Digital Commons Network^™

A Short Solution Of The Kissing Number Problem In Dimension Three, Alexey Glazyrin

School of Mathematical & Statistical Sciences Faculty Publications

We give a short solution of the kissing number problem in dimension three.

Security Attacks And Countermeasures In Smart Homes, Hasibul Alam, Emmett Tomai

Computer Science Faculty Publications

The Internet of Things (IoT) application is visible in all aspects of humans’ day-to-day affairs. The demand for IoT is growing at an unprecedented rate, from wearable wristwatches to autopilot cars. The smart home has also seen significant advancements to improve the quality of lifestyle. However, the security and privacy of IoT devices have become primary concerns as data is shared among intelligent devices and over the internet in a smart home network. There are several attacks - node capturing attack, sniffing attack, malware attack, boot phase attack, etc., which are conducted by adversaries to breach the security of smart …

Continuous Semi-Supervised Nonnegative Matrix Factorization, Michael R. Lindstrom, Xiaofu Ding, Feng Liu, Anand Somayajula, Deanna Needell

School of Mathematical & Statistical Sciences Faculty Publications

Nonnegative matrix factorization can be used to automatically detect topics within a corpus in an unsupervised fashion. The technique amounts to an approximation of a nonnegative matrix as the product of two nonnegative matrices of lower rank. In certain applications it is desirable to extract topics and use them to predict quantitative outcomes. In this paper, we show Nonnegative Matrix Factorization can be combined with regression on a continuous response variable by minimizing a penalty function that adds a weighted regression error to a matrix factorization error. We show theoretically that as the weighting increases, the regression error in training …

Air Pollution In South Texas: A Short Communication Of Health Risks And Implications, Sai Deepak Pinakana, Esmeralda Mendez, Ismaila Ibrahim, Md. Salahuddin Majumder, Amit U. Raysoni

School of Earth, Environmental, & Marine Sciences Faculty Publications

Air pollution is a major public health concern. The region of South Texas in the United States has experienced high levels of air pollution in recent years due to an increase in population, cross-border trade between the U.S.A. and Mexico, and high vehicular activity. This review assesses the relationships between human health and air pollution in South Texas. A thorough scientific search was performed using PubMed, Science Direct, and ProQuest, with most of the literature focusing on the source apportionment of particulate matter that is 2.5 microns or less in width (PM2.5), Carbon Dioxide (CO2), carbon monoxide (CO), Black Carbon …

Lacunary Eta Quotients With Identically Vanishing Coefficients, Timothy Huber, James Mclaughlin, Dongxi Ye

School of Mathematical & Statistical Sciences Faculty Publications

For |q|<1 >, define fi=∏∞n=1(1−qin) , and let (A(q),B(q)) be any of the pairs (f41,f81f22), (f41,f101f23), (f61,f42f21), (f61,f141f42), (f101,f62f21), (f141,f53f1),(f141,f82f21). For any such pair (A(q),B(q)) , define the sequences {a(n)} and {b(n)} to be the coefficients of qn of A(q) and B(q) , respectively. Then for each pair it is shown that a(n) vanishes if and only if b(n) vanishes. In each case, a criterion is given which states precisely when a(n)=b(n)=0 . Moreover, for the pairs (f261,f93f1) , (f261,f162f61) it is shown that a(n)=b(n)=0 if 12n+13 satisfies a criteria of Serre for a(n)=0 .

Population Of Merging Compact Binaries Inferred Using Gravitational Waves Through Gwtc-3, R. Abbott, T. Abbott, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wen Hui Wang

Physics & Astronomy Faculty Publications

We report on the population properties of compact binary mergers inferred from gravitational-wave observations of these systems during the first three LIGO-Virgo observing runs. The Gravitational-Wave Transient Catalog 3 (GWTC-3) contains signals consistent with three classes of binary mergers: binary black hole, binary neutron star, and neutron star–black hole mergers. We infer the binary neutron star merger rate to be between 10 and 1700  Gpc−3 yr−1 and the neutron star–black hole merger rate to be between 7.8 and 140  Gpc−3 yr−1, assuming a constant rate density in the comoving frame and taking the union of 90% credible intervals for methods …

