http://hdl.handle.net/10993/150 Search this channel search http://orbilu.uni.lu/simple-search http://hdl.handle.net/10993/41773 Title: Phase diagram of spin-1 chains with Dzyaloshinskii-Moriya interaction <br/> <br/>Author, co-author: Tschirhart, Hugo; Ong, Ernest; Sengupta, Pinaki; Schmidt, Thomas <br/> <br/>Abstract: We investigate an antiferromagnetic spin-1 Heisenberg chain in the presence of Dyzaloshinskii-Moriya interactions (DMI) and an external magnetic field. We study the resulting spin chain using a combination of numerical and analytical techniques. Using DMRG simulations to determine the spectral gap and the entanglement spectrum, we map out the phase diagram as a function of magnetic field strength and DMI strength. We provide a qualitative interpretation for these numerical findings by mapping the spin-1 chain on a spin-1/2 ladder and using a bosonization approach. Tue, 21 Jan 2020 07:44:39 GMT http://hdl.handle.net/10993/41759 Title: Functional Convergence of U-processes with Size-Dependent Kernels <br/> <br/>Author, co-author: Döbler, Christian; Kasprzak, Mikolaj; Peccati, Giovanni Mon, 20 Jan 2020 16:15:46 GMT http://hdl.handle.net/10993/41746 Title: Phase transition for the volume of high-dimensional random polytopes <br/> <br/>Author, co-author: Bonnet, Gilles; Kabluchko, Zakhar; Turchi, Nicola Mon, 20 Jan 2020 15:30:04 GMT http://hdl.handle.net/10993/41744 Title: Geometry of ℓp-Balls : Classical Results and Recent Developments <br/> <br/>Author, co-author: Prochno, Joscha; Thäle, Christoph; Turchi, Nicola Mon, 20 Jan 2020 15:23:47 GMT http://hdl.handle.net/10993/41740 Title: The isotropic constant of random polytopes with vertices on convex surfaces <br/> <br/>Author, co-author: Prochno, Joscha; Thäle, Christoph; Turchi, Nicola Mon, 20 Jan 2020 15:14:02 GMT http://hdl.handle.net/10993/41738 Title: Threshold phenomena for high-dimensional random polytopes <br/> <br/>Author, co-author: Bonnet, Gilles; Chasapis, Giorgos; Grote, Julian; Temesvari, Daniel; Turchi, Nicola Mon, 20 Jan 2020 15:00:49 GMT http://hdl.handle.net/10993/41737 Title: Limit theorems for random polytopes with vertices on convex surfaces <br/> <br/>Author, co-author: Turchi, Nicola; Wespi, Florian Mon, 20 Jan 2020 14:51:47 GMT http://hdl.handle.net/10993/41734 Title: Monotonicity of facet numbers of random convex hulls <br/> <br/>Author, co-author: Bonnet, Gilles; Grote, Julian; Temesvari, Daniel; Thäle, Christoph; Turchi, Nicola; Wespi, Florian Mon, 20 Jan 2020 14:44:05 GMT http://hdl.handle.net/10993/41728 Title: Random polytopes: central limit theorems for intrinsic volumes <br/> <br/>Author, co-author: Thäle, Christoph; Turchi, Nicola; Wespi, Florian Mon, 20 Jan 2020 14:20:43 GMT http://hdl.handle.net/10993/41722 Title: Realignment of Liquid Crystal Shells Driven by Temperature- Dependent Surfactant Solubility <br/> <br/>Author, co-author: Sharma, Anjali; Jampani, Venkata; Lagerwall, Jan <br/> <br/>Abstract: We investigate dynamic director field variations in shells of the nematic liquid crystal (LC) compound, 4-cyano-4′-pentylbiphenyl, suspended in and containing immiscible aqueous phases. The outer and inner shell interfaces are stabilized by the cationic surfactant, cetyl trimethyl ammonium bromide (CTAB), and by the water soluble polymer, poly(vinyl alcohol) (PVA), respectively. PVA and surfactant solutions normally promote tangential and orthogonal alignments, respectively, of the LC director. The rather high Krafft temperature of CTAB, TK ≈25 °C, means that its solubility in water is below the critical micelle concentration at room temperature in most labs. Here,we study the effect of cooling/heating past TK on