4,408 research outputs found

    Blockchain-based electronic voting protocol

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    Current electronic voting protocol require a centralized system to control the whole procedure from ballot inputs to result outputs and election monitoring. Meanwhile, blockchain technology provide a decentralized system which open across the whole network of untrusted participants. Applying blockchain technology into electronic voting protocol through a proper architecture can instil characteristic such as data confidentiality, data integrity and data authenticity. In this paper, we going to discuss a proposed method on how to leverage the advantages from blockchain into electronic voting protocol. This blockchain-based electronic voting protocol promise to provide a secure electronic election process given the proposed system works. We implement a protocol using blockchain to turn election protocol into an automated control system without relying any single point of entity. Lastly, we discuss the characteristics of our proposed blockchain-based electronic voting protocol in this paper. However, there are also emerging challenges and limitations awaiting to overcome. This paper gives a comprehensive overview of our proposed protocol

    Discovery of Eight z ~ 6 Quasars in the Sloan Digital Sky Survey Overlap Regions

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    We present the discovery of eight quasars at z~6 identified in the Sloan Digital Sky Survey (SDSS) overlap regions. Individual SDSS imaging runs have some overlap with each other, leading to repeat observations over an area spanning >4000 deg^2 (more than 1/4 of the total footprint). These overlap regions provide a unique dataset that allows us to select high-redshift quasars more than 0.5 mag fainter in the z band than those found with the SDSS single-epoch data. Our quasar candidates were first selected as i-band dropout objects in the SDSS imaging database. We then carried out a series of follow-up observations in the optical and near-IR to improve photometry, remove contaminants, and identify quasars. The eight quasars reported here were discovered in a pilot study utilizing the overlap regions at high galactic latitude (|b|>30 deg). These quasars span a redshift range of 5.86<z<6.06 and a flux range of 19.3<z_AB<20.6 mag. Five of them are fainter than z_AB=20 mag, the typical magnitude limit of z~6 quasars used for the SDSS single-epoch images. In addition, we recover eight previously known quasars at z~6 that are located in the overlap regions. These results validate our procedure for selecting quasar candidates from the overlap regions and confirming them with follow-up observations, and provide guidance to a future systematic survey over all SDSS imaging regions with repeat observations.Comment: AJ in press (8 pages

    Review on Leakage Resilient Key Exchange Security Model

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    In leakage resilient cryptography, leakage resilient key exchange protocols are constructed to defend against leakage attacks. Then, the key exchange protocol is proved with leakage resilient security model to determine whether its security proof can provide the security properties it claimed or to find out any unexamined flaw during protocol building. It is an interesting work to review the meaningful security properties provided by these security models. This work review how a leakage resilient security model for a key exchange protocol has been evolved over years according to the increasing security requirement which covers a different range of attacks. The relationship on how an adversary capability in the leakage resilient security model can be related to real-world attack scenarios is studied. The analysis work for each leakage resilient security model here enables a better knowledge on how an adversary query addresses different leakage attacks setting, thereby understand the motive of design for a cryptographic primitive in the security model

    ShapeBots: Shape-changing Swarm Robots

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    We introduce shape-changing swarm robots. A swarm of self-transformable robots can both individually and collectively change their configuration to display information, actuate objects, act as tangible controllers, visualize data, and provide physical affordances. ShapeBots is a concept prototype of shape-changing swarm robots. Each robot can change its shape by leveraging small linear actuators that are thin (2.5 cm) and highly extendable (up to 20cm) in both horizontal and vertical directions. The modular design of each actuator enables various shapes and geometries of self-transformation. We illustrate potential application scenarios and discuss how this type of interface opens up possibilities for the future of ubiquitous and distributed shape-changing interfaces.Comment: UIST 201

    Metabolic effects of a 24-week energy-restricted intervention combined with low or high dairy intake in overweight women:An NMR-based metabolomics investigation

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    We investigated the effect of a 24-week energy-restricted intervention with low or high dairy intake (LD or HD) on the metabolic profiles of urine, blood and feces in overweight/obese women by NMR spectroscopy combined with ANOVA-simultaneous component analysis (ASCA). A significant effect of dairy intake was found on the urine metabolome. HD intake increased urinary citrate, creatinine and urea excretion, and decreased urinary excretion of trimethylamine-N-oxide (TMAO) and hippurate relative to the LD intake, suggesting that HD intake was associated with alterations in protein catabolism, energy metabolism and gut microbial activity. In addition, a significant time effect on the blood metabolome was attributed to a decrease in blood lipid and lipoprotein levels due to the energy restriction. For the fecal metabolome, a trend for a diet effect was found and a series of metabolites, such as acetate, butyrate, propionate, malonate, cholesterol and glycerol tended to be affected. Overall, even though these effects were not accompanied by a higher weight loss, the present metabolomics data reveal that a high dairy intake is associated with endogenous metabolic effects and effects on gut microbial activity that potentially impact body weight regulation and health. Moreover, ASCA has a great potential for exploring the effect of intervention factors and identifying altered metabolites in a multi-factorial metabolomic study

    Contribution of the C-terminal region within the catalytic core domain of HIV-1 integrase to yeast lethality, chromatin binding and viral replication

