cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Planet formation in stellar binaries: Global simulations of planetesimal growth
Creators: name: Silsbee, Kedron
name: Rafikov, Roman R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Planet formation around one component of a tight, eccentric binary system such as $γ$ Cephei (with semimajor axis around 20 AU) is theoretically challenging because of destructive high-velocity collisions between planetesimals. Despite this fragmentation barrier, planets are known to exist in such orbital configurations. Here we present a novel numerical framework for carrying out multi-annulus coagulation-fragmentation calculations of planetesimal growth, which fully accounts for the specifics of planetesimal dynamics in binaries, details of planetesimal collision outcomes, and the radial transport of solids in the disk due to the gas drag-driven inspiral. Our dynamical inputs properly incorporate the gravitational effects of both the eccentric stellar companion and the massive non-axisymmetric protoplanetary disk in which planetesimals reside, as well as gas drag. We identify a set of disk parameters that lead to successful planetesimal growth in systems such as $γ$ Cephei or $α$ Centauri starting from $1-10$ km size objects. We identify the apsidal alignment of a protoplanetary disk with the binary orbit as one of the critical conditions for successful planetesimal growth: It naturally leads to the emergence of a dynamically quiet location in the disk (as long as the disk eccentricity is of order several percent), where favorable conditions for planetesimal growth exist. Accounting for the gravitational effect of a protoplanetary disk plays a key role in arriving at this conclusion, in agreement with our previous results. These findings lend support to the streaming instability as the mechanism of planetesimal formation. They provide important insights for theories of planet formation around both binary and single stars, as well as for the hydrodynamic simulations of protoplanetary disks in binaries (for which we identify a set of key diagnostics to verify).
description: Accepted to A&A
Chirality induced anomalous-Hall effect in helical spin crystals
Creators: name: Binz, B.
name: Vishwanath, A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Under pressure, the itinerant helimagnet MnSi displays unusual magnetic properties. We have previously discussed a BCC helical spin crystal as a promising starting point for describing the high pressure phenomenology. This state has topologically nontrivial configurations of the magnetization field. Here we note the consequences for magneto-transport that arise generally from such spin textures. In particular a skyrmion density induced `topological' Hall effect, with unusual field dependence, is described.
description: 4 pages, 3 figures, to appear in the proceedings of SCES 07 (the international conference on strongly correlated electron systems 2007 in Houston, USA)
A Charged Doubly Spinning Black Ring
Creators: name: Hoskisson, James
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: This paper calculates the general form of a 5d metric when fundamental string and momentum charges are added. This is accomplished using the standard method of boosting and T-dualising a solution to Einstein's equations, where the solution has three Killing vectors and is expressed in a generic form. The thermodynamical properties of the charged solution are derived and the physical implications of the solution are then examined with the two-charge dual spinning black ring being used as an example.
description: 22 pages, 4 figures
Relationship between physicochemical properties of proteins and their foaming characteristics
Creators: name: Townsend, Althea-Ann E.
Publisher: name: University of British Columbia
Year: 2010

