cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: Mathematical models for cell-substrate interaction
Creators: name: McNicol, Gordon Robert
Publisher: name: University of Glasgow
Year: 2024

description: To function and survive cells need to be able to sense and respond to their local environment through mechanotransduction. Crucially, mechanical and biochemical perturbations initiate cell signaling cascades, which can induce responses such as growth, apoptosis, proliferation and differentiation. At the heart of this process are actomyosin stress fibres (SFs), which form part of the cell cytoskeleton, and focal adhesions (FAs), which bind this cytoskeleton to the extra-cellular matrix (ECM). In addition to their structural role, FAs additionally serve as signaling hubs for changes in cell function. It follows that understanding the formation of these structures is a prerequisite for any attempt to elucidate how mechanical and biochemical cues influence cell behaviour.

The focus of this thesis is on the development of mathematical models to describe the coupled formation and maturation of cell-substrate adhesions and cell cytoskeleton in non-motile cells. In particular, we formulate a zero-dimensional bio-chemical model and one- and two-dimensional bio-chemo-mechanical models to describe the development of SFs and FAs and activation of ROCK signaling. We use a large family of PDEs (or ODEs) to describe three sets of biochemical events: the polymerisation of actin and subsequent bundling into contractile SFs; the formation and maturation of cell-substrate adhesions; and the activation of signaling proteins in response to FA and SF formation. In our one- and two-dimensional models, the evolution of these key proteins is coupled to a Kelvin-Voigt viscoelastic description of the cell cytoplasm and the ECM. We employ these various models to understand how cells respond to external and intracellular cues in vitro and are able to reproduce, and elucidate the mechanism of, a range of experimentally observed phenomena. This includes non-uniform cell striation and cells forming weaker SFs and FAs on softer substrates. It follows that the developed models provide a platform for systematic investigation into how the cell biochemistry and mechanics influence cell development and facilitates prediction of internal cell measurements that are difficult to ascertain experimentally.
Enhancing Human-robot Collaboration by Exploring Intuitive Augmented Reality Design Representations
Creators: name: Eze, Chrisantus
name: Crick, Christopher
Publisher: name: arXiv
Year: 2023
Subjects: subject: Robotics (cs.RO)
subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: As the use of Augmented Reality (AR) to enhance interactions between human agents and robotic systems in a work environment continues to grow, robots must communicate their intents in informative yet straightforward ways. This improves the human agent's feeling of trust and safety in the work environment while also reducing task completion time. To this end, we discuss a set of guidelines for the systematic design of AR interfaces for Human-Robot Interaction (HRI) systems. Furthermore, we develop design frameworks that would ride on these guidelines and serve as a base for researchers seeking to explore this direction further. We develop a series of designs for visually representing the robot's planned path and reactions, which we evaluate by conducting a user survey involving 14 participants. Subjects were given different design representations to review and rate based on their intuitiveness and informativeness. The collated results showed that our design representations significantly improved the participants' ease of understanding the robot's intents over the baselines for the robot's proposed navigation path, planned arm trajectory, and reactions.
Light Curves and Colors of the Ejecta from Dimorphos after the DART Impact
Creators: name: Graykowski, Ariel
name: Lambert, Ryan A.
name: Marchis, Franck
name: Cazeneuve, Dorian
name: Dalba, Paul A.
name: Esposito, Thomas M.
name: Peluso, Daniel O'Conner
name: Sgro, Lauren A.
name: Blaclard, Guillaume
name: Borot, Antonin
name: Malvache, Arnaud
name: Marfisi, Laurent
name: Powell, Tyler M.
name: Huet, Patrice
name: Limagne, Matthieu
name: Payet, Bruno
name: Clarke, Colin
name: Murabana, Susan
name: Owen, Daniel Chu
name: Wasilwa, Ronald
name: Fukui, Keiichi
name: Goto, Tateki
name: Guillet, Bruno
name: Huth, Patrick
name: Ishiyama, Satoshi
name: Kukita, Ryuichi
name: Mitchell, Mike
name: Primm, Michael
name: Randolph, Justus
name: Rivett, Darren A.
name: Ryno, Matthew
name: Shimizu, Masao
name: Toullec, Jean-Pierre
name: Will, Stefan
name: Yue, Wai-Chun
name: Camilleri, Michael
name: Graykowski, Kathy
name: Janetzke, Ron
name: Janke, Des
name: Kardel, Scott
name: Loose, Margaret
name: Pickering, John W.
name: Smith, Barton A.
name: Transom, Ian M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: On 26 September 2022 the Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, a satellite of the asteroid 65803 Didymos. Because it is a binary system, it is possible to determine how much the orbit of the satellite changed, as part of a test of what is necessary to deflect an asteroid that might threaten Earth with an impact. In nominal cases, pre-impact predictions of the orbital period reduction ranged from ~8.8 - 17.2 minutes. Here we report optical observations of Dimorphos before, during and after the impact, from a network of citizen science telescopes across the world. We find a maximum brightening of 2.29 $\pm$ 0.14 mag upon impact. Didymos fades back to its pre-impact brightness over the course of 23.7 $\pm$ 0.7 days. We estimate lower limits on the mass contained in the ejecta, which was 0.3 - 0.5% Dimorphos' mass depending on the dust size. We also observe a reddening of the ejecta upon impact.
description: Accepted by Nature
Towards Generalized Robot Assembly through Compliance-Enabled Contact Formations
Creators: name: Morgan, Andrew S.
name: Bateux, Quentin
name: Hao, Mei
name: Dollar, Aaron M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Robotics (cs.RO)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Contact can be conceptualized as a set of constraints imposed on two bodies that are interacting with one another in some way. The nature of a contact, whether a point, line, or surface, dictates how these bodies are able to move with respect to one another given a force, and a set of contacts can provide either partial or full constraint on a body's motion. Decades of work have explored how to explicitly estimate the location of a contact and its dynamics, e.g., frictional properties, but investigated methods have been computationally expensive and there often exists significant uncertainty in the final calculation. This has affected further advancements in contact-rich tasks that are seemingly simple to humans, such as generalized peg-in-hole insertions. In this work, instead of explicitly estimating the individual contact dynamics between an object and its hole, we approach this problem by investigating compliance-enabled contact formations. More formally, contact formations are defined according to the constraints imposed on an object's available degrees-of-freedom. Rather than estimating individual contact positions, we abstract out this calculation to an implicit representation, allowing the robot to either acquire, maintain, or release constraints on the object during the insertion process, by monitoring forces enacted on the end effector through time. Using a compliant robot, our method is desirable in that we are able to complete industry-relevant insertion tasks of tolerances <0.25mm without prior knowledge of the exact hole location or its orientation. We showcase our method on more generalized insertion tasks, such as commercially available non-cylindrical objects and open world plug tasks.
Nonlinear Optical Probe of Indirect Excitons
Creators: name: Nalitov, A. V.
name: Vladimirova, M.
name: Kavokin, A. V.
name: Butov, L. V.
name: Gippius, N. A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose the application of nonlinear optics for studies of spatially indirect excitons in coupled quantum wells. We demonstrate, that despite their vanishing oscillator strength, indirect excitons can strongly contribute to the photoinduced reflectivity and Kerr rotation. This phenomenon is governed by the interaction between direct and indirect excitons. Both dark and bright states of indirect excitons can be probed by these nonlinear optical techniques.
General relativistic precession and the long-term stability of the solar system
Creators: name: Brown, Garett
name: Rein, Hanno
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: The long-term evolution of the solar system is chaotic. In some cases, chaotic diffusion caused by an overlap of secular resonances can increase the eccentricity of planets when they enter into a linear secular resonance, driving the system to instability. Previous work has shown that including general relativistic contributions to the planets' precession frequency is crucial when modelling the solar system. It reduces the probability that the solar system destabilizes within 5 Gyr by a factor of 60. We run 1280 additional N-body simulations of the solar system spanning 12.5 Gyr where we allow the GR precession rate to vary with time. We develop a simple, unified, Fokker-Planck advection-diffusion model that can reproduce the instability time of Mercury with, without, and with time-varying GR precession. We show that while ignoring GR precession does move Mercury's precession frequency closer to a resonance with Jupiter, this alone does not explain the increased instability rate. It is necessary that there is also a significant increase in the rate of diffusion. We find that the system responds smoothly to a change in the precession frequency: There is no critical GR precession frequency below which the solar system becomes significantly more unstable. Our results show that the long-term evolution of the solar system is well described with an advection-diffusion model.
description: 8 pages, 4 figures, accepted for publication in MNRAS
Computing upper cluster algebras
Creators: name: Matherne, Jacob P.
name: Muller, Greg
Publisher: name: arXiv
Year: 2013
Subjects: subject: Commutative Algebra (math.AC)
subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 13F60

