Life-Space Mobility and Aging in Place

Research on older adults explores the notion of “aging in place”—providing older adults the opportunity to continue to occupy familiar surroundings, to live in their own homes and communities. But oftentimes one’s ability to stay or leave, particularly in old age, depends on the built environment. Mobility is the ability to meet the basic needs to access goods, activities, services, and social interactions as they relate to quality of life. Thus, mobility is essential to older adults due to their limited, or gradually reducing, physical and cognitive abilities. In transportation research, mobility is often regarded in terms of travel behavior and it is measured by the number of outside-home travel. However, in other fields, including public health, it refers to the relative ease and freedom of movement in all of its forms. This study intends to broaden the understanding of the environmental factors on older adults’ mobility in different life spaces, from one’s bedroom to sidewalk, from home to a final destination via walking, public transit and/or driving. We document and examine 1) the ways in which older adults talk about, understand, and make meaning of their experiences and conditions related to life-space mobility and, 2) how these frames of reference guide their ability to be able to age in place. To achieve these aims, we developed a life-space mobility assessment tool and conduct semi-structured interviews with 25 older adults who have participated in home accessibility modification programs in the U.S. Western region. Given that interviewees already have engaged in some level of self-determination to improve their lives at home, we are interested in their life-space mobility and which opportunities they might see to improve their auto sufficiency. Our work provides both a basis and springboard for studying further geographies and discussion about policy initiatives to effectively and equitably address growing mobility disparities

Space, mobility, and interaction

This chapter introduces Interactionist theory and research concerning the social organisation of space and mobility. The chapter discusses both classic and contemporary studies in demonstrating the ways in which ‘space’ is not a ‘container’ of social action, but is accomplished in and through interaction and, consequently, mobilities. I trace these more recent developments from the early insights of pragmatist and phenomenological philosophy and the Chicago School ethnographies. Moving forward, the chapter outlines some of the interactionist contribution to studies of place and landscape, before considering the centrality of space (and territories in particular) and movement in Erving Goffman’s notion of interaction order. The chapter also discusses space and mobility as resources for the accomplishment of interaction in, for example, encounters between strangers in public space. Finally, the chapter introduces research that has focused upon interactions that take place open the move, and the social organisation of mobile formations and mobilities in a range of contexts and settings. In sum, the chapter outlines the ways in which Interactionism is necessarily concerned with matters of space and mobility, not as sub-fields or topics, but as the very stuff of the social world

Universality and non-universality of mobility in heterogeneous single-file systems and Rouse chains

We study analytically the tracer particle mobility in single-file systems with distributed friction constants. Our system serves as a prototype for non-equilibrium, heterogeneous, strongly interacting Brownian systems. The long time dynamics for such a single-file setup belongs to the same universality class as the Rouse model with dissimilar beads. The friction constants are drawn from a density $\varrho(\xi)$ and we derive an asymptotically exact solution for the mobility distribution $P[\mu_0(s)]$, where $\mu_0(s)$ is the Laplace-space mobility. If $\varrho$ is light-tailed (first moment exists) we find a self-averaging behaviour: $P[\mu_0(s)]=\delta[\mu_0(s)-\mu(s)]$ with $\mu(s)\propto s^{1/2}$. When $\varrho(\xi)$ is heavy-tailed, $\varrho(\xi)\simeq \xi^{-1-\alpha} \ (0<\alpha<1)$ for large $\xi$ we obtain moments $\langle [\mu_s(0)]^n\rangle \propto s^{\beta n}$ where $\beta=1/(1+\alpha)$ and no self-averaging. The results are corroborated by simulations.Comment: 8 pages, 4 figures, REVTeX, to appear in Physical Review

Self-reported life-space mobility in the first year after ischemic stroke: longitudinal findings from the MOBITEC-Stroke project

Background Life-space mobility is defined as the size of the area in which a person moves about within a specified period of time. Our study aimed to characterize life-space mobility, identify factors associated with its course, and detect typical trajectories in the first year after ischemic stroke. Methods MOBITEC-Stroke (ISRCTN85999967; 13/08/2020) was a cohort study with assessments performed 3, 6, 9 and 12 months after stroke onset. We applied linear mixed effects models (LMMs) with life-space mobility (Life-Space Assessment; LSA) as outcome and time point, sex, age, pre-stroke mobility limitation, stroke severity (National Institutes of Health Stroke Scale; NIHSS), modified Rankin Scale, comorbidities, neighborhood characteristics, availability of a car, Falls Efficacy Scale-International (FES-I), and lower extremity physical function (log-transformed timed up-and-go; TUG) as independent variables. We elucidated typical trajectories of LSA by latent class growth analysis (LCGA) and performed univariate tests for differences between classes. Results In 59 participants (mean age 71.6, SD 10.0 years; 33.9% women), mean LSA at 3 months was 69.3 (SD 27.3). LMMs revealed evidence (p ≤ 0.05) that pre-stroke mobility limitation, NIHSS, comorbidities, and FES-I were independently associated with the course of LSA; there was no evidence for a significant effect of time point. LCGA revealed three classes: “low stable”, “average stable”, and “high increasing”. Classes differed with regard to LSA starting value, pre-stroke mobility limitation, FES-I, and log-transformed TUG time. Conclusion Routinely assessing LSA starting value, pre-stroke mobility limitation, and FES-I may help clinicians identify patients at increased risk of failure to improve LSA

The association between physical activity and body mass index, quality of life, life-space mobility and successful aging in older adults.

