According to socioemotional selectivity theory (SST), old age is associated with a greater emphasis on self-regulation of emotional states, a focus that fosters a bias in processing positively valenced material in older adults. There is disagreement, however, about whether the “positivity bias” suggested by SST influences performance on memory tasks. Some studies suggest that older adults remember more positive than negative information, or simply less negative information, relative to younger adults, whereas other studies report no such differences. This thesis examined (1) whether variations across studies in encoding instructions or in personal relevance of study materials could account for these inconsistencies, and (2) whether differences in attention at encoding to positive, negative, and neutral stimuli could account for the positivity bias in older adults’ later memory for the stimuli. In Experiment 1, younger and older adults were instructed either to passively view positive, negative, and neutral pictures or to actively categorize them by valence. On a subsequent incidental recall test, older adults recalled equal numbers of positive and negative pictures, whereas younger adults recalled negative pictures best. There was no effect of encoding instructions. Crucially, when pictures were grouped into high and low personal relevance according to participants’ ratings, a positivity bias emerged only for low relevance pictures. In Experiment 2, attention to pictures at encoding was directly manipulated through use of a divided attention paradigm. Although divided attention lowered recall in both age groups, attention did not interact with age and valence. Taken together, the results suggest that variability in the personal relevance of study pictures may be the factor underlying cross-study differences in whether a positivity bias is observed in older adults’ memory.

A comparative study on the age changes in rat skeletal muscle tissue was performed using rats of different ages. The gastrocnemius muscle from rats of 3, 6, and 22 months of age was removed and examined for the presence of Type I fibers. Myosin ATPase histochemistry was used to differentiate between Type I and Type II fibers. A count of the number of Type I fibers in the entire gastrocnemius was made using fiber maps obtained from the stained muscle samples. The total number of fibers in some of the muscle samples was also determined.The results indicated a steady decline in the total number of muscle fibers from the ages of 3 to 22 months. With the exception of the 6 month group, the number of Type I fibers remained fairly constant. However, there was a definite increase in the percentage of Type I fibers found in the 22 month rats. An increase in the diameter of the muscle fibers in the 22 month rats was also observed.Ball State UniversityMuncie, IN 47306

Six experiments were conducted to examine the factors modulating the size of age differences in recollection. The research presented in the current thesis was guided by the notions of self-initiated processing and environmental support. Older and younger adults’ performance in recollection was measured by Jacoby’s (1990) process dissociation procedure (PDP); the age differences as a function of self-initiated processing demands of the task and the amount of support provided to the participants were assessed by manipulating the encoding (Experiments 2.1, 2.2, and 2.3) and retrieval (Experiments 3.1, 3.2, and 3.3) contexts. Experiments 2.1, 2.2, and 2.3 examined interactions of aging and encoding contexts. Recollection under baseline conditions (i.e. visually presented words) was contrasted with recollection of items encoded under contexts that are assumed to enhance memory. The results showed differential age-related patterns of benefits from encoding conditions: Presenting pictures with words benefited older adults more than younger adults; word generation benefited both groups equally; and presenting sound effects with visual words benefited younger more than older adults. Experiments 3.1, 3.2, and 3.3 investigated age-related changes in retrieval processes and their interactions with retrieval contexts. In each of the three experiments, some of the test lists were constructed so that participants had to recollect specific aspects of the encoding event to differentiate between the to-be-included and to-be-excluded items, whereas other test lists were constructed so that they only had to recollect general aspects. Older adults showed reduced levels of recollection than younger adults for the high-specificity test lists only (Experiment 3.1). Encoding manipulations improved (Experiment 3.2) or reduced (Experiment 3.3) recollection performance but the effects did not interact with test, whereas DA at retrieval (Experiment 3.3) in younger adults partly mimicked aging. In summary, the six experiments showed that older adults have greater difficulties in spontaneously carrying out distinctive and integrative processes at encoding, and in accessing specific information at retrieval compared to their younger counterparts. These age-related changes further interact with the processing demanded or afforded by the encoding and retrieval conditions.

Most persons with a dementia are cared for in the home by family members who experience a broad and considerable amount of stress and whose caregiving careers may include planning for or initiating moves to memory care units (MCUs). This study examines the decision-making processes of primary informal caregivers regarding their care recipients' moves to MCUs. Grounded theory methods were used to collect and analyze data in two long-term care (LTC) facilities varying in characteristics including capacity, state licensure, fees, and resident profiles. Specific aims are two-fold: 1) advance an understanding of how primary informal caregivers of persons with a dementia made decisions for formal memory care, and 2) identify the important factors related to the decision-making process.

