203 research outputs found

    Terahertz quantum cryptography

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    A well-known empirical rule for the demand of wireless communication systems is that of Edholm's law of bandwidth. It states that the demand for bandwidth in wireless short-range communications doubles every 18 months. With the growing demand for bandwidth and the decreasing cell size of wireless systems, terahertz (THz) communication systems are expected to become increasingly important in modern day applications. With this expectation comes the need for protecting users' privacy and security in the best way possible. With that in mind, we show that quantum key distribution can operate in the THz regime and we derive the relevant secret key rates against realistic collective attacks. In the extended THz range (from 0.1 to 50 THz), we find that below 1 THz, the main detrimental factor is thermal noise, while at higher frequencies it is atmospheric absorption. Our results show that high-rate THz quantum cryptography is possible over distances varying from a few meters using direct reconciliation, to about 220m via reverse reconciliation. We also give a specific example of the physical hardware and architecture that could be used to realize our THz quantum key distribution scheme

    Identification of new autoantibody specificities directed at proteins involved in the transforming growth factor β pathway in patients with systemic sclerosis

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    International audienceABSTRACT: INTRODUCTION: Antinuclear antibodies (ANA), usually detected by indirect immunofluorescence on HEp-2 cells, are identified in 90% of patients with systemic sclerosis (SSc). Thus, approximately 10% of SSc patients have no routinely detectable autoantibodies, and for 20% to 40% of those with detectable ANA, the ANA do not have identified specificity (non-identified ANA). In this work, we aimed to identify new target autoantigens in SSc patients. METHODS: Using a proteomic approach combining 2-D electrophoresis and immunoblotting with HEp-2 cell total and enriched nuclear protein extracts as sources of autoantigens, we systematically analysed autoantibodies in SSc patients. Sera from 45 SSc patients were tested in 15 pools from groups of 3 patients with the same phenotype. A sera pool from 12 healthy individuals was used as a control. Proteins of interest were identified by mass spectrometry and analysed using Pathway Studio software. RESULTS: We identified 974 and 832 protein spots in HEp-2 cell total and enriched nuclear protein extracts, respectively. Interestingly, alpha-enolase was recognised by immunoglobulin-G (IgG) from all pools of patients in both extracts. Fourteen and 4 proteins were recognised by IgG from at least 75% of the 15 pools in total and enriched nuclear protein extracts, respectively, whereas 15 protein spots were specifically recognised by IgG from at least 4 of the 10 pools from patients with non-identified ANA. The IgG intensity for a number of antigens was higher in sera from patients than in those from healthy controls; these antigens included triosephosphate isomerase, superoxide dismutase mitochondrial precursor, heterogeneous nuclear ribonucleoprotein L and lamin A/C. In addition, peroxiredoxin-2, cofilin-1 and calreticulin were specifically recognised by sera from phenotypic subsets of patients with non-identified ANA. Interestingly, several identified target antigens were involved in the transforming growth factor-beta pathway. CONCLUSIONS: We identified several new target antigens shared among patients with SSc or specific to a given phenotype. The specification of new autoantibodies could help in understanding the pathophysiology of SSc. Moreover, these autoantibodies could represent new diagnostic and/or prognostic markers for SSc

    Identification of target antigens of anti-endothelial cell and anti-vascular smooth muscle cell antibodies in patients with giant cell arteritis: a proteomic approach

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    International audienceABSTRACT: INTRODUCTION: Immunological studies of giant cell arteritis (GCA) suggest that a triggering antigen of unknown nature could generate a specific immune response. We thus decided to detect autoantibodies directed against endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) in the serum of GCA patients and to identify their target antigens. METHODS: Sera from 15 GCA patients were tested in 5 pools of 3 patients' sera and compared to a sera pool from 12 healthy controls (HCs). Serum immunoglobulin G (IgG) reactivity was analysed by 2-D electrophoresis and immunoblotting with antigens from human umbilical vein ECs (HUVECs) and mammary artery VSMCs. Target antigens were identified by mass spectrometry. RESULTS: Serum IgG from GCA patients recognised 162 ± 3 (mean ± SD) and 100 ± 17 (mean ± SD) protein spots from HUVECs and VSMCs, respectively, and that from HCs recognised 79 and 94 protein spots, respectively. In total, 30 spots from HUVECs and 19 from VSMCs were recognised by at least two-thirds and three-fifths, respectively, of the pools of sera from GCA patients and not by sera from HCs. Among identified proteins, we found vinculin, lamin A/C, voltage-dependent anion-selective channel protein 2, annexin V and other proteins involved in cell energy metabolism and key cellular pathways. Ingenuity pathway analysis revealed that most identified target antigens interacted with growth factor receptor-bound protein 2. CONCLUSIONS: IgG antibodies to proteins in the proteome of ECs and VSMCs are present in the sera of GCA patients and recognise cellular targets that play key roles in cell biology and maintenance of homeostasis. Their potential pathogenic role remains to be determined

