cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Cosmological frames for theories with absolute parallelism
Creators: name: Ferraro, Rafael
name: Fiorini, Franco
Publisher: name: arXiv
Year: 2011
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The vierbein (tetrad) fields for closed and open Friedmann-Robertson-Walker cosmologies are hard to work out in most of the theories featuring absolute parallelism. The difficulty is traced in the fact that these theories are not invariant under local Lorentz transformations of the vierbein. We illustrate this issue in the framework of f(T) theories and Born-Infeld determinantal gravity. In particular, we show that the early Universe as described by the Born-Infeld scheme is singularity free and naturally inflationary as a consequence of the very nature of Born-Infeld gravitational action.
description: 8 pages, 1 figure. Talk given at the 8th Alexander Friedmann International Seminar on Gravitation and Cosmology, Rio de Janeiro, Brazil, June 2011. Submitted to the Proceedings
Mixed Signal Timing Techniques for SPAD Direct Time-of-Flight Imaging Sensors
Creators: name: MORRISON, DANIEL JAMES
Publisher: name: Monash University
Year: 2021
Subjects: subject: 90604 Microelectronics and Integrated Circuits
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: 90605 Photodetectors, Optical Sensors and Solar Cells

description: The capability of fabricating structures known as SPADs on CMOS processes has led to the development of 3D cameras that measure the time-of-flight of a laser pulse. SPADs sense single-photons with low timing jitter allowing accurate distance measurements, so 2D SPAD arrays that are co-integrated with per-pixel timing circuits can capture a distance image. This thesis investigates mixed signal approaches for photon timing, introducing a digital technique using multistage LFSRs and an analog technique resistant to PVT variation, readout noise, and capacitive discharge. A SPAD sensor combining both techniques is presented demonstrating high linearity, resolution, and a long timing range.
Scale-dependent halo bias from scale-dependent growth
Creators: name: Parfrey, Kyle
name: Hui, Lam
name: Sheth, Ravi K.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We derive a general expression for the large-scale halo bias, in theories with a scale-dependent linear growth, using the excursion set formalism. Such theories include modified gravity models, and models in which the dark energy clustering is non-negligible. A scale dependence is imprinted in both the formation and evolved biases by the scale-dependent growth. Mergers are accounted for in our derivation, which thus extends earlier work which focused on passive evolution. There is a simple analytic form for the bias for those theories in which the nonlinear collapse of perturbations is approximately the same as in general relativity. As an illustration, we apply our results to a simple Yukawa modification of gravity, and use SDSS measurements of the clustering of luminous red galaxies to constrain the theory's parameters.
description: 14 pages, submitted to Phys. Rev. D
MPEC 2023-H231 : 2019 HF3 = 2020 LC1
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2019 HF3 = 2020 LC1

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Teraelectronvolt Astronomy
Creators: name: Hinton, J. A.
name: Hofmann, W.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Ground-based gamma-ray astronomy, which provides access to the TeV energy range, is a young and rapidly developing discipline. Recent discoveries in this waveband have important consequences for a wide range of topics in astrophysics and astroparticle physics. This article is an attempt to review the experimental status of this field and to provide the basic formulae and concepts required to begin the interpretation of TeV observations.
description: 51 pages, 18 figures (v2 - updated 2 references)
People’s Preferences in the Adoption of New Mobility Technologies: A Case Study of Puget Sound Region
Creators: name: Saud Bashar Al Fadhili
Publisher: name: University of Illinois at Chicago
Year: 2020
Subjects: Uncategorized

description: This is a study where U.S cities are classified according to their demographics, transportation modes and the number of shared bikes and vehicles using hierarchical clustering and principle component analysis. An MNL model is developed using the Puget Sound Regional Council Household Travel Survey in addition to other land use and trip characteristics. After that, several Probit models were developed to test the factors affecting people’s interests and concerns regarding AV technology using the same survey. It was found that US cities fall into four clusters with the majority of US cities fell into one cluster because of their suburban planning and their auto-centric transportation systems. The Multinomial Logit model explores the mode choice in Seattle, an outstanding city and is known for its multimodality. It was found what previous literature points out to the factors affecting the mode choice, which are personal, household, trip, and land use variable. In the end, an order probit model was developed to model the factors affecting the level of interests and concerns towards Autonomous vehicles.
Utilizing the vehicle seat base for whiplash mitigation during rear-end collisions
Creators: name: Figueira, Alicia DaSilva
Publisher: name: University of British Columbia
Year: 2016

