cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Tunneling magnetothermopower in magnetic tunnel junctions
Creators: name: Lopez-Monis, Carlos
name: Matos-Abiague, Alex
name: Fabian, Jaroslav
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: 530 Physik

description: Thermally induced spin-dependent transport across magnetic tunnel junctions (MTJs) is theoretically investigated. We analyze the thermal analog of Slonczewski's model (as well as its limiting case—Julliere's model) of tunneling magnetoresistance and obtain analytical expressions for the junction thermopower and the tunneling magnetothermopower (TMT). The analytical model is tested numerically for the special case of an Al2O3-based MTJ, for which we analyze the dependence of the thermopower and TMT on the relative magnetization orientations, as well as on the barrier height and thickness. We show that at a certain barrier height TMT vanishes, separating the region of positive and negative TMT. As its electrical prototype, this thermal spin transport model should serve as a phenomenological benchmark for analyzing experimental and first-principles calculations of thermopower in magnetic tunnel junctions. The analytical expressions can be used as a first estimate of the magnetothermopower of the junctions using ab initio band structure data of the junction ferromagnets.
Ultralong spin decoherence times in graphene quantum dots with a small number of nuclear spins
Creators: name: Fuchs, Moritz
name: Schliemann, John
name: Trauzettel, Björn
Publisher: name: Universität Regensburg
Year: 2013
Subjects: subject: 530 Physik

description: We study the dynamics of an electron spin in a graphene quantum dot, which is interacting with a bath of less than ten nuclear spins via the anisotropic hyperfine interaction. Due to substantial progress in the fabrication of graphene quantum dots, the consideration of such a small number of nuclear spins is experimentally relevant. This choice allows us to use exact diagonalization to calculate the long-time average of the electron spin as well as its decoherence time. We investigate the dependence of spin observables on the initial states of nuclear spins and on the position of nuclear spins in the quantum dot. Moreover, we analyze the effects of the anisotropy of the hyperfine interaction for different orientations of the spin quantization axis with respect to the graphene plane. Interestingly, we then predict remarkable long decoherence times of more than 10 ms in the limit of few nuclear spins.
Determining gas transfer velocities and CO₂ evasion fluxes from streams using carbon dioxide as a tracer
Creators: name: McDowell, Mollie Jean
Publisher: name: University of British Columbia
Year: 2017

description: Evasion of carbon dioxide (CO₂) from headwater streams is a dominant process controlling the fate of terrestrially-derived carbon (C) in inland waters. However, methodological limitations associated with determining the gas transfer velocity of carbon dioxide (kCO₂) in headwater streams inhibit efforts to accurately quantify CO₂ emissions. In this thesis, I present a proof of concept for a tracer gas method that mitigates common issues associated with conventional methods for determining kCO₂. In this method, a datalogger controls in situ stream sensors that measure the partial pressure of CO₂ (pCO₂) and other stream parameters as well as a solenoid valve connected to a compressed CO₂ cylinder. Automated injections of CO₂ were made via an aquatic diffuser located on the stream bed. Infrared gas-analyzing (IRGA) CO₂-type sensors enclosed in waterproof, gas-permeable membranes located downstream from the diffuser continuously measured aqueous pCO₂ and equilibrate to elevated values during CO₂ injections. The difference between upstream and downstream pCO₂ values during CO₂ injection relative to pre-injection concentrations permitted calculation of both the CO₂ flux from the reach and kCO₂. This method improves upon conventional methods due to its automation, in situ measurement, and use of CO₂ as a tracer rather than another gas, thereby reducing analytical error and increasing the frequency and timing with which measurements can be made relative to conventional methods. I tested this method in a headwater stream in southwestern British Columbia. I calculated kCO₂ and continuous CO₂ emissions from the reach and compared both datasets to hydrogeomorphic parameters as well as values in the literature. Values of kCO₂ were generally above the average values reported in the literature, but they corresponded well to values reported for steep, turbulent headwater streams. Values of kCO₂ varied in relation to discharge, flow velocity, and stream temperature. CO₂ emissions from the stream were highest during high flow events. Headwater streams, which have been shown to be "hotspots" for CO₂ emissions, can also be considered as exhibiting "hot moments" of CO₂ evasion.
2022 Brings Two New QGIS Books
Creators: name: Menke, Kurt
Publisher: name: Zenodo
Year: 2023
Subjects: QGIS, Locate Press, Books

description: Both Discover QGIS 3.x and QGIS for Hydrological Applications were updated in 2022. Combined these represent more than 600 pages of updated and current QGIS educational material. Both books have important updates, as both QGIS and supporting libraries have undergone large changes in the 3 years since the 1st editions were published. The talk highlights the content and important updates to each book. This includes exercise examples from each.
Classical and quantum polyhedra
Creators: name: Schliemann, John
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: 530 Physik

