4,356 research outputs found

    Toward an Energy Efficient Language and Compiler for (Partially) Reversible Algorithms

    Full text link
    We introduce a new programming language for expressing reversibility, Energy-Efficient Language (Eel), geared toward algorithm design and implementation. Eel is the first language to take advantage of a partially reversible computation model, where programs can be composed of both reversible and irreversible operations. In this model, irreversible operations cost energy for every bit of information created or destroyed. To handle programs of varying degrees of reversibility, Eel supports a log stack to automatically trade energy costs for space costs, and introduces many powerful control logic operators including protected conditional, general conditional, protected loops, and general loops. In this paper, we present the design and compiler for the three language levels of Eel along with an interpreter to simulate and annotate incurred energy costs of a program.Comment: 17 pages, 0 additional figures, pre-print to be published in The 8th Conference on Reversible Computing (RC2016

    Thermal tolerance of allis shad (Alosa alosa) embryos and larvae: Modeling and potential applications

    Get PDF
    International audienceThe objective of this study was to assess the potential effects of climate change on the survival of allis shad early life history stages. Embryos and larvae were exposed to temperatures ranging from 5 to 35 °C. No embryonic survival was recorded at extreme temperatures (≤10 and ≥30 °C), and no larval survival was observed at 5 or 35 °C. Based on these experimental results, a survival model was developed to predict survival rates at different temperatures for embryos and larvae up to 14 days post hatch. The model confirmed that embryonic daily survival is more impacted by temperature than larval survival. The highest survival rates (greater than 80%) were found for temperatures between 15.7 and 25.6 °C for embryos and between 14.6 and 26.7 °C for larvae. This survival model can be used to explore the impact of temperature on recruitment of allis shad in southern France. Preliminary analysis from two different rivers suggests that cold temperatures may have a strong impact on embryonic and larval survival

    Disruption of the prostaglandin metabolome and characterization of the pharmaceutical exposome in fish exposed to wastewater treatment works effluent as revealed by nanoflow-nanospray mass spectrometry-based metabolomics

    Get PDF
    Fish can be exposed to a complex mixture of chemical contaminants, including pharmaceuticals, present in discharges of wastewater treatment works (WwTWs) effluents. There is little information on the effects of effluent exposure on fish metabolism, especially the small molecule signaling compounds which are the biological target of many pharmaceuticals. We applied a newly developed sensitive nanoflow-nanospray mass spectrometry nontargeted profiling technique to identify changes in the exposome and metabolome of roach (Rutilus rutilus) exposed to a final WwTWs effluent for 15 days. Effluent exposure resulted in widespread reduction (between 50% and 90%) in prostaglandin (PG) profiles in fish tissues and plasma with disruptions also in tryptophan/serotonin, bile acid and lipid metabolism. Metabolite disruptions were not explained by altered expression of genes associated with the PG or tryptophan metabolism. Of the 31 pharmaceutical metabolites that were detected in the effluent exposome of fish, 6 were nonsteroidal anti-inflammatory drugs but with plasma concentrations too low to disrupt PG biosynthesis. PGs, bile acids, and tryptophan metabolites are important mediators regulating a diverse array of physiological systems in fish and the identity of wastewater contaminants disrupting their metabolism warrants further investigation on their exposure effects on fish health

    Measuring Strategic Uncertainty in Coordination Games

    Get PDF
    Lecture on the first SFB/TR 15 meeting, Gummersbach, July, 18 - 20, 2004This paper explores predictability of behavior in coordination games with multiple equilibria. In a laboratory experiment we measure subjects' certainty equivalents for three coordination games and one lottery. Attitudes towards strategic uncertainty in coordination games are related to risk aversion, experience seeking, gender and age. From the distribution of certainty equivalents among participating students we estimate probabilities for successful coordination in a wide range of coordination games. For many games success of coordination is predictable with a reasonable error rate. The best response of a risk neutral player is close to the global-game solution. Comparing choices in coordination games with revealed risk aversion, we estimate subjective probabilities for successful coordination. In games with a low coordination requirement, most subjects underestimate the probability of success. In games with a high coordination requirement, most subjects overestimate this probability. Data indicate that subjects have probabilistic beliefs about success or failure of coordination rather than beliefs about individual behavior of other players

    Sexual reprogramming and estrogenic sensitization in wild fish exposed to ethinylestradiol.

