408 research outputs found

    The Rotating-Wave Approximation: Consistency and Applicability from an Open Quantum System Analysis

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    We provide an in-depth and thorough treatment of the validity of the rotating-wave approximation (RWA) in an open quantum system. We find that when it is introduced after tracing out the environment, all timescales of the open system are correctly reproduced, but the details of the quantum state may not be. The RWA made before the trace is more problematic: it results in incorrect values for environmentally-induced shifts to system frequencies, and the resulting theory has no Markovian limit. We point out that great care must be taken when coupling two open systems together under the RWA. Though the RWA can yield a master equation of Lindblad form similar to what one might get in the Markovian limit with white noise, the master equation for the two coupled systems is not a simple combination of the master equation for each system, as is possible in the Markovian limit. Such a naive combination yields inaccurate dynamics. To obtain the correct master equation for the composite system a proper consideration of the non-Markovian dynamics is required.Comment: 17 pages, 0 figures

    Duration of Outpatient Antibiotic Therapy for Common Outpatient Infections, 2017.

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    Our objective was to describe the duration of antibiotic therapy for the management of common outpatient conditions. The median duration of antibiotic courses for most common conditions, except for acute cystitis, was 10 days, in many cases exceeding guideline-recommended durations

    Changes in outpatient antibiotic prescribing for acute respiratory illnesses, 2011 to 2018.

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    OBJECTIVES: To describe acute respiratory illnesses (ARI) visits and antibiotic prescriptions in 2011 and 2018 across outpatient settings to evaluate progress in reducing unnecessary antibiotic prescribing for ARIs. DESIGN: Cross-sectional study. SETTING AND PATIENTS: Outpatient medical and pharmacy claims captured in the IBM MarketScan commercial database, a national convenience sample of privately insured individuals aged <65 years. METHODS: We calculated the annual number of ARI visits and visits with oral antibiotic prescriptions per 1,000 enrollees overall and by age category, sex, and setting in 2011 and 2018. We compared these and calculated prevalence rate ratios (PRRs). We adapted existing tiered-diagnosis methodology for International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes. RESULTS: In our study population, there were 829 ARI visits per 1,000 enrollees in 2011 compared with 760 ARI visits per 1,000 enrollees in 2018. In 2011, 39.3% of ARI visits were associated with ≥1 oral antibiotic prescription versus 36.2% in 2018. In 2018 compared with 2011, overall ARI visits decreased 8% (PRR, 0.92; 99.99% confidence interval [CI], 0.92-0.92), whereas visits with antibiotic prescriptions decreased 16% (PRR, 0.84; 99.99% CI, 0.84-0.85). Visits for antibiotic-inappropriate ARIs decreased by 9% (PRR, 0.91; 99.99% CI, 0.91-0.92), and visits with antibiotic prescriptions for these conditions decreased by 32% (PRR, 0.68; 99.99% CI, 0.67-0.68) from 2011 to 2018. CONCLUSIONS: Both the rate of antibiotic prescriptions per 1,000 enrollees and the percentage of visits with antibiotic prescriptions decreased modestly from 2011 to 2018 in our study population. These decreases were greatest for antibiotic-inappropriate ARIs; however, additional reductions in inappropriate antibiotic prescribing are needed

    Antibiotic prescribing for acute gastroenteritis during ambulatory care visits-United States, 2006-2015.