description: Quantum polyhedra constructed from angular momentum operators are the building blocks of space in its quantum description as advocated by loop quantum gravity. Here we extend previous results on the semiclassical properties of quantum polyhedra. Regarding tetrahedra, we compare the results from a canonical quantization of the classical system with a recent wave-function-based approach to the large-volume sector of the quantum system. Both methods agree in the leading order of the resulting effective operator (given by an harmonic oscillator), while minor differences occur in higher corrections. Perturbative inclusion of such corrections improves the approximation to the eigenstates. Moreover, the comparison of both methods leads also to a full wave function description of the eigenstates of the (square of the) volume operator at negative eigenvalues of large modulus. For the case of general quantum polyhedra described by discrete angular momentum quantum numbers we formulate a set of quantum operators fulfilling in the semiclassical regime the standard commutation relations between momentum and position. Differently from previous formulations, the position variable here is chosen to have dimension of (Planck) length squared which facilitates the identification of quantum corrections. Finally, we provide expressions for the pentahedral volume in terms of Kapovich-Millson variables.
Agnès Schaffauser. Salim Bachi
Creators: name: Alouani, Sara
Publisher: name: Fondazione Università Ca’ Foscari Venezia, Italia
Year: 2020

description:

Schaffauser, A. (éd.) (2019). Salim Bachi. Paris : L’Harmattan, 266 pp. Autour des écrivains maghrébins.

description: Il Tolomeo
MPEC 2023-J05 : DAILY ORBIT UPDATE (2023 May 1)
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Noncentrosymmetric plasmon modes and giant terahertz photocurrent in a two-dimensional plasmonic crystal
Creators: name: Popov, V. V.
name: Fateev, D. V.
name: Ivchenko, Eougenious
name: Ganichev, Sergey
Publisher: name: Universität Regensburg
Year: 2015
Subjects: subject: 530 Physik
subject: 73.20.Mf, 78.67.Pt, 07.57.−c

description: We introduce and theoretically study the plasmon-photogalvanic effect in a planar noncentrosymmetric plasmonic crystal containing a homogeneous two-dimensional electron system gated by a periodic metal grating with an asymmetric unit cell. The plasmon-photogalvanic dc current arises due to the two-dimensional electron drag by the noncentrosymmetric plasmon modes excited under normal incidence of terahertz radiation. We show that the collective plasmon modes of the planar plasmonic crystal become strongly noncentrosymmetric in the weak-coupling regime of their anticrossing. A large plasmon wave vector (which is typically by two-three orders of magnitude greater than the terahertz photon wave vector) along with strong near-field enhancement at the plasmon resonance make the plasmonic drag a much stronger effect compared to the photon drag observed in conventional two-dimensional electron systems.
Michela A. Calderaro. Sheer Bliss: A Creole Journey
Creators: name: Perry, Amanda T.
Publisher: name: Fondazione Università Ca’ Foscari Venezia, Italia
Year: 2020

description:

Calderaro, M.A. (2020). Sheer Bliss: A Creole Journey. Kingston, Jamaica: The University of West Indies Press, 2020.

description: Il Tolomeo
Idempotents in representation rings of quivers
Creators: name: Kinser, Ryan
name: Schiffler, Ralf
Publisher: name: arXiv
Year: 2010
Subjects: subject: Representation Theory (math.RT)
subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 16G20 (Primary), 06A99, 19A22 (Secondary)

description: For an acyclic quiver Q, we solve the Clebsch-Gordan problem for the projective representations by computing the multiplicity of a given indecomposable projective in the tensor product of two indecomposable projectives. Motivated by this problem for arbitrary representations, we study idempotents in the representation ring of Q (the free abelian group on the indecomposable representations, with multiplication given by tensor product). We give a general technique for constructing such idempotents and for decomposing the representation ring into a direct product of ideals, utilizing morphisms between quivers and categorical Moebius inversion.
description: 30 pages, v2: small improvements in exposition
Plasmons and screening in a monolayer of MoS₂
Creators: name: Scholz, Andreas
name: Stauber, Tobias
name: Schliemann, John
Publisher: name: Universität Regensburg
Year: 2013
Subjects: subject: 530 Physik

description: We investigate the dynamical dielectric function of a monolayer of molybdenum disulfide within the random phase approximation. While in graphene damping of plasmons is caused by interband transitions, due to the large direct band gap in monolayer MoS2 collective charge excitations enter the intraband electron hole continuum similarly to the situation in two-dimensional electron and hole gases. Since there is no electron-hole symmetry in MoS2, the plasmon energies in p- and n-doped samples clearly differ. The breaking of spin degeneracy caused by the large intrinsic spin-orbit interaction leads to a beating of Friedel oscillations for sufficiently large carrier concentrations, for holes as well as for electrons.
Tunneling anisotropic thermopower and Seebeck effects in magnetic tunnel junctions
Creators: name: Lopez-Monis, Carlos
name: Matos-Abiague, Alex
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: 530 Physik

description: The tunneling anisotropic magnetothermopower (TAMT) and the tunneling anisotropic spin-Seebeck (TASS) effects are studied for a magnetic tunnel junction (MTJ) composed of a ferromagnetic electrode, a zinc-blende semiconductor, and a normal metal. We develop a theoretical model for describing the dependence of a thermally induced tunneling current across the MTJ on the in-plane orientation of the magnetization in the ferromagnetic layer. The model accounts for the specific Bychkov-Rashba and Dresselhaus spin-orbit interactions present in these systems, which are responsible for the C2v symmetry we find in the TAMT and the TASS.
Isospectral Alexandrov Spaces
Creators: name: Engel, Alexander
name: Weilandt, Martin
Publisher: name: arXiv
Year: 2011
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 58J53, 58J50 (Primary) 53C20, 51F99 (Secondary)

