cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Diarylheptanoid glycosides of Myrica salicifolia bark
Creators: name: Makule, Edna
name: Schmidt, Thomas J.
name: Heilmann, Jörg
name: Kraus, Birgit
Publisher: name: Universität Regensburg
Year: 2017
Subjects: subject: Morella salicifolia; Myricaceae; diarylheptanoid glycosides; myricanol; juglanin
subject: 540 Chemie

description: A methanolic extract of Morella salicifolia bark was fractionated by various chromatographic techniques yielding six previously unknown cyclic diarylheptanoids, namely, 7-hydroxymyricanol 5-O-β-d-glucopyranoside (1), juglanin B 3-O-β-d-glucopyranoside (2), 16-hydroxyjuglanin B 17-O-β-d-glucopyranoside (3), myricanone 5-O-β-d-gluco-pranosyl-(1→6)-β-d-glucopyranoside (4), neomyricanone 5-O-β-d-glucopranosyl-(1→6)-β-d-glucopyranoside (5), and myricanone 17-O-α-l-arabino-furanosyl-(1→6)-β-d-glucopyranoside (6), respectively, together with 10 known cyclic diarylheptanoids. The structural diversity of the diarylheptanoid pattern in M. salicifolia resulted from varying glycosidation at C-3, C-5, and C-17 as well as from substitution at C-11 with hydroxy, carbonyl or sulfate groups, respectively. Structure elucidation of the isolated compounds was achieved on the basis of one- and two-dimensional nuclear magnetic resonance (NMR) as well as high-resolution electrospray ionisation mass spectrometry (HR-ESI-MS) analyses. The absolute configuration of the glycosides was confirmed after hydrolysis and synthesis of O-(S)-methyl butyrated (SMB) sugar derivatives by comparison of their 1H-NMR data with those of reference sugars. Additionally, absolute configuration of diarylheptanoid aglycones at C-11 was determined by electronic circular dichroism (ECD) spectra simulation and comparison with experimental CD spectra after hydrolysis.
On deconvolution of distribution functions
Creators: name: Dattner, I.
name: Goldenshluger, A.
name: Juditsky, A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics

description: The subject of this paper is the problem of nonparametric estimation of a continuous distribution function from observations with measurement errors. We study minimax complexity of this problem when unknown distribution has a density belonging to the Sobolev class, and the error density is ordinary smooth. We develop rate optimal estimators based on direct inversion of empirical characteristic function. We also derive minimax affine estimators of the distribution function which are given by an explicit convex optimization problem. Adaptive versions of these estimators are proposed, and some numerical results demonstrating good practical behavior of the developed procedures are presented.
description: Published in at http://dx.doi.org/10.1214/11-AOS907 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Adduct Under Field – a Qualitative Approach to Account for Solvent Effect on Hydrogen Bonding
Creators: name: Shenderovich, Ilya G.
name: Denisov, Gleb S.
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: solvent effect; hydrogen bond; NMR; condensed matter; polarizable continuum model; reaction field; external electric field; proton transfer
subject: 540 Chemie

description: The location of a mobile proton in acid-base complexes in aprotic solvents can be predicted using a simplified Adduct under Field (AuF) approach, where solute–solvent effects on the geometry of hydrogen bond are simulated using a fictitious external electric field. The parameters of the field have been estimated using experimental data on acid-base complexes in CDF3/CDClF2. With some limitations, they can be applied to the chemically similar CHCl3 and CH2Cl2. The obtained data indicate that the solute–solvent effects are critically important regardless of the type of complexes. The temperature dependences of the strength and fluctuation rate of the field explain the behavior of experimentally measured parameters.
A Network-Based Meta-Population Approach to Model Rift Valley Fever Epidemics
Creators: name: Xue, Ling
name: Scott, H. Morgan
name: Cohnstaedt, Lee.
name: Scoglio, Caterina
Publisher: name: arXiv
Year: 2010
Subjects: subject: Other Quantitative Biology (q-bio.OT)
subject: FOS: Biological sciences

description: Rift Valley fever virus (RVFV) has been expanding its geographical distribution with important implications for both human and animal health. The emergence of Rift Valley fever (RVF) in the Middle East, and its continuing presence in many areas of Africa, has negatively impacted both medical and veterinary infrastructures and human health. Furthermore, worldwide attention should be directed towards the broader infection dynamics of RVFV. We propose a new compartmentalized model of RVF and the related ordinary differential equations to assess disease spread in both time and space; with the latter driven as a function of contact networks. The model is based on weighted contact networks, where nodes of the networks represent geographical regions and the weights represent the level of contact between regional pairings for each set of species. The inclusion of human, animal, and vector movements among regions is new to RVF modeling. The movement of the infected individuals is not only treated as a possibility, but also an actuality that can be incorporated into the model. We have tested, calibrated, and evaluated the model using data from the recent 2010 RVF outbreak in South Africa as a case study; mapping the epidemic spread within and among three South African provinces. An extensive set of simulation results shows the potential of the proposed approach for accurately modeling the RVF spreading process in additional regions of the world. The benefits of the proposed model are twofold: not only can the model differentiate the maximum number of infected individuals among different provinces, but also it can reproduce the different starting times of the outbreak in multiple locations. Finally, the exact value of the reproduction number is numerically computed and upper and lower bounds for the reproduction number are analytically derived in the case of homogeneous populations.
description: published on Journal of Theoretical biology
NAD(P)H:quinone oxidoreductase 1 (NQO1) P187S polymorphism and prostate cancer risk in Caucasians
Creators: name: Stoehr, Christine G.
name: Nolte, Elke
name: Wach, Sven
name: Wieland, Wolf F.
name: Hofstädter, Ferdinand
Publisher: name: Universität Regensburg
Year: 2012
Subjects: subject: prostate cancer; NQO1; case-control study; restriction fragment length polymorphism analysis
subject: 610 Medizin