Transport Effects In Non-Hermitian Nonreciprocal Systems: General Approach, Hamed Ghaemi-Dizicheh

Physics & Astronomy Faculty Publications

In this paper, we present a unifying analytical framework for identifying conditions for transport effects such as reflectionless and transparent transport, lasing, and coherent perfect absorption in non-Hermitian nonreciprocal systems using a generalized transfer matrix method. This provides a universal approach to studying the transport of tight-binding platforms, including higher-dimensional models and those with an internal degree of freedom going beyond the previously studied case of one-dimensional chains with nearest-neighbor couplings. For a specific class of tight-binding models, the relevant transport conditions and their signatures of non-Hermitian, nonreciprocal, and topological behavior are analytically tractable from a general perspective. We investigate …

Multi-Scale Hybridized Topic Modeling: A Pipeline For Analyzing Unstructured Text Datasets Via Topic Modeling, Keyi Cheng, Stefan Inzer, Adrian Leung, Xiaoxian Shen, Deanna Needell, Todd Presner, Michael Perlmutter, Michael R. Lindstrom, Joyce Chew

School of Mathematical & Statistical Sciences Faculty Publications

We propose a multi-scale hybridized topic modeling method to find hidden topics from transcribed interviews more accurately and more efficiently than traditional topic modeling methods. Our multiscale hybridized topic modeling method (MSHTM) approaches data at different scales and performs topic modeling in a hierarchical way utilizing first a classical method, Nonnegative Matrix Factorization, and then a transformer-based method, BERTopic. It harnesses the strengths of both NMF and BERTopic. Our method can help researchers and the public better extract and interpret the interview information. Additionally, it provides insights for new indexing systems based on the topic level. We then deploy our …

Assessment Of Air Pollution Levels During Sugarcane Stubble Burning Event In La Feria, South Texas, Usa, Sai Deepak Pinakana, Edward Robles, Esmeralda Mendez, Amit U. Raysoni

School of Earth, Environmental, & Marine Sciences Faculty Publications

Agricultural stubble burning is the third largest source of air pollution after vehicular and industrial emissions. Fine particulate matter (PM2.5), volatile organic compounds (VOCs), carbon monoxide (CO), nitrogen dioxide (NO2), and black carbon (BC) are some of the pollutants emitted during such burning events. The Lower Rio Grande Valley (RGV) region of South Texas is a major hub of agricultural activity, and sugarcane farming is one of them. Unfortunately, this activity results in episodic events of high air pollution in this low-resourced, Hispanic/Latino majority region of the U.S.–Mexico border. This study presents results from a sugarcane site in La Feria, …

Health And Safety Effects Of Airborne Soil Dust In The Americas And Beyond, Daniel Q. Tong, Thomas E. Gill, William A. Sprigg, Robert Scott Van Pelt, Alexander Baklanov, Bridget Marie Barker, Jesse E. Bell, Juan Castillo, Santiago Gassó, Cassandra Gaston, Amit U. Raysoni

School of Earth, Environmental, & Marine Sciences Faculty Publications

Risks associated with dust hazards are often underappreciated, a gap between the knowledge pool and public awareness that can be costly for impacted communities. This study reviews the emission sources and chemical, physical, and biological characteristics of airborne soil particles (dust) and their effects on human and environmental health and safety in the Pan-American region. American dust originates from both local sources (western United States, northern Mexico, Peru, Bolivia, Chile, and Argentina) and long-range transport from Africa and Asia. Dust properties, as well as the trends and interactions with criteria air pollutants, are summarized. Human exposure to dust is associated …

On Characterization Of The Exponential Distribution Via Hypoexponential Distributions, George Yanev

School of Mathematical & Statistical Sciences Faculty Publications

The sum of independent, but not necessary identically distributed, exponential random variables follows a hypoexponential distribution. We focus on a particular case when all but one rate parameters of the exponential variables are identical. This is known as exponentially modified Erlang distribution in molecular biology. We prove a characterization of the exponential distribution, which complements previous characterizations via hypoexponential distribution with all rates different from each other.

