cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Contested imaginaries of global justice in the internationalization of higher education
Creators: name: Stein, Sharon
Publisher: name: University of British Columbia
Year: 2017

description: An emergent ‘critical turn’ in the study and practice of higher education internationalization has generated incisive analyses of the ethical and political implications of international engagements. This reflexive moment, however, also risks renaturalizing an imperial global imaginary, which I trace in this dissertation to the fact that higher education scholars and practitioners in the Global North have yet to substantively unpack the transnational colonial dimensions of the modern Western university. I argue that practitioners and scholars of internationalization have an obligation to face higher education’s historical and contemporary complicity in empire, as well as our own. This is particularly necessary in the context of nation-states that were founded through conquest, and whose ongoing colonial entanglements have both local and global dimensions. Working from a decolonial orientation and an underlying commitment to denaturalize violent and unsustainable patterns of thinking, being, and relating, I ask how inherited frames of liberal justice and humanist theories of change operate in the mainstream study and practice of internationalization in the United States and Canada. In the areas of curriculum internationalization, international student mobility, and global citizenship, I identify a tendency to reassert as universal what are in fact situated, partial, and often Euro-supremacist epistemological and ontological assumptions about the world and the purposes of higher education. Further, these assumptions often calibrate even critical scholarship, which largely remains enframed by what is possible and desirable within the frames of colonial modernity and its promises of security, prosperity, and universality. By identifying the limits of justice within these frames, there is an opportunity to think, be, and relate differently, but at these moments of possibility there is also a tendency to seek out the old comforts and assurances promised by imperial frames. To interrupt this circular tendency requires tracing both the immediate symptoms and the root causes of global injustice, attending to our enduring attachments to the promises offered by the colonial architectures of modern existence, and making a commitment to wrestle with the complexities and difficulties of learning from past mistakes, disinvesting from harmful systems and subjectivities, and experimenting responsibly with alternative possibilities.
title: "Ritratto di donna su busto moderno", arte romana, inv. CLXXIX (ITA/EN)
title: Scheda catalogo digitale Borghese
titleType: AlternativeTitle
Creators: name: Clementi, Jessica
name: Galleria Borghese
Publisher: name: Galleria Borghese
Year: 2024

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

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

Collegamento al catalogo digitale:

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

EN: https://www.collezionegalleriaborghese.it/en
Enhanced coupling through π-stacking in imidazole-based molecular junctions
Creators: name: Fu, Tianren
name: Smith, Shanelle
name: Camarasa-Gómez, María
name: Yu, Xiaofang
name: Xue, Jiayi
name: Nuckolls, Colin
name: Evers, Ferdinand
name: Venkataraman, Latha
name: Wei, Sujun
Publisher: name: Universität Regensburg
Year: 2019
Subjects: subject: 530 Physik

description: We demonstrate that imidazole based π–π stacked dimers form strong and efficient conductance pathways in single-molecule junctions using the scanning-tunneling microscope-break junction (STM-BJ) technique and density functional theory-based calculations. We first characterize an imidazole-gold contact by measuring the conductance of imidazolyl-terminated alkanes (im-N-im, N = 3–6). We show that the conductance of these alkanes decays exponentially with increasing length, indicating that the mechanism for electron transport is through tunneling or super-exchange. We also reveal that π–π stacked dimers can be formed between imidazoles and have better coupling than through-bond tunneling. These experimental results are rationalized by calculations of molecular junction transmission using non-equilibrium Green's function formalism. This study verifies the capability of imidazole as a Au-binding ligand to form stable single- and π-stacked molecule junctions at room temperature.
Health sciences libraries in Germany: new directions
Creators: name: Knüttel, Helge
name: Krause, Evamaria
name: Semmler-Schmetz, Martina
name: Reimann, Iris
name: Metzendorf, Maria-Inti
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: Germany; Access to information; Libraries, health care; Library services; Librarianship, health science
subject: 020 Bibliotheks- und Informationswissenschaft

description: This feature is part of a series about medical library services in various countries. It gives an overview of the state of and selected current developments of medical library services to support research, education and clinical practice in Germany. Findings from an online survey and issues of access to health information are discussed in relation to the German health care system.
Impact of the Sensory and Sympathetic Nervous System on Fracture Healing in Ovariectomized Mice
Creators: name: Niedermair, Tanja
name: Straub, Rainer H.
name: Brochhausen, Christoph
name: Grässel, Susanne
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: fracture; substance P; alpha-CGRP; sympathectomy; sympathetic nerve fibers; ovariectomy; sensory nervous system; bone repair; bone remodeling
subject: 610 Medizin

