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Articles 61 - 90 of 534

Full-Text Articles in Physical Sciences and Mathematics

Measurements Of The Gamma(Upsilon)P -> P ’Pi(+)Pi(- )Cross Section With The Clas Detector For 0.4 Gev2 < Q(2) < 1.0 Gev2 And 1.3 Gev < W < 1.825 Gev, G. Fedotov, Iu A. Skorodumina, V. D. Burkert, R. W. Gothe, K. Hicks, V. Mokeev, S. Adhikari, Gerard P. Gilfoyle, Et. Al. Aug 2018

Measurements Of The Gamma(Upsilon)P -> P ’Pi(+)Pi(- )Cross Section With The Clas Detector For 0.4 Gev2 < Q(2) < 1.0 Gev2 And 1.3 Gev < W < 1.825 Gev, G. Fedotov, Iu A. Skorodumina, V. D. Burkert, R. W. Gothe, K. Hicks, V. Mokeev, S. Adhikari, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

New results on the single-differential and fully integrated cross sections for the process γvp -> p'π+π- are presented. The experimental data were collected with the CLAS detector at Jefferson Laboratory. Measurements were carried out in the kinematic region of the reaction invariant mass W from 1.3 to 1.825 GeV and the photon virtuality Q2 from 0.4 to 1.0 GeV2. The cross sections were obtained in narrow Q2 bins (0.05 GeV2) with the smallest statistical uncertainties achieved in double-pion electroproduction experiments to date. The results were found to be in …

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Exclusive Photoproduction Of Pi Degrees Up To Large Values Of Mandelstam Variables S, T, And U With Clas, M. C. Kunkel, M. J. Amaryan, I. I. Strakovsky, J. Ritman, G. R. Goldstein, K. P. Adhikari, S. Adhikari, Gerard P. Gilfoyle, Et. Al. Jul 2018

Exclusive Photoproduction Of Pi Degrees Up To Large Values Of Mandelstam Variables S, T, And U With Clas, M. C. Kunkel, M. J. Amaryan, I. I. Strakovsky, J. Ritman, G. R. Goldstein, K. P. Adhikari, S. Adhikari, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

Exclusive photoproduction cross sections have been measured for the process γp -> pπ0 [e+ e- (γ)] with the Dalitz decay final state using tagged photon energies in the range of Eγ = 1.275 – 5.425 GeV. The complete angular distribution of the final state π0, for the entire photon energy range up to large values of t and u, has been measured for the first time. The data obtained show that the cross section dσ / dt, at mid to large angles, decreases with energy as s-6.89 +/- 0.26 …

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Semi-Inclusive Pi(0) Target And Beam-Target Asymmetries From 6 Gev Electron Scattering With Clas, S. Jawalkar, S. Koirala, H. Avakian, P. Bosted, K. A. Griffioen, C. Keith, S. E. Kuhn, Gerard P. Gilfoyle, Et. Al. Jul 2018

Semi-Inclusive Pi(0) Target And Beam-Target Asymmetries From 6 Gev Electron Scattering With Clas, S. Jawalkar, S. Koirala, H. Avakian, P. Bosted, K. A. Griffioen, C. Keith, S. E. Kuhn, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

We present precision measurements of the target and beam-target spin asymmetries from neutral pion electroproduction in deep-inelastic scattering (DIS) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. We scattered 6-GeV, longitudinally polarized electrons off longitudinally polarized protons in a cryogenic 14NH3 target, and extracted double and single target spin asymmetries for ep→e′ π0 X in multidimensional bins in four-momentum transfer (1.0 2 < 3.2 GeV2), Bjorken -x (0.12 < x < 0.48), hadron energy fraction (0.4 < z 0.7), tranverse pion meomentum (0 < PT < 1.0 GeV), and azimuthal angle ϕh between the lepton scattering and hadron production planes. We extracted asymmetries as a function of both x …

