Ontario Research Articles

Platform-mediated territorial stigmatization and destigmatization: Unpacking Reddit discussions on moving to “the other” London

This paper interrogates the role of digital platforms in advancing territorial stigma. Drawing from research that has discerned the channels with which territorial stigma has been produced and mediated through — commonly referred to as ‘modes’ — I argue digital platforms are a mode in their own right. Digital platforms are on par with, and may have already surpassed, pre-platform media modes (e.g., newspapers, television) in terms of their use for forming preconceptions of cities in lieu of lived experience. Accordingly, this study investigates discussions on the social networking platform Reddit, about moving to the mid-sized city of London, Ontario in Canada. I use a hybrid thematic analysis to identify (de)stigmatizing content within a topic-based forum (a subreddit). The results show that the platform mediated its users’ reproduction of territorial stigmas stemming from pre-platform modes, rather than having generated entirely novel stigmas. Moreover, many users enacted or reworked established territorial destigmatization strategies to contest, counter, or cope with London’s territorial stigma. This paper contributes to territorial stigma research by examining a lesser-known mid-sized city, which in turn expands the current understanding of stigmatization in Canada hitherto limited to its materialization in large cities. By demonstrating Reddit’s modal potentiality, the paper provides the necessary empirical basis for future studies interested in examining other digital platforms through the theoretical framework of territorial stigma. Furthermore, it encourages future conceptualizations of the media mode of territorial stigma production to include digital platforms alongside traditional and mass media.

Longer-term impacts of the COVID-19 pandemic on obstructive sleep apnoea (OSA)-related healthcare: a province-based study

RationaleFollowing marked reductions in sleep medicine care early in the COVID-19 pandemic, there is limited information about the recovery of these services. We explored long-term trends in obstructive sleep apnoea...

Length of Postpartum Hospital Stays During COVID-19: Findings From a Convergent Parallel Mixed-Methods Study

ObjectivesWe examined the length of postpartum hospitalization for live births during the COVID-19 pandemic and explored how pandemic circumstances influenced postpartum hospital experiences. MethodsWe conducted a cross-provincial, convergent parallel mixed-methods study in Ontario (ON) and British Columbia (BC), Canada. We included birthing persons (BPs) with an in-hospital birth in ON from 1 January to 31 March 2019, 2021, and 2022 (quantitative), and BPs (≥18 years) in ON or BC from 1 May 2020 to 1 December 2021 (qualitative). We linked multiple health administrative datasets at ICES and developed multivariable linear regression models to examine the length of hospital stay (quantitative). We conducted semi-structured interviews using qualitative descriptive to understand experiences of postpartum hospitalization (qualitative). Data integration occurred during design and interpretation. ResultsRelative to 2019, postpartum hospital stays decreased significantly by 3.29 hours (95% CI –3.58 to –2.99; 9.2% reduction) in 2021 and 3.89 hours (95% CI –4.17 to –3.60; 9.0% reduction) in 2022. After adjustment, factors associated with shortened stays included: giving birth during COVID-19, social deprivation (more ethnocultural diversity), midwifery care, multiparity, and lower newborn birth weight. Postpartum hospital experiences were impacted by risk perception of COVID-19 infection, clinical care and hospital services/amenities, visitor policies, and duration of stay. ConclusionsLength of postpartum hospital stays decreased during COVID-19, and qualitative findings described unmet needs for postpartum services. The integration of large administrative and interview data expanded our understanding of observed differences. Future research should investigate the impacts of shortened stays on health service outcomes and personal experiences.

Comparing birth experiences and satisfaction with midwifery care before and after the implementation of Canada's first Alongside Midwifery Unit (AMU).