description: NAD(P)H:quinone oxidoreductase 1 (NQO1) catalyses the reduction of quinoid compounds to hydroquinones, preventing the generation of free radicals and reactive oxygen. A “C” to “T” transversion at position 609 of NQO1, leading to a nonsynonymous amino acid change (Pro187Ser, P187S), results in an altered enzyme activity. No NQO1 protein activity was detected in NQO1 609TT genotype, and low to intermediate activity was detected in NQO1 609CT genotype compared with 609CC genotype. Thus, this polymorphism may result in altered cancer predisposition. For prostate cancer, only sparse data are available. We therefore analyzed the distribution of the NQO1 P187S SNP (single nucleotide polymorphism) in prostate cancer patients and a healthy control group. Allelic variants were determined using RFLP analysis. Overall, 232 patients without any malignancy and 119 consecutive prostate cancer patients were investigated. The genotype distribution in our cohorts followed the Hardy–Weinberg equilibrium in cases and controls. The distribution of the NQO1 codon 187 SNP did not differ significantly between prostate cancer patients and the control group (p = 0.242). There was also no association between the allelic variants and stage or Gleason score of the tumors. The NQO1 P187S SNP was not significantly associated with an increased prostate cancer risk in our cohorts. The SNP has also no influence on histopathological characteristics of the tumors. A combined analysis of all available data from published European studies also showed no significant differences in the genotype distribution between controls and prostate cancer patients. Our data suggest a minor role of the NQO1 nucleotide 609 polymorphism in prostate carcinogenesis.
A Multilevel Approach For Nonnegative Matrix Factorization
Creators: name: Gillis, Nicolas
name: Glineur, François
Publisher: name: arXiv
Year: 2010
Subjects: subject: Optimization and Control (math.OC)
subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: Nonnegative Matrix Factorization (NMF) is the problem of approximating a nonnegative matrix with the product of two low-rank nonnegative matrices and has been shown to be particularly useful in many applications, e.g., in text mining, image processing, computational biology, etc. In this paper, we explain how algorithms for NMF can be embedded into the framework of multilevel methods in order to accelerate their convergence. This technique can be applied in situations where data admit a good approximate representation in a lower dimensional space through linear transformations preserving nonnegativity. A simple multilevel strategy is described and is experimentally shown to speed up significantly three popular NMF algorithms (alternating nonnegative least squares, multiplicative updates and hierarchical alternating least squares) on several standard image datasets.
description: 23 pages, 10 figures. Section 6 added discussing limitations of the method. Accepted in Journal of Computational and Applied Mathematics
Closed timelike curves, superluminal signals, and "free will" in universal quantum mechanics
Creators: name: Nikolic, H.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We explore some implications of the hypothesis that quantum mechanics (QM) is universal, i.e., that QM does not merely describe information accessible to observers, but that it also describes the observers themselves. From that point of view, "free will" (FW) - the ability of experimentalists to make free choices of initial conditions - is merely an illusion. As a consequence, by entangling a part of brain (responsible for the illusion of FW) with a distant particle, one may create nonlocal correlations that can be interpreted as superluminal signals. In addition, if FW is an illusion, then QM on a closed timelike curve can be made consistent even without the Deutch nonlinear consistency constraint.
description: 8 pages, revised, accepted for publication in Advanced Science Letters
Inelastic light scattering by intrasubband spin-density excitations in GaAs-AlGaAs quantum wells with balanced Bychkov-Rashba and Dresselhaus spin-orbit interaction: Quantitative determination of the spin-orbit field
Creators: name: Gelfert, Sven
name: Frankerl, C.
name: Reichl, C.
name: Schuh, Dieter
name: Salis, G.
name: Wegscheider, Werner
name: Bougeard, Dominique
name: Korn, Tobias
name: Schüller, Christian
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: 530 Physik

