1,575 research outputs found
Origines et contributions génétiques des fondatrices et des fondateurs de la population québécoise
Cette Ă©tude prĂ©sente une analyse des origines gĂ©ographiques et de la contribution gĂ©nĂ©tique des ancĂȘtres fondateurs de la population du QuĂ©bec. Ă lâaide de donnĂ©es tirĂ©es du ficher BALSAC et du Registre de la population du QuĂ©bec ancien, un corpus de 2223 gĂ©nĂ©alogies ascendantes couvrant lâensemble du territoire quĂ©bĂ©cois a Ă©tĂ© construit. Ces gĂ©nĂ©alogies remontent jusquâau 17e siĂšcle et couvrent en moyenne plus de neuf gĂ©nĂ©rations. Tous les liens gĂ©nĂ©alogiques unissant lâensemble des individus identifiĂ©s dans les ascendances ont Ă©tĂ© Ă©tablis. Les rĂ©sultats indiquent quâenviron 81 pour cent du pool gĂ©nique quĂ©bĂ©cois sâexplique par des fondatrices et fondateurs venus de France au 17e siĂšcle. Des diffĂ©rences importantes existent toutefois selon le lieu dâorigine en France et selon le sexe des fondateurs. Les rĂ©sultats ont aussi mis en Ă©vidence la prĂ©sence de nombreux liens dâapparentement Ă©loignĂ© dans cette population.This study analyzes the geographic origins and genetic contributions of the founding ancestors of the QuĂ©bec population. The authors used data from the BALSAC population register and the Early Quebec population register to build a corpus of 2,223 ascending genealogies covering the entire territory of QuĂ©bec. These genealogies go back to the 17th century and on average include more than 9 generations. Genealogical links between all individuals identified in the genealogies were established. Results show that approximately 81% of QuĂ©becâs gene pool derives from the founders who came from France in the 17th century. There are however important differences in foundersâ genetic contribution according to gender and place of origin in France. Genealogical analyses also reveal the existence of many distant kinship ties within this population
La contribution des Acadiens au peuplement des régions du Québec
Les Acadiens sont des descendants dâimmigrants français qui se sont Ă©tablis principalement au xviie siĂšcle en Nouvelle-Ăcosse et au Nouveau-Brunswick. En 1755, les autoritĂ©s britanniques ont ordonnĂ© la dĂ©portation des Acadiens qui ont Ă©tĂ© dispersĂ©s dans les colonies anglaises dâAmĂ©rique, en France et en Angleterre. On estime que de 2 000 Ă 4 000 Acadiens se sont Ă©tablis au QuĂ©bec. Lâobjectif de cette Ă©tude est de mesurer et de caractĂ©riser lâimpact de lâapport migratoire acadien sur le pool gĂ©nique quĂ©bĂ©cois contemporain. Les donnĂ©es utilisĂ©es proviennent dâun corpus gĂ©nĂ©alogique comprenant 2 340 ascendances. Les lieux dâorigine des ancĂȘtres, la frĂ©quence de leurs mentions dans les gĂ©nĂ©alogies ainsi que leur contribution gĂ©nĂ©tique aux diffĂ©rentes populations rĂ©gionales du QuĂ©bec ont Ă©tĂ© analysĂ©s. Les rĂ©sultats rĂ©vĂšlent que de 46 % Ă 100 % des ascendances, selon la rĂ©gion, comprennent au moins un ancĂȘtre dâorigine acadienne. La contribution des fondateurs acadiens est particuliĂšrement Ă©levĂ©e aux Ăles-de-la-Madeleine, oĂč 86 % du pool gĂ©nique leur est attribuable. Les populations de la GaspĂ©sie (27 %) et de la CĂŽte-Nord (14 %), affichent aussi une importante contribution acadienne.The Acadians are descendants of French immigrants who settled mainly in Nova Scotia and New Brunswick during the xviith century. In 1755, the British authorities ordered the deportation of Acadians who were then dispersed in France, England and the English colonies of America. It is estimated that between 2 000 and 4 000 Acadians settled in Quebec. The purpose of this study was to measure and characterize the impact of Acadian migration on the contemporary Quebec gene pool. Data was obtained from a genealogical corpus consisting of 2 340 ascendances. Place of origin of founding ancestors, frequency of their mention in the genealogies and their genetic contribution to the various regional populations of Quebec were analysed. Results show that, depending on the region, 46 % to 100 % of ascendances contain at least one Acadian ancestor. The contribution of Acadian founders is particularly high in the Ăles-de-la-Madeleine region, where 86 % of the gene pool is explained by Acadians. GaspĂ©sie (27 %) and CĂŽte-Nord (14 %) populations also display an important Acadian contribution
L'histoire inachevée de la régulation du marché du riz à Madagascar
L'envolĂ©e des prix du riz en 2005 Ă Madagascar, impulsĂ©e de l'extĂ©rieur, a crĂ©Ă© l'opportunitĂ© de rĂ©nover le mode de rĂ©gulation d'une filiĂšre hautement stratĂ©gique mais faiblement performante. A partir d'une lecture institutionnelle du fonctionnement du marchĂ©, d'une approche historique de la rĂ©gulation de la filiĂšre et d'une analyse Ă©conomique des mĂ©canismes de la crise, l'article fournit les Ă©lĂ©ments d'explication conduisant Ă envisager de nouvelles rĂšgles du jeu pour un pilotage de la filiĂšre redistribuant les rĂŽles entre l'Ătat et le marchĂ©. (RĂ©sumĂ© d'auteur
A metabolic link between mitochondrial ATP synthesis and liver glycogen metabolism: NMR study in rats re-fed with butyrate and/or glucose
Prevalence of respiratory symptoms in an athlete population
