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Search Results: 1 - 10 of 325553 matches for " Buchman Aron S "
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Risk Aversion is Associated with Decision Making among Community-Based Older Persons
Patricia A. Boyle,Aron S. Buchman,David A. Bennett
Frontiers in Psychology , 2012, DOI: 10.3389/fpsyg.2012.00205
Abstract: Background: Risk aversion is associated with many important decisions among younger and middle aged persons, but the association of risk aversion with decision making has not been well studied among older persons who face some of the most significant decisions of their lives. Method: Using data from 606 community-dwelling older persons without dementia from the Rush Memory and Aging Project, an ongoing longitudinal epidemiologic study of aging, we examined the association of risk aversion with decision making. Risk aversion was measured using standard behavioral economics questions in which participants were asked to choose between a certain monetary payment ($15) versus a gamble in which they could gain more than $15 or gain nothing; potential gamble gains ranged from $20 to $300 with the gain amounts varied randomly over questions. Decision making was measured using a 12 item version of the Decision Making Competence Assessment Tool. Findings: In a linear regression model adjusted for age, sex, education, and income, greater risk aversion was associated with poorer decision making [estimate = ?1.03, standard error (SE) = 0.35, p = 0.003]. Subsequent analyses showed that the association of risk aversion with decision making persisted after adjustment for global cognitive function as well as executive and non-executive cognitive abilities. Conclusion: Similar to findings from studies of younger persons, risk aversion is associated with poorer decision making among older persons who face a myriad of complex and influential decisions.
Poor Decision Making Is a Consequence of Cognitive Decline among Older Persons without Alzheimer’s Disease or Mild Cognitive Impairment
Patricia A. Boyle, Lei Yu, Robert S. Wilson, Keith Gamble, Aron S. Buchman, David A. Bennett
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0043647
Abstract: Objective Decision making is an important determinant of health and well-being across the lifespan but is critical in aging, when many influential decisions are made just as cognitive function declines. Increasing evidence suggests that older adults, even those without dementia, often make poor decisions and are selectively vulnerable to scams. To date, however, the factors associated with poor decision making in old age are unknown. The objective of this study was to test the hypothesis that poor decision making is a consequence of cognitive decline among older persons without Alzheimer’s disease or mild cognitive impairment. Methods Participants were 420 non-demented persons from the Memory and Aging Project, a longitudinal, clinical-pathologic cohort study of aging in the Chicago metropolitan area. All underwent repeated cognitive evaluations and subsequently completed assessments of decision making and susceptibility to scams. Decision making was measured using 12 items from a previously established performance-based measure and a self-report measure of susceptibility to scams. Results Cognitive function data were collected over an average of 5.5 years prior to the decision making assessment. Regression analyses were used to examine whether the prior rate of cognitive decline predicted the level of decision making and susceptibility to scams; analyses controlled for age, sex, education, and starting level of cognition. Among 420 persons without dementia, more rapid cognitive decline predicted poorer decision making and increased susceptibility to scams (p’s<0.001). Further, the relations between cognitive decline, decision making and scams persisted in analyses restricted to persons without any cognitive impairment (i.e., no dementia or even mild cognitive impairment). Conclusions Poor decision making is a consequence of cognitive decline among older persons without Alzheimer’s disease or mild cognitive impairment, those widely considered “cognitively healthy.” These findings suggest that even very subtle age-related changes in cognition have detrimental effects on judgment.
