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Over 50 years ago, a marine estuary was converted to a wastewater stabilization basin for treatment of primarily pulp and paper effluent. As a result, the basin was immediately converted to a 'freshwater' environment and subsequently accumulated a thin layer of black, organic-rich sediment containing varying amounts of dioxins and furans, metals, polycyclic aromatic hydrocarbons, and petroleum hydrocarbons. Previous studies on the site have shown that the majority of this contamination in the basin appears to have been contained within this black sediment layer and not migrated to any significant extent into the original underlying marine sediments. The purpose of this study is to examine sediment porewater chemistry changes that have occurred over 51 years of operation of the stabilization basin with the intent of better understanding why contamination has been minimal into the underlying natural marine sediments. Field and laboratory testing is presented to characterize the physical, chemical, and mineralogical sediments in the basin. Porewater chemistry profiles obtained from this work are then used in combination with a one-dimensional contaminant transport model to examine the role of diffusion, sorption, and upward groundwater flux in the porewater profiles found for the sediments. Key words: contaminant migration, diffusion, sorption, barrier, pulp and paper Il y a plus de 50 ans, un estuaire marin a ete converti en bassin de stabilisation des eaux usees pour le traitement d'effluents principalement issus du secteur de la pate a papier. En consequence, le bassin a ete immediatement converti en un environnement << d'eau douce >> et a ensuite accumule une fine couche de sediments noirs, riches en matieres organiques, contenant des quantites variables de dioxines et de furanes, de metaux, d'hydrocarbures aromatiques polycycliques et d'hydrocarbures petroliers. Des etudes anterieures sur le site ont montre que la majorite de cette contamination dans le bassin semble avoir ete contenue dans cette couche de sediments noirs et n'a pas migre de maniere significative dans les sediments marins sousjacents originaux. Le but de cette etude est d'examiner les changements de la chimie de l'eau interstitielle des sediments qui se sont produits au cours des 51 annees d'exploitation du bassin de stabilisation dans l'intention de mieux comprendre pourquoi la contamination a ete minimale dans les sediments marins naturels sous-jacents. Des essais sur le terrain et en laboratoire sont presentes pour caracteriser les sediments physiques, chimiques et mineralogiques du bassin. Les profils chimiques des eaux interstitielles obtenus a partir de ce travail sont ensuite utilises en combinaison avec un modele unidimensionnel de transport des contaminants pour examiner le role de la diffusion, de la sorption et du flux ascendant des eaux souterraines dans les profils des eaux interstitielles trouves pour les sediments. [Traduit par la Redaction] Mots-cles : migration des contaminants, diffusion, sorption, barriere, pate et papier, 1. Introduction Boat Harbour (BH) is the stabilization basin, which until 2020, comprised part of a wastewater treatment facility located near Pictou, Nova Scotia, Canada. A tidal estuary until 1967, [...]

Wood discoloration was investigated in 721 paper birch (Betula papyrifera Marsh.) trees from 146 sites across the managed forest of Quebec, Canada. Discoloration was present at breast height in 85% of trees, but its impact was limited in terms of tree basal area and volume, with proportions of 6.4% and 3.6%, respectively. These two measures were strongly correlated. Discoloration changed wood appearance but had no effect on microfibril angle and modulus of elasticity. Discolored wood was nevertheless denser, probably due to the accumulation of colored extractives. Predictive models were also developed and applied to 415 711 paper birch trees from 51689 inventory plots across the province to study regional variation. Higher proportions of discolored basal area were obtained in the southwestern areas of the province where the climate is warmer and drier. In these areas, paper birch trees are larger and, likely, support bigger branches which can cause larger columns of discoloration when broken. Lower proportions were found in eastern regions where snowfall is more abundant. Smaller, more flexible branches in trees growing in these areas could explain this result. This study confirms the feasibility of large-scale mapping of wood discoloration in standing trees based on forest inventory and climate data. Key words: paper birch, wood discoloration, wood properties, regional variation, climate. La coloration du bois a ete etudiee chez 721 tiges de bouleau blanc (Betula papyrifera Marsh.) provenant de 146 sites repartis a travers la foret amenagee du Quebec, au Canada. La coloration etait presente chez 85 % des arbres mais son impact etait faible : elle occupait seulement 6,4 % de la surface terriere et 3,6 % du volume des tiges. Ces deux variables etaient etroitement correlees. La coloration a modifie l'apparence du bois mais n'a eu aucun effet sur l'angle des microfibrilles ni sur le module d'elasticite. Le bois colore est neanmoins plus dense, vraisemblablement a cause de l'accumulation de matieres extractibles colorees. Des modeles de prediction ont egalement ete elabores et appliques a 415 711 tiges de bouleau blanc provenant de 51689 parcelles d'inventaire reparties a travers la province pour etudier la variation regionale. De plus grandes proportions de surface terriere de bois colore ont ete obtenues dans les regions du sud-ouest de la province oU le climat est plus chaud et plus sec. Dans ces regions, les tiges de bouleau blanc sont plus grosses et supportent probablement de plus grosses branches qui peuvent causer de plus grandes colonnes de coloration lorsqu'elles cassent. De plus faibles proportions de coloration ont ete trouvees dans les regions de l'est oU les chutes de neige sont plus abondantes. Le fait que les arbres croissant dans ces regions aient des branches plus petites et plus flexibles pourrait expliquer ce resultat. Cette etude confirme que la cartographie de la coloration a grande echelle dans les arbres sur pied est realisable a partir de donnees d'inventaire forestier et du climat. [Traduit par la Redaction] Mots-cles: bouleau blanc, coloration du bois, proprietes du bois, variation regionale, climat., Introduction Paper birch (Betula papyrifera Marsh.) is one of the most abundant hardwood species in Canada with a natural range from eastern to western coast (Safford et al. 1990). In [...]