description: The relationship between the foaming characteristics of proteins and some of their physicochemical properties in bulk solution were examined. The physico-chemical properties which were investigated in relation to foaming were hydrophobicity, charge density, secondary structure, molecular flexibility, dispersibility, viscosity and surface tension, Eleven, model proteins, (ribonuclease, ovomucoid, trypsin, lysozyme, pepsin, ovalbumin, conalbu-min, bovine serum albumin., K-casein, β-lactoglobulin, β-casein) and eight food proteins.(soy, pea, sunflower and canola isolates, pro-pulse, Promine-D, whole casein, acid solubilized gluten) were used. It was found that the average hydrophobicity of proteins could be measured using cis-parinaric acid as a probe of the hydrophobic regions, after the samples had been uncoiled by heating for 1.0. min at 100°C in the presence of 1.5% sodium dodecyl sulphate. Hydrophobicity measured in this way showed a significant linear correlation (r = 0.820, P <0.01 ) with the calculated average hydrophobicity values of Bigelow. Two regression equations.were generated, which accounted for approximately 77% of the variability in the foaming capacities of the proteins; one included hydrophobicity and dispersibility and the other involved hydrophobicity and viscosity as the independent variables. High hydrophobicity and viscosity, and moderate dispersibility were associated with optimum foaming capacity. Although charge density influenced the foaming capacity of proteins its role in determining this property seemed to be a minor one. Highest foaming capacity was exhibited by the most flexible proteins. There was a significant negative relationship (r =-0.726, P<0.01) between foam stability and the reciprocal charge density. This indicated that electrostatic repulsion between protein molecules had an important destabilizing effect on foams. It was demonstrated that hydrophobicity plays an important role in determining the foaming behaviour of protein solutions. Unlike, emulsification, which is dependent on surface hydrophobicity, the hydrophobicity of the uncoiled protein molecule is important for foaming.
2M17091769+3127589: a mass-transfer binary with an extreme mass ratio
Creators: name: Miller, Annaliese
name: Kounkel, Marina
name: Sun, Meng
name: Dixon, Don
name: Boggio, Chase
name: Covey, K. R.
name: Stassun, Keivan G.
name: Mathieu, Robert
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present the orbital solution of a peculiar double-lined spectroscopic and eclipsing binary system, 2M17091769+3127589. This solution was obtained by a simultaneous fit of both APOGEE radial velocities and TESS and ASAS-SN light curves to determine masses and radii. This system consists of an $M=0.256^{+0.010}_{-0.006}$ $M_\odot$, $R=3.961^{+0.049}_{-0.032}$ $R_{\odot}$ red giant and a hotter $M=1.518 ^{+0.057}_{-0.031}$ $M_\odot$, $R=2.608^{+0.034}_{-0.321}$ $R_{\odot}$ subgiant. Modelling with the MESA evolutionary codes indicates that the system likely formed 5.26 Gyrs ago, with a $M=1.2$ $M_\odot$ primary that is now the system's red giant and a $M=1.11$ $M_\odot$ secondary that is now a more massive subgiant. Due to Roche-lobe overflow as the primary ascends the red giant branch, the more evolved "primary" (i.e., originally the more massive star of the pair) is now only one-sixth as massive as the "secondary". Such a difference between the initial and the current mass ratio is one of the most extreme detected so far. Evolutionary modelling suggests the system is still engaged in mass transfer, at a rate of $\dot{M} \sim 10^{-9}$ $M_\odot$ yr$^{-1}$, and it provides an example of a less evolved precursor to some of the systems that consist of white dwarfs and blue stragglers.
description: Accepted to AJ; 12 pages, 8 figures
Early dynamics and violent relaxation of multi-mass rotating star clusters
Creators: name: Livernois, A. R.
name: Vesperini, E.
name: Tiongco, M.
name: Varri, A. L.
name: Dalessandro, E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present the results of a study aimed at exploring, by means of N-body simulations, the evolution of rotating multi-mass star clusters during the violent relaxation phase, in the presence of a weak external tidal field. We study the implications of the initial rotation and the presence of a mass spectrum for the violent relaxation dynamics and the final properties of the equilibria emerging at the end of this stage. Our simulations show a clear manifestation of the evolution towards spatial mass segregation and evolution towards energy equipartition during and at the end of the violent relaxation phase. We study the final rotational kinematics and show that massive stars tend to rotate more rapidly than low-mass stars around the axis of cluster rotation. Our analysis also reveals that during the violent relaxation phase, massive stars tend to preferentially segregate into orbits with angular momentum aligned with the cluster's angular momentum, an effect previously found in the context of the long-term evolution of star clusters driven by two-body relaxation.
description: 18 pages, 20 figures, 1 appendix. Accepted for publication in MNRAS
The structure of line-driven winds
Creators: name: Lucy, L. B.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Following procedures pioneered by Castor, Abbott & Klein (1975, [CAK]), spherically-symmetric supersonic winds for O stars are computed for matching to plane-parallel moving reversing layers (RL's) from Paper I (Lucy 2007). In contrast to a CAK wind, each of these solutions is singularity-free, thus allowing its mass-loss rate to be fixed by the regularity condition at the sonic point within the RL. Moreover, information propagation in these winds by radiative-acoustic waves is everywhere outwardly-directed, justifying the implicit assumption in Paper I that transonic flows are unaffected by inwardly-directed wave motions.
description: Accepted by A&A; 7 pages, 1 table, 4 figures
Identifying Business Models of Open Data Intermediaries: A Review
Creators: name: Shaharudin, Ashraf
name: van Loenen, Bastiaan
name: Janssen, Marijn
Publisher: name: Zenodo
Year: 2022
Subjects: open data
intermediaries
infomediaries
business models
revenue
value