Cognitive function is associated with risk aversion in community-based older persons
Patricia A Boyle, Lei Yu, Aron S Buchman, David I Laibson, David A Bennett
BMC Geriatrics , 2011, DOI: 10.1186/1471-2318-11-53
Abstract: Using data from 369 community-dwelling older persons without dementia from the Rush Memory and Aging Project, an ongoing longitudinal epidemiologic study of aging, we examined the correlates of risk aversion and tested the hypothesis that cognition is negatively associated with risk aversion. Global cognition and five specific cognitive abilities were measured via detailed cognitive testing, and risk aversion was measured using standard behavioral economics questions in which participants were asked to choose between a certain monetary payment ($15) versus a gamble in which they could gain more than $15 or gain nothing; potential gamble gains ranged from $21.79 to $151.19 with the gain amounts varied randomly over questions. We first examined the bivariate associations of age, education, sex, income and cognition with risk aversion. Next, we examined the associations between cognition and risk aversion via mixed models adjusted for age, sex, education, and income. Finally, we conducted sensitivity analyses to ensure that our results were not driven by persons with preclinical cognitive impairment.In bivariate analyses, sex, education, income and global cognition were associated with risk aversion. However, in a mixed effect model, only sex (estimate = -1.49, standard error (SE) = 0.39, p < 0.001) and global cognitive function (estimate = -1.05, standard error (SE) = 0.34, p < 0.003) were significantly inversely associated with risk aversion. Thus, a lower level of global cognitive function and female sex were associated with greater risk aversion. Moreover, performance on four out of the five cognitive domains was negatively related to risk aversion (i.e., semantic memory, episodic memory, working memory, and perceptual speed); performance on visuospatial abilities was not.A lower level of cognitive ability and female sex are associated with greater risk aversion in advanced age.Compelling economics, behavioral economics, and neuroeconomics studies have shown that r
Association of total daily physical activity with disability in community-dwelling older persons: a prospective cohort study
Shah Raj C,Buchman Aron S,Leurgans Sue,Boyle Patricia A
BMC Geriatrics , 2012, DOI: 10.1186/1471-2318-12-63
Abstract: Background Based on findings primarily using self-report measures, physical activity has been recommended to reduce disability in old age. Collecting objective measures of total daily physical activity in community-dwelling older adults is uncommon, but might enhance the understanding of the relationship of physical activity and disability. We examined whether greater total daily physical activity was associated with less report of disability in the elderly. Methods Data were from the Rush Memory and Aging Project, a longitudinal prospective cohort study of common, age-related, chronic conditions. Total daily physical activity was measured in community-dwelling participants with an average age of 82 using actigraphy for approximately 9 days. Disability was measured via self-reported basic activities of daily living (ADL). The odds ratio and 95% Confidence Interval (CI) were determined for the baseline association of total daily physical activity and ADL disability using a logistic regression model adjusted for age, education level, gender and self-report physical activity. In participants without initial report of ADL disability, the hazard ratio and 95% CI were determined for the relationship of baseline total daily physical activity and the development of ADL disability using a discrete time Cox proportional hazard model adjusted for demographics and self-report physical activity. Results In 870 participants, the mean total daily physical activity was 2. 9 × 105 counts/day (range in 105 counts/day = 0.16, 13. 6) and the mean hours/week of self-reported physical activity was 3.2 (SD = 3.6). At baseline, 718 (82.5%) participants reported being independent in all ADLs. At baseline, total daily physical activity was protective against disability (OR per 105 counts/day difference = 0.55; 95% CI = 0.47, 0.65). Of the participants without baseline disability, 584 were followed for 3.4 years on average. Each 105 counts/day additional total daily physical activity was associated with reduced hazard of developing disability by 25% (HR = 0.75, 95% CI = 0.66, 0.84). The results were unchanged after controlling for important covariates including cognition, depressive symptoms, and chronic health conditions. Conclusions Greater total daily physical activity is independently associated with less disability even after controlling for self-reported physical activity.
Using a Body-Fixed Sensor to Identify Subclinical Gait Difficulties in Older Adults with IADL Disability: Maximizing the Output of the Timed Up and Go
Aner Weiss, Anat Mirelman, Aron S. Buchman, David A. Bennett, Jeffrey M. Hausdorff
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0068885
Abstract: Objective The identification and documentation of subclinical gait impairments in older adults may facilitate the appropriate use of interventions for preventing or delaying mobility disability. We tested whether measures derived from a single body-fixed sensor worn during traditional Timed Up and Go (TUG) testing could identify subclinical gait impairments in community dwelling older adults without mobility disability. Methods We used data from 432 older adults without dementia (mean age 83.30±7.04 yrs, 76.62% female) participating in the Rush Memory and Aging Project. The traditional TUG was conducted while subjects wore a body-fixed sensor. We derived measures of overall TUG performance and different subtasks including transitions (sit-to-stand, stand-to-sit), walking, and turning. Multivariate analysis was used to compare persons with and without mobility disability and to compare individuals with and without Instrumental Activities of Daily Living disability (IADL-disability), all of whom did not have mobility disability. Results As expected, individuals with mobility disability performed worse on all TUG subtasks (p<0.03), compared to those who had no mobility disability. Individuals without mobility disability but with IADL disability had difficulties with turns, had lower yaw amplitude (p<0.004) during turns, were slower (p<0.001), and had less consistent gait (p<0.02). Conclusions A single body-worn sensor can be employed in the community-setting to complement conventional gait testing. It provides a wide range of quantitative gait measures that appear to help to identify subclinical gait impairments in older adults.
