cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Entanglement Spectroscopy of a Driven Solid-State Qubit and Its Detector
Creators: name: Goorden, M. C.
name: Thorwart, Michael
name: Grifoni, Milena
Publisher: name: Universität Regensburg
Year: 2004
Subjects: subject: 530 Physik

description: We study the asymptotic dynamics of a driven quantum two-level system coupled via a quantum detector to the environment. We find multiphoton resonances which are due to the entanglement of the qubit and the detector. Different regimes are studied by employing a perturbative Floquet-Born-Markov approach for the qubit detector system, as well as nonperturbative real-time path integral schemes for the driven spin-boson system. We find analytical results for the resonances, including the red and the blue sidebands. They agree well with those of exact ab initio calculations.
Correlated sequential tunneling in Tomonaga-Luttinger liquid quantum dots
Creators: name: Thorwart, Michael
name: Egger, R.
name: Grifoni, Milena
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik

description: We investigate tunneling through a quantum dot formed by two strong impurites in a spinless Tomonaga-Luttinger liquid. Upon employing a Markovian master equation approach, we compute the linear conductance due to sequential tunneling processes. Besides the previously used lowest-order Golden Rule rates describing uncorrelated sequential tunneling (UST) processes, we systematically include higher-order correlated sequential tunneling (CST) diagrams within the standard Weisskopf-Wigner approximation. We provide estimates for the parameter regions where CST effects are shown to dominate over UST. Focusing mainly on the temperature dependence of the conductance maximum, we discuss the relation of our results to previous theoretical and experimental results.
LOFT - a Large Observatory For x-ray Timing
Creators: name: Feroci, M.
name: Stella, L.
name: Vacchi, A.
name: Labanti, C.
name: Rapisarda, M.
name: Attinà, P.
name: Belloni, T.
name: Campana, R.
name: Campana, S.
name: Costa, E.
name: Del Monte, E.
name: Donnarumma, I.
name: Evangelista, Y.
name: Israel, G. L.
name: Muleri, F.
name: Porta, P.
name: Rashevsky, A.
name: Zampa, G.
name: Zampa, N.
name: Baldazzi, G.
name: Bertuccio, G.
name: Bonvicini, V.
name: Bozzo, E.
name: Burderi, L.
name: Corongiu, A.
name: Covino, S.
name: Dall'Osso, S.
name: De Martino, D.
name: Di Cosimo, S.
name: Di Persio, G.
name: Di Salvo, T.
name: Fuschino, F.
name: Grassi, M.
name: Lazzarotto, F.
name: Malcovati, P.
name: Marisaldi, M.
name: Mastropietro, M.
name: Mereghetti, S.
name: Morelli, E.
name: Orio, M.
name: Pellizzoni, A.
name: Pacciani, L.
name: Papitto, A.
name: Picolli, L.
name: Possenti, A.
name: Rubini, A.
name: Soffitta, P.
name: Turolla, R.
name: Zampieri, L.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The high time resolution observations of the X-ray sky hold the key to a number of diagnostics of fundamental physics, some of which are unaccessible to other types of investigations, such as those based on imaging and spectroscopy. Revealing strong gravitational field effects, measuring the mass and spin of black holes and the equation of state of ultradense matter are among the goals of such observations. At present prospects for future, non-focused X-ray timing experiments following the exciting age of RXTE/PCA are uncertain. Technological limitations are unavoidably faced in the conception and development of experiments with effective area of several square meters, as needed in order to meet the scientific requirements. We are developing large-area monolithic Silicon Drift Detectors offering high time and energy resolution at room temperature, which require modest resources and operation complexity (e.g., read-out) per unit area. Based on the properties of the detector and read-out electronics that we measured in the lab, we developed a realistic concept for a very large effective area mission devoted to X-ray timing in the 2-30 keV energy range. We show that effective areas in the range of 10-15 square meters are within reach, by using a conventional spacecraft platform and launcher of the small-medium class.
description: 13 pages, 8 figures, 1 table, Proceedings of SPIE Vol. 7732, Paper No. 7732-66, 2010
Polycyclic aromatic hydrocarbons in the dwarf galaxy IC 10
Creators: name: Wiebe, D. S.
name: Egorov, O. V.
name: Lozinskaya, T. A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Infrared observations from the Spitzer Space Telescope archive are used to study the dust component of the interstellar medium in the IC~10 irregular galaxy. Dust distribution in the galaxy is compared to the distributions of H$α$ and [SII] emission, neutral hydrogen and CO clouds, and ionizing radiation sources. The distribution of polycyclic aromatic hydrocarbons (PAH) in the galaxy is shown to be highly non-uniform with the mass fraction of these particles in the total dust mass reaching 4%. PAHs tend to avoid bright HII regions and correlate well with atomic and molecular gas. This pattern suggests that PAHs form in the dense interstellar gas. We propose that the significant decrease of the PAH abundance at low metallicity is observed not only globally (at the level of entire galaxies), but also locally (at least, at the level of individual HII regions). We compare the distribution of the PAH mass fraction to the distribution of high-velocity features, that we have detected earlier in wings of H$α$ and SII lines, over the entire available galaxy area. No conclusive evidence for shock destruction of PAHs in the IC~10 galaxy could be found.
description: Accepted for publication in Astronomy Reports
Anisotropy of Magnetic Interactions in the Spin-Ladder Compound (C$_5$H$_{12}$N)$_2$CuBr$_4$
Creators: name: Čižmár, E.
name: Ozerov, M.
name: Wosnitza, J.
name: Thielemann, B.
name: Krämer, K. W.
name: Rüegg, Ch.
name: Piovesana, O.
name: Klanjšek, M.
name: Horvatić, M.
name: Berthier, C.
name: Zvyagin, S. A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Magnetic excitations in the spin-ladder material (C$_5$H$_{12}$N)$_2$CuBr$_4$ [BPCB] are probed by high-resolution multi-frequency electron spin resonance (ESR) spectroscopy. Our experiments provide a direct evidence for a biaxial anisotropy ($\sim 5\%$ of the dominant exchange interaction), that is in contrast to a fully isotropic spin-ladder model employed for this system previously. It is argued that this anisotropy in BPCB is caused by spin-orbit coupling, which appears to be important for describing magnetic properties of this compound. The zero-field zone-center gap in the excitation spectrum of BPCB, $Δ_0/k_{B}=16.5$ K, is detected directly. Furthermore, an ESR signature of the inter-ladder exchange interactions is obtained. The detailed characterization of the anisotropy in BPCB completes the determination of the full spin hamiltonian of this exceptional spin-ladder material and shows ways to study anisotropy effects in spin ladders.
description: 6 pages, 6 figures
Abundance determination in HII regions from spectra without the [OII]3727+3729 line
Creators: name: Pilyugin, L. S.
name: Mattsson, L.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We suggest an empirical calibration for determination of oxygen and nitrogen abundances and electron temperature in HII regions where the [OII]3727+3729 line (R_2) is not available. The calibration is based on the strong emission lines of OIII, NII, and SII (NS calibration) and derived using the spectra of HII regions with measured electron temperatures as calibration datapoints. The NS calibration makes it possible to derive abundances for HII regions in nearby galaxies from the SDSS spectra where R_2 line is out of the measured wavelength range, but can also be used for the oxygen and nitrogen abundances determinations in any HII region independently whether the nebular oxygen line [OII]3727+3729 is available or not. The NS calibration provides reliable oxygen and nitrogen abundances for HII regions over the whole range of metallicities.
description: 6 pages, 4 figures, accepted for publication in the MNRAS
Pathogenesis of leishmania infection in human macrophages : role of leishmania chaperonin 10 and modulation of host miRNA
Creators: name: Colineau, Lucie
Publisher: name: University of British Columbia
Year: 2019

