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- PublicationAccès libreQuantifying the probability of decline in quality : implications for selection management in northern hardwood forests(MDPI, 2023-01-31) Moreau, Guillaume; Cecil-Cockwell, Malcolm J. L.; Achim, Alexis; Bédard, Steve; Guillemette, François; Caspersen, John PeterNorthern hardwoods are susceptible to a wide range of defects that can reduce the amount of sound wood with desirable qualities, such as the clear sapwood of sugar maple trees. Yet, the rate at which trees decline in quality due to the development of such defects has never been quantified in northern hardwood forests due to a dearth of repeat inventories that record the appearance of defects over time. As a result, it remains uncertain whether, and how, selection management reduces the probability of decline in quality. In this study, we quantify the rate at which trees decline in quality due to the development of defects, and we test several hypotheses regarding the influence of selection management on quality. Our results show that (1) the probability of decline in quality increases as trees grow larger; (2) crown dieback also increases the probability of decline in quality; (3) the probability of decline in quality is slightly lower in managed stands than in unmanaged stands, and (4) the probability of decline in quality increases with the mean annual temperature of the site. Finally, we combined our estimates of the probability of decline in quality with previous estimates of the probability of mortality to assess the overall risk associated with retaining trees of different species, sizes, and vigour profiles. The resulting metric can inform efforts to improve the management of northern hardwood forests by providing an integrated estimate of the risk that the value of a tree will be reduced, or eliminated, due to mortality or decline in quality.
- PublicationRestreintUtilisation du sacubitril/valsartan (EntrestoMD) chez les patients atteints d’insuffisance cardiaque avec fraction d’éjection abaissée à la clinique d’insuffisance cardiaque de l’IUCPQ-UL(Montréal : Association des pharmaciens des établissements de santé du Québec, 2021-04-22) Lacroix, Catherine; Boisvert, Julie-A.; Vachon, Audrey; Méthot, JulieContexte : Le sacubitril/valsartan a été approuvé au Canada pour le traitement de l’insuffisance cardiaque avec fraction d’éjection abaissée à la suite des résultats positifs obtenus dans l’étude PARADIGM-HF, et il est utilisé dans notre institut depuis décembre 2015. Étant donné la faible représentation de la population canadienne dans les études à répartition aléatoire, il est pertinent d’analyser le profil d’utilisation du sacubitril/valsartan chez les patients du Québec. Méthode : Cette étude descriptive, rétrospective et longitudinale a été menée auprès de patients traités par sacubitril/valsartan entre le 1er décembre 2015 et le 31 mars 2017 à la clinique d’insuffisance cardiaque de l’Institut universitaire de cardiologie et de pneumologie de Québec – Université Laval. Résultats : Un total de 271 patients a entrepris un traitement par sacubitril/valsartan durant cette période. Les analyses de données recueillies (n = 271) indiquent que 38,0 % d’entre eux ont atteint la dose cible de 194/206 mg (400 mg) par jour à la fin de l’étude. L’atteinte de la dose cible semble être influencée par l’âge, la fonction rénale ainsi que par la prise initiale d’un bloqueur des canaux calciques. En cours de suivi, la dose de furosémide a été réduite chez 31,9 % des patients. Les symptômes d’hypotension (20,8 %) ont constitué l’effet indésirable le plus fréquent. Conclusion : Cette étude a permis d’accroître le niveau de connaissances sur le profil d’utilisation du sacubitril/valsartan en ce qui a trait à l’atteinte de la dose cible, à la survenue d’effets indésirables et à l’ajustement de la médication cardiovasculaire concomitante dans la population québécoise.
- PublicationAccès librePuzzling about policy paradigms : precision and progress(London : Routledge, 2014-03-10) Daigneault, Pierre-MarcNo abstract
- PublicationAccès libreCorrection, update, and enhancement of vectorial forestry road maps using ALS data, a pathfinder, and seven metrics(Elsevier, 2022-09-21) Roussel, Jean-Romain; Bourdon, Jean-François; Morley, Ilythia D.; Coops, Nicholas C.; Achim, AlexisAccurate information about forestry roads is a key aspect of forest management in terms of economy (e.g. accessibility, cost, optimal path) and ecology (e.g. wildfire and wildlife protection). In Canada, and in fact, globally, most provincial, state or territory governments maintain vectorial information on the forestry roads under their jurisdiction. However, official maps are not always accurate, may lack road attributes of interest and are not always up-to-date. Airborne Laser Scanning (ALS) has become an established technology to accurately characterize and map broad territories by providing high density 3D point-clouds with, at least, 3 or 4 measurements per square meter. This paper addresses the problem of the automatic updating, fixing, and enhancement of vectorial forestry road maps over large landscapes (¿10000 km2). For this purpose, we developed a production ready, documented and open-source software. From metrics derived from the point-cloud the method produces a raster of road probability. It then uses an existing, inaccurate, map of the road network to define approximate start and end points for each road. Then, a pathfinder retrieves the accurate road shape by computing the least cost path between the two points on the probability raster. Using the accurate road position given by the algorithm, road width and road state are then estimated based the on characteristics of the point-cloud. We demonstrate that our algorithm retrieves the centrelines of roads in a natively vectorial form with an error below 3 m in 95% of the roads using a fully automatic method. The accuracy of the road location allows us to derive other accurate measurements, including the state of the roads.