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A Multi-Size Study Of Gold Nanoparticle Degradation And Reformation In Ceramic Glazes, Nathan Nl. Dinh, Luke T. Dipasquale, Michael C. Leopold, Ryan H. Coppage Jun 2018

A Multi-Size Study Of Gold Nanoparticle Degradation And Reformation In Ceramic Glazes, Nathan Nl. Dinh, Luke T. Dipasquale, Michael C. Leopold, Ryan H. Coppage

Chemistry Faculty Publications

Most traditional ceramic glazes employ high amounts of transition metal colorants that are toxic to the environment and can cause health issues in humans through surface leaching. Gold nanoparticles (Au-NPs) have been found to be environmentally friendly and non-toxic alternative metal colorant in ceramic glazes. The plasmon band observed with Au-NPs can result in vibrant solutions by manipulating NP size, shape, and concentration; however, the effects of traditional firing in both reductive and oxidative kilns on Au-NPs are poorly understood. Aside from ancient art processes whose mechanisms have not been fully explored, the use of Au-NPs as suspended ceramic glaze …

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Electrostatic Alignment Of Electrospun Peo Fibers By The Gap Method Increases Individual Fiber Modulus In Comparison To Non-Aligned Fibers Of Similar Diameter, Christopher Fryer, Meghan Scharnagl, Christine C. Helms Jun 2018

Electrostatic Alignment Of Electrospun Peo Fibers By The Gap Method Increases Individual Fiber Modulus In Comparison To Non-Aligned Fibers Of Similar Diameter, Christopher Fryer, Meghan Scharnagl, Christine C. Helms

Physics Faculty Publications

Studies on the alignment, physical and mechanical properties of individual electrospun fibers provide insight to their formation, production and optimization. Here we measure the alignment, diameter and modulus of individual fibers formed using the electrostatic gap method. We find electrostatic alignment produces fibers with a smaller diameter than their nonaligned counterparts have. Therefore, due to the dependence of fiber modulus on diameter aligned fibers have a higher modulus. Furthermore, we show that aligned and nonaligned fibers of the similar diameter have different moduli. Aligned fibers have a modulus 1.5 to 2 times larger than nonaligned fibers of the similar diameter.

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Hard Exclusive Pion Electroproduction At Backward Angles With Clas, K. M. Park, R. W. Gothe, B. Pire, K. Semenov-Tian-Shansky, J. -M. Laget, K. P. Adhikari, Gerard P. Gilfoyle, Et. Al. May 2018

Hard Exclusive Pion Electroproduction At Backward Angles With Clas, K. M. Park, R. W. Gothe, B. Pire, K. Semenov-Tian-Shansky, J. -M. Laget, K. P. Adhikari, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

We report on the first measurement of cross sections for exclusive deeply virtual pion electroproduction off the proton, ep→e′nπ+, above the resonance region at backward pion center-of-mass angles. The φπ⁎-dependent cross sections were measured, from which we extracted three combinations of structure functions of the proton. Our results are compatible with calculations based on nucleon-to-pion transition distribution amplitudes (TDAs). These non-perturbative objects are defined as matrix elements of three-quark-light-cone-operators and characterize partonic correlations with a particular emphasis on baryon charge distribution inside a nucleon. Keywords: TDA, Exclusive single pion, Eletroproduction, CLAS

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Measurement Of The Beam Asymmetry Sigma And The Target Asymmetry T In The Photoproduction Of Omega Mesons Off The Proton Using Clas At Jefferson Laboratory, P. Roy, Z. Akbar, S. Park, V. Crede, A. V. Anisovich, I. Denisenko, E. Klempt, Gerard P. Gilfoyle May 2018

Measurement Of The Beam Asymmetry Sigma And The Target Asymmetry T In The Photoproduction Of Omega Mesons Off The Proton Using Clas At Jefferson Laboratory, P. Roy, Z. Akbar, S. Park, V. Crede, A. V. Anisovich, I. Denisenko, E. Klempt, Gerard P. Gilfoyle