description: The peripheral nervous system modulates bone repair under physiological and pathophysiological conditions. Previously, we reported an essential role for sensory neuropeptide substance P (SP) and sympathetic nerve fibers (SNF) for proper fracture healing and bone structure in a murine tibial fracture model. A similar distortion of bone microarchitecture has been described for mice lacking the sensory neuropeptide α-calcitonin gene-related peptide (α-CGRP). Here, we hypothesize that loss of SP, α-CGRP, and SNF modulates inflammatory and pain-related processes and also affects bone regeneration during fracture healing under postmenopausal conditions. Intramedullary fixed femoral fractures were set to 28 days after bilateral ovariectomy (OVX) in female wild type (WT), SP-, α-CGRP-deficient, and sympathectomized (SYX) mice. Locomotion, paw withdrawal threshold, fracture callus maturation and numbers of TRAP-, CD4-, CD8-, F4/80-, iNos-, and Arg1-positive cells within the callus were analyzed. Nightly locomotion was reduced in unfractured SP-deficient and SYX mice after fracture. Resistance to pressure was increased for the fractured leg in SP-deficient mice during the later stages of fracture healing, but was decreased in α-CGRP-deficient mice. Hypertrophic cartilage area was increased nine days after fracture in SP-deficient mice. Bony callus maturation was delayed in SYX mice during the later healing stages. In addition, the number of CD 4-positive cells was reduced after five days and the number of CD 8-positive cells was additionally reduced after 21 days in SYX mice. The number of Arg1-positive M2 macrophages was higher in α-CGRP-deficient mice five days after fracture. The alkaline phosphatase level was increased in SYX mice 16 days after fracture. Absence of α-CGRP appears to promote M2 macrophage polarization and reduces the pain threshold, but has no effect on callus tissue maturation. Absence of SP reduces locomotion, increases the pain-threshold, and accelerates hypertrophic callus tissue remodeling. Destruction of SNF reduces locomotion after fracture and influences bony callus tissue remodeling during the later stages of fracture repair, whereas pain-related processes are not affected.
Cohomology of the second Voronoi compactification of A_4
Creators: name: Hulek, Klaus
name: Tommasi, Orsola
Publisher: name: arXiv
Year: 2011
Subjects: subject: Algebraic Geometry (math.AG)
subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 14K10 (Primary) 14F25, 14C15, 14D22 (Secondary)

description: In this paper we compute the cohomology groups of the second Voronoi compactification of the moduli space of abelian fourfolds in all degrees with the exception of the middle degree 10. We also compute the cohomology groups of the perfect cone compactification in degree < 10. The main tool is the investigation of the strata of the compactification corresponding to semi-abelic varieties with constant torus rank.
description: v2: 41 pages, mostly expository changes
Current Trends in the Optical Characterization of Two-Dimensional Carbon Nanomaterials
Creators: name: Kröner, Anton
name: Hirsch, Thomas
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: graphene, graphene oxide, carbon nanomaterial, optical characterization, methods, defects
subject: 540 Chemie

description: Graphene and graphene-related materials have received great attention because of their outstanding properties like Young's modulus, chemical inertness, high electrical and thermal conductivity, or large mobility. To utilize two-dimensional (2D) materials in any practical application, an excellent characterization of the nanomaterials is needed as such dimensions, even small variations in size, or composition, are accompanied by drastic changes in the material properties. Simultaneously, it is sophisticated to perform characterizations at such small dimensions. This review highlights the wide range of different characterization methods for the 2D materials, mainly attributing carbon-based materials as they are by far the ones most often used today. The strengths as well as the limitations of the individual methods, ranging from light microscopy, scanning electron microscopy, transmission electron microscopy, scanning transmission electron microscopy, scanning tunneling microscopy (conductive), atomic force microscopy, scanning electrochemical microscopy, Raman spectroscopy, UV–vis, X-ray photoelectron spectroscopy, X-ray fluorescence spectroscopy, energy-dispersive X-ray spectroscopy, Auger electron spectroscopy, electron energy loss spectroscopy, X-ray diffraction, inductively coupled plasma atomic emission spectroscopy to dynamic light scattering, are discussed. By using these methods, the flake size and shape, the number of layers, the conductivity, the morphology, the number and type of defects, the chemical composition, and the colloidal properties of the 2D materials can be investigated.
Elimination of Hyperimaginaries and Stable Independence in simple CM-trivial theories
Creators: name: Palacin, Daniel
name: Wagner, Frank Olaf
Publisher: name: arXiv
Year: 2010
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics

description: In a simple CM-trivial theory every hyperimaginary is interbounded with a sequence of finitary hyperimaginaries. Moreover, such a theory eliminates hyperimaginaries whenever it eliminates finitary hyperimaginaries. In a supersimple CM-trivial theory, the independence relation is stable.
Pseudo-spin-dependent scattering in carbon nanotubes
Creators: name: Mayrhofer, Leonhard
name: Bercioux, Dario
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: The breaking of symmetry is the ground on which many physical phenomena are explained. This is important in particular for bipartite lattice structure as graphene and carbon nanotubes, where particle-hole and pseudo-spin are relevant symmetries. Here we investigate the role played by the defect-induced breaking of these symmetries in the electronic scattering properties of armchair single-walled carbon nanotubes. From Fourier transform of the local density of states we show that the active electron scattering channels depend on the conservation of the pseudo-spin. Further, we show that the lack of particle-hole symmetry is responsible for the pseudo-spin selection rules observed in several experiments. This symmetry breaking arises from the lattice reconstruction appearing at defect sites. Our analysis gives an intuitive way to understand the scattering properties of carbon nanotubes, and can be employed for newly interpret several experiments on this subject. Further, it can be used to design devices such as pseudo-spin filter by opportune defect engineering.
A Motion Illusion Reveals Mechanisms of Perceptual Stabilization
Creators: name: Beer, Anton L.
name: Heckel, Andreas
name: Greenlee, Mark W.
Publisher: name: Universität Regensburg
Year: 2008
Subjects: subject: Transcranial random noise stimulation, Motor cortex, fMRI finger tapping, Cortical inhibition
subject: 150 Psychologie