description: Inelastic light scattering experiments on low-energy intrasubband spin-density excitations (SDEs) are performed in (001)-grown modulation-doped GaAs-AlGaAs single quantum wells in in-plane external magnetic fields. The investigated samples possess balanced linear Bychkov-Rashba (α) and Dresselhaus (β) spin-orbit strengths in two different configurations, α=β and α=−β. Both configurations lead to an extreme anisotropy of the spin splitting of the conduction band, where the in-plane directions of maximum spin splitting for both configurations are perpendicular to each other. The spin splitting asymmetry can be directly detected via the SDE by breaking of the time-reversal symmetry due to transfer of a momentum q in the quantum-well plane. In addition, the application of an in-plane magnetic field Bext⊥q allows us to modulate the effective magnetic field. Via a numerical line-shape analysis of the experimental SDE spectra, we determine the relevant parameters of the samples. We find that the linear spin-orbit strength |α|=β is comparable for both samples, while the electron g factors are markedly different. Furthermore, we experimentally quantify the values of the maximum internal spin-orbit fields, which are as high as Bso∼18T for both samples.
The Interstitial Interface within the Renal Stem/Progenitor Cell Niche Exhibits an Unique Microheterogeneous Composition
Creators: name: Minuth, Will W.
name: Denk, Lucia
Publisher: name: Universität Regensburg
Year: 2013
Subjects: subject: kidney; transmission electron microscopy; stem/progenitor cell niche; interstitial interface; extracellular matrix; cupromeronic blue; ruthenium red; tannic acid
subject: 570 Biowissenschaften, Biologie

description: Repair of parenchyma by stem/progenitor cells is seen as a possible alternative to cure acute and chronic renal failure in future. To learn about this therapeutic purpose, the formation of nephrons during organ growth is under focus of present research. This process is triggered by numerous morphogenetic interactions between epithelial and mesenchymal cells within the renal stem/progenitor cell niche. Recent data demonstrate that an astonishingly wide interstitial interface separates both types of stem/progenitor cells probably controlling coordinated cell-to-cell communication. Since conventional fixation by glutaraldehyde (GA) does not declare in transmission electron microscopy the spatial separation, improved contrasting procedures were applied. As a consequence, the embryonic cortex of neonatal rabbit kidneys was fixed in solutions containing glutaraldehyde in combination with cupromeronic blue, ruthenium red or tannic acid. To obtain a comparable view to the renal stem/progenitor cell niche, the specimens had to be orientated along the cortico-medullary axis of lining collecting ducts. Analysis of tissue samples fixed with GA, in combination with cupromeronic blue, demonstrates demasked extracellular matrix. Numerous braces of proteoglycans cover, as well, the basal lamina of epithelial stem/progenitor cells as projections of mesenchymal stem/progenitor cells crossing the interstitial interface. Fixation with GA containing ruthenium red or tannic acid illustrates strands of extracellular matrix that originate from the basal lamina of epithelial stem/progenitor cells and line through the interstitial interface. Thus, for the first time, improved contrasting techniques make it possible to analyze in detail a microheterogeneous composition of the interstitial interface within the renal stem/progenitor cell niche.
From social risk to shared purpose : reframing mining’s approach to corporate social responsibility
Creators: name: Fraser, Jocelynn
Publisher: name: University of British Columbia
Year: 2017

description: From transportation to infrastructure, from energy to information technology, mining makes a significant contribution to society. It also impacts the lives of millions of people living in regions where mining occurs. Today, an increasing number of individuals and groups have earned a legitimate right to be considered as stakeholders in projects affecting their communities. This has given rise to mining-community conflict and is forcing companies to reconsider the approach to earning and retaining social approval. Global mining leaders have been working to implement policies and practices aligned with corporate social responsibility (CSR) tenets yet conflict between mining companies and the communities that host extractive operations appears to be growing. This research seeks to quantify incidents of mining-community conflict and test a theory that reframing CSR to create shared value could deliver financial returns to mining operations while advancing economic and social conditions in associated communities. It is suggested that the UN 2030 Sustainable Development Goals (SDGs) provide a context for reframing CSR as a strategic business imperative. A new model of engagement is proposed that places the SDGs at the centre of mining-community engagement to align mining with the values of society and rebuild the sector’s current trust deficit. A multi-method research approach is used. The quantitative portion analyzes mining community conflicts from 2012 – 2015 as reported in the international media. Media coverage was hand-coded using a system adapted from conflict literature, and a document analysis of a sub-set of the conflict situations was employed to explore the results. A qualitative, theory-building case study investigates collaboration between personnel at the Cerro Verde Mine and regional stakeholders to address regional water supply issues and develop a strategy with parallel goals: improving operational performance while delivering tangible social benefits. The research seeks to contributes to CSR as a management strategy. The findings confirm there is both monetary and reputational value to investing in core social needs that intersect with business interests. A new model to build trust in mining and advance progress on the SDGs is proposed, and a concept presented that places CSR approaches within life-of-mine stages.
Quantifying nanoscale electromagnetic fields in near-field microscopy by Fourier demodulation analysis
Creators: name: Mooshammer, Fabian
name: Huber, Markus A.
name: Sandner, Fabian
name: Plankl, Markus
name: Zizlsperger, Martin
name: Huber, Rupert
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: scattering-type SNOM, mid-infrared, nanoscopy, tomography, finite element method, demodulated fields
subject: 530 Physik

