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For smectic C* (SmC*) liquid crystals, configured in a bookshelf-type geometry between two horizontal parallel plates, with the bottom plate fixed and the top plate free to move, it is known from experiment that pumping can occur when an electric field is applied, i.e. an upward movement of the top plate through mechanical vibrations when the electric field is suddenly reversed. In this paper we revisit an earlier mathematical model for fast electric field reversal by removing an assumption made there on the velocity field; instead, we arrive at a time-dependent, two-dimensional squeeze-film model, which can ultimately be formulated in terms of a highly nonlinear integro-differential equation. Subsequent analysis leads to an unexpected solvability condition involving the five SmC* viscosity coefficients regarding the existence and uniqueness of solutions. Furthermore, we find that, when solutions do exist, they imply that the plate can move down as well as up, with the final resting position turning out to be dependent on the initial conditions; this is in stark contrast to the results of the earlier model.
This study presents a high-fidelity direct numerical simulation (DNS) framework tailored for investigating turbulent flows through complex porous structures. It employs a compressible Navier–Stokes solver based on the spectral difference (SD) method, with immersed boundary conditions (IBCs) implemented via the Brinkman penalisation technique and integrated using a Strang splitting approach. A pressure gradient scaling (PGS) strategy is incorporated to improve computational efficiency. To provide realistic inflow conditions, synthetic turbulence is injected at the inlet using a random Fourier modes method. The methodology is validated in several stages. First, the IBC approach is tested against results from a body-fitted mesh, showing strong agreement in the mean velocity field. Next, the effectiveness of the PGS technique is demonstrated by comparing scaled and unscaled simulations, both of which yield consistent velocity fields and spectral content. Finally, the full DNS-SD framework is benchmarked against finite volume method results from the literature, successfully reproducing key turbulence characteristics, including two-point correlations. The validated solver is ultimately applied to simulate turbulent flow through a complex porous geometry. The results illustrate the robustness of the approach and highlight its potential for advancing the understanding of turbulence in porous materials.
This article examines the experience and transformation of the late Yuan Huizhou scholar Zhao Pang (1319–1369) during the transition from the Yuan dynasty to the Ming. In contrast to his reputation as a reclusive scholar devoted to his studies of the classics, and to later appraisals that viewed him as a Yuan “remnant,” Zhao actively engaged with the transition as it happened in his home region. Recovering this history from the writings in his collected works, this article reveals his attitude toward the powers that governed Huizhou in this period and shows both how his attitude remained consistent and how it changed. In place of the framework of loyalty and dynastic identity, this article proposes that local literati like Zhao Pang are better interpreted through local realities, and put in the context of the forms of literati writing and political participation that developed in the specific political system of the Yuan.
Magneto-gravity-precessional instability, which results from the excitation of resonant magneto-inertia-gravity (MIG) waves by a background shear generic to precessional flows, is addressed here. Two simple background precession flows, that of Kerswell (1993 Geophys. Astrophys. Fluid Dyn. vol 72, no. 1–4, pp. 107–144), and that of Mahalov (1993 Phys. Fluids A: Fluid Dyn. vol. 5, no. 4, pp. 891–900), are considered. We analytically perform an asymptotic analysis to order ${ O}(\varepsilon ),$ where $\varepsilon$ denotes the Poincaré number, i.e. the precession parameter, and determine the maximum growth rate of the destabilizing subharmonic resonances of MIG waves: that between two fast modes, that between two slow modes and that between a fast mode and a slow mode (mixed modes). The domains of the $(K_0 B_0/\varOmega _0, N/\varOmega _0)\hbox{-}$plane for which this instability operates are identified, where $1/K_0$ denotes a characteristic length scale, $B_0$ is the unperturbed Alfvén velocity, $\varOmega _0$ is the rotation rate and $N$ denotes the Brunt–Väisälä frequency. We demonstrate that the $N\rightarrow 0$ limit is, in fact, singular (discontinuous). At large $K_0B_0/\varOmega _0,$ stable stratification acts to suppress the destabilizing resonance between two fast modes as well as that between two slow modes, whereas it revives the destabilizing resonance between a fast mode and a slow mode provided $N\lt \varOmega _0,$ because, without stratification, the maximal growth rate of this instability approaches zero as $K_0B_0/\varOmega _0\rightarrow +\infty .$ This would be relevant for the generation of the mean electromotive force, and hence, the $\alpha \hbox{-}$effect in helical magnetized precessional flows under weak stable stratification. Diffusive effects on the instability is considered in the simple case where the magnetic and thermal Prandtl numbers are both equal to one.
