21 research outputs found

    A usability study of elliptic curves

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    In the recent years, the need of information security has rapidly increased due to an enormous growth of data transmission. In this thesis, we study the uses of elliptic curves in the cryptography. We discuss the elliptic curves over finite fields, attempts to attack; discrete logarithm, Pollard’s rho algorithm, baby-step giant-step algorithm, Pohlig-Hellman algorithm, function field sieve, and number field sieve. The main cryptographic reason to use elliptic curves over finite fields is to provide arbitrarily large finite cyclic groups having a computationally difficult discrete logarithm problem

    A nationwide virtual research education program for medical students in Pakistan: Methodological framework, feasibility testing, and outcomes

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    Introduction: Equipping young medical trainees with fundamental research skills can be a promising strategy to address the need for professionals who can understand and responsibly communicate evolving scientific evidence during a pandemic. Despite an ardent interest to partake in research, most educational institutions in Pakistan and other low-middle income countries have not yet adopted a comprehensive strategy for research skills education. The authors aimed to design and assess the feasibility of implementing the first nation-wide virtual research workshop for medical students in Pakistan. Methods: The course Beginners Guide to Research, designed as a nation-wide virtual research workshop series, was conducted for medical students across Pakistan in June 2020. Four interactive live workshops took place online on alternate days from June 22nd, 2020, to June 27th, 2020, each lasting 1-2 h. Outcomes included: (i) reach, (ii) efficacy as indexed by pre-post change in score pertaining to knowledge and application of research and (iii) self-rated perceptions about understanding of research on a Likert scale. Results: 3,862 participants enrolled from 41 cities and 123 institutions. Enrolled participants belonged to the following provinces: Sindh (n = 1,852, 48.0%), Punjab (n = 1,767, 45.8%), Khyber Pakhtunkhwa (n = 109, 2.8%), Azad Jammu and Kashmir (n = 84, 2.2%) Balochistan (n = 42, 1.1%). We also saw a few registrations from international students (n = 8, 0.2%). Mean (SD) age of enrolled medical students was 21.1 (2.1) years, 2,453 (63.5%) participants were female and 2,394 (62.0%) were from private-sector medical colleges. Two thousand ninety-three participants participants filled out all four pre-test and post-test forms. The total median knowledge score improved from 39.7 to 60.3% with the highest improvements in concepts of research bioethics and literature search (p \u3c 0.001) with greater change for females compared to males (+20.6 vs. +16.2%, p \u3c 0.001) and private institutions compared to public ones (+16.2 vs. +22.1%, p \u3c 0.001). Conclusion: The overwhelming enrollment and significant improvement in learning outcomes (\u3e50% of baseline) indicate feasibility of a medical student-led research course during a pandemic, highlighting its role in catering to the research needs in the LMICs

    Implications for sequencing of biologic therapy and choice of second anti-TNF in patients with inflammatory bowel disease: results from the IMmunogenicity to Second Anti-TNF Therapy (IMSAT) therapeutic drug monitoring study

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    THE NEUROSPORA CRASSA CIRCADIAN CLOCK: AN ORDERLY LOOP DRIVEN BY A DISORDERED CONDUCTOR

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    120 pagesCircadian clocks are composed from cell-autonomous molecular oscillators that set gene expression rhythms and thereby enable organisms to pace their metabolism to changes in light and temperature. Transcriptional-translational negative feedback loops (TTFLs) generate oscillating levels of the transcriptional repressor proteins, such as the central clock component of the fungal clock, Frequency (FRQ).In the filamentous fungus, Neurospora crassa, the white-collar complex serves as a transcriptional activator that turns on the expression of the frq gene. The resulting protein, Frequency (FRQ) forms a complex with FRH (FRQ-interacting helicase) and Casein-Kinase I (CK1a.) Collectively, the latter three proteins form the FFC complex that then inhibits the white-collar complex activity, thereby resetting the clock. Currently, there is a dearth of structural and biophysical data on FRQ and these complexes. In particular, a key question concerns how FRQ is able to orchestrate the clock with very little predicted tertiary structure. Here I present the reconstitution of FRQ and the FFC complex in varying phosphorylation states and the results of an array of biophysical experiments aimed at defining their structural properties. Our integrative structural biology approach provides the first domain-specific structural details on FRQ and the repressive FFC complex. My experiments demonstrate that FRQ, although mostly disordered, contains an ordered core, undergoes phosphorylation-driven structural changes and uses phase-separation to sequester clock proteins and regulate their enzymatic activities.2024-09-0

    Low-power backscatter relay network

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    This paper proposes a full duplex relay scheme for ambient backscatter devices which require little or no power for operation. The ambient backscatter devices reflect radio signals from ambient sources such as TV tower, FM radio station, etc. Because of the backscattering of radio signals, such devices have small coverage range. To extend the network coverage of such devices, relaying is the most conventional way, which is previously used for extending the coverage range of radio networks such as LTE, WiFi and so on. In this paper, the backscatter devices assist other backscatter devices to relay the information to their destination nodes. Because of the full duplex characteristics at the relaying node, they can send their own information while receiving signals from the source node. We propose the relaying procedure for full duplex backscatter nodes and investigate the its performance in terms of throughput by performing simulations

    Information processing and wireless energy harvesting in interference-aware public safety networks

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    In a public safety environment, user equipments (UEs) located within the coverage area of evolved NodeB, relay network services to out-of-coverage UEs. However, relay UEs in public safety environments are typically energy constrained and cannot operate indefinitely without recharging. Radio frequency energy harvesting has been proposed as a solution for recharging wireless UEs. In this paper, we propose a scheme for extending the lifetime of a public safety network by wirelessly charging relay UEs. In addition, we propose a relay selection method considering the battery status of relay UEs. The proposed relay selection is defined as a bipartite graph matching problem and the optimal relay is obtained through matching games technique. The proposed scheme not only improves the network lifetime but also extend the network coverage. We also conduct system level simulations to evaluate the performance of the proposed scheme. Simulation results show that the overall performance of the system is improved in terms of achievable throughput and network lifetime

    Information Processing and Wireless Energy Harvesting in Two-Way Amplify-and-Forward Relay Networks

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    Wireless energy harvesting is an efficient way to prolong the lifetime of energy constrained networks. In this paper, a two-way amplify-and-forward (AF) based relay network is considered, where two communicating nodes concurrently transmit there information signals to a relay node using time switching based relaying protocol (TSR). The relay node is energy constrained and therefore it first harvests the energy from the received radio frequency (RF) signals. After successful energy harvesting the relay utilizes the harvested energy to amplify and forward the received information signal to its destination. We derive the analytical expression for outage probability and achievable throughput at the receiving nodes. Our numerical results verify our analytical derivation and shows the effect of different system parameters on achievable throughput at receiving nodes
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