cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
(A)symmetries of weak decays at and near the kinematic endpoint
Creators: name: Hiller, Gudrun
name: Zwicky, Roman
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: At the kinematic endpoint of zero recoil physical momenta are parallel which leads to symmetries in the decay distributions. We implement this observation for decays of the type $A \to (B_1 B_2) C$ by extending the helicity formalism to include an unphysical timelike polarisation. The symmetries of the helicity amplitudes are worked out for a generic dimension six Hamiltonian for a $B \to V \ell \ell$ decay type. We obtain \emph{exact} predictions for angular observables, e.g.,for the fraction of longitudinally polarized vector mesons, $F_L = 1/3$, which may be used to guide experimental analyses. We investigate the vicinity of the endpoint through an expansion in the three momentum of the vector meson. New physics can be searched for in the slope of the observables near the endpoint. Current experimental data on $B \to K^* \ell \ell$ decays are found to be in agreement with our predictions within uncertainties. Application to other semileptonic $B$ and $D$ decays, including $B \to V \ell^+ \ell^-$, $V=K^*,ϕ, ρ$ and $B \to V \ell ν$, $V=ρ,D^*$ is straightforward. For hadronic modes of the types $B \to V p \bar p, V Λ\bar Λ, ..$ and $B \to V ππ, V πK, .. $ endpoint relations apply as long as they are not overwhelmed by sizeable final state interactions between the $V$ and the hadron pair.
description: 23pp, 3 figures, v2 to appear in JHEP, minor additions - conclusions unchanged
D2.3 Specification of the Cloud Certification Language – v1
Creators: name: Petrocchi, Marinella
Publisher: name: Zenodo
Year: 2022
Subjects: MEDINA Cloud Certification Language
MEDINA CNL
CNL Editor
Domain Specific Language
MEDINA Ontology

description: This is the first of the three deliverables resulting from Task 2.3, Task 2.4 and Task 2.5.
 This set of deliverables will present the definition and implementation of the Cloud Certification Language which encompasses three major phases: 1) the encoding of requirements of cloud certification schemas – written in natural language -- in a Controlled Natural Language (CNL), so called MEDINA CNL; 2) the editing of the requirements in MEDINA CNL through an editor tool; 3) the mapping of the CNL requirements to a domain specific language DSL.
title: Flipped oder Flopped? Inverted Classroom in der Hochschullehre
Creators: name: Hawelka, Birgit
Publisher: name: Zentrum für Hochschul- und Wissenschaftsdidaktik, Universität Regensburg
Year: 2021

description: Eine Zusammenschau verschiedener Meta-Analysen zu flipped classroom zeigt ein differenziertes Bild zur Wirksamkeit dieser Methode.
NNLO QCD subtraction for top-antitop production in the $q\bar{q}$ channel
Creators: name: Abelof, Gabriel
name: Ridder, Aude Gehrmann-De
name: Maierhöfer, Philipp
name: Pozzorini, Stefano
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present the computation of the double real and real-virtual contributions to top-antitop pair production in the quark-antiquark channel at leading colour. The $q \bar q \to t \bar{t} g$ amplitudes contributing to the real-virtual part are computed with OpenLoops, and their numerical stability in the soft and collinear regions is found to be sufficiently high to perform a realistic NNLO calculation in double precision. The subtraction terms required at real-real and real-virtual levels are constructed within the antenna subtraction formalism extended to deal with the presence of coloured massive final state particles. We show that those subtraction terms approximate the real-real and real-virtual matrix elements in all their singular limits.
description: 54 pages, 10 figures
An efficient method to compute the residual phase on a Lefschetz thimble
Creators: name: Cristoforetti, M.
name: Di Renzo, F.
name: Eruzzi, G.
name: Mukherjee, A.
name: Schmidt, C.
name: Scorzato, L.
name: Torrero, C.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We propose an efficient method to compute the so-called residual phase that appears when performing Monte Carlo calculations on a Lefschetz thimble. The method is stochastic and its cost scales linearly with the physical volume, linearly with the number of stochastic estimators and quadratically with the length of the extra dimension along the gradient flow. This is a drastic improvement over previous estimates of the cost of computing the residual phase. We also report on basic tests of correctness and scaling of the code.
description: New simulations, new plot, new appendix added. To appear in PRD. 9 pages, 3 figures
The tunable quantum spin ladder Cu(Qnx)(Cl$_{(1-x)}$Br$_{x}$)$_{2}$
Creators: name: Povarov, K. Yu.
name: Lorenz, W. E. A.
name: Xiao, F.
name: Landee, C. P.
name: Krasnikova, Y.
name: Zheludev, A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report magnetic, specific heat and ESR measurements on a series of $S=1/2$ spin ladder compounds Cu(Qnx)(Cl$_{(1-x)}$Br$_{x}$)$_{2}$. Down to $T=2$ K all the observables can be described by the spin ladder model with about 1% of $S=1/2$ impurities in the background, which are present even in a nominally pure Cu(Qnx)Cl$_{2}$ and Cu(Qnx)Br$_{2}$, for the whole range of $0\leq x\leq1$. We extract ladder exchange constants $J_{l}(x)$ and $J_{r}(x)$ as well as the gap value $Δ(x)$ by comparing the experimental data to quantum Monte-Carlo simulations. As the ESR measurements show the $g$-factor of impurities to be precisely equal to $g$-factor of the ladder spins, we suppose the impurities to be the consequence of structural defects resulting in a broken ladder ends.
description: 8 pages, 7 figures
High-frequency rectification in graphene lateral p-n junctions
Creators: name: Vasilyev, A.
name: Vasileva, G. Yu.
name: Novikov, S.
name: Tarasenko, S. A.
name: Danilov, Sergey N.
name: Ganichev, Sergey
Publisher: name: Universität Regensburg
Year: 2018
Subjects: subject: 530 Physik

