Browsing by Subject "Age"
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Item Age-Related Effects on Markers of Inflammation and Cartilage Metabolism in Response to an Intra-Articular Lipopolysaccharide Challenge(2014-11-25) Kahn, Meredith KEighteen Quarter Horses were utilized in a randomized complete design for a 28 d experiment to evaluate age-related effects on inflammation and cartilage turnover after induction of a single inflammatory insult using lipopolysaccharide (LPS). Horses were grouped by age, with yearlings (yearling; n = 3 males, n = 3 females), 2 to 3 yr olds (2/3; n = 2 males, n = 4 females), and mature 5 to 8 yr olds (mature; n = 2 males, n = 4 females). On d 0, all horses were housed individually and fed diets that met or exceeded NRC (2007) requirements. On d 14, horses were challenged with an intra-articular injection of LPS. Carpal joints were randomly assigned to receive 0.5 ng LPS solution obtained from E. coli O55:B5, or 0.8mL sterile lactated Ringer?s solution as a contralateral control. Synovial fluid was collected prior to LPS injection at pre-injection h 0 (PIH 0) and 6, 12, 24, 168, and 336 h post-injection. Samples were later analyzed using commercial ELISA kits for prostaglandin E2 (PGE2), collagenase cleavage neoepitope (C2C), and carboxypropeptide of type II collagen (CPII). Heart rate (HR), respiratory rate (RR), and rectal temperature (RT) were monitored over the first 24 h and carpal circumference and surface temperature were recorded with additional measurements at 168 and 336 h. Data were analyzed using PROC MIXED procedure of SAS. Values for RT, HR, and RR were within normal range. HR and RT were influenced by age (P < 0.01), while RR was unaffected by age (P ? 0.21). Joint circumference was not influenced by age (P = 0.84), but circumference and surface temperature increased (P < 0.01) over time across all age groups. Synovial PGE2 concentrations tended (P = 0.09) to be influenced by age with yearlings having lower (P = 0.03) concentrations than mature horses. Synovial C2C concentrations were affected by age with yearlings and 2/3 yr olds having lower (P < 0.01) concentrations than mature horses. Concentrations of synovial CPII were influenced by age with yearlings and 2/3 yr old having lower (P ? 0.02) concentrations than mature horses. Ratios of CPII:C2C were influenced by age with mature and 2/3 yr old horses having increased (P < 0.01) values compared to yearlings. These results indicate that inflammation and corresponding cartilage turnover in response to LPS administration vary with age.Item Care of older adults with Alzheimer's Dementia in Nigeria(2012-05) Oranye, Patricia Nkoli-Ezinwa; Marquardt, Thomas P.; Li, ShengDementia is a syndrome characterized by multiple cognitive deficits, that are sufficient to interfere with daily living and social and occupational functioning (Gabrowski & Damasio, 2004). Alzheimer’s Dementia (AD) is the most common cause of dementia in adults and the risk of developing the disease increases with age. Alzheimer’s Dementia is a disease that is misunderstood in Nigeria because of the nature and time of onset of the condition; memory loss associated with Alzheimer’s Dementia is assumed to be a normal part of aging. This report investigates the quality of care that is provided to older adults with Alzheimer’s Dementia in Nigeria and offers recommendations for improved rehabilitation servicesItem Changes in the relationship between age and happiness(Texas Tech University, 1978-05) Witt, David DeanNot availableItem Characterization of insulin-like growth factor-I gene expression and post-receptor signaling in skeletal muscle following tourniquet-induced ischemia reperfusion injury in young and old mice(2007-12) Hammers, David Wayne; Farrar, Roger P.Pneumatic tourniquet (TK) use is common during orthopedic surgery, making postoperative recovery from ischemia-reperfusion injury (I/R) a considerable affliction to the elderly. To characterize age-related mechanisms in skeletal muscle I/R recovery, 6- month (young) and 24-month-old (old) C57 B/L mice underwent 2 hours of TK-induced ischemia, followed by 1, 3, 5, or 7 days of recovery. More damage and muscle mass loss was seen in old in response to the I/R injury than young. Old subjects demonstrate both reductions and temporal shifts in total IGF-I, IGF-I Ea, and IGF-I Eb gene expression in the first 7 days compared to the young. Old subjects also show significant reductions in Akt-dependent pro-anabolic signaling (mTOR and FoxO3) through the time course, but were more pronounced at day 7. These data demonstrate that aged skeletal muscle is characterized by more damage and impaired recovery following TK-induced I/R damage, and link the significantly blunted IGF-I expression and signaling during the early course of recovery to this phenomenon.Item A cohort perspective of U.S. adult mortality(2011-05) Masters, Ryan Kelly; Hummer, Robert A.; Hayward, Mark D.; Powers, Daniel A.; Umberson, Debra J.; Krueger, Patrick M.This dissertation advances a cohort perspective to analyze trends in racial and educational disparities in U.S. adult mortality. The project is organized around three themes. First, I emphasize that recent temporal changes in U.S. adult mortality risk are rooted in cohort forces. Unfortunately, much of the mortality literature has failed to account