Globally, midwifery-led birthing units are associated with favourable clinical outcomes and positive birth experiences. As part of our evaluation of Canada's first Alongside Midwifery Unit (AMU) at Markham Stouffville Hospital, we sought to explore and compare birth experiences and satisfaction among midwifery clients who gave birth on the AMU with midwifery clients who gave birth on the traditional obstetric unit prior to AMU implementation. We conducted a structured, online, cross-sectional survey of midwifery clients in the six months before, and up to 18 months after, opening of the AMU at Markham Stouffville Hospital, Ontario Canada. The survey contained validated measures of satisfaction including personal capacity and participation; perceived safety, control, and security; professional support; and satisfaction. Descriptive statistics and tests of significance were completed in SPSS. A total of 193 responses were included in our analyses (pre-AMU n = 47, post-AMU n = 146). All participants had positive experiences in the four domains assessed. Compared to those who gave birth with midwives on the Labour unit, those who gave birth on the AMU indicated more positive experiences for some measures. Perceptions pertaining to being an active participant in care, to security and sense of control were more positive among those who gave birth on the AMU. The AMU in Ontario is associated with high levels of satisfaction during birth, particularly the perception of being actively engaged in decision making, having a sense of control and safety, and having confidence in the care provider team. Care received on the AMU does not compromise birth experiences or satisfaction and may be associated with greater autonomy and agency for the person giving birth.

Comparative Safety Analysis of Nabilone Versus Opioids: A Population-Based Cohort Study.

Some have advocated that nabilone be used rather than opioids to manage chronic, noncancer pain, since the former drug may have a better safety profile. We compared the safety of incident nabilone use relative to incident opioid use with respect to multiple clinically important outcomes. A population-based, retrospective cohort study. Province of Ontario, Canada. Persons aged 12 years and older, diagnosed with a musculoskeletal condition within the past 3 years prior to the index date. Incident nabilone use, with incident opioid use serving as the reference group. Within 3 months following the index date, we separately evaluated for pneumonia, motor vehicle accidents, falls or fractures, mental and behavioral disorder due to psychoactive substance use, and all-cause mortality. A total of 18,863 incident nabilone users were propensity score matched to an equal number of opioid users. In the overall matched analysis, incident nabilone users vs. incident opioid users had significantly lower rates of pneumonia (hazard ratio [HR] 0.78, 95% CI 0.63-0.96), falls or fractures (HR 0.56, 95% CI 0.50-0.64), and all-cause mortality (HR 0.79, 95% CI 0.65-0.95), but significantly higher rate of mental or behavioral disorder (HR 2.23, 95% CI 1.45-3.43). There was no significant difference between groups with respect to rate of motor vehicle accidents. Unmeasured confounding may have influenced results. While usage of nabilone relative to opioids was associated with reduced rates of pneumonia, falls or fractures, and all-cause mortality, it was simultaneously associated with an increased rate of adverse mental health outcomes. This picture of mixed safety results raises concerns with the policy approach of broadly substituting use of opioids with nabilone. Ontario Ministry of Health.

The associations of supervised consumption services with the rates of opioid-related mortality and morbidity outcomes at the public health unit level in Ontario (Canada): A controlled interrupted time-series analysis.

This study aimed to assess the impact of the implementation of legally sanctioned supervised consumption sites (SCS) in the Canadian province of Ontario on opioid-related deaths, emergency department (ED) visits and hospitalisations at the public health unit (PHU) level. Monthly rates per 100,000 population of opioid-related deaths, ED visits and hospitalisations for PHUs in Ontario between December 2013 and March 2022 were collected. Aggregated and individual analyses of PHUs with one or more SCS were conducted, with PHUs that instituted an SCS being matched to control units that did not. Autoregressive integrated moving average models were used to estimate the impact of SCS implementation on opioid-related deaths, ED visits and hospitalisations. Twenty-one legally sanctioned SCS were implemented across nine PHUs in Ontario during the study period. Interrupted time series analyses showed no statistically significant changes in opioid-related death rates in aggregated analyses of intervention PHUs (increase of 0.02 deaths/100,000 population/month; p = 0.27). Control PHUs saw a significant increase of 0.38 deaths/100,000 population/month; p < 0.001. No statistically significant changes were observed in the rates of opioid-related ED visits in intervention PHUs (decrease of 0.61 visits/100,000 population/month; p = 0.39) or controls (increase of 0.403 visits; p = 0.76). No statistically significant changes to the rates of opioid-related hospitalisations were observed in intervention PHUs (0 hospitalisations/100,000 population/month; p = 0.98) or controls (decrease of 0.05 hospitalisations; p = 0.95). This study did not find significant mortality or morbidity effects associated with SCS availability at the population level in Ontario. In the context of a highly toxic drug supply, additional interventions will be required to reduce opioid-related harms.