According to socioemotional selectivity theory (SST), old age is associated with a greater emphasis on self-regulation of emotional states, a focus that fosters a bias in processing positively valenced material in older adults. There is disagreement, however, about whether the “positivity bias” suggested by SST influences performance on memory tasks. Some studies suggest that older adults remember more positive than negative information, or simply less negative information, relative to younger adults, whereas other studies report no such differences. This thesis examined (1) whether variations across studies in encoding instructions or in personal relevance of study materials could account for these inconsistencies, and (2) whether differences in attention at encoding to positive, negative, and neutral stimuli could account for the positivity bias in older adults’ later memory for the stimuli. In Experiment 1, younger and older adults were instructed either to passively view positive, negative, and neutral pictures or to actively categorize them by valence. On a subsequent incidental recall test, older adults recalled equal numbers of positive and negative pictures, whereas younger adults recalled negative pictures best. There was no effect of encoding instructions. Crucially, when pictures were grouped into high and low personal relevance according to participants’ ratings, a positivity bias emerged only for low relevance pictures. In Experiment 2, attention to pictures at encoding was directly manipulated through use of a divided attention paradigm. Although divided attention lowered recall in both age groups, attention did not interact with age and valence. Taken together, the results suggest that variability in the personal relevance of study pictures may be the factor underlying cross-study differences in whether a positivity bias is observed in older adults’ memory.

Continually improving population health in the context of increased life expectancy challenges the assumption that aging invariably leads to significant physical decline. Currently, there is a perception that physical function and hence, independence, can be maintained well into later life (Ory, Hoffman, Hawkins, Sanner & Mockenhaupt, 2003). Given the growing proportion of older adults in many industrialized nations, it is imperative to consider possible factors that influence behaviour, which may in turn contribute to functional losses that have hitherto been attributed to aging. For example, pervasive ageist stereotypes may play a role in reducing older adults’ opportunities to independently perform physical tasks (i.e. removal of difficult or challenging physical tasks from older adult residences; younger individuals insisting on physical help that is unneeded) so that ability is gradually compromised by disuse. This study explores the potential for such reduced opportunity among community-dwelling older adults using a questionnaire-based methodology and hypothetical stimulus scenarios. In the scenarios, participants’ mature children offer the older adults unsolicited help with two functional tasks: rising from a sofa and grocery shopping. The 52 study participants (mean age = 78.4 ± 6.0 years) were each asked to report their independence preference, anticipated affective responses, behavioural intentions, self-efficacy for relevant physical skills, relation-inferred self-efficacy (RISE), attribution for why the help was offered, and perceived benefits of accepting and declining the help. Using a Social Cognitive Theory (SCT) framework, individuals with higher self-efficacy, stronger preference for independence, or more perceived benefits of declining relative to those of accepting help were expected to be more likely to intend to decline assistance. In addition to being related to intentions, these factors, along with lower RISE beliefs, were expected to be associated with greater negative affect. Finally, RISE was anticipated to be directly proportional to self-efficacy and thus, attribution of the offered help to physical (versus social) reasons was hypothesized to relate to lower self-efficacy and RISE. Primary study hypotheses were generally not supported, with a few exceptions. First, as hypothesized, those who perceived more benefits associated with declining help were more likely to decline and less likely to accept the offered help (p ≤ 0.005). Second, the more perceived benefits associated with declining help (relative to those associated with accepting help), the less total positive affect older adults reported (r ≤ -0.31, p ≤ 0.02). Third, individuals who had higher self-efficacy also reported higher RISE (r ≥ 0.34, p ≤ 0.01). Finally, those who made physical attributions for the offer of help reported lower RISE (p ≤ 0.009), and lower shopping self-efficacy (p = 0.004). Secondary analyses provided some insight into the lack of support for study hypotheses regarding the receipt of unsolicited assistance. For example, both high self-efficacy beliefs (mean = 85.1 ± 15.8% for rising and 91.5 ± 11.2% for shopping) and low TUG times (mean = 12.2 ± 4.7s) suggested that the sample was particularly high-functioning. This would help to explain why self-efficacy was not found to be significantly related to participant intentions to accept help. Another explanation for this finding is the influence of social factors considered by older adults in these helping situations. Participant intentions could have been based on anticipated social rather than physical benefits. This rationale was supported by high rates of selection for socially-relevant perceived benefits of receiving help. Further examination also confirmed that participants generally reported very low levels of total negative affect. This would partially account for the absence of a relationship between perceived benefits and negative affect, even though the former was shown to be correlated with total positive affect. Despite raising as many questions as it answers, the present study succeeds in illustrating the perceptions of higher functioning older adults in situations where physical help is offered to them. Although these participants would not require any help with the physical tasks presented, on average, older adults indicated that they would likely accept the offered assistance approximately half of the time. When the findings of the two sets of analyses are considered, they suggest that much research is needed to understand the perspective of older adults in helping situations. Assumptions about older adults’ reactions to receiving assistance with physical tasks may not be straightforward. Having the ability to function independently may not necessarily mean that older adults refuse assistance. Like younger adults, they may interpret the social situation in terms of a variety of outcomes. Indeed, if researchers do not consider complex interpretations for how older adults function in regard to physical independence, they may be letting personal ageism shape their research. Consequently, there is cause to pursue further research in this underserved area of investigation into the perceptions and actions of older adults. Future studies in this vein may make use of the lessons learned from this exploratory investigation.