description: We observe a dc electric current in response to terahertz radiation in lateral inter-digitated double-comb graphene p-n junctions. The junctions were fabricated by selective ultraviolet irradiation inducing p-type doping in intrinsic n-type epitaxial monolayer graphene. The photocurrent exhibits a strong polarization dependence and is explained by electric rectification in p-n junctions.
The sorcerer's pharmacy
Creators: name: Wallace, Ella Faye
Publisher: name: No Publisher Supplied
Year: 2018

description: How do traditions of magic, both practical and literary, interact with texts about plant- and substance-based remedies in ancient Greece and Rome, and what role does genre play in the manifestation and transmission of these traditions? This is the question that my research seeks to answer, through the methods of lexicography, close reading, and comparison of magical texts with pharmaceutical literature from four significant authors. Each chapter represents a case study of one of these authors: Theophrastus and Nicander of Colophon, who wrote in Greek; and Pliny the Elder and Scribonius Largus, who wrote in Latin. My analysis of the interplay of magic, remedy, genre, and botany in each author has revealed the development, through time, of what I term a pharmaceutical-didactic subgenre, created through the editorial decisions and selective curatorship of writers who sought to educate others in botanical and pharmaceutical topics, and, often, to display their breadth of knowledge in these subjects. At the heart of this subgenre lies the problem of dangerous or othered information: to what extent is recording it reasonable or unreasonable, ethical or immoral, traditional or subversive? How is it justified or erased, spoken or unspoken? Under what circumstances does an author preserve the sorcerer’s pharmacy? It is my hope that this approach will, beyond the limits of this thesis, prove useful for the examination of other authors of this genre in the classical period, and for their reception in the medieval era.
title: Tools für die Lehre – 4 digitale Helfer für den Unterricht
Creators: name: Greiner, Florian
Publisher: name: Zentrum für Hochschul- und Wissenschaftsdidaktik, Universität Regensburg
Year: 2021

description: Der Beitrag stellt 4 digitale Helfer für den Unterricht zu folgenden Einsatzszenarien vor: Darstellen von Inhalten, Aktivieren von Teilnehmern, kollaboratives Schreiben und Visualisieren von Ideen.
Robustness of continuous-variable entanglement via geometrical nonlinearity
Creators: name: Djorwé, Philippe
name: Engo, S. G. Nana
name: Woafo, Paul
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We propose a scheme to generate robust stationary continuous-variable entanglement in optomechanical systems, based on geometrical nonlinearity that occurs for large mechanical displacements. Such nonlinearity is often used to correct the dynamics of the systems in the strong coupling regime. It appears that geometrical nonlinearity enhances the entanglement and shifts its maximum towards high detuning values. Using the experimental parameters, we find that such a scheme generates a very robust entanglement against thermal decoherence even at room temperature. Our results show that geometrical nonlinearity affects entanglement as the optomechanical quantum interface.
description: 6 pages, 5 figures
Bird diversity in ‘paricá’ (Schizolobium amazonicum Huber ex Ducke) plantations and forest fragments in Eastern Amazon: taxonomic diversity, ecological guilds, and functional trait composition
Creators: name: de Carvalho Barros, Fernanda
name: Almeida, Sara Miranda
name: Cerqueira, Pablo Vieira
name: Silva, Larissa Cardoso
name: Santos, Marcos Pérsio Dantas
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Ecology
subject: FOS: Biological sciences
subject: Plant Biology
subject: 60506 Virology

description: Monoculture may drastically reduce biodiversity and change communities’ structure due to habitat simplification. Plantations of Schizolobium amazonicum Huber ex Ducke (‘paricá’) has been expanding in the Amazon region due to the increased demand for veneer and plywood production. Our objective was to assess whether bird communities in paricá plantations and forested areas differ in terms of composition, richness, abundance, trophic structure, and functional trait composition. This study was conducted in young paricá plantations (1 to 5 years) and forest fragments in eastern Amazon, state of Pará, Brazil. We sampled birds in five plantation sites (each paired with a nearby forested area) using both the point-count method and mist nets. We recorded 208 bird species, 132 in forest fragments and 94 in plantations. Comparatively, habitats showed distinct species composition and trait composition, with few shared species (n = 18). Paricá plantations did not support forest species, while forest fragments harbored specialized bird communities that are more sensitive to environmental change as well as endangered species. In this way, the protection of these forested areas surrounding paricá plantations is a priority for forest biodiversity conservation, given the rapid deforestation in the Brazilian Amazon.
E-learning Readiness: Understanding the Measurement of its Dimensions
Creators: name: Majid, Ishfaq
Publisher: name: figshare
Year: 2022
Subjects: subject: 130306 Educational Technology and Computing
subject: FOS: Educational sciences
subject: Education
subject: 130103 Higher Education

