Physical Sciences and Mathematics Commons^™

Sphingomyelin And Gm1 Influence Huntingtin Binding To, Disruption Of, And Aggregation On Lipid Membranes, Maxmore Chaibva, Xiang Gao, Pranav Jain, Warren A. Campbell, Shelli L. Frey, Justin Legleiter

Faculty & Staff Scholarship

Huntington disease (HD) is an inherited neurodegenerative disease caused by the expansion beyond a critical threshold of a polyglutamine (polyQ) tract near the N- terminus of the huntingtin (htt) protein. Expanded polyQ promotes the formation of a variety of oligomeric and fibrillar aggregates of htt that accumulate into the hallmark proteina- ceous inclusion bodies associated with HD. htt is also highly associated with numerous cellular and subcellular membranes that contain a variety of lipids. As lipid homeostasis and metabolism abnormalities are observed in HD patients, we investigated how varying both the sphingomyelin (SM) and ganglioside (GM1) contents modifies the interactions …

Existence Of Global Solutions For Nonlinear Magnetohydrodynamics With Finite Larmor Radius Corrections, Fariha Elsrrawi, Harumi Hattori

Faculty & Staff Scholarship

We discuss the existence of global solutions to the magnetohydrodynamics (MHD) equations, where the effects of finite Larmor radius corrections are taken into account. Unlike the usual MHD, the pressure is a tensor and it depends on not only the density but also the magnetic field. We show the existence of global solutions by the energy methods. Our techniques of proof are based on the existence of local solution by semigroups theory and a priori estimate.

Onsager Reciprocal Relations: Microscopic (Onsager) Or Macroscopic (Sliepcevich), R. E. "Buddy" Babcock

Chemical Engineering Faculty Publications and Presentations

This paper is a combination of the discussion of two nineteenth century theoretical giantsLars Onsager and C. M. Sliepcevich, their works in general, and specifically the famousreciprocal relations of Onsager with respect to irreversible thermodynamics. Emphasis isplaced on their penetrating depth and breadth of analysis so inherently necessary in theirproblem-solving endeavors. The landscape of their work will be laid out for the readerby a comparison of Onsager’s microscopic statistical mechanics derivation of the famousreciprocal relationships and a macroscopic thermodynamic derivation published by C. M.Sliepsevich that led to considerable discussion in the literature in the 1960’s. Somelabelled this discussion a controversy; …

Higher Cluster Categories And Qft Dualities, Sebastián Franco, Gregg Musiker

Publications and Research

We introduce a unified mathematical framework that elegantly describes minimally supersymmetry gauge theories in even dimensions, ranging from six dimensions to zero dimensions, and their dualities. This approach combines and extends recent developments on graded quivers with potentials, higher Ginzburg algebras, and higher cluster categories (also known as m-cluster categories). Quiver mutations studied in the context of mathematics precisely correspond to the order-(m + 1) dualities of the gauge theories. Our work indicates that these equivalences of quiver gauge theories sit inside an infinite family of such generalized dualities.

Global Constraints On Top Quark Anomalous Couplings, Frédéric Déliot, Ricardo Faria, Miguel C. N. Fiolhais, Pedro Lagarelhos, António Onofre, Christopher M. Pease, Ana Vasconcelos

Publications and Research

The latest results on top quark physics, namely single top quark production cross sections, W-boson helicity and asymmetry measurements are used to probe the Lorentz structure of the Wtb vertex. The increase of sensitivity to new anomalous physics contributions to the top quark sector of the standard model is quantified by combining the relevant results from Tevatron and the Large Hadron Collider. The results show that combining an increasing set of available precision measurements in the search for new physics phenomena beyond the standard model leads to significant sensitivity improvements, especially when compared with the current expectation for the …

Octet Baryons In Large Magnetic Fields, Amol Deshmukh, Brian C. Tiburzi

Publications and Research

Magnetic properties of octet baryons are investigated within the framework of chiral perturbation theory. Utilizing a power counting for large magnetic fields, the Landau levels of charged mesons are treated exactly giving rise to baryon energies that depend nonanalytically on the strength of the magnetic field. In the small-field limit, baryon magnetic moments and polarizabilities emerge from the calculated energies. We argue that the magnetic polarizabilities of hyperons provide a testing ground for potentially large contributions from decuplet pole diagrams. In external magnetic fields, such contributions manifest themselves through decuplet-octet mixing, for which possible results are compared in a few …