description: This paper develops techniques for producing presentations of upper cluster algebras. These techniques are suited to computer implementation, and will always succeed when the upper cluster algebra is totally coprime and finitely generated. We include several examples of presentations produced by these methods.
description: 19 pages, 4 examples
Probability distributions with binomial moments
Creators: name: Mlotkowski, Wojciech
name: Penson, Karol A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Probability (math.PR)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: We prove that if $p\geq 1$ and $-1\leq r\leq p-1$ then the binomial sequence $\binom{np+r}{n}$, $n=0,1,...$, is positive definite and is the moment sequence of a probability measure $ν(p,r)$, whose support is contained in $\left[0,p^p(p-1)^{1-p}\right]$. If $p>1$ is a rational number and $-11$ the measures $ν(p,-1)$ and $ν(p,0)$ are certain free convolution powers of the Bernoulli distribution. Finally we prove that the binomial sequence $\binom{np+r}{n}$ is positive definite if and only if either $p\geq 1$, $-1\leq r\leq p-1$ or $p\leq 0$, $p-1\leq r \leq 0$. The measures corresponding to the latter case are reflections of the former ones.
Study of negative thermal expansion in the frustrated spinel ZnCr2Se4
Creators: name: Chen, X. L.
name: Yang, Z. R.
name: Tong, W.
name: Huang, Z. H.
name: Zhang, L.
name: Zhang, S. L.
name: Song, W. H.
name: Pi, L.
name: Sun, Y. P.
name: Tian, M. L.
name: Zhang, Y. H.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The origin of negative thermal expansion (NTE) in the bond frustrated ZnCr2Se4 has been explored. ESR and FTIR document an ideal paramagnetic state above 100 K, below which ferromagnetic clusters coexist with the paramagnetic state down to TN. By fitting the inverse susceptibility above 100 K using a modified paramagnetic Curie-Weiss law, an exponentially changeable exchange integral J is deduced. In the case of the variable J, magnetic exchange and lattice elastic energy couple with each other effectively via magnetoelastic interaction in the ferromagnetic clusters, where NTE occurs at a loss of exchange energy while a gain of lattice elastic one.
description: 5 pages, 5 figures
C-Graded Vertex Algebras and Conformal Flow
Creators: name: Laber, Rob
name: Mason, Geoffrey
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: 17B69

