cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Path Integrals and the WKB approximation in Loop Quantum Cosmology
Creators: name: Ashtekar, Abhay
name: Campiglia, Miguel
name: Henderson, Adam
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We follow the Feynman procedure to obtain a path integral formulation of loop quantum cosmology starting from the Hilbert space framework. Quantum geometry effects modify the weight associated with each path so that the effective measure on the space of paths is different from that used in the Wheeler-DeWitt theory. These differences introduce some conceptual subtleties in arriving at the WKB approximation. But the approximation is well defined and provides intuition for the differences between loop quantum cosmology and the Wheeler-DeWitt theory from a path integral perspective.
description: 21 pages, 4 figures
Dissipation of spin angular momentum in magnetic switching
Creators: name: Stamm, C.
name: Tudosa, I.
name: Siegmann, H. C.
name: Stöhr, J.
name: Dobin, A. Y.
name: Woltersdorf, Georg
name: Heinrich, B.
name: Vaterlaus, A.
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik
subject: 76.90.+d
subject: 75.30.Ds
subject: 75.70.Ak

description: Applying one ultrashort magnetic field pulse, we observe up to 10 precessional switches of the magnetization direction in single crystalline Fe films of 10 and 15 atomic layers. We find that the rate at which angular momentum is dissipated in uniform large angle spin precession increases with time and film thickness, surpassing the intrinsic ferromagnetic resonance spin lattice relaxation of Fe by nearly an order of magnitude.
Scattering of spin current injected in Pd(001)
Creators: name: Foros, J.
name: Woltersdorf, Georg
name: Heinrich, B.
name: Brataas, A.
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: palladium, iron, ferromagnetic materials, metallic thin films, magnetic thin films, magnetic multilayers, spin polarised transport, spin fluctuations, magnetisation, ferromagnetic resonance
subject: 530 Physik
subject: 75.50.Bb
subject: 75.70.Cn
subject: 72.25.Rb
subject: 72.25.Ba
subject: 75.70.Ak
subject: 72.25.Mk
subject: 75.30.Ds
subject: 75.47.Np
subject: 75.40.Gb
subject: 76.50.+g
subject: 75.60.Ej

description: We have studied spin pumping in Pd/Fe(001) ultrathin crystalline films prepared on GaAs(001) by ferromagnetic resonance (FMR). FMR measurements show that the Pd(001) overlayers lead to an appreciable attenuation of the spin current, which was generated by the precessing magnetization of Fe. Pd overlayers thicker than about 10 nm act as perfect spin sinks. It is argued that the loss of spin coherence in Pd is caused by scattering with spin fluctuations. (c) 2005 American Institute of Physics.
Atomistic simulations of the implantation of low energy boron and nitrogen ions into graphene
Creators: name: Åhlgren, E. H.
name: Kotakoski, J.
name: Krasheninnikov, A. V.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: By combining classical molecular dynamics simulations and density functional theory total energy calculations, we study the possibility of doping graphene with B/N atoms using low-energy ion irradiation. Our simulations show that the optimum irradiation energy is 50 eV with substitution probabilities of 55% for N and 40% for B. We further estimate probabilities for different defect configurations to appear under B/N ion irradiation. We analyze the processes responsible for defect production and report an effective swift chemical sputtering mechanism for N irradiation at low energies (~125 eV) which leads to production of single vacancies. Our results show that ion irradiation is a promising method for creating hybrid C-B/N structures for future applications in the realm of nanoelectronics.
Mode degeneracy due to vortex core removal in magnetic disks
Creators: name: Hoffmann, F.
name: Woltersdorf, Georg
name: Perzlmaier, K.
name: Slavin, A. N.
name: Tiberkevich, V. S.
name: Bischof, A.
name: Weiss, Dieter
name: Back, Christian
Publisher: name: Universität Regensburg
Year: 2007
Subjects: subject: 530 Physik

description: The mode spectrum of micrometer-sized ferromagnetic Permalloy disks, exhibiting a vortex ground state, is investigated by means of time-resolved scanning Kerr microscopy. The temporal evolution of the magnetization is probed after application of a fast in-plane field pulse. The lowest order azimuthal mode, a mode with only one diametric node, splits into a doublet as the disk diameter decreases. Theoretical models show that this splitting is a consequence of the interaction of the mode with the gyrotropic motion of the vortex core. Our experiments and micromagnetic simulations confirm that by removing the vortex core from the disk, the mode splitting vanishes.
An XMM-Newton view of Planetary Nebulae in the Small Magellanic Cloud. The X-ray luminous central star of SMP SMC 22
Creators: name: Mereghetti, S.
name: Krachmalnicoff, N.
name: La Palombara, N.
name: Tiengo, A.
name: Rauch, T.
name: Haberl, F.
name: Filipovic, M. D.
name: Sturm, R.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: During an X-ray survey of the Small Magellanic Cloud, carried out with the XMM-Newton satellite, we detected significant soft X-ray emission from the central star of the high-excitation planetary nebula SMP SMC 22. Its very soft spectrum is well fit with a non local thermodynamical equilibrium model atmosphere composed of H, He, C, N, and O, with abundances equal to those inferred from studies of its nebular lines. The derived effective temperature of 1.5x10^5 K is in good agreement with that found from the optical/UV data. The unabsorbed flux in the 0.1-0.5 keV range is about 3x10^{-11} erg cm^-2 s^-1, corresponding to a luminosity of 1.2x10^37 erg/s at the distance of 60 kpc. We also searched for X-ray emission from a large number of SMC planetary nebulae, confirming the previous detection of SMP SMC 25 with a luminosity of (0.2-6)x10^35 erg/s (0.1-1 keV). For the remaining objects that were not detected, we derived flux upper limits corresponding to luminosity values from several tens to hundreds times smaller than that of SMP SMC 22. The exceptionally high X-ray luminosity of SMP SMC 22 is probably due to the high mass of its central star, quickly evolving toward the white dwarf's cooling branch, and to a small intrinsic absorption in the nebula itself.
description: Accepted for publication on Astronomy and Astrophysics
Polarization Selective Magnetic Vortex Dynamics and Core Reversal in Rotating Magnetic Fields
Creators: name: Curcic, Michael
name: Van Waeyenberge, Bartel
name: Vansteenkiste, Arne
name: Weigand, Markus
name: Sackmann, Vitalij
name: Stoll, Hermann
name: Faehnle, Manfred
name: Tyliszczak, Tolek
name: Woltersdorf, Georg
name: Back, Christian H.
name: Schuetz, Gisela
Publisher: name: Universität Regensburg
Year: 2008
Subjects: subject: 530 Physik
subject: 75.40.Gb
subject: 75.60.Jk
subject: 75.75.+a

