Search

Red heartwood, a dark nonhomogenous discolouration in paper birch trees ( Marsh.), limits the applications and uses of sawn boards to nonvisible low-value products, thus resulting in substantial value loss. The occurrence and distribution of red heartwood were investigated in 12 paper birch trees grown in the province of Quebec, Canada. The youngest tree was 62 years old at breast height and the oldest 86 years old for an average of 75 years old. In this study, 225 occurrences of external traits, relating to branch scars and forks, previously proposed as initiation points for red heartwood were identified and measured. The distribution of red heartwood was digitally mapped and the effect of these external traits on the red heartwood surface and shape inside each tree was examined. Results show that red heartwood initiates from an external trait and that multiple external traits can contribute to the development of a red heartwood column following the longitudinal axis of the stem. Red heartwood appeared to initiate mainly from external traits at the base of the tree. A modelling exercise indicated that the width of the red heartwood column inside a standing tree can be estimated from branch scar width and height from the ground. Tree vigour could not be linked to the proportion of red heartwood inside standing trees. A three-dimensional analysis of log shape could potentially be used to detect red heartwood presence in a log before processing to optimize the log sawing pattern. [ABSTRACT FROM AUTHOR]

Normal paper birch (Betula papyrifera Marsh.) wood has a clear and uniform color. However, some paper birch trees contain reddish-brown-, discolored wood known as red heartwood. Its occurrence, proportion, and vertical distribution were investigated. One hundred and fifty trees were randomly sampled from three stands located at the Montmorency Forest, 75 km north of Quebec City, Quebec, Canada. A subsample of 18 trees showing occurrence of red heartwood at stump height were felled, and 5 cm thick disks were cut at every 0.5 m of height. Red heartwood volume, proportion, and vertical distribution were determined from the disks. Trees with larger diameter at breast height and lower tree height had a higher probability of red heartwood occurrence. Red heartwood starts occurring in 40-year-old trees on average in the stands studied. The volume of red heartwood was positively correlated with tree age, and the proportion of red heartwood was positively related to tree age, and negatively related to the amount of sunlight on the live crown. Red heartwood proportion was 13.3% of the tree merchantable volume, mostly located under the live crown. Le bois de bouleau à papier (Betula papyrifera Marsh.) est normalement clair et uniforme. Toutefois, le bois de couleur brun-rougeâtre présent chez certains bouleaux est appelé cœur rouge. Sa présence, sa proportion et sa distribution verticale dans l’arbre ont été étudiées. Cent cinquante arbres furent sélectionnés aléatoirement dans trois peuplements de la Forêt Montmorency à 75 km au nord de la ville de Québec, Québec, Canada. Un sous-échantillon de 18 arbres présentant du cœur rouge à hauteur de souche ont été abattus et découpés en disques de 5 cm d’épaisseur à tous les 5 m afin de mesurer le volume, la proportion et la distribution verticale du cœur rouge. La probabilité de présence de cœur rouge était plus élevée chez les arbres petits et de fort diamètre. Le cœur rouge était présent dans les arbres de 40 ans et plus en moyenne dans les peuplements étudiés. Le volume de cœur rouge était corrélé positivement avec l’âge de l’arbre. Sa proportion était corrélée positivement avec l’âge de l’arbre et négativement avec la quantité de lumière atteignant la cime vivante. La proportion moyenne de cœur rouge était 13,3 % du volume marchand de l’arbre et il était principalement situé sous la cime vivante. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article offers information about several research papers related to various aspects of food and nutrition. It includes food security of Syrian refugee households in Canada, maternal mental health and infant feeding style, childcare director perceptions on healthy food consumption, the effect of food advertisements on food intake, and associations between intuitive eating levels and desire to eat during pregnancy.

