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We study the temperature–velocity (TV) relation for laminar adiabatic and diabatic hypersonic boundary layers. By applying an asymptotic expansion to the compressible boundary-layer temperature equation, we derive a first-order equation for the TV relation, where the zeroth-order solution is found to be the classical Crocco–Busemann quadratic relation. The ensuing relation predicts accurately the temperature profile by using the velocity for hypersonic boundary layers with Chapman, power and Sutherland viscosity laws, arbitrary heat capacity ratios, variable Prandtl numbers close to unity and Mach number of up to 10. The Mach-number- and wall-temperature-independent quantities in our relation are also investigated. The present relation has the potential to function as a temperature wall model for laminar hypersonic boundary layers, especially for cold-wall cases.
The racial segregation of schools is commonly cited as the foundational injustice of the U.S. education system and an ongoing impediment to educational equality. For liberal experts and reformers, school segregation is defined as a pattern of racially separate schools serving either White students or students of color. This paper argues that this prevailing understanding of the school segregation issue is intellectually inadequate and politically limiting. Drawing on a case study of Chicago’s movement for racial educational justice in the 1960s, I show that this simple framing of the issue initially gained prominence as an alternative to the more radical and contextualized critique of urban school segregation articulated by local Black grassroots activists. In contrast with official liberal discourse and reform proposals, Black urban activists in the early 1960s challenged school segregation as a set of educational policies and practices that render schools both separate and unequal, locking Black students out of more privileged White schools and contributing to the uneven development of schools across the racial divide. By recovering this suppressed grassroots critique of urban school segregation, this paper calls for a broader theorization of contemporary school segregation as dynamic and relational rather than a static statistical pattern that simply compounds the existing concentration of disadvantage within segregated neighborhoods.
To enhance the supervision of regional environmental issues, China initiated a nationwide campaign in 2007 to establish environmental courts and formulate local environmental regulations. This study selected Shanghai and Shenzhen A-share listed companies from 2004 to 2021 as its research sample to examine the impact of local environmental legislation and the establishment of environmental courts on corporate carbon emissions. The findings indicate that the combined effect of these measures significantly curbs carbon emissions. Additionally, the study identifies that the intensity of local environmental court establishment and the implementation of corporate pollution charges or environmental protection taxes are critical mechanisms through which environmental legislation and court establishment reduce corporate carbon emissions. Finally, the interaction of environmental legislation and court establishment on corporate carbon emissions is most pronounced in regions where the government exhibits lower environmental concern, in state-owned enterprises, in enterprises located in the eastern region and in highly polluted cities.
Ethnographic methods of all varieties contend with the idea of the “truth” of accounts and the meanings attached to them, as well as the importance of context in mitigating truth or falseness in how these accounts are presented. Discerning truth from lies and the purpose of both in the context of making meaning in a time and place is at the heart of the ethnographic enterprise. Because powerful images or messages evoke emotional reactions on social media or contributory websites like message boards, the relative accuracy of the representations they make is often less important than their reach and the ways they make and remake “reality” for their audiences. A picture or an image, even one attributed to a context or a meaning wholly independent of the context from which it emerged, becomes part of how people online see or experience an event. The context in which information is presented and the speakers or presenters of this information also condition its uptake and resonance. This paper argues that ethnography is uniquely suited to understand the effects and reach of decontextualized information and the ways it makes meaning, both on- and offline.
For decades, the study of Chartism has been one of the most vibrant fields of modern British history. Indeed, this nineteenth-century radical movement was a major empirical focus for proponents of the so-called linguistic turn that has exerted such a major influence on the discipline. Interest in the Chartists does not abate, with valuable recent studies all combining—to greater or lesser extent—close attention to Chartist verbal and symbolic forms of communication with novel thematic concerns. However, more remains to be said about the language of Chartism, the topic that provided the original impetus for so much subsequent work. Specifically, the generally accepted argument that languages of constitutionalism and democracy were inextricably intertwined can be questioned, a task made easier by digitization of key organs of the Chartist press. This article revisits this intertwining in the pages of the Northern Star from the movement’s beginnings in the late 1830s to its disintegration in the late 1840s. It commences with results of a quantitative analysis of Chartist discourse and reconsideration of the relationship between the constitutional and democratic idioms in the movement’s early phase. Four factors are then discussed, which help explain the increasing prevalence of the language of democracy through the 1840s: heightened social conflict during the general strike of 1842; Chartist engagement in formal politics; international developments; and the crisis of 1848. However, despite the dominant linguistic trend, connections between democracy and social class, forged in the early 1840s, were not immutable but contingent.