Master Integrals For Double Real Radiation Emission In Heavy-To-Light Quark Decay, Roberto Bonciani, Alessandro Broggio, Leandro Cieri, Andrea Ferroglia

Publications and Research

We evaluate analytically the master integrals for double real radiation emission in the b → uW* decay, where b and u are a massive and massless quark, respectively, while W* is an off-shell charged weak boson. Since the W boson can subsequently decay in a lepton anti-neutrino pair, the results of the present paper constitute a further step toward a fully analytic computation of differential distributions for the semileptonic decay of a b quark at NNLO in QCD. The latter partonic process plays a crucial role in the study of inclusive semileptonic charmless decays of B mesons. Our …

Prompt Photon-Jet Angular Correlations At Central Rapidities In P + A Collisions, Sanjin Benić, Adrian Dumitru

Publications and Research

Photon-jet azimuthal correlations in proton-nucleus collisions are a promising tool for gaining information on the gluon distribution of the nucleus in the regime of nonlinear color fields. We compute such correlations from the process $g → q\bar{q}γ$ in the rapidity regime where both the projectile and target light-cone momentum fractions are small. By integrating over the phase space of the quark which emits the photon, subject to the restriction that the photon picks up most of the transverse momentum (to pass an isolation cut), we effectively obtain a g + A → qγ process. For nearly back-to-back photon-jet configurations we …

Bipartite Field Theories And D-Brane Instantons, Sebastían Franco, Eduardo García-Valdecasas, Angel M. Uranga

Publications and Research

We study D-brane instantons in systems of D3-branes at toric CY 3-fold singularities. The instanton effect can be described as a backreaction modifying the geometry of the mirror configuration, in which the breaking of U(1) symmetries by the instanton translates into the recombination of gauge D-branes, which also directly generates the instanton-induced charged field theory operator. In this paper we describe the D-brane instanton backreaction in terms of a combinatorial operation in the bipartite dimer diagram of the original theory. Interestingly, the resulting theory is a general Bipartite Field Theory (BFT), defined by a bipartite graph tiling a general (possibly …

Baryon Magnetic Moments: Symmetries And Relations, Assumpta Parreño, Martin J. Savage, Brian C. Tiburzi, Jonas Wilhelm, Emmanuel Chang, William Detmold, Kostas Orginos

Publications and Research

Magnetic moments of the octet baryons are computed using lattice QCD in background magnetic fields, including the first treatment of the magnetically coupled Σ⁰- Λ system. Although the computations are performed for relatively large values of the up and down quark masses, we gain new insight into the symmetries and relations between magnetic moments by working at a three-flavor mass-symmetric point. While the spinflavor symmetry in the large N_c limit of QCD is shared by the naïve constituent quark model, we find instances where quark model predictions are considerably favored over those emerging in the large N …

The Effects Of Different Versions Of A Gateway Stem Course On Student Attitudes And Beliefs, Xiangming Wu, Jessica Deshler, Edgar Fuller

Faculty & Staff Scholarship

Background

Substantial research has been conducted focusing on student outcomes in mathematics courses in order to better understand the ways in which these outcomes depend on the underlying instructional methodologies found in the courses. From 2009 to 2014, the Mathematical Association of America (MAA) studied Calculus I instruction in United States (US) colleges and universities in the Characteristics of Successful Programs of College Calculus (CSPCC). One aspect of this study attempted to understand the impact of these courses on student experience.

Results

In this paper, we describe results from an examination of the effect of course structure on students’ attitudes …

Enhanced Hot Electron Lifetimes In Quantum Wells With Inhibited Phonon Coupling, Hamidreza Esmaielpour, Vincent R. Whiteside, Herath P. Piyathilaka, Sangeetha Vijeyaragunathan, Bin Wang, Echo Adcock-Smith, Kenneth P. Roberts, Tetsuya D. Mishima, Michael B. Santos, Alan D. Bristow, Ian R. Sellers

Faculty & Staff Scholarship

Hot electrons established by the absorption of high-energy photons typically thermalize on a picosecond time scale in a semiconductor, dissipating energy via various phonon-mediated relaxation pathways. Here it is shown that a strong hot carrier distribution can be produced using a type-II quantum well structure. In such systems it is shown that the dominant hot carrier thermalization process is limited by the radiative recombination lifetime of electrons with reduced wavefunction overlap with holes. It is proposed that the subsequent reabsorption of acoustic and optical phonons is facilitated by a mismatch in phonon dispersions at the InAs-AlAsSb interface and serves to …