description: Visual illusions are valuable tools for the scientific examination of the mechanisms underlying perception. In the peripheral drift illusion special drift patterns appear to move although they are static. During fixation small involuntary eye movements generate retinal image slips which need to be suppressed for stable perception. Here we show that the peripheral drift illusion reveals the mechanisms of perceptual stabilization associated with these micromovements. In a series of experiments we found that illusory motion was only observed in the peripheral visual field. The strength of illusory motion varied with the degree of micromovements. However, drift patterns presented in the central (but not the peripheral) visual field modulated the strength of illusory peripheral motion. Moreover, although central drift patterns were not perceived as moving, they elicited illusory motion of neutral peripheral patterns. Central drift patterns modulated illusory peripheral motion even when micromovements remained constant. Interestingly, perceptual stabilization was only affected by static drift patterns, but not by real motion signals. Our findings suggest that perceptual instabilities caused by fixational eye movements are corrected by a mechanism that relies on visual rather than extraretinal (proprioceptive or motor) signals, and that drift patterns systematically bias this compensatory mechanism. These mechanisms may be revealed by utilizing static visual patterns that give rise to the peripheral drift illusion, but remain undetected with other patterns. Accordingly, the peripheral drift illusion is of unique value for examining processes of perceptual stabilization.
Smooth Gowdy symmetric generalized Taub-NUT solutions
Creators: name: Beyer, Florian
name: Hennig, Jörg
Publisher: name: arXiv
Year: 2011
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We study a class of S3 Gowdy vacuum models with a regular past Cauchy horizon which we call smooth Gowdy symmetric generalized Taub-NUT solutions. In particular, we prove existence of such solutions by formulating a singular initial value problem with asymptotic data on the past Cauchy horizon. The result of our investigations is that a future Cauchy horizon exists for generic asymptotic data. Moreover, we derive an explicit expression for the metric on the future Cauchy horizon in terms of the asymptotic data on the past horizon. This complements earlier results about S2xS1 Gowdy models.
description: 56 pages, 1 figure. The new version contains a detailed explanation of the Fuchsian method on the 2-sphere
Spectrum of Tendon Pathologies: Triggers, Trails and End-State
Creators: name: Steinmann, Sara
name: Pfeifer, Christian G.
name: Brochhausen, Christoph
name: Docheva, Denitsa
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: tendon pathologies; tendinopathy; tendinitis; tendinosis; tendon rupture; risk factors; tendinopathy management
subject: 610 Medizin

description: The biggest compartment of the musculoskeletal system is the tendons and ligaments. In particular, tendons are dense tissues connecting muscle to bone that are critical for the integrity, function and locomotion of this system. Due to the increasing age of our society and the overall rise in engagement in extreme and overuse sports, there is a growing prevalence of tendinopathies. Despite the recent advances in tendon research and due to difficult early diagnosis, a multitude of risk factors and vague understanding of the underlying biological mechanisms involved in the progression of tendon injuries, the toolbox of treatment strategies remains limited and non-satisfactory. This review is designed to summarize the current knowledge of triggers, trails and end state of tendinopathies.
Interactions between Auditory and Visual Semantic Stimulus Classes: Evidence for Common Processing Networks for Speech and Body Actions
Creators: name: Meyer, Georg F.
name: Greenlee, Mark W.
name: Wuerger, Sophie
Publisher: name: Universität Regensburg
Year: 2011
Subjects: subject: 150 Psychologie

