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The formal and informal arrangements underpinning constitutional settlements reflect the relationships at the foundations of the economy and the polity. There is mutual embedding of the economy within the intertwined collective objectives characterising the polity, and of the polity within the web of material interdependencies characterising the economy. This mutual embeddedness defines the ‘constitution’ of political economy as the pattern of connectivity reflecting the relationship between the political constitution and the economic constitution. This has deep implications for the dynamics of the economy and the polity, as well as for the character and effectiveness of actions by stakeholders in both spheres.
The evolution of the mixing layer in rotation-driven Rayleigh–Taylor (RT) turbulence is investigated theoretically and numerically. It is found that the evolution of the turbulent mixing layer in rotation-driven RT turbulence is self-similar, but the width of the mixing layer does not follow the classical quadratic growth observed in planar RT turbulence induced by constant external acceleration. Based on the approach used in cylindrical RT turbulence without rotation (Zhao et al. 2021, Phys. Rev. E, vol. 104, 055104), a theoretical model is established to predict the growth of mixing widths in rotation-driven RT turbulence, and the model’s excellent agreement with direct numerical simulations (DNS) serves to validate its reliability. The model proposes a rescaled time that allows for the unification of the evolutions of the mixing layers in rotation-driven RT turbulence with various Atwood numbers and rotation numbers. It is further identified that the growth law described by the model of rotation-driven RT turbulence can be recovered to quadratic growth when the effects of geometrical curvature, radial inhomogeneity of the centrifugal force, and Coriolis force become negligible. Moreover, based on the DNS results, we find that turbulent mixing layers in rotation-driven RT turbulence cover a wide range of length scales. The strong rotation at the same Atwood number enhances the generation of fine-scale structures but is not conducive to overall fluid mixing within the mixing layer.
This review comprehensively examines the current evidence on the dietary management of chronic constipation, and the dietary recommendations presented in clinical guidelines for chronic constipation. Several randomised controlled trials (RCT) have investigated the effect of dietary supplements, foods and drinks in chronic constipation. Systematic reviews and meta-analyses of these RCTs have demonstrated that psyllium supplements, specific probiotic supplements, magnesium oxide supplements, kiwifruits, prunes, rye bread and high mineral water content may be effective in the management of constipation. However, despite the plethora of evidence, current clinical guidelines only offer a limited number of dietary recommendations. The most commonly recommended dietary strategy in clinical guidelines is dietary fibre, followed by senna supplements and psyllium supplements. The least commonly recommended dietary strategies are magnesium oxide, Chinese herbal supplements, prunes and high mineral-content water. Several evidence-based dietary strategies are omitted by current clinical guidelines (e.g. kiwifruits), while some strategies that are recommended are not always supported by evidence (e.g. insoluble fibre supplement). Dietary recommendations in clinical guidelines can also be ambiguous, lacking outcome-specific recommendations and information for appropriate implementation. Future RCTs are needed to assess currently under-investigated dietary approaches that are nevertheless commonly recommended, and future clinical guidelines should include dietary recommendations supported by available evidence.
Addition of polymers modifies a turbulent flow in a manner that depends non-trivially on the interplay of fluid inertia, quantified by the Reynolds number $\textit{Re}$, and the elasticity of the dissolved polymers, given by the Deborah number $\textit{De}$. We use direct numerical simulations to study polymeric flows at different $\textit{Re}$ and $\textit{De}$ numbers, and uncover various features of their dynamics. Polymeric flows exhibit a non-unique scaling of the energy spectrum that is a function of $\textit{Re}$ and $\textit{De}$, owing to different dominant contributions to the total energy flux across scales, with the weakening of fluid nonlinearity with decreasing $\textit{Re}$ also leading to the reduction of the polymeric scaling range. This behaviour is also manifested in the real space scaling of structure functions. We also shed light on how the addition of polymers results in slowing down the fluid nonlinear cascade resulting in a depleted flux, as velocity fluctuations with less energy persist for longer times in polymeric flows, especially at intermediate $\textit{Re}$ numbers. These velocity fluctuations exhibit intermittent, large deviations similar to that in a Newtonian flow at large $\textit{Re}$, but differ more and more as $\textit{Re}$ becomes smaller. This observation is further supported by the statistics of fluid energy dissipation in polymeric flows, whose distributions collapse on to the Newtonian at large $\textit{Re}$, but increasingly differ from it as $\textit{Re}$ decreases. We also show that polymer dissipation is significantly less intermittent compared with fluid dissipation, and even less so when elasticity becomes large. Polymers, on an average, dissipate more energy when they are stretched more, which happens in extensional regions of the flow. However, owing to vortex stretching, regions with large rotation rates also correlate with large polymer extensions, albeit to a relatively less degree than extensional regions.
Critical International Relations Theory (CIRT) is in ‘crisis’. Some argue for a recovery of ‘the inspirational quality’ of Horkheimer and Adorno’s first-generation negative critique. Certainly the challenge of right-wing populism begs questions of CIRT’s ‘consolatory’ cosmopolitanism. I have two concerns however. First, these proposals underplay the reasons why first-generation theorising failed; secondly, CIRT risks throwing the second-generation Habermas–Linklater ‘baby’ out with the ‘bathwater’ at the moment it has particular value. I do two things. I look back to pre-Habermasian Critical Theory, but I set a future agenda based on the Pragmatism of John Dewey. This helps CIRT realise the emancipatory potential in IR’s recent ‘practice turn’, addressing concerns that CIRT is disengaged. It also brings balance to negative and positive critiques, offering a novel challenge to critical/problem-solving binaries in ways that speak to real-world challenges like climate change. Second, I look forward from Habermasian-inspired theory to the third-generation (and Pragmatist-inspired) ‘recognition theory’ of Honneth. This brings a critical edge to IR ontological security studies, further develops the praxeological branch of CIRT, and better informs the political left’s response to the alienating effects of the liberal international order and the rise of right-wing populism.
Let Fn be the free group on $n \geq 2$ generators. We show that for all $1 \leq m \leq 2n-3$ (respectively, for all $1 \leq m \leq 2n-4$), there exists a subgroup of ${\operatorname{Aut}(F_n)}$ (respectively, ${\operatorname{Out}(F_n)}$), which has finiteness of type Fm but not of type $FP_{m+1}(\mathbb{Q})$; hence, it is not m-coherent. In both cases, the new result is the upper bound $m= 2n-3$ (respectively, $m = 2n-4$), as it cannot be obtained by embedding direct products of free noncyclic groups, and certifies higher incoherence up to the virtual cohomological dimension and is therefore sharp. As a tool of the proof, we discuss the existence and nature of multiple inequivalent extensions of a suitable finite-index subgroup K4 of ${\operatorname{Aut}(F_2)}$ (isomorphic to the quotient of the pure braid group on four strands by its centre): the fibre of four of these extensions arise from the strand-forgetting maps on the braid groups, while a fifth is related with the Cardano–Ferrari epimorphism.