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 …

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 …

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 …

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 …

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 …

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 …

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 …

Accuracy Of A Sacral Drilling With A Custom 3d Printed Drilling Guide Or Free-Hand Technique In Canine Experimental Sacroiliac Luxation, Daniel Mccarthy

LSU Master's Theses

ABSTRACT

The objective of this study was to improve the accuracy of drilling during the repair of sacroiliac luxation with a 3D-printed patient-specific drill guide (3D-GDT) compared to free-hand drilling technique (FHDT). A blinded, randomized, prospective study was performed including sixteen canine cadavers (20-25 kg) euthanized for reasons not related to the study. Dorsal, bilateral, sacroiliac luxations (SILs) were created experimentally. A pelvic CT was performed pre- and post-drilling. The FHDT was drilled followed by 3D-GDT for each sacrum. CT and 3D measurements of craniocaudal and dorsoventral angles were compared between FHDT and 3D-GDT, as well as deviations of entry …

Characteristics And Causal Factors For The Receptive-Expressive Gap In Typically Developed Spanish-English Adult Bilinguals, Rachael Janelle Javaherian

LSU Master's Theses

A receptive-expressive language gap occurs when a standardized receptive score is statistically greater than an expressive score in either a primary or a second language. In bilingual children, gap studies already exist for determining language impairment. In adults, there are few studies; nevertheless, one needs to distinguish between typical language patterns of bilingualism due to non-pathological loss of L1 skills versus problems resulting from accidents, disease, or age. To this end, the present study attempted to expand findings of studies by Gibson et al. (2012 and 2014) that focused on analysis of the gap and possible factors influencing its existence …

Role Of Aim2 Inflammasome In Pulmonary Host Defense Against Staphylococcus Aureus-Induced Pneumonia, Bibek Dhakal

LSU Master's Theses

Bacterial pneumonia is the leading cause of death in children under the age of five, claiming the lives of two million children each year. Staphylococcus aureus is the extracellular Gram-positive bacteria that causes necrotizing pneumonia. Moreover, the spread of antibiotic-resistant and hypervirulent strains has made treatment more challenging. Absent in melanoma 2 (AIM2) is a dsDNA-sensing cytosolic innate immune receptor that activates inflammasomes and is crucial for host defense against intracellular bacteria and DNA viruses. However, its role in extracellular bacterial pathogen-induced pneumonia is unclear. Therefore, understanding how AIM2 initiates host responses during Staphylococcus aureus is crucial for the development …

Informing Viral Surveillance Of Oropouche Virus: An Emerging Arbovirus, Christine E. Walsh

LSU Master's Theses

Arboviruses are viruses transmitted by hematophagous arthropod vectors. Many of these viruses pose a threat to human health. While some infections may be asymptomatic, others may produce febrile illness, or manifest in life threatening conditions. Symptomatic diagnosis of patients with generalized febrile illness can be confounded due to the various diseases that present clinically in the same manner, and a lack of available diagnostic tests. Surveillance efforts can be used to create awareness about the prevalence of neglected tropical arthropod-borne pathogens, such as Oropouche virus (OROV), and inform preparedness measures for disease outbreaks (SURVEILLANCE SENTENCE). OROV is an arbovirus and …

Modeling Of Island Block Scatter For Intensity Modulated Bolus Electron Conformal Therapy, Joseph G. Scotto

LSU Master's Theses

Purpose: Bolus electron conformal therapy (BECT) benefits treatment of the post-mastectomy chest wall, head and neck, paraspinal muscles, and extremities. Patient dose heterogeneities caused by bolus can be reduced through intensity modulation (IM) across the incident electron beam. This requires passive radiotherapy intensity modulation for electrons (PRIME) devices, which utilize tungsten pins (island blocks) imbedded in machinable foam. IM-BECT treatment planning requires accurate dose calculation using the pencil beam redefinition dose algorithm (PBRA). Currently, the PBRA models island blocks as perfect collimators. This work explores models to account for electrons scattering into and out of the sides of island blocks. …

Structural Shielding Considerations For Vmat, Ana Lucia Dieguez

LSU Master's Theses

Introduction: As noted in National Council on Radiation Protection and Measurements (NCRP) Report 151, the medical physicist or other qualified expert has the responsibility to keep abreast of any new technology or treatment method that could potentially impact structural shielding design. Volumetric arc therapy (VMAT) became prevalent after the publication of Report 151 and thus was not explicitly addressed in Report 151. If the shielding-related characteristics of VMAT differ enough from the expectations of Report 151, especially in the circumstance of a vault utilized exclusively for VMAT, a shielding design based on Report 151 could potentially be inadequate. The …

Characterizing Receptive Vocabulary Knowledge In Minimally Verbal Children With Autism Spectrum Disorder, Allison Menting

LSU Master's Theses

Background: Delayed or impaired language skills are common characteristics of children with autism spectrum disorder (ASD). Currently, there is little research examining the receptive language profile in children with ASD, and even less is known about children with ASD who are minimally verbal. The current study aimed to characterize the receptive vocabulary profile of minimally verbal children with ASD and to examine whether this profile differs from their typically developing peers. Methods: Participants included 31 minimally verbal children with ASD, aged 60-118 months, who were reported to produce between 0-10 words, 124 typical developing toddlers, aged 9-14 months, who were …

Validation Of A Respiratory Gating System For Automated Delivery Of The Deep Inspiration Breath-Hold Technique, Michael G. Stock

LSU Master's Theses

Purpose: To validate the performance of a respiratory gating system for the automated delivery of the deep inspiration breath-hold (DIBH) technique.