the LC shell director configuration. Within a certain concentration range,CTAB in the outer aqueous phase (and PVA in the inner) switches the LC director field from hybrid to uniformly orthogonal upon cooling below TK. We argue that the effect is related to the migration of the surfactant through the fluid LC membraneinto the initially surfactant-free aqueous PVA solution, triggered by the drastically reduced water solubility of CTAB at T < TK.The results suggest that LC shells can detect solutes in the continuous phase, provided there is sufficient probability that thesolute migrates through the LC into the inner aqueous phase. Mon, 20 Jan 2020 13:50:46 GMT http://hdl.handle.net/10993/41719 Title: Multivariate normal approximation on the Wiener space: new bounds in the convex distance <br/> <br/>Author, co-author: Nourdin, Ivan; Peccati, Giovanni; Yang, Xiaochuan Mon, 20 Jan 2020 13:43:01 GMT http://hdl.handle.net/10993/41718 Title: Gaussian Random Measures Generated by Berry's Nodal Sets <br/> <br/>Author, co-author: Peccati, Giovanni; Vidotto, Anna Mon, 20 Jan 2020 13:34:15 GMT http://hdl.handle.net/10993/41716 Title: From deformation theory of wheeled props to classification of Kontsevich formality maps <br/> <br/>Author, co-author: Andersson, Assar; Merkulov, Sergei <br/> <br/>Abstract: We study homotopy theory of the wheeled prop controlling Poisson structures on arbitrary formal graded finite-dimensional manifolds and prove, in particular, that Grothendieck-Teichmueller group acts on that wheeled prop faithfully and homotopy non-trivially. Next we apply this homotopy theory to the study of the deformation complex of an arbitrary Maxim Kontsevich formality map and compute the full cohomology group of that deformation complex in terms of the cohomology of a certain graph complex introduced earlier by Maxim Kontsevich in [K1] and studied by Thomas Willwacher in [W1]. Mon, 20 Jan 2020 12:46:10 GMT http://hdl.handle.net/10993/41714 Title: Grothendieck-Teichmueller group, operads and graph complexes: a survey <br/> <br/>Author, co-author: Merkulov, Sergei <br/> <br/>Abstract: This paper attempts to provide a more or less self-contained introduction into theory of the Grothendieck-Teichmueller group and Drinfeld associators using the theory of operads and graph complexes. Mon, 20 Jan 2020 12:43:27 GMT http://hdl.handle.net/10993/41659 Title: Kummer extensions of number fields (the case of rank 2) II <br/> <br/>Author, co-author: Perucca, Antonella Fri, 17 Jan 2020 14:54:41 GMT http://hdl.handle.net/10993/41650 Title: Thermodynamics of Chemical Waves <br/> <br/>Author, co-author: Avanzini, Francesco; Falasco, Gianmaria; Esposito, Massimiliano Fri, 17 Jan 2020 09:10:57 GMT http://hdl.handle.net/10993/41645 Title: Proceedings of the FEniCS Conference 2017 <br/> <br/>Editor: Hale, Jack <br/> <br/>Abstract: Proceedings of the FEniCS Conference 2017 that took place 12-14 June 2017 at the University of Luxembourg, Luxembourg. Fri, 17 Jan 2020 07:25:08 GMT http://hdl.handle.net/10993/41634 Title: Excitation-intensity dependence of shallow and deep-level photoluminescence transitions in semiconductors <br/> <br/>Author, co-author: Spindler, Conrad; Galvani, Thomas; Wirtz, Ludger; Rey, Germain; Siebentritt, Susanne Thu, 16 Jan 2020 04:30:02 GMT http://hdl.handle.net/10993/41625 Title: The Evolution of Erythrocytes Becoming Red in Respect to Fluorescence <br/> <br/>Author, co-author: Hertz, Laura; Ruppenthal, Sandra; Simionato, Greta; Stephan, Quint; Kihm, Alexander; Abay, Asena; Petkoya-Kirova, Polina; Boehm, Ulrich; Weissgerber, Petra; Wagner, Christian; Laschke, Matthias W.; Kaestner, Lars <br/> <br/>Abstract: Very