description: Protozoan parasites of the genus Leishmania infect macrophages in their mammalian hosts causing a spectrum of diseases known as the leishmaniases. The search for parasite and host factors that support macrophage infection is a focus of significant interest. Here, I studied two aspects of the host-pathogen interaction: the role of the leishmania protein chaperonin 10 (CPN10) and the impact of leishmania infection on host cell micro RNA (miRNA) expression. The heat shock protein CPN10 is secreted by leishmania in exosomes and its human homolog has immunosuppressive properties. Two genetically modified strains of Leishmania donovani (Ld) were generated: one overexpressing CPN10 (CPN10+++) and the second, a CPN10 single allele knockdown (CPN10+/−). When compared with the wild-type (WT) parental strain, CPN10+/− Ld showed higher infection rates and parasite loads in human macrophages after 24 h of infection. Conversely, CPN10+++ Ld was associated with lower initial infection rates. We found that this unexpected apparent gain-of-function for the knockdown was a result of CPN10+/− Ld being more readily internalized than WT Ld. However, the CPN10+/- strain also displayed significantly impaired intracellular survival. Taken together, these findings identify leishmania CPN10 as a novel effector that negatively regulates the rate of parasite uptake by macrophages while being required for intracellular survival. miRNAs have recently emerged as ubiquitous regulators of gene expression. Here, we used miRNA expression profiling to ask whether leishmania target their host cell miRNA machinery as a novel virulence strategy. The data show that leishmania infection of human macrophages induces a genome-wide downregulation of host miRNAs. This repression takes place at the level of miRNA gene transcription as the synthesis rates of primary miRNAs are markedly decreased in infected cells. Expression of the host transcription factor c-Myc is markedly upregulated by infection and silencing of c-Myc both reverses miRNA suppression and brings about a significant reduction in leishmania survival. These findings identify c-Myc as a novel and essential leishmania virulence factor by proxy that targets the host miRNA machinery and promotes pathogen survival.
title: Universität Kassel, Vorlesungsverzeichnis WiSe 2018 / 2019
Creators: name: (:Unkn) Unknown
Publisher: name: Universität Kassel
Year: 2018
Subjects: subject: 350
subject: 370
subject: Universität Kassel
subject: Vorlesungsverzeichnis