description: Presentation of the extended abstract at the TODO International Conference on Open Data in Zagreb, Croatia on 29 November 2022. Open data has various potential benefits, including stimulating innovation, enhancing accountability and transparency, and improving the reproducibility and dissemination of academic research. However, current open data initiatives have various shortcomings, including the mismatch between the supply and demand of open data and the lack of its reuse. To address these weaknesses, the role of open data intermediaries in facilitating the use of and access to open data is considered instrumental. Nevertheless, some literature noted the lack of development of their business models, which may compromise their long-term survival. Before their business models can be further developed, a clear view of the existing business models is needed. Hence, the objective of this extended abstract is to review current business models of open data intermediaries in academic literature.
Signatures of multifractality in a periodically driven interacting Aubry-André model
Creators: name: Sarkar, Madhumita
name: Ghosh, Roopayan
name: Sen, Arnab
name: Sengupta, K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study the many-body localization (MBL) transition of Floquet eigenstates in a driven, interacting fermionic chain with an incommensurate Aubry-André potential and a time-periodic hopping amplitude as a function of the drive frequency $ω_D$ using exact diagonalization (ED). We find that the nature of the Floquet eigenstates change from ergodic to Floquet-MBL with increasing frequency; moreover, for a significant range of intermediate $ω_D$, the Floquet eigenstates exhibit non-trivial fractal dimensions. We find a possible transition from the ergodic to this multifractal phase followed by a gradual crossover to the MBL phase as the drive frequency is increased. We also study the fermion auto-correlation function, entanglement entropy, normalized participation ratio (NPR), fermion transport and the inverse participation ratio (IPR) as a function of $ω_D$. We show that the auto-correlation, fermion transport and NPR displays qualitatively different characteristics (compared to their behavior in the ergodic and MBL regions) for the range of $ω_D$ which supports multifractal eigenstates. In contrast, the entanglement growth in this frequency range tend to have similar features as in the MBL regime; its rate of growth is controlled by $ω_D$. Our analysis thus indicates that the multifractal nature of Floquet-MBL eigenstates can be detected by studying auto-correlation function and fermionic transport of these driven chains. We support our numerical results with a semi-analytic expression of the Floquet Hamiltonian obtained using Floquet perturbation theory (FPT) and discuss possible experiments which can test our predictions.
description: 16 pages , 15 figures
Needs, opportunities and challenges for improving grass pea: summary report
Creators: name: NISD, The
name: Heaton, Matt
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 300105
subject: Genetically modified field crops and pasture
classificationCode: 300210
subject: Sustainable agricultural development
classificationCode: 300406
subject: Crop and pasture improvement (incl. selection and breeding)
classificationCode: 410199
subject: Climate change impacts and adaptation not elsewhere classified

description: Grass pea (Lathyrus sativus) is an underutilised crop with great potential for nutritious, climate-smart and regenerative agriculture. Interest has recently increased in grass pea research, and new resources have become available. This summary collates what researchers see as the needs, challenges and opportunities for breeding improved grass pea. Overall, there is a sense that momentum is gathering behind grass pea research, and building cohesive, strategic direction would accelerate this change. Researchers share concerns of how grass pea is perceived and funded but see opportunities to scale up research. New grass pea research resources play a role in these opportunities and the report shares key traits for breeding targets. The report concludes with suggested next steps to accelerate the delivery of improved grass pea in farmers’ fields.
Stress induced stripe formation in Pd/W(110)
Creators: name: Mentes, T. O.
name: Locatelli, A.
name: Aballe, L.
name: Bauer, E.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: A stress-induced stripe phase of submonolayer Pd on W(110) is observed by low-energy electron microscopy. The temperature dependence of the pattern is explained by the change both in the boundary free energy and elastic relaxation energy due to the increasing boundary width. The stripes are shown to disorder when the correlation length of the condensed phase becomes comparable to its period, while the condensate to lattice-gas transition takes place at a higher temperature, as revealed by low-energy electron diffraction.
description: 4 pages, 3 figures
Global well-posedness to the 2D Cauchy problem of nonhomogeneous heat conducting Navier-Stokes and magnetohydrodynamic equations with vacuum at infinity
Creators: name: Zhong, Xin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We revisit the 2D Cauchy problem of nonhomogeneous heat conducting magnetohydrodynamic (MHD) equations in $\mathbb{R}^2$. For the initial density allowing vacuum at infinity, we derive the global existence and uniqueness of strong solutions provided that the initial density and the initial magnetic decay not too slowly at infinity. In particular, the initial data can be arbitrarily large. This improves our previous work where the initial density has non-vacuum states at infinity. The result could also be viewed as an extension of the study in L{ü}-Xu-Zhong for the inhomogeneous case to the full inhomogeneous situation. The method is based on delicate spatial weighted estimates and the structural characteristic of the system under consideration. As a byproduct, we get the global existence of strong solutions to the 2D Cauchy problem for nonhomogeneous heat conducting Navier-Stokes equations with vacuum at infinity.
description: 23 pages
Ion source and 4-grid analyzer for the proton injector for FAIR
Creators: name: Berezov, R.
name: Adonin, A.
name: Chauvin, N.
name: Fils, J.
name: Ivanova, Violetta
name: Ullmann, C.
Publisher: name: GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt
Year: 2014
Subjects: Physics

description: GSI Scientific Report 2013 - GSI Report 2014-1
Asymptotic optimality of a cross-validatory predictive approach to linear model selection
Creators: name: Chakrabarti, Arijit
name: Samanta, Tapas
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistics Theory (math.ST)
subject: Methodology (stat.ME)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 62J05 (Primary) 62F15 (Secondary)

description: In this article we study the asymptotic predictive optimality of a model selection criterion based on the cross-validatory predictive density, already available in the literature. For a dependent variable and associated explanatory variables, we consider a class of linear models as approximations to the true regression function. One selects a model among these using the criterion under study and predicts a future replicate of the dependent variable by an optimal predictor under the chosen model. We show that for squared error prediction loss, this scheme of prediction performs asymptotically as well as an oracle, where the oracle here refers to a model selection rule which minimizes this loss if the true regression were known.
description: Published in at http://dx.doi.org/10.1214/074921708000000110 the IMS Collections (http://www.imstat.org/publications/imscollections.htm) by the Institute of Mathematical Statistics (http://www.imstat.org)
Cryogenics for SIS100 Accelerator
Creators: name: Streicher, B.
name: Eisel, T.
name: Kauschke, M.
name: Schroeder, Claus
name: Kollmus, H.
Publisher: name: GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt
Year: 2014
Subjects: Physics

