TY - JOUR AB - Recent studies suggest that unstable, nonchaotic solutions of the Navier-Stokes equation may provide deep insights into fluid turbulence. In this article, we present a combined experimental and numerical study exploring the dynamical role of unstable equilibrium solutions and their invariant manifolds in a weakly turbulent, electromagnetically driven, shallow fluid layer. Identifying instants when turbulent evolution slows down, we compute 31 unstable equilibria of a realistic two-dimensional model of the flow. We establish the dynamical relevance of these unstable equilibria by showing that they are closely visited by the turbulent flow. We also establish the dynamical relevance of unstable manifolds by verifying that they are shadowed by turbulent trajectories departing from the neighborhoods of unstable equilibria over large distances in state space. AU - Suri, Balachandra AU - Tithof, Jeffrey AU - Grigoriev, Roman AU - Schatz, Michael ID - 136 IS - 2 JF - Physical Review E TI - Unstable equilibria and invariant manifolds in quasi-two-dimensional Kolmogorov-like flow VL - 98 ER - TY - JOUR AB - Background: Transport protein particle (TRAPP) is a multisubunit complex that regulates membrane trafficking through the Golgi apparatus. The clinical phenotype associated with mutations in various TRAPP subunits has allowed elucidation of their functions in specific tissues. The role of some subunits in human disease, however, has not been fully established, and their functions remain uncertain. Objective: We aimed to expand the range of neurodevelopmental disorders associated with mutations in TRAPP subunits by exome sequencing of consanguineous families. Methods: Linkage and homozygosity mapping and candidate gene analysis were used to identify homozygous mutations in families. Patient fibroblasts were used to study splicing defect and zebrafish to model the disease. Results: We identified six individuals from three unrelated families with a founder homozygous splice mutation in TRAPPC6B, encoding a core subunit of the complex TRAPP I. Patients manifested a neurodevelopmental disorder characterised by microcephaly, epilepsy and autistic features, and showed splicing defect. Zebrafish trappc6b morphants replicated the human phenotype, displaying decreased head size and neuronal hyperexcitability, leading to a lower seizure threshold. Conclusion: This study provides clinical and functional evidence of the role of TRAPPC6B in brain development and function. AU - Marin Valencia, Isaac AU - Novarino, Gaia AU - Johansen, Anide AU - Rosti, Başak AU - Issa, Mahmoud AU - Musaev, Damir AU - Bhat, Gifty AU - Scott, Eric AU - Silhavy, Jennifer AU - Stanley, Valentina AU - Rosti, Rasim AU - Gleeson, Jeremy AU - Imam, Farhad AU - Zaki, Maha AU - Gleeson, Joseph ID - 691 IS - 1 JF - Journal of Medical Genetics SN - 0022-2593 TI - A homozygous founder mutation in TRAPPC6B associates with a neurodevelopmental disorder characterised by microcephaly epilepsy and autistic features VL - 55 ER - TY - JOUR AB - Borel probability measures living on metric spaces are fundamental mathematical objects. There are several meaningful distance functions that make the collection of the probability measures living on a certain space a metric space. We are interested in the description of the structure of the isometries of such metric spaces. We overview some of the recent results of the topic and we also provide some new ones concerning the Wasserstein distance. More specifically, we consider the space of all Borel probability measures on the unit sphere of a Euclidean space endowed with the Wasserstein metric W_p for arbitrary p >= 1, and we show that the action of a Wasserstein isometry on the set of Dirac measures is induced by an isometry of the underlying unit sphere. AU - Virosztek, Daniel ID - 284 IS - 1-2 JF - Acta Scientiarum Mathematicarum SN - 0001-6969 TI - Maps on probability measures preserving certain distances - a survey and some new results VL - 84 ER - TY - JOUR AB - In this paper we define and study the classical Uniform Electron Gas (UEG), a system of infinitely many electrons whose density is constant everywhere in space. The UEG is defined differently from Jellium, which has a positive constant background but no constraint on the density. We prove that the UEG arises in Density Functional Theory in the limit of a slowly varying density, minimizing the indirect Coulomb energy. We also construct the quantum UEG and compare it to the classical UEG at low density. AU - Lewi, Mathieu AU - Lieb, Élliott AU - Seiringer, Robert ID - 180 JF - Journal de l'Ecole Polytechnique - Mathematiques SN - 2429-7100 TI - Statistical mechanics of the uniform electron gas VL - 5 ER - TY - JOUR AB - For ultrafast fixation of biological samples to avoid artifacts, high-pressure freezing (HPF) followed by freeze substitution (FS) is preferred over chemical fixation at room temperature. After HPF, samples are maintained at low temperature during dehydration and fixation, while avoiding damaging recrystallization. This is a notoriously slow process. McDonald and Webb demonstrated, in 2011, that sample agitation during FS dramatically reduces the necessary time. Then, in 2015, we (H.G. and S.R.) introduced an agitation module into the cryochamber of an automated FS unit and demonstrated that the preparation of algae could be shortened from days to a couple of hours. We argued that variability in the processing, reproducibility, and safety issues are better addressed using automated FS units. For dissemination, we started low-cost manufacturing of agitation modules for two of the most widely used FS units, the Automatic Freeze Substitution Systems, AFS(1) and AFS2, from Leica Microsystems, using three dimensional (3D)-printing of the major components. To test them, several labs independently used the modules on a wide variety of specimens that had previously been processed by manual agitation, or without agitation. We demonstrate that automated processing with sample agitation saves time, increases flexibility with respect to sample requirements and protocols, and produces data of at least as good quality as other approaches. AU - Reipert, Siegfried AU - Goldammer, Helmuth AU - Richardson, Christine AU - Goldberg, Martin AU - Hawkins, Timothy AU - Hollergschwandtner, Elena AU - Kaufmann, Walter AU - Antreich, Sebastian AU - Stierhof, York ID - 163 IS - 12 JF - Journal of Histochemistry and Cytochemistry SN - 0022-1554 TI - Agitation modules: Flexible means to accelerate automated freeze substitution VL - 66 ER -