The Coronavirus Pandemic and Mental Health Presentations of Young Children.

Children under the age of four are emotionally vulnerable to global disasters, such as the COVID-19 pandemic given the lack of socialization opportunities and coping mechanisms, and susceptibility to heightened caregiver stress. Currently, the extent to which the pandemic impacted the mental health of clinically referred young children is unknown. To evaluate how children's mental health outcomes were impacted during the pandemic, interRAI Early Years assessments (N = 1343) were obtained from 11 agencies across the Province of Ontario, during pre-pandemic and pandemic timepoints. Findings demonstrated that the number of completed assessments declined during the pandemic. Further, children's emotional concerns differed before and during the pandemic, whereby children exhibited greater emotional dysregulation during the pandemic. However, there were no significant differences when examining caregiver distress, parenting strengths, child distractibility/inattention or behavioural issues. Implications for young children and their families, clinicians, and policy makers are discussed.

Biologically Effective Dose of Diflufenican for the Control of Multiple Herbicide-Resistant Waterhemp in Soybean

Waterhemp biotypes have evolved resistance to Weed Science Society of America (WSSA) Herbicide Groups 2, 5, 9, 14, and 27 in Ontario Canada, are present in 15 counties, spanning a distance of 800 km across southern Ontario, and cause an average soybean yield loss of 42%. Five field experiments were established in growers&amp;rsquo; fields in southwestern Ontario to determine the biologically effective doses of diflufenican (Group 12) applied preemergence (PRE) to control multiple herbicide-resistant waterhemp in soybean. The calculated diflufenican doses to elicit 50, 80, and 95% control of MHR waterhemp were 71, 164, and 304 g ai ha-1 at 2 weeks after herbicide application (WAA); 50, 115, and 214 g ai ha-1 at 4 WAA; and 69, 158, and 294 g ai ha-1 at 8 WAA, respectively. The calculated diflufenican doses that caused a 50, 80, and 95% reduction in MHR waterhemp density were 28, 70, and Non-est. g ai ha-1 and the doses that caused a 50, 80, and 95% reduction in MHR waterhemp biomass were 44, 109, and Non-est. g ai ha-1, respectively. The calculated diflufenican doses that resulted in 50, 80, and 95% of the soybean yield of the industry standard herbicide (flumioxazin/pyroxasulfone) were 3, 12, and 57 g ai ha-1, respectively. Diflufenican (180 g ai ha-1) PRE controlled MHR waterhemp 89, 92, and 85%; metribuzin (300 g ai ha-1) PRE controlled MHR waterhemp 94, 84, and 69%; and flumioxazin/pyroxasulfone (105/134 g ai ha-1) PRE controlled MHR waterhemp 100, 99, and 98% at 2, 4, and 8 WAA, respectively. Diflufenican, metribuzin, and flumioxazin/pyroxasulfone applied PRE reduced MHR waterhemp density 96, 84, and 100% and biomass 93, 67, and 99%, respectively at 8 WAA. Diflufenican, metribuzin, and flumioxazin/pyroxasulfone applied PRE caused 9, 0, and 4% visible soybean injury, respectively but the injury was transient and caused no adverse effect on seed moisture content or seed yield of soybean. This study concludes that diflufenican and metribuzin applied PRE provide comparable MHR waterhemp control; however, control was lower than flumioxazin/pyroxasulfone.

