1,197 research outputs found

    Quantum key distribution and 1 Gbit/s data encryption over a single fibre

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    We perform quantum key distribution (QKD) in the presence of 4 classical channels in a C-band dense wavelength division multiplexing (DWDM) configuration using a commercial QKD system. The classical channels are used for key distillation and 1 Gbps encrypted communication, rendering the entire system independent from any other communication channel than a single dedicated fibre. We successfully distil secret keys over fibre spans of up to 50 km. The separation between quantum channel and nearest classical channel is only 200 GHz, while the classical channels are all separated by 100 GHz. In addition to that we discuss possible improvements and alternative configurations, for instance whether it is advantageous to choose the quantum channel at 1310 nm or to opt for a pure C-band configuration.Comment: 9 pages, 7 figure

    Super-resolution far-field ghost imaging via compressive sampling

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    Much more image details can be resolved by improving the system's imaging resolution and enhancing the resolution beyond the system's Rayleigh diffraction limit is generally called super-resolution. By combining the sparse prior property of images with the ghost imaging method, we demonstrated experimentally that super-resolution imaging can be nonlocally achieved in the far field even without looking at the object. Physical explanation of super-resolution ghost imaging via compressive sampling and its potential applications are also discussed.Comment: 4pages,4figure

    Sustainability, Peak oil

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    none4openDe leo Federica, Pier paolo Miglietta, Stefania Massari, Marcello RubertiDE LEO, Federica; Miglietta, PIER PAOLO; Massari, Stefania; Ruberti, Marcell

    Green technologies for sustainable water management: Introduction and overview

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    © 2016 American Society of Civil Engineers. This chapter presents the background, current development and future opportunities of green technologies and issues to facilitate strategic planning of sustainable water management systems. It describes the fundamental concepts and current and future applications of green technologies for sustainable improvement in water management. The chapter discusses the appropriate approaches and policies in achieving sustainable objectives and promoting green design and supplies for water utilization. Sustainable water management has received great attention over recent years because of its substantial benefits to the environment, society, and economy. Improvements in water management are likely to come from green technologies fueled by individual curiosity, dedicated effort, and opportunities within a strategic program supported by national and international agencies, universities, and industries. These innovations can significantly contribute to less nonrenewable resource requirement, reduced carbon footprint, greenhouse gas emissions and costs, minimized water losses, and enhanced removal of contaminants

    Dupilumab improves lung function in patients with uncontrolled, moderate-to-severe asthma

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    Background: Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin-4 and interleukin-13, key drivers of type 2 inflammation. In the phase 3 LIBERTY ASTHMA QUEST trial (NCT02414854) in patients with uncontrolled, moderate-to-severe asthma, add-on dupilumab 200 mg or 300 mg every 2 weeks reduced exacerbations and improved forced expiratory volume in 1 s (FEV1) and quality of life over 52 weeks. This analysis evaluates dupilimab's effect on lung function in the overall population, and subgroups with baseline elevated type 2 inflammatory biomarkers. Methods: Patients were randomised to 52 weeks of subcutaneous dupilumab 200 mg every 2 weeks, 300 mg every 2 weeks, or matched-volume placebos. Lung function outcomes were analysed in the overall population, in patients with ≥150 eosinophils·µL−1, ≥300 eosinophils·µL−1, ≥25 ppb fractional exhaled nitric oxide (FeNO), and both ≥150 eosinophils·µL−1 and ≥25 ppb FeNO, at baseline. Results: Dupilumab treatment (200 mg and 300 mg every 2 weeks) resulted in significant improvements versus placebo after 52 weeks in pre-bronchodilator FEV1 (0.20 and 0.13 L, respectively, versus placebo) and post-bronchodilator FEV1 (0.19 and 0.13 L, respectively), forced vital capacity (FVC) (0.20 and 0.14 L, respectively), forced expiratory flow (0.19 and 0.13 L·s−1, respectively) and pre-bronchodilator FEV1/FVC ratio (1.75% and 1.61%, respectively) in the overall population (p<0.001). Difference versus placebo in post-bronchodilator FEV1 slope of change (weeks 4–52) was significant (0.04 L·year−1; p<0.05). Greater improvements were achieved in patients with elevated baseline blood eosinophil and/or FeNO levels for most outcomes. Conclusions: Dupilumab improves lung function outcomes, including large and small airway measurements and fixed airway obstruction, in patients with uncontrolled, moderate-to-severe asthma; particularly in patients with elevated biomarkers of type 2 inflammation

    Novel octaketide macrolides related to 6-deoxyerythronolide B provide evidence for iterative operation of the erythromycin polyketide synthase

