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Introduction: There were repeated reports of increased cannabis sales, use and health impacts in Canada during the COVID‐19 pandemic. However, it was unclear whether the increases were due to pandemic effects or industry expansion. Methods: We performed interrupted time series regressions of monthly per capita legal cannabis sales from March 2019 to February 2021, first with national averages, then with provincial/territorial data after adjusting for store density. We considered two interruption alternatives: January 2020, when product variety increased; and March 2020, when pandemic restrictions began. Results: The provincial/territorial regression with the January interruption explained R2 = 69.6% of within‐jurisdiction variation: baseline monthly per capita sales growth averaged $0.21 (95% confidence interval [CI] 0.15, 0.26), sales immediately dropped in January by $1.02 (95% CI −1.67, −0.37), and monthly growth thereafter increased by $0.16 (95% CI 0.06, 0.25). With the March interruption, the regression instead explained 68.7% of variation: baseline sales growth averaged $0.14 (95% CI 0.06, 0.22), there was no immediate drop and growth thereafter increased by $0.22 per month (95% CI 0.08, 0.35). Discussion and Conclusions: Increasing cannabis sales during the pandemic was consistent with pre‐existing trends and increasing store numbers. The extra increased growth was more aligned with January's new product arrivals than with March's pandemic measures, though the latter cannot be ruled out. We found little evidence of pandemic impacts on Canada's aggregate legal cannabis sales. We therefore caution against attributing increased population‐level cannabis use or health impacts primarily to the pandemic. [ABSTRACT FROM AUTHOR]

Presents a study that examined the effect of ion bombardment on the morphology of compact lead films. Analysis of the Auger electron spectra; Evaluation of the scanning electron micrographs; Measurement of the optical properties of the lead film.

Objective We model Pickett's Charge at the Battle of Gettysburg to see whether the Confederates could have achieved victory by committing more infantry, executing a better barrage, or facing a weaker defense. Methods Our mathematical modeling is based on Lanchester equations, calibrated using historical army strengths. We weight the Union artillery and infantry two different ways using two sources of data, and so have four versions of the model. Results The models estimate that a successful Confederate charge would have required at least one to three additional brigades. An improved artillery barrage would have reduced these needs by about one brigade. A weaker Union defense could have allowed the charge to succeed as executed. Conclusions The Confederates plausibly had enough troops to take the Union position and alter the battle's outcome, but likely too few to further exploit such a success. [ABSTRACT FROM AUTHOR]

Researchers use a mathematical model to perform a counterfactual study of the 1854 Charge of the Light Brigade. They first calibrate the model with historical data so that it reproduces the actual charge's outcome. They then adjust the model to see how that outcome might have changed if the Heavy Brigade had joined the charge and/or if the charge had targeted the Russian forces on the heights instead of those in the valley. The results suggest that all the counterfactual attacks would have led to heavier British casualties. However, a charge by both brigades along the valley might plausibly have yielded a British victory. [ABSTRACT FROM PUBLISHER]

Purpose -- The purpose of this paper is to highlight and discuss the unique safety and protection requirements for the electrical microgrid system in a turboelectric distributed propulsion aircraft. Design/methodology/approach -- The NASA N3-X concept aircraft requirements were considered. The TeDP system was decomposed into three subsystems: turbogenerator, distribution system and propulsors. Unique considerations for each of these subsystems were identified. Findings -- The fail-safe requirements for a TeDP system require a divergence from the standard safety case used for conventional propulsion systems. Advantages in flight control and single-engine-out scenarios can be realized using TeDP. Additionally, a targeted use of energy storage and reconfigurability may enable seamless response to propulsion systems failures. Practical implications -- The concepts discussed in this paper will assist to guide the early conceptual and preliminary design and evaluation of TeDP architectures. Originality/value -- The safety case for TeDP architectures is currently immature. The work presented here acts to frame some of the major issues when designing, evaluating and verifying TeDP conceptual architectures. [ABSTRACT FROM AUTHOR]

Purpose -- This article is aims to inform aircraft propulsion system designers of the implications which fundamental power distribution design assumptions have on the effectiveness and viability of turboelectric distributed propulsion (TeDP) systems. Improvements and challenges associated with selecting alternating or direct current for normal- and superconducting distribution systems are presented. Additionally, for superconducting systems, the benefits of bi-polar DC distribution are discussed, as well as the implications of operating voltage on the mass and efficiency of TeDP grid components. Design/methodology/approach -- The approach to this paper selects several high-level fundamental configuration decisions, which must be made, and it qualitatively discusses potential implications of these decisions. Findings -- Near term TeDP architectures which employ conventionally conducting systems may benefit from alternating current (AC) distribution concepts to eliminate the mass and losses associated with power conversion. Farther term TeDP concepts which employ superconducting technologies may benefit from direct current (DC) distribution to reduce the cryocooling requirements stemming from AC conduction losses. Selecting the operating voltage for superconducting concepts requires a divergence from the present day criteria employed with terrestrial superconducting transmission systems. Practical implications -- The criteria presented in the paper will assist in the early conceptual architecting of TeDP systems. Originality/value -- The governing principles behind the configuration of multi-MW airborne electrical microgrid systems are presently immature. This paper represents a unique look and the motivating principles behind fundamental electrical configuration decisions in the context of TeDP. [ABSTRACT FROM AUTHOR]

