cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Modeling and simulation of vascular tumors embedded in evolving capillary networks
Creators: name: Fritz, Marvin
name: Jha, Prashant K.
name: Köppl, Tobias
name: Oden, J. Tinsley
name: Wagner, Andreas
name: Wohlmuth, Barbara
Publisher: name: arXiv
Year: 2021
Subjects: subject: Tissues and Organs (q-bio.TO)
subject: FOS: Biological sciences
subject: 65M08, 65M60, 76S05, 76Z05, 92C17, 92C42

description: In this work, we present a coupled 3D-1D model of solid tumor growth within a dynamically changing vascular network to facilitate realistic simulations of angiogenesis. Additionally, the model includes erosion of the extracellular matrix, interstitial flow, and coupled flow in blood vessels and tissue. We employ continuum mixture theory with stochastic Cahn--Hilliard type phase-field models of tumor growth. The interstitial flow is governed by a mesoscale version of Darcy's law. The flow in the blood vessels is controlled by Poiseuille flow, and Starling's law is applied to model the mass transfer in and out of blood vessels. The evolution of the network of blood vessels is orchestrated by the concentration of the tumor angiogenesis factors (TAFs); blood vessels grow towards the increasing TAFs concentrations. This process is not deterministic, allowing random growth of blood vessels and, therefore, due to the coupling of nutrients in tissue and vessels, makes the growth of tumors stochastic. We demonstrate the performance of the model by applying it to a variety of scenarios. Numerical experiments illustrate the flexibility of the model and its ability to generate satellite tumors. Simulations of the effects of angiogenesis on tumor growth are presented as well as sample-independent features of cancer.
description: 36 pages, 22 figures
Non-perturbative fixed point in a non-equilibrium phase transition
Creators: name: Canet, L.
name: Chaté, H.
name: Delamotte, B.
name: Dornic, I.
name: Muñoz, M. A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We apply the non-perturbative renormalization group method to a class of out-of-equilibrium phase transitions (usually called ``parity conserving'' or, more properly, ``generalized voter'' class) which is out of the reach of perturbative approaches. We show the existence of a genuinely non-perturbative fixed point, i.e. a critical point which does not seem to be Gaussian in any dimension.
description: 4 pages, 2 figures. Submitted version with slightly amended discussion on earlier perturbative renormalisation group results
title: Der Russland-Ukraine-Konflikt – über Putins Kalkül und die deutsche Verantwortung
title: Interview mit Prof. Dr. Ricarda Vulpius
titleType: Subtitle
Creators: name: Vulpius, Ricarda
Publisher: name: University of Muenster, Institutional Repository MIAMI
Year: 2024
Subjects: subject: 900 History, geography, and auxiliary disciplines
subject: 947 Russia and neighboring east European countries

