Digital Commons Network^™

Investigation Of Subcellular Damage And Long-Term Non-Cancerous Cardiovascular Effects Following Whole-Body Photon Irradiation, Nousha Afshari

LSU Doctoral Dissertations

Current radiobiological models focus primarily on nuclear DNA damage and fail to fully explain radiation-induced noncancerous health effects. This dissertation investigates whether non-nuclear subcellular structures contribute to radiation-induced biological damage through experimental biomarker analysis and computational microdosimetry. The central hypothesis posits that whole-body photon irradiation results in subcellular non-nuclear damage, specifically increased circulating mitochondrial DNA concentrations, that correlates with radiation dose and long-term noncancerous effects such as cardiovascular disease.

Specific Aim 1 measured mitochondrial and nuclear DNA concentrations in banked blood samples from 72 Chinese rhesus macaques that previously received whole-body photon irradiation ($0-10$ Gy) from Cobalt-60 or LINAC sources. …

Increasing The Economic And Social Viability Of Carbon Capture Using Biomass Slurry Fracture Injection, Zachary G. Laird

LSU Master's Theses

The climate is changing. This is a fact not a statement, not a theory, and not a falsehood, this is a fact. At the current projections the world’s average temperature is expected to rise by at least 2°C from pre-industrial averages by 2050 (Emissions Pathways to 2100 - Climate Action Tracker, 2024). This temperature rise will be catastrophic for a vast number of communities. What is driving this changing climate? Humans. In particular the carbon emissions caused by human activities. As humans we consume large amounts of meat, causing the need for cattle to increase, generating large amounts …

A Theory Of Fundamental Strata For Twisted Formal Connections, Sorawit Viwanthananut

LSU Doctoral Dissertations

Let $G$ be a complex reductive group. A fundamental stratum for $G$ is a triple $(x,r,\beta)$ where $x$ is a point in the Bruhat-Tits building of $G$, $r$ is a nonnegative real number called depth of the stratum, and $\beta$ is a semistable functional on the Moy-Prasad filtration of $\fg$ associated to $x$ at level $r$. Fundamental strata were first introduced to classify admissible representations of a $p$-adic reductive group. More recently, Bremer and Sage have shown that fundamental strata play an important role in the geometric Langlands program and developed a theory of fundamental strata for $G$-connections. In this …

The Oboe Thread: Tracing The Evolution Of Viet Cuong's Compositional Voice, Devin Gilbreath

LSU Doctoral Dissertations

Viet Cuong is an emerging and highly regarded American composer currently serving on the faculty at the University of Nevada, Las Vegas, where he teaches composition, orchestration, and music theory. Cuong's academic credentials include degrees from prestigious institutions such as the Curtis Institute of Music, Princeton University, and the Peabody Conservatory of Music. Over the years, his compositional portfolio has expanded significantly, encompassing a diverse range of genres and mediums, including vocal, orchestral, wind band, and chamber music. His chamber works, in particular, stand out for their fusion of diverse genres and instrumentation. One area in which Cuong has made …

Strichartz Estimates For Many Particle Dispersive Equations, Tristan Reynoso

LSU Doctoral Dissertations

Dispersive equations are useful for describing a wide variety of phenomena in which solutions disperse through the space as time progresses. These equations show up frequently in physics, especially when studying quantum mechanical and fluid related systems. The single particle variants of equations such as the Schr\"{o}dinger and Wave equations have been studied at great length throughout modern history. Over the last couple decades progress has been made toward extending single particle dispersive equations to cover their many body counterparts. Space-time Strichartz estimates for the homogenous $N$-particle Schr\"{o}dinger equation with small interacting potentials was recently established on both $\mathbb{R}^d$ and …

Elucidation Of A Role In Biofilm Production For The Tyrosine Catabolism Pathway In Vibrio Cholerae And Analysis Of Reversible Phase Variation In Vibrio Vulnificus, Aheli S. Mukerji

