cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Investigation into the role of eosinophils in pulmonary metastasis and primary tumours in mouse models of breast cancer
Creators: name: Collier, Jenna Lynn
Publisher: name: University of British Columbia
Year: 2017

description: Eosinophils are multifunctional granulocytes with potent immune modulatory and cytotoxic capabilities. Despite the presence of eosinophils in various solid tumours and eosinophilia being a prognosistic indicator in some cancers, the role of this innate immune cell has been largely overlooked in the context of cancer. Specifically, the role of eosinophils in pulmonary metastasis is poorly described despite their prevalence in the lung and association with various pulmonary diseases. I sought to delineate the role of eosinophils in murine models of metastatic breast cancer using novel mouse models of genetic eosinophil deficiency (ddGATA) and by immunodepletion in orthotopic mouse models of cancer using an anti-IL-5 antibody. I hypothesize that eosinophils enhance pulmonary metastasis in mouse models of breast cancer, but do not affect the vascularization of the primary tumour. Eosinophils are increased 5.8-fold in the lungs of mice bearing 4T1 metastatic mammary tumours (p<0.001) which may be due to an observed 4-fold increase in the expression of CCL24 (p<0.0001) that is produced by mMDSCs. Moreover, some resident eosinophils appeared to differentiate into a novel CD11bhiGr-1hi subset in the pre-metastatic lungs. Immunological depletion of eosinophils using anti-IL-5 antibody did not affect the growth or vascularization of 4T1 tumours, or metastatic development by 3 weeks post-implant of the primary tumour. Surprisingly, there was a trend towards an increase in tumour cell colonization of the lungs by IV injected LLC—but not E0771-LMB—tumour cells in ddGATA mice relative to WT controls; indicating that eosinophils may exert anti-tumour effects in this model. Furthermore, IL-5Tg mice exhibiting eosinophilia had a 5-fold decrease in the number of lung Tregs (p<0.001) and were significantly protected from tumour cell colonization of the lungs. Our data suggests that a pro-inflammatory subset of CD11b hiGr-1hi eosinophils may be present in the pre-metastatic lungs and additional eosinophils are recruited to the metastatic lung in response to CCL24 produced by mMDSCs. However, eosinophils do not significantly influence pulmonary metastasis or primary tumour growth or vascularization in mouse models of breast cancer. Furthermore, our data indicates that IL-5 may be exerting pleiotropic effects on other immune cell populations.
The structure of the old Galactic Bulge revealed by Type II Cepheids
Creators: name: Braga, Vittorio Francesco
name: Contreras, R.
name: Zoccali, M.
name: Nikzat, F.
Publisher: name: Zenodo
Year: 2019

description: In the Galactic Bulge, metal-rich Red Clump stars, trace an X-shaped structure (Zoccali & Valenti 2016). However, the spatial distribution of old and more metal-poor Bulge stars, as traced by RR Lyrae (RRLs), is still under discussion (Dékany et al. 2013; Pietrukowicz et al. 2015; Kunder et al. 2016).
Type II Cepheids (T2Cs) are old, low-mass post-Horizontal Branch stars. Like the RRLs, T2Cs trace old stellar populations, but they are 1-3 mag brighter. T2Cs are distance indicators that obey a Period-Luminosity relation which is more accurate in the NIR, and practically metallicity-independent (Di Criscienzo et al. 2007).
We use the Ks-band VVV light curves of 894 T2Cs in the OGLE IV catalog (Soszynski et al. 2017) to inspect the structure of the Bulge. We find a distance of the Galactic Center of 8.46 kpc, which is larger than estimates obtained with similar tracers (RRLs, 8.30 kpc). The difference is due to the fact that we used a new reddening law (Alonso-Garcia et al. 2017) and a 3D, distance-dependent reddening map (Schultheis et al. 2014). We also find, as in Pietrukowicz et al. (2015), a tilted ellipsoid, with stars at positive Galactic longitude (l) closer than stars at negative l. We use VVV and Gaia proper motions to show that Bulge T2Cs have the properties an old, kinematically hot population, as expected. Finally, we find that the average difference between VVV and Gaia proper motions of T2Cs is similar to the proper motion of Sgr A*, in the Galactic Center.
Asymptotic syzygies of algebraic varieties
Creators: name: Ein, Lawrence
name: Lazarsfeld, Robert
Publisher: name: arXiv
Year: 2011
Subjects: subject: Algebraic Geometry (math.AG)
subject: Commutative Algebra (math.AC)
subject: FOS: Mathematics