description: GSI Scientific Report 2013 - GSI Report 2014-1
title: ‚Places of Remembrance’: Spaces for Historical and Political Literacy. A Lesson Report
Creators: name: Offen, Susanne
Publisher: name: sowi-online e.V., Bielefeld
Year: 2018

description: Purpose: The article shows the use of specific educational media in social studies in vocational schools to foster a differentiated historical and political literacy.

Design/methodology/approach: Accordingly, the article examines a sequence of lessons taught by the author in a vocational classroom, fostering reflexive historical-political awareness of Germany’s post-war coping with the fascist constitution 1933-1945 and specifically of contemporary legal proceedings concerning the persecution and subsequent murder of six million Jewish people during the Holocaust.

Findings: Teaching techniques comprise explorative learning through guided city walks, document analysis and expert visits, in-class-discussions, the  and individual student-teacher-conversations and, particularly, contact with exhibits employed as educational media, originating from an art exhibition in public space covering various unsettling steps of exclusion against Jewish citizens before 1942.

These materials turn out to bridge the gap from ignorance to learning by the acquisition of knowledge, demonstrating the use of artistic visual representations as educational media in the social studies classroom, especially while addressing students with little prior knowledge and understanding.

Research limitations/implications: As a lesson report, the article draws on classroom observations.

Practical implications: The approach presented includes various implications for classroom application.
description: JSSE - Journal of Social Science Education, 4-2017 Constructing the Legitimate Knowledge
Generalized Space-time Noncommutative Inflation
Creators: name: Xue, Wei
name: Chen, Bin
name: Wang, Yi
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the noncommutative inflation with a time-dependent noncommutativity between space and time. From the numerical analysis of power law inflation, there are clues that the CMB spectrum indicates a nonconstant noncommutative inflation. Then we extend our treatment to the inflation models with more general noncommutativity and find that the scalar perturbation power spectrum depends sensitively on the time varying of the spacetime noncommutativity. This stringy effect may be probed in the future cosmological observations.
description: 15 pages, 2 figures
Design of a Mutual Inductance Based Quench Detector for the Corrector Magnets of the SIS100
Creators: name: Ayet, S.
name: Floch, E.
name: Freisleben, W.
name: Koch, K.
name: Szwangruber, P.
Publisher: name: GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt
Year: 2014
Subjects: Physics

description: GSI Scientific Report 2013 - GSI Report 2014-1
Edge states in graphene in magnetic fields -- a speciality of the edge mode embedded in the n=0 Landau band
Creators: name: Arikawa, Mitsuhiro
name: Hatsugai, Yasuhiro
name: Aoki, Hideo
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: While usual edge states in the quantum Hall effect(QHE) reside between adjacent Landau levels, QHE in graphene has a peculiar edge mode at E=0 that reside right within the n=0 Landau level as protected by the chiral symmetry. We have theoretically studied the edge states to show that the E=0 edge mode, despite being embedded in the bulk Landau level, does give rise to a wave function whose charge is accumulated along zigzag edges. This property, totally outside continuum models, implies that the graphene QHE harbors edges distinct from ordinary QHE edges with their topological origin. In the charge accumulation the bulk states re-distribute their charge significantly, which may be called a topological compensation of charge density. The real space behavior obtained here should be observable in an STM imaging.
description: 4 pages, 9 figures
Trace Elemental Behavior in the Solar Nebula: Synchrotron X-ray Fluorescence Analyses of CM and CR Chondritic Iron Sulfides and Associated Metal
Creators: name: Singerling, Sheryl A.
name: Sutton, Stephen R.
name: Lanzirotti, Antonio
name: Newville, Matthew
name: Brearley, Adrian J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: We have performed a coordinated focused ion beam (FIB)-scanning and transmission electron microscopy (S/TEM), electron probe microanalysis (EMPA)-synchrotron X-ray fluorescence (SXRF) microprobe study to determine phase-specific microstructural characteristics and high-resolution in situ trace element concentrations of primary pyrrhotite, pentlandite, and associated metal grains from chondrules in CM2 and CR2 carbonaceous chondrites. This work is the first of its kind to link trace element chemical and microstructural observations in chondritic sulfides in an attempt to determine formation mechanisms and conditions of primary sulfides in these meteorite groups. SXRF microprobe analyses allowed the concentrations of the minor and trace elements, Co, Cu, Ge, Zn, and Se to be quantified, in addition to Fe and Ni, at a spatial resolution of 2 microns. The similarity between the CM and CR PPI sulfide trace element patterns provides evidence for a common formation mechanism for this type of sulfide grain in both meteorite groups. In addition, the SRM sulfide and metal have comparable trace element patterns that indicates a genetic relationship between the two, such as sulfidization of metal. Enrichments in Ni, Co, Cu, and Se are consistent with the chalcophile/siderophile behavior of these elements. The observed depletions in Ge suggest that it may have been lost by evaporation or else was never incorporated into the metal or sulfide precursor materials. The depletion in Zn may also be attributable to evaporation, but, being partially lithophile, may also have been preferentially incorporated into silicates during chondrule formation. Trace element concentrations support crystallization from an immiscible sulfide melt in chondrules for formation of the PPI grains and sulfidization of metal for the origin of the SRM grains.
description: 47 pages including appendices, 12 figures in main paper, 5 tables in main paper
'Give me your love (introduction)' 2016. in: Give Me Your Love, Oberon Books, London.
Creators: name: Talbot, Richard James
Publisher: name: University of Salford
Year: 2021
Subjects: classificationCode: 360403
subject: Drama, theatre and performance studies