Physics Faculty Publications

The photoproduction of omega mesons off the proton has been studied in the reaction γp -> pω using the CEBAF Large Acceptance Spectrometer (CLAS) and the frozen-spin target in Hall B at the Thomas Jefferson National Accelerator Facility. For the first time, the target asymmetry T has been measured in photoproduction from the decay ω -> π+π-π0, using a transversely polarized target with energies ranging from just above the reaction threshold up to 2.8 GeV. Significant nonzero values are observed for these asymmetries, reaching about 30-40% in the third-resonance region. New measurements for the …

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Glocalizing The Composition Classroom With Google Apps For Education, Daniel L. Hocutt, Maury Elizabeth Brown May 2018

Glocalizing The Composition Classroom With Google Apps For Education, Daniel L. Hocutt, Maury Elizabeth Brown

School of Professional and Continuing Studies Faculty Publications

Composing practices in a digitally networked world are inherently intercultural, and situate local needs and constraints within global opportunities and concerns. Global technologies like Google Apps for Education (GAFE) allow students to compose collaboratively across place and time; to do so, students and teachers must navigate a complex local network of institutional policy, learning outcomes, situational needs, and composing practices while also being aware of the global implications of using the interface to compose, review, edit, and share with others. The chapter describes using GAFE in locally situated composition classes. Using such technologies requires a focus on glocalization and an …

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Evaluation Of Agricultural Land Cover Representations On Regional Climate Model Simulations In The Brazilian Cerrado, Stephanie A. Spera, Jonathan M. Winter, Jonathan W. Chipman May 2018

Evaluation Of Agricultural Land Cover Representations On Regional Climate Model Simulations In The Brazilian Cerrado, Stephanie A. Spera, Jonathan M. Winter, Jonathan W. Chipman

Geography and the Environment Faculty Publications

Examining interactions between large-scale land cover and land use change and regional climate in areas undergoing dynamic land transformations, like the Brazilian Cerrado, is crucial for understanding tradeoffs between human needs and ecosystem services. Yet regional climate models often do not include accurate land cover data of these complex landscapes. We use National Center for Atmospheric Research’s Weather Research and Forecasting (WRF) model coupled to the Noah-Multiparameterization (Noah-MP) land surface model to run 10-year climate simulations across Brazil to assess (1) whether an accurate, regionally validated land cover data set with two, new agricultural land cover classifications improves model simulation …

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Clark Measures And A Theorem Of Ritt, Isabelle Chalendar, Pamela Gorkin, Jonathan R. Partington, William T. Ross Apr 2018

Clark Measures And A Theorem Of Ritt, Isabelle Chalendar, Pamela Gorkin, Jonathan R. Partington, William T. Ross

Department of Math & Statistics Faculty Publications

We determine when a finite Blaschke product B can be written, in a non-trivial way, as a composition of two finite Blaschke products (Ritt's problem) in terms of the Clark measure for B. Our tools involve the numerical range of compressed shift operators and the geometry of certain polygons circumscribing the numerical range of the relevant operator. As a consequence of our results, we can determine, in terms of Clark measures, when two finite Blaschke products commute.

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Versatile Sarcosine Biosensing Schemes Utilizing Layer-By-Layer Construction Of Carbon Nanotube-Chitosan Composite Films, Michael J. Pannell, Elizabeth E. Doll, Najwa Labban, Mulugeta B. Wayu, Julie A. Pollack, Michael C. Leopold Apr 2018

Versatile Sarcosine Biosensing Schemes Utilizing Layer-By-Layer Construction Of Carbon Nanotube-Chitosan Composite Films, Michael J. Pannell, Elizabeth E. Doll, Najwa Labban, Mulugeta B. Wayu, Julie A. Pollack, Michael C. Leopold

