Bianchi's classification of 3-dimensional Lie algebras revisited

We present Bianchi's proof on the classification of real (and complex) $3$-dimensional Lie algebras in a coordinate free version from a strictly representation theoretic point of view. Nearby we also compute the automorphism groups and from this the orbit dimensions of the corresponding orbits in the algebraic variety $X\subseteq\Lambda^2V^*\otimes V$ describing all Lie brackets on a fixed vector space $V$ of dimension $3$. Moreover we clarify which orbits lie in the closure of a given orbit and therefore the topology on the orbit space $X/G$ with $G=\mathrm{Aut}(V)$

Das neue Pflichtpraktikum an Handelsakademien – Was berichten Schüler/innen über Umsetzung und Kompetenzerwerb?

Pflichtpraktika sind in den Curricula österreichischer berufsbildender Schulen bereits seit Langem verankert. Eine Ausnahme stellten bisher die kaufmännischen Schulen dar. Mit dem Lehrplan 2014 wurde nun aber auch in diesem Schultyp eine verpflichtende Praxisphase eingeführt, um die Employability der Absolvent/inn/en zu stärken. Mit dieser Innovation sind umfangreiche Erwartungen verbunden. Es stellt sich die Frage, inwieweit diese tatsächlich eingelöst werden können. Erstaunlicherweise sind die Lernprozesse, die sich im Rahmen derartiger Praxisphasen bzw. durch die Verbindung von schulischem und betrieblichem Lernen vollziehen, bisher nur wenig wissenschaftlich erforscht. Ziel dieses Beitrags ist es vor diesem Hintergrund, im Rahmen einer Interviewstudie zu untersuchen, wie Handelsakademie-Schüler/innen die derzeitige Umsetzung des Pflichtpraktikums in Bezug auf Vorbereitungs-, Durchführungs- und Nachbereitungsphase erleben und welche konkreten Beiträge zum eigenen Kompetenzerwerb sie den einzelnen Phasen zuschreiben. Auf Basis der Erkenntnisse werden Handlungsempfehlungen für die gezielte Weiterentwicklung der Konzeption und Implementation des Pflichtpraktikums abgeleitet

Methoden zur sechsdimensionalen Objektlageerkennung aus Tiefenbildern

Im Rahmen der vorliegenden Arbeit wurde ein neues Software-System zur Objektlageerkennung aus Tiefenbildern unter teilweiser Hinzunahme bekannter Einzelalgorithmen komplett implementiert. Es umfasst die Bildaufnahme und Tiefenbildrekonstruktion aus den Daten einer Stereokamera mit Musterprojektion, die Segmentierung der Objektpunkte vom Hintergrund sowie die Grob- und Feinlageerkennung. Ein zusätzlich integriertes Modelltraining erlaubt es, alle für die Lageerkennung eines Bauteiletyps notwendigen Grunddaten automatisch und innerhalb kurzer Zeit zu erfassen. Die Evaluation des implementierten Gesamtsystem anhand eines für die Produktion bei der Robert Bosch GmbH repräsentativen Bauteilespektrums zeigte, dass mehr als 40% der Bauteiletypen mit der erforderlichen Genauigkeit erkannt und damit im üblichen Anwendungsfall von einem Montageroboter zuverlässig gegriffen werden können. Die Taktzeitvorgabe von durchschnittlich 0,5 Sekunden pro Objektlage-Erkennungsvorgang wird ohne Hardwarebeschleunigung eingehalten. Mit dem Ziel, das Spektrum der erkennbaren Bauteiletypen zu erweitern, wurden die verbliebenen Hauptursachen für Fehl-Erkennungen herausgearbeitet. An erster Stelle steht demnach eine unzureichende Tiefenbildrekonstruktion, die insbesondere im Falle von Glanzpunkten auf der Oberfläche der beleuchteten Objekte auftreten kann. Im abschließenden Kapitel wird dargestellt, dass Lichtfelder ein zielführendes Konzept zur Tiefenbildrekonstruktion bieten, das gegenüber Glanzflecken robust ist und darüber hinaus durch Übertragung der in der Stereotiefenbildrekonstruktion angewandten Methode der Musterprojektion wesentlich verbessert und weiter ausgebaut werden kann

Mn-based Heusler compounds and CoFeB thin films with perpendicular anisotropy

Glas M. Mn-based Heusler compounds and CoFeB thin films with perpendicular anisotropy. Bielefeld: Universität Bielefeld; 2016

Titanium Nitride as a Seed Layer for Heusler Compounds

Titanium nitride (TiN) shows low resistivity at room temperature, high thermal stability and thus has the potential to serve as seed layer in magnetic tunnel junctions. High quality TiN thin films with regard to the crystallographic and electrical properties were grown and characterized by X-ray diffraction and 4-terminal transport measurements. Element specific X-ray absorption spectroscopy revealed pure TiN in the bulk. To investigate the influence of a TiN seed layer on a ferro(i)magnetic bottom electrode, an out-of-plane magnetized Mn2.45Ga as well as in- and out-of-plane magnetized Co2FeAl thin films were deposited on a TiN buffer, respectively. The magnetic properties were investigated using a superconducting quantum interference device (SQUID) and anomalous Hall effect (AHE) for Mn2.45Ga. Magneto optical Kerr effect (MOKE) measurements were carried out to investigate the magnetic properties of Co2FeAl. TiN buffered Mn2.45Ga thin films showed higher coercivity and squareness ratio compared to unbuffered samples. The Heusler compound Co2FeAl showed already good crystallinity when grown at room temperature

Insights into the electronic structure of Co2FeSi from x-ray magnetic linear dichroism