description: Introduction to the playscript (the playscript is by Jon Haynes and David Woods)

 ISBN: 9781783193448
Effects of drugs on miniature end-plate currents at the mouse neuromuscular junction
Creators: name: Pennefather, Peter
Publisher: name: University of British Columbia
Year: 2010

description: Digital averaging and analysis of miniature endplate currents (MEPCs) from mouse diaphragm was used to characterize the normal MEPC and its modification by a variety of drugs. Under normal conditions the decay of MEPCs showed consistent deviations from a simple exponential consisting in a progressive increase of rate constant, followed by a slow tail. Receptor blockade by d-tubocurarine (dTC), a-bungarotoxin, and other agents thought to occupy ACh-binding sites reduced MEPC amplitude, accelerated MEPC decay by about 30% (making it about equal to decay rate of channels opened by exogenous acetylcholine), and eliminated the early deviations from an exponential decay; dTC also abolished the late tail. Examination of the interaction of acetylcholinesterase (AChE) poisoning and receptor blockade on MEPC height and time course indicated that normally most quantal ACh is captured by receptors and, as predicted by theoretical consideration, a rather large degree of receptor blockade is necessary to reduce MEPC height. MEPC tails were exaggerated by AChE poisoning and exogenous ACh or carba-chol. The latter agents reduced MEPC height in a fashion inconsistent with blockade of ACh binding and concurrent modulation of the tail suggested an important role of desensitized receptors in tail generation. A number of other drug actions are also described quantitatively: (a) channel prolongation, typical of alcohols but also found with ketones and some amines; (b) 'channel plugging', typical of local anaesthetics but also found with many other agents, including long chain alcohols, and (c) an action to reduce MEPC size without reducing net response to exogenous agonist typical of volatile anaesthetics, associated with increase rather than decrease of ACh binding to receptor. Criteria for distinguishing different modes of modification of receptor function are discussed.
Role of the rho meson in the description of pion electroproduction experiments at JLab
Creators: name: Faessler, Amand
name: Gutsche, Thomas
name: Lyubovitskij, Valery E.
name: Obukhovsky, Igor T.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the p(e,e' pi+)n reaction in the framework of an effective Lagrangian approach including nucleon, pi and rho meson degrees of freedom and show the importance of the rho-meson t-pole contribution to sigmaT, the transverse part of cross section. We test two different field representations of the rho meson, vector and tensor, and find that the tensor representation of the rho meson is more reliable in the description of the existing data. In particular, we show that the rho-meson t-pole contribution, including the interference with an effective non-local contact term, sufficiently improves the description of the recent JLab data at invariant mass W less 2.2 GeV and Q2 less 2.5 GeV2/c2. A ``soft'' variant of the strong piNN and rhoNN form factors is also found to be compatible with these data. On the basis of the successful description of both the sigmaL and sigmaT parts of the cross section we discuss the importance of taking into account the sigmaT data when extracting the charge pion form factor Fpi from sigmaL.
description: 23 pages, 6 figures, accepted for publication in Phys. Rev. C
Dynamic DNA nanomaterials to modulate ligand binding for biosensing and drug delivery
Creators: name: Puyat, Derek Ledesma
Publisher: name: No Publisher Supplied
Year: 2024