Chemistry Faculty Publications

Layer-by-layer composite films of carbon nanotubes (CNTs) within a chitosan matrix with sarcosine oxidase enzyme and capped with Nafion have been developed and optimized as a versatile 1st generation amperometric sarcosine biosensing platform that operates successfully both as an isolated sarcosine sensor as well as a functional component within a creatinine sensor. Accurate measurement of sarcosine in urine and creatinine in blood may help with early diagnosis of diseases such as prostate cancer and renal failure, respectively. In this study, each material within the film is systematically optimized toward sarcosine sensitivity, including a critical evaluation of different CNTs effect on …

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The Radio Synchrotron Background: Conference Summary And Report, Jack Singal, J. Haider, M. Ajello, D. R. Ballantyne, Emory F. Bunn, J. Condon, J. Dowell, Et. Al. Mar 2018

The Radio Synchrotron Background: Conference Summary And Report, Jack Singal, J. Haider, M. Ajello, D. R. Ballantyne, Emory F. Bunn, J. Condon, J. Dowell, Et. Al.

Physics Faculty Publications

We summarize the radio synchrotron background workshop that took place 2017 July 19–21 at the University of Richmond. This first scientific meeting dedicated to the topic was convened because current measurements of the diffuse radio monopole reveal a surface brightness that is several times higher than can be straightforwardly explained by known Galactic and extragalactic sources and processes, rendering it by far the least well understood photon background at present. It was the conclusion of a majority of the participants that the radio monopole level is at or near that reported by the ARCADE 2 experiment and inferred from several …

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Double K-S(0) Photoproduction Off The Proton At Clas, S. Chandavar, J. T. Goetz, K. Hicks, D. Keller, M. C. Kunkel, M. Paolone, D. P. Weygand, Gerard P. Gilfoyle, Et. Al. Feb 2018

Double K-S(0) Photoproduction Off The Proton At Clas, S. Chandavar, J. T. Goetz, K. Hicks, D. Keller, M. C. Kunkel, M. Paolone, D. P. Weygand, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

The f0 (1500) meson resonance is one of several contenders to have significant mixing with the lightest glueball. This resonance is well established from several previous experiments. Here we present the first photoproduction data for the f0 (1500) via decay into the K-S(0) K-S(0) channel using the CLAS detector. The reaction γp -> fJp -> K-S(0) K-S(0) p, where J = 0,2, was measured with photon energies from 2.7-5.1 GeV. A clear peak is seen at 1500 MeV in the background subtracted invariant mass spectra of the two kaons. This is enhanced if the measured …

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Erythrocytes And Vascular Function: Oxygen And Nitric Oxide, Christine C. Helms, M. T. Gladwin, Daniel B. Kim-Shapiro Feb 2018

Erythrocytes And Vascular Function: Oxygen And Nitric Oxide, Christine C. Helms, M. T. Gladwin, Daniel B. Kim-Shapiro

Physics Faculty Publications

Erythrocytes regulate vascular function through the modulation of oxygen delivery and the scavenging and generation of nitric oxide (NO). First, hemoglobin inside the red blood cell binds oxygen in the lungs and delivers it to tissues throughout the body in an allosterically regulated process, modulated by oxygen, carbon dioxide and proton concentrations. The vasculature responds to low oxygen tensions through vasodilation, further recruiting blood flow and oxygen carrying erythrocytes. Research has shown multiple mechanisms are at play in this classical hypoxic vasodilatory response, with a potential role of red cell derived vasodilatory molecules, such as nitrite derived nitric oxide and …

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Hill Functions For Stochastic Gene Regulatory Networks From Master Equations With Split Nodes And Time-Scale Separation, Ovidiu Lipan, Cameron Ferwerda Feb 2018

Hill Functions For Stochastic Gene Regulatory Networks From Master Equations With Split Nodes And Time-Scale Separation, Ovidiu Lipan, Cameron Ferwerda

