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Approximation Theory and Complex Dynamics (open access)

Approximation Theory and Complex Dynamics

Data management plan for the grant, "Approximation Theory and Complex Dynamics." This project involves the study of approximation theory in the setting of complex functions, with applications to complex dynamics. Approximation theory seeks to understand the extent to which the behavior of a general function can be effectively modeled by that of functions drawn from a more restricted class. Efficient approximation of functions is of relevance for numerical calculation. Since the only calculations that can be carried out numerically are the elementary operations of addition, subtraction, multiplication, and division, in practical terms it is of importance to understand when the values of general functions are well approximated by the values of either polynomial or rational functions. In many situations, the values of the approximant resemble those of the general function only for a sampling of input values. What can be said about values of the approximant for other choices of input? This is the main question studied in this project, with the following application in mind: when a general function is iterated to produce a dynamical system, to what extent does the dynamical behavior of an approximant resemble the dynamical behavior of the original function? The project will also contribute …
Date: 2023-09-01/2026-08-31
Creator: Lazebnik, Kirill
Object Type: Text
System: The UNT Digital Library
Badly approximable points on self-affine sponges and the lower Assouad dimension (open access)

Badly approximable points on self-affine sponges and the lower Assouad dimension

This article highlights a connection between Diophantine approximation and the lower Assouad dimension by using information about the latter to show that the Hausdorff dimension of the set of badly approximable points that lie in certain non-conformal fractals, known as self-affine sponges, is bounded below by the dynamical dimension of these fractals. The results, which are the first to advance beyond the conformal setting, encompass both the case of Sierpiński sponges/carpets (also known as Bedford–McMullen sponges/carpets) and the case of Barański carpets.
Date: June 20, 2017
Creator: Das, Tushar; Fishman, Lior; Simmons, David & Urbański, Mariusz
Object Type: Article
System: The UNT Digital Library
Collaborative Research: Conference: Texas-Oklahoma Representations and Automorphic forms (TORA) (open access)

Collaborative Research: Conference: Texas-Oklahoma Representations and Automorphic forms (TORA)

Data management plan for the grant, "Collaborative Research: Conference: Texas-Oklahoma Representations and Automorphic forms (TORA)."
Date: 2024-01-01/2026-12-31
Creator: Beneish, Lea
Object Type: Text
System: The UNT Digital Library
Collaborative Research: Using Uncertainty Quantification and Validated Computational Models to Analyze Pumping Performance of Valveless, Tubular Hearts (open access)

Collaborative Research: Using Uncertainty Quantification and Validated Computational Models to Analyze Pumping Performance of Valveless, Tubular Hearts

Data management plan for the research grant, "Collaborative Research: Using Uncertainty Quantification and Validated Computational Models to Analyze Pumping Performance of Valveless, Tubular Hearts." This project will develop a computational model of the essential features of the circulatory system: the electrical activity of the heart, muscle contractions of the tube walls, and the fluid-structure interactions of the heart walls and blood within. This computational framework aims to be faithful to that of a real, model animal (tunicate, or sea squirt). The model will then be analyzed with mathematical tools to determine the physical limits of the pumping system. Results of this project will improve the understanding of human heart development at the earliest stages. Also, it will point to how the large, multi-chambered hearts of vertebrates could have evolved from smaller structures.
Date: 2022-05-01/2025-04-30
Creator: He, Yanyan & Cain, John
Object Type: Text
System: The UNT Digital Library
Conference: Dynamical Systems and Fractal Geometry (open access)

Conference: Dynamical Systems and Fractal Geometry

Data management plan for the grant, "Conference: Dynamical Systems and Fractal Geometry."
Date: 2024-04-15/2025-03-31
Creator: Allaart, Pieter C.
Object Type: Text
System: The UNT Digital Library
Deciphering pathogenicity and antibiotic resistance islands in methicillin-resistant Staphylococcus aureus genomes (open access)

Deciphering pathogenicity and antibiotic resistance islands in methicillin-resistant Staphylococcus aureus genomes