Hospital sink drains are recognized reservoirs for gram-negative bacteria (GNB). This study evaluates the efficacy of a sink drain disinfection strategy using hydrogen peroxide-based foam, mechanical cleaning, and drain cover replacement in reducing GNB bioburden in a neonatal intensive care unit (NICU).
Methods:
We conducted a prospective cohort study of 30 NICU room sinks comparing three interventions: (1) foam disinfection alone (n = 5), (2) foam with mechanical cleaning (n = 5), and (3) foam with drain cover replacement (n = 5), and (4) foam, mechanical cleaning, and drain cover replacement (n = 5), to controls (no intervention, n = 10). Samples from sink drains, faucets, counters, basins, and drain covers were collected at baseline (Day 0) and post-intervention (Days 1, 3, 5, and 7). Bacterial colony counts were analyzed using linear regression models.
Results:
At baseline, sink drains and drain covers had the highest bioburden (total GNB mean ln-CFU: 15.4 and 16.4), with Pseudomonas aeruginosa (33%) and Stenotrophomonas maltophilia (39%) as predominant isolates. The intervention combining foam, mechanical cleaning, and drain cover replacement achieved the greatest bioburden reduction on Day 1 in drains (mean ln-CFU reduction = 11.0, 95% CI: 6.4, 16.0, p < 0.001) and covers (mean reduction = 14.0, 95% CI: 8.7, 19.0, p < 0.001), with sustained effects through Day 7. Recolonization to ∼50% of baseline was evident by Day 5 in both sites.
Conclusions:
Physical bioburden removal improved the effect of a foaming disinfectant in reducing GNB. However, recolonization occurred by day 5.
Gauge theories are often characterized as possessing ‘redundancy’ or ‘excess structure’. This, in turn, motivates reducing the gauge symmetries, commonly through ‘symplectic reduction’ in the Hamiltonian framework. However, there are multiple ways to formulate a Hamiltonian gauge theory. This paper examines the relationship between the formulation of a Hamiltonian gauge theory and the attribution of excess structure. I argue that one can formulate a Hamiltonian gauge theory such that symplectic reduction does not remove structure, and there-fore that the role of symplectic reduction cannot be purely to remove ‘excess structure’. I discuss in what sense symplectic reduction is thereby motivated.
This study employs three-dimensional particle-resolved simulations of planar shocks passing through a suspension of stationary solid particles to study wake-induced gas-phase velocity fluctuations, termed pseudo-turbulence. Strong coupling through interphase momentum and energy exchange generates unsteady wakes and shocklets in the interstitial space between particles. A Helmholtz decomposition of the velocity field shows that the majority of pseudo-turbulence is contained in the solenoidal component from particle wakes, whereas the dilatational component corresponds to the downstream edge of the particle curtain where the flow chokes. One-dimensional phase-averaged statistics of pseudo-turbulent kinetic energy (PTKE) are quantified at various stages of flow development. Reduction in PTKE is observed with increasing shock Mach number due to decreased production, consistent with single-phase compressible turbulence. The anisotropy in Reynolds stresses is found to be relatively constant through the curtain and consistent over all the conditions simulated. Analysis of the budget of PTKE shows that the majority of turbulence is produced through drag and balanced by viscous dissipation. The energy spectra of the streamwise gas-phase velocity fluctuations reveal an inertial subrange that begins at the mean interparticle spacing and decays with a power law of $-5/3$ and steepens to $-3$ at scales much smaller than the particle diameter. A two-equation model is proposed for PTKE and its dissipation. The model is implemented within a hyperbolic Eulerian-based two-fluid model and shows excellent agreement with the particle-resolved simulations.
This study examines whether different biodiversity proxies – species, habitat and functionality – satisfy the scope sensitivity and plausibility criteria in willingness to pay (WTP) estimation using a choice experiment in Manu National Park, Peru. We introduce the network of species interactions as a proxy for functionality and apply latent class (LC) models, including attribute non-attendance (ANA), to account for heterogeneity in preferences. Our results indicate that functionality is the only proxy consistently meeting both validity criteria across all specifications. LC analysis reveals two segments: one (74.4 per cent) displaying coherent, scope-sensitive WTP across biodiversity attributes, and another (25.6 per cent) less engaged, disregarding standard proxies but still valuing networks. Even under ANA constraints, networks remain salient for less attentive respondents, underscoring their cognitive accessibility in complex ecological contexts. These findings highlight the methodological and policy relevance of functionality-based proxies for biodiversity valuation in megadiverse environments, where conventional measures may fail to elicit behaviourally consistent responses.