description: Incongruencies between auditory and visual signals negatively affect human performance and cause selective activation in neuroimaging studies; therefore, they are increasingly used to probe audiovisual integration mechanisms. An open question is whether the increased BOLD response reflects computational demands in integrating mismatching low-level signals or reflects simultaneous unimodal conceptual representations of the competing signals. To address this question, we explore the effect of semantic congruency within and across three signal categories (speech, body actions, and unfamiliar patterns) for signals with matched low-level statistics. In a localizer experiment, unimodal (auditory and visual) and bimodal stimuli were used to identify ROIs. All three semantic categories cause overlapping activation patterns. We find no evidence for areas that show greater BOLD response to bimodal stimuli than predicted by the sum of the two unimodal responses. Conjunction analysis of the unimodal responses in each category identifies a network including posterior temporal, inferior frontal, and premotor areas. Semantic congruency effects are measured in the main experiment. We find that incongruent combinations of two meaningful stimuli (speech and body actions) but not combinations of meaningful with meaningless stimuli lead to increased BOLD response in the posterior STS (pSTS) bilaterally, the left SMA, the inferior frontal gyrus, the inferior parietal lobule, and the anterior insula. These interactions are not seen in premotor areas. Our findings are consistent with the hypothesis that pSTS and frontal areas form a recognition network that combines sensory categorical representations (in pSTS) with action hypothesis generation in inferior frontal gyrus/premotor areas. We argue that the same neural networks process speech and body actions.
Deep subseafloor sediments in Guaymas Basin harbor cosmopolitan microbiota and traces of hydrothermal populations
Creators: name: Morono, Yuki
name: Aiello, Ivano
name: Edgcomb, Virginia P.
name: Mara, Paraskevi
name: Beaudoin, David
name: Geller-McGrath, David
name: Teske, Andreas
Publisher: name: Springer Nature
Year: 2024

description: Environmental factors shape subsurface microbial ecosystems, and well-characterized sites are ideal for determining how environmental parameters shape sediment communities. Sediments from eight geologically and thermally distinct sites were drilled during International Ocean Discovery Program Expedition 385 in Guaymas Basin, an expedition focused on the hydrothermal deep biosphere. Using high-throughput 16S ribosomal nucleic acid sequencing, cell counts, phylogenetics, metatranscriptomics, and mineralogical/elemental X-ray spectroscopy, we examine linkages and feedbacks between mineral composition, temperature, geochemistry, and microbial populations. We show subsurface life is dominated by heterotrophic, cosmopolitan prokaryotes that thrive within a range of sediments and temperature conditions across Guaymas Basin. Hydrothermally-affiliated lineages are detected in low numbers at sites with steepest temperature gradients, within communities of mesophilic taxa that occur throughout Guaymas Basin and in other marine subsurface habitats. Thus, hydrothermal lineages do not replace the cosmopolitan, mesophilic subsurface community, but remain specific to sites where volcanic intrusions drive hydrothermal circulation.
Phase-field modelling of abnormal grain growth
Creators: name: Liu, Ying
Publisher: name: University of British Columbia
Year: 2017

description: Heterogeneous grain structures may develop due to abnormal grain growth during thermo-mechanical processing of polycrystalline materials ranging from metals to ceramics. This phenomenon must be controlled in practical applications where typically homogeneous grain structures are desired. Recent advances in experimental and computational techniques have, thus, stimulated to revisit the underlying growth mechanisms. Here, phase field modelling is used to systematically evaluate conditions for abnormal grain growth. Grain boundaries are classified into two classes, i.e. high and low mobility boundaries. Three different approaches are considered for having high and low mobility boundaries: (i) Critical threshold angle of grain boundary disorientation above which boundaries are highly mobile; (ii) Two grain types A and B with either the AB or the AA boundaries being highly mobile; (iii) Three grain types A, B and C with AB boundaries being highly mobile. For these different scenarios, 2D and 3D simulations have been performed to quantify the effect of variations in the mobility ratio, threshold angle and fractions of grain types, respectively, on the potential onset of abnormal grain growth and the degree of heterogeneity in the resulting grain structures. The required mobility ratios to observe abnormal grain growth are quantified as a function of the fraction of high mobility boundaries. The microstructure evolutions during abnormal grain growth are analyzed in terms of the spatial distribution of the highly mobile boundaries.
Holographic inflation and holographic dark energy from entropy of the anti-de Sitter black hole
Creators: name: Huang, Qihong
name: Huang, He
name: Xu, Bing
name: Zhang, Kaituo
Publisher: name: arXiv
Year: 2025
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Based on the entropy of anti-de Sitter black hole, a new holographic dark energy model has been proposed. When the Hubble horizon and particle horizon are chosen as the IR cutoff, the late-time accelerated expansion of universe is realized. In this paper, we consider the Hubble horizon as the IR cutoff to investigate holographic inflation and slow-roll inflation in this model. We find that slow-roll inflation with the chaotic potential $V_{0}ϕ^{n}$ is favored by Planck results for some special cases, such as $n=1/3$ and $n=1/2$, while holographic inflation is not supported by Planck results. Then, we analyze the reheating temperature and the number of reheating e-folds in this model, and we find that the results favor the cases $n=1/3$ and $n=1/2$. Finally, we use the dynamical analysis method, statefinder diagnostic pairs, and the Hubble diagram to analyze this model. Our results indicate that when $b^{2}$ takes a small value, this model cannot be distinguished from the standard $Λ$CDM model and can serve as an alternative to it.
The mean point of vergence is biased under projection
Creators: name: Wang, Xi
name: Holmqvist, Kenneth
name: Alexa, Marc
Publisher: name: Universität Regensburg
Year: 2019
Subjects: subject: eye movement, eye tracking, fixations, gaze, vergence, bias, calibration
subject: 150 Psychologie

