How did populist governments handle the COVID-19 pandemic? Did they act as erratic, irrational and unsound – in short: ‘populist’ – as observers expected them to do? Through which social policies did they respond to the hardships caused by the pandemic? And, what does populist governance explain about these governments’ social policies? This article explores these questions through a comparative analysis of a diverse set of six populist governments. We first conceptualize, operationalize and measure populist governance by constructing a novel Populist Governance Index. Second, we describe and measure governments’ welfare policies through a novel Social Policy Response Index. Third, we relate social policy responses to variations in populist governance across countries. Our mixed-method study suggests that populism explains the politics rather than the policies of populist governments. We conclude that this is the case because populism fundamentally defines a mode of governance rather than policy content

The natural variability of atmospheric 14C has been significantly altered by anthropogenic activities linked to technological advancements and energy consumption over the past two and a half centuries. The Suess effect, a consequence of the combustion of old carbon (fossil fuels) since the mid-18th century and the bomb peak from the mid-20th century’s thermonuclear tests, has obscured the natural 14C signal in the atmosphere. This study presents a 14C analysis of leaves, flowers, and grass collected from various locations worldwide. Over the last 10 years, more than 150 samples have been collected and used as materials for experiments conducted by students in physics lab classes (Department of Physics, ETH Zurich) or as part of school projects. Short-lived vegetal fragments are ideal material for teaching radiocarbon dating and demonstrating our research. The collection of data presented here underscores the sensitivity of radiocarbon analysis for detecting fossil carbon components. Trees from urban sites worldwide demonstrate a dilution of the atmospheric 14C concentration of 2–3%. Trees growing close to busy roads and traffic show a dilution of up to 10%. Moreover, the data show a fading trend of the bomb peak observed from 2015 to the present, as well as the direct impact of fossil CO2 on the 14C concentration of the living biota around us.

Levels of cancellativity in commutative monoids M, determined by stable-rank values in $\mathbb {Z}_{> 0} \cup \{\infty \}$ for elements of M, are investigated. The behavior of the stable ranks of multiples $ka$, for $k \in \mathbb {Z}_{> 0}$ and $a \in M$, is determined. In the case of a refinement monoid M, the possible stable-rank values in archimedean components of M are pinned down. Finally, stable rank in monoids built from isomorphism or other equivalence classes of modules over a ring is discussed.

Photovoltaic (PV) has proved to be one of the most compact, durable and economic power generating systems developed by mankind. The potential of solar energy is being used for sustainable development and to meet the increasing power demand. Floating solar photovoltaic (FSPV) is a comparatively newer concept of installing the PV system on the surface of water bodies. Despite its several advantages, it is found that FSPV systems in the sea need to be restricted, and multiple islanded structures should be preferred to reduce the side effects in aquatic ecosystems. The most preferred site for installing FSPV is in the reservoir of hydro plant as integration with the grid and hydro system becomes easy. The USA, the European Union and Southern and Eastern Asia mainly Japan, Indonesia, the Philippines, China and India have very long coastline which can be effectively used for FSPV installation and meeting the load demand through clean and renewable sources without exhausting the land. In India, over 5000 dams are already functional with a total reservoir area of 14855.57 square kilometers. Only 2% covering the reservoirs can add a total of 89.1 TWh of energy to the grid annually during 8 h of sunlight at conversion efficiency of 25% with an underestimate of only 5 months of proper sunlight. It can be achieved with minimum installation costs and maintenance costs. Sustainable development ensures that energy production must also have minimal or nil harmful impact on nature and humankind. This paper lays emphasis on all the technical aspects of the FSPV system and reliable ways to prevent and overcome it efficiently. Moreover, the integration of FSPV with other different non-conventional sources to boost energy production is also analyzed.

Quantitative research has established a strong association between ethnopolitical exclusion and civil war onset, but direct investigation of the proposed causal pathway has been limited. This article applies large-N qualitative analysis (LNQA) to 15 post–Cold War cases to trace how exclusion may generate grievances, mobilization, and conflict escalation. In nine cases, grievance-based mobilization preceded civil war, and escalation followed governments’ reliance on indiscriminate repression or on inconsistent mixes of rejection and accommodation. In six cases, however, conflict itself produced exclusion, revealing recursive dynamics rather than a one-way sequence. These findings refine grievance theory by showing that escalation is shaped by patterns of state response and that exclusion may also emerge as a result of violence. More broadly, the study demonstrates how systematic qualitative analysis across multiple cases can trace mechanisms, address concerns about endogeneity and measurement validity, and still support cautious generalization.

In this paper, we investigate the ideal structure of uniform Roe algebras for general metric spaces beyond the scope of Yu’s Property A. Inspired by the ideal of ghost operators coming from expander graphs and in contrast to the notion of geometric ideal, we introduce a notion of ghostly ideal in a uniform Roe algebra, whose elements are locally invisible in certain directions at infinity. We show that the geometric ideal and the ghostly ideal are, respectively, the smallest and the largest element in the lattice of ideals with a common invariant open subset of the unit space of the coarse groupoid by Skandalis–Tu–Yu, and hence the study of ideal structure can be reduced to classifying ideals between the geometric and the ghostly ones. We also provide a criterion to ensure that the geometric and the ghostly ideals have the same $K$-theory, which helps to recover counterexamples to the coarse Baum–Connes conjectures. Moreover, we introduce a notion of partial Property A for a metric space to characterize the situation in which the geometric ideal coincides with the ghostly ideal. As an application, we provide a concrete description for the maximal ideals in a uniform Roe algebra in terms of the minimal points in the Stone–Čech boundary of the space.