description: Confining light to sharp metal tips has become a versatile technique to study optical and electronic properties far below the diffraction limit. Particularly near-field microscopy in the mid-infrared spectral range has found a variety of applications in probing nanostructures and their dynamics. Yet, the ongoing quest for ultimately high spatial resolution down to the single-nanometer regime and quantitative three-dimensional nano-tomography depends vitally on a precise knowledge of the spatial distribution of the near fields emerging from the probe. Here, we perform finite element simulations of a tip with realistic geometry oscillating above a dielectric sample. By introducing a novel Fourier demodulation analysis of the electric field at each point in space, we reliably quantify the distribution of the near fields above and within the sample. Besides inferring the lateral field extension, which can be smaller than the tip radius of curvature, we also quantify the probing volume within the sample. Finally, we visualize the scattering process into the far field at a given demodulation order, for the first time, and shed light onto the nanoscale distribution of the near fields, and its evolution as the tip-sample distance is varied. Our work represents a crucial step in understanding and tailoring the spatial distribution of evanescent fields in optical nanoscopy.
Polynomial invariants of graphs on surfaces
Creators: name: Askanazi, R.
name: Chmutov, S.
name: Estill, C.
name: Michel, J.
name: Stollenwerk, P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Combinatorics (math.CO)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 05C10, 05C31, 57M15, 57M25, 57M27

description: For a graph embedded into a surface, we relate many combinatorial parameters of the cycle matroid of the graph and the bond matroid of the dual graph with the topological parameters of the embedding. This will give an expression of the polynomial, defined by M.Las Vergnas in a combinatorial way using matroids as a specialization of the Krushkal polynomial, defined using the symplectic structure in the first homology group of the surface.
description: to appear in Quantum Topology
Cyclic Nucleotide Signalling in Kidney Fibrosis
Creators: name: Schinner, Elisabeth
name: Wetzl, Veronika
name: Schlossmann, Jens
Publisher: name: Universität Regensburg
Year: 2015
Subjects: subject: signalling; cyclic nucleotides; cyclic guanosine monophosphate; cyclic adenosine monophosphate; kidney fibrosis
subject: 615 Pharmazie

description: Kidney fibrosis is an important factor for the progression of kidney diseases, e.g., diabetes mellitus induced kidney failure, glomerulosclerosis and nephritis resulting in chronic kidney disease or end-stage renal disease. Cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) were implicated to suppress several of the above mentioned renal diseases. In this review article, identified effects and mechanisms of cGMP and cAMP regarding renal fibrosis are summarized. These mechanisms include several signalling pathways of nitric oxide/ANP/guanylyl cyclases/cGMP-dependent protein kinase and cAMP/Epac/adenylyl cyclases/cAMP-dependent protein kinase. Furthermore, diverse possible drugs activating these pathways are discussed. From these diverse mechanisms it is expected that new pharmacological treatments will evolve for the therapy or even prevention of kidney failure.
title: "Busto di Afrodite tipo Saffo", arte romana, inv. CLXXIV (ITA/EN)
title: Scheda catalogo digitale Borghese
titleType: AlternativeTitle
Creators: name: Clementi, Jessica
name: Galleria Borghese
Publisher: name: Galleria Borghese
Year: 2024

description: Pubblicazione delle schede delle opere conservate nel museo ed estratte dal catalogo digitale di

Galleria Borghese, nelle due versioni esistenti online, in italiano e inglese.

Collegamento al catalogo digitale:

ITA: https://www.collezionegalleriaborghese.it/

EN: https://www.collezionegalleriaborghese.it/en
Detection of Abnormal Extracellular Matrix in the Interstitium of Regenerating Renal Tubules
Creators: name: Minuth, Will W.
name: Denk, Lucia
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: kidney; stem/progenitor cells; abnormal development; extracellular matrix; glutaraldehyde; cupromeronic blue; ruthenium red; tannic acid; transmission electron microscopy
subject: 570 Biowissenschaften, Biologie

description: Stem/progenitor cells are promising candidates for the regeneration of parenchyma in acute and chronic renal failure. However, recent data exhibit that survival of stem/progenitor cells after implantation in diseased renal parenchyma is restricted. To elaborate basic parameters improving survival, cell seeding was simulated under advanced in vitro conditions. After isolation, renal stem/progenitor cells were mounted in a polyester interstitium for perfusion culture. During generation of tubules, chemically defined CO2 Independent Medium or Leibovitz’s L-15 Medium was applied. Specimens were then fixed for transmission electron microscopy to analyze morphological features in generated tubules. Fixation in conventional glutaraldehyde (GA) solution shows development of tubules each exhibiting a polarized epithelium, an intact basal lamina and an inconspicuous interstitium. In contrast, special fixation of specimens in GA solution containing cupromeronic blue, ruthenium red or tannic acid unveils previously not visible extracellular matrix. Control experiments elucidate that a comparable extracellular matrix is not present in the interstitium of the matured kidney. Thus, generation of renal tubules in combination with advanced fixation of specimens for electron microscopy demonstrates that development of abnormal features in the newly developed interstitium has to be considered, when repair of renal parenchyma is performed by implantation of stem/progenitor cells.
Norrin protects retinal ganglion cells from excitotoxic damage via the induction of LIF
Creators: name: Kassumeh, S.
name: Leopold, Stephanie Anna
name: Fuchshofer, Rudolf
name: Tamm, Ernst R.
name: Ohlmann, Andreas
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: Lif; retinal ganglion cells; neuroprotection; excitotoxic damage; NMDA; apoptosis; Norrin; Wnt/β-catenin signaling
subject: 570 Biowissenschaften, Biologie

