Canada’s air transportation policy case study: The greater Moncton international airport

Airports are a major economic engine for the region that it serves. In today's fast paced global economy, easy access to world markets is crucial to companies seeking to expand and take full advantage of business opportunities. This paper will explore how changes to Transport Canada's air policy, from divestiture in 1994 to proposed amendments to the National Airports Policy in 2003, have impacted the Greater Moncton International Airport. An analysis of the policy reveals that while the devolution of Canada's national airport system to local control has been a success, the proposed amendments will negatively affect the way the Greater Moncton Airport Authority serves the public, airport users and, most importantly, the local community.Keywords: Greater Moncton International Airport, divestiture, airport polic

Accélération de l’oxydation et passivation de sulfures dans des stériles miniers afin de réduire le potentiel de génération de drainage neutre contaminé

Résumé L’exploitation minière génère beaucoup de rejets. Ces rejets sont divisés en deux catégories : les résidus, qui sont générés à la suite du traitement du minerai, et les stériles, qui sont générés lors de l’extraction pour atteindre le minéral d’intérêt. Ces rejets sont généralement entreposés en surface et exposés aux conditions ambiantes et climatiques, plus particulièrement à l’oxygène de l’air et l’eau de pluie. Les stériles sont particulièrement problématiques, notamment en raison de leur granulométrie étalée. Ceux-ci sont entreposés en halde pouvant couvrir plusieurs dizaines d’hectares et mesurer plusieurs centaines de mètres de hauteur. Les matériaux miniers sont susceptibles de contenir des minéraux réactifs, comme par exemple des sulfures. Ces sulfures s’oxydent en présence d’eau et d’oxygène et affectent la qualité des eaux de drainage, c’est-à-dire les eaux s’écoulant au travers de la halde et rejetées à l’environnement. Ces réactions chimiques peuvent mener à l’acidification de l’eau, pour certains sulfures, comme la pyrite, et sa contamination en métaux, phénomène nommé drainage minier acide (DMA). Lorsqu’il y a présence de minéraux neutralisant en quantité suffisante pour conserver le pH neutre, mais qu’il y a présence de métaux, ce phénomène est alors nommé drainage neutre contaminé (DNC). Le DNC est la conséquence, notamment, de la solubilité élevée de métaux à pH près de la neutralité, par exemple le nickel, le cobalt et le cuivre. L’objectif de ce projet est d’étudier la possibilité d’utiliser l’oxydation forcée et la passivation afin de réduire le potentiel de génération de drainage neutre contaminé d’un stérile faiblement sulfureux. Ce projet a été réalisé en partenariat avec la mine Lac Tio, propriété de Rio Tinto Fer et Titane. Cette mine est située sur la Côte-Nord du Québec, Canada, à 43 km au nord-est d’Havre-Saint-Pierre. Cette mine à ciel ouvert est en opération depuis 1950. Rio Tinto Fer et Titane y exploite le plus gros gisement d’ilménite massive au monde avec un tonnage annuel d’environ 86 Mt et une superficie d’exploitation d’environ 2,51 Mm2. À la mine Lac Tio, des concentrations en nickel sporadiquement supérieures à la limite de la Directive 019 sont observées à l’effluent non traité. La Directive 019 permet d’établir une limite de concentration des contaminants dans les eaux minières, entre autres (MELCC, 2012). Cette limite est établie à 0,5 mg/L de nickel extractible en moyenne mensuelle (MELCC, 2012). Le stérile ayant été déterminé comme non générateur acide par de nombreuses études antérieures, les eaux de drainage font l’objet d’un DNC en nickel. De plus, un phénomène de sorption du nickel sur le plagioclase et l’ilménite cause un délai du relargage du nickel dans les eaux de drainage de dizaines d’années. Ainsi, les eaux environnantes pourraient faire l’objet d’une contamination en nickel des dizaines, voire des centaines d’années suite à la fermeture de la mine. Suite à une caractérisation, il a été déterminé que le stérile utilisé pour les essais de laboratoire contient environ 15% d’un plagioclase d’une composition semblable à la labradorite, 16% d’hématite, 52% d’ilménite et des traces de pyrite. L’ilménite est la phase contenant les sulfures qui seraient à l’origine du DNC. Afin d’empêcher l’oxydation des sulfures, il faut éliminer l’un des réactifs, soit l’oxygène ou l’eau. Dans un climat humide comme celui du Québec, il est plus avantageux de limiter les interactions avec l’oxygène. Diverses méthodes ont été développées pour contrer le phénomène de DMA. Par contre, des études antérieures, notamment sur le stérile Tio, ont montré que les méthodes de restauration et de gestion des rejets miniers utilisées pour le DMA ne sont pas toujours applicables au DNC. Ainsi, au cours de ce projet, la possibilité de forcer l’oxydation des sulfures et de passiver les surfaces afin de réduire à la source le potentiel de génération de DNC à long terme en diminuant la réactivité des sulfures par