description: Rear-end collisions are the most common type of automobile impact; whiplash is the predominant resulting injury which imposes a significant cost on victims, their families, and their employers. These costs include high medical expenses and major insurance claims, and result in lengthy absences from work, chronic pain, and suffering. There have been several advances leading to improved safety designs of the vehicle seat, the primary safety device for mitigating whiplash injuries. Although these advances have been beneficial, injuries continue to occur. Ideally, several safety devices, incorporating multiple seat components, should be utilized in order to compound their injury reduction effects. Currently, there is very little the seat base contributes to the safety of the occupant, therefore, there is considerable opportunity to increase safety through the redesign and use of the seat base. This research utilizes the seat base to implement energy absorbing aluminum foam as an intermediary material between the seat and the vehicle frame, which replaces their rigid connection. During a collision, the impact energy path will be interrupted and partially absorbed by the crushing foam. The relative motion between the seat and vehicle decreases the relative acceleration between the head and body, thereby reducing the peak force experienced by the occupant, and therefore the risk and severity of whiplash injuries. This research first developed a computer-based model of this concept and created a database of a variety of foam material properties through experimental testing. Using a model is a fast and inexpensive method, compared to building and physically testing various concepts, for predicting an occupant's dynamic response to an impact, and allows flexibility in the design of devices for individual vehicle manufacturers. The current research developed a physical prototype of the whiplash mitigating system, for the first time. Measurements from experimental tests were used to assess the effectiveness of the model in predicting the physical behaviour of the system, and of the concept behind the whiplash mitigating system. It was found that the concept has potential for reducing risk of injuries, however, the effectiveness of the model in predicting physical behaviour of an occupant needs improvement.
The QGP shear viscosity -- elusive goal or just around the corner?
Creators: name: Shen, Chun
name: Bass, Steffen A
name: Hirano, Tetsufumi
name: Huovinen, Pasi
name: Qiu, Zhi
name: Song, Huichao
name: Heinz, Ulrich W
Publisher: name: arXiv
Year: 2011
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: With the new viscous hydrodynamic + hadron cascade hybrid code VISHNU, a rather precise (O(25%)) extraction of the QGP shear viscosity (eta/s)_QGP from heavy-ion elliptic flow data is possible if the initial eccentricity of the collision fireball is known with <5% accuracy. At this point, eccentricities from initial state models differ by up to 20%, leading to an O(100%) uncertainty for (eta/s)_QGP. It is shown that a simultaneous comparison of elliptic and triangular flow, v_2 and v_3, puts strong constraints on initial state models and can largely eliminate the present uncertainty in (eta/s)_QGP. The variation of the differential elliptic flow v_2(p_T) for identified hadrons between RHIC and LHC energies provides additional tests of the evolution model.
description: 4 pages, 4 figures. Contribution to the proceedings for Quark Matter 2011, to appear in J. Phys. G
Non-equilibrium transport theory of the singlet-triplet transition: perturbative approach
Creators: name: Horváth, Bertalan
name: Lazarovits, Bence
name: Zaránd, Gergely
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We use a simple iterative perturbation theory to study the singlet-triplet (ST) transition in lateral and vertical quantum dots, modeled by the non-equilibrium two-level Anderson model. To a great surprise, the region of stable perturbation theory extends to relatively strong interactions, and this simple approach is able to reproduce all experimentally-observed features of the ST transition, including the formation of a dip in the differential conductance of a lateral dot indicative of the two-stage Kondo effect, or the maximum in the linear conductance around the transition point. Choosing the right starting point to the perturbation theory is, however, crucial to obtain reliable and meaningful results.
Ethanol and the Female Brain: Estrogen as a Regulator of Ethanol Reward and Drinking Behavior
Creators: name: Hilderbrand, Elisa Rachel
Publisher: name: University of Illinois at Chicago
Year: 2020
Subjects: Uncategorized