description: We construct the first non-trivial examples of compact non-isometric Alexandrov spaces which are isospectral with respect to the Laplacian and not isometric to Riemannian orbifolds. This construction generalizes independent earlier results by the authors based on Schueth's version of the torus method.
description: 15 pages, no figures; minor clarifications
Extending pseudo-Anosov maps to compression bodies
Creators: name: Biringer, Ian
name: Johnson, Jesse
name: Minsky, Yair
Publisher: name: arXiv
Year: 2010
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 57M50

description: We show that a pseudo-Anosov map on a boundary component of an irreducible 3-manifold has a power that partially extends to the interior if and only if its (un)stable lamination is a projective limit of meridians. The proof is through 3-dimensional hyperbolic geometry, and involves an investigation of algebraic limits of convex cocompact compression bodies.
description: 29 pages
Spin relaxation mechanism in graphene: resonant scattering by magnetic impurities
Creators: name: Kochan, Denis
name: Gmitra, Martin
name: Fabian, Jaroslav
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: 530 Physik

description: We propose that the observed small (100 ps) spin relaxation time in graphene is due to resonant scattering by local magnetic moments. At resonances, magnetic moments behave as spin hot spots: the spin-flip scattering rates are as large as the spin-conserving ones, as long as the exchange interaction is greater than the resonance width. Smearing of the resonance peaks by the presence of electron-hole puddles gives quantitative agreement with experiment, for about 1 ppm of local moments. Although magnetic moments can come from a variety of sources, we specifically consider hydrogen adatoms, which are also resonant scatterers. The same mechanism would also work in the presence of a strong local spin-orbit interaction, but this would require heavy adatoms on graphene or a much greater coverage density of light adatoms. To make our mechanism more transparent, we also introduce toy atomic chain models for resonant scattering of electrons in the presence of a local magnetic moment and Rashba spin-orbit interaction.
Weight cycling and Serre-type conjectures for unitary groups
Creators: name: Emerton, Matthew
name: Gee, Toby
name: Herzig, Florian
Publisher: name: arXiv
Year: 2011
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11F30

description: We prove that for forms of U(3) which are compact at infinity and split at places dividing a prime p, in generic situations the Serre weights of a mod p modular Galois representation which is irreducible when restricted to each decomposition group above p are exactly those previously predicted by the third author. We do this by combining explicit computations in p-adic Hodge theory, based on a formalism of strongly divisible modules and Breuil modules with descent data which we develop in the paper, with a technique that we call "weight cycling".
description: 66 pages
Resonant internal Quantum transitions and femtosecond radiative decay of excitons in monolayer WSe2
Creators: name: Pöllmann, Christoph
name: Steinleitner, Philipp
name: Leierseder, Ursula
name: Nagler, Philipp
name: Plechinger, Gerd
name: Porer, Michael
name: Bratschitsch, R.
name: Schüller, Christian
name: Korn, Tobias
name: Huber, Rupert
Publisher: name: Universität Regensburg
Year: 2015
Subjects: subject: 530 Physik

description: Atomically thin two-dimensional crystals have revolutionized materials science1, 2, 3. In particular, monolayer transition metal dichalcogenides promise novel optoelectronic applications, owing to their direct energy gaps in the optical range4, 5, 6, 7, 8, 9. Their electronic and optical properties are dominated by Coulomb-bound electron–hole pairs called excitons10, 11, 12, 13, 14, 15, 16, 17, 18, whose unusual internal structure13, symmetry15, 16, 17, many-body effects18 and dynamics have been vividly discussed. Here we report the first direct experimental access to all 1s A excitons, regardless of momentum—inside and outside the radiative cone—in single-layer WSe2. Phase-locked mid-infrared pulses reveal the internal orbital 1s–2p resonance, which is highly sensitive to the shape of the excitonic envelope functions and provides accurate transition energies, oscillator strengths, densities and linewidths. Remarkably, the observed decay dynamics indicates an ultrafast radiative annihilation of small-momentum excitons within 150 fs, whereas Auger recombination prevails for optically dark states. The results provide a comprehensive view of excitons and introduce a new degree of freedom for quantum control, optoelectronics and valleytronics of dichalcogenide monolayers19, 20, 21, 22, 23, 24.
Sara Florian. Caribbean Counterpoint: The Aesthetics of Salt in Lasana Sekou
Creators: name: De Capitani, Lucio
Publisher: name: Fondazione Università Ca’ Foscari Venezia, Italia
Year: 2020

description:

Florian, S. (2019). Caribbean Counterpoint: The Aesthetics of Salt in Lasana Sekou. Philipsburg, St. Martin: House of Nehesi, 176 pp.