description: We report on the observation of magnetic vortex dynamics in response to rotating magnetic fields in submicron platelets. Unlike linear fields or spin polarized currents, which excite both vortex core polarization states, an in-plane rotating field can selectively excite one of the polarization states. We demonstrate by direct imaging with time-resolved scanning x-ray microscopy that the rotating field only excites the gyrotropic mode if the rotation sense of the field coincides with the vortex gyration sense and that such a field can selectively reverse the vortex polarization.
Magnetization dynamics of the ferrimagnet CoGd near the compensation of magnetization and angular momentum
Creators: name: Binder, M.
name: Weber, A.
name: Mosendz, O.
name: Woltersdorf, Georg
name: Izquierdo, M.
name: Neudecker, I.
name: Dahn, J. R.
name: Hatchard, T. D.
name: Thiele, J.-U.
name: Back, Christian
name: Scheinfein, M. R.
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: 530 Physik
subject: 75.40.Gb
subject: 75.50.Gg
subject: 76.50.+g

description: Magnetization dynamics in alloys of ferrimagnetic CoGd have been studied in the vicinity of the magnetization and angular momentum compensation point as a function of alloy composition and temperature. In agreement with standard mean-field treatments of the dynamics of the total magnetization we observe an increase of the precessional frequency and the effective damping parameter near the angular momentum compensation point. We demonstrate the consistency of the magnetization dynamics extracted from frequency domain methods such as ferromagnetic resonance and time resolved laser pump-probe measurements.
Imaging magnetic excitations in confined magnetic structures
Creators: name: Neudecker, I.
name: Hoffmann, F.
name: Woltersdorf, G.
name: Back, C. H.
Publisher: name: Universität Regensburg
Year: 2008
Subjects: subject: 530 Physik

description: In this paper we revisit some particular aspects concerning the dynamic magnetization of thin Ni80Fe20 discs. In particular we address details of the excitation spectrum of Ni80Fe20 discs subjected to in-plane magnetic cw microwave fields. In this case imaging the dynamic magnetization allows us to estimate the internal magnetic field of the ferromagnetic element.
From SuperTIGER to TIGERISS
Creators: name: Rauch, B. F.
name: Zober, W. V.
name: Abarr, Q.
name: Akaike, Y.
name: Binns, W. R.
name: Fernandez-Borda, Roberto
name: Bose, R. G.
name: Brandt, T. J.
name: Braun, D. L.
name: Buckley, J. H.
name: Cannady, Nicholas
name: Coutu, S.
name: Crabill, R. M.
name: Dowkontt, P. F.
name: Israel, M. H.
name: Kandula, M.
name: Krizmanic, J. F.
name: Labrador, A. W.
name: Labrador, W.
name: Lisalda, L.
name: Martins, J. Vanderlei
name: McPherson, M. P.
name: Mewaldt, R. A.
name: Mitchell, J. G.
name: Mitchell, J. W.
name: Mognet, S. A I.
name: Murphy, R. P.
name: De Nolfo, G. A.
name: Nutter, S.
name: Olevitch, M. A.
name: Osborn, N. E.
name: Pastrana, I. M.
name: Sakai, K.
name: Sasaki, M.
name: Smith, S.
name: Tolentino, H. A.
name: Walsh, N. E.
name: Ward, J. E.
name: Washington, D.
name: West, A. T.
name: Williams, L. P.
Publisher: name: MDPI
Year: 2024
Subjects: International Space Station
cosmic ray sources
s-process
high-altitude balloons
galactic cosmic rays
r-process
cosmic ray detectors