We use a dynamic, global computable general equilibrium (CGE) model to capture the economic impacts of internet adoption, modeled through reduced demand in the newsprint and printing and writing paper (pulp and paper) industries. Global newsprint consumption is estimated to fall dramatically by 2030. We rely on estimates from another study that captures the change in global pulp and paper consumption using the global forest products model (GFPM), based on two scenarios: (i) full per capita internet adoption by 2100 and (ii) more rapid full internet adoption by 2050. We incorporate reductions in pulpwood consumption into a global multiregional dynamic CGE model to estimate economy- wide impacts in Canadian provinces, the United States, and the rest of the world. Results indicated that the year 2050 internet adoption scenario would result in a reduction in cumulative discounted gross domestic product (GDP) by as much as 17% in some regions of Canada, reduce GDP by 5.8% in the United States, and increase GDP by 3.3% in the rest of the world from 2006 to 2030. These findings highlight the costs of internet adoption, leaving net benefit analysis of adoption to future work. Key words: internet adoption, pulp and paper, computable general equilibrium, global impacts. Nous avons utilise un modele d'equilibre general calculable (EGC) dynamique et mondial pour saisir les repercussions economiques de l'adoption de l'Internet, modelisees selon la reduction de la demande dans l'industrie du papier journal et des papiers d'impression et d'ecriture (pates et papiers). On estime que la consommation mondiale de papier journal chutera dramatiquement d'ici 2030. Nous nous appuyons sur les estimations d'une autre etude qui saisit le changement de la consommation mondiale des pates et papiers en utilisant le modele mondial des produits forestiers sur la base de deux scenarios : l'adoption de l'Internet par tous les habitants (i) d'ici 2100 et (ii) plus rapidement, soit d'ici 2050. Nous avons inclus les reductions de consommation de bois de pate dans un modele mondial et multiregional d'EGC dynamique pour estimer les impacts sur l'ensemble de l'economie dans les provinces canadiennes, les Etats-Unis et le reste du monde. Les resultats demontrent que le scenario d'adoption de l'Internet d'ici 2050 aurait pour consequence une reduction du PIB cumule actualise de pres de 17 % dans certaines regions du Canada et de 5,8 % aux Etats-Unis ainsi qu'une augmentation de 3,3 % du PIB dans le reste du monde entre 2006 et 2030. Ces conclusions mettent en evidence les couts de l'adoption de l'Internet laissant l'analyse des benefices nets de l'adoption a des recherches ulterieures. [Traduit par la Redaction] Mots-cles: adoption de l'Internet, pates et papier, equilibre general calculable, impacts mondiaux., 1. Introduction The demand for newspaper and other print media has begun to decline worldwide after decades of growth (see Fig. 1). This reduction can potentially be attributed to a [...]

We analyze the total factor productivity (TFP) of the pulp and paper industry in three Canadian provinces (British Columbia, Ontario, and Quebec) and in three United States (US) states that are contiguously located south of the border (Washington, Illinois, and Maine) over the period of 1971 to 2005. We find that the industry in the three Canadian provinces had much higher TFP growth rates in the era following the Free-Trade Agreement (FTA) signed in 1988. In terms of productivity level, this relative TFP surge allowed the industry in Ontario and British Columbia to move ahead of Illinois and Washington, respectively; however, Quebec trailed further Maine, which is the overall leader in the sample. Our results in this particular case reveal that the Canadian pulp and paper industry did not contribute to the overall Canada-US productivity gap. Key words: total factor productivity, income convergence, pulp and paper industry, Free-Trade Agreement (FTA), productivity puzzle. Nous avons analyse la productivity totale des facteurs (PTF) de l'industrie des pates et papiers dans trois provinces canadiennes (Colombie-Britannique, Ontario et Quebec) et trois etats americains situes immediatement au sud de la frontiere (Washington, Illinois et Maine) pour la periode de 1971 a 2005. Nous avons remarque que l'industrie dans les trois provinces canadiennes avait un taux de croissance de la PTF bien plus elevee pour la periode suivant l'Accord de libre -echange signe en 1988. En ce concerne le niveau de productivite, l'augmentation relative de la PTF a permis a l'industrie de l'Ontario et de la Colombie-Britannique de devancer respectivement l'lllinois et Washington; cependant le Quebec accuse toujours un certain retard sur le Maine qui est le chef de file dans notre echantillon. Dans ce cas particulier, nos resultats revelent que l'industrie canadienne des pates et papiers ne contribue pas a l'ecart global de productivite entre le Canada et les Etats -Unis. [Traduit par la Redaction] Mots-cles : productivite totale des facteurs, convergence des revenus, industrie des pates et papier, Accord de libre-echange, casse-tete de la productivite., 1. Introduction 'Canada has a serious productivity growth problem. The statistical evidence is unambiguous and of long standing.' (1) Real gross domestic product (GDP) per capita increased at a slightly [...]

A novel, simple, and low-cost spray painting technique has been developed for the fabrication of microfluidic paper-based devices. The devices that we developed utilize aerosol spray paint to build hydrophobic barriers and employ a hole puncher to obtain paper-based patterned layers and paper dots without using any specialized instruments (e.g., without a laser cutter). The entire manufacturing process is extremely simple, inexpensive, and rapid, which means that it can be applied broadly. Furthermore, the application of the device to iron detection was demonstrated. A linear relationship between the colour value and the iron concentration was observed from 0 to 0.02 g/L. The developed microfluidic paper-based device for iron detection exhibited a low detection limit (0.00090 g/L), good selectivity, and acceptable recovery. Key words: microfluidic paper-based device, spray painting, colorimetry, iron. Nous avons mis au point une nouvelle technique de pulverisation de peinture simple et peu couteuse pour fabriquer des dispositifs microfluidiques a base de papier. A l'aide ces dispositifs, nous avons employe de la peinture en aerosol pour fabriquer des barrieres hydrophobes et, au moyen d'un poincon, nous avons pu obtenir des couches a motifs en papier et des rondelles de papier sans avoir recours a des instruments specialises (p. ex., sans dispositif de coupe au laser). Tout le processus de fabrication est extremement simple, rapide et peu couteux, ce qui permet son application a grande echelle. Par ailleurs, nous avons demontre l'application du dispositif a la detection du fer. Nous avons observe une relation lineaire entre l'intensite de la couleur et la concentration du fer dans l'intervalle de 0 a 0,02 g/L. Le dispositif microfluidique a base de papier employe applique a la detection du fer a montre une faible limite de detection (0,00090 g/L), une bonne selectivite et un taux de recuperation acceptable. [Traduit par la Redaction] Mots-cles : dispositif microfluidique a papier, peinture en aerosol, colorimetrie, fer., Introduction Microfluidic paper-based analytical devices ([mu]PADs) have emerged at the intersection of engineering, physics, chemistry, biochemistry, nanotechnology, and biotechnology, with practical applications in the design of systems in which low [...]

