Search

In this paper we make a survey of some of our previous works devoted to the studies of sheared flows with emphasis put on their applications to geophysics and astrophysics. Some relevant related topics are geophysical fluids, with possible involved dynamo effects in magnetized cases, fluid behavior in stellar interiors and the study of stability of astrophysical accretion disks. These works include the findings of new invariants and the generalization of previous results of the current literature in terms of dispersion relations, wave-vortex decomposition and so on, for various systems which all share the common feature of being under differential rotation (i .e with both pure rotation and shear) but with also possible additional effects like precession, medium stratification, buoyancy, gravity and magnetic fields. Our main tool relies on the use of rapid distorsion theory for analysis of perturbations and interactions with the mean flow in terms of sheared waves with time dependent wave vectors with further linear theory performed in the spectral space. This method allows in particular the description of sub-critical instabilities which can exhibit finite time transient growth phenomena and non linear transverse cascades, in otherwise time asymptotically linearly spectral stable flows. We stress also on the general comment/observation that for these systems the linear perturbations can be regenerated by suitable phase tuning feedbacks between them and their triggered non linear perturbations, which make possible the comparison at least asymptotically in time of the predictions of the linear spectral analysis 1 with the results obtained with full DNS (direct numerical simulations) performed on the same total systems. (This paper may be considered as a 'complement' to the paper subcritical instabilities in neutral fluids and plasmas , to appear in the same special issue)

Do municipal mergers affect the democratic development at the local level? Numerous countries initiated municipal reforms in order to increase efficiency, administrative quality, and cost savings. Existing research focuses on the effect on local economic efficiency or political efficacy. However, few studies show effect of mergers on local democracy clearly. With this gap in mind, we focus on the recent municipal mergers in the Austrian State of Styria. The reform presents a natural experimental setting, which allows for a controlled test of the effect of ‘size on voter turnout. We contend that, as a consequence of the merger, individual votes lose weight. We expect turnout in merged municipals to decrease compared to the elections prior to the merger. We use aggregate data from the 2010 and 2015 municipal elections in Styria and employ regression models to test our argument empirically. The results support our argument. (VLID)3768976

SummaryWe present the largest exome sequencing study of autism spectrum disorder (ASD) to date (n=35,584 total samples, 11,986 with ASD). Using an enhanced Bayesian framework to integrate de novo and case-control rare variation, we identify 102 risk genes at a false discovery rate ≤ 0.1. Of these genes, 49 show higher frequencies of disruptive de novo variants in individuals ascertained for severe neurodevelopmental delay, while 53 show higher frequencies in individuals ascertained for ASD; comparing ASD cases with mutations in these groups reveals phenotypic differences. Expressed early in brain development, most of the risk genes have roles in regulation of gene expression or neuronal communication (i.e., mutations effect neurodevelopmental and neurophysiological changes), and 13 fall within loci recurrently hit by copy number variants. In human cortex single-cell gene expression data, expression of risk genes is enriched in both excitatory and inhibitory neuronal lineages, consistent with multiple paths to an excitatory/inhibitory imbalance underlying ASD.