This work demonstrates that magnetohydrodynamic (MHD) stable, quasi-isodynamic (QI) stellarator equilibria with reduced turbulence can be generated with an optimised coilset. We present one such equilibrium which, when being generated by coils, maintains the benefits of its excellent QI quality (low neoclassical transport at small particle collisionality net toroidal current and good fast-particle confinement) while demonstrating ideal-MHD stability and lower ion-temperature-gradient-driven turbulent heat flux than W7-X. As a consequence of its optimised rotational transform profile, this plasma equilibrium has nested flux surfaces and a chain of large islands at the plasma’s edge, for which we present an island divertor design. It additionally features an electron root – a large region in the plasma core in which the radial electric field points outwards, towards the plasma boundary – which provides a potential solution for preventing impurity accumulation in a fusion device.

Can international organizations (IOs) effectively shape attitudes held by individuals? Under what conditions does the public perceive information supplied by IOs as more trustworthy than information provided by other authorities? With the exponential growth of social network platforms, many IOs utilize them to engage individuals directly. Building on the growing literature on IOs’ engagement with the public, we examine if and under what conditions such effort is effective. We adopt insights from the literature on information source effect to theorize that the information disseminated by IOs is more effective than that by domestic health officials in shaping individuals’ attitudes when the IOs are portrayed as impartial and equipped with expertise in the relevant issue area. We test the hypotheses in the context of the World Health Organization (WHO) and the COVID-19-related measures. Our analysis of the survey experiment with a sample of 2865 Americans shows that political independents trust COVID-19-related information provided by the WHO more than information supplied by domestic public health officials, especially when the professional expertise the WHO staff commands is highlighted. In comparison, our analysis indicates that the information source effect is muted when information is delivered to individuals with strongly held existing attitudes, Democrats and Republicans in the case of COVID-19-related information in the United States.

Are nuclear weapons useful for coercion, and, if so, what factors increase the credibility and effectiveness of nuclear threats? While prominent scholars like Thomas Schelling argue that nuclear brinkmanship, or the manipulation of nuclear risk, can effectively coerce adversaries, others contend nuclear weapons are not effective tools of coercion, especially when designed to achieve offensive and revisionist objectives. Simultaneously, there is broad debate about the incorporation of automation via artificial intelligence into military systems, especially nuclear command and control. We develop a theoretical argument that nuclear threats implemented with automated nuclear launch systems are more credible compared to those implemented via non-automated means. By reducing human control over nuclear use, leaders can more effectively tie their hands and thus signal resolve, even if doing so increases the risk of nuclear war and thus is extremely dangerous. Preregistered survey experiments on an elite sample of United Kingdom Members of Parliament and two public samples of UK citizens provide support for these expectations, showing that in a crisis scenario involving a Russian invasion of Estonia, automated nuclear threats can increase credibility and willingness to back down. From a policy perspective, this paper highlights the dangers of countries adopting automated nuclear systems for malign purposes, and contributes to the literatures on coercive bargaining, weapons of mass destruction, and emerging technology.

How does China strategically allocate foreign aid to increase its influence on South China Sea disputes? We posit that China uses foreign aid as a tool of strategic appeasement to manage militarized interstate disputes, particularly targeting claimant states with smaller winning coalitions that are more susceptible to aid influence. The results of our empirical analysis show that China is more likely to allocate aid to the ASEAN SCS claimants with a smaller winning coalition. These findings not only support the notion of foreign aid as a strategic tool employed by China to mitigate tensions in the South China Sea but also highlight the vulnerability of certain recipient states. This article contributes to the foreign assistance and conflict literature by examining the conditionality of claimant donors’ decisions to provide foreign aid to other claimant recipients.

Women tend to be underconfident about their financial knowledge. In this longitudinal study, we tested two interventions intended to raise financial confidence and engagement in positive financial management behaviors among young Canadian women (N = 1119). One intervention included a brief educational task, teaching participants definitions of financial terms. Another intervention challenged social beliefs about financial competence by prompting participants to describe and browse other women’s stories about financial competence experiences on a website. Directly after the interventions, financial confidence ratings from women assigned to either or both of the intervention conditions were about 6% higher than ratings in a control condition. This effect persisted one week later, though a month later the size of the effect had dropped to non-significance. Confidence was linked to better financial management behaviors and more savings. Results also showed that participants in all conditions reported higher financial confidence and better financial management behaviors at later vs. earlier surveys. We conclude that simply reporting on financial attitudes and behaviors over time can increase women’s financial confidence and recommend fostering discourse about finances to close the gender gap in financial confidence.

Based on the High Magnetic field Helicon eXperiment (HMHX), considering parabolic distribution and Gaussian distribution of radial plasma density, the HELIC code was used to study the parameter optimisation design of a helicon wave plasma (HWP) source. Some parameters (antenna type, radio frequency, discharge gas, plasma radius, magnetic field) were selected. The results show that a half-helix antenna is the excitation antenna and a frequency of 13.56 MHz is the most commonly used power source for HMHX. Argon and nitrogen are selected as discharge gases to achieve the best effect of power deposition. In order to realise hydrogen–HWP discharge, a new antenna with plasma radius of 10.5 mm and antenna radius of 13.5 mm can be designed. For the new antenna, when the magnetic field intensity is 1000 Gs, the best discharge effect can be achieved. The results of this paper can provide guidance for the design of a plasma source for HWP discharge under different conditions in the future.

