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Would transitioning from conventional to organic oat grains production reduce environmental impacts? A LCA case study in North-East Canada
Get PDFOat is mainly produced in northern latitude countries such as Canada, which is world's second largest producer. Hence it is necessary to study the environmental impacts of alternative farming systems to conventional oat production in order to improve its environmental performance. A life cycle assessment (LCA) was conducted to compare the environmental impacts and potential improvement opportunities of conventional and organic oat grain production using three different functional units (FU); per mass (t−1 of grains), surface area (ha−1) and gross sales income (1000 CAD−1). Most data were collected from a major farm located in Quebec, Canada. Our analysis shows that organic production is globally preferable based on the area and monetary FUs, whereas conventional production has lower impacts for 11 midpoint impact categories per ton of grain produced. In addition, organic production has higher damages on human health and ecosystem quality, both per ton of grain and per hectare. The relevance of each FU is discussed in the article. The hotspots of conventional oat production are the production and use of synthetic fertilizers, while those of organic oat production are the use of organic fertilizers and manure transportation. A sensitivity analysis showed that the choice of the N2O emission factor and phosphorus emission model considerably affects the magnitude of the impacts on climate change and freshwater eutrophication. Also, the implementation of green manure in the rotation system and the reduction of manure transport distances would significantly affect the results. In conclusion, our LCA case study does not support the idea that converting conventional oat grain production to organic agriculture would systematically decrease environmental impacts in eastern Canada. The environmental benefits largely depend on specific farmer practices and regional context
Modeling of the Heat Exchange, the Phase Change, and Dissolution of Alumina Injected in Electrolysis Cells
No full textFor the aluminum industry, understanding each step of alumina addition to the electrolysis bath is critical to reach optimal process conditions. From the injection to the complete dissolution, several physical and chemical mechanisms are interacting: solid and fluid mechanics, heat transfer, phase change, and dissolution. The mathematical model presented in this article uses the discrete element method (DEM) to consider the solid alumina powder as a granular material. It is coupled to the “smoothed particle hydrodynamics” (SPH) method to simulate the liquid electrolyte. The second layer of the model is used to calculate the heat transfer and coalescence of solid materials resulting from alumina sintering and bath solidification. Then, phase change is integrated into the model to consider the solidification of the bath. Sequentially, the dissolution of the alumina particles is reproduced and studied to analyse the injection of the alumina in the future
Predicting vertical LNAPL distribution in the subsurface under the fluctuating water table effect
Get PDFThe present study proposes a methodology for predicting the vertical LNAPL distribution within an aquifer by considering the influence of water table fluctuations. The LNAPL distribution is predicted by combining (i) information on air/LNAPL and LNAPL/water interface elevations with (ii) the initial elevation of the water table without LNAPL effect. Data used in the present study were collected during groundwater monitoring undertaken over a period of four months at a LNAPL-impacted observation well. In this study, the water table fluctuations raised the free LNAPL in the subsurface to an elevation of 206.63 m, while the lowest elevation was 205.70 m, forming a thickness of 0.93 m of LNAPL-impacted soil. Results show that the apparent LNAPL thickness in the observation well is found to be 3 times greater than the actual free LNAPL thickness in soil; a finding that agrees with previous studies reporting that apparent LNAPL thickness in observation wells typically exceeds the free LNAPL thickness within soil by a factor estimated to range between 2 and 10. The present study provides insights concerning the transient variation of LNAPL distribution within the subsurface and highlights the capability of the proposed methodology to mathematically predict the actual LNAPL thickness in the subsurface, without the need to conduct laborious field tests. Practitioners can use the proposed methodology to determine by how much the water table should be lowered, through pumping, to isolate the LNAPL-impacted soil within the unsaturated zone, which can then be subjected to in-situ vadose zone remedial treatment
Superhydrophobic micro-nanofibers from PHBV-SiO2 biopolymer composites produced by electrospinning