description: Die Lage an der ukrainischen Grenze ist seit Wochen angespannt. Im Podcast bewertet Prof. Dr. Ricarda Vulpius vom Institut für osteuropäische Geschichte - Expertin für russländische Imperiumsgeschichte und die Geschichte der Ukraine - die aktuelle Situation. Die im Konflikt um die Ukraine von Russlands Präsidenten Wladimir Putin geforderten "Sicherheitsgarantien" hält sie vor allem für einen Ausdruck psychologischer Unsicherheit: "Putin hat ein Bedürfnis nach Anerkennung und Augenhöhe, er fühlt sich vom Süden bis in den Norden umzingelt." Im Gespräch geht es auch um die Rolle Deutschlands. Aus ihrer Sicht müsse sich Deutschland von der Grundhaltung lösen, dass es im Hinblick auf den Zweiten Weltkrieg ausschließlich Russland gegenüber eine historische Schuld habe. "Wir müssen endlich erkennen, dass wir genauso der Ukraine gegenüber in der Verantwortung stehen."
Large Bychkov-Rashba spin-orbit coupling in high-mobility GaN/AlGaN heterostructures
Creators: name: Schmult, S.
name: Manfra, M. J.
name: Punnoose, A.
name: Sergent, A. M.
name: Baldwin, K. W.
name: Molnar, R. J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present low temperature magnetoconductivity measurements of a density-tunable and high mobility two-dimensional electron gas confined in the wide bandgap GaN/AlGaN system. We observed pronounced anti-localization minima in the low-field conductivity, indicating the presence of strong spin-orbit coupling. Density dependent measurements of magnetoconductivity indicate that the coupling is mainly due to the Bychkov-Rashba mechanism. In addition, we have derived a closed-form expression for the magnetoconductivity, allowing us to extract reliable transport parameters for our devices. The Rashba spin-orbit coupling constant is $α_{so}$ $\sim$ 6$\times$ 10$^{-13}$eVm, while the conduction band spin-orbit splitting energy amounts to $Δ_{so}$ $\sim$ 0.3meV at n$_e$=1$\times10^{16}$m$^{-2}$.
description: Accepted for publication in PRB
How Fragmentation Can Undermine the Public Health Response to COVID-19
Creators: name: Chen, Andrew Tzer-Yeu
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computers and Society (cs.CY)
subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: Responses to COVID-19 have largely been led by local, national, and international public health agencies, who have activated their pandemic plans and opened the epidemiological toolkit of modelling, testing, isolation and movement restrictions, surveillance, and contact tracing. In the contemporary tech-heavy world, many assumed that the common manual process of human investigators and phone calls could or should be replaced by digital solutions. But it's not as simple as "add more technology" - the complex way in which users and societies interact with the technology has significant impacts on effectiveness. When efforts are not well co-ordinated, fragmentation in system design and user experience can negatively impact the public health response. This article briefly covers the journey of how contact tracing registers and digital diaries evolved in New Zealand during the COVID-19 pandemic, the initial poor outcomes caused by the lack of central co-ordination, and the later improvement.
description: 7 pages, 5 figures, published by ACM Interactions (online at https://interactions.acm.org/blog/view/how-fragmentation-can-undermine-the-public-health-response-to-covid-19, in magazine in 2021)
Fracture Surfaces as Multiscaling Graphs
Creators: name: Bouchbinder, Eran
name: Procaccia, Itamar
name: Santucci, Stephane
name: Vanel, Loic
Publisher: name: arXiv
Year: 2005
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Fracture paths in quasi-two-dimenisonal (2D) media (e.g thin layers of materials, paper) are analyzed as self-affine graphs $h(x)$ of height $h$ as a function of length $x$. We show that these are multiscaling, in the sense that $n^{th}$ order moments of the height fluctuations across any distance $\ell$ scale with a characteristic exponent that depends nonlinearly on the order of the moment. Having demonstrated this, one rules out a widely held conjecture that fracture in 2D belongs to the universality class of directed polymers in random media. In fact, 2D fracture does not belong to any of the known kinetic roughening models. The presence of multiscaling offers a stringent test for any theoretical model; we show that a recently introduced model of quasi-static fracture passes this test.
description: 4 pages, 5 figures
Discovery of an M-type Companion to the Herbig Ae Star V1787 Ori
Creators: name: Arun, R.
name: Mathew, Blesson
name: Rengaswamy, Sridharan
name: Manoj, P.
name: Narang, Mayank
name: Kartha, Sreeja S.
name: Maheswar, G.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The intermediate mass Herbig Ae star V1787 Ori is a member of the L1641 star-forming region in the Orion A molecular cloud. We report the detection of an M-type companion to V1787 Ori at a projected separation of 6.66" (corresponding to 2577 au), from the analysis of VLT/NACO adaptive optics $K_s$-band image. Using astrometric data from Gaia DR2, we show that V1787 Ori A and B share similar distance ($d$ $\sim$ 387 pc) and proper motion, indicating that they are physically associated. We estimate the spectral type of V1787 Ori B to be M5 $\pm$ 2 from color--spectral type calibration tables and template matching using SpeX spectral library. By fitting PARSEC models in the Pan-STARRS color-magnitude diagram, we find that V1787 Ori B has an age of 8.1$^{+1.7}_{-1.5}$ Myr and a mass of 0.39$^{+0.02}_{-0.05}$ $M_\odot$. We show that V1787 Ori is a pre-main sequence wide binary system with a mass ratio of 0.23. Such a low mass ratio system is rarely identified in Herbig Ae/Be binary systems. We conclude this work with a discussion on possible mechanisms for the formation of V1787 Ori wide binary system.
description: 10 pages,3 tables, 5 figures, accepted for publication in MNRAS
The "DODO" survey I: limits on ultra-cool substellar and planetary-mass companions to van Maanen's star (vMa 2)
Creators: name: Burleigh, M. R.
name: Clarke, F. J.
name: Hogan, E.
name: Brinkworth, C. S.
name: Bergeron, P.
name: Dufour, P.
name: Dobbie, P. D.
name: Levan, A. J.
name: Hodgkin, S. T.
name: Hoard, D. W.
name: Wachter, S.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report limits in the planetary-mass regime for companions around the nearest single white dwarf to the Sun, van Maanen's star (vMa 2), from deep J-band imaging with Gemini North and Spitzer IRAC mid-IR photometry. We find no resolved common proper motion companions to vMa 2 at separations from 3" - 45", at a limiting magnitude of J~23. Assuming a total age for the system of 4.1 +/-1 Gyr, and utilising the latest evolutionary models for substellar objects, this limit is equivalent to companion masses >7 +/-1 Mjup (T~300K). Taking into account the likely orbital evolution of very low mass companions in the post-main sequence phase, these J-band observations effectively survey orbits around the white dwarf progenitor from 3 - 50AU. There is no flux excess detected in any of the complimentary Spitzer IRAC mid-IR filters. We fit a DZ white dwarf model atmosphere to the optical BVRI, 2MASS JHK and IRAC photometry. The best solution gives T=6030 +/- 240K, log g=8.10 +/-0.04 and, hence, M= 0.633 +/-0.022Msun. We then place a 3sigma upper limit of 10 +/-2 Mjup on the mass of any unresolved companion in the 4.5 micron band.
description: Accepted for publication in MNRAS Letters
Squaring the Triangle: Insulating Ground State of $Na_{0.5}CoO_{2}$
Creators: name: Choy, Ting-Pong
name: Galanakis, Dimitrios
name: Phillips, Philip
Publisher: name: arXiv
Year: 2005
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We demonstrate that at a filling of $n=1.5$, an hexatic insulating state obtains in the extended Hubbard model on a triangular lattice. Composed of two tetragonal sublattices with fillings of $n=1$ and $n=2$, the insulating state is charge ordered and possesses an antiferromagnetic superlattice with dimension $a\times\sqrt{3}$. Two distinct energy scales arise in our model, a charge gap for the insulator and the effective exchange interaction in the antiferromagnet. Our model is capable of explaining both qualitatively and quantitatively the Hall coefficient including the sign change, the temperature dependence of the resistivity and the persistence of antiferromagnetism above the insulating state.
description: 4.1 pages, 2 figures: The published version contains an explicit calculation of the dc resistivity as well as the Hall coefficient, both of which are compared with experiment
NO SILÊNCIO DAS IMAGENS: Arte e ilustração na obra de Nelson Cruz
Creators: name: Spinelli, Mirella
Publisher: name: Zenodo
Year: 2020
Subjects: Arte
Art
Imagem
Image