for the fact that the sociohistorical conditions of U.S. cohorts have changed dramatically, and these changes have tremendous implications for population health and mortality trends. My work clearly shows the pitfalls of omitting these cohort effects from analyses of U.S. adult mortality risk. Second, I illustrate that because exposure to social and health conditions have changed over time, resources in adulthood are growing increasingly important in shaping U.S. adult mortality risk. In this regard, my findings also highlight growing disparities in U.S. mortality across race/ethnic gender groups. Third, I advance a cohort theory of U.S. mortality, drawing from both “fundamental cause” theory and a life course perspective of mortality but couching them in a cohort framework to highlight the importance of historical changes in U.S. social and health contexts in both childhood and adulthood. This cohort perspective is then used to analyze three central topics in the U.S. mortality literature: the black-white crossover in older-adult mortality, the growing educational gap in U.S. adult mortality, and the origins and persistence of black-white inequalities in U.S. adult mortality. I estimate hierarchical age-period-cohort cross-classified random effects models using National Health Interview Survey-Linked Mortality Files between 1986 and 2006 to simultaneously analyze age, period, and cohort patterns of U.S. adult mortality rates. I find (1) the black-white crossover is a cohort-specific phenomenon, (2) educational disparities in U.S. adult mortality rates are growing across birth cohorts, not time periods, and (3) racial disparities in U.S. adult mortality rates stem from cumulative racial stratification across both cohorts and the life course. Such findings have direct consequences for both mortality theories and policy recommendations. Only by considering the disparate sociohistorical conditions that U.S. cohorts have endured across their life courses can we fully understand and address current and future health disparities in the United States.Item Effects of aging or diet on oxidative modification and antioxidant enzymes(2011-05) Rosales, Brittany N; Grammas, Paula; Popp, R. Lisa; Syapin, Peter J.Aging is a risk factor for the development of many diseases. The mechanisms by which aging and age-related diseases progress are not entirely clear, however, evidence suggests that aberrant amounts of reactive oxygen species (ROS) play a role in both the aging process and the pathogenesis of age-related maladies. Oxidative stress and resulting oxidative modifications of lipids and proteins have been linked to cellular dysfunction and disease, and specifically implicated in the development of several age-related afflictions. A decline in cardiac and hepatic function is associated with aging, and previous studies report a relationship between oxidative stress and the occurrence of heart and liver disease. The objective of this study was to determine whether aging or dietary–induced oxidative stress caused deleterious oxidative modifications to the cellular content of the heart and liver, and if age or diet affect the expression of antioxidant enzymes. Fischer 344 male rats at 6, 12, and 18 months of age were exposed to oxidative stress-inducing diets (high fat or high homocysteine). Lipid peroxidation was determined as an indicator of oxidative modification. In addition, the expression levels of antioxidant enzymes, superoxide dismutase (MnSOD and ZnSOD), glutathione peroxidase 1 (GPX1), and catalase, were determined at the RNA and protein level by RT-PCR and western blot respectively. This study found that aging and diet are associated with increased oxidative modification, as well as with alterations to the expression of antioxidant enzymes.Item The effects of emotion on dissociable learning systems across the lifespan(2014-08) Gorlick, Marissa Ann; Maddox, W. ToddContemporary cognitive theory recognizes several dissociable learning systems that are critical in understanding different patterns of performance. Rule Based learning is mediated predominantly by the frontal lobe and is available to conscious control. Here executive function and working memory develop verbalizable rules guided by corrective feedback. Procedural learning is based on integrating non-verbal information from multiple sources and is predominantly mediated by the striatum. Here habitual stimulus-response associations develop using corrective feedback. Perceptual Representation learning is based on passive familiarity predominantly mediated by the visual cortex. Here learning is not guided by on conscious evaluations or feedback. Age-related deficits in learning have been well documented, however dissociable learning systems approaches demonstrated the greatest declines occur in feedback-driven learning. In the face of declines, older adults maintain several well-persevered aspects of cognition. For example, older adults sometimes show enhanced processing of positive emotionally arousing stimuli, but this positivity bias reverses when cognitive control resources are limited becoming a negativity bias. Unlike previous work that explores emotional stimuli directly, the goal of Chapters 1 and 2 is to use emotional feedback to improve learning outcomes. In addition, older adults have a performance advantage over younger