This article explores the use of an information-entropy-based gene clustering method for genomic island detection in MRSA.
Date: November 16, 2017
Creator: Jani, Mehul; Sengupta, Soham; Hu, Kelsey & Azad, Rajeev K.
Object Type: Article
System: The UNT Digital Library
Dense Locally Finite Subgroups of Automorphism Groups of Ultraextensive Spaces (open access)

Dense Locally Finite Subgroups of Automorphism Groups of Ultraextensive Spaces

Article verifying a conjecture of Vershik by showing that Hall’s universal countable locally finite group can be embedded as a dense subgroup in the isometry group of the Urysohn space and in the automorphism group of the random graph. It shows the same for all automorphism groups of known infinite ultraextensive spaces.
Date: August 18, 2021
Creator: Etedadialiabadi, Mahmood; Gao, Su; Le Maître, François & Melleray, Julien
Object Type: Article
System: The UNT Digital Library
Descriptive Complexity in Cantor Series (open access)

Descriptive Complexity in Cantor Series

Article discusses how a Cantor series expansion for a real number x with respect to a basic sequence Q=(q), where qi≥2, is a generalization of the base b expansion to an infinite sequence of bases. The authors show that for any basic sequence the set of distribution normal numbers is Π03-complete, and if Q is 1-divergent then the sets of normal and ratio normal numbers are Π03-complete.
Date: September 27, 2021
Creator: Airey, Dylan; Jackson, Steve & Mance, Bill
Object Type: Article
System: The UNT Digital Library
Duals of Tirilman spaces have unique subsymmetric basic sequences (open access)

Duals of Tirilman spaces have unique subsymmetric basic sequences

Article describes how the Tirilman spaces were introduced by Casazza and Shura as variations of the spaces constructed by Tzafriri. We prove that all subsymmetric basic sequences in the dual space are equivalent to its canonical subsymmetic but not symmetric basis.
Date: September 5, 2023
Creator: Dilworth, Steven J.; Kutzarova, Denka; Sari, Bünyamin & Stankov, Svetozar
Object Type: Article
System: The UNT Digital Library
Environmental vibrios represent a source of antagonistic compounds that inhibit pathogenic Vibrio cholerae and Vibrio parahaemolyticus strains (open access)

Environmental vibrios represent a source of antagonistic compounds that inhibit pathogenic Vibrio cholerae and Vibrio parahaemolyticus strains

This article predicts that marine-derived bacteria should inhibit Vibrio pathogens and may be a source of unique antibiotic compounds.
Date: March 10, 2017
Creator: Burks, David J.; Norris, Stephen; Kauffman, Kathryn M.; Joy, Abigail; Arevalo, Philip; Azad, Rajeev K. et al.
Object Type: Article
System: The UNT Digital Library
Estimating Hausdorff measure for Denjoy maps (open access)

Estimating Hausdorff measure for Denjoy maps

Article describes how the authors plant to deal with orientation preserving homeomorphisms and, more specifically, diffeomorphisms of the unit circle S1. By employing the recurrence method worked out in Pawelec the authors provide effective lower estimates of the proper-dimensional Hausdorff measure of minimal sets of circle homeomorphisms that are not conjugate to any rotation.
Date: October 20, 2023
Creator: Pawelec, Łukasz & Urbański, Mariusz
Object Type: Article
System: The UNT Digital Library
The exact consistency strength of the generic absoluteness for the universally Baire sets (open access)

The exact consistency strength of the generic absoluteness for the universally Baire sets

Article describes how a set of reals is universally Baire if all of its continuous preimages in topological spaces have the Baire property. The authors show that over some mild large cardinal theory, sealing is equiconsistent with LSA-over-uB.
Date: January 18, 2023
Creator: Sargsyan, Grigor & Trang, Nam
Object Type: Article
System: The UNT Digital Library
Existence and nonexistence of radial solutions for semilinear equations with bounded nonlinearities on exterior domains (open access)

