212 research outputs found

    Towards Energy Consumption Verification via Static Analysis

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    In this paper we leverage an existing general framework for resource usage verification and specialize it for verifying energy consumption specifications of embedded programs. Such specifications can include both lower and upper bounds on energy usage, and they can express intervals within which energy usage is to be certified to be within such bounds. The bounds of the intervals can be given in general as functions on input data sizes. Our verification system can prove whether such energy usage specifications are met or not. It can also infer the particular conditions under which the specifications hold. To this end, these conditions are also expressed as intervals of functions of input data sizes, such that a given specification can be proved for some intervals but disproved for others. The specifications themselves can also include preconditions expressing intervals for input data sizes. We report on a prototype implementation of our approach within the CiaoPP system for the XC language and XS1-L architecture, and illustrate with an example how embedded software developers can use this tool, and in particular for determining values for program parameters that ensure meeting a given energy budget while minimizing the loss in quality of service.Comment: Presented at HIP3ES, 2015 (arXiv: 1501.03064

    FastGAE: Scalable Graph Autoencoders with Stochastic Subgraph Decoding

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    Graph autoencoders (AE) and variational autoencoders (VAE) are powerful node embedding methods, but suffer from scalability issues. In this paper, we introduce FastGAE, a general framework to scale graph AE and VAE to large graphs with millions of nodes and edges. Our strategy, based on stochastic subgraph decoding, significantly speeds up the training of graph AE and VAE while preserving or even improving performances. We demonstrate the effectiveness of FastGAE on various real-world graphs, outperforming the few existing approaches to scale graph AE and VAE by a wide margin

    Recurrent boosting effects of short inactivity delays on performance: an ERPs study

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    <p>Abstract</p> <p>Background</p> <p>Recent studies investigating off-line processes of consolidation in motor learning have demonstrated a sudden, short-lived improvement in performance after 5–30 minutes of post-training inactivity. Here, we investigated further this behavioral boost in the context of the probabilistic serial reaction time task, a paradigm of implicit sequence learning. We looked both at the electrophysiological correlates of the boost effect and whether this phenomenon occurs at the initial training session only.</p> <p>Findings</p> <p>Reaction times consistently improved after a 30-minute break within two sessions spaced four days apart, revealing the reproducibility of the boost effect. Importantly, this improvement was unrelated to the acquisition of the sequential regularities in the material. At both sessions, event-related potentials (ERPs) analyses disclosed a boost-associated increased amplitude of a first negative component, and shorter latencies for a second positive component.</p> <p>Conclusion</p> <p>Behavioral and ERP data suggest increased processing fluency after short delays, which may support transitory improvements in attentional and/or motor performance and participate in the final setting up of the neural networks involved in the acquisition of novel skills.</p

    Safety evaluation of steviol glycoside preparations, including rebaudioside AM, obtained by enzymatic bioconversion of highly purified stevioside and/or rebaudioside A stevia leaf extracts

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    [EN] The EFSA Panel on Food Additives and Flavourings (FAF) provides a scientific opinion on the safety of steviol glycoside preparations, including rebaudioside AM, obtained by enzymatic bioconversion of highly purified stevioside and/or rebaudioside A stevia leaf extracts. These steviol glycoside preparations are produced via enzymatic bioconversion of highly purified stevioside and/or rebaudioside A extracts obtained from stevia plant using two UDP-glucosyltransferases and one sucrose synthase enzymes produced by the genetically modified strains of E. coli K-12 that facilitate the transfer of glucose to purified stevia leaf extracts via glycosidic bonds. The Panel considered that the parental strain is a derivative of E. coli K-12 which is well characterised and its safety has been documented; therefore, it is considered to be safe for production purposes. The Panel concluded that there is no safety concern for steviol glycoside preparations, including rebaudioside AM, obtained by enzymatic bioconversion of highly purified stevioside and/or rebaudioside A stevia leaf extracts using UDP-glucosyltransferases and sucrose synthase enzymes produced by the genetically modified strains of E. coli K-12, to be used as a food additive. The Panel recommends the European Commission to consider the proposal of establishing separate specifications for steviol glycoside preparations, including rebaudioside AM, obtained by enzymatic bioconversion of highly purified stevioside and/or rebaudioside A stevia leaf extracts in Commission Regulation (EU) No 231/2012. (C) 2021 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.Younes, M.; Aquilina, G.; Castle, L.; Engel, K.; Fowler, P.; Frutos Fernandez, MJ.; Furst, P.... (2021). Safety evaluation of steviol glycoside preparations, including rebaudioside AM, obtained by enzymatic bioconversion of highly purified stevioside and/or rebaudioside A stevia leaf extracts. EFSA Journal. 19(8):1-22. https://doi.org/10.2903/j.efsa.2021.669112219