adults in perceptual representation learning in the absence of feedback. This suggests that the processes that underlie this mode of learning are relatively intact, however it is unclear what these processes are and how they contribute to performance. The dissociable memory systems that underlie rule based and perceptual representation learning demonstrate asymmetric age-related declines that may be driving these differences. Chapter 3 explores age-related changes processes during learning. Chapter 3 also highlights a younger adult deficit in perceptual representation learning. Generating rules depends on narrow attention to features, and perceptual representations depend on broad attention to the whole stimulus. Task-irrelevant emotional primes influence the scope of attention where negative arousal narrows and positive arousal broadens, which likely affects rule based and perceptual representation learning systems differently. Chapter 4 explores how task-irrelevant emotional primes influence attention and interact with learning system to enhance performance in younger adults.Item Elders' Opinions on the Right to Die: Factors that make a Difference(2017-04-12) Medina, Adrianna; Titterington, Victoria; Payne, John; Zhang, YanGiven that the elder segment of the United States’ population will soon account for 20% of our overall population, the opinions and welfare of our elders has become increasingly important. This has led to the resurgence of interest in Right to Die laws. With six U.S. states and the District of Columbia having passed right to die laws, which allow physician assisted suicide to be used in specific circumstances, the need for elders’ opinions on the matter arose. This exploratory study has looked into what sociodemographic factors, specifically the increase of age, affect elders’ opinions on physician assisted suicide. Using a Pew Research Data set with descriptive and chi square statistics to analyze bivariate and multivariate interactions within the data set. The data set consisted of a nation wide sample of 690 people age 18 to 99 years old. Age, race, religion and marital status all had significant effects on a person’s opinion of PAS. When controlling for religion age did have a significant interaction with PAS response in the religions of Catholicism and Judaism. The findings from these future studies would greatly contribute to the areas of public policy/legislation, end of life decisions and the right to die movement by informing advocacy groups, state senates, state houses, healthcare providers and our government where regions are standing on PAS and most importantly which segments of the population will change their opinions over time. As the opinions of youth have been proven to be different in certain sociodemographic variables it is important for law makers to know the trends of how these age groups will change, and what segment of the population they possess, so that it can be accounted for when making policy.Item Essays on income taxes and household production(2013-05) Wikle, Jocelyn Smith; Hamermesh, Daniel S.Couples make dynamic joint decisions, including how much each spouse works at home and in the market throughout life. By building a dynamic model of taxation, I quantify the welfare gains of moving to a gender-based tax. Further, I explore the implications of a gender-based income tax for labor market and time-use choices within a couple, taking into account changing labor market attachment through life. The key finding is that while gender-based taxation always improves household and social welfare, the model-specific household time allocations and government policy implications depend on underlying assumptions about gender differences. I model the inefficiency of income tax due to pooling old individuals and young individuals who differ in their skill distribution and use of time. Because age is correlated with ability and time investments in education, allowing tax rules to vary with age shrinks labor distortions. I use an overlapping generations model to study the effect of an age-based income tax on efficiency. I analytically show the efficiency gains and I numerically estimate a welfare gain equivalent to 5% of aggregate consumption when age-based taxes are implemented. Adult women generally, and married women in particular, spend more time than men doing housework and childcare activities. While gender differences in time-use patterns among adults at home are readily accepted and well documented, the onset and development of gender time-use differences over the adolescent years and into early adulthood are not well understood. In this research, I describe the development of time-use gender differences over the teenage years and into the early adult years using American Time Use Survey (ATUS) data, with a focus on activities relating to family duties and child care activities. I find gender divergence in home duties prior to the teenage years, which sharply stratifies upon high school graduation. Further, I find that time-use outcomes disproportionately impact women from disadvantaged socio-economic and family backgrounds.Item Gender, aging, and major depressive disorder in Ukraine(2011-05) Chamberlin, Margaret Shively; Stolp, Chandler; Buckley, Cynthia J.The World Health Organization has made global mental health a priority since