description: Purpose: To investigate whether and how leukemia inhibitory factor (Lif) is involved in mediating the neuroprotective effects of Norrin on retinal ganglion cells (RGC) following excitotoxic damage. Norrin is a secreted protein that protects RGC from N-methyl-d-aspartate (NMDA)-mediated excitotoxic damage, which is accompanied by increased expression of protective factors such as Lif, Edn2 and Fgf2. Methods: Lif-deficient mice were injected with NMDA in one eye and NMDA plus Norrin into the other eye. RGC damage was investigated and quantified by TUNEL labeling 24 h after injection. Retinal mRNA expression was analyzed by quantitative real-time polymerase chain reaction following retinal treatment. Results: After intravitreal injection of NMDA and Norrin in wild-type mice approximately 50% less TUNEL positive cells were observed in the RGC layer when compared to NMDA-treated littermates, an effect which was lost in Lif-deficient mice. The mRNA expression for Gfap, a marker for Müller cell gliosis, as well as Edn2 and Fgf2 was induced in wild-type mice following NMDA/Norrin treatment but substantially blocked in Lif-deficient mice. Conclusions: Norrin mediates its protective properties on RGC via Lif, which is required to enhance Müller cell gliosis and to induce protective factors such as Edn2 or Fgf2.
2.1c Pedagogical Strategies, Approaches and Methodologies to Support Numeracy in Post-primary Schools
Creators: name: Grimes, Paul
name: Dooley, Thérèse
name: Nic Mhuirí, Siún
Publisher: name: Zenodo
Year: 2022
Subjects: Pedagogical Strategies, Approaches and Methodologies, Numeracy, Post-primary

description: 2.1c
Role of immunological memory cells as a therapeutic target in multiple sclerosis
Creators: name: Bose, Tanima
Publisher: name: Universität Regensburg
Year: 2017
Subjects: subject: multiple sclerosis; MS; central memory T cells; TCM; effector memory T cells; TEM; resident memory T cells; TRM
subject: 610 Medizin

description: Pharmacological targeting of memory cells is an attractive treatment strategy in various autoimmune diseases, such as psoriasis and rheumatoid arthritis. Multiple sclerosis is the most common inflammatory disorder of the central nervous system, characterized by focal immune cell infiltration, activation of microglia and astrocytes, along with progressive damage to myelin sheaths, axons, and neurons. The current review begins with the identification of memory cell types in the previous literature and a recent description of the modulation of these cell types in T, B, and resident memory cells in the presence of different clinically approved multiple sclerosis drugs. Overall, this review paper tries to determine the potential of memory cells to act as a target for the current or newly-developed drugs.
Haldane Statistics in the Finite Size Entanglement Spectra of Laughlin States
Creators: name: Hermanns, M.
name: Chandran, A.
name: Regnault, N.
name: Bernevig, B. Andrei
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We conjecture that the counting of the levels in the orbital entanglement spectra (OES) of finite-sized Laughlin Fractional Quantum Hall (FQH) droplets at filling $ν=1/m$ is described by the Haldane statistics of particles in a box of finite size. This principle explains the observed deviations of the OES counting from the edge-mode conformal field theory counting and directly provides us with a topological number of the FQH states inaccessible in the thermodynamic limit- the boson compactification radius. It also suggests that the entanglement gap in the Coulomb spectrum in the conformal limit protects a universal quantity- the statistics of the state. We support our conjecture with ample numerical checks.
description: 4.1 pages, published version
A new short proof for the uniqueness of the universal minimal space
Creators: name: Gutman, Yonatan
name: Li, Hanfeng
Publisher: name: arXiv
Year: 2011
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: We give a new short proof for the uniqueness of the universal minimal space. The proof holds for the uniqueness of the universal object in every collection of topological dynamical systems closed under taking projective limits and possessing universal objects.
description: Minor changes. To appear in Proc. Amer. Math. Soc
Lack of a retinal phenotype in a Syne-2/Nesprin-2 knockout mouse model
Creators: name: Falk, Nathalie
name: Joachimsthaler, A.
name: Kessler, K.
Publisher: name: Universität Regensburg
Year: 2019
Subjects: subject: Syne-2; Pericentrin; retina; nuclear migration; primary cilium; ciliogenesis
subject: 610 Medizin