description: A pesquisa visa analisar as ilustrações de Nelson Cruz para o livro Os Trabalhos da
 Mão, texto de Alfredo Bosi, buscando o entendimento sobre a poética do ilustrador.
 Para tal, investiga o processo criativo de Nelson Cruz e suas conexões com as artes
 visuais para a elaboração de suas ilustrações. Primeiramente, estudar-se-á o uso das
 citações, em partes ou na totalidade, ao trabalho de pintores consagrados pela História
 da Arte ocidental. Em seguida, analisar-se-ão as possibilidades experimentais em torno
 das imagens e sua integração à escritura. Examinar-se-á o processo de recepção das
 imagens, investigando as interseções entre a arte e a ilustração. Para tanto, a pesquisa
 parte das reflexões conceituais que permeiam os estudos sobre a ideia da citação, de
 Antoine Compagnon. A partir dessa perspectiva, será examinada a multiplicação e a
 democratização do acesso às imagens da arte pela noção da reprodutibilidade técnica
 apresentada por Walter Benjamin. Em seguida, pretende-se observar as possibilidades
 de compreensão da imagem pelo espectador, tendo como aporte teórico a ideia de
 movimento da imagem pelo sentido de aproximação e de distância apontados por
 Georges Didi-Huberman. Por fim, serão assinaladas as conexões entre imagem, cultura
 e memória, para o qual utlilizaremos os aportes do Atlas Mnemosine de Aby Warburg
 como referencial para estudar a transformação do sentido das imagens da História da
 Arte ao longo do tempo. The present research aims to analyze Nelson Cruz's illustrations for the book Os
 Trabalhos da Mão (text by Alfredo Bosi) seeking an understanding of the illustrator's
 poetics, the recurrent use of quotes, in part or in whole, to the work of painters
 consecrated by History of Western Art and its possibilities for the experience and
 expansion of meanings for the reading of images by the reader of the illustrated book.
 To this end, the analysis begins with the reflection on the technical reproducibility,
 multiplication and popularization of access to printed images, according to Walter
 Benjamin. Then, the possibilities of understanding the image by the viewer and
 specifically by the reader of the illustrated book are analyzed, based on the concepts of
 Georges Didi-Huberman. The citations to the works of other artists run through the
 thoughts of Antoine Compagnon and the connections between image, culture and
 memory, having as reference the development of Atlas Mnemosyne by Aby Warburg.
Integrable triples in semisimple Lie algebras
Creators: name: De Sole, Alberto
name: Jibladze, Mamuka
name: Kac, Victor G.
name: Valeri, Daniele
Publisher: name: arXiv
Year: 2020
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Mathematical Physics (math-ph)
subject: Rings and Algebras (math.RA)
subject: Representation Theory (math.RT)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We classify all integrable triples in simple Lie algebras, up to equivalence. The importance of this problem stems from the fact that for each such equivalence class one can construct the corresponding integrable hierarchy of bi-Hamiltonian PDE. The simplest integrable triple $(f,0,e)$ in $\mathfrak{sl}_2$ corresponds to the KdV hierarchy, and the triple $(f,0,e_θ)$, where $f$ is the sum of negative simple root vectors and $e_θ$ is the highest root vector of a simple Lie algebra, corresponds to the Drinfeld-Sokolov hierarchy.
Droplet Evaporation on Porous Nanochannels for High Heat Flux Dissipation
Creators: name: Poudel, Sajag
name: Zou, An
name: Maroo, Shalabh C.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Droplet wicking and evaporation in porous nanochannels is experimentally studied on a heated surface at temperatures ranging from 35oC to 90oC. The fabricated geometry consists of cross-connected nanochannels of height 728 nm with micropores of diameter 2 um present at every channel intersection; the pores allow water from a droplet placed on the top surface to wick into the channels. Droplet volume is also varied and a total of 16 experimental cases are conducted. Wicking characteristics such as wicked distance, capillary pressure, viscous resistance and propagation coefficient are obtained at the high surface temperatures. Evaporation flux from the nanochannels/micropores is estimated from the droplet experiments, but is also independently confirmed via a new set of experiments where water is continuously fed to the sample through a microtube such that it matches the evaporation rate. Heat flux as high as ~294 W/cm2 is achieved from channels and pores. The experimental findings are applied to evaluate the use of porous nanochannels geometry in spray cooling application, and is found to be capable of dissipating high heat fluxes upto ~77 W/cm2 at temperatures below nucleation, thus highlighting the thermal management potential of the fabricated geometry.
description: 11 pages, 7 figures, under review in a Journal. Supplemental Information can be provided upon request
Hurwitz spaces of Galois coverings of P^1 with Galois groups Weyl groups
Creators: name: Kanev, Vassil
Publisher: name: arXiv
Year: 2005
Subjects: subject: Algebraic Geometry (math.AG)
subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: 14H10, 14H30, 20F36, 20F55