description: This paper studies the asymptotic behavior of the syzygies of a smooth projective variety X as the positivity of the embedding line bundle grows. We prove that as least as far as grading is concerned, the minimal resolution of the ideal of X has a surprisingly uniform asymptotic shape: roughly speaking, generators eventually appear in almost all degrees permitted by Castelnuovo-Mumford regularity. This suggests in particular that a widely-accepted intuition derived from the case of curves -- namely that syzygies become simpler as the degree of the embedding increases -- may have been misleading. For Veronese embeddings of projective space, we give an effective statement that in some cases is optimal, and conjecturally always is so. Finally, we propose a number of questions and open problems concerning asymptotic syzygies of higher-dimensional varieties.
description: Sections renumbered to conform to published version. To appear in Invent. Math
PointDGMamba: Domain Generalization of Point Cloud Classification via Generalized State Space Model
Creators: name: Yang, Hao
name: Zhou, Qianyu
name: Sun, Haijia
name: Li, Xiangtai
name: Liu, Fengqi
name: Lu, Xuequan
name: Ma, Lizhuang
name: Yan, Shuicheng
Publisher: name: arXiv
Year: 2024
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Domain Generalization (DG) has been recently explored to improve the generalizability of point cloud classification (PCC) models toward unseen domains. However, they often suffer from limited receptive fields or quadratic complexity due to using convolution neural networks or vision Transformers. In this paper, we present the first work that studies the generalizability of state space models (SSMs) in DG PCC and find that directly applying SSMs into DG PCC will encounter several challenges: the inherent topology of the point cloud tends to be disrupted and leads to noise accumulation during the serialization stage. Besides, the lack of designs in domain-agnostic feature learning and data scanning will introduce unanticipated domain-specific information into the 3D sequence data. To this end, we propose a novel framework, PointDGMamba, that excels in strong generalizability toward unseen domains and has the advantages of global receptive fields and efficient linear complexity. PointDGMamba consists of three innovative components: Masked Sequence Denoising (MSD), Sequence-wise Cross-domain Feature Aggregation (SCFA), and Dual-level Domain Scanning (DDS). In particular, MSD selectively masks out the noised point tokens of the point cloud sequences, SCFA introduces cross-domain but same-class point cloud features to encourage the model to learn how to extract more generalized features. DDS includes intra-domain scanning and cross-domain scanning to facilitate information exchange between features. In addition, we propose a new and more challenging benchmark PointDG-3to1 for multi-domain generalization. Extensive experiments demonstrate the effectiveness and state-of-the-art performance of PointDGMamba.
description: Published on Proceedings of the AAAI Conference on Artificial Intelligence (AAAI) 2025;
Griffiths phase in the thermal quantum Hall effect
Creators: name: Mildenberger, A.
name: Evers, Ferdinand
name: Narayanan, R.
name: Mirlin, A. D.
name: Damle, K.
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: 530 Physik

description: Two-dimensional disordered superconductors with broken spin-rotation and time-reversal invariance, e.g., with px+ipy pairing, can exhibit plateaus in the thermal Hall coefficient (the thermal quantum Hall effect). Our numerical simulations show that the Hall insulating regions of the phase diagram can support a sub-phase where the quasiparticle density of states is divergent at zero energy, ρ(E)∼∣E∣∣1∕z−1, with a nonuniversal exponent z>1, due to the effects of rare configurations of disorder (Griffiths phase).
Chemically-dissected main-sequence rotation curves of the Galactic bulge
Creators: name: Clarkson, Will
name: Calamida, Annalisa
name: Sahu, Kailash
name: Gennaro, Mario
Publisher: name: Zenodo
Year: 2019

description: I will report results from an ongoing study using archival Hubble Space Telescope imaging observations in seven filters over a multi-year time-baseline, for several fields towards the inner Galactic bulge. Thanks to the broad wavelength coverage of the WFC3 Bulge Treasury Survey, we can chart for the first time the proper motion-based rotation curves of the inner Milky Way as traced separately by relatively metal-rich and metal-poor main sequence tracer samples.  While the velocity dispersion behavior is qualitatively in line with some previous spectroscopic indications at similar Galactic latitudes, the metallicity-difference in rotation curves has not previously been observed, probably because ours is the first study to break down chemo-dynamical indications by distance along a single line of sight.
ACTIVAR EL APRENDIZAJE EN EL AULA A TRAVÉS DEL MÉTODO DE INNOVACIÓN DOCENTE AULA INVERTIDA
Creators: name: Fidalgo-Blanco, Ángel
Publisher: name: Zenodo
Year: 2023
Subjects: Aula Invertida
Adaptatividad
Método MAIN
Personalización

