Entropy Content During Nanometric Stick-Slip Motion

To explore the existence of self-organization during friction, this paper considers the motion of all atoms in a systems consisting of an Atomic Force Microscope metal tip sliding on a metal slab. The tip and the slab are set in relative motion with constant velocity. The vibrations of individual atoms with respect to that relative motion are obtained explicitly using Molecular Dynamics with Embedded Atom Method potentials. First, we obtain signatures of Self Organized Criticality in that the stick-slip jump force probability densities are power laws with exponents in the range (0.5, 1.5) for aluminum and copper. Second, we characterize the dynamical attractor by the entropy content of the overall atomic jittering. We find that in all cases, friction minimizes the entropy and thus makes a strong case for self-organization

Aging well with a lifelong disability: a scoping review

Background and Objectives: Existing literature highlights notable health and social inequalities for people aging with a lifelong disability and the need for research to better understand how we can support this group to age well. This scoping review mapped existing literature related to “aging well” in people with lifelong disabilities. Research Design and Methods: Five scientific databases and gray literature sources were searched for studies related to “aging well” and “lifelong disability” (defined as a disability that a person had lived with since birth or early childhood). Results: We identified 81 studies that discussed aging well with a lifelong disability, with most (70%) focusing on intellectual disabilities. Two themes captured existing research on aging well with a lifelong disability: (1) framing aging well with a lifelong disability, which included the ways that people with lifelong disability, their supporters, and existing research frame aging well for this group and (2) supporting people to age well with a lifelong disability, which involves the micro-, meso-, and macro-level factors where research suggests interventions to facilitate aging well could be situated. Discussion and Implications: This synthesis highlights how aging well is currently framed in the literature and where interventions to improve aging well in this group could be situated. Literature highlights the importance of considering multilevel interventions to improve aging well. Evidence gaps include the lack of research conducted with groups other than those with intellectual disabilities and the need for more research examining aging well interventions.</p