description: We prove the irreducibility of the Hurwitz spaces which parametrize Galois coverings of P^1 whose Galois group is an arbitrary Weyl group and the local monodromies are reflections. This generalizes a classical theorem due to Clebsch and Hurwitz.
description: Latex, 15 pages
Extending the frequency reach of pulsar timing array based gravitational wave search without high cadence observations
Creators: name: Wang, Yan
name: Mohanty, Soumya D.
name: Cao, Zhoujian
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Gravitational wave (GW) searches using pulsar timing arrays (PTAs) are assumed to be limited by the typical average observational cadence of $1/(2~{\rm weeks})$ for a single pulsar to GW frequencies $\lesssim 4\times 10^{-7}$ Hz. We show that this assumption is incorrect and that a PTA can detect signals with much higher frequencies, which are preserved in the data due to aliasing, by exploiting asynchronous observations from multiple pulsars. This allows an observation strategy that is scalable to future large-scale PTAs containing $O(10^3)$ pulsars, enabled by the Five-hundred meter Aperture Spherical Telescope and the Square Kilometer Array, without requiring a higher per-pulsar observation cadence. We show that higher frequency GW observations, reaching up to $4\times 10^{-4}$ Hz with an SKA-era PTA, have significant astrophysical implications, such as (i) a three orders of magnitude better constraint than current high-cadence observations on GW strain in the $[10,400]$ $μ{\rm Hz}$ band, and (ii) sensitive tests of the no-hair theorem in the mass range of supermassive black hole binaries using their inspiral, merger, and ringdown signals.
description: 8 pages, 3 figures, 1 table. Revised version, to be published in ApJL
Misunderstanding Japan : language, education, and cultural identity
Creators: name: Bailey, Arthur Allan
Publisher: name: University of British Columbia
Year: 2009