RNA interference (RNAi) is a useful tool to assess gene function by knocking down expression of a target gene and has been used successfully in domestic and laboratory organisms. However, the use of RNAi for functional genomics has not fully extended into ecological model organisms in natural environments. Assessment of gene function in the wild is important because gene function can be environmentally and context dependent. Here, we present a case study using RNAi to assess gene function in wild paper wasps Polistes metricus, to test roles for two candidate genes (NADH dehydrogenase (NADHdh) and retinoid and fatty acid binding protein (RfaBp)) in the development of reproductive castes. Previous studies have shown that these genes are upregulated in larvae that become queens compared to workers, but this pattern was reversed in the laboratory, making field-based studies necessary. We orally administered dsRNA to larvae in field colonies and found evidence of a short-term knockdown followed by a compensatory rebound in expression for RfaBp. We also observed the predicted worker-like decrease in lipid stores in NADHdh dsRNA treated wasps, suggesting a possible role for NADHdh in caste development. We discuss our results in the context of challenges for using RNAi for functional genomics in ecological model organisms in the field. Key words: RNA interference, ecological genomics, Polistes, eusociality, castes. L'interference a l'ARN (RNAi) est un outil utile pour etudier la fonction des genes en abaissant l'expression d'un gene cible et il a ete employe avec succes chez des organismes domestiques ou de laboratoire. Cependant, l'emploi du RNAi en genomique fonctionnelle n'est pas encore largement repandu chez des organismes ecologiques modeles en conditions naturelles. L'etude de la fonction genique a l'etat sauvage est importante car la fonction peut etre dependante de l'environnement ou du contexte. Dans ce travail, les auteurs presentent une etude de cas ou le RNAi est utilise pour etudier la fonction genique chez la guepe Polistes metricus sauvage, specifiquement pour examiner le role de deux genes candidats (NADH dehydrogenase (NADHdh) et Retinoid and fatty acid binding protein (RfaBp)) dans le developpement des castes reproductives. Des etudes anterieures ont montre que ces genes etaient exprimes plus fortement chez les larves qui devenaient des reines que chez celles devenant des ouvrieres, mais cette expression se trouvait inversee en laboratoire et il devenait ainsi necessaire d'examiner cette question en conditions naturelles. Les auteurs ont administre oralement des dsRNA a des larves dans des colonies sur le terrain et ont trouve des evidences d'une reduction a court terme du gene RfaBp, suivie d'une hausse compensatoire. Ils ont egalement observe la diminution predite au sein des reservoirs lipidiques chez les types d'ouvrieres parmi les guepes de traitees avec un dsRNA ciblant NADHdh. Cela suggere un role possible de NADHdh dans le developpement des castes. Les auteurs discutent de leurs resultats dans le contexte des defis poses par l'emploi du RNAi en genomique fonctionnelle chez des organismes ecologiques modeles sur le terrain. [Traduit par la Redaction] Mots-cles: interference a l'ARN, genomique ecologique, Polistes, eusocialite, castes., Introduction RNA interference (RNAi) is a powerful tool for functional genomics, which utilizes organisms' innate molecular machinery to knock down expression of target genes (Agrawal et al. 2003). RNAi has [...]

Translating to the Community (T2C) is a social biorepository designed to advance new diagnostic tools and realign community--clinical processes, with the aim to mitigate the short- and long-term impacts of fetal alcohol spectrum disorder (FASD) as well as prenatal alcohol exposure and its co-morbidities and behaviors. In this paper, we describe the evolution of this repository as a new translational partnership to advance a precision-medicine approach to FASD. Key to its evolution was a partnership between academic researchers, Indigenous communities, families, and a regional diagnostic clinic. We further describe the rationale for social biobanking, the type of banking, ethical engagement of families, communities, and clinics, their roles in repository design, governance, translation, and research activities, types of data collected from families, and how the study data are managed, reported, and accessed. The repository design includes biological samples, social-contextual healthsurvey data, and clinical data (which are linkable to administrative data) from community and clinical cohorts of diagnosed children, children prenatally exposed but not diagnosed, children suspected to have had a prenatal exposure, and related siblings, biological parents, and unrelated children and their parents. From these cohorts and families, potential studies drawing on this data will shed light on various risk factors, social and biological pathways, and service utilization issues, with the aim to implement primary and secondary prevention and intervention strategies. Key words: fetal alcohol spectrum disorder, social genomic biorepository, translational studies, community and family participation, Indigenous, ethics and governance. << Translating to the Community (T2C) >> (Transfert a la communaute) est un bio-referentiel social concu pour faire progresser le developpement de nouveaux outils diagnostiques et realigner la communaute et les processus cliniques, dans le but d'attenuer les impacts a court et long termes des troubles du spectre de l'alcoolisation foetale (TSAF), de l'exposition prenatale a l'alcool, de leurs comorbidites et des comportements qui leur sont associes. Dans cet article, les auteurs decrivent l'evolution de cereferentiel comme nouvel outil departenariat translationnel afin de promouvoir une approche de medecine de precision dans les TSAF. L'element cle de cette evolution a ete un partenariat entre les chercheurs universitaires, les communautes autochtones, les familles et une clinique regionale de diagnostic. Ils decrivent plus en detail les raisons d'etablir une bio-banque sociale, le type de stockage, l'engagement ethique des familles, des communautes et des cliniques, leur role dans la conception et la gouvernance du referentiel, ainsi que dans les activites de recherche et de transfert realisees, les types de donnees recueillies des familles et comment ces donnees d'etudes sont gerees, rapportees et rendues accessibles. Comme il a ete concu, le referentiel comprend des echantillons biologiques, des donnees d'enquetes sociales, contextuelles et de sante, ainsi que des donnees cliniques (qui peuvent etre correlees aux donnees administratives) a partir des cohortes des communautes et cliniques d'enfants diagnostiques, d'enfants exposes a l'alcool durant la periode prenatale mais non diagnostiques, d'enfants que l'on croit avoir ete exposes a l'alcool durant la periode prenatale et leurs freres et soeurs, leurs parents biologiques, des enfants non apparentes et leurs parents. A partir de ces cohortes et des familles, les etudes potentielles s'appuyant sur ces donnees feront la lumiere sur differents facteurs de risque, les parcours sociaux et biologiques, et les problematiques d'utilisation des services, dans le but de mettre en oeuvre des strategies de prevention et d'intervention primaires et secondaires. [Traduit par la Redaction] Mots-cles : troubles du spectre de l'alcoolisation foetale, bio-referentiel social, etudes translationnelles, participation des communautes et des familles, Autochtone, ethique et gouvernance., Introduction Globally, fetal alcohol spectrum disorder (FASD), a result of a prenatal exposure to alcohol (prenatal alcohol exposure; PAE), is the most common neurodevelopmental condition, exceeding 1% worldwide with an [...]

