1,637 research outputs found

    Decoding billions of integers per second through vectorization

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    In many important applications -- such as search engines and relational database systems -- data is stored in the form of arrays of integers. Encoding and, most importantly, decoding of these arrays consumes considerable CPU time. Therefore, substantial effort has been made to reduce costs associated with compression and decompression. In particular, researchers have exploited the superscalar nature of modern processors and SIMD instructions. Nevertheless, we introduce a novel vectorized scheme called SIMD-BP128 that improves over previously proposed vectorized approaches. It is nearly twice as fast as the previously fastest schemes on desktop processors (varint-G8IU and PFOR). At the same time, SIMD-BP128 saves up to 2 bits per integer. For even better compression, we propose another new vectorized scheme (SIMD-FastPFOR) that has a compression ratio within 10% of a state-of-the-art scheme (Simple-8b) while being two times faster during decoding.Comment: For software, see https://github.com/lemire/FastPFor, For data, see http://boytsov.info/datasets/clueweb09gap

    Signalling Responses Following Varying Sequencing of Strength and Endurance Training in a Fed State.

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    The objective of this study was to compare anabolic signalling responses to differing sequences of concurrent strength and endurance training in a fed state.Eighteen resistance-trained males were randomly assigned to the following experimental conditions; i) strength training (ST), ii) strength followed by endurance training (ST-END) or iii) endurance followed by strength training (END-ST). Muscle tissue samples were taken from the vastus lateralis before each exercise protocol, upon cessation of exercise, and 1 h-post cessation of strength training. Tissue was analysed for total and phosphorylated (p-) signalling proteins linked to the mTOR and AMPK networks.Strength training performance was similar between ST, ST-END and END-ST. p-S6k1 was elevated from baseline 1 h post training in ST and ST-END (both p < 0.05). p-4E-BP1 was significantly lower than baseline post ST (p = 0.01), while 1 h post exercise in the ST-END condition p-4E-BP1 was significantly greater than post exercise (p = 0.04). p-ACC was elevated from baseline both post and 1 h post exercise (both p < 0.05) in the END-ST condition. AMPK, mTOR, p38, PKB, eEF2 responded similarly to the ST, ST-END and END-ST. Signalling responses to ST, ST-END and END were largely similar. As such it cannot be ascertained which sequence of concurrent strength and endurance training is most favourable in promoting anabolic signalling.These data indicate that in the case of the present study an acute bout of concurrent training of differing sequences elicited similar responses of the AMPK and mTOR networks

    When the path is never shortest: a reality check on shortest path biocomputation

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    Shortest path problems are a touchstone for evaluating the computing performance and functional range of novel computing substrates. Much has been published in recent years regarding the use of biocomputers to solve minimal path problems such as route optimisation and labyrinth navigation, but their outputs are typically difficult to reproduce and somewhat abstract in nature, suggesting that both experimental design and analysis in the field require standardising. This chapter details laboratory experimental data which probe the path finding process in two single-celled protistic model organisms, Physarum polycephalum and Paramecium caudatum, comprising a shortest path problem and labyrinth navigation, respectively. The results presented illustrate several of the key difficulties that are encountered in categorising biological behaviours in the language of computing, including biological variability, non-halting operations and adverse reactions to experimental stimuli. It is concluded that neither organism examined are able to efficiently or reproducibly solve shortest path problems in the specific experimental conditions that were tested. Data presented are contextualised with biological theory and design principles for maximising the usefulness of experimental biocomputer prototypes.Comment: To appear in: Adamatzky, A (Ed.) Shortest path solvers. From software to wetware. Springer, 201

    Spectral Line-by-Line Pulse Shaping of an On-Chip Microresonator Frequency Comb

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    We report, for the first time to the best of our knowledge, spectral phase characterization and line-by-line pulse shaping of an optical frequency comb generated by nonlinear wave mixing in a microring resonator. Through programmable pulse shaping the comb is compressed into a train of near-transform-limited pulses of \approx 300 fs duration (intensity full width half maximum) at 595 GHz repetition rate. An additional, simple example of optical arbitrary waveform generation is presented. The ability to characterize and then stably compress the frequency comb provides new data on the stability of the spectral phase and suggests that random relative frequency shifts due to uncorrelated variations of frequency dependent phase are at or below the 100 microHertz level.Comment: 18 pages, 4 figure

    Efficacy and Safety of Umeclidinium/Vilanterol in Current and Former Smokers with COPD: A Prespecified Analysis of The EMAX Trial.