description: The purpose of this work is to explore the roles of education and language in the creation of Japanese cultural identity. Education means first "schooling," but it also expands to include all cultural learning. In the attempt to unravel the inter-relationships of abstract concepts such as education, culture, identity, language and Japan, our understandings are necessarily influenced by our own education. Attempts by the educated elite of one culture to understand other cultures constitutes an intellectual conflict of interest that questions academic conventions, such as objectivity. In this work, I interweave expository and narrative chapters in an attempt to create a new "methodology" or "approach" to the study of culture, which I call cultural hermeneutics. The autobiographical chapters present an ongoing self-reflection upon my developing understanding of Japan. I have studied and taught in Japan for many years, and my increasing familiarity with things Japanese has gradually moved me beyond the boundaries of previous identities, and into spaces that once separated me from Japanese culture, involving me in the formation of new hybrid cultural identities. After an introductory chapter, the dissertation is split into three parts. The first part deals with the challenges of cultural hermeneutics as a methodology. The second part examines how the languages of Japan and foreign language education in Japan influence the formation of Japanese cultural identities. The third part explores how ideological debates, such as those about education, nationalism and internationalization, play a role in forming cultural identities. I conclude that identities are constantly contested by voices from both within and without the "imagined communities" of cultures. This contest is in progress even before we come to study "Culture." Because change is inherent to living cultures, and because lived experience is so abundant and complex, the knowledge we inherit about cultures is always incomplete, and full of prejudice and misunderstandings. We can never arrive at final understandings of cultures, not even our own. Nevertheless, it is important to continue conversations about cultures because they can lead us to form deepened understandings, and because these conversations ultimately contribute to greater self-understanding.
Surveying the side-chain network approach to protein structure and dynamics: The SARS-CoV-2 spike protein as an illustrative case
Creators: name: Halder, Anushka
name: Anto, Arinnia
name: Subramanyan, Varsha
name: Bhattacharyya, Moitrayee
name: Vishveshwara, Smitha
name: Vishveshwara, Saraswathi
Publisher: name: arXiv
Year: 2020
Subjects: subject: Biomolecules (q-bio.BM)
subject: Other Condensed Matter (cond-mat.other)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: Network theory-based approaches provide valuable insights into the variations in global structural connectivity between differing dynamical states of proteins. Our objective is to review network-based analyses to elucidate such variations, especially in the context of subtle conformational changes. We present technical details of the construction and analyses of protein structure networks, encompassing both the non-covalent connectivity and dynamics. We examine the selection of optimal criteria for connectivity based on the physical concept of percolation. We highlight the advantages of using side-chain based network metrics in contrast to backbone measurements. As an illustrative example, we apply the described network approach to investigate the global conformational change between the closed and partially open states of the SARS-CoV-2 spike protein. This conformational change in the spike protein is crucial for coronavirus entry and fusion into human cells. Our analysis reveals global structural reorientations between the two states of the spike protein despite small changes between the two states at the backbone level. We also observe some differences at strategic locations in the structures, correlating with their functions, asserting the advantages of the side-chain network analysis. Finally we present a view of allostery as a subtle synergistic-global change between the ligand and the receptor, the incorporation of which would enhance the drug design strategies.
description: 35 pages, 6 figures
Evidence for collisional depolarization of the \ion{Ba}{ii} $λ4554$ line in the low chromosphere
Creators: name: Derouich, M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Context. Rigorous modeling of the \ion{Ba}{ii} $λ4554$ formation is potentially interesting since this strongly polarized line forms in the solar chromosphere where the magnetic field is rather poorly known. Aims. To investigate the role of isotropic collisions with neutral hydrogen in the formation of the polarized \ion{Ba}{ii} $λ4554$ line and, thus, in the determination of the magnetic field. Methods. Multipole relaxation and transfer rates of the $d$ and p-states of \ion{Ba}{ii} by isotropic collisions with neutral hydrogen are calculated. We consider a plane parallel layer of \ion{Ba}{ii} situated at the low chromosphere and anisotropically illuminated from below which produces linear polarization in the $λ4554$ line by scattering processes. To compute that polarization, we solve the statistical equilibrium equations for \ion{Ba}{ii} levels including collisions, radiation and magnetic field effects. Results. Variation laws of the relaxation and transfer rates with hydrogen number density $n_{\textrm {\scriptsize H}}$ and temperature are deduced. The polarization of the $λ4554$ line is clearly affected due to isotropic collisions with neutral hydrogen although the collisional depolarization of its upper level $^2P_{3/2}$ is negligible. This is because the alignment of the metastable levels $^2D_{3/2}$ and $^2D_{5/2}$ of the \ion{Ba}{ii} are vulnerable to collisions. At the height of formation of the $λ4554$ line where $n_{\textrm {\scriptsize H}} \sim 2 \times 10^{14}$ cm$^{-3}$, we find that the neglecting of the collisions induces inaccuracy of $\sim$ 25% on the calculation of the polarization and $\sim$ 35 % inaccuracy on microturbulent magnetic field determination.
description: 12 pages, 4 figures, accepted for publication in A&A
Barrier crossing of semiflexible polymers
Creators: name: Kraikivski, P.
name: Lipowsky, R.
name: Kierfeld, J.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We consider the motion of semiflexible polymers in double-well potentials. We calculate shape, energy, and effective diffusion constant of kink excitations, and in particular their dependence on the bending rigidity of the semiflexible polymer. For symmetric potentials, the kink motion is purely diffusive whereas kink motion becomes directed in the presence of a driving force on the polymer. We determine the average velocity of the semiflexible polymer based on the kink dynamics. The Kramers escape over the potential barriers proceeds by nucleation and diffusive motion of kink-antikink pairs, the relaxation to the straight configuration by annihilation of kink-antikink pairs. Our results apply to the activated motion of biopolymers such as DNA and actin filaments or synthetic polyelectrolytes on structured substrates.
description: 7 pages, 3 figures
Stochastic gravitoelectromagnetic inflation
Creators: name: Aguilar, J. E. Madriz
name: Bellini, Mauricio
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Gravitoelectromagnetic inflation was recently introduced to describe, in an unified manner, electromagnetic, gravitatory and inflaton fields in the early (accelerated) inflationary universe from a 5D vacuum state. In this paper, we study a stochastic treatment for the gravitoelectromagnetic components $A_B=(A_μ,ϕ)$, on cosmological scales. We focus our study on the seed magnetic fields on super Hubble scales, which could play an important role in large scale structure formation of the universe.
description: final version published in Phys. Lett. B
A curadoria de experiência no programa de residência artística do Bolsa Pampulha de 2003 a 2016 Belo Horizonte 2020
Creators: name: Bakir, Rosimary de Freitas
Publisher: name: Zenodo
Year: 2020
Subjects: Curadoria
Residência artística
Artistic residence
curatorship