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    AbstractBackground: The macrolide antibiotic erythromycin A, like other complex aliphatic polyketides, is synthesised by a bacterial modular polyketide synthase (PKS). Such PKSs, in contrast to other fatty acid and polyketide synthases which work iteratively, contain a separate set or module of enzyme activities for each successive cycle of polyketide chain extension, and the number and type of modules together determine the structure of the polyketide product. Thus, the six extension modules of the erythromycin PKS (DEBS) together catalyse the production of the specific heptaketide 6-deoxyerythronolide B.Results: A mutant strain of the erythromycin producer Saccharopolyspora erythraea, which accumulates the aglycone intermediate erythronolide B, was found unexpectedly to produce two novel octaketides, both 16-membered macrolides. These compounds were detectable in fermentation broths of wild-type S. erythraea, but not in a strain from which the DEBS genes had been specifically deleted. From their structures, both of these octaketides appear to be aberrant products of DEBS in which module 4 has ‘stuttered’, that is, has catalysed two successive cycles of chain extension.Conclusions: The isolation of novel DEBS-derived octaketides provides the first evidence that an extension module in a modular PKS has the potential to catalyse iterative rounds of chain elongation like other type I FAS and PKS systems. The factors governing the extent of such ‘stuttering’ remain to be determined

    Building a Social Mandate for Climate Action: Lessons from COVID-19

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    The COVID-19 imposed lockdown has led to a number of temporary environmental side effects (reduced global emissions, cleaner air, less noise), that the climate community has aspired to achieve over a number of decades. However, these benefits have been achieved at a massive cost to welfare and the economy. This commentary draws lessons from the COVID-19 crisis for climate change. It discusses whether there are more sustainable ways of achieving these benefits, as part of a more desirable, low carbon resilient future, in a more planned, inclusive and less disruptive way. In order to achieve this, we argue for a clearer social contract between citizens and the state. We discuss how COVID-19 has demonstrated that behaviours can change abruptly, that these changes come at a cost, that we need a ‘social mandate’ to ensure these changes remain in the long-term, and that science plays an important role in informing this process. We suggest that deliberative engagement mechanisms, such as citizens’ assemblies and juries, could be a powerful way to build a social mandate for climate action post-COVID-19. This would enable behaviour changes to become more accepted, embedded and bearable in the long-term and provide the basis for future climate action

    Assessing the Quality of Care for Pneumonia in Integrated Community Case Management: A Cross-Sectional Mixed Methods Study

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    Background Pneumonia is the leading infectious cause of mortality in children under five worldwide. Community-level interventions, such as integrated community case management, have great potential to reduce the burden of pneumonia, as well as other diseases, especially in remote populations. However, there are still questions as to whether community health workers (CHW) are able to accurately assess symptoms of pneumonia and prescribe appropriate treatment. This research addresses limitations of previous studies using innovative methodology to assess the accuracy of respiratory rate measurement by CHWs and provides new evidence on the quality of care given for children with symptoms of pneumonia. It is one of few that assesses CHW performance in their usual setting, with independent re-examination by experts, following a considerable period of time post-training of CHWs. Methods In this cross-sectional mixed methods study, 1,497 CHW consultations, conducted by 90 CHWs in two districts of Luapula province, Zambia, were directly observed, with measurement of respiratory rate for children with suspected pneumonia recorded by video. Using the video footage, a retrospective reference standard assessment of respiratory rate was conducted by experts. Counts taken by CHWs were compared against the reference standard and appropriateness of the treatment prescribed by CHWs was assessed. To supplement observational findings, three focus group discussions and nine in depth interviews with CHWs were conducted. Results and Conclusion The findings support existing literature that CHWs are capable of measuring respiratory rates and providing appropriate treatment, with 81% and 78% agreement, respectively, between CHWs and experts. Accuracy in diagnosis could be strengthened through further training and the development of improved diagnostic tools appropriate for resource-poor settings

    Public opinion on energy crops in the landscape: considerations for the expansion of renewable energy from biomass

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    Public attitudes were assessed towards two dedicated biomass crops – Miscanthus and Short Rotation Coppice (SRC), particularly regarding their visual impacts in the landscape. Results are based on responses to photographic and computer-generated images as the crops are still relatively scarce in the landscape. A questionnaire survey indicated little public concern about potential landscape aesthetics but more concern about attendant built infrastructure. Focus group meetings and interviews indicated support for biomass end uses that bring direct benefits to local communities. Questions arise as to how well the imagery used was able to portray the true nature of these tall, dense, perennial plants but based on the responses obtained and given the caveat that there was limited personal experience of the crops, it appears unlikely that wide-scale planting of biomass crops will give rise to substantial public concern in relation to their visual impact in the landscape
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