48 research outputs found

    Darboux-Egoroff Metrics, Rational Landau-Ginzburg Potentials and the Painleve VI Equation

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    We present a class of three-dimensional integrable structures associated with the Darboux-Egoroff metric and classical Euler equations of free rotations of a rigid body. They are obtained as canonical structures of rational Landau-Ginzburg potentials and provide solutions to the Painleve VI equation.Comment: 20 page

    Non-Abelian Geometric Phases and Conductance of Spin-3/2 Holes

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    Angular momentum J=3/2J=3/2 holes in semiconductor heterostructures are showed to accumulate nonabelian geometric phases as a consequence of their motion. We provide a general framework for analyzing such a system and compute conductance oscillations for a simple ring geometry. We also analyze a figure-8 geometry which captures intrinsically nonabelian interference effects.Comment: 4 pages, 3 figures (encapsulated PostScript) Replaced fig. 1 and fig.

    Berry effect in acoustical polarization transport in phononic crystals

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    We derive the semiclassical equations of motion of a transverse acoustical wave packet propagating in a phononic crystal subject to slowly varying perturbations. The formalism gives rise to Berry effect terms in the equations of motion, manifested as the Rytov polarization rotation law and the polarization-dependent Hall effect. We show that the formalism is also applicable to the case of non-periodic inhomogeneous media, yielding explicit expressions for the Berry effect terms.Comment: To appear in JETP Let

    Berry and Pancharatnam Topological Phases of Atomic and Optical Systems

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    Theoretical and experimental studies of Berry and Pancharatnam phases are reviewed. Basic elements of differential geometry are presented for understanding the topological nature of these phases. The basic theory analyzed by Berry in relation to magnetic monopoles is presented. The theory is generalized to nonadiabatic processes and to noncyclic Pancharatnam phases. Different systems are discussed including polarization optics, n-level atomic systems, neutron interferometry and molecular topological phases.Comment: Review article,72 pages, 186 reference

    Analysis of genome-wide genetic variants on liver specific gene expression and chromatin state

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    The past decade of genome-wide association studies (GWAS) has produced a wealth of data pertaining to complex diseases, but understanding the causality of identified variants has remained a challenge. One major problem is that the vast majority of candidate variants lie in noncoding regions while downstream analyses have primarily focused on protein coding genes, whose functional consequences upon mutation are often more predictable. Noncoding variants often operate by altering transcription factor binding sites. This can lead to downstream changes in chromatin state and gene expression. To assess global effects on expression, and chromatin state resulting from noncoding variation, we have generated RNA-seq and ChIP-seq data from genotyped, human transplant liver samples. In order to identify genetic variants associated with gene expression variation (eQTLs) on a genomic scale, we have built an analytical framework utilizing RASQUAL¹, which allows considerations of phased haplotypes. The RASQUAL method leverages differences in read depth and allelic composition for exceptional statistical power even with low sample sizes. Studying intermediate phenotypes proximal to well-understood biochemical mechanisms such as histone modification and mRNA expression allows for meaningful inferences into the effects of noncoding variants that can be tested experimentally via reporter assays. Here, we have succeeded in mapping numerous significant eQTLs and caQTLs in liver. Continuations of this work will include functional validation of these QTLs and colocalization with relevant GWAS variants

    Akteursnetze nachhaltigen Wirtschaftens in laendlichen Gebieten Ostdeutschlands

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    SIGLEAvailable from TIB Hannover: F03B1168 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDeutsche Forschungsgemeinschaft, Bonn (Germany)DEGerman

    Der LHRH-Rezeptor als therapeutische Zielstruktur bei triple negativen Mammakarzinomen

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    Zielsetzung: Tripel negative Mammakarzinome (TNBC) repräsentieren einen speziellen Mammakarzinomsubtyp, der weder Östrogenrezeptoren, Progesteronrezeptoren noch Her2neu Rezeptoren exprimiert. TNBC sind mit einer schlechten Prognose assoziiert. Die Therapieoptionen sind limitiert. Wir konnten bereits eine effektive Tumorwachstumsinhibition in triple negativen Mammakarzinommodellen mit LHRH-Rezeptor-Expression in vivo mit einem zielgerichteten zytotoxischen Hybrid zeigen. In dieser Studie überprüfen wir die Expression des LHRH-Rezeptors an einem humanen triple negativen Mammakarzinomkollektiv um eine klinische Relevanz zu diskutieren. Material und Methoden: Die Rezeptorexpression wurde mittels Immunhistochemie an 69 Tumorproben ermittelt und auf Korrelation bzw. Unterschiede in Tumorgröße, Nodalstatus, Grading und histologischer Typ überprüft. Weiterhin wurde ein kleines Kollektiv mit BRCA 1/2 Mutation (n = 9) auf die Expression des LHRH-R überprüft. Ergebnisse: Von den 69 untersuchten TNBC-Gewebeproben zeigten 34 (49%) Proben eine Expression des LHRH-R. Wir konnten keine Unterschiede in Tumorgröße, Nodalstatus oder histologschem Typ darstellen. Von den 9 untersuchten Gewebeproben mit BRCA 1/2 Mutation zeigten alle eine Expression des LHRH-R. Zusammenfassung: Der LHRH-Rezeptor könnte eine relevante Zielstruktur in der Therapie des triple negativen Mammakarzinoms darstellen
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