description: PDF zum Online-Vorlesungsverzeichnis
Ab initio theory of the lattice thermal conductivity in diamond
Creators: name: Ward, Alister
name: Broido, David
name: Stewart, Derek A.
name: Deinzer, Gernot
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: ab initio calculations, Boltzmann equation, density functional theory, diamond, elemental semiconductors, phonon spectra, potential energy functions, thermal conductivity
subject: 530 Physik
subject: 66.70.-f
subject: 63.20.kg
subject: 71.15.Mb

description: We present a first-principles theoretical approach to calculate the lattice thermal conductivity of diamond based on an exact solution of the Boltzmann transport equation. Density-functional perturbation theory is employed to generate the harmonic and third-order anharmonic interatomic force constants that are required as input. A central feature of this approach is that it provides accurate representations of the interatomic forces and at the same time introduced no adjustable parameters. The calculated lattice thermal conductivities for isotopically enriched and naturally occurring diamond are both in very good agreement with experimental data. The role of the scattering of heat-carrying acoustic phonons by optic branch phonons is also investigated. We show that inclusion of this scattering channel is indispensable in properly describing the thermal conductivity of semiconductors and insulators. The accurate adjustable-parameter-free results obtained herein highlight the promise of this approach in providing predictive descriptions of the lattice thermal conductivity of materials.
Mapping the magnetic anisotropy in (Ga,Mn)As nanostructures
Creators: name: Hoffmann, Frank
name: Woltersdorf, Georg
name: Wegscheider, Werner
name: Einwanger, Andreas
name: Weiss, Dieter
name: Back, Christian
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: coercive force, ferromagnetic resonance, gallium arsenide, magnetic anisotropy, manganese compounds, nanostructured materials, semimagnetic semiconductors
subject: 530 Physik
subject: 75.75.+a; 75.30.Gw; 75.50.Pp; 76.50.+g

description: Anisotropic strain relaxation in (Ga,Mn)As nanostructures was studied combining time-resolved Kerr microscopy and ferromagnetic resonance techniques. Local resonance measurements on individual narrow stripes patterned along various crystallographic directions reveal that the easy axis of the magnetization can be forced perpendicular to the strain relaxation direction. Spatially resolved measurements on disk-shaped and rectangular (Ga,Mn)As structures allow us to directly visualize these local changes in the magnetic anisotropy. We show that the strain-induced edge anisotropy allows for an effective control of the coercive field in stripe structures.
Correlated sequential tunneling through a double barrier for interacting one-dimensional electrons
Creators: name: Thorwart, Michael
name: Egger, R.
name: Grifoni, Milena
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik

description: The problem of resonant tunneling through a quantum dot weakly coupled to spinless Tomonaga-Luttinger liquids has been studied. We compute the linear conductance due to sequential tunneling processes upon employing a master equation approach. Besides the previously used lowest-order golden rule rates describing uncorrelated sequential tunneling processes, we systematically include higher-order correlated sequential tunneling (CST) diagrams within the standard Weisskopf-Wigner approximation. We provide estimates for the parameter regions where CST effects can be important. Focusing mainly on the temperature dependence of the peak conductance, we discuss the relation of these findings to previous theoretical and experimental results.
All-Electrical Measurement of the Density of States in (Ga,Mn)As
Creators: name: Neumaier, Daniel
name: Turek, Marko
name: Wurstbauer, Ursula
name: Vogl, Anton
name: Utz, Martin
name: Wegscheider, Werner
name: Weiss, Dieter
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: 530 Physik
subject: 75.50.Pp; 71.20.-b; 73.23.-b

description: We report on electrical measurements of the effective density of states in the ferromagnetic semiconductor material (Ga,Mn)As. By analyzing the conductivity correction to an enhanced electron-electron interaction the electrical diffusion constant was extracted for (Ga,Mn)As samples of different dimensionality. Using the Einstein relation allows us to deduce the effective density of states of (Ga,Mn)As at the Fermi energy.
Gull wing morphing allows active control of trade-offs in efficiency, maneuverability and stability
Creators: name: Harvey, Christina
Publisher: name: University of British Columbia
Year: 2019

description: Birds flying in turbulent conditions demonstrate impressive flight stability and control. This versatility is hypothesized to derive from dynamic wing shape changes, an ability termed wing morphing. Bird wings can morph passively through inertial or aerodynamic loading of flexible components or actively when birds stimulate their network of intrinsic wing muscles. The majority of active wing morphing is actuated through the wrist or elbow joints. Wrist flexion improves high-speed and turning performance, but little is known about the morphology or aerodynamic consequences of morphing the elbow joint. Here we show that gulls gliding in unsteady environments reduce their passive stability by actively reducing their elbow angle. We first photographed gulls in gliding flight to quantify their wing shapes. We next used cadavers to determine the viable range of elbow angles and isolate the subset that was used by gliding gulls. The behavioral observations and cadaver manipulations revealed an in vivo gliding elbow angle range of 90°-154° and that there is a significant reduction of the elbow angle used by gulls as local wind speeds and gusts increase. Next, wings were prepared and dried across the full range of elbow angles and tested in a wind tunnel at varied turbulence intensities. These force measurements revealed that the lower elbow angles used by gliding gulls had improved aerodynamic efficiency but reduced passive pitch stability. Moreover, we found that the in vivo elbow range captures the majority of the available aerodynamic variation. Collectively, our results indicate a coupling in efficiency and stability in avian gliding and that wing morphing allows gulls to modulate aerodynamic trade-offs which may allow for a steadier flight path in an unsteady environment.
Alireza Abiz. Censorship of Literature in Post-Revolutionary Iran Politics and Culture Since 1979
Creators: name: Fomeshi, Behnam
Publisher: name: figshare
Year: 2022
Subjects: subject: 200523 Middle Eastern Literature
subject: FOS: Languages and literature