    Get PDF
    addresses: School of Biosciences, University of Exeter, Exeter EX4 4PS, United Kingdom. [email protected]: Journal Article; Research Support, Non-U.S. Gov'tCopyright © 2009 American Chemical Society. Post print version of article deposited. The final published version is available from: http://dx.doi.org/10.1021/es802661pGlobally, feminization responses in wild male freshwater fish are caused by exposure to estrogenic chemicals, including natural and synthetic estrogens, contained in effluentsfromwastewater treatment works. In U.K. rivers, feminization responses, including intersex, are widespread in wild roach (Rutilus rutilus) populations, and severely affected fish have a reduced reproductive success. We exposed roach to environmentally relevant concentrations of the contraceptive estrogen 17alpha-ethinylestradiol (EE2) for up to 2 years, including intermittent and repeated exposures,to determine effects on sexual development and subsequent responsiveness to estrogen. Exposure of roach to EE2 (at 4 ng/L) for 2 years resulted in sex reversal in males, leading to an all-female population with two cohorts in terms of their stages of ovarian development one paralleling the control females and one at a significantly less advanced stage, which we propose were sex-reversed males. Differing developmental and maturing rates of the putative sex-reversed males compared with control females would question their functional capability as females in the wild. Early-life exposure to environmentally relevant concentrations of EE2 sensitized females to estrogen, as determined by the measurement of the responses of estrogen-sensitive genes in a further EE2 challenge 398 days after the original exposure. In the wild, exposure to environmentally relevant concentrations of EE2 during early life has significantly wider implications for the sexual physiology in fish than has thus far been determined

    High-sensitivity transition-edge-sensed bolometers: improved speed and characterization with AC and DC bias

    Full text link
    We report on efforts to improve the speed of low-G far-infrared transition-edged-sensed bolometers. We use a fabrication process that does not require any dry etch steps to reduce heat capacity on the suspended device and measure a reduction in the detector time constant. However, we also measure an increase in the temperature-normalized thermal conductance (G), and a corresponding increase in the noise-equivalent power (NEP). We employ a new near-IR photon-noise technique using a near-IR laser to calibrate the frequency-domain multiplexed AC system and compare the results to a well-understood DC circuit. We measure an NEP white noise level of 0.8 aW/rtHz with a 1/f knee below 0.1 Hz and a time constant of 3.2 ms.Comment: 27 pages, 16 figures. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in J. Appl. Phys. 134 (9) and may be found at https://doi.org/10.1063/5.015720

    The ESCAPE project : Energy-efficient Scalable Algorithms for Weather Prediction at Exascale

    Get PDF
    In the simulation of complex multi-scale flows arising in weather and climate modelling, one of the biggest challenges is to satisfy strict service requirements in terms of time to solution and to satisfy budgetary constraints in terms of energy to solution, without compromising the accuracy and stability of the application. These simulations require algorithms that minimise the energy footprint along with the time required to produce a solution, maintain the physically required level of accuracy, are numerically stable, and are resilient in case of hardware failure. The European Centre for Medium-Range Weather Forecasts (ECMWF) led the ESCAPE (Energy-efficient Scalable Algorithms for Weather Prediction at Exascale) project, funded by Horizon 2020 (H2020) under the FET-HPC (Future and Emerging Technologies in High Performance Computing) initiative. The goal of ESCAPE was to develop a sustainable strategy to evolve weather and climate prediction models to next-generation computing technologies. The project partners incorporate the expertise of leading European regional forecasting consortia, university research, experienced high-performance computing centres, and hardware vendors. This paper presents an overview of the ESCAPE strategy: (i) identify domain-specific key algorithmic motifs in weather prediction and climate models (which we term Weather & Climate Dwarfs), (ii) categorise them in terms of computational and communication patterns while (iii) adapting them to different hardware architectures with alternative programming models, (iv) analyse the challenges in optimising, and (v) find alternative algorithms for the same scheme. The participating weather prediction models are the following: IFS (Integrated Forecasting System); ALARO, a combination of AROME (Application de la Recherche a l'Operationnel a Meso-Echelle) and ALADIN (Aire Limitee Adaptation Dynamique Developpement International); and COSMO-EULAG, a combination of COSMO (Consortium for Small-scale Modeling) and EULAG (Eulerian and semi-Lagrangian fluid solver). For many of the weather and climate dwarfs ESCAPE provides prototype implementations on different hardware architectures (mainly Intel Skylake CPUs, NVIDIA GPUs, Intel Xeon Phi, Optalysys optical processor) with different programming models. The spectral transform dwarf represents a detailed example of the co-design cycle of an ESCAPE dwarf. The dwarf concept has proven to be extremely useful for the rapid prototyping of alternative algorithms and their interaction with hardware; e.g. the use of a domain-specific language (DSL). Manual adaptations have led to substantial accelerations of key algorithms in numerical weather prediction (NWP) but are not a general recipe for the performance portability of complex NWP models. Existing DSLs are found to require further evolution but are promising tools for achieving the latter. Measurements of energy and time to solution suggest that a future focus needs to be on exploiting the simultaneous use of all available resources in hybrid CPU-GPU arrangements

    Measurement of Charge Asymmetries in Charmless Hadronic in B Meson Decays

    Full text link
    We search for CP-violating asymmetries (Acp) in the B meson decays to K+- pi-+, K+- pi0, Ks pi+-, K+- eta', and omega pi+-. Using 9.66 million Upsilon(4S) decays collected with the CLEO detector, the statistical precision on Acp is in the range of \pm 0.12 to \pm 0.25 depending on decay mode. While CP-violating asymmetries of up to \pm 0.5 are possible within the Standard Model, the measured asymmetries are consistent with zero in all five decay modes studied.Comment: 10 pages, 3 figure
    • …
    corecore