description: The Trans-Iron Galactic Element Recorder (TIGER) family of instruments is optimized to measure the relative abundances of the rare, ultra-heavy galactic cosmic rays (UHGCRs) with atomic number (Z) Z ≥ 30. Observing the UHGCRs places a premium on exposure that the balloon-borne SuperTIGER achieved with a large area detector (5.6 m²) and two Antarctic flights totaling 87 days, while the smaller (∼1 m²) TIGER for the International Space Station (TIGERISS) aims to achieve this with a longer observation time from one to several years. SuperTIGER uses a combination of scintillator and Cherenkov detectors to determine charge and energy. TIGERISS will use silicon strip detectors (SSDs) instead of scintillators, with improved charge resolution, signal linearity, and dynamic range. Extended single-element resolution UHGCR measurements through ₈₂Pb will cover elements produced in s-process and r-process neutron capture nucleosynthesis, adding to the multi-messenger effort to determine the relative contributions of supernovae (SNe) and Neutron Star Merger (NSM) events to the r-process nucleosynthesis product content of the galaxy.
title: Failure to repair damaged NAD(P)H blocks de novo serine synthesis in human cells
Creators: name: Adhish Walvekar
name: Marc Omer Warmoes
name: Dean Cheung
name: Tim Sikora
name: Gemma Gomez Giro
name: Sebastian Perrone
name: Lisa Dengler
name: Francois Unger
name: Bruno Filipe Rodrigues Dos Santos
name: Floriane Gavotto
name: Xiangyi Dong
name: Julia Becker-Kettern
name: Yong-Jun Kwon
name: Christian Jäger
name: Jens Christian Schwamborn
name: Nicole J Van Bergen
name: John Christodoulou
name: Carole Linster
Publisher: name: LCSB
Year: 2023

description: Metabolism is error prone. The central metabolic cofactors NADH and NADPH for instance can undergo enzymatically catalyzed or spontaneous hydration, converting them into redox-inactive products designated NADHX and NADPHX. The metabolite repair enzymes NAXD and NAXE convert these damaged compounds back to the functional NAD(P)H cofactors. Pathogenic loss-of-function variants in NAXE and NAXD lead to development of the neurometabolic disorders named as progressive, early-onset encephalopathy with brain edema and/or leukoencephalopathy (PEBEL1 and PEBEL2, respectively). To gain insights into the molecular disease mechanisms, we investigated the metabolic impact of NAXD deficiency in human cell models. HAP1 NAXD knockout (NAXDko) cells showed growth impairment specifically in a basal medium containing galactose instead of glucose. Surprisingly, the galactose-grown NAXDko cells displayed only subtle signs of mitochondrial impairment, whereas metabolomic analyses revealed a strong inhibition of the cytosolic, de novo serine synthesis pathway in those cells as well as in NAXD patient-derived fibroblasts. We identified inhibition of 3-phosphoglycerate dehydrogenase as the root cause for this metabolic perturbation. The NAD precursor nicotinamide riboside (NR) and inosine exerted beneficial effects on HAP1 cell viability under galactose stress, with more pronounced effects in NAXDko cells. Metabolomic profiling in supplemented cells indicated that NR and inosine act via different mechanisms that at least partially involve the serine synthesis pathway. Taken together, our study identified a metabolic vulnerability in NAXD deficient cells that can be targeted by small molecules such as NR or inosine, opening perspectives in the search for mechanism-based therapeutic interventions in PEBEL disorders.
New Gauge Fields from Extension of Parallel Transport of Vector Spaces to Underlying Scalar Fields
Creators: name: Benioff, Paul
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Gauge theories can be described by assigning a vector space V(x) to each space time point x. A common set of complex numbers, C, is usually assumed to be the set of scalars for all the V{x}. This is expanded here to assign a separate set of scalars, C{x}, to V{x} for each x. The freedom of choice of bases, expressed by the action of a gauge group operator on the V{x}, is expanded here to include the freedom of choice of complex scale factors, c_{y,x}, as elements of GL(1,C) that relate C{y} to C{x}. A gauge field representation of c_{y,x} gives two gauge fields, A(x) and iB(x). Inclusion of these fields in the covariant derivatives of Lagrangians results in A(x) appearing as a gauge boson for which mass is optional and B(x) as a massless gauge boson. B(x) appears to be the photon field. The nature of A(x) is not known at present. One does know that the coupling constant of A(x) to matter fields is very small compared to the fine structure constant.
description: 16 pages,1 figure, paper for talk at SPIE conference, April 27-29, 2011
Pulse pair generation from coherently prepared atomic ensembles
Creators: name: Moretti, D.
name: Felinto, D.
name: Tabosa, J. W. R.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We report a detailed investigation on the generation of pulse pairs during the readout of a coherence grating stored in a cold atomic ensemble. The pulse shapes and the split of the retrieved energy between the two pulses are studied as a function of the relative intensities of the two reading fields, and a minimum is observed for the total retrieved energy. We introduce a simplified analytical theory for the process, considering a three-level atomic system, which explains all the most striking experimental features.
description: 9 pages, 6 figures
Absence of halfmetallicity in defect-free Cr, Mn-delta-doped Digital Magnetic Heterostructures
Creators: name: Beiuşeanu, F.
name: Horea, C.
name: Macocian, E. -V.
name: Jurcuţ, T.
name: Vitos, L.
name: Chioncel, L.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We present results of a combined density functional and many-body calculations for the electronic and magnetic properties of the defect-free digital ferromagnetic heterostructures obtained by doping GaAs with Cr and Mn. While local density approximation/(+U) predicts half-metallicity in these defect-free delta-doped heterostructures, we demonstrate that local many-body correlations captured by Dynamical Mean Field Theory induce within the minority spin channel non-quasiparticle states just above $E_F$. As a consequence of the existence of these many-body states the half-metallic gap is closed and the carriers spin polarization is significantly reduced. Below the Fermi level the minority spin highest valence states are found to localize more on the GaAs layers being independent of the type of electronic correlations considered. Thus, our results confirm the confinement of carriers in these delta-doped heterostructures, having a spin-polarization that follow a different temperature dependence than magnetization. We suggest that polarized hot-electron photoluminescence experiments might bring evidence for the existence of many-body states within the minority spin channel and their finite temperature behavior.
description: 10 pages 8 figures, submitted to PRB
The equation of state of the n-vector model: collective variables method
Creators: name: Kozak, P. R.
name: Kozlovskii, M. P.
name: Usatenko, Z.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: The critical behavior of the three-dimensional n-vector model in the presence of an external field is investigated. Mathematical description is performed with the collective variables (CV) method in the framework of the $ρ^4$ model approximation at the microscopic level without any adjustable parameters. The recurrence relations of the renormalization group (RG) as functions of the external field and temperature were found. The analytical expression for the free energy of the system for temperatures $T>T_c$ and different n was obtained. The equation of state of the n-vector model for general case of small and large external fields was written. The explicit form of the correspondent scaling function for different values of the order parameter was derived. The obtained results are in qualitative agreement with the data of Monte Carlo simulations.
description: 25 pages, 8 figures
Arbitration and the public policy exception in Mexico : local exceptions to global standards
Creators: name: Cedillo Corral, Erika Marcela
Publisher: name: University of British Columbia
Year: 2018

