Turbulent Micropolar SPH Fluids with Foam

In this paper we introduce a novel micropolar material model for the simulation of turbulent inviscid fluids. The governing equations are solved by using the concept of Smoothed Particle Hydrodynamics (SPH). SPH fluid simulations suffer from numerical diffusion which leads to a lower vorticity, a loss in turbulent details and finally in less realistic results. To solve this problem we propose a micropolar fluid model. The micropolar fluid model is a generalization of the classical Navier-Stokes equations, which are typically used in computer graphics to simulate fluids. In contrast to the classical Navier-Stokes model, micropolar fluids have a microstructure and therefore consider the rotational motion of fluid particles. In addition to the linear velocity field these fluids have a field of microrotation which represents existing vortices and provides a source for new ones. Our novel micropolar model can generate realistic turbulences, is linear and angular momentum conserving, can be easily integrated in existing SPH simulation methods and its computational overhead is negligible. Another important visual feature of turbulent liquids is foam. Therefore, we present a post-processing method which considers microrotation in the foam generation. It works completely automatic and requires only one user-defined parameter to control the amount of foam

A Membrane-Bound Vertebrate Globin

The family of vertebrate globins includes hemoglobin, myoglobin, and other O2-binding proteins of yet unclear functions. Among these, globin X is restricted to fish and amphibians. Zebrafish (Danio rerio) globin X is expressed at low levels in neurons of the central nervous system and appears to be associated with the sensory system. The protein harbors a unique N-terminal extension with putative N-myristoylation and S-palmitoylation sites, suggesting membrane-association. Intracellular localization and transport of globin X was studied in 3T3 cells employing green fluorescence protein fusion constructs. Both myristoylation and palmitoylation sites are required for correct targeting and membrane localization of globin X. To the best of our knowledge, this is the first time that a vertebrate globin has been identified as component of the cell membrane. Globin X has a hexacoordinate binding scheme and displays cooperative O2 binding with a variable affinity (P50∼1.3–12.5 torr), depending on buffer conditions. A respiratory function of globin X is unlikely, but analogous to some prokaryotic membrane-globins it may either protect the lipids in cell membrane from oxidation or may act as a redox-sensing or signaling protein

Phylogeny of Echinoderm Hemoglobins

Recent genomic information has revealed that neuroglobin and cytoglobin are the two principal lineages of vertebrate hemoglobins, with the latter encompassing the familiar myoglobin and α-globin/β-globin tetramer hemoglobin, and several minor groups. In contrast, very little is known about hemoglobins in echinoderms, a phylum of exclusively marine organisms closely related to vertebrates, beyond the presence of coelomic hemoglobins in sea cucumbers and brittle stars. We identified about 50 hemoglobins in sea urchin, starfish and sea cucumber genomes and transcriptomes, and used Bayesian inference to carry out a molecular phylogenetic analysis of their relationship to vertebrate sequences, specifically, to assess the hypothesis that the neuroglobin and cytoglobin lineages are also present in echinoderms.The genome of the sea urchin Strongylocentrotus purpuratus encodes several hemoglobins, including a unique chimeric 14-domain globin, 2 androglobin isoforms and a unique single androglobin domain protein. Other strongylocentrotid genomes appear to have similar repertoires of globin genes. We carried out molecular phylogenetic analyses of 52 hemoglobins identified in sea urchin, brittle star and sea cucumber genomes and transcriptomes, using different multiple sequence alignment methods coupled with Bayesian and maximum likelihood approaches. The results demonstrate that there are two major globin lineages in echinoderms, which are related to the vertebrate neuroglobin and cytoglobin lineages. Furthermore, the brittle star and sea cucumber coelomic hemoglobins appear to have evolved independently from the cytoglobin lineage, similar to the evolution of erythroid oxygen binding globins in cyclostomes and vertebrates.The presence of echinoderm globins related to the vertebrate neuroglobin and cytoglobin lineages suggests that the split between neuroglobins and cytoglobins occurred in the deuterostome ancestor shared by echinoderms and vertebrates

Fast Corotated FEM using Operator Splitting

In this paper we present a novel operator splitting approach for corotated FEM simulations. The deformation energy of the corotated linear material model consists of two additive terms. The first term models stretching in the individual spatial directions and the second term describes resistance to volume changes. By formulating the backward Euler time integration scheme as an optimization problem, we show that the first term is invariant to rotations. This allows us to use an operator splitting approach and to solve both terms individually with different numerical methods. The stretching part is solved accurately with an optimization integrator, which can be done very efficiently because the system matrix is constant over time such that its Cholesky factorization can be precomputed. The volume term is solved approximately by using the compliant constraints method and Gauss‐Seidel iterations. Further, we introduce the analytic polar decomposition which allows us to speed up the extraction of the rotational part of the deformation gradient and to recover inverted elements. Finally, this results in an extremely fast and robust simulation method with high visual quality that outperforms standard corotated FEMs by more than two orders of magnitude and even the fast but inaccurate PBD and shape matching methods by more than one order of magnitude without having their typical drawbacks. This enables a very efficient simulation of complex scenes containing more than a million elements