Case-cohort design as an efficient approach to evaluating COVID-19 vaccine effectiveness, waning, heterologous immune effect and optimal dosing interval

Though widely applied in other epidemiological fields, the case-cohort study design has seen little application in the field of vaccinology. Case-cohort studies use probabilistic sampling and reweighting to draw inferences about effects (in this case vaccine efficacy) at the population level in an efficient manner. The SARS-CoV-2 pandemic was met with high vaccine uptake, and high rates of population testing prior to the emergence of Omicron variants of concern, in Ontario, Canada, providing an ideal environment for application of case-cohort methodology. We combined a population-based case line list and vaccination database for the province of Ontario between December 2020 and October 2021. Risk of infection after vaccination was evaluated in all laboratory-confirmed vaccinated SARS-CoV-2 cases, and a 2 % sample of vaccinated controls, evaluated using survival analytic methods, including construction of Cox proportional hazards models. Vaccination status was treated as a time-varying covariate. First and second doses of SARS-CoV-2 vaccine markedly reduced risk of infection (first dose efficacy 68 %, 95 % CI 67 %–69 %; second dose efficacy 88 %, 95 % CI 87–88 %). In multivariable models, extended dosing intervals were associated with lowest risk of breakthrough infection (HR for redosing 0.64 (95 % CI 0.61–0.67) at 6–8 weeks). Heterologous vaccine schedules that mixed viral vector vaccine first doses with mRNA second doses were significantly more effective than mRNA only vaccines. Risk of infection largely vanished during the time period 4–6 months after the second vaccine dose, but rose markedly thereafter. We conclude that a case-cohort design provided an efficient means to identify strong protective effects associated with SARS-CoV-2 vaccination in real time, and also served to quantify the timing and magnitude of infection breakthrough risk in the same cohort. Heterologous vaccination and extended dosing intervals improved the durability of immune response.

Pathogen Surveillance in Swallows (family Hirundinidae): Investigation into Role as Avian Influenza Vector in Eastern Canada Agricultural Landscapes.

First detected in Atlantic Canada in December 2021, highly pathogenic avian influenza virus (HPAIV) subtype H5N1 clade 2.3.4.4b, A/Goose/Guangdong/1/96 lineage, has caused massive mortality in wild birds and domestic poultry in North America. Swallows (Hirundinidae), abundant in North American agricultural ecosystems, have been proposed as possible (bridge) species for HPAIV transmission between wild and domestic birds. We aimed to seek evidence of the potential role of swallows in bridging AIV infection between wild bird reservoirs and poultry flocks in eastern Canada. During a wide-scale outbreak of HPAIV in wild birds and poultry farms across eastern Canada, 200 samples were collected from swallow breeding sites in the Canadian provinces of New Brunswick, Nova Scotia, Ontario, and Quebec, June-August 2022. Samples came from Barn Swallow (Hirundo rustica; n=142), Tree Swallow (Tachycineta bicolor; n=56), and Cliff Swallow (Petrochelidon pyrrhonota; n=2) nests. All samples tested negative for AIV, suggesting that HPAIV and low pathogenic AIV (LPAIV) strains were probably not circulating widely in swallows during the 2022 breeding season in eastern Canada; thus swallows may present a low risk of transmitting AIV. Within a management context, these findings suggest that removing nests of Barn Swallows, a species at risk in Canada, from the exterior of biosecure domestic poultry facilities may not significantly reduce risks of HPAI transmission to poultry.

Resource Utilization and Costs Associated With Cardiogenic Shock Complicating Myocardial Infarction: A Population-Based Cohort Study

BackgroundCardiogenic shock due to acute myocardial infarction (AMI-CS) is associated with significant short- and long-term morbidity and mortality. Despite this, little is known about associated cost. ObjectivesThe purpose of this study was to evaluate the health care costs and resource use associated with AMI-CS using administrative data from the province of Ontario, Canada. MethodsThis was a retrospective cohort study of adult patients with AMI-CS from April 2009 to March 2019. One-year costs following index admission were reported at an individual level. We used generalized linear models to identify factors associated with increased cost. We stratified patients by revascularization strategy to compare cost in each group and examined total cost at a patient level per individual fiscal year. ResultsWe included 9,789 consecutive patients with AMI-CS across 135 centers in Ontario (mean age 70.5 years; 67.7% male). Mortality in-hospital was 30.2%, and mortality at 2 years was 45.9%. The median inpatient cost per patient was $23,912 (IQR: $12,234-$41,833) with a median total 1-year cost of $37,913 (IQR: $20,113-$66,582). The median 1-year cost was $17,730 (IQR: $9,323-$38,379) for those who died in hospital, and $45,713 (IQR: $29,688-$77,683) for those surviving to discharge, with $12,719 (IQR: $4,262-$35,275) occurring after discharge. Patients who received coronary artery bypass grafting incurred the highest cost among revascularization groups. No significant differences were observed in cost per fiscal year from 2009 to 2019. ConclusionsAMI-CS is associated with significant health care costs, both during the index hospitalization and following discharge. To optimize cost-effectiveness, future therapies should aim to reduce disability in addition to improving mortality.