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We compared three methods for estimating current-year spruce budworm (Choristoneura fumiferana (Clem.)) defoliation from 2014 to 2021 using a network of 99 permanent sample plots in central Gaspé Peninsula, Québec. Percent current-year defoliation was measured by assessing shoots from mid-crown branches, ocular ratings of all individual trees using binoculars, and provincial government aerial surveys. Ocular survey defoliation differed from branch sample defoliation in 5–6 out of 7 years, consistently underestimating defoliation, across the full range of defoliation severity observed. Nested mixed-effect models for fir–spruce combined, balsam fir, white spruce, and black spruce ocular survey defoliation bias resulted in marginal R2 of 0.40, 0.47, 0.82, and 0.86, respectively. Current defoliation severity and its interaction with previous year defoliation and weather conditions significantly affected ocular survey bias. Correspondence of aerial survey estimates and mean plot defoliation occurred in only 43% of all plot-years and ranged from 14%–58% in individual years. Differences between aerial survey defoliation and plot values mainly resulted from assigning an adjacent class (e.g., light <30% assigned as moderate 31%–70% defoliation) or misplaced defoliation polygon boundaries, suggesting that assignment of aerial survey defoliation to plots or specific ground areas needs ground truth sampling. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents development of a multivariate forest structural complexity index based on relationships between field-based structural variables and geospatial data. Remote sensing has been widely used to model individual forest structural attributes at many scales. As opposed to, or in addition to, individual structural parameters such as leaf area index or tree height, overall structural complexity information can enhance forest inventories and provide a variety of information to forest managers, including identifying damage and disturbance as well as indicators of habitat or biodiversity. In this study, a multivariate modelling technique, redundancy analysis, was implemented to derive a model incorporating both horizontal and vertical structural attributes as predicted by an ensemble of high-resolution multispectral airborne imagery and topographic variables. The first redundancy analysis axis of the final model explained 35% of the total variance of the field variables and was used as the complexity index. With a root mean squared error of 19.9%, the model was capable of differentiating four to five relative levels of complexity. This paper presents the forest ecological and modelling aspects of the research. A related paper presents the remote sensing aspects, including application of the model to map predicted structural complexity, map validation, and testing of the method at multiple scales. Cet article présente le développement d'un indice multivarié de complexité de la structure de la forêt basé sur les relations entre des variables structurales mesurées sur le terrain et des données géospatiales. La télédétection a été largement utilisée pour modéliser les attributs structuraux de la forêt à plusieurs échelles. Contrairement à, ou en plus, des paramètres structuraux individuels comme l'indice de surface foliaire ou la hauteur des arbres, une information globale au sujet de la complexité structurale peut améliorer les inventaires forestiers et fournir une variété de renseignements aux aménagistes forestiers, incluant l'identification des dommages et des perturbations aussi bien que des indicateurs d'habitat ou de biodiversité. Dans cette étude, une technique de modélisation multivariée, l'analyse de redondance, a été appliquée pour dériver un modèle qui incorpore des attributs, tant horizontaux que verticaux de la structure, prédits par un ensemble d'images aériennes multispectrales à haute résolution et des variables topographiques. Le premier axe de l'analyse de redondance du modèle final expliquait 35 % de la variance totale des variables terrain et a été utilisé comme indice de complexité. Avec une erreur quadratique moyenne de 19,9 %, le modèle était capable de différencier quatre à cinq niveaux de complexité. Cet article présente les aspects de la recherche reliés à la modélisation et à l'écologie forestière. Un autre article présente les aspects reliés à la télédétection, incluant l'application du modèle pour cartographier la complexité structurale prédite, la validation de la cartographie et l'essai de la méthode à plusieurs échelles. [ABSTRACT FROM AUTHOR]

