1,100 research outputs found

    Repeat-Until-Success quantum computing using stationary and flying qubits

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    We introduce an architecture for robust and scalable quantum computation using both stationary qubits (e.g. single photon sources made out of trapped atoms, molecules, ions, quantum dots, or defect centers in solids) and flying qubits (e.g. photons). Our scheme solves some of the most pressing problems in existing non-hybrid proposals, which include the difficulty of scaling conventional stationary qubit approaches, and the lack of practical means for storing single photons in linear optics setups. We combine elements of two previous proposals for distributed quantum computing, namely the efficient photon-loss tolerant build up of cluster states by Barrett and Kok [Phys. Rev. A 71, 060310(R) (2005)] with the idea of Repeat-Until-Success (RUS) quantum computing by Lim et al. [Phys. Rev. Lett. 95, 030505 (2005)]. This idea can be used to perform eventually deterministic two-qubit logic gates on spatially separated stationary qubits via photon pair measurements. Under non-ideal conditions, where photon loss is a possibility, the resulting gates can still be used to build graph states for one-way quantum computing. In this paper, we describe the RUS method, present possible experimental realizations, and analyse the generation of graph states.Comment: 14 pages, 7 figures, minor changes, references and a discussion on the effect of photon dark counts adde

    Housing stability and diabetes among people living in New York city public housing

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    Public housing provides affordable housing and, potentially, housing stability for low-income families. Housing stability may be associated with lower incidence or prevalence and better management of a range of health conditions through many mechanisms. We aimed to test the hypotheses that public housing residency is associated with both housing stability and reduced risk of diabetes incidence, and the relationship between public housing and diabetes risk varies by levels of housing stability. Using 2004-16 World Trade Center Health Registry data, we compared outcomes (housing stability measured by sequence analysis of addresses, self-reported diabetes diagnoses) between 730 New York City public housing residents without prevalent diabetes at baseline and 730 propensity score-matched non-public housing residents. Sequence analysis found 3 mobility patterns among all 1460 enrollees, including stable housing (65%), limited mobility (27%), and unstable housing patterns (8%). Public housing residency was associated with stable housing over 12 years. Diabetes risk was not associated with public housing residency; however, among those experiencing housing instability, a higher risk of diabetes was found among public housing versus non-public housing residents. Of those stably housed, the association remained insignificant. These findings provide important evidence for a health benefit of public housing via housing stability among people living in public housing

    Thermal-aware 3D Microarchitectural Floorplanning

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    Next generation deep submicron processor design will need to take into consideration many performance limiting factors. Flip flops are inserted in order to prevent global wire delay from becoming nonlinear, enabling deeper pipelines and higher clock frequency. The move to 3D ICs will also likely be used to further shorten wirelength. This will cause thermal issues to become a major bottleneck to performance improvement. In this paper we propose a floorplanning algorithm which takes into consideration both thermal issues and profile weighted wirelength using mathematical programming. Our profile-driven objective improves performance by 20% over wirelength-driven. While the thermal-driven objective improves temperature by 24% on average over the profile-driven case

    \u3cem\u3eBorrelia burgdorferi\u3c/em\u3e EbfC Defines a Newly-Identified, Widespread Family of Bacterial DNA-Binding Proteins

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    The Lyme disease spirochete, Borrelia burgdorferi, encodes a novel type of DNA-binding protein named EbfC. Orthologs of EbfC are encoded by a wide range of bacterial species, so characterization of the borrelial protein has implications that span the eubacterial kingdom. The present work defines the DNA sequence required for high-affinity binding by EbfC to be the 4 bp broken palindrome GTnAC, where ‘n’ can be any nucleotide. Two high-affinity EbfC-binding sites are located immediately 5′ of B. burgdorferi erp transcriptional promoters, and binding of EbfC was found to alter the conformation of erp promoter DNA. Consensus EbfC-binding sites are abundantly distributed throughout the B. burgdorferi genome, occurring approximately once every 1 kb. These and other features of EbfC suggest that this small protein and its orthologs may represent a distinctive type of bacterial nucleoid-associated protein. EbfC was shown to bind DNA as a homodimer, and site-directed mutagenesis studies indicated that EbfC and its orthologs appear to bind DNA via a novel α-helical ‘tweezer’-like structure

    Predicting COVID-19 infection risk in people who are immunocompromised by antibody testing.