A novel multi-objective robust possibilistic flexible programming to design a sustainable apparel closed-loop supply chain network

Designing a sustainable Closed-Loop Supply Chain (CLSC) network is imperative for the apparel industry, given its escalating adverse effects on economic, environmental, and social dimensions. In this study, a novel tri-objective location-allocation optimization model is specifically developed for designing a sustainable apparel CLSC, incorporating the industry's unique facilities. The aim of the model is to simultaneously minimize the costs and negative environmental impacts while maximizing social benefits under demands and returns uncertainty. A notable research contribution lies in addressing the unique challenges of treating different types of returns, including commercial, End Of Use (EOU) and End Of Life (EOL) returns due to their uncertain quality and quantity. Additionally, the model optimizes the environmental performance levels of production facilities, a novel aspect in the apparel CLSC research. Moreover, the flexibility of constraints related to the demand fulfilment is considered. To cope with such flexibility and uncertainties, a new hybrid robust possibilistic flexible programming model is developed, by extending the previous methodologies. A core innovation of this solution approach lies in the pioneering utilization of hexagonal fuzzy numbers for uncertain epistemic parameters, making a significant advancement in the field of CLSC. Comparative analysis with the similar studies demonstrates the superiority of the proposed model, incorporating hexagonal fuzzy numbers over the method using triangular fuzzy numbers. Furthermore, AUGMECON method using lexicographic optimization is applied to handle the multi-objective model. The application of the proposed model is shown focusing on Southwestern Ontario in Canada. The results reveal that commercial and EOU returns have a more detrimental impact on economic, environmental, and social sustainability aspects compared to EOL returns.

Resiliency against food insecurity among the Black population in Scarborough during the COVID-19 pandemic

BackgroundOne of the effects of the COVID-19 pandemic is the increased level of food insecurity, especially during the first wave. Food insecurity is an indication of poverty and results in serious health and social effects. Even though several studies have been conducted to assess the impact of COVID-19, there is a paucity of information on the role of individual community members and local organizations in addressing food insecurity in the province of Ontario, Canada. Consequently, the objective of this study is to examine the role of individuals and community organizations in addressing food insecurity challenges among the Black population in Scarborough in the Greater Toronto Area.MethodsThis qualitative study recruited 20 Black participants from the TAIBU Community Health Center (CHC) located in Scarborough. Furthermore, the study recruited eight nurses and two Black doctors in the Greater Toronto Area (GTA) but only one affiliated with TAIBU. In-depth interviews were used to gather information for analysis. The study used manual coding and NVivo software to analyze the qualitative data.ResultsThe study found that there was a reported incidence of food insecurity among the population but new local food aid organizations sprang up to assist the existing ones in tackling food insecurity. However, the study found that the operations of food aid organizations are not sustainable.ConclusionsDespite the reported cases of food insecurity, local community organizations and individual community members volunteered to support people to boost their resiliency to food insecurity. The findings of the study highlight the role of community organizations in addressing food insecurity during crises including pandemics. Based on the health effects of food insecurity, the study recommends that both federal and provincial governments prioritize food insecurity as a major public health issue.

Participation in Special Olympics reduces the rate for developing diabetes in adults with intellectual and developmental disabilities.