Electron Paramagnetic Resonance And Optical Absorption Study Of Acceptors In Cdsip2 Crystals, E M. Scherrer, L E. Halliburton, E M. Golden, K T. Zawilski, P G. Schunemann, F K. Hopkins, K L. Averett, N C. Giles

Faculty & Staff Scholarship

Cadmium silicon diphosphide (CdSiP2) is a nonlinear material often used in optical parametric oscillators (OPOs) to produce tunable laser output in the mid-infrared. Absorption bands associated with donors and acceptors may overlap the pump wave- length and adversely affect the performance of these OPOs. In the present investigation, electron paramagnetic resonance (EPR) is used to identify two unintentionally present acceptors in large CdSiP2 crystals. These are an intrinsic silicon-on-phosphorus anti- site and a copper impurity substituting for cadmium. When exposed to 633 nm laser light at temperatures near or below 80 K, they convert to their neutral paramagnetic charge states …

Electrical Detection Of Charge-To- Spin And Spin-To-Charge Conversion In A Topological Insulator Bi2te3 Using Bn/Al2o3 Hybrid Tunnel Barrier, C.H. Li, O.M.J. Van't Erve, C. Yan, L. Li, B.T. Jonker

Faculty & Staff Scholarship

One of the most striking properties of three-dimensional topological insulators (TIs) is spin-momentum locking, where the spin is locked at right angles to momentum and hence an unpolarized charge current creates a net spin polarization. Alternatively, if a net spin is injected into the TI surface state system, it is distinctively associated with a unique carrier momentum and hence should generate a charge accumulation, as in the so-called inverse Edelstein effect. Here using a Fe/Al2O3/BN tunnel barrier, we demonstrate both effects in a single device in Bi2Te3: the electrical detection of the spin accumulationgenerated by an unpolarized current flowing through …

Item-Level Gender Fairness In The Force And Motion Conceptual Evaluation And The Conceptual Survey Of Electricity And Magnetism, Rachel Henderson, Paul Miller, John Stewart, Adrienne Traxler, Rebecca Lindell

Faculty & Staff Scholarship

Gender gaps on the most widely used conceptual inventories created by physics education researchers have been extensively studied. Most of the research exploring the consistent gender gaps has been performed at the student level using the total evaluation score; less research has been performed examining these assessments at the item level and this research has been predominately restricted to the Force Concept Inventory (FCI). Many studies have identified subsets of FCI items as unfair to either men or women. An item is fair if men and women of equal ability in conceptual physics score equally on the item. This study …

Multidimensional Item Response Theory And The Force Concept Inventory, John Stewart, Cabot Zabriskie, Seth Devore, Gay Stewart

Faculty & Staff Scholarship

Research on the test structure of the Force Concept Inventory (FCI) has largely been performed with exploratory methods such as factor analysis and cluster analysis. Multidimensional Item Response Theory (MIRT) provides an alternative to traditional exploratory factor analysis which allows statistical testing to identify the optimal number of factors. Application of MIRT to a sample of N 1⁄4 4716 FCI post-tests identified a 9-factor solution as optimal. Additional analysis showed that a substantial part of the identified factor structure resulted from the practice of using problem blocks and from pairs of similar questions. Applying MIRT to a reduced set of …

Reconstructing Phase Diagrams From Local Measurements Via Gaussian Processes: Mapping The Temperature-Composition Space To Confidence, Dhiren K. Pradhan, Shalini Kumari, Evgheni Strelcov, Dillip K. Pradhan, Ram S. Katiyar, Sergei V. Kalinin, Nouamane Laanait, Rama K. Vasudevan

Faculty & Staff Scholarship

We show the ability to map the phase diagram of a relaxor-ferroelectric system as a function of temperature and composition through local hysteresis curve acquisition, with the voltage spectroscopy data being used as a proxy for the (unknown) microscopic state or thermodynamic parameters of materials. Given the discrete nature of the measurement points, we use Gaussian processes to reconstruct hysteresis loops in temperature and voltage space, and compare the results with the raw data and bulk dielectric spectroscopy measurements. The results indicate that the surface transition temperature is similar for all but one composition with respect to the bulk. Through …