description: Recent decades have seen a dramatic increase in the incidence of alcohol use disorder (AUD) among women. Despite the substantial risk that AUD poses to women’s health, however, females remain underrepresented in AUD research, and little information about alcohol’s effects on the female brain is available to guide the development of more effective preventative and treatment measures. A growing body of evidence implicates the ovarian steroid hormone 17β-estradiol (E2) as a regulator of female drinking behavior, but the neurological mechanisms via which E2 regulates alcohol intake are unknown. Here I have demonstrated that E2 enhances the rewarding properties of alcohol (ethanol) in female mice, as measured by the conditioned place preference (CPP) test. This is the first study to demonstrate that estradiol regulates ethanol reward in female mice. To investigate potential neural mechanisms by which E2 may act to enhance ethanol reward and drinking behavior, I have conducted a series of behavioral and molecular tests manipulating the activity or expression of the classical estrogen receptors (ERs), ERα and ERβ, to which E2 binds with approximately equal affinity. First, using ERα- and ERβ-selective agonists, I showed that the classical ERs regulate ethanol CPP in female mice. Notably, my results suggest that activation of both ERα and ERβ is required for estrogenic enhancement of ethanol reward. This finding is complemented by my experiments using the drinking in the dark (DID) test, which models voluntary, binge-like ethanol drinking. Using RNAi-mediated knockdown, I demonstrated that ERα or ERβ in the ventral tegmental area (VTA) contribute to the regulation of ethanol consumption by gonadally intact female mice. Knocking down intra-VTA expression of either classical ER significantly reduced binge-like ethanol intake in females. Importantly, this was a sex-specific effect, because knockdown of either receptor failed to produce a decrease in drinking in male mice. In conclusion, my research builds upon existing studies, supporting the idea that E2 may enhance female vulnerability to AUD by increasing ethanol reward and binge-like drinking. Future research should investigate the potential for sex-specific treatment options, including medications that regulate ovarian hormone production and/or modulate the activity of ERs in the brain.
Four-loop QCD analysis of the Bjorken sum rule vs data
Creators: name: Khandramai, V. L.
name: Pasechnik, R. S.
name: Shirkov, D. V.
name: Solovtsova, O. P.
name: Teryaev, O. V.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the polarized Bjorken sum rule at low momentum transfers in the range $0.22
description: 6 pages, 7 figures
Probing photo-induced melting of antiferromagnetic order in La0.5Sr1.5MnO4 by ultrafast resonant soft X-ray diffraction
Creators: name: Ehrke, H.
name: Tobey, R. I.
name: Wall, S.
name: Cavill, S. A.
name: Först, M.
name: Khanna, V.
name: Garl, Th.
name: Stojanovic, N.
name: Prabhakaran, D.
name: Boothroyd, A. T.
name: Gensch, M.
name: Mirone, A.
name: Reutler, P.
name: Revcolevschi, A.
name: Dhesi, S. S.
name: Cavalleri, A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Photo-excitation in complex oxides1 transfers charge across semicovalent bonds, drastically perturbing spin and orbital orders2. Light may then be used in compounds like magnetoresistive manganites to control magnetism on nanometre lengthscales and ultrafast timescales. Here, we show how ultrafast resonant soft x-ray diffraction can separately probe the photo-induced dynamics of spin and orbital orders in La0.5Sr1.5MnO4. Ultrafast melting of CE antiferromagnetic spin order is evidenced by the disappearance of a (1/4,1/4,1/2) diffraction peak. On the other hand the (1/4,1/4,0) peak, reflecting orbital order, is only partially reduced. Cluster calculations aid our interpretation by considering different magnetically ordered states accessible after photo-excitation. Nonthermal coupling between light and magnetism emerges as a primary aspect of photo-induced phase transitions in manganites.
description: 7 pages manuscript, 4 figures
Tangent-point self-avoidance energies for curves
Creators: name: Strzelecki, Pawel
name: von der Mosel, Heiko
Publisher: name: arXiv
Year: 2010
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 28A75, 49Q10, 53A04, 57M25