To enhance public understanding of the outcomes of cannabis legalization in Canada and avoid this skewed situation, provincial and territorial governments must become more transparent with their cannabis data. Despite the many potential impacts of the legalization of cannabis in Canada, provincial and territorial governments' poor disclosure of data about their recreational sales hinders researchers' efforts to study the the medical and social effects of legalization. [Extracted from the article]

Background: This study estimated the relationships between increases in legal cannabis stores, legal cannabis sales, and cannabis prevalence in Canadian provinces between 2018 and 2020.Method: Government data were used to calculate changes in licensed store numbers, retail sales dollars, and past-three-month users in 10 provinces across six time periods. The resulting N = 60 observations were standardized per million residents aged 15 and up, and then analyzed via linear regression.Results: Store growth explained 46.3% of the variation in provincial sales growth; each added store was associated with added quarterly sales of $305 (95% CI: $208 to $402) thousand. By contrast, store growth explained only 7.7% of the variation in provincial user growth; each added store was associated with 696 (95% CI: 58-1334) added users.Conclusion: From 2018 to 2020, Canada's rapid cannabis retail expansion was strongly related to legal sales growth but only weakly related to prevalence growth. This implies prevalence growth during that period was related more to legalization's other aspects and/or to the continuation of already-existing trends. [ABSTRACT FROM AUTHOR]

Abstract: The annual egg production (AEP) of cod (Gadus morhua), plaice (Pleuronectes platessa) and haddock (Melanogrammus aeglefinus) in the Irish Sea during the 2008 spawning season was estimated using generalized additive models (GAMs that further developed previous applications of the annual egg production method to Irish Sea stocks by including 2-D spatial smoothing, automatic selection of the degree of smoothing and precision estimates. The estimates of AEP from the GAMs were compared to those from a stratified mean method and the sensitivity of the estimates to different model specifications, outliers, boundary effects and prediction period was assessed. The influence of outlying large observations was notable but overall the estimates of AEP were robust to the factors studied, with effect sizes comparable to the estimates’ coefficients of variation. [Copyright &y& Elsevier]

Abstract: The use of egg production methods to estimate the spawning stock biomass (SSB) of fish depends critically on establishing the biological basis underpinning the methods. In this paper we review recent developments in knowledge of several key aspects of reproductive biology relevant to the estimation of annual egg production and daily specific fecundity at the individual and population level, as required in particular for application of the Annual and Daily Egg Production Methods respectively. The parameters to be estimated include spawning frequency, potential annual fecundity or batch fecundity, and rates of atresia prior to and during the spawning season. The initial development of egg production survey methods led to a significant growth in understanding of the reproductive biology of the target fish species. Drivers for further developments have come from the extension of the surveys to more species and areas, an increasing interest in evaluating time-series of reproductive potential in stocks, and the needs for research and development in support of marine aquaculture. A growing number of studies on field-caught and captive fish since the 1990s have led to important advances in our understanding of the triggering of maturation and gametogenesis, the subsequent processes of oocyte (follicle) growth and vitellogenesis, regulation of fecundity through atresia, batch spawning dynamics, and the influence of extrinsic factors such as day length, temperature and feeding. We conclude that the biological basis for egg production survey methods is now extremely well established for the main species being surveyed. However, the extension of the methods to a wider range of species has highlighted the practical difficulties in obtaining sufficiently precise and unbiased estimates of key parameters such as spawning fraction or sex ratio that are influenced by spatial distribution or catchability of several population components (e.g. mature, immature active spawning or spent). The definition and validation of spawning markers also remains a challenge, particularly for new species being surveyed. Given the often high cost of egg production surveys, particularly the annual method, there is a need for simulation studies to determine the relative performance of simpler and less expensive approaches to tracking SSB from egg surveys for use in stock assessment. Developments that expand the quantity and utility of the information yielded by the surveys, including integration of the surveys into broader ecosystem studies, could also be considered a way to improve cost-effectiveness. [Copyright &y& Elsevier]

Video-assisted parathyroidectomy (VAP) is a new approach to parathyroid exploration for primary hyperparathyroidism (PH). We examined the VAP learning curve and hypothesized that compared with conventional minimally invasive parathyroidectomy (MIS), VAP has similar complication rates and the added benefit of a shorter hospital length of stay. Using a case-control study design, patients with PH with single-focus imaging results undergoing VAP or MIS were compared during a 5-year VAP implementation period. VAP was possible in 18 per cent of patients undergoing initial parathyroid exploration. In comparing 125 VAP cases with 95 MIS control subjects, patients undergoing MIS had higher mean preoperative levels of calcium (P = 0.007) and parathyroid hormone (P = 0.008), greater mean adenoma weight (P < 0.001), and increased long-term mortality (4% MIS vs 0% VAP, P = 0.03). Mean operative time, in-house analgesia use, and operative complications did not differ. The rate of conversion from VAP to MIS was 14 per cent. Patients undergoing VAP were less likely to require an overnight hospital stay (P = 0.01). VAP is a safe surgical option for selected patients with PH, offering improved cosmesis with operative times comparable to conventional MIS. VAP can be done with a low conversion rate even during implementation and allows the added benefit of shorter hospital stay. [ABSTRACT FROM AUTHOR]

