Energy Transfer and Triadic Interactions in Compressible Turbulence

Using a two-point closure theory, the Eddy-Damped-Quasi-Normal-Markovian (EDQNM) approximation, we have investigated the energy transfer process and triadic interactions of compressible turbulence. In order to analyze the compressible mode directly, the Helmholtz decomposition is used. The following issues were addressed: (1) What is the mechanism of energy exchange between the solenoidal and compressible modes, and (2) Is there an energy cascade in the compressible energy transfer process? It is concluded that the compressible energy is transferred locally from the solenoidal part to the compressible part. It is also found that there is an energy cascade of the compressible mode for high turbulent Mach number (M(sub t) greater than or equal to 0.5). Since we assume that the compressibility is weak, the magnitude of the compressible (radiative or cascade) transfer is much smaller than that of solenoidal cascade. These results are further confirmed by studying the triadic energy transfer function, the most fundamental building block of the energy transfer

New Technologies’ Promise to the Self and the Becoming of the Sacred: Insights from Georges Bataille’s Concept of Transgression

This article draws on Georges Bataille’s concept of transgression, a key element in Bataille’s theory of the sacred, to highlight structural implications of the way the self-empowerment ethos of new technologies suffuses the digital tracking culture. Pointing to the original conceptual stance of transgression, worked out against prohibition, I first argue that, beyond a critique of new technologies’ promise of self-empowerment as coming at the expense of an acknowledgement of the ultimate taboo—death—is the problem of the sanitizing of the tension between the crossing of the line of the symbolic taboo and prohibition; this undermines a “libidinal investment” towards the sacred, which is central in Bataille’s theory. Second, focussing on “eroticism”, since this embodies the emancipative potential of the Bataillean sacred, I argue that while a fear of eroticism marks out the digital technological realm, this is covered up by the blurring of boundaries between pleasure, fun and sex(iness) that currently governs our experience with technological devices

Transmission tree of the highly pathogenic avian influenza (H5N1) epidemic in Israel, 2015

The transmission tree of the Israeli 2015 epidemic of highly pathogenic avian influenza (H5N1) was modelled by combining the spatio-temporal distribution of the outbreaks and the genetic distance between virus isolates. The most likely successions of transmission events were determined and transmission parameters were estimated. It was found that the median infectious pressure exerted at 1 km was 1.59 times (95% CI 1.04, 6.01) and 3.54 times (95% CI 1.09, 131.75) higher than that exerted at 2 and 5 km, respectively, and that three farms were responsible for all seven transmission events. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13567-016-0393-2) contains supplementary material, which is available to authorized users

Mapping of bioavailable strontium isotope ratios in France for archaeological provenance studies

Strontium isotope ratios (⁸⁷Sr/⁸⁶Sr) of archaeological samples (teeth and bones) can be used to track mobility and migration across geologically distinct landscapes. However, traditional interpolation algorithms and classification approaches used to generate Sr isoscapes are often limited in predicting multiscale ⁸⁷Sr/⁸⁶Sr patterning. Here we investigate the suitability of plant samples and soil leachates from the IRHUM database (www.irhumdatabase.com) to create a bioavailable ⁸⁷Sr/⁸⁶Sr map using a novel geostatistical framework. First, we generated an ⁸⁷Sr/⁸⁶Sr map by classifying ⁸⁷Sr/⁸⁶Sr values into five geologically-representative isotope groups using cluster analysis. The isotope groups were then used as a covariate in kriging to integrate prior geological knowledge of Sr cycling with the information contained in the bioavailable dataset and enhance ⁸⁷Sr/⁸⁶Sr predictions. Our approach couples the strengths of classification and geostatistical methods to generate more accurate ⁸⁷Sr/⁸⁶Sr predictions (Root Mean Squared Error = 0.0029) with an estimate of spatial uncertainty based on lithology and sample density. This bioavailable Sr isoscape is applicable for provenance studies in France, and the method is transferable to other areas with high sampling density. While our method is a step forward in generating accurate ⁸⁷Sr/⁸⁶Sr isoscapes, the remaining uncertainty also demonstrates that fine-modelling of ⁸⁷Sr/⁸⁶Sr variability is challenging and requires more than geological maps for accurately predicting ⁸⁷Sr/⁸⁶Sr variations across the landscape. Future efforts should focus on increasing sampling density and developing predictive models to further quantify and predict the processes that lead to ⁸⁷Sr/⁸⁶Sr variability.Funding was provided by ARC DP110101415 (Grün, Spriggs, Armstrong, Maureille and Falguères) Understanding the migrations of prehistoric populations through direct dating and isotopic tracking of their mobility patterns. Part of this research was supported by the Australian French Association for Science & Technology through the ACT Science Fellowship program (2013) to M. Willme