description: Deoxyribonucleic acids (DNA) are macromolecules that code genetic information and serve as the blueprint for life. DNA molecules are also used to build various nanoobjects due to their canonical base pairs, programmable assembly addressable structures and adaptable modifications. Compared to other self-assembly molecules, DNA allows for precise control due to its programmable and predictable base pairs. In this thesis, I primarily focused on two research topics of DNA binding to ligands. The first topic is to study how DNA molecules bind to small molecule ligands. A short strand of DNAs called G-quadruplex and i-motifs are used to examine the complex formation between drug and DNA. DNA-drug complexes were characterized by dynamic light scattering and spectrometry to evaluate the drug loading efficiency. We also primarily tested DNA-drug complexes for lipid nanoparticles delivery to kill cancer cells. Another topic is to study how DNA molecules were modulated for binding to ATP. We used a special DNA structure called aptamer. Aptamers are short, single-stranded DNA or RNA molecules that selectively bind to a target molecule. Aptamer-complement duplex (ACD) is often used to design molecular switches capable of producing a detectable signal or triggering a structural change upon aptamer binding to a target. However, such aptamer switches generally face an increased dissociation constant (Kd) due to the energy barrier of the complementary duplex. We reported a competitive hybridization mechanism to modulate the binding affinity of an ACD to a target adenosine. Using the computation-guided design, we calculated the aptamer folding energy for the duplex length from 11-nt to 15-nt, and experimentally measured increased apparent Kd values resulted from these extended duplexes. Using a set of strands to compete with the ACD hybridization, it reduced the aptamer folding energy to facilitate aptamer switches with decreased apparent Kd values ranging from over 400 μM without a competing strand to ~30 μM with a competing strand. This competitive aptamer switch was also found sensitive to single-nucleotide mutations of a competing strand. Our work provides an approach to modulate the binding affinity and the sensitivity of aptamer-complement duplexes, which could be useful in the nucleic acids-based sensing and nanomedicine.
Money grows on (proof-)trees: the formal FA1.2 ledger standard
Creators: name: Gabbay, Murdoch
name: Jakobsson, Arvid
name: Sojakova, Kristina
Publisher: name: arXiv
Year: 2021
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences
subject: D.2.4; F.3.1; K.4.4; K.7.3

description: Once you have invented digital money, you may need a ledger to track who owns what -- and an interface to that ledger so that users of your money can transact. On the Tezos blockchain this implies: a smart contract (distributed program), storing in its state a ledger to map owner addresses to token quantities, and standardised entrypoints to transact on accounts. A bank does a similar job -- it maps account numbers to account quantities and permits users to transact -- but in return the bank demands trust, it incurs expense to maintain a centralised server and staff, it uses a proprietary interface ... and it may speculate using your money and/or display rent-seeking behaviour. A blockchain ledger is by design decentralised, inexpensive, open, and it won't just bet your tokens on risky derivatives (unless you ask). The FA1.2 standard is an open standard for ledger-keeping smart contracts on the Tezos blockchain. Several FA1.2 implementations already exist. Or do they? Is the standard sensible and complete? Are the implementations correct? And what are they implementations \emph{of}? The FA1.2 standard is written in English, a specification language favoured by wet human brains but notorious for its incompleteness and ambiguity when rendered into dry and unforgiving code. In this paper we report on a formalisation of the FA1.2 standard as a Coq specification, and on a formal verification of three FA1.2-compliant smart contracts with respect to that specification. Errors were found and ambiguities were resolved; but also, there now exists a \emph{mathematically precise} and battle-tested specification of the FA1.2 ledger standard. We will describe FA1.2 itself, outline the structure of the Coq theories -- which in itself captures some non-trivial and novel design decisions of the development -- and review the detailed verification of the implementations.
Mass loss and very low-metallicity stars
Creators: name: Hirschi, Raphael
name: Chiappini, Cristina
name: Meynet, Georges
name: Ekstrom, Sylvia
name: Maeder, Andre
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Mass loss plays a dominant role in the evolution of massive stars at solar metallicity. After discussing different mass loss mechanisms and their metallicity dependence, we present the possibility of strong mass loss at very low metallicity. Our models at Z=1e-8 show that stars more massive than about 60 solar masses may lose a significant fraction of their initial mass in the red supergiant phase. This mass loss is due to the surface enrichment in CNO elements via rotational and convective mixing. Our 85 solar mass model ends its life as a fast rotating WO type Wolf-Rayet star. Therefore the models predict the existence of type Ic SNe and long and soft GRBs at very low metallicities. Such strong mass loss in the red supergiant phase or the Omega-Gamma limit could prevent the most massive stars from ending as pair-creation supernovae. The very low metallicity models calculated are also very interesting from the nucleosynthesis point of view. Indeed, the wind of the massive star models can reproduce the CNO abundances of the most metal-poor carbon-rich star known to date, HE1327-2326. Finally, using chemical evolution models, we are able to reproduce the evolution of CNO elements as observed in the normal extremely metal poor stars.
description: 8 pages, 3 figures, to appear in the proceedings of the conference on "Unsolved Problems in Stellar Physics", Cambridge, 2-6 July 2007
Ultra high frequency ultrasound enables real-time visualization of blood supply from chorioallantoic membrane to human autosomal dominant polycystic kidney tissue
Creators: name: Schueler, Jan
name: Kuenzel, Jonas
name: Thuesing, Anna
name: Pion, Eric
name: Behncke, Rose Yinghan
name: Haegerling, Rene
name: Fuchs, Dieter
name: Kraus, Andre
name: Buchholz, Bjoern
name: Huang, Boqiang
name: Merhof, Dorit
name: Werner, Jens M.
name: Schmidt, Katharina Maria
name: Hackl, Christina
name: Aung, Thiha
name: Haerteis, Silke
Publisher: name: Universität Regensburg
Year: 2024
Subjects: subject: 610 Medizin

