104 research outputs found
Apprivoiser une bĂȘte noire
Sous forme d'un rĂ©cit chronologique et dynamique Ă deux voix, et avec comme toile de fond une association de ce qui est agrĂ©able avec ce qui l'est moins, les auteurs de cet article prĂ©sentent leur expĂ©rience d'une pratique pĂ©dagogique de pairage de cours en vue de faire Ă©merger et de stimuler l'intĂ©rĂȘt pour le français chez des Ă©tudiants ayant des difficultĂ©s dans cette matiĂšre, les cours concernĂ©s Ă©tant Mise Ă niveau en français (MNF) et un cours non obligatoire de psychologie, donc choisi par les Ă©tudiants eux-mĂȘmes, DifficultĂ©s psychologiques et sexuelles. S'appuyant sur une succession d'activitĂ©s d'Ă©criture, suivies de corrections, le dĂ©roulement de l'expĂ©rimentation d'interdisciplinaritĂ© est illustrĂ© par un tableau dĂ©taillĂ©, oĂč sont mis en lumiĂšre les points communs entre les deux cours. Chacun leur tour, les deux auteurs commentent les rĂ©sultats de cette expĂ©rience, soulignant l'avantage de la correction similaire dans chaque cours, qui a permis aux Ă©tudiants de corriger leurs lacunes en français, et envisageant la gĂ©nĂ©ralisation de cette pratique Ă d'autres disciplines, comme les mathĂ©matiques
Biodiversity of lepidopteran pests and their parasitoids in organic and conventional cranberry crop
A 2-year study was conducted in the main cranberry (Vaccinium macrocarpon Aiton) growing region of QuĂ©bec to determine the biodiversity of lepidopteran pests and their parasitoids, which may differ in organic and conventional integrated pest management (IPM) systems. We also aimed to compare densities and parasitism on five caterpillar pest species of primary economic importance: Macaria sulphurea (Packard), Macaria brunneata (Thunberg), Xylena nupera (Lintner), Rhopobota naevana (HĂŒbner) and Sparganothis sulfureana (Clemens), which accounted for more than 80% of the pest community each year. The lepidopteran pest communities clearly varied between the two pest management systems, suggesting efficacy differences among them. Rhopobota naevana was dominant on organic farms, whereas conventional farms had greater pest richness and evenness, with M. sulphurea, M. brunneata and X. nupera being the most abundant. Based on laboratory rearing of field collected caterpillars, the parasitoid community was composed of 25 species or taxa (22 from primary pests) and communities were not significantly different between the two farming regimes. The most common species belonged to the braconid genera Aleiodes, Meteorus, Microplitis, Oncophanes; ichneumonids Hyposoter, Exetastes, Phytodietus; and tachinids Campylocheta, Nemorilla. Of the five primary pests, X. nupera was the most parasitized, while no parasitoids were reared from M. brunneata. Annual parasitism rate of the primary pests ranged 20â40% and data showed that it was explainable by host availability rather than farming system
Nature of fatty acids in high fat diets differentially delineates obesity-linked metabolic syndrome components in male and female C57BL/6J mice
<p>Abstract</p> <p>Background</p> <p>Adverse effects of high-fat diets (HFD) on metabolic homeostasis are linked to adipose tissue dysfunction. The goal of this study was to examine the effect of the HFD nature on adipose tissue activity, metabolic disturbances and glucose homeostasis alterations in male mice compared with female mice.</p> <p>Methods</p> <p>C57BL/6J mice were fed either a chow diet or HFD including vegetal (VD) or animal (AD) fat. Body weight, plasmatic parameters and adipose tissue mRNA expression levels of key genes were evaluated after 20 weeks of HFD feeding.</p> <p>Results</p> <p>HFD-fed mice were significantly heavier than control at the end of the protocol. Greater abdominal visceral fat accumulation was observed in mice fed with AD compared to those fed a chow diet or VD. Correlated with weight gain, leptin levels in systemic circulation were increased in HFD-fed mice in both sexes with a significant higher level in AD group compared to VD group. Circulating adiponectin levels as well as adipose tissue mRNA expression levels were significantly decreased in HFD-fed male mice. Although its plasma levels remained unchanged in females, adiponectin mRNA levels were significantly reduced in adipose tissue of both HFD-fed groups with a more marked decrease in AD group compared to VD group. Only HFD-fed male mice were diabetic with increased fasting glycaemia. On the other hand, insulin levels were only increased in AD-fed group in both sexes associated with increased resistin levels. VD did not induce any apparent metabolic alteration in females despite the increased weight gain. Peroxisome Proliferator-Activated Receptors gamma-2 (PPARγ2) and estrogen receptor alpha (ERα) mRNA expression levels in adipose tissue were decreased up to 70% in HFD-fed mice but were more markedly reduced in male mice as compared with female mice.