LSU Doctoral Dissertations

Biofilms produced by the cholera pathogen Vibrio cholerae not only enhance its ability to survive in the environment but also allow pathogenic success of the bacterium. This organism also undergoes phase variation, switching between smooth and rugose colonial phenotypes, the latter forming much more vibrio polysaccharide (VPS) resulting in more robust biofilms and subsequently having an increased level of persistence. In a previous study, many genes were found to be upregulated in the transition from the smooth to the rugose phenotype. Here, several of these upregulated genes were investigated for their potential role in biofilm production, and an additional gene, …

Magnetic Field Enabled Assembly And Propulsion Of Colloidal Particles In A Magnetic Medium, Hashir M. Gauri

LSU Doctoral Dissertations

Colloidal particles are nano/micro meter-sized particles dispersed in a fluid medium and serve as diverse building blocks for assembling complex structures. The ease of tunability of the shape, size, and interparticle interactions of colloidal particles facilitates their assembly into rich structures and phases that mirror the assembly process of atomic systems. Often regarded as "big atoms" colloidal particles provide an ideal model system for investigating complex phenomena in condensed matter, such as crystallization and nucleation. While the assembly of colloids under thermodynamic equilibrium has been extensively studied, recent interest has shifted toward exploring colloids in non-equilibrium conditions to create dynamic …

Anion Exchange Membrane Durability For Electrochemical Co2 Reduction In Membrane Electrode Assembly Cells, Soundarzo Tasnim

LSU Master's Theses

The electrochemical reduction of CO₂ using membrane electrode assembly (MEA) cells has emerged as a promising approach for carbon capture and conversion into valuable products. This study investigates the degradation mechanisms of anion exchange membranes (AEMs) in CO₂ reduction applications, focusing on Sustainion X37-50, PiperION, and FAA-3-50. The research analyzes the impact of chemical and mechanical degradation on membrane performance, highlighting key stability challenges in long-term operation. Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS) were employed to monitor functional group stability and ionic conductivity loss over extended operation. The results indicate that hydroxide-induced degradation leads to nucleophilic …

Energy Equity In The Built Environment: Analyzing Building Energy Consumption For American Low-Income Households, Sorena Vosoughkhosravi

LSU Doctoral Dissertations

The built environment consumes a significant amount of energy in the United States, with outdated and inefficient affordable housing increasing financial pressure on low-income households (LIHs) who face high energy burdens. This research aims to assess the energy performance of American households, focusing on LIHs, to promote energy justice by providing data-driven insights and models for energy efficiency improvements. More specifically, this research aims to (1) create a large-scale national residential building energy dataset by integrating the American Housing Survey and the Residential Energy Consumption Survey using machine learning techniques; (2) analyze and model American household occupancy profiles by leveraging …

Stream Fish Assemblage Dynamics And Barriers To Aquatic Connectivity In The Ichawaynochaway Creek Watershed, Georgia, Usa, Jake R. Duhé

LSU Master's Theses

Stream fishes in the southeastern United States are adapted to hydrological disturbances such as droughts. However, this region is projected to experience increasingly frequent and severe disturbances that will elevate water demands given increasing agricultural and urban development. Further, road-stream crossings (RSCs) are abundant features in these streams that can exacerbate drought-mediated stream fragmentation and impede movements by many aquatic organisms, including fishes, when poorly constructed. These compounding effects may adversely affect the diversity and abundances of resident stream fishes, but their interactions remain poorly understood, warranting rigorous testing of how droughts and RSCs influence stream fish dynamics. I assessed …

Predictive Indicators For Graduation Upon Acceptance Into A Naacls-Approved Medical Laboratory Science Program, Warren Hovis

LSU Doctoral Dissertations

The primary purpose of this study was to determine the influence of selected academic and personal demographic characteristics on student success at a NAACLS-accredited medical laboratory science program in the southern portion of the United States.

