Program equivalence checking is the task of confirming that two programs have the same behavior on corresponding inputs. We develop a calculus based on symbolic execution and coinduction to check the equivalence of programs in a non-strict functional language. Additionally, we show that our calculus can be used to derive counterexamples for pairs of inequivalent programs, including counterexamples that arise from non-termination. We describe a fully automated approach for finding both equivalence proofs and counterexamples. Our implementation, nebula, proves equivalences of programs written in Haskell. We demonstrate nebula’s practical effectiveness at both proving equivalence and producing counterexamples automatically by applying nebula to existing benchmark properties.

Refugee youth are at high risk for trauma-related disorders – outcomes not only the result of pre-migration trauma, but consequences of diverse post-migration stressors. This study identified individual, parental, and environmental factors – some potentially modifiable – associated with trajectories of psychological risk and resilience in 291 Syrian and Iraqi refugee youth during resettlement in the U.S. Data was collected at arrival and at two follow-up visits up to 7 years post-arrival. Linear mixed modeling assessed predictors of posttraumatic stress disorder (PTSD), anxiety, and depression trajectories. Victimization trauma (i.e., assault) and lower maternal subjective social status predicted more severe PTSD (p = .046, f 2 = .07; p < .001, f 2 = .23) and anxiety (p = .008, f2 = .05; p = .002, f 2 = .11) trajectories in youth. Paternal unemployment predicted less stable PTSD (p = .009, f2 = .13) and anxiety (p < .001, f 2 = .10) trajectories. More severe depression trajectories were associated with female sex (p = .045, f 2 = .06) and death threat traumas (p = .014, f 2 = .07). Findings identified predictors of long-term risk and resilience for refugee youth, as well as potentially modifiable ecological risk factors. Victimization and death threat trauma exposure could be salient in identifying youth at high risk for trauma-related symptoms early in resettlement. Indicators of financial security were also associated with symptoms, suggesting environmental intervention targets.

We show that the class of Krasner hyperfields is not elementary. To show this, we determine the rational rank of quotients of multiplicative groups in field extensions. We also discuss some related questions.

The histories of the DSM and ICD classifications are set out so as to identify weaknesses and limitations that can affect their application in medico-legal reporting. These are illustrated by reference to published judgments and three detailed case studies. The analysis and case studies identify how expert witnesses’ reliance on the DSM and ICD can be challenged in order to seek to undermine their evidence.

In February 1744 in Paris, the Swedish physician Abraham Bäck (1713–95), better known as Carl Linnaeus’s best friend, dissected the cadaver of an unidentified sub-Saharan man. In contrast to the widespread exploitation of the enslaved dead in North America, cadavers of dark-skinned Africans remained rare in the anatomical theatres of eighteenth-century Europe. Scarcity not only increased their market value in medical circles interested in skin colour: in Europe, empirical anatomists often used these rare remains for building their medical authority. This article explores the rise of an empiricist social culture of racial anatomy in the European Enlightenment by following the case of Bäck, whose research on ‘black’ skin also provides a little-known counterpart to Linnaeus’s racial anthropology. Bäck’s case illustrates not only how European anatomists often wrote accounts of skin colour which best showcased their medical skills but also how the production of racial pseudoscience became increasingly driven by the authoritative rise of empiricism, the expansion of the slave trade, and the Enlightenment’s fascination with human differences.

We determine the average size of the $3$-torsion in class groups of G-extensions of a number field when G is any transitive $2$-group containing a transposition, for example $D_4$. It follows from the Cohen–Lenstra–Martinet heuristics that the average size of the p-torsion in class groups of G-extensions of a number field is conjecturally finite for any G and most p (including $p\nmid |G|$). Previously this conjecture had only been proven in the cases of $G=S_2$ with $p=3$ and $G=S_3$ with $p=2$. We also show that the average $3$-torsion in a certain relative class group for these G-extensions is as conjectured, proving new cases of the Cohen–Lenstra–Martinet heuristics. Our new method also works for many other permutation groups G that are not $2$-groups.

In this paper we solve a long-standing problem which goes back to Laurent Schwartz’s work on mean periodic functions. Namely, we completely characterize those locally compact Abelian groups having spectral synthesis. So far a characterization theorem was available for discrete Abelian groups only. Here we use a kind of localization concept for the ideals of the Fourier algebra of the underlying group. We show that localizability of ideals is equivalent to synthesizability. Based on this equivalence we show that if spectral synthesis holds on a locally compact Abelian group, then it holds on each extensions of it by a locally compact Abelian group consisting of compact elements, and also on any extension to a direct sum with a copy of the integers. Then, using Schwartz’s result and Gurevich’s counterexamples, we apply the structure theory of locally compact Abelian groups to obtain our characterization theorem.

As the first article in its March 1889 issue, The Classical Review published a short piece jointly authored by Henry Sidgwick and John Grote: a dialogue between Socrates and friends and John’s brother, George Grote. This brief but complex and playful dialogue is a microcosm of a broader discussion between a group of friends, colleagues, and relatives in the third quarter of the nineteenth century about individual happiness, justice and the good of the community. This article introduces the dialogue and places it in the context of two important wider debates in order to show how this brief dialogue illuminates the intellectual milieu of the time and the personalities involved. The first is a debate about how to read and engage with Plato’s philosophical dialogues. The second is a debate about utilitarianism, the nature of happiness, and the correct end of human actions.

