Collisionless zonal flow (ZF) saturation is analytically investigated using a reduced two-field fluid model for ion temperature gradient-driven turbulence subject to a three-wavevector, five-mode truncation that includes the interaction of an unstable mode, the ZF and a stable mode. Using weak-turbulence closure theory, a wave kinetic equation (WKE) is derived describing the temporal evolution of the ZF energy spectrum for this system according to linear and nonlinear dynamics. The terms in the nonlinear time evolution operator, which describe resonant energy transfer among triads of fluctuations, are expressed as matrices whose elements are arithmetic combinations of the linear eigenvalues of the individual modes participating in a given interaction. In the collisionless limit, the matrices characterising ZF drive and damping become highly symmetric, and conditions are found for spectral saturation in this regime. A set of stationary solutions to the WKE are found that describe a state of turbulence in which the nonlinearly driven stable modes reach identical levels as the linearly driven unstable modes, producing identical rates of up- and down-gradient thermal energy transport at each fluctuation length scale. Generalisation to the non-truncated system is briefly discussed.

Rousseau’s civil religion in the Social Contract has been interpreted as either an authoritarian institution that reinforces the collectivist ideal of the Social Contract or as a non-coercive proposal aimed at promoting toleration. This article offers an alternative account that emphasizes popular sovereignty as both the source and object of civil religion. On this reading, civil religion is a democratic choice by a sovereign people of the kind of beliefs and behavior they want to collectively endorse and expect from each other. When established by the people, civil religion serves the higher function of exemplifying and preserving political freedom in a political community. Recognizing the popular roots of civil religion helps us to understand it as an essential condition for maintaining the body politic that Rousseau envisions in the Social Contract and an important component of his democratic thought.

Interest is growing in how relational ontologies and more-than-human design methodologies – so-called ‘entanglement’ theories – might inform digital music research. To what extent does the growing popularity of such theories portend a change in technical or musical practices versus putting new gloss on long-standing ideas? Can or should entanglement theories be distilled into concrete design frameworks? This paper starts from the opposite premise: rather than offering an unambiguous roadmap for designers, entanglement theories are at their most powerful in destabilising ideas and worldviews that have become so ingrained as to become invisible. In digital musical instrument (DMI) design, this barely visible infrastructure consists partly of an ecosystem of stable, context-agnostic concepts about music: analytical descriptors such as notes, pitches, onsets and gestures which get inverted into the building blocks of sound-producing technical systems. However, design is not as simple as inverted analysis. This paper argues that treating familiar musical concepts as authoritative is responsible for several long-standing conundrums facing DMI research. The paper juxtaposes ideas from entanglement literature with brief vignettes concerning instruments new and old, arguing that musical instruments enact the very concepts they take as pre-existing, and that everything about musical discourse and practice should remain up for grabs.

In this paper, we construct an implementable algorithm that solves the conjugacy problem in twisted right-angled Artin groups (T-RAAGs). In certain cases, the complexity is known to be linear, by reducing the problem to the twisted conjugacy problem in RAAGs. We also show that T-RAAGs are biautomatic, providing an alternative solution to the conjugacy problem.

Although functional reasoning is ubiquitous in biology, and philosophers have concentrated intensely on theorizing function naturalistically, the measurement of function has largely been ignored. Given its centrality in life science practices, there is good reason to scrutinize functional measurement in detail. I undertake a preliminary analysis of this issue by focusing on the measurement of function in the context of biomechanics to make several observations (e.g., functioning is a complex organismal property that cannot be reduced to a single measured variable) and then draw out novel consequences for debates about biological function and philosophy of science discussions of measurement.

Searches of unassociated gamma-ray sources in the Fermi-LAT catalogues have led to the discoveries of around a fifth of all known millisecond pulsars (MSPs). These searches have almost exclusively been performed at radio frequencies above 300MHz, where dispersion and scattering in the interstellar medium are less significant. We report on a shallow survey for pulsars targeting 308 unassociated Fermi-LAT sources in archival MurchisonWidefield Array (MWA) observations from the Southern-sky MWA Rapid Two-metre (SMART) pulsar survey at 154MHz. This is the largest radio survey of unassociated Fermi-LAT sources to date, and only the second to be conducted below 300MHz after a survey with the Low Frequency Array (LOFAR) that discovered three MSPs. Each source was observed for 20 min by digitally beamforming the MWA tile voltages. Searches were then performed using a new pipeline that implements a semi-coherent dispersion removal scheme for MWA data, enabling greater sensitivities to MSPs than is possible with fully-incoherent dispersion removal (e.g. 2–3 times better sensitivity for dispersion measures between 20–40 cm−3 pc). The pipeline was tested by blindly detecting five known MSPs, four of which are in short-orbit binaries. No new pulsars were identified in the survey, which we attribute to insufficient sensitivity. We estimate flux density limits of approximately 30–220 mJy at 154MHz (or 0.7–5.2 mJy at 1.4GHz) for a spin period of 2 ms and a duty cycle of 28%, with a dependence on the sky temperature and the offset from the phase-centre of the primary beam. We discuss how the improved instantaneous sensitivity from the Phase III upgrade of the MWA will increase the number of detectable gamma-ray pulsars by ∼ 30% for the same integration time. Additionally, the real-time beamformer (under development) will enable longer observations with sensitivities that are more competitive with previous surveys of Fermi-LAT sources. The semi-coherent search pipeline we have developed will also be useful for searches of supernova remnants, globular clusters, and pulsar candidates identified in imaging surveys, all of which will help to inform the significance of future surveys with SKA-Low.

Engineering design applications that emphasize positive societal impacts are growing in popularity, yet often overlook the critical importance of engineering designers’ and stakeholders’ positionalities – their unique identities, experiences and resulting perspectives and social positions relative to others – in shaping design decisions. Insufficient attention to positionality can limit designers’ abilities to navigate complex problem contexts, engage diverse perspectives and address power dynamics, ultimately constraining the effectiveness and equity of design outcomes. However, little is known about how designers conceptualize and account for positionality in practice, particularly in the early stages of design when problem framing decisions are made. Therefore, this study explored how 10 engineering students and 10 practitioners conceptualized positionality in the initial stages of design for “social good,” where its impacts are especially pronounced. Each participant engaged in a written reflection and semistructured interview. Key findings include limitations in participants’ available language and strategies for accounting for positionality in design processes, particularly in the early stages, and that participants’ learning about positionality was largely driven by exposure to diverse identities and contexts. These insights highlight the limitations of engineering training and skillsets in design-for-social-good and emphasize the need for strategic, intentional consideration of positionality in design practice and education.