Both academic and demographic categories were selected on students who entered the medical laboratory science program from 2014 to 2019 (pre-COVID). The sanitized, archived data set was provided by the MLS department and the registrar and student affairs office at the participating school. The extant data set contained academic and demographic variables, collected over a five-year period, of initially over 170 accepted MLS students. …

Investigating Hurricane-Induced Salt Variation Across The Land-Estuary-Ocean Continuum Using A Dynamically Coupled Hydrological-Ocean Model, Xiaochen Zhao, Z. George Xue, Daoyang Bao, John Warner, Yanda Ou

Faculty Publications

Salinity variations across the Land-Estuary-Ocean (LEO) continuum are critical for coastal ecosystems and impact the socioeconomic benefits to local communities. However, evaluating these variations is challenging due to the complex interactions of terrestrial and oceanic processes, including river discharge, winds, tides, sea level rise, and storms. This study incorporates a salinity module into a newly developed dynamically coupled hydrological-ocean model on the COAWST platform, which is, to the best of our knowledge, the first process-based modeling that achieves seamless two-way land-ocean water and salt exchanges across the LEO continuum, facilitating simulations of landward salt input and transport. Using Hurricane Florence …

Ab Initio Informed 20ne(P, Pα)16o Reaction Elucidates The Emergence Of Alpha Clustering From Chiral Potentials, G. H. Sargsyan, Kazuki Yoshida, Kazuyuki Ogata, K. D. Launey, J. E. Escher, D. Langr, T. Dytrych

Faculty Publications

We report on the first ab initio informed α knock-out reaction in the intermediate-mass region, with the aim to probe the underlying chiral potential and its impact on the emergence of alpha clustering in this mass region. The theoretical predictions of the α+¹⁶O clustering in the ²⁰Ne ground state, based on the ab initio symmetry-adapted no-core shell model with continuum, yield a triple differential cross section for ²⁰Ne(p, pα)¹⁶O that is in a remarkable agreement with the data. This allows us to examine predictions of surface and in-medium α-cluster features that emerge from the …

Fermi Detection Of Gamma-Ray Emission From The Hot Coronae Of Radio-Quiet Active Galactic Nuclei, Jun Rong Liu, Jian Min Wang, Zi Hao Zhao, D. F. Torres, J. B. Thayer, H. Tajima, D. J. Suson, P. Spinelli, G. Spandre, E. J. Siskind, C. Sgrò, D. Serini, P. M. Saz Parkinson, M. Sánchez-Conde, O. Reimer, A. Reimer, M. Razzano, B. Rani, R. Rando, S. Rainò, G. Principe, T. A. Porter, R. Pillera, M. Pesce-Rollins, M. Persic, G. Panzarini, D. Paneque, J. F. Ormes, E. Orlando, M. Orienti, N. Omodei, R. Niwa, M. Negro

Faculty Publications

Relativistic jets around supermassive black holes are well-known powerful γ-ray emitters. In the absence of the jets in radio-quiet active galactic nuclei, how the supermassive black holes work in γ-ray bands is still unknown despite great observational efforts in the past three decades. Here, considering the previous efforts, we carefully select an active galactic nucleus sample composed of 37 nearby Seyfert galaxies with ultrahard X-rays for γ-ray detection by excluding all potential contamination in this band. Adopting a stacking technique, we report the significant γ-ray detection (test statistic 30.6, or 5.2σ) from the sample using 15-year Fermi-LAT observations. We find …

Source Origins Of Hunter-Harvested Waterfowl In Arkansas And Louisiana, Shannon C. Stemaly

LSU Master's Theses

Understanding variability in breeding origins of harvested waterfowl is important for effective population management and regional conservation. Band-recovery data are often used to estimate harvest derivation and inform resource allocation for cross-seasonal conservation. However, uneven spatial and temporal banding effort across species' breeding ranges may result in an incomplete understanding of summer origins and recruitment, particularly if portions of the breeding range are inaccessible. Analysis of stable-hydrogen isotope ratios in duck feathers (δ²H_f) provides an alternative method for identifying source origins of unmarked populations since environmental deuterium values follow a predictable latitudinal gradient across North …

Metabolic And Physiological Regulation In C. Elegans: Insights Into Sperm Activation And Peroxisome-Mediated Longevity, Yash Flora