Eleven percent of Georgians and 13.3% of all Americans are currently over the age of 65. The segment of elderly adults in the United States is the fastest growing subpopulation, attributed to both average lifespan increases and a significant aging of "the baby boomer generation". Thus it is increasingly important that health and policy professionals give attention to issues of health and well-being faced by the aging population. One such issue, financial exploitation of the elderly, has received a large amount of media attention and public concern over the last several years, due to a large increase in the recorded prevalence of the problem. It has been estimated by some studies that financial exploitation of the elderly occurs in 4-5% of the aged population. A variety of legislation, both state and federal, has attempted to address and curb the problem. Like many states, Georgia has successfully passed and implemented such legislation; however as numbers of exploitation continue to increase, it is clear that all states still require a number of policy changes in order to truly eliminate the problem. The purpose of this capstone project is to synthesize scientific research dedicated to financial exploitation of the elderly and, describe current policies in place to address this problem. Finally, policy recommendations for the State of Georgia will be offered so that response and prevention systems effectively reduce the occurrence of this crime.

Concentrated solar power systems are expected to be sited in desert locations where the direct normal irradiation is above 1800 kWh/m2.year. These systems include large solar collector assemblies, which account for a significant share of the investment cost. Solarreflectors are the main components of these solar collector assemblies and dust/sand storms may affect their reflectance properties, either by soiling or by surface abrasion. While soiling can be reverted by cleaning, surface abrasion is a non reversible degradation.The aim of this project was to study the accelerated aging of second surface silvered thickglass solar reflectors under simulated sandstorm conditions and develop a multi-parametric model which relates the specular reflectance loss to dust/sand storm parameters: wind velocity, dust concentration and time of exposure. This project focused on the degradation caused by surface abrasion.Sandstorm conditions were simulated in a prototype environmental test chamber. Material samples (6cm x 6cm) were exposed to Arizona coarse test dust. The dust stream impactedthese material samples at a perpendicular angle. Both wind velocity and dust concentrationwere maintained at a stable level for each accelerated aging test. The total exposure time in the test chamber was limited to 1 hour. Each accelerated aging test was interrupted every 4 minutes to measure the specular reflectance of the material sample after cleaning.The accelerated aging test campaign had to be aborted prematurely due to a contamination of the dust concentration sensor. A robust multi-parametric degradation model could thus not be derived. The experimental data showed that the specular reflectance loss decreasedeither linearly or exponentially with exposure time, so that a degradation rate could be defined as a single modeling parameter. A correlation should be derived to relate this degradation rate to control parameters such as wind velocity and dust/sand concentration.The sandstorm chamber design would have to be updated before performing further accelerated aging test campaigns. The design upgrade should improve both the reliability of the test equipment and the repeatability of accelerated aging tests. An outdoor exposure test campaign should be launched in deserts to learn more about the intensity, frequencyand duration of dust/sand storms. This campaign would also serve to correlate the results of outdoor exposure tests with accelerated exposure tests in order to develop a robust service lifetime prediction model for different types of solar reflector materials.

We continually encounter different ground terrain such as slippery, compliant, uneven, rocky, and irregular terrain when walking, yet we know very little about how individuals safely negotiate this type of complex environment. Furthermore, we know little about how aging affects stability in these situations despite the increased risk of falls and fall-related injuries among older adults. Paramount to our comprehension of how individuals safely traverse challenging ground terrain is to understand how visual information is utilized as vision is the first line of defense for preparing for and/or avoiding potentially hazardous terrain or obstacles. Thus, the objective of this thesis was to provide a better understanding towards how individuals negotiate different ground terrain in the environment to maintain dynamic stability and prevent the occurrence of a fall. In particular, the role of vision and the effects of aging were investigated. Three studies focused on the role of vision while negotiating varying ground terrain while two studies examined stability across these surfaces. Two main conclusions can be drawn from the results of the three studies on the role of vision. First, regardless of age individuals fixate on highly task-relevant areas (i.e. surfaces eventually stepped on) in an on-line manner and by fixating approximately two steps ahead. Second, visual information from the lower visual field is important for negotiating varying ground terrain. This latter finding has implications for older adults who wear multi-focal glasses and suggests that these individuals should be cautious when wearing these glasses in complex environments. In terms of stability, the results suggest that young and older adults demonstrate greater instability when walking across varying unstable ground terrain compared to solid level ground. Older adults are particularly more unstable in the medial-lateral direction when negotiating the challenging terrain, which may explain the frequency of laterally directed falls and increased hip-fracture risk with advancing age. Interestingly, older adults appear more stable in the anterior-posterior direction; although, this can largely be explained by the cautious gait strategy (i.e. slower walking speed and shorter steps) adopted by these individuals. The results of the studies of my thesis provide valuable insight into how individuals safely negotiate different types of challenging ground terrain when walking. Importantly, this knowledge can serve as an initial step in attempting to reduce falling among those at risk.