Robust Topological Phase In Proximitized Core–Shell Nanowires Coupled To Multiple Superconductors, Tudor D. Stanescu, Anna Stitek, Andrei Manolescu

Faculty & Staff Scholarship

We consider core–shell nanowires with prismatic geometry contacted with two or more superconductors in the presence of a mag- netic field applied parallel to the wire. In this geometry, the lowest energy states are localized on the outer edges of the shell, which strongly inhibits the orbital effects of the longitudinal magnetic field that are detrimental to Majorana physics. Using a tight-binding model of coupled parallel chains, we calculate the topological phase diagram of the hybrid system in the presence of non-vanishing transverse potentials and finite relative phases between the parent superconductors. We show that having finite relative phases strongly …

Reducing Uncertainties In Applying Remotely Sensed Land Use And Land Cover Maps In Land-Atmosphere Interaction: Identifying Change In Space And Time, Yaqian He, Timothy A. Warner, Brenden E. Mcneil, Eungul Lee

Faculty & Staff Scholarship

Land use and land cover (LULC) data are a central component of most land-atmosphere interaction studies, but there are two common and highly problematic scale mismatches between LULC and climate data. First, in the spatial domain, researchers rarely consider the impact of scaling up fine-scale LULC data to match coarse-scale climate datasets. Second, in the temporal domain, climate data typically have sub-daily, daily, monthly, or annual resolution, but LULC datasets often have much coarser (e.g., decadal) resolution. We first explored the effect of three spatial scaling methods on correlations among LULC data and a land surface climatic variable, latent heat …

Gender Fairness Within The Force Concept Inventory, Adrienne Traxler, Rachel Henderson, John Stewart, Gay Stewart, Alexis Papak, Rebecca Lindell

Faculty & Staff Scholarship

Research on the test structure of the Force Concept Inventory (FCI) has largely ignored gender, and research on FCI gender effects (often reported as “gender gaps”) has seldom interrogated the structure of the test. These rarely crossed streams of research leave open the possibility that the FCI may not be structurally valid across genders, particularly since many reported results come from calculus-based courses where 75% or more of the students are men. We examine the FCI considering both psychometrics and gender disaggregation (while acknowledging this as a binary simplification), and find several problematic questions whose removal decreases the apparent gender …

Comparing Source Rock Maturity With Pore Size Distribution And Fluid Saturation In The Bakken-Three Forks Petroleum System, Williston Basin, North Dakota, Adedoyin Suleman Adeyilola

Theses and Dissertations

With the continuous demand for fossil fuel and advancement in technology, the unconventional petroleum resources have come into limelight. The Devonian Three Forks Formation consisting of carbonate and clastic sediments is an unconventional oil accumulation

containing about 3.73 billion barrels of technically recoverable oil. However, understanding rock properties of the various lithofacies and fluid saturation is still challenging.

The petroleum prospectivity was evaluated by integrating organic maturity and hydrocarbon generation with porosity distribution and fluid saturation in the Ambrose field and adjacent fields. The organic maturity was done with a programmed pyrolysis analysis (Source

Rock Analyzer) using samples taken at …

Computing Eigenmodes Of Elliptic Operators On Manifolds Using Radial Basis Functions, Vladimir Delengov

CGU Theses & Dissertations

In this work, a numerical approach based on meshless methods is proposed to obtain eigenmodes of Laplace-Beltrami operator on manifolds, and its performance is compared against existing alternative methods. Radial Basis Function (RBF)-based methods allow one to obtain interpolation and differentiation matrices easily by using scattered data points. We derive expressions for such matrices for the Laplace-Beltrami operator via so-called Reilly’s formulas and use them to solve the respective eigenvalue problem. Numerical studies of proposed methods are performed in order to demonstrate convergence on simple examples of one-dimensional curves and two-dimensional surfaces.

Linear Stability Analysis With Solution Patterns Due To Varying Thermal Diffusivity For A Convective Flow In A Porous Medium, Dambaru Bhatta

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Here we investigate the effect of the vertical rate of change in thermal diffusivity due to a hydrothermal convective flow in a horizontal porous medium. The continuity equation, the heat equation and the momentum-Darcy equation constitute the governing system for the flow in a porous medium. Assuming a vertically varying basic state, we derive the linear system and from this linear system, we compute the critical Rayleigh and wave numbers. Using fourth-order Runge-Kutta and shooting methods, we obtain the marginal stability curves and linear solutions to analyze the solution pattern for different diffusivity parameters.