    Die Kritik der Politischen Ökonomie der Medien/Kommunikation: ein hochaktueller Ansatz

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    This debate article discusses how topical the approach of the Critique of the Political Economy of Media/Communication is today. The paper analyses the status of this field. At the international level, there is a longer tradition in the Critical Political Economy of Media/Communication, especially in the United Kingdom and North America. Since the start of the new crisis of capitalism in 2008, the interest in Marx’s works has generally increased. At the same time communicative and ideological features of societal changes’ unpredictable turbulences have become evident. This contribution introduces some specific approaches. It also discusses 14 aspects of why the complex, multidimensional, open and dynamic research approach of the critique of capitalism and society that goes back Marx’s theory remains relevant today

    Metamaterials Application in Sensing

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    Metamaterials are artificial media structured on a size scale smaller than wavelength of external stimuli, and they can exhibit a strong localization and enhancement of fields, which may provide novel tools to significantly enhance the sensitivity and resolution of sensors, and open new degrees of freedom in sensing design aspect. This paper mainly presents the recent progress concerning metamaterials-based sensing, and detailedly reviews the principle, detecting process and sensitivity of three distinct types of sensors based on metamaterials, as well as their challenges and prospects. Moreover, the design guidelines for each sensor and its performance are compared and summarized

    Materials R&D for a timely DEMO: Key findings and recommendationsof the EU Roadmap Materials Assessment Group

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    The findings of the EU Fusion Programme’s ‘Materials Assessment Group’ (MAG), assessing readiness ofStructural, Plasma Facing (PF) and High Heat Flux (HHF) materials for DEMO, are discussed. These areincorporated into the EU Fusion Power Roadmap [1], with a decision to construct DEMO in the early2030s.The methodology uses project-based and systems-engineering approaches, the concept of TechnologyReadiness Levels, and considers lessons learned from Fission reactor material development. ‘Baseline’materials are identified for each DEMO role, and the DEMO mission risks analysed from the known lim-itations, or unknown properties, associated with each baseline material. R&D programmes to addressthese risks are developed. The DEMO assessed has a phase I with a ‘starter blanket’: the blanket mustwithstand @le;2 MW yr m−2fusion neutron flux (equivalent to ∼20 dpa front-wall steel damage). The base-line materials all have significant associated risks, so development of ‘Risk Mitigation Materials’ (RMM)is recommended. The R&D programme has parallel development of the baseline and RMM, up to ‘down-selection’ points to align with decisions on the DEMO blanket and divertor engineering definition. ITERlicensing experience is used to refine the issues for materials nuclear testing, and arguments are devel-oped to optimise scope of materials tests with fusion neutron (‘14 MeV’) spectra before DEMO designfinalisation. Some 14 MeV testing is still essential, and the Roadmap requires deployment of a ≥30 dpa(steels) testing capability by 2026. Programme optimisation by the pre-testing with fission neutronson isotopically- or chemically-doped steels and with ion-beams is discussed along with the minimum14 MeV testing programme, and the key role which fundamental and mission-oriented modelling canplay in orienting the research

    Internet-based cognitive behavior therapy for obsessive compulsive disorder: A pilot study

