Digital Commons Network^™

Neuromuscular Function Following Lengthening Contractions, Geoffrey A. Power

Electronic Thesis and Dissertation Repository

Unaccustomed lengthening contractions have been shown to impair muscle function - however little is known regarding this impairment on muscle power - specifically, the velocity component of power during voluntary contractions in humans. The four studies presented in my thesis investigated power-loss following lengthening contractions in healthy young and old women and young men.

The purpose of Study 1 was to determine reliability of velocity-dependent power of the dorsiflexors using the isotonic mode of the Biodex Dynamometer. I determined the isotonic mode is reliable and can be used to track changes in velocity and power following fatigue and lengthening contractions. …

Neuroprotective Effects Of Long-Term Endurance Training On The Cortical Autonomic Network In The Aging Brain, Torri A. Luchyshyn

Electronic Thesis and Dissertation Repository

This study tested whether long-term endurance training in older adults (ET; n = 15, 55 ± 4 years, relative VO₂max = 50 ± 8 ml/kg/min) would alter cardiovagal control and preserve the cortical autonomic network compared to age-matched controls (CON; n = 15, 56 ± 4 years, relative VO₂max = 37 ± 9 ml/kg/min). The hypothesis predicts 1) altered deactivation patterns of the ventral medial prefrontal cortex (vMPFC) in response to isometric hand grip (IHG) and 2) greater indices of cardiovagal control; a) increased baroreflex sensitivity at rest, b) greater heart rate change (ΔHR) and c) …

Influence Of A Short-Term, Multicomponent Intervention On Balance And Strength Among The Elderly, Pamela C. Webert

Master's Theses and Doctoral Dissertations

Background: Few studies have combined strength and balance training to assess improvement of activities of daily living among subjects over the age of 65. The purpose of this study was to demonstrate how an eight-week balance and strength training program can lead to improvements in activities of daily living among elderly individuals.

Methods: The subjects consisted of 14 elderly women and 3 elderly men who were all residents of an independent living community. There were 10 subjects in the intervention group and 7 subjects in the control group. The intervention group participated in a supervised balance and strength …

Lower Extremities Muscle Strength Associated With Early Signs Of Mobility Dependence Among Older Adults Age 65 Years And Older, Moshe Marko

Exercise Science - Dissertations

Background: Loss of muscle strength is evident even in apparently healthy older adults. functionally limited due to an increasing discrepancy between their own physiological capabilities (i.e. physiological impairments) and the challenges set forth by the environment. Functional limitations lead to clinical mobility disability. Clinical mobility disability is associated with physical dependence, poor quality of life, and mortality. Treatment of age-related clinical mobility disability should focus on the prevention of the condition rather than its consequences. Identifying opportunities for early screening and prevention of clinical mobility disability requires a better understanding of the functional loss prior to this medical condition. …

Development Of Methods For Assessing The Effect Of Moisture And Aging On Sliceability Of Cheese, Jess Perrie

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Sliceability is a cheese’s ability to cut cleanly into thin slices, resist breakage or fracture at slices edges, and undergo a high level of bending before breaking. Intuitively, sliceability depends on the chemistry, microstructural, and rheological properties of the casein network. Currently there is no reported scientific research investigating evaluation methods of cheese slice quality, as well as properties that influence a cheese’s ability to slice.

In this study, a method for slice quality evaluation was developed on purchased cheese and performed on commercial cheeses and experimental cheeses manufactured at three different moisture contents (40.6%, 37.0%, and 33.9%). In addition, …

Effects Of Thymus Size And Involution On The Contribution Of Recent Thymic Emigrants To The Peripheral T Cell Pool, Michelle L. Bolner

Dissertations & Theses (Open Access)

The contribution of recent thymic emigrants (RTEs) to the peripheral naïve T cell population is necessary to maintain diversity of the T cell receptor (TCR) repertoire and produce immune responses against newly encountered antigens.

The thymus involutes with age, after irradiation or chemotherapy, and due to severe viral infections. Thymus involution results in decreased thymopoiesis and RTE output leading to a reduced diversity of peripheral T cells. This increases susceptibility to disease and impairs immune responsiveness to vaccines. Therefore, studies aimed at maintaining or regenerating thymic function are integral for maintaining and restoring peripheral TCR diversity.

Mice that express a …

Promoting Thymopoiesis With Age: Potential Role Of The Transcription Factor Foxn1, Erin Christine Zook

Dissertations

It is known that the elderly are more susceptible to illnesses and infections and respond poorly to immunization. A contributing factor to a decrease in the immune response in the elderly is the decline in the production of naïve T cell by the thymus. In the thymus, the notch receptor expressed on early T cell progenitors (ETP) binds to its ligand expressed on thymic epithelial cells (TEC), signaling ETP to develop through a series of developmental stages before maturing into naive T cells. Because ETP are non-self renewing, the thymus relies on the bone marrow (BM) for a continuous supply …

Aging, Stem Cells And The Cancer Stem Cell Hypothesis, Dave Comstock

Dissertations and Theses

No abstract provided.

The Molecular And Behavioral Characterization Of Cav1.3 Over-Expressing Mice, Jamie Nicole Slater

Master's Theses and Doctoral Dissertations

Age-related cognitive decline refers to the memory impairment and difficulty learning new tasks that occurs during the normal process of aging. There are many possible changes that occur at the neuronal level that could account for age-related cognitive decline. One hypothesis suggests that a dysregulation of neuronal intracellular calcium concentration contributes to age-related cognitive deficits. Previous research suggests that an increase in neuronal L-type voltage-gated calcium channels (LVGCCs) occurs in the brain during aging. This increase could account for altered intracellular calcium concentration and lead to agerelated cognitive decline. A line of transgenic mice that over-express the LVGCC Ca_{V …}