Medicine and Health Sciences Commons^™

Post-Modeling Adjustments And Delivered Dose Verification Of The 6fff Beam Model Commissioned For The Monaco Treatment Planning System, Grant C. Debevec

LSU Master's Theses

External beam radiation therapy has been shown to be an effective treatment method for tumors and abnormalities of the spine and vertebral region. Treating the spine using a stereotactic body radiation therapy (SBRT) technique can reduce toxicity to the spinal cord. The 6 MV flattening filter free (6FFF) beam model is currently used to plan and calculate dose for SBRT treatment plans, and the treatment plans are delivered using a linear accelerator (LINAC).

The commissioned beam model represents an invariant component of a LINAC. For volumetric modulated arc therapy (VMAT) treatment plans, the multileaf collimator (MLC) positions are changing throughout …

The Theory Of X-Ray And Neutron Interferometry Using A Modulated Phase Grating, Hunter C. Meyer

LSU Master's Theses

Grating interferometry exploits wave interference to simultaneously image multiple physical properties of an object and can be performed using X-rays or neutrons. The modulated phase grating interferometer (MPGI) is a recently developed interferometry system that allows for the simultaneous acquisition of attenuation, differential-phase contrast, and dark-field images, which highlight X-ray or neutron absorption, refraction, and small angle scatter, respectively. This interferometry system uses a single grating, with a relatively high period envelope function, to produce interference fringes that can be directly resolved by standard high resolution detectors. The grating is sampled at a relatively low pitch, to meet coherence requirements …

Different Error Patterns Of /L/ In Children And Speech-Language Pathologists' Perception And Treatment, Grace E. Lemoine

LSU Master's Theses

Children often simplify target speech sounds using phonological processes, or common developmental error patterns. However, some children produce less common error patterns that differ from common errors. In the current study, less common errors involving /l/ sounds were studied as the phoneme /l/ is a sound that is subject to frequent misarticulations in young children and perceptual confusion among listeners. The current study focused on less common errors because studies have suggested that atypical errors can indicate weak phonological representations and poor phonological awareness skills, which can have long-term effects on children’s literacy skills. Therefore, the aim of the current …

Language Beliefs And Practices Of Caregivers In The Deep South, Maria Maldonado

LSU Master's Theses

The 30 million word gap refers to the disparity in early language exposure between low socioeconomic status (SES) children and their higher SES peers; a gap that is thought to negatively impact children’s language development and future academic success. Although many early intervention approaches have proven effective in promoting language development among low SES children, they often fall short in terms of cultural responsiveness, which in turn affects caregiver buy-in. Culturally and linguistically diverse children disproportionately live in poverty, as such there is a need for research to inform more responsive interventions that take a strengths- based approach and build …

Patient Specific Normalized Glandular Dose Range Estimate For Mammography, Lacey Medlock

LSU Master's Theses

Breast cancer is the most common type of cancer among women in the United States. It is also the second leading cause of death by cancer among women in the United States. Early detection is key to preventing fatalities. There are over 39 million mammography screening procedures performed yearly [3]. We know that exposure to radiation, including in routine mammography, may induce secondary cancers [4]. Thus, it is important to be able to accurately estimate the dose delivered to a patient during breast cancer screening. The dose delivered to a patient is regulated in the US and in many other …

Evaluating Vaccine Management Strategies For Edwardsiella Ictaluri Infections In Zebrafish (Danio Rerio), Brandy Malbrough

LSU Master's Theses

Aquaculture is a globally important industry that faces significant challenges due to infectious diseases, which can result in substantial financial losses. In 2011, a new strain of Edwardsiella ictaluri emerged as a major pathogen affecting zebrafish in the ornamental fish industry, leading to high mortality rates and posing a severe threat to the sector. Vaccines provide potential benefits for disease prevention in aquaculture, particularly live-attenuated vaccines (LAVs), which induce strong host immune responses. Bacterial attenuation for vaccine development has evolved from serial passage to more targeted genetic modification techniques. However, regulatory constraints limit the availability of licensed LAVs for aquaculture. …

Development And Testing Of A Mapcheck3-Based Patient-Specific Qa Method For Prime Intensity Modulators Used With Bolus Electron Conformal Therapy, James T. Crist

LSU Master's Theses

Purpose: Irregular surfaces in bolus electron conformal therapy (BECT) create target volume dose inhomogeneity, which off-axis intensity modulation (IM) can reduce. This research developed and tested a patient-specific clinical quality assurance (QA) procedure for fabricated Passive Radiotherapy Intensity Modulation for Electrons (PRIME) devices used for IM-BECT delivery.