The objective of this paper is to compare field test results obtained in a stiff sensitive clay from Quebec using prebored, instrumented sharp cone tests (ISCTs) with those deduced from prebored and self-boring pressuremeter tests (PMTs and SBPMTs, respectively) and vane shear tests (VSTs). Comparisons are also made with triaxial test results. It is shown that undrained shear strengths Su deduced from PMTs and ISCTs are greatly overestimated with respect to the values inferred from SBPMTs and VSTs. As for the shear modulus G, the opposite is true. These discrepancies are considered to arise from initial disturbance and unloading caused by drilling of pilot holes in the case of PMTs and ISCTs. Interpretation problems may be also related to the existence of very high lateral pressures at rest in the clay deposit. L’objectif de cet article est de comparer les résultats d’essais in situ obtenus dans une argile sensible raide du Quebec à l’aide d’essais au cône effilé instrumenté préforé « ISCT »avec ceux déduits d’essais au pressiomètre autoforeur et préforé « SBPMT et PMT, respectivement , et d’essais scissométriques de chantier « VST ». Une comparaison est effectuée aussi avec les résultats obtenus au laboratoire au moyen d’essais triaxiaux. Il est montré que les valeurs de la résistance au cisaillement non drainé Su, déduites des essais pressiométriques et au cône effilé préforés, sont beaucoup plus élevées que celles obtenues au pressiomètre autoforeur et au scissomètre. Par contre, les modules de cisaillement G sont beaucoup plus faibles dans les essais pressiométriques et au cône effilé préforés. Ces différences sont probablement dues au remaniement et au déchargement initial du sol, causés par le forage des avant-trous utilisés pour effectuer les essais au pressiomètre et au cône effilé préforés. Les problèmes d’interprétation peuvent être aussi le résultat de l’existence de pressions latérales au repos très élevées dans le dépôt argileux. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents the results of an exploratory analysis of falling weight deflectometer (FWD) data collected on a large project about the spring thaw behaviour of pavements. The test site includes four test sections, two of which are conventional flexible pavement structures, whereas the other two are built with a cement-treated base. The aim of this study is to verify the applicability of using FWD time history data to evaluate damage to a road during the thawing period. The applicability of the analysis techniques is verified through the phase angle and dissipated energy. The data analyzed were obtained from tests conducted with an FWD on one flexible pavement test section. The results obtained showed a clear difference between the winter, thawing, and summer periods. It was found that the phase angle and dissipated energy can be used to evaluate the road damage during the thawing period through quantification of the phase angle and dissipated energy. These factors can also be used to describe the pavement behaviour in terms of elasticity and viscoelasticity. Cet article présente les résultats d'une analyse exploratoire de données de déflectomètre à masse tombante (FWD) colligées lors d'un grand projet sur le comportement des chaussées lors du dégel du printemps. Le site d'essai comprend quatre sections : deux ont des structures conventionnelles de chaussée flexible et les deux autres sont construites sur une fondation traitée au ciment. L'objectif de l'étude est de vérifier l'applicabilité des données historiques FWD pour évaluer le dommage à la route durant la période de dégel. L'applicabilité des techniques d'analyse est vérifiée par l'angle de phase et l'énergie dissipée. Les données analysées ont été obtenues lors d'essais réalisés avec le déflectomètre à masse tombante sur une section d'essai de chaussé flexible. Les résultats montrent une différence évidente entre les périodes d'hiver, de dégel et d'été. Il s'est avéré que l'angle de phase et l'énergie dissipée peuvent être utilisés pour évaluer les dommages à la route durant la période de dégel en quantifiant l'angle de phase et l'énergie dissipée et en décrivant le comportement de la chaussée en termes d'élasticité et de viscoélasticité. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article presents information about the articles published in the August 1, 2004 issue of the journal "Canadian Journal of Botany." This issue is a collection of invited, peer-reviewed symposium papers from the 4th International Conference on Mycorrhizae held in Montreal, Quebec, in August 2003.

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The hydraulic conductivity of six compacted tills from northern Quebec with different grain-size distributions has been studied in saturated conditions in the laboratory. The results show that compaction conditions play an important role in hydraulic conductivity. When considering the hydraulic conductivities of specimens compacted at degrees of saturation greater than the optimum, there is a good correlation with the content of clay-size particles. This paper provides a good practical tool for evaluating preliminary hydraulic conductivity values of compacted tills from northern Quebec on the basis of their grain-size distribution and compaction conditions.Key words: till, hydraulic conductivity, grain-size distribution, compaction conditions.La conductivité hydraulique de six tills du nord québécois présentant des granulométries différentes a été étudiée en conditions saturées, en laboratoire. Les résultats montrent que les conditions de compactage jouent un rôle important dans la conductivité hydraulique qui en résulte. Lorsque l'on considère les conductivités hydrauliques mesurées sur des échantillons compactés à des degrés de saturation plus élevés que celui à l'optimum, on obtient une bonne corrélation avec le pourcentage de particules de dimensions argileuses. Cet article fournit donc un bon outil pratique pour une évaluation préliminaire de la conductivité hydraulique des tills du nord québécois sur la base de leur granulométrie et des conditions de compactage.Mots clés : till, conductivité hydraulique, granulométrie, conditions de compactage. [ABSTRACT FROM AUTHOR]