Since the early 1980s, the Supreme Court of India has recognised a wide catalogue of unenumerated rights as functional extensions of the right to life stipulated in Article 21 of the Constitution of India, including a right to shelter. For the most part, the right has meant unenforceable state duties and access to administrative justice under Article 32 of the Constitution, in ways that substantively deviate from the standards envisaged under Article 11(1) of the International Covenant on Economic, Social and Cultural Rights, and which find a paradigmatic example of constitutionalisation in Section 26 of the Constitution of South Africa. This relatively uncontested understanding of the right is, however, complicated by a line of High Court decisions, most notably Sudama Singh and Ajay Maken, which heavily rely on international human rights standards and South African constitutional jurisprudence to expand the procedural guarantees afforded in forced evictions. Far from being a general trend, this interpretative approach has the merit of exposing key deficiencies in the traditional right to shelter approach and creatively counterweighing the otherwise constitutionally pre-eminent unconditional prohibition of encroachments on public land.
The Royal Historical Society’s June 2024 Update to the ‘Race Ethnicity & Equality in UK History: A Report and Resource for Change’ notes some important progress in terms of increased ethnic and racial diversity amongst history students and staff but acknowledges that more work is needed to both sustain and further advance these changes. In this Comment we argue that colleagues and the RHS should prioritise the development of critical pedagogies in history university education and evidence their impact on student outcomes. We share reflections on and data from our collaborative work between September 2021 and August 2024 developing an innovative module with the highly diverse history student cohort at SOAS, University of London, to help colleagues consider how they might undertake related projects in their own institutions.
This paper considers option valuation under finite mixture models in a discrete-time economy. Specifically, the Esscher transform is employed to select a pricing kernel. Novel finite mixture models with negative-shifted Gamma and negative-shifted inverse Gaussian distributions are developed. A hybrid finite mixture model that allows different parametric forms for component distributions is introduced to incorporate model uncertainty. An empirical characteristic function estimation method is employed to estimate the finite mixture models. Closed-form pricing formulas for a European call option are obtained for some finite mixture models. Empirical examples using data on the Bitcoin-USD prices are provided to illustrate an application of the proposed models to value Bitcoin options.
Thelaziasis, also known as thelaziosis, is a neglected vector-borne disease caused by parasitic nematodes from the genus Thelazia, belonging to the family Thelaziidae. The disease is transmitted biologically by various fly species, including the genus Musca (family Muscidae), Phortica (family Drosophilidae), and Fannia (family Fanniidae). These flies act as intermediate hosts (IHs) by depositing infective third-stage larvae (L3) during their tear feeding. Thelazia spp., such as T. gulosa, T. skrjabini, and T. rhodesi, inhabit the ocular regions of various animals, including humans and birds. Adult Thelazia worms are slender and creamy-white, measuring between 8–12 mm in males and 12–21 mm in females, with females releasing live larvae into the host’s tear secretions. The presence of these parasites can lead to serious ocular conditions such as keratitis, conjunctivitis, and even blindness. Diagnosis typically involves identifying the adult nematodes in the conjunctival sac, where they appear as active, slender, creamy-white organisms. Management of the infection can include the physical removal of the parasites and the use of effective anthelmintics like Eprinomectin, Doramectin, Ivermectin and Levamisole, administered either subcutaneously or intramuscularly. Regular deworming and treatment of infected animals are essential practices in areas where the disease is endemic, and effective prevention and control strategies are necessary to mitigate its impact. Hence, this comprehensive review has provided updated information about the oldest known but neglected and re-emerging parasitic disease in bovines worldwide.