description: The point of interest in three-dimensional space in eye tracking is often computed based on intersecting the lines of sight with geometry, or finding the point closest to the two lines of sight. We first start by theoretical analysis with synthetic simulations. We show that the mean point of vergence is generally biased for centrally symmetric errors and that the bias depends on the horizontal vs. vertical error distribution of the tracked eye positions. Our analysis continues with an evaluation on real experimental data. The error distributions seem to be different among individuals but they generally leads to the same bias towards the observer. And it tends to be larger with an increased viewing distance. We also provided a recipe to minimize the bias, which applies to general computations of eye ray intersection. These findings not only have implications for choosing the calibration method in eye tracking experiments and interpreting the observed eye movements data; but also suggest to us that we shall consider the mathematical models of calibration as part of the experiment.
Premotor Cortex Is Sensitive to Auditory–Visual Congruence for Biological Motion
Creators: name: Wuerger, Sophie
name: Parkes, Laura
name: Lewis, P. A.
name: Crocker-Buque, A.
name: Rutschmann, Roland M.
name: Meyer, Georg F.
Publisher: name: Universität Regensburg
Year: 2012
Subjects: subject: 150 Psychologie

description: The auditory and visual perception systems have developed special processing strategies for ecologically valid motion stimuli, utilizing some of the statistical properties of the real world. A well-known example is the perception of biological motion, for example, the perception of a human walker. The aim of the current study was to identify the cortical network involved in the integration of auditory and visual biological motion signals. We first determined the cortical regions of auditory and visual coactivation (Experiment 1); a conjunction analysis based on unimodal brain activations identified four regions: middle temporal area, inferior parietal lobule, ventral premotor cortex, and cerebellum. The brain activations arising from bimodal motion stimuli (Experiment 2) were then analyzed within these regions of coactivation. Auditory footsteps were presented concurrently with either an intact visual point-light walker (biological motion) or a scrambled point-light walker; auditory and visual motion in depth (walking direction) could either be congruent or incongruent. Our main finding is that motion incongruency (across modalities) increases the activity in the ventral premotor cortex, but only if the visual point-light walker is intact. Our results extend our current knowledge by providing new evidence consistent with the idea that the premotor area assimilates information across the auditory and visual modalities by comparing the incoming sensory input with an internal representation.
description: Posted Online November 29, 2011
Four-And-A-Half LIM-Domain Protein 2 (FHL2) Deficiency Aggravates Cholestatic Liver Injury
Creators: name: Sommer, Judith
name: Dorn, Christoph
name: Gäbele, Erwin
name: Bataille, Frauke
name: Freese, Kim
name: Seitz, Tatjana
name: Thasler, Wolfgang E.
name: Büttner, Reinhard
name: Weiskirchen, Ralf
name: Bosserhoff, Anja
name: Hellerbrand, Claus
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: four-and-a-half LIM-domain protein 2; FHL2; cholestatic liver injury; bile acids
subject: 615 Pharmazie

description: Cholestasis occurs in different clinical circumstances and leads to severe hepatic disorders. The four-and-a-half LIM-domain protein 2 (FHL2) is a scaffolding protein that modulates multiple signal transduction pathways in a tissue- and cell context-specific manner. In this study, we aimed to gain insight into the function of FHL2 in cholestatic liver injury. FHL2 expression was significantly increased in the bile duct ligation (BDL) model in mice. In Fhl2-deficient (Fhl2-ko) mice, BDL caused a more severe portal and parenchymal inflammation, extended portal fibrosis, higher serum transaminase levels, and higher pro-inflammatory and pro-fibrogenic gene expression compared to wild type (wt) mice. FHL2 depletion in HepG2 cells with siRNA resulted in a higher expression of the bile acid transporter Na+-taurocholate cotransporting polypeptide (NTCP) gene. Furthermore, FHL2-depleted HepG2 cells showed higher expression of markers for oxidative stress, lower B-cell lymphoma 2 (Bcl2) expression, and higher Bcl2-associated X protein (BAX) expression after stimulation with deoxycholic acid (DCA). In hepatic stellate cells (HSCs), FHL2 depletion caused an increased expression of TGF-β and several pro-fibrogenic matrix metalloproteinases. In summary, our study shows that deficiency in FHL2 aggravates cholestatic liver injury and suggests FHL2-mediated effects on bile acid metabolisms and HSCs as potential mechanisms for pronounced hepatocellular injury and fibrosis.
Twin-atom beams
Creators: name: Bücker, Robert
name: Grond, Julian
name: Manz, Stephanie
name: Berrada, Tarik
name: Betz, Thomas
name: Koller, Christian
name: Hohenester, Ulrich
name: Schumm, Thorsten
name: Perrin, Aurélien
name: Schmiedmayer, Jörg
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present highly efficient emission of twin-atom beams into a single transversal mode of a waveguide potential. The source is a one-dimensional degenerate Bose gas in the first radially excited state. We directly measure a suppression of fluctuations in the atom number difference between the beams to 0.37(3) with respect to the classical expectation, equivalent to 0.11(2) after correcting for detection noise. Our results underline the high potential of ultracold atomic gases as sources for quantum matter wave optics and will enable the implementation of schemes previously unattainable with massive particles
description: 7 pages (including supplementary material), 5 figures
Ocean Data Hours - Ocean Race - Ocean Village - Genova Pavillion - Alicante 11.01.2023
Creators: name: Novellino, Antonio
Publisher: name: Zenodo
Year: 2023
Subjects: EMODnet Physics
EMODnet Ingestion
SO-CHIC
OCEN:ICE
NAUTILOS
EuroSea
BlueCloud2026
DSH2030
RAISE Liguria