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    People with blood cancers have an increased risk of severe COVID-19 disease despite booster vaccine doses.1 This group, like other disease groups at increased risk of severe COVID-19, includes individuals with highly heterogeneous immune responses to vaccination.2 Although vaccine response studies and population studies identify similar diseases and treatments associated with increased risk of severe COVID-19, a direct correlation between antibody levels after vaccination and infection risk has been difficult to define. Identification of a laboratory correlate of infection risk would allow doctors and policy makers to target additional COVID-19 treatment or prophylactic efforts to people who are most in need

    Pre-hospital management protocols and perceived difficulty in diagnosing acute heart failure

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    Aim To illustrate the pre-hospital management arsenals and protocols in different EMS units, and to estimate the perceived difficulty of diagnosing suspected acute heart failure (AHF) compared with other common pre-hospital conditions. Methods and results A multinational survey included 104 emergency medical service (EMS) regions from 18 countries. Diagnostic and therapeutic arsenals related to AHF management were reported for each type of EMS unit. The prevalence and contents of management protocols for common medical conditions treated pre-hospitally was collected. The perceived difficulty of diagnosing AHF and other medical conditions by emergency medical dispatchers and EMS personnel was interrogated. Ultrasound devices and point-of-care testing were available in advanced life support and helicopter EMS units in fewer than 25% of EMS regions. AHF protocols were present in 80.8% of regions. Protocols for ST-elevation myocardial infarction, chest pain, and dyspnoea were present in 95.2, 80.8, and 76.0% of EMS regions, respectively. Protocolized diagnostic actions for AHF management included 12-lead electrocardiogram (92.1% of regions), ultrasound examination (16.0%), and point-of-care testings for troponin and BNP (6.0 and 3.5%). Therapeutic actions included supplementary oxygen (93.2%), non-invasive ventilation (80.7%), intravenous furosemide, opiates, nitroglycerine (69.0, 68.6, and 57.0%), and intubation 71.5%. Diagnosing suspected AHF was considered easy to moderate by EMS personnel and moderate to difficult by emergency medical dispatchers (without significant differences between de novo and decompensated heart failure). In both settings, diagnosis of suspected AHF was considered easier than pulmonary embolism and more difficult than ST-elevation myocardial infarction, asthma, and stroke. Conclusions The prevalence of AHF protocols is rather high but the contents seem to vary. Difficulty of diagnosing suspected AHF seems to be moderate compared with other pre-hospital conditions

    Epitaxial Growth and Processing of Compound Semiconductors

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    Contains an introduction and reports on six research projects.Defense Advanced Research Projects Agency/U.S. Navy - Office of Naval Research University Research Initiative Subcontract N00014-92-J-1893Joint Services Electronics Program Grant DAAH04-95-1-0038National Center for Integrated Photonics Technology Contract 542-381National Science Foundation Grant DMR 92-02957MIT Lincoln Laboratory Contract BX-6085National Center for Integrated Photonics Technology Subcontract 542-383U.S. Air Force - Office of Scientific Research Grant F49620-96-1-0126U.S. Navy - Office of Naval Research Grant N00014-91-J-1956National Science Foundation Grant DMR 94-0033

    First results from the JWST Early Release Science Program Q3D: Ionization cone, clumpy star formation and shocks in a z=3z=3 extremely red quasar host

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    Massive galaxies formed most actively at redshifts z=13z=1-3 during the period known as `cosmic noon.' Here we present an emission-line study of an extremely red quasar SDSSJ165202.64+172852.3 host galaxy at z=2.94z=2.94, based on observations with the Near Infrared Spectrograph (NIRSpec) integral field unit (IFU) on board JWST. We use standard emission-line diagnostic ratios to map the sources of gas ionization across the host and a swarm of companion galaxies. The quasar dominates the photoionization, but we also discover shock-excited regions orthogonal to the ionization cone and the quasar-driven outflow. These shocks could be merger-induced or -- more likely, given the presence of a powerful galactic-scale quasar outflow -- these are signatures of wide-angle outflows that can reach parts of the galaxy that are not directly illuminated by the quasar. Finally, the kinematically narrow emission associated with the host galaxy presents as a collection of 1 kpc-scale clumps forming stars at a rate of at least 200 MM_{\odot} yr1^{-1}. The ISM within these clumps shows high electron densities, reaching up to 3,000 cm3^{-3} with metallicities ranging from half to a third solar with a positive metallicity gradient and V band extinctions up to 3 magnitudes. The star formation conditions are far more extreme in these regions than in local star-forming galaxies but consistent with that of massive galaxies at cosmic noon. JWST observations reveal an archetypical rapidly forming massive galaxy undergoing a merger, a clumpy starburst, an episode of obscured near-Eddington quasar activity, and an extremely powerful quasar outflow simultaneously.Comment: 19 pages, 8 figures. Accepted for publication in Ap