description: Il Tolomeo
The maximum of Brownian motion minus a parabola
Creators: name: Groeneboom, Piet
Publisher: name: arXiv
Year: 2010
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60J65, 60J75

description: We derive a simple integral representation for the distribution of the maximum of Brownian motion minus a parabola, which can be used for computing the density and moments of the distribution, both for one-sided and two-sided Brownian motion.
description: 7 pages, 4 figures, to appear in the Electronic Journal of Probability
Does the Tennessee Master Beef Producer Program Impact Technical Efficiency
Creators: name: Boyer, Christopher N.
name: Yu, T. Edward
name: Rhinehart, Justin
name: Ahles, Amelia
name: Gill, Mackenzie
name: Boyer, Christopher N.
name: Yu, T. Edward
name: Rhinehart, Justin
name: Ahles, Amelia
name: Gill, Mackenzie
Publisher: name: Unknown
Year: 2020
Subjects: Agricultural and Food Policy
Livestock Production/Industries
Farm Management

description: The impacts of the Tennessee Master Beef Producer (MBP) program on the technical efficiency (TE) of Tennessee beef production was estimated using county-level data in 2007, 2012, and 2017. A two-stage, double bootstrap method was used to measure TE by county and year, and identify any statistical relationship between MBP and TE. TE of beef production changed statewide during this time period. We found a positive relationship in MBP participation and county-level TE of beef production. Results are helpful in targeting locations for future education and provide evidence on the effectiveness of MBP.
Cities and climate change : power games and greenwashing through transnational urban networks
Creators: name: Pjevovic, Dushan
Publisher: name: University of British Columbia
Year: 2017

description: The 21st century is the century of the city. As urbanization continues, cities will stand at the forefront of environmental progress. In the last ten years, the landscape of environmental politics has been filled with mayors who make grand claims and give significant praise to transnational urban networks. Furthermore, networks have done an excellent job of positioning themselves as important actors in climate change. However, there is sufficient reason to question whether these networks should be perceived as sources of progressive climate change policies. In this thesis, I argue that networks reinforce existing imbalances in world politics and create a Realist subset, composed of cities, in international society. Additionally, networks are advertisement boards rather than causes of progressive climate change policies. They merely report already performed actions and serve as platforms for information dissemination. Moreover, I argue that the true purpose of networks, and one of the main reasons they are expanding their influence, is hidden behind smoke and mirrors. Mayors use networks to build a “green” image, a presence and a reputation that extends beyond the borders of their city. In fact, mayors have used this leverage to further their political journey, with several of them continuing careers as Presidents. I go on to argue that most climate change issues are domestic problems that are being framed as international problems through transnational urban networks. Networks have unjustifiably taken credit for many progressive climate change policies and have relegated domestic politics to the status of a marginal player in what is best described as a power game. In fact, at times, networks have formed self-serving partnerships that could be interpreted as subtle forms of intimidation.
Notes on beta-deformations of the pure spinor superstring in AdS(5) x S(5)
Creators: name: Bedoya, Oscar A.
name: Beviláqua, L. Ibiapina
name: Mikhailov, Andrei
name: Rivelles, Victor O.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the properties of the vertex operator for the beta-deformation of the superstring in AdS(5) x S(5) in the pure spinor formalism. We discuss the action of supersymmetry on the infinitesimal beta-deformation, the application of the homological perturbation theory, and the relation between the worldsheet description and the spacetime supergravity description.
description: LaTeX, 74pp.
Charge-transfer excited states in phosphorescent organo-transition metal compounds: a difficult case for time dependent density functional theory?
Creators: name: Niehaus, Thomas A.
name: Hofbeck, T.
name: Yersin, Hartmut
Publisher: name: Universität Regensburg
Year: 2015
Subjects: subject: 530 Physik
subject: 540 Chemie

description: Light emitting organo-transition metal complexes have found widespread use in the past. The computational modelling of such compounds is often based on time-dependent density functional theory (TDDFT), which enjoys popularity due to its numerical efficiency and simple black-box character. It is well known, however, that TDDFT notoriously underestimates energies of charge-transfer excited states which are prominent in phosphorescent metal–organic compounds. In this study, we investigate whether TDDFT is providing a reliable description of the electronic properties in these systems. To this end, we compute 0–0 triplet state energies for a series of 17 pseudo-square planar platinum(II) and pseudo-octahedral iridium(III) complexes that are known to feature quite different localization characteristics ranging from ligand-centered (LC) to metal-to-ligand charge transfer (MLCT) transitions. The calculations are performed with conventional semi-local and hybrid functionals as well as with optimally tuned range-separated functionals that were recently shown to overcome the charge transfer problem in TDDFT. We compare our results against low temperature experimental data and propose a criterion to classify excited states based on wave function localization. In addition, singlet absorption energies and singlet–triplet splittings are evaluated for a subset of the compounds and are also validated against experimental data. Our results indicate that for the investigated complexes charge-transfer is much less pronounced than previously believed.
description: Open Access Komponente aus der Allianzlizenz
Efficient Multi-Template Learning for Structured Prediction
Creators: name: Mao, Qi
name: Tsang, Ivor W.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Machine Learning (cs.LG)
subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: Conditional random field (CRF) and Structural Support Vector Machine (Structural SVM) are two state-of-the-art methods for structured prediction which captures the interdependencies among output variables. The success of these methods is attributed to the fact that their discriminative models are able to account for overlapping features on the whole input observations. These features are usually generated by applying a given set of templates on labeled data, but improper templates may lead to degraded performance. To alleviate this issue, in this paper, we propose a novel multiple template learning paradigm to learn structured prediction and the importance of each template simultaneously, so that hundreds of arbitrary templates could be added into the learning model without caution. This paradigm can be formulated as a special multiple kernel learning problem with exponential number of constraints. Then we introduce an efficient cutting plane algorithm to solve this problem in the primal, and its convergence is presented. We also evaluate the proposed learning paradigm on two widely-studied structured prediction tasks, \emph{i.e.} sequence labeling and dependency parsing. Extensive experimental results show that the proposed method outperforms CRFs and Structural SVMs due to exploiting the importance of each template. Our complexity analysis and empirical results also show that our proposed method is more efficient than OnlineMKL on very sparse and high-dimensional data. We further extend this paradigm for structured prediction using generalized $p$-block norm regularization with $p>1$, and experiments show competitive performances when $p \in [1,2)$.
From the Ground Up: A Look at Kansas’ First Year of Industrial Hemp Production
Creators: name: Ebert, Kerri
name: Hoch, Braden
name: Taylor, Hannah
name: Schwab, Benjamin
name: Ebert, Kerri
name: Hoch, Braden
name: Taylor, Hannah
name: Schwab, Benjamin
Publisher: name: Unknown
Year: 2020
Subjects: Agricultural and Food Policy
Crop Production/Industries