description: Syne-2 (also known as Nesprin-2) is a member of a family of proteins that are found primarily in the outer nuclear membrane, as well as other subcellular compartments. Syne-2 contains a C-terminal KASH transmembrane domain and is part of a protein network that associates the nuclear envelope to the cytoskeleton via the binding to actin filaments. Syne-2 plays a role in nuclear migration, nuclear positioning during retinal development, and in ciliogenesis. In a previous study, we showed a connection between Syne-2 and the multifunctional scaffold protein Pericentrin (Pcnt). The elimination of the interaction of Syne-2 and Pcnt showed defects in nuclear migration and the formation of outer segments during retinal development, as well as disturbances in centrosomal migration at the beginning of ciliogenesis in general. In this study, the Syne-2 KO mouse model Nesprin-2△ABD (Syne-2tm1Ngl, MGI) with special attention to Pcnt and ciliogenesis was analyzed. We show reduced expression of Syne-2 in the retina of the Syne-2 KO mouse but found no significant structural—and only a minor functional—phenotype. For the first time, detailed expression analyses showed an expression of a Syne-2 protein larger than 400 kDa (~750 kDa) in the Syne-2/Nesprin-2 KO mouse. In conclusion, the lack of an overt phenotype in Syne-2/Nesprin-2 KO mice suggests the usage of alternative translational start sites, producing Syne-2 splice variants with an intact Pcnt interaction site. Nevertheless, deletion of the actin-binding site in the Syne-2/Nesprin-2 KO mouse revealed a high variability in scotopic oscillatory potentials assuming a novel function of Syne-2 in synchronizing inner retinal processes.
Differentially methylated regions interrogated for metastable epialleles associate with offspring adiposity
Creators: name: Kechris, Katerina J
name: Waldrop, Stephanie W
name: Borengasser, Sarah J
name: Niemiec, Sierra S
name: Sauder, Katherine A
name: Dabelea, Dana
name: Perng, Wei
name: Starling, Anne P
name: Yang, Ivana V
Publisher: name: Taylor & Francis
Year: 2024

description: Aim: Assess if cord blood differentially methylated regions (DMRs) representing human metastable epialleles (MEs) associate with offspring adiposity in 588 maternal-infant dyads from the Colorado Health Start Study.Materials & methods: DNA methylation was assessed via the Illumina 450K array (~439,500 CpG sites). Offspring adiposity was obtained via air displacement plethysmography. Linear regression modeled the association of DMRs potentially representing MEs with adiposity.Results & conclusion: We identified two potential MEs, ZFP57, which associated with infant adiposity change and B4GALNT4, which associated with infancy and childhood adiposity change. Nine DMRs annotating to genes that annotated to MEs associated with change in offspring adiposity (false discovery rate <0.05). Methylation of approximately 80% of DMRs identified associated with decreased change in adiposity.
Modular invariant Frobenius algebras from ribbon Hopf algebra automorphisms
Creators: name: Fuchs, Jurgen
name: Schweigert, Christoph
name: Stigner, Carl
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Algebra (math.QA)
subject: High Energy Physics - Theory (hep-th)
subject: Category Theory (math.CT)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: For any finite-dimensional factorizable ribbon Hopf algebra H and any ribbon automorphism omega of H, we establish the existence of the following structure: an H-bimodule F_omega and a bimodule morphism Z_omega from Lyubashenko's Hopf algebra object K for the bimodule category to F_omega. This morphism is invariant under the natural action of the mapping class group of the one-punctured torus on the space of bimodule morphisms from K to F_omega. We further show that the bimodule F_omega can be endowed with a natural structure of a commutative symmetric Frobenius algebra in the monoidal category of H-bimodules, and that it is a special Frobenius algebra iff H is semisimple. The bimodules K and F_omega can both be characterized as coends of suitable bifunctors. The morphism Z_omega is obtained by applying a monodromy operation to the coproduct of F_omega; a similar construction for the product of F_omega exists as well. Our results are motivated by the quest to understand the bulk state space and the bulk partition function in two-dimensional conformal field theories with chiral algebras that are not necessarily semisimple.
description: 44 pages, some figures. v2: Several changes and clarifications, conclusions unchanged. v3: typos corrected
Constraining Dark Matter Properties with Gamma-Rays from the Galactic Center with Fermi-LAT
Creators: name: Bernal, Nicolas
name: Palomares-Ruiz, Sergio
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the capabilities of the Fermi-LAT instrument on board of the Fermi mission to constrain particle dark matter properties, as annihilation cross section, mass and branching ratio into dominant annihilation channels, with gamma-ray observations from the galactic center. Besides the prompt gamma-ray flux, we also take into account the contribution from the electrons/positrons produced in dark matter annihilations to the gamma-ray signal via inverse Compton scattering off the interstellar photon background, which turns out to be crucial in the case of dark matter annihilations into mu+mu- and e+e- pairs. We study the signal dependence on different parameters like the region of observation, the density profile, the assumptions for the dark matter model and the uncertainties in the propagation model. We also show the effect of the inclusion of a 20% systematic uncertainty in the gamma-ray background. If Fermi-LAT is able to distinguish a possible dark matter signal from the large gamma-ray background, we show that for dark matter masses below ~200 GeV, Fermi-LAT will likely be able to determine dark matter properties with good accuracy.
description: 38 pages, 13 figures, 4 tables; to match published version
The stratification of attendance at cultural activities in Canada
Creators: name: Vanzella Yang, Adam
Publisher: name: University of British Columbia
Year: 2017

