Sustainable forest management using decision theaters : rethinking participatory planning

Involving stakeholders in the decision-making process can be very complex and time consuming. Decision theater (DT), which enables the combination of visualization and decision modeling capabilities together with human capacity of insight and interaction, is proposed for addressing this challenging problem in the forest sector. A generic framework for designing DTs to support participatory planning in the forest sector is proposed. To enable DT implementation and support decision-making in the DT in the province of Québec, Canada, the conceptual design of a decision-support system called Forest Community-DSS (FC-DSS) has been developed. Implementing FC-DSS along with other technologies in a DT environment can contribute to engage the stakeholders in the decision-making process by increasing participation frequency, collecting more inputs from the stakeholders, supporting the development and evaluation of alternative options and the selection of preferred alternatives. A DT-based collaboration approach would contribute to address the multiple issues of the stakeholders involved in participatory planning in Québec. Other Canadian provinces and other countries facing similar issues can benefit from the proposed approach

Effet des conditions de broyage sur les propriétés structurales et magnétiques des nanomatériaux FeAl élaborés par mécanosynthèse

148 p. : ill. ; 30 cmDes poudres nanocristallines (Fe0.8Al0.2)100-xSix et (Fe0.75Al0.25)100-xSix ont été élaborées par mécanosynthèse à l'aide d'un vario-broyeur planétaire innovant " pulverisette 4 " à haute énergie. La formation des composés ainsi que les propriétés physiques ont été étudiées en fonction du pourcentage de silicium, x, (x = 0, 5, 10, 15 et 20 at%) en utilisant les techniques de Diffraction des rayons X (DRX), Microscopie Electronique à Balayage (MEB), analyse des rayons X par Dispersion d'Energie (EDX) , Spectroscopie MÀssbauer et magnétométrie à échantillon vibrant (VSM). Les micrographies MEB des poudres des deux séries montrent que leurs particules se présentent sous forme d'agglomérats qui possèdent une forme lamellaire pour les alliages sans silicium puis prennent progressivement une forme arrondie accompagnés d'un affinement dans leurs tailles avec l'augmentation de pourcentage de Si. L'analyse EDX a montré que la composition finale de chaque échantillon est très proche de sa composition nominale ainsi que l'absence de contamination. L'affinement des spectres de DRX obtenus a révélé la formation de la solution solide désordonnée monophasé pour chaque échantillon des deux séries, en raison de l'occupation aléatoire des sites de la maille conventionnelle (cc) de À-Fe par les atomes d'Al et de Si. Cet affinement a aussi montré que l'augmentation de la teneur en Si dans les deux séries d'alliages a pour effet de diminuer linéairement le paramètre de maille. D'autre part, la taille moyenne des grains, (nm), décroît pour les deux séries mais d'une manière différente. L'analyse des spectres MÀssbauer, collectés à 300 K, correspondant aux échantillons des deux séries (Fe0.8Al0.2)100-xSix et (Fe0.75Al0.25)100-xSix confirme les résultats obtenus par la DRX pour ce qui concerne la formation de la solution solide FeAl et Fe(Al, Si) après 72 h de broyage. De plus, elle a fournit des informations supplémentaires, que la DRX n'a pas pu révéler, sur l'existence de différents environnements magnétiques pour les atomes de fer et la formation des phases non ferromagnétiques. Les courbes d'hystérésis, prises à 300 K, de tous les échantillons des deux séries montrent que tous les alliages sont des matériaux magnétiques dou

Évolution de la phénologie de la nidification des oiseaux à la Forêt Montmorency de 1995 à 2020

La phénologie de migration de nombreuses espèces d'oiseaux a changé depuis quelques décennies, mais à ce jour on ne sait pas jusqu'à quel point de tels changements se reflètent sur la phénologie de la nidification. Étudier la nidification des oiseaux de la forêt boréale, souvent surnommée la crèche d'oiseaux de l'Amérique du Nord, est semé de défis à cause de l'étendue géographique. J'ai évalué la phénologie de nidification des oiseaux chanteurs durant les 26 dernières années dans une forêt boréale de l'Est du Canada, la Forêt Montmorency. Je me suis basée sur l'observation du transport de nourriture chez les adultes comme indice du statut parental, en tenant compte de la détection imparfaite de ce statut par l'entremise de modèles hiérarchiques d'occupation de sites. Les modèles ont révélé un recul de deux semaines de la saison de nidification chez les résidents et les migrateurs de courte distance et d'un mois chez les migrateurs de longue distance durant la période d'étude. Ces résultats vont à l'encontre des attentes liées à l'avancée de la migration printanière en Amérique du Nord et nous rappellent l'intérêt des études régionales lorsque nous nous intéressons à la phénologie de la reproduction.The migration phenology of many bird species has changed over the past few decades, but the extent to which such changes affect the nesting phenology remains little known. Studying avian reproduction in the boreal forest, often referred to as North America's bird nursery, is challenging because of the large size of this biome. I evaluated songbird nesting phenology during the past 26 years in a boreal forest in eastern Canada, Forêt Montmorency. I used the observation of food transport in adults as an indicator of parental status, considering the imperfect detection of this status through hierarchical models of site occupancy. Contrary to expectations related to the advance of spring migration in North America, models revealed a delay of two weeks in the nesting season for residents and short-distance migrants and of one month in long-distance migrants during the study period. These results remind us of the value of regional studies when we are interested in reproductive phenology

