By comparing the budget of a data-driven quasi-linear approximation (DQLA) (Holford, Lee & Hwang, J. Fluid Mech., vol. 980, 2024, A12) and direct numerical simulation (DNS) (Lee & Moser, J. Fluid Mech., vol. 860, 2019, pp. 886–938), the energetics of linear models for wall-bounded turbulence are assessed. The DQLA is implemented with the linearised Navier–Stokes equations with a stochastic forcing term and an eddy viscosity diffusion model. The self-consistent nature of the DQLA allows for a global comparison across all wavenumbers to assess the role of the various terms in the linear model in replicating the features present in DNS. Starting from the steady-state second-order statistics of a Fourier mode, a spectral budget equation is derived, connecting Lyapunov-like equations to the transport budget equations obtained from DNS. It is found that the DQLA and DNS are in good qualitative agreement for the streamwise-elongated structures present in DNS, comparing well for production, viscous transport and wall-normal turbulent transport. However, the DQLA does not have an energy-conservative nonlinear term. This results in no dissipation under molecular viscosity, with energy instead being dissipated locally through the eddy viscosity model, which models the energy removal by the nonlinear term at integral length scales. Comparison of the pressure–strain statistics also highlights the absence of the streak instability, with production and forcing mainly being retained in the streamwise and wall-normal components or shifted to the spanwise component. It is demonstrated that the eddy viscosity diffusion term locally enforces a self-similar budget, making the model for the nonlinear term self-consistent with a logarithmic mean profile. Implications and recommendations to improve the current eddy viscosity enhanced linear models are also discussed concerning the comparison with DNS, as well as considerations with regard to pressure statistics to mimic the role of the streak instability through colour of turbulence models.

In this paper, the authors introduce a new notion called the quantum wreath product, which is the algebra $B \wr _Q \mathcal {H}(d)$ produced from a given algebra B, a positive integer d and a choice $Q=(R,S,\rho ,\sigma )$ of parameters. Important examples that arise from our construction include many variants of the Hecke algebras, such as the Ariki–Koike algebras, the affine Hecke algebras and their degenerate version, Wan–Wang’s wreath Hecke algebras, Rosso–Savage’s (affine) Frobenius Hecke algebras, Kleshchev–Muth’s affine zigzag algebras and the Hu algebra that quantizes the wreath product $\Sigma _m \wr \Sigma _2$ between symmetric groups.

In the first part of the paper, the authors develop a structure theory for the quantum wreath products. Necessary and sufficient conditions for these algebras to afford a basis of suitable size are obtained. Furthermore, a Schur–Weyl duality is established via a splitting lemma and mild assumptions on the base algebra B. Our uniform approach encompasses many known results which were proved in a case by case manner. The second part of the paper involves the problem of constructing natural subalgebras of Hecke algebras that arise from wreath products. Moreover, a bar-invariant basis of the Hu algebra via an explicit formula for its extra generator is also described.

This DNS study considers transition to turbulence in plane Couette flow (pCf) with a rough stationary wall and a smooth moving wall. The roughness elements are square ribs of height $k=0.2h$ (where $h$ is the half-channel height). Two different pitch separations, $\lambda =2k$ and $10k$, are considered, i.e. d-type and k-type roughness, respectively. The transition in both rough pCf cases takes place through a stage of alternate laminar–turbulent bands aligned in an oblique fashion. However, roughness causes a shift in the transitional Reynolds number ($Re$) range. In the k-type roughness, stable bands are observed in the range $Re \in [300, 325]$, which is a downwards shift from the transitional $Re$ range for the smooth pCf ($Re \in [325,400]$). The d-type roughness, on the other hand, surprisingly shifts the transitional $Re$ range upwards to $Re \in [350,425]$. This peculiar behaviour is associated with the ability of the ribs to shed and regenerate vorticity. Large-scale components extracted using a filtering process relate to the transition bands and flow parallel to the oblique laminar–turbulent boundaries. Counter-rotating vortices are present in the turbulent regions of the flow field, which exist in tandem with the high- and low-velocity streaks. Another interesting observation is the secondary Reynolds shear stresses, $-\overline {v^{\prime }u^{\prime }}$ and $-\overline {w^{\prime }v^{\prime }}$, which are non-zero in the transitional regime, in contrast to the turbulent regime where they are negligible.

In this paper, we use an information theoretic approach called cumulative residual extropy (CRJ) to compare mixed used systems. We establish mixture representations for the CRJ of mixed used systems and then explore the measure and comparison results among these systems. We compare the mixed used systems based on stochastic orders and stochastically ordered conditional coefficients vectors. Additionally, we derive bounds for the CRJ of mixed used systems with independent and identically distributed components. We also propose the Jensen-cumulative residual extropy (JCRJ) divergence to calculate the complexity of systems. To demonstrate the utility of these results, we calculate and compare the CRJ and JCRJ divergence of mixed used systems in the Exponential model. Furthermore, we determine the optimal system configuration based on signature under a criterion function derived from JCRJ in the exponential model.