Adults with intellectual and developmental disabilities (IDD) have a significantly higher prevalence of Type 2 diabetes than the general population. Evidence that lifestyle and/or behavioural interventions, such as participation in Special Olympics, decreases the risk of developing diabetes in adults with IDD could help minimize health disparities and promote overall health in this population. This was a 20-year retrospective cohort study of adults with IDD (30-39 years) in the province of Ontario, Canada, that compared hazard rates of diabetes among Special Olympics participants (n = 4145) to non-participants (n = 31,009) using administrative health databases housed at ICES. Using cox proportional hazard models, crude and adjusted hazard ratios were calculated for the association between the primary independent variable (Special Olympics participation status) and the dependent variable (incident diabetes cases). After controlling for other variables, the hazard ratio comparing rates for developing diabetes between Special Olympics participants and non-participants was 0.85. This represents a 15% reduction in the hazard among Special Olympics participants when followed for up to 20 years. This result was statistically significant and represents a small effect size. Special Olympics could be considered a complex intervention that promotes physical activity engagement through sport participation, health screenings, and the promotion of healthy eating habits through educational initiatives. This study provides evidence that Special Olympics participation decreases the rate for developing diabetes.

Socio-spatial insights into evictions governance and tenant movements during the COVID-19 pandemic

The COVID-19 pandemic and related economic effects have served to thrust rental housing insecurity into the public spotlight. Documenting the extent of pandemic displacement in the City of Ottawa and province of Ontario, Canada, this article provides insight on evictions governance, urban marginality, and social struggle. The socio-legal developments surrounding pandemic evictions offer a compelling case in which to analyze the governance of urban marginality in its various intricacies. During the pandemic, the Ontario government passed legislation to protect tenants from eviction, yet also passed legislation that criminalized tenants organizing against evictions. Tenants engaged in informal actions to stop evictions were met with the threat of formal legal sanctions; evictions moratoria—as a mechanism of care—were coupled with punitive forms of urban marginality governance, such as through evictions tribunals and the criminalization of dissent. Using a mixed-methods approach, we temporally and spatially map the scale and measure the impact of pre- and post-pandemic evictions—documenting that evictions tend to occur in areas with high core housing need and racialized neighbourhoods. We also examine the emergence of new social movements to fight displacement and assess the varied government and landlord responses—including evictions moratoria, tribunal eviction blocks, and the criminalization of tenant organizing.

SARS-CoV-2 viral titer measurements in Ontario, Canada wastewaters throughout the COVID-19 pandemic

During the COVID-19 pandemic, the Province of Ontario, Canada, launched a wastewater surveillance program to monitor SARS-CoV-2, inspired by the early work and successful forecasts of COVID-19 waves in the city of Ottawa, Ontario. This manuscript presents a dataset from January 1, 2021, to March 31, 2023, with RT-qPCR results for SARS-CoV-2 genes and PMMoV from 107 sites across all 34 public health units in Ontario, covering 72% of the province’s and 26.2% of Canada’s population. Sampling occurred 2–7 times weekly, including geographical coordinates, serviced populations, physico-chemical water characteristics, and flowrates. In doing so, this manuscript ensures data availability and metadata preservation to support future research and epidemic preparedness through detailed analyses and modeling. The dataset has been crucial for public health in tracking disease locally, especially with the rise of the Omicron variant and the decline in clinical testing, highlighting wastewater-based surveillance’s role in estimating disease incidence in Ontario.

Calcineurin Inhibitor in NEuRoloGically deceased donors to decrease kidney delayed graft function study: study protocol of the CINERGY Pilot randomised controlled trial

IntroductionMost solid organ transplants originate from donors meeting criteria for death by neurological criteria (DNC). Within the organ donor, physiological responses to brain death increase the risk of ischaemia reperfusion...

