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Longitudinal Associations Between Functional Disability, Depression, And Suicide In Middle-Aged And Older Adults, Julie Ann Lutz Jan 2019

Longitudinal Associations Between Functional Disability, Depression, And Suicide In Middle-Aged And Older Adults, Julie Ann Lutz

Graduate Theses, Dissertations, and Problem Reports

Suicide is a significant public health problem among older adults in the United States and around the world. There has been little research to date on longitudinal change in functional disability and depressive symptoms, both of which have been posited to be associated with suicide risk among middle-aged and older adults, and their association with death by suicide. The aims of this study were to 1) characterize longitudinal change in functional disability and depressive symptoms separately; 2) characterize the directional associations between functional disability and depressive symptoms in bivariate models; and 3) determine how different patterns of change among these …


The Role Of Sirt1 In Skeletal Muscle Function And Repair Of Older Mice, Matthew John Myers Jan 2019

The Role Of Sirt1 In Skeletal Muscle Function And Repair Of Older Mice, Matthew John Myers

Graduate Theses, Dissertations, and Problem Reports

Human skeletal muscle is a highly metabolic tissue necessary for mobility and coordination. Responsible for approximately one-fifth of the resting human metabolism, skeletal muscle is also an important regulator of metabolites like glucose and contributes to the regulation of body temperature. Although there is a gradual decline in muscle mass associated with aging, a certain percentage of the population suffer from severe muscle mass and strength deterioration, classified as sarcopenia (5-13% for people aged 60-70 years old, 11-50% for those 80 or older). Sarcopenia is linked to increased morbidity and mortality rates in the elderly population, while annual healthcare costs …


Short Beam Shear Strength Evaluations Of Gfrp Composites: Correlations Through Accelerated And Natural Aging, William Todd Barker Jan 2019

Short Beam Shear Strength Evaluations Of Gfrp Composites: Correlations Through Accelerated And Natural Aging, William Todd Barker

Graduate Theses, Dissertations, and Problem Reports

Fiber Reinforced Polymers (FRP) composites have been materials of interest in replacing or reinforcing steel, wood, and concrete, but lack of understanding of degradation under physical and chemical aging is a main concern. Through many years of research, the understanding of aging or durability of GFRPs has improved. To be able to evaluate aging related degradation rates, an accelerated aging methodology under varying environments is introduced. Accelerated aging is a concept used to age composites in a lab controlled environment under varying pH conditions (2 to 13) and temperatures (~ -20° to +160°F). Once acceleratedly aged testing is completed, Arrhenius …


Quantifying Human Biological Age: A Machine Learning Approach, Syed Ashiqur Rahman Jan 2019

Quantifying Human Biological Age: A Machine Learning Approach, Syed Ashiqur Rahman

Graduate Theses, Dissertations, and Problem Reports

Quantifying human biological age is an important and difficult challenge. Different biomarkers and numerous approaches have been studied for biological age prediction, each with its advantages and limitations. In this work, we first introduce a new anthropometric measure (called Surface-based Body Shape Index, SBSI) that accounts for both body shape and body size, and evaluate its performance as a predictor of all-cause mortality. We analyzed data from the National Health and Human Nutrition Examination Survey (NHANES). Based on the analysis, we introduce a new body shape index constructed from four important anthropometric determinants of body shape and body size: body …