description: We consider C-graded vertex algebras, which are vertex algebras V with a C-grading such that V is an admissible V-module generated by 'lowest weight vectors'. We show that such vertex algebras have a 'good' representation theory in the sense that there is a Zhu algebra A(V) and a bijection between simple admissible V-modules and simple A(V)-modules. We also consider pseudo vertex operator algebras, which are C-graded vertex algebras with a conformal vector such that the homogeneous subspaces of V are generalized eigenspaces for L(0); essentially, these are VOAs that lack any semisimplicity or integrality assumptions on L(0). As a motivating example, we show that deformation of the conformal structure (conformal flow) of a strongly regular VOA (eg a lattice theory, or WZW model) is a path in a space whose points are PVOAs.
An efficient lossless compression technique for remote sensing images using segmentation based band reordering heuristics
Creators: name: Afjal, Masud Ibn
name: Palash Uddin
name: Mamun, Al
name: Marjan, Abu
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Space Science
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 20199 Astronomical and Space Sciences not elsewhere classified
subject: FOS: Physical sciences
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: 80699 Information Systems not elsewhere classified
subject: FOS: Computer and information sciences
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics

description: The size of remote sensing (RS) image is indeed massive due to hundreds capturing wavelengths bands used for collecting information about the ground surface. The data in the RS images are often redundant spatially, spectrally and temporally which thus give a sufficient prospect for compressing the images in different domains. In this paper, we propose a band reordering scheme to be applied on the segmented subgroup datasets of an original RS image dataset towards presenting a hybrid lossless compression technique. The proposed dataset segmentation-based band reordering process employs two heuristics, i.e. consecutive continuity limit of previous bands and continuity breakdown thresholds to be used for efficient coding of reordered dataset towards attaining better on-board compression. The aim of the proposed compression strategy is thus to increase compression gain through reordering each highly correlated bands’ segment in the RS data-cube for efficient coding. The performance of the proposed band reordering method is measured using the Consultative Committee for Space Data Systems (CCSDS) recommended lossless CCSDS 123.0-B-1 and three-dimensional (3D) Context-based Adaptive Lossless Image Codec (CALIC) predictors. The experimental results illustrate substantially higher compression of the proposed method than that of the state-of-the-art standards using various real RS hyperspectral and hyperspectral sound datasets. Quantitatively, the compression performances are increased by 0.10%–0.66% using CCSDS and 0.65–2.52% using 3D-CALIC for hyperspectral Airborne Visible InfraRed Imaging Spectrometer (AVIRIS) datasets, 0.26%–1.00% using CCSDS and 2.16–2.57% using 3D-CALIC for hyperspectral Hyperion datasets and 4.61%–7.36% using CCSDS and 4.05%–4.88% using 3D-CALIC for hyperspectral sounder datasets by the proposed compression technique. Besides, the proposed compression scheme outperforms state-of-the-art investigated compression methods.
L'alba di Superman - Lois e Clark dal New Deal alla guerra 1941-1945
Creators: name: Bonfà, Ileano
Publisher: name: Zenodo
Year: 2019
Subjects: Superman
Clark Kent
Lois Lane
Comics
New Deal and Popular Culture
Fumetti
New Deal e cultura di massa

description: ABSTRACT

The first Superman comics were published during the New Deal. The problems faced by the New Deal (financial speculation, corruption, poverty, unemployment, social security) can be found in the comics. Siegel and Shuster, like many comics authors, were American Jews, a social group that typically supported Roosevelt and his politics. In the years leading to the 1941-1945 war the United States slowly moved from isolationism to interventionism; Superman comics testify this evolution and indeed anticipate it. We then consider Lois Lane, its role of reporter and its narrative function, hinting at the evolution of the character.

