234 research outputs found
LâĂ©volution du lit du Saint-Laurent dans le secteur de Contrecoeur (QuĂ©bec) depuis un siĂšcle
Des levĂ©s hydrographiques du gouvernement canadien datant de 1898, 1945 et 1988, ont Ă©tĂ© comparĂ©s afin d'Ă©tablir la cartographie des changements survenus au lit du Saint-Laurent dans le secteur de Contrecoeur, Ă mi-chemin entre MontrĂ©al et Sorel. Depuis 1850, la dynamique hydrosĂ©dimentaire de ce tronçon long de 8 km a dĂ» se rĂ©Ă©quilibrer au fur et Ă mesure de l'agrandissement du chenal de navigation maritime. Au moyen d'un logiciel de gĂ©omatique, des modĂšles bathymĂ©triques dĂ©taillĂ©s ont Ă©tĂ© Ă©laborĂ©s Ă partir des cartes de levĂ©s historiques fournies par le Service hydrographique du Canada. AprĂšs ajustement des cadres gĂ©ographiques et du zĂ©ro des cartes, les patrons spatiaux de changements bathymĂ©triques consĂ©cutifs Ă l'Ă©rosion ou Ă la sĂ©dimentation ont pu ĂȘtre dĂ©terminĂ©s par comparaison de ces modĂšles. Les cartes qui en rĂ©sultent illustrent les principales Ă©tapes de l'agrandissement de la voie maritime ainsi que l'Ă©volution des dĂ©pĂŽts de dĂ©blais de dragage. Il appert, par exemple, qu'un volume important de dĂ©blais laissĂ© Ă la marge ouest du chenal entre 1898 et 1945 a Ă©tĂ© dispersĂ© vers l'aval entre 1945 et 1988, aprĂšs avoir Ă©tĂ© remis en suspension par les courants et les vagues en marge du chenal maritime. L'intĂ©rĂȘt principal de notre Ă©tude rĂ©side nĂ©anmoins dans l'Ă©clairage nouveau qu'il donne Ă la dynamique d'ensemble du lit fluvial, bien au delĂ du chenal draguĂ©. Entre 1898 et 1988, de vastes secteurs du lit ont Ă©tĂ© recouverts de 0,5 Ă 1 m additionnel de sĂ©diments. Le chenal central Ă l'ouest de l'Ăźle Saint-Ours semble particuliĂšrement touchĂ©, le taux moyen de sĂ©dimentation y ayant Ă©tĂ© de 1,5 cm/a entre 1945 et 1988. L'instabilitĂ© du lit s'est accĂ©lĂ©rĂ©e depuis 1945 et semble ĂȘtre attribuable, en partie du moins, Ă la perturbation de l'Ă©quilibre hydrosĂ©dimentaire causĂ©e par l'agrandissement rĂ©pĂ©tĂ© du chenal maritime.Canadian government hydrographie surveys from 1898, 1945 and 1988 are compared to reveal long-term patterns of bathymĂ©trie change in the St. Lawrence River, in the Contrecoeur area between MontrĂ©al and Sorel. Since 1850, the hydraulic and sedimentary balance of this reach has been affected by repeated dredging to expand the main navigation channel. Using GIS software, detailed bathymĂ©trie models of the reach for each of the years 1898, 1945 and 1988 were produced by interpolation through the archival soundings for each of these periods provided by the Canadian Hydrographie Service. After careful adjustment of reference water planes and planimetric coordinate systems, maps of bed changes were derived by comparing the different models. Major expansions of the navigation channel can be followed as well as the evolution of the main dredge spoil areas. In particular, considerable volumes of dredge spoil deposited at the margin of the ship channel between 1898 and 1945 are seen to have been re-entrained and dispersed downstream by 1988. Most interestingly, the maps of bed changes reveal substantial rates of sediment deposition over much of the river bed, well away from the ship channel. Over wide areas, deposition of between 0.5 and 1 m of new sediment since 1898 is observed. Bed aggradation has been particularly intense in the central channel west of Ile Saint-Ours, where it has averaged 1.5 cm/year between 1945 and 1988. In part at least, this tendency to bed aggradation over much of the river may be a reaction to the man-made concentration of the flow in the enlarged ship channel.Hydrographische Vermessungen von 1898, 1945 und 1988 wurden verglichen, um die Veranderungen im Bett des Sankt Lorenz im Bereich von Contrecoeur kartographisch festzuhalten. Seit 1850 musste die hydrosedimentare Dynamik dieses 8 km Iangen StĂčckes entsprechend der Verbreiterung der Seewegfahrrinne jeweils ein neues Gleichgewicht finden. Mit Hilfe einer geomatischen Software wurden detaillierte Tiefenmodelle erstellt, ausgehend von Karten historischer Vermessungen, die der kanadische hydrographische Service zur Verfugung stellte. Nach Abstimmung der