description: We study a two-point self-avoidance energy $E_q$ which is defined for all rectifiable curves in $R^n$ as the double integral along the curve of $1/r^q$. Here $r$ stands for the radius of the (smallest) circle that is tangent to the curve at one point and passes through another point on the curve, with obvious natural modifications of this definition in the exceptional, non-generic cases. It turns out that finiteness of $E_q(γ)$ for $q\ge 2$ guarantees that $γ$ has no self-intersections or triple junctions and therefore must be homeomorphic to the unit circle or to a closed interval. For $q>2$ the energy $E_q$ evaluated on curves in $R^3$ turns out to be a knot energy separating different knot types by infinite energy barriers and bounding the number of knot types below a given energy value. We also establish an explicit upper bound on the Hausdorff-distance of two curves in $R^3$ with finite $E_q$-energy that guarantees that these curves are ambient isotopic. This bound depends only on $q$ and the energy values of the curves. Moreover, for all $q$ that are larger than the critical exponent $2$, the arclength parametrization of $γ$ is of class $C^{1,1-2/q}$, with Hölder norm of the unit tangent depending only on $q$, the length of $γ$, and the local energy. The exponent $1-2/q$ is optimal.
description: 23 pages, 1 figure
Distorted 5-dimensional vacuum black hole
Creators: name: Abdolrahimi, Shohreh
name: Shoom, Andrey A.
name: Page, Don N.
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper we study how the distortion generated by a static and neutral distribution of external matter affects a 5-dimensional Schwarzschild-Tangherlini black hole. A solution representing a particular class of such distorted black holes admits an RxU(1)xU(1) isometry group. We show that there exists a certain duality transformation between the black hole horizon and a stretched singularity surfaces. The space-time near the distorted black hole singularity has the same topology and Kasner exponents as those of a 5-dimensional Schwarzschild-Tangherlini black hole. We calculate the maximal proper time of free fall of a test particle from the distorted black hole horizon to its singularity and find that, depending on the distortion, it can be less, equal to, or greater than that of a Schwarzschild-Tangherlini black hole of the same horizon area. This implies that due to the distortion, the singularity of a Schwarzschild-Tangherlini black hole can come close to its horizon. A relation between the Kretschmann scalar calculated on the horizon of a 5-dimensional static, asymmetric, distorted black hole and the trace of the square of the Ricci tensor of the horizon surface is derived.
description: 20 pages, 9 figures
A detection pipeline for galactic binaries in LISA data
Creators: name: Littenberg, Tyson B.
Publisher: name: arXiv
Year: 2011
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Galaxy is suspected to contain hundreds of millions of binary white dwarf systems, a large fraction of which will have sufficiently small orbital period to emit gravitational radiation in band for space-based gravitational wave detectors such as the Laser Interferometer Space Antenna (LISA). LISA's main science goal is the detection of cosmological events (supermassive black hole mergers, etc.) however the gravitational signal from the galaxy will be the dominant contribution to the data -- including instrumental noise -- over approximately two decades in frequency. The catalogue of detectable binary systems will serve as an unparalleled means of studying the Galaxy. Furthermore, to maximize the scientific return from the mission, the data must be "cleansed" of the galactic foreground. We will present an algorithm that can accurately resolve and subtract >10000 of these sources from simulated data supplied by the Mock LISA Data Challenge Task Force. Using the time evolution of the gravitational wave frequency, we will reconstruct the position of the recovered binaries and show how LISA will sample the entire compact binary population in the Galaxy.
description: 12 pages, 8 figures
Measuring Feature-Level Participation and Efficacy with Online Teacher Professional Development (oTPD)
Creators: name: Riel, Jeremy
Publisher: name: University of Illinois at Chicago
Year: 2020
Subjects: Uncategorized

description: Over the last three decades, there have been substantial advances in the literature on understanding the essential design principles and necessary features of teacher professional development (PD) programs to support implementation of new curricula and standards. However, although there is a consensus in the research community on the design principles for PD programs, the field also lacks evidence on the specific technologies, media, and strategies for implementing professional development design principles in an effective way. To address this gap in the literature, this dissertation investigated the design of an online teacher professional development (oTPD) program focused on supporting teachers’ voluntary first-time implementation of a novel curriculum called GlobalEd, and whether this program had any effect on both teachers’ implementation adherence and subsequent student achievement. The PD program was analyzed at the feature level by measuring the degree to which each design feature in the PD was used by the participating teachers (n = 41 teachers). To examine whether participation in PD features predicted teachers’ adherence to curriculum implementation tasks, OLS regression models were used to identify that more “active” PD design features that encouraged mindful participation, like message board discussions and generating written projects were found to have a positive predictive effect on curriculum adherence. Conversely, passive media features like email reading and video watching were found to not have any effect in predicting adherence. Finally, hierarchical linear models (HLM) with students nested within teachers’ classrooms were used to investigate whether teachers’ participation in PD features had a predictive effect on student achievement (n = 773 students). No significant predictive effects were observed on both PD participation or adherence on student achievement. As a result, this dissertation provides direct evidence on the efficacy of specific implementation media and technologies that map to long-standing accepted PD design principles. Commitments to design principles that emphasize active learning and relevance to practice are specifically supported. In addition, this dissertation emphasizes the necessity of researchers’ mindfulness of data grain size and the importance of conducting basic research in teacher professional development to ensure that meaningful effects of PD can be observed.
Gluon production on two centers and the effective action approach
Creators: name: Braun, M. A.
name: Lipatov, L. N.
name: Salykin, M. Yu.
name: Vyazovsky, M. I.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Application of the effective action formalism is studied for processes in which the reggeons may split. It is shown that the gluon production on two centers is described by the contribution of the Reggeon-to-two-Reggeons-plus-Particle vertex supplemented by certain singular contributions from the double gluon exchange. The rules for longitudinal integrations are established from the comparison to perturbative QCD amplitude. Convenient expressions for application to the inclusive gluon production are derived.
description: 15 pages, 7 figures; some misprints corrected; submitted to Eur.Phys.Jour. C
Excitation of the molecular gas in the nuclear region of M82
Creators: name: Loenen, A. F.
name: van der Werf, P. P.
name: Güsten, R.
name: Meijerink, R.
name: Israel, F. P
name: Requena-Torres, M. A.
name: García-Burillo, S.
name: Harris, A. I.
name: Klein, T.
name: Kramer, C.
name: Lord, S.
name: Martín-Pintado, J.
name: Röllig, M.
name: Stutzki, J.
name: Szczerba, R.
name: Weiß, A.
name: Philipp-May, S.
name: Yorke, H.
name: Caux, E.
name: Delforge, B.
name: Helmich, F.
name: Lorenzani, A.
name: Morris, P.
name: Philips, T. G.
name: Risacher, C.
name: Tielens, A. G. G. M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present high resolution HIFI spectroscopy of the nucleus of the archetypical starburst galaxy M82. Six 12CO lines, 2 13CO lines and 4 fine-structure lines are detected. Besides showing the effects of the overall velocity structure of the nuclear region, the line profiles also indicate the presence of multiple components with different optical depths, temperatures and densities in the observing beam. The data have been interpreted using a grid of PDR models. It is found that the majority of the molecular gas is in low density (n=10^3.5 cm^-3) clouds, with column densities of N_H=10^21.5 cm^-2 and a relatively low UV radiation field (GO = 10^2). The remaining gas is predominantly found in clouds with higher densities (n=10^5 cm^-3) and radiation fields (GO = 10^2.75), but somewhat lower column densities (N_H=10^21.2 cm^-2). The highest J CO lines are dominated by a small (1% relative surface filling) component, with an even higher density (n=10^6 cm^-3) and UV field (GO = 10^3.25). These results show the strength of multi-component modeling for the interpretation of the integrated properties of galaxies.
description: Accepted for publication in A&A Letters
Additional file 1 of Frequency and severity of prehospital obstetric events encountered by emergency medical services in the United States
Creators: name: Cash, Rebecca E.
name: Swor, Robert A.
name: Samuels-Kalow, Margaret
name: Eisenbrey, David
name: Kaimal, Anjali J.
name: Camargo, Carlos A.
Publisher: name: figshare
Year: 2021
Subjects: subject: Biochemistry
subject: Medicine
subject: Cell Biology
subject: Genetics
subject: FOS: Biological sciences
subject: Neuroscience
subject: Pharmacology
subject: Biotechnology
subject: Science Policy
subject: Immunology
subject: FOS: Clinical medicine
subject: Cancer
subject: 111714 Mental Health
subject: FOS: Health sciences
subject: 110309 Infectious Diseases
subject: 60506 Virology

