cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Boson-peak vibrational modes in glasses feature hybridized phononic and quasilocalized excitations
Creators: name: Lerner, Edan
name: Bouchbinder, Eran
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: A hallmark of structural glasses and other disordered solids is the emergence of excess low-frequency vibrations, on top of the Debye spectrum $D_{\rm Debye}(ω)$ of phonons ($ω$ denotes the vibrational frequency), which exist in any solid whose Hamiltonian is translationally invariant. These excess vibrations -- a signature of which is a THz peak in the reduced density of states $D(ω)/D_{\rm Debye}(ω)$, known as the boson peak -- have resisted a complete theoretical understanding for decades. Here, we provide direct numerical evidence that vibrations near the boson peak consist of hybridizations of phonons with many quasilocalized excitations, the latter were recently shown to generically populate the low-frequency tail of the vibrational spectra of structural glasses quenched from a melt and of disordered crystals. Our results suggest that quasilocalized excitations exist up to and in the vicinity of the boson-peak frequency, and hence constitute fundamental building blocks of the excess vibrational modes in glasses.
description: 9 pages, 6 figures. v2: additional analysis + 2 new figures
TiN-GST-TiN All-Optical Reflection Modulator for 2 $μ$m Waveband Reaching 85% Efficiency
Creators: name: Bhuiyan, Md Asif Hossain
name: Mitu, Shamima Akter
name: Choudhury, Sajid Muhaimin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: In this study, we present an all-optical reflection modulator for 2$μ$m communication band exploiting a nano-gear-array metasurface and a phase-change-material Ge$_2$Sb$_2$Te$_5$ (GST). The reflectance of the structure can be manipulated by altering the phase of GST by employing optical stimuli. The paper shows details on the optical and opto-thermal modeling techniques of GST. Numerical investigation reveals that the metastructure exhibits a conspicuous changeover from $\sim$ 99% absorption to very poor interaction with the operating light depending on the switching states of the GST, ending up with 85\% modulation depth and only 0.58 dB insertion loss. Due to noticeable differences in optical responses, we can demonstrate a high extinction ratio of 28 dB and a commendable FOM of 49, so far the best modulation performance in this wavelength window. In addition, real-time tracking of the reflectance during phase transition manifests high-speed switching expending low energy per cycle, on the order of sub-nJ. Hence, given its overall performance, the device will be a paradigm for the optical modulators for upcoming 2 $μ$m communication technology.
Black Hole Discs and Spheres in Galactic Nuclei -- Exploring the Landscape of Vector Resonant Relaxation Equilibria
Creators: name: Máthé, Gergely
name: Szölgyén, Ákos
name: Kocsis, Bence
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Vector resonant relaxation (VRR) is known to be the fastest gravitational process that shapes the geometry of stellar orbits in nuclear star clusters. This leads to the realignment of the orbital planes on the corresponding VRR time scale $t_{\rm VRR}$ of a few million years, while the eccentricity $e$ and semimajor axis $a$ of the individual orbits are approximately conserved. The distribution of orbital inclinations reaches an internal equilibrium characterised by two conserved quantities, the total potential energy among stellar orbits, $E_{\rm tot}$, and the total angular momentum, $L_{\rm tot}$. On timescales longer than $t_\mathrm{VRR}$, the eccentricities and semimajor axes change slowly and the distribution of orbital inclinations are expected to evolve through a series of VRR equilibria. Using a Monte Carlo Markov Chain method, we determine the equilibrium distribution of orbital inclinations in the microcanonical ensemble with fixed $E_{\rm tot}$ and $L_{\rm tot}$ for isolated nuclear star clusters with a power-law distribution of $a$, $e$, and $m$, where $m$ is the stellar mass. We explore the possible equilibria for $9$ representative $E_{\rm tot}$--$L_{\rm tot}$ pairs that cover the possible parameter space. For all cases, the equilibria show anisotropic mass segregation where the distribution of more massive objects is more flattened than that for lighter objects. Given that stellar black holes are more massive than the average main sequence stars, these findings suggest that black holes reside in disc-like structures within nuclear star clusters for a wide range of initial conditions.
description: Version accepted for publication in MNRAS
Quantum speed limits in arbitrary phase spaces
Creators: name: Meng, Weiquan
name: Xu, Zhenyu
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Quantum speed limits (QSLs) provide an upper bound for the speed of evolution of quantum states in any physical process. Based on the Stratonovich-Weyl correspondence, we derive a universal QSL bound in arbitrary phase spaces that is applicable for both continuous variable systems and finite-dimensional discrete quantum systems. This QSL bound allows the determination of speed limit bounds in specific phase spaces that are tighter than those in Wigner phase space or Hilbert space under the same metric, as illustrated by several typical examples, e.g., a single-mode free field and $N$-level quantum systems in phase spaces. This QSL bound also provides an experimentally realizable way to examine the speed limit in phase spaces relevant to applications in quantum information and quantum optics.
description: 11 pages, 2 figures
Additional file 1 of Employers most desirable attributes in early-career physiotherapists: a content analysis of job advertisements
Creators: name: McAleer, R.
name: Hanson, L.
name: Kenny, A.