geographischen Rahmen und der Planimetrie konnten durch Vergleich dieser Modelle die rĂ umlichen Muster der TiefenverĂ nderungen aufgrund von Erosion oder Sedimentierung bestimmt werden. Die so entstandenen Karten illustrieren die wichtigsten Etappen der Vergrosserung des Seewegs sowie die Entwicklung der AbIagerungen von Baggeraushubmaterial. Es scheint, z.B. dass eine bedeutende Menge von Aushubmaterial, das man am westlichsten Rand der Fahrrinne zwischen 1898 und 1945 liess, zwischen 1945 und 1988 stromabwĂ rts verstreut wurde, nachdem es durch Stromungen und Wellen am Rand des Seewegs wieder aufgelĂŽst worden war. Das Hauptinteresse unserer Untersuchung bes-teht jedoch in dem neuen Licht, das sie auf die Gesamtdynamik des Flussbettes wirft, weit iiber die ausgebaggerte Fahrrinne hinaus. Zwischen 1898 und 1988 wurden weite Abschnitte des Flussbettes mit einer zusĂ tzlichen Sedimentschicht von 0,5 bis 1 m bedeckt. Die zentrale Fahrrinne westlich von der lnsel St. Ours scheint besonders betroffen, die durchschnittliche Sedimentierungsrate war hier 1,5cm/Jahr zwischen 1945 und 1988. Die Labilitat des Flussbettes hat sich seit 1945 beschleunigt und scheint mindestens zum Teil auf die StĂŽrung des hydro-sedimentaren Gleichgewichts durch die wiederholte Vergrosserung des Seewegs zurĂčckzufĂčhren zu sein
An analytic formula for Macdonald polynomials
We give the explicit analytic development of any Jack or Macdonald polynomial
in terms of elementary (resp. modified complete) symmetric functions. These two
developments are obtained by inverting the Pieri formula.Comment: 8 pages; research announcement submitted to Comptes Rendus Math.
Acad. Sci. Paris for publicatio
Développement systématique d'une intervention tailoring internet automatisée faisant la promotion de la pratique d'activités physiques réguliÚre chez les personnes atteintes du diabÚte de type 2 insuffisamment actives : intégration de la Théorie de l'autodétermination, de l'entretien motivationnel et du I-Change Model
Le diabĂšte de type 2 (Db2) pose un dĂ©fi important pour les instances de santĂ© publique au QuĂ©bec et la pratique rĂ©guliĂšre dâactivitĂ©s physiques fait partie intĂ©grante du traitement de la maladie. Alors que seulement 30% des QuĂ©bĂ©cois atteints du Db2 sont suffisamment actifs vis-Ă -vis les recommandations canadiennes, des programmes efficaces faisant la promotion de la pratique rĂ©guliĂšre dâactivitĂ©s physiques et ayant la capacitĂ© de rejoindre un grand nombre dâindividus de cette population sont en demande. Objectif : Lâobjectif du mĂ©moire est de dĂ©crire le dĂ©veloppement systĂ©matique de lâintervention DiabĂšte en Forme (DEF), une intervention tailoring (c.-Ă -d. individualisĂ©e) basĂ©e strictement sur Internet et visant lâadoption de la pratique rĂ©guliĂšre dâactivitĂ©s physiques chez les personnes atteintes du Db2 au QuĂ©bec. Comme le tailoring sur Internet est une approche rĂ©cente et prometteuse en promotion de la santĂ©, ce mĂ©moire pourra servir de modĂšle de dĂ©veloppement pour les professionnels intĂ©ressĂ©s Ă dĂ©velopper des interventions similaires. MĂ©thode : La conception de lâintervention a Ă©tĂ© rĂ©alisĂ©e en utilisant une adaptation du modĂšle de dĂ©veloppement dâintervention tailoring de Kreuter et collĂšgues. Une Ă©tape supplĂ©mentaire dâĂ©valuation de lâutilisabilitĂ© de lâintervention a Ă©tĂ© ajoutĂ©e au modĂšle de dĂ©veloppement afin dâajuster celui-ci Ă une intervention Internet. RĂ©sultats : Une intervention de huit semaines a Ă©tĂ© dĂ©veloppĂ©e sous un cadre thĂ©orique intĂ©grant le I-Change Model, la ThĂ©orie de lâAutodĂ©termination (TAD) et lâentretien motivationnel (EM). Les composantes clĂ©s de lâintervention incluent un outil permettant lâauto-monitorage du niveau dâactivitĂ©s physiques du participant, un outil de plan dâaction et huit sĂ©ances motivationnelles basĂ©es principalement sur lâattitude, lâefficacitĂ© personnelle, la pratique dâactivitĂ©s physiques, lâintention et le type de motivation des participants. LâĂ©valuation de lâutilisabilitĂ© de lâintervention a permis de rĂ©aliser plusieurs amĂ©liorations prĂ©alables Ă lâimplantation de lâintervention. Conclusion : LâĂ©valuation de lâutilisabilitĂ© constitue une Ă©tape