We study the mode transition algebras and Zhu algebras in the setting of & Zopf;-graded vertex algebras, with particular focus on the Weyl vertex algebra V at central charge 2 (also known as bosonic ghosts or the beta gamma-system). We show that the mode transition algebras of V admit unity elements that form a family of strong unities in the sense of Damiolini-Gibney-Krashen. The existence of unities for the mode transition algebra of V allows us to explicitly construct all higher level Zhu algebras of V. We further analyze weak V-modules induced from Zhu algebras, proving that every such module is already induced from the level-zero Zhu algebra. We then prove that all indecomposable reducible weight modules induced from a Zhu algebra are not weakly interlocked, and hence not strongly interlocked in the sense of Barron-Batistelli-Orosz Hunziker-Yamskulna. More generally, we show that the property of being weakly interlocked is preserved under the action of an invertible Li's Delta operator. As an application, we prove that all indecomposable reducible weight V-modules obtained via spectral flow of Zhu-induced modules are likewise not weakly interlocked. These results clarify the role of being weakly interlocked in the modularity properties of bosonic ghost modules previously studied by Ridout-Wood and Allen-Wood. (c) 2026 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
PurposeThis study investigates the impact of military-experienced board members on firm-level investment efficiency, focusing on Indonesian non-financial listed companies from 2011 to 2019. It integrates upper echelons and imprinting theories to explain how military backgrounds shape corporate decision-making, particularly in relation to risk preferences.Design/methodology/approachBased on 2,648 firm-year observations, this study employs fixed-effects regression to analyze the relationship between military experience and investment efficiency. To address endogeneity and ensure robustness, we apply Heckman's two-stage regression, coarsened exact matching (CEM), propensity score matching (PSM) and the generalized method of moments (GMM).FindingsThe results reveal a significantly positive association between military-experienced boards and investment efficiency. This effect is particularly pronounced in underinvesting firms, in firms operating in low-concentration industries, and where board commissioners have military backgrounds. The positive association is also evident in the context of R&D efficiency.Originality/valueThese findings suggest that appointing board commissioners with military backgrounds can enhance disciplined and context-sensitive investment decisions. However, military discipline alone may not substitute for financial expertise, underscoring the need for a balanced board composition.
JWST has revealed a population of red, compact, high-redshift ( z ∼ 3–10) objects referred to as “Little Red Dots” (LRDs). These objects exhibit unusual spectral features reminiscent of stellar spectra with blackbody-like spectral energy distributions, large hydrogen Balmer breaks, Balmer line absorption, and classical stellar absorption features such as calcium H&K and the calcium triplet. Following the recent suggestion that these may be actively accreting direct-collapse black holes in the process of assembly, i.e., quasi-stars, we present evolutionary models of quasi-stars using our recently released, publicly available MESA-QUEST modeling framework. We compute a grid of models spanning a range of black hole masses and predict the luminosities, temperatures, surface gravities, and lifetimes of these objects. We find that these models lie along a Hayashi track once they hit their “late stage,” which constitutes the majority of their lives (∼20 Myr). We present scaling relations for estimating the mass of a quasi-star as a function of the bolometric luminosity, as well as the bolometric luminosity as a function of the effective temperature for the Hayashi track. The short lifetimes in tandem with the observed number density of LRDs imply the possibility that every supermassive black hole detected at these epochs was once a quasi-star. We compare synthetic spectra of our quasi-star models to observations of LRDs, and show that these models are broadly capable of reproducing the continuum spectra of observed LRDs. These results indicate that quasi-stars are promising candidates for the origin of supermassive black holes via direct collapse in the early Universe.
The use of technology within single-case design research has expanded exponentially across disciplines, which necessitates a better understanding of global scientific knowledge and patterns. We aimed to empirically map the evolution of knowledge in single-case design methodology using technology. In the semi-automated screening process, we identified 3,637 publications from the Web of Science, spanning the years 1970 to 2025. The Journal of Applied Behavior Analysis was ranked highest in h-index and g-index, and Behavior Analysis in Practice had the highest m-index. The United States was the country with the most authors affiliated. A total of 15 topics emerged through contextualized topic modeling. Primary topics most addressed across decades included health interventions, video modeling, telehealth services, and function-based interventions (topical coverage = 10.83
There is growing evidence that student experiences of school climate are closely linked to both individual and school-level outcomes. To support data-driven school improvement efforts, it is essential to use reliable and valid measures of school climate, especially brief tools that reduce response burden, ensure accessibility, and enhance feasibility. Using bifactor analysis, this study examined the psychometric properties of the Community and Youth Collaborative Institute School Climate Experience Survey - Middle/High School Student Short Form (CAYCI-SES-SF). Data were collected from 1,509 middle and high school students. Findings indicated the short 29-item version of the survey supports a general factor structure, suggesting it can function as a comprehensive, brief, psychometrically sound tool. The shortened instrument demonstrated strong overall reliability and adequate reliability for some subscales. However, variability in factor loadings and omega coefficients points to the need for further scale refinement. Overall, the study provides initial evidence for the use of the abbreviated CAYCI-SES-SF to assess school climate in educational settings.
