Publications by authors named "Pascal Sirois"

The case of the deepwater redfish (Sebastes mentella) in the Gulf of St. Lawrence (GSL) is a compelling example of drastic fluctuations in annual recruitment strength, characteristic of spasmodic stocks. After three decades of low abundance, the emergence of three consecutive strong year classes in 2011-2013 resulted in an unprecedented increase in biomass.

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Article Synopsis
  • Heart failure due to heat stress is a significant concern for aquatic ectotherms, and mitochondrial dysfunction may play a key role in this issue.
  • The study focused on the thermal sensitivity of cardiac mitochondria in three-spined stickleback fish, examining factors like temperature, fatty acid composition, and age.
  • Results showed that while temperature strongly affected mitochondrial respiration, fish age also influenced it, revealing higher EPA levels in older fish but no direct correlation with critical thermal maximum (CTmax).
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In the northern Gulf of St. Lawrence (nGSL), redfish (Sebastes mentella and Sebastes fasciatus combined) are at record levels of abundance following the strong recruitment of three consecutive cohorts in 2011-2013 and have become by far the most abundant demersal fish in the region. Understanding redfish trophic relationships is essential for the effective management and conservation of species in the nGSL ecosystem.

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Epigenetic modifications are thought to be one of the molecular mechanisms involved in plastic adaptive responses to environmental variation. However, studies reporting associations between genome-wide epigenetic changes and habitat-specific variations in life history traits (e.g.

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Increasing evidence shows that structural variants represent an overlooked aspect of genetic variation with consequential evolutionary roles. Among those, copy number variants (CNVs), including duplicated genomic regions and transposable elements (TEs), may contribute to local adaptation and/or reproductive isolation among divergent populations. Those mechanisms suppose that CNVs could be used to infer neutral and/or adaptive population genetic structure, whose study has been restricted to microsatellites, mitochondrial DNA and Amplified fragment length polymorphism markers in the past and more recently the use of single nucleotide polymorphisms (SNPs).

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Trace metals found in the calcified structures of fish (i.e. otolith, scales and vertebrae) serve as proxies for the ambient water composition at the time of mineralization, and these trace metals are increasingly used as a tool for assessing population structure and the migratory patterns of fish.

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Identification of stocks and quantification of their relative contribution to recruitment are major objectives toward improving the management and conservation of marine exploited species. Next-generation sequencing allows for thousands of genomic markers to be analyzed, which provides the resolution needed to address these questions in marine species with weakly differentiated populations. Greenland Halibut () is one of the most important exploited demersal species throughout the North Atlantic, in particular in the Gulf of St.

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Gene flow has tremendous importance for local adaptation, by influencing the fate of de novo mutations, maintaining standing genetic variation and driving adaptive introgression. Furthermore, structural variation as chromosomal rearrangements may facilitate adaptation despite high gene flow. However, our understanding of the evolutionary mechanisms impending or favouring local adaptation in the presence of gene flow is still limited to a restricted number of study systems.

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Supplementation stocking is a commonly used management tool to sustain exploited fish populations. Possible negative consequences of supplementation on local stocks are a concern for the conservation of wild fish populations. However, the direct impacts of supplementation on life history traits of local populations have rarely been investigated.

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The effects of introgression on parasitism in brook charr Salvelinus fontinalis were investigated in 28 lakes with various levels of stocking in Québec, Canada. No effect of genetic background on parasitism was found at the individual level. Body length seemed to explain most of the variation observed at this level, with largest fish being more infected.

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Understanding genomic signatures of divergent selection underlying long-term adaptation in populations located in heterogeneous environments is a key goal in evolutionary biology. In this study, we investigated neutral, adaptive and deleterious genetic variation using 7,192 SNPs in 31 Lake Trout (Salvelinus namaycush) populations (n = 673) from Québec, Canada. Average genetic diversity was low, weakly shared among lakes, and positively correlated with lake size, indicating a major role for genetic drift subsequent to lake isolation.

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Article Synopsis
  • Ecological speciation helps explain how new species emerge, particularly in Lake Superior's lake trout, which show various ecotypes based on habitat and resource use.
  • A study analyzed genetic data from 486 lake trout across four sites, revealing significant but weak genetic differentiation, indicating higher gene flow among ecotypes within the same site compared to those from different sites.
  • Evidence of divergent selection linked to traits like lipid metabolism and vision was found, although there wasn't a strong parallel genetic response despite some phenotypic similarities among ecotypes from different locations.
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Perturbations on ecosystems can have profound immediate effects and can, accordingly, greatly alter the natural community. Land-use such as forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. The objective of this study was to evaluate the impact of forest harvesting on trophic structure in eastern Canadian Boreal Shield lakes.

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Background: The introduction of a new technology in hospitals - Automated Dispensing Units (ADUs) - aims to contribute to more secure, safe, efficient and cost effective health services. Several studies highlight the beneficial effects of similar technologies as well as their cost-savings potential but there is little literature exploring nurses' perceptions and attitudes towards technology acceptance and the impact on technology use in a healthcare unit.

Objective: This research aimed to explore nurses' perceptions and attitudes towards current technology use on their units and towards the introduction of ADU technology and use with nursing staff in two different hospitals in South-East New-Brunswick, Canada.

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Brasenia schreberi Gmel. (Cabombaceae) is an aquatic plant that grows in eastern Asia, Australia, Africa, and North and Central America. B.

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The capelin (Mallotus villosus) is a widespread marine fish species for which previous work has identified geographically distinct mtDNA clades, the frontiers of which are well within adult and larval dispersal capabilities. Here, we use AFLPs to test for the presence of nuclear gene flow among clades. In addition, we evaluate genetic structuring within one clade, the Northwest Atlantic (NWA).

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