Methods: To evaluate MapCheck3 (MC3) diode array accuracy, electron dose measurements beneath PRIME devices were compared with scanned measurements in a water phantom. Lateral dose profile comparisons were made for 35 combinations of five beam energies (7-20MeV) and seven PRIME devices - converging and diverging island blocks (pins) having 100-68.8% intensities. To evaluate …

Intensity Modulated Bolus Electron Conformal Therapy (Im-Bect): Methods For Quality Assurance Of Prime Intensity Modulators And Evaluation Of Planned Im-Bect Dose Distributions, Andrew S. Mcguffey

LSU Doctoral Dissertations

Purpose: Intensity-modulated bolus electron conformal therapy (IM-BECT) shapes homogeneous dose distributions to superficial, irregularly-shaped target volumes, avoiding nearby critical structures. This dissertation provides research useful for translating IM-BECT to the radiotherapy clinic by: (1) developing and testing a factory quality assurance (QA) method for fabricated Passive Radiotherapy Intensity Modulator for Electrons (PRIME) devices and (2) verifying an IM-BECT planning and delivery process using end-to-end tests.

Methods: The IM-BECT planning and delivery process determines beam parameters and treatment devices (cutout, bolus, PRIME device) using .decimal’s (Sanford, FL) ElectronRT (eRT) planning system; calculates dose using a pencil-beam redefinition algorithm modified for PRIME …

Reasoning The Voice: Toward A Diagnostic And Prescriptive Technique In The Teaching Of Singing, Carlos E. Santelli

LSU Doctoral Dissertations

Voice pedagogy literature often draws a parallel between a doctor’s ability to diagnose illness and prescribe treatment, and a voice teacher’s ability to identify vocal obstacles and design solutions. The core of these parallel procedures lies in an ability to utilize critical reasoning skills within highly specific contexts. Medical literature describes this as “clinical reasoning” and has studied it as a learned process. Voice pedagogy literature has traditionally described this as an innate process which is solely developed through experience. This document broadly examines the ways in which medical literature has broken down clinical reasoning into specific cognitive processes and …

Design, Construction, And Testing Of Recombinant Dna-Based Vaccines For Protection Against Salmonella Enterica Subspecies Enterica Serovar Javiana, Ashley Edwards

LSU Doctoral Dissertations

In the United States, Salmonella Javiana is among the top 5 most common nontyphoidal Salmonella serotypes, with a 325% increase in infection rate since 1970. Globally, nontyphoidal Salmonella leads to approximately 93.8 million illnesses and 155,000 deaths annually, with disproportionate impacts in developing countries. In the United States alone, these infections lead to over $4 billion in costs, the majority of which are attributed to those expenses incurred from mortalities. The zoonotic nature of nontyphoidal Salmonellae and their ability to survive on and within vegetation mean huge economic burden potential for various agricultural industries as well, especially since some of …

Regenerative Medicine For Tendon/Ligament Injuries: De Novo Equine Tendon/Ligament Neotissue Generation And Application, Takashi Taguchi

LSU Doctoral Dissertations

Tendon and ligament injuries are debilitating conditions across species. Poor regenerative capacities of these tissues limit restoration of original functions. The first study evaluated the effect of cellular administration on tendon/ligament injuries in horses using meta-analysis. The cellular administration was effective in restoring ultrasonographic echogenicity and increasing vascularity during early phase of healing. Additionally, it improved microstructural organization of healed tissue in terms of cellularity and fiber alignment. However, the study did not support its use for increasing rate of return to performance, expression/deposition of tendon-specific genes/proteins, or mechanical properties.