description: Este documento es un resumen del curso “Activar el Aprendizaje en el Aula (Presencial/online): Método de Aula Invertida Híbrida. Impartido de forma online en la Universidad de Zaragoza del 13 al 17 de abril de 2023. El curso ha seguido un formato en “Y”. La parte superior representa dos líneas de aprendizaje: la primera se enfoca en el proceso de diseño de un proyecto general de innovación educativa (donde se incluye el método de Aula Invertida) y la segunda línea trabaja con el propio método de Aula Invertida. La parte de convergencia de la “Y” une las dos líneas y se centra en el diseño y aplicación del método de Aula Invertida. El curso se ha impartido mediante el propio modelo de Aula Invertida. De esta forma, las personas que participen como estudiantes en este curso tendrán un aprendizaje experiencial, permitiendo experimentar con distintas estrategias y conociendo en primera persona los puntos fuertes y débiles del método. 2 actividades asíncronas online de 1 hora de duración cada una. Son actividades online que los estudiantes realizan de forma individual y previa a las sesiones presenciales, como son visualización de videos y realización de Micro-Tareas prácticas. 2 actividades síncronas online de 3 horas de duración cada una. Las actividades características son la puesta en común de los resultados de las Micro Tareas de las sesiones asíncronas, las micro lecciones magistrales y el trabajo colaborativo. En las sesiones asíncronas se ha trabajado con una de las partes superiores de la “Y”, mientras que la primera sesión síncrona correspondió a la otra parte de la “Y” y la segunda sesión síncrona trató de la parte común de la “Y”. Se ha utilizado la plataforma Moodle tanto para organizar el material del curso como para poner ejemplos de aula invertida aplicada en varias modalidades. Este material se corresponde con las presentaciones, ampliándolas con referencias (principalmente de los autores del curso), así como información complementaria. Todo este material está publicado en abierto con licencia Creative Commons (con citación, sin derecho a modificación ni uso comercial) y se emplea en los distintos cursos de Aula Invertida que imparten los autores del mismo. Aunque este material es público y puede ser considerado como un resumen del curso, está preparado para los participantes en el mismo y, por esta razón, algunas imágenes y tablas contienen más carga conceptual para las personas que han participado en las actividades que para un lector externo al curso.
Search for Exoplanet Transits in the Galactic Bulge
Creators: name: Cortes, Caddy
name: Minniti, Dante
name: Villanova, Sandro
Publisher: name: Zenodo
Year: 2019

description: The study of exoplanets provides us with a greater understanding of planetary system formation, what are their structures and compositions. In this project, our aim is to search and characterize extrasolar planets in the Galactic Bulge and to establish whether there is a relationship with existing exoplanets in the Disk of the Milky Way. This will be done using photometric catalogs through the K2 mission and VVV survey. With these data, we will search for exoplanets in this field using the transit technique. We present the discovery of five exoplanet candidates, in which three warm Jupiters and two hot Jupiters detected in the Galactic Bulge with K2 data. Our candidates have a period between 3.6 and 35.2 days. One of them is a planet orbiting a variable star. Here, we will report preliminary planet catalogs and their properties.
The Cosmological Impact of Luminous TeV Blazars III: Implications for Galaxy Clusters and the Formation of Dwarf Galaxies
Creators: name: Pfrommer, Christoph
name: Chang, Philip
name: Broderick, Avery E.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: A subset of blazars emit TeV gamma rays which annihilate and pair produce on the extragalactic background light. We have argued in Broderick et al. (2011, Paper I) that plasma beam instabilities can dissipate the pairs' energy locally. This heats the intergalactic medium and dramatically increases its entropy after redshift z~2, with important implications for structure formation: (1) This suggests a scenario for the origin of the cool core (CC)/non-cool core (NCC) bimodality in galaxy clusters and groups. Early forming galaxy groups are unaffected because they can efficiently radiate the additional entropy, developing a CC. However, late forming groups do not have sufficient time to cool before the entropy is gravitationally reprocessed through successive mergers - counteracting cooling and raising the core entropy further. Hence blazar heating works different than feedback by active galactic nuclei, which balances radiative cooling but is unable to transform CC into NCC clusters due to the weak coupling to the cluster gas. (2) We predict a suppression of the Sunyaev-Zel'dovich power spectrum on angular scales smaller than 5' due to the globally reduced central pressure of groups and clusters forming after z~1. (3) Our redshift dependent entropy floor increases the characteristic halo mass below which dwarf galaxies cannot form by a factor of ~10 (50) at mean density (in voids) over that found in models that include photoionization alone. This prevents the formation of late forming dwarf galaxies (z<2) with masses ranging from 10^{10} to 10^{11} M_sun for redshifts z~2 to 0, respectively. This may help resolve the "missing satellite problem" in the Milky Way and the "void phenomenon" of the low observed abundances of dwarf satellites compared to cold dark matter simulations and may bring the observed early star formation histories into agreement with galaxy formation models. (abridged)
description: 22 pages, 7 figures, update that matches the final version in the ApJ
Exact Relations between Multifractal Exponents at the Anderson Transition
Creators: name: Mirlin, A. D.
name: Fyodorov, Y. V.
name: Mildenberger, A.
name: Evers, Ferdinand
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: 530 Physik

description: Two exact relations between mutlifractal exponents are shown to hold at the critical point of the Anderson localization transition. The first relation implies a symmetry of the multifractal spectrum linking the exponents with indices q<1/2 to those with q>1/2. The second relation connects the wave-function multifractality to that of Wigner delay times in a system with a lead attached.
Surface Criticality and Multifractality at Localization Transitions
Creators: name: Subramaniam, A. R.
name: Gruzberg, I. A.
name: Ludwig, A. W. W.
name: Evers, Ferdinand
name: Mildenberger, A.
name: Mirlin, A. D.
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: 530 Physik

description: We develop the concept of surface multifractality for localization-delocalization (LD) transitions in disordered electronic systems. We point out that the critical behavior of various observables related to wave functions near a boundary at a LD transition is different from that in the bulk. We illustrate this point with a calculation of boundary critical and multifractal behavior at the 2D spin quantum Hall transition and in a 2D metal at scales below the localization length.
Wave function statistics at the symplectic two-dimensional Anderson transition: Bulk properties
Creators: name: Mildenberger, A.
name: Evers, Ferdinand
Publisher: name: Universität Regensburg
Year: 2007
Subjects: subject: 530 Physik