Screening and risk assessment for sleep-related breathing disorders in individuals living with spinal cord injury

ObjectivesThis research work was performed: (1) To assess the accessibility of in-laboratory polysomnography for individuals with spinal cord injury (SCI); (2) to evaluate the validity of four screening questionnaires for sleep-related breathing disorders (SRBDs); and (3) to assess the association between anthropometric features and apnea-hypopnea index (AHI). MethodsAn Environmental scan (E-scan) was performed in the province of Ontario, where all sleep clinics were invited to complete the E-scan survey. Furthermore, a cross-sectional study was performed at a rehabilitation hospital (Canada), where consecutive adults with subacute/chronic (>1 month) SCI were recruited. Using a home-based screening sleep test (HBSST), the validity of the Berlin, STOP, Medical Outcomes Study Sleep Scale [MOS-SS], and STOP-Bang screening questionnaires was assessed. The association between AHI and three features (i.e., neck circumference, body mass index [BMI] and oropharynx opening as assessed using the Modified Mallampati classification [MMC]) was evaluated. ResultsAccording to the E-scan, access to polysomnography is limited for the SCI population in Ontario. Of the 28 participants with SCI (11 females, 17 males; mean age: 54.9 years) included in the cross-sectional study, 32.1 % were diagnosed with moderate-to-severe SRBD. The performance of the questionnaires was considered insufficient for screening of individuals living with SCI. AHI was not associated with neck circumference, BMI, or MMC. ConclusionsThose results suggest that the use of a HBSST could overcome the barriers for individuals with SCI to access diagnostic testing of SRBDs. The use of screening questionnaires and risk assessment for SRBDs in the SCI population is unreliable.

Political Dynasties in Canada

Abstract Using a unique dataset of legislators' electoral and biographical data in the Canadian provinces of Ontario, Quebec, New Brunswick, Nova Scotia and the federal parliament, this article analyses the extent to which family dynasties affected the career development of legislators since the mid-18th century. We find that the prevalence of dynasties was higher in provincial legislatures than it was in the federal parliament, that the number of dynasties in the Senate increased until the mid-20th century, and that the proportion of dynastic legislators at the subnational level was similar to the numbers seen in the United Kingdom during the early 19th century. Our results confirm the existence of a clear career benefit in terms of cabinet and senate appointments. In contrast to the American case and in line with the United Kingdom experience, we find no causal relationship between a legislator's tenure length and the presence of a dynasty.

Modelling Diameter at Breast Height Distribution for Eight Commercial Species in Natural-Origin Mixed Forests of Ontario, Canada

Diameter at breast height (DBH) is a unique attribute used to characterize forest growth and development for forest management planning and to understand forest ecology. Forest managers require an array of DBHs of forest stands, which can be reconstructed using selected probability distribution functions (PDFs). However, there is a lack of practices that fit PDFs of sub-dominating species grown in natural mixed forests. This study aimed to fit PDFs and develop predictive models for PDF parameters, so that the predicted distribution would represent dynamic forest structures and compositions in mixed forest stands. We fitted three of the simplest forms of PDFs, log-normal, gamma, and Weibull, for the DBH of eight tree species, namely balsam fir (Abies balsamea [L.] Mill.), eastern white pine (Pinus strobus L.), paper birch (Betula papyrifera Marshall), red maple (Acer rubrum L.), red pine (Pinus resinosa Aiton), trembling aspen (Populus tremuloides Michx), and white spruce (Picea glauca [Moench] Voss), all grown in natural-origin mixed forests in Ontario province, Canada. We estimated the parameters of the PDFs as a function of DBH mean and standard deviation for these species. Our results showed that log-normal fit the best among the three PDFs. We demonstrated that the predictive model could estimate the recovered parameters unbiasedly for all species, which can be used to reconstruct the DBH distributions of these tree species. In addition to prediction, the cross-validated R2 for the DBH mean ranged between 0.76 for red maple and 0.92 for red pine. However, the R2 for the regression of the standard deviation ranged between 0.00 for red pine and 0.69 for sugar maple, although it produced unbiased predictions and a small mean absolute bias. As these mean and standard deviations are regressed with dynamic covariates (such as stem density and stand basal area), in addition to climate and static geographic variables, the predicted DBH distribution can reflect change over time in response to management or any type of disturbance in the regime of the given geography. The predictive model-based DBH distributions can be applied to the design of appropriate silviculture systems for forest management planning.