Publisher: name: figshare
Year: 2024
Subjects: subject: Medicine
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified
subject: Science Policy

description: Supplementary Material 1
Anomalous skew-scattering nonlinear Hall effect and chiral photocurrents in {\it PT}-symmetric antiferromagnets
Creators: name: Ma, Da
name: Arora, Arpit
name: Vignale, Giovanni
name: Song, Justin C. W.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Berry curvature and skew-scattering play central roles in determining both the linear and nonlinear anomalous Hall effects. Yet in {\it PT}-symmetric antiferromagnetic metals, Hall effects from either intrinsic Berry curvature mediated anomalous velocity or the conventional skew-scattering process individually vanish. Here we reveal an unexpected nonlinear Hall effect that relies on both Berry curvature and skew-scattering working in cooperation. This anomalous skew-scattering nonlinear Hall effect (ASN) is {\it PT}-even and dominates the low-frequency nonlinear Hall effect for {\it PT}-symmetric antiferromagnetic metals. Surprisingly, we find that in addition to its Hall response, ASN produces helicity dependent photocurrents, in contrast to other known {\it PT}-even nonlinearities in metals which are helicity blind. This characteristic enables to isolate ASN and establishes new photocurrent tools to interrogate the antiferromagnetic order of {\it PT}-symmetric metals.
Tunable nodal kagome superconductivity in charge ordered RbV3Sb5
Creators: name: Guguchia, Z.
name: Mielke, C.
name: Das, D.
name: Gupta, R.
name: Yin, J. -X.
name: Liu, H.
name: Yin, Q.
name: Christensen, M. H.
name: Tu, Z.
name: Gong, C.
name: Shumiya, N.
name: Gamsakhurdashvili, Ts.
name: Elender, M.
name: Dai, Pengcheng
name: Amato, A.
name: Shi, Y.
name: Lei, H. C.
name: Fernandes, R. M.
name: Hasan, M. Z.
name: Luetkens, H.
name: Khasanov, R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Unconventional superconductors often feature competing orders, small superfluid density, and nodal electronic pairing. While unusual superconductivity has been proposed in the kagome metals AV3Sb5, key spectroscopic evidence has remained elusive. Here we utilize pressure-tuned (up to 1.85 GPa) and ultra-low temperature (down to 18 mK) muon spin spectroscopy to uncover the unconventional nature of superconductivity in RbV3Sb5. At ambient pressure, we detect an enhancement of the width of the internal magnetic field distribution sensed by the muon ensemble, indicative of time-reversal symmetry breaking charge order. Remarkably, the superconducting state displays nodal energy gap and a reduced superfluid density, which can be attributed to the competition with the novel charge order. Upon applying pressure, the charge-order transitions are suppressed, the superfluid density increases, and the superconducting state progressively evolves from nodal to nodeless. Once charge order is eliminated, we find a superconducting pairing state that is not only fully gapped, but also spontaneously breaks time-reversal symmetry. Our results point to unprecedented tunable nodal kagome superconductivity competing with time-reversal symmetry-breaking charge order and offer unique insights into the nature of the pairing state.
description: 22 pages, 10 figures
Additional file 1 of Global, regional, and national burden of intracerebral hemorrhage and its attributable risk factors from 1990 to 2021: results from the 2021 Global Burden of Disease Study
Creators: name: Xu, Libo
name: Wang, Zhenhao
name: Wu, Wenchao
name: Li, Mao
name: Li, Qingsong
Publisher: name: figshare
Year: 2024
Subjects: Medicine
Biotechnology
Biological Sciences not elsewhere classified
Science Policy

description: Supplementary Material 1
Intergenerationelle psychomotorische Förderung, eine Idee
Creators: name: Jenzer, Elsbeth
name: Kottlow, Micaela
Publisher: name: Zenodo
Year: 2012
Subjects: Psychomotorik
Psychomotoriktherapie
Bachelorarbeit

description: Im Kontext der vermehrt durchgeführten Generationenprojekte geht es in dieser Arbeit um die Idee der Intergenerationellen Psychomotorischen Förderung IPMF. Die Arbeit geht folgenden Fragen nach: Eignet sich die psychomotorische Förderung PMF für intergenerationelles Arbeiten? Weshalb? Welche Vor- bzw. Nachteile ergeben sich bei der IPMF gegenüber herkömmlicher psychomotorischer Förderung bzw. gegenüber der Motogeragogik? Wie könnte IPMF in der Praxis umgesetzt werden? Anhand einer Literaturrecherche werden die Grundlagen der Motogeragogik und des intergenerationellen Arbeitens dargestellt. Durch die Verknüpfung dieser beiden Bereiche wird die IPMF begründet. Mit Bezugnahme auf praktische Erfahrungen aus der PMF, aus der Motogeragogik und aus intergenerationellen Projekten werden für die praktische Umsetzung Rahmenbedingungen aufgezeigt und konkrete Spielideen vorgeschlagen.
