Estimating risk of emergency room visits for asthma from personal versus fixed site measurements of NO2

Background: We examined the impact of data source and exposure measurement error for ambient NO2 on risk estimates derived from a case-crossover study of emergency room visits for asthma in Windsor, Canada between 2002 and 2009. Methods: Paired personal and fixed-site NO2 data were available from an independent population (47 children and 48 adults) in Windsor between 2005 and 2006. We used linear regression to estimate the relationship and measurement error variance induced between fixed site and personal measurements of NO2, and through a series of simulations, evaluated the potential for a Bayesian model to adjust for this change in scale and measurement error. Finally, we re-analyzed data from the previous case-crossover study adjusting for the estimated change in slope and measurement error. Results: Correlations between paired NO2 measurements were weak (R2≤0.08) and slopes were far from unity (0.0029≤β≤0.30). Adjusting the previous case-crossover analysis suggested a much stronger association between personal NO2 (per 1 ppb) (Odds Ratio (OR)=1.276, 95% Credible Interval (CrI): 1.034, 1.569) and emergency room visits for asthma among children relative to the fixed-site estimate (OR=1.024, 95% CrI 1.004–1.045). Conclusions: Our findings suggest that risk estimates based on fixed-site NO2concentrations may differ substantially from estimates based on personal exposures if the change in scale and/or measurement error is large. In practice, one must always keep the scale being used in mind when interpreting risk estimates and not assume that coefficients for ambient concentrations reflect risks at the personal level

La gestion des biosolides de papetières au Québec : quelle serait la meilleure option pour réduire les émissions de gaz à effet de serre? (Pulp and paper mill sludge management in Quebec: what should be the best option to reduce greenhouse gas emissions?)

Les biosolides de papetières (BP) sont des matières organiques résiduelles provenant du processus d’épuration des effluents de l’industrie des pâtes et papiers. Le gouvernement québécois vise à réduire de 20 % les émissions de gaz à effet de serre (GES) par rapport au niveau de 1990 et à bannir la matière organique des lieux d’élimination d’ici 2020, ce qui affectera probablement la gestion des BP. Cette étude vise à quantifier les émissions de GES provenant des trois principales filières de gestion des BP : l’enfouissement, l’épandage sur sol agricole et la combustion avec récupération de chaleur. Les émissions de GES de l’enfouissement ont été mesurées à l’échelle pilote et celles de l’épandage, l’ont été pour des doses respectant les recommandations agronomiques. Les émissions de la combustion ont été mesurées à la cheminée de chaudières à biomasse utilisant entre 10 et 40 % de BP mélangés aux combustibles. L’enfouissement était la filière la plus émettrice de GES (0,90 t éq. CO2 t-1 BP secs), alors que les émissions étaient inférieures pour l’épandage (0,12 t éq. CO2 t-1 BP secs) et la combustion (0,00057-0,13 t éq. CO2 t-1 BP secs). L’épandage agricole et la combustion seraient de bonnes alternatives à l’enfouissement pour atténuer les émissions de GES. Toutefois, il serait nécessaire de multiplier les mesures d’émissions pour en augmenter la précision et assurer des scénarios robustes si l’on vise à initier l’élaboration d’un nouveau protocole d’obtention de crédits compensatoires pour le système de plafonnement et d’échange de droits d’émission de GES au Québec. Pulp and paper mill sludge (PPMS) is an organic residual generated from the paper mill wastewater treatments. The Quebec’s government policies aim to reduce the greenhouse gas emissions (GHG) by 20% below the level of 1990 and to ban disposal (landfilling and incineration without energy recovery) of organic material by 2020, which will likely affect PPMS management. This study aims at quantifying GHG emissions from the three main practices currently used to manage PPMS: landfilling, land application in agriculture and combustion for energy recovery. GHG emissions from landfilling were measured at the pilot-scale and those from land were measured following PPMS application at rates based on local agronomic recommendations. GHG emissions from combustion were measured at the chimney of biomass boilers using 10 to 40% PPMS in the fuel. Landfilling had the highest GHG emissions (0.90 t CO2e t-1 dry PPMS) whereas those from land application (0.12 t CO2e t-1 dry PPMS) and combustion (0.00057-0.13 t CO2e t-1 dry PPMS) were lower. Application of PPMS to agricultural land and combustion would therefore be good alternatives to landfilling to abate GHG emissions. However, more measurements would be required to increase the accuracy on the emission quantifications and start building a new offset credit protocol to be used in the Quebec cap-and-trade system for GHG emission allowances applied bylaw

Spatiotemporal Patterns in Nest Box Occupancy by Tree Swallows Across North America

Data from the North American Breeding Bird Survey (BBS) suggest that populations of aerial insectivorous birds are declining, particularly in northeastern regions of the continent, and particularly since the mid-1980s. Species that use nest boxes, such as Tree Swallows (Tachycineta bicolor), may provide researchers with large data sets that better reveal finer-scale geographical patterns in population trends. We analyzed trends in occupancy rates for ca. 40,000 Tree Swallow nest-box-years from 16 sites across North America. The earliest site has been studied intensively since 1969 and the latest site since 2004. Nest box occupancy rates declined significantly at five of six (83%) sites east of -78° W longitude, whereas occupancy rates increased significantly at four of ten sites (40%) west of -78° W longitude. Decreasing box occupancy trends from the northeast were broadly consistent with aspects of a previous analysis of BBS data for Tree Swallows, but our finding of instances of increases in other parts of the continent are novel. Several questions remain, particularly with respect to causes of these broad-scale geographic changes in population densities of Tree Swallows. The broad geographic patterns are consistent with a hypothesis of widespread changes in climate on wintering, migratory, or breeding areas that in turn may differentially affect populations of aerial insects, but other explanations are possible. It is also unclear whether these changes in occupancy rates reflect an increase or decrease in overall populations of Tree Swallows. Regardless, important conservation steps will be to unravel causes of changing populations of aerial insectivores in North America