description: Over the last five years, industrial hemp began to re-enter mainstream agriculture through the 2014 Farm Bill pilot program legalizing the study of growth, cultivation, and marketing of industrial hemp by state departments of agriculture and higher education institutions for research purposes. The 2018 Farm Bill expanded opportunities for industrial hemp production beyond research creating a national commercial industrial hemp production program that allows states, Indian Tribes, and Territories to submit plans for regulating and monitoring their own industrial hemp production programs. This paper looks at Kansas’ experience during its first growing season under the pilot research program.
Listen, the Landscape: The Nature Narratives in Jacob Ross’ Short Story Collection Tell No-One About This
Creators: name: Ramos-Rodriguez, Michelle
Publisher: name: Fondazione Università Ca’ Foscari Venezia, Italia
Year: 2020

description:

Ross, J. (2017). Tell No-One About This. England: Peepal Tree.

description: Il Tolomeo
Synthesis and anti-bacterial evaluation of novel thio- and oxazepino[7,6-b]quinolones
Creators: name: Mommahed Heravi, Majid
name: Hamidi, Hoda
name: Tajbakhsh, Mahmoud
name: Shiri, Morteza
name: Oskooie, Hossein A.
name: Shintre, Suhas A.
name: Koorbanally, Neil A.
Publisher: name: figshare
Year: 2022
Subjects: subject: 30303 Optical Properties of Materials
subject: FOS: Chemical sciences
subject: 30502 Natural Products Chemistry
subject: 30302 Nanochemistry and Supramolecular Chemistry
subject: 30701 Quantum Chemistry
subject: 39904 Organometallic Chemistry
subject: 40204 Organic Geochemistry
subject: FOS: Earth and related environmental sciences
subject: 60105 Cell Neurochemistry
subject: FOS: Biological sciences
subject: Organic Chemistry
subject: 30599 Organic Chemistry not elsewhere classified
subject: 30205 Non-metal Chemistry
subject: Nuclear Chemistry
subject: 110199 Medical Biochemistry and Metabolomics not elsewhere classified
subject: FOS: Clinical medicine
subject: 30504 Organic Green Chemistry

description: Cyclocondensation of 2-chloroquinoline-3-carbaldehydes and 2-thiophenol/2-aminophenols led to the formation of benzo[2,3][1,4]thio- or oxazepino[7,6-b]quinolines. Ugi reaction of the latter compound with various carboxylic acids and isocyanides gave novel oxazepino[7,6-b]quinoline derivatives. All compounds were evaluated for their anti-bacterial and anti-fungal activities. Among them, compounds 4a, 4b and 4d showed moderate to good activity.
title: "Statua di Ecate tricorpore", arte romana, inv. CXC (ITA/EN)
title: Scheda catalogo digitale Borghese
titleType: AlternativeTitle
Creators: name: Ciccarello, Giulia
name: Galleria Borghese
Publisher: name: Galleria Borghese
Year: 2024

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

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

Collegamento al catalogo digitale:

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

EN: https://www.collezionegalleriaborghese.it/en
Multiuser broadcast erasure channel with feedback - capacity and algorithms
Creators: name: Gatzianas, Marios
name: Georgiadis, Leonidas
name: Tassiulas, Leandros
Publisher: name: arXiv
Year: 2010
Subjects: subject: Information Theory (cs.IT)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Computer and information sciences

description: We consider the $N$-user broadcast erasure channel with $N$ unicast sessions (one for each user) where receiver feedback is regularly sent to the transmitter in the form of ACK/NACK messages. We first provide a generic outer bound to the capacity of this system; we then propose a virtual-queue-based inter-session mixing coding algorithm, determine its rate region and show that it achieves capacity under certain conditions on channel statistics, assuming that instantaneous feedback is known to all users. Removing this assumption results in a rate region that asymptotically differs from the outer bound by 1 bit as $L\to \infty$, where $L$ is the number of bits per packet (packet length). For the case of arbitrary channel statistics, we present a modification of the previous algorithm whose rate region is identical to the outer bound for N=3, when instant feedback is known to all users, and differs from the bound by 1 bit as $L\to \infty$, when the 3 users know only their own ACK. The proposed algorithms do not require any prior knowledge of channel statistics.
description: 54 pages, 3 figures, 3 tables, submitted to IEEE Transactions on Information Theory. Updated version to match reviewer comments
Photoinduced pseudospin effects in silicene beyond the off-resonant condition
Creators: name: López, Alexander
name: Scholz, Andreas
name: Santos, Benjamin
name: Schliemann, John
Publisher: name: Universität Regensburg
Year: 2015
Subjects: subject: 530 Physik