Gibbs sampling of complex valued distributions
Creators: name: Salcedo, L. L.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: A new technique is explored for the Monte Carlo sampling of complex-valued distributions. The method is based on a heat bath approach where the conditional probability is replaced by a positive representation of it on the complex plane. Efficient ways to construct such representations are also introduced. The performance of the algorithm is tested on small and large lattices with a $λϕ^4$ theory with quadratic nearest-neighbor complex coupling. The method works for moderate complex couplings, reproducing reweighting and complex Langevin results and fulfilling various Schwinger-Dyson relations.
description: 23 pages, 2 tables, 11 figure. Major revision
Diffusion of Immunoglobulin G in Shed Vaginal Epithelial Cells and in Cell-Free Regions of Human Cervicovaginal Mucus
Creators: name: Cone, Richard A.
name: Anderson, Deborah J.
name: Schroeder, Holly A.
name: Nunn, Kenetta L.
name: Wang, Ying-Ying
name: Woods, Karen
name: Lai, Samuel K.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2016

description: Human cervicovaginal mucus (CVM) is a viscoelastic gel containing a complex mixture of mucins, shed epithelial cells, microbes and macromolecules, such as antibodies, that together serve as the first line of defense against invading pathogens. Here, to investigate the affinity between IgG and different mucus constituents, we used Fluorescence Recovery After Photobleaching (FRAP) to measure the diffusion of IgG in fresh, minimally modified CVM. We found that CVM exhibits substantial spatial variations that necessitate careful selection of the regions in which to perform FRAP. In portions of CVM devoid of cells, FRAP measurements using different IgG antibodies and labeling methods consistently demonstrate that both exogenous and endogenous IgG undergo rapid diffusion, almost as fast as in saline, in good agreement with the rapid diffusion of IgG in mid-cycle endocervical mucus that is largely devoid of cells. This rapid diffusion indicates the interactions between secreted mucins and IgG must be very weak and transient. IgG also accumulated in cellular debris and shed epithelial cells that had become permeable to IgG, which may allow shed epithelial cells to serve as reservoirs of secreted IgG. Interestingly, in contrast to cell-free regions of CVM, the diffusion of cell-associated IgG was markedly slowed, suggesting greater affinity between IgG and cellular constituents. Our findings contribute to an improved understanding of the role of IgG in mucosal protection against infectious diseases, and may also provide a framework for using FRAP to study molecular interactions in mucus and other complex biological environments.
Pulse based Variational Quantum Optimal Control for hybrid quantum computing
Creators: name: de Keijzer, Robert
name: Tse, Oliver
name: Kokkelmans, Servaas
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: This work studies pulse based variational quantum algorithms (VQAs), which are designed to determine the ground state of a quantum mechanical system by combining classical and quantum hardware. In contrast to more standard gate based methods, pulse based methods aim to directly optimize the laser pulses interacting with the qubits, instead of using some parametrized gate based circuit. Using the mathematical formalism of optimal control, these laser pulses are optimized. This method has been used in quantum computing to optimize pulses for quantum gate implementations, but has only recently been proposed for full optimization in VQAs. Pulse based methods have several advantages over gate based methods such as faster state preparation, simpler implementation and more freedom in moving through the state space. Based on these ideas, we present the development of a novel adjoint based variational method. This method can be tailored towards and applied in neutral atom quantum computers. This method of pulse based variational quantum optimal control is able to approximate molecular ground states of simple molecules up to chemical accuracy and is able to compete with the gate based variational quantum eigensolver in terms of total number of quantum evaluations. The total evolution time $T$ and the form of the control Hamiltonian $H_c$ are important factors in the convergence behavior to the ground state energy, both having influence on the quantum speed limit and the controllability of the system.
description: 15 pages, 16 figures
A Mathematical Runtime Analysis of the Non-dominated Sorting Genetic Algorithm III (NSGA-III)
Creators: name: Wietheger, Simon
name: Doerr, Benjamin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Neural and Evolutionary Computing (cs.NE)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: The Non-dominated Sorting Genetic Algorithm II (NSGA-II) is the most prominent multi-objective evolutionary algorithm for real-world applications. While it performs evidently well on bi-objective optimization problems, empirical studies suggest that it is less effective when applied to problems with more than two objectives. A recent mathematical runtime analysis confirmed this observation by proving the NGSA-II for an exponential number of iterations misses a constant factor of the Pareto front of the simple 3-objective OneMinMax problem. In this work, we provide the first mathematical runtime analysis of the NSGA-III, a refinement of the NSGA-II aimed at better handling more than two objectives. We prove that the NSGA-III with sufficiently many reference points -- a small constant factor more than the size of the Pareto front, as suggested for this algorithm -- computes the complete Pareto front of the 3-objective OneMinMax benchmark in an expected number of O(n log n) iterations. This result holds for all population sizes (that are at least the size of the Pareto front). It shows a drastic advantage of the NSGA-III over the NSGA-II on this benchmark. The mathematical arguments used here and in previous work on the NSGA-II suggest that similar findings are likely for other benchmarks with three or more objectives.