A cross-sectional study of the prevalence of intensity of infection with Schistosoma japonicum in 50 irrigated and rain-fed villages in Samar Province, the Philippines

BACKGROUND: Few studies have described heterogeneity in Schistosoma japonicum infection intensity, and none were done in Philippines. The purpose of this report is to describe the village-to-village variation in the prevalence of two levels of infection intensity across 50 villages of Samar Province, the Philippines. METHODS: This cross-sectional study was conducted in 25 rain-fed and 25 irrigated villages endemic for S. japonicum between August 2003 and November 2004. Villages were selected based on irrigation and farming criteria. A maximum of 35 eligible households were selected per village. Each participant was asked to provide stool samples on three consecutive days. All those who provided at least one stool sample were included in the analysis. A Bayesian three category outcome hierarchical cumulative logit regression model with adjustment for age, sex, occupation and measurement error of the Kato-Katz technique was used for analysis. RESULTS: A total of 1427 households and 6917 individuals agreed to participate in the study. A total of 5624 (81.3%) participants provided at least one stool sample. The prevalences of those lightly and at least moderately infected varied from 0% (95% Bayesian credible interval (BCI): 0%–3.1%) to 45.2% (95% BCI: 36.5%–53.9%) and 0% to 23.0% (95% BCI: 16.4%–31.2%) from village-to-village, respectively. Using the 0–7 year old group as a reference category, the highest odds ratio (OR) among males and females were that of being aged 17–40-year old (OR = 8.76; 95% BCI: 6.03–12.47) and 11–16-year old (OR = 8.59; 95% BCI: 4.74–14.28), respectively. People who did not work on a rice farm had a lower prevalence of infection than those working full time on a rice farm. The OR for irrigated villages compared to rain-fed villages was 1.41 (95% BCI: 0.50–3.21). DISCUSSION: We found very important village-to-village variation in prevalence of infection intensity. This variation is probably due to village-level variables other than that explained by a crude classification of villages into the irrigated and non-irrigated categories. We are planning to capture this spatial heterogeneity by updating our initial transmission dynamics model with the data reported here combined with 1-year post-treatment follow-up of study participants

Beyond technology : a scoping review of features that promote fidelity and authenticity in simulation-based health professional education

Conceptualizations of fidelity in simulation often refer to physical, conceptual, and psychological dimensions. Besides simulator technologies, practical features that enhance the fidelity and authenticity of simulated activities from educators' and learners’ perspectives remain nebulous. This study is a scoping review (Levac, Colquhoun, & O'Brien, 2010). From 42 articles, eight features were identified: content drawn from real life, interaction and feedback, performance expectations, preparation of the environment, presence of an actual patient, logical and adaptive scenarios, sociological fidelity, and cueing. This article provides guidance in the design of high-fidelity, authentic simulations, even in the absence of technologically advanced simulators

Clinically Apparent Arterial Thrombosis in Persons with Systemic Vasculitis

Objective. To estimate the incidence rate of clinically apparent arterial thrombotic events and associated comorbidities in patients with primary systemic vasculitis. Methods. Using large cohort administrative data from Quebec, Canada, we identified patients with vasculitis, including polyarteritis nodosa (PAN) and granulomatosis with polyangiitis (GPA). Incident acute myocardial infarctions (AMIs) and cerebrovascular accidents (CVAs) after the diagnosis of vasculitis were ascertained in the PAN and GPA group via billing and hospitalization data. These were compared to rates of a general population comparator group. The incidences of comorbidities (type 2 diabetes mellitus, dyslipidemia, and hypertension) were also collected. Results. Among the 626 patients identified with vasculitis, 19.7% had PAN, 2.9% had Kawasaki disease, 23.8% had GPA, 52.4% had GCA, and 1.3% had Takayasu arteritis. The AMI rate was substantially higher in males aged 18–44 with PAN, with rates up to 268.1 events per 10,000 patient years [95% CI 67.1–1070.2], approximately 30 times that in the age- and sex-matched control group. The CVA rate was also substantially higher, particularly in adults aged 45–65. Patients with vasculitis had elevated incidences of diabetes, dyslipidemia, and hypertension versus the general population. Conclusion. Atherothrombotic rates were elevated in patients identified as having primary systemic vasculitis. While incident rates of cardiovascular comorbidities were also increased, the substantial elevation in AMIs seen in young adults suggests a disease-specific component which requires further investigation

A conceptual framework of student professionalization for health professional education and research

Objectives To present a conceptual framework of student professionalization for health professional education and research. Methods Synthesis and discussion of a program of research on competency-based education. Results Competency-based education relies on active, situation-based group learning strategies to prepare students to become health professionals who are connected to patient and population needs. Professionalization is understood as a dynamic process of imagining, becoming, and being a member of a health profession. It rests on the evolution of three interrelated dimensions: professional competencies, professional culture, and professional identity. Professionalization occurs throughout students’ encounters with meaningful learning experiences that involve three core components: the roles students experience in situations bounded within specific contexts. Educational practices conducive to professionalization include active learning, reflection, and feedback. Conclusions This conceptual framework drives a research agenda aimed at understanding how students become health professional and how learning experiences involving action, reflection, and feedback foster that process and the advancement of professional practices