Phase Diagram of Vertically Shaken Granular Matter

A shallow, vertically shaken granular bed in a quasi 2-D container is studied experimentally yielding a wider variety of phenomena than in any previous study: (1) bouncing bed, (2) undulations, (3) granular Leidenfrost effect, (4) convection rolls, and (5) granular gas. These phenomena and the transitions between them are characterized by dimensionless control parameters and combined in a full experimental phase diagram.Comment: 11 pages, 14 figures, submitted to "Physics of Fluids

Interplay between advective, diffusive and active barriers in (rotating) Rayleigh–Bénard flow

Our understanding of the material organization of complex fluid flows has benefited recently from mathematical developments in the theory of objective coherent structures. These methods have provided a wealth of approaches that identify transport barriers in three-dimensional (3-D) turbulent flows. Specifically, theoretical advances have been incorporated into numerical algorithms that extract the most influential advective, diffusive and active barriers to transport from data sets in a frame-indifferent fashion. To date, however, there has been very limited investigation into these objectively defined transport barriers in 3-D unsteady flows with complicated spatiotemporal dynamics. Similarly, no systematic comparison of advective, diffusive and active barriers has been carried out in a 3-D flow with both thermally driven and mechanically modified structures. In our study, we utilize simulations of turbulent rotating Rayleigh–Bénard convection to uncover the interplay between advective transport barriers (Lagrangian coherent structures), material barriers to diffusive heat transport, and objective Eulerian barriers to momentum transport. For a range of (inverse) Rossby numbers, we identify each type of barrier and find intriguing relationships between momentum and heat transport that can be related to changes in the relative influence of mechanical and thermal forces. Further connections between bulk behaviours and structure-specific behaviours are also developed

Toward Understanding Polar Heat Transport Enhancement in Subglacial Oceans on Icy Moons

The interior oceans of several icy moons are considered as affected by rotation. Observations suggest a larger heat transport around the poles than at the equator. Rotating Rayleigh-Bénard convection (RRBC) in planar configuration can show an enhanced heat transport compared to the non-rotating case within this “rotation-affected” regime. We investigate the potential for such a (polar) heat transport enhancement in these subglacial oceans by direct numerical simulations of RRBC in spherical geometry for Ra = 106 and 0.7 ≤ Pr ≤ 4.38. We find an enhancement up to 28% in the “polar tangent cylinder,” which is globally compensated by a reduced heat transport at low latitudes. As a result, the polar heat transport can exceed the equatorial by up to 50%. The enhancement is mostly insensitive to different radial gravity profiles, but decreases for thinner shells. In general, polar heat transport and its enhancement in spherical RRBC follow the same principles as in planar RRBC.</p

Optimal heat transport in rotating Rayleigh-B\'{e}nard convection at large Rayleigh numbers

The heat transport in rotating Rayleigh-B\'enard convection (RBC) can be significantly enhanced for moderate rotation, i.e., for an intermediate range of Rossby numbers $Ro$, compared to the non-rotating case. At Rayleigh numbers $Ra\lesssim5\cdot10^8$, the largest heat transport enhancement (HTE) is achieved when the thicknesses of kinetic and thermal boundary layer are equal. However, experimental and numerical observations show that, at larger $Ra$ ($\gtrsim5\cdot10^8$), the maximal HTE starts to deviate from the expected optimal boundary layer ratio and its amplitude decreases drastically. We present data from direct numerical simulations of rotating RBC in a periodic domain in the range of $10^7\leq Ra\leq10^{10}$ and $0\leq Ro^{-1}\leq40$ for Prandtl number $Pr=4.38$ and $6.4$ to identify the reason for the transition to this large $Ra$ regime of HTE. Our analysis reveals that the transition occurs once the bulk flow at the optimal boundary layer ratio changes to geostrophic turbulence for large $Ra$. In that flow state, the vertically coherent vortices, which support HTE by Ekman pumping at smaller $Ra$, dissolve into vertically decorrelated structures in the bulk, such that the enhancing effect of Ekman pumping and the influence of the boundary layer ratio become small. Additionally, more heat leaks out of the Ekman vortices as the fraction of thermal dissipation in the bulk increases. We find that the rotation induced shearing at the plates helps to increase the thermal dissipation in the bulk, and thus acts as a limiting factor for HTE at large $Ra$: beyond a certain ratio of wall shear stress to vortex strength, the heat transport decreases irrespectively of the boundary layer ratio. This $Pr$ dependent threshold, which roughly corresponds to a bulk accounting for $\approx1/3$ of the total thermal dissipation, sets the maximal HTE and the optimal rotation rate at large $Ra$.Comment: Main article: 21 pages, 10 figures; Supplementary material: 6 pages, 4 figures; Published in Phys. Rev. Fluid

