2,303 research outputs found

    Weightless: Lossy Weight Encoding For Deep Neural Network Compression

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    The large memory requirements of deep neural networks limit their deployment and adoption on many devices. Model compression methods effectively reduce the memory requirements of these models, usually through applying transformations such as weight pruning or quantization. In this paper, we present a novel scheme for lossy weight encoding which complements conventional compression techniques. The encoding is based on the Bloomier filter, a probabilistic data structure that can save space at the cost of introducing random errors. Leveraging the ability of neural networks to tolerate these imperfections and by re-training around the errors, the proposed technique, Weightless, can compress DNN weights by up to 496x with the same model accuracy. This results in up to a 1.51x improvement over the state-of-the-art

    Drosophila, metabolomics and insecticide action

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    The growing problem of insecticide resistance is jeopardising current pest control strategies and current insecticide development pipelines are failing to provide new alternatives quickly enough. Metabolomics offers a potential solution to the bottleneck in insecticide target discovery. As a proof of concept, metabolomics data for permethrin exposed Drosophila melanogaster was analysed and interpreted. Changes in the metabolism of amino acids, glycogen, glycolysis, energy, nitrogen, NAD+, purine, pyrimidine, lipids and carnitine were observed along with markers for acidosis, ammonia stress, oxidative stress and detoxification responses. Many of the changed metabolites and pathways had never been linked to permethrin exposure before. A model for the interaction of the observed changes in metabolites was proposed. From the metabolic pathways with the largest changes, candidate genes from tryptophan catabolism were selected to determine if the perturbed pathways had an effect on survival when exposed to permethrin. Using QPCR it was found that all genes in the entire pathway were downregulated by permethrin exposure with the exception of vermilion suggesting an active response to try and limit flux through tryptophan catabolism during permethrin exposure. Knockdown of the tryptophan catabolising genes vermilion, cinnabar and CG6950 in Drosophila using whole fly RNAi resulted in changes in susceptibility to permethrin for both topical and oral routes of exposure. Knockdown of the candidate genes also caused changes in susceptibility when the insecticides fenvalerate, DDT, chlorpyriphos and hydramethylnon were orally administered. These results show that tryptophan catabolism knockdown has an effect on surviving insecticides with a broad range in mode of action. Symptoms that occur in Drosophila during exposure to the different insecticides were also noted. To gain further understanding into the mechanisms affecting survival, tissue specific knockdown was performed revealing tissue and gender specific changes in survival when vermilion, cinnabar and CG6950 are knocked down. Metabolomics was performed on the knockdown strains to determine the efficacy of the knockdowns on tryptophan catabolism and to identify any knock-on effects. The results indicate that tryptophan metabolite induced perturbations to energy metabolism and glycosylation also occur in Drosophila along with apparent changes in the absorption of ectometabolites. As the knockdown of vermilion, cinnabar and CG6950 tended to result in reduced susceptibility to insecticides, they would make poor targets for insecticidal compounds, however, they may be the first examples of genes that are not directly involved in insecticide metabolism or cuticle synthesis that increase insecticide tolerance in Drosophila. As the first metabolomics data set showed evidence for oxidative stress during permethrin exposure, preliminary work was begun for identifying the tissue specificity and timing of oxidative stress in both Dipterans and Lepidopterans using Drosophila and Bombyx mori as models. In Drosophila oxidative stress did not begin immediately suggesting that the insecticide itself is not a cause, however, a rapid increase in oxidative stress occured over a six hour period after a day of oral exposure implicating catabolites of permethrin. Bombyx were highly susceptible to permethrin showing oxidative stress in the Malpighian tubule and silk gland when exposed. This study has shown that metabolomics is highly effective at identifying pathways which modulate survival to insecticide exposure. It has also brought insight into how insecticide induced pathology may cause death. Data has also been generated which could help characterize the putative transaminase CG6950

    Ultraviolet Imaging of the Globular Cluster 47 Tucanae

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    We have used the Ultraviolet Imaging Telescope to obtain deep far-UV (1620 Angstrom), 40' diameter images of the prototypical metal-rich globular cluster 47 Tucanae. We find a population of about 20 hot (Teff > 9000 K) objects near or above the predicted UV luminosity of the hot horizontal branch (HB) and lying within two half-light radii of the cluster center. We believe these are normal hot HB or post-HB objects rather than interacting binaries or blue stragglers. IUE spectra of two are consistent with post-HB phases. These observations, and recent HST photometry of two other metal-rich clusters, demonstrate that populations with rich, cool HB's can nonetheless produce hot HB and post-HB stars. The cluster center also contains an unusual diffuse far-UV source which is more extended than its V-band light. It is possible that this is associated with an intracluster medium, for which there was earlier infrared and X-ray evidence, and is produced by C IV emission or scattered light from grains.Comment: 13 pages AASLaTeX including one postscript figure and one bitmapped image, JPEG format. Submitted to the Astronomical Jorunal. Full Postscript version available at http://www.astro.virginia.edu/~bd4r