description: The wave function statistics at the Anderson transition in a two-dimensional disordered electron gas with spin-orbit coupling is studied numerically. In addition to highly accurate exponents (α0=2.172±0.002,τ2=1.642±0.004), we report three qualitative results. (i) The anomalous dimensions are invariant under q→(1−q) which is in agreement with a recent analytical prediction and supports the universality hypothesis. (ii) The multifractal spectrum is not parabolic and therefore differs from behavior suspected, e.g., for (integer) quantum Hall transitions in a fundamental way. (iii) The critical fixed point satisfies conformal invariance.
Quantum chemistry calculations for molecules coupled to reservoirs: Formalism, implementation, and application to benzenedithiol
Creators: name: Arnold, A.
name: Weigend, F.
name: Evers, Ferdinand
Publisher: name: Universität Regensburg
Year: 2007
Subjects: subject: 530 Physik

description: Modern quantum chemistry calculations are usually implemented for isolated systems—big molecules or atom clusters; total energy and particle number are fixed. However, in many situations, like quantum transport calculations or molecules in a electrochemical environment, the molecule can exchange particles (and energy) with a reservoir. Calculations for such cases require to switch from the canonical to a grand canonical description, where one fixes the chemical potential rather than particle number. To achieve this goal, the authors propose an implementation in standard quantum chemistry packages. An application to the nonlinear charge transport through 1,4-benzenedithiol will be presented. They explain the leading finite bias effect on the transmission as a consequence of a nonequilibrium Stark effect and discuss the relation to earlier work.
Zero-bias molecular electronics: Exchange-correlation corrections to Landauer's formula
Creators: name: Koentopp, Max
name: Burke, Kieron
name: Evers, Ferdinand
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: 530 Physik

description: We show that standard first principles calculations of transport through single molecules miss exchange-correlation corrections to the Landauer formula—the conductance is calculated at the Hartree level. Furthermore, the lack of derivative discontinuity in approximations can cause large errors for molecules weakly coupled to the electrodes. From the Kubo response theory, both the Landauer formula and these corrections in the limit of zero bias are derived and calculations are presented.
The X17 boson and the d(p,e+ e-)3He and d(n,e+ e-)3H processes: a theoretical analysis
Creators: name: Viviani, M.
name: Filandri, E.
name: Girlanda, L.
name: Gustavino, C.
name: Kievsky, A.
name: Marcucci, L. E.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The present work deals with the e+ e- pair production in the d(p,e+e-)3He and d(n,e+ e-)3H processes, in order to evidentiate possible effects due to the exchange of a hypothetical low-mass boson, the so-called X17. These processes are studied for energies of the incident beams in the range 18-30 MeV, in order to have a sufficient energy to produce such a boson, whose mass is estimated to be around 17 MeV. We first analyze them as a purely electromagnetic processes, in the context of a state-of-the-art approach to nuclear strong-interaction dynamics and nuclear electromagnetic currents, derived from chiral effective field theory chiEFT. Next, we examine how the exchange of a hypothetical low-mass boson would impact the cross sections for such processes. We consider several possibilities, that this boson is either a scalar, pseudoscalar, vector, or axial particle. The main aim of the study is to exploit the specular structure of the 3He and 3H nuclei to investigate the isospin dependency of the X17-nucleon interaction, as the alleged "proto-phobicity".
description: 19 pages, 15 figures, new version with more details, added two appendices. arXiv admin note: text overlap with arXiv:2104.07808
Exact Ground State Density-Functional Theory for Impurity Models Coupled to External Reservoirs and Transport Calculations
Creators: name: Schmitteckert, Peter
name: Evers, Ferdinand
Publisher: name: Universität Regensburg
Year: 2008
Subjects: subject: 530 Physik

description: A method is presented employing the density matrix renormalization group to construct exact ground state (GS) exchange correlation functionals for models of correlated electrons coupled to leads. We apply it to show that conductance calculations with Kohn-Sham GS density-functional theory can yield quantitative results in the Coulomb blockade regime. Our study is relevant for “molecular electronics” since it strongly suggests that the well documented discrepancies between theoretical and experimental transport coefficients originate (mainly) from approximations in GS functionals.
Universality of the Edge-Tunneling Exponent of Fractional Quantum Hall Liquids
Creators: name: Wan, Xin
name: Evers, Ferdinand
name: Rezayi, E. H.
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik

description: In a microscopic model of fractional quantum Hall liquids with electron-electron interactions and confinement, we calculate the edge Green’s function via exact diagonalization. Our results for ν=1/3 and 2/3 suggest that, in the presence of Coulomb interaction, “external” parameters such as the sharpness of the edge and the strength of the edge confining potential, which can lead to edge reconstruction, may cause deviations from universality in the edge-tunneling I−V exponent. In particular, we do not find any direct dependence of this exponent on the range of the interaction potential as suggested by recent calculations in contradiction to the topological nature of the edge.
The Convex Geometry of Linear Inverse Problems
Creators: name: Chandrasekaran, Venkat
name: Recht, Benjamin
name: Parrilo, Pablo A.
name: Willsky, Alan S.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Optimization and Control (math.OC)
subject: Statistics Theory (math.ST)
subject: FOS: Mathematics