R.M. QUIGLEY AWARDThe R.M. Quigley Award is given out each year to the best paper published in Canadian Geotechnical Journal (CGJ) in the previous year. Bob Quigley was one of [...]

Abstract: A flexible, lightweight, and high conductivity current collector is the key element that enables fabrication of a high-performance, flexible lithium-ion battery. Here, we report a thin, lightweight, and flexible [...]

Better pulp quality control, especially relating to product sheet strength, can offer an important means to improve the market superiority of a pulp. However, aside from lignin content, few pulp properties can be easily measured in a timely manner for process control. The present report proves a principle on a novel Raman system and a systematic chemometric approach, allowing for rapid spectral data acquisition and definitive spectrochemical analysis of wet pulp under harsh manufacturing conditions. By incorporating sophisticated chemometrics strategies that combine wavelet transform with a tem-plate-oriented genetic algorithm feature selection and partial least squares multivariate classification, this instrument system extracts maximum analytical information from raw Raman spectra to accurately predict the physicomechanical properties of sheet products. Our work has tested and refined these routines by drawing upon the systematic analysis of 26 bleached soft-wood kraft pulps formulated to yield challenges representative of those encountered in common pulp fibre and sheet analyses. Satisfactory calibration results suggest that a Raman gauge can be developed that has the capacity to continuously assay pulp to predict the physicomechanical properties of sheet paper in real time. Un meilleur controle de la qualite de la pate, particulierement en lien avec la solidite du papier en feuille, peut of-frir un moyen important pour augmenter la superiorite de la pate sur le marche. Cependant, mis a part la teneur en lignine, peu de proprietes de la pate peuvent etre facilement mesurees assez rapidement pour la commande de processus. Cet article demontre le principe d'un nouveau systeme Raman et d'une approche chimiometrique systematique qui permet l'acquisition rapide de donnees spectrales et l'analyse spectrochimique definitive de la pate humide dans des conditions de fabrication difficiles. En incorporant des strategies sophistiquees de chimiometrique qui combinent la transformation en ondelettes avec la selection de caracteristiques au moyen d'algorithmes genetiques bases sur un gabarit et la classification multivariee par les moindres carres partiels, ce systeme instrumental extrait un maximum d'information analytique a partir des spectres bruts de Raman pour predire avec precision les proprietes physicomecaniques du papier en feuille. Nous avons teste et raffine ces routines en se basant sur l'analyse de 26 pates kraft blanchies de resineux formulees de maniere a offrir des defis representa-tifs de ceux que l'on rencontre dans l'analyse courante des pates de fibre et du papier en feuille. Des resultats de calibration satisfaisants indiquent qu'il est possible de mettre au point une jauge Raman capable de tester en continue la pate pour predire les proprietes physicochimiques du papier en feuille en temps reel. [Traduit par la Redaction], Introduction Raman spectroscopy offers a unique means to rapidly measure pulp fibre properties and processing-related changes in these properties, nondestructively, with little or no sample preparation and little sensitivity to [...]

This paper studies substitution between main categories of imported pulp and paper products and between imported and domestic pulp and paper products in the US market. A restricted translog subcost function approach was employed to derive the elasticity of substitution. The results suggest that Canadian pulp and paper products are competitive and have maintained their competitiveness in the US market, and therefore, the challenges faced by the Canadian pulp and paper industry are not because of the loss of its product competitiveness but are due to other reasons such as declining demand for paper products in the United States. It seems that if the Canadian pulp and paper industry wants to retain its dominant position in the world market place, it will have to create global reach and develop new markets. Cet article s'interesse a la substitution entre les principales categories de produits de pates et papiers et entre les produits de pates et papiers importes et domestiques sur le marche americain. Une approche basee sur une fonction translog restreinte de sous-cout a ete utilisee pour determiner l'elasticite de substitution. Les resultats indiquent que les produits de pates et papiers canadiens sont competitifs, qu'ils ont maintenu leur competitivite sur le marche americain et que les defis rencontres par l'industrie canadienne des pates et papiers ne sont pas dus a une perte de competitivite de ses produits mais plutot a d'autres facteurs tels que la diminution de la demande pour les produits du papier aux Etats-Unis. Il semble que si l'industrie canadienne des pates et papiers desire maintenir sa position dominante sur le marche mondial, elle devra adopter une perspective globale et developper de nouveaux marches. [Traduit par la Redaction], Introduction The Canadian pulp and paper products industry is a cornerstone of the Canadian economy and one of the major contributors to Canadian exports. Any deterioration in the performance of [...]