description: This dissertation examines the tension between globalization and local legal contexts by reference to the interpretation in Mexico of the public policy exception in the New York Convention on the Recognition and Enforcement of Foreign Arbitral Awards. Globalization has promoted convergence of legal norms and institutions that materialize in international conventions and organizations to facilitate trade. This has forced states to adopt global standards and reform their legal systems to effectively participate in the global trade arena. However, the effects of these dynamics on local legal systems are often disregarded or not considered. This dissertation demonstrates that the interpretation and implementation in Mexico of the public policy exception under the New York Convention reflect the impact of local legal arrangements on globalized standards. Additionally, it reveals that a pluralistic approach to this exception advances a more inclusive perspective for the implementation of globalized standards while at the same time offering certainty. A pluralistic approach to the public policy exception creates a space to acknowledge and honor the diversity of legal systems coexisting globally and legitimizes local approaches to public policy. Accordingly, local legal systems do not need to import foreign definitions but can define their interpretation of public policy from within by using their local elements. Using historical, doctrinal, documentary, and qualitative analyses, this study examines the development of international standards, by reference to the public policy exception, and Mexico as an example of a local legal context. For examining local contexts, this study suggests the use of four factors –language, legal tradition, legal context, and legal culture– to understand the local approach to public policy in combination with relevant local elements. In the case of Mexico, the relevant elements examined are legislation, scholarship, court precedents, cases, and the perspective of local legal actors. These factors and elements are used to suggest components to establish a guideline for the interpretation and implementation of the public policy exception in Mexico.
Evidence for a Magnetic Proximity Effect up to Room Temperature at Fe/(Ga,Mn)As Interfaces
Creators: name: Maccherozzi, F.
name: Sperl, M.
name: Panaccione, G.
name: Minar, J.
name: Polesya, S.
name: Ebert, H.
name: Wurstbauer, U.
name: Hochstrasser, M.
name: Rossi, G.
name: Woltersdorf, Georg
name: Wegscheider, Werner
name: Back, Christian H.
Publisher: name: Universität Regensburg
Year: 2008
Subjects: subject: 530 Physik
subject: 5.50.Pp
subject: 71.20.Nr
subject: 78.70.Dm

description: We report x-ray magnetic circular dichroism and superconducting quantum interference device magnetometry experiments to study magnetic order and coupling in thin Fe/(Ga,Mn)As(100) films. We observe induced magnetic order in the (Ga,Mn)As layer that extends over more than 2 nm, even at room temperature. We find spectroscopic evidences of a hybridized d configuration of Mn atoms in Fe/(Ga,Mn)As, with negligible Mn diffusion and/or MnFe intermixing. We show by experiment as well as by theory that the magnetic moment of the Mn ions couples antiparallel to the moment of the Fe overlayer.
title: Optimierung des Order-to-Cash-Prozesses in Industrieunternehmen durch den Einsatz von Robotic Process Automation
title: Eine kritische Literaturrecherche
titleType: Subtitle
Creators: name: Keiser, Katharina
Publisher: name: FH Vorarlberg (Fachhochschule Vorarlberg)
Year: 2021
Subjects: subject: 650 Management