description: In applications throughout science and engineering one is often faced with the challenge of solving an ill-posed inverse problem, where the number of available measurements is smaller than the dimension of the model to be estimated. However in many practical situations of interest, models are constrained structurally so that they only have a few degrees of freedom relative to their ambient dimension. This paper provides a general framework to convert notions of simplicity into convex penalty functions, resulting in convex optimization solutions to linear, underdetermined inverse problems. The class of simple models considered are those formed as the sum of a few atoms from some (possibly infinite) elementary atomic set; examples include well-studied cases such as sparse vectors and low-rank matrices, as well as several others including sums of a few permutations matrices, low-rank tensors, orthogonal matrices, and atomic measures. The convex programming formulation is based on minimizing the norm induced by the convex hull of the atomic set; this norm is referred to as the atomic norm. The facial structure of the atomic norm ball carries a number of favorable properties that are useful for recovering simple models, and an analysis of the underlying convex geometry provides sharp estimates of the number of generic measurements required for exact and robust recovery of models from partial information. These estimates are based on computing the Gaussian widths of tangent cones to the atomic norm ball. When the atomic set has algebraic structure the resulting optimization problems can be solved or approximated via semidefinite programming. The quality of these approximations affects the number of measurements required for recovery. Thus this work extends the catalog of simple models that can be recovered from limited linear information via tractable convex programming.
Efficient and systematic calculation of arbitrary observables for the matrix product state excitation ansatz
Creators: name: Osborne, Jesse J.
name: McCulloch, Ian P.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Numerical methods based on matrix product states (MPSs) are currently the de facto standard for calculating the ground-state properties of (quasi-)one-dimensional quantum many-body systems. While the properties of the low-lying excitations in such systems are often studied in this MPS framework through _dynamics_ by means of time-evolution simulations, we can also look at their _statics_ by directly calculating eigenstates corresponding to these excitations. The so-called MPS excitation ansatz is a powerful method for finding such eigenstates with a single-particle character in the thermodynamic limit. Although this excitation ansatz has been used quite extensively, a general method for calculating expectation values for these states is lacking in the literature: we aim to fill this gap by presenting a recursive algorithm to calculate arbitrary observables expressed as matrix product operators. This method concisely encapsulates existing methods for -- as well as extensions to -- the excitation ansatz, such as excitations with a larger spatial support and multi-particle excitations, and is robust enough to handle further innovations. We demonstrate the versatility of our method by studying the low-lying excitations in the spin-1 Heisenberg chain and the one-dimensional Hubbard model, looking at how the excitations converge in the former, while in the latter, we present a refined method of targeting single-particle excitations inside a continuum by minimizing the energy _variance_ rather than the energy itself. We hope that this technique will foster further advancements with the excitation ansatz.
Boundary multifractality in critical one-dimensional systems with long-range hopping
Creators: name: Mildenberger, A.
name: Subramaniam, A. R.
name: Narayanan, R.
name: Evers, Ferdinand
name: Gruzberg, I. A.
name: Mirlin, A. D.
Publisher: name: Universität Regensburg
Year: 2007
Subjects: subject: 530 Physik

description: Boundary multifractality of electronic wave functions is studied analytically and numerically for the power-law random banded matrix (PRBM) model, describing a critical one-dimensional system with long-range hopping. The peculiarity of the Anderson localization transition in this model is the existence of a line of fixed points describing the critical system in the bulk. We demonstrate that the boundary critical theory of the PRBM model is not uniquely determined by the bulk properties. Instead, the boundary criticality is controlled by an additional parameter characterizing the hopping amplitudes of particles reflected by the boundary.
Anderson transitions
Creators: name: Evers, Ferdinand
name: Mirlin, Alexander D.
Publisher: name: Universität Regensburg
Year: 2008
Subjects: subject: 530 Physik

description: The physics of Anderson transitions between localized and metallic phases in disordered systems is reviewed. The term “Anderson transition” is understood in a broad sense, including both metal-insulator transitions and quantum-Hall-type transitions between phases with localized states. The emphasis is put on recent developments, which include multifractality of critical wave functions, criticality in the power-law random banded matrix model, symmetry classification of disordered electronic systems, mechanisms of criticality in quasi-one-dimensional and two-dimensional systems and survey of corresponding critical theories, network models, and random Dirac Hamiltonians. Analytical approaches are complemented by advanced numerical simulations.
Algorithmic randomness, reverse mathematics, and the dominated convergence theorem
Creators: name: Avigad, Jeremy
name: Dean, Edward
name: Rute, Jason
Publisher: name: arXiv
Year: 2011
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics
subject: 03B30, 03D32, 03F60