une couche de passivation sur la surface des minéraux sulfureux a été étudiée. De nombreuses études montrent qu’il est possible d’utiliser une solution oxydante et/ou passivante afin de précipiter les oxy-hydroxydes de fer et créer une couche de passivation. Ces études ont été produites sur des sulfures purs fins ou du matériel à fine granulométrie à forte teneur en sulfures. Ainsi, lors de l’étude ici-présentée, il était question de montrer si un tel traitement pourrait être efficace sur un matériel grossier à faible teneur en sulfure. Pour ce faire, l’utilisation d’une solution de traitement sur le stérile a été étudiée en essais cinétiques en laboratoire. Huit différentes solutions ont été testées en mini-cellules de 400g. Le peroxyde d’hydrogène, le silicate de sodium et le phosphate de potassium sont les principaux agents testés en mini-cellules, en combinaison ou non avec un agent tampon, le carbonate de sodium. Les résultats ont montré que les solutions de peroxyde tamponné (I), de silicate de sodium (II) et de silicate accompagné de peroxyde et de carbonate (III) sont potentiellement des traitements efficaces. Par la suite, les trois solutions montrant les meilleurs résultats ont été testées en colonnes de 70kg. Lors de ces essais, la solution de peroxyde tamponné a montré les meilleurs résultats quant à la diminution du potentiel de génération de DNC à long terme. Le taux de lixiviation du nickel a été diminué de 1,4x10-3 mg/kg/jour (non traité) à 4,0x10-5 mg/kg/jour (traité), ce qui représente une diminution de 97%. De plus, la lixiviation du soufre a diminué de moitié. Finalement, la solution montrant les meilleurs résultats en termes de diminution du DNC en colonnes, soit le peroxyde d’hydrogène tamponné, a été testé en cellule expérimentale de 64 tonnes afin de déterminer la possibilité d’utiliser un tel traitement sur le terrain. Les résultats de cet essai préliminaire de terrain ont relevé le potentiel de cette approche, mais des essais supplémentaires sont nécessaire pour confirmer l’applicabilité. Pour conclure, une analyse de cycle de vie (ACV) a permis de quantifier et déterminer les impacts potentiels sur la santé humaine et la qualité des écosystèmes d’un tel traitement. L’utilisation d’une solution de peroxyde tamponné sur une cellule expérimentale a été étudiée, dans le cadre d’une analyse de cycle de vie, en comparaison avec la situation actuelle, où l’effluent est traité à l’aide d’un coagulant pour retirer le nickel. Le logiciel Simapro 8.4 a été utilisé, ainsi que la méthode IMPACT World+ et la base de données ecoinvent version 3.4 afin de modéliser cette étude en 2019 au Québec pour une période de 100 ans. Les impacts sur la santé humaine et la qualité des écosystèmes seraient diminués à environ 15% de ce qu’ils représentent pour le scénario actuel selon les résultats de l’ACV. Pour terminer, il est important de mentionner que ce projet porte sur le cas particulier de la mine Lac Tio. Afin d’appliquer un tel traitement à d’autres matériels, il serait important d’effectuer d’autres tests. Par contre, cette étude a permis de montrer l’efficacité d’une nouvelle approche de réduction du potentiel de génération de DNC provenant de stériles faiblement sulfureux. En effet, suite à un traitement au peroxyde tamponné au carbonate de sodium en colonnes de laboratoire, une couche de passivation a été observée. De plus, le taux de lixiviation du nickel a diminué de deux ordres de grandeur. Finalement, une analyse de cycle de vie montre qu’un tel traitement pourraient possiblement diminuer à 15% les impacts environnementaux possible du traitement du drainage neutre contaminé. ---------- Abstract Mine exploitation generates large amounts of solid wastes, which are divided into tailings, produced by the mineral processing, and waste rock, produced from the excavation to reach the ore of interest. These residues are piled at the surface, exposed to ambient and seasonal conditions, especially the oxygen from air and rainwater. Waste rock are the most problematic, particularly for their wide spread particle size distribution. These are piled in waste rock piles of tens of hectares and measuring hundreds of meters in height. Solid wastes may contain minerals that are reactive to oxygen and water, for example sulfides. Sulfides oxidize when in contact with water and oxygen and affect the drainage water quality i.e. the water that flows trough the waste rock pile and are rejected to the environment. These reactions can lead to water acidification, for some sulfides such as pyrite, and high metal concentrations. This phenomenon is called acid mine drainage (AMD). When enough neutralizing material is present to keep a near neutral pH but water still shows high concentrations of metals, it is called contaminated neutral drainage (CND). Contaminated neutral drainage is the consequence, for instance, of the high solubility of metals at near neutral pH, like nickel, cobalt and copper. The objective of this project was to study the possibility to use forced oxidation and passivation