description: Scholars have debated the relative applicability of homology and omnivorousness, two theories of cultural stratification, for explaining links between socioeconomic position and cultural repertoires. However, the discussion has mostly focused on musical tastes rather than attendance at cultural activities. Using data from the 2005 and 2010 Canadian General Social Survey on Time Use, I examine how measures of socioeconomic position predict attendance at twelve different kinds of cultural activities. I apply three analytical techniques to these datasets: (1) binary logistic regressions to investigate the socioeconomic bases of attendance at each cultural activity, (2) ordered logistic regressions to assess the nature of the relationship between socioeconomic position and omnivorous attendance, and (3) latent class analyses to inductively identify patterns of attendance and the socioeconomic bases thereof. Controlling for demographic factors, I find that education and income are both positively associated with attendance at each activity and with omnivorous cultural engagement. The latent class models reveal three distinct groups of attendees: highbrow omnivores, selective omnivores, and inactive people. Education and income predict membership in the two omnivorous groups, with stronger effects for highbrow omnivores. I confirm that omnivorousness is associated with cultural and economic elites but also reveal different gradations of omnivorousness, thus suggesting that the two theoretical frameworks are to a degree entangled with one another.
American Step-Up and Step-Down Default Swaps under Levy Models
Creators: name: Leung, Tim Siu-Tang
name: Yamazaki, Kazutoshi
Publisher: name: arXiv
Year: 2010
Subjects: subject: Pricing of Securities (q-fin.PR)
subject: Optimization and Control (math.OC)
subject: FOS: Economics and business
subject: FOS: Mathematics
subject: 60G51, 91B25, 91B70

description: This paper studies the valuation of a class of default swaps with the embedded option to switch to a different premium and notional principal anytime prior to a credit event. These are early exercisable contracts that give the protection buyer or seller the right to step-up, step-down, or cancel the swap position. The pricing problem is formulated under a structural credit risk model based on Levy processes. This leads to the analytic and numerical studies of several optimal stopping problems subject to early termination due to default. In a general spectrally negative Levy model, we rigorously derive the optimal exercise strategy. This allows for instant computation of the credit spread under various specifications. Numerical examples are provided to examine the impacts of default risk and contractual features on the credit spread and exercise strategy.
description: 35 pages, 5 figures
Genetic Mouse Models as In Vivo Tools for Cholangiocarcinoma Research
Creators: name: Erice, O.
name: Vallejo, A.
name: Ponz-Sarvise, M.
name: Saborowski, M.
name: Calvisi, Diego F.
Publisher: name: Universität Regensburg
Year: 2019
Subjects: subject: cholangiocarcinoma; biliary tract; hydrodynamic injection; genetically-engineered mice; in vivo models
subject: 610 Medizin

description: Cholangiocarcinoma (CCA) is a genetically and histologically complex disease with a highly dismal prognosis. A deeper understanding of the underlying cellular and molecular mechanisms of human CCA will increase our current knowledge of the disease and expedite the eventual development of novel therapeutic strategies for this fatal cancer. This endeavor is effectively supported by genetic mouse models, which serve as sophisticated tools to systematically investigate CCA pathobiology and treatment response. These in vivo models feature many of the genetic alterations found in humans, recapitulate multiple hallmarks of cholangiocarcinogenesis (encompassing cell transformation, preneoplastic lesions, established tumors and metastatic disease) and provide an ideal experimental setting to study the interplay between tumor cells and the surrounding stroma. This review is intended to serve as a compendium of CCA mouse models, including traditional transgenic models but also genetically flexible approaches based on either the direct introduction of DNA into liver cells or transplantation of pre-malignant cells, and is meant as a resource for CCA researchers to aid in the selection of the most appropriate in vivo model system.
Summing over spacetime dimensions in quantum gravity
Creators: name: Curiel, E.
name: Finster, Felix
name: Isidro, José Maria
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: Feynman propagators; quantum of length; quantum gravity
subject: 510 Mathematik

description: Quantum-gravity corrections (in the form of a minimal length) to the Feynman propagator for a free scalar particle in RD are shown to be the result of summing over all dimensions D′≥D of RD′ , each summand taken in the absence of quantum gravity.
On nighttime turbulent exchange within and above a sloped vineyard
Creators: name: Everard, Kelsey
Publisher: name: University of British Columbia
Year: 2017