description: E-Learning is the most popular open learning multimedia modality of delivering education and training. It is used for enhancing learning opportunities and facilitating student access and success in education. It offers a multimedia environment which supports interactive communication where the users have full control of their learning. The state of being ready for E-learning i,e. E-learning Readiness (ELR) is an essential condition which determines whether the students, faculty members and educational institutions can successfully embrace it or not. To determine the ELR, the research available on ELR claims that various factors like “Technological Readiness, Psychological Readiness, Content Readiness, Infrastructure Readiness” etc determine ELR. Before considering E-learning as a feasible option to deliver education in higher education (HE), it becomes vital to examine and measure these factors. Hence the main objective of the present study is to explore about the factors of E-learning and also to explore the indicators to measure these factors. The study concludes that the indicators in technological readiness should measure participants’ technological skills, their competence and knowledge on E-learning technology and they should measure the advanced technological skills of the participants rather than just their basic ICT skills.
 The indicators of psychological readiness should measure mental preparedness, views & opinions and attitude towards E-learning of both students and faculties. For Infrastructure readiness, the indicators in this dimension should rate the ICT infrastructure in the institution/organization. Moreover, the indicators in Pedagogical readiness should measure the knowledge of faculties to utilize various E-learning based teaching strategies.
Graphene-enhanced plasmonic nanohole arrays for environmental sensing in aqueous samples
Creators: name: Genslein, Christa
name: Hausler, Peter
name: Kirchner, Eva-Maria
name: Bierl, Rudolf
name: Baeumner, Antje J.
name: Hirsch, Thomas
Publisher: name: Universität Regensburg
Year: 2016
Subjects: subject: diethyl phthalate; environmental sensing; nanohole array; nanosphere lithography; surface plasmon resonance
subject: 530 Physik
subject: 540 Chemie

description: The label-free nature of surface plasmon resonance techniques (SPR) enables a fast, specific, and sensitive analysis of molecular interactions. However, detection of highly diluted concentrations and small molecules is still challenging. It is shown here that in contrast to continuous gold films, gold nanohole arrays can significantly improve the performance of SPR devices in angle-dependent measurement mode, as a signal amplification arises from localized surface plasmons at the nanostructures. This leads consequently to an increased sensing capability of molecules bound to the nanohole array surface. Furthermore, a reduced graphene oxide (rGO) sensor surface was layered over the nanohole array. Reduced graphene oxide is a 2D nanomaterial consisting of sp2-hybridized carbon atoms and is an attractive receptor surface for SPR as it omits any bulk phase and therefore allows fast response times. In fact, it was found that nanohole arrays demonstrated a higher shift in the resonance angle of 250–380% compared to a continuous gold film. At the same time the nanohole array structure as characterized by its diameter-to-periodicity ratio had minimal influence on the binding capacity of the sensor surface. As a simple and environmentally highly relevant model, binding of the plasticizer diethyl phthalate (DEP) via π-stacking was monitored on the rGO gold nanohole array realizing a limit of detection of as low as 20 nM. The concentration-dependent signal change was studied with the best performing rGO-modified nanohole arrays. Compared to continuous gold films a diameter-to-periodicity ratio (D/P) of 0.43 lead to a 12-fold signal enhancement. Finally, the effect of environmental waters on the sensor was evaluated using samples from sea, lake and river waters spiked with analytically relevant amounts of DEP during which significant changes in the SPR signal are observed. It is expected that this concept can be successfully transferred to enhance the sensitivity in SPR sensors.
Protecting Privacy through Distributed Computation in Multi-agent Decision Making
Creators: name: Leaute, Thomas
name: Faltings, Boi
Publisher: name: arXiv
Year: 2014
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Cryptography and Security (cs.CR)
subject: Multiagent Systems (cs.MA)
subject: FOS: Computer and information sciences