Existence and nonexistence of radial solutions for semilinear equations with bounded nonlinearities on exterior domains

Article studies radial solutions of ∆u + K(r)f(u) = 0 on the exterior of the ball of radius R > 0 centered at the origin in ℝᶰ where f is odd with f < 0 on (0, β), f > 0 on (β, δ), f ≡ 0 for u > δ, and where the function K(r) is assumed to be positive and K(r) → 0 as r → ∞.
Date: December 1, 2020
Creator: Iaia, Joseph A.
Object Type: Article
System: The UNT Digital Library
Existence and Nonexistence of Solutions for Sublinear Equations on Exterior Domains (open access)

Existence and Nonexistence of Solutions for Sublinear Equations on Exterior Domains

This article studies radial solutions of Δu + K(r)ƒ(u) = 0 on the exterior of the ball of radius R > 0, BR, centered at the origin in ℝN with u = 0 on @BR where ƒ is odd with ƒ < 0 on (0; β), ƒ > 0 on (β;∞), f(u) ~ uᵖ with 0 < p < 1 for large u and K(r) ~ r⁻ᵅ for large r.
Date: September 13, 2017
Creator: Iaia, Joseph A.
Object Type: Article
System: The UNT Digital Library
Existence and Nonexistence of Solutions for Sublinear Problems With Prescribed Number of Zeros on Exterior Domains (open access)

Existence and Nonexistence of Solutions for Sublinear Problems With Prescribed Number of Zeros on Exterior Domains

This article proves the existence of radial solutions of Δu + K(r)ƒ(u) = 0 on the exterior of the ball, of radius R, centered at the origin in ℝᴺ such that limᵣ→∞u(r) = 0 if R > 0 is sufficiently small.
Date: May 16, 2017
Creator: Joshi, Janak
Object Type: Article
System: The UNT Digital Library
Existence of Infinitely Many Solutions for Singular Semilinear Problems on Exterior Domains (open access)

Existence of Infinitely Many Solutions for Singular Semilinear Problems on Exterior Domains

Article proving the existence of infinitely many radial solutions of ∆𝓊+𝐾(𝓇) ƒ (𝓊) = 0 on the exterior of the ball of radius R > 0, BR, centered at the origin in ℝᴺ with u = 0 on ∂BR and lim/r→∞ 𝓊(𝓇) = 0 where N > 2, f is odd with f < 0 on (0, β), f > 0 on (β, ∞), f is superlinear for large u, ƒ(𝓊) ∼ −1/(|𝓊|𝘲⁻¹𝓊) with 0 < q < 1 for small u, and 0 < 𝐾(𝓇) ≤ 𝐾₁/r∝ with 𝑁 + q(𝑁 − 2) < ∝ < 2(𝑁− 1) for large r.
Date: March 9, 2018
Creator: Iaia, Joseph A.
Object Type: Article
System: The UNT Digital Library
Existence of solutions for semilinear problems on exterior domains (open access)

Existence of solutions for semilinear problems on exterior domains

Article proves the existence of an infinite number of radial solutions to ∆u+K(r)f(u) = 0 on ℝᶰ such that limᵣ →∞ u(r) = 0 with prescribed number of zeros on the exterior of the ball of radius R > 0 where f is odd with f < 0 on (0, β), f > 0 on (β, ∞) with f superlinear for large u, and K(r) ∼ r ⁻ᵅ with α > 2(N − 1).
Date: April 15, 2020
Creator: Iaia, Joseph A.
Object Type: Article
System: The UNT Digital Library
Existence of Solutions for Sublinear Equations on Exterior Domains (open access)

Existence of Solutions for Sublinear Equations on Exterior Domains

This article proves the existence of an infinite number of radial solutions of Δu+K(r)ƒ(u) = 0, one with exactly n zeros for each nonnegative integer n on the exterior of the ball of radius R > 0, Bʀ, centered at the origin in ℝᴺ with u = 0 on ∂Bʀ and limᵣ→∞u(r) = 0 where N > 2, f is odd with ƒ < 0 on (0; β), ƒ > 0 on (β;∞), ƒ(u) ~ uᵖ with 0 < p < 1 for large u and K(r) ~ r-α with 0 < α < 2 for large r.
Date: October 10, 2017
Creator: Iaia, Joseph A.
Object Type: Article
System: The UNT Digital Library
Foias Numbers (open access)

