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

Convergent evolution of hemoglobin switching in jawed and jawless vertebrates

BACKGROUND: During development, humans and other jawed vertebrates (Gnathostomata) express distinct hemoglobin genes, resulting in different hemoglobin tetramers. Embryonic and fetal hemoglobin have higher oxygen affinities than the adult hemoglobin, sustaining the oxygen demand of the developing organism. Little is known about the expression of hemoglobins during development of jawless vertebrates (Agnatha). RESULTS: We identified three hemoglobin switches in the life cycle of the sea lamprey. Three hemoglobin genes are specifically expressed in the embryo, four genes in the filter feeding larva (ammocoete), and nine genes correspond to the adult hemoglobin chains. During the development from the parasitic to the reproductive adult, the composition of hemoglobin changes again, with a massive increase of chain aHb1. A single hemoglobin chain is expressed constitutively in all stages. We further showed the differential expression of other globin genes: Myoglobin 1 is most highly expressed in the reproductive adult, myoglobin 2 expression peaks in the larva. Globin X1 is restricted to the embryo; globin X2 was only found in the reproductive adult. Cytoglobin is expressed at low levels throughout the life cycle. CONCLUSION: Because the hemoglobins of jawed and jawless vertebrates evolved independently from a common globin ancestor, hemoglobin switching must also have evolved convergently in these taxa. Notably, the ontogeny of sea lamprey hemoglobins essentially recapitulates their phylogeny, with the embryonic hemoglobins emerging first, followed by the evolution of larval and adult hemoglobins. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12862-016-0597-0) contains supplementary material, which is available to authorized users

Deutsches Zentralregister für kindliche Hörstörungen (DZH) - Qualitätssicherung pädaudiologischer Diagnostik

Hintergrund: Das Deutsche Zentralregister für kindliche Hörstörungen (DZH) erfasst in der Klinik für Audiologie und Phoniatrie der Charité Daten von Kindern mit permanenten Hörstörungen. Als Auszug aus einer Gesamtauswertung nach fast 25 Jahren soll hier die Frage beantwortet werden, inwieweit das Register Daten zur Qualitätssicherung der Diagnostik und Aussagen zur Prävalenz kindlicher Hörstörungen in Deutschland liefern kann.Material und Methoden: Es handelt sich um eine zweistufige Abfrage. Die Mitarbeit erfolgt auf freiwilliger Basis durch Kooperation vieler ärztlicher Kollegen. Zuerst wird nach der Anzahl neudiagnostizierter Kinder mit permanenten Hörstörungen mittels einer Antwortpostkarte gefragt. Danach erfolgt das Ausfüllen eines Fragebogens mit Angaben zu anamnestischen und medizinischen Daten für jedes dieser Kinder. Es werden Datenabfragen und -analysen in einer ACCESS-Datenbank vorgenommen.Ergebnisse: Anhand des Postkartenrücklaufes in Relation zur Geburtenrate wird die Prävalenz permanenter Hörstörungen im ersten Lebensjahr für die Jahre 2019, 2018 und 2017 auf 0,135%, 0,108% und 0,112% geschätzt. Über die vergangenen Jahrzehnte kann im DZH eine Verringerung des Alters bei (Verdacht auf) Diagnose einer permanenten Hörstörung festgestellt werden. Das mittlere Alter bei Verdacht auf eine Hörstörung betrug 1986 4,5 Jahre (n=141, anteilig Kinder <12 Monate: 26%), 1996 2,9 J. (n=559, anteilig <12 M. 30%), 2006 2,0 J. (n=492, anteilig <12 M. 55%), 2016 0,2 J. (n=195, anteilig <12 M. 94%). Die Sicherstellung der Diagnose war dann im Mittel im Alter von 1986 6,9 J. (n=170, anteilig Kinder <12 M. 10%), 1996= 4,0 J. (n=637, anteilig <12 M. 16%), 2006= 3,3 J. (n=543, anteilig <12 M. 37%), 2016= 0,7 J. (n=217, anteilig <12 M. 79%). Die Sicherstellung der Diagnose und Therapiestart unterschieden sich nicht signifikant.Diskussion: Das Register liefert interessante Daten zur Qualitätssicherung in der Diagnostik und Therapieeinleitung, die in einer Gesamtauswertung veröffentlicht werden. Z.B. ist eine Reduzierung des Diagnosealters über die letzten Jahrzehnte anhand des DZH zu belegen. Auch für eine frühzeitigere Verdachtsdiagnose auf eine Hörstörung ist ein Zusammenhang mit Einführung des Neugeborenenhörscreenings durch den Beschluss des gemeinsamen Bundesausschuss 2009 festzustellen.Fazit: Die Datenauswertung des DZH hat in der Pädaudiologie einen großen Stellenwert

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

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