description:
The author does justice to a subject often mentioned, yet rarely studied. He succeeds in its purpose, i.e., providing “as genuine a picture as possible of the censorship of literature after the 1979 Revolution” followed by discussing “the effects of this unique censorship regime on the Iranian literature of the time” (9). Drawing from his experience as a censored reader, writer, and publisher, he begins with an illuminating account of his experience as a child and a teenager in (post)revolutionary Iran.
The Multifrequency Campaign on 3C 279 in January 2006
Creators: name: Collmar, W.
name: Böttcher, M.
name: Krichbaum, T. P.
name: Agudo, I.
name: Bottacini, E.
name: Bremer, M.
name: Burwitz, V.
name: Cuccchiara, A.
name: Grupe, D.
name: Gurwell, M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present the results of a multifrequency campaign from radio to hard X-ray energies on the blazar 3C 279 during an optical high-state in January 2006. We give the observational results (multifrequency light curves and spectra) and compile an SED. This complements an SED from an optical low-state in June 2003. Surprisingly the two SEDs differ only in their high-energy synchrotron emission (near-IR - UV), while the low-energy inverse-Compton emission (X- to Gamma-rays) remained unchanged. By interpreting with a steady-state leptonic emission model, the variability among the SED can be reproduced by a change solely of the low-energy cutoff of the relativistic electron distribution. In an internal shock model for blazar emission, such a change could e.g. achieved through a varying relative Lorentz factor of colliding shells producing internal shocks in the jet.
description: 11 pages, 9 figures, A&A accepted
Duality relation for quantum ratchets
Creators: name: Peguiron, J.
name: Grifoni, Milena
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik

description: A duality relation between the long-time dynamics of a quantum Brownian particle in a tilted ratchet potential and a driven dissipative tight-binding model is reported. It relates a situation of weak dissipation in one model to strong dissipation in the other one, and vice versa. We apply this duality relation to investigate transport and rectification in ratchet potentials: From the linear mobility we infer ground-state delocalization for weak dissipation. We report reversals induced by adiabatic driving and temperature in the ratchet current and its dependence on the potential shape.
Arrays of Josephson junctions between unconventional superconductors
Creators: name: Khveshchenko, D. V.
name: Crooks, R.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We study large arrays of mesoscopic junctions between gapless superconductors where the tunneling processes of both, particle-hole and Cooper, pairs give rise to a strongly retarded effective action which, contrary to the standard case, can not be readily characterized in terms of a local Josephson energy. This complexity is expected to arise in, e.g., the grain boundary and c-axis junctions in layered high-T_c superconductors. A new representation for describing collective phenomena in this system is introduced, and its phase diagram is discussed, alongside the electrical conductivity.
description: Latex, 4+ pages, 1 figure
Advances in the Development of Micropattern Gaseous Detectors with Resistive Electrodes
Creators: name: Fonte, P.
name: Martinengo, P.
name: Nappi, E.
name: Oliveira, R.
name: Peskov, V.
name: Pietropaolo, F.
name: Picchi, P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: We describe the most recent efforts made by various groups in implementing resistive electrodes in micropattern gaseous detectors with the aim to combine in the same design the best features of RPCs (for the example, their robustness and spark protection property) with the high granularity and thus the good position resolution offered by microelectronic technology. In the stream of this activity, we have recently developed two novel detectors with resistive electrodes: one was based on resistive micromeshes and the second one is a MSGC with resistive electrodes. We have demonstrated that the resistive meshes are a convenient construction element for various designs of spark protective detectors: RPCs type, GEM type and MICROMEGAS type. These new detectors enable to considerably enhance the RPC and micropattern detectors applications since they feature not only a high position resolution but also a relatively good energy resolution (25-30 persent FWHM at 6 keV) and, if necessary, they can operate in cascaded mode allowing the achievement of a high overall gas gain. The main conclusion from these studies is that the implementation of resistive electrodes in micropattern detectors makes them fully spark protected; on this basis we consider this direction very promising.
Noncollinear single-electron spin-valve transistors
Creators: name: Wetzels, Wouter
name: Bauer, Gerrit E. W.
name: Grifoni, Milena
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik

description: We study interaction effects on transport through a small metallic cluster connected to two ferromagnetic leads (a single-electron spin-valve transistor) in the “orthodox model” for the Coulomb blockade. The nonlocal exchange between the spin accumulation on the island and the ferromagnetic leads is shown to affect the transport properties such as the electric current and spin-transfer torque as a function of the magnetic configuration, gate voltage, and applied magnetic field.
Superconducting energy gap in MgCNi3 single crystals: Point-contact spectroscopy and specific-heat measurements
Creators: name: Pribulova, Z.
name: Kacmarcik, J.
name: Marcenat, C.
name: Szabo, P.
name: Klein, T.
name: Demuer, A.
name: Rodiere, P.
name: Jang, D. J.
name: Lee, H. S.
name: Lee, H. G.
name: Lee, S. -I.
name: Samuely, P.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Specific heat has been measured down to 600 mK and up to 8 Tesla by the highly sensitive AC microcalorimetry on the MgCNi3 single crystals with Tc ~ 7 K. Exponential decay of the electronic specific heat at low temperatures proved that a superconducting energy gap is fully open on the whole Fermi surface, in agreement with our previous magnetic penetration depth measurements on the same crystals. The specific-heat data analysis shows consistently the strong coupling strength 2D/kTc ~ 4. This scenario is supported by the direct gap measurements via the point-contact spectroscopy. Moreover, the spectroscopy measurements show a decrease in the critical temperature at the sample surface accounting for the observed differences of the superfluid density deduced from the measurements by different techniques.
Cosmological Solutions in Five Dimensional Minimal Supergravity
Creators: name: Ghezelbash, A. M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We construct new non-stationary cosmological solutions to five-dimensional minimal supergravity that don't have any tri-holomorphic U(1) isometries. Our new solutions, in part, contain some of the previously constructed solutions to the minimal supergravity. The c-function of solutions shows monotonic increasing/decreasing behaviour in time, in agreement with the expected behaviour of c-function in spacetimes with positive cosmological constant.
description: 13 pages, 4 figures
Corales/Corals
Creators: name: Tello-Musi, José Luis
name: Ugalde, Diana
name: Simoes, Nuno
name: Guerra, Alberto
Publisher: name: Zenodo
Year: 2019
Subjects: subject: Biodiversity
subject: Caribbean
subject: Coral
subject: Ecology
subject: FOS: Biological sciences
subject: Ecosystem Ecology
subject: Gulf of Mexico
subject: Marine Biodiversity
subject: Marine Biology
subject: Marine Ecology
subject: Marine Environment
subject: Species diversity

description: This Infographic is a product of BDMY (https://www.bdmy.org.mx) project, that
 was produced with funds of the Harte Research Institute for Gulf of
 Mexico Studies, and CONABIO (Mexico).
 The information in the infographic was reviewed and validated by a
 group of specialists in the taxon.
2PPS – Publish/Subscribe with Provable Privacy
Creators: name: Abdelwahab Gaballah, Sarah
name: Coijanovic, Christoph
name: Strufe, Thorsten
name: Mühlhäuser, Max
Publisher: name: Institute of Electrical and Electronics Engineers (IEEE)
Year: 2021
Subjects: privacy
anonymity
publish
subscribe
social media
messenger

description: Publish/Subscribe systems like Twitter and Reddit let users communicate with many recipients without requiring prior personal connections. The content that participants of these systems publish and subscribe to is typically public, but they may nevertheless wish to remain anonymous. While many existing systems allow users to omit explicit identifiers, they do not address the obvious privacy risks of being associated with content that may contain a wide range of sensitive information. We present 2PPS (Twice-Private Publish-Subscribe), the first pub/sub protocol to deliver strong provable privacy protection for both publishers and subscribers, leveraging Distributed Point Function-based secret sharing for publishing and Private Information Retrieval for subscribing. 2PPS does not require trust in other clients and its privacy guarantees hold as long as even a single honest server participant remains. Furthermore, it is scalable and delivers latency suitable for microblogging applications. A prototype implementation of 2PPS can handle 100,000 concurrent active clients with 5 seconds end-to-end latency and significantly lower bandwidth requirements than comparable systems.
Helicity and Electron-Correlation Effects on Transport Properties of Double-Walled Carbon Nanotubes
Creators: name: Wang, Shidong
name: Grifoni, Milena
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik

description: We study the asymptotic dynamics of a driven spin-boson system where the environment is formed by a broadened localized mode. Upon exploiting an exact mapping, an equivalent formulation of the problem in terms of a quantum two-state system (qubit) coupled to a harmonic oscillator which is itself Ohmically damped, is found. We calculate the asymptotic population difference of the two states in two complementary parameter regimes. For weak damping and low temperature, a perturbative Floquet-Born-Markovian master equation for the qubit-oscillator system can be solved. We find multi-photon resonances corresponding to transitions in the coupled quantum system and calculate their line-shape analytically. In the complementary parameter regime of strong damping and/or high temperatures, non-perturbative real-time path integral techniques yield analytic results for the resonance line shape. In both regimes, we find very good agreement with exact results obtained from a numerical real-time path-integral approach. Finally, we show for the case of strong detuning between qubit and oscillator that the width of the n-photon resonance scales with the nth Bessel function of the driving strength in the weak-damping regime.
Optical Tomography of Photon-Added Coherent States, Even/Odd Coherent States and Thermal States
Creators: name: Korennoy, Ya. A.
name: Man'ko, V. I.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Explicit expressions for optical tomograms of the photon-added coherent states, even/odd photon-added coherent states and photon-added thermal states are given in terms of Hermite polynomials. Suggestions for experimental homodyne detection of the considered photon states are presented.
description: 10 pages, 8 figures
Gilbert Malcolm Sproat, British Columbia Indian reserve commissioner (1876-1880), and the "humanitarian civilizing" of indigenous peoples
Creators: name: Pike, Sarah P.
Publisher: name: University of British Columbia
Year: 2018

description: Gilbert Malcolm Sproat (1834-1913) was one of British Columbia’s first post-confederation Indian reserve commissioners. He served two years as the joint commissioner to the Joint Indian Reserve Commission (1876-1878) and then two more years as the sole commissioner of a reconstituted commission (1878-1880). In these capacities, Sproat left thousands of handwritten pages analyzing his decisions allotting Indian reserves and providing his thoughts more generally about Indigenous peoples and their relationship to the new settler society. His legacy remains today most obviously in surveyed Indian reserve boundaries that represent more than just lines on maps: they also represent the ideas, beliefs, and reasoning that generated them. Through a comprehensive review of Sproat’s writing and an attention to his “intellectual history,” I analyze Sproat’s own explanations to elucidate what he believed about Indigenous peoples and why, and how those beliefs affected his reserve-allotment decisions. I conclude that two fields of 19th-century thought influenced Sproat most strongly: the push for Indigenous “civilization” and humanitarianism. Further, the idea at the core of Sproat’s beliefs is that the only way Canada’s Indigenous “civilization” program would succeed is if Indigenous people were the primary actors in their own “civilization.” By reviewing Sproat’s adult life prior to becoming reserve commissioner and his four-year tenure as reserve commissioner with these new insights, one can see his drive for the “humanitarian civilizing” of Indigenous peoples running throughout his decisions. This broader knowledge about Sproat’s influences, in turn, provide additional perspectives on the Indian reserve-creation process in British Columbia. Whereas previous scholars have addressed Sproat as an adjunct to other primary investigations, I begin with Sproat. I approach him from the perspective of a legal historian interested in the intersection of land; Indigenous occupation, rights, and ownership of land; and settler law about land and Indigenous people. I conclude that he was very much a man of his time, not of ours, and he can be best understood in light of his intellectual, legal, social, and cultural context, including as part of the liberal order framework, an emerging paradigm through which to analyze and understand Canadian history.
qSOFC - Quality assurance in SOFC manufacturing
Creators: name: McPhail, S.J.
name: Litke, A.
name: Höppener, R.
name: Rautanen, M.
name: Pylypko, S.
name: Õunpuu, E.
name: Hailer, S.
name: Noponen, M.
name: Berger, R.
name: Aheimer, S.
Publisher: name: Zenodo
Year: 2021

description: Poster presented at the European Fuel Cell Conference 2017 (EFC2017 - 12-15 December 2017, Naples - Italy) resuming main objective and results of the European project qSOFC (Automated mass-manufacturing and quality assurance of Solid Oxide Fuel Cell stacks). This project has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking grant agreement No 735160. This Joint Undertaking receives support from The European Union’s Horizon 2020 Research and Innovation programme.
Cutoff-Free Traveling Wave NMR
Creators: name: Tang, Joel A.
name: Wiggins, Graham C.
name: Sodickson, Daniel K.
name: Jerschow, Alexej
Publisher: name: arXiv
Year: 2011
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Recently, the concept of traveling-wave NMR/MRI was introduced by Brunner et al. (Nature 457, 994-992 (2009)), who demonstrated MR images acquired using radio frequency (RF) waves propagating down the bore of an MR scanner. One of the significant limitations of this approach is that each bore has a specific cutoff frequency, which can be higher than most Larmor frequencies of at the magnetic field strengths commonly in use for MR imaging and spectroscopy today. We overcome this limitation by using a central conductor in the waveguide and thereby converting it to a transmission line (TL), which has no cutoff frequency. Broadband propagation of waves through the sample thus becomes possible. NMR spectra and images with such an arrangement are presented and genuine traveling wave behavior is demonstrated. In addition to facilitating NMR spectroscopy and imaging in smaller bores via traveling waves, this approach also allows one to perform multinuclear traveling wave experiments (an example of which is shown), and to study otherwise difficult-to-access samples in unusual geometries.
description: 25 pages, 7 figures, previously presented at (1) World-Wide NMR Conference (ISMAR/Ampere joint meeting), Florence, Italy, July 9, 2010, and (2) Experimental NMR Conference, Asilomar, CA, April 13, 2011
Understanding the molecular mechanisms underlying glia-glia communication in the Drosophila peripheral nerve
Creators: name: Das, Mriga
Publisher: name: University of British Columbia
Year: 2018

