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- Creators: Arizona State University
- Creators: Honeycutt, Claire
- Member of: Theses and Dissertations
- Member of: Barrett, The Honors College Thesis/Creative Project Collection
- Status: Published
Description
Alzheimer's Disease (AD) is a progressive neurodegenerative disease accounting for 50-80% of dementia cases in the country. This disease is characterized by the deposition of extracellular plaques occurring in regions of the brain important for cognitive function. A primary component of these plaques is the amyloid-beta protein. While a natively unfolded protein, amyloid-beta can misfold and aggregate generating a variety of different species including numerous different soluble oligomeric species some of which are precursors to the neurofibrillary plaques. Various of the soluble amyloid-beta oligomeric species have been shown to be toxic to cells and their presence may correlate with progression of AD. Current treatment options target the dementia symptoms, but there is no effective cure or alternative to delay the progression of the disease once it occurs. Amyloid-beta aggregates show up many years before symptoms develop, so detection of various amyloid-beta aggregate species has great promise as an early biomarker for AD. Therefore reagents that can selectively identify key early oligomeric amyloid-beta species have value both as potential diagnostics for early detection of AD and as well as therapeutics that selectively target only the toxic amyloid-beta aggregate species. Earlier work in the lab includes development of several different single chain antibody fragments (scFvs) against different oligomeric amyloid-beta species. This includes isolation of C6 scFv against human AD brain derived oligomeric amyloid-beta (Kasturirangan et al., 2013). This thesis furthers research in this direction by improving the yields and investigating the specificity of modified C6 scFv as a diagnostic for AD. It is motivated by experiments reporting low yields of the C6 scFv. We also used the C6T scFv to characterize the variation in concentration of this particular oligomeric amyloid-beta species with age in a triple transgenic AD mouse model. We also show that C6T can be used to differentiate between post-mortem human AD, Parkinson's disease (PD) and healthy human brain samples. These results indicate that C6T has potential value as a diagnostic tool for early detection of AD.
ContributorsVenkataraman, Lalitha (Author) / Sierks, Michael (Thesis advisor) / Rege, Kaushal (Committee member) / Pauken, Christine (Committee member) / Arizona State University (Publisher)
Created2013
Description
This research examined successful aging in a convenience sample of 14 women in Phoenix, Arizona. The study used a mixed methods approach involving individual interviews and administration of a standardized instrument designed to measure success using an alternative construct, gerotranscendence. Explorative questions were designed to gather data regarding diverse women's lived experiences. In order to examine the impact of lived experiences on successful aging, demographics were collected and participants were administered the gerotranscendence scale further revised. Findings reveal that when success is conceptualized using gerotranscendence theory, women of color may still appear less successful than their white counterparts. Narratives yielded rich data regarding the influence of factors such as care giving and violated expectations. This research helps to expand the knowledge base on factors that impact successful aging of diverse women. This research contributes to the field of social work by providing insight into the complex factors that impact diverse woman, which may aid in the empowerment of social workers to advocate for more effective macro interventions for diverse older women.
ContributorsRansom, Nicole (Author) / Bonifas, Robin (Thesis advisor) / Anthony, Elizabeth (Committee member) / Gustavson, Kristen (Committee member) / Arizona State University (Publisher)
Created2013
Description
ABSTRACT Caregiving studies generally do not focus on the post-caregiving phase of care, or African Americans post-caregivers (AAPCGs). This mixed-methods study guided by the Transitions Theory, explored the experiences of 40 AAPCGs residing in Los Angeles, California and Phoenix, Arizona, whose loved ones died within the last 10 years. Data collection tools included individual interviews, demographic questionnaire, CES-D, Brief Cope, and Social Support. Findings present the specific aims of the study. Aim 1 dealt with the types, patterns and properties of post-caregiving transitions (PCT). Many AAPCGs experienced multiple, simultaneous transitions that continued to impact their lives many years after caregiving ends. Aim 2 dealt with factors that facilitate or inhibit healthy PCT. Facilitators include: Being satisfied with care provided; fulfilling death-bed promises; living out the legacy of the deceased; deep spiritual beliefs in God and support of family, friends and church. Inhibitors include: Experiencing a deep sense of loss, confusion, depression, loneliness, and guilt; physical challenges such as fatigue and exhaustion, breathing problems, dizziness, fainting, cognitive difficulties, pain, headaches, hypertension and insomnia; family conflicts, job or home loss that linger long after PCT. Aim 3 involves process indicators including: connectedness with family, friends, co-workers, church and God; returning to work or school. Coping strategies that helped AAPCGs include: productive ventures, family mementoes, reminiscing, new baby, or visiting cemetery. Appropriate coping led to outcome indicators of mastery such as new environment; making decisions; taking actions; readying oneself for another caregiving role; preparing for one's own life and death; or caring for self. Fluid integrative identities include: Sense of balance, peacefulness and joy, fulfillment, compassion; remembering without pain; or new identity. Implications for practice, policy, education and research include: Care providers and policy makers must ensure that AA caregivers receive adequate EOL and hospice information and support for adequate preparation of loved one's death. Geriatric educators must design and implement curricular programming that includes the post-caregiving phase as a very important phase of caregiving. Researchers should design culturally-congruent assessment tools or improve the checklist developed in this study to appropriately measure PCT; and also develop culturally-relevant interventions to facilitate healthy PCT.