description: Ultra high frequency (UHF) ultrasound enables the visualization of very small structures that cannot be detected by conventional ultrasound. The utilization of UHF imaging as a new imaging technique for the 3D-in-vivo chorioallantoic membrane (CAM) model can facilitate new insights into tissue perfusion and survival. Therefore, human renal cystic tissue was grafted onto the CAM and examined using UHF ultrasound imaging. Due to the unprecedented resolution of UHF ultrasound, it was possible to visualize microvessels, their development, and the formation of anastomoses. This enabled the observation of anastomoses between human and chicken vessels only 12 h after transplantation. These observations were validated by 3D reconstructions from a light sheet microscopy image stack, indocyanine green angiography, and histological analysis. Contrary to the assumption that the nutrient supply of the human cystic tissue and the gas exchange happens through diffusion from CAM vessels, this study shows that the vasculature of the human cystic tissue is directly connected to the blood vessels of the CAM and perfusion is established within a short period. Therefore, this in-vivo model combined with UHF imaging appears to be the ideal platform for studying the effects of intravenously applied therapeutics to inhibit renal cyst growth.
Probing Minimal Flavor Violation at the LHC
Creators: name: Grossman, Yuval
name: Nir, Yosef
name: Thaler, Jesse
name: Volansky, Tomer
name: Zupan, Jure
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: If the LHC experiments discover new particles that couple to the Standard Model fermions, then measurements by ATLAS and CMS can contribute to our understanding of the flavor puzzles. We demonstrate this statement by investigating a scenario where extra SU(2)-singlet down-type quarks are within the LHC reach. By measuring masses, production cross sections and relative decay rates, minimal flavor violation (MFV) can in principle be excluded. Conversely, these measurements can probe the way in which MFV applies to the new degrees of freedom. Many of our conclusions are valid in a much more general context than this specific extension of the Standard Model.
description: 18 pages, 1 figure, appendix added, journal version
SHarD: A beam dynamics simulationcode for dielectric laser acceleratorsbased on spatial harmonic field expansion
Creators: name: Ody, Alexander
name: Crisp, Sophie
name: Musumeci, Pietro
name: Cesar, David
name: England, R. Joel
Publisher: name: arXiv
Year: 2021
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: FOS: Physical sciences

description: In order to demonstrate acceleration of electrons to relativistic scales by an on chipdielectric laser accelerator (DLA), a ponderomotive focusing scheme capable of capturingand transporting electrons through nanometer-scale apertures over extended interactionlengths has been proposed. We present a Matlab-based numerical code (SHarD) utilizinga spatial harmonic expansion of the fields within the dielectric structure to simulate theevolution of the beam phase space distribution in this scheme. The code can be usedto optimize key-parameters for the accelerator performance such as the final energy,transverse spot size evolution and total number of electrons accelerated through currentlyfabricated structures. Eventually, the simulation model will be applied to inform thephase mask profile to be added to a pulse front tilt drive laser pulse using a liquid crystalmask in the experimental setup being assembled at UCLA Pegasus Laboratory.
description: 12 pages, 4 figures, 1 table, Manuscript Accepted at NIM-A
title: Patriotic Celebrations in Educational Commemoration Practices in Ukraine
Creators: name: Verbytska, Polina
name: Guyver, Robert
name: Kendzor, Petro
Publisher: name: JSSE - Journal of Social Science Education
Year: 2019

description: • School commemoration is an organized process influenced by social memory discourse

• Holiday celebrations reflect the transformation of the official holidays calendar

• Complex relations exist between school patriotic rituals, official aims and civic identity

• Military conflict influences the strengthening of patriotic character in school celebrations

• Patriotic rituals display elements of contradiction between citizenship and patriotic education discourses





Purpose: This study aims to provide information on the main tendencies across the transformation of the official holidays calendar in Ukraine over the last decades and to demonstrate its influence on school celebrations. Also discussed here is the role of these factors in the parallel but sometimes contradictory processes of the students’ civic identity formation.




Design/Methodology/Approach: The article is based on documentary analysis, an interdisciplinary literature review and an examination of current practices with regard to national holidays in Ukraine. Patriotic rituals are analyzed through examples and evidence of school celebrations of the main calendar dates, including audiovisual materials in different school settings. The authors’ observations have been corroborated with evidence from Ukrainian students and teachers as seen in the results of the questionnaire. These reflect their perception and experience of school celebrations.




Findings: The results demonstrate that the transformation of the official holidays calendar in Ukraine has had an impact on school commemoration practices. This in turn has become a factor in the formation of students’ civic identity. School patriotic rituals reflect a contradiction between the discourses of citizenship, patriotism and national upbringing in an emergent democracy in the continuing context of military conflict.




