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Antenna-pattern measurements obtained from a double-metal supra-terahertz-frequency (supra-THz) quantum cascade laser (QCL) are presented. The QCL is mounted within a mechanically micro-machined waveguide cavity containing dual diagonal feedhorns. Operating in continuous-wave mode at 3.5 THz, and at an ambient temperature of ~60 K, QCL emission has been directed via the feedhorns to a supra-THz detector mounted on a multi-axis linear scanner. Comparison of simulated and measured far-field antenna patterns shows an excellent degree of correlation between beamwidth (full-width-half-maximum) and sidelobe content and a very substantial improvement when compared with unmounted devices. Additionally, a single output has been used to successfully illuminate and demonstrate an optical breadboard arrangement associated with a future supra-THz Earth observation space-borne payload. Our novel device has therefore provided a valuable demonstration of the effectiveness of supra-THz diagonal feedhorns and QCL devices for future space-borne ultra-high-frequency Earth-observing heterodyne radiometers.
Introduction: Many drugs, including cannabis and alcohol, cause impairment and contribute to motor vehicle collisions (MVCs). Policy makers require knowledge of the prevalence of drug use in crash-involved drivers, and types of drugs used in order to develop effective prevention programs. This issue is particularly relevant with the recent legalization of cannabis. We aim to study the prevalence of alcohol, cannabis, sedating medications, and other drugs in injured drivers from 4 Canadian Provinces. Methods: This prospective cohort study obtained excess clinical blood samples from consecutive injured drivers who attended a participating Canadian trauma centre following a MVC. Blood samples were analyzed using a broad spectrum toxicology screen capable of detecting cannabinoids, cocaine, amphetamines (including their major analogues), and opioids as well as psychotropic pharmaceuticals (including antihistamines, benzodiazepines, other hypnotics, and sedating antidepressants). Alcohol and cannabinoids were quantified. Health records were reviewed to extract demographic, medical, and MVC information using a standardized data collection tool. Results: This study has been collecting data in 4 trauma centres in British Columbia (BC) since 2011 and was launched in 2 trauma centres in Alberta (AB), 1 in Saskatchewan (SK), and 2 in Ontario (ON) in 2018. In preliminary results from BC (n = 2412), 8% of injured drivers tested positive for THC and 13% for alcohol. Preliminary results from other provinces (n = 301) suggest a regional variation in prevalence of drivers testing positive for THC (10% - 27%), alcohol (17% - 29%), and other drugs. By May 2018, an estimated 4500 cases from BC, 600 from AB, 150 from SK, and 650 from ON will have been analyzed. We will report the prevalence of positive tests for alcohol, THC, other recreational drugs, and sedating medications, pre and post cannabis legalization. The number of cases with alcohol and/or THC levels above Canadian per se limits will also be reported. Results will be reported according to province, driver sex, age, single vs. multi vehicle crashes, and requirement for hospital admission. Conclusion: This will be among the largest international datasets on drug use by injured drivers. Our findings will provide patterns of drug and alcohol impairment in 4 Canadian provinces pre and post cannabis legalization. The significance of these findings and implication for impaired driving policy and prevention programs in Canada will be discussed.
Introduction: Emergency department (ED) return visits are used for quality monitoring. Health information technology (HIT) has historically supported return visit programs in the same hospital or hospital system. The Emergency Department Return Visit Quality Program (EDRVQP) is a novel population level continuous quality improvement (QI) program connecting EDs across Ontario that leverages HIT. We sought to describe the EDRVQP HIT architecture, experience of participants, enabling program factors and barriers. Methods: The Informatics Stack conceptual framework was used to describe the HIT architecture. A literature review of peer-reviewed background literature, and stakeholder organization reports was conducted. Purposive sampling identified key informants. Semi-structured interviews were conducted until saturation. Common themes were identified by inductive qualitative thematic analysis. Results: Twenty-three participants from 15 organizations were interviewed. The EDRVQP architecture description is presented across the Informatics Stack. The levels from most comprehensive to most basic are world, organization, perspectives/roles, goals/functions, workflow/behaviour/adoption, information systems, modules, data/information/knowledge/algorithms, and technology. Enabling factors were a high rate of EHR adoption, provincial legislative mandate for data collection and program membership, use of functional and data standards, local variability, phased deployment, and QI and patient safety culture. Two main barriers were increased case turnaround time and privacy legislation. Conclusion: The Informatics Stack framework provides a robust approach to thoroughly describe the HIT architecture of this population health programs. The EDRVQP is a population health program that illustrates the pragmatic use of continuous QI methodology across a population (provincial) level.