ContributorsUme, Ebere Peace (Author) / Evans, Bronwynne C. (Thesis advisor) / Coon, David W. (Thesis advisor) / Keller, Colleen S (Committee member) / Arizona State University (Publisher)
Created2013
Description
After natural menopause in women, androstenedione becomes the primary hormone secreted by the residual follicle deplete ovaries. Two independent studies, in rodents that had undergone ovarian follicular depletion, found that higher serum androstenedione levels correlated with increased working memory errors. This led to the hypothesis that androstenedione impairs memory. The current study directly tested this hypothesis, examining the cognitive effects of androstenedione administration in a rodent model. Middle-aged ovariectomized rats received vehicle or one of two doses of androstenedione (4 or 8 mg/kg daily). Rats were tested on a spatial working and reference memory maze battery including the water radial arm maze, Morris maze, and delay-match-to-sample task. Results showed that androstenedione at the highest dose impaired reference memory and working memory, including ability to maintain performance as memory demand was elevated. The latter was true for both high temporal demand memory retention of one item of spatial information, as well as the ability to handle multiple items of spatial working memory information. Glutamic acid decarboxylase (GAD) levels were measured in multiple brain regions to determine whether the gamma-aminobutyric acid (GABA) system mediates androstenedione's cognitive impairments. Results showed that higher entorhinal cortex GAD levels were correlated with poorer Morris maze performance, regardless of androstenedione treatment. These findings suggest that androstenedione, the main hormone produced by the follicle deplete ovary, is detrimental to spatial learning, reference memory, and working memory, and that spatial reference memory performance might be related to the GABAergic system.
ContributorsCamp, Bryan Walter (Author) / Bimonte-Nelson, Heather A. (Thesis advisor) / Olive, Michael F (Committee member) / Conrad, Cheryl D. (Committee member) / Arizona State University (Publisher)
Created2012
Description
Cognitive function declines with normal age and disease states, such as Alzheimer's disease (AD). Loss of ovarian hormones at menopause has been shown to exacerbate age-related memory decline and may be related to the increased risk of AD in women versus men. Some studies show that hormone therapy (HT) can have beneficial effects on cognition in normal aging and AD, but increasing evidence suggests that the most commonly used HT formulation is not ideal. Work in this dissertation used the surgically menopausal rat to evaluate the cognitive effects and mechanisms of progestogens proscribed to women. I also translated these questions to the clinic, evaluating whether history of HT use impacts hippocampal and entorhinal cortex volumes assessed via imaging, and cognition, in menopausal women. Further, this dissertation investigates how sex impacts responsiveness to dietary interventions in a mouse model of AD. Results indicate that the most commonly used progestogen component of HT, medroxyprogesterone acetate (MPA), impairs cognition in the middle-aged and aged surgically menopausal rat. Further, MPA is the sole hormone component of the contraceptive Depo Provera, and my research indicates that MPA administered to young-adult rats leads to long lasting cognitive impairments, evident at middle age. Natural progesterone has been gaining increasing popularity as an alternate option to MPA for HT; however, my findings suggest that progesterone also impairs cognition in the middle-aged and aged surgically menopausal rat, and that the mechanism may be through increased GABAergic activation. This dissertation identified two less commonly used progestogens, norethindrone acetate and levonorgestrel, as potential HTs that could improve cognition in the surgically menopausal rat. Parameters guiding divergent effects on cognition were discovered. In women, prior HT use was associated with larger hippocampal and entorhinal cortex volumes, as well as a modest verbal memory enhancement. Finally, in a model of AD, sex impacts responsiveness to a dietary cognitive intervention, with benefits seen in male, but not female, transgenic mice. These findings have clinical implications, especially since women are at higher risk for AD diagnosis. Together, it is my hope that this information adds to the overarching goal of optimizing cognitive aging in women.
