Développements en analyse génétique du comportement humain : application de l'analyse hiérarchique multi-niveau au devis de jumeaux

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal

Gene–environment interplay in the link of friends’ and non-friends’ behaviors with children’s social reticence in a competitive situation

This study used a genetically informed design to assess the effects of friends’ and nonfriends’ reticent and dominant behaviors on children’s observed social reticence in a competitive situation. Potential gene–environment correlations (rGE) and gene–environment interactions (GxE) in the link between (a) friends’ and nonfriends’ behaviors and (b) children’s social reticence were examined. The sample comprised 466 twin children (i.e., the target children), each of whom was assessed in kindergarten together with a same-sex friend and two nonfriend classmates of either sex. Multilevel regression analyses revealed that children with a genetic disposition for social reticence showed more reticent behavior in the competitive situation and were more likely to affiliate with reticent friends (i.e., rGE). Moreover, a higher level of children’s reticent behavior was predicted by their friends’ higher social reticence (particularly for girls) and their friends’ higher social dominance, independently of children’s genetic disposition. Children’s social reticence was also predicted by their nonfriends’ behaviors. Specifically, children were less reticent when male nonfriends showed high levels of social reticence in the competitive situation, and this was particularly true for children with a genetic disposition for social reticence (i.e., GxE). Moreover, children genetically vulnerable for social reticence seemed to foster dominant behavior in their female nonfriend peers (i.e., rGE). In turn, male nonfriends seemed to be more dominant as soon as the target children were reticent, even if the target children did not have a stable genetic disposition for this behavior

Phenotypic and genetic associations between reading comprehension, decoding skills, and ADHD dimensions : evidence from two population-based studies

BACKGROUND: The phenotypic and genetic associations between decoding skills and ADHD dimensions have been documented but less is known about the association with reading comprehension. The aim of the study is to document the phenotypic and genetic associations between reading comprehension and ADHD dimensions of inattention and hyperactivity/impulsivity in early schooling and compare them to those with decoding skills. METHODS: Data were collected in two population-based samples of twins (Quebec Newborn Twin Study - QNTS) and singletons (Quebec Longitudinal Study of Child Development - QLSCD) totaling ≈ 2300 children. Reading was assessed with normed measures in second or third grade. Teachers assessed ADHD dimensions in kindergarten and first grade. RESULTS: Both decoding and reading comprehension were correlated with ADHD dimensions in a similar way: associations with inattention remained after controlling for the other ADHD dimension, behavior disorder symptoms and nonverbal abilities, whereas associations with hyperactivity/impulsivity did not. Genetic modeling showed that decoding and comprehension largely shared the same genetic etiology at this age and that their associations with inattention were mostly explained by shared genetic influences. CONCLUSION: Both reading comprehension and decoding are uniquely associated with inattention through a shared genetic etiology

Prenatal, concurrent, and sex-specific associations between blood lead concentrations and IQ in preschool Canadian children

Background: Lead exposure predicts altered neurodevelopment and lower intelligence quotient (IQ) in children, but few studies have examined this association in children who have relatively low blood lead concentrations. Objectives: To test the associations between blood lead concentrations and cognitive function in Canadian preschoolers, with a possible moderation by sex. Methods: The data were gathered from 609 mother-child pairs from the Maternal–Infant Research on Environmental Chemicals (MIREC) Study. Lead was measured in umbilical and maternal blood, and in children's venous blood at age 3–4 years. Cognitive function was measured with the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III) at 3–4 years. We tested the relationship between WPPSI-III scores and blood lead concentrations with multiple linear regression, adding child sex as a moderator. Results: Median blood lead concentrations for the mother at 1st trimester and 3rd trimester of pregnancy, and for cord and child blood were 0.60 μg/dL, 0.58 μg/dL, 0.79 μg/dL and 0.67 μg/dL, respectively. We found no association between cord blood lead concentrations and WPPSI-III scores in multivariable analyses. However, cord blood lead concentrations showed a negative association with Performance IQ in boys but not in girls (B = 3.44; SE = 1.62; 95% CI: 0.82, 5.98). No associations were found between WPPSI-III scores and prenatal maternal blood or concurrent child blood lead concentrations. Conclusions: Prenatal blood lead concentrations below 5 μg/dL were still associated with a decline in cognitive function in this Canadian cohort, but only for boys

Le numérique : une culture genrée : études et recherches

Comprend des références bibliographiques

Les discours sur le temps d’écran : valeurs sociales et études scientifiques

Comprend des références bibliographiques.Ce document préparatoire pour le Rapport sur l’état et les besoins de l’éducation portant sur le numérique, lequel paraîtra à la fin de l’année 2020, fait état des plus récentes recensions d’écrits scientifiques sur les associations entre le temps d’exposition aux écrans et différents aspects du développement des enfants et des jeunes. Il compare le discours scientifique à un discours plus ancien de résistance aux médias, fondé sur des valeurs. Thèmes abordés : * Contexte historique du discours de résistance aux médias * Recensions des écrits scientifiques sur le temps d’exposition aux écrans * Convergence et divergence du discours scientifique et du discours de la résistance aux médias * Recommandations des associations de pédiatres et des organismes de santé publiques dans différents pay