SOMMARIO

Le prime storie di Superman sono contemporanee al New Deal. I problemi affrontati dal New Deal (speculazione finanziaria, corruzione, povertà, disoccupazione, sicurezza sociale) sono presenti nei fumetti. Come molti autori di comics, Siegel e Shuster erano  ebrei americani, un gruppo sociale che in genere sosteneva Roosevelt e la sua politica. Negli anni che portarono alla guerra 1941-1945 gli Stati Uniti lentamente si spostarono dall’isolazionismo all’interventismo; le storie di Superman testimoniano questa evoluzione ed anzi la anticipano. Si considera poi il ruolo di reporter e la funzione narrativa del personaggio di Lois Lane, accennando alla sua evoluzione.
Gravitational Instability of Gas-Dust Circumnuclear Disks in Galaxies
Creators: name: Tkachenko, Roman
name: Korchagin, Vladimir
name: Jmailov, Boris
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We numerically study the origin of the multi-armed spiral structure observed in the circumnuclear gaseous mini-disks of nearby galaxies. We show that the presence of dust in such disks and its interaction with the gravitationally stable gaseous component leads to the development of a multi-armed spiral structure. As a particular example, we study the formation of the multi-armed spiral pattern in the mini-disk of the galaxy NGC 4736, for which the observational data for the rotation and the density distribution are available. We find that the multi-armed spiral structure grows in the stable gaseous mini-disk of NGC 4736 if the gas-to-dust ratio is about 5-20 percent. We also demonstrate that together with the dust concentration, the important factor for the development of instability is the size of the dust grains. A nonlinear multi-armed spiral pattern develops in the stable gaseous disk with sizes of grains larger than one micron. If future observations confirm the presence of a large amount of dust in the mini-disks of galaxies, this will pinpoint the mechanism of the formation of the multi-armed spiral structure in them.
description: 15 pages, 6 figures; https://www.mdpi.com/2075-4434/11/2/41
Supplementary Material from Sex-related communicative functions of voice spectral energy in human chorusing
Creators: name: Keller, Peter E.
name: Lee, Jennifer
name: König, Rasmus
name: Novembre, Giacomo
Publisher: name: The Royal Society
Year: 2023
Subjects: classificationCode: 310499
subject: Evolutionary biology not elsewhere classified
classificationCode: 310901
subject: Animal behaviour
classificationCode: 520499
subject: Cognitive and computational psychology not elsewhere classified

description: Supplementary material, including more detailed description of the methods, analyses of audio stimuli, raw data for listener responses, and detailed results of analyses of listener responses, is available at: https://doi.org/10.5061/dryad.jh9w0vthn
Experimental and Numerical Simulation Research on Oxy-fuel Co-Combustion of Coal and Biomass in Fluidized Beds
Creators: name: LIU, QINWEN
Publisher: name: Monash University
Year: 2023
Subjects: Chemical engineering design

description: This thesis explores a novel clean combustion technology, the oxy-fuel co-firing of coal and biomass in fluidized beds, which is expected to achieve negative CO2 emissions. This work conducts oxy-fuel co-firing of coal/biomass on a 10 kWth fluidized bed and reveals the characteristics of co-combustion, CO2 enrichment, and pollutant emission laws, which enrich the knowledge system of fluidized bed oxy-fuel combustion. In addition, the numerical simulation method of a multifuel particle reaction system has been developed, which enriches the research methods and lays the foundation for the development of simulations of multiphase reaction systems with over three fuels.
Time-series photometry of Earth flyby asteroid 2012 DA14
Creators: name: Terai, Tsuyoshi
name: Urakawa, Seitaro
name: Takahashi, Jun
name: Yoshida, Fumi
name: Oshima, Goichi
name: Aratani, Kenta
name: Hoshi, Hisaki
name: Sato, Taiki
name: Ushioda, Kazutoshi
name: Oasa, Yumiko
Publisher: name: arXiv
Year: 2013
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Context. The object 2012 DA14 is a near-Earth asteroid with a size of several tens of meters. It had approached closely the Earth on 15 February, 2013 UT, providing an opportunity for precise measurements of this tiny asteroid. Aims. The solar phase angle of 2012 DA14 had varied widely around its closest approach but was almost constant during the following night. We performed time-series photometric observations on those two nights to determine the rotational properties and phase effect. Methods. The observations were carried out using the 0.55-m telescope at Saitama University, Japan. The R-band images were obtained continuously over a 2 hr period at the closest approach and for about 5 hr on the next night. Results. The lightcurve data from the second night indicates a rotational period of 11.0 +1.8/-0.6 hr and a peak-to-peak amplitude of 1.59 +/- 0.02 mag. The brightness variation before and after the closest approach was separated into two components that are derived from the rotation and phase effect. We found that the phase curve slope of this asteroid is significantly shallower than those of other L-type asteroids. Conclusions. We suggest that 2012 DA14 is coated with a coarse surface that lacks fine regolith particles and/or a high albedo surface.
description: 4 pages, 4 figures, accepted for publication in Astronomy and Astrophysics
NUMERICAL INVESTIGATION ON THE DEFORMATION CHARACTERSTICS OF SADDLE DAM: A CASE OF GRAND ETHIOPIAN RENAISSANCE DAM
Creators: name: BINIAM ASSEFA
Publisher: name: Zenodo
Year: 2021