description: Additional file 1: Table S1. Identification of EMS 911 activations for a potential obstetric event in patients of childbearing age (12-50 years).
Probing gluon and heavy-quark nuclear PDFs with photon + heavy quark production in pA collisions
Creators: name: Stavreva, T.
name: Schienbein, I.
name: Arleo, F.
name: Kovarik, K.
name: Olness, F.
name: Yu, J. Y.
name: Owens, J. F.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a detailed phenomenological study of direct photon production in association with a heavy-quark jet in pA collisions at the Relativistic Heavy Ion Collider (RHIC) and at the Large Hadron Collider (LHC) at next-to-leading order in QCD. The dominant contribution to the cross-section comes from the gluon--heavy-quark (gQ) initiated subprocess, making γ+ Q production a process very sensitive to both the gluon and the heavy-quark parton distribution functions (PDFs). Additionally, the RHIC and LHC experiments are probing complementary kinematic regions in the momentum fraction x_2 carried by the target partons. Thus, the nuclear production ratio R^{γ+Q}_{pA} can provide strong constraints, over a broad x-range, on the poorly determined nuclear parton distribution functions which are extremely important for the interpretation of results in heavy-ion collisions.
Cross-link governed dynamics of biopolymer networks
Creators: name: Broedersz, Chase P.
name: Depken, Martin
name: Yao, Norman Y.
name: Pollak, Martin R.
name: Weitz, David A.
name: MacKintosh, Frederick C.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Physical sciences

description: Cytoskeletal networks of biopolymers are cross-linked by a variety of proteins. Experiments have shown that dynamic cross-linking with physiological linker proteins leads to complex stress relaxation and enables network flow at long times. We present a model for the mechanical properties of transient networks. By a combination of simulations and analytical techniques we show that a single microscopic timescale for cross-linker unbinding leads to a broad spectrum of macroscopic relaxation times, resulting in a weak power-law dependence of the shear modulus on frequency. By performing rheological experiments, we demonstrate that our model quantitatively describes the frequency behavior of actin network cross-linked with $α$-Actinin-$4$ over four decades in frequency.
description: 4 pages
Phytochemical Investigation of a Traditional West African Ethnomedicinal Plant, Icacina trichantha
Creators: name: Guo, Brian Chen
Publisher: name: University of Illinois at Chicago
Year: 2020
Subjects: Uncategorized