description: We analyze the pointwise convergence of a sequence of computable elements of L^1(2^omega) in terms of algorithmic randomness. We consider two ways of expressing the dominated convergence theorem and show that, over the base theory RCA_0, each is equivalent to the assertion that every G_delta subset of Cantor space with positive measure has an element. This last statement is, in turn, equivalent to weak weak König's lemma relativized to the Turing jump of any set. It is also equivalent to the conjunction of the statement asserting the existence of a 2-random relative to any given set and the principle of Sigma_2 collection.
The spatial construal of TIME in Indonesian: Evidence from language and gesture
Creators: name: Rajeg, Gede Primahadi Wijaya
Publisher: name: Zenodo
Year: 2023
Subjects: gesture
co-speech gesture
cognitive linguistics
spatiotemporal metaphor
metafora waktu
metafora temporal
metafora spasial
space-time metaphoric mapping
Indonesian linguistics
temporal gesture
conceptual metaphor
metafora konseptual
metafora waktu bahasa Indonesia
corpus linguistics
linguistik korpus
linguistik kognitif

description: Slides presented at the International Multimodal Communication Centre (IMCC) Research Seminar Series, University of Oxford. The talk is derived from the open-access paper below, which should preferably cited when the slides are referred to: Rajeg, Gede Primahadi Wijaya, Poppy Siahaan & Alice Gaby. 2022. The Spatial Construal of TIME in Indonesian: Evidence from Language and Gesture. Linguistik Indonesia 40(1). 1–24. https://doi.org/10.26499/li.v40i1.297. The repository for the data and R codes can be accessed here, here, or here. The recording of this presentation will be published on the IMCC's YouTube channel.
Brain Connectivity Studies on Structure-Function Relationships: A Short Survey with an Emphasis on Machine Learning
Creators: name: Wein, Simon
name: Deco, Gustavo
name: Tomé, Ana Maria
name: Goldhacker, Markus
name: Malloni, Wilhelm M.
name: Greenlee, Mark W.
name: Lang, Elmar W.
Publisher: name: Universität Regensburg
Year: 2021
Subjects: subject: 150 Psychologie

description: This short survey reviews the recent literature on the relationship between the brain structure and its functional dynamics. Imaging techniques such as diffusion tensor imaging (DTI) make it possible to reconstruct axonal fiber tracks and describe the structural connectivity (SC) between brain regions. By measuring fluctuations in neuronal activity, functional magnetic resonance imaging (fMRI) provides insights into the dynamics within this structural network. One key for a better understanding of brain mechanisms is to investigate how these fast dynamics emerge on a relatively stable structural backbone. So far, computational simulations and methods from graph theory have been mainly used for modeling this relationship. Machine learning techniques have already been established in neuroimaging for identifying functionally independent brain networks and classifying pathological brain states. This survey focuses on methods from machine learning, which contribute to our understanding of functional interactions between brain regions and their relation to the underlying anatomical substrate.
Stabilizer notation for Spekkens' toy theory
Creators: name: Pusey, Matthew F.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Spekkens has introduced a toy theory [Phys. Rev. A, 75, 032110 (2007)] in order to argue for an epistemic view of quantum states. I describe a notation for the theory (excluding certain joint measurements) which makes its similarities and differences with the quantum mechanics of stabilizer states clear. Given an application of the qubit stabilizer formalism, it is often entirely straightforward to construct an analogous application of the notation to the toy theory. This assists calculations within the toy theory, for example of the number of possible states and transformations, and enables superpositions to be defined for composite systems.
description: 7+4 pages, 5 tables. v2: Clarifications added and typos fixed in response to referee comments
Lowering of surface melting temperature in atomic clusters with a nearly closed shell structure
Creators: name: Bagrets, A.
name: Werner, R.
name: Evers, Ferdinand
name: Schneider, G.
name: Schooss, D.
name: Wölfle, P.
Publisher: name: Universität Regensburg
Year: 2010
Subjects: subject: 530 Physik

description: We investigate the interplay of particle number, N, and structural properties of selected clusters with N=12 up to N=562 by employing Gupta potentials parameterized for Aluminum and extensive Monte Carlo simulations. Our analysis focuses on closed shell structures with extra atoms. The latter can put the cluster under a significant stress and we argue that typically such a strained system exhibits a reduced energy barrier for (surface) diffusion of cluster atoms. Consequently, also its surface melting temperature, TS, is reduced, so that TS separates from and actually falls well below the bulk value. The proposed mechanism may be responsible for the suppression of the surface melting temperature observed in recent experiments.
Oscillatory Correlates of Selective Restudy
Creators: name: Wirth, Michael
name: Pastötter, Bernhard
name: Bäuml, Karl-Heinz T.
Publisher: name: Universität Regensburg
Year: 2021
Subjects: subject: 150 Psychologie