Objective: To evaluate the toxicity of extracts from disposable chopsticks, toothpicks, and paper cups on L-929 cells. Methods: We followed national standards to prepare the extracts from disposable chopsticks, toothpicks, and paper cups used for the cell culture media, and the morphology of L-929 cells was observed with an optical microscope. The loss rate for adherent cells was evaluated with the trypan blue exclusion method, and cell proliferation was determined using the WST-1 assay. Results: Compared with the control group, the cells cultured in media containing the extracts showed signs of apoptosis and necrosis after culturing for 4 or 7 days, and the loss rate for adherent cells was significantly increased (P < 0.05). An obvious decrease in cell viability was also observed (P < 0.05). Conclusion: The extracts from disposable chopsticks, toothpicks, and paper cups can affect the growth and proliferation of L-929 cells and are potentially toxic to humans. Key words: disposable daily necessities, cytotoxicity, WST-1 assay. Objectifs : Evaluer la toxicite d'extraits de baguettes, de cure-dents et de verres de carton jetables sur les cellules L-929. Methode : Les extraits de baguettes, de cure-dents et de verres de carton jetables ont ete utilises pour preparer le milieu de culture cellulaire selon les standards nationaux, et la morphologie des cellules L-929 a ete observee en microscopie optique. Le taux de perte de cellules adherentes a ete evalue par coloration d'exclusion au bleu de trypan et la proliferation cellulaire a ete determinee par un dosage WST-1. Resultats : Comparativement au groupe controle, les cellules cultivees dans le milieu contenant les extraits presentaient des signes d'apoptose et de necrose apres une culture de 4 ou 7 jours, et le taux de perte de cellules adherentes etait significativement accru (P < 0,05). Une diminution evidente de la viabilite cellulaire etait aussi observee (P < 0,05). Conclusion : Les extraits de baguettes, de cure-dents et de verres de carton jetables peuvent affecter la croissance et la proliferation des cellules L-929 et sont potentiellement nefastes pour la sante humaine. [Traduit par la Redaction] Mots-cles : produit de necessite quotidienne jetable, cytotoxicite, dosage WST-1., Introduction Disposable chopsticks, toothpicks, and paper cups are daily necessities; however, there is a deficiency with respect to the safety data for these items. For example, during production, residues from [...]

Abstract: Aerated stabilization basins (ASBs) currently account for about one third of the pulp and paper industry's secondary treatment capacity. We surveyed mills with ASBs to analyze design and operating [...]

Aagard, Troels Aitken, Alec Akoglu, Ahmet Allard, Michel Ansdell, Kevin Archibald, Donnelly Arnaud, Emmanuelle Atkinson, Gail Averianov, Alexander Azizi, Hossain Baird, Graham Barendregt, Rene Barr, Sandra Bauer, Bernard Bedard, Jean [...]

Organizers International Union of Forest Research Organizations (IUFRO) Working Group 8.01.06 (Boreal and Alpine Forest Ecosystem Unit), co-sponsored by Working Groups 7.03.07 (Population Dynamics of Forest Insects) and 7.03.05 (Ecology [...]

Red heartwood, a dark nonhomogenous discolouration in paper birch trees (Betula papyrifera 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. Resume: Le coeur rouge, une coloration foncee irreguliere du bois presente chez certains bouleaux blancs (Betula papyrifera Marsh.), limite les applications et les usages du bois scies a des produits non visibles de faible valeur, ce qui entraine une perte de valeur substantielle. La presence et la distribution du coeur rouge ont ete etudiees chez 12 bouleaux blancs croissant dans la province de Quebec, au Canada. L'arbre le plus jeune avait 62 ans a hauteur de poitrine et le plus vieux avait 86 ans; la moyenne d'age etait de 75 ans. Dans cette etude, 225 defauts externes relies a des cicatrices de branche et a des fourches, precedemment consideres comme points d'origine du coeur rouge, ont ete identifies et mesures. La distribution du coeur rouge a ete cartographiee numeriquement et l'effet de ces defauts externes sur la surface et la forme du coeur rouge a ete examine dans chaque arbre. Les resultats montrent que le coeur rouge est initie a partir d'un defaut externe et que plusieurs defauts externes peuvent contribuer au developpement d'une colonne de bois de coeur rouge le long de l'axe longitudinal de la tige. Le coeur rouge semblait etre initie surtout a partir de defauts externes situes a la base de la tige. Un exercice de modelisation a indique que la largeur de la colonne de bois de coeur rouge a l'interieur d'un arbre sur pied peut etre estimee a partir de la largeur des cicatrices de branche et de leur hauteur a partir du sol. La vigueur de l'arbre ne pouvait etre reliee a la proportion de bois de coeur rouge a l'interieur d'un arbre sur pied. Une analyse tridimensionnelle de la forme des billes pourrait possiblement etre utilisee pour detecter la presence du coeur rouge dans une bille avant d'etre transformee afin d'optimiser le schema de debit de la bille. [Traduit par la Redaction], Introduction Physical and visual characteristics influence both the value and utilization of wood in appearance products such as furniture and wood flooring. Among these characteristics, wood colour is a determinant [...]