LSU Doctoral Dissertations

Organelle dynamics lie at the heart of cellular signaling and metabolic regulation, orchestrating physiological processes such as reproduction and aging across the lifespan. In this dissertation, I investigate how organelle-based signaling coordinates sperm activation and modulates organismal aging in the nematode Caenorhabditis elegans. I identify SPIN-4, a previously uncharacterized Spinster family transporter, as a key regulator of spermiogenesis. SPIN-4 is strongly expressed in developing sperm, localizes to the plasma membrane, and promotes sperm activation by facilitating the export of sphingosine-1-phosphate (S1P). Loss of spin-4 results in defective pseudopod formation, reduced motility, and compromised fertility, phenotypes that can be rescued …

Understanding The Effect Of Chiral Nn Parametrization On Nuclear Shapes From An Ab Initio Perspective, Kevin S. Becker, Kristina D. Launey, Andreas Ekström, Grigor H. Sargsyan, Darin C. Mumma, Tomáš Dytrych, Daniel Langr, Jerry P. Draayer

Faculty Publications

The ab initio symmetry-adapted no-core shell model naturally describes nuclear deformation and collectivity, and is therefore well-suited to studying the dynamics and coexistence of shapes in atomic nuclei. For the first time, we analyze how these features in low-lying states of⁶Li and¹²C are impacted by the underlying realistic nucleon-nucleon interaction. We find that the interaction parametrization has a notable but limited effect on collective shapes in the lowest⁶Li and¹²C states, while collective structures in the excited 2⁺ state of¹²C are significantly more sensitive to the interaction parameters and exhibits …

Examining Family Accommodation In Early Childhood, Allison Smith Dupre

LSU Doctoral Dissertations

The relationship between parent and child anxiety is well established. One factor that may account for this relationship is family accommodation (how family members alter their behavior to alleviate child distress). Family accommodation has been studied in child anxiety for the past decade and has been linked to increased parent and child anxiety. However, little research has focused on a young sample without clinical elevations of anxiety. Acknowledging the impact of family accommodation on child anxiety, the strong link between parent anxiety and accommodation, and the importance of early intervention, this study aimed to expand the literature of family accommodation …

On Excursions Associated With A Certain Local Time Of Simple Symmetric Random Walks, With Applications, Takahiko Fujita, Naohiro Yoshida

Journal of Stochastic Analysis

In this note, some applications of excursions associated with a certain local time of simple symmetric random walks are presented. Specifically, the excursions are applied to calculate some probability distributions of interest regarding the random walks. Furthermore, a solution of the Skorokhod embedding problem for random walks is obtained through the excursions.

Citizen Perceptions On The Use, Management And Availability Of Green Spaces In A Mediterranean Region, Daniel Jato-Spino, Fabio Capra-Ribeiro, Vanessa Moscardo, Laura Gallardo

Faculty Publications

Green spaces (GS) are vital for environmental sustainability and public well-being. Understanding public perceptions of GS can promote their distribution aligned with citizens’ preferences. This study explores the alignment between perceptions of GS use, management and availability, captured via a questionnaire in the Valencian Community (Spain), with the objective reality determined through Geographic Information Systems (GIS). Data were collected from 94 participants, with 72 % using GS for relaxation, 54 % for physical exercise and 51 % for walking. Most respondents (78 %) preferred natural reserves as their primary type of GS. While 38 % believed GS were equitably distributed, …

Intersectionality And Experiences With Mental Health Care: Transgender And Gender Diverse Autistic Adults, Megan Callahan

LSU Doctoral Dissertations

Current prevalence rates of autism spectrum disorder (ASD) in transgender and gender diverse (TGD) populations range between 4 and 13% (Thrower et al., 2020). Studies into autistic TGD individuals’ experiences with healthcare have primarily collected qualitative data, identifying themes including barriers to healthcare, invalidation of both autistic and TGD identities, difficulty finding competent providers, limited support and resources, and refusal of care (Cooper et al., 2022; Maroney & Horne, 2022; Hall et al., 2020). N = 3094 self-identified TGD adults completed the 2017 TransLifeline Mental Health Survey, a collaborative effort between the National LGBTQ Task Force and the TransLifeline, which …