description: Prior behavioral work has shown that selective restudy of some studied items leaves recall of the other studied items unaffected when lag between study and restudy is short, but improves recall of the other items when lag is prolonged. The beneficial effect has been attributed to context retrieval, assuming that selective restudy reactivates the context at study and thus provides a retrieval cue for the other items (Bäuml, 2019). Here the results of two experiments are reported, in each of which subjects studied a list of items and then, after a short 2-min or a prolonged 10-min lag, restudied some of the list items. Participants' electroencephalography (EEG) was recorded during both the study and restudy phases. In Experiment 2, but not in Experiment 1, subjects engaged in a mental context reinstatement task immediately before the restudy phase started, trying to mentally reinstate the study context. Results of Experiment 1 revealed a theta/alpha power increase from study to restudy after short lag and an alpha/beta power decrease after long lag. Engagement in the mental context reinstatement task in Experiment 2 eliminated the decrease in alpha/beta power. The results are consistent with the view that the observed alpha/beta decrease reflects context retrieval, which became obsolete when there was preceding mental context reinstatement.
An Investigation of Particle-Hole Asymmetry in the Cuprates via Electronic Raman Scattering
Creators: name: Moritz, B.
name: Johnston, S.
name: Devereaux, T. P.
name: Muschler, B.
name: Prestel, W.
name: Hackl, R.
name: Lambacher, M.
name: Erb, A.
name: Komiya, Seiki
name: Ando, Yoichi
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: In this paper we examine the effects of electron-hole asymmetry as a consequence of strong correlations on the electronic Raman scattering in the normal state of copper oxide high temperature superconductors. Using determinant quantum Monte Carlo simulations of the single-band Hubbard model, we construct the electronic Raman response from single particle Green's functions and explore the differences in the spectra for electron and hole doping away from half filling. The theoretical results are compared to new and existing Raman scattering experiments on hole-doped La$_{2-x}$Sr$_{x}$CuO$_{4}$ and electron-doped Nd$_{2-x}$Ce$_{x}$CuO$_{4}$. These findings suggest that the Hubbard model with fixed interaction strength qualitatively captures the doping and temperature dependence of the Raman spectra for both electron and hole doped systems, indicating that the Hubbard parameter U does not need to be doping dependent to capture the essence of this asymmetry.
description: 13 pages, 10 figures
Impact of Digitization on Employee attrition management A fact check with a special reference to the IT Industry in Bangalore
Creators: name: Kiran Luthra, Ravi
name: Ranganathan, Dr Senthilkumar
Publisher: name: figshare
Year: 2023
Subjects: Humanitarian disasters, conflict and peacebuilding

description: The research paper's objective is to determine the behavioral changes in the IT Sector employee due to high attrition. There is much buzz around Digitization in the IT sphere, touching the lives of thousands of employees to bring system transparency toward employee welfare schemes and employability conditions. The study aims to go deeper into the adopted changes by the IT industry vis-à-vis an outcome related to future design thinking. The research is based on secondary data published by IT organizations and papers published with an impact on employee behavior during COVID-19 to onboard and offload employees by applying digital platforms in the HR space to identify the current research trends and research gap. The research paper identifies gaps in adopting a digital platform with merits and demerits of Digitization, introducing staff isolation, drop-in social exchange practice, faceless expressions, simplifying routine tasks, and employee engagement methods lead to dissatisfaction in employees. The research paper provides a direction based on research publications, feedback from different organizations' HR fertility, and their experience due to diversification. It is a unique study that presents the diverse views from research areas in HR practices followed to do employee engagement and studying employee behavior towards employability satisfaction/dissatisfaction leading to higher attrition.
IT EMPLOYEE WANTS FROM THEIR EMPLOYER VIS-À-VIS THE EMPLOYER'S PRODUCTIVITY EXPECTATION IN TODAY'S COVID-19 CONTEXT- A CASE STUDY ABOUT THE IT SECTOR'S ONGOING ATTRITION CHALLENGES
Creators: name: Kiran Luthra, Ravi
name: Ranganathan, Dr Senthilkumar
Publisher: name: figshare
Year: 2023
Subjects: Research, science and technology policy

description: Covid 19 pandemic shook the world in late December 2019 and took away more than two and a half years in a modern civilized society. IT companies that boosted the Golden BCP standards implementation in the organization were complete whitewash. Businesses, people, Infra, and Government machinery had no choice but to pump money into the employee to save employees from the competition and sustain committed deliverables. Thankfully, IT company leaders put the act together bravely and put the recovery process by introducing Work from Home (WFH) immediately and arranged IT hardware infra at the doorstep of employees with the flexibility to operate from anywhere. As per KPMG, IT Companies spent around US$15bn extra a week (stress wave. The largest -19 on Information from organizations with a combined technology spend of over US $250 bn in 2021, which is 3.4% against 1.7% of the average investment required to run an operation. The objective of the case study is to analyze the three complex situations that arise during the Covid 19 a. High attrition, b. High investment from employer, c. Low productivity challenges. IT companies are on the path of business recovery, whereas stress continues on employee expectations vs. employee productivity.
Microlocal KZ functors and rational Cherednik algebras
Creators: name: McGerty, Kevin
Publisher: name: arXiv
Year: 2010
Subjects: subject: Representation Theory (math.RT)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: Following the work of Kashiwara-Rouquier and Gan-Ginzburg, we define a family of exact functors from category $\mathcal O$ for the rational Cherednik algebra in type $A$ to representations of certain "coloured braid groups" and calculate the dimensions of the representations thus obtained from standard modules. To show that our constructions also make sense in a more general context, we also briefly study the case of the rational Cherednik algebra corresponding to complex reflection group $\mathbb Z/l\mathbb Z$.
description: Revised to improve exposition, giving more details on the construction of the microlocal local systems and providing background information on twisted D-modules in an appendix
Putting Stress in Historical Context: Why It Is Important That Being Stressed Out Was Not a Way to Be a Person 2,000 Years Ago
Creators: name: Hutmacher, Fabian
Publisher: name: Universität Regensburg
Year: 2021
Subjects: subject: 150 Psychologie