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    INTRODUCTION: Smoking may reduce the efficacy of inhaled corticosteroids (ICS) in patients with chronic obstructive pulmonary disease (COPD), but its impact on bronchodilator efficacy is unclear. This analysis of the EMAX trial explored efficacy and safety of dual- versus mono-bronchodilator therapy in current or former smokers with COPD. METHODS: The 24-week EMAX trial evaluated lung function, symptoms, health status, exacerbations, clinically important deterioration, and safety with umeclidinium/vilanterol, umeclidinium, and salmeterol in symptomatic patients at low exacerbation risk who were not receiving ICS. Current and former smoker subgroups were defined by smoking status at screening. RESULTS: The analysis included 1203 (50%) current smokers and 1221 (50%) former smokers. Both subgroups demonstrated greater improvements from baseline in trough FEV1 at week 24 (primary endpoint) with umeclidinium/vilanterol versus umeclidinium (least squares [LS] mean difference, mL [95% CI]; current: 84 [50, 117]; former: 49 [18, 80]) and salmeterol (current: 165 [132, 198]; former: 117 [86, 148]) and larger reductions in rescue medication inhalations/day over 24 weeks versus umeclidinium (LS mean difference [95% CI]; current: - 0.42 [- 0.63, - 0.20]; former: - 0.25 - 0.44, - 0.05]) and salmeterol (current: - 0.28 [- 0.49, - 0.06]; former: - 0.29 [- 0.49, - 0.09]). Umeclidinium/vilanterol increased the odds (odds ratio [95% CI]) of clinically significant improvement at week 24 in Transition Dyspnea Index versus umeclidinium (current: 1.54 [1.16, 2.06]; former: 1.32 [0.99, 1.75]) and salmeterol (current: 1.37 (1.03, 1.82]; former: 1.60 [1.20, 2.13]) and Evaluating Respiratory Symptoms-COPD versus umeclidinium (current: 1.54 [1.13, 2.09]; former: 1.50 [1.11, 2.04]) and salmeterol (current: 1.53 [1.13, 2.08]; former: 1.53 [1.12, 2.08]). All treatments were well tolerated in both subgroups. CONCLUSIONS: In current and former smokers, umeclidinium/vilanterol provided greater improvements in lung function and symptoms versus umeclidinium and salmeterol, supporting consideration of dual-bronchodilator therapy in symptomatic patients with COPD regardless of their smoking status

    Investigation of the Interaction between the Large and Small Subunits of Potato ADP-Glucose Pyrophosphorylase

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    ADP-glucose pyrophosphorylase (AGPase), a key allosteric enzyme involved in higher plant starch biosynthesis, is composed of pairs of large (LS) and small subunits (SS). Current evidence indicates that the two subunit types play distinct roles in enzyme function. Recently the heterotetrameric structure of potato AGPase has been modeled. In the current study, we have applied the molecular mechanics generalized born surface area (MM-GBSA) method and identified critical amino acids of the potato AGPase LS and SS subunits that interact with each other during the native heterotetrameric structure formation. We have further shown the role of the LS amino acids in subunit-subunit interaction by yeast two-hybrid, bacterial complementation assay and native gel. Comparison of the computational results with the experiments has indicated that the backbone energy contribution (rather than the side chain energies) of the interface residues is more important in identifying critical residues. We have found that lateral interaction of the LS-SS is much stronger than the longitudinal one, and it is mainly mediated by hydrophobic interactions. This study will not only enhance our understanding of the interaction between the SS and the LS of AGPase, but will also enable us to engineer proteins to obtain better assembled variants of AGPase which can be used for the improvement of plant yield

    Ovine pedomics : the first study of the ovine foot 16S rRNA-based microbiome

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    We report the first study of the bacterial microbiome of ovine interdigital skin based on 16S rRNA by pyrosequencing and conventional cloning with Sanger-sequencing. Three flocks were selected, one a flock with no signs of footrot or interdigital dermatitis, a second flock with interdigital dermatitis alone and a third flock with both interdigital dermatitis and footrot. The sheep were classified as having either healthy interdigital skin (H), interdigital dermatitis (ID) or virulent footrot (VFR). The ovine interdigital skin bacterial community varied significantly by flock and clinical condition. The diversity and richness of operational taxonomic units was greater in tissue from sheep with ID than H or VFR affected sheep. Actinobacteria, Bacteriodetes, Firmicutes and Proteobacteria were the most abundant phyla comprising 25 genera. Peptostreptococcus, Corynebacterium and Staphylococcus were associated with H, ID and VFR respectively. Sequences of Dichelobacter nodosus, the causal agent of ovine footrot, were not amplified due to mismatches in the 16S rRNA universal forward primer (27F). A specific real time PCR assay was used to demonstrate the presence of D. nodosus which was detected in all samples including the flock with no signs of ID or VFR. Sheep with ID had significantly higher numbers of D. nodosus (104-109 cells/g tissue) than those with H or VFR feet

    Computer Controlled Automated Assay for Comprehensive Studies of Enzyme Kinetic Parameters

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    Stability and biological activity of proteins is highly dependent on their physicochemical environment. The development of realistic models of biological systems necessitates quantitative information on the response to changes of external conditions like pH, salinity and concentrations of substrates and allosteric modulators. Changes in just a few variable parameters rapidly lead to large numbers of experimental conditions, which go beyond the experimental capacity of most research groups. We implemented a computer-aided experimenting framework (“robot lab assistant”) that allows us to parameterize abstract, human-readable descriptions of micro-plate based experiments with variable parameters and execute them on a conventional 8 channel liquid handling robot fitted with a sensitive plate reader. A set of newly developed R-packages translates the instructions into machine commands, executes them, collects the data and processes it without user-interaction. By combining script-driven experimental planning, execution and data-analysis, our system can react to experimental outcomes autonomously, allowing outcome-based iterative experimental strategies. The framework was applied in a response-surface model based iterative optimization of buffer conditions and investigation of substrate, allosteric effector, pH and salt dependent activity profiles of pyruvate kinase (PYK). A diprotic model of enzyme kinetics was used to model the combined effects of changing pH and substrate concentrations. The 8 parameters of the model could be estimated from a single two-hour experiment using nonlinear least-squares regression. The model with the estimated parameters successfully predicted pH and PEP dependence of initial reaction rates, while the PEP concentration dependent shift of optimal pH could only be reproduced with a set of manually tweaked parameters. Differences between model-predictions and experimental observations at low pH suggest additional protonation-sites at the enzyme or substrates critical for enzymatic activity. The developed framework is a powerful tool to investigate enzyme reaction specifics and explore biological system behaviour in a wide range of experimental conditions
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