This paper concerns the petrogenesis of the 504 ± 3 Ma Mont Chagnon massif, the southern extension of the Orford ophiolite in the Quebec Appalachians. The evolution of this massif is summarized in three stages marked by different magmatic series. In the Late Cambrian, the onset of southeastern subduction of the Iapetus basin generated an immature oceanic island arc made up of light rare-earth-element-depleted tholeiites, now preserved in the massif as a portion of the intrusive crustal unit, the dyke complex, and part of the lower volcanic unit. A phase of arc splitting, and concomitant partial erosion of the crustal section, was shortly followed by the eruption of rhyolite genetically related to felsic and low-Ti dykes, and trondhjemite. The geochemistry of these magmas bear some similarities with boninitic series. We believe these liquids derived from the partial melting of the Iapetus amphibolitized oceanic crust, with that of its Laurentian-derived sediments and nearby peridotite, either found as a trapped sliver above the subducting slab or as the slab itself. The final stage, preserved in the massif as a part of the intrusive section, the upper volcanic rocks, and the late-stage dykes, represents the back-arc opening. An ocean-island component is involved in the back-arc related petrogenetic processes, producing magmas with compositions intermediate between arc tholeiites and enriched back-arc basin basalts. This is the first report that the Iapetus basin was locally closing as early as Late Cambrian in the southern Quebec area.Cet article traite de la pétrogenèse du massif du mont Chagnon, daté à 504 ± 3 Ma, qui est l'extension méridionale de l'ophiolite d'Orford dans les Appalaches du Québec. L'évolution de ce massif est résumée en trois étapes déterminées par des suites magmatiques différentes. Au Cambrien tardif, le début de la subduction vers le sud-est d'Iapetus a crée un arc insulaire océanique immature composé de tholéiites appauvries en terres rares légères, maintenant préservées dans le massif en tant qu'une portion de l'unité crustale intrusive, le complexe de dykes et une partie de l'unité volcanique inférieure. Une phase de division de l'arc, et l'érosion partielle concomitante de la section de la croûte, a été suivie de près par l'éruption de rhyolite, génétiquement reliée aux dykes felsiques et à ceux faibles en Ti, de même qu'à la trondhjémite. La géochimie de ces magmas comporte des similitudes avec les séries boninitiques. Nous croyons que ces liquides proviennent de la fusion partielle de la croûte amphibolitisée d'Iapetus, de ses sédiments dérivés du craton Laurentia et de la péridotite avoisinante, qui se trouvent soit coincés en tant qu'écaille au-dessus de la lithosphère en subduction ou soit en tant que lithosphère subductée elle-même. L'étape finale, préservée dans le massif en tant qu'une partie de la section intrusive, les roches volcaniques supérieures et les dykes tardifs, représente l'ouverture de l'arrière-arc. Une composante d'île océanique est impliquée dans les processus pétrogénétiques reliés à l'arrière-arc, produisant des magmas dont les compositions sont intermédiaires entre les tholéiites d'arc et les basaltes enrichis de bassins d'arrière-arc. Ceci est le premier rapport qu'Iapetus se refermait localement aussi tôt que le Cambrien tardif dans le sud du Québec.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Highlights the Peptide Receptors: From Gene to Therapy, an international multidisciplinary symposium held in Montreal, Quebec from July 29 to August 2, 2001. Contents of the symposium; Sponsors of the symposium; List of papers presented in the symposium.

Highlights the Peptide Receptors: From Gene to Therapy, an international multidisciplinary symposium held in Montreal, Quebec in 2001. Topics discussed in the symposium; List of papers presented in the symposium.