    Safety evaluation of crosslinked polyacrylic acid polymers (carbomer) as a new food additive

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    [EN] The EFSA Panel on Food Additives and Flavourings (FAF) provides a scientific opinion on the safety of crosslinked polyacrylic acid polymers (carbomer) proposed for use as food additive in solid and liquid food supplements. Carbomer is formed from the monomer, acrylic acid, which is polymerised and crosslinked with allyl pentaerythritol (APE). The polymers are synthesised in ethyl acetate using as free-radical polymerisation initiator. In vivo data showed no evidence for systemic availability or biotransformation of carbomer. Carbomer does not raise a concern regarding genotoxicity. Considering the available data set, the Panel derived an acceptable daily intake (ADI) of 190 mg/kg body weight (bw) per day based on a no observed adverse effect level (NOAEL) of 1,500 mg/kg bw per day from a sub-chronic 13-week study in rat, applying a compound specific uncertainty factor (UF) of 8. At the proposed maximum use levels, the exposure estimates ranged at the mean from 1.1 to 90.2 mg/kg bw per day and at the p95 from 12.5 to 237.4 mg/kg bw per day. At the proposed typical use level, the exposure estimates ranged at the mean from 0.7 to 60.2 mg/kg bw per day and at the p95 from 10.3 to 159.5 mg/kg bw per day. The Panel noted that the maximum proposed use levels would result in exposure estimates close to or above the ADI. The Panel also noted that level of exposure to carbomer from its proposed use is likely to be an overestimation. Taking a conservative approach, the Panel considered that exposure to carbomer would not give rise to a safety concern if the proposed maximum use level for solid food supplements is lowered to the typical use level reported by the applicant. (C) 2021 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.Younes, M.; Aquilina, G.; Engel, K.; Fowler, P.; Frutos Fernandez, MJ.; Furst, P.; Gürtler, R.... (2021). Safety evaluation of crosslinked polyacrylic acid polymers (carbomer) as a new food additive. EFSA Journal. 19(8):1-26. https://doi.org/10.2903/j.efsa.2021.669312619

    Safety evaluation of buffered vinegar as a food additive

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    [EN] The EFSA Panel on Food Additives and Flavourings (FAF) provides a scientific opinion on the safety of buffered vinegar as a new food additive. Buffered vinegar is a liquid or dried product prepared by adding sodium/potassium hydroxides (E 524 to E 525) and sodium/potassium carbonates (E 500 to E 501) to vinegar, compliant with European Standard EN 13188:2000 and exclusively obtained from an agricultural source origin (except wood/cellulose). The primary constituents of buffered vinegar are acetic acid and its salts. No biological or toxicological data obtained with the proposed food additive were submitted by the applicant as part of the dossier as, following oral ingestion, buffered vinegar dissociates into the acetic anion and acetate a natural constituent of the diet, and of the human body for which extensive data on their biological effects exist and for which EFSA in 2013 has previously concluded that the establishment of an acceptable daily intake (ADI) is not considered necessary. At the proposed maximum/typical use levels, the mean exposure to buffered vinegar from its use as a food additive expressed as acetic acid equivalents ranged from 8.9 mg/kg body weight (bw) per day in infants to 280.3 mg/kg bw per day in children. The 95th percentile of exposure to buffered vinegar ranged from 27.9 mg/kg bw per day in infants to 1,078 mg/kg bw per day in toddlers. The Panel concluded that there is no safety concern for the use of buffered vinegar as a food additive at the proposed maximum/typical use levels. The Panel could not conclude on the safety for the proposed uses at quantum satis as Group I food additive since the resulting exposure could not be estimated.The Panel wishes to thank the following for the support provided to this scientific output: Alkiviadis Stagkos-Georgiadis.Younes, M.; Aquilina, G.; Degen, G.; Engel, K.; Fowler, P.; Frutos Fernandez, MJ.; Fürst, P.... (2022). Safety evaluation of buffered vinegar as a food additive. EFSA Journal. 20(7):1-21. https://doi.org/10.2903/j.efsa.2022.735112120

