185,470 research outputs found

    Reliability-Aware Power Management Of Multi-Core Systems (MPSoCs)

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    Long-term reliability of processors in embedded systems is experiencing growing attention since decreasing feature sizes and increasing power consumption have a negative influence on the lifespan. Among other measures, the reliability can be influenced significantly by Dynamic Power Management (DPM), since it affects the processor\u27s temperature. Compared to single-core systems reconfigurable multi-core SoCs offer much more possibilities to optimize power and reliability. The impact of different DPM-strategies on the lifespan of multi-core processors is the focus of this presentation. It is shown that the long-term reliability of a multi-core system can be influenced deliberately with different DPM strategies and that temperature cycling greatly influences the estimated lifespan. In this presentation, a new reliability-aware dynamic power management (RADPM) policy is explained

    Uncoupling lifespan and healthspan in Caenorhabditis elegans longevity mutants

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    Aging research has been very successful at identifying signaling pathways and evolutionarily conserved genes that extend lifespan with the assumption that an increase in lifespan will also increase healthspan. However, it is largely unknown whether we are extending the healthy time of life or simply prolonging a period of frailty with increased incidence of age-associated diseases. Here we use Caenorhabditis elegans, one of the premiere systems for lifespan studies, to determine whether lifespan and healthspan are intrinsically correlated. We conducted multiple cellular and organismal assays on wild type as well as four long-lived mutants (insulin/insulin-like growth factor-1, dietary restriction, protein translation, mitochondrial signaling) in a longitudinal manner to determine the health of the animals as they age. We find that some long-lived mutants performed better than wild type when measured chronologically (number of days). However, all long-lived mutants increased the proportion of time spent in a frail state. Together, these data suggest that lifespan can no longer be the sole parameter of interest and reveal the importance of evaluating multiple healthspan parameters for future studies on antiaging interventions

    Bridging Time Scales in Cellular Decision Making with a Stochastic Bistable Switch

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    Cellular transformations which involve a significant phenotypical change of the cell's state use bistable biochemical switches as underlying decision systems. In this work, we aim at linking cellular decisions taking place on a time scale of years to decades with the biochemical dynamics in signal transduction and gene regulation, occuring on a time scale of minutes to hours. We show that a stochastic bistable switch forms a viable biochemical mechanism to implement decision processes on long time scales. As a case study, the mechanism is applied to model the initiation of follicle growth in mammalian ovaries, where the physiological time scale of follicle pool depletion is on the order of the organism's lifespan. We construct a simple mathematical model for this process based on experimental evidence for the involved genetic mechanisms. Despite the underlying stochasticity, the proposed mechanism turns out to yield reliable behavior in large populations of cells subject to the considered decision process. Our model explains how the physiological time constant may emerge from the intrinsic stochasticity of the underlying gene regulatory network. Apart from ovarian follicles, the proposed mechanism may also be of relevance for other physiological systems where cells take binary decisions over a long time scale.Comment: 14 pages, 4 figure

    The AI Bus architecture for distributed knowledge-based systems

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    The AI Bus architecture is layered, distributed object oriented framework developed to support the requirements of advanced technology programs for an order of magnitude improvement in software costs. The consequent need for highly autonomous computer systems, adaptable to new technology advances over a long lifespan, led to the design of an open architecture and toolbox for building large scale, robust, production quality systems. The AI Bus accommodates a mix of knowledge based and conventional components, running on heterogeneous, distributed real world and testbed environment. The concepts and design is described of the AI Bus architecture and its current implementation status as a Unix C++ library or reusable objects. Each high level semiautonomous agent process consists of a number of knowledge sources together with interagent communication mechanisms based on shared blackboards and message passing acquaintances. Standard interfaces and protocols are followed for combining and validating subsystems. Dynamic probes or demons provide an event driven means for providing active objects with shared access to resources, and each other, while not violating their security

    Multiple morbidities in companion dogs: a novel model for investigating age-related disease