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    <p>Abstract</p> <p>Background</p> <p>Cognitive behavior therapy (CBT) is widely regarded as an effective treatment for obsessive compulsive disorder (OCD), but access to CBT therapists is limited. Internet-based CBT (ICBT) with therapist support is a way to increase access to CBT but has not been developed or tested for OCD. The aim of this study was to evaluate ICBT for OCD.</p> <p>Method</p> <p>An open trial where patients (N = 23) received a 15-week ICBT program with therapist support consisting of psychoeducation, cognitive restructuring and exposure with response prevention. The primary outcome was the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), which was assessed by a psychiatrist before and immediately after treatment. Secondary outcomes were self-rated measures of OCD symptoms, depressive symptoms, general functioning, anxiety and quality of life. All assessments were made at baseline and post-treatment.</p> <p>Results</p> <p>All participants completed the primary outcome measure at all assessment points. There were reductions in OCD symptoms with a large within-group effect size (Cohen's <it>d </it>= 1.56). At post-treatment, 61% of participants had a clinically significant improvement and 43% no longer fulfilled the diagnostic criteria of OCD. The treatment also resulted in statistically significant improvements in self-rated OCD symptoms, general functioning and depression.</p> <p>Conclusions</p> <p>ICBT with therapist support reduces OCD symptoms, depressive symptoms and improves general functioning. Randomized trials are needed to confirm the effectiveness of this new treatment format.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01348529">NCT01348529</a></p

    Power Exhaust Concepts and Divertor Designs for Japanese and European DEMO Fusion Reactors

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    Concepts of the power exhaust and divertor design have been developed, with a high priority in the pre-conceptual design phase of the Japan-Europe Broader Approach DEMO Design Activity. A common critical issue is the large power exhaust and its fraction in the main plasma and divertor by the radiative cooling. Different exhaust concepts in the main plasma and divertor have been developed for JA and EU DEMOs. JA proposed a conventional closed divertor geometry to challenge large Psep/Rp handling of 30-35 MWm-1 in order to maintain the radiation fraction in the main plasma at the ITER-level (fradmain = Pradmain/Pheat ~0.4) and higher plasma performance. EU challenged both increasing fradmain to ~0.65 and handling the ITER-level Psep/Rp in the open divertor geometry. Power exhaust simulations have been performed by SONIC (JA) and SOLPS5.1 (EU) with corresponding Psep = 250-300 MW and 150-200 MW, respectively. Both results showed that large divertor radiation fraction (Praddiv/Psep 0.8) was required to reduce both peak qtarget ( 10MWm-2) and Te,idiv. In addition, the JA divertor performance with EU-reference Psep of 150MW showed benefit of the closed geometry to reduce the peak qtarget and Te,idiv near the separatrix, and to produce the partial detachment. Integrated designs of the water cooled divertor target, cassette and coolant pipe routing have been developed in both EU and JA, based on the tungsten (W) monoblock concept with Cu-alloy pipe. For year-long operation, DEMO-specific risks such as radiation embrittlement of Cu-interlayers and Cu-alloy cooling pipe were recognized, and both foresee higher water temperature (130-200 °C) compared to that for ITER. At the same time, several improved technologies of high heat flux components have been developed in EU, and different heat sink design, i.e. Cu-alloy cooling pipes for targets and RAFM steel ones for the baffle, dome and cassette, was proposed in JA. The two approaches provide important case-studies of the DEMO divertor, and will significantly contribute to both DEMO designs

    An RND-Type Efflux System in Borrelia burgdorferi Is Involved in Virulence and Resistance to Antimicrobial Compounds

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    Borrelia burgdorferi is remarkable for its ability to thrive in widely different environments due to its ability to infect various organisms. In comparison to enteric Gram-negative bacteria, these spirochetes have only a few transmembrane proteins some of which are thought to play a role in solute and nutrient uptake and excretion of toxic substances. Here, we have identified an outer membrane protein, BesC, which is part of a putative export system comprising the components BesA, BesB and BesC. We show that BesC, a TolC homolog, forms channels in planar lipid bilayers and is involved in antibiotic resistance. A besC knockout was unable to establish infection in mice, signifying the importance of this outer membrane channel in the mammalian host. The biophysical properties of BesC could be explained by a model based on the channel-tunnel structure. We have also generated a structural model of the efflux apparatus showing the putative spatial orientation of BesC with respect to the AcrAB homologs BesAB. We believe that our findings will be helpful in unraveling the pathogenic mechanisms of borreliae as well as in developing novel therapeutic agents aiming to block the function of this secretion apparatus
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