The findings led to the second study that engineered implantable …

Exploring The Interactive, Linguistic, And Conceptual Dimensions Of Parent Input And Their Role In Children's Pragmatic Development, Nickolas T. Day

LSU Master's Theses

The development of children’s pragmatic language, which can be defined as conversational competence in social contexts, has been attributed to variation in the language they hear in their environment. When studying the impact language input has on pragmatic development, it is important for clinicians and linguists to measure both the quantity and quality of this language input. Measures of quality, however, are much more relevant when studying the development of pragmatic language, as discussed in Zhang (2020) and Hirsh-Pasek et al. (2015). Rowe and Snow (2016) discussed three dimensions of language quality: interactive, linguistic and conceptual. There is a current …

Effect Of Furosemide Administration On Plasma Analytes And Urine Enzyme Excretion In Two Reptilian Species, Kathryn Metcalf

LSU Master's Theses

Renal disease is a common ailment of captive reptiles that is often closely linked to chronic, subclinical states of dehydration. Currently, the diagnosis of renal disease in reptiles is poorly characterized and often relies on invasive diagnostic techniques (e.g., renal biopsy) for definitive diagnosis. A potential outlet for the further characterization of renal dysfunction in reptiles is the induction of dehydration by furosemide therapy. Furosemide is a loop diuretic that is commonly used in mammalian patients for the treatment of congestive heart failure. The utility of furosemide in reptiles is poorly characterized, however, both experimental and clinical utility of this …

Identifying Key Language Research Priorities In Autistic Children According To Parents, Taylor Hale

LSU Master's Theses

The lack of involvement of the autistic community and its stakeholders in autism research has led to a call to action. At present, autism researchers have limited knowledge about stakeholders’ priorities for research. The current study aimed to bridge the disconnect between the extant autism research and the recent neurodiversity movement by surveying key stakeholders – parents of autistic children – on their perspectives on autism research that focuses on language. Twenty-six parents of autistic children completed an online survey on their views on autism language research with an option to participate in a follow-up interview. Six parents participated in …

Contribution Of The Microbiome On Reproductive Outcomes During Pregnancy, Kalie Beckers

LSU Doctoral Dissertations

A series of translational comparative studies were performed to investigate the effects of the maternal microbiome on reproductive function and outcomes. With the launch of the human microbiome project in 2007, the next generation sequencing of microbiomes is booming. It is not only in the human medicine field, but also in veterinary species. This study specifically investigates the fecal microbiome in blood pressure high sublime 5 (BPH/5) mouse model that spontaneously develops preeclampsia (PE) and obesity. Additionally, the equine reproductive tract microbiome was explored and compared to microbiome of other host body sites. The BPH/5 mouse is a translational model …

Switch-Like Behavior Of Lysosomes And Vcp Supports Spermatocyte Health And Development In Drosophila, Tyler James Butsch

LSU Doctoral Dissertations

Changes to societal norms, such as the educational, marital, and child-bearing expectations have coincided with significant increases in infertility worldwide. Surprisingly, male infertility is responsible for approximately half of all infertility cases worldwide. Thus, a better understanding of sperm development, and how it is affected by age, may permit the design and application of therapeutics to treat various cases male infertility. Here, I have found that lysosomes acidify as germ cells enter the spermatocyte stage. Once active, lysosomes turn over E-cadherin, and likely other proteins, to support plasma membrane stability. Notably, aging negatively impacts lysosome acidification, which can be reversed …

The Effect Of High Fraction Of Inspired Oxygen On Human Motor Learning Processes, Zheng Wang

LSU Doctoral Dissertations

Human motor learning processes are fundamental for our daily activities and can be adversely affected by neurologic conditions. Motor learning largely depends on successfully integrating cognitive and motor-related sensory information. A simple, easily accessible treatment that could enhance these learning processes would be exciting and clinically impactful. In this dissertation, we explore the effect of normobaric 100% oxygen treatment (NbOxTr) during different motor learning tasks and investigate the brain oxygenation changes during the process. In the visuomotor adaptation task (VMA), when participants adapted to a visual distortion between visual feedback and hand movements, participants with NbOxTr exhibited better movement planning …

The Effect Of Word-Learning Biases On Early Vocabulary Acquisition In Young Children On The Autism Spectrum, Claire C. Bourgeois