to reduce the contaminated neutral drainage generation potential from low sulfide waste rock. This project was realized in partnership with the Lac Tio mine, property of Rio Tinto Iron and Titanium. This mine is located in the Côte-Nord region of Quebec, Canada, 43 km north-east from Havre-Saint-Pierre. This open pit mine is in operation since 1950. Rio Tinto Iron and Titanium exploits at Lac Tio mine the world’s biggest massive ilmenite deposit. With an annual extraction of 86 Mt and an area of 2.51 Mm2, huge waste rock piles overlook the field. At Lac Tio mine, nickel concentrations sporadically higher than the environmental limit are observed at the untreated mine effluent. The limit is established by the Directive 019 at a monthly mean of 0.5 mg/L of extractible nickel (MELCC, 2012). The material has been determined as non-acid generating by numerous previous studies. The drainage water is submitted to nickel CND. Sorption phenomenon of nickel on plagioclase and ilmenite causes a delay in nickel release of tens of years. Indeed, surrounding waters will be submitted to nickel contamination for tens, maybe even hundreds of years after mine closure. Following characterization, the material used in the laboratory tests was determined to be composed of 15% plagioclase of composition close to labradorite, 16% hematite, 52% ilmenite, and traces of pyrite. Ilmenite is the sulfide bearing phase that is the source of nickel CND. To prevent sulfide oxidation, one of its reactive component, either oxygen or water, needs to be limited. In a humid climate like Quebec, it is more advantageous to limit oxygen. Multiple methods have been developed to limit AMD. Although these are effective for AMD, they are not always applicable to CND. In this project, the possibility to force sulfide oxidation or to passivate sulfide surfaces to reduce, at the source, the CND generation potential was studied in a long-term view by limiting sulfides reactivity by creating a passivation layer on sulphides surfaces. Numerous studies show that it is possible to use an oxidant and/or passivating solution to force iron oxy-hydroxide precipitation on sulfides surfaces. These tests were done on pure fine sulfides or on fine grained, high sulfides composition, residues. In the present study, the possibility to use this kind of treatment on a coarse, low sulfide, waste rock was studied. To do so, the use of a treatment solution on the waste rock was studied in kinetic tests on a laboratory scale. Eight different solutions were tested in 400g weathering cells. Hydrogen peroxide, sodium silicate and potassium phosphate were the main product tested in weathering cells, in combination or not with a buffer, sodium carbonate. Results showed that the solutions of buffered peroxide (I), sodium silicate (II) and silicate with carbonate and peroxide (III) could be potential effective treatments. Then, the three solutions that showed the best results were tested in 70kg columns. For these tests, the buffered peroxide solution showed the best results in term of reduction of the nickel CND generation potential. The nickel release rate was reduced from 14x10-4 mg/kg/day (untreated) to 4x10-5 mg/kg/day (treated), which represent a reduction of 97%. In addition, sulfur release rate was reduced by half. Finally, the solution that showed the best results, the buffered peroxide, was tested on a 64 tons experimental field cell to determine if it is possible to use this kind of solution to treat waste rock. The results of this preliminary field showed the potential of this approach, but further tests are necessary to confirm the applicability. To conclude, a life cycle assessment was made to quantify and compare the potential impacts on human health and ecosystem quality of this kind of treatment. The use of a buffered peroxide solution on an experimental cell was studied trough a life cycle assessment, comparing it to the actual scenario, where the effluent is treated with a coagulant to remove nickel. Simapro 8.4 software, the IIMPACT World+ method and the ecoinvent 3.4 version database were used for modeling the study in Quebec for 100 years. Results showed that treating the waste rock could reduce the time needed for treating the effluent. In addition, the impact on human health and ecosystem quality were reduced to 15% of the actual scenario impacts. To conclude, it is important to mention that this project was tested on Lac Tio mine waste rock. To use this kind of treatment on another material, it is important to proceed to more tests. Nonetheless, the study showed the efficiency of a new approach to reduce the CND generation potential from low sulfide waste rock. Following waste rock treatment with a peroxide and carbonate solution in laboratory columns, a passivation layer was observed on pyrite surfaces. In addition, the nickel lixiviation rate was reduced by two order of magnitude. Finally, a life cycle assessment showed that this kind of treatment could possibly lower to 15% the possible environmental impacts of CND treatment

