1,084 research outputs found

    The role of membrane curvature for the wrapping of nanoparticles

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    A hierarchical key pre-distribution scheme for fog networks

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    Security in fog computing is multi-faceted, and one particular challenge is establishing a secure communication channel between fog nodes and end devices. This emphasizes the importance of designing efficient and secret key distribution scheme to facilitate fog nodes and end devices to establish secure communication channels. Existing secure key distribution schemes designed for hierarchical networks may be deployable in fog computing, but they incur high computational and communication overheads and thus consume significant memory. In this paper, we propose a novel hierarchical key pre-distribution scheme based on “Residual Design” for fog networks. The proposed key distribution scheme is designed to minimize storage overhead and memory consumption, while increasing network scalability. The scheme is also designed to be secure against node capture attacks. We demonstrate that in an equal-size network, our scheme achieves around 84% improvement in terms of node storage overhead, and around 96% improvement in terms of network scalability. Our research paves the way for building an efficient key management framework for secure communication within the hierarchical network of fog nodes and end devices. KEYWORDS: Fog Computing, Key distribution, Hierarchical Networks

    System level design of a full-duplex wireless transceiver for brain-machine interfaces

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    We propose a new wireless communication architecture for implanted systems that simultaneously stimulates neurons and record neural responses. This architecture can support large numbers of electrodes (>500), providing 100 Mb/s for the downlink of stimulation signals, and gigabits per second for the uplink of neural recordings. We propose a full-duplex transceiver architecture that shares one antenna for both the ultrawideband (UWB) and the 2.45-GHz industrial, scientific, and medical band. A new pulse shaper is used for the gigabits per second uplink to simplify the transceiver design, while supporting several modulation formats with high data rates. To validate our system-level design for brain-machine interfaces, we present an ex-vivo experimental demonstration of the architecture. While the system design is for an integrated solution, the proof-of-concept demonstration uses discrete components. Good bit error rate performance over a biological channel at 0.5-, 1-, and 2-Gb/s data rates for uplink telemetry (UWB) and 100 Mb/s for downlink telemetry (2.45-GHz band) are achieved

    A cyber-kill-chain based taxonomy of crypto-ransomware features

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    In spite of being just a few years old, ransomware is quickly becoming a serious threat to our digital infrastructures, data and services. Majority of ransomware families are requesting for a ransom payment to restore a custodian access or decrypt data which were encrypted by the ransomware earlier. Although the ransomware attack strategy seems to be simple, security specialists ranked ransomware as a sophisticated attack vector with many variations and families. Wide range of features which are available in different families and versions of ransomware further complicates their detection and analysis. Though the existing body of research provides significant discussions about ransomware details and capabilities, the all research body is fragmented. Therefore, a ransomware feature taxonomy would advance cyber defenders’ understanding of associated risks of ransomware. In this paper we provide, to the best of our knowledge, the first scientific taxonomy of ransomware features, aligned with Lockheed Martin Cyber Kill Chain (CKC) model. CKC is a well-established model in industry that describes stages of cyber intrusion attempts. To ease the challenge of applying our taxonomy in real world, we also provide the corresponding ransomware defence taxonomy aligned with Courses of Action matrix (an intelligence-driven defence model). We believe that this research study is of high value for the cyber security research community, as it provides the researchers with a means of assessing the vulnerabilities and attack vectors towards the intended victims

    A novel variant of SLC26A4 and first report of the c.716T>A variant in Iranian pedigrees with non-syndromic sensorineural hearing loss

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    The autosomal recessive non-syndromic hearing loss (ARNSHL) can be associated with variants in solute carrier family 26, member 4 (SLC26A4) gene and is the second most common cause of ARNSHL worldwide. Therefore, this study aims to determine the contribution of the SLC26A4 genotype in the hearing loss (HL) of 40 ARNSHL pedigrees in Iran. A cohort of the 40 Iranian pedigrees with ARNSHL, having no mutation in the GJB2 gene, was selected. The linkage analysis with five short tandem repeat (STR) markers linked to SLC26A4 was performed for the 40 ARNSHL pedigrees. Then, two out of the 40 pedigrees with ARNSHL that linked to DFNB4 locus were further screened to determine the variants in all exons of SLC26A4 gene by direct DNA sequencing. The 21 exons of SCL26A4 were analyzed for the two pedigrees. A known variant (c.716T>A homozygote), it is the first reported incidence in Iran, a novel variant (c.493A>C homozygote) were detected in the two pedigrees and pathogenesis of c.493A>C confirmed in this study with review 100 hearing ethnically matched controls by PCR-RFLP analysis. The present study suggests that the SLC26A4 gene plays a crucial role in the HL occurring in Iranian pedigrees. Also, the results probably support the specificity and unique spectrum of SLC26A4 variants among Iranian HL patients. Molecular study of SLC26A4 gene may lead to elucidation of the profile of the population-specific variants which has importance in diagnostics of HL

    Intra-arterial tert-Butyl-Hydroperoxide Infusion Induces an Exacerbated Sensory Response in the Rat Hind Limb and is Associated with an Impaired Tissue Oxygen Uptake

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    The objective of this study was to investigate oxidative stress and oxygen extraction mechanisms in an animal model of continuous intra-arterial infusion of a free radical donor and in an in vitro model using isolated mitochondria. tert-Butyl-hydroperoxide (tert-BuOOH, 25 mM) was infused for 24 h in the left hind limb of rats to induce soft tissue damage (n = 8). After 7 days, we assessed local sensory response, tissue oxygen consumption, oxygen radicals, and antioxidant levels. In vitro mitochondrial function was measured after stimulation of isolated mitochondria of skeletal muscle cells with increasing doses of tert-BuOOH. tert-BuOOH infusion resulted in an increased skin temperature (p = 0.04), impaired function, and a significantly increased pain sensation (p = 0.03). Venous oxygen saturation levels (p = 0.01) and the antioxidant ceruloplasmin (p = 0.04) were increased. tert-BuOOH inhibited mitochondrial function in vitro. Induction of free radical formation in the rat hind limb results in an exacerbated sensory response and is associated with impaired oxygen extraction, which likely results from mitochondrial dysfunction caused by free radicals
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