Gamma Irradiation Effects On Physical And Electronic Properties Of Monolayer Cvd Grown Graphene, Chintan P. Chavda, Ashok Srivastava, Erin Vaughan, Jianwei Wang, Manas Ranjan Gartia, Georgios Veronis

Faculty Publications

Two-dimensional material graphene has proven to have remarkable electrical and photonic properties, opening the door to a wide range of uses, including employment under the harsh conditions of space. The creation of graphene on various substrate types is known to be possible via a number of approaches, including direct deposition and the substrate transfer process. In this work, we used an argon plasma, methane as a carbon source, and a nanoCVD-8G graphene reactor to deposit monolayer graphene (MLG) on transition metal substrates for studying the effects of gamma irradiation on the physical and electronic properties. Graphene's crystalline structure is investigated …

Development And Demonstration Of The Operational Sustainability Index (Opsi): A Multidimensional Metric For Building Performance Evaluation, Oluwafemi Awolesi, Margaret Reams

Faculty Publications

In promoting sustainable cities and societies, accelerating the shift from sustainable building design to sustainable building operations is essential. A persistent challenge lies in the absence of a unified, multidimensional metric that enables meaningful performance comparisons across buildings of similar types and functions, both regionally and globally. This study develops and demonstrates the operational sustainability index (OPSi)—a novel metric grounded in case study research that integrates indoor environmental quality (IEQ) and energy utility quality (EUQ). OPSi is applied to six buildings in three comparative cases: (1) LEED-certified and non-certified dormitories, (2) LEED-certified and non-certified event buildings, and (3) male- and …

Maximum-Likelihood Estimation Of Glandular Fraction For Mammography And Its Effect On Microcalcification Detection, Bryce J. Smith, Joyoni Dey, Lacey Medlock, David Solis, Krystal Kirby

Faculty Publications

Breast tissue is mainly a mixture of adipose and fibro-glandular tissue. Cancer risk and risk of undetected breast cancer increases with the amount of glandular tissue in the breast. Therefore, radiologists must report the total volume glandular fraction or a BI-RADS classification in screening and diagnostic mammography. In this work, a Maximum Likelihood algorithm accounting for count statistics and scatter is shown to estimate the pixel-wise glandular fraction from mammographic images. The pixel-wise glandular fraction provides information that helps localize dense tissue. The total volume glandular fraction can be calculated from pixel-wise glandular fraction. The algorithm was implemented for images …

High-Significance Detection Of Correlation Between The Unresolved Gamma-Ray Background And The Large-Scale Cosmic Structure, B. Thakore, M. Negro, M. Regis, S. Camera, D. Gruen, N. Fornengo, A. Roodman, A. Porredon, T. Schutt, A. Cuoco, A. Alarcon, A. Amon, K. Bechtol, M. Becker, G. Bernstein, A. Campos, A. Carnero Rosell, M. Carrasco Kind, R. Cawthon, C. Chang, R. Chen, A. Choi, J. Cordero, C. Davis, J. Derose, H. Diehl, S. Dodelson, C. Doux, A. Drlica-Wagner, K. Eckert, J. Elvin-Poole, S. Everett, A. Ferté

Faculty Publications

Our understanding of the γ-ray sky has improved dramatically in the past decade, however, the unresolved γ-ray background (UGRB) still has a potential wealth of information about the faintest γ-ray sources pervading the Universe. Statistical cross-correlations with tracers of cosmic structure can indirectly identify the populations that most characterize the γ-ray background. In this study, we analyze the angular correlation between the γ-ray background and the matter distribution in the Universe as traced by gravitational lensing, leveraging more than a decade of observations from the Fermi-Large Area Telescope (LAT) and 3 years of data from the Dark Energy Survey (DES). …

X-Ray Polarization Of The Magnetar 1e 1841−045, Rachael Stewart, George A. Younes, Alice K. Harding, Zorawar Wadiasingh, Matthew G. Baring, Michela Negro, Tod E. Strohmayer, Wynn C.G. Ho, Mason Ng, Zaven Arzoumanian, Hoa Dinh Thi, Niccolò Di Lalla, Teruaki Enoto, Keith Gendreau, Chin Ping Hu, Alex Van Kooten, Chryssa Kouveliotou, Alexander Mcewen