- PublicationRestreintSelf-organizing or organizing one another? Cycling groups’ participation to planning(London : Routledge, Taylor & Francis, 2022-06-15) Béliveau-Côté, Guillaume; Cloutier, Geneviève; Houde-Tremblay, Émilie; Chembessi, ChedrakStudies on planning have traditionally exposed how institutional participation opposes informal modes of participation. But do activists have to choose between the two? Suggesting that there is a grey-zone, recent work has focused on the distinct paths that individuals take to engage in civic life. We argue that strategies that involves both civil society-led and traditional approaches may help defend planning options, especially for those not considered in formal decision-making in local planning. In what ways can the interrelation of traditional and nontraditional modes of participation help bring forth new ideas? Building on a case study of urban activists tackling issues regarding cycling in Québec City (Québec, Canada), we observed how they connect planning with different modes of participation. Activists take part in the debate on urban planning through institutional platforms, demonstrating their desire to be recognized. Also, they take actions to increase the legitimacy of alternative modes of mobility.
- PublicationAccès libreLimiting properties of an equiprobable sampling scheme for 0–1 matrices(North-Holland, 2021-01-19) Rivest, Louis-PaulA sampling scheme that selects a random 0-1 matrix of size uniformly in the set of 0-1 matrices with predetermined row and column totals is investigated. The limits, as goes to and is fixed, of the column relative frequencies is derived. The limiting values give a sampling design for a population of units that generalizes the conditional Poisson sampling design introduced by Hajek. A method to calculate the joint selection probabilities for this new design using the known single inclusion probabilities is presented. Numerical examples show that the limiting theorem provides good approximations to the fixed column probabilities of a random matrix.
- PublicationRestreintInfluence of the menstrual cycle on the timing of acute coronary events in premenopausal women.(New York, NY : Excerpta Medica, Inc., 2003-05-10) Hamelin, Bettina; Méthot, Julie; Arsenault, Marie; Pilote, Sylvie; Poirier, Paul; Plante, Sylvain; Bogaty, PeterDuring their reproductive years, women have a low incidence of coronary artery disease, which increases markedly 10 to 15 years after menopause. It has long been hypothesized that this increased risk is at least in part due to the absence of female hormones, in particular, 17β-estradiol. This hypothesis was supported by data from epidemiological studies, which suggested that hormone replacement therapy would protect postmenopausal women from coronary artery disease. However, recent placebo-controlled trials designed to test the cardioprotective effects of a regimen of estrogens plus progestin have found no reduction in cardiovascular events or progression of angiographic lesions. Nevertheless, acute administration of 17β-estradiol affects the vasculature by modulating the nitric oxide–L-arginine pathway, and improves endothelial function and prolongs the time to ST-segment depression and exercise time, in postmenopausal women with coronary artery disease. These data suggest that the acute effects of 17β-estradiol could subside rapidly when levels are low during menses. Therefore, we sought to determine whether premenopausal women would be at greater risk of developing an acute coronary event when blood levels of 17β-estradiol levels are low during the menstrual cycle.
- PublicationRestreintFire as a driver of wood mechanical traits in the boreal forest(Elsevier, 2020-08-04) Waldron, Kaysandra; Auty, David; Tong, Tessie; Ward, Charles; Pothier, David; Paes Torquato, Luciane; Achim, AlexisIn boreal forests where the fire return interval is long, the high structural variability of stands may affect wood traits. Here, we build on earlier work that revealed a difference in wood mechanical traits of black spruce between regular (regenerated from fire in the last 200 years) and irregular (undisturbed by fire for at least 200 years) stands. This study aimed to identify the ecological drivers of this variation in wood traits. To do so, we first sought to corroborate existing results on the effects of stand structure induced by the time since the last stand-replacing fire (TSLF) on wood mechanical stiffness in the eastern boreal forest of Canada. Results confirmed that black spruce from regular stands tend to produce wood with higher modulus of elasticity (MOE) than those from irregular stands. For both regular and irregular stands, we compared a set of linear models that were defined a priori to determine the structural and site productivity variables having the largest influence on MOE. The ‘growth efficiency index’ (aboveground woody biomass production per unit leaf area) was the best predictor of MOE variation among regular stands. For irregular stands, the model with TSLF as the sole explanatory variable was a better predictor of MOE than any other candidate model. However, we did not find strong evidence of a direct relationship between TSLF and wood traits, since our best models explained a relatively small proportion of the variance. Our results suggest that differences in wood traits could be attributable to the seed or layer origin of the trees and/or to the length of time trees remain in the understory. We propose that intensive wood production strategies focus on stands of the first post-fire cohort.