description: As large-scale theft of data from corporate servers is becoming increasingly common, it becomes interesting to examine alternatives to the paradigm of centralizing sensitive data into large databases. Instead, one could use cryptography and distributed computation so that sensitive data can be supplied and processed in encrypted form, and only the final result is made known. In this paper, we examine how such a paradigm can be used to implement constraint satisfaction, a technique that can solve a broad class of AI problems such as resource allocation, planning, scheduling, and diagnosis. Most previous work on privacy in constraint satisfaction only attempted to protect specific types of information, in particular the feasibility of particular combinations of decisions. We formalize and extend these restricted notions of privacy by introducing four types of private information, including the feasibility of decisions and the final decisions made, but also the identities of the participants and the topology of the problem. We present distributed algorithms that allow computing solutions to constraint satisfaction problems while maintaining these four types of privacy. We formally prove the privacy properties of these algorithms, and show experiments that compare their respective performance on benchmark problems.
Joint Latency and Cost Optimization for Erasure-coded Data Center Storage
Creators: name: Xiang, Yu
name: Lan, Tian
name: Aggarwal, Vaneet
name: Chen, Yih-Farn R
Publisher: name: arXiv
Year: 2014
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: Information Theory (cs.IT)
subject: Optimization and Control (math.OC)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Modern distributed storage systems offer large capacity to satisfy the exponentially increasing need of storage space. They often use erasure codes to protect against disk and node failures to increase reliability, while trying to meet the latency requirements of the applications and clients. This paper provides an insightful upper bound on the average service delay of such erasure-coded storage with arbitrary service time distribution and consisting of multiple heterogeneous files. Not only does the result supersede known delay bounds that only work for a single file or homogeneous files, it also enables a novel problem of joint latency and storage cost minimization over three dimensions: selecting the erasure code, placement of encoded chunks, and optimizing scheduling policy. The problem is efficiently solved via the computation of a sequence of convex approximations with provable convergence. We further prototype our solution in an open-source, cloud storage deployment over three geographically distributed data centers. Experimental results validate our theoretical delay analysis and show significant latency reduction, providing valuable insights into the proposed latency-cost tradeoff in erasure-coded storage.
description: 14 pages, presented in part at IFIP Performance, Oct 2014
Cryptic diversity in a neotropical avian species complex untangled by neglected genetic evidence
Creators: name: Forcina, Giovanni
name: Boesman, Peter
name: Jowers, Michael J.
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Evolutionary Biology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified
subject: Plant Biology

description: Over the last two decades, vocal and genetic data have been extensively used in avian studies addressing taxonomic and systematic issues. However, even when multiple lines of evidence lean toward lumping or splitting of species, some taxonomic committees refuse to acknowledge their validity until convincing genetic evidence is produced and integrated with other sources of data. As a case in point, the genus Pseudocolaptes (Furnariidae) consists of three mostly allopatric and overtly distinct neotropical taxa differing in plumage and vocal features: the Streaked Tuftedcheek (P. boissonneautii), the Buffy Tuftedcheek (P. lawrencii), and the contentious Pacific Tuftedcheek (P. johnsoni). In this study, we assemble already available mitochondrial and nuclear DNA sequences to assess their taxonomy and to provide appointed committees with specific proof to ascertain the number of Pseudocolaptes species. Phylogenetic inference and species delimitation analysis indicate three species equally divergent from each other. We hope that this work will contribute to resolve the long-lasting taxonomical confusion regarding this genus, and that proper future conservation plans will be adopted to preserve each species within the inhabited biodiversity hotspot.
On the kinematic separation of field and cluster stars across the Bulge globular NGC 6528
Creators: name: Lagioia, E. P.
name: Milone, A. P.
name: Stetson, P. B.
name: Bono, G.
name: Moroni, P. G. Prada
name: Dall'Ora, M.
name: Aparicio, A.
name: Buonanno, R.
name: Calamida, A.
name: Ferraro, I.
name: Gilmozzi, R.
name: Iannicola, G.
name: Matsunaga, N.
name: Monelli, M.
name: Walker, A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present deep and precise multi-band photometry of the Galactic Bulge globular cluster NGC6528. The current dataset includes optical and near-infrared images collected with ACS/WFC, WFC3/UVIS, and WFC3/IR on board the Hubble Space Telescope. The images cover a time interval of almost ten years and we have been able to carry out a proper-motion separation between cluster and field stars. We performed a detailed comparison in the m_F814W, m_F606W - m_F814W Color-Magnitude Diagram with two empirical calibrators observed in the same bands. We found that NGC6528 is coeval with and more metal-rich than 47Tuc. Moreover, it appears older and more metal-poor than the super-metal-rich open cluster NGC6791. The current evidence is supported by several diagnostics (red horizontal branch, red giant branch bump, shape of the sub-giant branch, slope of the main sequence) that are minimally affected by uncertainties in reddening and distance. We fit the optical observations with theoretical isochrones based on a scaled-solar chemical mixture and found an age of 11 +- 1 Gyr and an iron abundance slightly above solar ([Fe/H = +0.20). The iron abundance and the old cluster age further support the recent spectroscopic findings suggesting a rapid chemical enrichment of the Galactic Bulge.
description: 14 pages, 12 figures (2 at low resolution); added references; corrected figure 3, 4, 5, 8 and 9; results unchanged. Erratum to be published in ApJ
title: Teaching Analysis Poll (TAP) – mehr als qualitative Evaluation
Creators: name: Hawelka, Birgit
Publisher: name: Zentrum für Hochschul- und Wissenschaftsdidaktik, Universität Regensburg
Year: 2021

