Étude du comportement cyclique de résidus miniers avec inclusions drainantes par des essais sur table sismique.

RÉSUMÉ Lors de l’exploitation minière, le minerai est broyé afin d’en extraire les minéraux ayant une valeur commerciale. Lorsque les éléments ciblés ont été retirés de la roche, les rejets produits sont typiquement déposés dans des parcs à résidus miniers sous forme d’une pulpe (mélange de roche concassée et d’eau) ayant une teneur en eau élevée. Les parcs à résidus miniers sont généralement ceinturés, en tout ou en partie, par des digues. Dans le passé, il est arrivé que des digues cèdent en raison de contraintes trop élevées causées par des sollicitations mécaniques sévères pouvant mener à la liquéfaction des résidus miniers. Et même si les techniques de construction se sont graduellement améliorées, la fréquence de rupture des digues de parcs à résidus miniers reste encore largement supérieure à celle des digues de rétention d’eau. Lors d’un séisme ou d’un événement pouvant causer des sollicitations dynamiques (p. ex. dynamitage ou passage d’un camion), il est possible que certains matériaux subissent des effets pouvant mener à leur liquéfaction. Les résidus provenant de mines en roches dures (comme on en retrouve plusieurs en Abitibi) possèdent les caractéristiques qui les rendent particulièrement susceptibles à la liquéfaction, soit : une cohésion quasi-nulle, une granulométrie silteuse, un faible indice de densité et un degré de saturation élevé. Ce type de matériau tend à se contracter lorsqu’il est soumis à des sollicitations mécaniques. Si le matériau est saturé, la contraction peut engendrer une augmentation des pressions interstitielles qui réduit les contraintes effectives, et qui peut provoquer la liquéfaction du matériau. Dans ce cas, les contraintes appliquées sur le parement amont des digues peuvent être suffisamment élevées pour engendrer une rupture. Plusieurs études ont permis de mieux comprendre le phénomène de la liquéfaction ainsi que les méthodes pour caractériser les matériaux qui y sont susceptibles. D’autres recherches ont permis d’établir des méthodes pour prévenir la liquéfaction ou en limiter les effets. Ces travaux ont surtout portés sur les sols sableux et silteux; très peu ont été faits sur des résidus miniers et aucun ne comprend des essais sur table sismique (à la connaissance de l’auteur). Le projet de recherche présenté dans ce mémoire a pour but d’aider à mieux comprendre les facteurs qui mènent à la liquéfaction des résidus miniers afin d’en réduire le potentiel. ----------ABSTRACT The ore of an operating mine is extracted and concentrated to obtain minerals of commercial value. The residual material (tailings) resulting from this milling operation is usually mixed with water to create a slurry that is pumped to an impoundment. Such tailings storage facilities are typically surrounded, in part or totally, by dikes. Over the years, dike failures have occurred in tailings storage facilities because of the large stresses caused by severe mechanical loading which can liquefy tailings. Even though the construction techniques for dikes in tailings impoundments has gradually improved over the last few decades, their rate of failure is still much greater than for water retention dams. During an earthquake or other events that can cause significant cyclic stresses (i.e. vibration caused by blasting or by heavy machinery), some materials react in a way that can lead to their liquefaction. Tailings from hard rock mines (like those found in Abitibi, Quebec) are particularly sensitive to liquefaction because of their physical characteristics, which include: no or low cohesion, silt-like grain size, low density index ID, and a high degree of saturation Sr (≈ 100 %). When subjected to cyclic loadings this type of material tends to contract. This contraction can lead to an increase in the porewater pressures that reduces the effective stresses and can ultimately cause liquefaction. In this case, the stresses applied to the upstream face of the retaining dike can be large enough to cause failure. Many studies were undertaken to better understand the physics of liquefaction and to characterize liquefiable materials. Researchers have also developed methods to prevent liquefaction or to limit its effects. These studies were mostly conducted on naturally occurring soils, such as sands and silts; there has been relatively little work on tailings, and none included shaking table testing (to the knowledge of the Author). The project presented in this Masters’ thesis aims to improve our knowledge of the factors that lead to liquefaction of tailings in order to reduce the risks. To do so, tests were completed in the laboratory using a shaking table. Nine tests were conducted using an aluminum box with a plan surface of one square meter, with a height of 75 cm. One test was done on sand, and eight others on tailings. Of the latter, three were completed on tailings only, three were done with a cylindrical inclusion (rigid and/or draining) in the tailings and two were conducted with a continuous draining inclusion across the tailings

