129 research outputs found

    TRIAD zoning in Quebec: Experiences and results after 5 years

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    The TRIAD approach to forest management involves dividing the forest into 3 zones, each with its own management\ud objectives, but with the overall goal of increasing the ecological and economic sustainability of the forest. For the past 5 years, we have been experimenting with TRIAD zoning in central Quebec, incorporating social interests into the original concept of TRIAD management. Results generally indicate that this approach is economically viable, socially acceptable, and preferable ecologically in this area. Although much remains to be done, thus far the consensus among the\ud various project participants is that this approach may be a good fit for the public forest of Canada

    An environmentally benign antimicrobial nanoparticle based on a silver-infused lignin core

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    Silver nanoparticles have antibacterial properties, but their use has been a cause for concern because they persist in the environment. Here, we show that lignin nanoparticles infused with silver ions and coated with a cationic polyelectrolyte layer form a biodegradable and green alternative to silver nanoparticles. The polyelectrolyte layer promotes the adhesion of the particles to bacterial cell membranes and, together with silver ions, can kill a broad spectrum of bacteria, including Escherichia coli, Pseudomonas aeruginosa and quaternary-amine-resistant Ralstonia sp. Ion depletion studies have shown that the bioactivity of these nanoparticles is time-limited because of the desorption of silver ions. High-throughput bioactivity screening did not reveal increased toxicity of the particles when compared to an equivalent mass of metallic silver nanoparticles or silver nitrate solution. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles

    The nature of singlet exciton fission in carotenoid aggregates.

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    Singlet exciton fission allows the fast and efficient generation of two spin triplet states from one photoexcited singlet. It has the potential to improve organic photovoltaics, enabling efficient coupling to the blue to ultraviolet region of the solar spectrum to capture the energy generally lost as waste heat. However, many questions remain about the underlying fission mechanism. The relation between intermolecular geometry and singlet fission rate and yield is poorly understood and remains one of the most significant barriers to the design of new singlet fission sensitizers. Here we explore the structure-property relationship and examine the mechanism of singlet fission in aggregates of astaxanthin, a small polyene. We isolate five distinct supramolecular structures of astaxanthin generated through self-assembly in solution. Each is capable of undergoing intermolecular singlet fission, with rates of triplet generation and annihilation that can be correlated with intermolecular coupling strength. In contrast with the conventional model of singlet fission in linear molecules, we demonstrate that no intermediate states are involved in the triplet formation: instead, singlet fission occurs directly from the initial 1B(u) photoexcited state on ultrafast time scales. This result demands a re-evaluation of current theories of polyene photophysics and highlights the robustness of carotenoid singlet fission.This work was supported by the EPSRC (UK) (EP/G060738/ 1), the European Community (LASERLAB-EUROPE, grant agreement no. 284464, EC’s Seventh Framework Programme; and Marie-Curie ITN-SUPERIOR, PITN-GA-2009-238177), and the Winton Programme for the Physics of Sustainability. G.C. acknowledges support by the European Research Council Advanced Grant STRATUS (ERC-2011-AdG No. 291198). J.C. acknowledges support by the Royal Society Dorothy Hodgkin Fellowship and The University of Sheffield’s Vice- Chancellor’s Fellowship scheme.This is the final published version. It was first made available by ACS at http://pubs.acs.org/doi/abs/10.1021/jacs.5b01130

    Bim and Mcl-1 exert key roles in regulating JAK2V617F cell survival

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    <p>Abstract</p> <p>Background</p> <p>The JAK2<sup>V617F </sup>mutation plays a major role in the pathogenesis of myeloproliferative neoplasms and is found in the vast majority of patients suffering from polycythemia vera and in roughly every second patient suffering from essential thrombocythemia or from primary myelofibrosis. The V617F mutation is thought to provide hematopoietic stem cells and myeloid progenitors with a survival and proliferation advantage. It has previously been shown that activated JAK2 promotes cell survival by upregulating the anti-apoptotic STAT5 target gene Bcl-xL. In this study, we have investigated the role of additional apoptotic players, the pro-apoptotic protein Bim as well as the anti-apoptotic protein Mcl-1.</p> <p>Methods</p> <p>Pharmacological inhibition of JAK2/STAT5 signaling in JAK2<sup>V617F </sup>mutant SET-2 and MB-02 cells was used to study effects on signaling, cell proliferation and apoptosis by Western blot analysis, WST-1 proliferation assays and flow cytometry. Cells were transfected with siRNA oligos to deplete candidate pro- and anti-apoptotic proteins. Co-immunoprecipitation assays were performed to assess the impact of JAK2 inhibition on complexes of pro- and anti-apoptotic proteins.</p> <p>Results</p> <p>Treatment of JAK2<sup>V617F </sup>mutant cell lines with a JAK2 inhibitor was found to trigger Bim activation. Furthermore, Bim depletion by RNAi suppressed JAK2 inhibitor-induced cell death. Bim activation following JAK2 inhibition led to enhanced sequestration of Mcl-1, besides Bcl-xL. Importantly, Mcl-1 depletion by RNAi was sufficient to compromise JAK2<sup>V617F </sup>mutant cell viability and sensitized the cells to JAK2 inhibition.</p> <p>Conclusions</p> <p>We conclude that Bim and Mcl-1 have key opposing roles in regulating JAK2<sup>V617F </sup>cell survival and propose that inactivation of aberrant JAK2 signaling leads to changes in Bim complexes that trigger cell death. Thus, further preclinical evaluation of combinations of JAK2 inhibitors with Bcl-2 family antagonists that also tackle Mcl-1, besides Bcl-xL, is warranted to assess the therapeutic potential for the treatment of chronic myeloproliferative neoplasms.</p