description: The major causes of damages of concrete face rockfill dams (CFRD) is displacement of the dam body. Many historical evidences proved that when the settlement of dam crest is greater than 1% of the dam height, cracks on the face slab and openings occur which results in high leakage rate resulting in operation problem of the dam. In addition, several high CFRDs have experienced the cracking of the concrete face during first reservoir impounding.

In this study, deformation characteristics of a concrete faced rock-fill dam (CFRD) of the Grand Ethiopian Renaissance dam was investigated. Secondary data was used to model the foundation and embankment materials. Two dimensional plane strain finite element analyses were carried out to assess the displacements in the dam both for construction and impoundment stages by using finite element method (FEM) computer program PLAXIS 2D. The hardening soil model is used to represent the nonlinear, inelastic and stress dependent behavior of rock-fill materials and Hoek-Brown model to simulate the foundation rock and linear elastic model is used to represent the stress-strain behavior of face slab, Plinth, and access gallery.
Constraints from dwarf galaxies on black hole seeding and growth models with current and future surveys
Creators: name: Chadayammuri, Urmila
name: Bogdan, Akos
name: Ricarte, Angelo
name: Natarajan, Priyamvada
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Dwarf galaxies are promising test beds for constraining models of supermassive and intermediate-mass black holes (MBH) via their black hole occupation fraction (BHOF). Disentangling seeding from the confounding effects of mass assembly over a Hubble time is a challenging problem, that we tackle in this study with a suite of semi-analytical models (SAMs). We show how measured BHOF depends on the lowest black hole mass or AGN luminosity achieved by a survey. To tell seeding models apart, we need to detect or model all AGN brighter than $10^{37}\ \rm{erg \ s^{-1}}$ in galaxies of $M_* \sim 10^{8-10} \ \rm{M_{\odot}}$. Shallower surveys, like eRASS, cannot distinguish between seed models even with the compensation of a much larger survey volume. We show that the AMUSE survey, with its inference of the MBH population underlying the observed AGN, strongly favors heavy seed models, growing with either a power-law Eddington Ratio Distribution Function (ERDF) or one in which black hole accretion is tagged to the star-formation rate (AGN-MS). These two growth channels can then be distinguished by the AGN luminosity function at $> 10^{40}\ \rm{erg \ s^{-1}}$, with the AGN-MS model requiring more accretion than observed at z $\sim$ 0. Thus, current X-ray observations favour heavy seeds whose Eddington ratios follow a power-law distribution. The different models also predict different radio scaling relations, which we quantify using the fundamental plane of black hole activity. We close with recommendations for the design of upcoming multi-wavelength campaigns that can optimally detect MBHs in dwarf galaxies.
description: Accepted to ApJ
Supersymmetric quantum mechanics and Painleve equations
Creators: name: Bermudez, David
name: C, David J. Fernández
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In these lecture notes we shall study first the supersymmetric quantum mechanics (SUSY QM), specially when applied to the harmonic and radial oscillators. In addition, we will define the polynomial Heisenberg algebras (PHA), and we will study the general systems ruled by them: for zero and first order we obtain the harmonic and radial oscillators, respectively; for second and third order PHA the potential is determined by solutions to Painleve IV (PIV) and Painleve V (PV) equations. Taking advantage of this connection, later on we will find solutions to PIV and PV equations expressed in terms of confluent hypergeometric functions. Furthermore, we will classify them into several solution hierarchies, according to the specific special functions they are connected with.
description: 38 pages, 20 figures. Lecture presented at the XLIII Latin American School of Physics: ELAF 2013 in Mexico City
Energy levels and radiative rates for transitions in Ti VII
Creators: name: Aggarwal, KM
name: Keenan, FP
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We report calculations of energy levels, radiative rates, oscillator strengths and line strengths for transitions among the lowest 231 levels of Ti VII. The general-purpose relativistic atomic structure package ({\sc grasp}) and flexible atomic code ({\sc fac}) are adopted for the calculations. Radiative rates, oscillator strengths and line strengths are provided for all electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2) and magnetic quadrupole (M2) transitions among the 231 levels, although calculations have been performed for a much larger number of levels (159,162). In addition, lifetimes for all 231 levels are listed. Comparisons are made with existing results and the accuracy of the data is assessed. In particular, the most recent calculations reported by Singh {\em et al} [Can J. Phys. {\bf 90} (2012) 833] are found to be unreliable, with discrepancies for energy levels of up to 1 Ryd and for radiative rates of up to five orders of magnitude for several transitions, particularly the weaker ones. Based on several comparisons among a variety of calculations with two independent codes, as well as with the earlier results, our listed energy levels are estimated to be accurate to better than $1\%$ (within 0.1 Ryd), whereas results for radiative rates and other related parameters should be accurate to better than $20\%$.
description: Text 11p, Tables 6, to appear in Physica Scripta 88 (2013) XXX. arXiv admin note: substantial text overlap with arXiv:1307.2732, arXiv:1307.2471
Strongly correlated electron system in the magnetic field
Creators: name: Sherman, A.
name: Schreiber, M.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The energy spectrum of the two-dimensional t-J model in a perpendicular magnetic field is investigated. The density of states at the Fermi level as a function of the inverse magnetic field $\frac{1}{B}$ reveals oscillations in the range of hole concentrations $0.08
description: 14 pages, 4 figures
The Turing Way: Reproducible, Inclusive, Collaborative Data Science
Creators: name: Steele, Anne Lee
Publisher: name: Zenodo
Year: 2023
Subjects: open science
reproducibility