description: Long version of a paper appearing at IJCAI 2023
Non-associative plasticity for structural instability of cylindrical shells in the inelastic range
Creators: name: Nasikas, Apostolos
Publisher: name: The University of Edinburgh
Year: 2022
Subjects: non‐associative plasticity
pseudo‐corner theory
shell buckling
structural instability
finite element analysis
metal shell strength
computational plasticity

description: Thick-walled cylindrical metal shells, commonly used in tubular structures and pipelines, during their lifetime may be subjected to considerable compressive loads, which can lead to local buckling. In modelling their structural behaviour, the use of standard J2 flow plasticity is known to produce unrealistically high buckling load estimates. Alternative constitutive models, which consider the formation of yield surface ‘corners’, can provide more accurate predictions, but they have been used scarcely, due to the limitations and complexities they introduce. The present work develops an efficient and versatile plasticity model to simulate the structural response of metal shells under compressive loads. It combines the simplicity of a Von Mises yield surface, with a non-associative flow rule, mimicking the effect of a yield surface corner. The model allows for tracing the equilibrium path of the shells and identifying structural instability in a consistent manner. A robust backward-Euler integration scheme is developed, suitable for three-dimensional (solid) and shell finite elements. The corresponding algorithmic moduli are obtained for nonlinear isotropic hardening materials. The nonlinear dependence of plastic strain increments on the direction of total strain increments is accounted for rigorously. The constitutive model is implemented in Abaqus as a user material subroutine (UMAT). Simulations of thick-walled metal cylinders under uniform compression show good agreement with experimental data in predicting the buckling and post-buckling performance of shells. The influence of geometric imperfection is considered, and comparisons are made with models employing the J2 flow plasticity. The reliability of the developed approach is further demonstrated by investigating more demanding problems of bending and pressure in inelastic cylinders, taking into account ovalization, bifurcation instabilities, imperfection. These problems involve non-trivial prebuckling equilibrium paths, non-uniform loading and significant non-proportionality, before instability onsets, which activate the model’s particular features, and illustrate their role in the evolution of buckling. Analyses showcase the model’s capabilities, producing accurate instability estimates, ultimate load and deformation predictions in line with experiments and clarify aspects of the buckling of inelastic shells. Extending a traditional practice, a simple method is presented for estimating the instability of inelastic cylinders under bending and pressure loads, drawing on similarities in their buckling with that of cylinders under compression.
Frontal effective connectivity increases with task demands and time on task: a Dynamic Causal Model of electrocorticogram in macaque monkeys
Creators: name: Wegner, Katharina
name: Wilson, Charles R. E.
name: Procyk, Emmanuel
name: Friston, Karl J.
name: Van de Steen, Frederik
name: Pinotsis, Dimitris A.
name: Marinazzo, Daniele
Publisher: name: arXiv
Year: 2022
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: FOS: Biological sciences

description: We apply Dynamic Causal Models to electrocorticogram recordings from two macaque monkeys performing a problem-solving task that engages working memory, and induces time-on-task effects. We thus provide a computational account of changes in effective connectivity within two regions of the fronto-parietal network, the dorsolateral prefrontal cortex and the pre-supplementary motor area. We find that forward connections between the two regions increased in strength when task demands increased, and as the experimental session progressed. Similarities in the effects of task demands and time on task allow us to interpret changes in frontal connectivity in terms of increased attentional effort allocation that compensates cognitive fatigue.
title: Das Konzept des Lehrens mit Epistemologie zur Vermittlung von Gender als Querschnittsthema in der Hochschullehre
title: Ein lernendes Projekt
titleType: Subtitle
Creators: name: Eckert, Lena
Publisher: name: Humboldt-Universität zu Berlin
Year: 2014
Subjects: subject: Gender
subject: Epistemologie
subject: Lehre
subject: Hochschule
subject: Wissen
subject: 378 Hochschulbildung
subject: Didaktik
subject: Lehrmethode

description: Gender als Struktur- und Analysekategorie in die Hochschullehrezu integrieren, ist eine besondere Herausforderung, selbst für interessierte Lehrende. In diesem Aufsatz wird das Konzept des Lehrens mit Epistemologie vorgestellt, das die Inhalte der Fachdisziplinen einerseits mit den Gender Studies und andererseits mit diversity- und gendersensiblen Didaktiken verknüpft. Im Rahmen eines Forschungsprojektes wurden zusammen mit Lehrenden aus den Geistes- und Sozialwissenschaften sowie der Informatik diversity- und gendersensible Lehreinheiten entworfen, die ohne großen Aufwand in die bestehenden Curricula integrierbar sind. Die Lehreinheiten bestehen aus eineinhalb Zeitstunden, orientieren sich am vorhandenen Wissen der Lehrenden, sind in der Methodik an diversity- und gendersensiblen Didaktiken ausgerichtet und stellen epistemologische Fragen an die jeweiligen Disziplinen.