A Longitudinal Study Of The Effect Of Individual And Socio-Cultural Factors On Students’ Creativity, Hye-Sook Park, Seokmin Kang, Sungyeun Kim

Teaching and Learning Faculty Publications

This longitudinal study investigated how characteristics of individual and social relationships affect Korean students’ creativity development. Fifth graders (male: 3,623, female: 3,701) from 242 schools in Korea were followed annually from their 5th to 9th grades (indicating from the 5th elementary school grade to the 3rd middle school grade in the Korean school system). Exploratory factor analysis, internal consistency reliability (coefficient alpha), confirmatory factor analysis, and two-level growth model methods were performed. We investigated all nine constructs and their related items by checking metric and scalar invariance assumptions. When the measurement invariance assumptions were satisfied, we used the mean of …

Port-Of-Entry Simulation Model For Potential Wait Time Reduction And Air Quality Improvement: A Case Study At The Gateway International Bridge In Brownsville, Texas, Usa, Benjamin Stewart, Hiram Moya, Amit U. Raysoni, Esmeralda Mendez, Matthew Vechione

School of Earth, Environmental, & Marine Sciences Faculty Publications

The mathematical study known as queueing theory has recently become a major point of interest for many government agencies and private companies for increasing efficiency. One such application is vehicle queueing at an international port-of-entry (POE). When queueing, fumes from idling vehicles negatively affect the overall health and well-being of the community, especially the U.S. Customs and Border Protection (CBP) agents that work at the POEs. As such, there is a need to analyze and optimize the border crossing queuing operations to minimize wait times and number of vehicles in the queue and, thus, reduce the vehicle emissions. For this …

Powerful Radio Sources In The Southern Sky. I. Optical Identifications, Francesco Massaro, S. V. White, A. García-Pérez, A. Jimenez-Gallardo, A. Capetti, C. C. Cheung, W. R. Forman, C. Mazzucchelli, A. Paggi, Juan P. Madrid

Physics & Astronomy Faculty Publications

Since the early sixties, our view of radio galaxies and quasars has been drastically shaped by discoveries made thanks to observations of radio sources listed in the Third Cambridge Catalog and its revised version (3CR). However, the largest fraction of data collected to date on 3CR sources was performed with relatively old instruments, rarely repeated and/or updated. Importantly, the 3CR contains only objects located in the Northern Hemisphere, thus having limited access to new and innovative astronomical facilities. To mitigate these limitations, we present a new catalog of powerful radio sources visible from the Southern Hemisphere, extracted from the GLEAM …

A Review Of Literature On The Usage Of Low-Cost Sensors To Measure Particulate Matter, Amit U. Raysoni, Sai Deepak Pinakana, Esmeralda Mendez, Dawid K. Wladyka, Katarzyna Sepielak, Owen Temby

School of Earth, Environmental, & Marine Sciences Faculty Publications

With advances in technological sciences, individuals can utilize low-cost air monitoring sensors to record air quality at homes, schools, and businesses. Air quality data collected from LCSs are publicly accessible, informing the community of the air quality around them. It is important to measure local and regional particulate matter (PM) concentrations to keep the public involved, especially those with specific health concerns, such as asthma, wheezing, and seasonal allergies. The number of studies involving the use of LCSs to evaluate PM levels is increasing with more manufacturers producing ‘easy to use’ LCSs targeting the public. The goal of this review …

A Candidate Magnetic Helium-Core White Dwarf In The Globular Cluster Ngc 6397, Manuel Pichardo Marcano, Liliana E. Rivera Sandoval, Thomas J. Maccarone, Rene D. Rohrmann, Craig O. Heinke, Diogo Belloni, Leandro G. Althaus, Arash Bahramian