Technological growth in production and efficient utilization of input factors are the two biggest contributors to total factor productivity (TFP). TFP of the four major forest industries (logging, pulp and paper, sawmill, and veneer and plywood industries) of Ontario are compared by analyzing their production structures using duality theory in production and costs. The study uses annual data of output and four inputs--labour, capital, energy and materials--from 1967 to 2003. Different restrictions on the translog cost function are applied to each industry to determine the cost function that best describes each industry's technology, which is further used to estimate Morishima elasticities of substitution, ownprice and cross-price elasticities, rate of technological change, and TFP. The production structure of sawmill and veneer and plywood industries is found to be linear homogeneous and homothetic, and that of logging and pulp and paper industries is non-homothetic. Further, Hicks neutral technological change for all four industries is rejected, indicating that the production structure in all four industries is biased in favour of certain inputs and against others. This suggests that policies that improve the efficiency of each industry should focus on input-saving factors of that industry, thereby improving its competitive position. Resume: Le progres technologique dans la production et l'utilisation efficace des intrants sont les deux elements qui contribuent le plus a la productivite globale des facteurs (PGF). La PGF de quatre grandes industries forestieres (exploitation forestiere, pates et papiers, sciage ainsi que placages et contreplaques) de l'Ontario est comparee en analysant leur structure de production et en utilisant la theorie de la dualite dans la production et les couts. L'etude utilise les donnees annuelles de production et de quatre intrants--la main-d'oeuvre, le capital, l'energie et les matieres premieres--de 1967 a 2003. La fonction de cout translog de chaque industrie est restreinte de differentes facons afin de determiner la fonction de cout qui decrit le mieux la technologie de chaque industrie. Cette fonction est ensuite utilisee pour evaluer les elasticite s de substitution de Morishima, les elasticites-prix et les elasticites-prix croises, le taux de changement technologique et la PGF. Les structures de production de l'industrie du sciage et de l'industrie des placages et contreplaques sont lineaires homogenes et homothetiques alors que celles de l'industrie de l'exploitation forestiere et de l'industrie des pates et papiers ne sont pas homothetiques. De plus, il n'y a pas de progres technique neutre au sens de Hicks dans les quatre industries, indiquant que leur structure de production favorise certains inputs et en neglige d'autres. Ces resultats indiquent que les politiques visant a ameliorer l'efficacite de chaque industrie devraient se concentrer sur les mesures d'economie specifiques aux intrants que privilegie chaque industrie et ainsi ameliorer leur position concurrentielle. [Traduit par la Redaction], Introduction With over 72 million hectares of forest land, representing 16% of Canada's total estimated forests, the province of Ontario is a critical contributor to Canada's forest products industries (Ontario [...]

The in-vitro culture of arbuscular mycorrhizal fungi on excised roots, especially when performed on bicompartmented Petri dishes, has proven to be an efficient system for the production of root-free fungal material. However, even after the contact between fungal hyphae and the excised roots in the proximal root compartment has occurred, up to several weeks may be required for the fungal runner hyphae to cross the median Petri dish wall and reach the distal fungal compartment. This delay is particularly long for the cultivation of slow-growing strains that usually colonize the substrate less aggressively. The delay is due to the difficulty the runner hyphae have in crossing the median Petri dish wall that separates compartments. To facilitate the passage of the fungus across the median wall, a 'paper bridge' system has been devised and tested with a number of arbuscular mycorrhizal fungal strains. This method substantially accelerated fungal propagation and simplified the manipulations necessary. The proposed paper-bridge system is described and its advantages discussed. Key words: arbuscular mycorrhizal fungi. Glomus, paper bridge, in-vitro culture. La culture in vitro des champignons mycorhiziens arbusculaires sur racines excisees, notamment en boites de Petri bi-compartintentees, constitue un systeme efficace de production axenique de champignon. Bien que le contact hyphe-racines s'effectue rapidement dans le compartiment racine, plusieurs semaines peuvent etre requises par les hyphes pour traverser dans la partie distale du systeme. Ce delai, particulierement long pour les souches a croissance lente et peu agressives, est du principalement a la difficulte pour les hyphes de traverser la cloison centrale qui separe les compartiments. Afin de remedier a celle difficulte un >> poni de papier << teste sur une diversite de souches myeorhiziennes s'est avere efficace pour accelerer la propagation fongique tout en simplifiant substantiellement les manipulations. Le systeme est decrit et ses avantages discutes. Mots-cles: champignons mycorhiziens arbusculaires. Glomus, pont papier, culture in vitro., Introduction Since 1975, when Hepper and Mosse first established cultures of arbuscular mycorrhizae (AM) on excised roots, tremendous improvements have been made with the use of Ri T-DNA transformed roots [...]

Abstract: 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, [...]

R.M. QUIGLEY AWARD The R.M. Quigley Award is given out each year to the best paper published in Canadian Geotechnical Journal (CGJ) in the previous year. Bob Quigley was one [...]

The kinetics of the spontaneous, proton- and [Al.sup.III]-catalysed hydrolyses of the C1--O4' bond in 1,5-anhydro-cellobiitol have been measured at elevated temperatures (125.0-220.0°C). Data for the first two processes extrapolate to the expression k = (8.6 ± 2.1 x [10.sup.-16]) + (1.4 ± 0.2 x [10.sup.-9-pH]) [s.sup.-1] at 25°C. These room-temperature figures were used to model cellulose depolymerization by the af Ekenstam equation. The spontaneous process is too slow to contribute to loss of paper strength on aging, and even the acid-catalysed process is significant only below ~pH 4.0. However, the spontaneous hydrolysis readily accounts for the reduction of cellulose degree of polymerization (DP) during alkaline (e.g., kraft) pulping of cellulose fibres. Efficient electrophilic catalysis by [Al.sup.III] was observed at 150.0°C in 0.1 mol/L succinate buffers of room temperature pH 3.05 and 3.35 ([k.sub.2] = 8.1 ± 0.4 x [10.sup.-3] and 4.2 ± 0.2 x [10.sup.-3] (mol/L)-1 [s.sup.-1], respectively). The apparent activation energy of the [Al.sup.III]-catalysed process was 31 ± 4 kJ [mol.sup.-1], lower than that of the proton-catalysed path, suggesting the electrophilic catalysis increases in importance as the temperature approaches ambient. Consequently, it appears that the culprit in the impermanence of 'rosin-alum'-sized paper is [Al.sup.III], directly acting as a Lewis acid, not the [Al.sup.III] hydration sphere as a Bronsted acid Conservation measures should either address this or be generic (e.g., low-temperature storage). Key words: cellulose, hydrolysis, kraft pulping, paper conservation, rosin-alum sizing. Resume : Operant a des temperatures elevees (125,0 a 220,0°C), on a mesure les vitesses des reactions d'hydrolyse, spontanee et catalysees par le proton ou l'aluminium(III), de la liaison C1--O4' du 1,5-anhydrocellobiitol. Les donnees pour les deux premiers processus conduisent a l'expression k = (8,6 ± 2,1 x [10.sup.-16]) + (1,4 ± 0,2 x [10.sup.-9-pH]) [s.sup.-1] extrapolee a 25°C. On a utilise ces valeurs a la temperature ambiante comine modele pour la depolymerisation de la cellulose par l'equation de af Ekenstam. Le processus spontane est trop lent pour contribuer a une perte de la force du papier avec l'age; le processus catalyse par un acide n'est significatif qu'a des pH inferieurs a environ 4,0. Toutefois, l'hydrolyse spontanee permet d'expliquer facilement la reduction du degre de polymerisation (DP) de la cellulose durant le traitement alcalin (kraft) des fibres de cellulose. On a observe une catalyse electrophile efficace par l'aluminium(III) a 150,0°C, dans des tampons de succinate, a la temperature ambiante et a des pH de 3,05 et 3,35 ([k.sub.2] = 8,1 ± 0,4 x [10.sup.-3] et 4,2 ± 0,2 x [10.sup.-3] [(mol/L).sup.-1] [s.sup.-1] respectivement). L'energie d'activation apparente pour le processus catalyse par l'aluminium(III) est de 31 ± 4 kJ [mol.sup.-1], inferieure a celle du processus catalyse par le proton, ce qui suggere que la catalyse electrophile augmente en importance lorsque la temperature tend vers la temperature ambiante. En consequence, il semble que le coupable de la non permanence du papier collage a la rosine et a l'alun serait l'aluminium(III) qui agirait directement comine acide de Lewis et non pas la sphere d'hydratation de l'aluminium(III) qui agirait comine un acide de Bronsted. Les mesures de conservation devraient tenir compte de ces conclusions ou etre generiques, tel qu'un entreposage a basse temperature. Mots cles : cellulose, hydrolyse, pulpage alcalin, conservation du papier, traitement a la rosine et a l'alun. [Traduit par la Redaction], Introduction The loss of mechanical strength of cellulose fibres with age is an important limiting factor in the preservation of paper documents and, to a lesser extent, textiles. The degradation [...]