Get PDFElectrospinning is a relatively simple technique for producing continuous fibers of various sizes and morphologies. In this study, an intrinsically hydrophilic poly(3-hydroxybutarate-co-3-hydroxyvalerate) (PHBV) biopolymer strain was electrospun from a solution under optimal processing conditions to produce bilayers of beadless micro-fibers and beaded nano-fibers. The fibrous mats produced from the pure PHBV solution exhibited hydrophilicity with complete wetting. Incorporation of polydimethylsiloxane (PDMS) treated silica into the electrospinning solutions resulted in a non-wetting state with increased fiber roughness and enhanced porosity; however, the fiber mats displayed high water droplet-adhesion. The SiO2–incorporated fibrous mats were then treated with stearic acid at an activation temperature of 80 °C. This treatment caused fiber surface plasticization, creating a tertiary hierarchical roughness owing to the interaction of PHBV chains with the polar carboxyl groups of the stearic acid. Scanning electron microscopy was used to assess the influence of the electrospinning process parameters and the incorporation of nanoparticles on surface morphology of the fibers; energy dispersive X-ray spectroscopy confirmed the presence of SiO2 nanoparticles. Fourier transform infrared spectroscopy was performed to study the incorporation of SiO2 and the interaction of stearic acid with PHBV at various concentrations. The chemical interaction between stearic acid and PHBV was confirmed, while SiO2 nanoparticles were successfully incorporated into the PHBV fibers at concentrations up to 4.5% by weight. The incorporation of nanoparticles and plasticization altered the thermal properties of PHBV and a decrease in crystalline fraction was observed. The stearic acid modified bilayers produced from the micro-nano-fibrous composites showed very low water droplet sticking, a roll off angle of approximately 4° and a high static contact angle of approximately 155° were achieved
Abondance des poissons fourrages littoraux du lac Saint-Jean en 2021
Get PDFLes poissons fourrages littoraux constituent un maillon essentiel, quoique souvent méconnu, des réseaux trophiques aquatiques. Ce terme rassemble tous les petits poissons (jeunes de l’année et adultes) qui nourrissent les poissons piscivores, dont plusieurs sont ciblés par la pêche sportive. Au lac Saint-Jean, il s’agit de l’éperlan arc-en-ciel, du méné émeraude, du méné à tache noire, du naseux des rapides, de la ouitouche, de l’omisco, du fouille-roche zébré d’un an et plus (≥1+) et des jeunes de l'année (0+) de catostomidés (meunier rouge et meunier noir) et de perchaude. Le projet d’acquisition de connaissances sur les poissons fourrages littoraux du lac Saint-Jean est porté par les intervenants du milieu régional et a pour but de mesurer les variations interannuelles de l’abondance de ces différentes espèces indicatrices. L’échantillonnage des poissons fourrages littoraux du lac Saint-Jean a été effectué à 161 stations par deux équipes de trois échantillonneurs du 6 au 23 juillet 2021, entre 05:00 et 13:00. La turbidité (NTU) et la température ( ̊C) de l’eau étaient mesurées à chaque station suivant le coup de seine. En 2021, 27 013 poissons (25 620 jeunes de l’année et 1 393 poissons d’un an et plus) ont été capturés, c’est-à-dire le plus faible nombre de poisson capturé pour chaque stade depuis le début du projet en 2019. L’abondance relative moyenne calculée d’après la moyenne géométrique était de 54 poissons par coup de seine (0+ et ≥1+). Les indices d’abondance et d’occurrence des espèces indicatrices mesurés en 2021 étaient cependant similaires à ceux mesurés en 2020. Les espèces indicatrices présentant les indices d’abondance les plus élevés sont la perchaude 0+ et les catostomidés 0+, ainsi que le fouille-roche zébré ≥1+. L’indice d’occurrence révèle que ces espèces étaient aussi celles les plus fréquemment capturées. Les indices d’abondance de plusieurs espèces indicatrices de poissons fourrages littoraux étaient statistiquement corrélées à la turbidité de l’eau, la corrélation la plus élevée venant avec le total des poissons fourrages ≥1+ (ρ = 0,49; p <0,0001), comme c’était le cas en 2020
Generation of three induced pluripotent stem cell lines (UQACi003-A, UQACi004-A, and UQACi006-A) from three patients with KRT5 epidermolysis bullosa simplex mutations
Get PDFHeterozygous mutations within Keratin 5 (KRT5) are common genetic causes of epidermolysis bullosa simplex (EBS), a skin fragility disorder characterized by blisters, which appear after minor trauma. Using CytoTune®Sendai virus, we generated three human induced pluripotent stem cell (iPSC) lines from three EBS patients carrying respectively the single heterozygous mutations in KRT5, c.449 T > C, c.980 T > C, and c.608 T > C. All lines display normal karyotype, expressed high levels of pluripotent markers, and can differentiate into derivatives of the three germ layers. These iPSCs are helpful for a better understanding of the EBS pathogenesis and developing novel therapeutic approaches
A modular runtime enforcement model using multi-traces
Get PDFRuntime enforcement seeks to provide a valid replacement to any misbehaving sequence of events of a running system so that the correct sequence complies with a user-defined security policy. However, depending on the capabilities of the enforcement mechanism, multiple possible replacement sequences may be available, and the current literature is silent on the question of how to choose the optimal one. In this paper, we propose a new model of enforcement monitors, that allows the comparison between multiple alternative corrective enforcement actions and the selection of the optimal one, with respect to an objective user-defined gradation, separate from the security policy. These concepts are implemented using the event stream processor BeepBeep and a use case is presented. Experimental evaluation shows that our proposed framework can dynamically select enforcement actions at runtime, without the need to manually define an enforcement monitor