Physics & Astronomy Faculty Publications

We report a peculiar variable blue star in the globular cluster (GC) NGC 6397, using Hubble Space Telescope optical imaging. Its position in the colour–magnitude diagrams and its spectrum are consistent with this star being a helium-core white dwarf (He WD) in a binary system. The optical light curve shows a periodicity at 18.5 h. We argue that this periodicity is due to the rotation of the WD and possibly due to magnetic spots on the surface of the WD. This would make this object the first candidate magnetic He WD in any GC, and the first candidate magnetic WD …

Amplifying Reactivity Of Metal Hydrides: A Heterotrimetallic Nial2(Μ2-H)2 Catalyst For The Dearomatization Of N-Heterocycles, Edgardo De Leon, Fernando Gonzalez, Preetika Bauskar, Sergio Gonzalez-Eymard, David De Los Santos, Manar Shoshani

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Identifying methods to modulate the reactivity of metal hydrides is lacking yet highly desirable given the role they play in a plethora of catalytic applications. Herein we report novel methodology to amplify the reactivity of metal hydrides through the design of well-defined heterometallic bridged hydride species. Catalytic hydroboration of quinolines was dramatically altered by the addition of a secondary metal to bridge the Al–hydride species LAlH. Specifically, the addition of Ni(COD)2 led to the formation of novel heterotrimetallic species 1 which features Ni participating in 3-center bonding with sterically accessible Al–H species and exhibits catalytic hydroboration of sterically encumbered quinolines …

Modeling And Computation For Unsteady Blood Flow And Solute Concentration In A Constricted Porous Artery, Daniel N. Riahi, Saulo Orizaga

School of Mathematical & Statistical Sciences Faculty Publications

We investigated a physical system for unsteady blood flow and solute transport in a section of a constricted porous artery. The aim of this study was to determine effects of hematocrit, stenosis, pulse oscillation, diffusion, convection and chemical reaction on the solute transport. The significance of this study was uncovering combined roles played by stenosis height, hematocrit, pulse oscillation period, reactive rate, blood speed, blood pressure force and radial and axial extent of the porous artery on the solute transported by the blood flow in the described porous artery. We used both analytical and computational methods to determine blood flow …

Isomerization Of Galactose To Tagatose: Recent Advances In Non-Enzymatic Isomerization, Jikai Zhao, Zhuo Wang, Qing Jin, Danyi Feng, Juhee Lee

School of Earth, Environmental, & Marine Sciences Faculty Publications

The valorization of galactose derived from acid whey to low-calorie tagatose has gained increasing attention. Enzymatic isomerization is of great interest but faces several challenges, such as poor thermal stability of enzymes and a long processing time. In this work, non-enzymatic (supercritical fluids, triethylamine, arginine, boronate affinity, hydrotalcite, Sn-β zeolite, and calcium hydroxide) pathways for galactose to tagatose isomerization were critically discussed. Unfortunately, most of these chemicals showed poor tagatose yields (70%). The latter is able to form a tagatose–calcium hydroxide–water complex, which stimulates the equilibrium toward tagatose and prevents sugar degradation. Nevertheless, the excessive use of calcium hydroxide may …

Quantification Of Hydraulic Trait Control On Plant Hydrodynamics And Risk Of Hydraulic Failure Within A Demographic Structured Vegetation Model In A Tropical Forest (Fates–Hydro V1.0), Chonggang Xu, Bradley O. Christoffersen, Zachary Robbins, Ryan G. Knox, Rosie A. Fisher, Rutuja Chitra-Tarak, Martijn Slot, Kurt C. Solander, Lara M. Kueppers, Charles D. Koven, Nate G. Mcdowell

School of Integrative Biological & Chemical Sciences Faculty Publications

Vegetation plays a key role in the global carbon cycle and thus is an important component within Earth system models (ESMs) that project future climate. Many ESMs are adopting methods to resolve plant size and ecosystem disturbance history, using vegetation demographic models. These models make it feasible to conduct more realistic simulation of processes that control vegetation dynamics. Meanwhile, increasing understanding of the processes governing plant water use, and ecosystem responses to drought in particular, has led to the adoption of dynamic plant water transport (i.e., hydrodynamic) schemes within ESMs. However, the extent to which variations in plant hydraulic traits …