Combinations of motor measures more strongly predict adverse health outcomes in old age: the rush memory and aging project, a community-based cohort study
Aron S Buchman, Sue E Leurgans,, Patricia A Boyle,, Julie A Schneider,, Steven E Arnold, David A Bennett
BMC Medicine , 2011, DOI: 10.1186/1741-7015-9-42
Abstract: In total, 949 people without dementia, history of stroke or Parkinson's disease, who were participating in the Rush Memory and Aging Project (a longitudinal community-based cohort study), underwent assessment at study entry. From this, three constructs were derived: 1) physical frailty based on grip strength, timed walk, body mass index and fatigue; 2) Parkinsonian Signs Score based on the modified motor section of the Unified Parkinson's Disease Rating Scale; and 3) a motor construct, based on nine strength measures and nine motor performances. Disability and cognitive status were assessed annually. A series of Cox proportional-hazards models, controlling for age, sex and education, were used to examine the association of each of these three constructs alone and in various combinations with death, disability and Alzheimer's disease (AD).All three constructs were related (mean r = 0.50, all P < 0.001), and when considered individually in separate proportional-hazards models, were associated with risk of death, incident disability and AD. However, when considered together, combinations of these constructs more strongly predicted adverse health outcomes.Physical frailty, parkinsonian signs score and global motor score are related constructs that capture different aspects of motor function. Assessments using several motor constructs may more accurately identify people at the highest risk of adverse health consequences in old age.Loss of motor function is a common consequence of old age, and is associated with adverse health consequences [1-5]. The specific motor abilities impaired in old age vary, and encompass a wide spectrum, including reduced gait speed and loss of muscle strength and bulk, balance, and dexterity [6-8]. Thus, the growing public-health challenge of identifying motor impairment in old age is complicated by the variability of its clinical expression.Currently there is no single scale that can be used to assess motor impairments. Several constructs base
Loneliness and the rate of motor decline in old age: the rush memory and aging project, a community-based cohort study
Aron S Buchman, Patricia A Boyle, Robert S Wilson, Bryan D James, Sue E Leurgans, Steven E Arnold, David A Bennett
BMC Geriatrics , 2010, DOI: 10.1186/1471-2318-10-77
Abstract: At baseline, loneliness was assessed with a 5-item scale in 985 persons without dementia participating in the Rush Memory and Aging Project, a longitudinal community-based cohort study. Annual detailed assessment of 9 measures of muscle strength and 9 motor performances were summarized in a composite measure of global motor function.Linear mixed-effects models which controlled for age, sex and education, showed that the level of loneliness at baseline was associated with the rate of motor decline (Estimate, -0.016; S.E. 0.006, p = 0.005). For each 1-point higher level of loneliness at baseline, motor decline was 40% more rapid; this effect was similar to the rate of motor decline observed in an average participant 4 years older at baseline. Furthermore, this amount of motor decline per year was associated with about a 50% increased risk of death. When terms for both feeling alone (loneliness) and being alone were considered together in a single model, both were relatively independent predictors of motor decline. The association between loneliness and motor decline persisted even after controlling for depressive symptoms, cognition, physical and cognitive activities, chronic conditions, as well as baseline disability or a history of stroke or Parkinson's disease.Among community-dwelling older persons, both feeling alone and being alone are associated with more rapid motor decline, underscoring the importance of psychosocial factors and motor decline in old age.Loss of motor function is a common consequence of aging and is associated with adverse health consequences[1-5]. The specific motor abilities impaired in old age vary and encompass a wide spectrum including loss of muscle strength and bulk, balance, dexterity and reduced gait speed which can occur even in the absence of overt diseases[6-8]. By 2030, 20% of Americans, roughly 72 million people, will be 65 years of age or older[9], and by the age of 80 years or older, the fastest growing segment, 40% or more will
Associations between Quantitative Mobility Measures Derived from Components of Conventional Mobility Testing and Parkinsonian Gait in Older Adults
Aron S. Buchman, Sue E. Leurgans, Aner Weiss, Veronique VanderHorst, Anat Mirelman, Robert Dawe, Lisa L. Barnes, Robert S. Wilson, Jeffrey M. Hausdorff, David A. Bennett
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0086262
Abstract: Objective To provide objective measures which characterize mobility in older adults assessed in the community setting and to examine the extent to which these measures are associated with parkinsonian gait. Methods During conventional mobility testing in the community-setting, 351 ambulatory non-demented Memory and Aging Project participants wore a belt with a whole body sensor that recorded both acceleration and angular velocity in 3 directions. We used measures derived from these recordings to quantify 5 subtasks including a) walking, b) transition from sit to stand, c) transition from stand to sit, d) turning and e) standing posture. Parkinsonian gait and other mild parkinsonian signs were assessed with a modified version of the original Unified Parkinson’s Disease Rating Scale (mUPDRS). Results In a series of separate regression models which adjusted for age and sex, all 5 mobility subtask measures were associated with parkinsonian gait and accounted for 2% to 32% of its variance. When all 5 subtask measures were considered in a single model, backward elimination showed that measures of walking sit to stand and turning showed independent associations with parkinsonian gait and together accounted for more than 35% of its variance. Cross-validation using data from a 2nd group of 258 older adults showed similar results. In similar analyses, only walking was associated with bradykinesia and sway with tremor. Interpretation Quantitative mobility subtask measures vary in their associations with parkinsonian gait scores and other parkinsonian signs in older adults. Quantifying the different facets of mobility has the potential to facilitate the clinical characterization and understanding the biologic basis for impaired mobility in older adults.