description: We study the photoinduced manipulation of charge carriers in monolayer silicene subject to intense electromagnetic terahertz radiation. Considering the Dirac cone approximation and going beyond the off-resonant condition for large frequencies of the radiation field, where only virtual photon processes are allowed, we present the exact zero-momentum pseudospin polarization and numerical results for the quasienergy band structure and time-averaged density of states. We find that resonant processes, due to real photon emission and absorbtion processes, induce a band inversion that qualitatively modifies the quasienergy spectrum. These band-structure changes manifest themselves as an inversion of the averaged pseudospin polarization. Through the analysis of the time-averaged density of states we find that effective photoinduced gap manipulation can only be achieved in the intermediate and strong matter-radiation coupling regime where the off-resonant approximation breaks down.
Spin-orbit coupling in fluorinated graphene
Creators: name: Irmer, Susanne
name: Frank, Tobias
name: Putz, Sebastian
name: Gmitra, Martin
name: Kochan, Denis
name: Fabian, Jaroslav
Publisher: name: Universität Regensburg
Year: 2015
Subjects: subject: 530 Physik

description: We report on theoretical investigations of the spin-orbit coupling effects in fluorinated graphene. First-principles density functional calculations are performed for the dense and dilute adatom coverage limits. The dense limit is represented by the single-side semifluorinated graphene, which is a metal with spin-orbit splittings of about 10 meV. To simulate the effects of a single adatom, we also calculate the electronic structure of a 10×10 supercell, with one fluorine atom in the top position. Since this dilute limit is useful to study spin transport and spin relaxation, we also introduce a realistic effective hopping Hamiltonian, based on symmetry considerations, which describes the supercell bands around the Fermi level. We provide the Hamiltonian parameters which are best fits to the first-principles data. We demonstrate that, unlike for the case of hydrogen adatoms, fluorine's own spin-orbit coupling is the principal cause of the giant induced local spin-orbit coupling in graphene. The sp3 hybridization induced transfer of spin-orbit coupling from graphene's σ bonds, important for hydrogenated graphene, contributes much less. Furthermore, the magnitude of the induced spin-orbit coupling due to fluorine adatoms is about 1000 times more than that of pristine graphene, and 10 times more than that of hydrogenated graphene. Also unlike hydrogen, the fluorine adatom is not a narrow resonant scatterer at the Dirac point. The resonant peak in the density of states of fluorinated graphene in the dilute limit lies 260 meV below the Dirac point. The peak is rather broad, about 300 meV, making the fluorine adatom only a weakly resonant scatterer.
Optical conductivity of hydrogenated graphene from first principles
Creators: name: Putz, Sebastian
name: Gmitra, Martin
name: Fabian, Jaroslav
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: 530 Physik

description: We investigate the effect of hydrogen coverage on the optical conductivity of single-side hydrogenated graphene from first-principles calculations. To account for different degrees of uniform hydrogen coverage we calculate the complex optical conductivity for graphene supercells of various sizes, each containing a single additional hydrogen atom. We use the linearized augmented plane wave method, as implemented in the wien2k density functional theory code, to show that the hydrogen coverage strongly influences the complex optical conductivity and thus the optical properties, such as absorption, of hydrogenated graphene. We find that the optical conductivity of graphene in the infrared, visible, and ultraviolet range has different characteristic features depending on the degree of hydrogen coverage. This opens up new possibilities to tailor the optical properties of graphene by reversible hydrogenation, and to determine the hydrogen coverage of hydrogenated graphene samples in the experiment by contact-free optical absorption measurements.
Kin-selected signal transfer through mycorrhizal networks in Douglas-fir
Creators: name: Gorzelak, Monika A
Publisher: name: University of British Columbia
Year: 2017