description: On 19 May, 16:00-16:30 London time (UTC+1) (in your timezone) we will be hosting Anne Lee Steele, Community Manager for The Turing Way project at The Alan Turing Institute. Anne will overview the cluster of efforts emerging and the different types of pathways at The Turing Way, an open source community-driven book on reproducible, ethical and collaborative data science. The format of the talk is: 5 min - Intro 15 min - Presentation 10 min - Q&A (not recorded) We will facilitate open discussions in the Q&A with attendees to learn about their perspectives on the topic via a shared document (links shared upon registration). This event is being co-hosted by EDS book - a computational notebook community for Open Environmental Science, Climate Informatics - an open community interested in research combining climate science with approaches from statistics, machine learning and data mining and Environmental Data Science Journal - part of Cambridge University Press and Assessment designed to highlight the potential of artificial intelligence and data science to enhance our understanding of the environment, and to address climate change.
Non-Fourier heat transport in nanosystems
Creators: name: Benenti, Giuliano
name: Donadio, Davide
name: Lepri, Stefano
name: Livi, Roberto
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Energy transfer in small nanosized systems can be very different from that in their macroscopic counterparts due to reduced dimensionality, interaction with surfaces, disorder, and large fluctuations. Those ingredients may induce non-diffusive heat transfer that requires to be taken into account on small scales. We provide an overview of the recent advances in this field from the points of view of nonequilibrium statistical mechanics and atomistic simulations. We summarize the underlying basic properties leading to violations of the standard diffusive picture of heat transport and its universal features, with some historical perspective. We complete this scenario by illustrating also the effects of long-range interaction and integrability on non-diffusive transport. Then we discuss how all of these features can be exploited for thermal management, rectification and to improve the efficiency of energy conversion. We conclude with a review on recent achievements in atomistic simulations of anomalous heat transport in single polymers, nanotubes and two-dimensional materials. A short account of the existing experimental literature is also given.}
description: Invited review article, La Rivista del Nuovo Cimento, to appear
What teachers see : the centrality of noticing in the skill of teaching
Creators: name: Batisla-Ong, Lorelei J.
name: 0000-0003-1351-0862
Publisher: name: The University of Texas at Austin
Year: 2023
Subjects: Music teaching
Teacher observation
Observation
Teaching skill
Professional development
Eye tracking
Teaching expertise

