Thesis (Ph.D.)--Virginia Commonwealth University, 2008. / Prepared for: Dept. of Human Genetics. Title from thesis description page. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1964. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 58-60.

<p> Colorado is facing demographic changes as the senior share of the population rapidly increases. Simultaneously, Denver residents are not prepared to age in place. Their homes do not include accessible features, such as those incorporated into universal design or visitability standards, which support an individual&rsquo;s ability to stay in the home as their capabilities decline over time. Furthermore, there are no legal requirements to provide accessible features in single-family homes to support residents aging in place. To investigate this problem, the study explored why Denver residents, along with design and construction professionals, are not adequately preparing homes for aging in place. The study assessed and compared levels of aging-in-place design feature awareness, implementation, knowledge of associated costs, and support for policies of the features in single-family homes from the perspective of the residents and professionals. The author administered two online surveys for Denver residents and design and construction professionals. The resident sample size was 177, a response rate of 15%. The professional sample size was 71, a response rate of 6%. The resident survey found 93% of the respondents wants to live independently, but only 33% of the residents were familiar with aging in place. The professional survey found 94% of the surveyed professionals recognize the importance of living independently, but only 46% of the professionals are extremely/very familiar with aging in place. Despite the lack of awareness, both groups expressed high levels of support for universal design and visitability features in new construction. Nearly 68% of the residents and 80% of the professionals support universal design in new construction homes. A bivariate regression analysis revealed there was a statistically significant relationship between the number of accessible features in the resident's home and the resident's satisfaction with his/her home as a place for older adults to live as they age. The researcher makes recommendations for the City and County of Denver in order to further integrate universal design and visitability in new construction and remodeled homes.</p><p>

In previous epidemiologic studies, poor physical function has been associated with increased risks of nursing home placement, hospitalization, and mortality in older adults. However, these associations are subject to confounding and misclassification. Studies to date do not adequately account for these biases; previous studies have evaluated only cross-sectional associations, followed participants for less than ten years, or inadequately controlled for confounders by using only baseline values of characteristics that vary over time.5,75,106 In addition, no study has finely controlled for age, the strongest predictor of both physical function and health outcomes such as mortality and institutionalization in older adults. This dissertation is comprised of three studies that evaluated the associations between physical performance and skeletal health, respectively, with mortality and long-term nursing home residence while utilizing age-based risk set sampling, evaluating mediation by osteoporotic fractures, and controlling for death as a competing risk. All studies in this dissertation use data from the Study of Osteoporotic Fractures, a longitudinal epidemiologic study of older women with over 20 years of follow-up. Study 1 evaluated the association between physical performance and incident disability, using time-dependent exposures and confounders, and age-based risk sets to control for age. Women with poorer performance based on individual measures of physical function had an increased risk of incident disability over follow-up. Similarly, a whole body summary physical performance score was linearly associated with increased risk of death. Study 2 evaluates the association between low bone mineral density and mortality. Women with low bone mineral density were more likely to experience a fracture and to die compared to women with normal bone mineral density. Mediation analyses suggested that incident fracture had a measureable impact on this association, though this varied by fracture site. Study 3 evaluates the association between slow gait speed and risk of long-term nursing home placement while controlling for death as a competing risk. Women with slow gait speed had an increased risk of long-term nursing home residence, which was slightly attenuated when considering death as a competing risk. These results extend previous studies of the health effects of physical function among older women. The findings underscore the clinical importance of physical function and bone mineral density (BMD) for identifying older adults for whom interventions to improve their physical function may prolong their independence and optimize health.

This study consists of an inquiry into whether reminiscing and related characteristics, notably the concept of life reviewing, appear adaptive features of the aging process, as has been suggested in the recent literature. The attempt was made to produce more thorough evidence for this question than previous studies, firstly by obtaining more individually sensitive measures of losses incurred in old age, and using person subjective but carefully monitored indices of adjustment. The analysis was performed on forty eight subjects (aged 68 - 92 yrs. of mean age 80 yrs.) living alone in sheltered housing accommodation in five London boroughs. Reminiscing, life reviewing, and use of the past in general attitudinal and informative conversation were quantified by obtaining one hour recordings of the subjects' conversations with the author in a naturalistic setting and performing a rigorous procedure of analysis on the transcripts of same. Reliability over time was demonstrated for each of the categories. Affect of reminiscing was also noted and a measure obtained of satisfaction with past life. Subjects were rated as well on their conversation over the whole time period of visiting (averaging six visits per person over two years). An examination of the results revealed that life reviewing, defined in this study by the willingness of the subject in his reminiscing to engage in interpretations and evaluations of his past self and expressions of his past subjective states, did indeed appear related to adjustment for subjects who indicated dissatisfaction with their past lives. Past life satisfaction and affect of reminiscing emerged as general adaptive factors, independent of any effect of presently incurred loss upon them. An ability to reminisce when provoked seems to be an adaptive characteristic of old age, and avoidance of an unpleasant past a maladaptive one.

No description available.