Goodsir, F., Armstrong, M. J., Witthames, P. R., Maxwell, D. L., and Fox, C. J. 2008. The use of species-specific TaqMan probes for identifying early stage gadoid eggs following formaldehyde fixation. – ICES Journal of Marine Science, 65: 1573–1577.Surveys of fish eggs are increasingly being used to monitor the spawning areas and stock status of commercially important species such as Atlantic cod (Gadus morhua), but early stage cod eggs are visually indistinguishable from those of several other common co-occurring species, including haddock (Melanogrammus aeglefinus) and whiting (Merlangius merlangus). In recent surveys in the Irish and North Seas, a molecular identification technique (TaqMan multiplex real-time polymerase chain-reaction) assay has been used to overcome this problem. The method needs high-quality DNA, so the current protocol requires that individual “cod-like” eggs are “presorted” from plankton hauls on board ship and immediately preserved in ethanol. This increases seagoing staff costs, can be a difficult process at sea, and means that plankton sampling cannot be undertaken from non-specialized vessels such as fishing boats. Successful application of TaqMan probes to DNA from eggs preserved in formalin would overcome these problems, but previous attempts have resulted in poor success. In this study, batches of hatchery-sourced cod, haddock, and whiting eggs were fixed in 4% buffered formalin for up to 3 weeks, then transferred to a formaldehyde-free solution for 1, 2, or 3 months. After these periods they were assessed visually for fixation quality and analysed using species-specific TaqMan probes. Eggs, which had been fixed for up to 3 weeks in formalin, were identified successfully, although the positive rate (84–96%) was slightly lower than samples preserved throughout in ethanol (92–99%). There was no increase in the percentage of eggs misidentified comparing formalin-fixed and ethanol-preserved material. These results suggest that TaqMan probes can be applied successfully to fish eggs fixed in 4% buffered formalin for up to 3 weeks. [ABSTRACT FROM PUBLISHER]

Background: This study estimated legal products' share of Canada's total cannabis consumption during the first year of recreational legalisation, October 2018 to September 2019.Methods: Government data was used to estimate monthly recreational sales in dollars per capita, grams per user, and percentage share of kilograms or litres consumed. As explanatory factors, the analysis considered provincial differences in retail pricing (percentage mark-ups) and store density (stores per million users), as well as national monthly production of dry cannabis (kilograms) and cannabis oil (litres) finished products.Results: Legal recreational products' share of Canada's overall cannabis consumption began at 7.8% in October 2018 and grew to 23.7% by September 2019, with an average of 14.5% over the first 12 months. Sales growth was delayed by shortages of both dry cannabis products and licensed stores, but not cannabis oils. Across the 10 provinces, legal recreational shares in September 2019 varied from 13% to 70%; differences in store densities and retail prices partly explained the variation. Prince Edward Island's large 70% share seemed due to it having minimal product shortages, high store densities, and low prices.Conclusions: Legal recreational products captured market share to the extent they were available, accessible, and low-priced. Problems with those factors slowed the initial expansion of legal product sales but also suggested ways to gradually increase their market share. [ABSTRACT FROM AUTHOR]

Previous work by Armstrong and Atkins examined age replacement and spare ordering decisions for a system which contained one machine subject to random failure and with only one spare machine in stock or on order at any one time. In this technical note we consider several extensions to that work which generalize the cost terms and the order lead time while retaining the one-machine one-spare structure of the original paper. [ABSTRACT FROM AUTHOR]

Presents information on determining the system reliability and various measures of the importance of a component in relation to a system. Identification of the measures; What the measures cover; Indepth look at the failure-mode models in relation to its properties.

Turbine-engine-driven distributed electrical aircraft power systems [also referred to as turboelectric distributed propulsion (TeDP)] are proposed for providing thrust for future aircraft with superconducting components operating at 77 K, in order for performance and emission targets to be met. The proposal of such systems presents a radical change from current state-of-the-art aeroelectrical power systems. Central to the development of such power systems are architecture design trades which must consider system functionality and performance, system robustness, and fault ridethrough capability, in addition to the balance between mass and efficiency. This paper presents a quantitative comparison of the three potential candidate architectures for TeDP electrical networks. This analysis provides the foundations for establishing the feasibility of these different architectures subject to design and operational constraints. The findings of this paper conclude that a purely ac synchronous network performs best in terms of mass and efficiency, but similar levels of functionality and controllability to an architecture with electrical decoupling via dc cannot readily be achieved. If power electronic converters with cryocoolers are found to be necessary for functionality and controllability purposes, then studies show that a significant increase in the efficiency of solid-state switching components is necessary to achieve specified aircraft performance targets. [ABSTRACT FROM AUTHOR]