- PublicationAccès libreWhen lexical statistics and the grammar conflict: learning and repairing weight effects in stress([Washington, DC] : Linguistic Society of America, 2019-12-17) Garcia, Guilherme D.In weight-sensitive languages, stress is influenced by syllable weight. As a result, heavy syllables should attract, not repel, stress. The Portuguese lexicon, however, presents a case where weight seems to negatively impact stress: antepenultimate stress is more frequent in light antepenultimate syllables than in heavy ones. This pattern is phonologically unexpected and appears to contradict the typology of weight and stress: it is a case where lexical statistics and the grammar conflict. Portuguese also contains gradient, not categorical, weight effects, which weaken as we move away from the right edge of the word. In this article, I examine how native speakers’ grammars capture these subtle weight effects, and whether the negative antepenultimate weight effect is learned or repaired. I show that speakers learn the gradient weight effects in the language, but do not learn the unnatural negative effect. Instead, speakers repair this pattern and generalize a positive weight effect to all syllables in the stress domain. This study thus provides empirical evidence that speakers may not only ignore unnatural patterns, but also learn the opposite pattern.
- PublicationAccès libreThe changing culture of silviculture(London Milford, 2021-11-13) Achim, Alexis; Moreau, Guillaume; Coops, Nicholas C.; Axelson, Jodi N.; Barrette, Julie; Bédard, Steve; Byrne, Kenneth E.; Caspersen, John Peter; Dic, Adam R.; D’Orangeville, Loïc; Drolet, Guillaume; Eskelson, Bianca N.I.; Filipescu, Cosmin N.; Flamand-Hubert, Maude; Goodbody, Tristan R.H.; Griess, Verena C.; Hagerman, Shannon M.; Keys, Kevin; Lafleur, Benoit; Girona, Miguel Montoro; Morris, Dave M.; Nock, Charles A.; Pinno, Bradley D.; Raymond, Patricia; Roy, Vincent; Schneider, Robert; Soucy, Michel; Stewart, Bruce; Sylvain, Jean-Daniel; Taylor, Anthony R.; Thiffault, Évelyne; Thiffault, Nelson; Vepakomma, Udaya; White, Joanne C.Changing climates are altering the structural and functional components of forest ecosystems at an unprecedented rate. Simultaneously, we are seeing a diversification of public expectations on the broader sustainable use of forest resources beyond timber production. As a result, the science and art of silviculture needs to adapt to these changing realities. In this piece, we argue that silviculturists are gradually shifting from the application of empirically derived silvicultural scenarios to new sets of approaches, methods and practices, a process that calls for broadening our conception of silviculture as a scientific discipline. We propose a holistic view of silviculture revolving around three key themes: observe, anticipate and adapt. In observe, we present how recent advances in remote sensing now enable silviculturists to observe forest structural, compositional and functional attributes in near-real-time, which in turn facilitates the deployment of efficient, targeted silvicultural measures in practice that are adapted to rapidly changing constraints. In anticipate, we highlight the importance of developing state-of-the-art models designed to take into account the effects of changing environmental conditions on forest growth and dynamics. In adapt, we discuss the need to provide spatially explicit guidance for the implementation of adaptive silvicultural actions that are efficient, cost-effective and socially acceptable. We conclude by presenting key steps towards the development of new tools and practical knowledge that will ensure meeting societal demands in rapidly changing environmental conditions. We classify these actions into three main categories: reexamining existing silvicultural trials to identify key stand attributes associated with the resistance and resilience of forests to multiple stressors, developing technological workflows and infrastructures to allow for continuous forest inventory updating frameworks, and implementing bold, innovative silvicultural trials in consultation with the relevant communities where a range of adaptive silvicultural strategies are tested. In this holistic perspective, silviculture can be defined as the science of observing forest condition and anticipating its development to apply tending and regeneration treatments adapted to a multiplicity of desired outcomes in rapidly changing realities.