24-Hour Rhythms of DNA Methylation and Their Relation with Rhythms of RNA Expression in the Human Dorsolateral Prefrontal Cortex
Andrew S. P. Lim ,Gyan P. Srivastava,Lei Yu,Lori B. Chibnik,Jishu Xu,Aron S. Buchman,Julie A. Schneider,Amanda J. Myers,David A. Bennett,Philip L. De Jager
PLOS Genetics , 2014, DOI: doi/10.1371/journal.pgen.1004792
Abstract: Circadian rhythms modulate the biology of many human tissues, including brain tissues, and are driven by a near 24-hour transcriptional feedback loop. These rhythms are paralleled by 24-hour rhythms of large portions of the transcriptome. The role of dynamic DNA methylation in influencing these rhythms is uncertain. While recent work in Neurospora suggests that dynamic site-specific circadian rhythms of DNA methylation may play a role in modulating the fungal molecular clock, such rhythms and their relationship to RNA expression have not, to our knowledge, been elucidated in mammalian tissues, including human brain tissues. We hypothesized that 24-hour rhythms of DNA methylation exist in the human brain, and play a role in driving 24-hour rhythms of RNA expression. We analyzed DNA methylation levels in post-mortem human dorsolateral prefrontal cortex samples from 738 subjects. We assessed for 24-hour rhythmicity of 420,132 DNA methylation sites throughout the genome by considering methylation levels as a function of clock time of death and parameterizing these data using cosine functions. We determined global statistical significance by permutation. We then related rhythms of DNA methylation with rhythms of RNA expression determined by RNA sequencing. We found evidence of significant 24-hour rhythmicity of DNA methylation. Regions near transcription start sites were enriched for high-amplitude rhythmic DNA methylation sites, which were in turn time locked to 24-hour rhythms of RNA expression of nearby genes, with the nadir of methylation preceding peak transcript expression by 1–3 hours. Weak ante-mortem rest-activity rhythms were associated with lower amplitude DNA methylation rhythms as were older age and the presence of Alzheimer's disease. These findings support the hypothesis that 24-hour rhythms of DNA methylation, particularly near transcription start sites, may play a role in driving 24-hour rhythms of gene expression in the human dorsolateral prefrontal cortex, and may be affected by age and Alzheimer's disease.
Ciclo reproductivo y fecundidad parcial de Isacia conceptionis (Perciformes, Haemulidae) en La Herradura, Coquimbo, Chile
Cortés,Niris; Aron,Alejandro;
Revista de biología marina y oceanografía , 2011, DOI: 10.4067/S0718-19572011000100016
Abstract: this study analyses reproductive aspects of the fish isacia conceptionis based on 280 females collected at la herradura bay, northern chile, between april 1995 and march 1996, using histological analysis of the ovaries, measurement of gonadosomatic and gonadic indices and the batch fecundity. five maturity stages for the ovary were described. mature females were partial spawner because of simultaneous presence of oocytes at different maturity stages. the high frequency of mature females and high gonadosomatic and gonadic indices observed during austral winter and summer suggest two spawning seasons. the estimated batch fecundity (f) for total length (lt) was f = 0.0003lt3.9701 and for total weight (pt) was f = 0.2255pt1.1539.
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