description: Robotic Process Automation (RPA) ist eine relativ neue Technologie, die die Automatisierung von regelbasierten Aufgaben ermöglicht. Obwohl bestehende Literatur darauf hinweist, dass zusätzlich zur RPA-Implementierung eine Prozessoptimierung vorzunehmen ist, wurde bislang nicht beschrieben, wie dieses Vorgehen aussehen kann. Deshalb zeigt die vorliegende Arbeit, wie bei der Automatisierung von Abläufen die damit verbundene Optimierung durchzuführen ist und wie im Fall des Order-to-Cash-Prozesses von Industrieunternehmen automatisierbare Prozesse ausgewählt werden können. Zudem wird beleuchtet, wie bereits bestehende IT-Systeme für die Prozessautomatisierung eingesetzt werden können. Dazu werden mithilfe einer Literaturrecherche neue Erkenntnisse gewonnen, die zeigen, zu welchem Zeitpunkt eine Prozessoptimierung in Verbindung mit einer Automatisierung durchzuführen ist. Zudem wird die Verwendung der RPA-Technologie kritisch beleuchtet und festgestellt, dass unabhängig von der Art der Automatisierung eine Prozessoptimierung vorzunehmen ist. Die Arbeit liefert somit einen wertvollen Beitrag zum aktuellen Stand der Wissenschaft und gibt Hinweise für die Anwendung in der Praxis.
description: Robotic Process Automation (RPA) is an emerging technology that enables the automation of rule-based tasks. Although existing literature points out that process optimisation must be performed in addition to RPA implementation, it has not been described yet how this procedure can look like. Therefore, this thesis provides an overview of how the associated optimisation can be conducted during the automation of processes and how, in the case of the order-to-cash process of industrial companies, processes that are suitable for automation can be selected. In addition, it is examined how already existing IT systems can be used for process automation. For this purpose, new insights are gained by means of a literature research, showing at which point a process optimisation in connection with an automation has to be carried out. Furthermore, the use of RPA technology is critically examined and it is determined that process optimisation must be carried out regardless of the type of automation. Thus, the thesis provides a valuable contribution to the current state of science and gives advice for application in practice.
An algorithm for the Cartan-Dieudonné theorem on generalized scalar product spaces
Creators: name: Rodríguez-Andrade, M. A.
name: Aragón-González, G.
name: Aragón, J. L.
name: Verde-Star, Luis
Publisher: name: arXiv
Year: 2010
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 15A23, 15A30, 15A66

description: We present an algorithmic proof of the Cartan-Dieudonné theorem on generalized real scalar product spaces with arbitrary signature. We use Clifford algebras to compute the factorization of a given orthogonal transformation as a product of reflections with respect to hyperplanes. The relationship with the Cartan-Dieudonné-Scherk theorem is also discussed in relation to the minimum number of reflections required to decompose a given orthogonal transformation.
description: 25 pages
Monoclonal antibodies to common epitopes of the human alpha/beta T-cell receptor preferentially activate CD45RA+ T-cells
Creators: name: Schwinzer, Reinhard
name: Schlitt, Hans-Jürgen
name: Wonigeit, Kurt
Publisher: name: Universität Regensburg
Year: 1992
Subjects: subject: 610 Medizin
subject: Animals
subject: Antibodies, Monoclonal/immunology
subject: Antigens, CD/immunology
subject: Antigens, CD3
subject: Antigens, CD45
subject: Antigens, Differentiation, T-Lymphocyte/immunology
subject: Cell Division
subject: Cell Line
subject: Flow Cytometry
subject: Histocompatibility Antigens/immunology
subject: Humans
subject: Interleukin-2/pharmacology
subject: Lymphocyte Activation/immunology
subject: Rats
subject: Receptors, Antigen, T-Cell/immunology
subject: Receptors, Antigen, T-Cell, alpha-beta/immunology
subject: Receptors, Interleukin-2/analysis
subject: T-Lymphocyte Subsets/immunology

description: The murine monoclonal antibody BMA 031 (IgG2b) is directed to a monomorphic epitope on the human alpha/beta T-cell receptor. In contrast to anti-CD3 antibodies of the IgG2b isotype, BMA 031 is able to induce a proliferative response in T-cells from IgG2b low responders. This response occurs independently of cross-linking conditions indicating that the mode of activation differs from stimulation by the anti-CD3 antibody OKT3 (IgG2a) which strictly depends on cross-linking conditions. to further characterize the stimulatory potential of the two antibodies we studied the lymphocyte subsets responsive to stimulation by BMA 031 and OKT3. In CD45RA+ cells both antibodies exhibited similar effects. They induced weak expression of the 55-kDa chain of the interleukin-2 receptor (CD25), virtually no interleukin-2 secretion, but nevertheless strong proliferation. In CD45R0+ cells OKT3 and BMA 031 showed markedly different effects. OKT3 stimulated strong CD25 expression, strong interleukin-2 production, and marked proliferation. In contrast, CD45R0+ cells stimulated by BMA 031 showed only weak CD25 expression but neither interleukin-2 production nor proliferation. These data suggest that CD45RA+ and CD45R0+ cells differ in their capability to produce interleukin-2 upon stimulation via the CD3/T-cell receptor complex and also in the requirement for interleukin-2 to mount a proliferative response. The differential effect of OKT3 and BMA 031 in CD45R0+ cells probably results from the failure of BMA 031 to trigger interleukin-2 production which may be a consequence of its inability to induce CD3/T-cell receptor cross-linking in IgG2b low responders BMA 031 is therefore a useful tool for the selective activation of CD45RA+ cells in these individuals.
Waist of the sphere for maps to manifolds
Creators: name: Karasev, R. N.
name: Volovikov, A. Yu.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Metric Geometry (math.MG)
subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 28A75, 52A38, 55R80

description: We generalize the sphere waist theorem of Gromov and the Borsuk--Ulam type measure partition lemma of Gromov--Memarian for maps to manifolds.
Gilbert damping in single and multilayer ultrathin films: Role of interfaces in nonlocal spin dynamics
Creators: name: Urban, R.
name: Woltersdorf, Georg
name: Heinrich, B.
Publisher: name: Universität Regensburg
Year: 2001
Subjects: subject: 530 Physik
subject: 75.40.Gb
subject: 75.70.-i
subject: 76.50.+g
subject: 76.60.Es