importante prĂ©cĂ©dant lâimplantation dâune intervention tailoring Internet afin dâoptimiser celle-ci et de lâadapter adĂ©quatement Ă la population cible. LâefficacitĂ© et la pertinence du cadre thĂ©orique utilisĂ© pourront ĂȘtre analysĂ©es suite Ă lâĂ©valuation dâimpact et de processus.Background: Type 2 diabetes (T2D) is a major challenge for public health authorities in Canada and regular physical activity is a key factor in the management of this disease. Given that less than half of people with T2D in Canada are sufficiently active to meet the recommendations, effective programs targeting the adoption of regular PA are in demand for this population. Many researchers argued that web-based tailored interventions targeting PA is a promising and effective avenue for sedentary populations like Canadians with T2D, but few aimed to describe the detailed development of this kind of intervention. Objective: This masterâs thesis aims to describe the systematic development of the DiabĂšte en Forme (DEF) web-based tailored intervention promoting regular PA among adult Canadian Francophones with T2D, which can be used as a reference for health professionals interested in developing similar interventions. This masterâs thesis also explores the integration of theoretical components derived from the I-Change Model, Self-Determination (SDT) Theory and Motivational Interviewing (MI), a potential path for enhancing the effectiveness of tailored interventions on PA adoption and maintenance. Method: The intervention was built using an adaptation of the program-planning model for tailored interventions developed by Kreuter and his colleagues. An additional step was added to the model to evaluate the interventionâs usability prior to the implementation phase. Results: An eight-week intervention was developed using a theoretical framework integrating the three models previously mentioned. The key components of the intervention include a self-monitoring tool for PA behaviour, a weekly action planning tool and eight tailored motivational sessions based on attitude, self-efficacy, intention, type of motivation, PA behaviour and other constructs and techniques. Usability evaluation, a step added to the original program-planning model, helped to make several improvements to the intervention prior to the implementation phase. Conclusion: Usability evaluation is an essential step in the development of a web-based tailored intervention in order to make pre-implementation improvements. The effectiveness and relevance of the theoretical framework used for the intervention will be analyzed following the process and impact evaluation. Implications for future research are discussed
Portrait de l'écrivain en ascÚte: Ralph Waldo Emerson et la modernité des exercices spirituels
[Ă l'origine dans / Was originally part of : ThĂšses et mĂ©moires - FAS - DĂ©partement de littĂ©rature comparĂ©e]Ce mĂ©moire dĂ©montre que la pratique littĂ©raire de lâĂ©crivain amĂ©ricain Ralph Waldo Emerson sâinscrit dans le sillage de la tradition des exercices spirituels mise au jour par lâhellĂ©niste Pierre Hadot et quâelle permet de penser une modernitĂ© insoupçonnĂ©e par ce dernier. La production de textes littĂ©raires devient alors une maniĂšre dâĂ©tablir « une relation originale avec lâunivers » (cf. lâintroduction de Nature).
Le premier chapitre explique la spĂ©cificitĂ© de la spiritualitĂ© traditionnelle, oĂč lâĂ©criture consiste Ă implanter en soi le texte de la tradition. La pratique littĂ©raire de Marc AurĂšle, SĂ©nĂšque et saint Augustin est Ă©tudiĂ©e afin de montrer comment ils tĂąchent de vivre conformĂ©ment Ă la conception de la transcendance qui est la leur : personnelle chez les stoĂŻciens, institutionnelle chez les chrĂ©tiens.
Le deuxiĂšme chapitre montre comment Emerson renverse le rapport traditionnel au texte dans la vie de lâesprit en arguant que la rĂ©vĂ©lation du Christ est, Ă lâorigine, une expĂ©rience personnelle de la transcendance qui nâest pas institutionnalisable. Il se dĂ©gage de cette confrontation romantique avec le christianisme un concept de littĂ©rature liĂ© au mysticisme et insĂ©parable dâune comprĂ©hension « expressiviste » du langage (Charles Taylor).
