title: Disuse and aging, 2009.
abstract: BACKGROUND
  Knowledge of the basic processes determinative of the life courses of older persons has progressed dramatically in the past few years. This article is an update of a similar survey performed 27 years ago.
  
  
  METHODS
  A literature review of recent contributions gathered from a variety of disciplines seeks a more sturdy and consistent heuristic from which derivative work may proceed.
  
  
  RESULTS
  Publications from basic and clinical sciences as well as related nonmedical fields reveal a new conceptual framework for the understanding of human aging, which suggests a broader framework of contributing agencies and their policy implications.
  
  
  CONCLUSIONS
  Aging is not a disease and therefore demands a different lens for analysis. This article provides a deeper focus and insists on the inclusion of a heightened sense of the participation of time. Incorporation of the imperatives applied by the Second Law of Thermodynamics is the foundation of the new definitions.
authors.affiliation: Stanford University School of Medicine, 167 Bolivar Lane, Portola Valley, CA 94028, USA. drwbortz@aol.com
authors.forename: Walter
authors.initials: W
authors.lastname: Bortz
mesh_terms: D000375:Aging / Q000502:physiology*; D006801:Humans; D020966:Muscular Disorders, Atrophic; D009473:Neuronal Plasticity / Q000502:physiology