The preconsolidation pressure and overconsolidation ratio profiles are the most important factors related to the mechanical behaviour of clay deposits. They are interpreted on the basis of a limited number of laboratory tests, but the near-continuous information provided by the piezocone can allow local data to be extrapolated to an entire site. Numerous methods have been proposed for relating piezocone data to preconsolidation pressure and the overconsolidation ratio, but their validity is still uncertain. In this paper, nine methods are compared on the basis of data collected on 31 sensitive clay sites in Quebec whose preconsolidation pressure profiles are well known. Each method is briefly presented and the most promising are identified. The simplest method, which directly relates preconsolidation pressure to net tip resistance, also appears to be the most effective.Key words: clay, preconsolidation pressure, overconsolidation ratio, piezocone, correlations.Les profils de pression de préconsolidation et du rapport de surconsolidation constituent les éléments les plus importants en ce qui concerne le comportement mécanique des dépôts argileux. Leur évaluation se fait par un nombre limité d'essais de laboratoire, mais les données fournies par le piézocône de manière presque continue peuvent permettre une extrapolation à l'ensemble du site de ces données locales. De nombreuses méthodes ont été proposées pour corréler les données du piézocône et la pression de préconsolidation ou le rapport de surconsolidation mais leur validité est encore incertaine. Dans le présent article, neuf méthodes sont examinées à partir de données provenant de 31 sites d'argile sensible de la province du Québec pour lesquels les profils de pression de préconsolidation sont bien connus. Chaque méthode est brièvement présentée et les méthodes les plus intéressantes sont identifiées. Il semble que la relation entre la pression de préconsolidation et la résistance en pointe nette, qui est la plus simple, est aussi la plus efficace.Mots clés : argile, pression de préconsolidation, rapport de surconsolidation, piézocône, corrélations. [ABSTRACT FROM AUTHOR]

This paper presents the results of an extensive field investigation of several instrumented road sections in the Province of Quebec, Canada. Falling-weight deflectometer tests, static load tests on embedded plates at different depths, large dynamic cone penetration (DCP) tests, and piezocone tests (CPTU) were performed to study the mechanical response of the pavement. A correlation between elastic deformation modulus inferred from the plate load tests and DCP penetration index was obtained for nine different sites. A correlation between the equivalent elastic modulus of uniform subgrade soils and piezocone tip resistance was also established using data from the falling-weight deflectometer. A procedure for calculating the deflection basin for any pavement system placed over a more complex subgrade stratigraphy was proposed using these correlations. The proposed procedure was validated on two sites and its performance was adequate, since the calculated deflection basins agreed well with the measured deflection basins.Key words: penetration test, piezocone, deflection, pavement, in situ.Cet article présente les résultats d'une étude élaborée sur le terrain de plusieurs sections de route instrumentées dans la Province de Québec, Canada. Des essais au déflectomètre à masse tombante, de chargement statique sur des plaques enfouies à différentes profondeurs, de pénétration dynamique d'un gros cône (DCP), et de piézocône (CPTU) ont été réalisés pour étudier la réponse mécanique de la chaussée. Une corrélation entre le module de déformation élastique déduit des essais de chargement de plaques et l'indice de pénétration DCP a été obtenue pour neuf sites différents. Une corrélation entre le module élastique équivalent des sols de fondations uniformes et la résistance en pointe du piézocône a aussi été établie au moyen des données du déflectomètre à masse tombante. En partant de ces corrélations, on a proposé une procédure pour calculer le bassin de déflexion pour n'importe quel système de chaussée reposant sur une stratigraphie d'infrastructure complexe. La procédure proposée a été validée sur deux sites et sa performance a été adéquate puisque les bassins de déflexion calculés concordaient bien avec les valeurs mesurées.Mots clés : essai de pénétration, piézocône, déflexion, chaussée, in situ.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