description: It was not until the middle of the twentieth century that scientists and Western societies began to label the combination of physiological and psychological responses that people display when things are getting too much and out of balance as “stress.” However, stress is commonly understood as a universal mechanism that exists across times and cultures. In a certain sense, this universality claim is correct: the physiological and endocrinological mechanisms underlying the stress response are not a modern invention of our body. In another sense, the universality claim is potentially problematic: stress has become, but has not always been, a way to be a person. That is, the social practices, in which the physiological and endocrinological stress mechanisms are embedded, are not the same across times and cultures. Crucially, these social practices are not a negligible by-product, but form an essential part of the way stress is commonly understood and experienced. Against this background, one may still decide to use the word “stress” when speaking about other times and cultures. Nevertheless, one should at least be cautious when doing so for three reasons. First, using the word “stress” when referring to societies different from our own may create the impression of a similarity between then and now, which does not actually exist. Second, it may blind us to the nature of the differences between times and cultures. Third, it naturalizes a contemporary scientific concept, which is more adequately viewed as the result of complex social, historical, and societal processes. Putting the stress concept in historical context and acknowledging that its use emerged in a specific historical environment enables us to take a step back and to think about the ways that stress shapes our lives. In other words, viewing stress as a culture-bound concept can give us the possibility to reflect upon our modern societies, in which the concept emerged.
Two-dimensional stellar kinematics with SINFONI: probing the gravitational potential of local LIRGs
Creators: name: Crespo Gómez, Alejandro
name: Piqueras López, J.
name: Arribas, S.
Publisher: name: Zenodo
Year: 2019

description: Local Ultra/Luminous Infrared Galaxies (U/LIRGs) have become the main laboratories to study the processes governing galaxy evolution and, thus, the evolution of the universe, at high spatial resolution and in high S/MN regime. Most of the previous Integral Field Spectroscopic (IFS) studies have been focused on studying the different phases of the gas. However, stars are the main component that governs the dynamics of these complex systems, and it is key to understand how LIRGs builds up their mass during their evolution.  In this work, we present a SINFONI 2D-kinematical study of the stellar component for a sample of 10 local LIRGs. We have developed a model to infer the gravitational potential based on the photometry taken with NICMOS/F160W and the 2D stellar kinematics. We use a Markov Chain Monte Carlo to compare the SINFONI velocity maps, extracted from the CO absorption bands, with those expected from the stellar potentials and, estimate their dynamical masses. We will introduce the method and present preliminary results.
Duality and cohomology in M-theory with boundary
Creators: name: Sati, Hisham
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Differential Geometry (math.DG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We consider geometric and analytical aspects of M-theory on a manifold with boundary Y. The partition function of the C-field requires summing over harmonic forms. When Y is closed Hodge theory gives a unique harmonic form in each de Rham cohomology class, while in the presence of a boundary the Hodge-Morrey-Friedrichs decomposition should be used. This leads us to study the boundary conditions for the C-field. The dynamics and the presence of the dual to the C-field gives rise to a mixing of boundary conditions with one being Dirichlet and the other being Neumann. We describe the mixing between the corresponding absolute and relative cohomology classes via Poincaré duality angles, which we also illustrate for the M5-brane as a tubular neighborhood. Several global aspects are then considered. We provide a systematic study of the extension of the E8 bundle and characterize obstructions. Considering Y as a fiber bundle, we describe how the phase looks like on the base, hence providing dimensional reduction in the boundary case via the adiabatic limit of the eta invariant. The general use of the index theorem leads to a new effect given by a gravitational Chern-Simons term CS on Y whose restriction to the boundary would be a generalized WZW model. This suggests that holographic models of M-theory can be viewed as a sector within this index-theoretic approach.
description: 19 pages
Elastic properties of graphene flakes: Boundary effects and lattice vibrations
Creators: name: Bera, S.
name: Arnold, A.
name: Evers, Ferdinand
name: Narayanan, R.
name: Wölfle, P.
Publisher: name: Universität Regensburg
Year: 2010
Subjects: subject: 530 Physik

description: We present a phenomenological theory together with explicit calculations of the electronic ground-state energy, the surface contribution, and the elastic constants (“Lamé parameters,” i.e., Poisson ratio, Young’s modulus) of graphene flakes on the level of the density-functional theory employing different standard functionals. We observe that the Lamé parameters in small flakes can differ from the bulk values by 30% for hydrogenated zigzag edges. The change results from the edge of the flake that compresses the interior. When including the vibrational zero-point motion, we detect a decrease in the bending rigidity, κ, by ∼26%. The vibrational frequencies flow with growing N due to the release of the edge-induced compression. We calculate the corresponding Grüneisen parameters and find good agreement with previous authors.