Faculty Publications

We report on IXPE and NuSTAR observations beginning 40 days after the 2024 outburst onset of magnetar 1E 1841−045, marking the first IXPE observation of a magnetar in an enhanced state. Our spectropolarimetric analysis indicates that both a blackbody (BB) plus double power-law (PL) and a double blackbody plus power-law spectral model fit the phase-averaged intensity data well, with a hard PL tail (Γ = 1.19 and 1.35, respectively) dominating above ≈5 keV. For the former model, we find the soft PL (the dominant component at soft energies) exhibits a polarization degree (PD) of ≈30% while the hard PL displays …

A Polarized View Of The Young Pulsar Wind Nebula 3c 58 With Ixpe, N. Bucciantini, J. Wong, R. W. Romani, F. Xie, C. Y. Ng, S. Silvestri, N. Di Lalla, Y. J. Yang, S. Zhang, P. Slane, W. T. Ye, M. Pilia, N. Omodei, M. Negro

Faculty Publications

Pulsar wind nebulae (PWNe) are among the most efficient particle accelerators in the Universe; however, the physical conditions and magnetic geometry in their inner regions remain poorly understood. X-ray polarization now provides a unique opportunity to investigate the magnetic field structure and turbulence properties close to the sites where high energy particles are accelerated. Here, we report on recent X-ray polarization measurements of the PWN 3C 58 by the International X-ray Polarimeter Explorer (IXPE). 3C 58 is a young system that displays a characteristic jet-torus structure that, unlike those in other PWNe, is observed almost edge-on. This nebula exhibits a …

Anomalous Collective Modes In Atomic Nuclei Within The Proton-Neutron Interacting Boson Model, Wei Teng, Yu Zhang, Sheng Nan Wang, Feng Pan, Chong Qi, J. P. Draayer

Faculty Publications

Novel collective modes characterized by a B4/2 ratio (≡B(E2;41⁺→21⁺)/B(E2;21⁺→01⁺)) less than 1.0 that were observed recently have been identified within the proton-neutron interacting boson model (IBM-2) using the consistent-Q Hamiltonian. These modes are shown to give rise to triaxial spectral features, including significant band mixing. The results provide a compelling explanation for the deeply suppressed B4/2 ratio observed in ¹⁶⁶W, ^168,170Os, and ¹⁷²Pt, offering new insights into the B(E2) anomaly phenomenon in neutron-deficient nuclei.

Theory Of Two-Level Tunneling Systems In Superconductors, Junguang He, Wei Ting Lin, J. A. Sauls

Faculty Publications

We develop a field theory formulation for the interaction of an ensemble of two-level tunneling systems (TLSs) with the electronic states of a superconductor. Predictions for the impact of two-level tunneling systems on superconductivity are presented, including Tc and the spectrum of quasiparticle states for conventional BCS superconductors. We show that nonmagnetic TLS impurities in conventional s-wave superconductors can act as pair-breaking or pair-enhancing defects depending on the level population of the distribution of TLS impurities. We present calculations of the enhancement of superconductivity, both Tc and the order parameter, for TLS defects in thermal equilibrium with the electrons and …

Quantum Classical Algorithm For The Study Of Phase Transitions In The Hubbard Model Via Dynamical Mean-Field Theory, Anshumitra Baul, Herbert Fotso, Hanna Terletska, Ka Ming Tam, Juana Moreno

Faculty Publications

Modeling many-body quantum systems is widely regarded as one of the most promising applications for near-term noisy quantum computers. However, in the near term, system size limitation will remain a severe barrier for applications in materials science or strongly correlated systems. A promising avenue of research is to combine many-body physics with machine learning for the classification of distinct phases. We present a workflow that synergizes quantum computing, many-body theory, and quantum machine learning (QML) for studying strongly correlated systems. In particular, it can capture a putative quantum phase transition of the stereotypical strongly correlated system, the Hubbard model. Following …