Texas School Social Workers: Who And Where Are They?, George Padilla, Velma D. Menchaca, Astrid Gandaria

Organization and School Leadership Faculty Publications

School social workers have a long history in American education and much research is needed to better understand their role and impact in schools. Texas schools employ one of the highest numbers of school social workers in the country, but there is also little to no research related to their demographics, working conditions, or effectiveness. Only one recent study on Texas school social workers was found in the research literature. This report analyzes Texas state reports, available to the public on the internet or by specific request from the Texas Education Agency, to develop a descriptive and exploratory overview of …

Speed Of Sound For Hadronic And Quark Phases In A Magnetic Field, Efrain J. Ferrer, Aric Hackebill

Physics & Astronomy Faculty Publications

In this paper we calculate the speed of sound for three phases that may exist inside a magnetized hybrid neutron star at different density regions: A hadronic phase at low densities, quark-matter in the magnetic dual chiral density wave (MDCDW) phase at intermediate densities and a free-quark phase modeled by the MIT bag model at higher densities. It is found that the speed of sound exhibits a non-monotonic behavior, that goes from values smaller than the conformal limit ( c 2 s < 1 / 3 ) in the hadronic phase, to peak ( c 2 s > 1 / 3 ) in the MDCDW phase, to finally reach the conformal limit ( c 2 s …

Multicultural Counselor Supervision And Perceived Differences On Client Outcome, Andrew Perez, Saara Grizzell, Jerome Fischer, Jennifer Jazinski

School of Rehabilitation Services & Counseling Faculty Publications

The purpose of this study was to examine the differences between counselor supervisors’ and supervisees’ perceptions of the impact of multicultural supervision on client outcome. Counselor supervisors and supervisees may have differences in how much they believe multicultural factors affect client outcome and this study aimed to determine what differences exist. There were 61 participants in the study consisting of faculty, counselor supervisors, counselors, and graduate students in counseling-related fields. The current study found that multicultural supervision/competence alone predicted supervisor perceptions of client outcome. The findings suggest that training in supervision and multicultural supervision is vital to the professional development …

Hearing Healthcare Professionals’ Views About Over-The-Counter (Otc) Hearing Aids: Analysis Of Retrospective Survey Data, Vinaya Manchaiah, Anu Sharma, Hansapani Rodrigo, Abram Bailey, Karina C. De Sousa, De Wet Swanepoel

School of Mathematical & Statistical Sciences Faculty Publications

Over-the-counter hearing aids have been available to consumers in the US since 17 October 2022 following a ruling by the Food and Drug Administration. However, their reception by hearing healthcare professionals (HHP) has been mixed, and concerns have been expressed by many HHPs. The aim of this study was to examine the concerns that HHPs have towards over-the-counter (OTC) hearing aids. The study used a retrospective survey design. The survey data of HHPs (n = 730) was obtained from Hearing Tracker. A 22-item structured questionnaire was administered using a Question Scout platform. Descriptive analyses examined reported areas of concern and …

Are Avocados Toast? A Framework To Analyze Decision-Making For Emerging Epidemics, Applied To Laurel Wilt, Berea A. Etherton, Robin A. Choudhury, R. I. Alcalá-Briseño, Y. Xing, A. I. Plex Sulá, D. Carrillo, J. Wasielewski, L. L. Stelinski, K. A. Grogan, F. Ballen

School of Earth, Environmental, & Marine Sciences Faculty Publications

CONTEXT

When emerging pathogens threaten global food security, collective actionfor disease management is key for protecting food systems. We evaluate how the informal exchange of information about epidemic and economic outcomes can influence the management decisions of individuals and the resulting epidemics, in the context of the avocado laurel wilt epidemic in south Florida.

