Abbildendes Raman Deuterium Stable Isotope Probing von Fluidgemischen in Tropfen und Mikrokanälen

Die Verdunstung von komplexen Gemischen ist im täglichen Leben allgegenwärtig. Beim Malen, Tintenstrahldrucken und Kleben verdunsten Lösemittel, während andere relevante Bestandteile der Farbe, Tinte oder des Klebstoffs auf der Oberfläche haften bleiben. Auch wenn Flüssigkeiten auf Oberflächen (ungewollt) eintrocknen und Rückstände zurückbleiben, spielt die Verdunstung bei diesen Trocknungsprozessen eine große Rolle. Die einzelnen Komponenten verdampfen unterschiedlich schnell, wodurch sich Konzentrationsgradienten in den Gemischen bilden, die mithilfe der Ramanspektroskopie charakterisiert werden können.Werden chemisch ähnliche Substanzen untersucht, muss eine Komponente davon chemisch markiert werden, damit die Substanzen mit der Ramanspektroskopie unterschieden werden können. Diese Methode wird zum Beispiel auch beim Raman Deuterium Stable Isotope Probing praktiziert. Eine Art der Markierung kann die Substitution von Wasserstoffatomen durch Deuteriumatome sein. Mit dieser Arbeit konnte die Raman Deuterium Stable Isotope Probing Methode zur Untersuchung chemisch ähnlicher Substanzen an zwei Beispielsystemen und -versuchsaufbauten etabliert werden. Um Mischungsverhältnisse und Mischungsverhalten von Fluiden auch in derMikrofluidik untersuchen zu können, wurden Experimente mit Ramanspektroskopie in Mikrokanälen durchgeführt. Für die Ramanspektroskopie benötigen die verwendeten Mikrosysteme eine hohe Transparenz, weshalb eine Methode für den 3D Druck transparenter Mikrosysteme entwickelt wurde. Das Drucken transparenter Bauteile (für verschiedene Anwendungen) ist mit stereolithographischem 3D Druck möglich. Ein kommerziell erhältlicher 3D Drucker wurde modifiziert, um die Transparenz der gedruckten Bauteile zu erhöhen. Mithilfe dieser Konfiguration wurde die Transparenz der Bauteile so weit erhöht, dass sie für die Ramanspektroskopie verwendet werden können. Durch die Kombination beider Methoden – Raman Deuterium stable isotope probing und transparenter 3D Druck – wurde eine Möglichkeit geschaffen, das Mischungsverhalten chemisch ähnlicher Substanzen in 3D gedruckten Mikrokanälen zu charakterisieren

Berry phase in entangled systems: a proposed experiment with single neutrons

The influence of the geometric phase, in particular the Berry phase, on an entangled spin-1/2 system is studied. We discuss in detail the case, where the geometric phase is generated only by one part of the Hilbert space. We are able to cancel the effects of the dynamical phase by using the ``spin-echo'' method. We analyze how the Berry phase affects the Bell angles and the maximal violation of a Bell inequality. Furthermore we suggest an experimental realization of our setup within neutron interferometry.Comment: 10 pages, 6 figures, Introduction extended, References adde

Engineering of triply entangled states in a single-neutron system

We implemented a triply entangled Greenberger-Horne-Zeilinger(GHZ)-like state and coherently manipulated the spin, path, and energy degrees of freedom in a single neutron system. The GHZ-like state was analyzed with an inequality derived by Mermin: we determined the four expectation values and finally obtained M = 2.558 +/- 0.004 > 2, which exhibits a clear violation of the noncontextual assumption and confirms quantum contextuality.Comment: 4 pages, 2figure

GFAP antibodies show protective effect on oxidatively stressed neuroretinal cells via interaction with ERP57

The pathogenesis of glaucoma, a common neurodegenerative disease, involves an immunologic component. Changes in the natural autoantibody profile of glaucoma patients were detected, showing not only up-regulated but also down-regulated immunoreactivities. In recent studies we were able to demonstrate that the antibody changes have a large influence on protein profiles of neuroretinal cells. Furthermore we could demonstrate neuroprotective potential of one of the down-regulated antibodies (gamma-synuclein antibody). Anti-GFAP antibody is another antibody found down-regulated in glaucoma patients. Since GFAP expression is intensified in glaucomatous retina, the aim of this study was to detect the effect of GFAP antibodies on neuroretinal cells. This is realized with a viability-test as well as proteomic analysis of cells incubated with GFAP antibodies. Furthermore, possible interaction partners of the GFAP antibody in neuroretinal cells were identified by western blot, mass spectrometry and indirect immunofluorescence staining. We found that the GFAP antibody is able to protect cells from oxidative stress, which is due to changed protein expressions of the actin cytoskeleton. Furthermore we detected a cross-reaction of the antibody to endoplasmic reticulum resident protein 57 on the cell membrane, which seems to lead to a changed signaling in the cells triggering the protective effects

