Core Ideas High‐frequency N2O emission data was subsampled to assess sampling frequency errors. Mid‐morning sampling was adequate to derive daily average N2O emission during events. Twice‐weekly sampling gave an uncertainty of –6 to +12% during spring thaw. Twice weekly + sample after >10 mm rainfall had –1 to +19% error after fertilization. An infrequent sampling protocol can introduce bias into N2O studies. Different methods are used to measure nitrous oxide (N2O), a potent greenhouse gas emitted from agricultural soils. While some methods (e.g. micrometeorological methods) conduct near‐continuous measurements, manual chambers measure discontinuously. Estimates of N2O emissions based on discontinuous measurements can carry errors due to: (i) diurnal variation and (ii) integration of emissions over time. This study evaluated these two sources of uncertainties and identified the optimal sampling strategy for emission following spring‐thaw events (ST) and nitrogen fertilization (NF). Two times of day (mid‐morning [MM] and mid‐afternoon [MA]) and three sampling frequencies suggested in the literature on N2O emissions (bi‐weekly [BW], weekly [W], twice weekly [TW] for the ST, and W, TW, and TW plus extra sample after rainfall events >10 mm for the NF) were created by subsampling a high‐frequency reference dataset. We show that the mid‐morning sampling strategy effectively represented the daily N2O emission average, while the mid‐afternoon strategy overestimated fluxes by 14 and 32% for the ST and NF, respectively. For the ST, the weekly mid‐morning sampling protocol resulted in errors ranging from –3 to +33%, with lower uncertainties when sampling frequency increased to TW (–6 to +12%). The TW mid‐morning sampling also was adequate for the NF datasets (–5 to +19%), with narrower uncertainty levels when an additional sample was taken after >10 mm rainfall (–1 to +19%). These results provide increased confidence in selecting the sampling strategy for discontinuous measurements following N fertilization and STs in cropping systems.

Background A variety of routine childhood and adolescent meningococcal vaccination programs using monovalent (serogroup C) and quadrivalent (A, C, Y, W) conjugate vaccines have been implemented in Canada since 2002, resulting in a decrease in invasive meningococcal disease (IMD) incidence, particularly in serogroup C. Meningococcal vaccines have also been used for outbreak response, including the multicomponent vaccine serogroup B vaccine. This report describes the epidemiology of IMD in Canada from 2012 to 2019. Methods Case data were obtained from the National Enhanced IMD Surveillance System between January 1, 2012 and December 31, 2019. Isolates were sent to the National Microbiology Laboratory for confirmation of serogroup and further studies including phenotype and clonal complex identification. Results A total of 983 cases of IMD were reported between 2012 and 2019. Overall, the age-adjusted incidence of IMD from 2012 to 2019 was 0.34 cases per 100,000 population per year when standardized to the Canadian 2011 population age distribution (95% CI: 0.32–0.36). Infants younger than one year of age had the highest average age-specific incidence rate (3.6 cases per 100,000 population per year, 95% CI: 2.8–4.3). The highest age-adjusted incidence rate was associated with serogroup B (0.17 cases per 100, 000 population per year, 95% CI: 0.16–0.19). Prior to 2015, most invasive serogroup W isolates were identified as clonal complex 22 (ST-22 CC) and the increase in serogroup W in Canada in recent years has been associated with the replacement of the endemic ST-22 CC with the hyper-virulent ST-11 CC. Conclusion Invasive meningococcal disease is a rare but severe infection in Canada that mostly affects the very young. Serogroup B continues to account for the greatest proportion of disease. Serogroup W associated with ST-11 CC is becoming a growing contributor of disease in all age groups not protected by serogroup W-containing vaccines.

Environmental lead exposure is a population health concern in many low- and middle-income countries. Lead is found throughout Myanmar and prior to the 1940s the country was the largest producer of lead worldwide. The aim of this study was to examine any potential association between lead mining and adult literacy rates at the level of 330 townships in Myanmar. Townships were identified as lead or non-lead mining areas and 2015 census data were examined with association being identified using descriptive, analytical and spatial statistical methods. Overall, there does appear to be a significant relationship between lead mining activity and adult literacy levels among townships with both low access (p = 0.05; OR = 2.701 (1.136–6.421)) as well with high access to safe sanitation (p = 0.01; OR = 18.40 (1.794–188.745)). Local Indicators of Spatial Association (LISA) cluster maps confirm these findings. This exploratory analysis is a first step in the examination of potential environmental lead exposure and its implications in Myanmar.

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