Childhood sports participation and adolescent sport profile

Abstract : Objectives: We aimed to increase understanding of the link between sport specialization during childhood and adolescent physical activity (PA). The objectives were as follows: (1) describe the natural course of sport participation over 5 years among children who are early sport samplers or early sport specializers and (2) determine if a sport participation profile in childhood predicts the sport profile in adolescence. Methods: Participants (n = 756, ages 10-11 years at study inception) reported their participation in organized and unorganized PA during in-class questionnaires administered every 4 months over 5 years. They were categorized as early sport samplers, early sport specializers, or nonparticipants in year 1 and as recreational sport participants, performance sport participants, or nonparticipants in years 2 to 5. The likelihood that a childhood sport profile would predict the adolescent profile was computed as relative risks. Polynomial logistic regression was used to identify predictors of an adolescent sport profile. Results: Compared with early sport specialization and nonparticipation, early sport sampling in childhood was associated with a higher likelihood of recreational participation (relative risk, 95% confidence interval: 1.55, 1.18-2.03) and a lower likelihood of nonparticipation (0.69, 0.51-0.93) in adolescence. Early sport specialization was associated with a higher likelihood of performance participation (1.65, 1.19-2.28) but not of nonparticipation (1.01, 0.70-1.47) in adolescence. Nonparticipation in childhood was associated with nearly doubling the likelihood of nonparticipation in adolescence (1.88, 1.36-2.62). Conclusions: Sport sampling should be promoted in childhood because it may be linked to higher PA levels during adolescence

Study into the use of the GNSS for maritime structure analysis

Certain civilian uses of the Global Positioning System (GPS) now demand levels of precision exceeding the original military specifications for the system. For example, at present, GPS is used in surveying, navigation and monitoring applications. Although GPS has been used previously to monitor the structural integrity of civilian structures such as bridges and towers, the experimental conditions have one significant difference: These structures are all immobile allowing for fixed references to be used.This research’s ultimate aim was to conduct a feasibility study into the use of GPS, and of the soon to be deployed Galileo constellation, in structural monitoring of maritime vessels. Under these conditions, a fixed base station as was used in previous structural monitoring is not a valid approach. New techniques, or variations on the current ones, were examined to deal with this lack of a fixed reference.This thesis considers the simulator that was developed in the early phases of the project and the results that were generated. An expanded version of the simulator is then explained, alongside the processes used to model structural deformation experienced by a ship at sea. Frequency analysis of the simulator results is also performed and the results detailed. It is found that frequency-domain analysis allows for the identification of different movements seen on the structure. In addition, an analysis of the impact the deployment of the Galileo constellation is conducted using simulation. This simulation found a drop of about 20% in Dilution of Precision (DOP) over several areas.This thesis then examines some of the field work, that aimed to measure rigidbody motion, that was conducted onboard Red Jet 4, a catamaran-type vessel. The experimental setup is described, and the results are briefly considered.A method for determining the optimal configuration of the receiver network is also proposed alongside an algorithm to detect plastic deformation of a vessel structure. Finally, this report considers the original project objectives and how these were or were not met. Should sufficient accuracy be achieved by a GPS receiver network, it is possible to use the system to monitor ship structures

Studies toward total synthesis of (±)-caldaphnidine C via one-pot sequential intramolecular Vilsmeier–Haack and azomethine ylide 1,3-dipolar cycloaddition

An application of a one-pot sequential Vilsmeier–Haack cyclization and intramolecular azomethine ylide 1,3-dipolar cycloaddition toward the total synthesis of (±)-caldaphnidine C is presented. It allowed an efficient formation of three cycles with perfect control of four of the five newly created stereogenic centers including one all-carbon quaternary center. Two synthetic strategies to produce the key-step precursor, the investigation and optimization of the cyclization partners (nucleophile, azomethine ylide, and dipolarophile), and further derivatization of the cycloadduct are reported

La capacité d’influence des cadres supérieurs en ressources humaines auprès des membres du comité de direction