Understanding the Effects of Lactose Hydrolysis Modeling on the Main Oligosaccharides in Goat Milk Whey Permeate.

Enzymatic hydrolysis of lactose is a crucial step to improve the efficiency and selectivity of membrane-based separations toward the recovery of milk oligosaccharides free from simple sugars. Response surface methodology was used to investigate the effects temperature (25.9 to 54.1 °C) and amount of enzyme (0.17 to 0.32% w/w) at 1, 2, and 4 h of reaction on the efficiency of lactose hydrolysis by Aspergillus oryzae β-galactosidase, preservation of major goat whey oligosaccharides, and on the de-novo formation of oligosaccharides. Lactose hydrolysis above 99% was achieved at 1, 2, and 4 h, not being significantly affected by temperature and amount of enzyme within the tested conditions. Formation of 4 Hexose (Hex) and 4 Hex 1 Hex and an increased de-novo formation of 2 Hex 1 N-Acetyl-Neuraminic Acid (NeuAc) and 2 Hex 1 N-Glycolylneuraminic acid (NeuGc) was observed in all treatments. Overall, processing conditions using temperatures ≤40 °C and enzyme concentration ≤0.25% resulted in higher preservation/formation of goat whey oligosaccharides

Preconception counselling resource for women with diabetes

Women with diabetes need to plan for pregnancy if they are to reduce their risk of poor pregnancy outcome. While care providers have focused on setting up specialist pre-pregnancy planning clinics to help women prepare for pregnancy, the majority of women do not attend, entering pregnancy unprepared. A major barrier to accessing this care, and a consequence of poor preconception counselling, is a lack of knowledge as to the need to plan and the reasons why. This project addressed an urgent need to raise awareness of the importance of planning for pregnancy among women with diabetes and among the healthcare professionals (HCPs) caring for them. Focus groups with the target groups informed the development of a preconception counselling resource for women with diabetes. Originally produced as a DVD (Diabetes UK funding), this resource has been embedded in routine care in Northern Ireland (NI) since 2010. A subsequent service evaluation of pregnancy planning indicators undertaken across all five antenatal-metabolic clinics in NI indicated that women who viewed the resource were better prepared for pregnancy. In order to increase the positive impact of the resource and to ensure longer term sustainability the DVD was converted to a website, http://www.womenwithdiabetes.net (Public Health Agency NI funding). The evaluation also highlighted that women with type 2 diabetes were a hard to reach group. As these women are often cared for outside of specialist clinics, it is pertinent that all HCPs caring for women with diabetes are aware of the importance of preconception counselling. Funding also supported the development of an e-learning continuing professional development (CPD) resource within the website. The e-learning resource has since been embedded into existing CPD programmes and is an important tool to ensure that all HCPs caring for women with diabetes are empowered to provide preconception counselling at every opportunity

GEAR-Up: Generative AI and External Knowledge-based Retrieval Upgrading Scholarly Article Searches for Systematic Reviews

