Life Sciences Commons^™

Neural Correlates Of Audiovisual Speech Perception In Aphasia And Healthy Aging, Sarah H. Baum

Dissertations & Theses (Open Access)

Understanding speech in face-to-face conversation utilizes the integration of multiple pieces of information, most importantly the auditory vocal sounds and visual lip movements. Prior studies of the neural underpinnings of audiovisual integration in the brain have provided converging evidence to suggest that neurons within the left superior temporal sulcus (STS) provide a critical neural hub for the integration of auditory and visual information in speech. While most studies of audiovisual processing focus on neural mechanisms within healthy, young adults, we currently know very little about how changes to the brain can affect audiovisual integration in speech. To examine this further, …

Electromechanical Delay Of The Dorsiflexors In Young And Old Women, In H. Choi

Electronic Thesis and Dissertation Repository

PURPOSE: The aim of the current study was to examine the effect on electromechanical delay (EMD) in the dorsiflexors of young and old women during maximal isometric voluntary and electrically evoked contractions, and after a bout of lengthening contractions. METHODS: Nine young (25.1±1.3 years) and nine old (68.3±6.1 years) women performed baseline isometric contractions with evoked twitches followed by a series of dynamic lengthening contractions using a Biodex multi-joint dynamometer. Maximal isometric voluntary and evoked contractions were measured to assess EMD. Time points were recorded at baseline, mid-point of the intervention, post-task termination, and during recovery at 0.5, 2, 10, …

Recovery From Muscle Fatigue In Young And Older Adults: Implications For Physical Function, Stephen A. Foulis

Open Access Dissertations

As adults age, skeletal muscles become smaller and weaker, which can ultimately lead to declines in physical function and disability. In general, older adults produce less isometric force and dynamic power than younger adults. The effects of this weakness are amplified following a series of muscle contractions that result in muscle fatigue. Since daily routines consist of repeated series of activity followed by rest, it is important to understand how muscle recovers from fatigue. In particular, muscle power has been shown to be related to physical function and balance. Thus, understanding the process of recovery from muscle fatigue will help …

Aging And Obesity Models In Osteoarthritis, Sara Ohora

Electronic Thesis and Dissertation Repository

Osteoarthritis (OA) is a degenerative joint disease whose exact mechanisms are not well understood, but aging and obesity are common risk factors. To determine the role of transforming growth factor-alpha (TGFα) in obesity-associated OA, Tgfa null and control mice on control and high fat diets were compared. In addition, spontaneous OA was investigated in aging C57BL/6J mice. Quantitative magnetic resonance was used to assess body composition in the obesity model, while gait analysis, histological staining and OARSI scoring were used to determine OA in both models. Mice on high fat diet developed no OA, but Tgfa null mice weighed significantly …

The Chromatin Remodeling Protein Atrx In Development And Maintenance Of Mouse Skeletal Tissues, Lauren A. Solomon

Electronic Thesis and Dissertation Repository

Alpha-thalassemia X-linked mental retardation (ATR-X) syndrome is a rare genetic disorder associated with severe developmental delay, mental retardation and craniofacial dysmorphism. This syndrome is caused by mutations in the ATRX gene which encodes a member of the SWI/SNF family of chromatin remodeling proteins. ATR-X patients exhibit dwarfism and skeletal defects, including hand and foot deformities. I hypothesized that the skeletal deformities in ATR-X syndrome are due to a direct role of ATRX in the development of the skeleton. My objective was to characterise skeletal phenotypes observed in three animal models conditionally deficient for ATRX in different skeletal tissues. Mice lacking …

Exercise Alters Glial Cell Line-Derived Neurotrophic Factor (Gdnf) Protein Content In The Spinal Cord, Monica Janine Mccullough

Dissertations

Neurotrophic factors may play a role in exercise-induced neuroprotective effects; however, it is not known if exercise mediates changes in glial cell line-derived neurotrophic factor (GDNF) protein levels in the spinal cord. The aim of the studies described herein was to determine if exercise alters GDNF protein expression in the lumbar spinal cord of healthy and diseased animals. The lumbar spinal cord was analyzed from adult rats aged 6-, 12-, 18- and 24-months, and from transgenic amyotrophic lateral sclerosis (ALS) mice and wild-type mice aged 3 months. Animals had undergone either forced wheel running, voluntary wheel running or swimming for …

Subcellular Analysis Of The Disulfide Proteome In P66shc Expressing Nerve Cells, Tyler Cann

Electronic Thesis and Dissertation Repository

The longevity associated protein p66Shc has been suggested to regulate organismal lifespan through initiation of apoptotic pathways. Following stress-induced translocation into the mitochondria, p66Shc promotes increased reactive oxygen species (ROS) production and triggers poorly defined downstream signaling events that lead to decreased cell viability. Protein disulfide bonding has recently emerged as aROSdependent post-translational modification that regulates protein function and signaling processes. Using the mouse hippocampal HT-22 cell line, I sought to determine the changes in the disulfide proteome associated with p66Shc mediatedROSproduction. Through Redox 2D-SDSPAGEanalysis of mitochondrial and cytosolic extracts, redox sensitive proteins altered by p66Shc mediatedROSformation were identified. Of …

The Effects Of 6-Weeks Of Resistance Training On The Neuromuscular Fatigue Threshold In Older Adults, Nadia Emerson