Au cours des dernières années, un nombre croissant d’auteurs en gestion des ressources humaines se sont intéressés aux rôles que peuvent jouer les services des RH et les cadres supérieurs en RH dans le développement de la stratégie de l’entreprise. Toutefois, il est pertinent de se demander dans quel contexte l’exercice de ces rôles devient légitime. Selon certains auteurs, c’est particulièrement le cas lorsque l’entreprise se retrouve face à des défis exigeants au plan des ressources humaines.Donc, compte tenu du contexte actuel caractérisé par une économie sous pression, les cadres supérieurs en RH devraient être en mesure d’en profiter pour devenir des partenaires influents auprès du comité de direction. Cependant, nous savons très peu de choses sur la capacité d’influence des cadres supérieurs en RH, particulièrement auprès des membres du comité de direction, de même que l’écart potentiel qui peut exister entre la perception de ces derniers et celle que les cadres supérieurs RH entretiennent à leur propre égard en ce qui concerne leur capacité d’influence.Dans le cadre de notre recherche, le terrain ciblé se compose de cadres supérieurs en RH travaillant majoritairement dans la grande région de Montréal. Au total, nous avons rencontré 41 cadres supérieurs en RH afin de mesurer leur capacité d’influence. Suite à l’entretien, nous les avons invités à distribuer un questionnaire à des membres de leur comité de direction qu’ils avaient influencé au cours des trois dernières années.Les analyses révèlent que les cadres supérieurs en RH tendent à surestimer leur capacité d’influence auprès des membres de l’équipe de direction par rapport au jugement porté par leurs collègues exécutifs ou de leur supérieur immédiat. Enfin, nos résultats montrent qu’une bonne réputation, une solide crédibilité ainsi qu’un pouvoir de référence élevé peuvent faciliter l’exercice de l’influence des cadres supérieurs en RH.Over the past few years, an increasing number of authors in the human resource management field have developed an interest in the roles played by HR departments and HR executives in the formulation of the business strategy. However, it is relevant to examine in which context the use of these roles becomes legitimate. According to a number of authors, this is particularly the case when businesses are facing demanding human resource challenges.Therefore, taking into account the current context characterized by an economy under pressure, HR executives should be in a good position to benefit from such a context to become influential partners within their respective top management committee. However, very little is known about the extent to which members of the top management committee perceive HR executives as having a high capability to influence them. Also, so far, no one has addressed the gap that may exist between the perception of the top management committee members and the perception HR executives hold for themselves with regards to their capability to influence the latter.In this study, we chose to investigate HR executives who come mainly from the greater Montreal area. In total, we met 41 HR executives for whom we investigated their influence capability. Following the interview, we invited each HR executive to hand out a short questionnaire to each member of the top management committee that they had tried to influence over the last three years.Results show that, overall, HR executives tend to overestimate their influence capability when compared to the perception of their executive colleagues and chief officer. Finally, this study also confirmed that a good reputation, a solid credibility and high referent power can facilitate the capability of HR executives to influence others.Durante los últimos años, una cantidad creciente de autores en recursos humanos se han interesado a los roles que los servicios de RH y los directivos de RH pueden jugar en el desarrollo de la estrategia de la empresa. No obstante, es pertinente preguntarse en qué contexto el ejercicio de esos roles deviene legitimo. Según ciertos autores, esto sucede particularmente cuando la empresa se encuentra frente a desafíos exigentes en el plano de los recursos humanos.Por ello, teniendo en cuenta el contexto actual caracterizado por una economía bajo presión, los directivos de recursos humanos deberían estar en condiciones de aprovechar para devenir socios influyentes del comité de dirección. Sin embargo, sabemos muy poco sobre la capacidad de influencia de estos directivos de RH, particularmente frente a los miembros del comité de dirección, de igual modo que sobre la distancia potencial que puede existir entre la percepción de estos últimos y la percepción de los directivos de RH respecto a sí mismos y su capacidad de influencia.En el cuadro de nuestra investigación, el terreno seleccionado se compone de directivos de RH que trabajan mayoritariamente en la gran región de Montreal. En total, hemos encontrado 41 directivos de RH con el fin de medir su capacidad de influencia. Después de la entrevista, les invitábamos a distribuir un cuestionario a los miembros de su comité de dirección que habían sido influenciados por ellos durante los últimos tres anos.Los análisis revelan que los directivos de RH tienden a sobrestimar su capacidad de influencia frente a los miembros del equipo de dirección respecto a la opinión de sus colegas ejecutivos o de sus superiores inmediatos. Por último, nuestros resultados muestran que una buena reputación, una solida credibilidad así que un poder de referencia elevado pueden facilitar el ejercicio de influencia de los directivos de RH

One size does not fit all : identifying clusters of physical activity, screen time, and sleep behaviour co-development from childhood to adolescence