OBJECTIVES

In scenario analyses, we addressed how socioeconomic networks, laurel wilt epidemic networks, policy incentive structures, and social behaviors combine to influence (a) information exchange across this region, (b) growers' decisions about disease management, and (c) epidemic spread and yield loss. We identified the scenarios …

P-Adic Cellular Neural Networks, B. A. Zambrano-Luna, Wilson A. Zuniga-Galindo

School of Mathematical & Statistical Sciences Faculty Publications

In this article we introduce the p-adic cellular neural networks which are mathematical generalizations of the classical cellular neural networks (CNNs) introduced by Chua and Yang. The new networks have infinitely many cells which are organized hierarchically in rooted trees, and also they have infinitely many hidden layers. Intuitively, the p-adic CNNs occur as limits of large hierarchical discrete CNNs. More precisely, the new networks can be very well approximated by hierarchical discrete CNNs. Mathematically speaking, each of the new networks is modeled by one integro-differential equation depending on several p-adic spatial variables and the time. We …

Non-Hermitian Floquet-Free Analytically Solvable Time-Dependent Systems, Hamed Ghaemi-Dizicheh, Hamidreza Ramezani

Physics & Astronomy Faculty Publications

The non-Hermitian models, which are symmetric under parity (P) and time-reversal (T) operators, are the cornerstone for the fabrication of new ultra-sensitive optoelectronic devices. However, providing the gain in such systems usually demands precise control of nonlinear processes, limiting their application. In this paper, to bypass this obstacle, we introduce a class of time-dependent non-Hermitian Hamiltonians (not necessarily Floquet) that can describe a two-level system with temporally modulated on-site potential and couplings. We show that implementing an appropriate non-Unitary gauge transformation converts the original system to an effective one with a balanced gain and loss. This …

Molecular Research In Pancreatic Cancer: Small Molecule Inhibitors, Their Mechanistic Pathways And Beyond, Shaila A. Shetu, Nneoma James, Gildardo Rivera-Sanchez, Debasish Bandyopadhyay

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Pancreatic enzymes assist metabolic digestion, and hormones like insulin and glucagon play a critical role in maintaining our blood sugar levels. A malignant pancreas is incapable of doing its regular functions, which results in a health catastrophe. To date, there is no effective biomarker to detect early-stage pancreatic cancer, which makes pancreatic cancer the cancer with the highest mortality rate of all cancer types. Primarily, mutations of the KRAS, CDKN2A, TP53, and SMAD4 genes are responsible for pancreatic cancer, of which mutations of the KRAS gene are present in more than 80% of pancreatic cancer cases. Accordingly, there is a …

The Application Of Transition Metal Sulfide Nanomaterials And Their Composite Nanomaterials In The Electrocatalytic Reduction Of Co2: A Review, Jason Parsons, Mataz Alcoutlabi

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Electrocatalysis has become an important topic in various areas of research, including chemical catalysis, environmental research, and chemical engineering. There have been a multitude of different catalysts used in the electrocatalytic reduction of CO2, which include large classes of materials such as transition metal oxide nanoparticles (TMO), transition metal nanoparticles (TMNp), carbon-based nanomaterials, and transition metal sulfides (TMS), as well as porphyrins and phthalocyanine molecules. This review is focused on the CO2 reduction reaction (CO2RR) and the main products produced using TMS nanomaterials. The main reaction products of the CO2RR include carbon monoxide (CO), formate/formic acid (HCOO−/HCOOH), methanol (CH3OH), ethanol …

Increased Floodplain Inundation In The Amazon Since 1980, Ayan Fleischmann, Fabrice Papa, Stephen K. Hamilton, Alice Fassoni-Andrade, Sly Wongchuig, Jhan Carlo Espinoza, Rodrigo Paiva, John Melack, Etienne Fluet-Chouinard, Rafael M. Almeida

School of Earth, Environmental, & Marine Sciences Faculty Publications

Extensive floodplains throughout the Amazon basin support important ecosystem services and influence global water and carbon cycles. A recent change in the hydroclimatic regime of the region, with increased rainfall in the northern portions of the basin, has produced record-breaking high water levels on the Amazon River mainstem. Yet, the implications for the magnitude and duration of floodplain inundation across the basin remain unknown. Here we leverage state-of-the-art hydrological models, supported by in situ and remote sensing observations, to show that the maximum annual inundation extent along the central Amazon increased by 26% since 1980. We further reveal increased flood …