SCRIPTORIUM (Université de Moncton)
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Inhibition of transglutaminase 2 (TG2) ameliorates ventricular fibrosis in isoproterenol-induced heart failure in rats
No full textAims: Transglutaminase (TG) inhibitors represent promising therapeutic interventions in cardiac fibrosis and related dysfunctions. However, it remains unknown how TG inhibition, TG2 in particular, affects the signaling systems that drive pathological fibrosis. This study aimed to examine the effect TG inhibition by cystamine on the progression of isoproterenol (ISO)-induced cardiac fibrosis and dysfunction in rats. Materials and methods: Cardiac fibrosis was established by intraperitoneal injection of ISO to rats (ISO group), followed by 6 weeks of cystamine injection (ISO + Cys group). The control groups were administered normal saline alone or with cystamine. Hemodynamics, lipid profile, liver enzymes, urea, and creatinine were assessed in conjunction with heart failure markers (serum NT-proANP and cTnI). Left ventricular (LV) and atrial (LA) fibrosis, total collagen content, and mRNA expression of profibrotic markers including TG2 were quantified by Masson's trichrome staining, LC-MS/MS and quantitative PCR, respectively. Key findings: Cystamine administration to ISO rats significantly decreased diastolic and mean arterial pressures, total cholesterol, triglycerides, LDL, liver enzymes, urea, and creatinine levels, while increasing HDL. NT-proANP and cTnI serum levels remained unchanged. In LV tissues, significant reductions in ISO-induced fibrosis and elevated total collagen content were achieved after cystamine treatment, together with a reduction in TG2 concentration. Reduced mRNA expression of several profibrotic genes (COL1A1, FN1, MMP-2, CTGF, periostin, CX43) was also evidenced in LV tissues of ISO rats upon cystamine administration, whereas TGF-β1 expression was depressed in LA tissues. Cystamine decreased TG2 mRNA expression in the LV of control rats, while LV expression of TG2 was relatively low in ISO rats irrespective of cystamine treatment. Significance: TG2 inhibition by cystamine in vivo exerted cardioprotective effects against ISO-induced cardiac fibrosis in rats decreasing the LV abundance of several profibrotic markers and the content of TG2 and collagen, suggesting that TG2 pharmacological inhibition could be beneficial to alleviate cardiac fibrosis.udemauteur: Carole Tranchan
Impact if ultrasonication on the contents, profiles and biofunctional properties of free and bound phenolics from white desert truffle (Tirmania nivea) and its protein fractions
No full textThe molecular and biofunctional properties of protein and phenolic fractions in edible truffles remain largely unknown. This study examined the effect of ultrasonication on the contents, profiles, and bioactive properties of free and bound phenolics (FP and BP) from desert truffle (Tirmania nivea) and its protein fractions. Protein fractions from the Osborne extraction scheme were biochemically and structurally characterized. The albumin fraction showed the highest abundance (16.8%) and yield (35.8%). Total phenolic contents were the highest in non-sonicated samples (3.5–34.1 mg/g), particularly in the albumin fraction and in whole truffle. FP extracted at 30 °C (FP-30 °C) accounted for the largest proportion of total phenolics in all protein fractions, whereas BP-30 °C and FP-60 °C were predominant in non-sonicated and sonicated truffle, respectively. The highest antioxidant activity was obtained with FP-30 °C extracts from non-sonicated albumins, globulins and truffle (91.9, 72.7 and 30.0%), followed by BP-30 °C from non-sonicated albumins (25.4%) and FP-60 °C from sonicated glutelins-1 (24.2%). High inhibition of α-amylase was evidenced in several extracts, including FP-30 °C from non-sonicated glutelins-1 (99.2%) and FP-30 °C from sonicated globulins (72.4%). Several extracts also displayed high inhibition of angiotensin I-converting enzyme (ACE), including FP-60 °C from non-sonicated glutelins-1 (65.1%) and sonicated glutelins-1 (71.1%) and globulins (64.7%). Most extracts were rich in epicatechin, gallic acid, chlorogenic acid and catechin. Correlations between phenolic content, antioxidant activity, anti-α-amylase and anti-ACE activities were influenced by sonication. Sonication reduced the particle size of the proteins and modified their structural characteristics. These findings demonstrate that white desert truffle proteins co-occur with bioactive phenolics whose functionalities can be tailored by protein fractionation and sonication.udemauteur: Carole Tranchan