description: In this dissertation, a phytochemical analysis of a West African ethnomedicinal plant, Icacina trichantha, was carried out. A bioassay-guided fractionation approach was applied to find novel secondary metabolites from plant extract material. The structures of these new compounds were elucidated using spectroscopic methods including HRESIMS, NMR, CD spectroscopy, and x-ray crystallography. The isolated natural products were evaluated for their cytotoxic and anti-germination activities.
Reimagining the poltergeist in twentieth-century America and Britain
Creators: name: Laursen, Christopher
Publisher: name: University of British Columbia
Year: 2016

description: In creating the psychokinesis hypothesis, twentieth-century American and British psychical researchers, psychoanalysts, and parapsychologists moved the poltergeist away from centuries of religious and spiritual attribution – that it was actions of unseen spirits of the dead, elementals, or demonic forces – into the realm of scientific boundary-work that explored unseen worlds: the human mind, consciousness, and invisible forces and organisms. Boundary-work involved a process of establishing and sustaining ideas that could be presented to the larger scientific community. Poltergeist researchers viewed themselves as pioneers who were expanding scientific knowledge, with a goal of establishing epistemic authority on the phenomenon. While spiritual attributions remained popular, as did suspicions of deceptive behaviour, poltergeist researchers managed to establish the psychokinesis hypothesis as a significant, well-known potential explanation for the poltergeist – one that suggested the human mind could affect the material environment. I argue that collaborative knowledge-making between researchers and the people who directly experienced poltergeist manifestations enabled the psychokinesis hypothesis. To this day, no one is certain what causes the poltergeist phenomenon, and very few individuals actively study it first-hand. The hypothesis was as much a mischievous force in the transformative dynamics of twentieth-century American and British culture and science as the poltergeist itself was in disrupting individual lives.
Surface dangling bond states and band-lineups in hydrogen-terminated Si, Ge, and Ge/Si nanowires
Creators: name: Kagimura, R.
name: Nunes, R. W.
name: Chacham, H.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report an ab initio study of the electronic properties of surface dangling-bond (SDB) states in hydrogen-terminated Si and Ge nanowires with diameters between 1 and 2 nm, Ge/Si nanowire heterostructures, and Si and Ge (111) surfaces. We find that the charge transition levels e(+/-) of SDB states behave as a common energy reference among Si and Ge wires and Si/Ge heterostructures, at 4.3 +/- 0.1 eV below the vacuum level. Calculations of e(+/-) for isolated atoms indicate that this nearly constant value is a periodic-table atomic property.
description: 4 pages, 5 figures, two-column format
A Potential Canid Large Animal Model for Cleft
Creators: name: Yena Jun
Publisher: name: University of Illinois at Chicago
Year: 2020
Subjects: Uncategorized

description: Objective: Advances in biomaterials and bioprinting may soon allow for custom-printed bone grafts, such as for alveolar clefts. Prior to in vivo studies in humans, a large animal model may be needed to test safety and efficacy. We herein describe the size and shape of spontaneous alveolar clefts in Nova Scotia Duck Tolling Retrievers (NSDTR). Methods: CT scans were obtained for 10 NSDTRs with natural bilateral cleft. Cleft defects were modeled using 3D slicer and measured for volume and superoinferior height. This data was compared with average volumetric and shape data from a human sample (n=35). NSDTR clefts were superoinferiorly taller and considerably mesiodistally narrower than human clefts, but were absolutely larger in terms of volume (p<0.001). Conclusions: While NSDTR may provide a sufficient model for narrow alveolar clefts, the biomechanical and physiological challenges posed by very wide cleft defects are unlikely to be well-mimicked in this model organism.
Observation of Multi-Gap Superconductivity in GdO(F)FeAs by Andreev Spectroscopy
Creators: name: Shanygina, T. E.
name: Ponomarev, Ya. G.
name: Kuzmichev, S. A.
name: Mikheev, M. G.
name: Tchesnokov, S. N.
name: Omel'yanovskii, O. E.
name: Sadakov, A. V.
name: Eltsev, Yu. F.
name: Dormidontov, A. S.
name: Pudalov, V. M.
name: Usol'tsev, A. S.
name: Khlybov, E. P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We have studied current-voltage characteristics of Andreev contacts in polycrystalline GdO$_{0.88}$F$_{0.12}$FeAs samples with bulk critical temperature ${T_c}$ = (52.5 \pm 1)K using break-junction technique. The data obtained cannot be described within the single-gap approach and suggests the existence of a multi-gap superconductivity in this compound. The large and small superconducting gap values estimated at T = 4.2K are ΔL = 10.5 \pm 2 meV and ΔS = 2.3 \pm 0.4 meV, respectively.
description: 5 pages, 4 figures, submitted to JETP Letters
Resistance Reimagined: Disability and the Hidden Transcripts of Everyday Resistance
Creators: name: Horowitz, Emily
Publisher: name: University of Illinois at Chicago
Year: 2020
Subjects: Uncategorized