description: High frequency three-dimensional wind and distributed temperature measurements were taken over a ~7˚ vineyard slope in the Southern Okanagan Valley, British Columbia, Canada, during three weeks in July 2016. Approximately 17% of the nighttime is characterised by drainage flow along the local slope. Drainage conditions are characterised by inverted temperatures beginning around z/hc = 0.39, where z is the height above ground level (AGL) and hc is the canopy height (~2.3 m AGL), and near-surface lapses. A jet maximum is observed around z/hc = 1.65, while a weak inflection point is observed near the canopy top, suggesting influence from both drainage layer and canopy layer dynamics on the turbulent field. The greatest observed fluxes in both the stream-wise momentum flux and the sensible heat flux are near the top of the canopy, consistent with the location of the inflection point. Calculated two-point length scales from distributed temperature measurements reveal that turbulent structures are smallest near the canopy top. Conditional sampling of the 3-D ultrasonic wind components and acoustic temperature indicate that a large fraction of canopy layer transport is driven by canopy-top turbulence, with sweeps dominating over ejections, particularly at z/hc = 0.65. Results presented here are important both for nighttime vineyard management techniques and for further understanding on particle dispersion.
Holographic field theory models of dark energy in interaction with dark matter
Creators: name: Micheletti, Sandro M. R.
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We discuss two lagrangian interacting dark energy models in the context of the holographic principle. The potentials of the interacting fields are constructed. The models are compared with CMB distance information, baryonic acoustic oscilations, lookback time and the Constitution supernovae sample. For both models the results are consistent with a non vanishing interaction between dark sectors - with more than three standard deviations of confidence for one of them. Moreover, in both cases, the sign of coupling is consistent with dark energy decaying into dark matter, alleviating the coincidence problem.
description: arXiv admin note: substantial text overlap with arXiv:0912.3992
Derivations and Dirichlet forms on fractals
Creators: name: Ionescu, Marius
name: Rogers, Luke G.
name: Teplyaev, Alexander
Publisher: name: arXiv
Year: 2011
Subjects: subject: Operator Algebras (math.OA)
subject: Mathematical Physics (math-ph)
subject: Functional Analysis (math.FA)
subject: Metric Geometry (math.MG)
subject: Spectral Theory (math.SP)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 81Q35, 28A80, 58J42, 46L87, 31C25, 34B45, 60J45, 94C99

description: We study derivations and Fredholm modules on metric spaces with a local regular conservative Dirichlet form. In particular, on finitely ramified fractals, we show that there is a non-trivial Fredholm module if and only if the fractal is not a tree (i.e. not simply connected). This result relates Fredholm modules and topology, and refines and improves known results on p.c.f. fractals. We also discuss weakly summable Fredholm modules and the Dixmier trace in the cases of some finitely and infinitely ramified fractals (including non-self-similar fractals) if the so-called spectral dimension is less than 2. In the finitely ramified self-similar case we relate the p-summability question with estimates of the Lyapunov exponents for harmonic functions and the behavior of the pressure function.
description: to appear in the Journal of Functional Analysis 2012
Working Desks as a Classification Tool for Personality Style: A Pilot Study for Validation
Creators: name: Render, Anna
name: Siebertz, Markus
name: Günther, Bianca
name: Jansen, Petra
Publisher: name: Universität Regensburg
Year: 2019
Subjects: subject: 796 Sport

description: We shape our surroundings; form the rooms we live in, so that we feel comfortable in them. This shows parts of our personality – it can be inferred from our environment. In this study, we created stereotypical desks embodying different personality styles and let 190 students choose which desk fits – in their subjective perspective – the most to their personality. To determine their personality style, the personality style and disorder inventory (PSSI) was used. Correspondence analysis (CA) was conducted to investigate the relationship between personality styles and choice of desks. Results did not show convergence of personality styles and desks. Contrary to the popular scientific idea, personality and creation of surroundings were not related; regarding our study, the relation is uninterpretable suggesting an individual’s desk choice is not statistically dependent on one’s individual’s highest PSSI subscale. The study can be regarded as a pilot project for desk designs as classification tool for personality.
A note on entropic uncertainty relations of position and momentum
Creators: name: Schürmann, Thomas
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider two entropic uncertainty relations of position and momentum recently discussed in literature. By a suitable rescaling of one of them, we obtain a smooth interpolation of both for high-resolution and low-resolution measurements respectively. Because our interpolation has never been mentioned in literature before, we propose it as a candidate for an improved entropic uncertainty relation of position and momentum. Up to now, the author has neither been able to falsify nor prove the new inequality. In our opinion it is a challenge to do either one.
description: 2 pages, 2 figures, 2 references added
Chern-Simons functions on toric Calabi-Yau threefolds and Donaldson-Thomas theory
Creators: name: Hua, Zheng
Publisher: name: arXiv
Year: 2011
Subjects: subject: Algebraic Geometry (math.AG)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: In this paper, we give a construction of the global Chern-Simons functions for toric Calabi-Yau stacks of dimension three using strong exceptional collections. The moduli spaces of sheaves on such stacks can be identified with critical loci of these functions. We give two applications of these functions. First, we prove Joyce's integrality conjecture of generalized DT invariants on local surfaces. Second, we prove a dimension reduction formula for virtual motives, which leads to two recursion formulas for motivic Donaldson-Thomas invariants.
description: A rewritten versoin. Some references added