80 research outputs found

    Reusable and Extensible Fault Tolerance for RESTful Applications

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    Abstract—Despite the simplicity and scalability benefits of REST, rendering RESTful web applications fault-tolerant requires that the programmer write vast amounts of non-trivial, ad-hoc code. Network volatility, HTTP server errors, service outages—all require custom fault handling code, whose effective implementation requires considerable programming expertise and effort. To provide a systematic and principled ap-proach to handling faults in RESTful applications, we present FT-REST—an architectural framework for specifying fault tolerance functionality declaratively and then translating these specifications into platform-specific code. FT-REST encapsu-lates fault tolerance strategies in XML-based specifications and compiles them to modules that reify the requisite fault tolerance. To validate our approach, we have applied FT-REST to enhance several realistic RESTful applications to withstand the faults described in their FT-REST specifications. As REST is said to apply verbs (HTTP commands) to nouns (URIs), FT-REST enhances this conceptual model with adverbs that render REST reliable via reusable and extensible fault tolerance. Keywords-fault tolerance, web services, REST, software reusability, software extensibilit

    Microsprinklers wet larger soil volume; boost almond yield, tree growth

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    In the Arbuckle area of the Sacramento Valley, a 22-acre orchard was planted in 1990 with four almond varieties (‘Nonpareil’, ‘Butte’, ‘Carmel’ and ‘Monterey’). The orchard was irrigated with three types of microirrigation — surface drip, subsurface drip and microsprinklers. The orchard soils are 3 to 4 feet of gravelly, loamy sand overlaying a restricting clay layer. The coarse-textured soil with its low water-holding capacity allows little lateral movement of water from the microirrigation emission device. Under these soil conditions, microsprinkler-irrigated trees produced larger almond yields and showed greater tree growth. In addition, irrigation system evaluations show that all three microirrigation systems provide excellent irrigation uniformity levels after 8 years of operation with only routine maintenance

    A Microrobotic System For Protein Streak Seeding

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    We present a microrobotic system for protein crystal micromanipulation tasks. The focus in this report is on a task called streak seeding, which is used by crystallographers to entice certain protein crystals to grow. Our system features a set of custom designed micropositioner end-effectors we call microshovels to replace traditional tools used by crystallographers for this task. We have used micro-electrical mechanical system (MEMS) techniques to design and manufacture various shapes and quantities of microshovels. Visual feedback from a camera mounted on the microscope is used to control the micropositioner as it lowers a microshovel into the liquid containing the crystals for poking and streaking. We present experimental results that illustrate the applicability of our approach

    Automated streak-seeding with micromachined silicon tools

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    Captured by Evil: The Idea of Corruption in Law

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    Corruption is one of the most powerful words in the English language. When it comes to the treatment of corruption by law, however, corruption is a troubled concept. With increasing recognition of the costs of corruption for economic development, democratic governance, international aid programs, and other world goals, attempts to articulate what this destructive force is have led to an avalanche of theoretical writing. In the last fifteen years, corruption has been variously defined as the violation of law, a public servant\u27s breach of public duty, an agent\u27s betrayal of a principal\u27s interests, the pursuit of secrecy, the denial of equality in political influence, and other ways. In the end, however, all of these efforts fall short. Corruption is more than law-breaking: it is more than breaching public duties. To say that A is a thief or that A has breached his duty is not to say that A is corrupt. The latter is far more powerful, far more emotional, far more essential than the others. It is more than secrecy, or the denial of equal opportunity. It is a searing indictment, somehow, not only of A\u27s act but of A\u27s character. It is a statement not only of what A has done, but of what A has become. Corruption is, I argue, a far more powerful idea than these existing legal understandings have articulated: it is the idea of capture by evil, the possession of the individual by evil, in law. Just as we once believed in corruption of the blood in American law, which decreed that offspring of those who had committed crimes were believed to be irrevocably tainted by their parents\u27 depravity, so we still retain - through the idea of corruption - the belief that individual evil extends beyond acts of wrongdoing, or the denial of equal opportunity, or breach of the public trust. It is this idea of corruption, I argue - the idea of capture by evil - that, although unarticulated, drives our understandings of corruption in law. It drives our understanding of corrupt judges, who, once corrupt, we believe will act so in every case. It drives our understanding of campaign finance reform, where we fear deep corruption of the process from the occurrence of corrupt acts. It drives our understanding of corruption as a systemic effect and systemic influence, which presents institutional dangers that are greater than other crimes, and that requires purgation rather than simple law enforcement. This Article explores this deeper understanding of corruption, its impacts in areas such as judicial corruption and campaign finance reform, and its implications for the principle of the rule of law

    Proteomic DIGE analysis of the mitochondria-enriched fraction from aged rat skeletal muscle

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    Skeletal muscle aging is associated with a loss in tissue mass and contractile strength, as well as fiber type shifting and bioenergetic adaptation processes. Since mitochondria represent the primary site for energy generation via oxidative phosphorylation, we investigated potential changes in the expression pattern of the mitochondrial proteome using the highly sensitive DIGE approach. The comparative analysis of the mitochondria-enriched fraction from young adult versus aged muscle revealed an age-related change in abundance for 39 protein species. MS technology identified the majority of altered proteins as constituents of muscle mitochondria. An age-dependent increase was observed for NADH dehydrogenase, the mitochondrial inner membrane protein mitofilin, peroxiredoxin isoform PRX-III, ATPase synthase, succinate dehydrogenase, mitochondrial fission protein Fis1, succinate-coenzyme A ligase, acyl-coenzyme A dehydrogenase, porin isoform VDAC2, ubiquinol-cytochrome c reductase core I protein and prohibitin. Immunoblotting, enzyme testing and confocal microscopy were used to validate proteomic findings. The DIGE-identified increase in key mitochondrial elements during aging agrees with the concept that sarcopenia is associated with a shift to a slower contractile phenotype and more pronounced aerobic-oxidative metabolism. This suggests that mitochondrial markers are reliable candidates that should be included in the future establishment of a biomarker signature of skeletal muscle aging
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