1,357 research outputs found

    Quantum gate characterization in an extended Hilbert space

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    We describe an approach for characterizing the process of quantum gates using quantum process tomography, by first modeling them in an extended Hilbert space, which includes non-qubit degrees of freedom. To prevent unphysical processes from being predicted, present quantum process tomography procedures incorporate mathematical constraints, which make no assumptions as to the actual physical nature of the system being described. By contrast, the procedure presented here ensures physicality by placing physical constraints on the nature of quantum processes. This allows quantum process tomography to be performed using a smaller experimental data set, and produces parameters with a direct physical interpretation. The approach is demonstrated by example of mode-matching in an all-optical controlled-NOT gate. The techniques described are non-specific and could be applied to other optical circuits or quantum computing architectures.Comment: 4 pages, 2 figures, REVTeX (published version

    Roles and responsibilities of Governors in the UK Overseas Territories : prerogative power and democratic accountability

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    Relations between the United Kingdom (UK) and its 14 Overseas Territories (OTs) are long-standing and multifaceted. Each of the ten inhabited OTs has its own parliament or council, and in most cases, a Cabinet; yet, their governance remains based on a ‘partnership’ with the UK, with a division of responsibilities between them. The role of the Governor in ensuring that this ‘partnership’ works effectively is crucial. However, there are concerns about how Governors often exercise their powers (deriving authority from Royal prerogative) and whether a ‘democratic deficit’ exists. They must also navigate the sometimes-competing interests between the UK and the OTs, which can be challenging. This article highlights and interrogates some of these complexities and difficulties at a time when the power and reach of the British Monarch – and thus by association OT Governors – is under scrutiny. In particular, the article considers: the Governor’s softer, day-to-day influencing role; their more formal constitutional powers, where they can and do intervene in legislative matters; and if the ‘democratic deficit’ inherent in the position can be addressed by greater representation of the OTs in the UK Parliament.peer-reviewe

    Prevalence of treatment-resistant hypertension after considering pseudo-resistance and morbidity: a cross-sectional study in Irish primary care

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    peer-reviewedBackground To confirm treatment-resistant hypertension (TRH), ambulatory blood pressure measurement (ABPM) must exclude white-coat hypertension (WCH), three or more medications should be prescribed at the optimal doses tolerated, and non-adherence and lifestyle should be examined. Most previous studies have not adequately considered pseudo-resistance and merely provide an apparent TRH (aTRH) prevalence figure. Aim To conduct a cross-sectional study of the prevalence of aTRH in general practice, and then consider pseudo-resistance and morbidity. Design and setting With support, 16 practices ran an anatomical therapeutic chemical (ATC) drug search, identifying patients on any possible hypertensive medications, and then a search of individual patients' electronic records took place. Method ABPM was used to rule out WCH. The World Health Organization-defined daily dosing guidelines determined adequate dosing. Adherence was defined as whether patients requested nine or more repeat monthly prescriptions within the past year. Results Sixteen practices participated (n = 50 172), and 646 patients had aTRH. Dosing was adequate in 19% of patients, 84% were adherent to medications, as defined by prescription refill, and 43% had ever had an ABPM. Using a BP cut-off of 140/90 mmHg, the prevalence of aTRH was 9% (95% confidence interval [CI] = 9.0 to 10.0). Consideration of pseudo-resistance further reduced prevalence rates to 3% (95% CI = 3.0 to 4.0). Conclusion Reviewing individual patient records results in a lower estimate of prevalence of TRH than has been previously reported. Further consideration for individual patients of pseudo-resistance additionally lowers these estimates, and may be all that is required for management in the vast majority of cases.PUBLISHEDpeer-reviewe

    Nonverbal Vocalizations as Speech: Characterizing Natural-Environment Audio from Nonverbal Individuals with Autism

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    The study of nonverbal vocalizations, such as sighs, grunts, and monosyllabic sounds, has largely revolved around the social and affective implications of these sounds within typical speech. However, for individuals who do not use any traditional speech, including those with non- or minimally verbal (nv/mv) autism, these vocalizations contain important, individual-specific affective and communicative information. This paper outlines the methodology, analysis, and technology to investigate the production, perception, and meaning of nonverbal vocalizations from nv/mv individuals in natural environments. We are developing novel signal processing and machine learning methods that will help enable augmentative communication technology, and we are producing a nonverbal vocalization dataset for public release. We hope this work will expand the scientific understanding of these exceptional individuals’ language development and the field of communication more generally

    Nonverbal Vocalizations as Speech: Characterizing Natural-Environment Audio from Nonverbal Individuals with Autism