description: Teaching Analysis Poll (TAP) kombiniert Evaluation und Beratung. Damit bietet es eine datenbasierte Grundlage zur Fortentwicklung von Lehrveranstaltungen.
The financial performance of the most valuable brands: A global empirical investigation
Creators: name: Dorfleitner, Gregor
name: Rößle, Felix
name: Lesser, Kathrin
Publisher: name: Universität Regensburg
Year: 2019
Subjects: subject: Business
subject: 330 Wirtschaft

description: We investigate the financial performance of the most valuable brands as provided by the publicly available Interbrand list on an annual basis. By applying standard multi-factor performance evaluation models, and the new five-factor model of Fama and French (2015), we observe that the most valuable brands outperform the market during the overall period from 2000 to June 2018 as well as during different market conditions. However, the extent of the outperformance is much larger during bear than during normal periods, suggesting that the most valuable brands tend to perform better during weak financial market periods. Moreover, we find that the outperformance is driven by only a few industries, e.g., business services, technology and retail. Analyzing the financial performance of the most valuable brands provided by Forbes and BrandZ reveals similar results to those of Interbrand.
title: Does entropy modulate the prediction of German long-distance verb particles?
Creators: name: Stone, Kate
name: Vasishth, Shravan
name: Malsburg, Titus von der
Publisher: name: Universitätsverlag Potsdam
Year: 2022
Subjects: subject: 500 Naturwissenschaften und Mathematik

description: In this paper we examine the effect of uncertainty on readers’ predictions about meaning. In particular, we were interested in how uncertainty might influence the likelihood of committing to a specific sentence meaning. We conducted two event-related potential (ERP) experiments using particle verbs such as turn down and manipulated uncertainty by constraining the context such that readers could be either highly certain about the identity of a distant verb particle, such as turn the bed […] down, or less certain due to competing particles, such as turn the music […] up/down. The study was conducted in German, where verb particles appear clause-finally and may be separated from the verb by a large amount of material. We hypothesised that this separation would encourage readers to predict the particle, and that high certainty would make prediction of a specific particle more likely than lower certainty. If a specific particle was predicted, this would reflect a strong commitment to sentence meaning that should incur a higher processing cost if the prediction is wrong. If a specific particle was less likely to be predicted, commitment should be weaker and the processing cost of a wrong prediction lower. If true, this could suggest that uncertainty discourages predictions via an unacceptable cost-benefit ratio. However, given the clear predictions made by the literature, it was surprisingly unclear whether the uncertainty manipulation affected the two ERP components studied, the N400 and the PNP. Bayes factor analyses showed that evidence for our a priori hypothesised effect sizes was inconclusive, although there was decisive evidence against a priori hypothesised effect sizes larger than 1μV for the N400 and larger than 3μV for the PNP. We attribute the inconclusive finding to the properties of verb-particle dependencies that differ from the verb-noun dependencies in which the N400 and PNP are often studied.
description: Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe; 785
Constraining the Natural MSSM through tunneling to color-breaking vacua at zero and non-zero temperature
Creators: name: Camargo-Molina, J. E.
name: Garbrecht, B.
name: O'Leary, B.
name: Porod, W.
name: Staub, F.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We re-evaluate the constraints on the parameter space of the minimal supersymmetric standard model from tunneling to charge- and/or color-breaking minima, taking into account thermal corrections. We pay particular attention to the region known as the Natural MSSM, where the masses of the scalar partners of the top quarks are within an order of magnitude or so of the electroweak scale. These constraints arise from the interaction between these scalar tops and the Higgs fields, which allows the possibility of parameter points having deep charge- and color-breaking true vacua. In addition to requiring that our electro-weak-symmetry-breaking, yet QCD- and electromagnetism-preserving vacuum has a sufficiently long lifetime at zero temperature, also demanding stability against thermal tunneling further restricts the allowed parameter space.
description: 7 pages, 2 figures, software available from http://vevacious.hepforge.org/ - version 2 matches that accepted for publication in Phys. Lett. B
The critical tension in the Cascading DGP model
Creators: name: Sbisà, Fulvio
name: Koyama, Kazuya
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study the behaviour of weak gravitational fields in the 6D Cascading DGP model using a bulk-based approach. To deal with the ambiguity in the thin limit of branes of codimension higher than one, we consider a specific regularization of the internal structure of the branes where the 5D brane can be considered thin with respect to the 4D one. We consider the solutions corresponding to pure tension sources on the 4D brane, and study perturbations at first order around these background solutions. We adopt a 4D scalar-vector-tensor decomposition, and focus on the scalar sector of perturbations. We show that, in a suitable 4D limit, the trace part of the 4D metric perturbations obeys a decoupled equation which suggests that it is a ghost for background tensions smaller than a critical tension, while it is a healthy field otherwise. We give a geometrical interpretation of the existence of the critical tension and of the reason why the relevant field is a ghost or not depending on the background tension. We however find a value of the critical tension which is different from the one already found in the literature. Differently from the results in the literature, our analysis implies that, choosing the background tension suitably, we can construct ghost-free models for any value of the free parameters of the theory. We suggest that the difference lies in the procedure used to evaluate the pillbox integration across the codimension-2 brane. We confirm the validity of our analysis by performing numerically the integration in a particular case where the solution inside the thick cod-2 brane is known exactly. We stress that the singular structure of the perturbation fields in the nested branes set-ups is very subtle, and that great care has to be taken when deriving the codimension-2 junction conditions.
description: 42 pages, 6 figures, version accepted for publication in JCAP
Modified Linear Projection for Large Spatial Data Sets
Creators: name: Hirano, Toshihiro
Publisher: name: arXiv
Year: 2014
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Recent developments in engineering techniques for spatial data collection such as geographic information systems have resulted in an increasing need for methods to analyze large spatial data sets. These sorts of data sets can be found in various fields of the natural and social sciences. However, model fitting and spatial prediction using these large spatial data sets are impractically time-consuming, because of the necessary matrix inversions. Various methods have been developed to deal with this problem, including a reduced rank approach and a sparse matrix approximation. In this paper, we propose a modification to an existing reduced rank approach to capture both the large- and small-scale spatial variations effectively. We have used simulated examples and an empirical data analysis to demonstrate that our proposed approach consistently performs well when compared with other methods. In particular, the performance of our new method does not depend on the dependence properties of the spatial covariance functions.
description: 29 pages, 5 figures, 4 tables
title: Open Educational Resources finden und rechtssicher verwenden
Creators: name: Bachmaier, Regine
Publisher: name: Zentrum für Hochschul- und Wissenschaftsdidaktik, Universität Regensburg
Year: 2021