Le leadership partagé dans l'exercice du rôle de passeur culturel: les cas de directions d'école francophones de la région sud-est du Nouveau-Brunswick
Get PDFAfin d’encadrer les personnes intervenant dans les environnements scolaires en milieux linguistiques minoritaires dans leurs actions en réponse aux besoins particuliers de ceux-ci, des organismes provinciaux, dont les ministères de l’Éducation de l’Ontario et du Nouveau-Brunswick, ont choisi de miser sur un mode de gestion basé sur le leadership partagé (Gouvernement de l’Ontario, Ministère de l’Éducation, 2011; Ministère de l’Éducation et du Développement de la petite enfance du Nouveau-Brunswick, 2014). Bien qu’ayant fait ses preuves dans divers milieux (Luc, 2016), très peu de recherches existent quant à l’apport du leadership partagé dans le domaine de l’éducation, et encore moins dans le cadre d’un aménagement linguistique et culturel en milieu linguistique minoritaire. Afin de commencer à combler ce manque au niveau de la recherche, nous avons tenté de comprendre comment se manifeste le leadership partagé dans les discours des directions d’école reliées à leur rôle de passeur culturel. En nous basant sur une approche par étude de cas multiples (Merriam, 1998), nous observons dans cette thèse les caractéristiques du leadership partagé exercées par deux directions d’école en milieu francophone minoritaires du Sud-Est du Nouveau-Brunswick dans leurs récits relatifs à leur rôle de passeur culturel dans leurs écoles respectives. Par l’analyse de leurs discours, nous constatons que la majorité des caractéristiques du leadership partagé est présente dans les actions décrites par les deux directions participant à l’étude. Toutefois, nous relevons des différences considérables pour certaines caractéristiques quant au moment où elles se manifestent, à la façon qu’elles sont exercées et au degré d’exercice. Ces différences semblent principalement influencées par deux facteurs : le contexte où les caractéristiques sont exercées, soit le sous-rôle du passeur culturel privilégié, et les environnements où agissent les directions d’école. Bien que n’ayant pas été étudiés au sein de l’étude, certains indicatifs nous portent à croire que le niveau de formation en leadership partagé des directions d’école joue également un rôle dans la présence de ces différences. Les résultats de cette étude mettent en lumière un besoin important de poursuivre les recherches sur le leadership partagé en milieu scolaire minoritaire et sur sa place dans l’aménagement linguistique et culturel. Elles mettent également en évidence le besoin d’offrir de la formation et de l’accompagnement au sujet du leadership partagé aux directions des écoles afin qu’elles puissent l’exercer pleinement. Mots clés : directions d’école, leadership partagé, milieu francophone minoritaire, construction identitaire, passeur culturel
L'effet d'une intervention éducative pour les précepteurs et préceptrices sur l'efficacité personnelle, les intentions et les attentes
Get PDFLa préparation des préceptrices est fondamentale au succès du préceptorat. Toutefois, il est actuellement observé qu’elles ne sont pas adéquatement préparées pour accompagner les étudiantes. L’environnement de travail surchargé, les infirmières épuisées ainsi que la pénurie complexifient le rôle des préceptrices. Le but de cette étude est d’évaluer l’effet d’une intervention éducative sur l’efficacité personnelle, les intentions et les attentes des préceptrices. Cette étude prétest-posttest a été menée auprès des préceptrices accompagnant des étudiantes au préceptorat de l’année académique 2021-2022 de l’École réseau de science infirmière de l’Université de Moncton au Nouveau-Brunswick. À la suite d’une invitation par courriel, 20 préceptrices ont complété des questionnaires en ligne, avant et après avoir reçu une formation en ligne. Les résultats ont montré une augmentation de leur efficacité personnelle, leurs intentions à renouveler leur rôle de préceptrice et de leurs attentes envers leur performance. Les préceptrices ont estimé la formation pertinente, adaptée à leurs besoins d’apprentissage et facile à naviguer. En conclusion, une formation en ligne pour les préceptrices est un moyen efficace, accessible et peu coûteux afin d’augmenter les connaissances de celles-ci. Il serait également pertinent de développer une formation hybride avec la collaboration d’acteurs importants visant à contribuer à la rétention des préceptrices tout en palliant les besoins d’apprentissages