Introduction: Effective communication to develop a shared understanding of patient expectations is critical to a positive encounter in the Emergency Department (ED). However, there is limited research examining Patient/Caregiver (P/C ) expectations in the ED and what factors lead to P/C presentation. This study aims to address this gap by answering the following questions: 1) What are common P/C reported factors affecting ED presentation? 2) What are common P/C expectations of an ED visit? 3) How do P/C expectations vary based on ED site or factors affecting presentation in the ED? Methods: The Preparing Emergency Patients and Providers (PrEPP) tool was designed to collect P/C expectations, worries, perceived causes of symptoms, and factors affecting presentation from a convenience sample of patient visits to the emergency department (ED). The PrEPP tool was provided to all P/Cs with CTAS 2-5 when they registered at one of 4 EDs in the Halifax area from January to June 2016. Completed tools were collected in a REDCap database where qualitative data was coded into categories (i.e. presenting illness, injury). Descriptive and chi-squared statistical analyses were performed. Results: In total, 11,418 PrEPP tools were collected; representing 12% of the total ED visits to the 4 ED sites during the study period. The main factors affecting ED presentation were: self-referral 68%, family/friends 20%, telehealth 8%, unable to see their GP 7%, GP referral 6%, or walk-in-clinic 5%. P/Cs main causes of worry were: presenting illness 19%, injury 15%, or pain 14%. The main expectations for the ED visit were to get a: physician's opinion 73%, x-ray 40%, or blood test 20%. Most P/Cs indicated they did not expect medication during (63%), or after (66%), their ED visit. There were significant differences in P/C expectations between adult and pediatric EDs (χ2 = 720.949, df = 14, P = 0.000) and those P/Cs unable or able to access primary care prior to ED presentation (χ2 = 38.980, df = 1, P = 0.000). The rate of expecting a physician's opinion at the pediatric ED was higher than the adult ED (77.6% vs 70.9%), while lower for expecting CT/MRIs (4.6% vs 11.4%). P/Cs who were unable to access primary care prior to ED presentation expected services which were available at primary care at a higher rate than those who accessed primary care (58.5% vs 36.7%). Conclusion: Our findings identify some of the factors that influence P/C's decision to present to the ED and their expectations of the ED visit.
Introduction: Effective communication to develop a shared understanding of patient/caregiver (P/C) expectations is critical during emergency department (ED) encounters. However, there is limited research examining the use of communication tools of P/C expectations to improve communication in the ED. The objective of this study was to examine satisfaction with a patient expectations questionnaire, known as the PrEPP tool, and its impact on communication and management of patients in the ED. Methods: The PrEPP tool collected P/C expectations over 3 phases of the study. In phase1, the PrEPP tool was distributed to all P/Cs (CTAS score of 2 to 5) in four EDs in Nova Scotia. In phase 2 the PrEPP tool was refined to a 5-item questionnaire. In phase 3 the PrEPP tool was re-implemented over a six-month period. Follow-up surveys were distributed to P/Cs via email (phase 1, 3) and HCPs on iPads in the ED (phase 3) to determine the impact of the tool on communication and management of patients. Entries were compiled on a REDCap database and descriptive statistics were used to analyze responses related to satisfaction.The PrEPP tool collected P/C expectations over 3 phases of the study. In phase1, the PrEPP tool was distributed to all P/Cs (CTAS score of 2 to 5) in four EDs in Nova Scotia. In phase 2 the PrEPP tool was refined to a 5-item questionnaire. In phase 3 the PrEPP tool was re-implemented over a six-month period. Follow-up surveys were distributed to P/Cs via email (phase 1, 3) and HCPs on iPads in the ED (phase 3) to determine the impact of the tool on communication and management of patients. Entries were compiled on a REDCap database and descriptive statistics were used to analyze responses related to satisfaction. Results: In Phase 1, 11418 PrEPP tools and 147 surveys (29% response rate) were collected from January-June 2016. The majority of P/Cs found the PrEPP questionnaire easy to complete (95.9%) and felt HCPs met their expectations (87.1%). In Phase 3, 951 P/C (31.1% response rate) and 128 HCP surveys were collected. Of P/C respondents 45.9% felt PrEPP helped to communicate expectations, while 49.7% said that they would like to use it on future ED visits. The majority of P/C respondents (75.4%) indicated their expectations were met during their visit to the ED. Of those whose expectations were not met, 69% felt their expectations were not discussed. The majority of HCP respondents (90.4%) indicated they used the PrEPP tool at least sometimes. Also, 78.4% said it influenced patient communication and 42% indicated the tool influenced management of patients at least sometimes. Conclusion: Obtaining expectations early in the patient encounter may provide opportunities for improved communication in the ED. P/Cs found the PrEPP tool easy to use to communicate their expectations and HCPs felt it influenced communication and management of patients in the ED. Further qualitative thematic analysis is needed to explore how the PrEPP tool impacted ED visits.