description: Mycorrhizal networks create pathways for movement of resources and information molecules belowground. A mycorrhizal network is formed when two or more plants are linked by the same mycorrhizal fungus. Experiments have demonstrated movement of carbon and nitrogen between Douglas-fir and neighboring plants in response to source-sink dynamics, seasonality, and differences in age of linked plants. Furthermore, the network appears to act a conduit for information chemicals, where defense chemicals are transferred in response to herbivory or pathogen attack. Because of recent evidence implying the capacity for Douglas-fir to recognize kin, as well as differential colonization of Douglas-fir by ectomycorrhizas based on tree relatedness, this thesis aimed to determine whether Douglas-fir would preferentially transfer carbon and/or nitrogen through mycorrhizal networks to kin over strangers in response to herbivory treatment. Using seedlings with and without access to a mycorrhizal network (restricted or permitted via mesh pore size), stable isotope probing was used to track carbon and nitrogen in the system. One seedling of a pair was designated as the 'donor' and defoliated immediately prior to photosynthesizing with 99%-¹³C-CO₂ as well as pulse-labelling with 99%-¹⁵N ammonium nitrate. Both a greenhouse and field experiments were performed to corroborate results. Transfer was determined by measuring δ¹³C and δ¹³N in tissues (needle, stem, root) of kin and stranger seedlings. Data was analyzed using linear mixed effects models. Significantly more carbon was transferred to kin than strangers, and through the mycorrhizal network than when the mycorrhizal network was blocked. Furthermore, herbivory (in the form of western spruce budworm defoliation as well as manual defoliation) induced transfer of carbon to kin over strangers. Douglas-fir families differed in their tendency to transfer carbon and nitrogen to kin. Molecules potentially involved in defense signaling were identified using liquid chromatography coupled with mass spectroscopy. Ectomycorrhizal fungi that can form mycorrhizal networks were found on all seedlings. We conclude that preferential carbon transfer through mycorrhizal networks occurs between kin in Douglas-fir and is amplified by herbivory stress. Herbivory is not necessary for transfer, as some transfer also occurred in the no-herbivory treatment.
Parallelizing the QUDA Library for Multi-GPU Calculations in Lattice Quantum Chromodynamics
Creators: name: Babich, Ronald
name: Clark, Michael A.
name: Joó, Bálint
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Graphics Processing Units (GPUs) are having a transformational effect on numerical lattice quantum chromodynamics (LQCD) calculations of importance in nuclear and particle physics. The QUDA library provides a package of mixed precision sparse matrix linear solvers for LQCD applications, supporting single GPUs based on NVIDIA's Compute Unified Device Architecture (CUDA). This library, interfaced to the QDP++/Chroma framework for LQCD calculations, is currently in production use on the "9g" cluster at the Jefferson Laboratory, enabling unprecedented price/performance for a range of problems in LQCD. Nevertheless, memory constraints on current GPU devices limit the problem sizes that can be tackled. In this contribution we describe the parallelization of the QUDA library onto multiple GPUs using MPI, including strategies for the overlapping of communication and computation. We report on both weak and strong scaling for up to 32 GPUs interconnected by InfiniBand, on which we sustain in excess of 4 Tflops.
description: 11 pages, 7 figures, to appear in the Proceedings of Supercomputing 2010 (submitted April 12, 2010)
Effect of electron-phonon interaction on the formation of one-dimensional electronic states in coupled Cl vacancies
Creators: name: Schuler, Bruno
name: Persson, Mats
name: Paavilainen, Sami
name: Pavliček, Niko
name: Gross, Leo
name: Meyer, Gerhard
name: Repp, Jascha
Publisher: name: Universität Regensburg
Year: 2015
Subjects: subject: 530 Physik

description: The formation of extended electron states in one-dimensional nanostructures is of key importance for the function of molecular electronic devices. Here, we study the effects of strong electron-phonon interaction on the formation of extended electronic states in intentionally created Cl vacancy pairs and chains in a NaCl bilayer on Cu(111). The interaction between the vacancies was tailored by fabricating vacancy pairs and chains of different orientation and separation with atomic precision using vertical manipulation. Small vacancy separations led to the formation of quantum-well-like vacancy states and localized interface states. By using scanning tunneling spectroscopy, we measured their energy splitting and broadening as a function of the intervacancy separation. Remarkably, the energy splitting between the vacancy states is enlarged by level repulsion resulting from the phonon dressing of the electronic states, as evidenced by theory.
In-plane tunneling anisotropic magnetoresistance in (Ga,Mn)As/GaAs Esaki diodes in the regime of the ecxess current
Creators: name: Shiogai, Junichi
name: Ciorga, Mariusz
name: Utz, Martin
name: Schuh, Dieter
name: Kohda, Makoto
name: Bougeard, Dominique
name: Nojima, Tsutomu
name: Weiss, Dieter
name: Nitta, Junsaku
Publisher: name: Universität Regensburg
Year: 2015
Subjects: subject: Tunneling, Anisotropy, Magnetic anisotropy, Tunneling diodes, Electric measurements
subject: 530 Physik

description: We investigate the angular dependence of the tunneling anisotropic magnetoresistance in (Ga,Mn)As/n-GaAs spin Esaki diodes in the regime where the tunneling process is dominated by the excess current through midgap states in (Ga,Mn)As. We compare it to similar measurements performed in the regime of band-to-band tunneling. Whereas the latter show biaxial symmetry typical for magnetic anisotropy observed in (Ga,Mn)As samples, the former is dominated by uniaxial anisotropy along the 〈110〉 axes.
"Putkisalon kartano" farm, Rantasalmi, Finland - Esittelyssä Putkisalon kartano
Creators: name: Den Herder
name: , Michael
Publisher: name: Zenodo
Year: 2018
Subjects: diversification
sheep breeding
cattle
horses
wood pastures
silvopastoralism

description: Putkisalon kartano sijaitsee 300 km Helsingistä pohjoiseen ja sen monipuolisesta toiminnasta vastaavat
Susanna Nuutinen ja Mikael Westerstråhle. Tila tuottaa jalostuseläimiä, karitsanlihaa ja viljaa. Tilalla on
myös metsää ja laajoja monimuotoisia perinnelaitumia. - The "Putkisalo kartano" farm is located 300 km north of Helsinki in the Finnish Lake District. The farm is managed by the farmers Susanna Nuutinen and Mikael Westerstråhle. It is a very diverse farm. The farm produces sheep for breeding and meat production, lamb meat and cereals. The farm also has some forest for timber production and manages traditional rural landscapes.
Carla Tempestoso. Il teatro di Caryl Phillips. Transnazionalità, identità e appartenenze
Creators: name: Capalbo, Giuseppe
Publisher: name: Fondazione Università Ca’ Foscari Venezia, Italia
Year: 2020

description:

Tempestoso, C. (2020). Il teatro di Caryl Phillips. Transnazionalità, identità e appartenenze. Roma: Aracne, 180 pp.

description: Il Tolomeo
A Feature Selection Method for Multivariate Performance Measures
Creators: name: Mao, Qi
name: Tsang, Ivor W.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Feature selection with specific multivariate performance measures is the key to the success of many applications, such as image retrieval and text classification. The existing feature selection methods are usually designed for classification error. In this paper, we propose a generalized sparse regularizer. Based on the proposed regularizer, we present a unified feature selection framework for general loss functions. In particular, we study the novel feature selection paradigm by optimizing multivariate performance measures. The resultant formulation is a challenging problem for high-dimensional data. Hence, a two-layer cutting plane algorithm is proposed to solve this problem, and the convergence is presented. In addition, we adapt the proposed method to optimize multivariate measures for multiple instance learning problems. The analyses by comparing with the state-of-the-art feature selection methods show that the proposed method is superior to others. Extensive experiments on large-scale and high-dimensional real world datasets show that the proposed method outperforms $l_1$-SVM and SVM-RFE when choosing a small subset of features, and achieves significantly improved performances over SVM$^{perf}$ in terms of $F_1$-score.
Market Makers; Exploring Gender Dynamics in Farmers Markets from Field to Booth
Creators: name: Ostrom, Marcia
name: Goldberger, Jessica R.
name: Smith, Katherine Selting
name: Ostrom, Marcia
name: Goldberger, Jessica R.
name: Smith, Katherine Selting
Publisher: name: Unknown
Year: 2020
Subjects: Farm Management
Labor and Human Capital

description: The number of farmers markets in the United States has increased dramatically in recent decades. A visible exemplar of efforts to capture more value for farmers and communities by relinking food production and consumption, farmers markets offer a window into the values and dynamics of alternative food movements. Research in Washington State found that half of farmer participants, 73% of market managers, and over 70% of shoppers are women. While a highly gendered division of labor is typical of mainstream agri-food systems, few scholars have critically examined these aspects of alternative food chains. We conclude that understanding farmers markets as intersecting, gendered spaces is critical to analyzing their potential contributions to food systems change and enhancing women’s lives and livelihoods.
Decoherence-assisted initialization of a resident hole spin polarization in a p-doped semiconductor quantum well
Creators: name: Kugler, Michael
name: Korzekwa, K.
name: Machnikowski, Pawel
name: Gradl, Christian
name: Furthmeier, Stephan
name: Griesbeck, Michael
name: Hirmer, Michael
name: Schuh, Dieter
name: Wegscheider, Werner
name: Kuhn, T.
name: Schueller, Christian
name: Korn, Tobias
Publisher: name: Universität Regensburg
Year: 2011
Subjects: subject: 530 Physik
subject: 78.67.De, 78.55.Cr, 78.47.D−

description: We investigate spin dynamics of resident holes in a p-modulation-doped GaAs/Al0.3Ga0.7As single quantum well. Time-resolved Faraday and Kerr rotation, as well as resonant spin amplification, are utilized in our study. We observe that nonresonant or high-power optical pumping leads to a resident hole spin polarization with opposite sign with respect to the optically oriented carriers, while low-power resonant optical pumping only leads to a resident hole spin polarization if a sufficient in-plane magnetic field is applied. The competition between two different processes of spin orientation strongly modifies the shape of resonant spin amplification traces. Calculations of the spin dynamics in the electron-hole system are in good agreement with the experimental Kerr rotation and resonant spin amplification traces and allow us to determine the hole spin polarization within the sample after optical orientation, as well as to extract quantitative information about spin dephasing processes at various stages of the evolution.
Bilingual Organic Farm Incubator Program Both Generates and Depends Upon Community Capital
Creators: name: Smith, Katherine
name: Ostrom, Marcia
name: Smith, Katherine
name: Ostrom, Marcia
Publisher: name: Unknown
Year: 2020
Subjects: Farm Management
Labor and Human Capital

description: Farm incubator programs have been presented as a solution to reduce barriers to entry for beginning farmers. While various forms of the farm incubator model have been documented in the literature, the significance of community capital building in the development of viable beginning farm businesses through farm incubator programs has not been investigated. Our participatory research with the bilingual, organic Viva Farms Incubator partnership in Western Washington shows how a farm incubator program can facilitate access for beginning and socially disadvantaged farmers of different races and cultures to access financial capital and markets through the development of social capital. In this case, cross-cultural capacity building appears to be both an end result and a necessary condition to connect diverse, new-entry farmers with education, farming infrastructure, and markets.