Le calcul parallèle des plus courts chemins temporels

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

The Prostaglandin F Synthase Activity of the Human Aldose Reductase AKR1B1 Brings New Lenses to Look at Pathologic Conditions

Prostaglandins are important regulators of female reproductive functions to which aldose reductases exhibiting hydroxysteroid dehydrogenase activity also contribute. Our work on the regulation of reproductive function by prostaglandins (PGs), lead us to the discovery that AKR1B5 and later AKR1B1were highly efficient and physiologically relevant PGF synthases. PGE2 and PGF2α are the main prostanoids produced in the human endometrium and proper balance in their relative production is important for normal menstruation and optimal fertility. Recent evidence suggests that PGE2/EP2 and PGF2α/FP may constitute a functional dyad with physiological relevance comparable to the prostacyclin-thromboxane dyad in the vascular system. We have recently reported that AKR1B1 was expressed and modulated in association with PGF2α production in response to IL-1β in the human endometrium. In the present study, we show that the human AKR1B1 (gene ID: 231) also known as ALDR1 or ALR2 is a functional PGF2α synthase in different models of living cells and tissues. Using human endometrial cells, prostate, and vascular smooth muscle cells, cardiomyocytes and endothelial cells we demonstrate that IL-1β is able to up regulate COX-2 and AKR1B1 proteins as well as PGF2α production under normal glucose concentrations. We show that the promoter activity of AKR1B1 gene is increased by IL-1β particularly around the multiple stress response region containing two putative antioxidant response elements adjacent to TonE and AP1. We also show that AKR1B1 is able to regulate PGE2 production through PGF2α acting on its FP receptor and that aldose reductase inhibitors like alrestatin, Statil (ponalrestat), and EBPC exhibit distinct and characteristic inhibition of PGF2α production in different cell models. The PGF synthase activity of AKR1B1 represents a new and important target to regulate ischemic and inflammatory responses associated with several human pathologies

Expression of genes related to prostaglandin synthesis or signaling in human subcutaneous and omental adipose tissue: depot differences and modulation by adipogenesis

Objectives. (1) To examine depot-specific PGE2 and PGF2α release and mRNA expression of enzymes or receptors involved in PG synthesis or signaling in human adipose tissues; (2) to identify changes in expression of these transcripts through preadipocyte differentiation; and (3) to examine associations between adipose tissue mRNA expression of these transcripts and adiposity measurements. Methods. Fat samples were obtained surgically in women. PGE2 and PGF2α release by preadipocytes and adipose tissue explants was measured. Expression levels of mRNA coding for enzymes or receptors involved in PG synthesis or signaling were measured by RT-PCR. Results. Cultured preadipocytes and explants from omental fat released more PGE2 and PGF2α than those from the subcutaneous depot and the corresponding transcripts showed consistent depot differences. Following preadipocyte differentiation, expression of PLA2G16 and PTGER3 mRNA was significantly increased whereas COX-1, COX-2, PTGIS, and PTGES mRNA abundance were decreased in both compartments ( for all). Transcripts that were stimulated during adipogenesis were those that correlated best with adiposity measurements. Conclusion. Cells from the omental fat compartment release more PGE2 and PGF2α than those from the subcutaneous depot. Obesity modulates expression of PG-synthesizing enzymes and PG receptors which likely occurs through adipogenesis-induced changes in expression of these transcripts. 1. Introductio

Clean and efficient energies for Europe : socio-economic impact of energy research