Extension of Dynamic Mode Decomposition for dynamic systems with incomplete information based on t-model of optimal prediction
Creators: name: Katrutsa, Aleksandr
name: Utyuzhnikov, Sergey
name: Oseledets, Ivan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Numerical Analysis (math.NA)
subject: Machine Learning (cs.LG)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: The Dynamic Mode Decomposition has proved to be a very efficient technique to study dynamic data. This is entirely a data-driven approach that extracts all necessary information from data snapshots which are commonly supposed to be sampled from measurement. The application of this approach becomes problematic if the available data is incomplete because some dimensions of smaller scale either missing or unmeasured. Such setting occurs very often in modeling complex dynamical systems such as power grids, in particular with reduced-order modeling. To take into account the effect of unresolved variables the optimal prediction approach based on the Mori-Zwanzig formalism can be applied to obtain the most expected prediction under existing uncertainties. This effectively leads to the development of a time-predictive model accounting for the impact of missing data. In the present paper we provide a detailed derivation of the considered method from the Liouville equation and finalize it with the optimization problem that defines the optimal transition operator corresponding to the observed data. In contrast to the existing approach, we consider a first-order approximation of the Mori-Zwanzig decomposition, state the corresponding optimization problem and solve it with the gradient-based optimization method. The gradient of the obtained objective function is computed precisely through the automatic differentiation technique. The numerical experiments illustrate that the considered approach gives practically the same dynamics as the exact Mori-Zwanzig decomposition, but is less computationally intensive.
Self-Regularized Prototypical Network for Few-Shot Semantic Segmentation
Creators: name: Ding, Henghui
name: Zhang, Hui
name: Jiang, Xudong
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: The deep CNNs in image semantic segmentation typically require a large number of densely-annotated images for training and have difficulties in generalizing to unseen object categories. Therefore, few-shot segmentation has been developed to perform segmentation with just a few annotated examples. In this work, we tackle the few-shot segmentation using a self-regularized prototypical network (SRPNet) based on prototype extraction for better utilization of the support information. The proposed SRPNet extracts class-specific prototype representations from support images and generates segmentation masks for query images by a distance metric - the fidelity. A direct yet effective prototype regularization on support set is proposed in SRPNet, in which the generated prototypes are evaluated and regularized on the support set itself. The extent to which the generated prototypes restore the support mask imposes an upper limit on performance. The performance on the query set should never exceed the upper limit no matter how complete the knowledge is generalized from support set to query set. With the specific prototype regularization, SRPNet fully exploits knowledge from the support and offers high-quality prototypes that are representative for each semantic class and meanwhile discriminative for different classes. The query performance is further improved by an iterative query inference (IQI) module that combines a set of regularized prototypes. Our proposed SRPNet achieves new state-of-art performance on 1-shot and 5-shot segmentation benchmarks.
description: Pattern Recognition (PR)
N-electron valence perturbation theory with reference wavefunctions from quantum computing: application to the relative stability of hydroxide anion and hydroxyl radical
Creators: name: Tammaro, Alessandro
name: Galli, Davide E.
name: Rice, Julia E.
name: Motta, Mario
Publisher: name: arXiv
Year: 2022
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum simulations of the hydroxide anion and hydroxyl radical are reported, employing variational quantum algorithms for near-term quantum devices. The energy of each species is calculated along the dissociation curve, to obtain information about the stability of the molecular species being investigated. It is shown that simulations restricted to valence spaces incorrectly predict the hydroxyl radical to be more stable than the hydroxide anion. Inclusion of dynamical electron correlation from non-valence orbitals is demonstrated, through the integration of the variational quantum eigensolver and quantum subspace expansion methods in the workflow of N-electron valence perturbation theory, and shown to correctly predict the hydroxide anion to be more stable than the hydroxyl radical, provided that basis sets with diffuse orbitals are also employed. Finally, we calculate the electron affinity of the hydroxyl radical using an aug-cc-pVQZ basis on IBM's quantum devices.
description: 12 pages, 6 figures
Isoscalar and neutron modes in the E1 spectra of Ni isotopes and the relevance of shell effects and the continuum
Creators: name: Papakonstantinou, P.
name: Hergert, H.
name: Roth, R.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We study theoretically the electric dipole transitions of even Ni isotopes at low energies, using the self-consistent quasi-particle random-phase approximation (RPA) with the D1S Gogny interaction and a continuum-RPA model with the SLy4 Skyrme force. We analyze isoscalar states, isovector states, and the dipole polarizability. We define a reference value for the polarizability, to remove a trivial dependence on the mass number. We compare our results with data and other calculations, with a focus on collective states, shell effects, and threshold transitions. Our results support the presence of a strong isoscalar transition, with little or moderate E1 strength, as a universal feature of ordinary nuclei. In moderately neutron-rich Ni isotopes, namely 68Ni and neighboring isotopes, this transition is found bimodal due to couplings with surface neutrons. An adequate treatment of the continuum states appears essential for describing suprathreshold E1 strength, especially beyond 68Ni. Very exotic isotopes (N>50) are found highly polarizable, with practically all their E1 strength in the continuum. The dipole polarizability and the neutron skin thickness are influenced by shell structure in different ways, so they can appear anticorrelated. A comparison with existing results for lighter (Ca) and heavier (Sn) nuclei suggests that the so-called pygmy dipole strength is influenced strongly by shell effects and that, partly for that reason, its isospin structure depends on the mass region.