</p> <p>Conclusions</p> <p>The nature of dietary fat determines the extent of metabolic alterations reflected in adipocytes through modifications in the pattern of adipokines secretion and modulation of key genes mRNA expression. Compared with males, female mice demonstrate higher capacity in controlling glucose homeostasis in response to 20 weeks HFD feeding. Our data suggest gender specific interactions between the diet's fatty acid source, the adipocyte-secreted proteins and metabolic disorders.</p
AmĂ©liorer la comprĂ©hension et la gestion des conflits dâintĂ©rĂȘts des experts conseillant la prise de dĂ©cisions en santĂ© publique
Ătude de cas / Case studyAu QueÌbec, au Canada et ailleurs dans le monde, des comiteÌs consultatifs dâexperts conseillent et orientent les deÌcideurs gouvernementaux dans le choix de nouveaux meÌdicaments, de vaccins aÌ utiliser ou encore dâinterventions aÌ mettre en place. ParalleÌlement, ces experts beÌneÌficient dâun appui de plus en plus important dâentreprises priveÌes pour reÌaliser leurs recherches ou en diffuser les reÌsultats. Cette situation les met aÌ risque de conflits dâinteÌreÌts et peut, eÌventuellement, miner la confiance de la population envers la prise de deÌcision publique. Cette eÌtude de cas suscite des reÌflexions pertinentes quant aÌ ce qui constitue une gestion saine et optimale des situations de conflits dâinteÌreÌts par les membres experts et les organisations dans lesquelles ils ont un roÌle-conseil.In QueÌbec, in Canada and elsewhere in the world, expert advisory committees advise and guide government decision-makers in the choice of new drugs, vaccines to be used or interventions to be put in place. In parallel, these experts are receiving increasing support from private companies to conduct their research or to disseminate the results of their research. Such situations place them at risk of conflicts of interest and may eventually undermine confidence in public decision-making. This case study stimulates reflection into what constitutes sound and optimal management of conflict of interest situations by expert members and the organizations in which they have an advising role
The Prostanoid 15-Deoxy-D 12,14 -Prostaglangin-J 2 Reduces Lung Inflammation and Protects Mice Against Lethal Influenza Infection
Background. Growing evidence indicates that influenza pathogenicity relates to altered immune responses and hypercytokinemia. Therefore, dampening the excessive inflammatory response induced after infection might reduce influenza morbidity and mortality. Methods. Considering this, we investigated the effect of the anti-inflammatory molecule 15-deoxy-D 12,14 -prostaglandin J 2 (15d-PGJ 2 ) in a mouse model of lethal influenza infection. Results. Administration of 15d-PGJ 2 on day 1 after infection, but not on day 0, protected 79% of mice against lethal influenza infection. In addition, this treatment considerably reduced the morbidity associated with severe influenza infection. Our results also showed that treatment with 15d-PGJ 2 decreased influenza-induced lung inflammation, as shown by the diminished gene expression of several proinflammatory cytokines and chemokines. Unexpectedly, 15d-PGJ 2 also markedly reduced the viral load in the lungs of infected mice. This could be attributed to maintained type I interferon gene expression levels after treatment. Interestingly, pretreatment of mice with a peroxisome proliferator-activated receptor gamma (PPARc) antagonist before 15d-PGJ 2 administration completely abrogated its protective effect against influenza infection. Conclusions. Our results demonstrate for the first time that treatment of mice with 15d-PGJ 2 reduces influenza morbidity and mortality through activation of the PPARc pathway. PPARc agonists could thus represent a potential therapeutic avenue for influenza infections
COMPARING GCĂGC-TOFMS-BASED METABOLOMIC PROFILING AND WOOD ANATOMY FOR FORENSIC IDENTIFICATION OF FIVE MELIACEAE (MAHOGANY) SPECIES
