Aging phenomena in polystyrene thin films

The aging behavior is investigated for thin films of atactic polystyrene through measurements of complex electric capacitance. During isothermal aging process the real part of the electric capacitance increases with aging time, while the imaginary part decreases with aging time. This result suggests that the aging time dependence of the real and imaginary parts are mainly associated with change in thickness and dielectric permittivity, respectively. In thin films, the thickness depends on thermal history of aging even above the glass transition. Memory and `rejuvenation' effects are also observed in the thin films.Comment: 4 pages, 2 figure

The Effect of an Aging Suit on Young and Middle-Aged Adults’ Attitudes Toward Older Adults

Background: Ageism, a type of discrimination based on a person’s age, can lead to negative attitudes, intolerance, and judgment towards older adults. With the increase of older adults in society, understanding the correlates of negative attitudes becomes increasingly important. The use of aging simulation (the action of imitating or pretending to be an older adult) is one largely unexplored intervention for reducing ageist attitudes. Purpose: The purpose of this study was to examine the effects of an aging suit on the attitudes of young and middle-aged adults toward older adults. We hypothesized that after performing senior fitness tests in an aging suit, young and middle-aged adults would have more positive attitudes towards older adults. Methodology: Subjects consisted of 18 males and 41 females between the ages of 18-59 years. All assessments took place in the Exercise Science Research Center at the University of Arkansas. Upon arrival, each participant took The Aging Semantic Differential (ASD), donned the Gerontological Test (GERT) Suit, to simulate aging, participated in senior fitness tests, and concluded by removing the GERT aging suit and retaking the ASD. A dependent samples t-test was used to compare the ASD scores (dependent variable) pre-aging suit and post-aging suit. Between subject factors of gender, prior fitness test experience, and professional experience working with older adults were also analyzed. Results: There were no significant differences on attitudes towards older adults after wearing the GERT aging suit compared to pre-test scores (p=.36). The mean ASD scores pre-aging suit and post-aging suit were 77.4 and 75.6. There was no group by time interaction for gender (p=.50), prior fitness test experience (p=.91), or professional experience working with older adults (p=.35). The mean age of participants was 28 years. Discussion: The results of this study do not support the hypothesis that attitudes towards older adults would become more positive after wearing the aging suit. The results highlight the need for more studies with a greater sample size and more age variety to clarify a link between an aging suit and an increase in positive attitudes towards older adults. Future studies should also include a comparison of an aging suit (aging simulation) to integrated learning experiences to better clarify the extent to which an aging suit could help increase positive attitudes towards older adults when compared to another intervention method

Aging Scaled Brownian Motion

Scaled Brownian motion (SBM) is widely used to model anomalous diffusion of passive tracers in complex and biological systems. It is a highly non-stationary process governed by the Langevin equation for Brownian motion, however, with a power-law time dependence of the noise strength. Here we study the aging properties of SBM for both unconfined and confined motion. Specifically, we derive the ensemble and time averaged mean squared displacements and analyze their behavior in the regimes of weak, intermediate, and strong aging. A very rich behavior is revealed for confined aging SBM depending on different aging times and whether the process is sub- or superdiffusive. We demonstrate that the information on the aging factorizes with respect to the lag time and exhibits a functional form, that is identical to the aging behavior of scale free continuous time random walk processes. While SBM exhibits a disparity between ensemble and time averaged observables and is thus weakly non-ergodic, strong aging is shown to effect a convergence of the ensemble and time averaged mean squared displacement. Finally, we derive the density of first passage times in the semi-infinite domain that features a crossover defined by the aging time.Comment: 10 pages, 8 figures, REVTe

Aging cellular networks: chaperones as major participants

We increasingly rely on the network approach to understand the complexity of cellular functions. Chaperones (heat shock proteins) are key "networkers", which have among their functions to sequester and repair damaged protein. In order to link the network approach and chaperones with the aging process, we first summarize the properties of aging networks suggesting a "weak link theory of aging". This theory suggests that age-related random damage primarily affects the overwhelming majority of the low affinity, transient interactions (weak links) in cellular networks leading to increased noise, destabilization and diversity. These processes may be further amplified by age-specific network remodelling and by the sequestration of weakly linked cellular proteins to protein aggregates of aging cells. Chaperones are weakly linked hubs [i.e., network elements with a large number of connections] and inter-modular bridge elements of protein-protein interaction, signalling and mitochondrial networks. As aging proceeds, the increased overload of damaged proteins is an especially important element contributing to cellular disintegration and destabilization. Additionally, chaperone overload may contribute to the increase of "noise" in aging cells, which leads to an increased stochastic resonance resulting in a deficient discrimination between signals and noise. Chaperone- and other multi-target therapies, which restore the missing weak links in aging cellular networks, may emerge as important anti-aging interventions.Comment: 7 pages, 4 figure

The Summit on Creativity and Aging in America

This report looks at how the federal government can leverage the arts to foster healthy aging and inclusive design for this growing population. This white paper features recommendations from the May 2015 Summit on Creativity and Aging in America, a convening of more than 70 experts hosted by the National Endowment for the Arts and the National Center for Creative Aging. The paper highlights recommendations on healthy aging, lifelong learning in the arts, and age-friendly community design. The summit was a precursor to the 2015 White House Conference on Aging, which addressed four major issues: retirement security, long-term services and supports, healthy aging, and elder abuse

Aging as dynamics in configuration space

The relaxation dynamics of many disordered systems, such as structural glasses, proteins, granular materials or spin glasses, is not completely frozen even at very low temperatures. This residual motion leads to a change of the properties of the material, a process commonly called aging. Despite recent advances in the theoretical description of such aging processes, the microscopic mechanisms leading to the aging dynamics are still a matter of dispute. In this Letter we investigate the aging dynamics of a simple glass former by means of molecular dynamics computer simulation. Using the concept of the inherent structure we give evidence that aging dynamics can be understood as a decrease of the effective configurational temperature T of the system. From our results we conclude that the equilibration process is faster when the system is quenched to T_c, the critical T of mode-coupling theory, and that thermodynamic concepts are useful to describe the out-of-equilibrium aging process.Comment: Latex 4 figure

Interplay between shear loading and structural aging in a physical gel

We show that the aging of the mechanical relaxation of a gelatin gel exhibits the same scaling phenomenology as polymer and colloidal glasses. Besides, gelatin is known to exhibit logarithmic structural aging (stiffening). We find that stress accelerates this process. However, this effect is definitely irreducible to a mere age shift with respect to natural aging. We suggest that it is interpretable in terms of elastically-aided elementary (coil$\to$helix) local events whose dynamics gradually slows down as aging increases geometric frustration