Relationship between sibling bullying, family functioning, and problem solving: A structural equation modeling
No full textIn this study, we tested a full structural model in which past involvement in sibling bullying mediates the relationships between, on the one hand, an intrusive parental style during conflicts between siblings and, on the other hand, current individual and family outcomes. The model under study is grounded in the coercion theory and the family system theory. A sample of 200 young adults, and their mothers, took part in the study. Results of structural equation modeling with four latent variables fit well the data. As hypothesized, an intrusive parental style during conflicts between siblings was related to higher levels of sibling bullying (including both perpetration and victimization) in childhood. Furthermore, young adults who were involved in sibling bullying as a child were now displaying less positive social problem-solving behaviors. Finally, past experiences of sibling bullying were related to current unkindness in the family.udemauteur: Geneviève Bouchard; Nadia Annie Sonie
Exploration of visual factors in the disgust-anger confusion: The importance of the mouth
No full textAccording to the perceptual-attentional limitations hypothesis, the confusion between expressions of disgust and anger may be due to the difficulty in perceptually distinguishing the two, or insufficient attention to their distinctive cues. The objective of the current study was to test this hypothesis as an explanation for the confusion between expressions of disgust and anger in adults using eye-movements. In Experiment 1, participants were asked to identify each emotion in 96 trials composed of prototypes of anger and prototypes of disgust. In Experiment 2, fixation points oriented participants’ attention toward the eyes, the nose, or the mouth of each prototype. Results revealed that disgust was less accurately recognised than anger (Experiment 1 and 2), especially when the mouth was open (Experiment 1 and 2), and even when attention was oriented toward the distinctive features of disgust (Experiment 2). Additionally, when attention was oriented toward certain zones, the eyes (which contain characteristics of anger) had the longest dwell times, followed by the nose (which contains characteristics of disgust; Experiment 2). Thus, although participants may attend to the distinguishing features of disgust and anger, these may not aid them in accurately recognising each prototype.udemauteur: Annie Roy-Charlan
Royal jelly mediates fibrotic signaling, collagen cross-linking and cell proliferation in cardiac fibroblasts
No full textRoyal jelly (RJ) is a multifunctional bee product with a unique composition and wide-ranging biological properties, including antioxidant, anti-inflammatory and antiproliferative activities. Still, little is known about the possible myocardial protective properties of RJ. Considering that sonication could enhance RJ bioactivity, this study aimed to assess the effects of non-sonicated (NS) and sonicated (S) RJ on fibrotic signaling, cell proliferation, and collagen production in cardiac fibroblasts. S-RJ was produced by ultrasonication at 20 kHz. Ventricular fibroblasts isolated from neonatal rats were cultured and treated with different concentrations of NS-RJ or S-RJ (0, 50, 100, 150, 200, and 250 µg/well). S-RJ significantly depressed the expression levels of transglutaminase 2 (TG2) mRNA across all the concentrations tested and was inversely associated with the expression of this profibrotic marker. S-RJ and NS-RJ displayed distinct dose-dependent effects on mRNA expression of several other profibrotic, proliferation, and apoptotic markers. Unlike NS-RJ, S-RJ elicited strong negative dose-dependent relationships with the expression of profibrotic markers (TG2, COL1A1, COL3A1, FN1, CTGF, MMP-2, α-SMA, TGF-β1, CX43, periostin), as well as proliferation (CCND1) and apoptotic (BAX, BAX/BCL-2) markers, indicating that RJ dose-response effects were significantly modified by sonification. NS-RJ and S-RJ increased the content of soluble collagen, while decreasing collagen cross-linking. Collectively, these findings show that S-RJ has a greater range of action than NS-RJ for downregulating the expression of biomarkers associated with cardiac fibrosis. Reduced biomarker expression and collagen cross-linkages upon cardiac fibroblast treatment with specific concentrations of S-RJ or NS-RJ suggests putative roles and mechanisms by which RJ may confer some protection against cardiac fibrosis.udemauteur: Carole Tranchan
La physique des lasers
No full textudemauteur: Jean-François BissonDocument original utilisé pour le cours Physique des lasers PHYS701
Improving wildland fire spread prediction using deep U-Nets
No full textForest fires are able to cause significant damage to humans and the earth's fauna and flora. If a fire is not detected and extinguished before it spreads, it can have disastrous results. In addition to satellite images, recent studies have shown that exploring both weather and topography characteristics is crucial for effectively predicting the propagation of wildfires. In this paper, we present FU-NetCastV2, a deep learning convolutional neural network for fire spread and burned area mapping. This algorithm predicts which areas around wildfires are at high risk of future spread. With an accuracy of 94.6% and an AUC of 97.7%, the model surpassed the literature by 3.7% and exhibited a 1.9% improvement over our previous model. The proposed approach was implemented using consecutive forest wildfire perimeters, satellite images, Digital Elevation Model maps, aspect, slope and weather data.udemauteur: Fadoua Khennou; Moulay Akhlouf
Platelet-derived microparticles provoke chronic lymphocytic leukemia malignancy through metabolic reprogramming
No full textBackground: It is well established that inflammation and platelets promote multiple processes of cancer malignancy. Recently, platelets have received attention for their role in carcinogenesis through the production of microvesicles or platelet-derived microparticles (PMPs), which transfer their biological content to cancer cells. We have previously characterized a new subpopulation of these microparticles (termed mito-microparticles), which package functional mitochondria. The potential of mitochondria transfer to cancer cells is particularly impactful as many aspects of mitochondrial biology (i.e., cell growth, apoptosis inhibition, and drug resistance) coincide with cancer hallmarks and disease progression. These metabolic aspects are particularly notable in chronic lymphocytic leukemia (CLL), which is characterized by a relentless accumulation of proliferating, immunologically dysfunctional, mature B-lymphocytes that fail to undergo apoptosis. The present study aimed to investigate the role of PMPs on CLL metabolic plasticity leading to cancer cell phenotypic changes. Methods: CLL cell lines were co-incubated with different concentrations of human PMPs, and their impact on cell proliferation, mitochondrial DNA copy number, OCR level, ATP production, and ROS content was evaluated. Essential genes involved in metabolic-reprogramming were identified using the bioinformatics tools, examined between patients with early and advanced CLL stages, and then validated in PMP-recipient CLLs. Finally, the impact of the induced metabolic reprogramming on CLLs’ growth, survival, mobility, and invasiveness was tested against anti-cancer drugs Cytarabine, Venetoclax, and Plumbagin. Results: The data demonstrated the potency of PMPs in inducing tumoral growth and invasiveness in CLLs through mitochondrial internalization and OXPHOS stimulation which was in line with metabolic shift reported in CLL patients from early to advanced stages. This metabolic rewiring also improved CLL cells' resistance to Cytarabine, Venetoclax, and Plumbagin chemo drugs. Conclusion: Altogether, these findings depict a new platelet-mediated pathway of cancer pathogenesis. We also highlight the impact of PMPs in CLL metabolic reprogramming and disease progression.udemauteur: Ehsan Gharib; Luc Boudreau; Nicolas Pichaud; Gilles Robichau