Contribution de modèle demande-contrôle-soutien à la variation des concentrations de cortisol salivaire

L’objectif principal de ce mémoire est d’approfondir les connaissances à propos de l’impact des stresseurs organisationnels sur la concentration du cortisol salivaire. Plus précisément, nous étudierons la contribution des modèles demande-contrôle de Karasek (1979) et demande-contrôle-soutien de Karasek et Theorell (1990) à la variation du cortisol salivaire chez les individus. Les associations entre les composantes principales de chacun des modèles (demandes psychologiques, latitude décisionnelle et soutien social), mais également les effets d’interaction inclus dans ces modèles, c’est-à-dire de l’effet modérateur de la latitude décisionnelle et du soutien social, seront étudiés. L’axe HPS a été associé aux symptômes de la santé mentale (Abelson et al., 2007; Havermans et al., 2011; Vreeburg et al., 2009b, 2010, 2013; Staufenbiel, 2013) ainsi qu’aux stresseurs en milieu de travail (Chida et Steptoe, 2009). À l’heure actuelle, le cortisol salivaire serait un indicateur de l’axe hypothalamo-pituito-surrénalien (HPS) le plus prometteur pour mesurer la réponse physiologique face à un événement stressant ou à un stress chronique (Maïna et al., 2009). Les données proviennent de l’étude SALVEO, menée par l’Équipe de recherche sur le travail et la santé mentale de l’Université de Montréal. Les résultats des analyses multiniveaux ne soutiennent pas l’implication du modèle demande-contrôle-soutien sur la concentration de cortisol. En effet, elles ne permettent pas de conclure que les effets, autant principaux que d’interaction, du modèle demande-contrôle-soutien expliquent la variation dans les concentrations de cortisol. La consommation de tabac est significativement reliée à la concentration de cortisol salivaire et doit être prise en considération dans les études futures. Par conséquent, ces résultats suggèrent que d’autres recherches sont nécessaires pour comprendre comment les stresseurs du travail s’incorporent à l’individu au niveau physiologique. Des connaissances approfondies de ces associations permettraient de mieux comprendre les associations entre le stress à long terme et les effets sur la santé, c’est-à-dire, comment les tensions au travail affectent la santé mentale à long terme (Karhula et al., 2015).The main objective of this master thesis is to increase the knowledge about the impact of organisational factors on salivary cortisol concentrations. Especially, the models demand-control (Karasek, 1979) and demand-control-support (Karasek and Theorell, 1990) will be studied in relationship to the salivary cortisol. The objectives of this study are to investigate the associations between the main components of each model (psychological demands, decision latitude and social support), but also patterns of interaction effects, i.e. the effect moderator of decision latitude and social support. It has been shown that the HPA axis would be linked to symptoms of mental health (Abelson et al., 2007; Havermans et al. 2011; Vreeburg et al. 2009b, 2010, 2013; Staufenbiel, 2013) as well as stressors in the workplace (Chida and Steptoe, 2009). Currently, salivary cortisol, an indicator of the hypothalamic-pituitary-adrenal axis (HPA) or the axis of stress management, would be the most promising for measuring the physiological response to a stressful event or chronic stress (Maïna et al. 2009). The data results come from the SALVEO surveys led by the research team on work and mental health of University of Montreal (ERTSM). Results of multilevel analyses do not support the involvement of the demand - control - support model to changes in cortisol concentration. Indeed, they do not suggest that the main effects as much as the interaction effects of the demand-control-support model, explain the variation in cortisol levels. Tobacco consumption is significantly related to salivary cortisol concentration and must be taken into account in previous studies. Therefore, these results suggest that further research is needed to understand how the occupational stressors are incorporated into the individual at the physiological level. Depth knowledge of these associations would help to understand the associations between long-term stress and health effects or how job strain affects long-term mental health (Karhula et al. 2015)

A Parameterization of the Microphysical Processes Forming Many Types of Winter Precipitation