Methods: The gating system utilized an automatic gating interface (Elekta Response) which connected a marker-based respiratory motion monitoring system to the linear accelerator control system. The gating system was characterized dosimetrically and temporally using two distinct approaches. Central-axis output and energy constancy were evaluated across 8 beam-matched linear accelerators. Additionally, a representative set of 5 treatment plans were delivered both non-gated and gated to a 2D diode array (MapCHECK). The respiratory motion monitoring system optically tracked a reflective marker …

Anesthetic Combination Of Alfaxalone, Dexmedetomidine And Hydromorphone For Comparison Of Endoscopy-Guided Intubation And Blind Orotracheal Intubation In Domestic Rabbits (Oryctolagus Cuniculus), Stephanie Reabel

LSU Master's Theses

Domestic rabbits have a high risk of anesthesia-related mortality compared to other companion animals. Factors that may contribute to increased mortality include drug-induced cardiopulmonary effects (Grint & Murison 2008; Navarrete-Calvo et al. 2013), difficulty performing intubation (Aeschbacher 1995; Flecknell 2016; Wenger et al. 2017) or damage to laryngeal and tracheal tissues following orotracheal intubation (Grint et al. 2006; Phaneuf et al. 2006; Engbers et al. 2017).

Alfaxalone is a neuroactive steroid that produces induction of anesthesia and cardiorespiratory depression in a dose-dependent manner when injected intravenously. The ability to induce anesthesia via an intramuscular (IM) route has several advantages in …

Five Love Languages: Assessment Of Marital Satisfaction In African American Couples, Freddricka C. Lee

LSU Master's Theses

This mixed-methods study examined marital satisfaction among five (n = 10) heterosexual, African American married couples. In particular, this study examined how acknowledging a partner’s love language (Chapman, 1995) can affect these couples’ level of marital satisfaction. The participants were native to the South and ranged from 26-55 years of age. Quantitative and qualitative analysis of the data revealed couples were satisfied with their marriages. Although only marginally significant, the findings also revealed acknowledging a spouse’s love language was positively related to higher levels of marital satisfaction. Seven themes emerged throughout the interviews, namely communication; financial stability; understand a spouse’s …

Voice Therapy: Racial Disparities In Adherence And Clinically Significant Outcomes, Amber D. Burks

LSU Master's Theses

Voice therapy is evidence-based, behavioral intervention that can reduce functional and organic voice disorders. Despite its proven effectiveness, non-adherence to voice therapy is still an issue. Research shows that an estimated 65% of patients who initiate voice therapy drop out before reaching therapeutic goals. Voice therapy outcomes are largely dependent on patients’ adherence to treatment regimens, but there is limited information concerning factors that may be associated with voice therapy adherence and therapeutic outcomes for patients who successfully complete voice therapy.

The purpose of this study was to investigate which demographic factors could be associated with higher adherence rates to …

Determining The Effects Of Exogenous Human Chorionic Gonadotropin And Pregnant Mare Serum Gonadotropin On Plasma Testosterone, Testicular Volume, And Semen Production In Leopard Geckos (Eublepharis Macularius), Alexandra Mason

LSU Master's Theses

Planet earth has now entered into its sixth mass extinction as a result of expanding human populations, posing an unprecedented threat to biologic diversity. Climate change, habitat fragmentation, wildlife trade, pollution, and biological invasions are just a few consequences of human activities that have directly contributed to unprecedented species extinctions. While widespread amphibian declines have gained more recent attention, it has been proposed that reptiles may be in even greater danger of extinction worldwide. Unfortunately, many reptiles are destined to go extinct before many of their basic biologic traits, including reproductive methods, have even been determined.

In order to mitigate …

Assessing The Validity Of The Estimation Of Population Affinity From The Maxillary Hard Palate: An Empirical Approach Using A Modern Forensic Sample, Christopher M. Goden

LSU Master's Theses

In response to Beathard and DiGangi’s (2020) call to action for empirical assessment of population affinity estimation methodology, this study investigates the validity of maxillary palate shape as an indicator of ancestral population affinity for human skeletal remains through the use of Elliptical Fourier Analysis (EFA) and Linear Discriminant Function Analysis (DFA). Further, this study also places emphasis on the expressed variation of palate shape within and between population groups exemplified by Principal Component Analysis (PCA) of EFA data.

Computed tomography scans of 180 individuals of Black, White, and Hispanic population affinities were obtained from the New Mexico Decedent Imaging …

Modeling Cumulative Risk During The Covid-19 Pandemic: Psychosocial And Socioeconomic Factors For Older Minority Adults, James F. Osborne Iv

LSU Master's Theses

Continued response to the sum consequences of the COVID-19 pandemic has disparately affected the physical and mental health of older minority adults in the United States. SARS-CoV-2 created an acute epidemiological crisis of public health coinciding with a chronic pandemic of accentuated psychosocial stress. Biological and socio-economic risk of morbidity and mortality follow a demographic gradient of subjectively constructed social status that disproportionally threatens older adults and minority racial/ethnic communities. Pathways to increased socio-economic and psychosocial vulnerability are multifactorial and complex. Factors of race, socio-economic status, gender, and age, each contribute to individualized profiles of vulnerability to risk exposure.

The …