To analyze the effects of strain rate and viscoplastic strain on consolidation of natural clay, this paper presents a nonlinear viscoplastic model in which viscoplastic behaviour is modeled by a unique effective stress (σ'[sub v] ) – viscous strain (ℇ[sub v] ) – viscous strain rate (ℇ[sup ·] [sub v] ) relationship. The proposed model can consider the effects of strain rate and viscoplastic strain on consolidation, to take into account the difference in strain rate between laboratory and field conditions, and the combined processes of generation and dissipation of pore pressure during consolidation. This model can also predict the behaviour of clay during stepwise loading, constant rate of strain, and relaxation of effective stress. The predicted values using numerical analysis are compared with measured values in laboratory tests and in situ, under an embankment built on soft clay at Berthierville, Quebec. It is possible to estimate the consolidation behaviour of natural clay with reasonable accuracy using the proposed nonlinear viscoplastic model.Key words: consolidation, soft clay, strain rate, viscoplastic, relaxation.Dans le but d'analyser les effets de la vitesse de déformation et de la déformation viscoplastique sur la consolidation de l'argile naturelle, cet article présente un modèle viscoplastique non linéaire dans lequel le comportement est modélisé par une relation unique contrainte effective-déformation visqueuse-vitesse de déformation visqueuse σ'[sub v] – ℇ[sub v] – ℇ[sup ·] [sub v] . Le modèle proposé peut prendre en considération les effets de la vitesse de déformation et de la déformation viscoplastique sur la consolidation pour tenir compte de la différence dans les vitesses de déformation entre les conditions en laboratoire et sur le chantier, de même que les processus combinés de génération et de dissipation de la pression interstitielle durant la consolidation. Ce modèle peut aussi prédire le comportement de l'argile en incluant le chargement par étape, la vitesse de déformation constante, et la relaxation de la contrainte effective. Les valeurs prédites au moyen de l'analyse numérique sont comparées avec celles mesurées dans les essais en laboratoire et in situ sous un remblai construit sur de l'argile molle à Berthierville, Québec. Il est possible d'estimer le comportement en consolidation de l'argile naturelle avec une précision raisonnable au moyen du modèle viscoplastique non linéaire proposé. Mots clés : consolidation, argile molle, vitesse de déformation, viscoplastique, relaxation.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

The seismic attenuation in concrete has seldom been studied, although it is an important parameter for survey design. In this paper, the seismic Q factor is estimated from data measured at the Carillon dam. Three methods were used for this study: amplitude decay yielding a value of 5.1 ± 1.6, spectral ratio giving a value of 8.3 ± 3.5, and a value of 7.5 ± 14.9 was obtained from the rise-time technique. These values are weak compared with what is generally observed in rocks, and slightly lower than values obtained on laboratory concrete samples. However, the average P wave velocity measured on the investigated area is 4081 ± 95 m·s[sup –1] , an indication of the good quality of the material. Consequently, this strong attenuation could be attributed on one hand to energy loss, and on the other hand to scattering caused by the intrinsic cement–aggregate composition of concrete. It is also possible that an inadequate sensor coupling had the effect of reducing the observed Q value. Key words: seismic attenuation, concrete dams, microseismic monitoring, coupling.Paramètre important pour la planification de levés sismiques, l'atténuation sismique a été peu étudiée dans les bétons. Dans cet article, le facteur de qualité sismique Q est évalué au barrage de Carillon selon les méthodes du rapport des amplitudes, du rapport des spectres d'amplitude et du temps de montée. Les mesures obtenues sont respectivement de 5,1 ± 1,6, de 8,3 ± 3,5 et de 7,5 ± 14,9. Ces valeurs sont faibles en regard de ce qui est généralement observé dans les roches, et légèrement plus faibles que des valeurs mesurées sur des bétons en laboratoire. Par ailleurs, le béton de la partie du barrage auscultée présente une vitesse d'onde P moyenne de 4081 ± 95 m·s[sup –1] , indiquant une bonne qualité du matériau. En conséquence, la forte atténuation pourrait être attribuable d'une part à la perte de l'énergie sismique sous forme de friction, et d'autre part à une atténuation de diffusion occasionnée par la composition ciment-granulat intrinsèque du béton. Il est également possible qu'un couplage inadéquat des capteurs ait pour effet de réduire la valeur observée de Q. Mots clés : atténuation sismique, barrages en béton, auscultation microsismique, couplage. [ABSTRACT FROM AUTHOR]