description: Open Educational Resources (OER) sind freie Bildungsmaterialien. Der Beitrag bietet einen Überblick, wo man OER findet und wie man diese nutzen kann.
Bird diversity in ‘paricá’ (Schizolobium amazonicum Huber ex Ducke) plantations and forest fragments in Eastern Amazon: taxonomic diversity, ecological guilds, and functional trait composition
Creators: name: de Carvalho Barros, Fernanda
name: Almeida, Sara Miranda
name: Cerqueira, Pablo Vieira
name: Silva, Larissa Cardoso
name: Santos, Marcos Pérsio Dantas
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Ecology
subject: FOS: Biological sciences
subject: Plant Biology

description: Monoculture may drastically reduce biodiversity and change communities’ structure due to habitat simplification. Plantations of Schizolobium amazonicum Huber ex Ducke (‘paricá’) has been expanding in the Amazon region due to the increased demand for veneer and plywood production. Our objective was to assess whether bird communities in paricá plantations and forested areas differ in terms of composition, richness, abundance, trophic structure, and functional trait composition. This study was conducted in young paricá plantations (1 to 5 years) and forest fragments in eastern Amazon, state of Pará, Brazil. We sampled birds in five plantation sites (each paired with a nearby forested area) using both the point-count method and mist nets. We recorded 208 bird species, 132 in forest fragments and 94 in plantations. Comparatively, habitats showed distinct species composition and trait composition, with few shared species (n = 18). Paricá plantations did not support forest species, while forest fragments harbored specialized bird communities that are more sensitive to environmental change as well as endangered species. In this way, the protection of these forested areas surrounding paricá plantations is a priority for forest biodiversity conservation, given the rapid deforestation in the Brazilian Amazon.
Sampling biases of small non-volant mammals (Mammalia: Rodentia and Didelphimorphia) surveys in Paraná state, Brazil
Creators: name: Pereira, Alan Deivid
name: Bogoni, Juliano André
name: Siqueira, Micaela Heloise
name: Bovendorp, Ricardo Siqueira
name: Vidotto-Magnoni, Ana Paula
name: Orsi, Mário Luís
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Ecology
subject: FOS: Biological sciences
subject: Sociology
subject: FOS: Sociology
subject: Cancer
subject: Science Policy
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: Plant Biology

description: The lack of information on biological aspects of small mammals in Brazil fits into two of the main gaps in knowledge of biodiversity – the Linnean and Wallacean shortfall. We performed a broad compilation of studies developed in the Paraná state to consolidate the first list of non-volant small mammal species. Furthermore, we indicate which regions lack information and greater sampling efforts to understand the biological aspects of small mammals. We listed 50 species belonging to 30 genera, five families, and two orders, which represent 37% of marsupials and small rodent species occurring in the Brazilian Atlantic Forest. Our results indicate that are regions in the Paraná state, such as the southwest, without a single record of small mammals, reveling a Wallacean shortfall of approximately 138.584 km2. Studies on the small-bodied mammal fauna in the state of Paraná are influenced by accessibility bias, concentrated at sites less than 50 kilometers distant from cities, roads, or airports. New research will not only have the challenge of knowing the species richness in regions that are still poorly or hitherto no studied, but also evaluate the state and the population dynamics of the species that persist in densely anthropized areas.
Serotonin and tryptophan metabolites, autoantibodies and gut microbiome in APECED
Creators: name: Naskali, E.
name: Dettmer, Katja
name: Oefner, Peter J.
name: Pereira, P. A. B.
name: Krohn, K.
name: Auvinen, P.
name: Ranki, A.
name: Kluger, N.
Publisher: name: Universität Regensburg
Year: 2019
Subjects: subject: APECED; Paneth cells; constipation; diarrhea; entero-endrocrine cells; serotonin
subject: 610 Medizin