description: 14 pages, incl. 10 figures (v2) and 1 table; (v2: clarifications and minor restructuring to improve readability; one extra figure)
Dynamical renormalization and universality in classical multifield cosmological models
Creators: name: Lazaroiu, C. I.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study the scaling behavior of classical multifield cosmological models with complete scalar manifold $({\cal M},{\cal G})$ and positive smooth scalar potential $Φ$, introducing a dynamical renormalization group action which relates their UV and IR limits. We show that the RG flow of such models interpolates between a modification of the geodesic flow of $({\cal M},{\cal G})$ (obtained in the UV limit) and the gradient flow of $({\cal M},{\cal G},V)$ (obtained in the IR limit), where the classical effective potential $V$ is proportional to $\sqrt{2Φ}$. Using this fact, we show that two-field models whose scalar manifold has constant Gaussian curvature equal to $-1$, $0$ or $1$ are infrared universal in the sense that they suffice to describe the first order IR approximants of cosmological orbits for all two-field models with positive smooth scalar potential.
description: 55 pages, 2 figures; v2: minor corrections, reference added
Disparities in Depressive Symptoms and Antidepressant Treatment by Gender and Race/Ethnicity among People Living with HIV in the United States
Creators: name: Bengtson, Angela M.
name: Crane, Heidi M.
name: Mathews, W. Christopher
name: Heine, Amy
name: Safren, Steven
name: Mugavero, Michael J.
name: Pence, Brian W.
name: Christopoulos, Katerina
name: Napravnik, Sonia
name: Moore, Richard
name: Gaynes, Bradley N.
name: Fredericksen, Rob J.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2016

description: To describe disparities along the depression treatment cascade, from indication for antidepressant treatment to effective treatment, in HIV-infected individuals by gender and race/ethnicity.
Connectedness of random set attractors
Creators: name: Scheutzow, Michael
name: Vorkastner, Isabell
Publisher: name: Technische Universität Berlin
Year: 2018
Subjects: subject: 510 Mathematik
subject: random dynamical system
subject: pullback attractor
subject: weak attractor
subject: pullback continuity
subject: measurable selection

description: Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
description: This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
description: We examine the question whether random set attractors for continuous-time random dynamical systems on a connected state space are connected. In the deterministic case, these attractors are known to be connected. In the probabilistic setup, however, connectedness has only been shown under stronger connectedness assumptions on the state space. Under a weak continuity condition on the random dynamical system we prove connectedness of the pullback attractor on a connected space. Additionally, we provide an example of a weak random set attractor of a random dynamical system with even more restrictive continuity assumptions on an even path-connected space which even attracts all bounded sets and which is not connected. On the way to proving connectedness of a pullback attractor we prove a lemma which may be of independent interest and which holds without the assumption that the state space is connected. It states that even though pullback convergence to the attractor allows for exceptional nullsets which may depend on the compact set, these nullsets can be chosen independently of the compact set (which is clear for σ-compact spaces but not at all clear for spaces which are not σ-compact).
Improving multiple-try Metropolis with local balancing
Creators: name: Gagnon, Philippe
name: Maire, Florian
name: Zanella, Giacomo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computation (stat.CO)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Multiple-try Metropolis (MTM) is a popular Markov chain Monte Carlo method with the appealing feature of being amenable to parallel computing. At each iteration, it samples several candidates for the next state of the Markov chain and randomly selects one of them based on a weight function. The canonical weight function is proportional to the target density. We show both theoretically and empirically that this weight function induces pathological behaviours in high dimensions, especially during the convergence phase. We propose to instead use weight functions akin to the locally-balanced proposal distributions of Zanella (2020), thus yielding MTM algorithms that do not exhibit those pathological behaviours. To theoretically analyse these algorithms, we study the high-dimensional performance of ideal schemes that can be thought of as MTM algorithms which sample an infinite number of candidates at each iteration, as well as the discrepancy between such schemes and the MTM algorithms which sample a finite number of candidates. Our analysis unveils a strong distinction between the convergence and stationary phases: in the former, local balancing is crucial and effective to achieve fast convergence, while in the latter, the canonical and novel weight functions yield similar performance. Numerical experiments include an application in precision medicine involving a computationally-expensive forward model, which makes the use of parallel computing within MTM iterations beneficial.