Systematic reviews (SRs) - the librarian-assisted literature survey of scholarly articles takes time and requires significant human resources. Given the ever-increasing volume of published studies, applying existing computing and informatics technology can decrease this time and resource burden. Due to the revolutionary advances in (1) Generative AI such as ChatGPT, and (2) External knowledge-augmented information extraction efforts such as Retrieval-Augmented Generation, In this work, we explore the use of techniques from (1) and (2) for SR. We demonstrate a system that takes user queries, performs query expansion to obtain enriched context (includes additional terms and definitions by querying language models and knowledge graphs), and uses this context to search for articles on scholarly databases to retrieve articles. We perform qualitative evaluations of our system through comparison against sentinel (ground truth) articles provided by an in-house librarian. The demo can be found at: https://youtu.be/zMdP56GJ9mU

Adolescent stress, help-seeking intentions, subjective achievement and life satisfaction in New Zealand: Tests of mediation, moderated mediation and moderation

© 2021 John Wiley & Sons Ltd. We present the results of a study examining adolescent help-seeking intentions (HSIs), stress, subjective school achievement and life satisfaction. Using a cross-sectional design with a sample of New Zealand adolescents (n = 1601), we tested whether HSIs could mediate or moderate relations between stress and subjective achievement, and between stress and life satisfaction. We inspected these dynamics alongside different help sources (informal and formal) and domains where stress might be experienced (school and personal). Using mediation testing, findings suggest that informal HSIs have at least some influence on the relations between stress and well-being indicators, whereas formal HSIs did not. Conditional indirect effects for the mediation models (moderated mediation) revealed that gender and age did not moderate the relations between stress and informal HSIs, or between stress and well-being indicators with one exception: gender moderated the relation between personal stress and informal HSIs. In most models, tests of moderation lent support for a protective-reactive model in which HSIs reduce the adverse effects of stress on well-being indicators. Discussion focuses on modelling and promoting help-seeking activities across diverse support sources, and doing so earlier in life so that adolescents can benefit from well-honed coping strategies

Polymeric nanocapsules prevent oxidation of core-loaded molecules: evidence based on the effects of docosahexaenoic acid and neuroprostane on breast cancer cells proliferation

International audienceBackground:Nanocapsules, as a delivery system, are able to target drugs and other biologically sensitive moleculesto specific cells or organs. This system has been intensively investigated as a way to protect bioactives drugs frominactivation upon interaction with the body and to ensure the release to the target. However, the mechanism ofimproved activity of the nanoencapsulated molecules is far from being understood at the cellular and subcellularlevels. Epidemiological studies suggest that dietary polyunsaturated fatty acids (PUFA) can reduce the morbidityand mortality from breast cancer. This influence could be modulated by the oxidative status of the diet and it hasbeen suggested that the anti-proliferative properties of docosahexaenoic acid (DHA) are enhanced by pro-oxidantagents Methods:The effect of encapsulation of PUFA on breast cancer cell proliferation in different oxidative mediumwas evaluated in vitro. We compared the proliferation of the human breast cancer cell line MDA-MB-231 and ofthe non-cancer human mammary epithelial cell line MCF-10A in different experimental conditions. Results:DHA possessed anti-proliferative properties that were prevented by alpha-tocopherol (an antioxidant) andenhanced by the pro-oxidant hydrogen peroxide that confirmsthat DHA has to be oxidized to exert its anti-proliferativeproperties. We also evaluated the anti-proliferative effects of the 4(RS)-4-F4t-neuroprostane, a bioactive, non-enzymaticoxygenated metabolite of DHA known to play a major role inthe prevention of cardiovascular diseases. DHA-loadednanocapsules was less potent than non-encapsulated DHA while co-encapsulation of DHA with H2O2maintainedthe inhibition of proliferation. The nanocapsules slightly improves the anti-proliferative effect in the case of4(RS)-4-F4t-neuroprostane that is more hydrophilic than DHA. Conclusion:Overall, our findings suggest that the sensitivity of tumor cell lines to DHA involves oxidized metabolites.They also indicate that neuroprostane is a metabolite participating in the growth reducing effect of DHA, but it is not thesole. These results also suggest that NC seek to enhance the stability against degradation, enhance cellular availability,and control the release of bioactive fatty acids following their lipophilicities