description: Timely, free and open exchange for oceanographic observational data is essential for forecasting models and their role in the weather and the climate, decision making and sustainable management of the ocean and environment etc. This presentation shows how data management and FAIRness are crucial for ensuring ocean sustainable management and exploitation.
Exponential Formulas and Lie Algebra Type Star Products
Creators: name: Meljanac, Stjepan
name: Škoda, Zoran
name: Svrtan, Dragutin
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Algebra (math.QA)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 16S30, 16S32, 16A58, 81T75

description: Given formal differential operators $F_i$ on polynomial algebra in several variables $x_1,...,x_n$, we discuss finding expressions $K_l$ determined by the equation $\exp(\sum_i x_i F_i)(\exp(\sum_j q_j x_j)) = \exp(\sum_l K_l x_l)$ and their applications. The expressions for $K_l$ are related to the coproducts for deformed momenta for the noncommutative space-times of Lie algebra type and also appear in the computations with a class of star products. We find combinatorial recursions and derive formal differential equations for finding $K_l$. We elaborate an example for a Lie algebra $su(2)$, related to a quantum gravity application from the literature.
Towards unambiguous calculation of the topological entropy for mixed states
Creators: name: Wootton, James R.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Calculation of topological order parameters, such as the topological entropy and topological mutual information, are used to determine whether states possess topological order. Their calculation is expected to give reliable results when the ground states of gapped Hamiltonians are considered, since non-topological correlations are suppressed by a finite correlation length. However, studies of thermal states and the effects of incoherent errors require calculations involving mixed states. Here we show that such mixed states can effectively lead to a diverging correlation length, and hence may give misleading results when these order parameters are calculated. To solve this problem, we propose a novel method to calculate the quantity, allowing topologically ordered states to be identified with greater confidence.
description: 6 pages, 2 figures
A generalized model for Yang-Fourier transforms in fractal space
Creators: name: Yang, Xiao-Jun
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 28A80, 26A99, 26A15

description: Local fractional calculus deals with everywhere continuous but nowhere differentiable functions in fractal space. The Yang-Fourier transform based on the local fractional calculus is a generalization of Fourier transform in fractal space. In this paper, local fractional continuous non-differentiable functions in fractal space are studied, and the generalized model for the Yang-Fourier transforms derived from the local fractional calculus are introduced. A generalized model for the Yang-Fourier transforms in fractal space and some results are proposed in detail.
description: X. J. Yang, A generalized model for Yang-Fourier transforms in fractal space, Advances in Intelligent Transportation Systems, 1(3) (2012) 80-85
Magneto-optic and transverse-transport properties of noncollinear antiferromagnets
Creators: name: Wimmer, Sebastian
name: Mankovsky, Sergiy
name: Minár, Ján
name: Yaresko, Alexander N.
name: Ebert, Hubert
Publisher: name: Universität Regensburg
Year: 2019
Subjects: subject: 530 Physik

description: Previous studies on the anomalous Hall effect in coplanar noncollinear antiferromagnets are revisited and extended to magneto-optic properties, namely magneto-optic Kerr effect (MOKE) and x-ray magnetic dichroism (XMCD). Starting from group-theoretical considerations the shape of the frequency-dependent conductivity tensor for various actual and hypothetical spin configurations in cubic and hexagonal Mn3X compounds is determined. Calculated MOKE and x-ray dichroism spectra are used to confirm these findings and to give estimates of the size of the effects. For Mn3IrPt and Mn3PtRh alloys the concentration dependence of the anomalous and spin Hall conductivity is studied in addition.
What If? Experimental History on Television
Creators: name: Weeks, Rebecca
Publisher: name: Media Design School
Year: 2024
Subjects: classificationCode: 4303
subject: Historical studies
classificationCode: 3605
subject: Screen and digital media

description: Amazon Prime’s The Man in the High Castle (2015–2019) is representative of the experimental approaches to history that have appeared in great numbers during the era of Peak television. Based on Philip K. Dick’s alternate history novel, the show takes place in a version of 1962 where the Axis powers won the Second World War and the United States has been split into three separate zones. The series’ embrace of fiction does not hinder its ability to engage in historical discourse but, instead, facilitates it. While many historians and scholars tend to be critical of film and television’s ability to sweep the audience up in the emotion and drama of the past and offer simplistic and outright inaccurate interpretations, The Man in the High Castle counteracts such critiques by constantly making the audience aware of the fabricated nature of what they are watching. Transporting an examination of Nazi Germany, Imperial Japan, and mid-century America to an alternate reality forces viewers to recall what they know and hold it up against what they see on screen. Audiences are encouraged to grapple with complex questions about contingency and determinism, while identifying similarities and differences in the historical record.
The removal mechanism of natural organic matter by ion exchange resins from thermodynamic perspectives
Creators: name: Rahmani, Sonia
Publisher: name: University of British Columbia
Year: 2017