description: Objective Intestinal autoimmunity with gastrointestinal (GI) dysfunction has been shown in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). Patients lack entero-endocrine (EE) cells and have circulating autoantibodies (Aabs) against critical enzymes in serotonin (5-HT) biosynthesis. Design We sought to determine the serum levels of 5-HT, tryptophan (Trp) metabolites and L-DOPA in 37 Finnish APECED patients and to correlate their abundance with the presence of TPH and AADC Aabs, GI dysfunction and depressive symptoms. We also performed an exploratory analysis of the gut microbiome. Methods Serum 5-HT, L-DOPA and Trp metabolite levels were determined by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). TPH and AADC Aabs were measured by ELISA. Depression was assessed with a structured RBDI questionnaire. The V3-V4 regions of the bacterial 16S rRNA gene were sequenced for gut microbiome exploration. Results Serum 5-HT levels were significantly decreased (130 ± 131 nmol/L vs 686 ± 233 nmol/L, P < 0.0001) in APECED patients with TPH-1 (±AADC) Aabs compared to controls and patients with only AADC Aabs. Reduced 5-HT levels correlated with constipation. The genus Escherichia/Shigella was overrepresented in the intestinal microbiome. No correlation between serum Trp, 5-HT or l-DOPA levels and the RBDI total score, fatigue or sleep disorders was found. Conclusions This exploratory study found low serum levels of 5-HT to be associated with constipation and the presence of TPH-1 and AADC Aabs, but not with symptoms of depression. Hence, serum 5-HT, TPH1 and AADC Aabs should be determined in APECED patients presenting with GI symptoms.
Magnetic Force Sensing Using a Self-Assembled Nanowire
Creators: name: Rossi, N.
name: Gross, B.
name: Dirnberger, Florian
name: Bougeard, Dominique
name: Poggio, M.
Publisher: name: Universität Regensburg
Year: 2019
Subjects: subject: Nanowire, magnetic force microscopy, nanomagnetism, torque magnetometry, MnAs nanocrystal, sequential crystallization
subject: 530 Physik