Key words: Ukrainian holidays celebrations, commemoration, patriotic rituals in school, civic identity, patriotism, citizenship education, democratic values.
description: JSSE - Journal of Social Science Education, Bd. 18 Nr. 1 (2019)
Hybrid symmetry epitaxy of superconducting Fe(Te,Se) film on a topological insulator
Creators: name: Yao, Xiong
name: Brahlek, Matthew
name: Yi, Hee Taek
name: Jain, Deepti
name: Mazza, Alessandro R.
name: Han, Myung-Geun
name: Oh, Seongshik
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: It is challenging to grow an epitaxial four-fold compound superconductor (SC) on six-fold topological insulator (TI) platform due to stringent lattice-matching requirement. Here, we demonstrate that Fe(Te,Se) can grow epitaxially on a TI (Bi2Te3) layer due to accidental, uniaxial lattice match, which is dubbed as "hybrid symmetry epitaxy". This new growth mode is critical to stabilizing robust superconductivity with TC as high as 13 K. Furthermore, the superconductivity in this FeTe1-xSex/Bi2Te3 system survives in Te-rich phase with Se content as low as x = 0.03 but vanishes at Se content above x = 0.56, exhibiting a phase diagram that is quite different from that of the conventional Fe(Te,Se) systems. This unique heterostructure platform that can be formed in both TI-on-SC and SC-on-TI sequences opens a route to unprecedented topological heterostructures.
description: 41 pages, 14 figures, accepted by Nano Letters
Exchange energy dominated by large orbital spin-currents in $δ$-Pu
Creators: name: Cricchio, Francesco
name: Bultmark, Fredrik
name: Nordström, Lars
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The electronic structure of the anomalous $δ$-phase of Pu is analyzed by a general and exact reformulation of the exchange energy of the $f$-shell. It is found that the dominating contribution to the exchange energy is a polarization of orbital spin-currents that preserves the time reversal symmetry, hence a non-magnetic solution in accordance with experiments. The analysis brings a unifying picture of the role of exchange in the $5f$-shell with its relatively strong spin-orbit coupling. The results are in good accordance with recent measurements of the branching ratio for the $d$ to $f$ transition in the actinides.
description: 6 pages, 1 figure, 2 tables
Perturbation Method for Classical Spinning Particle Motion: I. Kerr Space-Time
Creators: name: Singh, Dinesh
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: This paper presents an analytic perturbation approach to the dynamics of a classical spinning particle, according to the Mathisson-Papapetrou-Dixon (MPD) equations of motion, with a direct application to circular motion around a Kerr black hole. The formalism is established in terms of a power series expansion with respect to the particle's spin magnitude, where the particle's kinematic and dynamical degrees are expressed in a completely general form that can be constructed to infinite order in the expansion parameter. It is further shown that the particle's squared mass and spin magnitude can shift due to a classical analogue of radiative corrections that arise from spin-curvature coupling. Explicit expressions are determined for the case of circular motion near the event horizon a Kerr black hole, where the mass and spin shift contributions are dependent on the initial conditions of the particle's spin orientation. A preliminary analysis of the stability properties of the orbital motion in the Kerr background due to spin-curvature interactions is explored and briefly discussed.
description: 23 pages; REVTeX file; 9 figures; Accepted for publication in Phys. Rev. D
title: Κατασκευή συστήματος ηλεκτροκαρδιογράφου με τη χρήση προγραμματιζόμενου μικροελεγκτή
title: Creation of an electrocardiograph system using a programmable microcontroller
titleType: AlternativeTitle
Creators: name: Πανσεληνάς, Ανδρέας
Publisher: name: Πανεπιστήμιο Δυτικής Αττικής
Year: 2022
Subjects: Ηλεκτροκαρδιογράφος
Καρδιακός ρυθμός
Arduino
Μικροεπεξεργαστής

description: Σκοπός αυτής της διπλωματικής εργασίας είναι η κατασκευή ενός συστήματος ηλεκτροκαρδιογράφου για την παρακολούθηση της καρδιακής λειτουργίας με τη χρήση πλατφόρμας Arduino. Το πρώτο μέρος αφορά τη μελέτη της λειτουργίας της καρδιάς και του καρδιακού συστήματος, τα μέρη που τα αποτελούν, καθώς και τα κύρια προβλήματα από τα οποία μπορεί να υποφέρει μια καρδιά και γίνεται να εντοπιστούν με τη χρήση ηλεκτροκαρδιογράφου. Στο δεύτερο μέρος γίνεται μελέτη των βιοσημάτων της καρδιάς, του φυσιολογικού καρδιογραφήματος, καθώς και της αρχής λειτουργίας του ηλεκτροκαρδιογράφου και των διαφόρων τύπων ηλεκτροκαρδιογράφου. Στο τελευταίο μέρος, εξηγούνται τα διάφορα εξαρτήματα ενός καρδιογράφου καθώς και οι αρχές λειτουργίας τους. Έπειτα, εξηγείται η διαδικασία υλοποίησης της κατασκευής, η δημιουργία του κώδικα και ο τρόπος λειτουργίας της κατασκευής.