description: Natural organic matter (NOM), a constituent in surface drinking water sources, requires removal to minimize its negative impacts on water quality and water treatment processes. Ion exchange (IEX) has been considered as an effective technology for the removal of NOM. However, despite many studies on the IEX removal of NOM, the removal mechanism and the molecular interactions involved in the IEX process are quite unknown due to the complexity of the NOM molecular structure. This research aimed to investigate the NOM removal with a focus on fundamentals underpinning the IEX process and the molecular interactions/forces that drive the retention of NOM onto the IEX resins. Different isolates of NOM along with some pure organic acids were studied. Hydrophobicity was found to play a key role in the removal process. The changes that the hydrophobic moieties impose to the structure of water molecules (i.e., entropy reduction) were found very influential in determining the selectivity of the IEX process. Moreover, the removal of UV-absorbing compounds (more hydrophobic fraction of NOM) was enhanced in the presence of sodium sulphate, as the electrostatic interactions are screened by added salt and consequently the entropic contribution to the removal is promoted. Nonetheless, the entropic contribution from the resin phase (i.e., hydrophobic resin backbone) was shown to negatively impact the removal of UV-absorbing compounds. Overall, combining the findings, it is concluded that the difference in the hydrophobicity (entropy) of the water and the resin phase is the main driving force in transferring NOM molecules from water to the resin. The contribution of the electrostatic and hydrophobic effects to the removal of NOM by IEX resins was further evaluated by quantitative characterization of the thermodynamic properties using isothermal titration calorimetry technique. The results confirmed the significance of entropic contribution to the removal of components with higher hydrophobic characteristics. Findings of this research provide a quantitative framework for the interpretation of the experimental results and facilitate the proper design of the IEX process for different water sources and under various conditions.
Repetition Probability Does Not Affect fMRI Repetition Suppression for Objects
Creators: name: Kovács, Gyula
name: Kaiser, Daniel
name: Kaliukhovich, D.
name: Vidnyánszky, Zoltán
name: Vogels, R.
Publisher: name: Universität Regensburg
Year: 2013
Subjects: subject: 150 Psychologie

description: Previously several functional magnetic resonance imaging (fMRI) studies point toward the role of perceptual expectations in determining adaptation or repetition suppression (RS) in humans. These studies showed that the probability of repetitions of faces within a block influences the magnitude of adaptation in face-related areas of the human brain (Summerfield et al., 2008). However, a current macaque single-cell/local field potential (LFP) recording study using objects as stimuli found no evidence for the modulation of the neural response by the repetition probability in the inferior temporal cortex (Kaliukhovich and Vogels, 2010). Here we examined whether stimulus repetition probability affects fMRI repetition suppression for nonface object stimuli in the human brain. Subjects were exposed to either two identical [repetition trials (RTs)] or two different [alternation trials (ATs)] object stimuli. Both types of trials were presented blocks consisting of either 75% [repetition blocks (RBs)] or 25% [alternation blocks (ABs)] of RTs. We found strong RS, i.e., a lower signal for RTs compared to ATs, in the object sensitive lateral occipital cortex as well as in the face-sensitive occipital and fusiform face areas. More importantly, however, there was no significant difference in the magnitude of RS between RBs and ABs in each of the areas. This is in agreement with the previous monkey single-unit/LFP findings and suggests that RS in the case of nonface visual objects is not modulated by the repetition probability in humans. Our results imply that perceptual expectation effects vary for different visual stimulus categories.
Temporal Integration of Movement: The Time-Course of Motion Streaks Revealed by Masking
Creators: name: Alais, A.
name: Apthorp, A.
name: Karmann, Anna
name: Cass, J.
Publisher: name: Universität Regensburg
Year: 2011
Subjects: subject: 150 Psychologie

description: Temporal integration in the visual system causes fast-moving objects to leave oriented ‘motion streaks’ in their wake, which could be used to facilitate motion direction perception. Temporal integration is thought to occur over 100 ms in early cortex, although this has never been tested for motion streaks. Here we compare the ability of fast-moving (‘streaky’) and slow-moving fields of dots to mask briefly flashed gratings either parallel or orthogonal to the motion trajectory. Gratings were presented at various asynchronies relative to motion onset (from to ms) to sample the time-course of the accumulating streaks. Predictions were that masking would be strongest for the fast parallel condition, and would be weak at early asynchronies and strengthen over time as integration rendered the translating dots more streaky and grating-like. The asynchrony where the masking function reached a plateau would correspond to the temporal integration period. As expected, fast-moving dots caused greater masking of parallel gratings than orthogonal gratings, and slow motion produced only modest masking of either grating orientation. Masking strength in the fast, parallel condition increased with time and reached a plateau after 77 ms, providing an estimate of the temporal integration period for mechanisms encoding motion streaks. Interestingly, the greater masking by fast motion of parallel compared with orthogonal gratings first reached significance at 48 ms before motion onset, indicating an effect of backward masking by motion streaks.
Photocycle Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor QuasAr1
Creators: name: Penzkofer, Alfons
name: Silapetere, Arita
name: Hegemann, Peter
Publisher: name: Universität Regensburg
Year: 2019
Subjects: subject: QuasAr1; Archaerhodopsin 3; genetically encoded fluorescent voltage sensor; absorption spectroscopic characterization; fluorescence studies; photocycle dynamics; photoisomerization; deprotonation; reprotonation
subject: 530 Physik