In the seventeenth century, Chinese philologists rejected imperial orthodoxy and sought to return to the ways of antiquity through textual criticism; they described their approach using a first century phrase: “Seeking Truth from Facts” (shishi qiushi, 實事求是). Two centuries later, Mao Zedong appropriated this phrase to encapsulate his approach towards revolutionary work, which privileged the first-hand investigation of local socioeconomic conditions. In between these episodes, shishi qiushi was found in automobile advertisements, missionary translations, and on the gates of Confucian academies. Since the 1700s, Chinese intellectuals have found shishi qiushi strangely alluring, and employed the phrase to describe their intellectual and moral commitments. To explain this longevity, this article provides a genealogy of shishi qiushi and argues that the phrase came to be associated with the epistemic values of reflexivity, expertise, and syncretism. These qualities became valued by Chinese intellectuals as they navigated a rapidly changing world.
Credibility theory provides a fundamental framework in actuarial science for estimating policyholder premiums by blending individual claims experience with overall portfolio data. Bühlmann and Bühlmann–Straub credibility models are widely used because, in the Bayesian hierarchical setting, they are the best linear Bayes estimators, minimizing the Bayes risk (expected squared error loss) within the class of linear estimators given the experience data for a particular risk class. To improve estimation accuracy, quadratic credibility models incorporate higher-order terms, capturing more information about the underlying risk structure. This study develops a robust quadratic credibility (RQC) framework that integrates second-order polynomial adjustments of robustly transformed ground-up loss data, such as winsorized moments, to improve stability in the presence of extreme claims or heavy-tailed distributions. Extending semi-linear credibility, RQC maintains interpretability while enhancing statistical efficiency. We establish its asymptotic properties, derive closed-form expressions for the RQC premium, and demonstrate its superior performance in reducing mean square error (MSE). We additionally derive semi-linear credibility structural parameters using winsorized data, further strengthening the robustness of credibility estimation. Analytical comparisons and empirical applications highlight RQC’s ability to capture claim heterogeneity, offering a more reliable and equitable approach to premium estimation. This research advances credibility theory by introducing a refined methodology that balances efficiency, robustness, and practical applicability across diverse insurance settings.
Cardiovascular disease (CVD) is the leading cause of death worldwide. Research suggests people with Mental Health Disorders (MHDs) have increased CVD risk. However, knowledge gaps exist regarding CVD risk management for general practice patients with MHD, and interventions that might improve CVD prevention. This study examined the perspectives of general practice professionals in Ireland on cardiovascular risk assessment for patients already diagnosed with MHD and to describe current approaches to identifying this population using the Mental Health Finder (MHF) tool.
Methods:
An embedded mixed-methods design was adopted, guided by constructivist grounded theory and the Social Ecological Model. Aggregated anonymised data, including availability and use of the MHF tool, were collected from five practices and analysed in SPSS. In-depth semi-structured interviews were conducted with 12 general practitioners and three practice nurses. Qualitative data were analysed using Braun and Clarke’s Reflexive Thematic Analysis.
Results:
Of the five practices, two had access to the MHF tool. These reported combined prevalence of 18.7% for MHD compared with 0.5–11.5% in practices without the tool, highlighting the importance of systematic identification. Qualitative analysis generated four themes: (1) prevalence of MHD in general practice, (2) association between MHD and CVD risk, (3) CVD risk management in patients with MHD, and (4) holistic care.
Conclusion:
CVD risk assessment for patients with MHD in general practice is largely opportunistic and unstructured. Participants highlighted the need for structured frameworks, protocols, and enhanced supports to enable systematic cardiovascular assessment and management in this population.