Ecrire un article scientifique en anglais: guide de rédaction dans la langue de Darwin

C’est bien connu, les étudiants universitaires francophones préfèrent écrire dans leur langue maternelle. Voilà pourtant qu’on leur recommande de publier leurs résultats de recherche dans des revues savantes anglaises. L’effort supplémentaire en vaut-il la peine ? Absolument ! Pour rejoindre la communauté scientifique, il faut en maîtriser la langue. Et ce n’est pas tout. En plus d’être rédigé en anglais, votre article devra être clair, bien écrit et impeccablement structuré pour passer l’épreuve de la révision scientifique, puis être enfin publié dans une revue respectable. Commencez-vous à sentir la pression ? Vous vous apercevrez que l’anglais scientifique est un langage particulier que même les anglophones doivent acquérir. L’anglais des sciences n’est pas exactement la langue de Shakespeare dans sa forme et ses fonctions; je préfère l’appeler la langue de Darwin. C’est pour en apprendre le style et les codes que je vous propose ce guide de rédaction

Household overcrowding and psychological distress among Nunavik Inuit adolescents: a longitudinal study

About half of Nunavik Inuit live in overcrowded households compared to very few Canadians from the general population. Living in overcrowded households is associated with greater risks of suffering from mental health problems for Canadian adolescents. The present work aims at studying prospectively the hypothesised relationship between household overcrowding at childhood and psychological distress during adolescence among Nunavik Inuit, as well as the hypothesised relationship between these phenomena when they are both measure at adolescence. Recruited as part of the Nunavik Child Development Study, 220 participants were met at 11 years old in average and then when they were 18 years old in average. Household overcrowding was assessed using the people per room ratio. Psychological distress symptoms were operationalised at adolescence using depressive symptoms and suicidal thoughts. The results did not show that childhood household crowding had a long-term effect on psychological distress. An absence of moderation by sex of the association was also found in the present study. Despite those results, household crowding could be a risk factor only when in interaction with other elements related with poverty or housing or could be experienced as a difficulty for adolescents on other aspects than depressive symptoms and suicidal thoughts

Prenatal exposure to polybrominated diphenyl ethers and predisposition to frustration at 7 months : results from the MIREC study

Background: Prenatal exposure to polybrominated diphenyl ethers (PBDEs) has been associated with cognitive deficits and behavioral problems in children. To date, no study has examined this exposure in association with neurobehavioral development in infants younger than 12 months assessed with observational tasks. Objectives: This study examined the relation between prenatal PBDE concentrations and predisposition to frustration, assessed by the arm restraint task (ART), in Canadian infants. Methods: In a prospective longitudinal study conducted in Canada, exposure to nine PBDE congeners was measured in maternal plasma during the first trimester of pregnancy. The ART was used to measure predisposition to frustration in infancy (N = 333; mean age = 6.9 months), as assessed by negative vocalizations (crying and screaming) and physical reactivity (discomfort movements). Results: Maternal plasma PBDE-47 concentrations collected during pregnancy were associated with negative vocalizations using the ART (adjusted Relative Risk [aRR] = 1.04, 95% CI: 1.00, 1.09). Prenatal PBDE-99 concentrations during pregnancy were also related to a shift to the left in the tail of the distribution of onset of negative vocalizations as measured by a decrease of 38 s (95% CI: −78.1, 1.3) in the 75th quantile of the distribution for infants whose mothers had detectable levels of PBDE-99 compared to infants of mothers with undetectable levels. Similarly, infants whose mothers had detectable levels of PBDE-100 showed an increase of 24.1 s (95% CI: 4.1, 44.1) in the 75th quantile of the distribution of proportion of time in negative vocalizations compared with infants of mothers with undetectable levels. Finally, the association between PBDE-47 and PBDE153, and physical reactivity was significantly modified by sex (p < 0.1), with opposite patterns in girls and boys. Conclusions: Prenatal exposure to PBDEs was associated with increased incidence of crying and screaming with delayed onset of discomfort movement, which may indicate a predisposition to frustration and lack of habituation in infants younger than 12 months from the general populatio

Developing a quality curriculum in a technological era

There is considerable rhetoric internationally around the need for national curricula to reflect the changes that are taking place in the world outside school. This raises questions about what a quality curriculum in a technological era should look like, and equally challenging issues about how to achieve the necessary changes in schooling in order for such a curriculum to be realised. This paper summarises the views of 11 experts from seven countries. It introduces a sociocultural framework that highlights the complexity of achieving alignment between policies and practice spanning the national to local school to classroom levels. Three key issues that underpin alignment are then explored, each of which link with the issue of trust: stakeholders engagement; teacher professionalism; summative assessment. By exploring and exemplifying these three issues the paper indicates potential ways of addressing them and provides ‘tools to think with’ to enhance future curriculum development initiatives