Part 2 of a special issue of selected papers from the IACS 4th Cardiovascular Forum for Promoting Centers of Excellence and Young Investigators held in Sherbrooke, Quebec, Canada, on 22-24 [...]

Abstract: This study investigated the use of bark and combined paper sludge to develop a suitable plant growth substrate and to establish a vegetation cover on bark-covered land. Field experiments [...]

Abstract: The decay of coarse woody debris is a key component in the formation of forest soil and in the biogeochemical cycles of Ca and Mg. We tracked changes in [...]

This article was written to serve as an introduction to this issue of the Canadian Journal of Chemistry that honors the contributions to chemistry of Professor D.R. Arnold. It summarizes the observations reported in a communication that appeared in the Journal of the American Chemical Society 30 years ago in June 1973. This historically important communication laid the foundation for his program on the photochemical generation and reactivity of radical ions in solution and also served as a guide for a developing area of interest of many other research groups. Key words: photochemical electron transfer, radical cations, photo NOCAS, benzylic radicals.

Procurement for forest companies with pulp and paper mills aims to ensure that a sufficient volume of wood supply enters the production process. Numerous suppliers and contract types are available; however, their selection is a complex decision for procurement managers.In addition, managers typically dedicate a portion of their wood fiber demand to each group of suppliers, which is referred to as a portfolio strategy. Despite the available literature in contract selection, the consideration of contract types and their characteristics have not been addressed for the complex procurement process. In this study, a mixed-integer optimization model is proposed to best select contracts for pulp and paper procurement. The challenge was to plan deliveries in each time period to satisfy the demand of raw material at the mills. The potential of this model is demonstrated with a case study based on characteristics from a forest company in Quebec, Canada. A comparison between traditional fixed and flexible contracts is presented. Different portfolio strategies are also evaluated for groups of suppliers to investigate potential improvements. Key words: contract selection, procurement, mixed-integer programming, pulp and paper, supplier portfolio strategy. Resume : L'approvisionnement des compagnies forestieres qui produisent des pates et papiers vise a garantir qu'un volume suffisant de bois entre dans le processus de production. Plusieurs fournisseurs et types de contrat sont disponibles. Cependant, leur selection est une decision complexe pour les responsables de l'approvisionnement. De plus, les gestionnaires assurent habituellement a chaque groupe de fournisseurs une partie de la demande en bois, pratiquant ainsi une strategie de portefeuille. Malgre la documentation disponible sur la selection de contrat, les types de contrat et leurs caracteristiques ne sont pas pris en compte dans le processus complexe d'approvisionnement. Dans cette etude, un modele d'optimisation mixte en nombres entiers est propose pour mieux selectionner les contrats d'approvisionnement pour les pates et papiers. Le defi consistait a planifier les livraisons a chaque periode afin de satisfaire la demande en matieres premieres des usines. Le potentiel de ce modele est demontre par une etude de cas sur la base des caracteristiques d'une entreprise forestiere au Quebec (Canada). Une comparaison entre les contrats traditionnels fixes et les contrats flexibles est presentee. Differentes strategies de portefeuille sont egalement evaluees pour des groupes de fournisseurs afin d'etudier les ameliorations potentielles. [Traduit par la Redaction] Mots-cles : selection de contrat, approvisionnement, programmation mixte en nombres entiers, pates et papier, strategie de portefeuille de fournisseurs., Introduction Procurement planning for a pulp and paper company (PPC) includes the selection and management of a set of supplier contracts. Many challenges in the relationship between a PPC and [...]

R.M. QUIGLEY AWARD The R.M. Quigley Award is given out each year to the best paper published in Canadian Geotechnical Journal (CGJ) in the previous year. Bob Quigley was one [...]

The Canadian Journal of Earth Sciences 'Best Paper Award' is an annual award given jointly by Canadian Science Publishing (CSP) and the Geological Association of Canada (GAC). It reflects the [...]

R.M. QUIGLEY AWARD The R.M. Quigley Award is given out each year to the best paper published in Canadian Geotechnical Journal (CGJ) in the previous year. Bob Quigley was one [...]

Understanding the nature of the shoot apical meristem (SAM) is fundamental to understanding plant development, particularly the distinctive combination of reiterative pattern generation and flexibility that characterize plant growth. During [...]