description: Resistance studies is an emerging interdisciplinary field interested in analyzing various resistance practices and their relation to complex entanglements of power and resistance. Largely informed by the seminal work of James Scott in 1985, resistance studies is attentive not only to moments of collective direct action, revolution, and insurrection, but also to the small, informal, subtle and clandestine acts of “everyday resistance” employed by marginalized people. Despite the proliferation of resistance literature that accounts for this genre of small, informal everyday resistance, the everyday resistance of disabled people remains underexplored and undertheorized in resistance studies and in disability studies. This thesis uses discourse analysis to explore conceptual linkages and fissures between disability studies and resistance studies literature on power, disability oppression, and everyday resistance. Taking into consideration the complex systems of power that operate to isolate, exclude, control, surveille, and delegitimize disabled people and the multiple barriers to collective organizing, I suggest that discourses of disability resistance that focus exclusively on visible, collective resistance likely miss something important about how disability oppression and resistance operate. By attending more carefully to instances and patterns of everyday resistance of disabled people, disability and resistance studies scholars may not only begin to reimagine what resistance means, but also more critically evaluate how structures of domination operate to oppress disabled people. I conclude with a discussion of the challenges (both practical and ethical) associated with recognizing, accessing, excavating, decoding, and exposing “hidden transcripts” of everyday disability resistance in the archives and possibilities for recognizing and analyzing sites of contemporary everyday disability resistance.
Superconducting Condensation Energy of the Two-Dimensional Hubbard Model in the Large-Negative-t' Region
Creators: name: Yamaji, Kunihiko
name: Yanagisawa, Takashi
name: Miyazaki, Mitake
name: Kadono, Ryosuke
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We compute the superconducting condensation energies Econd of Hg1201 and Tl2201 cuprates by applying the variational Monte Carlo method to the two-dimensional Hubbard model, first, with the specific band parameters t' = -2t" = -0.25t appropriate for these highest-Tc single-CuO2-layer cuprates; t, t' and t" are the first-, second- and third-neighbor transfer energies, respectively. In the range of on-site Coulomb energy U of (7\sim10)t with optimal doping, we succeed in obtaining the bulk-limit Econd values by extrapolating the results. They sharply increase with increasing U and become comparable to experimental values when U \approx 9t. Next, Econd values at t' = -2t" = -0.18t demonstrate that with a fixed U the bulk-limit Econd quickly increases with a decrease in |t'| = 2t" in the large-|t'| region. Finally, we argue that the remoteness of the apex oxygen from the planar Cu in the two cuprates is considered to increase U and bring about the experimental magnitude of Econd. The present scheme explains the observed correlation between Tc and t' among cuprates.
description: Since the text part didn't appear, it is resubmitted. 19 pages
Real-Space Properties of Topological and Correlated Materials
Creators: name: Sagen Cocklin
Publisher: name: University of Illinois at Chicago
Year: 2020
Subjects: Uncategorized

description: Topological superconductors have been theorized to exhibit novel electronic states known as Majorana states. These states have interesting non-Abelian braiding statistics, which, along with their protection by the topological phase, make them prime candidate states for robust quantum computing. Due to the bulk-boundary correspondence in topological materials, these states are exhibited at the boundaries of materials making real-space probes, such as scanning tunneling spectroscopy (STS) necessary for their characterization. In this dissertation, I discuss the emergence of topological superconductivity in Fe/Re(0001)-O(2X1) as evidenced by STS measurements and compare with theory. I discuss tuning the dimension of generic topological superconductors, which may open the door to furthering the capabilities of engineering Majorana states. I describe a new model of topological superconductivity in FeSe0.45Te0.55. Finally, I examine the real-space probe shot-noise scanning tunneling spectroscopy using the Kondo effect as a testbed.
Critical mass and the dependency of research quality on group size
Creators: name: Kenna, Ralph
name: Berche, Bertrand
Publisher: name: arXiv
Year: 2010
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Academic research groups are treated as complex systems and their cooperative behaviour is analysed from a mathematical and statistical viewpoint. Contrary to the naive expectation that the quality of a research group is simply given by the mean calibre of its individual scientists, we show that intra-group interactions play a dominant role. Our model manifests phenomena akin to phase transitions which are brought about by these interactions, and which facilitate the quantification of the notion of critical mass for research groups. We present these critical masses for many academic areas. A consequence of our analysis is that overall research performance of a given discipline is improved by supporting medium-sized groups over large ones, while small groups must strive to achieve critical mass.
description: 16 pages, 6 figures consisting of 16 panels. Presentation and reference list improved for version 2
Cortical auditory evoked potentials to gaps in broadband noise in infants
Creators: name: Jordan, Rachel
Publisher: name: University of British Columbia
Year: 2016