In this study, 206 breast fillets were purchased from grocery stores in the province of Quebec and evaluated for the presence of different quality defects. Of these fillets, 48.5% showed breast muscle myopathies (BMM), 19.4% showed pale, soft, and exudative (PSE), and 6.8% showed dark, firm, and dry (DFD) attributes. BMM were equally present (P > 0.05) in fillets of economical, commercial, and high-quality brands, while PSE-like fillets were more present in economical brands (P < 0.0001). The combined effect of BMM and DFD induced significantly higher counts of Salmonella (P = 0.03) and Enterobacteriaceae (P = 0.03) in myopathic than in unaffected fillets. These quality defects also altered the nutritional quality of breast meat: BMM-affected fillets had greater fat content (P < 0.0001) and DFD fillets had lower protein content (P = 0.041) than normal fillets. The technological quality was only slightly impacted by BMM, while PSE-like fillets had higher cooking loss (P = 0.009) and a tougher texture after cooking (P < 0.0001) than DFD fillets. For the first time, this study confirmed the presence of multiple quality issues in the Quebec poultry supply chain, and provided valuable data to support future research efforts. [ABSTRACT FROM AUTHOR]

The Kamouraska Formation is a quartz-arenitic unit of latest Cambrian - earliest Ordovician age in the Quebec Appalachians that was deposited by hyperconcentrated to concentrated density flows in a meandering submarine canyon on the continental slope bordering the Iapetus Ocean, as outlined in a companion paper. Detailed petrographic study of the quartz arenites of the Kamouraska Formation combined with scanning electron microscopy of grain surface textures suggests that the quartz sands are of eolian origin having been derived from an inland desert or, less likely, a barrier beach dune system. Transport of the mature quartz-arenitic sand onto the shelf and deposition into the deep sea was not accompanied by substantial mixing with material from other sources thus preserving the inherited eolian characteristics. A modern analogue for the eolian interpretation of the deep-sea quartz-arenite beds is as follows: thick, Late Pleistocene eolian sand beds on a modern abyssal plain in the East Atlantic referred to as eolian-sand turbidites that were deposited in the deep sea during glacial sea level lowstands when eolian sand transport to canyon heads was enabled by an exposed and shortened shelf. Similarly, an established sea level lowstand at the Cambro-Ordovician boundary would have facilitated the introduction of eolian sand of the Kamouraska Foundation into canyon heads on the upper slope from where turbidity currents and related density flows were triggered. Correlation of the Kamouraska Formation with the quartz arenites of the Cairnside Formation of Quebec (Keeseville Formation in northern New York State, Nepean Formation in southern Ontario) links the deep-sea deposits with remnants of an inland dune system. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Reviews is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the Archean Blake River Group, mafic to intermediate fragmental units have controversially been proposed to have formed during the collapse of a giant submarine caldera. This paper describes and interprets these rocks, summarizing their physical characteristics, inferred origins, age relationships, and geochemical signatures. The widespread Stadacona member, south of Rouyn-Noranda, consists of several hundred metres of bedded volcaniclastic rocks interpreted to have been mostly deposited from aqueous density currents fed directly by explosive eruptions. The magmas involved in these eruptions were plagioclase-phyric, tholeiitic to transitional basalts. The similarly widespread D'Alembert tuff, in the northern part of the Blake River Group, shares many physical characteristics with the Stadacona member and is thought to have a similar origin. However, the D'Alembert tuff is approximately six million years younger than the Stadacona member. It is composed mostly of transitional to calc-alkaline andesites and basaltic andesites with very distinct trace element profiles. Volcaniclastic rocks from other areas, such as Tannahill Township in Ontario and the Monsabrais area in Quebec, are interpreted to represent mostly in situ to remobilized hyaloclastite, with no explosive eruptions involved in their genesis. Our observations and interpretations are not compatible with models in which the volcaniclastic units are emplaced during a catastrophic event in relation with the collapse of a giant caldera. Instead, the fragmental rocks were produced by various mechanisms at many distinct times during the evolution of the Blake River Group. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)