Le dernier chapitre examine lâascĂšse littĂ©raire dâEmerson : sa conception antiscolastique du « scholar » est Ă©tudiĂ©e puis mise en relief avec sa façon dâarrimer sa pratique de la pensĂ©e Ă une conception fluctuante de lâunivers. La derniĂšre section porte sur la façon dont son mode de vie expĂ©rimental suppose une conception de la littĂ©rature en tant que processus.This master thesis considers how the literary practice of Ralph Waldo Emerson might help us rethink the modern heritage in the tradition of spiritual exercises. The nineteenth century American writer followed the path of this antique tradition that was uncovered by the philosophy historian Pierre Hadot, allowing us to consider anew this tradition within the framework of modernity. It is thus possible to access an unexpected modernity of spiritual exercises, unknown to Hadot himself, characterized by the production of literary texts that convey what Emerson calls, âan original relation to the universe.â
The first chapter explains the specificity of traditional spirituality, where writing serves to incorporate traditional text into oneself. It considers the literary practice of Marcus Aurelius, Seneca and Saint Augustine, who all attempted to live according to their conception of transcendence: personal under stoicism, institutional within Christianity.
Chapter two illustrates how Emerson overturns the traditional way of behaving with a spiritual text. His critique of Christian theology shows that the revelation of Christ is, in its origin, a personal experience of transcendence that cannot be instituted. From this romantic dissension with Christianity emerges a theory of literature related to mysticism and in close ties with an âexpressivistâ conception of language (Charles Taylor).
The final chapter examines Emersonâs literary askesis. First explained is the antischolastic conception of the scholar, subsequently showing how his way of thinking is interrelated to a fluxional conception of the universe. Lastly demonstrated is how his experimental way of life relies on a conception of literature as process
Inversion of the Pieri formula for Macdonald polynomials
We give the explicit analytic development of Macdonald polynomials in terms
of "modified complete" and elementary symmetric functions. These expansions are
obtained by inverting the Pieri formula. Specialization yields similar
developments for monomial, Jack and Hall-Littlewood symmetric functions.Comment: 34 page
Comparing the behavioural thermoregulation response to heat stress by Atlantic salmon parr ( Salmo salar ) in two rivers
Climate change is expected to increase the frequency and magnitude of extreme thermal events in rivers. The Little Southwest Miramichi River (LSWM) and the Ouelle River (OR) are two Atlantic salmon (Salmo salar) rivers located in eastern Canada, where in recent years, water temperatures have exceeded known thermal limits (~23°C). Once temperature surpasses this threshold, juvenile salmon exploit thermal heterogeneity to behaviourally thermoregulate, forming aggregations in coolwater refuges. This study aimed to determine whether the behavioural thermoregulation response is universal across rivers, arising from common thermal cues. We detailed the temperature and discharge patterns of two geographically distinct rivers from 2010 to 2012 and compared these with aggregation onset temperature. PIT telemetry and snorkelling were used to confirm the presence of aggregations. Mean daily maximum temperature in 2010 was significantly greater in the OR versus the LSWM (p = 0.005), but not in other years (p = 0.090â0.353). Aggregations occurred on 14 and 9 occasions in the OR and LSWM respectively. Temperature at onset of aggregation was significantly greater in the OR (Tonset = 28.3°C) than in the LSWM (Tonset = 27.3°C; p = 0.049). Logistic regression models varied by river and were able to predict the probability of aggregation based on the preceding number of hours >23°C (R2 = 0.61 & 0.65; P50 = 27.4°C & 28.9°C; in the OR and LSWM respectively). These results imply the preceding local thermal regime may influence behaviour and indicate a degree of phenotypic plasticity, illustrating a need for localised management strategies
Temporal Development of Scour Holes around Submerged Stream Deflectors
Although the deflector structures used in many fish habitat rehabilitation schemes are frequently overtopped, few studies have examined the scour patterns created around submerged models. Furthermore, laboratory studies typically test smooth-surfaced structures, when those installed in
natural rivers are generally made of logs or boulders. This study uses rough-surfaced, paired deflectors to investigate the temporal evolution of scour for three overtopping ratios in identical approach flow conditions in a flume. Results show that when maintaining identical discharge,
raising deflector height and thus reducing the overtopping ratio (flow depth / structure height), an increased depth and volume of scour is generated next to the structures. The location of maximum depth and the rate of scouring with time is similar for the two highest deflectors (overtopping ratios of 1.22 and 1.83), but different for the lowest deflector model (overtopping ratio of 3.67). In order to improve the success rate of river restoration projects using in-stream structures, the overtopping ratio should be used in equations that predict scour depth evolution
with time
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