In this article, we clarify the relation between the squeezing function and the Fridman invariant corresponding to a general domain $\Omega $ (not necessarily convex), where $\Omega $ is defined by

$$ \begin{align*}\Omega = \bigg\lbrace z \in \mathbb{C}^{r_{1}}\times\mathbb{C}^{r_{2}}\times\cdots\times\mathbb{C}^{r_{s}} : \sum\limits_{i\in I_{k}} ||z_{i}||^{m_{i}} < 1, 1\leq k \leq p \bigg\rbrace,\end{align*} $$

with $I_{k}\cap I_{l} = \emptyset $ if $k\neq l$, $I_{1}\cup I_{2} \cup \cdots \cup I_{p} = \lbrace 1, 2, \ldots , s\rbrace $, $n = r_{1} + r_{2} + \cdots + r_{s}$ and $m_{i}> 0$ for all i. Furthermore, we give an example of a domain whose squeezing function corresponding to $\Omega $ is not plurisubharmonic.

The 15 years of mass balance monitoring (2010–25) on Rolleston Glacier in the Southern Alps of New Zealand has documented a mass loss of −11.5 m w.e. (−0.8 m w.e. a−1). An analysis of winter snow accumulation patterns indicated that secondary accumulation processes (avalanche and wind) contribute approximately 8% of annual accumulation. A geodetic change detection over the glacier highlighted that regardless of the additional input, the entire glacier has experienced net thinning in recent years. Assuming mass loss continues at the current accelerated rate of −1.2 m w. e. a−1 (2017–25) we estimate that Rolleston Glacier may vanish by mid-2060.

Effectively controlling systems governed by partial differential equations (PDEs) is crucial in several fields of applied sciences and engineering. These systems usually yield significant challenges to conventional control schemes due to their nonlinear dynamics, partial observability, high-dimensionality once discretized, distributed nature, and the requirement for low-latency feedback control. Reinforcement learning (RL), particularly deep RL (DRL), has recently emerged as a promising control paradigm for such systems, demonstrating exceptional capabilities in managing high-dimensional, nonlinear dynamics. However, DRL faces challenges, including sample inefficiency, robustness issues, and an overall lack of interpretability. To address these challenges, we propose a data-efficient, interpretable, and scalable Dyna-style model-based RL framework specifically tailored for PDE control. Our approach integrates Sparse Identification of Nonlinear Dynamics with Control within an Autoencoder-based dimensionality reduction scheme for PDE states and actions (AE+SINDy-C). This combination enables fast rollouts with significantly fewer environment interactions while providing an interpretable latent space representation of the PDE dynamics, facilitating insight into the control process. We validate our method on two PDE problems describing fluid flows—namely, the 1D Burgers equation and 2D Navier–Stokes equations—comparing it against a model-free baseline. Our extensive analysis highlights improved sample efficiency, stability, and interpretability in controlling complex PDE systems.

How do Euroskeptic parties adjust their rhetoric when the European Union expands its fiscal and redistributive role? We address this question by examining the impact of the next-generation EU (NGEU) program on parliamentary debates in Italy, the largest beneficiary of EU recovery funds. Drawing on an original dataset of over 700 hand-coded parliamentary statements covering 30 debates in the Italian Chamber of Deputies (2018–2024), we show that the launch of NGEU coincided with a measurable increase in supportive rhetoric toward the EU, especially among parties with Euroskeptic profiles, a shift that is not solely attributable to changes in government status. Our findings suggest that EU-level redistributive policies can contribute to altering, at least temporarily, domestic party discourse in parliament, pointing to the domestic political relevance of fiscal integration

The cold, low carbon dioxide (CO2) conditions of the Pleistocene epoch fundamentally structured ecosystems, profoundly influencing the evolutionary trajectory of Homo sapiens and other large mammals. Although often considered uniquely stable, the Holocene is more usefully viewed as just another Pleistocene interglacial interval that was naturally trending towards a renewed glacial phase. However, rapid anthropogenic greenhouse gas emission rates have reversed this trajectory and might have now foreclosed the prospect of returning to cyclic glacial climates for millennia. A large set of flora and fauna has benefited from low CO2 conditions, which we define as low-CO2 dependents. By elevating atmospheric CO2 concentrations beyond levels seen for millions of years, we have accelerated global warming beyond the adaptive capacities of many species and ecosystems. African savannas and grasslands are particularly relevant in this context because this was the environment in which the human species evolved. These biomes have been previously maintained by fire and carbon scarcity but are now experiencing woody encroachment driven by rising CO2. The resultant global reforestation further threatens biodiversity adapted to open ecosystems, while rewilding initiatives must therefore pair prehistoric analogues with explicit climate-fitness tests that anticipate mid-century CO2 trajectories. Addressing these complex challenges requires both targeted local interventions and systemic policy reforms, grounded in a pragmatic recognition of the transient nature of the Holocene. Recognising the transience of any single baseline allows conservation and agriculture to plan for a dynamic, overshoot-prone future.

Can Hartian positivism adequately explain disagreements, among U.S. officials, about the correct method of statutory interpretation? Ronald Dworkin influentially argued it cannot. Dworkin maintained that (1) debates about the correct method of statutory interpretation are ‘theoretical’ disagreements; and (2) Hartian positivism cannot explain theoretical disagreements, except by positing implausible confusion or disingenuity on the part of legal officials. I show here that (1) is false. A disagreement about the correct method of statutory interpretation need not involve a theoretical disagreement of any kind. It may instead involve a purely ‘denotational’ disagreement among officials—i.e., a disagreement about the denotation of a concept appearing in a criterion of legal validity that all officials accept. I argue that, since the U.S. statutory interpretation debate plausibly is a purely denotational one, it does not pose the difficulties for Hartian positivism that Dworkin and other critics have supposed.