Persistent currents in a strongly interacting multicomponent Bose gas on a ring
Creators: name: Pecci, Giovanni
name: Aupetit-Diallo, Gianni
name: Albert, Mathias
name: Vignolo, Patrizia
name: Minguzzi, Anna
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We consider a two-component Bose-Bose mixture at strong repulsive interactions in a tightly confining, one-dimensional ring trap and subjected to an artificial gauge field. By employing the Bethe Ansatz exact solution for the many-body wavefunction, we obtain the ground state energy and the persistent currents. For each value of the applied flux, we then determine the symmetry of the state under particles exchange. We find that the ground-state energy and the persistent currents display a reduced periodicity with respect to the case of non-interacting particles, corresponding to reaching states with fractional angular momentum per particle. We relate this effect to the change of symmetry of the ground state under the effect of the artificial gauge field. Our results generalize the ones previously reported for fermionic mixtures with both attractive and repulsive interactions and highlight the role of symmetry in this effect
description: 12 pages, 2 figures, 3 tables
Three-dimensional Printing of Mycelium Hydrogels into Living Complex Materials
Creators: name: Gantenbein, Silvan
name: Colucci, Emanuele
name: Käch, Julian
name: Trachsel, Etienne
name: Coulter, Fergal B.
name: Rühs, Patrick A.
name: Masania, Kunal
name: Studart, André R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Biological living materials, such as animal bones and plant stems, are able to self-heal, regenerate, adapt and make decisions under environmental pressures. Despite recent successful efforts to imbue synthetic materials with some of these remarkable functionalities, many emerging properties of complex adaptive systems found in biology remain unexplored in engineered living materials. Here, we report on a three-dimensional printing approach that harnesses the emerging properties of fungal mycelium to create living complex materials that self-repair, regenerate and adapt to the environment while fulfilling an engineering function. Hydrogels loaded with the fungus Ganoderma lucidum are 3D printed into lattice architectures to enable mycelial growth in a balanced exploration and exploitation pattern that simultaneously promotes colonization of the gel and bridging of air gaps. To illustrate the potential of such living complex materials, we 3D print a robotic skin that is mechanically robust, self-cleaning, and able to autonomously regenerate after damage.
Disparities in Early Transitions to Obesity in Contemporary Multi-Ethnic U.S. Populations
Creators: name: Reis, Jared P.
name: Holliday, Katelyn M.
name: Heiss, Gerardo
name: Hardy, Shakia T.
name: Lin, Dan Yu
name: Daviglus, Martha L.
name: Shay, Christina M.
name: Schreiner, Pamela J.
name: Avery, Christy L.
name: Zeng, Donglin
name: Engeda, Joseph C.
name: Chakladar, Sujatro
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2016

description: Few studies have examined weight transitions in contemporary multi-ethnic populations spanning early childhood through adulthood despite the ability of such research to inform obesity prevention, control, and disparities reduction.
A Quantitative Criterion for Defining Planets
Creators: name: Margot, Jean-Luc
Publisher: name: arXiv
Year: 2015
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: A simple metric can be used to determine whether a planet or exoplanet can clear its orbital zone during a characteristic time scale, such as the lifetime of the host star on the main sequence. This criterion requires only estimates of star mass, planet mass, and orbital period, making it possible to immediately classify 99% of all known exoplanets. All 8 planets and all classifiable exoplanets satisfy the criterion. This metric may be useful in generalizing and simplifying the definition of a planet.
description: Accepted for publication in the Astronomical Journal; 7 pages, 6 figures
Polar Codes-based Information Reconciliation Scheme with Frozen Bits Erasure Strategy for Quantum Key Distribution
Creators: name: Tang, Bang-Ying
name: Wu, Chun-Qing
name: Peng, Wei
name: Liu, Bo
name: Yu, Wan-Rong
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Information reconciliation (IR) ensures the correctness of quantum key distribution systems, by correcting the error bits existed in the sifted keys. In this article, we propose a polar codes-based IR scheme with the frozen bits erasure strategy, where an equivalent transmission of sifted keys is conducted, so that the frozen bits in the decoding procedure is erased to 0. Thus, our IR scheme can be implemented efficiently without the assumption of true random numbers. Furthermore, we implement the proposed IR scheme with the fast simplified successive cancellation list decoder and its throughput reaches to 0.88Mbps with the yield of 0.8333, where the decoder list size is 16, the block size is 1Mb and the quantum bit error rate is 0.02.
description: 11 pages, 5 figures
Total Reaction Cross Sections in CEM and MCNP6 at Intermediate Energies
Creators: name: Kerby, Leslie M.
name: Mashnik, Stepan G.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Accurate total reaction cross section models are important to achieving reliable predictions from spallation and transport codes. The latest version of the Cascade Exciton Model (CEM) as incorporated in the code CEM03.03, and the Monte Carlo N-Particle transport code (MCNP6), both developed at Los Alamos National Laboratory (LANL), each use such cross sections. Having accurate total reaction cross section models in the intermediate energy region ($\sim$50 MeV to $\sim$5 GeV) is very important for different applications, including analysis of space environments, use in medical physics, and accelerator design, to name just a few. The current inverse cross sections used in the preequilibrium and evaporation stages of CEM are based on the Dostrovsky {\it et al.} model, published in 1959. Better cross section models are available now. Implementing better cross section models in CEM and MCNP6 should yield improved predictions for particle spectra and total production cross sections, among other results. Our current results indicate this is, in fact, the case.