    Application of the LOICZ Methodology to the Mediterranean Sea

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    From a broad perspective, the LOICZ (Land-Ocean Interactions in the Coastal Zone) approach attempts to evaluate coastal change from a system perspective and assumes that the effects taking place are due to pressures within the whole basin. The LOICZ methodology was applied to the Mediterranean Sea in order to estimate its water, salt and nutrient budget, as well as to gain insights into its biogeochemical cycles. In order to undertake this budget approach, various input data relative to the three budgets were gathered for the time period of 1996 to 2005. In the case of the Mediterranean Sea, it was seen that there is still a gap between LOICZ data requirements and the standard monitoring practices in the coastal zone, both from a spatial as well as temporal viewpoint. The results show that on average over the time period 1996 to 2005, the phosphorous and nitrogen budgets of 1.35·10-2 mmol m-2 d-1 and 3.22·10-1 mmol m-2 d-1, respectively, suggest an excess of release over uptake. The budget calculations translate to the fact that on average the Mediterranean Sea acts as a sink of phosphorous and nitrogen. No specific, statistically relevant trend of the water quality and ecosystem functioning of the Mediterranean Sea was observed. An examination of the stoichiometric linkage of C, N and P through the Redfield ratio indicates that nitrogen fixation and production of dissolved inorganic carbon dominate over denitrification and consumption of dissolved inorganic carbon via net organic production.JRC.H.5-Rural, water and ecosystem resource

    CHORUS Deliverable 3.3: Vision Document - Intermediate version

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    The goal of the CHORUS vision document is to create a high level vision on audio-visual search engines in order to give guidance to the future R&D work in this area (in line with the mandate of CHORUS as a Coordination Action). This current intermediate draft of the CHORUS vision document (D3.3) is based on the previous CHORUS vision documents D3.1 to D3.2 and on the results of the six CHORUS Think-Tank meetings held in March, September and November 2007 as well as in April, July and October 2008, and on the feedback from other CHORUS events. The outcome of the six Think-Thank meetings will not just be to the benefit of the participants which are stakeholders and experts from academia and industry – CHORUS, as a coordination action of the EC, will feed back the findings (see Summary) to the projects under its purview and, via its website, to the whole community working in the domain of AV content search. A few subjections of this deliverable are to be completed after the eights (and presumably last) Think-Tank meeting in spring 2009

    Feasibility Study of the Application of the LOICZ Budget to the Mediterranean Sea

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    The Mediterranean Sea is an important regional EU sea and often used to assess the impacts of global change on the environment, due to its practically enclosed character. As most of the northern part is bordered by the EU, it is also of interest in the evaluation of the environmental and economic impact of the implementation of the EU Water Framework Directive and related environmental legislation. For this purpose, the feasibility to carry out a budget approach, developed in LOICZ (Land Ocean Interactions in the Coastal Zone) project has been analyzed. The activities carried out allow to conclude that all budget components can be reliably estimated and such budget correctly set up. In particular: - estimates for precipitation and evaporation of the Mediterranean Sea can be obtained from ECMWF; other sources for estimates of such variables are available, and in a further implementation of this work a comparison between estimate sets will be carried out; - estimates of annual flow and nutrient output to the Mediterranean Sea as required by the LOICZ budget can be obtained via the setting up of the AVGWLF model, with reasonable operating expense (time and effort) and with acceptable assumptions made for information/data not available for some or all of the regions, especially in the Asian and North African part of the Mediterranean; - exchanges through the Gibraltar and Dardanelles Straits can also be reliably estimated, based on previous studies. It is recognized that the estimates of all budget components, as illustrated in the paragraphs above, can be improved. It is foreseen that some of these improvements will be obtained already in the actual implementation of the LOICZ budget.JRC.H.5-Rural, water and ecosystem resource

    Evaluation of Oxalate Content of Some Indigenous and Produced Spices and Seasonings in Ghana

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    In this paper, six indigenous (LS) and fifteen industry produced spices and seasonings (IPS)  available to consumer have been examined for its oxalate content using Ultra Violet –Visible spectroscopy with a view to provide useful information towards their effective use. The oxalate content of the LS was found to be between 0.74±0.04 –4.99±0.26 mg/g whereas that of the IPS was between 0.05±0.0-7.5±0.0 mg/g. Although the LS recorded a higher average oxalate content than the IPS, the difference was not statistically significant (p<0.05). Among the IPS samples curry based spices had higher oxalate content. Keywords: anti-nutritional factors, oxalate, seasonings, spices, Ghan

    Hepcidin Is an Antibacterial, Stress-Inducible Peptide of the Biliary System

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    BACKGROUND/AIMS: Hepcidin (gene name HAMP), an IL-6-inducible acute phase peptide with antimicrobial properties, is the key negative regulator of iron metabolism. Liver is the primary source of HAMP synthesis, but it is also produced by other tissues such as kidney or heart and is found in body fluids such as urine or cerebrospinal fluid. While the role of hepcidin in biliary system is unknown, a recent study demonstrated that conditional gp130-knockout mice display diminished hepcidin levels and increased rate of biliary infections. METHODS: Expression and localization of HAMP in biliary system was analyzed by real time RT-PCR, in-situ hybridization, immunostaining and -blotting, while prohepcidin levels in human bile were determined by ELISA. RESULTS: Hepcidin was detected in mouse/human gallbladder and bile duct epithelia. Biliary HAMP is stress-inducible, in that it is increased in biliary cell lines upon IL-6 stimulation and in gallbladder mucosa of patients with acute cholecystitis. Hepcidin is also present in the bile and elevated prohepcidin levels were observed in bile of primary sclerosing cholangitis (PSC) patients with concurrent bacterial cholangitis compared to PSC subjects without bacterial infection (median values 22.3 vs. 8.9; p = 0.03). In PSC-cholangitis subjects, bile prohepcidin levels positively correlated with C-reactive protein and bilirubin levels (r = 0.48 and r = 0.71, respectively). In vitro, hepcidin enhanced the antimicrobial capacity of human bile (p<0.05). CONCLUSION: Hepcidin is a stress-inducible peptide of the biliary epithelia and a potential marker of biliary stress. In the bile, hepcidin may serve local functions such as protection from bacterial infections
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