We study the pricing of foreign silver coins circulating in China during the period from 1866 to 1924. Spanish and Mexican silver dollar coins often traded at prices substantially larger than their bullion value. These premiums are associated with global economic and political conditions, proxies for Chinese political and banking uncertainty, and seasonal production cycles and market conditions for China’s export commodities. Diagnostic tests using the value of copper money and imports often confirm our interpretation. Our evidence suggests how rational currency traders, bankers, merchants, farmers and consumers sustained an informal monetary system during this era.
Arguments from failure – arguments that an institution must expand its powers because another institution is failing in some way 'to do its job' – are commonplace. From structural reform litigation, where courts sometimes assume administrative or legislative functions, to the Uniting for Peace Resolution of the UN General Assembly, to the recent bill quashing British subpostmasters' convictions – such arguments are offered in justification for unorthodox exercises of public power. But in spite of their popularity, we lack a good understanding of these arguments in legal terms. This is partly because failure itself is a highly malleable concept and partly because arguments from failure blur into other more familiar legal doctrines about implied powers or emergencies. We can do better. We should recognize arguments from failure as a distinct concept of public law and understand that contemporary constitutional theory offers us tools to evaluate such arguments in different settings This title is also available as open access on Cambridge Core.
This is a comprehensive history of South Asian humanitarian aid in the context of armed conflicts in the colonial period. Adopting an international and transnational approach, the book focuses on relief initiatives from the First World War to the Second World War and the early post-war years. Through five case studies, this book offers new insights into the history of volunteer societies and non-state organisations in British India. It enhances readers' understanding of late colonial public and political activism on the Indian subcontinent. The book makes a significant contribution to the global history of humanitarianism, offering a nuanced understanding of the subject. This is achieved through an in-depth, context-sensitive exploration of relief work in a non-Western setting, focusing on the significance of Indian actors for the development of a transnational civil society.This title is also available as open access on Cambridge Core.
The apparent inconsistency in state practice on the identification of governments, especially since the early 1990s, has led to the suggestion that there exists no settled international legal framework comprised of objective criteria for identifying the government of a state. The logical conclusion, defended by some, is that recognition is constitutive of governmental status.1 This raises theoretical and practical concerns, for example on the freedom of each state to choose its government and on the number of states that must accord recognition for a specific claimant to enjoy governmental status. Against this background, the present essay suggests2 that there exists an objective international legal framework for identifying the government of a state. It first discusses conceptual, practical, and other factors in favor of this position. It then describes the relevance of recognition of governmental status to ascertaining this framework, before discussing the content and rationalization of the elements comprising this framework. It suggests, in contrast to most pieces in this symposium,3 that effective control is not as significant as it once was in assessing governmental status.
We report a nearly complete mitochondrial genome (mitogenome) of Echinostoma caproni (Egyptian isolate), which was reassembled and thoroughly annotated from whole-genome sequencing data available from Sequence Read Archive (accession No. ERS055227). Although a mitogenome of E. caproni has previously been deposited in GenBank (accession No. AP017706), it represents a partial sequence lacking the transfer RNA (tRNA)-Ser2 and possessing only a short non-coding region. In contrast, the newly reconstructed mitogenome in this study is 14,549 bp in length and comprises 12 protein-coding genes, 22 tRNA genes, 2 ribosomal RNA genes, and a 1,256 bp non-coding region containing 4 repeat units. The annotated sequence has been deposited in the Third Party Annotation database in GenBank (accession No. BK071757). Phylogenetic inference based on mitogenomic data indicates that E. caproni is closely related to E. miyagawai strains. This improved mitogenome provides a reliable genomic resource for comparative mitogenomic analyses and phylogenetic studies within the family Echinostomatidae.