description: We present a scanning magnetic force sensor based on an individual magnet-tipped GaAs nanowire (NW) grown by molecular beam epitaxy. Its magnetic tip consists of a final segment of single-crystal MnAs formed by sequential crystallization of the liquid Ga catalyst droplet. We characterize the mechanical and magnetic properties of such NWs by measuring their flexural mechanical response in an applied magnetic field. Comparison with numerical simulations allows the identification of their equilibrium magnetization configurations, which in some cases include magnetic vortices. To determine a NW’s performance as a magnetic scanning probe, we measure its response to the field profile of a lithographically patterned current-carrying wire. The NWs’ tiny tips and their high force sensitivity make them promising for imaging weak magnetic field patterns on the nanometer-scale, as required for mapping mesoscopic transport and spin textures or in nanometer-scale magnetic resonance.
Increase in Tc and change of crystal structure by high-pressure annealing in BiS2-based superconductor CeO0.3F0.7BiS2
Creators: name: Kajitani, Joe
name: Hiroi, Takafumi
name: Omachi, Atsushi
name: Miura, Osuke
name: Mizuguchi, Yoshikazu
Publisher: name: arXiv
Year: 2014
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Recently, several types of BiS2-based superconductor such as Bi4O4S3, REO1-xFxBiS2 (RE: rare earth) and Sr1-xLaxFBiS2 have been discovered. In this study, we have investigated the crystal structure and the superconducting properties for two kinds of polycrystalline samples (As-grown and high-pressure-annealed samples) of the BiS2-based superconductor CeO0.3F0.7BiS2. We found that both the As-grown and the high-pressure-annealed CeO0.3F0.7BiS2 samples show bulk superconductivity. A higher Tc was observed in the high-pressure-annealed sample. The Tc of CeO0.3F0.7BiS2 increased from Tczero = 2.7 K to Tczero = 3.7 K by high-pressure annealing. The lattice constant of a and c axis did not show remarkable differences between the As-grown and the high-pressure-annealed samples. Nevertheless, the peak symmetry of the (200) peak seemed to become more symmetric while the (004) peak did not show such a difference, indicating that the crystal structure within the ab plane changed to a higher-symmetric phase, a perfect tetragonal, by high-pressure annealing in CeO0.3F0.7BiS2.
description: 13 pages, 3 figures. Submitted to ICSM2014 proceedings
Element Substitution Effect on Superconductivity in BiS2-Based NdO_{1-x}F_xBiS_2
Creators: name: Hiroi, Takafumi
name: Kajitani, Joe
name: Omachi, Atsushi
name: Miura, Osuke
name: Mizuguchi, Yoshikazu
Publisher: name: arXiv
Year: 2014
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Recently, new layered superconductors having a BiS2-type conduction layer have been discovered. NdO1-xFxBiS2 is a typical BiS2-based superconductor with a maximum Tc of 5.4 K. In this study, the effect of element substitution within the superconducting layer of BiS2-based NdO0.5F0.5BiS2 was investigated. We systematically synthesized two kinds of polycrystalline samples of NdO0.5F0.5Bi(S1-xSex)2 and NdO0.5F0.5Bi1-ySbyS2 by a two-step solid-state reaction method. The phase purity and the changes in lattice constants were investigated by x-ray diffraction. The superconducting properties were investigated by magnetic susceptibility and electrical resistivity measurements. It was found that the partial substitution of S by Se resulted in the uniaxial lattice expansion along the a axis. The superconducting transition temperature were gradually degraded with increasing Se concentration in NdO0.5F0.5Bi(S1-xSex)2. When Bi was partially substituted by Sb, the uniaxial lattice contraction along the c axis was observed in NdO0.5F0.5Bi1-ySbyS2. In the Sb-substituted system, a metal-insulator transition was observed with increasing Sb concentration.
description: 14 pages, 4 figures. Submitted to ICSM2014 proceedings
Phenomenology of dark energy: exploring the space of theories with future redshift surveys
Creators: name: Piazza, Federico
name: Steigerwald, Heinrich
name: Marinoni, Christian
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We use the effective field theory of dark energy to explore the space of modified gravity models which are capable of driving the present cosmic acceleration. We identify five universal functions of cosmic time that are enough to describe a wide range of theories containing a single scalar degree of freedom in addition to the metric. The first function (the effective equation of state) uniquely controls the expansion history of the universe. The remaining four functions appear in the linear cosmological perturbation equations, but only three of them regulate the growth history of large scale structures. We propose a specific parameterization of such functions in terms of characteristic coefficients that serve as coordinates in the space of modified gravity theories and can be effectively constrained by the next generation of cosmological experiments. We address in full generality the problem of the soundness of the theory against ghost-like and gradient instabilities and show how the space of non-pathological models shrinks when a more negative equation of state parameter is considered. This analysis allows us to locate a large class of stable theories that violate the null energy condition (i.e. super-acceleration models) and to recover, as particular subsets, various models considered so far. Finally, under the assumption that the true underlying cosmological model is the $Λ$ Cold Dark Matter ($Λ$CDM) scenario, and relying on the figure of merit of EUCLID-like observations, we demonstrate that the theoretical requirement of stability significantly narrows the empirical likelihood, increasing the discriminatory power of data. We also find that the vast majority of these non-pathological theories generating the same expansion history as the $Λ$CDM model predict a different, lower, growth rate of cosmic structures.
description: v1: 28 pages, 20 pdf figures. v2: 29 pages, minor improvements in the text, figures improved
Gauge Theory on Twisted $κ$-Minkowski: Old Problems and Possible Solutions
Creators: name: Dimitrijevic, Marija
name: Jonke, Larisa
name: Pachol, Anna
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We review the application of twist deformation formalism and the construction of noncommutative gauge theory on $κ$-Minkowski space-time. We compare two different types of twists: the Abelian and the Jordanian one. In each case we provide the twisted differential calculus and consider ${U}(1)$ gauge theory. Different methods of obtaining a gauge invariant action and related problems are thoroughly discussed.
Direct- and resolved-photon threshold resummation for polarized high- pT hadron production at COMPASS
Creators: name: Uebler, Claudia
name: Schäfer, Andreas
name: Vogelsang, Werner
Publisher: name: Universität Regensburg
Year: 2017
Subjects: subject: QCD HARD SCATTERING; CROSS-SECTIONS; PARTON DISTRIBUTIONS; PHOTOPRODUCTION; COLLISIONS;
subject: 530 Physik

description: We complete our earlier study of the "direct" part of the cross section and spin asymmetry for the photoproduction process gamma N -> hX by analyzing the "resolved" contribution, for which the photon couples like a hadron through its parton structure. The incident photon and nucleon are longitudinally polarized and one observes a hadron h at high transverse momentum pT. Soft or collinear gluon emissions generate large logarithmic threshold corrections which we resum to next-to-leading logarithmic order. We compare our results with recent spin asymmetry data by the COMPASS Collaboration, highlighting the role of the fragmentation functions.
Superconducting Transitions in Flat Band Systems
Creators: name: Iglovikov, V. I.
name: Hébert, F.
name: Grémaud, B.
name: Batrouni, G. G.
name: Scalettar, R. T.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The physics of strongly correlated quantum particles within a flat band was originally explored as a route to itinerant ferromagnetism and, indeed, a celebrated theorem by Lieb rigorously establishes that the ground state of the repulsive Hubbard model on a bipartite lattice with unequal number of sites in each sublattice must have nonzero spin S at half-filling. Recently, there has been interest in Lieb geometries due to the possibility of novel topological insulator, nematic, and Bose-Einstein condensed (BEC) phases. In this paper, we extend the understanding of the attractive Hubbard model on the Lieb lattice by using Determinant Quantum Monte Carlo to study real space charge and pair correlation functions not addressed by the Lieb theorems.