Illegal logging and associated trade have increased worldwide. Such environmental crimes represent a major threat to forest ecosystems and society, causing distortions in market prices, economic instability, ecological deterioration, and poverty. To prevent illegal imports of forest products, there is a need to develop wood identiïŹcation methods for identifying tree species regulated by the Convention on International Trade in Species of Wild Fauna andFlora in Trade (CITES) and other look-alike species. In this exploratory study, we applied metabolomic proïŹling of ïŹve species (Swietenia mahagoni, Swietenia macrophylla, Cedrela odorata, Khaya ivorensis, and Toona ciliata) using two-dimensional gas chromatog- raphy combined with time-of-ïŹight mass spectrometry (GC3GC-TOFMS). We also performed qualitative, quantitative (based on the measurement of vessel area, tangential vessel lumina diameter,vessel element length, ray height, and ray width), and machine-vision aided (XyloTron) wood anatomy on a subsample of wood specimens to explore thepotential and limits of each approach. Fifty dried xylaria wood specimens were ground, extracted with methanol, and subsequently analyzed by GC3GC-TOFMS. In this study, the four genera could easily be identiïŹed using qualitative wood anatomy and chemical proïŹling. At the spe- cies level, Swietenia macrophylla and Swietenia mahagoni specimens were found to share many major metabolites and could only be differentiated after feature selection guided by cluster resolution (FS-CR) and visualization using Principal Component Analysis (PCA). Expectedly, specimens from the two Swiete- nia spp. could not be distinguished based on qualitative wood anatomy. However, signiïŹcant differences in quantitative anatomical features were obtained for these two species. Excluding T. ciliata that was not included in the reference database of end grain images at the time of testing (2021), the XyloTron could successfully identify the majority of the specimens to the right genus and 50% of the specimens to the right species. The machine-vision tool was particularly successful at identifying Cedrela odorata samples, where all samples were correctly identiïŹed. Despite the limited number of specimens available for thisstudy, our preliminary results indicate that GC3GC-TOFMS-based metabolomic proïŹles could be used as comple- mentary method to differentiate CITES-regulated wood specimens at the genus and species levels.
Portrait of blood-derived extracellular vesicles in patients with Parkinson's disease.
The production of extracellular vesicles (EV) is a ubiquitous feature of eukaryotic cells but pathological events can affect their formation and constituents. We sought to characterize the nature, profile and protein signature of EV in the plasma of Parkinson's disease (PD) patients and how they correlate to clinical measures of the disease. EV were initially collected from cohorts of PD (nâŻ=âŻ60; Controls, nâŻ=âŻ37) and Huntington's disease (HD) patients (Pre-manifest, nâŻ=âŻ11; manifest, nâŻ=âŻ52; Controls, nâŻ=âŻ55) - for comparative purposes in individuals with another chronic neurodegenerative condition - and exhaustively analyzed using flow cytometry, electron microscopy and proteomics. We then collected 42 samples from an additional independent cohort of PD patients to confirm our initial results. Through a series of iterative steps, we optimized an approach for defining the EV signature in PD. We found that the number of EV derived specifically from erythrocytes segregated with UPDRS scores corresponding to different disease stages. Proteomic analysis further revealed that there is a specific signature of proteins that could reliably differentiate control subjects from mild and moderate PD patients. Taken together, we have developed/identified an EV blood-based assay that has the potential to be used as a biomarker for PD
Cartographie des mesures de soutien Ă la santĂ© mentale des Ă©tudiant.es et des employĂ©.es de lâUQAC
Cartographie des mesures de soutien Ă la santĂ© mentale des Ă©tudiant.es et des employĂ©.es de lâUQA
Santé mentale et population universitaire : un laboratoire-vivant au service de la communauté : rapport de recherche
Cette Ă©tude a trois objectifs : 1) Identifier les principaux enjeux de santĂ© des Ă©tudiant·es et des employé·es de lâUQAC en contexte pandĂ©mique, 2) RĂ©pertorier lâensemble des mesures de soutien Ă la santĂ© mises Ă la disposition des Ă©tudiant·es et des employé·es de lâUQAC, et 3) Identifier de nouvelles solutions Ă mettre en place afin de pallier les manques et de soutenir les Ă©tudiant·es et les employé·es de lâUQAC
- âŠ