    Safety of the proposed amendment of the specifications for enzymatically produced steviol glycosides (E 960c): Rebaudioside D produced via enzymatic bioconversion of purified stevia leaf extract

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    [EN] The EFSA Panel on Food Additives and Flavourings (FAF Panel) provides a scientific opinion on the safety of a proposed amendment of the specifications of enzymatically produced steviol glycosides (E 960c) with respect to the inclusion of rebaudioside D produced via enzyme-catalysed bioconversion of purified stevia leaf extract. Rebaudioside D (95% on dry basis) is produced via enzymatic bioconversion of purified stevia leaf extract using uridine diphosphate (UDP)-glucosyltransferase (UGT) and sucrose synthase enzymes produced by the genetically modified yeast K. phaffii UGT-A, that facilitates the transfer of glucose to purified stevia leaf extract via glycosidic bonds. The same enzymes from K. phaffii UGT-A may be used in the manufacturing process of the food additive, rebaudioside M produced via enzyme modification of steviol glycosides from stevia (E 960c(i)). The Panel considered that separate specifications would be needed for this food additive produced via the manufacturing process described in the current application, aligned with those already established for E 960c(i). The Panel concluded that there is no toxicological concern for Rebaudioside D produced via enzymatic bioconversion of purified stevia leaf extract using UDP-glucosyltransferase and sucrose synthase produced by a genetically modified strain of the yeast K. phaffii. However, based on the available data, the Panel could not exclude the possibility that some residual amount of DNA coding for the kanamycin resistance gene could remain in the final product. Should this gene propagate in microbiota due to the presence of recombinant DNA in the final product, this would be of concern. Therefore, the Panel concluded that the safety of Rebaudioside D produced via this enzymatic bioconversion was not sufficiently demonstrated with the available data given that the absence of recombinant DNA was not shown.Younes, M.; Aquilina, G.; Engel, K.; Fowler, P.; Frutos Fernandez, MJ.; Fürst, P.; Gürtler, R.... (2022). Safety of the proposed amendment of the specifications for enzymatically produced steviol glycosides (E 960c): Rebaudioside D produced via enzymatic bioconversion of purified stevia leaf extract. EFSA Journal. 20(5):1-23. https://doi.org/10.2903/j.efsa.2022.729112320

    Safety evaluation of long-chain glycolipids from Dacryopinax spathularia

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    [EN] The EFSA Panel on Food Additives and Flavourings (FAF) provides a scientific opinion on the safety of long-chain glycolipids from Dacryopinax spathularia (also called AM-1) as a food additive. AM-1 is a purified mixture of long-chain glycolipid congeners obtained by fermentation of the edible non-genetically modified fungus Dacryopinax spathularia. AM-1 glycolipids have very low oral bioavailability and overall available toxicology data do not demonstrate any adverse effects of the proposed food additive. Considering the available data set the Panel established an ADI of 10 mg/kg bw per day based on a range of NOAELs between 1,000 and 1,423 mg/kg bw per day (the highest doses tested), from the reproductive and a prenatal developmental toxicity studies in rats and 90-day studies in rat and dog. At the proposed maximum use levels, the exposure estimates ranged at the mean from 0.01 to 1.07 mg/kg bw per day and at the p95 from 0 to 3.1 mg/kg mg/kg bw per day. At the proposed typical use levels, the exposure estimates ranged at the mean from < 0.01 mg/kg bw per day to 0.23 mg/kg bw per day and at the p95 from 0 to 0.64 mg/kg bw per day. The Panel noted that the highest estimate of exposure of 3.1 mg/kg bw per day (in toddlers) is within the established ADI of 10 mg/kg bw per day and concluded that the exposure to long-chain glycolipids from Dacryopinax spathularia does not raise a safety concern at the uses and use levels proposed by the applicant.Younes, M.; Aquilina, G.; Engel, K.; Fowler, P.; Frutos Fernandez, MJ.; Furst, P.; Gurtler, R.... (2021). Safety evaluation of long-chain glycolipids from Dacryopinax spathularia. EFSA Journal. 19(6):1-28. https://doi.org/10.2903/j.efsa.2021.660912819