description: A dissertação investiga questões relativas à atuação da curadoria na residência artística, tendo como objeto de estudo as seis primeiras edições do Programa de Residência Artística Bolsa Pampulha do Museu de Arte da Pampulha em Belo Horizonte. O estudo trata das inquietações da inteligência curatorial nos processos artísticos coletivos que têm a experiência como elemento fundador. Apresenta Harald Szeemann e Walter Zanini como precursores de uma curadoria que poderia ser intitulada como curadoria de experiência, trazendo à tona as inúmeras mudanças que ocorreram nos processos de criação artística a partir da década de sessenta, quando a obra de arte não é mais materializada apenas em objeto, mas está composta de subjetividades e inter-relacionamentos, e destacando teóricos que trataram da experiência e da expropriação da experiência, conceitos esses sintonizados com a modalidade da residência artística. Discorre da indissociabilidade e do hibridismo no trabalho curatorial do Programa do MAP, tensionando o campo expositivo como um campo de experiências. Por meio de um estudo teórico minucioso das seis edições do Programa de Arte Residência Bolsa Pampulha, e de entrevistas com curadores que já atuaram no programa, estabelece o conceito de curadoria de experiência. The dissertation investigates issues related to the role of curatorship in artistic residency, having as its object of study the first six editions of the Bolsa Pampulha Artistic Residency Program at the Pampulha Museum of Art in Belo Horizonte. The study deals with the concerns of curatorial intelligence in collective artistic processes that have experience as a founding element. It presents Harald Szeemann and Walter Zanini as precursors of a curatorship that could be titled as curatorship of experience, bringing to light the countless changes that occurred in artistic creation processes from the 1960s onwards, when the work of art is no longer materialized only in object, but it is composed of subjectivities and inter-relationships, and highlighting theorists who dealt with experience and the expropriation of experience, concepts that are in tune with the modality of artistic residency. It discusses the inseparability and hybridity in the curatorial work of the MAP Program, stressing the exhibition field as a field of experiences. Through a detailed theoretical study of the six editions of the Bolsa Pampulha Art Residency Program, and interviews with curators who have already worked in the program, it establishes the concept of experience curation.
title: Inelastic finite deformation beam modeling, simulation, and validation of additively manufactured lattice structures
Creators: name: Weeger, Oliver
name: Valizadeh, Iman
name: Mistry, Yash
name: Bhate, Dhruv
Publisher: name: Elsevier
Year: 2024

description: Lattice-type periodic metamaterials with beam-like struts have been extensively investigated in recent years thanks to the progress in additive manufacturing technologies. However, when lattice structures are subject to large deformations, computational simulation for design and optimization remains a major challenge due to complex nonlinear and inelastic effects, such as instabilities, contacts, rate-dependence, plasticity, or damage. In this contribution, we demonstrate for the first time the efficient and accurate computational simulation of beam lattices using a finite deformation 3D beam formulation with inelastic material behavior, instability analysis, and contacts. In particular, the constitutive model captures elasto-visco-plasticity with damage/softening from the Mullins effect. Thus, the formulation can be applied to the modeling of both stiffer metallic and more flexible polymeric materials. The approach is demonstrated and experimentally validated in application to additively manufactured lattice structures made from Polyamide 12 by laser sintering and from a highly viscous polymer by vat hotopolymerization. For compression tests executed until densification or with unloading and at different rates, the beam simulations are in very good agreement with experiments. These results strongly indicate that the consideration of all nonlinear and inelastic effects is crucial to accurately model the finite deformation behavior of lattice structures. It can be concluded that this can be effectively attained using inelastic beam models, which opens the perspective for simulation-based design and optimization of lattices for practical applications.
GREI Data citation best practices for repositories
Creators: name: Puebla, Iratxe
name: Neumann, Stan
name: Stathis, Kelly
name: Gauthier, Julian
name: Hamelers, Audrey
name: Nielsen, Lars Holm
name: Belletti, Luca
name: Elliott, Fitz
name: Hahnel, Mark
Publisher: name: Zenodo
Year: 2024
Subjects: Generalist Repository Ecosystem Initiative (GREI)
Generalist Repositories
Open Data
Data Citations

description: The Generalist Repository Ecosystem Initiative (GREI) has as one of its objectives the implementation of open metrics. A consistent approach to data citations is an important step to drive meaningful metrics that provide visibility on data usage, signal the added value of data repositories and enable reporting on the reach of NIH-funded research data. 

All of the GREI repositories (Dataverse, Dryad, Figshare, Open Science Framework, Mendeley Data, Vivli, and Zenodo) already collect data citations or have it on their roadmap to add this feature. Building on their practices and experience in this area and in collaboration with Make Data Count, this group of generalist repositories has developed a set of recommendations for handling data citations at repositories.
Capacity of trace decreasing quantum operations and superadditivity of coherent information for a generalized erasure channel
Creators: name: Filippov, Sergey N.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Losses in quantum communication lines severely affect the rates of reliable information transmission and are usually considered to be state-independent. However, the loss probability does depend on the system state in general, with the polarization dependent losses being a prominent example. Here we analyze biased trace decreasing quantum operations that assign different loss probabilities to states and introduce the concept of a generalized erasure channel. We find lower and upper bounds for the classical and quantum capacities of the generalized erasure channel as well as characterize its degradability and antidegradability. We reveal superadditivity of coherent information in the case of the polarization dependent losses, with the difference between the two-letter quantum capacity and the single-letter quantum capacity exceeding $7.197 \cdot 10^{-3}$ bit per qubit sent, the greatest value among qubit-input channels reported so far.
description: 16 pages, 5 figures
Magic in the spectra of the XXZ quantum chain with boundaries at Delta=0 and Delta=-1/2
Creators: name: de Gier, Jan
name: Nichols, Alexander
name: Pyatov, Pavel
name: Rittenberg, Vladimir
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We show that from the spectra of the U_q (sl(2)) symmetric XXZ spin-1/2 finite quantum chain at Delta=-1/2 (q=e^{pi i/3}) one can obtain the spectra of certain XXZ quantum chains with diagonal and non-diagonal boundary conditions. Similar observations are made for Delta=0 (q=e^{pi i/2}). In the finite-size scaling limit the relations among the various spectra are the result of identities satisfied by known character functions. For the finite chains the origin of the remarkable spectral identities can be found in the representation theory of one and two boundaries Temperley-Lieb algebras at exceptional points. Inspired by these observations we have discovered other spectral identities between chains with different boundary conditions.
description: 29 pages
Goltz, Hermann (Hrsg.), Akten des Internationalen Doktor Johannes-Lepsius-Symposiums an der Martin-Luther-Universität
Creators: name: Heyer, Friedrich
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 37 Nr. 3 (1988): Ökumenische Rundschau, Band 37, Heft 3
Efficient Subspace Search in Data Streams
Creators: name: Fouché, Edouard
name: Kalinke, Florian
name: Böhm, Klemens
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Data Structures and Algorithms (cs.DS)
subject: FOS: Computer and information sciences