    Get PDF
    The study of nonverbal vocalizations, such as sighs, grunts, and monosyllabic sounds, has largely revolved around the social and affective implications of these sounds within typical speech. However, for individuals who do not use any traditional speech, including those with non- or minimally verbal (nv/mv) autism, these vocalizations contain important, individual-specific affective and communicative information. This paper outlines the methodology, analysis, and technology to investigate the production, perception, and meaning of nonverbal vocalizations from nv/mv individuals in natural environments. We are developing novel signal processing and machine learning methods that will help enable augmentative communication technology, and we are producing a nonverbal vocalization dataset for public release. We hope this work will expand the scientific understanding of these exceptional individuals’ language development and the field of communication more generally

    Safer Prescribing:A Trial of Education, Informatics, and Financial Incentives

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    BACKGROUND High-risk prescribing and preventable drug-related complications are common in primary care. We evaluated whether the rates of high-risk prescribing by primary care clinicians and the related clinical outcomes would be reduced by a complex intervention. METHODS In this cluster-randomized, stepped-wedge trial conducted in Tayside, Scotland, we randomly assigned participating primary care practices to various start dates for a 48-week intervention comprising professional education, informatics to facilitate review, and financial incentives for practices to review patients’ charts to assess appropriateness. The primary outcome was patient-level exposure to any of nine measures of high-risk prescribing of nonsteroidal antiinflammatory drugs (NSAIDs) or selected antiplatelet agents (e.g., NSAID prescription in a patient with chronic kidney disease or coprescription of an NSAID and an oral anticoagulant without gastroprotection). Prespecified secondary outcomes included the incidence of related hospital admissions. Analyses were performed according to the intention-to-treat principle, with the use of mixed-effect models to account for clustering in the data. RESULTS A total of 34 practices underwent randomization, 33 of which completed the study. Data were analyzed for 33,334 patients at risk at one or more points in the preintervention period and for 33,060 at risk at one or more points in the intervention period. Targeted high-risk prescribing was significantly reduced, from a rate of 3.7% (1102 of 29,537 patients at risk) immediately before the intervention to 2.2% (674 of 30,187) at the end of the intervention (adjusted odds ratio, 0.63; 95% confidence interval [CI], 0.57 to 0.68; P<0.001). The rate of hospital admissions for gastrointestinal ulcer or bleeding was significantly reduced from the preintervention period to the intervention period (from 55.7 to 37.0 admissions per 10,000 person-years; rate ratio, 0.66; 95% CI, 0.51 to 0.86; P = 0.002), as was the rate of admissions for heart failure (from 707.7 to 513.5 admissions per 10,000 person-years; rate ratio, 0.73; 95% CI, 0.56 to 0.95; P = 0.02), but admissions for acute kidney injury were not (101.9 and 86.0 admissions per 10,000 person-years, respectively; rate ratio, 0.84; 95% CI, 0.68 to 1.09; P = 0.19). CONCLUSIONS A complex intervention combining professional education, informatics, and financial incentives reduced the rate of high-risk prescribing of antiplatelet medications and NSAIDs and may have improved clinical outcomes

    Swift Observations of GRB 050603: An afterglow with a steep late time decay slope

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    We report the results of Swift observations of the Gamma Ray Burst GRB 050603. With a V magnitude V=18.2 about 10 hours after the burst the optical afterglow was the brightest so far detected by Swift and one of the brightest optical afterglows ever seen. The Burst Alert Telescope (BAT) light curves show three fast-rise-exponential-decay spikes with T90T_{90}=12s and a fluence of 7.6×10−6\times 10^{-6} ergs cm−2^{-2} in the 15-150 keV band. With an Eγ,iso=1.26×1054E_{\rm \gamma, iso} = 1.26 \times 10^{54} ergs it was also one of the most energetic bursts of all times. The Swift spacecraft began observing of the afterglow with the narrow-field instruments about 10 hours after the detection of the burst. The burst was bright enough to be detected by the Swift UV/Optical telescope (UVOT) for almost 3 days and by the X-ray Telescope (XRT) for a week after the burst. The X-ray light curve shows a rapidly fading afterglow with a decay index α\alpha=1.76−0.07+0.15^{+0.15}_{-0.07}. The X-ray energy spectral index was βX\beta_{\rm X}=0.71\plm0.10 with the column density in agreement with the Galactic value. The spectral analysis does not show an obvious change in the X-ray spectral slope over time. The optical UVOT light curve decays with a slope of α\alpha=1.8\plm0.2. The steepness and the similarity of the optical and X-ray decay rates suggest that the afterglow was observed after the jet break. We estimate a jet opening angle of about 1-2∘^{\circ}Comment: 14 pages, accepted for publication in Ap
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