legal and factual claims, perspectivalism must close the legal perspective according to some inference rule. As it happens, however, the only defensible candidates render perspectivalism incompatible with Hartian Orthodoxy.