How do perceptions of demographic change affect the strength of white identity and corresponding attitudes toward immigrants, immigration and personal perceptions of victimhood? While white identity has received scholarly attention in the United States, we know much less about its effects in Canada. We conducted a preregistered survey experiment in which we exposed respondents to different framings on Canada’s increasing ethnic diversity. We find that perceiving demographic change increases feelings of white identity, particularly when framed as an increase in Canada’s visible minority or immigrant population. However, exposure to these trends does not in turn robustly affect respondents’ attitudes toward immigrants, immigration admission preferences or own perceptions of personal victimhood. These findings suggest that white identity is both present and can be primed in Canada; however, it has not yet been politically mobilized in the same way as in other contexts, such as the United States.
This article examines two ruined monumental architectural complexes in ancient Oaxaca: the Main Plaza of Monte Albán and the acropolis of Río Viejo. I consider how the material vibrancy of these ruins differed in ways that both brought together and destabilized communities. After its abandonment, the ruins of the Main Plaza, as well as the mountain on which it was built, continued to assemble substances important to human well-being, including rain, clouds, sky, mountains, ancestors, and deities. People periodically journeyed to the plaza to make offerings and bury their revered dead, thereby constituting a broader identity and community. In contrast, the earthen architecture of the acropolis, located in the center of Río Viejo, rapidly decayed in the tropical lowland climate. The reemergence of hierarchy at Río Viejo in the Late Classic period activated material memories of rupture held in the ruins that threatened and resisted new forms of community and political authority.
The interaction between a forward-facing step (FFS) and single-frequency Tollmien–Schlichting (TS) waves is investigated with experiments and two-dimensional (2-D) direct numerical simulations (DNS). Dedicated hot-wire anemometry and particle image velocimetry measurements in the vicinity of the FFS provide characterisation of the perturbation field, as well as validation of the DNS results. Comparison between experiments, 2-D DNS, and linear parabolised stability equations confirm the 2-D nature of the flow and the linearity of the instability mechanisms around the FFS. Upstream of the step, TS waves are gradually amplified by the increasing adverse pressure gradient. In the step vicinity, both mean flow and perturbation field exhibit abrupt distortion, with decoupling of the base flow-oriented growth rate components indicating significant non-modal evolution. Downstream of the step, the mean flow recovers to baseline conditions, but the perturbation field remains highly distorted. Linear stability theory results suggest the presence of superimposed modes on the original TS mode in this region. Despite their decay in the streamwise direction, their presence imprints modifications in the TS wave growth and shape, manifested as the tilting of the perturbation structure in and against the mean flow shear direction. This initiates a reversed Orr mechanism, characterised by a region of stabilisation followed by destabilisation further downstream. Eventually, the TS waves realign to their asymptotic (modal) behaviour. Overall, the FFS destabilises the TS wave far downstream. However, the streamwise extent and magnitude of the stabilisation downstream of the FFS remain significant.
This essay highlights hitherto overlooked continuities between Husserl’s phenomenological idealism and Hegel’s absolute idealism. I focus on Husserl’s account of essence and argue that some of Husserl’s core expositions of essences suggest that they are akin to Hegelian concrete universals: like concrete universals, phenomenological essences are ideal entities instantiated in particulars and exemplify a structure of unity-in-difference. Husserl’s proximity to these Hegelian tenets is evident in his account of the ego’s self-constitution, which is broadly consistent with Hegel’s account of the determination of the Concept. Appreciating Husserl’s similarities with Hegel suggests a means of reconciling competing metaphysical, epistemic, and transcendental interpretations of Husserl’s idealism. By revealing the extent to which the transcendental character of Husserl’s phenomenology is embedded within some absolute idealist commitments, these results locate Husserl in hybrid philosophical territory, between transcendental and absolute versions of idealism, allowing him to reconcile his transcendental and realist commitments, and offering him a defence against the charge that he succumbs to an unsophisticated and unattractive form of subjectivism.
Nematode records and specimens from the South Australian Museum, Australian Museum, CSIRO Wildlife Collection, Queensland Museum, Western Australian Museum, and Natural History Museum, London, of 1107 individuals of Rattus fuscipes were examined. The nematode community comprised 19 families, 36 genera, and 44 identified species. Mastophorus muris and unidentified heligmonellids were recovered from 4 individuals of R. f. fuscipes. Rattus f. assimilis was infected with 40 identified species of nematode from 955 individuals; R. f. coracius 18 species from 107 individuals; and R. f. greyii 8 species from 28 individuals. Rattus fuscipes harboured 18 species in Northern Queensland, 27 species in Southern Queensland, 27 species in New South Wales, 19 species in Victoria, and 8 species in South Australia. A bootstrap analysis of the R. f. greyii nematode community indicated that 91.3% of species had been found. No core species were revealed. The Trichostrongylidae dominated with Nippostrongylus magnus, and Odilia emanuelae occurring in all the populations. Nippostrongylus magnus, 43% prevalence, in Victoria and Physaloptera troughtoni, 42% prevalence, in South Australia were secondary species. Sorensen’s indices indicated that R. f. assimilis and R. f. coracius had the most similar nematode communities, 54.8%. Overall, the Northern and Southern Queensland populations were most similar (77.3%) and the New South Wales and South Australian populations least similar (22.9%). The identifications of Heterakis spumosa, Physaloptera troughtoni, Rictularia mackerrasae, and Pterygodermatites pearsoni were confirmed. The species composition of the nematode community of R. fuscipes suggested a scenario of coevolution, host switching, recently acquired and occasional infections in a community of cosmopolitan, regional, and indigenous species. Species throughout the component communities of R. fuscipes indicated that climate and habitat were also determinants of species composition.