    Effectiveness of integrating a pragmatic pathway for prescribing liraglutide 3.0mg in weight management services (STRIVE study): a multicentre, open-label, parallel-group, randomized controlled trial

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    Summary. Background: An effective prescribing pathway for liraglutide 3 mg, an approved obesity pharmacotherapy, may improve treatment access. This trial compared a targeted prescribing pathway for liraglutide 3 mg with multiple stopping rules in specialist weight management services (SWMS) to standard SWMS care. Methods: This phase four, two-year, multicentre, open-label, parallel-group, real-world randomized clinical trial (ClinicalTrials.gov: NCT03036800) enrolled adults with BMI ≥35 kg/m2 plus prediabetes, type 2 diabetes, hypertension or sleep apnoea from five SWMS in Ireland and UK. Participants were randomly allocated (2:1, stratified by centre and BMI) to SWMS care plus a targeted prescribing pathway for once daily subcutaneous liraglutide 3 mg (intervention) with stopping rules at 16 (≥5% weight loss, WL), 32 (≥10% WL) and 52 weeks (≥15% WL) or to SWMS care alone (control) through an online randomization service. The primary outcome was WL ≥15% at 52 weeks, assessed by complete cases analysis. All randomized participants were included in safety analysis. Findings From November 28, 2017 to February 28, 2020, 434 participants were screened, and 392 randomized (260 intervention; 132 control), while 294 (201 intervention; 93 control) included in the 52 weeks complete case analysis. More intervention than control participants achieved WL ≥15% at 52 weeks [51/201 (25.4%) vs 6/93 (6.5%); odds ratio 5.18; 95% CI 2.09, 12.88; p < 0.0001]. More adverse events occurred in the intervention (238/260, 91.5%; two deaths) than control (89/132, 67.4%; no deaths) group. Interpretation: A targeted prescribing pathway for liraglutide 3 mg helps more people achieve ≥15% WL at 52 weeks than standard care alone

    First results from the JWST Early Release Science Program Q3D: The Warm Ionized Gas Outflow in z ~ 1.6 Quasar XID 2028 and its Impact on the Host Galaxy

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    Quasar feedback may regulate the growth of supermassive black holes, quench coeval star formation, and impact galaxy morphology and the circumgalactic medium. However, direct evidence for quasar feedback in action at the epoch of peak black hole accretion at z ~ 2 remains elusive. A good case in point is the z = 1.6 quasar WISEA J100211.29+013706.7 (XID 2028) where past analyses of the same ground-based data have come to different conclusions. Here we revisit this object with the integral field unit of the Near Infrared Spectrograph (NIRSpec) on board the James Webb Space Telescope (JWST) as part of Early Release Science program Q3D. The excellent angular resolution and sensitivity of the JWST data reveal new morphological and kinematic sub-structures in the outflowing gas plume. An analysis of the emission line ratios indicates that photoionization by the central quasar dominates the ionization state of the gas with no obvious sign for a major contribution from hot young stars anywhere in the host galaxy. Rest-frame near-ultraviolet emission aligned along the wide-angle cone of outflowing gas is interpreted as a scattering cone. The outflow has cleared a channel in the dusty host galaxy through which some of the quasar ionizing radiation is able to escape and heat the surrounding interstellar and circumgalactic media. The warm ionized outflow is not powerful enough to impact the host galaxy via mechanical feedback, but radiative feedback by the AGN, aided by the outflow, may help explain the unusually small molecular gas mass fraction in the galaxy host.Comment: 17 pages, 9 figures, accepted for publication in The Astrophysical Journa
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