LSU Master's Theses

Background: Vocabulary composition and word-learning biases are closely interrelated in typical development. Such word-learning biases are influenced by perceptually and conceptually salient word features, including imageability, concreteness, iconicity, and attention to shape. Autistic children often have delayed language acquisition, but there is currently little research examining the underlying mechanisms autistic children use to acquire words. The current study aimed to examine the noun composition of autistic children across a range of vocabulary sizes by examining associations between expressive noun vocabulary size and imageability, iconicity, concreteness and evidence for the shape bias, and to examine whether these patterns differ from their …

Gis Automated Delineation And Analysis Of Cancer Service Areas In The United States, Changzhen Wang

LSU Doctoral Dissertations

Delineating a meaningful and reliable geographic unit pertaining to cancer care is essential in examining geographic variations in cancer care for better analysis, management, and planning. Public health researchers have devoted great efforts to defining various service areas, which; however, lack scientific rigor or are unrepresentative of the highly specialized cancer care markets, and their methods have become obsolete in the era of big data and high geo-computation. This study develops the “Spatially Constrained Leiden (ScLeiden)” method, a network community detection algorithm in Geographic Information Systems (GIS), and applies it to delineate a series of coherent cancer service …

Evaluation Of Residual Antibacterial Effects On Canine Skin Surface And Hairs Following Treatment With Five Commercial Mousse Products Against Staphylococcus Pseudintermedius In Vitro, Chi-Yen Wu

LSU Master's Theses

Topical products are essential treatments for canine superficial bacterial folliculitis. However, studies for commercial products typically evaluate antibacterial effects on hairs rather than the skin surface. In addition, the interference from the hair length has not been evaluated in these studies. Therefore, the study objective for this study was to evaluate the residual antibacterial effects of five mousse products, (1) 2% chlorhexidine and 2% miconazole, (2) 0.05% phytosphingosine, (3) 2% salicylic acid and 10% ethyl lactate, (4) 3% chlorhexidine and 0.5% climbazole, and (5) 2% chlorhexidine and 1% ketoconazole on both the skin surface and hairs in both short- and …

Individual Differences In The Criminogenic Effects Of Discrimination: An Exploration Of The Role Of Impulse Control And Callous-Unemotional Traits, Toni Walker

LSU Doctoral Dissertations

The association between perceived discrimination and engagement in criminal offending has been well studied, especially in samples of minority (predominantly Black, Hispanic, and Latinx) adolescents. Several theories have been developed (Social Schematic Theory) and adapted (General Strain Theory) in an attempt to explain how harmful, discriminatory experiences may have an effect on an individual’s behavior. There may be variability in how an individual responds to perceived discrimination, however, but the moderating role of personality characteristics has not been explored. Impulse control and callous-unemotional (CU) traits are both established predictors of offending and may also relate to the mechanisms that theories …

In-Phantom Film Measurements Of Two Treatment Planning Systems For Single-Fraction Spine Sbrt, Michael J. Taylor

LSU Master's Theses

Purpose: Treatment planning accuracy for spine stereotactic body radiation therapy (SBRT) varies depending on the dose calculation algorithm utilized in the treatment planning system (TPS). This project compared the end-to-end accuracy between spine SBRT plans calculated in a convolution-superposition based TPS (TPS_CS) and Monte Carlo based TPS (TPS_MC) with radiochromic film measurements. The hypothesis was that TPS_MC would calculate the dose gradient in the critical region between the vertebral body and the spinal cord more accurately than TPS_CS.

Methods: Single-fraction spine SBRT treatments following RTOG 0631 and local institutional guidelines were planned in …

Intra-Articular Buprenorphine In Horses, Gabriel Castro-Cuellar Dr

LSU Master's Theses

Opioid drugs have the potential of provide local analgesia in inflamed joints. To date, morphine is the only opioid that has been tested for intra-articular (IA) administration in horses. Having an alternative drug, other than morphine, could widen the therapeutic options, particularly in cases of drug shortages or inaccessibility to specific drugs. The work presented in this dissertation reports the cytotoxic effects of buprenorphine on cultured equine chondrocytes, and the pharmacokinetic, pharmacodynamic and analgesic effects, of IA administered buprenorphine in horses with experimentally induced synovitis.