Experimental evidence both for and against a half-metallic ground-state of the Heusler compound Co2FeSi has been published. Density functional theory based calculations suggest a non half-metallic ground state. It has been argued, that on-site Coulomb interaction of the d electrons has to be taken into account via the LDA+U method, which predicts a half-metallic ground-state for U = 2.5...4.5 eV. X-ray magnetic linear dichroism (XMLD) can be used as a tool to assess the appropriateness of the LDA+U approach: the calculated spectra within the LDA+U or GGA+U schemes are different from those within the LDA or GGA. Due to its ability to separate different orbital symmetries, XMLD allows us to distinguish between different models of the electronic structure of Co2FeSi. In this article we discuss experimental XMLD spectra and compare them with detailed first principles calculations. Our findings give evidence for the inadequacy of the LDA+U or GGA+U band structures, whereas constrained calculations with the GGA and a fixed spin moment of 6 \mu_B give better overall agreement between experiment and theory.Comment: 9 pages, 6 figures, 3 table

Th17-Related Genes and Celiac Disease Susceptibility

Th17 cells are known to be involved in several autoimmune or inflammatory diseases. In celiac disease (CD), recent studies suggest an implication of those cells in disease pathogenesis. We aimed at studying the role of genes relevant for the Th17 immune response in CD susceptibility. A total of 101 single nucleotide polymorphisms (SNPs), mainly selected to cover most of the variability present in 16 Th17-related genes (IL23R, RORC, IL6R, IL17A, IL17F, CCR6, IL6, JAK2, TNFSF15, IL23A, IL22, STAT3, TBX21, SOCS3, IL12RB1 and IL17RA), were genotyped in 735 CD patients and 549 ethnically matched healthy controls. Case-control comparisons for each SNP and for the haplotypes resulting from the SNPs studied in each gene were performed using chi-square tests. Gene-gene interactions were also evaluated following different methodological approaches. No significant results emerged after performing the appropriate statistical corrections. Our results seem to discard a relevant role of Th17 cells on CD risk

A protein-truncating R179X variant in RNF186 confers protection against ulcerative colitis

Protein-truncating variants protective against human disease provide in vivo validation of therapeutic targets. Here we used targeted sequencing to conduct a search for protein-truncating variants conferring protection against inflammatory bowel disease exploiting knowledge of common variants associated with the same disease. Through replication genotyping and imputation we found that a predicted protein-truncating variant (rs36095412, p.R179X, genotyped in 11,148 ulcerative colitis patients and 295,446 controls, MAF = up to 0.78%) in RNF186, a single-exon ring finger E3 ligase with strong colonic expression, protects against ulcerative colitis (overall P = 6.89 x 10(-7), odds ratio = 0.30). We further demonstrate that the truncated protein exhibits reduced expression and altered subcellular localization, suggesting the protective mechanism may reside in the loss of an interaction or function via mislocalization and/or loss of an essential transmembrane domain.Peer reviewe

Structural and Magnetic Properties of Sputter-Deposited Mn-Fe-Ga Thin Films

Niesen A, Sterwerf C, Glas M, Schmalhorst J-M, Reiss G. Structural and Magnetic Properties of Sputter-Deposited Mn-Fe-Ga Thin Films. IEEE Transactions on Magnetics. 2016;52(7): 2600404.We investigated the structural and magnetic properties of sputter-deposited Mn-Fe-Ga compounds. The crystallinity of the Mn-Fe-Ga thin films was confirmed using X-ray diffraction. X-ray reflection and atomic force microscopy measurements were utilized to investigate the surface properties, roughness, thickness, and density of the deposited Mn-Fe-Ga. Depending on the stoichiometry, as well as the used substrates [SrTiO3 (001) and MgO (001)] or buffer layer (TiN), Mn-Fe-Ga crystallized in the cubic or the tetragonally distorted phase. Anomalous Hall effect and alternating gradient magnetometry measurements confirmed strong perpendicular magnetocrystalline anisotropy. Hard magnetic behavior was reached by tuning the composition. TiN-buffered Mn2.7Fe0.3Ga revealed sharper switching of the magnetization compared with the unbuffered layers

Effects of M101-an extracellular hemoglobin-applied during cardiopulmonary resuscitation: An experimental rodent study.

During and immediately after cardiac arrest, cerebral oxygen delivery is impaired mainly by microthrombi and cerebral vasoconstriction. This may narrow capillaries so much that it might impede the flow of red blood cells and thus oxygen transport. The aim of this proof-of-concept study was to evaluate the effect of M101, an extracellular hemoglobin-based oxygen carrier (Hemarina SA, Morlaix, France) derived from Arenicola marina, applied during cardiac arrest in a rodent model, on markers of brain inflammation, brain damage and regional cerebral oxygen saturation.27 Wistar rats subjected to 6 min of asystolic cardiac arrest were infused M101 (300 mg/kg) or placebo (NaCl 0.9%) concomitantly with start of cardiopulmonary resuscitation. Brain oxygenation and five biomarkers of inflammation and brain damage (from blood, cerebrospinal fluid, and homogenates from four brain regions) were measured 8 hours after return of spontaneous circulation. In these 21 different measurements, M101-treated animals were not significantly different from controls except for phospho-tau (p-tau) only in single cerebellum regions (p = 0.048; ANOVA of all brain regions: p = 0.004). Arterial blood pressure increased significantly only at 4-8 min after return of spontaneous circulation (p < 0.001) and acidosis decreased (p = 0.009).While M101 applied during cardiac arrest did not significantly change inflammation or brain oxygenation, the data suggest cerebral damage reduction due to hypoxic brain injury, measured by p-tau. Global burden of ischemia appeared reduced since acidosis was less severe. Whether post-cardiac arrest infusion of M101 improves brain oxygenation is unknown and needs to be investigated