    Genetic deficiency of indoleamine 2,3-dioxygenase promotes gut microbiota-mediated metabolic health.

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    The association between altered gut microbiota, intestinal permeability, inflammation and cardiometabolic diseases is becoming increasingly clear but remains poorly understood1,2. Indoleamine 2,3-dioxygenase is an enzyme induced in many types of immune cells, including macrophages in response to inflammatory stimuli, and catalyzes the degradation of tryptophan along the kynurenine pathway. Indoleamine 2,3-dioxygenase activity is better known for its suppression of effector T cell immunity and its activation of regulatory T cells3,4. However, high indoleamine 2,3-dioxygenase activity predicts worse cardiovascular outcome5-9 and may promote atherosclerosis and vascular inflammation6, suggesting a more complex role in chronic inflammatory settings. Indoleamine 2,3-dioxygenase activity is also increased in obesity10-13, yet its role in metabolic disease is still unexplored. Here, we show that obesity is associated with an increase of intestinal indoleamine 2,3-dioxygenase activity, which shifts tryptophan metabolism from indole derivative and interleukin-22 production toward kynurenine production. Indoleamine 2,3-dioxygenase deletion or inhibition improves insulin sensitivity, preserves the gut mucosal barrier, decreases endotoxemia and chronic inflammation, and regulates lipid metabolism in liver and adipose tissues. These beneficial effects are due to rewiring of tryptophan metabolism toward a microbiota-dependent production of interleukin-22 and are abrogated after treatment with a neutralizing anti-interleukin-22 antibody. In summary, we identify an unexpected function of indoleamine 2,3-dioxygenase in the fine tuning of intestinal tryptophan metabolism with major consequences on microbiota-dependent control of metabolic disease, which suggests indoleamine 2,3-dioxygenase as a potential therapeutic target

    Safety evaluation of buffered vinegar as a food additive

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    The EFSA Panel on Food Additives and Flavourings (FAF) provides a scientific opinion on the safety of buffered vinegar as a new food additive. Buffered vinegar is a liquid or dried product prepared by adding sodium/potassium hydroxides (E 524 to E 525) and sodium/potassium carbonates (E 500 to E 501) to vinegar, compliant with European Standard EN 13188:2000 and exclusively obtained from an agricultural source origin (except wood/cellulose). The primary constituents of buffered vinegar are acetic acid and its salts. No biological or toxicological data obtained with the proposed food additive were submitted by the applicant as part of the dossier as, following oral ingestion, buffered vinegar dissociates into the acetic anion and acetate a natural constituent of the diet, and of the human body for which extensive data on their biological effects exist and for which EFSA in 2013 has previously concluded that the establishment of an acceptable daily intake (ADI) is not considered necessary. At the proposed maximum/typical use levels, the mean exposure to buffered vinegar from its use as a food additive expressed as acetic acid equivalents ranged from 8.9 mg/kg body weight (bw) per day in infants to 280.3 mg/kg bw per day in children. The 95th percentile of exposure to buffered vinegar ranged from 27.9 mg/kg bw per day in infants to 1,078 mg/kg bw per day in toddlers. The Panel concluded that there is no safety concern for the use of buffered vinegar as a food additive at the proposed maximum/typical use levels. The Panel could not conclude on the safety for the proposed uses at quantum satis as Group I food additive since the resulting exposure could not be estimated
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