Physics Faculty Publications

The deterministic Hill function depends only on the average values of molecule numbers. To account for the fluctuations in the molecule numbers, the argument of the Hill function needs to contain the means, the standard deviations, and the correlations. Here we present a method that allows for stochastic Hill functions to be constructed from the dynamical evolution of stochastic biocircuits with specific topologies. These stochastic Hill functions are presented in a closed analytical form so that they can be easily incorporated in models for large genetic regulatory networks. Using a repressive biocircuit as an example, we show by Monte Carlo …

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Measurement Of The Q(2) Dependence Of The Deuteron Spin Structure Function G(1) And Its Moments At Low Q(2) With Clas, K. P. Adhikari, A. Deur, L. El Fassi, H. Kang, S. E. Kuhn, M. Ripani, K. Slifer, Gerard P. Gilfoyle, Et. Al. Feb 2018

Measurement Of The Q(2) Dependence Of The Deuteron Spin Structure Function G(1) And Its Moments At Low Q(2) With Clas, K. P. Adhikari, A. Deur, L. El Fassi, H. Kang, S. E. Kuhn, M. Ripani, K. Slifer, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

We measured the g1 spin structure function of the deuteron at low Q2, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W ≈ 1.9  GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γd1 and the spin polarizability γ0d are precisely determined down to a minimum Q2 of 0.02  GeV2 for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first …

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Lithography-Free, Omnidirectional, Cmos-Compatible Alcu Alloys For Thin-Film Superabsorbers, Mariama Rebello De Sousa Dias, Chen Gong, Zachary A. Benson, Marina S. Leite Jan 2018

Lithography-Free, Omnidirectional, Cmos-Compatible Alcu Alloys For Thin-Film Superabsorbers, Mariama Rebello De Sousa Dias, Chen Gong, Zachary A. Benson, Marina S. Leite

Physics Faculty Publications

Superabsorbers based on metasurfaces have recently enabled the control of light at the nanoscale in unprecedented ways. Nevertheless, the sub‐wavelength features needed to modify the absorption band usually require complex fabrication methods, such as electron‐beam lithography. To overcome the scalability limitations associated with the fabrication of metallic nanostructures, engineering the optical response of superabsorbers by metal alloying is proposed, instead of tuning the geometry/size of the nanoscale building blocks. The superior performance of thin film AlCu alloys as the metallic component of planar bilayer superabsorbers is numerically demonstrated. This alloy outperforms its pure constituents as well as other metals, such …

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Artificial Intelligence And It Professionals, Sunil Mithas, Thomas Kude, Jonathan W. Whitaker Jan 2018

Artificial Intelligence And It Professionals, Sunil Mithas, Thomas Kude, Jonathan W. Whitaker

Management Faculty Publications

How will continuing developments in artificial intelligence (AI) and machine learning influence IT professionals? This article approaches this question by identifying the factors that influence the demand for software developers and IT professionals, describing how these factors relate to AI, and articulating the likely impact on IT professionals.

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University Of Richmond Sustainability Plan 2019-2025, University Of Richmond Jan 2018

University Of Richmond Sustainability Plan 2019-2025, University Of Richmond

Plans

University of Richmond’s Sustainability Plan is a blueprint for how we as a campus community will achieve a long-term vision of integrating sustainability into the fabric of the University. The result of a yearlong collaborative effort involving hundreds of stakeholders, the plan lays out clear steps to bolster the development of sustainability in the curriculum, support environmental management of our campus, promote a culture of sustainability, and further integrate stewardship into administrative policies and procedures. The time frame for the goals, strategies, and actions articulated in this plan is 2019-2025.