Several types of precipitation, such as freezing rain, ice pellets, and wet snow, are commonly observed during winter storms. The objective of this study is to better understand the formation of these winter precipitation types. To address this issue, detailed melting and refreezing of precipitation was added onto an existing bulk microphysics scheme. These modifications allow the formation of mixed-phase particles and these particles in turn lead to, or affect, the formation of many of the other types of precipitation. The precipitation type characteristics, such as the mass content, liquid fraction, and threshold diameters formed during a storm over St John’s, Newfoundland, Canada, are studied and compared with observations. Many of these features were reproduced by the model. Sensitivity experiments with the model were carried out to examine the dependence of precipitation characteristics in this event on thresholds of particle evolution in the new parameterization

Home for a White Season : Measuring precipitation in the Saint John River Valley

Canada First Research Excellence FundNon-Peer ReviewedPersonal account of a scientist's engagement with government agencies and local citizens to produce new understanding of rain and snow patterns in New Brunswick's Saint John River valley

CASE 6: A Rapid Risk Assessment Tool: Determining the Risk of New/Emerging/Re-Emerging Infectious Diseases in Canada

The protagonist, Dr. Anna Moreno, is an epidemiologist at the Public Health Agency of Canada (PHAC), where she manages the Public Health Risk Sciences Department. Her role includes managing monthly meetings and advising when it is necessary to use the Rapid Risk Assessment (RRA) tool to conduct an analysis of any emerging infectious disease relevant to Canada. The case presents a fictitious situation in which a series of outbreaks of an influenzalike infectious disease have occurred in certain regions of the Americas. In response to outbreaks of severe respiratory and influenza-like symptoms within the Americas and the more than 100 associated deaths over the past month, the World Health Organization has declared the unknown infectious disease a Public Health Emergency of International Concern (PHEIC). Anna has a meeting that morning, and she will need to prepare an approach to create a working group responsible for conducting an RRA for this unknown disease. Challenges arise because the existing scientific evidence and literature about the disease is limited and Anna will need to defer to the expert knowledge of her team while minimizing expert opinion bias. Given the general standards of RRAs, the assessment should be conducted within the next 24 to 48 hours. Knowing that the outcomes of the risk assessment will set the landscape for the PHAC’s response to the PHEIC, Anna and her team will need to ensure the assessment is conducted in a timely and efficient manner. The results of the RRA will be presented to upper management before being disseminated to the general public. Finally, the case includes a case study, based on true events, of the initial application of the tool to the 2015 Zika virus disease outbreak. Although the initial assessment led to the conclusion that Canadians were at minimal risk, unexpected subsequent Zika outbreaks in 2016 revealed the need to refine and adapt the RRA tool. This case study emphasizes the importance of completing a risk assessment at multiple time points throughout the course of a disease to capture the complexities of evolving information and circumstances. The pedagogical value of presenting this case is rooted in presenting a real-world situation and exposing students to the complexities of translating foundational public health practices to social contexts that do not allow for typical solutions. Although it is necessary to learn concrete knowledge in a classroom environment, this information serves as a foundation to build on through experience within the public health field. Being immersed in real-world situations is imperative for enabling students to visualize how this knowledge may not translate perfectly during a public health event. This case will complement the focus on emergency preparedness and monitoring and managerial control mechanisms emphasized in the course MPH 9010- Managing Health Services. This level of public health response provides direction and recommendations for all sectors in the face of urgent events, such as infectious disease outbreaks

Erratum to: Spatial spin-up of fine scales in a regional climate model simulation driven by low-resolution boundary condition

The capture of the public servant in a criminal investigation is subject to special rules and different to those for the capture of individuals, since the imprisonment of an official can affect continuity, speed and efficiency of the civil service, an equally important constitutional value. Therefore, as a rule capturing the public servant must be preceded by a request for suspensión by the prosecution, and to proceed without suspension, the prosecutor in his providence should motivate the reasons and arguments why not affects the normal functioning of public administration. The lack of motivation for this essential aspect, affords a fact that becomes appropriate procedural habeas corpus as an effective mechanism guarantees of personal freedom. Similarly appropriate habeas corpus when catching public server ordered by a prosecutor without functional competence to advance research, by setting a path made by organic defect.La captura del servidor público investigado en un proceso penal está sujeta a reglas especiales y diversas a las previstas para la captura de los particulares, por cuanto la privación de la libertad de un funcionario puede afectar la continuidad, celeridad y eficacia de la función pública, como un valor constitucional igualmente relevante. Por tal motivo, como regla general,la captura del servidor público debe estar precedida de la solicitud de suspensión por parte de la Fiscalía General de la Nación y para que proceda sin suspensión previa, el fiscal debe consignar en su providencia las razones y argumentos por los cuales no se afecta el normal funcionamiento de la administración pública. La ausencia de motivación de este aspecto esencial constituye una vía de hecho procedimental que torna procedente la acción de habeas corpus, como mecanismo efectivo de garantía de la libertad personal. De igual manera, procede el habeas corpus cuando la captura del servidor público la ordena un fiscal sin competencia funcional para adelantar la investigación, por configuración de una vía de hecho por defecto orgánico