description: The retinal photocycle dynamics of the fluorescent voltage sensor QuasAr1 (Archaerhodopsin 3 P60S-T80S-D95H-D106H-F161V mutant from Halorubrum sodomense) in pH 8 Tris buffer was studied. The samples were photoexcited to the first absorption band of the protonated retinal Schiff base (PRSB) Ret_580 (absorption maximum at λmax ≈ 580 nm), and the retinal Schiff base photoisomerization and protonation state changes were followed by absorption spectra recordings during light exposure and after light exposure. Ret_580 turned out to be composed of two protonated retinal Schiff base isomers, namely Ret_580I and Ret_580II. Photoexcitation of Ret_580I resulted in barrier-involved isomerization to Ret_540 (quantum yield ≈ 0.056) and subsequent retinal proton release leading to Ret_410 deprotonated retinal Schiff base (RSB). In the dark, Ret_410 partially recovered to Ret_580I and partially stabilized to irreversible Ret_400 due to apoprotein restructuring (Ret_410 lifetime ≈ 2 h). Photoexcitation of Ret_580II resulted in barrier-involved isomerization to Ret_640 (quantum yield ≈ 0.00135) and subsequent deprotonation to Ret_370 (RSB). In the dark, Ret_370 partially recovered to Ret_580II and partially stabilized to irreversible Ret_350 due to apoprotein restructuring (Ret_370 lifetime ≈ 10 h). Photocycle schemes and reaction coordinate diagrams for Ret_580I and Ret_580II were developed and photocyle parameters were determined.
Single spontaneous photon as a coherent beamsplitter for an atomic matterwave
Creators: name: Tomkovič, Jiří
name: Schreiber, Michael
name: Welte, Joachim
name: Kiffner, Martin
name: Schmiedmayer, Jörg
name: Oberthaler, Markus K.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In spontaneous emission an atom in an excited state undergoes a transition to the ground state and emits a single photon. Associated with the emission is a change of the atomic momentum due to photon recoil. Photon emission can be modified close to surfaces and in cavities. For an ion, localized in front of a mirror, coherence of the emitted resonance fluorescence has been reported. In free space experiments demonstrated that spontaneous emission destroys motional coherence. Here we report on motional coherence created by a single spontaneous emission event close to a mirror surface. The coherence in the free atomic motion is verified by atom interferometry. The photon can be regarded as a beamsplitter for an atomic matterwave and consequently our experiment extends the original recoiling slit Gedanken experiment by Einstein to the case where the slit is in a robust coherent superposition of the two recoils associated with the two paths of the quanta.
description: main text: 5 pages, 4 figure; supplementary information: 8 pages, 1 figure
Spin transport in hydrogenated graphene
Creators: name: Soriano, David
name: Tuan, Dinh Van
name: Dubois, Simon
name: Gmitra, Martin
name: Cummings, Aron W.
name: Kochan, Denis
name: Ortmann, Frank
name: Charlier, Jean-Christophe
name: Fabian, Jaroslav
name: Roche, Stephan
Publisher: name: Universität Regensburg
Year: 2015
Subjects: subject: spin transport, hydrogenated graphene, magnetism
subject: 530 Physik

description: In this review we discuss the multifaceted problem of spin transport in hydrogenated graphene from a theoretical perspective. The current experimental findings suggest that hydrogenation can either increase or decrease spin lifetimes, which calls for clarification. We first discuss the spin–orbit coupling induced by local re-hybridization and C–H defect formation together with the formation of a local magnetic moment. First-principles calculations of hydrogenated graphene unravel the strong interplay of spin–orbit and exchange couplings. The concept of magnetic scattering resonances, recently introduced by Kochan et al (2014 Phys. Rev. Lett. 112 116602) is revisited by describing the local magnetism through the self-consistent Hubbard model in the mean field approximation in the dilute limit, while spin relaxation lengths and transport times are computed using an efficient real space order N wavepacket propagation method. Typical spin lifetimes on the order of 1 ns are obtained for 1 ppm of hydrogen impurities (corresponding to a transport time of about 50 ps), and the scaling of spin lifetimes with impurity density is described by the Elliott–Yafet mechanism. This reinforces the statement that local defect-induced magnetism can be at the origin of the substantial spin polarization loss in the clean graphene limit.