We conduct a numerical study on the drag-reduction mechanism of an opposition- controlled turbulent channel flow from the viewpoint of a symbolic dynamics approach. The effect of the virtual wall formed by the opposition control is maximised at the location of the detection plane $y_d^+ \approx 10$. At this wall-normal location, the local link strength of the self-loop of network nodes representing the negative correlation pattern between the streamwise and wall-normal velocity fluctuations is maximised in the uncontrolled flow. In the controlled case, the multiscale complexity–entropy causality plane and the spatial permutation entropy at $y_d^+ \approx 10$ indicate that the drag-reduction effect is attributed to the reduction of the region where streaks actively coalesce and separate and the suppression of the regeneration cycle in the region near the wall.

During the Third Indochina War (1979-1991), the ideological alignments of involved parties differed from those during the Second Indochina War, also known as the Vietnam War. Whereas the Second Indochina War pitted communists squarely against non-communists and anti-communists, the Third Indochina War was more complicated and less ideological or political, with communists often fighting against other communists due to the Sino-Soviet ideological split. The enemy of one's enemy was frequently viewed as a friend, often leading to unlikely alliances not rooted in ideological or political similarities. In this article, I argue that it is important to consider the unlikely alliances that emerged during the Third Indochina War by focusing on the particular cross-border interactions and conflicts between communists and non-communists that occurred in the Emerald Triangle, the tri-border region between Laos, Cambodia and Thailand. Focusing particularly on the Lao insurgent perspective, I consider how Lao anti-communist insurgents, the Khmer Rouge, the Communist Party of Thailand, other armed groups, and the Thai military participated in transnational collaboration in this region during the Third Indochina War. In particular, based largely on Lao-language interviews with key figures in the Lao insurgency conducted for over a decade, I examine how Lao insurgents interacted with Khmer Rouge to oppose a common enemy, communist Vietnam and their allies, the People's Republic of Kampuchea and the Lao People's Democratic Republic, and how the Thai military supported them, but only insofar as it enabled them to maintain control over security inside Thailand.

While physical activity reduces the risk for chronic disease development, evidence suggests those experiencing early life growth-restriction do not express positive adaptations in response to physical activity. The purpose of this study was to examine the effects of low birthweight (LBW) on markers of chronic disease, adult physical activity, and the response to physical activity engagement in a longitudinal human cohort study. Data from the Framingham Offspring Cohort were organized to include participants with birthweight, physical activity, and chronic disease biomarker/treatment data available at two timepoints (exam 5 and exam 9, 19-year difference). A two-way ANCOVA was performed to determine the association of LBW and sex on physical activity engagement (63.0% female, 10.4% LBW). A multinomial logistic regression was performed to examine the associations of low birthweight and sex on chronic disease development while adjusting for physical activity. LBW was associated with elevated blood glucose and triglycerides (Exam 9). Though not statistically significant (p = 0.08), LBW females potentially spent more time in sedentary activity at exam 5 than LBW males and normal birthweight (NBW) females. LBW males spent significantly more time (p = 0.03) sedentary at exam 9 compared to NBW males and LBW females. There were no differences in the likelihood of chronic disease treatment between groups. Chronic disease biomarkers remained elevated when adjusted for total physical activity. In conclusion, LBW participants in the Framingham Offspring Cohort were not more likely to be treated for chronic diseases when controlling for physical activity engagement, though biomarkers of chronic disease remained elevated.

The conflict over abortion in the United States shows no sign of abatement. Both supporters and opponents of abortion rights have mobilized movements, engaged in collective action, suffered defeats and won victories, and survived over many decades. To understand how the current battle is likely to progress, we need to examine the movement/countermovement dynamics that drive the mobilization and outcomes of the opposing movements (Meyer and Staggenborg 1996). This article demonstrates how ongoing mobilization is fueled by the strategies and tactics of each side, which are strongly influenced by the actions of their opponents.

Several broadleaf crops on the Canadian prairies suffer economic damage by Lygus bugs (Hemiptera: Miridae), populations of which are suppressed by parasitoids in the genus Peristenus (Hymenoptera: Braconidae). We used three different methods to assess levels of this parasitism for different instars of Lygus collected in southern Alberta, Canada. Screening Lygus for Peristenus DNA using a molecular polymerase chain reaction (PCR) method identified levels of parasitism ranging from 35 (second and third instars) to 47 (fifth instars) per cent. With dissection, parasitoids were recovered from 13 (second instars) to 44 (fifth instars) per cent of Lygus. For Lygus collected in the field and reared in the lab, Peristenus emerged from about 22 per cent of individuals. Our results show that use of PCR or dissection for fifth-instar larvae provides comparable estimates of parasitism. For earlier instars, PCR identifies levels of parasitism undetected using dissection – that is, 2.7-fold more for second instars in the present study. For the purposes of pest management and conservation biological control, dissection can provide adequate estimates of parasitism to inform a decision to reduce insecticides to protect Peristenus parasitoids.