Foias Numbers

This article identifies the principal features in Foias’ original proof and streamlines them into a general result. The result gives further evidence to the observation that the connection between the sequence with initial seed the Foias constant and the Prime Number Theorem must be fortuitous.
Date: December 30, 2018
Creator: Anghel, Nicolae
Object Type: Article
System: The UNT Digital Library
GAW20: methods and strategies for the new frontiers of epigenetics and pharmacogenomics (open access)

GAW20: methods and strategies for the new frontiers of epigenetics and pharmacogenomics

Article presents an overview of the data sets and the contributions analyzing data related to human lipid-related phenotypes, DNA methylation, and single-nucleotide markers in a study involving a pharmaceutical intervention.
Date: September 17, 2018
Creator: Tintle, Nathan L.; Fardo, David W.; de Andrade, Mariza; Aslibekyan, Stella; Bailey, Julia N.; Bermejo, Justo Lorenzo et al.
Object Type: Article
System: The UNT Digital Library
A gene based approach to test genetic association based on an optimally weighted combination of multiple traits (open access)

A gene based approach to test genetic association based on an optimally weighted combination of multiple traits

In this article, the authors propose a statistical method by Testing an Optimally Weighted Combination of Multiple traits (TOW-CM) to test the association between multiple traits and multiple variants in a genomic region (a gene or pathway). They investigate the performance of the proposed method through extensive simulation studies. Their simulation studies show that the proposed method has correct type I error rates and is either the most powerful test or comparable with the most powerful tests. Additionally, they illustrate the usefulness of TOW-CM based on a COPDGene study.
Date: August 9, 2019
Creator: Zhang, Jianjun; Sha, Qiuying; Liu, Guanfu & Wang, Xuexia
Object Type: Article
System: The UNT Digital Library
Gene-based association tests using GWAS summary statistics and incorporating eQTL (open access)

Gene-based association tests using GWAS summary statistics and incorporating eQTL

Article proposes a powerful and computationally efficient gene-based association test, called Overall. Using extended Simes procedure, Overall aggregates information from three types of traditional gene-based association tests and also incorporates expression quantitative trait locus (eQTL) information into a gene-based association test using GWAS summary statistics. The results show that this newly developed method can identify more significant genes than other methods.
Date: March 3, 2022
Creator: Cao, Xuwei; Wang, Xuexia; Zhang, Shuanglin & Sha, Qiuying
Object Type: Article
System: The UNT Digital Library
A gene based combination test using GWAS summary data (open access)

A gene based combination test using GWAS summary data

Article describes how gene-based association tests provide a useful alternative and complement to the usual single marker association tests, especially in genome-wide association studies (GWAS). The authors propose a test named OWC based on summary statistics from GWAS data.
Date: January 3, 2023
Creator: Zhang, Jianjun; Liang, Xiaoyu; Gonzales, Samantha; Liu, Jianguo; Gao, Xiaoyi Raymond & Wang, Xuexia
Object Type: Article
System: The UNT Digital Library
Gene-Level Analysis of Anthracycline-Induced Cardiomyopathy in Cancer Survivors (open access)

Gene-Level Analysis of Anthracycline-Induced Cardiomyopathy in Cancer Survivors

Article describes how anthracyclines are highly effective in treating cancer, despite increased risk of cardiomyopathy. This study examined gene-level associations with cardiomyopathy among cancer survivors using whole-exome sequencing data.
Date: September 12, 2023
Creator: Sharafeldin, Noha; Zhou, Liting; Singh, Purnima; Crossman, David K.; Wang, Xuexia; Hagerman, Lindsey et al.
Object Type: Article
System: The UNT Digital Library