Impact de l'âge et du sexe sur le quotient respiratoire à jeun

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Impact de l'entraînement en musculation et d'un régime hypocalorique sur la composition corporelle et la dépense énergétique de femmes post ménopausées en surpoids ou obèses

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

Innovation through Wearable Sensors to Collect Real-Life Data among Pediatric Patients with Cardiometabolic Risk Factors

Background. While increasing evidence links environments to health behavior, clinicians lack information about patients’ physical activity levels and lifestyle environments. We present mobile health tools to collect and use spatio-behavioural lifestyle data for personalized physical activity plans in clinical settings. Methods. The Dyn@mo lifestyle intervention was developed at the Sainte-Justine University Hospital Center to promote physical activity and reduce sedentary time among children with cardiometabolic risk factors. Mobility, physical activity, and heart rate were measured in free-living environments during seven days. Algorithms processed data to generate spatio-behavioural indicators that fed a web-based interactive mapping application for personalised counseling. Proof of concept and tools are presented using data collected among the first 37 participants recruited in 2011. Results. Valid accelerometer data was available for 5.6 (SD=1.62) days in average, heart rate data for 6.5 days, and GPS data was available for 6.1 (2.1) days. Spatio-behavioural indicators were shared between patients, parents, and practitioners to support counseling. Conclusion. Use of wearable sensors along with data treatment algorithms and visualisation tools allow to better measure and describe real-life environments, mobility, physical activity, and physiological responses. Increased specificity in lifestyle interventions opens new avenues for remote patient monitoring and intervention

Comparison of earthquake-triggered turbidites from the Saguenay (Eastern Canada) and Reloncavi (Chilean margin) Fjords: implications for paleoseismicity and sedimentology

International audienceHigh-resolution seismic profiles along with physical and sedimentological properties of sediment cores from the Saguenay (Eastern Canada) and Reloncavi (Chile) Fjords allowed the identification of several decimeter to meter-thick turbidites. In both fjords, the turbidites were associated with large magnitude historic and pre-historic earthquakes including the 1663 AD (M > 7) earthquake in the Saguenay Fjord, and the 1960 (M 9.5), 1837 (M ~ 8) and 1575 AD major Chilean subduction earthquakes in the Reloncavi Fjord. In addition, a sand layer with exoscopic characteristics typical of a tsunami deposit was observed immediately above the turbidite associated with the 1575 AD earthquake in the Reloncavi Fjord and supports both the chronology and the large magnitude of that historic earthquake. In the Saguenay Fjord, the earthquake-triggered turbidites are sometimes underlying a hyperpycnite associated with the rapid breaching and draining of a natural dam formed by earthquake-triggered landslides. Similar hyperpycnal floods were also recorded in historical and continental geological archives for the 1960 and 1575 AD Chilean subduction earthquakes, highlighting the risk of such flood events several weeks or months after main earthquake. In both fjords, as well as in other recently recognized earthquake-triggered turbidites, the decimeter-to meter-thick normally-graded turbidites are characterized by a homogeneous, but slightly fining upward tail. Finally, this paper also emphasizes the sensitivity of fjords to record historic and pre-historic seismicity

Surface-enhanced tractography (SET)

In this work, we exploit the T1 weighted image in conjunction with cortical surface boundary to improve the precision of tractography under the cortex. We show that utilizing the cortical interface and a surface flow, to model the superficial white matter streamlines, enhance and improve tractography trajectory near the cortex. Our novel surface-enhanced tractography reduces the gyral bias, the length bias and the amount of false positive streamlines produced by tractography. This method improves the reproducibility and the cortical surface coverage of tractograms which are crucial for connectomics studies. The usage of cortical surfaces, extracted from the standardly acquired 1 mm isotropic T1, is a straightforward and effective way to improve existing tractography processing pipelines and structural connectivity studies

Bundle-specific tractography with incorporated anatomical and orientational priors

