12,050 research outputs found

    Challenges of Internet of Things and Big Data Integration

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    The Internet of Things anticipates the conjunction of physical gadgets to the In-ternet and their access to wireless sensor data which makes it expedient to restrain the physical world. Big Data convergence has put multifarious new opportunities ahead of business ventures to get into a new market or enhance their operations in the current market. considering the existing techniques and technologies, it is probably safe to say that the best solution is to use big data tools to provide an analytical solution to the Internet of Things. Based on the current technology deployment and adoption trends, it is envisioned that the Internet of Things is the technology of the future, while to-day's real-world devices can provide real and valuable analytics, and people in the real world use many IoT devices. Despite all the advertisements that companies offer in connection with the Internet of Things, you as a liable consumer, have the right to be suspicious about IoT advertise-ments. The primary question is: What is the promise of the Internet of things con-cerning reality and what are the prospects for the future.Comment: Proceedings of the International Conference on International Conference on Emerging Technologies in Computing 2018 (iCETiC '18), 23rd -24th August, 2018, at London Metropolitan University, London, UK, Published by Springer-Verla

    Fractional quantum Hall effect in the absence of Landau levels

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    It has been well-known that topological phenomena with fractional excitations, i.e., the fractional quantum Hall effect (FQHE) \cite{Tsui1982} will emerge when electrons move in Landau levels. In this letter, we report the discovery of the FQHE in the absence of Landau levels in an interacting fermion model. The non-interacting part of our Hamiltonian is the recently proposed topologically nontrivial flat band model on the checkerboard lattice \cite{sun}. In the presence of nearest-neighboring repulsion (UU), we find that at 1/3 filling, the Fermi-liquid state is unstable towards FQHE. At 1/5 filling, however, a next-nearest-neighboring repulsion is needed for the occurrence of the 1/5 FQHE when UU is not too strong. We demonstrate the characteristic features of these novel states and determine the phase diagram correspondingly.Comment: 6 pages and 4 figure

    Pyomelanin produced by Vibrio cholerae confers resistance to predation by Acanthamoeba castellanii

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    © FEMS 2017. Protozoan predation is one of the main environmental factors constraining bacterial growth in aquatic environments, and thus has led to the evolution of a number of defence mechanisms that protect bacteria from predation. These mechanisms may also function as virulence factors in infection of animal and human hosts. Whole transcriptome shotgun sequencing of Vibrio cholerae biofilms during predation by the amoebae, Acanthamoeba castellanii, revealed that 131 transcripts were significantly differentially regulated when compared to the non-grazed control. Differentially regulated transcripts included those involved in biosynthetic and metabolic pathways. The transcripts of genes involved in tyrosine metabolism were down-regulated in the grazed population, which indicates that the tyrosine metabolic regulon may have a role in the response of V. cholerae biofilms to A. castellanii predation. Homogentisate 1, 2-dioxygenase (HGA) is the main intermediate of the normal L-tyrosine catabolic pathway which is known to auto-oxidize, leading to the formation of the pigment, pyomelanin. Indeed, a pigmented mutant, disrupted in hmgA, was more resistant to amoebae predation than the wild type. Increased grazing resistance was correlated with increased production of pyomelanin and thus reactive oxygen species (ROS), suggesting that ROS production is a defensive mechanism used by bacterial biofilms against predation by amoebae A. castellanii

    Visual Analytics for Network Security and Critical Infrastructures

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    A comprehensive analysis of cyber attacks is important for better understanding of their nature and their origin. Providing a sufficient insight into such a vast amount of diverse (and sometimes seemingly unrelated) data is a task that is suitable neither for humans nor for fully automated algorithms alone. Not only a combination of the two approaches but also a continuous reasoning process that is capable of generating a sufficient knowledge base is indispensable for a better understanding of the events. Our research is focused on designing new exploratory methods and interactive visualizations in the context of network security. The knowledge generation loop is important for its ability to help analysts to refine the nature of the processes that continuously occur and to offer them a better insight into the network security related events. In this paper, we formulate the research questions that relate to the proposed solution

    The evolution of parasitic and mutualistic plant-virus symbioses through transmission-virulence trade-offs.