AbstractThis study aimed to look at the prevalence and type of respiratory symptoms experienced by athletes and to assess the possible influence on the perception of symptoms of training duration and environment. A group of 698 athletes (107 with diagnosed or self-reported asthma) filled out a questionnaire on their respiratory condition. They exercised either in cold air (n=176), dry air (n=384), humid air (n=95) or mixed dry and humid air (n=43). Past exercise-related symptoms reported by athletes were breathlessness (48.7%), phlegm production (22.8%), wheezing (15.6%), cough (15.2%), and chest tightness (7.4%). Only 25% of asthmatic athletes reported having current exercise-induced symptoms of breathlessness, 21.7%, wheezing and 17.4%, chest tightness; current exercise-induced symptoms of breathlessness, wheezing or chest tightness were also reported, respectively, in 38.9%, 3.6% and 2.7% of athletes without a diagnosis of asthma. The perception of exercise-induced symptoms was not influenced by the duration of training or environment. In conclusion, (1) a minority of asthmatic athletes report troublesome respiratory symptoms with exercise, (2) breathlessness is not more frequently reported in asthmatic athletes than in those without such diagnosis while cough and wheezing are more common in asthmatic subjects and (3) the prevalence of respiratory symptoms is independent of training environment and duration of training
Calving photocensus of the RiviĂšre George Caribou Herd and comparison with an independent census
Vertical photographs of the calving grounds have been used since 1984 to estimate the caribou (Rangifer tarandus) population of the Rivière George Caribou Herd (RGCH) in Northern Québec and Labrador. In spite of large confidence intervals, the 1984 and 1988 estimates suggested that the herd stabilized at more than 650 000 caribou (fall estimate including calves) making the RGCH the largest caribou herd in the world. Between 1984 and 1990, studies suggested that the former rapid growth of the herd deteriorated the calving and summer habitats. This poor habitat quality affected physical condition, pregnancy rate and calf survival. It was important to have a valid estimate of the herd size and a photocensus was done in June 1993. Contrary to previous censuses, a slightly different sampling design was applied in 1993. Two methods were used to estimate the number of females in the June population. In the first method, the number of females was derived from the estimated number of calves on the photographs and from the June female/calf ratio. The second method was used in the previous census and is based on the number of adults on the photos and on the June female/adult ratio. It is suggested that the first method of estimating female abundance in June is better due to sampling problems associated with a strong adult sex segregation during calving. From the first method, the herd size in October 1993 was estimated at 583 829 adults (±33.79%) and at 749 869 caribou including calves (±33.15%) while the second method provided estimates of 764 221 adults (±23.55%) and 981 565 caribou including calves (±22.64%). It was possible to compare those population estimates with an independent census. In July 1993, an oblique photocensus of the post-calving aggregations was conducted by Russell et al. (1996). A new analysis of their raw data provided an estimate of 608 384 adults (±14.35%). Both estimates from the June and July photocensus were combined. From the first and second method respectively, combined herd size estimates were 775 891 (±13.40%) and 823 375 (±12.36%) caribou including calves. The management implications are discussed and it is emphasized that the herd is still underharvested
Pouvons-nous rĂ©duire la dose dâazote aprĂšs un retour de prairie?
Affiche prĂ©sentĂ©e dans le cadre du Colloque de l'ARC, «Des racines et des ailes pour la recherche collĂ©giale», dans le cadre du 85e CongrĂšs de lâAcfas, UniversitĂ© McGill, MontrĂ©al, les 8 et 9 mai 2017.Au QuĂ©bec, les Ă©missions de gaz Ă effet de serre (GES) dâorigine agricole reprĂ©sentent prĂšs de 8 % des Ă©missions totales. Environ 40 % des Ă©missions agricoles dĂ©coule de lâusage des engrais minĂ©raux et des engrais de ferme. Tout apport excĂ©dentaire dâengrais azotĂ© dans les cultures se traduit par des Ă©missions supplĂ©mentaires dâoxyde nitreux (N2O), un puissant gaz Ă effet de serre qui contribue aux Ă©missions de GES. Plusieurs Ă©tudes ont dĂ©montrĂ© que la culture de maĂŻs nâavait pas besoin dâapports importants dâazote en postlevĂ©e, aprĂšs des retours de prairie. En collaboration avec des producteurs agricoles, 16 sites dâessais de fertilisation azotĂ©e ont Ă©tĂ© implantĂ©s sur des retours de prairie ayant reçu des engrais de ferme. Les traitements consistaient Ă apporter 4 doses dâazote minĂ©ral (0, 40, 80 et 120 kg N/ha). La teneur en nitrates du sol ainsi que les rendements Ă la rĂ©colte ont Ă©tĂ© Ă©valuĂ©s. La teneur en nitrates a confirmĂ© lâeffet significatif de la prairie et des engrais de ferme sur la teneur en azote disponible pour le maĂŻs. Lâapport dâazote minĂ©ral nâa pas eu dâeffet significatif sur les rendements en azote, Ă lâexception dâun site. Le maĂŻs cultivĂ© sur un retour de prairie ne nĂ©cessite pas un ajout dâengrais minĂ©ral. Ăliminer lâapport dâazote rĂ©duit tant les Ă©missions de GES que les dĂ©penses en engrais pour les producteurs
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