International audienceAnatomical white matter bundles vary in shape, size, length, and complexity, making diffusion MRI tractography reconstruction of some bundles more difficult than others. As a result, bundles reconstruction often suffers from a poor spatial extent recovery. To fill-up the white matter volume as much and as best as possible, millions of streamlines can be generated and filtering techniques applied to address this issue. However, well-known problems and biases are introduced such as the creation of a large number of false positives and over-representation of easy-to-track parts of bundles and under-representation of hard-to-track.To address these challenges, we developed a Bundle-Specific Tractography (BST) algorithm. It incorporates anatomical and orientational prior knowledge during the process of streamline tracing to increase reproducibility, sensitivity, specificity and efficiency when reconstructing certain bundles of interest. BST outperforms classical deterministic, probabilistic, and global tractography methods. The increase in anatomically plausible streamlines, with larger spatial coverage, helps to accurately represent the full shape of bundles, which could greatly enhance and robustify tract-based and connectivity-based neuroimaging studies

Very long intergenic non-coding RNA transcripts and expression profiles are associated to specific childhood acute lymphoblastic leukemia subtypes.

Very long intergenic non-coding RNAs (vlincRNAs) are a novel class of long transcripts (~50 kb to 1 Mb) with cell type- or cancer-specific expression. We report the discovery and characterization of 256 vlincRNAs from a cohort of 64 primary childhood pre-B and pre-T acute lymphoblastic leukemia (cALL) samples, of which 61% are novel and specifically expressed in cALL. Validation was performed in 35 pre-B and pre-T cALL primary samples. We show that their expression is cALL immunophenotype and molecular subtype-specific and correlated with epigenetic modifications on their promoters, much like protein-coding genes. While the biological functions of these vlincRNAs are still unknown, our results suggest they could play a role in cALL etiology or progression

Réponses comportementales de cerfs de Virginie à la suite de la construction d’une autoroute traversant leur aire d’hivernage au Québec

Des clôtures hautes de 2,4 m, 5 passages inférieurs pour la faune et 30 sautoirs ont été aménagés sur 6,5 km d’un nouveau tronçon d’autoroute traversant l’aire d’hivernage de cerfs de Virginie de la rivière Calway, en Beauce. Un suivi de 7 ans, commencé environ 1 an avant le début des premiers travaux, a porté sur les effets de cette route sur l’utilisation de l’habitat hivernal par les cerfs et sur l’efficacité des mesures d’atténuation. Ces mesures se sont avérées efficaces pour limiter le nombre de collisions impliquant le cerf et elles devraient être intégrées aux futurs projets routiers. Les passages fauniques ont tous été utilisés par les cerfs soit durant la période d’hivernage (1), soit durant les migrations (4). De façon générale, les cerfs sont restés fidèles à leur habitat hivernal, mais les individus qui occupaient l’emprise avant son déboisement ont modifié l’emplacement et la superficie de leur domaine vital. La superficie et le recouvrement interannuel du ravage n’ont pas changé significativement pendant notre étude, ni non plus la proportion des cerfs résidents et migrateurs. Pour ces derniers, la présence de la nouvelle route n’a pas semblé affecter le lieu de migration estivale. Aucun cerf suivi n’a été victime de collision routière. La principale cause de mortalité des cerfs pendant notre étude a été la chasse sportive

On the intrahemispheric connectivity of the monkey: a diffusion tractography and tract tracing analysis

In this work, we compare diffusion tractography with neuronal retrograde tract tracing of the frontal, cingulate and parietal areas of the monkey. In this work, we compare diffusion tractography with neuronal retrograde tract tracing of the frontal, cingulate and parietal areas of the monkey. We analyze the agreements between the tractography and the tracing for connected and not connected regions. We report an accuracy of 0.71across all pairs of regions, with twice the number of true positive than false positive connections. Some regions show accuracy higher than 0.80, while other regions show accuracy lower than 0.6. A further analysis of the location of false positive and false negative connections will help understand the limitations and improve diffusion tractography algorithms. We analyze the agreements between the tractography and the tracing for connected and not connected regions. We report an accuracy of 0.71 across all pairs of regions, with twice the number of true positive than false positive connections. Some regions show accuracy higher than 0.80, while other regions show accuracy lower than 0.6. Further analysis of the location of false positive and false negative connections will help understand the limitations and improve diffusion tractography algorithms