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    Virus-plant interactions range from parasitism to mutualism. Viruses have been shown to increase fecundity of infected plants in comparison with uninfected plants under certain environmental conditions. Increased fecundity of infected plants may benefit both the plant and the virus as seed transmission is one of the main virus transmission pathways, in addition to vector transmission. Trade-offs between vertical (seed) and horizontal (vector) transmission pathways may involve virulence, defined here as decreased fecundity in infected plants. To better understand plant-virus symbiosis evolution, we explore the ecological and evolutionary interplay of virus transmission modes when infection can lead to an increase in plant fecundity. We consider two possible trade-offs: vertical seed transmission vs infected plant fecundity, and horizontal vector transmission vs infected plant fecundity (virulence). Through mathematical models and numerical simulations, we show (1) that a trade-off between virulence and vertical transmission can lead to virus extinction during the course of evolution, (2) that evolutionary branching can occur with subsequent coexistence of mutualistic and parasitic virus strains, and (3) that mutualism can out-compete parasitism in the long-run. In passing, we show that ecological bi-stability is possible in a very simple discrete-time epidemic model. Possible extensions of this study include the evolution of conditional (environment-dependent) mutualism in plant viruses

    A risk-oriented tender evaluation system for construction projects in Malaysia

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    Purpose: This paper presents results of an empirical investigation involving private construction clients in Malaysia, which seeks to establish appropriate tender evaluation criteria and weightings for a risk-oriented tender evaluation system. Design/Methodology/Approach: At the initial stage of this study, a list of significant risks is identified and gathered through literature review. These risks are then mapped onto tender evaluation criteria. Following this, the identified risks and their mappings are validated through a questionnaire survey to determine appropriate criteria for tender evaluation. Weightings for the selected evaluation criteria are established through an analytic hierarchy process (AHP) group decision-making (GDM) method. Findings: In practice, different lists of criteria, covering tender’s technical capability and financial performance, are often used by different client organisations. However, there is a paucity of research behind the selection of these criteria and the weighting being attributed to different criteria. Originality/Value: This study provides an important and a valuable insight into the actual criteria used during tender evaluation practice based on an analysis of documentary evidence. Both current practice and existing tender evaluation studies failed to address the risk element adequately. There is a lack of an explicit link between evaluation criteria and project risks. This study fills this knowledge gap by identifying tender evaluation criteria through reviewing criteria used in practice and examining their links to risk factors

    Thiocarbamoyl Disulfides as Inhibitors of Urease and Ammonia Monooxygenase: Crystal Engineering for Novel Materials

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    The environmental sustainability of soil nitrogen fertilization is essential for the primary production of food for an expanding human population. In this framework, the control of soil enzymatic activities that impact the release of N-based compounds either in the atmosphere or in the underground waters is critical. The two enzymes that act as key players in the biogeochemical cycle of nitrogen are urease and ammonia monooxygenase (AMO), respectively, nickel- and copper-dependent enzymes. This article reveals the high efficacy of three molecules of the thiurams family, namely, thiram (tetramethylthiuram disulfide, TMTD), disulfiram (tetraethylthiuram disulfide, TETD), and tetraisopropylthiuram disulfide (TIPTD) as inhibitors of both the activities of jack bean (Canavalia ensiformis) urease (JBU) and Nitrosomonas europaea AMO. The water solubility of these compounds was significantly improved by the preparation of three novel inclusion complexes of beta-cydodextrin with TMTD, TETD, and TIPTD by mechanochemical synthesis, using green technology. The resulting beta-CD.thiuram complexes beta-CD.TMTD, (beta-CD)(2)-TETD, and (beta-CD)(2).TIPTD were all characterized by powder X-ray diffraction, thermogravimetric analysis, and solid-state NMR. A conformational polymorph of TIPTD was also detected and isolated via hot stage microscopy, and structurally characterized by single-crystal X-ray diffraction. Biological tests of enzymatic inhibition performed on JBU and AMO with the beta-CD.thiuram complexes showed the same inhibition efficacy as the isolated molecules, suggesting that the active species is, in all cases, the free thiuram, likely in equilibrium with the adduct in solution. These results have a great potential for improving the nitrogen use efficiency of soil fertilizers for a greener environment

    The limit of N=(2,2) superconformal minimal models

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    The limit of families of two-dimensional conformal field theories has recently attracted attention in the context of AdS/CFT dualities. In our work we analyse the limit of N=(2,2) superconformal minimal models when the central charge approaches c=3. The limiting theory is a non-rational N=(2,2) superconformal theory, in which there is a continuum of chiral primary fields. We determine the spectrum of the theory, the three-point functions on the sphere, and the disc one-point functions.Comment: 37 pages, 3 figures; v2: minor corrections in section 5.3, version to be published in JHE
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