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Chalcone And Cinnamate Synthesis Via One-Pot Enol Silane Formation-Mukaiyama Aldol Reactions Of Ketones And Acetate Esters, C. Wade Downey, Hadleigh M. Glist, Anna Takashima, Samuel R. Bottum, Grant J. Dixon Jan 2018

Chalcone And Cinnamate Synthesis Via One-Pot Enol Silane Formation-Mukaiyama Aldol Reactions Of Ketones And Acetate Esters, C. Wade Downey, Hadleigh M. Glist, Anna Takashima, Samuel R. Bottum, Grant J. Dixon

Chemistry Faculty Publications

Aryl alkyl ketones, acetate esters, and acetamides undergo facile one-pot enol silane formation, Mukaiyama aldol addition, and dehydrosilyloxylation in the presence of an amine base and excess trimethylsilyl trifluoromethanesulfonate. The chalcone and cinnamate products are generally recovered in high yield. The relative stoichiometry of the trimethylsilyl trifluoromethanesulfonate and amine base reagents determines whether the reaction yields the β- silyloxy carbonyl product or the α, β -unsaturated carbonyl.

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The Range And Valence Of A Real Smirnov Function, Timothy Ferguson, William T. Ross Jan 2018

The Range And Valence Of A Real Smirnov Function, Timothy Ferguson, William T. Ross

Department of Math & Statistics Faculty Publications

We give a complete description of the possible ranges of real Smirnov functions (quotients of two bounded analytic functions on the open unit disk where the denominator is outer and such that the radial boundary values are real almost everywhere on the unit circle). Our techniques use the theory of unbounded symmetric Toeplitz operators, some general theory of unbounded symmetric operators, classical Hardy spaces, and an application of the uniformization theorem. In addition, we completely characterize the possible valences for these real Smirnov functions when the valence is finite. To do so we construct Riemann surfaces we call disk trees …

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Multipliers Between Model Spaces, Emmanuel Fricain, Andreas Hartmann, William T. Ross Jan 2018

Multipliers Between Model Spaces, Emmanuel Fricain, Andreas Hartmann, William T. Ross

Department of Math & Statistics Faculty Publications

In this paper we examine the multipliers from one model space to another.

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A Probability Model For Strategic Bidding On The Price Is Right, Paul H. Kvam Jan 2018

A Probability Model For Strategic Bidding On The Price Is Right, Paul H. Kvam

Department of Math & Statistics Faculty Publications

The TV game show “The Price is Right” features a bidding auction called “Contestants’ Row” that rewards the player (out of 4) who bids closest to an item’s value, without overbidding. This paper considers ways in which players can maximize a winning probability based on the player's bidding order. We consider marginal strategies in which players assume opponents are bidding individually perceived values of the merchandise. Based on preceding bids of others, players have information available to create strategies. We consider conditional strategies in which players adjust bids knowing other players are using strategies. The last bidder has a large …

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Developing A Minimally Structured Mathematical Mode Of Cancer Treatment With Oncolytic Viruses And Dendritic Cell Injections, Jane L. Gevertz, Joanna R. Wares Jan 2018

Developing A Minimally Structured Mathematical Mode Of Cancer Treatment With Oncolytic Viruses And Dendritic Cell Injections, Jane L. Gevertz, Joanna R. Wares

Department of Math & Statistics Faculty Publications

Mathematical models of biological systems must strike a balance between being sufficiently complex to capture important biological features, while being simple enough that they remain tractable through analysis or simulation. In this work, we rigorously explore how to balance these competing interests when modeling murine melanoma treatment with oncolytic viruses and dendritic cell injections. Previously, we developed a system of six ordinary differential equations containing fourteen parameters that well describes experimental data on the efficacy of these treatments. Here, we explore whether this previously developed model is the minimal model needed to accurately describe the data. Using a variety of …

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One-Pot Enol Silane Formation-Alkylation Of Ketones With Propargyl Carboxylates Promoted By Trimethylsilyl Trifluoromethanesulfonate, C. Wade Downey, Danielle N. Confair, Yiqi Liu, Elizabeth D. Heafner Jan 2018

