35 research outputs found

    Interoperability in Open IoT Platforms: WoT-FIWARE Comparison and Integration

    Get PDF
    The rapid and exponential growth of the Internet of Things (IoT) has been generating a new breed of technologies that introduce several different protocols and interfaces. The Web of Things (WoT) architecture stands out as an emerging and poten- tial solution to improve interoperability across IoT platforms by describing well-defined software interfaces. However, few studies analyze and compare WoT to other interoperability solutions proposed in the IoT literature. In this paper, we attempt to bridge the gap by three main contributions. First, we qualitative compare the WoT approach with the well-known FIWARE- based interoperability solution.Second, based on the previous analysis, we design and implement a connector to bridge the WoT architecture to the FIWARE ecosystem. Third, we conduct a performance analysis emulating a real IoT-based environment to understand scalability, response time, and computer resource usage of the two interoperability solutions. The results reveal that conceptual design choices impact the applications’ performance: the WoT architecture effectively enables interoperability across IoT Platforms, though it incorporates several characteristics that hinder the implementation of applications. On the other hand, the FIWARE IoT Agent solution is platform-specific. Hence new implementations are needed for each different IoT data model

    A Microfluidic Device for the Investigation of Rapid Gold Nanoparticle Formation in Continuous Turbulent Flow

    Get PDF
    A new setup with an integrated microfluidic chip with small dead time, high time resolution and compatibility with in situ X-ray absorption (XAS) measurements is presented. It can also be combined with a free liquid jet. By using the microfluidic chip the short reaction times from 2 to 20 milliseconds can be observed, beyond that an external cyclone mixer for extended observation times was applied. The reduction of gold ions with tetrakis(hydroxy-methyl)phosphonium (THPC) has been investigated in the microfluidic setup to monitor this reaction yielding small gold nanoparticles, requiring preferentially a free liquid jet

    piggyBac is an effective tool for functional analysis of the Plasmodium falciparum genome

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Much of the <it>Plasmodium falciparum </it>genome encodes hypothetical proteins with limited homology to other organisms. A lack of robust tools for genetic manipulation of the parasite limits functional analysis of these hypothetical proteins and other aspects of the <it>Plasmodium </it>genome. Transposon mutagenesis has been used widely to identify gene functions in many organisms and would be extremely valuable for functional analysis of the <it>Plasmodium </it>genome.</p> <p>Results</p> <p>In this study, we investigated the lepidopteran transposon, <it>piggyBac</it>, as a molecular genetic tool for functional characterization of the <it>Plasmodium falciparum </it>genome. Through multiple transfections, we generated 177 unique <it>P. falciparum </it>mutant clones with mostly single <it>piggyBac </it>insertions in their genomes. Analysis of <it>piggyBac </it>insertion sites revealed random insertions into the <it>P. falciparum </it>genome, in regards to gene expression in parasite life cycle stages and functional categories. We further explored the possibility of forward genetic studies in <it>P. falciparum </it>with a phenotypic screen for attenuated growth, which identified several parasite genes and pathways critical for intra-erythrocytic development.</p> <p>Conclusion</p> <p>Our results clearly demonstrate that <it>piggyBac </it>is a novel, indispensable tool for forward functional genomics in <it>P. falciparum </it>that will help better understand parasite biology and accelerate drug and vaccine development.</p

    SUMO modification of the neuroprotective protein TDP1 facilitates chromosomal single-strand break repair

    Get PDF
    Breaking and sealing one strand of DNA is an inherent feature of chromosome metabolism to overcome torsional barriers. Failure to reseal broken DNA strands results in protein-linked DNA breaks, causing neurodegeneration in humans. This is typified by defects in tyrosyl DNA phosphodiesterase 1 (TDP1), which removes stalled topoisomerase 1 peptides from DNA termini. Here we show that TDP1 is a substrate for modification by the small ubiquitin-like modifier SUMO. We purify SUMOylated TDP1 from mammalian cells and identify the SUMOylation site as lysine 111. While SUMOylation exhibits no impact on TDP1 catalytic activity, it promotes its accumulation at sites of DNA damage. A TDP1 SUMOylation-deficient mutant displays a reduced rate of repair of chromosomal single-strand breaks arising from transcription-associated topoisomerase 1 activity or oxidative stress. These data identify a role for SUMO during single-strand break repair, and suggest a mechanism for protecting the nervous system from genotoxic stress