Suggesting Missing Information In Text Documents, Grant Michael Hodgson

Theses and Dissertations

A key part of contract drafting involves thinking of issues that have not been addressedand adding language that will address the missing issues. To assist attorneys with this task, we present a pipeline approach for identifying missing information within a contract section. The pipeline takes a contract section as input and includes 1) identifying sections that are similar to the input section from a corpus of contract sections; and 2) identifying and suggesting information from the similar sections that are missing from the input section. By taking advantage of sentence embedding and principal component analysis, this approach suggests sentences that …

Proceedings Of The Cuny Games Conference 4.0: The Interactive Course, Robert O. Duncan, Joe Bisz, Julie Cassidy, Kathleen Offenholley, Maura A. Smale, Carolyn Stallard, Deborah Sturm, Anders A. Wallace, Cuny Games Network

Publications and Research

Proceedings of the CUNY Games Conference, held from January 22-23, 2018, at the CUNY Graduate Center and Borough of Manhattan Community College.

Critical Play with History (Panel) - Composition & Storytelling - Health & Cognitive Sciences - Gaming Anthropology: Teaching Culture and Power Through Games and Design (Panel) - Twine & Writing Games - Easy Ideas II - STEM Games - Global Games for Change Catalog (Panel) - Comics & Active Learning - Fact Checking & Research - Computer Science & Game Design - SimGlobal: Building a Serious Roleplay Course for the Social Sciences (Panel) - Role Playing Games, Narrative, …

A Bayesian Hierarchical Approach To Multivariate Nonstationary Hydrologic Frequency Analysis, C. Bracken, K. D. Holman, B. Rajagopalan, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

We present a general Bayesian hierarchical framework for conducting nonstationary frequency analysis of multiple hydrologic variables. In this, annual maxima from each variable are assumed to follow a generalized extreme value (GEV) distribution in which the location parameter is allowed to vary in time. A Gaussian elliptical copula is used to model the joint distribution of all variables. We demonstrate the utility of this framework with a joint frequency analysis model of annual peak snow water equivalent (SWE), annual peak flow, and annual peak reservoir elevation at Taylor Park dam in Colorado, USA. Indices of largescale climate drivers—El Ni~no Southern …

Linear Dune Morphometrics In Titan’S Belet Sand Sea And A Comparison With The Namib Sand Sea, Corbin Robert Lewis

Theses and Dissertations

Despite atmospheric and compositional differences on Titan and Earth, the similarity in the shape and spacing of linear dunes of the Belet Sand Sea of Titan and the Namib Sand Sea of Earth suggests that comparisons will yield a better understanding of the dictating factors of duneforming processes. We present a methodology for the collection of dune width and spacing measurements representative of the Namib and Belet sand seas. 94,304 locations in Belet from Cassini SAR images and 5,563 locations in the Namib from IKONOS images are used for measurements. The average width and spacing of linear dunes in Belet …

Summary Tables: 2018 Richmond County, Virginia Shoreline Inventory, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Julie G. Bradshaw, Jessica Hendricks, Kory Angstadt, Carl Hershner

Reports

The Shoreline Inventory Summary Tables quantify observed conditions based on river systems, such as the combined length of linear features (e.g. shoreline miles surveyed, miles of bulkhead and revetment), the total number of point features (e.g. docks, boathouses, boat ramps) & total acres of polygon features (tidal marshes).

Summary Tables: 2018 Essex County, Virginia Shoreline Inventory Report, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Julie G. Bradshaw, Jessica Hendricks, David Stanhope, Carl Hershner

Reports

The Shoreline Inventory Summary Tables quantify observed conditions based on river systems, such as the combined length of linear features (e.g. shoreline miles surveyed, miles of bulkhead and revetment), the total number of point features (e.g. docks, boathouses, boat ramps) & total acres of polygon features (tidal marshes).

Segmenting Human Trajectory Data By Movement States While Addressing Signal Loss And Signal Noise, Sungsoon Hwang, Cynthia Vandemark, Navdeep Dhatt, Sai Yalla, Ryan Crews

Sungsoon Hwang