Energy entanglement in neutron interferometry

Entanglement between degrees of freedom, namely between the spin, path and (total) energy degrees of freedom, for single neutrons is exploited. We implemented a triply entangled Greenberger-Horne-Zeilinger(GHZ)-like state and coherently manipulated relative phases of two-level quantum subsystems. An inequality derived by Mermin was applied to analyze the generated GHZ-like state: we determined the four expectation values and finally obtained M=2.558 +/- 0.004 which is clearly above the threshold of 2. This demonstrates the violation of a Mermin-like inequality for triply entangled GHZ-like state in a single-particle system, which, in turn, exhibits a clear inconsistency between noncontextual assumptions and quantum mechanics and confirms quantum contextuality.Comment: 4 pages, 3 figure

Kochen-Specker theorem studied with neutron interferometer

The Kochen-Specker theorem theoretically shows evidence of the incompatibility of noncontextual hidden variable theories with quantum mechanics. Quantum contextuality is a more general concept than quantum non-locality which is quite well tested in experiments by using Bell inequalities. Within neutron interferometry we performed an experimental test of the Kochen-Specker theorem with an inequality, which identifies quantum contextuality, by using spin-path entanglement in a single neutron system. Here entanglement is achieved not between different particles, but between degrees of freedom, i.e., between spin and path degree of freedom. Appropriate combinations of the spin analysis and the position of the phase shifter allow an experimental verification of the violation of an inequality of the Kochen-Specker theorem. The observed value of (2.291 +/- 0.008), which is above the threshold of 1, clearly shows that quantum mechanical predictions cannot be reproduced by noncontextual hidden variable theories.Comment: 5 pages, 3 figure

Curricular Quality and Day-To-Day Learning Activities in Pre-School

The purpose of this paper is to show how curricular quality is related to the day-to-day activities experienced by children and the pedagogical activities of staff, both coded through systematic target child observations. Data were drawn from the Effective Provision of Pre-School Education (EPPE) and the Researching Effective Pedagogy in the Early Years Project (REPEY) studies. Curricular quality was measured by coding the ECERS-E, an English curricular extension to the well known ECERS-R. In centres scoring high on the ECERS-E, staff engaged in pedagogical practices that included more ‘sustained shared thinking’ and more ‘direct teaching’ such as questioning or modeling. In high scoring centres, children were also observed participating in more activities associated with early reading, emergent writing and active listening. Children in centres assessed as ‘adequate’ spent more time in activities associated with the ‘Physical Development’ and ‘Creative’ curriculum. Thus the ECERS-E gives higher scores to pedagogical practices and activities where staff take a more active role in children’s learning, including scaffolding young children’s play, especially in the communication and literacy domains of the curriculum

Corneal topometric, aberrometric and biomechanical parameters in mucopolysaccharidosis patients

AIMS: To report corneal topometric and aberrometric values in mucopolysaccharidosis (MPS) and to investigate their correlation with biomechanical corneal parameters. METHODS: One randomly chosen eye of 20 MPS patients with no to moderate corneal clouding and one eye of 23 healthy controls with comparable age were prospectively included into this study. Corneal surface regularity was assessed by index of surface variance (ISV), -vertical asymmetry (IVA), -height asymmetry (IHA), -height decentration (IHD); keratoconus index (KI), central keratoconus index (CKI) and Zernike indices of anterior and posterior corneal surface using Scheimpflug imaging (Pentacam). Corneal resistance factor (CRF) and corneal hysteresis (CH) were assessed by Ocular Response Analyzer. Statistical analyses were performed using Mann-Whitney-Test and Spearman Correlation Coefficients. RESULTS: IVA, ISV, IHD, IHA, but not KI and CKI were significantly higher in MPS patients compared to age matched healthy controls. Spherical aberration and asphericity coefficients either at the anterior or at the posterior corneal surface differed significantly between both groups. The grade of the MPS-associated corneal opacity correlated significantly with ISV (rho = 0.52), IVA (rho = 0.54), IHA (rho = 0.57) and IHD (rho = 0.48). Density of the MPS-affected corneas correlated significantly with ISV (rho = 0.52), IVA (rho = 0.72), IHA (rho = 0.57), IHD (rho = 0.69), 3rd order horizontal trefoil aberration at the posterior (rho = 0.62) and anterior surface (rho = 0.48) as well as with CH (rho = 0.55) and CRF (rho = 0.57). Spherical aberration at the back surface correlated with CRF and CH in MPS and in healthy controls. CONCLUSIONS: This is the first study analyzing shape of the corneal surface in MPS patients. Topometric indices of corneal asymmetry are significantly increased and correlate with MPS-related corneal opacity and density. Spherical aberration and asphericity coefficient at the front and at the back corneal surface differ significantly between MPS and healthy controls

Finding critical action learning through paradox:the role of action learning in the suppression and stimulation of critical reflection

In this article, we highlight paradoxical tensions generated by in-company action learning. We consider the implications of these tensions for critical action learning, which has critical reflection as a core element of its theory and practice. Using paradox theory as a lens, we analyze data from two in-company action learning programs and build a model relating to critical action learning that has four interlinked features. The model can help evaluate in-company action learning with a view to identifying emotional and political dynamics that are open (or closed) to critical reflection. Such identification assists in making judgements about the appropriateness of critical action learning within a specific organizational context. Our broader contribution is to frame action learning and critical action learning not only as separate approaches but also as potentially interlinked stages in an ongoing process of individual and organizational learning. </jats:p