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    OBJECTIVE: To describe national antibiotic prescribing for acute gastroenteritis (AGE). SETTING: Ambulatory care. METHODS: We included visits with diagnoses for bacterial and viral gastrointestinal infections from the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey (NAMCS/NHAMCS; 2006-2015) and the IBM Watson 2014 MarketScan Commercial Claims and Encounters Database. For NAMCS/NHAMCS, we calculated annual percentage estimates and 99% confidence intervals (CIs) of visits with antibiotics prescribed; sample sizes were too small to calculate estimates by pathogen. For MarketScan, we used Poisson regression to calculate the percentage of visits with antibiotics prescribed and 95% CIs, including by pathogen. RESULTS: We included 10,210 NAMCS/NHAMCS AGE visits; an estimated 13.3% (99% CI, 11.2%-15.4%) resulted in antibiotic prescriptions, most frequently fluoroquinolones (28.7%; 99% CI, 21.1%-36.3%), nitroimidazoles (20.2%; 99% CI, 14.0%-26.4%), and penicillins (18.9%; 99% CI, 11.6%-26.2%). In NAMCS/NHAMCS, antibiotic prescribing was least frequent in emergency departments (10.8%; 99% CI, 9.5%-12.1%). Among 1,868,465 MarketScan AGE visits, antibiotics were prescribed for 13.8% (95% CI, 13.7%-13.8%), most commonly for Yersinia (46.7%; 95% CI, 21.4%-71.9%), Campylobacter (44.8%; 95% CI, 41.5%-48.1%), Shigella (39.7%; 95% CI, 35.9%-43.6%), typhoid or paratyphoid fever (32.7%; (95% CI, 27.2%-38.3%), and nontyphoidal Salmonella (31.7%; 95% CI, 29.5%-33.9%). Antibiotics were prescribed for 12.3% (95% CI, 11.7%-13.0%) of visits for viral gastroenteritis. CONCLUSIONS: Overall, ∼13% of AGE visits resulted in antibiotic prescriptions. Antibiotics were unnecessarily prescribed for viral gastroenteritis and some bacterial infections for which antibiotics are not recommended. Antibiotic stewardship assessments and interventions for AGE are needed in ambulatory settings

    Perceptions of co-design, co-development and co-delivery (Co-3D) as part of the co-production process – Insights for climate services

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    Co-design, co-development, and co-delivery (Co-3D for short) are activities within the co-production research pathway that are increasingly being used in climate change science and adaptation projects. However, the research community is still coming to understand how best to incorporate Co-3D in practice, as each project has a specific context around stakeholder relationships, governance arrangements, and capacity to actively participate. This paper outlines five case studies from Australia as examples of different projects engaging with Co-3D in different ways in order to explore how Co-3D is being used and might be improved. Crucially, we include the perceptions and experiences of researchers, funders and end users, as well as our own critical reflections. Each of the projects self-describes as using ‘co-production’, but the extent and format varies widely with different combinations of co-design, co-development and/or co-delivery used in each. Our findings show that without clear understanding of Co-3D within the co-production process, aspects of Co-3D may not be properly considered in planning or implementation. Co-3D activities are not completely distinct, rather they form a continuum of engagement and integration across phases of project work. Thus, the specific definitions and delineations between these terms may not be required for them to be applied. However, practical and explicit negotiation of what ‘co-production’ means in different project contexts is needed so that all parties understand their roles and responsibilities. Further, more evaluations of outcomes and stakeholder experiences are required. We provide seven principles of Co-3D that should be considered when embarking on co-production projects

    Acquisition of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) carriage after exposure to systemic antimicrobials during travel: systematic review and meta-analysis

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    BACKGROUND: International travel is an important risk factor for colonization with extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE). Antimicrobial use during travel likely amplifies this risk, yet to what extent, and whether it varies by antimicrobial class, has not been established. METHODS: We conducted a systematic review that included prospective cohorts reporting both receipt of systemic antimicrobials and acquired ESBL-PE isolated from stool or rectum during international travel. We performed a random effects meta-analysis to estimate odds of acquiring ESBL-PE due to antimicrobials during travel, overall and by antimicrobial class. RESULTS: Fifteen studies were included. The study population was mainly female travellers from high income countries recruited primarily from travel clinics. Participants travelled most frequently to Asia and Africa with 10% reporting antimicrobial use during travel. The combined odds ratio (OR) for ESBL-PE acquisition during travel was 2.37 for antimicrobial use overall (95% confidence interval [CI], 1.69 to 3.33), but there was substantial heterogeneity between studies. Fluoroquinolones were the antibiotic class associated with the highest combined OR of ESBL-PE acquisition, compared to no antimicrobial use (OR 4.68, 95% CI, 2.34 to 9.37). CONCLUSIONS: The risk of ESBL-PE colonization during travel is increased substantially with exposure to antimicrobials, especially fluoroquinolones. While a small proportion of colonized individuals will develop a resistant infection, there remains the potential for onward spread among returning travellers. Public health efforts to decrease inappropriate antimicrobial usage during travel are warranted
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