The Little Bustard Tetrax tetrax has experienced steep population declines across its range, with Sardinia now hosting the last remaining Italian population and the only island population worldwide. We conducted a systematic island-wide survey in 2023, based on 969 point-count data, analysed through robust distance sampling, to assess population density, spatial distribution, habitat associations, and the role of protected areas. We estimated a total density of 0.89 males/km², with 85% of individuals concentrated in two highland subpopulations, i.e. Ozieri and Abbasanta. Highest densities occurred in hay meadows and heterogeneous landscapes, while arable and fallow lands supported lower densities. Protected areas hosted five times higher densities of Little Bustard than unprotected land. Land-use changes over the past 13 years and current soil degradation showed no significant association with current densities, suggesting that declines may be linked to earlier landscape transformations. Our results underscore the critical importance of protected areas and traditional agropastoral systems for the conservation of the Little Bustard in Sardinia. Urgent conservation planning is needed to maintain existing habitats and mitigate emerging threats from land-use change and infrastructure expansion.
Obsessive–compulsive disorder (OCD) is a debilitating mental disorder commonly treated with selective serotonin reuptake inhibitors, atypical antipsychotic augmentation and cognitive–behavioural therapy. However, up to 60% of people with OCD do not respond to these treatments. Therefore, a novel intervention, psilocybin-assisted psychotherapy (PAP), is an option of interest. Moreover, there is a need to better understand the mechanisms underpinning PAP’s effect on OCD symptoms.
Aims
We aimed to (a) establish the feasibility, tolerability and safety of administering PAP to adults with treatment-resistant OCD; (b) provide preliminary data on the clinical effects of PAP for treatment-resistant OCD, to inform the design of larger clinical trials; and (c) compare neuroimaging and neurophysiological markers pre- and post-PAP in treatment-resistant OCD.
Method
In this 12-week open-label trial, ten adults with treatment-resistant OCD will receive one 25 mg dose of psilocybin combined with psychological support. Feasibility, tolerability and safety will be assessed throughout. Clinical outcomes will be measured with the Yale–Brown Obsessive–Compulsive Scale. Exploratory measures will include brain imaging examining changes in dynamic connectivity from pre to post treatment, electroencephalogram to investigate changes in brain dynamics associated with psilocybin under acute conditions, and transcranial magnetic stimulation-electroencephalogram measures between baseline, provocation of OCD symptoms and up to 1-week post-dose.
Results
The study will provide important preliminary data on the feasibility and efficacy of PAP in adults with treatment-resistant OCD, as well as inform our understanding of neurobiological mechanisms.
Conclusions
The findings of the study will inform the design of larger randomised controlled trials and advance the field of psychedelic-assisted therapies.
America’s history and culture wars have escalated at pace since Donald Trump returned to office in January 2025. And while the President’s second term has been marked by a rapid stream of executive orders and supporting remarks, articles, and statements affecting all aspects of life, it has demonstrated a particular interest in the nation’s cultural assets and has coalesced on the Smithsonian Institution. This article argues that Trump’s attention to the Smithsonian Institution has arisen because 2026 is the 250th anniversary of American independence. It presents archival evidence from the Smithsonian alongside contemporary analysis to demonstrate that the political playbook being utilized by President Trump has an extensive history. To make its point, the article offers a case study of The West as America, an exhibition that was shown in 1991 at the Smithsonian and generated such political controversy that it ended up being the subject of extensive questioning in Congress. The article aims to show the clear similarity between political and public responses to the 1991 exhibition—which was designed to commemorate a national anniversary but occurred in a period of heightened history wars—with conservative attempts to regulate culture in 2025, ahead of “America 250.” It exemplifies how important historical inquiry is in informing decisions and responses to processes of cultural production in the current era.
Canadian political scientists have often taken a normative approach to political institutions like the constitution, the electoral system, and Parliament. An assumption that institutional reform can itself be a solution to political problems is also reflected in general public commentary and at times has been openly encouraged and supported by the Canadian state itself. This approach has many strengths but also deficiencies, particularly the degree to which it replicates existing understandings of the state, focused on the distribution of power among white men. The study of political institutions in Canada must continue growing to incorporate and integrate a greater diversity of perspectives, including interrogating and challenging their very foundations.