description: In the real world, data streams are ubiquitous -- think of network traffic or sensor data. Mining patterns, e.g., outliers or clusters, from such data must take place in real time. This is challenging because (1) streams often have high dimensionality, and (2) the data characteristics may change over time. Existing approaches tend to focus on only one aspect, either high dimensionality or the specifics of the streaming setting. For static data, a common approach to deal with high dimensionality -- known as subspace search -- extracts low-dimensional, `interesting' projections (subspaces), in which patterns are easier to find. In this paper, we address both Challenge (1) and (2) by generalising subspace search to data streams. Our approach, Streaming Greedy Maximum Random Deviation (SGMRD), monitors interesting subspaces in high-dimensional data streams. It leverages novel multivariate dependency estimators and monitoring techniques based on bandit theory. We show that the benefits of SGMRD are twofold: (i) It monitors subspaces efficiently, and (ii) this improves the results of downstream data mining tasks, such as outlier detection. Our experiments, performed against synthetic and real-world data, demonstrate that SGMRD outperforms its competitors by a large margin.
description: Accepted Manuscript to Information Systems, Volume 97, Elsevier. Final authenticated version: https://doi.org/10.1016/j.is.2020.101705
Yang-Baxter deformations of the Principal Chiral Model plus Wess-Zumino term
Creators: name: Hoare, B.
name: Lacroix, S.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A large class of integrable deformations of the Principal Chiral Model, known as the Yang-Baxter deformations, are governed by skew-symmetric R-matrices solving the (modified) classical Yang-Baxter equation. We carry out a systematic investigation of these deformations in the presence of the Wess-Zumino term for simple Lie groups, working in a framework that treats both inhomogeneous and homogeneous deformations on the same footing. After analysing the cohomological conditions under which such a deformation is admissible, we consider an action for the general Yang-Baxter deformation of the Principal Chiral Model plus Wess-Zumino term and prove its classical integrability. We also show how the model is found from a number of alternative formulations: affine Gaudin models, E-models, 4-dimensional Chern-Simons theory and, for homogeneous deformations, non-abelian T-duality.
description: 45 pages; v2: 46 pages, comments added, matches published version
Reconstruction and interpretation of photon Doppler velocimetry spectrum for ejecta particles from shock-loaded sample in vacuum
Creators: name: Shi, Xiao-Feng
name: Ma, Dong-Jun
name: Dang, Song-lin
name: Ma, Zong-Qiang
name: Sun, Hai-Quan
name: He, An-Min
name: Wang, Pei
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: The photon Doppler velocimetry (PDV) spectrum is investigated in an attempt to reveal the particle parameters of ejecta from shock-loaded samples in a vacuum. A GPU-accelerated Monte-Carlo algorithm, which considers the multiple-scattering effects of light, is applied to reconstruct the light field of the ejecta and simulate the corresponding PDV spectrum. The influence of the velocity profile, total area mass, and particle size of the ejecta on the simulated spectra is discussed qualitatively. To facilitate a quantitative discussion, a novel theoretical optical model is proposed in which the single-scattering assumption is applied. With this model, the relationships between the particle parameters of ejecta and the peak information of the PDV spectrum are derived, enabling direct extraction of the particle parameters from the PDV spectrum. The values of the ejecta parameters estimated from the experimental spectrum are in good agreement with those measured by a piezoelectric probe.
description: 12 pages, 18figures
Indépendance légale de la Banque Centrale et globalisation financière dans les pays en développement : une approche par la méthode (Driscoll &Kraay, 1998)
Creators: name: Adama BA
Publisher: name: Zenodo
Year: 2024