description: Development and maintenance of the peripheral nervous system (PNS) relies on glial cells that insulate and protect axons. In invertebrates, wrapping glia isolate axons into separate bundles similar to non-myelinating Schwann cells (NMSCs) in vertebrate Remak bundles. The mechanisms by which NMSCs communicate with each other remains unknown. In this thesis, we focused on identifying and characterizing proteins required for glia-glia communication in non-myelinating classes of glia using the Drosophila peripheral nerve as our model. We show that Innexin1 (Inx1) and Innexin2 (Inx2) based gap junctions (GJs) exist between two peripheral glial layers, the subperineurial glia (SPG) and wrapping glia (WG). WG survival is dependent on its communication with the SPG and is mediated by a channel rather than adhesive function of Inx2. Inx2 GJs mediate calcium pulses exclusively in the SPG and WG survival is not dependent on Ca²⁺ and inositol 1,4,5-trisphosphate (IP3). Therefore, we find that GJs mediate glia-glia communication to ensure the survival of WG through an unknown mechanism. We next tested the role of scaffolding complexes in mediating glia-glia communication and screened for the role of the PSD95-Dlg-ZO1 (PDZ) family of proteins. We identified a role for Dlg5, a membrane-associated guanyl kinase protein, in peripheral glia. Loss of Dlg5 results in glial disruptions, including loss of septate junction formation and axonal ensheathment. Dlg5 has multiple roles identified in other systems including trafficking of cadherins. However, in glia the loss of Dlg5 did not affect cadherin localization to spot adherens junctions (SAJs). Therefore, we find that Dlg5 plays a novel role in peripheral glial development. SAJs were previously identified in the Drosophila peripheral glia, but the composition and function of this complex had not been characterized. We find that classical cadherins associate with catenins in the peripheral nerve, and loss of DE-Cad but not DN-Cad leads to disruptions in glial morphology. However, loss of DE-Cad does not affect SAJ assembly, suggesting a redundancy with DN-Cad in peripheral glia. Taken together this thesis provides novel insights and proposed models by which glia communicate in the PNS and will help direct future work in NMSCs in all animals.
L'exposé oral en formation à distance
Creators: name: Pelletier, Caroline
Publisher: name: Université de Sherbrooke, Pôle d'innovation technopédagogique
Year: 2020
Subjects: Formation à distance
Enseignement à distance
Étudiants--Évaluation
Oraux
Exposé oral

description: Tableau des éléments à prendre en considération pour la décision de la méthode de présentation d'un exposé oral en formation à distance.
description: Ressources éducatives libres

REL

Open Educational Resources

OER
Dynamical generation of pseudoscalar resonances
Creators: name: Albaladejo, M.
name: Oller, J. A.
name: Roca, L.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We study the interactions between the f_0(980) and a_0(980) scalar resonances and the lightest pseudoscalar mesons. We first obtain the elementary interaction amplitudes, or interacting kernels, without including any ad hoc free parameter. This is achieved by using previous results on the nature of the lightest scalar resonances as dynamically generated from the rescattering of S-wave two-meson pairs. Afterwards, the interaction kernels are unitarized and the final S-wave amplitudes result. We find that these interactions are very rich and generate a large amount of pseudoscalar resonances that could be associated with the K(1460), π(1300), π(1800), η(1475) and X(1835). We also consider the exotic channels with isospin 3/2 and 1, having the latter positive G-parity. The former could be also resonant in agreement with a previous prediction.
description: 31 pages, 9 figures, to be published in PRD
Ultimate RF Performance Potential of Carbon Electronics
Creators: name: Koswatta, Siyuranga O.
name: Valdes-Garcia, Alberto
name: Steiner, Mathias B.
name: Lin, Yu-Ming
name: Avouris, Phaedon
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Carbon electronics based on carbon nanotube array field-effect transistors (AFETs) and 2-dimensional graphene field-effect transistors (GFETs) have recently attracted significant attention for potential RF applications. Here, we explore the ultimate RF performance potential for these two unique devices using semi-classical ballistic transport simulations. It is shown that the intrinsic current-gain and power-gain cutoff frequencies (fT and fMAX) above 1 THz should be possible in both AFETs and GFETs. Thus, both devices could deliver higher cut-off frequencies than traditional semiconductors such as Si and III-V's. In the case of AFETs, we show that their RF operation is not sensitive to the diameter variation of semiconducting tubes and the presence of metallic tubes in the channel. The ultimate fT and fMAX values in AFETs are observed to be higher than that in GFETs. The optimum device biasing conditions for AFETs require smaller biasing currents, and thus, lower power dissipation compared to GFETs. The degradation in high-frequency performance in the presence of external parasitics is also seen to be lower in AFETs compared to GFETs.
description: 12 pages, 11 figures, 2 tables
Spectroscopy of a driven solid-state qubit coupled to a structured environment
Creators: name: Goorden, M.
name: Thorwart, M.
name: Grifoni, Milena
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik

description: We study the asymptotic dynamics of a driven spin-boson system where the environment is formed by a broadened localized mode. Upon exploiting an exact mapping, an equivalent formulation of the problem in terms of a quantum two-state system (qubit) coupled to a harmonic oscillator which is itself Ohmically damped, is found. We calculate the asymptotic population difference of the two states in two complementary parameter regimes. For weak damping and low temperature, a perturbative Floquet-Born-Markovian master equation for the qubit-oscillator system can be solved. We find multi-photon resonances corresponding to transitions in the coupled quantum system and calculate their line-shape analytically. In the complementary parameter regime of strong damping and/or high temperatures, non-perturbative real-time path integral techniques yield analytic results for the resonance line shape. In both regimes, we find very good agreement with exact results obtained from a numerical real-time path-integral approach. Finally, we show for the case of strong detuning between qubit and oscillator that the width of the n-photon resonance scales with the nth Bessel function of the driving strength in the weak-damping regime.
Curvature of the QCD phase transition line in a finite volume
Creators: name: Klein, Bertram
name: Braun, Jens
name: Schaefer, Bernd-Jochen
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: The curvature which characterizes the QCD phase transition at finite temperature and small values of the chemical potential is accessible to lattice simulations. The results for this quantity which have been obtained by several different lattice simulation methods differ due to different numbers of flavors, different pion masses and different sizes of the simulation volume. In order to reconcile these results, it is important to investigate finite-volume effects on the curvature. We investigate the curvature of the chiral phase transition line at finite temperature and chemical potential in a finite volume. We use a phenomenological model for chiral symmetry breaking and apply non-perturbative functional renormalization group methods which account for critical long-range fluctuations at the phase transition. We find an intermediate volume region in which the curvature of the phase transition line is actually reduced relative to its infinite-volume value, provided periodic spatial boundary conditions are chosen for the quark fields. Size and location of this region depend on the value of the pion mass. Such an effect could account for differences in the curvature between lattice simulations in differently sized volumes and from functional methods in the infinite volume limit. We discuss implications of our results for the QCD phase diagram.
description: 7 pages, 2 figures, talk given at the XXVIII International Symposium on Lattice Field Theory, Lattice2010
Dissipative dynamics of a biased qubit coupled to a harmonic oscillator: Analytical results beyond the rotating wave approximation
Creators: name: Hausinger, Johannes
name: Grifoni, Milena
Publisher: name: Universität Regensburg
Year: 2008
Subjects: subject: Quantum dissipation , quantum computation
subject: 530 Physik
subject: 03.65.Yz
subject: 03.67.Lx
subject: 85.25.Cp

description: We study the dissipative dynamics of a biased two-level system (TLS) coupled to a harmonic oscillator (HO), the latter interacting with an Ohmic environment. Using Van-Vleck perturbation theory and going to second order in the coupling between TLS and HO, we show how the Hamiltonian of the TLS-HO system can be diagonalized analytically. Our model represents an improvement to the usually used Jaynes-Cummings Hamiltonian as an initial rotating wave approximation is avoided. By assuming a weak coupling to the thermal bath, analytical expressions for the time evolution of the populations of the TLS are found: the population is characterized by a multiplicity of damped oscillations together with a complex relaxation dynamics towards thermal equilibrium. The long time evolution is characterized by a single relaxation rate, which is largest at resonance and whose expression can be given in closed analytic form.
Seven Basic Tools Of Quality Control: The Appropriate Quality Techniques For Solving Quality Problems In The Organizations
Creators: name: Neyestani, Behnam
Publisher: name: Zenodo
Year: 2017

description: Dr. Kaoru Ishikawa was first total quality management guru, who has been associated with the development and advocacy of using the seven quality control (QC) tools in the organizations for problem solving and process improvements. Seven old quality control tools are a set of the QC tools that can be used for improving the performance of the production processes, from the first step of producing a product or service to the last stage of production. So, the general purpose of this paper was to introduce these 7 QC tools. This study found that these tools have the significant roles to monitor, obtain, analyze data for detecting and solving the problems of production processes, in order to facilitate the achievement of performance excellence in the organizations.
Electronic spectra of commensurate and incommensurate DWNTs in parallel magnectic field
Creators: name: Marganska, Magdalena
name: Wang, Shidong
name: Grifoni, Milena
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: 530 Physik

description: We study the electronic spectra of commensurate and incommensurate double-wall carbon nanotubes (DWNTs) of finite length. The coupling between nanotube shells is taken into account as an inter-shell electron tunneling. Selection rules for the inter-shell coupling are derived. Due to the finite size of the system, these rules do not represent exact conservation of the crystal momentum, but only an approximate one; therefore the coupling between longitudinal momentum states in incommensurate DWNTs becomes possible. The use of the selection rules allows a fast and efficient calculation of the electronic spectrum. In the presence of a magnetic field parallel to the DWNT axis, we find spectrum modulations that depend on the chiralities of the shells.