Abstract : Purpose: Canada was the first to adopt comprehensive 24-h movement guidelines that include recommendations for physical activity, screen time and sleep to promote health benefits. No studies have investigated the concurrent development of these behaviours in youth. The objectives were to assess adherence to the Canadian 24-h movement guidelines for children and youth and estimate co-development of self-reported moderate-to-vigorous intensity physical activity (MVPA), screen time and sleep during 8-years from childhood to adolescence. Methods: Nine hundred and twenty three participants of the MATCH study self-reported their MVPA, screen time and sleep duration at least twice over 8 years. MVPA and screen time were measured three times per year (24 cycles), and sleep was measured once per year (8 cycles). Guideline adherence was dichotomised as meeting each specific health behaviour recommendation or not. Multi-group trajectory modeling was used to identify unique trajectories of behavioural co-development. Analyses were stratified by sex. Results: Between 10 and 39% of youth did not meet any recommendation at the various cycles of data collection. More than half of youth met only one or two recommendation, and roughly 5% of participants met all three recommendations at one or more study cycle throughout the 8 years of follow-up. Four different trajectories of behavioural co-development were identified for boys and for girls. For boys and girls, a complier (good adherence to the guideline recommendations; 12% boys and 9% girls), a decliner (decreasing adherence to the guideline recommendations; 23% boys and 18% girls) and a non-complier group (low adherence to the guideline recommendations; 42% boys and 42% girls) were identified. In boys, a MVPA-complier group (high MVPA-low screen time; 23%) was identified, whereas in girls a screen-complier group (moderate screen time-low MVPA; 30%) was identified. Conclusions: There is a need to recognise that variations from general trends of decreasing MVPA, increasing screen time and decreasing sleep exist. Specifically, we found that although it is uncommon for youth to adhere to the Canadian 24-h movement guidelines, some youth displayed a high likelihood of attaining one or multiple of the behavioural recommendations. Further, patterns of adherence to the guidelines can differ across different subgroups of youth

Synthesis of the tetracyclic core of daphnilactone B-type and yuzurimine-type alkaloid

Abstract: The core of daphnilactone B-type and yuzurimine-type alkaloids was synthesized in only 16 steps from a known β-allyl-γ-butyrolactone. The key sequence of Vilsmeier–Haack cyclization and intramolecular azomethine ylide cycloaddition allowed the construction of, in a single step, three of the five rings common to all alkaloids found in both of these classes with perfect chemocontrol

Électronique de base pour un scanner bimodal TEP-TDM numérique

Lancée au milieu des années 70, la tomographie d'émission par positrons a rapidement suscité de l'intérêt, d'abord en neurologie et en cardiologie, puis en oncologie. Cette technique d'imagerie médicale, basée sur l'administration d'un marqueur radioactif spécifique à un sujet, permet l'analyse de l'activité métabolique et fonctionnelle en émettant des particules, captées par un scanner. Le principe de fonctionnement du scanner repose sur la détection de deux rayons émis colinéairement lorsqu'un positron s'annihile avec un électron. La tomographie d'émission par positrons, permettant de déterminer des foyers d'activité métaboliques, se distingue des techniques d'imagerie conventionnelles qui ne permettent qu'une localisation anatomique. La combinaison des deux types d'imagerie est devenue nécessaire afin de localiser plus précisément les foyers d'activités métaboliques. Plusieurs TEP pour petits animaux sont actuellement en fonction, dont celui de l'Université de Sherbrooke. Tous ces systèmes sont basés sur une architecture analogique qui, bien qu'acceptable au point de vue de ses performances, présente des inconvénients. Afin de palier à certains problèmes de l'architecture analogique et ouvrir de nouveaux champs de recherche, une architecture entièrement numérique pour l'acquisition a été proposée et mise de l'avant. Pour ce faire, des principes de conception sont d'abord énoncés. Ceux-ci représentent des prérequis à considérer lors de l'élaboration de l'architecture d'une carte d'acquisition entièrement numérique. Par la suite, une architecture incorporant ces prérequis est présentée, suivi des résultats obtenus à partir de la carte ainsi conçue. Dans un dernier temps, une analyse de ces résultats est présentée ainsi que des modifications pouvant améliorer l'architecture proposée. Une synthèse des sujets présentés conclut l'ouvrage

Étude des interactions fonctionnelles de la tétraboucle 900 de l'ARN ribosomique 16S dans le ribosome bactérien

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