description: Unique features of the Gilbert damping in magnetic multilayers were investigated by ferromagnetic resonance (FMR) using magnetic single and double layer structures prepared by molecular beam epitaxy. The FMR linewidth for the Fe films in the double layer structures was larger than the FMR linewidth in the single Fe films having the same thickness. The additional FMR linewidth scaled inversely with the film thickness, and increased linearly with increasing microwave frequency. These results demonstrate that a transfer of electron angular momentum between the magnetic layers leads to additional relaxation torques.
Highlights from the CALET observations for 7.5 years on the International Space Station
Creators: name: Torii, Shoji
name: Collaboration, CALET
name: Cannady, Nicholas
name: Hams, Thomas
name: Sakai, Kazuhiro
name: Et Al.
Publisher: name: Proceedings of Science
Year: 2023

description: 38th International Cosmic Ray Conference (ICRC2023), 26 July - 3 August, 2023, Nagoya, Japan
description: CALET Collaboration Authors: - O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, E. Berti, G. Bigongiari, W.R. Binns, M. Bongi, P. Brogi, A. Bruno, N. Cannady, G. Castellini, C. Checchia, M.L. Cherry, G. Collazuol, G.A. de Nolfo, K. Ebisawa, A.W. Ficklin, H. Fuke, S. Gonzi, T.G. Guzik, T. Hams, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M.H. Israel, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, K. Kobayashi, K. Kohri, H.S. Krawczynski, J.F. Krizmanic, P. Maestro, P.S. Marrocchesi, A.M. Messineo, J.W. Mitchell, S. Miyake, A.A. Moiseev, M. Mori, N. Mori, H.M. Motz, K. Munakata, S. Nakahira, J. Nishimura, S. Okuno, J.F. Ormes, S. Ozawa, L. Pacini, P. Papini, B.F. Rauch, S.B. Ricciarini, K. Sakai, T. Sakamoto, M. Sasaki, Y. Shimizu, A. Shiomi, P. Spillantini, F. Stolzi, S. Sugita, A. Sulaj, M. Takita, T. Tamura, T. Terasawa, S. Torii, Y. Tsunesada, Y. Uchihori, E. Vannuccini, J.P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, and W.V. Zober
description: The CALorimetric Electron Telescope (CALET) space experiment is a high-energy astroparticle physics mission installed on the International Space Station (ISS). The primary goals of the CALET mission include studying the details of galactic cosmic-ray acceleration and propagation, and searching for possible nearby sources of high-energy electrons and dark matter signatures. The CALET experiment is measuring the flux of cosmic-ray electrons (including positrons) to 20 TeV, gamma-rays to 10 TeV and nuclei with Z=1 to 40 up to 1,000 TeV. The instrument consists of two layers of segmented plastic scintillators for the identification of cosmic-rays via a measurement of their charge (CHD), a 3 radiation length thick tungsten-scintillating fiber imaging calorimeter (IMC) and a 27 radiation length thick lead-tungstate calorimeter (TASC). The instrument was launched on August 19, 2015 to the ISS and installed on the Japanese Experiment Module-Exposed Facility (JEM-EF). Since the start of operations in mid-October, 2015, CALET has been in continuous observation mode over 7.5 years and mainly triggering on high energy (>10 GeV) cosmic-ray showers without any major interruption. The number of triggered events over 10 GeV is nearly 1.86 billion events as of June 30, 2023. Here, we present the highlights of the CALET latest results, including the electron + positron energy spectrum, the spectra of protons and other nuclei, gamma-ray observations, as well as the characterization of on-orbit performance. Someresults on the electromagnetic counterpart search for LIGO/Virgo gravitational wave events and the observations of solar modulation and gamma-ray bursts are also included.
Mapping complex genomic translocations using Strand-seq
Creators: name: Yuen, Michael Wai-Keong
Publisher: name: University of British Columbia
Year: 2018

description: Template strand sequencing (Strand-seq) is a single cell sequencing approach which maintains 5’ -> 3’ directionality of sequence reads. I hypothesized that the directional information preserved can be used to map complex translocation events. Translocations often disrupt gene expression by reshuffling regulatory elements or by formation of novel fusion transcripts. Yet, detection is often difficult, confounded by complexities of the Structural Variations (SVs). I chose a cell line derived from a patient with pediatric Acute Lymphoblastic Leukemia (iALL) with a known complex karyotype. My aim was to explore Strand-seq’s ability in identifying breakpoints, linking translocation partners and resolving the configuration of SV, comparing low coverage Strand-seq data against high coverage Whole Genome Sequence (WGS) data as reference. The iALL cells selected for my study harbor complex translocations involving 4 chromosomes with 5 breakpoint positions that were previously validated by Fluorescent In Situ Hybridization (FISH). BreakpointR, a novel pipeline for Strand-seq analysis, was able to identify 18 breakpoints, 5 which were isolated for further analysis. These 5 breakpoints were identified with a resolution of 5-60kb, overlapping with the genomic positions of breakpoints identified by WGS analysis, validating the accuracy of BreakpointR. Despite the lower sequencing coverage of Strand-seq, 18 breakpoints were detected against WGS’s 119 breakpoints. Next, I developed a workflow to link translocation partners involved in the breakpoints, successfully linking 4 of 5 translocation partners; the final fragment remained unresolved due to lack of reads within the genomic interval, a limitation of low sequence coverage. By comparison, WGS successfully linked 4 of 5 translocation partners, its limitations of mapping across repetitive regions resulting in a different unresolved fragment. Post-translocation-partner matching and single cell resolution from Strand-seq allowed us to further interrogate expected breakpoints for each single cell. Strand-seq analysis identified an inversion of the 100kb fragment in chromosome 11, validated with Sanger sequencing, representing an additional layer of complexity not identified by the other approaches. I conclude that the application of Strand-seq should be further explored in the areas of SV mapping as it has been proven useful for complementing the inherent difficulties of complex SV mapping across repetitive regions.
Trade Policy Trends: Chinese Protectionism: Restriction on Canola Imports from Canada
Creators: name: Beaulieu, Eugene
name: Klemen, Dylan
Publisher: name: The School of Public Policy Publications
Year: 2019