Continually improving population health in the context of increased life expectancy challenges the assumption that aging invariably leads to significant physical decline. Currently, there is a perception that physical function and hence, independence, can be maintained well into later life (Ory, Hoffman, Hawkins, Sanner & Mockenhaupt, 2003). Given the growing proportion of older adults in many industrialized nations, it is imperative to consider possible factors that influence behaviour, which may in turn contribute to functional losses that have hitherto been attributed to aging. For example, pervasive ageist stereotypes may play a role in reducing older adults’ opportunities to independently perform physical tasks (i.e. removal of difficult or challenging physical tasks from older adult residences; younger individuals insisting on physical help that is unneeded) so that ability is gradually compromised by disuse. This study explores the potential for such reduced opportunity among community-dwelling older adults using a questionnaire-based methodology and hypothetical stimulus scenarios. In the scenarios, participants’ mature children offer the older adults unsolicited help with two functional tasks: rising from a sofa and grocery shopping. The 52 study participants (mean age = 78.4 ± 6.0 years) were each asked to report their independence preference, anticipated affective responses, behavioural intentions, self-efficacy for relevant physical skills, relation-inferred self-efficacy (RISE), attribution for why the help was offered, and perceived benefits of accepting and declining the help. Using a Social Cognitive Theory (SCT) framework, individuals with higher self-efficacy, stronger preference for independence, or more perceived benefits of declining relative to those of accepting help were expected to be more likely to intend to decline assistance. In addition to being related to intentions, these factors, along with lower RISE beliefs, were expected to be associated with greater negative affect. Finally, RISE was anticipated to be directly proportional to self-efficacy and thus, attribution of the offered help to physical (versus social) reasons was hypothesized to relate to lower self-efficacy and RISE. Primary study hypotheses were generally not supported, with a few exceptions. First, as hypothesized, those who perceived more benefits associated with declining help were more likely to decline and less likely to accept the offered help (p ≤ 0.005). Second, the more perceived benefits associated with declining help (relative to those associated with accepting help), the less total positive affect older adults reported (r ≤ -0.31, p ≤ 0.02). Third, individuals who had higher self-efficacy also reported higher RISE (r ≥ 0.34, p ≤ 0.01). Finally, those who made physical attributions for the offer of help reported lower RISE (p ≤ 0.009), and lower shopping self-efficacy (p = 0.004). Secondary analyses provided some insight into the lack of support for study hypotheses regarding the receipt of unsolicited assistance. For example, both high self-efficacy beliefs (mean = 85.1 ± 15.8% for rising and 91.5 ± 11.2% for shopping) and low TUG times (mean = 12.2 ± 4.7s) suggested that the sample was particularly high-functioning. This would help to explain why self-efficacy was not found to be significantly related to participant intentions to accept help. Another explanation for this finding is the influence of social factors considered by older adults in these helping situations. Participant intentions could have been based on anticipated social rather than physical benefits. This rationale was supported by high rates of selection for socially-relevant perceived benefits of receiving help. Further examination also confirmed that participants generally reported very low levels of total negative affect. This would partially account for the absence of a relationship between perceived benefits and negative affect, even though the former was shown to be correlated with total positive affect. Despite raising as many questions as it answers, the present study succeeds in illustrating the perceptions of higher functioning older adults in situations where physical help is offered to them. Although these participants would not require any help with the physical tasks presented, on average, older adults indicated that they would likely accept the offered assistance approximately half of the time. When the findings of the two sets of analyses are considered, they suggest that much research is needed to understand the perspective of older adults in helping situations. Assumptions about older adults’ reactions to receiving assistance with physical tasks may not be straightforward. Having the ability to function independently may not necessarily mean that older adults refuse assistance. Like younger adults, they may interpret the social situation in terms of a variety of outcomes. Indeed, if researchers do not consider complex interpretations for how older adults function in regard to physical independence, they may be letting personal ageism shape their research. Consequently, there is cause to pursue further research in this underserved area of investigation into the perceptions and actions of older adults. Future studies in this vein may make use of the lessons learned from this exploratory investigation.