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    <p>Abstract</p> <p>Background</p> <p>HIV-1 integrase (IN) is a key viral enzymatic molecule required for the integration of the viral cDNA into the genome. Additionally, HIV-1 IN has been shown to play important roles in several other steps during the viral life cycle, including reverse transcription, nuclear import and chromatin targeting. Interestingly, previous studies have demonstrated that the expression of HIV-1 IN induces the lethal phenotype in some strains of <it>Saccharomyces cerevisiae</it>. In this study, we performed mutagenic analyses of the C-terminal region of the catalytic core domain of HIV-1 IN in order to delineate the critical amino acid(s) and/or motif(s) required for the induction of the lethal phenotype in the yeast strain HP16, and to further elucidate the molecular mechanism which causes this phenotype.</p> <p>Results</p> <p>Our study identified three HIV-1 IN mutants, V165A, A179P and KR186,7AA, located in the C-terminal region of the catalytic core domain of IN that do not induce the lethal phenotype in yeast. Chromatin binding assays in yeast and mammalian cells demonstrated that these IN mutants were impaired for the ability to bind chromatin. Additionally, we determined that while these IN mutants failed to interact with LEDGF/p75, they retained the ability to bind Integrase interactor 1. Furthermore, we observed that VSV-G-pseudotyped HIV-1 containing these IN mutants was unable to replicate in the C8166 T cell line and this defect was partially rescued by complementation with the catalytically inactive D64E IN mutant.</p> <p>Conclusion</p> <p>Overall, this study demonstrates that three mutations located in the C-terminal region of the catalytic core domain of HIV-1 IN inhibit the IN-induced lethal phenotype in yeast by inhibiting the binding of IN to the host chromatin. These results demonstrate that the C-terminal region of the catalytic core domain of HIV-1 IN is important for binding to host chromatin and is crucial for both viral replication and the promotion of the IN-induced lethal phenotype in yeast.</p

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

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    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

    Augmented Lung Inflammation Protects against Influenza A Pneumonia

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    Influenza pneumonia causes high mortality every year, and pandemic episodes kill millions of people. Influenza-related mortality has been variously ascribed to an ineffective host response that fails to limit viral replication, an excessive host inflammatory response that results in lung injury and impairment of gas exchange, or to bacterial superinfection. We sought to determine whether lung inflammation promoted or impaired host survival in influenza pneumonia.To distinguish among these possible causes of influenza-related death, we induced robust lung inflammation by exposing mice to an aerosolized bacterial lysate prior to challenge with live virus. The treatment induced expression of the inflammatory cytokines IL-6 and TNF in bronchoalveolar lavage fluid 8- and 40-fold greater, respectively, than that caused by lethal influenza infection. Yet, this augmented inflammation was associated with striking resistance to host mortality (0% vs 90% survival, p = 0.0001) and reduced viral titers (p = 0.004). Bacterial superinfection of virus infected lungs was not observed. When mice were repeatedly exposed to the bacterial lysate, as would be clinically desirable during an influenza epidemic, there was no tachyphylaxis of the induced viral resistance. When the bacterial lysate was administered after the viral challenge, there was still some mortality benefit, and when ribavirin was added to the aerosolized bacterial lysate, host survival was synergistically improved (0% vs 93.3% survival, p<0.0001).Together, these data indicate that innate immune resistance to influenza can be effectively stimulated, and suggest that ineffective rather than excessive inflammation is the major cause of mortality in influenza pneumonia

    Simulation of double diffusive convection in fluid-saturated porous media by lattice Boltzmann method

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    The research on double diffusive convection in porous media is important to deepen our insights into sustainable development and environment protection. A lattice Boltzmann (LB) model for REV (representative elementary volume) scale simulation of double diffusive convection in fluid-saturated porous media is proposed in the present work. It can work well not only for porous media with uniform porosity but also for non-uniform porous media. Several benchmark tests are adopted to validate its capability. The good agreement with previous publications demonstrates its applicability. It can provide an alternative numerical tool for modelling complex heat and mass transfer in fluid-saturated porous media beyond double diffusive convection, such as heat and moisture transfer in multi-layer building materials

    Measurement of the pnppπ0πpn \to pp\pi^0\pi^- Reaction in Search for the Recently Observed Resonance Structure in dπ0π0d\pi^0\pi^0 and dπ+πd\pi^+\pi^- systems

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    Exclusive measurements of the quasi-free pnppπ0πpn \to pp\pi^0\pi^- reaction have been performed by means of pdpd collisions at TpT_p = 1.2 GeV using the WASA detector setup at COSY. Total and differential cross sections have been obtained covering the energy region s\sqrt s = (2.35 - 2.46) GeV, which includes the region of the ABC effect and its associated resonance structure. No ABC effect, {\it i.e.} low-mass enhancement is found in the π0π\pi^0\pi^--invariant mass spectrum -- in agreement with the constraint from Bose statistics that the isovector pion pair can not be in relative s-wave. At the upper end of the covered energy region tt-channel processes for Roper, Δ(1600)\Delta(1600) and ΔΔ\Delta\Delta excitations provide a reasonable description of the data, but at low energies the measured cross sections are much larger than predicted by such processes. Adding a resonance amplitude for the resonance at mm=~2.37 GeV with Γ\Gamma =~70 MeV and I(JP)= 0(3+)I(J^P)=~0(3^+) observed recently in pndπ0π0pn \to d\pi^0\pi^0 and pndπ+πpn \to d\pi^+\pi^- reactions leads to an agreement with the data also at low energies
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