description: L’étude utilise un panel de 42 pays en développement (PED) sur la période 2002 à 2017 pour analyser la relation entre l’indépendance légale de la Banque Centrale (IBC) et la globalisation financière. A l’aide du modèle de régression (Driscoll-Kraay, 1998), on montre un effet positif et significatif de la globalisation financière sur l’indépendance légale de la Banque Centrale. Le développement financier, l’ouverture commerciale sont aussi significativement et positivement corrélées à la l’indépendance légale de la banque centrale, alors que l’inflation est négativement et significativement corrélée. En effet, les résultats restent stables dans l’estimation d’un GMM système. Donc, plus les économies sont financièrement intégrées dans la finance globale, plus les banques centrales sont incitées être indépendante. L’indépendance de la Banque Centrale est un signal d’engagement crédible en faveur des acteurs de la globalisation financièrement.
Quiescent Cores and the Efficiency of Turbulence-Accelerated, Magnetically Regulated Star Formation
Creators: name: Nakamura, Fumitaka
name: Li, Zhi-Yun
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The efficiency of star formation, defined as the ratio of the stellar to total (gas and stellar) mass, is observed to vary from a few percent in regions of dispersed star formation to about a third in cluster-forming cores. This difference may reflect the relative importance of magnetic fields and turbulence in controlling star formation. We investigate the interplay between supersonic turbulence and magnetic fields using numerical simulations, in a sheet-like geometry. We demonstrate that star formation with an efficiency of a few percent can occur over several gravitational collapse times in moderately magnetically subcritical clouds that are supersonically turbulent. The turbulence accelerates star formation by reducing the time for dense core formation. The dense cores produced are predominantly quiescent, with subsonic internal motions. These cores tend to be moderately supercritical. They have lifetimes long compared with their local gravitational collapse time. Some of the cores collapse to form stars, while others disperse away without star formation. In turbulent clouds that are marginally magnetically supercritical, the star formation efficiency is higher, but can still be consistent with the values inferred for nearby embedded clusters. If not regulated by magnetic fields at all, star formation in a multi-Jeans mass cloud endowed with a strong initial turbulence proceeds rapidly, with the majority of cloud mass converted into stars in a gravitational collapse time. The efficiency is formally higher than the values inferred for nearby cluster-forming cores, indicating that magnetic fields are dynamically important even for cluster formation.
description: submitted to ApJ
$\mathbb{Z}_N$ Symmetries, Anomalies, and the Modular Bootstrap
Creators: name: Lin, Ying-Hsuan
name: Shao, Shu-Heng
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We explore constraints on (1+1)$d$ unitary conformal field theory with an internal $\mathbb{Z}_N$ global symmetry, by bounding the lightest symmetry-preserving scalar primary operator using the modular bootstrap. Among the other constraints we have found, we prove the existence of a $\mathbb{Z}_N$-symmetric relevant/marginal operator if $N-1 \le c\le 9-N$ for $N\leq4$, with the endpoints saturated by various WZW models that can be embedded into $(\mathfrak{e}_8)_1$. Its existence implies that robust gapless fixed points are not possible in this range of $c$ if only a $\mathbb{Z}_N$ symmetry is imposed microscopically. We also obtain stronger, more refined bounds that depend on the 't Hooft anomaly of the $\mathbb{Z}_N$ symmetry.
description: 26+13 pages, 10 figures, 2 tables; v2: minor revision
A study of extreme water waves using a hierarchy of models based on potential flow theory
Creators: name: Choi, Junho
Publisher: name: Zenodo
Year: 2024

description: # User instructions

Program that solves the Potential Flow Equations (PFE) on a 3D periodic domain using the modified mid-point scheme.

The simulation tracks the evolution of three line solitons as they interact, to produce an eight times higher splash than the initial height of each soliton.

## FILES

The code consists of five files:- `pot_sp3.py` is the main file that solves PFE;- `PFE_sp3energy.py`, `PFE_sp3_max.py`, `PFE_sp3_A.py`, and `PFE_sp3_maxA.py` are used for plotting the evolution of energy and maximum, amplitude of solitons in a far field (denoted by A), and maximum divided by A, respectively.

After the computation of `pot_sp3.py` is finished, four sets of data are produced:- solutions eta and Phi in "*data/height.pvd*", "*data/psi.pvd*", "*data/varphi.pvd*";- evolution of energy and maximum against time is saved in "*data/potflow3dperenergy.txt";

The computational data can be visualised as follows:- Solutions eta and Phi are pvd files that can be read with Paraview.- Time evolution of energy can be plotted by running file `PFE_sp3_energy.py`.- Time evolution of maximum of eta can be plotted by running file `PFE_sp3_max.py`.- Time evolution of A can be plotted by running file `PFE_sp3_A.py`.- Time evolution of maximum/A can be plotted by running file `PFE_sp3_maxA.py`.

Running time table when varying spatial resolution $\Delta x\approx\Delta y=200$. $T$ is the total simulation time defined as $T=t_{end}-t_{0}$ with $t_0=0{\rm s}$. $\Delta t=0.7139{\rm s}$ or $\Delta t BLE=0.005$.  In order to change order of basis, modify nCG (currently setting nCG=2). For $N_y$, modify multiple (currently setting mutiple=3), for $\Delta t BLE$ modify dtBLE(currently setting dtBLE=1/200).  All simuations were run on 40 cores of Leeds' arc4-HPC.