description: This dissertation comprises three projects, all of which are related to teacher observation. Previous research in multiple disciplines has shown that perceptions of ongoing events are an essential component of informed decision making, and that one of the hallmarks of expertise is the ability to accurately perceive relevant events in a given environment. The first project involves a music teacher in-service program that I designed and implemented in a small school district. The program was focused on aspects of teaching selected by the individual teacher participants. The second project was a study of gaze behavior in which I tracked the gaze of a novice and an expert teacher as they observed a video recording of a music lesson. The third project was a study of observation by expert and nonexpert teachers who observed video recordings of two brief music lessons. In each of these studies, I described what and how teachers see, how they talk about what they see, and how they experience teaching. The results suggest that experts’ observations of teaching differ from the observations of novices in systematic ways.
3D model of hydrogen atmospheric escape from HD209458b and HD189733b: radiative blow-out and stellar wind interactions
Creators: name: Bourrier, Vincent
name: Etangs, Alain Lecavelier des
Publisher: name: arXiv
Year: 2013
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Transit observations in Ly-alpha of HD209458b and HD189733b revealed signatures of neutral hydrogen escaping the planets. We present a 3D particle model of the dynamics of the escaping atoms, and calculate theoretical Ly-alpha absorption line profiles, which can be directly compared with the absorption observed in the blue wing of the line. For HD209458b the observed velocities of the escaping atoms up to -130km/s are naturally explained by radiation-pressure acceleration. The observations are well-fitted with an ionizing flux of about 3-4 times solar and a hydrogen escape rate in the range 10^9-10^11g/s, in agreement with theoretical predictions. For HD189733b absorption by neutral hydrogen was observed in 2011 in the velocity range -230 to -140km/s. These velocities are higher than for HD209458b and require an additional acceleration mechanism for the escaping hydrogen atoms, which could be interactions with stellar wind protons. We constrain the stellar wind (temperature ~3x10^4K, velocity 200+-20km/s and density in the range 10^3-10^7/cm3) as well as the escape rate (4x10^8-10^11g/s) and ionizing flux (6-23 times solar). We also reveal the existence of an 'escape-limited' saturation regime in which most of the escaping gas interacts with the stellar protons. In this regime, which occurs at proton densities above ~3x10^5/cm3, the amplitude of the absorption signature is limited by the escape rate and does not depend on the wind density. The non-detection of escaping hydrogen in earlier observations in 2010 can be explained by the suppression of the stellar wind at that time, or an escape rate of about an order of magnitude lower than in 2011. For both planets, best-fit simulations show that the escaping atmosphere has the shape of a cometary tail.
description: 21 pages, 26 figures, accepted for publication in A&A
The Storm in World Fertilizer Markets Continues
Creators: name: Beghin, John
name: Beghin, John
Publisher: name: Unknown
Year: 2022
Subjects: subject: International Relations/Trade
subject: Fertilizer
subject: price volatility
subject: nitrogen
subject: natural gas

description: This article updates the recent article on world fertilizer markets by Beghin and Nogueira (2021), which noted the perfect storm affecting global fertilizer markets through high demand, droughts affecting fertilizer supply, high fossil energy prices, covid-9-related supply-chain disruptions, and trade policies, all conspiring to elevate fertilizer nominal prices to levels not seen since 2008. In the last 10 months, the Ukraine-Russia war and associated trade sanctions have exacerbated the disruptions in fossil energy, grain, vegetable oil and fertilizer markets already present in 2021. On the more hopeful side, some US trade policy developments will help reduce US fertilizer prices. Trade restrictions put in place by some countries are concerning.
The Influence of the Galactic Bar on the Dynamics of Globular Clusters
Creators: name: Tkachenko, Roman
name: Korchagin, Vladimir
name: Jmailova, Anna
name: Carraro, Giovanni
name: Jmailov, Boris
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We make use of recent estimates for the parameters of the Milky Way's halo globular clusters and study the influence of the galactic bar on the dynamics of these clusters by computing their orbits. We use both an axisymmetric and non-axisymmetric galactic potentials, which include the rotating elongated bar/bulge structure. We account for observational errors both in the positions and in the velocities of the globular clusters and explore the influence of the bar on cluster's evolution. This is contained in the angular momentum-total energy plane, (Lz,E), which is widely exploited as an indicator of the groups of globular clusters that originated from the same accretion event. Particular attention is devoted to the Gaia-Sausage/Enceladus and Pontus structures identified recently as two independent accretion events. Our study shows that it is not possible to identify GSE and Pontus as different merger events.
description: 17 pages, 9 figures
The complete plastome of the green alga Oocystis borgei
Creators: name: Salim, Ana
Publisher: name: The University of Texas at Austin
Year: 2023
Subjects: Oocystis borgei
Complete plastome

description: The chlorophyte genus Oocystis Nägeli is in the Order Chlorellales of the Class Trebouxiophyceae. Species of Oocystis are common in the plankton assemblages of freshwaters worldwide. Research has shown the algal’s potential use in biotechnology for producing high-value bioactive by-products such as polyunsaturated fatty acids and fucose and as a bioindicator for saline wastewater treatment plants. Although species of Oocystis are abundant across various freshwater ecosystems, not many studies have analyzed the genomics of the genus. This study reports the full plastid genome (plastome) for a strain of Oocystis borgei. The assembled plastome is 98,917 bp in length with 91 genes of which 82 are protein encoding genes (CDS), 34 tRNAs, and 3 novel rRNAs. The inverted repeat (IR) size is 12,318 bp and the GC content is 32.5%. I compared the reconstructed plastome to NCBI published genomes in the Chlorellales to generate a maximum likelihood phylogeny. The phylogenetic relationships recovered are similar to previously published phylogenies of the Trebouxiophyceae. This study suggests that plastome data will be an important addition to understanding phylogenetic relationships within the Oocystaceae and to aid the further study of Oocystis borgei for application use.
Structure of Surface-H2O Layers of Ice-covered Planets with High-pressure Ice
Creators: name: Ueta, S.
name: Sasaki, T.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Many extrasolar (bound) terrestrial planets and free-floating (unbound) planets have been discovered. The existence of bound and unbound terrestrial planets with liquid water is an important question, and of particular importance is the question of their habitability. Even for a globally ice-covered planet, geothermal heat from the planetary interior may melt the interior ice, creating an internal ocean covered by an ice shell. In this paper, we discuss the conditions that terrestrial planets must satisfy for such an internal ocean to exist on the timescale of planetary evolution. The question is addressed in terms of planetary mass, distance from a central star, water abundance, and abundance of radiogenic heat sources. In addition, we investigate the structures of the surface-H2O layers of ice-covered planets by considering the effects of ice under high pressure (high-pressure ice). As a fiducial case, 1M$\oplus$ planet at 1 AU from its central star and with 0.6 to 25 times the H2O mass of Earth could have an internal ocean. We find that high-pressure ice layers may appear between the internal ocean and the rock portion on a planet with an H2O mass over 25 times that of Earth. The planetary mass and abundance of surface water strongly restrict the conditions under which an extrasolar terrestrial planet may have an internal ocean with no high-pressure ice under the ocean. Such high-pressure-ice layers underlying the internal ocean are likely to affect the habitability of the planet.
description: 27 pages, 6 figures, 1 table, accepted for publication in the Astrophysical Journal
Directing wholeness
Creators: name: Rae, Braxton
Publisher: name: The University of Texas at Austin
Year: 2023
Subjects: Wholeness
Blackness
Theatre
Intimacy direction
Communities
Arts