description: On March 3, 2019, China revoked the import licence for canola from Richardson International Ltd. (a large Canadian processor of grain based in Winnipeg). Chinese officials have cited pests as the reason for their action. The licence revocation occurs amid a conflict between Canada and China over the arrest in Canada of Huawei’s chief financial officer, Meng Wanzhou. Some see this as a retaliatory measure on the part of China, which has a history of using trade policy in political disputes.
description: The School of Public Policy Publications, Vol 12 (2019)
Ciclosporin metabolite pattern in blood and urine of liver graft recipients. II. Influence of cholestasis and rejection
Creators: name: Christians, U.
name: Kohlhaw, K.
name: Budniak, J.
name: Bleck, J. S.
name: Schottmann, R.
name: Schlitt, Hans-Jürgen
name: Almeida, V. M.
name: Deters, M.
name: Wonigeit, K.
name: Pichlmayr, R.
Publisher: name: Universität Regensburg
Year: 1991
Subjects: subject: Ciclosporin; Liver transplantation; metabolites; cholestasis; rejection;M19; M1A
subject: 610 Medizin
subject: Cholestasis/urine
subject: Chromatography, High Pressure Liquid
subject: Cyclosporine/urine
subject: Graft Rejection
subject: Humans
subject: Liver Transplantation
subject: Postoperative Complications
subject: Radioimmunoassay
subject: Time Factors

description: The pattern of metabolites of ciclosporin in blood and 24 h-urine of 58 liver graft recipients was routinely monitored by HPLC from transplantation until discharge from hospital. Liver function and ciclosporin metabolite pattern in patients with an uncomplicated clinical course and in those with cholestasis or acute rejection were compared. During cholestasis M19 and M1A, and during acute rejection M19, in blood were significantly elevated compared to the control group. Blood M19 was significantly correlated with bilirubin concentration and gamma-glutamyl transferase activity in serum, and M1A with the serum bilirubin concentration. Analysis of the metabolite pattern over the observation period showed higher concentrations of M19 and M1A in blood from patients with cholestasis and acute rejection than in the control group; concentrations were lower in the rejection group than in the cholestasis group. The metabolite pattern in 24 h-urine showed similar alterations in ciclosporin metabolite pattern to those in blood. Cholestasis and rejection shift the ciclosporin metabolite pattern in blood and urine to higher concentrations of M19 and M1A, whereas the concentrations of other metabolites and ciclosporin were not significantly affected.
Paley-Wiener spaces with vanishing conditions and Painlevé VI transcendents
Creators: name: Burnol, Jean-François
Publisher: name: arXiv
Year: 2010
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics

description: We modify the classical Paley-Wiener spaces $PW_x$ of entire functions of finite exponential type at most $x>0$, which are square integrable on the real line, via the additional condition of vanishing at finitely many complex points $z_1, ..., z_n$. We compute the reproducing kernels and relate their variations with respect to $x$ to a Krein differential system, whose coefficient (which we call the $μ$-function) and solutions have determinantal expressions. Arguments specific to the case where the "trivial zeros" $z_1, ..., z_n$ are in arithmetic progression on the imaginary axis allow us to establish for expressions arising in the theory a system of two non-linear first order differential equations. A computation, having this non-linear system at his start, obtains quasi-algebraic and among them rational Painlevé transcendents of the sixth kind as certain quotients of such $μ$-functions.
description: 30 pages
Layer resolved magnetization dynamics in coupled magnetic films using time-resolved x-ray magnetic circular dichroism with continuous wave excitation
Creators: name: Martin, T.
name: Woltersdorf, Georg
name: Stamm, C.
name: Duerr, H. A.
name: Mattheis, R.
name: Back, Christian H.
name: Bayreuther, Günther
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: cobalt alloys, ferromagnetic materials, iron alloys, magnetic circular dichroism, magnetic thin films, magnetisation, nickel alloys, ruthenium
subject: 530 Physik
subject: 75.60.Ej
subject: 78.20.Ls
subject: 75.70.-i