    SUMO-Targeted Ubiquitin Ligase, Rad60, and Nse2 SUMO Ligase Suppress Spontaneous Top1–Mediated DNA Damage and Genome Instability

    Get PDF
    Through as yet undefined proteins and pathways, the SUMO-targeted ubiquitin ligase (STUbL) suppresses genomic instability by ubiquitinating SUMO conjugated proteins and driving their proteasomal destruction. Here, we identify a critical function for fission yeast STUbL in suppressing spontaneous and chemically induced topoisomerase I (Top1)–mediated DNA damage. Strikingly, cells with reduced STUbL activity are dependent on tyrosyl–DNA phosphodiesterase 1 (Tdp1). This is notable, as cells lacking Tdp1 are largely aphenotypic in the vegetative cell cycle due to the existence of alternative pathways for the removal of covalent Top1–DNA adducts (Top1cc). We further identify Rad60, a SUMO mimetic and STUbL-interacting protein, and the SUMO E3 ligase Nse2 as critical Top1cc repair factors in cells lacking Tdp1. Detection of Top1ccs using chromatin immunoprecipitation and quantitative PCR shows that they are elevated in cells lacking Tdp1 and STUbL, Rad60, or Nse2 SUMO ligase activity. These unrepaired Top1ccs are shown to cause DNA damage, hyper-recombination, and checkpoint-mediated cell cycle arrest. We further determine that Tdp1 and the nucleotide excision repair endonuclease Rad16-Swi10 initiate the major Top1cc repair pathways of fission yeast. Tdp1-based repair is the predominant activity outside S phase, likely acting on transcription-coupled Top1cc. Epistasis analyses suggest that STUbL, Rad60, and Nse2 facilitate the Rad16-Swi10 pathway, parallel to Tdp1. Collectively, these results reveal a unified role for STUbL, Rad60, and Nse2 in protecting genome stability against spontaneous Top1-mediated DNA damage

    Profiling Service Function Chaining Behavior for NFV Orchestration

    No full text
    The concepts of Software Defined Networks (SDN) and Network Function Virtualization (NFV) have promoted network chaining, or Service Function Chain (SFC), quickly and simply. In dynamic infrastructure scenarios, the management of SFC introduces challenges both for the connection of these elements and for understanding their behavior when automatic elasticity is required. Currently, most existing approaches have addressed this challenge with probabilistic heuristics or AI-based techniques, considering only static management. This paper presents an approach for profiling SFC that can be used for predictive NFV orchestration purposes. We conducted a performance evaluation study based on testbed experimentation and queueing modeling. Our results confirm that an analytical model can be used for managing SFC orchestration, not only as a validation technique for NFV, but also as a heuristic for predictive resource allocation in production environments

    A Management Architecture for IoT Smart Solutions:Design and Implementation

    No full text
    none7siThe management of IoT solutions is a complex task due to their inherent distribution and heterogeneity. IoT management approaches focus on devices and connectivity, thus lacking a comprehensive understanding of the different software, hardware, and communication components that comprise an IoT-based solution. This paper pro- poses a novel four-layer IoT Management Architecture (IoTManA) that encompasses various aspects of a distributed infrastructure for managing, controlling, and moni- toring software, hardware, and communication components, as well as dataflows and data quality. Our architecture provides a cross-layer graph-based view of the end-to- end path between devices and the cloud. IoTManA has been implemented in a set of software components named IoT management system (IoTManS) and tested in two scenarios—Smart Agriculture and Smart Cities—showing that it can significantly contribute to harnessing the complexity of managing IoT solutions. The cross-layer graph-based modeling of IoTManA facilitates the implemented management system (IoTManS) to detect and identify root causes of typically distributed failures occur- ring in IoT solutions. We conducted a performance analysis of IoTManS focusing on two aspects—failure detection time and scalability—to demonstrate application sce- narios and capabilities. The results show that IoTManS can detect and identify the root cause of failures in 806ms to 90,036ms depending on its operation mode, adapt- ing to different IoT needs. Also, the IoTManS scalability is directly proportional to the scalability of the underlying IoT Platform, managing up to 5,000 components simultaneously.mixedSilva, Dener; Heideker, Alexandre; Zyrianoff, Ivan D.; Kleinschmidt, João H.; Roffia, Luca; Soininen, Juha-Pekka; Kamienski, Carlos A.Silva, Dener; Heideker, Alexandre; Zyrianoff, Ivan D.; Kleinschmidt, João H.; Roffia, Luca; Soininen, Juha-Pekka; Kamienski, Carlos A
    corecore