Estas notas de investigación son el resultado de un proceso etnográfico accidental e involuntario realizado a lo largo de 2023 en el estado de Durango, en el norte de México. Son un análisis preliminar de la información recolectada sobre la evidente presencia del crimen organizado y sus efectos en la vida cotidiana de los ciudadanos. La mayoría de los estudios sobre violencia en México —y América Latina— tienden a tratar situaciones de violencia extrema; o se enfocan en la población pobre y marginada, que sufre distintos tipos de opresión. Estas notas retratan una situación distinta en dos sentidos. Primero, surgen del trabajo de campo realizado en un entorno de aparente tranquilidad: Durango es actualmente uno de los estados más pacíficos del país, si se mide la paz por número de homicidios. Solo un centenar de personas son asesinadas anualmente, lo que es una anomalía en un país cruento, que reporta más de treinta mil muertes violentas cada año. Segundo, las notas emergen, principalmente, del testimonio de las clases medias y altas, segmentos de la población que también sufren las consecuencias de la violencia, pero que han sido largamente ignorados por la literatura. La investigación evidencia que el crimen organizado condiciona significativamente la vida cotidiana de los ciudadanos que viven en paz, pero con miedo. Los grupos criminales perturban el trabajo y el ocio de los ciudadanos, así como su relación con el gobierno. Este estudio también reflexiona sobre cómo el crimen organizado repercute en el funcionamiento normal del Estado y la democracia liberal.

We compute the integral Chow ring of the moduli stack of smooth elliptic curves with n marked points for $3\leq n\leq 10$.

Chronic coin shortages plagued Ireland and Britain's American colonies throughout the seventeenth and eighteenth centuries. Despite complaints, every proposal to mint money in early modern Britain's overseas Atlantic empire failed, whether in Ireland, the Caribbean, or North America. This article explains why. Although the rulers in the court and Parliament were sometimes enthusiastic about colonial mints, the Officers of the Royal Mint exercised enduring influence and managed to obstruct each of these projects. The evolution of the Mint officers’ advice into a maxim of monetary uniformity allowed the doctrine of “one certain standard” to survive the ensuing decades of upheaval as it shed its visible politics. While their advice grew out of the particular politics of the early Restoration, it gained special power and durability when it took on the character of technocratic expertise. Still, an investigation of the same actors’ treatment of a parallel issue—the rates of the foreign coins that circulated in colonies—reveals that an authoritarian style had an enduring hold on imperial monetary policy. This article offers an explanation for the British Empire's peculiar monetary geography, and also demonstrates the way that seemingly apolitical technical knowledge can disguise a potent politics.

The scientific literature indicates that chokeberry is widely used as a supplement to support the maintenance of the body’s homeostasis by reducing inflammation and oxidative stress. In recent years, positive effects of chokeberry on intestinal parameters have also been observed. Oxidative stress, inflammation, and according to recent reports, also the gut microbiome are closely related to the overall well-being and health of the population. This study, therefore, attempts to summarize all the health benefits of black chokeberry supplementation. This study was registered in PROSPERO (International Prospective Register of Systematic Reviews) under registration number CRD42023395969. Additionally, the systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. Electronic databases were searched in Web of Science, Pubmed, Scopus, and EBSCO using the following combination of the words “chokeberry or aronia” and “inflammation or oxidative stress or microbiota or microbiome or permeability or gut.” Ultimately, 57 studies were summarized in the review. Data analysis showed that black chokeberry has a positive effect on the reduction of inflammation, oxidative stress, and intestinal microflora, but the size of the changes varies and depends on many variables. Therefore, the researchers concluded that the compounds found in black chokeberry play a pivotal role in maintaining the overall balance within the system. This is a crucial consideration given the tendency for disturbances in organismal homeostasis to accompany disease processes and various disorders. However, further research is necessary to elucidate the mechanisms and optimize its use fully.

We show that a compact complex manifold X has no non-trivial nef $(1,1)$-classes if there is a non-biholomorphic bimeromorphic map $f\colon X\dashrightarrow Y$, which is an isomorphism in codimension 1 to a compact Kähler manifold Y with $h^{1,1}=1$. In particular, there exist infinitely many isomorphic classes of smooth compact Moishezon threefolds with no nef and big $(1,1)$-classes. This contradicts a recent paper (Strongly Jordan property and free actions of non-abelian free groups, Proc. Edinb. Math. Soc., 65(3) (2022), 736–746).