description: Time-resolved x-ray magnetic circular dichroism was used to investigate ferromagnetically coupled CoFe/Ru/NiFe bilayers. The magnetization dynamics was driven by a continuous wave excitation. The precessional motion of the individual layers was detected separately by tuning the x-ray photon energy to the L-3 absorption edge of either Ni or Co. Using two different waveguide stack geometries in-phase and antiphase excitation could be selected showing its effect in the measured precessional signal of the individual layers. In exchange-coupled bilayer two precessional modes were observed for each layer. The relative phase angles of the magnetic response between the two layers were found to be 8 and 133, for the two modes revealed their quasiacoustic and quasioptic character. (c) 2009 American Institute of Physics. [DOI: 10.1063/1.3068650]
Ciclosporin metabolite pattern in blood and urine of liver graft recipients. I. Association of ciclosporin metabolites with nephrotoxicity
Creators: name: Christians, U.
name: Kohlhaw, K.
name: Budniak, J.
name: Bleck, J. S.
name: Schottmann, R.
name: Schlitt, Hans-Jürgen
name: Almeida, V. M.
name: Deters, M.
name: Wonigeit, K.
name: Pichlmayr, R.
Publisher: name: Universität Regensburg
Year: 1991
Subjects: subject: Ciclosporin liver transplantation; metabolites; nephrotoxicity
subject: 610 Medizin
subject: Adult
subject: Chromatography, High Pressure Liquid
subject: Cyclosporine/urine
subject: Humans
subject: Kidney/physiology
subject: Liver/physiology
subject: Liver Transplantation

description: Blood ciclosporin (Cs) metabolite pattern in 58 liver grafted patients was routinely monitored by HPLC from the first Cs dose after transplantation until discharge from hospital. Eighteen patients with normal kidney function were allocated to Group I and 14 patients in Group II suffered Cs nephrotoxicity during their clinical course. There were no significant differences between both groups in blood Cs level, kidney function before transplantation, liver function or co-administration of other potentially nephrotoxic drugs. A correlation matrix involving both groups showed a significant correlation between the blood concentration of metabolite M1c9 and serum creatinine and urea, and an inverse correlation with creatinine clearance. During a nephrotoxic episode the blood concentrations of metabolites M1c9 and M1A were significantly elevated in patients in Group II. Analysis of the time course revealed significantly higher blood levels of M19 and M1c9 in Group II patients compared with those in Group I for the first 10 days after transplantation. Serum creatinine and urea concentrations remained significantly elevated, the creatinine clearance being significantly reduced throughout the period of observation. The elevated blood concentrations of ciclosporin metabolites M1c9 and M19 during nephrotoxic episodes suggest that these metabolites are associated with ciclosporin nephrotoxicity. It could not be decided if the elevated metabolite concentrations were the result of and/or the reason for impaired kidney function.
Two- and three-dimensional transient melt-flow simulation in vapour-pressure-controlled Czochralski crystal growth
Creators: name: Bänsch, Eberhard
name: Davis, Dominic
name: Langmach, Hartmut
name: Reinhardt, Gerd
name: Uhle, Manfred
Publisher: name: Weierstrass Institute
Year: 2003
Subjects: subject: axisymmetric
subject: buoyancy
subject: Czochralski
subject: crystal growth
subject: finite-element
subject: GaAs
subject: Navier-Stokes equations
subject: vapour-pressure controlled
subject: 35Q30
subject: 65M60
subject: 76-04
subject: 76D05

description: Flow and thermal properties associated with semiconductor melt flow in an axisymmetric crucible container are studied numerically. Axisymmetric and three-dimensional computational solutions are obtained using a standard-Galerkin, finite-element solver. The crucible and crystal are optionally rotated, and the influence of gravity (through buoyancy) is accounted for via a Boussinesq approximation in the controlling Navier-Stokes equations. The results indicate a strong dependence of the flow on both rotation and buoyancy. Results for axisymmetric flows, computed in both flat and curved geometries, are presented first, and strongly suggest that rotation of crystal and crucible in the same direction (iso-rotation) is most favourable for producing a desired convexity for the crystal/melt interface. Three-dimensional results are then presented for higher Reynolds numbers, and, in particular, reveal that for iso-rotation under moderate buoyancy, the flow undergoes a switch from a steady, 2D state to an unsteady 3D state, and that the temperature becomes non-trivially advected by the flow beneath the crystal. Further evidence reveals however, that on a time scale more appropriate to the crystal growth process, the (time-averaged) flow has a weaker three-dimensionality, in relation to its axisymmetric mode, and there is only slight distortion to the temperature field beneath the crystal.
An Early Warning System for Asteroid Impact
Creators: name: Tonry, John L.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Earth is bombarded by meteors, occasionally by one large enough to cause a significant explosion and possible loss of life. Although the odds of a deadly asteroid strike in the next century are low, the most likely impact is by a relatively small asteroid, and we suggest that the best mitigation strategy in the near term is simply to move people out of the way. We describe an "early warning" system that could provide a week's notice of most sizable asteroids or comets on track to hit the Earth. This system, dubbed "Asteroid Terrestrial-impact Last Alert System" (ATLAS), comprises two observatories separated by about 100km that simultaneously scan the visible sky twice a night, and can be implemented immediately for relatively low cost. The sensitivity of ATLAS permits detection of 140m asteroids (100 Mton impact energy) three weeks before impact, and 50m asteroids a week before arrival. An ATLAS alarm, augmented by other observations, should result in a determination of impact location and time that is accurate to a few kilometers and a few seconds. In addition to detecting and warning of approaching asteroids, ATLAS will continuously monitor the changing universe around us: most of the variable stars in our galaxy, many micro-lensing events from stellar alignments, luminous stars and novae in nearby galaxies, thousands of supernovae, nearly a million quasars and active galactic nuclei, tens of millions of galaxies, and a billion stars. With two views per day ATLAS will make the variable universe as familiar to us as the sunrise and sunset.
description: 33 pages, 7 figures, accepted for publication in PASP, Jan 2011