Electronic Theses and Dissertations

Age-related deficits in muscle mass, strength, and function place an increased burden of work on existing skeletal muscle and may lead to early onset of neuromuscular fatigue (NMF) during activities of daily living. Resistance exercise (RE) is the proven method for improving neuromuscular function in healthy older adults. PURPOSE: To investigate the effects of 6 weeks of RE on the NMF threshold as well as strength and functional performance in older adults. METHODS: Twenty-four older adults were randomly assigned to 6 weeks of RE (EXE; n = 12; age 72 ± 6.3 y; BMI 28.4 kg/m2 ) or control (CONT; …

Effect Of Advanced Age On The Innate Immune Response To Cutaneous Wound Infection, Aleah Lin Brubaker

Dissertations

An estimated 25 billion in US health care expenditure is spent on care of chronic, non-healing wounds. The failure to effectively heal wounds is often compounded by co-morbidities, such as diabetes or obesity. Another major patient population afflicted with chronic wounds are the elderly. Advanced age is associated with a decline in immunologic function that contributes to a poor response to vaccination, infection and tissue injury resulting in prolonged hospital stays and age-related morbidity and mortality. Specifically, clinical observations and laboratory studies have suggested an age-related decline in cutaneous wound healing, marked by protracted wound closure, wound dehiscence and chronic …

Changes In Sleep Architecture And Cognition With Age And Psychosocial Stress: A Study In Fischer 344 Rats, Heather M. Buechel

Theses and Dissertations--Pharmacology and Nutritional Sciences

Changes in both sleep architecture and cognition are common with age. Typically these changes have a negative connotation: sleep fragmentation, insomnia, and deep sleep loss as well as forgetfulness, lack of focus, and even dementia and Alzheimer’s disease. Research has shown that psychosocial stressors, such as isolation from family and friends or loss of a loved one can also have significant negative effects on sleep architecture and cognitive capabilities. This leaves the elderly in a particularly vulnerable situation: suffering from cognitive decline and sleep dysregulation already, and more likely to respond negatively to psychosocial stressors. Taking all of these factors …

Evidence For Renewal And Reconstitution Of Marginal Zone Macrophages In Young And Aged Mice, Erika Bahamon

Master's Theses

Aging in humans and mice correlates with decline in immune health, affecting both innate and adaptive immunity. Response against blood-borne bacterial pathogens is compromised because of the deterioration of the marginal zones of the spleen and decrease in frequency of marginal zone macrophages (MZM). This thesis asked if low cell turnover is the cause for the decrease of MZM, using cell proliferation to indicate cell turnover in spleens of mice. First, evidence showed MZM proliferation occurred in spleens of young mice and was decreased in the MZM from aged mice. Second, transfer of young bone marrow into old mice replenished …

Effect Of Estradiol Supplementation On Blood Estradiol And Metabolite Levels, And Hepatic Protein Expression, In Growing, Mature, And Senescent Beef Cattle, Edwena D. Miles

Theses and Dissertations--Animal and Food Sciences

Estradiol (Compudose®, COM) implants are extensively used in beef cattle production systems to alter body composition and feed efficiency. Little information exists about the physiological mechanisms affected by COM treatment in growing, mature, and senescent female cattle. Moreover, no reports describe the level of blood estradiol resulting from COM treatment. The effect of COM on levels of plasma estradiol and blood metabolites and proteins, and relative content of glutamine synthetase (GS) and other amino acid nitrogen-metabolizing enzymes in liver tissue, was studied using three experimental models relevant to cow-calf production regimens: senescent cows (Trial 1), young mature (young) versus senescent …

Effects Of Intranasally Administered Dnsp-11 On The Central Dopamine System Of Normal And Parkinsonian Fischer 344 Rats, James H. Sonne

Theses and Dissertations--Neuroscience

Due to the blood-brain barrier, delivery of many drugs to the brain has required intracranial surgery which is prone to complication. Here we show that Dopamine Neuron Stimulating Peptide 11 (DNSP-11), following non-invasive intranasal administration, protects dopaminergic neurons from a lesion model of Parkinson’s disease in the rat. A significant and dose-dependent increase in an index of dopamine turnover (the ratio of DOPAC to dopamine) was observed in the striatum of normal young adult Fischer 344 rats by whole-tissue neurochemistry compared to vehicle administered controls.

Among animals challenged with a moderate, unilateral 6-hydroxy-dopamine (6-OHDA) lesion of the substantia nigra, those …

The Role Of Macrophages In Exercise And Insulin Resistance In Human Skeletal Muscle, Jason S. Groshong

Theses and Dissertations--Physiology

Muscle biopsies were taken at baseline, post eccentric exercise, post aerobic training, and after training followed by eccentric exercise from adults with different health status. In Cell Western analysis of pAkt/Akt ratio suggests that muscle cells isolated from baseline biopsies respond to insulin in a dose dependent manner that tracks with sensitivity to insulin of the host; however, this is uncoupled from glucose disposal in vitro. Nitrotyrosine (NY), a marker of free radical damage, was employed to assess the efficacy of the exercise paradigm. NY immunohistochemistry on muscle cross-sections revealed that eccentric exercise significantly increased damage in older ( …

Innate Immune Responses To Respiratory Syncytial Virus: Age-Associated Changes, Terianne Maiko Wong

USF Tampa Graduate Theses and Dissertations

Respiratory syncytial virus (RSV) infection causes ~64 million cases of respiratory disease and 200,000 deaths annually worldwide, yet there is no broadly effective prophylactic or treatment regimen. RSV can produce acute respiratory illness in patients of all ages but strikes the age extremes, infants and the elderly, with highest frequency presumably due to innate immune deficiencies. A higher morbidity and mortality has been reported for the elderly above 65 years of age, which has been attributed to immune senescence. Efforts to generate an effective vaccine have thus far been unsuccessful.

The innate immune system provides the first line of defense …