Surface functionalization with polyethylene glycol and polyethyleneimine improves the performance of graphene-based materials for safe and efficient intracellular delivery by laser-induced photoporation

Nanoparticle mediated laser-induced photoporation is a physical cell membrane disruption approach to directly deliver extrinsic molecules into living cells, which is particularly promising in applications for both adherent and suspension cells. In this work, we explored surface modifications of graphene quantum dots (GQD) and reduced graphene oxide (rGO) with polyethylene glycol (PEG) and polyethyleneimine (PEI) to enhance colloidal stability while retaining photoporation functionality. After photoporation with FITC-dextran 10 kDa (FD10), the percentage of positive HeLa cells (81% for GQD-PEG, 74% for rGO-PEG and 90% for rGO-PEI) increased approximately two-fold compared to the bare nanomaterials. While for Jurkat suspension cells, the photoporation efficiency with polymer-modified graphene-based nanomaterial reached as high as 80%. Cell viability was >80% in all these cases. In addition, polymer functionalization proved to be beneficial for the delivery of larger macromolecules (FD70 and FD500) as well. Finally, we show that rGO is suitable for photoporation using a near-infrared laser to reach 80% FD10 positive HeLa cells at 80% cell viability. We conclude that modification of graphene-based nanoparticles with PEG and especially PEI provide better colloidal stability in cell medium, resulting in more uniform transfection and overall increased efficiency

Hexamolybdenum Clusters Supported on Graphene Oxide: Visible-Light Induced Photocatalytic Reduction of Carbon Dioxide into Methanol

International audienceHexamolybdenum (Mo6) cluster-based compounds namely Cs2Mo6Bri8Bra6 and (TBA)2Mo6Bri8Bra6 (TBA = tetrabutylammonium) were immobilized on graphene oxide (GO) nanosheets by taking advantage of the high lability of the apical bromide ions with oxygen-functionalities of GO nanosheets. The loading of Mo6 clusters on GO nanosheets was probed by Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM) and elemental mapping analyses. The developed GO-Cs2Mo6Bri8Brax and GO-(TBA)2Mo6Bri8Brax composites were then used as heterogeneous photocatalysts for the reduction of CO2 under visible light irradiation. After 24 h visible light illumination, the yield of methanol was found to be 1644 and 1294 μmol.g-1cat for GO-Cs2Mo6Bri8Brax and GO-(TBA)2Mo6Bri8Brax, respectively. The quantum yields of methanol by using GO-Cs2Mo6Bri8Brax and GO-(TBA)2Mo6Bri8Brax as catalysts with reference to Mo6 cluster units presented in 0.1g amount of catalyst were found to be 0.015 and 0.011, respectively. The role of immobilized Mo6 clusters-based compounds on GO nanosheets is discussed to understand the photocatalytic mechanism of CO2 reduction into methano

Peroxynitrite Activity of Hemin-Functionalized Reduced Graphene Oxide

Conducting interfaces modified with reduced graphene oxide (rGO) have shown improved electrochemical response for different analytes. The efficient formation of functionalized rGO based materials is thus of current interest for the development of sensitive and selective biosensors. Herein, we report a simple and environmentally friendly method for the formation of a hemin-functionalized rGO hybrid nanomaterial that exhibits remarkable sensitivity to peroxynitrite (ONOO−) in solution. The hemin-functionalized rGO hybrid nanomaterial was formed by mixing an aqueous solution of graphene oxide (GO) with hemin and sonicating the suspension for 5 h at room temperature. In addition to playing a key role in biochemical and electrocatalytic reactions, hemin has been proven to be a good reducing agent for GO. The sensitivity of the peroxynitrite sensor is ≈7.5 ± 1.5 nA mM−1 with a detection limit of 5 ± 1.5 nM