Overview of ceramic matrix composite research at NASA Glenn Research Center

In support of NASA’s Aeronautics Research Mission, the Glenn Research Center in Cleveland, OH, has been developing and assessing the performance of high temperature SiC/SiC ceramic matrix composites (CMCs), both with and without protective coatings, for turbine engine applications. Combinations of highly creep-resistant SiC fibers, advanced 3D weaves, durable environmental barrier coatings (EBCs), and a 2700°F-capable hybrid SiC matrix have been evaluated. The effects of steam and thermal gradients on composite durability and means of monitoring and modeling damage are also being investigated. Additional studies focused on understanding the creep of SiC fibers and the behavior of SiC/SiC minicomposites that are being tested under a range of conditions are helping GRC model the thermomechanical behavior of SiC/SiC CMCs. Higher TRL (Technology Readiness Level) testing is being pursued, and SiC/SiC composites with alternate matrices providing self-healing capability are being explored. An overview of those studies will be provided. The development and validation of models for predicting the effects of the environment on the durability of CMCs and EBCs and other operating-environment challenges including the effect of CMAS (calcium magnesium aluminosilicate) degradation of EBCs will be discussed. Previous oxide/oxide composite development efforts will also be reviewed

Genotype tunes pancreatic ductal adenocarcinoma tissue tension to induce matricellular fibrosis and tumor progression

Fibrosis compromises pancreatic ductal carcinoma (PDAC) treatment and contributes to patient mortality yet anti-stromal therapies are controversial. We found that human PDACs with impaired epithelial transforming growth factor β (TGF-β) signaling have elevated epithelial Stat3 activity and develop a stiffer, matricellular-enriched fibrosis associated with high epithelial tension and shorter patient survival. In several Kras-driven mouse models, both the loss of TGF-β signaling and elevated β1-integrin mechanosignaling engaged a positive feedback loop whereby Stat3 signaling promotes tumor progression by increasing matricellular fibrosis and tissue tension. In contrast, epithelial Stat3 ablation attenuated tumor progression by reducing the stromal stiffening and epithelial contractility induced by loss of TGF-β signaling. In PDAC patient biopsies, higher matricellular protein and activated Stat3 associated with SMAD4 mutation and shorter survival. The findings implicate epithelial tension and matricellular fibrosis in the aggressiveness of SMAD4 mutant pancreatic tumors, and highlight Stat3 and mechanics as key drivers of this phenotype

Targeting Human Central Nervous System Protein Kinases: An Isoform Selective p38αMAPK Inhibitor that Attenuates Disease Progression in Alzheimer\u27s Disease Mouse Models

The first kinase inhibitor drug approval in 2001 initiated a remarkable decade of tyrosine kinase inhibitor drugs for oncology indications, but a void exists for serine/threonine protein kinase inhibitor drugs and central nervous system indications. Stress kinases are of special interest in neurological and neuropsychiatric disorders due to their involvement in synaptic dysfunction and complex disease susceptibility. Clinical and preclinical evidence implicates the stress related kinase p38αMAPK as a potential neurotherapeutic target, but isoform selective p38αMAPK inhibitor candidates are lacking and the mixed kinase inhibitor drugs that are promising in peripheral tissue disease indications have limitations for neurologic indications. Therefore, pursuit of the neurotherapeutic hypothesis requires kinase isoform selective inhibitors with appropriate neuropharmacology features. Synaptic dysfunction disorders offer a potential for enhanced pharmacological efficacy due to stress-induced activation of p38αMAPK in both neurons and glia, the interacting cellular components of the synaptic pathophysiological axis, to be modulated. We report a novel isoform selective p38αMAPK inhibitor, MW01-18-150SRM (=MW150), that is efficacious in suppression of hippocampal-dependent associative and spatial memory deficits in two distinct synaptic dysfunction mouse models. A synthetic scheme for biocompatible product and positive outcomes from pharmacological screens are presented. The high-resolution crystallographic structure of the p38αMAPK/MW150 complex documents active site binding, reveals a potential low energy conformation of the bound inhibitor, and suggests a structural explanation for MW150\u27s exquisite target selectivity. As far as we are aware, MW150 is without precedent as an isoform selective p38MAPK inhibitor or as a kinase inhibitor capable of modulating in vivo stress related behavior