Repeated or prolonged activation of skeletal muscle results in an acute decline in the muscle's ability to produce force, which is typically referred to as fatigue. Muscle fatigue is likely related to the by-products of cellular metabolism, alterations in neural activation and diminished membrane excitability that have been shown to accompany repeated contractions. However, the complicated etiology of the fatigue process makes it difficult to understand the relative influence of these physiological responses. Computational modeling of the skeletal muscle response to repeated activation is an appealing means of gaining insight into the mechanisms of muscle fatigue. A reasonably comprehensive model would include components that represent motor neurons and populations of muscle fibers that reflect the range of metabolic and contractile characteristics known to exist in human skeletal muscle. Consideration of joint and connective tissue mechanical properties will add translational value by predicting whole joint segment behavior that can be validated by in vivo experimentation. The proposed dissertation project involved the development of a computational model incorporating multiple components meant to represent the function of the intact neuromuscular system. The complete model combines previously-validated models of neural activation and contractile behavior with a control function that attempts to match torque output to a pre-determined task. The model uses experimentally-derived functions describing metabolic cost and force inhibition to predict the loss of force generating capacity during repeated activation. Once tested using data from a group of adult men, the parameters of this model were altered to reflect age-related changes in the human neuromuscular system. The model's ability to predict the well-established phenomenon of age-related fatigue resistance during isometric contractions was then tested. The results from this series of studies support the utility of a computational approach to the investigation of muscle fatigue, and provide useful tools for future studies.

specialcollections@tulane.edu / The biological embedding of maternal adversity, both preconception and prenatal, can alter health trajectories of the next generation. Alterations in biological processes, including inflammation and accelerated aging, are proposed mechanisms through which adverse environmental and experiential exposures alter disease risk over the life-course. To identify biological pathways of transgenerational risk, we describe how maternal preconception adversity, assessed by adverse childhood experience score (ACEs), influences the development of her infant’s psychopathology risk and autonomic nervous system (ANS) by examining genomic and epigenomic alterations in both the infant and the placenta. Maternal ACEs elevated her infant’s externalizing behaviors at 18-months of age. Cellular aging, indexed by telomere length (TL) erosion, modified this relation; in infants with greater TL erosion from 4- to 18-months of age, higher maternal ACEs predicted higher externalizing behaviors. At 4-months of age, we examined infant ANS stress physiology and found that higher maternal ACEs predicted lower ANS stress response. Next, we examined TL in the placenta as a pathway conferring transgenerational risk. Higher maternal ACEs predicted shorter placental TL and placental TL modified the impact of maternal ACEs on her infant’s ANS; in placentas with shorter placental TL, higher maternal ACEs predicted greater ANS stress responsivity. To understand the molecular pathways impacted by maternal ACEs and related to TL, we examined placental mRNA expression of an inflammatory gene (CCL2), a gene linked to apoptosis (BCL2), and a gene tied to cellular senescence (GLB1). CCL2 expression modified the relation between higher maternal ACEs and shorter placental TL and CCL2 expression also contributed to the relation between shorter placental TL and decreased BCL2 expression. Lastly, shorter TL moderated the relation between CCL2 expression and both BCL2 and GLB1. The demonstration of the effects of maternal ACE exposure across generations highlights the need to further define the underlying mechanisms contributing to disease risk in the next generation. Maternal ACE exposure effects the placenta, the infant’s ANS, and the infant’s behavior through the first 18-months of life, which highlights the powerful impact of maternal early life adversity across generations and compliments the known lasting health risks found within the individual. / 1 / Christopher Jones

As dementia grows at an increasingly faster rate around the world, it has become imperative to identify its symptoms at an early stage. Dementia of the Alzheimer’s type (DAT) mainly disrupts cognitive functioning, but behavioral changes such as slow walking also occur. In an aging world with a growing dementia population, early identification has come to play an important role in the management and treatment of the disease. A simultaneous assessment of the behavioral and cognitive changes is recommended to be used to assist with early identification of dementia. A dual task of walking and talking is especially practical to identify early signs of dementia since individuals usually walk while doing something else such as talking on the phone or with another person. This study was an investigation into longitudinal changes in gait under different levels of cognitive load conditions: 1) the baseline condition was defined as normal walking with no simultaneous cognitive load, 2) the low cognitive load condition was defined as walking and counting numbers from a random number assigned, and finally 3) the high cognitive load condition was defined as walking and simultaneously completing a categorical naming task (generating as many words in a specific category as possible). Fourteen individuals with a mean age of 78 years who in the early (mild or moderate) stage of DAT (Mean DRS-2 score = 88.14, SD = 12.6) participated. For the walking task, the GAITRite© Portable Walkway system incorporating a 580-cm mat with embedded sensors to measure spatiotemporal parameters of gait and the accompanying software was employed. Once a month over a one-year period, participants walked across the GAITRite© Walkway mat. The gait analyses included Functional Ambulation Profile (FAP), stride length (SL), velocity, and double support time (DST). To more precisely examine the effects of concurrent cognitive load, participants completed the low and high cognitive load tasks while seated. Values in FAP, SL, and velocity decreased as tasks became more complex and as the disease progressed, while DST increased at the same rate. The comparison of walking and seated conditions indicated that participants’ performance on both number-counting and categorical naming tasks was poorer when they were walking rather than when they were seated. The results imply effectiveness of gait assessment during multitasking conditions for early diagnosis of DAT. Identifying DAT at an earlier stage is beneficial for the person with the disease, family members and caregivers, as well as health professionals. In this regard, the findings of this current investigation may establish a bridgehead for advances in the early identification of DAT. / A Dissertation submitted to the School of Communication Science and Disorders in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2018. / May 15, 2018. / Cognitive Load, Dementia, Early Identification, Gait / Includes bibliographical references. / Richard J. Morris, Professor Co-Directing Dissertation; Leonard L. LaPointe, Professor Co-Directing Dissertation; Colleen M. Kelley, University Representative; Katlin L. Lansford, Committee Member; Charles G. Maitland, Committee Member.

No description available.