20 Jahre Deutsches Zentralregister für kindliche Hörstörungen (DZH) - Ein Rückblick

Hintergrund: Das Deutsche Zentralregister für kindliche Hörstörungen (DZH) wurde 1994 von Prof. Manfred Gross konzipiert und aufgebaut. Es wird an der Klinik für Audiologie und Phoniatrie der Charité geführt und erfasst seit 1996 Kinder mit Hörstörungen aus ganz Deutschland. Inwieweit haben sich in den letzten 20 Jahren das Alter bei der Diagnosestellung und die therapeutische Versorgung von Kindern mit Hörstörungen geändert?Material und Methoden: Die Erfassung hörgestörter Kinder im DZH erfolgt retrospektiv in 2 Schritten: Fachärzte für Phoniatrie und Pädaudiologie, HNO-Ärzte und Pädiater, die bei Kindern die Diagnose einer Hörstörungen stellen, werden deutschlandweit angeschrieben. Sie melden mit einer Postkarte die Anzahl neu aufgetretener Fälle. Anschließend werden nach Einverständnis der Eltern detaillierte Meldebögen ausgefüllt.Ergebnisse: Zum Stichtag 30.04.2017 waren im DZH die Daten von 14.239 Kindern und mittlerweile Erwachsenen mit Hörstörungen registriert. Das Alter der Kinder bei Sicherung der Diagnose sank in den letzten 20 Jahren. Für die Geburtsjahrgänge 1985-1989 (Kohorte I, n=922) betrug das durchschnittliche Alter bei Diagnosestellung 6,2±4,4 Jahre (MW±SD), für die Geb.-Jgg 2010-2014 (Kohorte II, n=1123) 1,3±1,3 Jahre, und für die Geb.-Jgg 2015-2017 (Kohorte III, n=230) 0,4±0,3 Jahre. Diese Entwicklung betraf am deutlichsten geringgradige Hörstörungen (<40 dB HL): Für die Kohorte I lag der Diagnosezeitpunkt bei durchschnittlich 10,6±4,6 Jahren, für die Kohorte III im Mittel bei 1,7±1,1 Jahren. Das mittlere Intervall zwischen Vermutung und Sicherung der Diagnose unabhängig vom Hörstörungsgrad hat sich von 17,1±28,9 Monaten (Kohorte I), über 6,9±8,8 Monate (Kohorte II) auf 3,6±2,5 Monate (Kohorte III) reduziert. Das mittlere Intervall zwischen Sicherstellung der Diagnose und therapeutischer Versorgung verringerte sich von 24,3±33,1 Monaten (Kohorte I), über 8,6±10,7 Monate (Kohorte II) auf 4,7±3,0 Monate (Kohorte III), unabhängig vom Grad der Hörstörung.Fazit: Das Alter bei Diagnosestellung und das Zeitintervall bis zur therapeutischen Versorgung ist in den letzten Jahren deutlich reduziert worden. Mit der Weiterführung des DZH werden auch in Zukunft Informationen für epidemiologische und humangenetische Fragestellungen in Bezug auf kindliche Hörstörungen zur Verfügung stehen

Androglobin: a chimeric globin in metazoans that is preferentially expressed in mammalian testes

Comparative genomic studies have led to the recent identification of several novel globin types in the Metazoa. They have revealed a surprising evolutionary diversity of functions beyond the familiar O2 supply roles of hemoglobin and myoglobin. Here we report the discovery of a hitherto unrecognized family of proteins with a unique modular architecture, possessing an N-terminal calpain-like domain, an internal, circular permuted globin domain, and an IQ calmodulin-binding motif. Putative orthologs are present in the genomes of many metazoan taxa, including vertebrates. The calpain-like region is homologous to the catalytic domain II of the large subunit of human calpain-7. The globin domain satisfies the criteria of a myoglobin-like fold but is rearranged and split into two parts. The recombinantly expressed human globin domain exhibits an absorption spectrum characteristic of hexacoordination of the heme iron atom. Molecular evolutionary analyses indicate that this chimeric globin family is phylogenetically ancient and originated in the common ancestor to animals and choanoflagellates. In humans and mice, the gene is predominantly expressed in testis tissue, and we propose the name ‘‘androglobin’’ (Adgb). Expression is associated with postmeiotic stages of spermatogenesis and is insensitive to experimental hypoxia. Evidence exists for increased gene expression in fertile compared with infertile males