This article situates the work of famous “skeptical environmentalist” Bjørn Lomborg in current environmental debates, arguing that he represents a shift from a “market” to a “planning” orientation within promethean environmental discourse taking place since the early 2000s. Instead of seeing self-correcting markets as a panacea for all societal ills, “planning” prometheanism aims to address environmental problems such as climate change through public policy, state investment, and technology development. We investigate the genesis of Lomborg’s “planning” prometheanism and locate its key sources of inspiration in the works of American economists Julian Simon, William Nordhaus, and Thomas Schelling. Moreover, we argue that Lomborg’s approach is characterized by a technocratic skepticism toward democracy which derives from his reliance on rational-choice theory. Finally, highlighting the adaptability of promethean discourse, we suggest that Lomborg’s “planning” prometheanism represents a renaissance of 1950s promethean thought at a time when a post-neoliberal world is taking shape.

This article examines the role of religious law in the context of modern state formation in the Arabian Gulf sheikhdoms. It focuses on Qatar, where a dual legal system emerged out of contestations over political community in the aftermath of imperialism and oil. From the mid-twentieth century onward, the ruling family empowered both a sharia and a civil judiciary without fully clarifying the jurisdictional boundaries between the two judiciaries. Until the 2003 unification of the judiciary, litigants were seemingly free to take civil and criminal cases to a court of their choice. I suggest that the appeal of Qatar’s Sharia Courts lay primarily in the socially embedded nature of Islamic legal practice, the extra-legal functions fulfilled by sharia judges, and the transnational networks of Islamic institutions. While the appeal of the sharia was partly produced by the state, Islamic legal institutions also drew force from their oppositional stance toward modern state power. The Qatari case shows how legal actors can secure state recognition by positioning themselves as authentic cultural mediators against the alienating structures of modern bureaucracy when they offer an alternative model of justice grounded in a dense network of social relations and the provision of a wide range of services.

Is Christian nationalism a threat to democracy in Africa, and to what extent are its adherents “anti-democratic” as is often claimed? Using the Afrobarometer Round 7 (2016-18), I examine how extensive these attitudes are held among Africans. Although I find that the proportion of the population on the continent that holds Christian nationalist views is somewhat limited, I find support for the argument that Christian nationalists tend to be less supportive of democracy than others, and more receptive to authoritarian alternatives to democracy. However, they are not more likely to hold intolerant attitudes with regard to other religions and LGBTQ individuals. In addition, I do not find, contrary to the existing literature on Christian nationalism in Africa, that Pentecostals are more intolerant of out groups than other Africans.

The population-based structural health monitoring paradigm has recently emerged as a promising approach to enhance data-driven assessment of engineering structures by facilitating transfer learning between structures with some degree of similarity. In this work, we apply this concept to the automated modal identification of structural systems. We introduce a graph neural network (GNN)-based deep learning scheme to identify modal properties, including natural frequencies, damping ratios, and mode shapes of engineering structures based on the power spectral density of spatially sparse vibration measurements. Systematic numerical experiments are conducted to evaluate the proposed model, employing two distinct truss populations that possess similar topological characteristics but varying geometric (size and shape) and material (stiffness) properties. The results demonstrate that, once trained, the proposed GNN-based model can identify modal properties of unseen structures within the same structural population with good efficiency and acceptable accuracy, even in the presence of measurement noise and sparse measurement locations. The GNN-based model exhibits advantages over the classic frequency domain decomposition method in terms of identification speed, as well as against an alternate multilayer perceptron architecture in terms of identification accuracy, rendering this a promising tool for PBSHM purposes.

Indigenous peoples, rural and peasant populations, and Afro-descendants have increasingly disputed mining and other extractive ventures in the territories they inhabit in various regions of Latin America. This article introduces an open-access digital and bilingual curated repository of data that compiles legal and legal-like actions by various actors in the context of paradigmatic conflicts over mining in Central America and Mexico. It situates the relevance of this digital resource against the background of the increasing global recourse to law in socioenvironmental conflicts—a tendency that may be defined as the juridification of environmental politics. The article also places the database in relation to key debates in digital humanities and discusses potential uses as well as future developments and challenges to expanding and improving such a resource.

Recent literature has shown that appetite loss during ageing can lead to negative health outcomes in older adults, particularly malnutrition and mortality. However, its association with functional decline and the mechanisms driving this relationship are not well explored. This review summarises the current evidence regarding the potential effects of appetite loss on frailty and functional outcomes. Despite the limitations due to heterogeneous methodologies, including study designs, population characteristics and appetite assessments, most studies indicate that older adults with poor appetite tended to exhibit poor physical performance and increased functional limitations. Furthermore, the simultaneous weight loss in individuals experiencing appetite loss was associated with a higher risk of functional impairments. Finally, emerging evidence connects reduced appetite to biomarkers of ageing, including epigenetic alterations, chronic inflammation and the upregulation of GDF-15. Therefore, loss of appetite is a potential earlier marker of loss of function that deserves further investigation. Adopting a geroscience perspective may enhance our understanding of appetite loss during ageing and foster the development of effective interventions.