description: Purpose: There are currently no objective measures to evaluate hearing function in young infants with impaired temporal processing (e.g., Auditory Neuropathy Spectrum Disorder (ANSD)). The present study investigated cortical auditory evoked potentials (CAEPs) elicited to gaps in broadband noise to assess temporal processing ability in infants. This method has potential as a clinical tool in these populations. This study was intended as a first step to determine feasibility. Method: Participants were 10 adults and 22 infants with normal hearing. Stimuli were continuous broadband noise with 20, 50 and 100 ms gaps inserted once per second. CAEPs were recorded at Cz referenced to M1. Two replications (minimum of 75 trials each) were included for analysis and judged by three raters for response presence or absence. Results: CAEPs were interpreted as present for the majority of infants and adults to 20-, 50- and 100-ms gaps. The adults had responses in almost all cases, consistent with previous results. In most cases, the morphology of the infant response was consistent with previous results, that is, a single peak at approximately 200 ms. In some cases, however, the infant response was a plateau- shaped peak. Conclusions: These results suggest that it is feasible to record CAEPs in infants to gaps and that infants may have better gap detection abilities than previously thought (20 ms or better). Further research is needed to refine this technique and to extend it to clinical populations for clinical use.
Information-Theoretic Analysis of an Energy Harvesting Communication System
Creators: name: Ozel, Omur
name: Ulukus, Sennur
Publisher: name: arXiv
Year: 2010
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: In energy harvesting communication systems, an exogenous recharge process supplies energy for the data transmission and arriving energy can be buffered in a battery before consumption. Transmission is interrupted if there is not sufficient energy. We address communication with such random energy arrivals in an information-theoretic setting. Based on the classical additive white Gaussian noise (AWGN) channel model, we study the coding problem with random energy arrivals at the transmitter. We show that the capacity of the AWGN channel with stochastic energy arrivals is equal to the capacity with an average power constraint equal to the average recharge rate. We provide two different capacity achieving schemes: {\it save-and-transmit} and {\it best-effort-transmit}. Next, we consider the case where energy arrivals have time-varying average in a larger time scale. We derive the optimal offline power allocation for maximum average throughput and provide an algorithm that finds the optimal power allocation.
description: Published in IEEE PIMRC, September 2010
Top quark asymmetry from a non-Abelian horizontal symmetry
Creators: name: Jung, Sunghoon
name: Pierce, Aaron
name: Wells, James D.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Motivated by the persistence of a large measured top quark forward-backward asymmetry at the Tevatron, we examine a model of non-Abelian flavor gauge symmetry. The exchange of the gauge bosons in the $t$-channel can give a large asymmetry due to the forward Rutherford scattering peak. We address generic constraints on non-Abelian $t$-channel physics models including flavor diagonal resonances and potentially dangerous contributions to inclusive top pair cross sections. We caution on the general difficulty of comparing theoretical predictions for top quark signals to the existing experimental results due to potentially important acceptance effects. The first signature at the Large Hadron Collider can be a large inclusive top pair cross section, or like-sign dilepton events, although the latter signal is much smaller than in Abelian models. Deviations of the invariant mass distributions at the LHC will also be promising signatures. A more direct consistency check of the Tevatron asymmetry through the LHC asymmetry is more likely to be relevant at a later stage.
description: 21 pages, 7 figures
Information Networks to Derive Value from Social Media
Creators: name: Pankhuri Malhotra
Publisher: name: University of Illinois at Chicago
Year: 2020
Subjects: Uncategorized

description: The rise in electronic interactions has made information networks ubiquitous. Correspondingly, research across multiple domains has begun to acknowledge the social and economic value of these networks for business decision-making. In this dissertation, we derive brand networks from social media to provide statistical knowledge on online market structures and automatically infer brand associations over time. Compared to extant data mining approaches that rely on substantial human intervention, this unsupervised automated approach lets practitioners study the relative positioning of their brand not only against a set of common competitors but against any other brand in the ecosystem; thus, uncovering a broader picture on both within-industry competition and across-industry complementarities. To investigate the usefulness of our proposed methodology, we validate the findings from our automated approach against external survey ratings and conduct extensive robustness checks to ensure reliability of underlying Twitter data. Large scale data focused methods for brand management are relatively new and present many opportunities for future research. We hope the methods introduced in this dissertation serve as a foundation for researchers interested in leveraging implicit brand networks for gaining insights into consumers and brands.