In the current opioid epidemic, identifying high-risk patients among those with substance and opioid use may prevent deaths. The objective of this study was to determine whether frequent emergency department (ED) use and degree of frequent use are associated with mortality among ED patients with substance and opioid use.
This cohort study used linked population-based ED (National Ambulatory Care Reporting System) and mortality data from Alberta. All adults ≥ 18 years with substance or opioid use-related visits based on diagnostic codes from April 1, 2012, to March 31, 2013, were included (n = 16,389). Frequent use was defined by ≥ 5 visits in the previous year. Outcomes were unadjusted and adjusted (for age, sex, income) mortality within 90 days (primary), and 30 days, 365 days, and 2 years (secondary). To examine degree, frequent use was subcategorized into 5–10, 11–15, 16–20, and > 20 visits.
Frequent users were older, lower income, and made lower acuity visits than non-frequent users. Frequent users with substance use had higher mortality at 365 days (hazard ratio [HR] 1.36 [1.04, 1.77]) and 2 years (HR 1.32 [1.04, 1.67]), but not at 90 or 30 days. Mortality did not differ for frequent users with opioid use overall. By degree, patients with substance use and > 20 visits/year and with opioid use and 16–20 visits/year demonstrated a higher 365-day and 2-year mortality.
Among patients with substance use, frequent ED use and extremely frequent use (> 20 visits/year) were associated with long-term but not short-term mortality. These findings suggest a role for targeted screening and preventive intervention.
The majority of paediatric Clostridioides difficile infections (CDI) are community-associated (CA), but few data exist regarding associated risk factors. We conducted a case–control study to evaluate CA-CDI risk factors in young children. Participants were enrolled from eight US sites during October 2014–February 2016. Case-patients were defined as children aged 1–5 years with a positive C. difficile specimen collected as an outpatient or ⩽3 days of hospital admission, who had no healthcare facility admission in the prior 12 weeks and no history of CDI. Each case-patient was matched to one control. Caregivers were interviewed regarding relevant exposures. Multivariable conditional logistic regression was performed. Of 68 pairs, 44.1% were female. More case-patients than controls had a comorbidity (33.3% vs. 12.1%; P = 0.01); recent higher-risk outpatient exposures (34.9% vs. 17.7%; P = 0.03); recent antibiotic use (54.4% vs. 19.4%; P < 0.0001); or recent exposure to a household member with diarrhoea (41.3% vs. 21.5%; P = 0.04). In multivariable analysis, antibiotic exposure in the preceding 12 weeks was significantly associated with CA-CDI (adjusted matched odds ratio, 6.25; 95% CI 2.18–17.96). Improved antibiotic prescribing might reduce CA-CDI in this population. Further evaluation of the potential role of outpatient healthcare and household exposures in C. difficile transmission is needed.
Determination of the species of compounds present in ambient aerosols has received increasing interest in recent years (Harrison and Pio, 1983; Davis, 1984; Davis and Maughan, 1984; Harrison and Sturges, 1984; Sturges et al, 1989; Possanzini et al, 1992; Havliek et al., 1993), but the U.S. Environmental Protection Agency's conversion to the PM10 standard in 1987 has made quantitative analysis of fine particle aerosols more difficult because of the much smaller deposited mass on these filters, as well as the increased proportion of carbon-bearing material naturally present in the smaller diameter portion of the atmospheric aerosol size distribution. Under the old TSP (Total Suspended Particulate) collection protocol, filter loads of 400-2000 μg cm-2 of 10-20 μm mean diameter particles, corresponding to 24-hour collections at ambient concentrations of 100 to 500 μg m-3 at 40 CFM flow rates, resulted in excellent diffraction patterns scanned directly from filter segments.