ContributorsBraden, Brittany Blair (Author) / Bimonte-Nelson, Heather A. (Thesis advisor) / Neisewander, Janet L (Committee member) / Conrad, Cheryl D. (Committee member) / Baxter, Leslie C (Committee member) / Arizona State University (Publisher)
Created2012
Description
Generativity was first described by Erikson (1963) as an adult's concern for and commitment to promoting the welfare and development of future generations. Generativity is juxtaposed by stagnation in Erikson's stage of midlife (35-65 years old). The developmental hurdle faced at this point in the developmental cycle is whether a person will produce something of real value, both in the present and impacting future generations. Generative adults seek to give something back to society, generally behaving in a way to make the world a better place for others with no personal gain attached. The goal of the current study was to assess differences in levels of generativity at the final stage of adult life, and the potential functions that generativity can serve individuals. Results suggest that lowly generative individuals in older adult life tend to experience doubts about the impact they have had on the world and the lack of legacy they are leaving behind. Themes of highly generative participants included having felt they lived a purposeful and meaningful life, along with feeling fortunate and lucky in their lives. Also highly generative participants seemed to feel confident in the legacy they will leave behind after death. Results are discussed in light of the theories and findings of Erikson and McAdams.
ContributorsHauser, David (Author) / Kinnier, Richard T. (Thesis advisor) / Homer, Judith (Committee member) / Arciniega, Guillermo M. (Committee member) / Arizona State University (Publisher)
Created2013
Description
Gait and balance disorders are the second leading cause of falls in the elderly. Investigating the changes in static and dynamic balance due to aging may provide a better understanding of the effects of aging on postural control system. Static and dynamic balance were evaluated in a total of 21 young (21-35 years) and 22 elderly (50-75 years) healthy subjects while they performed three different tasks: quiet standing, dynamic weight shifts, and over ground walking. During the quiet standing task, the subjects stood with their eyes open and eyes closed. When performing dynamic weight shifts task, subjects shifted their Center of Pressure (CoP) from the center target to outward targets and vice versa while following real-time feedback of their CoP. For over ground walking tasks, subjects performed Timed Up and Go test, tandem walking, and regular walking at their self-selected speed. Various quantitative balance and gait measures were obtained to evaluate the above respective balance and walking tasks. Total excursion, sway area, and mean frequency of CoP during quiet standing were found to be the most reliable and showed significant increase with age and absence of visual input. During dynamic shifts, elderly subjects exhibited higher initiation time, initiation path length, movement time, movement path length, and inaccuracy indicating deterioration in performance. Furthermore, the elderly walked with a shorter stride length, increased stride variability, with a greater turn and turn-to-sit duration. Significant correlations were also observed between measures derived from the different balance and gait tasks. Thus, it can be concluded that aging deteriorates the postural control system affecting static and dynamic balance and some of the alterations in CoP and gait measures may be considered as protective mechanisms to prevent loss of balance.
ContributorsBalasubramanian, Shruthi (Author) / Krishnamurthi, Narayanan (Thesis advisor) / Abbas, James (Thesis advisor) / Buneo, Christopher (Committee member) / Arizona State University (Publisher)
Created2014
Description
The effects of aging on muscular efficiency are controversial. Proponents for increased efficiency suggest that age-related changes in muscle enhance efficiency in senescence. Exercise study results are mixed due to varying modalities, ages, and efficiency calculations. The present study attempted to address oxygen uptake, caloric expenditure, walking economy, and gross
et cycling efficiency in young (18-59 years old) and older (60-81 years old) adults (N=444). Walking was performed at three miles per hour by 86 young (mean = 29.60, standard deviation (SD) = 10.50 years old) and 121 older adults (mean = 66.80, SD = 4.50 years old). Cycling at 50 watts (60-70 revolutions per minute) was performed by 116 young (mean= 29.00, SD= 10.00 years old) and 121 older adults (m = 67.10 SD = 4.50 years old). Steady-state sub-maximal gross
et oxygen uptake and caloric expenditures from each activity and rest were analyzed. Net walking economy was represented by net caloric expenditure (kilocalories/kilogram/min). Cycling measures included percent gross
et cycling efficiency (kilo-calorie derived). Linear regressions were used to assess each measure as a function of age. Differences in age group means were assessed using independent t-tests for each modality (alpha = 0.05). No significant differences in mean oxygen uptake nor walking economy were found between young and older walkers (p>0.05). Older adults performing cycle ergometry demonstrated lower gross
et oxygen uptakes and lower gross caloric expenditures (p< 0.05).