To evaluate the potential cytotoxic effects on equine cartilage, chondrocytes were obtained from normal equine …

Implicit Bias In Speech-Language Pathology Students, Skyller Castello

LSU Master's Theses

Implicit racial biases have been documented across a variety of allied health professions. A systematic review conducted by FitzGerald and Hurst (2017) of implicit bias in healthcare professionals found that 20 out of 25 studies examined displayed bias against BIPOC in diagnosis, treatment recommendations, and other aspects of the medical care they received. A literature review completed by Hall et al. (2015) found similar results, stating that 9 of the 15 studies examined identified bias against Black clients. One allied healthcare profession, speech-language pathology, interacts with a diverse clientele in a clinical environment and yet have been excluded from much …

A Novel Endo Gia™ Staple Cartridge For Canine Lung Lobectomies, Alissa St. Blanc

LSU Master's Theses

The canine lungs are well suited for ventilation, gas exchange, and gas transport. In diseased states, changes within bronchi and pulmonary parenchyma alter the blood-gas interface. Diagnostic workups to characterize pulmonary disease may include blood gas analysis, bronchoalveolar lavage, tracheobronchoscopy, radiography and/or computed tomography. Surgical pulmonary diseases include cysts, bullae, and blebs; congenital anomalies; consolidation or abscessation; bronchiectasis; lacerations; lung lobe torsions; and neoplasia. Surgical options may include laceration repair, partial or total lung lobectomy, and pneumonectomy. These options are most commonly utilized in cases that fail medical management. Lung lobectomies were originally performed using suture ligation. Stapling devices have …

The Effects Of Dietary Interventions On Adverse Outcomes In Obese, Preeclamptic-Like Bph/5 Female Mice, Morgan Alston

Honors Theses

No abstract provided.

Whole Blood Transcriptome Analysis Of Insulin Sensitive And Insulin Dysregulated Mares, Sarah Lackey

Honors Theses

No abstract provided.

Visuomotor Rotation Adaptation And Workspace Manipulation: A Behavioral And Cognitive Emphasis, Reuben N. Addison

LSU Doctoral Dissertations

This is a three-study dissertation in which we aimed to broaden our knowledge of the mechanisms contributing to a 45° clockwise visuomotor adaptation by including variations in workspace. We provide behavioral and in one study physiological outcomes as evidence to support our conclusions. In the first experiment, we observed the adaptation of movement parameters such as pathlength, movement time, resultant velocity, and normalized jerk across groups trained with rotated visual feedback with both the left and right hands. Workspace location and hand differentially affected movement trajectory length. The group that practiced the task with their nondominant, left hand showed larger …

Evaluation Of Hippocampal Allostatic Load-Associated Factors In Animal Models Of Post-Traumatic Stress Disorder: Relevance To Human Ptsd, Dennis Parker Kelley

LSU Doctoral Dissertations

Post-traumatic stress disorder (PTSD) is associated with elevated allostatic load, nearly double the risk for metabolic syndrome, reduced hippocampal volume, and contextual memory processing deficits. Emerging evidence suggests that these stress effects may predispose individuals to the development of PTSD, and there is a known relationship between chronic stress and metabolic dysfunction. In this work, we utilized two rat models of PTSD to explore these connections. We used an acute predator odor stressor to investigate the relationship between PTSD-like behaviors and mitochondrial dysfunction in the hippocampus of rats, and we observed that conditioned place avoidance was associated with reduced mitochondrial …

A Bayesian Phase I/Ii Biomarker-Based Design For Identifying Subgroup-Specific Optimal Dose For Immunotherapy, Beibei Guo, Yong Zang

Faculty Publications

Immunotherapy is an innovative treatment that enlists the patient's immune system to battle tumors. The optimal dose for treating patients with an immunotherapeutic agent may differ according to their biomarker status. In this article, we propose a biomarker-based phase I/II dose-finding design for identifying subgroup-specific optimal dose for immunotherapy (BSOI) that jointly models the immune response, toxicity, and efficacy outcomes. We propose parsimonious yet flexible models to borrow information across different types of outcomes and subgroups. We quantify the desirability of the dose using a utility function and adopt a two-stage dose-finding algorithm to find the optimal dose for each …