young red blood cells, namely reticulocytes, can be quite easily recognized and labeled by cluster of differentiation antibodies (CD71 transferrin receptor) or by staining remnant RNA with thiazol orange. In contrast, age specific erythrocyte labeling is more difficult in later periods of their life time. While erythrocytes contain band 4.1 protein a molecular clock, so far it has not been possible to read this clock on individual cells. One concept to track erythrocytes during their life time is to mark them when they are young, either directly in vivo or ex vivo followed by a transfusion. Several methods like biotinylation, use of isotopes or fluorescent labeling have proved to be useful experimental approaches but also have several inherent disadvantages. Genetic engineering of mice provides additional options to express fluorescent proteins in erythrocytes. To allow co-staining with popular green fluorescent dyes like Fluo-4 or other fluorescein-based dyes, we bred a mouse line expressing a tandem red fluorescent protein (tdRFP). Within this Brief Research Report, we provide the initial characterisation of this mouse line and show application examples ranging from transfusion experiments and intravital microscopy to multicolour flow cytometry and confocal imaging. We provide a versatile new tool for erythrocyte research and discuss a range of experimental opportunities to study membrane processes and other aspects of erythrocyte development and aging with help of these animals. <br/> <br/>Commentary: Article Wed, 15 Jan 2020 14:19:10 GMT http://hdl.handle.net/10993/41624 Title: Glutaraldehyde - A Subtle Tool in the Investigation of Healthy and Pathologic Red Blood Cells <br/> <br/>Author, co-author: Abay, Asena; Simionato, Greta; Chachanidze, Revaz; Anna, Bogdanova; Hertz, Laura; Bianchi, Paola; van den Akker, Emile; von Lindern, Marieke; Leonetti, Marc; Minetti, Giampaolo; Wagner, Christian; Kaestner, Lars <br/> <br/>Abstract: Glutaraldehyde is a well-known substance used in biomedical research to fix cells. Since hemolytic anemias are often associated with red blood cell shape changes deviating from the biconcave disk shape, conservation of these shapes for imaging in general and 3D-imaging in particular like confocal microscopy, scanning electron microscopy or scanning probe microscopy is a common desire. Along with the fixation comes an increase in the stiffness of the cells. In the context of red blood cells this increased rigidity is often used to mimic malaria infected red blood cells because they are also stiffer than healthy red blood cells. However, the use of glutaraldehyde is associated with numerous pitfalls: (i) while the increase in rigidity by an application of increasing concentrations of glutaraldehyde is an analog process, the fixation is a rather digital event (all or none); (ii) addition of glutaraldehyde massively changes osmolality in a concentration dependent manner and hence cell shapes can be distorted; (iii) glutaraldehyde batches differ in their properties especially in the ratio of monomers and polymers (iv) handling pitfalls, like inducing shear artifacts of red blood cell shapes or cell density changes that needs to be considered, e.g., when working with cells in flow; (v) staining glutaraldehyde treated red blood cells need different approaches compared to living cells, for instance, because glutaraldehyde itself induces a strong fluorescence. Within this paper we provide documentation about the subtle use of glutaraldehyde on healthy and pathologic red blood cells and how to deal with or circumvent pitfalls. <br/> <br/>Commentary: Article Wed, 15 Jan 2020 14:17:15 GMT