et cycling efficiency in young (18-59 years old) and older (60-81 years old) adults (N=444). Walking was performed at three miles per hour by 86 young (mean = 29.60, standard deviation (SD) = 10.50 years old) and 121 older adults (mean = 66.80, SD = 4.50 years old). Cycling at 50 watts (60-70 revolutions per minute) was performed by 116 young (mean= 29.00, SD= 10.00 years old) and 121 older adults (m = 67.10 SD = 4.50 years old). Steady-state sub-maximal gross
et oxygen uptake and caloric expenditures from each activity and rest were analyzed. Net walking economy was represented by net caloric expenditure (kilocalories/kilogram/min). Cycling measures included percent gross
et cycling efficiency (kilo-calorie derived). Linear regressions were used to assess each measure as a function of age. Differences in age group means were assessed using independent t-tests for each modality (alpha = 0.05). No significant differences in mean oxygen uptake nor walking economy were found between young and older walkers (p>0.05). Older adults performing cycle ergometry demonstrated lower gross
et oxygen uptakes and lower gross caloric expenditures (p< 0.05).
ContributorsFlores, Michelle (Author) / Gaesser, Glenn A (Committee member) / Campbell, Kathryn D (Committee member) / Angadi, Siddhartha S (Committee member) / Arizona State University (Publisher)
Created2014
Description
This dissertation explored how immigrants cope with and thrive in old age by utilizing social networks, and the hindrances which may prevent this. Through ethnographic fieldwork and in-depth interviews at two senior centers in Phoenix, Arizona with a high concentration of an ethnic minority group - Asian and Latino, I describe what makes the Asian dominant center more resource abundant than its Latino counterpart given prevalent tight public funding. Both centers have a large number of seniors disenfranchised from mainstream institutions who bond together via similar experiences resulting from shared countries/regions of origin, language, and migration experience. The Asian center, however, is more successful in generating and circulating resources through "bonding" and "bridging" older immigrants who, therefore benefit more from their center affiliation than the Latinos at their center.
The abundance of resources at the Asian center flowing to the social networks of seniors are attributed to three factors: work and volunteer engagement and history, the organization of the center, and individual activities. At both centers seniors bond with each other due to shared ethnicity, language, and migration experience and share information and companionship in the language in which they feel most comfortable. What differentiated the two centers were the presence of several people well connected to individuals, groups, and institutions beyond the affiliated center. The presence of these "bridges" were critical when the centers were faced with budgetary constraints and Arizona was experiencing the effect of ongoing immigration policies. These "bridges" tend to come from shared ethnicity, and better social positions due to cumulative factors which include but are not limited to higher education, professional occupation, and work and volunteer history. I have also presented cases of individuals who, although have developed expertise from past work experiences and individual activities, have limited contribution to the resource flow because of the differences in ethnicity. The study also explored a gendered life course and its impact on the social network for older Asian and Latino immigrants.
The abundance of resources at the Asian center flowing to the social networks of seniors are attributed to three factors: work and volunteer engagement and history, the organization of the center, and individual activities. At both centers seniors bond with each other due to shared ethnicity, language, and migration experience and share information and companionship in the language in which they feel most comfortable. What differentiated the two centers were the presence of several people well connected to individuals, groups, and institutions beyond the affiliated center. The presence of these "bridges" were critical when the centers were faced with budgetary constraints and Arizona was experiencing the effect of ongoing immigration policies. These "bridges" tend to come from shared ethnicity, and better social positions due to cumulative factors which include but are not limited to higher education, professional occupation, and work and volunteer history. I have also presented cases of individuals who, although have developed expertise from past work experiences and individual activities, have limited contribution to the resource flow because of the differences in ethnicity. The study also explored a gendered life course and its impact on the social network for older Asian and Latino immigrants.
ContributorsFukui, Haruna Miyagawa (Author) / Menjivar, Cecilia (Thesis advisor) / Glick, Jennifer E. (Committee member) / McHugh, Kevin (Committee member) / Arizona State University (Publisher)
Created2014
Description
The purpose of the study is to gain a better understanding of baby boomers' attitudes toward video chat applications and software based on their user experiences through the measurement of the level of use, usefulness, usability and aesthetics preferences. 133 participants recruited at a local public library and at three senior centers took the survey and 14 respondents were interviewed. The results of the study indicate: (1) Baby boomers have diverse attitudes and experiences in video chatting, but their attitudes do not present a significant difference from those of older generations; (2) Baby boomers' preferences for interface design are influenced by their psychological characteristics rather than physical changes; (3) Family members and close friends are a great resource for assistance and motivation for boomers. The knowledge of motivational factors and barrier factors could help maintain the existing baby boomer users and encourage potential users by providing an improved video chat experience design for them to connect with younger generations. This research could also lead social services into the telehealth age by bridging the gap between a traditional intervention and modern instant video communication.
ContributorsShi, Ai (Author) / Herring, Donald (Thesis advisor) / Takamura, John (Committee member) / Sun, Fei (Committee member) / Arizona State University (Publisher)
Created2014