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    The proportion of men and women surviving over 65 years has been steadily increasing over the last century. In their later years, many of these individuals are afflicted with multiple chronic conditions, placing increasing pressure on healthcare systems. The accumulation of multiple health problems with advanced age is well documented, yet the causes are poorly understood. Animal models have long been employed in attempts to elucidate these complex mechanisms with limited success. Recently, the domestic dog has been proposed as a promising model of human aging for several reasons. Mean lifespan shows twofold variation across dog breeds. In addition, dogs closely share the environments of their owners, and substantial veterinary resources are dedicated to comprehensive diagnosis of conditions in dogs. However, while dogs are therefore useful for studying multimorbidity, little is known about how aging influences the accumulation of multiple concurrent disease conditions across dog breeds. The current study examines how age, body weight, and breed contribute to variation in multimorbidity in over 2,000 companion dogs visiting private veterinary clinics in England. In common with humans, we find that the number of diagnoses increases significantly with age in dogs. However, we find no significant weight or breed effects on morbidity number. This surprising result reveals that while breeds may vary in their average longevity and causes of death, their age-related trajectories of morbidities differ little, suggesting that age of onset of disease may be the source of variation in lifespan across breeds. Future studies with increased sample sizes and longitudinal monitoring may help us discern more breed-specific patterns in morbidity. Overall, the large increase in multimorbidity seen with age in dogs mirrors that seen in humans and lends even more credence to the value of companion dogs as models for human morbidity and mortality

    The effects of aging and maternal protein restriction during lactation on thymic involution and peripheral immunosenescence in adult mice.

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    Environmental factors such as nutrition during early life can influence long-term health, a concept termed developmental programming. Initial research was focused towards the effects on metabolic health but more recent studies have demonstrated effects on parameters such as lifespan and immunity. In this study we report that maternal protein restriction during lactation in mice, that is known to prolong lifespan, slows aging of the central and peripheral immune systems. Offspring of dams fed a postnatal low-protein (PLP) diet during lactation had a significant increase in thymic cellularity and T cell numbers across their lifespan compared to controls, and a less marked age-associated decrease in thymocyte cluster of differentiation (CD) 3 expression. PLP animals also demonstrated increased relative splenic cellularity, increased naïve: memory CD4+ and CD8+ T cell ratios, increased staining and density of germinal centres, and decreased gene expression of p16 in the spleen, a robust biomarker of aging. A slower rate of splenic aging in PLP animals would be expected to result in decreased susceptibility to infection and neoplasia. In conclusion nutritionally-induced slow postnatal growth leads to delayed aging of the adaptive immune system, which may contribute towards the extended lifespan observed in these animals.This work was supported by the BBSRC and the MRC. SEO is funded by the University of Cambridge MRC Metabolic Diseases Unit (MRC_MC_UU_12012/4).This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by Impact Journals

    Collaborative Crop Research Program

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    For over 30 years, The McKnight Foundation's Collaborative Crop Research Program (CCRP) has explored solutions for sustainable local food systems through agricultural research. The program grew out of the Foundation's Plant Biology Program, which was founded in 1983, and reflects the Foundation's long-time commitment to place-based grantmaking and learning from those working on the ground. In 2014, the Foundation engaged The Philanthropic Initiative (TPI) to develop a historic overview of the CCRP to capture its origins and evolution over the last 30 years. To develop this narrative, TPI interviewed past and current Board members, staff, consultants and grantees who had been involved at various stages in the lifespan of the program, and reviewed existing documents, reports and meeting notes.The report that follows is to serve as part of the "institutional memory" of The McKnight Foundation's Collaborative Crop Research Program. Its heavy reliance on individual recollections may detract from its precision, but such reflections bring to life the program's three decades of commitment, collaboration, and adaptation in an effort to contribute to a world where all have access to nutritious food that is sustainably produced by local people. While not an evaluative document, key moments of influence and impacts are noted along the way
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