CASE 8: Case Attribution for COVID-19: Who Counts What?

The COVID-19 pandemic has emerged as an important topic of discussion at the Public Health Agency of Canada’s federal, provincial, and territorial tables. Representatives from each Canadian province and territory have come together to discuss the discrepancies noted in the attribution of COVID-19 cases between jurisdictions. Senior epidemiologist, Nina Mendez, is leading a case attribution project to give provinces and territories a forum for discussing any jurisdiction issues they encounter when reporting COVID-19 cases. Nina notices discrepancies in the way provinces and territories are reporting cases, where the majority of jurisdictions have been reporting cases based on official permanent residence, however two jurisdictions have been attributing cases based on location of diagnosis. This discrepancy in attribution leads to a discussion about how different protocols influence the way public health measures are implemented within each jurisdiction. Specifically, in the context of when individuals such as students, commuters, visitors, or long-term temporary workers are away from their permanent residence long enough that the risk of disease transmission no longer applies to their permanent residence jurisdiction

Spatial spin-up of fine scales in a regional climate model simulation driven by low-resolution boundary conditions

In regional climate modelling, it is well known that domains should be neither too large to avoid a large departure from the driving data, nor too small to provide a sufficient distance from the lateral inflow boundary to allow the full development of the small-scale (SS) features permitted by the finer resolution. Although most practitioners of dynamical downscaling are well aware that the jump of resolution between the lateral boundary condition (LBC) driving data and the nested regional climate model affects the simulated climate, this issue has not been fully investigated. In principle, as the jump of resolution becomes larger, the region of interest in the limited-area domain should be located further away from the lateral inflow boundary to allow the full development of the SS features. A careless choice of domain might result in a suboptimal use of the full finer resolution potential to develop fine-scale features. To address this issue, regional climate model (RCM) simulations using various resolution driving data are compared following the perfect-prognostic Big-Brother protocol. Several experiments were carried out to evaluate the width of the spin-up region (i.e. the distance between the lateral inflow boundary and the domain of interest required for the full development of SS transient eddies) as a function of the RCM and LBC resolutions, as well as the resolution jump. The spin-up distance turns out to be a function of the LBC resolution only, independent of the RCM resolution. When varying the RCM resolution for a given resolution jump, it is found that the spin-up distance corresponds to a fixed number of RCM grid points that is a function of resolution jump only. These findings can serve a useful purpose to guide the choice of domain and RCM configuration for an optimal development of the small scales allowed by the increased resolution of the nested model

The Collection Efficiency of Shielded and Unshielded Precipitation Gauges. Part II: Modeling Particle Trajectories

The use of windshields to reduce the impact of wind on snow measurements is common. This paper investigates the catching performance of shielded and unshielded gauges using numerical simulations. In Part II, the role of the windshield and gauge aerodynamics, as well as the varying flow field due to the turbulence generated by the shield–gauge configuration, in reducing the catch efficiency is investigated. This builds on the computational fluid dynamics results obtained in Part I, where the airflow patterns in the proximity of an unshielded and single Alter shielded Geonor T-200B gauge are obtained using both time-independent [Reynolds-averaged Navier–Stokes (RANS)] and time-dependent [large-eddy simulation (LES)] approaches. A Lagrangian trajectory model is used to track different types of snowflakes (wet and dry snow) and to assess the variation of the resulting gauge catching performance with the wind speed. The collection efficiency obtained with the LES approach is generally lower than the one obtained with the RANS approach. This is because of the impact of the LES-resolved turbulence above the gauge orifice rim. The comparison between the collection efficiency values obtained in case of shielded and unshielded gauge validates the choice of installing a single Alter shield in a windy environment. However, time-dependent simulations show that the propagating turbulent structures produced by the aerodynamic response of the upwind single Alter blades have an impact on the collection efficiency. Comparison with field observations provides the validation background for the model results

Case 12 : Prioritizing Emerging and Re-Emerging Non-enteric Zoonotic Infectious Diseases: What Should we be Afraid of Next?