R.M. QUIGLEY AWARD The R.M. Quigley Award is given out each year to the best paper published in Canadian Geotechnical Journal (CGJ) in the previous year. Bob Quigley was one [...]

This study identifies new wood-based products with considerable potential and attractive markets, including textiles, liquid biofuels, platform chemicals, plastics, and packaging. We apply a mixed-methods review to examine how the position of the forest industry in a given value chain determines the respective production value. An assessment is provided as to the degree to which these emerging wood-based products could compensate for the foreseen decline of graphic paper markets in four major forest industry countries: USA, Canada, Sweden, and Finland. A 1%-2% market share in selected global markets implies a potential increase in revenues of 18-75 billion euros per annum in the four selected countries by 2030. This corresponds to 10%-43% of the production value of forest industries in 2016 and compares with a projected decline of graphic paper industry revenue of 5.5 billion euros by 2030. The respective impacts on wood use are manifold, as many of the new products utilize by-products as feedstock. The increase in primary wood use, which is almost entirely attributed to construction and to some extent textiles markets, would be in the range of 15-133 million [m.sup.3], corresponding to 2%-21% of the current industrial round-wood use in the selected countries.Key words: bioeconomy, competitiveness, forest industry, new wood-based products, value chain.Cette etude identifie de nouveaux produits a base de bois ayant un grand potentiel de developpement ainsi que des marches attrayants, tels que les textiles, les biocarburants liquides, les produits chimiques porteurs, les plastiques et les emballages. Nous avons utilise une revue des methodes mixtes pour analyser comment la position de l'industrie forestiere dans une chaine de valeur donnee determine la production de valeur pour les produits selectionnes. On presente une evaluation des chances que ces nouveaux produits puissent compenser le declin envisage dans le marche du papier graphique dans quatre principaux pays producteurs de bois: les Etats-Unis, le Canada, la Suede et la Finlande. Une augmentation de 1 a 2 % des parts de marche dans des secteurs precis represente un gain potentiel de revenus de 18 a 75 milliards d'euros par annee d'ici 2030, et ce pour les quatre pays. Cela represente 10 a 43 % de la valeur de la production des industries forestieres en 2016 comparativement a une diminution projetee des revenus de 5,5 milliards d'euros pour l'industrie du papier graphique d'ici 2030. Les impacts respectifs sur l'utilisation du bois sont nombreux, puisque plusieurs de ces nouveaux produits utilisent des sous- produits du bois comme matiere premiere. L'augmentation de l'utilisation primaire du bois, qui est presque entierement attribuable a la construction et jusqu'a un certain point aux marches du textile, representerait 15 a 133 milliards [m.sup.3], ce qui represente 2 a 21 % de l'utilisation actuelle du bois pour la transformation industrielle dans les pays selectionnes. [Traduit par la Redaction]Mots-cles: bioeconomie, competitivite, industrie forestiere, nouveaux produits du bois, chaine de valeur., 1. IntroductionThe 17 global sustainable development goals (United Nations (UN) 2015a) and the Paris climate agreement (UN 2015b) set internationally recognized goals that require transforming towards more sustainable business practices. [...]

The special issue is in two parts: Part 1 (August 2015) and Part 2 (September 2015). A list of the papers appearing in the August issue follows. Cette numero special [...]

The special issue is in two parts: Part 1 (August 2015) and Part 2 (September 2015). A list of the papers appearing in the September issue follows. Cette numero special [...]

Guest Editors / Directeurs scientifiques invites Istvan Baczko University of Szeged Szeged, Hungary Norbert Jost University of Szeged Szeged, Hungary Andras Varro University of Szeged Szeged, [...]

This position paper is the result of discussions between the Associate Editors and Editors of the Canadian Journal of Physiology and Pharmacology, which took place over the summer of 2013 [...]

This special issue celebrates the 25th anniversary of the International Conference on Amorphous and Nanocrystalline Semiconductors (ICANS). ICANS is a well-known premier conference in the area of amorphous and nanocrystalline [...]

It is always very satisfying for an editor to see excellent science published in our journal and to be able to recognize it with the Canadian Journal of Physics Best [...]

Physical organic chemistry provides us the tools and concepts to unravel the complexity of modern chemistry and biochemistry. The application of physical organic chemistry to problems ranging from biology, materials, [...]

The award for the best paper in the Canadian Journal of Physics for 2014 has been made for the paper, 'A review of imaging methods in analysis of works of [...]

Our Italian colleagues have taken a valuable initiative in selecting 20 of Professor Hutchinson's papers for facsimile reproduction in an attractive volume. The papers are supplemented by a two page [...]

The special issue is in 2 parts: Part 1 (February 2015) and Part 2 (March 2015). A list of the papers appearing in the February issue follows. Ce numero special [...]

The special issue is in 2 parts: Part 1 (February 2015) and Part 2 (March 2015). A list of the papers appearing in the March issue follows. Ce numero special [...]

The special issue is in two parts: Part 1 (January 2015) and Part 2 (February 2015). A list of the papers appearing in the February issue follows. Ce numero special [...]

On May 25, 2009, at the annual Geological Association of Canada luncheon, the first winner of the GAC--NRC Research Press, Canadian Journal of Earth Sciences Best Paper Award was announced. [...]

By nurturing new investigators, experienced scientists can simultaneously stimulate the creation of cutting-edge science and encourage burgeoning research careers. The 4th Young Investigators (YI) Forum of the CIHR Institute of [...]

The special issue is in two parts: Part 1 (August 2014) and Part 2 (October 2014). A list of the papers appearing in the October issue follows. Cette numero special [...]

The Canadian Journal of Earth Sciences 'Best Paper Award' is an annual award given jointly by Canadian Science Publishing (CSP) and the Geological Association of Canada. It reflects the Geological [...]

An international team of researchers led by Prof. Emeritus A.D. May are conducting research to improve our understanding of spectral line shapes and perfect their theoretical treatment. In recognition of [...]

It is always a pleasure when an excellent paper comes across the editor's desk, and especially so when it is a paper that is instructive to a wide audience. Often [...]