We enumerate the low-dimensional cells in the Voronoi cell complexes attached to the modular groups $\mathit {SL}_N(\mathbb{Z} )$ and $\mathit {GL}_N(\mathbb{Z} )$ for $N=8,9,10,11$, using quotient sublattice techniques for $N=8,9$ and linear programming methods for higher dimensions. These enumerations allow us to compute some cohomology of these groups and prove that $K_8(\mathbb{Z} ) = 0$. We deduce from it new knowledge on the Kummer-Vandiver conjecture.
This systematic review examined the associations of dietary factors such as nutrients, food intake, dietary patterns and dietary biomarkers with structural and functional brain MRI biomarkers, focusing on macrostructural, microstructural, lesion and perfusion measures, and functional activity/connectivity. Articles published in English were systematically searched in PubMed, Embase and PsycInfo up to 19 July 2024. A total of thirty-eight prospective cohort studies (twenty-three cross-sectional and fifteen longitudinal analyses) and thirteen intervention studies were included. Cross-sectional analyses revealed heterogenous associations: baked fish correlated with larger hippocampal volumes (β = 0·21), while oily fish, dairy products and tofu adversely related to ventricle grade. Pro-inflammatory dietary patterns were positively associated with silent infarct risk (DII Q4 v. Q1, OR = 1·77), whereas anti-inflammatory patterns tended to favour brain preservation. Longitudinal studies demonstrated more consistent protective associations: green tea consumption (+100 mL/d) reduced hippocampal atrophy by 0·024%/year, prudent dietary patterns preserved +203 mm3 left hippocampal volume over 4 years and higher plasma carotenoids decreased medial temporal lobe loss by 0·02 cm3/year. However, null findings were common across multiple dietary factors. Interventions showed limited structural benefits (effective in only two of six studies), while polyphenol-rich supplements more consistently improved cerebral perfusion and functional connectivity. Longitudinal and intervention studies demonstrated more consistent patterns than cross-sectional analyses; however, current evidence remains limited for clinical translation. Findings from cross-sectional analyses, despite being from prospective cohorts, require careful interpretation. Further replication across diverse populations and standardised long-term studies are needed before translating these associations into clinical practice.
Augustine and Aquinas assume that Moses’s law figures Christ. In this piece, I show how their complementary accounts of the old law rest upon other doctrinal emphases, namely providence, God the Father, and created things as participations in divine goodness. By drawing out these themes, I advance reflection on the worth of Moses’s law, unfolding how other doctrines structure loving attention to the law as indicative of Christ.
A data assimilation (DA) strategy based on an ensemble Kalman filter (EnKF) is used to enhance the predictive capabilities of scale-resolving numerical tools for the analysis of flows exhibiting cyclic behaviour. More precisely, an ensemble of numerical runs using large-eddy simulations (LES) for a compressible intake flow rig is augmented via the integration of high-fidelity data. This observation is in the form of instantaneous velocity measurements, which are sampled at localised sensors in the physical domain. Two objectives are targeted. The first objective is the calibration of an unsteady inlet condition suitable to capture the cyclic flow investigated. The second objective is the analysis of the synchronisation of the LES velocity field with the available observations. In order to reduce the computational costs required for this analysis, a hyper-localisation procedure (HLEnKF) is proposed and integrated in the library CONES, tailored to perform fast online DA. The proposed strategy performs a satisfactory calibration of the inlet conditions, and its robustness is assessed using two different prior distributions for the free parameters optimised in this task. The DA state estimation is efficient in obtaining accurate local synchronisation of the inferred velocity fields with the observed data. The modal analysis of the kinetic energy field provides additional insight into the improved reconstruction quality of the velocity field. Thus, the HLEnKF shows promising features for the calibration and synchronisation of scale-resolved turbulent flows, opening perspectives of applications for complex phenomena using advanced tools such as digital twins.