Aberrant Mitochondrial Homeostasis in the Skeletal Muscle of Sedentary Older Adults

The role of mitochondrial dysfunction and oxidative stress has been extensively characterized in the aetiology of sarcopenia (aging-associated loss of muscle mass) and muscle wasting as a result of muscle disuse. What remains less clear is whether the decline in skeletal muscle mitochondrial oxidative capacity is purely a function of the aging process or if the sedentary lifestyle of older adult subjects has confounded previous reports. The objective of the present study was to investigate if a recreationally active lifestyle in older adults can conserve skeletal muscle strength and functionality, chronic systemic inflammation, mitochondrial biogenesis and oxidative capacity, and cellular antioxidant capacity. To that end, muscle biopsies were taken from the vastus lateralis of young and age-matched recreationally active older and sedentary older men and women (N = 10/group; ♀  =  ♂). We show that a physically active lifestyle is associated with the partial compensatory preservation of mitochondrial biogenesis, and cellular oxidative and antioxidant capacity in skeletal muscle of older adults. Conversely a sedentary lifestyle, associated with osteoarthritis-mediated physical inactivity, is associated with reduced mitochondrial function, dysregulation of cellular redox status and chronic systemic inflammation that renders the skeletal muscle intracellular environment prone to reactive oxygen species-mediated toxicity. We propose that an active lifestyle is an important determinant of quality of life and molecular progression of aging in skeletal muscle of the elderly, and is a viable therapy for attenuating and/or reversing skeletal muscle strength declines and mitochondrial abnormalities associated with aging

Mitochondrial function as a determinant of life span

Average human life expectancy has progressively increased over many decades largely due to improvements in nutrition, vaccination, antimicrobial agents, and effective treatment/prevention of cardiovascular disease, cancer, etc. Maximal life span, in contrast, has changed very little. Caloric restriction (CR) increases maximal life span in many species, in concert with improvements in mitochondrial function. These effects have yet to be demonstrated in humans, and the duration and level of CR required to extend life span in animals is not realistic in humans. Physical activity (voluntary exercise) continues to hold much promise for increasing healthy life expectancy in humans, but remains to show any impact to increase maximal life span. However, longevity in Caenorhabditis elegans is related to activity levels, possibly through maintenance of mitochondrial function throughout the life span. In humans, we reported a progressive decline in muscle mitochondrial DNA abundance and protein synthesis with age. Other investigators also noted age-related declines in muscle mitochondrial function, which are related to peak oxygen uptake. Long-term aerobic exercise largely prevented age-related declines in mitochondrial DNA abundance and function in humans and may increase spontaneous activity levels in mice. Notwithstanding, the impact of aerobic exercise and activity levels on maximal life span is uncertain. It is proposed that age-related declines in mitochondrial content and function not only affect physical function, but also play a major role in regulation of life span. Regular aerobic exercise and prevention of adiposity by healthy diet may increase healthy life expectancy and prolong life span through beneficial effects at the level of the mitochondrion

Service-oriented product lines: a systematic mapping study

Software product line engineering and service-oriented architectures both enable organizations to capitalize on reuse of existing software assets and capabilities and improve competitive advantage in terms of development savings, product flexibility, time-to-market. Both approaches accommodate variation of assets, including services, by changing the software being reused or composing services according a new orchestration. Therefore, variability management in Service-oriented Product Lines (SoPL) is one of the main challenges today. In order to highlight the emerging evidence-based results from the research community, we apply the well-defined method of systematic mapping in order to populate a classification scheme for the SoPL field of interest. The analysis of results throws light on the current open issues. Moreover, different facets of the scheme can be combined to answer more specific research questions. The report reveals the need for more empirical research able to provide new metrics measuring efficiency and efficacy of the proposed models, new methods and tools supporting variability management in SoPL, especially during maintenance and verification and validation. The mapping study about SoPL opens further investigations by means of a complete systematic review to select and validate the most efficient solutions to variability management in SoPL.</jats:p

Business Process Lines and Decision Tables Driving Flexibility by Selection

A major challenge faced by organizations is to better capture business strategies into products and services at an ever-increasing pace as the business environment constantly evolves. We propose a novel methodology base on a Business Process Line (BPL) engineering approach to inject flexibility into process modeling phase and promote reuse and flexibility by selection. Moreover we suggest a decision-table (DT) formalism for eliciting, tracking and managing the relationships among business needs, environmental changes and process tasks. In a real case study we practiced the proposed methodology by leveraging the synergy of feature models, variability mechanisms and decision tables. The application of DT-based BPL engineering approach proves that the Business Process Line benefits from fundamental concepts like composition, reusability and adaptability and satisfies the requirements for process definition flexibilit