One-Pot Enol Silane Formation-Alkylation Of Ketones With Propargyl Carboxylates Promoted By Trimethylsilyl Trifluoromethanesulfonate, C. Wade Downey, Danielle N. Confair, Yiqi Liu, Elizabeth D. Heafner

Chemistry Faculty Publications

Ketones readily undergo conversion to enol silanes in the presence of trialkylamine base and trimethylsilyl trifluoromethanesulfonate (TMSOTf) and add to propargyl cations to yield b-alkynyl ketones. The propargyl cations are generated in the same reaction flask through the TMSOTf-promoted ionization of propargyl acetates or propargyl propionates. A range of enol silane precursors and propargyl carboxylates reacts efficiently (20 examples, up to 99% yield). Cyclization of a representative product in the presence of TMSOTf provided 61% yield of the trisubstituted furan.

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Finite Blaschke Products: A Survey, Stephan Ramon Garcia, Javad Mashreghi, William T. Ross Jan 2018

Finite Blaschke Products: A Survey, Stephan Ramon Garcia, Javad Mashreghi, William T. Ross

Department of Math & Statistics Faculty Publications

A finite Blaschke product is a product of finitely many automorphisms of the unit disk. This brief survey covers some of the main topics in the area, including characterizations of Blaschke products, approximation theorems, derivatives and residues of Blaschke products, geometric localization of zeros, and selected other topics.

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Equivalence Of Edge Bicolored Graphs On Surfaces, Oliver T. Dasbach, Heather M. Russell Jan 2018

Equivalence Of Edge Bicolored Graphs On Surfaces, Oliver T. Dasbach, Heather M. Russell

Department of Math & Statistics Faculty Publications

Consider the collection of edge bicolorings of a graph that are cellularly embedded on an orientable surface. In this work, we count the number of equivalence classes of such colorings under two relations: reversing colors around a face and reversing colors around a vertex. In the case of the plane, this is well studied, but for other surfaces, the computation is more subtle. While this question can be stated purely graph theoretically, it has interesting applications in knot theory.

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Multipliers Between Model Spaces, Emmanuel Fricain, Andreas Hartmann, William T. Ross Jan 2018

Multipliers Between Model Spaces, Emmanuel Fricain, Andreas Hartmann, William T. Ross

Department of Math & Statistics Faculty Publications

In this paper we examine the multipliers from one model space to another.

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Range Spaces Of Co-Analytic Toeplitz Operators, Emmanuel Fricain, Andreas Hartmann, William T. Ross Jan 2018

Range Spaces Of Co-Analytic Toeplitz Operators, Emmanuel Fricain, Andreas Hartmann, William T. Ross

Department of Math & Statistics Faculty Publications

In this paper we discuss the range of a co-analytic Toeplitz operator. These range spaces are closely related to de Branges-Rovnyak spaces (in some cases they are equal as sets). In order to understand its structure, we explore when the range space decomposes into the range of an associated analytic Toeplitz operator and an identifiable orthogonal complement. For certain cases, we compute this orthogonal complement in terms of the kernel of a certain Toeplitz operator on the Hardy space, where we focus on when this kernel is a model space (backward shift invariant subspace). In the spirit of Ahern-Clark, we …

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Optimal Weak Parallelogram Constants For L-P Spaces, Raymond Cheng, Javad Mashreghi, William T. Ross Jan 2018

Optimal Weak Parallelogram Constants For L-P Spaces, Raymond Cheng, Javad Mashreghi, William T. Ross

Department of Math & Statistics Faculty Publications

Inspired by Clarkson's inequalities for L-p and continuing work from [5], this paper computes the optimal constant C in the weak parallelogram laws parallel to f + g parallel to(r )+ C parallel to f - g parallel to(r )= 2(r-1 )(parallel to f parallel to(r) + parallel to g parallel to(r)) for the L-p spaces, 1 < p < infinity.

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