description: 13 pages, 15 figures, accepted for publication in Nuclear Instruments and Methods B
Synth4bench: a framework for generating synthetic genomics data for the evaluation of somatic variant calling algorithms
Creators: name: Fragkouli, Styliani-Christina
name: Nikos, Pechlivanis
name: Aspasia, Orfanou
name: Anastasiadou, Anastasia
name: Agathangelidis, Andreas
name: Psomopoulos, Fotis
Publisher: name: Zenodo
Year: 2023
Subjects: synthetic genomics data
somatic variant calling
TP53
synth4bench

description: Somatic variant calling algorithms are widely used to detect genomic alterations associated with cancer. Evaluating the performance of these algorithms can be challenging due to the lack of high-quality ground truth datasets. To address this issue, we developed a synthetic genomics data generation and evaluation framework for benchmarking somatic variant calling algorithms. We generated synthetic datasets based on sequence data from the TP53 gene, using the NEAT simulator. Subsequently, we thoroughly evaluated the performance of GATK-Mutect2 on these datasets, and compared the results to the “golden” files produced by NEAT containing the actual variations. Our results demonstrate that the synthetic datasets generated using our framework can accurately capture the complexity and diversity of real cancer genomic data. Moreover, the synthetic datasets provide an excellent ground truth for evaluating the performance of somatic variant calling algorithms. Altogether, our framework provides a valuable resource for testing the performance of somatic variant calling algorithms, enabling researchers to evaluate and improve the accuracy of these algorithms for cancer genomics applications.
Exponential Concentration for Geometric-Median-of-Means in Non-Positive Curvature Spaces
Creators: name: Yun, Ho
name: Park, Byeong U.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics

description: In Euclidean spaces, the empirical mean vector as an estimator of the population mean is known to have polynomial concentration unless a strong tail assumption is imposed on the underlying probability measure. The idea of median-of-means tournament has been considered as a way of overcoming the sub-optimality of the empirical mean vector. In this paper, to address the sub-optimal performance of the empirical mean in a more general setting, we consider general Polish spaces with a general metric, which are allowed to be non-compact and of infinite-dimension. We discuss the estimation of the associated population Frechet mean, and for this we extend the existing notion of median-of-means to this general setting. We devise several new notions and inequalities associated with the geometry of the underlying metric, and using them we study the concentration properties of the extended notions of median-of-means as the estimators of the population Frechet mean. We show that the new estimators achieve exponential concentration under only a second moment condition on the underlying distribution, while the empirical Frechet mean has polynomial concentration. We focus our study on spaces with non-positive Alexandrov curvature since they afford slower rates of convergence than spaces with positive curvature. We note that this is the first work that derives non-asymptotic concentration inequalities for extended notions of the median-of-means in non-vector spaces with a general metric.
Dual Energy Spectral CT Imaging for Colorectal Cancer Grading: A Preliminary Study
Creators: name: Yin, Yan
name: Zhang, Ke-Bei
name: Baigorri, Brian F.
name: Xu, Jian-Rong
name: Geng, Xiaochuan
name: Wu, Lian-Ming
name: Zhu, Jiong
name: Gong, Hong-Xia
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2016

description: ObjectivesTo assess the diagnostic value of dual energy spectral CT imaging for colorectal cancer grading using the quantitative iodine density measurements in both arterial phase (AP) and venous phase (VP).Methods81 colorectal cancer patients were divided into two groups based on their pathological findings: a low grade group including well (n = 13) and moderately differentiated cancer (n = 24), and a high grade group including poorly differentiated (n = 42) and signet ring cell cancer (n = 2). Iodine density (ID) in the lesions was derived from the iodine-based material decomposition (MD) image and normalized to that in the psoas muscle to obtain normalized iodine density (NID). The difference in ID and NID between AP and VP was calculated.ResultsThe ID and NID values of the low grade cancer group were, 14.65±3.38mg/mL and 1.70±0.33 in AP, and 21.90±3.11mg/mL and 2.05± 0.32 in VP, respectively. The ID and NID values for the high grade cancer group were 20.63±3.72mg/mL and 2.95±0.72 in AP, and 26.27±3.10mg/mL and 3.51±1.12 in VP, respectively. There was significant difference for ID and NID between the low grade and high grade cancer groups in both AP and VP (all p<0.001). ROC analysis indicated that NID of 1.92 in AP provided 70.3% sensitivity and 97.7% specificity in differentiating low grade cancer from high grade cancer.ConclusionsThe quantitative measurement of iodine density in AP and VP can provide useful information to differentiate low grade colorectal cancer from high grade colorectal cancer with NID in AP providing the greatest diagnostic value.