    Overview of the assessment practices of occupational therapists working in Quebec

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    Description. L'évaluation du client est primordiale dans la pratique de l'ergothérapie, notamment pour établir les priorités de traitement et pour vérifier l'efficacité des interventions. Les pratiques évaluatives des ergothérapeutes sont cependant peu documentées. But. Dresser un portrait des pratiques évaluatives des ergothérapeutes du Québec selon les dimensions personne-environnement-occupation et les clientèles. Méthodologie. Une enquête transversale a été réalisée à l'aide d'un sondage en ligne envoyé aux ergothérapeutes du Québec. Résultats. En pédiatrie, les ergothérapeutes utilisent majoritairement des outils standardisés des aptitudes physiques et neurologiques. L'évaluation d'adultes cible principalement les aptitudes physiques et la productivité. Auprès des aînés, l'évaluation repose surtout sur les aspects fonctionnels, particulièrement les aptitudes physiques, les soins personnels et la sécurité à domicile, et sur le dépistage des difficultés cognitives. Implications pour la pratique. L'évaluation ergothérapique serait généralement axée sur les aptitudes physiques. Pour assurer une approche holistique, l'occupation et l'environnement devraient être davantage considérés dans l'évaluation.Abstract : Background. In occupational therapy practice, client assessments are essential for establishing treatment priorities and determining the effectiveness of interventions. However, occupational therapists' assessment practices are not well documented. Purpose. This work aimed to provide an overview of the assessment practices of Quebec occupational therapists based on the person–environment–occupation components and clienteles. Method. A cross-sectional survey was conducted using an online survey that was sent to occupational therapists in Quebec. Findings. In paediatrics, occupational therapists tend to use standardized tools to assess physical and neurological abilities. Adult assessment focuses mainly on physical abilities and productivity. For seniors, assessment focuses mainly on functional aspects (physical abilities, personal care, and home safety) and screening for cognitive difficulties. Implications. Occupational therapy assessment mostly focuses on physicial abilities. To ensure a holistic approach, more occupational and environmental components should be included in the assessment practices

    Are community forestry principles at work in Ontario’s County, Municipal, and Conservation Authority forests?

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    Ontario’s County, Municipal and Conservation Authority forests have received little attention within the academic literature on community forestry in Canada. These “Agreement Forests”, as they were once called, are a product of the early 20th century and have been under local government management since the 1990s. Most are situated in Southern Ontario. In this article we investigate the extent to which community forestry principles are at work in these forests. Three principles—participatory governance, local benefits and multiple forest use—are analyzed using a composite score approach derived from survey data collected from nearly all of these forest organizations (response rate = 80%). Results indicate that most of these organizations do display attributes associated with community forestry principles, including a local governance process, public participation activities, local employment and multiple-use management. Traditional forestry employment is less strong than in similar studies of Crown land community forests; however, there is an important emphasis on non-timber activities. The article concludes that the County, Municipal and Conservation Authority forests represents a unique approach, which reflects the specific geographic and socio-economic context in which it resides. / Les forêts cantonales, municipales et des offices de conservation de l’Ontario n’ont reçu qu’une faible couverture dans la littérature scientifique sur la foresterie communautaire au Canada. Ces « forêts d’entente (Agreement Forests) », comme on les appelait avant, ont été créées au début du XXe siècle et gérées par les autorités locales depuis les années 1990. La majeure partie de ces forêts sont situées dans le sud de l’Ontario. Dans cet article, nous cherchons à voir jusqu’à quel point les principes de foresterie communautaire sont mis en application dans ces forêts. L’étude porte sur trois principes – la gouvernance participative, les bénéfices locaux et l’utilisation polyvalente de la forêt – qui furent analysés avec l’approche de résultats combinés utilisant les données d’un sondage effectué auprès de presque toutes ces organisations forestières (taux de réponse = 80 %). Les résultats indiquent que la plupart de ces organisations présentent effectivement certains attributs rappelant les principes de la foresterie communautaire, incluant un processus de gouvernance locale, des activités de participation du public, l’embauche locale et l’aménagement à des fins d’utilisation polyvalente. Les emplois forestiers traditionnels ont moins d’importance que dans les études similaires des forêts communautaires établies sur des terres publiques; par contre, on accorde beaucoup d’importance aux activités sans prélèvement de bois. L’article conclut que les forêts cantonales, municipales et des offices de conservation constituent une approche unique qui reflète bien le contexte géographique et socio-économique spécifique dans lequel elles sont établies.Financial support from the Fonds québécois de la recherché sur la société et la culture and the Social Sciences and Humanities Research Council.http://pubs.cif-ifc.org/doi/10.5558/tfc2012-13
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