As time progresses, new zoonoses make their way to the forefront in the media, in healthcare systems, in government projects, and in the daily lives of Canadians. Prioritization exercises carried out by public health experts can provide an indication for which zoonoses we should be most afraid of next, and ultimately most prepared for, especially in light of impeding changes in climate. Blake O’Neil and Brock Jansen have recently transitioned to new positions with the Health Professionals Guidance Unit at the Centre for Food-borne, Environmental, and Zoonotic Infectious Diseases. Together, they plan to develop health professional guidance documents and tools to aid in the prevention, early diagnosis, and clinical management of various emerging and re-emerging non-enteric zoonotic infectious diseases. To maintain efficiency when creating guidance documents and tools, Blake and Brock have commenced a prioritization exercise to determine which emerging and re-emerging non-enteric zoonotic infectious diseases are of the greatest threat to the health of Canadians as a result of climate change. To date, Blake and Brock have reviewed previously conducted internal and external prioritization exercises; received consultation from the National Microbiology Lab in Winnipeg, Manitoba; undertaken a literature review to explore zoonoses relevant to the Canadian context; and organized an advisory committee composed of external stakeholders from various healthrelated specialties. With the results from the literature review and the input from various stakeholder organizations, Blake and Brock have developed a list of zoonoses to be included in the prioritization exercise. The upcoming federal election tenders a very constrained timeframe for Blake and Brock, specifically for engaging with stakeholders external to the Public Health Agency of Canada. As public servants, Blake and Brock need to ensure government resources are not used for partisan advantage. Therefore, any stakeholder engagement would need to be paused when electoral campaigning begins until a Prime Minister is elected and the Senate and House of Commons resume. Furthermore, prior to the federal election, Blake and Brock must produce a list of priority emerging and re-emerging non-enteric zoonotic infectious diseases so they can begin developing health professional guidance documents and tools. The pair has only been able to identify two prioritization criteria thus far: measuring the number of incident cases within Canada for each zoonosis and measuring the severity of illness associated with each zoonosis. However, because severity of illness is relatively challenging to define, the pair continues to search for a unit of analysis that adequately represents the criterion. In addition, they must tailor the incidence formula to sufficiently capture the status of the zoonoses in Canada. Blake and Brock are now at a standstill in terms of identifying three additional prioritization criteria, defining what each criterion entails, and how each criterion will be measured

Impact of Wind Direction, Wind Speed, and Particle Characteristics on the Collection Efficiency of the Double Fence Intercomparison Reference

The accurate measurement of snowfall is important in various fields of study such as climate variability, transportation, and water resources. A major concern is that snowfall measurements are difficult and can result in significant errors. For example, collection efficiency of most gauge–shield configurations generally decreases with increasing wind speed. In addition, much scatter is observed for a given wind speed, which is thought to be caused by the type of snowflake. Furthermore, the collection efficiency depends strongly on the reference used to correct the data, which is often the Double Fence Intercomparison Reference (DFIR) recommended by the World Meteorological Organization. The goal of this study is to assess the impact of weather conditions on the collection efficiency of the DFIR. Note that the DFIR is defined as a manual gauge placed in a double fence. In this study, however, only the double fence is being investigated while still being called DFIR. To address this issue, a detailed analysis of the flow field in the vicinity of the DFIR is conducted using computational fluid dynamics. Particle trajectories are obtained to compute the collection efficiency associated with different precipitation types for varying wind speed. The results show that the precipitation reaching the center of the DFIR can exceed 100% of the actual precipitation, and it depends on the snowflake type, wind speed, and direction. Overall, this study contributes to a better understanding of the sources of uncertainty associated with the use of the DFIR as a reference gauge to measure snowfall