364 research outputs found

    NEURONIC SYSTEM INSIDE NEURONS: MOLECULAR BIOLOGY AND BIOPHYSICS OF NEURONAL MICROTUBULES

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    Neurons are highly specialized cells that input, process, store and output information. Interneuronal communication is achieved in four basic ways: (i) Ca2+ evoked exocytosis with chemical neurotransmission, (ii) gap junction electrotonic coupling, (iii) secretion of neurosteroids, nitric oxide and derivatives of the arachidonic acid acting in paracrine manner, and (iv) cellular adhesive protein interactions with scaffold protein reorganization. Central structure integrating these anisomorphic signals is the neuronal cytoskeleton that is considered to be both sensitive to the local electromagnetic ļ¬eld and prone to intense biochemical modiļ¬cation. With the use of biophysical modeling we have shown that the local electromagnetic ļ¬eld interaction with neuronal microtubules could result in formation of dissipationless waves (solitons) of tubulin tail conformational states that propagate along the microtubule outer surface. Soliton collisions may subserve the function of elementary computational gates and the output of the computation performed by the microtubules may be achieved by the energase action of the tubulin tails that control microtubule-associated protein and motor protein attachment/detachment on the microtubule outer surface

    Doctor of Philosophy

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    dissertationCross layer system design represents a paradigm shift that breaks the traditional layer-boundaries in a network stack to enhance a wireless network in a number of di erent ways. Existing work has used the cross layer approach to optimize a wireless network in terms of packet scheduling, error correction, multimedia quality, power consumption, selection of modulation/coding and user experience, etc. We explore the use of new cross layer opportunities to achieve secrecy and e ciency of data transmission in wireless networks. In the rst part of this dissertation, we build secret key establishment methods for private communication between wireless devices using the spatio-temporal variations of symmetric-wireless channel measurements. We evaluate our methods on a variety of wireless devices, including laptops, telosB sensor nodes, and Android smartphones, with diverse wireless capabilities. We perform extensive measurements in real-world environments and show that our methods generate high entropy secret bits at a signi cantly faster rate in comparison to existing approaches. While the rst part of this dissertation focuses on achieving secrecy in wireless networks, the second part of this dissertation examines the use of special pulse shaping lters of the lterbank multicarrier (FBMC) physical layer in reliably transmitting data packets at a very high rate. We rst analyze the mutual interference power across subcarriers used by di erent transmitters. Next, to understand the impact of FBMC beyond the physical layer, we devise a distributed and adaptive medium access control protocol that coordinates data packet tra c among the di erent nodes in the network in a best e ort manner. Using extensive simulations, we show that FBMC consistently achieves an order-of-magnitude performance improvement over orthogonal frequency division multiplexing (OFDM) in several aspects, including packet transmission delays, channel access delays, and e ective data transmission rate available to each node in static indoor settings as well as in vehicular networks

    Survey on Lightweight Primitives and Protocols for RFID in Wireless Sensor Networks

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    The use of radio frequency identification (RFID) technologies is becoming widespread in all kind of wireless network-based applications. As expected, applications based on sensor networks, ad-hoc or mobile ad hoc networks (MANETs) can be highly benefited from the adoption of RFID solutions. There is a strong need to employ lightweight cryptographic primitives for many security applications because of the tight cost and constrained resource requirement of sensor based networks. This paper mainly focuses on the security analysis of lightweight protocols and algorithms proposed for the security of RFID systems. A large number of research solutions have been proposed to implement lightweight cryptographic primitives and protocols in sensor and RFID integration based resource constraint networks. In this work, an overview of the currently discussed lightweight primitives and their attributes has been done. These primitives and protocols have been compared based on gate equivalents (GEs), power, technology, strengths, weaknesses and attacks. Further, an integration of primitives and protocols is compared with the possibilities of their applications in practical scenarios

    Neuronic system inside neurons: molecular biology and biophysics of neuronal microtubules

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    Neurons are highly specialized cells that input, process, store and output information. Interneuronal communication is achieved in four basic ways: (i) Ca2+ evoked exocytosis with chemical neurotransmission, (ii) gap junction electrotonic coupling, (iii) secretion of neurosteroids, nitric oxide and derivatives of the arachidonic acid acting in paracrine manner, and (iv) cellular adhesive protein interactions with scaffold protein reorganization. Central structure integrating these anisomorphic signals is the neuronal cytoskeleton that is considered to be both sensitive to the local electromagnetic field and prone to intense biochemical modification. With the use of biophysical modeling we have shown that the local electromagnetic field interaction with neuronal microtubules could result in formation of dissipationless waves (solitons) of tubulin tail conformational states that propagate along the microtubule outer surface. Soliton collisions may subserve the function of elementary computational gates and the output of the computation performed by the microtubules may be achieved by the energase action of the tubulin tails that control microtubule-associated protein and motor protein attachment/detachment on the microtubule outer surface.Biomedical Reviews 2004; 15: 67-75

    Drive (Quantum) Safe! ā€“ Towards PQ Authentication for V2V Communications

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    We tackle a challenging problem at the intersection of two emerging technologies: post-quantum cryptography (PQC) and vehicle-to-vehicle (V2V) communication with its strict requirements. We are the first to devise and evaluate a practical, provably secure design for integrating PQ authentication into the IEEE 1609.2 V2V security ecosystem. By theoretically and empirically analyzing the three PQ signature algorithms selected for standardization by NIST, as well as XMSS (RFC 8391), we propose a Partially Hybrid designā€”a tailored fusion of classical cryptography and PQCā€”for use during the nascent transition period to PQC. As opposed to a direct substitution of PQC for classical cryptography, our design meets the unique constraints of standardized V2V protocols

    Breaking the $IKEp182 Challenge

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    We report a break of the $IKEp182 challenge using a meet-in-the-middle attack strategy improved with multiple SIKE-specific optimizations. The attack was executed on the HPC cluster of the University of Luxembourg and required less than 10 core-years and 256TiB of high-performance network storage (GPFS). Different trade-offs allow execution of the attack with similar time complexity and reduced storage requirements of only about 70TiB
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