We develop a methodology for conducting inference on extreme quantiles of unobserved individual heterogeneity (e.g., heterogeneous coefficients and treatment effects) in panel data and meta-analysis settings. Inference is challenging in such settings: only noisy estimates of heterogeneity are available, and central limit approximations perform poorly in the tails. We derive a necessary and sufficient condition under which noisy estimates are informative about extreme quantiles, along with sufficient rate and moment conditions. Under these conditions, we establish an extreme value theorem and an intermediate order theorem for noisy estimates. These results yield simple optimization-free confidence intervals (CIs) for extreme quantiles. Simulations show that our CIs have favorable coverage and that the rate conditions matter for the validity of inference. We illustrate the method with an application to firm productivity differences across areas of varying population density. By analyzing the left tails of the productivity distributions, we find no evidence of stronger firm selection in more densely populated areas.

Welwitschia mirabilis, a unique gymnosperm native to Namibia and Angola, is a keystone plant species in the Namib Desert. It represents the only extremely long-lived non-clonal plant species occurring under hyperarid desert conditions, yet limited attempts have been made to accurately determine its age. Here, we present radiocarbon dates from a dead, sectioned Welwitschia of moderate size. We find the outer caudex tissue growth to progressively increase in age from the leaf base towards the ground level in this dwarf tree, while the inner cortex tissue becomes younger. Our sampling strategy revealed that the oldest tissue from this Welwitschia, found at the base of the caudex in the middle of the lobe, was dated to 531 ± 20 14C years, suggesting a vertical growth rate of approximately 0.47 to 0.67 mm/year. These findings can serve as a basis for future dating of larger, living individuals.

This article examines the adoption of voting methods designed to support individuals with intellectual disabilities in elections. It focuses on two widely used approaches, frequently explored in scholarly discourse: assisted voting and proxy voting. Both of these voting methods rely on third-party involvement and therefore require the consideration of the prohibition of plural voting in the Australian Constitution. The article concludes that while assisted voting and a limited form of proxy voting-where the proxy must strictly follow the elector’s explicit instructions-are constitutional, proxy voting becomes unconstitutional if the elector is unable to communicate their electoral judgment. Assisted voting therefore emerges as the most practical and constitutionally compliant option.

We investigated the epizoic diatoms colonizing the carapace of the spider crab Hyastenus hilgendorfi inhabiting Lake Timsah in the Suez Canal. A total of 63 individuals, free of macro-epibionts, were examined to assess the diversity, abundance, and seasonal dynamics of their associated diatom communities. A total of 61 diatom taxa belonging to 31 genera were recorded, with raphid pennate diatoms being the most dominant, particularly Navicula lanceolata. Diatom density and diversity exhibited clear seasonal variation, where Summer had the highest richness and Spring the highest cell densities. Overall, males hosted more diatom taxa than females, however, sex-specific differences fluctuated seasonally. The cluster analysis revealed distinct diatom assemblages between sexes and seasons, showing subtle but significant variation in epibiont structure. These findings provide the first detailed characterization of epizoic diatom assemblages on H. hilgendorfi. They suggest that seasonal variations in diatom communities may influence the crab’s camouflage effectiveness by altering biofilm characteristics which facilitate macro-epibiont settlement.

Given a number field F with ring of integers $\mathcal {O}_{F}$, one can associate to any torsion free subgroup of $\operatorname {SL}(2,\mathcal {O}_{F})$ of finite index a complete Riemannian manifold of finite volume with fibered cusp ends. For natural choices of flat vector bundles on such a manifold, we show that analytic torsion is identified with the Reidemeister torsion of the Borel-Serre compactification. This is used to obtain exponential growth of torsion in the cohomology for sequences of congruence subgroups.

Surrogacy, the engagement of third parties to perform biological roles, presents complex regulatory dilemmas. It raises questions about the ethics of commercializing human reproduction, especially when viewed through natural and cultural lenses. This article discusses the relevance of geopolitics in regulating artificial reproductive technology (ART) in Nigeria. It espouses the traditional health norm development approach to reproductive governance and dwells on surrogacy as a gendered concept, as it affects different categories of people in different ways in Nigeria. It examines Nigeria’s dominant cultural and religious ideologies against the extant legal framework, including family laws and judicial authorities. The article identifies the loopholes and relevance of geopolitics in the development of ART norms in Nigeria. There have been attempts to regulate ART to exclude recognizing surrogacy. The article concludes that the uncoordinated regulation is due to the geographical and socio-political norm development experience in the country. It recommends a cautious re-evaluation of the regulation of surrogacy through adopting Eager’s norm development approach. This position aims to redress the challenges confronting women in reproduction, in line with international norm development.

It is often thought that compulsory retirement funding gains support from paternalistic considerations. This paper examines this claim. I argue that compulsory retirement funding is more coherent when understood as an attempt at temporal smoothing than counterfactual insurance. An implication is that any paternalistic case for retirement funding faces problems that are more severe than they would be if compulsory retirement funding were insurance. I label these the problems of ‘inverted bias’ and of the ‘arbitrariness of income from labour’. The paper then makes some suggestions about how these points about paternalism bear on the problem of justice in retirement funding.

This paper examines the role of interviews in Australian protection visa decision-making, arguing that while not a statutory requirement, interviews are often constructively required to ensure procedural fairness and achieve reasonable satisfaction. The analysis explores the evolution of departmental policy from an initial presumption favouring interviews to a more exceptionalist approach driven by administrative efficiency. It argues that this shift creates tension with the underlying legal framework and risks legal error. Analysis of key cases such as Plaintiff S157/2002, Saeed, and Chen, alongside departmental policy, suggests that failure to make obvious inquiries or engage with applicants directly, particularly regarding credibility, can constitute jurisdictional error. The paper calls for balanced procedures that identify when interviews are necessary while maintaining efficient processing.