making it the center of world health day 2001, yet much of the current literature on mental health examines the subject within the context of the U.S. and Western Europe. This research takes a more global approach, shifting the focus to the issue of depression in Ukraine. Specifically this thesis analyzes data to examine the hypotheses that: 1) a statistically significant relationship exists between gender and depression prevalence in Ukraine; 2) women over the age of 50 in Ukraine have a significantly higher chance of suffering from depression than other age groups, unlike trends described in the literature; and 3) there are socio-economic and social factors present in Ukraine, which impact depression prevalence among women. A mixed-methodology, which utilizes analysis of quantitative data from the World Mental Health survey initiative, completed in Ukraine in 2004, and qualitative interview data, was employed to explore these hypotheses. Strong relationships are found between gender and depression and between depression and aging, particularly past the age of 50. Some socio-demographics of significance include low level of education, very inadequate financial resources and being on a pension. The conclusions that result from this analysis, describe an interesting case for assessment of global mental health issues. While the results are perhaps not generalizable far beyond Ukraine the conclusions drawn have interesting implications for how we study global mental health and the characteristics which make a person more or less vulnerable to mental illness.Item Social ties and physical activity patterns over the life course : gender, race, and age variations(2014-05) Lodge, Amy Caroline; Umberson, Debra; Angel, Jacqueline; Crosnoe, Robert; Gonzalez-Lopez, Gloria; Hayward, MarkIn this dissertation I explore the lived experiences and meanings underlying population patterns linking social ties and exercise. To do so, I frame an analysis of qualitative data from 60 in-depth interviews with 15 white women, 15 black women, 15 white men, and 15 black men with life course theory and critical perspectives on gender, race, and age. In Article 1, I examine how parental influence matters for individuals’ exercise trajectories (i.e., lived experiences of change or stability in exercise patterns) from childhood into adulthood, how adult life course transitions (e.g., parenthood) and turning points (e.g., injury) matter in relation to this influence for exercise trajectories, and how they matter differently at the intersection of race and gender. I develop the concepts of disrupted advantage and disadvantage to refer to my key finding that adult life experiences can disrupt processes of cumulative (dis)advantage around exercise in ways that differ at the intersection of race and gender. In Article 2, I examine the gendered processes through which intimate relationship formation and dissolution result in shifts in exercise habits and find that relationship formation shapes men’s and women’s exercise habits in distinctive ways. Further, these gendered processes are shaped by men’s and women’s relational gendered performances, which reveal the importance of a gender-as-relational perspective for understanding the links between relationship formation and gendered changes in exercise habits. Finally, in Article 3 I examine how body image, as socially constituted, shapes individuals’ motivation to exercise in ways that differ by gender, age, and race. I further examine how, through exercise intentions and practices, individuals craft meanings about the body, gender, race, and age.Item Trajectories of Life Satisfaction During the First 10 Years Following Traumatic Brain Injury(2014-05-23) Williamson, MeredithTo examine the predictive relationships of functional ability, gender, and age on the longitudinal trajectories of life satisfaction across 10 years following onset of traumatic brain injury (TBI). Participants were part of the Traumatic Brain Injury Model Systems (TBIMS) longitudinal study of outcomes following TBI. Hierarchical linear modeling (HLM) was employed to assess changes in life satisfaction across 10 years post-injury as a function of functional ability, gender and age. The sample included 7,813 participants (2,170 women, 5,643 men) who were included in the TBIMS database. Satisfaction with life across 10 years post-injury was measured by the Satisfaction with Life Scale administered at 1, 2, 5, and 10 years post-injury. The Functional Independence Measure (FIM?) was administered to measure functional ability at 1, 2, 5, and 10 years post-injury. Additional predictor variables included gender and age. Participants? life satisfaction scores remained stable across 10 years post-injury. Greater functional ability as measured by the FIM? Total scale, FIM? Cognitive subscale, and FIM? Motor subscale was associated with greater life satisfaction across time. A significant interaction effect between age and functional ability was present. Gender was not a significant predictor of life satisfaction. Life satisfaction across 10 years post-injury is relatively stable. Greater functional ability was associated with greater life satisfaction. Older participants with greater functional impairments had higher life satisfaction scores across 10 years post-injury compared to their younger counterparts.