Beyond Documentation: 3D Data in Archaeology

As the costs associated with the collection of 3D data continue to plummet, there is little doubt that the number of available archaeology-related 3D datasets will increase dramatically in the coming decade. While our analytical procedures continue to evolve as new applications are contemplated, analyses of 3D data are increasing in frequency within the archaeological literature. In this article, we seek to provide a brief overview of a few examples from our own research and explore some possibilities that may add value to existing collections. In the following pages, we discuss some of the ways that 3D data have been used in studies of morphometrics, public archaeology, excavation, and comparative endeavors

The genome sequence of the lesser marbled fritillary, Brenthis ino, and evidence for a segregating neo-Z chromosome

This is the final version. Available on open access from Oxford University Press via the DOI in this recordData availability: Supplementary Table 1 contains the metadata for the four individuals used for this project. The genome assembly, gene annotation, and raw sequence data can be found at the European Nucleotide Archive under project accession PRJEB49202. The scripts used for analyzing HiC data (chomper.py and HiC_view.py), the script used for calculating site degeneracy (partition_cds.py), and the script used for visualizing synteny (busco2synteny.py) can be found at the following github repository: https://github.com/A-J-F-Mackintosh/Mackintosh_et_al_2022_Bino. The mitochondrial genome sequence and the TE annotation can be found at the same repository.The lesser marbled fritillary, Brenthis ino (Rottemburg, 1775), is a species of Palearctic butterfly. Male Brenthis ino individuals have been reported to have between 12 and 14 pairs of chromosomes, a much-reduced chromosome number than is typical in butterflies. Here, we present a chromosome-level genome assembly for Brenthis ino, as well as gene and transposable element annotations. The assembly is 411.8 Mb in length with a contig N50 of 9.6 Mb and a scaffold N50 of 29.5 Mb. We also show evidence that the male individual from which we generated HiC data was heterozygous for a neo-Z chromosome, consistent with inheriting 14 chromosomes from one parent and 13 from the other. This genome assembly will be a valuable resource for studying chromosome evolution in Lepidoptera, as well as for comparative and population genomics more generally

Experimental Inoculation of Porcine Circovirus 3 (PCV-3) in Pregnant Gilts Causes PCV-3-Associated Lesions in Newborn Piglets that Persist until Weaning

Porcine circovirus 3 (PCV-3) has been detected in cases of reproductive failure but the pathogenesis of such infection is poorly understood. So far, experimental PCV-3 inoculations have been performed only in piglets. Therefore, through the experimental inoculation of pregnant gilts at two different time points (second and last third of gestation), this study aimed to evaluate the outcome of PCV-3 infection in dams and their offspring until weaning age. Two weeks postinoculation, all gilts became viremic and the infection lasted until the end of study. Farrowing occurred naturally, without evidence of reproductive disorders, and piglets showed no significant clinical signs from farrowing to weaning (21 day-old). However, majority of the delivered piglets were viremic, mostly until weaning age. Both newborn and weaned pigs showed different degrees of systemic, lymphohistiocytic arteritis and periarteritis. Lesions were more severe in the piglets infected during the second third of gestation and worsened at weaning. Additionally, PCV-3 detection in nervous and cardiac tissue and development of histopathological lesions in these tissues were gestational dependent, as only occurred in piglets infected at second third of pregnancy. Piglets with lesions raised to weaning age had less body weight than those without them. This study represents the first description of a PCV-3 experimental infection in pregnant gilts, which resulted in transplacental infection, histological lesions in piglets mimicking those of natural occurring disease, and lesser body weight in piglets with vascular lesions at weaning age. Obtained results allowed proposing a potential pathogenesis model for PCV-3 infection in swine.The authors would like to thank Marc Oliveras, Sílvia Puig, Albert Viñals, and Eduard Alibés for their excellent animal care technical assistance. This research was funded by Zoetis by means of an industrial doctorate from Catalan government (DI2019-083).info:eu-repo/semantics/publishedVersio