Université de Sherbrooke

About: Université de Sherbrooke is a education organization based out in Sherbrooke, Quebec, Canada. It is known for research contribution in the topics: Population & Receptor. The organization has 14922 authors who have published 28783 publications receiving 792511 citations. The organization is also known as: Universite de Sherbrooke & Sherbrooke University.

Combination of nanofluid and inserts for heat transfer enhancement

Abstract: Improving heat transfer is a critical subject for energy conservation systems which directly affects economic efficiency of these systems. There are active and passive methods which can be employed to enhance the rate of heat transfer without reducing the general efficiency of the energy conservation systems. Among these methods, passive techniques are more cost-effective and reliable in comparison with active ones as they have no moving parts. To achieve further improvements in heat transfer performances, some researchers combined passive techniques. This article performs a review of the literature on the area of heat transfer improvement employing a combination of nanofluid and inserts. Inserts are baffles, twisted tape, vortex generators, and wire coil inserts. The progress made and the current challenges for each combined system are discussed, and some conclusions and suggestions are made for future research.

Maternal BMI at the start of pregnancy and offspring epigenome-wide DNA methylation: findings from the pregnancy and childhood epigenetics (PACE) consortium

Abstract: Pre-pregnancy maternal obesity is associated with adverse offspring outcomes at birth and later in life. Individual studies have shown that epigenetic modifications such as DNA methylation could contribute. Within the Pregnancy and Childhood Epigenetics (PACE) Consortium, we meta-analysed the association between pre-pregnancy maternal BMI and methylation at over 450,000 sites in newborn blood DNA, across 19 cohorts (9,340 mother-newborn pairs). We attempted to infer causality by comparing the effects of maternal versus paternal BMI and incorporating genetic variation. In four additional cohorts (1,817 mother-child pairs), we meta-analysed the association between maternal BMI at the start of pregnancy and blood methylation in adolescents. In newborns, maternal BMI was associated with small (<0.2% per BMI unit (1 kg/m2), P < 1.06 × 10-7) methylation variation at 9,044 sites throughout the genome. Adjustment for estimated cell proportions greatly attenuated the number of significant CpGs to 104, including 86 sites common to the unadjusted model. At 72/86 sites, the direction of the association was the same in newborns and adolescents, suggesting persistence of signals. However, we found evidence for acausal intrauterine effect of maternal BMI on newborn methylation at just 8/86 sites. In conclusion, this well-powered analysis identified robust associations between maternal adiposity and variations in newborn blood DNA methylation, but these small effects may be better explained by genetic or lifestyle factors than a causal intrauterine mechanism. This highlights the need for large-scale collaborative approaches and the application of causal inference techniques in epigenetic epidemiology.

Development of an apparatus for biaxial testing using cruciform specimens

Abstract: A testing apparatus has been developed to study the behavior of sheet metals and composite materials under monotonic and cyclic biaxial loading conditions. This test facility employs cruciform specimens that are loaded in their plane. Problems encountered while developing the test system are discussed. We also discuss the difficulties common to test methods employing cruciform specimens. These relate to the design of a suitable specimen geometry and to the determination of the stresses throughout the specimen. A method for designing an optimal geometry for these specimens is presented. This method is based on the statistical tools of factorial and response surface designs. The statistical method, coupled with a finite-element analysis of the specimen, was successfully applied to optimize the geometry of a cruciform specimen with a circular reduced central region.

Relations with parents and with peers, temperament, and trajectories of depressed mood during early adolescence.

Abstract: The present study examined (a) whether groups of children can be empirically identified with distinct longitudinal profiles of depressed mood from late childhood through early adolescence, (b) to what extent these different longitudinal depression profiles are predicted by problematic relations with parents, same-sex peers, and other-sex peers, and (c) what role individuals' temperamental characteristics play in this context. Based on a sample of 414 early adolescents (197 girls), four groups were identified with distinct longitudinal profiles of depressed mood between ages 11 and 14: One group with consistently low levels of depressed mood, another with consistently moderate levels of depressed mood, a third group whose depressed mood increased sharply from late childhood through early adolescence, and a fourth group who already showed clinical-range levels of depressed mood during late childhood and whose depressive feelings increased even slightly more thereafter. Subsequent analyses revealed that rejection by same-sex peers was related to the odds of following an increasing trajectory of depressed mood, but only for girls with a highly reactive temperament. A problematic relationship with parents increased the odds of an elevated trajectory of depressed mood regardless of individual temperament. The theoretical and practical implications of these findings are discussed.

Dry matter content as a measure of dry matter concentration in plants and their parts

Abstract: Summary • This study compared the predictive ability of dry matter content (DMC, dry mass per fresh mass) of leaves, stems, roots and entire plants in relation to dry matter concentration (D, dry mass per volume of plant organ). Data came from 28 species of field-collected plants (woody and herbaceous) and 17 species of herbaceous plants grown in hydroponic sand culture. Specific leaf areas were also measured. • Dry matter content of the herbaceous plants grown in sand culture varied more between tissue types than did dry matter concentration but the correlation among plant parts was stronger when using DMC. Means and standard errors for DMC (g g−1) were 0.212 ± 0.009 (leaves), 0.176 ± 0.012 (support tissues) and 0.170 ± 0.021 (roots); for D (g cm−3) the values were 0.158 ± 0.010 (leaves), 0.168 ± 0.017 (support tissues) and 0.153 ± 0.013 (roots). • Leaf DMC provided approximate estimates of leaf D (r = 0.76) for the field-collected plants but sclerophyllous leaves from shrubs restricted to acidic bogs proved to be outliers. The relationship between these two variables was stronger in the herbaceous species grown in sand culture, especially so for whole plant estimates (r = 0.91). • Dry matter content and dry matter concentration were equally good predictors of specific leaf area.