Designing an interpretability-based model to explain the artificial intelligence algorithms in healthcare
Get PDFThe lack of interpretability in artificial intelligence models (i.e., deep learning, machine learning, and rules-based) is an obstacle to their widespread adoption in the healthcare domain. The absence of understandability and transparency frequently leads to (i) inadequate accountability and (ii) a consequent reduction in the quality of the predictive results of the models. On the other hand, the existence of interpretability in the predictions of AI models will facilitate the understanding and trust of the clinicians in these complex models. The data protection regulations worldwide emphasize the relevance of the plausibility and verifiability of AI models’ predictions. In response and to take a role in tackling this challenge, we designed the interpretability-based model with algorithms that achieve human-like reasoning abilities through statistical analysis of the datasets by calculating the relative weights of the variables of the features from the medical images and the patient symptoms. The relative weights represented the importance of the variables in predictive decision-making. In addition, the relative weights were used to find the positive and negative probabilities of having the disease, which indicated high fidelity explanations. Hence, the primary goal of our model is to shed light and give insights into the prediction process of the models, as well as to explain how the model predictions have resulted. Consequently, our model contributes by demonstrating accuracy. Furthermore, two experiments on COVID-19 datasets demonstrated the effectiveness and interpretability of the new model
French-Canadian Validation of the Traumatic Grief Inventory-Self Report (TGI-SR)
Get PDFThe Traumatic Grief Inventory Self-Report (TGI-SR), which aims to assess both Persistent Complex Bereavement Disorder and Prolonged Grief Disorder, has been validated in several languages. This study sought to validate the French-Canadian version. We conducted an online survey exploring the impact of the COVID-19 pandemic on grief. With data from 728 participants, the scale demonstrated high internal consistency, correlated significantly with three other scales known to measure similar concepts, and distinguished between groups known to be different. This study supports the use of the TGI-SR French-Canadian version by clinicians and researchers to assess complications of grief
Recension d’outils pédagogiques pour favoriser l’apprentissage et limiter la médicalisation des comportements des élèves du primaire et du secondaire. [Recension d’outils]
Get PDFLe processus de médicalisation est très fréquent durant l’enfance. Ce processus réfère au fait de transformer un problème non-médical en un problème qui est défini, compris, expliqué ou traité à l’aide d’un discours psychomédical (Conrad, 2007; Morel 2014). Un des exemples les plus frappants est sans aucun doute la prise en charge médicale des comportements d’hyperactivité, d’impulsivité et d’inattention sous le diagnostic de Trouble du déficit de l’attention avec ou sans hyperactivité (TDAH). Sans nier les bienfaits que peut avoir ce diagnostic lorsqu’il est bien établi et nécessaire, il reste que les plusieurs recherches scientifiques font état d’un surdiagnostic et d’une trop grande consommation de médicaments associés au trouble. De plus, la présence d’inégalités sociales basées sur le genre, l’âge et le statut socioéconomique rappelle que certains enfants ont plus de risque que d’autres de recevoir le diagnostic et donc que des aspects sociaux entrent en jeux dans le processus de médicalisation. Mis à part le TDAH, la médicalisation peut toucher plusieurs autres comportements et attitudes des enfants, tels que l’opposition, la gêne et les difficultés scolaires. Il est nécessaire de réduire la médicalisation, car elle amène son lot de conséquences négatives autant pour les élèves, que pour les adultes de l’école et pour toute la société. Le présent document a donc été conçu pour rappeler aux intervenants scolaires qu’ils.elles possèdent plusieurs compétences pédagogiques pour agir sur les difficultés et les problèmes, avant de les réfléchir de manière médicale. Ce document a été créé à la suite d’une série d’ateliers de cocréation avec des intervenants scolaires (enseignantes, techniciennes en éducation spécialisée, orthopédagogues, psychologues) visant à les sensibiliser au processus de médicalisation. Ces ateliers (n = 6) se sont tenus sur une période d’un an, d’octobre 2020 à 2021. Le présent document est conçu comme une boite à outils – une sorte d’aide-mémoire - où sont recensées plusieurs stratégies pédagogiques visant à aider les intervenants scolaires à faire face aux comportements moins adaptés à l’apprentissage. L’objectif est que les intervenants scolaires aient sous la main, à un seul endroit, une diversité de trucs pédagogiques pour les aider à consigner ce qui fonctionne ou non pour les élèves avec lesquels ils interagissent. Les différentes stratégies de cette recension sont regroupées selon le problème rencontré (ex. : organisation du temps, agitation, etc.)