In smectite analyses, the investigation of the attenuation contribution to quantitative x-ray diffraction (XRD) analysis is a most important topic, including Fe content and distribution. This is the first part of a comprehensive study on smectite analysis addressing the nature and location of Fe atoms within the octahedral sites, interlayer regions, and intergranular interfaces. This first paper treats the mass attenuation measurements and calculations (Davis and Johnson, 1987). Additional reports will be made in the future on Fe studies involving measured and calculated reference intensity ratio measurements and structural studies based on SEM and TEM analysis.
This article analyzes a number of yearly reports from the World Bank's Doing Business project, an ambitious international effort to measure various aspects of law and development, analyze their interrelationship, develop benchmarks for assessment of legal systems, and suggest legal reforms. After describing the methodology used, we analyze the strengths and limitations of the project, both as a scholarly enterprise and as a set of proposals for legal reform. Our analysis highlights the challenges associated with measuring legal variables in the face of legal complexity and uncertainty, measuring development when the concept of development is contested, tracing causal connections between law and development, and using scholarly research as a basis for legal reform.
We examine disturbances leading to optimal energy growth in a spatially developing, zero-pressure-gradient turbulent boundary layer. The slow development of the turbulent mean flow in the streamwise direction is modelled through a parabolized formulation to enable a spatial marching procedure. In the present framework, conventional spatial optimal disturbances arise naturally as the homogeneous solution to the linearized equations subject to a turbulent forcing at particular wavenumber combinations. A wave-like decomposition for the disturbance is considered to incorporate both conventional stationary modes as well as propagating modes formed by non-zero frequency/streamwise wavenumber and representative of convective structures naturally observed in wall turbulence. The optimal streamwise wavenumber, which varies with the spatial development of the turbulent mean flow, is computed locally via an auxiliary optimization constraint. The present approach can then be considered, in part, as an extension of the resolvent-based analyses for slowly developing flows. Optimization results reveal highly amplified disturbances for both stationary and propagating modes. Stationary modes identify peak amplification of structures residing near the centre of the logarithmic layer of the turbulent mean flow. Inner-scaled disturbances reminiscent of near wall streaks, and amplified over short streamwise distances, are identified in the computed streamwise energy spectra. In all cases, however, propagating modes surpass their stationary counterpart in both energy amplification and relative contribution to total fluctuation energy. We identify two classes of large-scale energetic modes associated with the logarithmic and wake layers of the turbulent mean flow. The outer-scaled wake modes agree well with the large-scale motions that populate the wake layer. For high Reynolds numbers, the log modes increasingly dominate the energy spectra with the predicted streamwise and wall-normal scales in agreement with superstructures observed in turbulent boundary layers.
In the final paragraph of The Origin of Species, Charles Darwin leaves us with the vision of Nature as an ‘entangled bank’, where individuals struggle to survive and reproduce in a world of competitors, predators, and parasites. In this chapter, I explore the games animals play in these struggles. Some are behavioural games, resulting in an extraordinary mix of cooperation and conflict in animal families, where sexual partners and parents and their offspring sometimes help one another, but sometimes cheat. Some are games played over evolutionary time, where strategies escalate over the generations between competitors, and between enemies and their victims, leading to extremes, not only in weaponry and cruelty, but in ornamentation and beauty, too. I illustrate these themes especially with examples of mating games in birds and evolutionary arms races between cuckoos and their hosts, to show how the rules of the games can be unravelled by a combination of bird watching and field experiments.
This article explores the origins of youth engagement in school, community and democracy. Specifically, it considers the role of psychosocial or non-cognitive abilities, like grit or perseverance. Using a novel original large-scale longitudinal survey of students linked to school administrative records and a variety of modeling techniques – including sibling, twin and individual fixed effects – the study finds that psychosocial abilities are a strong predictor of youth civic engagement. Gritty students miss less class time and are more engaged in their schools, are more politically efficacious, are more likely to intend to vote when they become eligible, and volunteer more. Our work highlights the value of psychosocial attributes in the political socialization of young people.