description: I want to find wholeness within the theatre. I want to create a world where sometimes things are good, sometimes things are bad, and sometimes they just are. Life isn't something that is only inherently traumatic, and it isn't something that is always joyful either; our art deserves to live in that space as well, and it's the art that I aim to make. Within this thesis, I intend to think through ways of directing wholeness by taking a critical eye to my own work, with a focus on Blackness, intimacy, and underestimated communities.
Elemental Compositions of Two Extrasolar Rocky Planetesimals
Creators: name: Xu, S.
name: Jura, M.
name: Koester, D.
name: Klein, B.
name: Zuckerman, B.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We report Keck/HIRES and HST/COS spectroscopic studies of extrasolar rocky planetesimals accreted onto two hydrogen atmosphere white dwarfs, G29-38 and GD 133. In G29-38, 8 elements are detected, including C, O, Mg, Si, Ca, Ti, Cr and Fe while in GD 133, O, Si, Ca and marginally Mg are seen. These two extrasolar planetesimals show a pattern of refractory enhancement and volatile depletion. For G29-38, the observed composition can be best interpreted as a blend of a chondritic object with some refractory-rich material, a result from post-nebular processing. Water is very depleted in the parent body accreted onto G29-38, based on the derived oxygen abundance. The inferred total mass accretion rate in GD 133 is the lowest of all known dusty white dwarfs, possibly due to non-steady state accretion. We continue to find that a variety of extrasolar planetesimals all resemble to zeroth order the elemental composition of bulk Earth.
description: 43 pages, 18 figures, 4 tables, ApJ Accepted
Goal-oriented Composition of Software Process Patterns
Creators: name: Münch, Jürgen
Publisher: name: arXiv
Year: 2014
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: The development of high-quality software or software-intensive systems requires custom-tailored process models that fit the organizational and project goals as well as the development contexts. These models are a necessary prerequisite for creating project plans that are expected to fulfill business goals. Although project planners require individual process models custom-tailored to their constraints, software or system developing organizations also require generic processes (i.e., reference processes) that capture project-independent knowledge for similar development contexts. The latter is emphazised by assessment approaches (such as CMMI, SPICE) that require explicit process descriptions in order to reach a certain capability or maturity level. Among other concepts such as polymorphism, templates, or generator-based descriptions, software process patterns are used to describe generic process knowledge. Several approaches for describing the architecture of process patterns have already been published (e.g., [7]). However, there is a lack of descriptions on how to compose process patterns for a specific decelopment context in order to gain a custom-tailored process model for a project. This paper focuses on the composition of process patterns in a goal-oriented way. First, the paper describes which information a process pattern should contain so that it can be used for systematic composition. Second, a composition method is sketched. Afterwards, the results of a proof-of-concept evaluation of the method are described. Finally, the paper is summarized and open research questions are sketched.
description: 5 pages
Robin boundary conditions in acoustic BTZ black holes
Creators: name: de Oliveira, Christyan C.
name: Mosna, Ricardo A.
name: Pitelli, João Paulo M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We introduce an analog model for the conformally coupled scalar field on the BTZ black hole. The model is based on the propagation of acoustic waves in a Laval nozzle. Since the BTZ black hole is not a globally hyperbolic spacetime, the dynamics of the scalar field is not well defined until extra boundary conditions are prescribed at its spatial infinity. We show that quasinormal modes (QNMs) satisfying Dirichlet, Neumann, and Robin boundary conditions in the BTZ black hole can be interpreted in terms of ordinary QNMs defined with respect to an appropriately extended nozzle. We also discuss the stability of our model with respect to small perturbations.
description: 12 pages, 6 figures