730 research outputs found

    Quantum resource estimates for computing elliptic curve discrete logarithms

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    We give precise quantum resource estimates for Shor's algorithm to compute discrete logarithms on elliptic curves over prime fields. The estimates are derived from a simulation of a Toffoli gate network for controlled elliptic curve point addition, implemented within the framework of the quantum computing software tool suite LIQUiUi|\rangle. We determine circuit implementations for reversible modular arithmetic, including modular addition, multiplication and inversion, as well as reversible elliptic curve point addition. We conclude that elliptic curve discrete logarithms on an elliptic curve defined over an nn-bit prime field can be computed on a quantum computer with at most 9n+2log2(n)+109n + 2\lceil\log_2(n)\rceil+10 qubits using a quantum circuit of at most 448n3log2(n)+4090n3448 n^3 \log_2(n) + 4090 n^3 Toffoli gates. We are able to classically simulate the Toffoli networks corresponding to the controlled elliptic curve point addition as the core piece of Shor's algorithm for the NIST standard curves P-192, P-224, P-256, P-384 and P-521. Our approach allows gate-level comparisons to recent resource estimates for Shor's factoring algorithm. The results also support estimates given earlier by Proos and Zalka and indicate that, for current parameters at comparable classical security levels, the number of qubits required to tackle elliptic curves is less than for attacking RSA, suggesting that indeed ECC is an easier target than RSA.Comment: 24 pages, 2 tables, 11 figures. v2: typos fixed and reference added. ASIACRYPT 201

    Methyl iodide poisoning presenting as a mimic of acute stroke: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Stroke mimics are usually non-vascular disease processes. These raise the possibility of a stroke and are common in clinical practice. It is necessary to distinguish these mimics in order to provide early and appropriate management, as well as reduce possible harm on our patient.</p> <p>Case presentation</p> <p>We report the case of a 50-year-old Caucasian man who developed symptoms suggestive of posterior circulation stroke after he was exposed to methyl iodide at his workplace. Results of stroke investigations of our patient were negative, and a detailed occupational history clinched the diagnosis. Acute presentation with a stroke-like picture is rare in cases of methyl iodide poisoning. We have attempted to discuss the differential diagnosis of stroke mimics through a review of literature.</p> <p>Conclusion</p> <p>Stroke mimics are difficult to diagnose in an emergency room situation and may be initially treated as stroke. This case report underlines the importance of history taking, especially occupational history, in the differential diagnosis of stroke. We also stress the need to recognize mimics at presentation in order to arrive at an early and appropriate management of patients.</p

    Building the foundation for a community-generated national research blueprint for inherited bleeding disorders: research priorities for mucocutaneous bleeding disorders

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    BACKGROUND: Excessive or abnormal mucocutaneous bleeding (MCB) may impact all aspects of the physical and psychosocial wellbeing of those who live with it (PWMCB). The evidence base for the optimal diagnosis and management of disorders such as inherited platelet disorders, hereditary hemorrhagic telangiectasia (HHT), hypermobility spectrum disorders (HSD), Ehlers-Danlos syndromes (EDS), and von Willebrand disease (VWD) remains thin with enormous potential for targeted research. RESEARCH DESIGN AND METHODS: National Hemophilia Foundation and American Thrombosis and Hemostasis Network initiated the development of a National Research Blueprint for Inherited Bleeding Disorders with extensive all-stakeholder consultations to identify the priorities of people with inherited bleeding disorders and those who care for them. They recruited multidisciplinary expert working groups (WG) to distill community-identified priorities into concrete research questions and score their feasibility, impact, and risk. RESULTS: WG2 detailed 38 high priority research questions concerning the biology of MCB, VWD, inherited qualitative platelet function defects, HDS/EDS, HHT, bleeding disorder of unknown cause, novel therapeutics, and aging. CONCLUSIONS: Improving our understanding of the basic biology of MCB, large cohort longitudinal natural history studies, collaboration, and creative approaches to novel therapeutics will be important in maximizing the benefit of future research for the entire MCB community

    Early acquisition and high nasopharyngeal co-colonisation by Streptococcus pneumoniae and three respiratory pathogens amongst Gambian new-borns and infants

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    BACKGROUND: Although Haemophilus influenzae type b (Hib), Staphylococcus aureus and Moraxella catarrhalis are important causes of invasive and mucosal bacterial disease among children, co-carriage with Streptococcus pneumoniae during infancy has not been determined in West Africa. METHODS: Species specific PCR was applied to detect each microbe using purified genomic DNA from 498 nasopharyngeal (NP) swabs collected from 30 Gambian neonates every two weeks from 0 to 6 months and bi-monthly up to 12 months. RESULTS: All infants carried S. pneumoniae, H. influenzae and M. catarrhalis at several time points during infancy. S.pneumoniae co-colonized the infant nasopharynx with at least one other pathogen nine out of ten times. There was early colonization of the newborns and neonates, the average times to first detection were 5, 7, 3 and 14 weeks for S. pneumoniae, H. influenzae, M. catarrhalis and S. aureus respectively. The prevalence of S. pneumoniae, H. influenzae and M. catarrhalis increased among the neonates and exceeded 80% by 13, 15 and 23 weeks respectively. In contrast, the prevalence of S. aureus decreased from 50% among the newborns to 20% amongst nine-week old neonates. S. pneumoniae appeared to have a strong positive association with H. influenzae (OR 5.03; 95% CI 3.02, 8.39; p<0.01) and M. catarrhalis (OR 2.20; 95% CI 1.29; p<0.01) but it was negatively associated with S. aureus (OR 0.53; 95% CI 0.30, 0.94; p=0.03). CONCLUSION: This study shows early acquisition and high co-carriage of three important respiratory pathogens with S. pneumoniae in the nasopharyngeal mucosa among Gambian neonates and infants. This has important potential implications for the aetiology of respiratory polymicrobial infections, biofilm formation and vaccine strategies

    Plasma Brain-Derived Neurotrophic Factor Levels Predict the Clinical Outcome of Depression Treatment in a Naturalistic Study

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    Remission is the primary goal of treatment for major depressive disorder (MDD). However, some patients do not respond to treatment. The main purpose of this study was to determine whether brain-derived neurotrophic factor (BDNF) levels are correlated with treatment outcomes. In a naturalistic study, we assessed whether plasma BDNF levels were correlated with clinical outcomes by measuring plasma BDNF in patients with depressive syndrome (MADRS score ≥18), and subsequently comparing levels between the subgroup of patients who underwent remission (MADRS score ≤8) and the subgroup who were refractory to treatment (non-responders). Patients with depressive syndrome who underwent remission had significantly higher plasma BDNF levels (p<0.001), regardless of age or sex. We also found a significant negative correlation between MADRS scores and plasma BDNF levels within this group (ρ = –0.287, p = 0.003). In contrast, non-responders had significantly lower plasma BDNF levels (p = 0.029). Interestingly, plasma BDNF levels in the non-responder group were significantly higher than those in the remission group in the initial stage of depressive syndrome (p = 0.002). Our results show that plasma BDNF levels are associated with clinical outcomes during the treatment of depression. We suggest that plasma BDNF could potentially serve as a prognostic biomarker for depression, predicting clinical outcome
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