Masters Degree. University of KwaZulu-Natal, Durban.The biggest threat to healthy aging is sedentary living with the golden years of most individuals being affected by disorders that are exacerbated by unhealthy lifestyles. Helping people age better is important and it can be achieved through participation in regular physical activity. Monitoring population levels of physical activity using subjective and objective measures is an important part of a public health response. This study aimed to determine the physical activity and body composition levels of older adults and the association of physical activity on body composition with health-related quality of life, life-space mobility and successful aging of life of older adults in Chatsworth, KwaZulu-Natal Province. A total of 210 older adults were randomly selected, both male and females, participated in the study and completed the Global Physical Activity Questionnaire, RAND Medical Outcomes Study 36-Item Health Survey, Life-Space Mobility Questionnaire and the Successful Aging Scale. BMI (kg/m2) was determined and step count was tracked for 7 days with the Omoron Pedometer. There were positive correlations between the participants actual physical activity and self-reported physical activity levels (r=0.183, p=0.008). The majority of the participants were overweight (51%, n=107). There was no significant relationship between BMI (r=0.63, p=0.366) and actual steps taken as well as no significant correlation with SF-36 and the average number of steps in 7 days of the participants (r=-0.112, p=0.107). A significant correlation between total LSQ (r=0.224, p=0.001) and SAS (r=-0.152, p=0.027) with the average number of steps in 7 days of the participant was noted. It was concluded that there is a positive relationship between self-reported physical activity and actual activity and life-space mobility and successful aging of life in older adults, but such relationship is not meaningfully predictive in this population. Strategies to improve physical inactivity in the elderly need to be implemented to ensure successful aging and quality of life in the elderly

Spectral Ewald Acceleration of Stokesian Dynamics for polydisperse suspensions

In this work we develop the Spectral Ewald Accelerated Stokesian Dynamics (SEASD), a novel computational method for dynamic simulations of polydisperse colloidal suspensions with full hydrodynamic interactions. SEASD is based on the framework of Stokesian Dynamics (SD) with extension to compressible solvents, and uses the Spectral Ewald (SE) method [Lindbo & Tornberg, J. Comput. Phys. 229 (2010) 8994] for the wave-space mobility computation. To meet the performance requirement of dynamic simulations, we use Graphic Processing Units (GPU) to evaluate the suspension mobility, and achieve an order of magnitude speedup compared to a CPU implementation. For further speedup, we develop a novel far-field block-diagonal preconditioner to reduce the far-field evaluations in the iterative solver, and SEASD-nf, a polydisperse extension of the mean-field Brownian approximation of Banchio & Brady [J. Chem. Phys. 118 (2003) 10323]. We extensively discuss implementation and parameter selection strategies in SEASD, and demonstrate the spectral accuracy in the mobility evaluation and the overall $\mathcal{O}(N\log N)$ computation scaling. We present three computational examples to further validate SEASD and SEASD-nf in monodisperse and bidisperse suspensions: the short-time transport properties, the equilibrium osmotic pressure and viscoelastic moduli, and the steady shear Brownian rheology. Our validation results show that the agreement between SEASD and SEASD-nf is satisfactory over a wide range of parameters, and also provide significant insight into the dynamics of polydisperse colloidal suspensions.Comment: 39 pages, 21 figure

Prediction of mobility entropy in an ambient intelligent environment

Ambient Intelligent (AmI) technology can be used to help older adults to live longer and independent lives in their own homes. Information collected from AmI environment can be used to detect and understanding human behaviour, allowing personalized care. The behaviour pattern can also be used to detect changes in behaviour and predict future trends, so that preventive action can be taken. However, due to the large number of sensors in the environment, sensor data are often complex and difficult to interpret, especially to capture behaviour trends and to detect changes over the long-term. In this paper, a model to predict the indoor mobility using binary sensors is proposed. The model utilizes weekly routine to predict the future trend. The proposed method is validated using data collected from a real home environment, and the results show that using weekly pattern helps improve indoor mobility prediction. Also, a new measurement, Mobility Entropy (ME), to measure indoor mobility based on entropy concept is proposed. The results indicate ME can be used to distinguish elders with different mobility and to see decline in mobility. The proposed work would allow detection of changes in mobility, and to foresee the future mobility trend if the current behaviour continues

REGULUS Electric Propulsion Module IoD in UniSat-7 Mission

T4i is a propulsion system company founded in 2014, originated from the Space Propulsion Group of University of Padua, Italy, and active in the market of small satellites. In the last decade T4i has been developing REGULUS, a cutting-edge electric propulsion system for in-space mobility fed with iodine propellant. REGULUS has been specifically designed for Cubesats and micro satellite platforms and it is based on a RF Magnetically Enhanced Plasma (MEP) thruster. Thanks to its standard interfaces it is conceived to be easily “plugged&played” into the satellite, without complex engineering procedures