Medicine and Health Sciences Commons^™

Effects Of Hearing Aid Amplification On Robust Neural Coding Of Speech, Jonathan Daniel Boley

Open Access Dissertations

Hearing aids are able to restore some hearing abilities for people with auditory impairments, but background noise remains a significant problem. Unfortunately, we know very little about how speech is encoded in the auditory system, particularly in impaired systems with prosthetic amplifiers. There is growing evidence that relative timing in the neural signals (known as spatiotemporal coding) is important for speech perception, but there is little research that relates spatiotemporal coding and hearing aid amplification.

This research uses a combination of computational modeling and physiological experiments to characterize how hearing aids affect vowel coding in noise at the level of …

An Epidemic Model Structured By The Time Since Last Infection, Jorge Alturo Alfaro Murillo

Open Access Dissertations

Epidemiological models structured by time since infection have their origin in the seminal work of 1927 by Kermack and McKendrick. Compared to ordinary differential equations (ODE) models, they are able to capture differences in infectivity of the individuals in a more suitable manner. Their use declined in the second half of the 20th century, probably because the theory for ODE models is more robust, complete and has proved successful in providing insights and predictions for many epidemiological problems. Nevertheless, it is important to understand in what occasions the inclusion of time since infection may alter the outcomes in a significant …

Developing A Drug Delivery System For Treatment Of Vocal Fold Scarring, Aaron Michael Kosinski

Open Access Dissertations

Vocal fold scarring is an affliction that results in the formation of a disorganized and stiff extracellular matrix (ECM) with abnormal ECM component densities & structures including a significant increase in collagen deposition. It is caused by improper healing post injury and results in profound changes in the biomechanical properties of the vocal folds impairing their ability to generate a normal mucosal wave during phonation.

Finding an effective treatment for vocal fold scarring has been elusive. Currently, treatments seek temporary solutions that correct glottal incompetence and reduce stiffness caused by the scar through the augmentation of the vocal folds using …

Assessing The Preparedness Of The Veterinary Profession To Communicate With Limited English Proficient Spanish-Speaking Pet Owners, Ruth Ellen Landau

Open Access Dissertations

The purpose of the present study was to assess the preparedness of the veterinary profession to communicate with limited English proficient Spanish-speaking pet owners (LEP SSPOs). Results of surveys with 393 Latino pet owners, 383 small animal veterinarians and staff, and over 2000 veterinary students indicate that interaction between veterinary professionals and LEP SSPOs is not a rare occurrence: Veterinarians in states with large established or fast-growing Latino communities are seeing LEP SSPOs and their pets on a regular basis: 89% of veterinarians have LEP Spanish-speaking clients, over half of these practitioners are seeing LEP SSPOs weekly, and over half …

Patients' Perceptions Of Provider Communication, Provider Knowledge And Provider Competence And Associations With Potentially Inappropriate Medication Use Among Medicare Part D Beneficiaries, Engels Nnamdi Obi

Open Access Dissertations

The objectives for this study were to determine prevalence and incidence of potentially inappropriate medication (PIM) use among community-dwelling Medicare Part D beneficiaries, and to assess associations between patients' perceptions of provider communication, provider knowledge, and provider competence with PIM use. A retrospective observational analysis was conducted using data from the Medicare Current Beneficiary Survey. Individuals were included in the prevalence sample if they were aged 65 years or older in 2008, continuously enrolled in Medicare Part D from October 2007 through December 2008, and living in the community from October 2007 through December 2008. Individuals were included in the …

Predicting Language Impairment Status: A Risk Factor Model, Johanna Maria Rudolph

Open Access Dissertations

The etiology of specific language impairment (SLI) is multifactorial. Research has shown that genetic, environmental, and developmental factors may influence the course of its development. Because many of these factors are present even before a child is born, it is possible that a child's risk of developing the disorder can be identified long before grammatical deficits are observed. The goal of this study was to develop and validate a screening tool to discriminate between children with SLI and typically developing (TD) children using risk factor information including gender, family history of communication or reading disorders, socioeconomic status, maternal and paternal …

Patient Perceptions Of Physicians And Medication Adherence Among Medicare Part D Beneficiaries, Lori Marquinne Ward

Open Access Dissertations

Ward, Lori Marquinne. Ph.D., Purdue University, December, 2013. Patient Perceptions of Physicians and Medication Adherence Among Medicare Part D Beneficiaries. Major Professor: Joseph Thomas III.

An observational database analysis using Medicare Current Beneficiary Survey data was conducted to examine patient perceptions of physicians and associations with adherence to antihypertensive medication among Medicare beneficiaries enrolled in Medicare Part D. The study sample included beneficiaries if they were 65 years or older, dwelling in the community, had a diagnosis of hypertension in 2007, were enrolled in Medicare Part D all 12 months in 2008, and had Medicare Part D claims for antihypertensive …

Altered Cholesterol Metabolism In Human Cancers Unraveled By Label-Free Spectroscopic Imaging, Shuhua Yue

Open Access Dissertations

Despite tremendous scientific achievements, cancer remains the second leading cause of death in the United States. Metabolic reprogramming has been increasingly recognized as a core hallmark of cancer. My dissertation work identified novel diagnostic markers and therapeutic targets for human cancers through the study of cholesterol in cancer cells.

Enabled by label-free Raman spectromicroscopy, we performed the first quantitative analysis of lipogenesis at single cell level in human patient cancerous tissues. Our imaging data revealed an unexpected, aberrant accumulation of esterified cholesterol in lipid droplets of high-grade prostate cancer and metastases, but not in normal prostate, benign prostatic hyperplasia, or …

Health Care Resource Utilization And Expenditures In Persons With Autosomal Dominant Polycystic Kidney Disease, Neeraj Neelakantan Iyer

Open Access Dissertations

The objectives of this study were to determine prevalence of autosomal dominant polycystic kidney disease (ADPKD), to determine all-cause health care resource utilization and all-cause health care expenditures, to determine incremental health care resource utilization, and to determine incremental health care expenditures associated with ADPKD. An observational database analysis of a privately insured population was conducted using information from a large administrative claims database. Individuals 18 years of age or older and enrolled in a tracked health plan anytime during the period from April 1, 2011 through March 31, 2012, were eligible for inclusion in the sample for determination of …

Neural Encoding Of Complex Signals In The Healthy And Impaired Auditory Systems, Saradha Ananthakrishnan

Open Access Dissertations

Individuals with sensorineural hearing loss (SNHL) typically experience difficulty in understanding speech. Our current knowledge of deficits in speech perception and encoding consequent to SNHL is restricted to psychophysical studies in humans and single-unit experiments in animals. However, the nature of degradation in neural encoding of speech following hearing impairment in humans has not been extensively researched. The objective of this dissertation is to provide a systematic evaluation of neurobiological signature of hearing loss at the subcortical level using an objective electrophysiological non-invasive neural index, the frequency following response (FFR). Subcortical neural encoding of speech signals is explored by quantifying …