Report of the independent expert panelLaunched in 1994, the Fourth Framework Programme (FP4) covering research and demonstration aimed to improve the security of energy supply and to reduce the impact of the production and use of energy on the environment, in particular CO2 and the other greenhouse gases. Other important EU objectives were also addressed including strengthening the technological basis of the energy industry (e.g. employment and export potential), improving European social and economic cohesion and contributing to co-operation with third countries. It also supported research on overall energy RTD strategy in the inter-disciplinary area of energy-environment-economy. Six years after the Programme’s launch, at a stage when most of the projects have been completed, and the Sixth Framework Programme is being planned, it was considered appropriate to assess not only the scientific and technical quality of the completed projects, but also their impact on society, the economy and the environment. The present analysis was organised to allow quick feedback for the preparation of the new Framework Programme. This was achieved by convening a panel of ten experts from different Member States. Using questionnaires, project final reports and direct contacts where necessary, the Panel investigated the expected overall impact by examining the scientific and technical results as well as the social and economic impact of a sample of about 90 already finished Non-Nuclear Energy projects, most of them three years ago (time necessary to expect some concrete results), representing in total a e84 million investment by the Commission. The contribution to Community policies, particularly emphasised in the present Framework Programme, as well as the Programmes’s addition to European Added Value were both explored. The results of this impact assessment of about one-fifth of the projects funded under the Non-Nuclear Energy Programme of the Fourth Framework Programme for the period 1994-1998 (better known as JOULE), were analysed and critically reviewed and are presented in this report. Among the main conclusions of the report, it is worth noting that the vast majority of the examined projects have developed new technical advances. Furthermore, the commercial leverage of funded research projects is positive and its major non-commercial impact is on the improvement of the environment and particularly on CO2 emissions. The social and economic impact remains, in general, limited, but could be improved through better understanding and application of the European Added Value principles. The Fifth Framework Programme made a further step towards refocusing European energy research and aiming to provide effective responses to the major challenges facing European society. It is important to fully exploit the experience and the results from the research undertaken under the FP4 since the knowledge generated relates directly to the objectives of the next Energy Research Programme. It also provides the groundwork for launching effective and innovative approaches to implementing the “European Research Area”. Based on the present pilot exercise, the remaining projects of the Non-Nuclear Energy Programme of the FP4 will be assessed to provide a full picture of the impact of the Programme. Finally, the present pilot exercise should help to provide a methodological base for other research programmes to develop quick-response, feedback to decision-makers to allow for the development of better informed research policies and actions. It should also help to bring more quickly the results and socio-economic implications of European research to European citizens, companies and institutions

Anti-Müllerian Hormone Signaling Regulates Epithelial Plasticity and Chemoresistance in Lung Cancer

© 2016 The Author(s)Anti-Müllerian hormone (AMH) and its type II receptor AMHR2, both previously thought to primarily function in gonadal tissue, were unexpectedly identified as potent regulators of transforming growth factor (TGF-β)/bone morphogenetic protein (BMP) signaling and epithelial-mesenchymal transition (EMT) in lung cancer. AMH is a TGF-β/BMP superfamily member, and AMHR2 heterodimerizes with type I receptors (ALK2, ALK3) also used by the type II receptor for BMP (BMPR2). AMH signaling regulates expression of BMPR2, ALK2, and ALK3, supports protein kinase B-nuclear factor κB (AKT-NF-κB) and SMAD survival signaling, and influences BMP-dependent signaling in non-small cell lung cancer (NSCLC). AMH and AMHR2 are selectively expressed in epithelial versus mesenchymal cells, and loss of AMH/AMHR2 induces EMT. Independent induction of EMT reduces expression of AMH and AMHR2. Importantly, EMT associated with depletion of AMH or AMHR2 results in chemoresistance but sensitizes cells to the heat shock protein 90 (HSP90) inhibitor ganetespib. Recognition of this AMH/AMHR2 axis helps to further elucidate TGF-β/BMP resistance-associated signaling and suggests new strategies for therapeutic targeting of EMT

Switch of noninvasive ventilation (NIV) to continuous positive airway pressure (CPAP) in patients with obesity hypoventilation syndrome: a pilot study

International audienceObesity is a major worldwide public health issue. The main respiratory complication stemming from obesity is obesity hypoventilation syndrome (OHS). Most of the OHS patients diagnosed during an exacerbation are treated with non invasive ventilation (NIV). Up to date, no prospective study has demonstrated in real life conditions the feasibility of a systematic protocoled switch of NIV to continuous positive airway pressure (CPAP), once stability is achieved

TOPAZ1, a Novel Germ Cell-Specific Expressed Gene Conserved during Evolution across Vertebrates

BACKGROUND: We had previously reported that the Suppression Subtractive Hybridization (SSH) approach was relevant for the isolation of new mammalian genes involved in oogenesis and early follicle development. Some of these transcripts might be potential new oocyte and granulosa cell markers. We have now characterized one of them, named TOPAZ1 for the Testis and Ovary-specific PAZ domain gene. PRINCIPAL FINDINGS: Sheep and mouse TOPAZ1 mRNA have 4,803 bp and 4,962 bp open reading frames (20 exons), respectively, and encode putative TOPAZ1 proteins containing 1,600 and 1653 amino acids. They possess PAZ and CCCH domains. In sheep, TOPAZ1 mRNA is preferentially expressed in females during fetal life with a peak during prophase I of meiosis, and in males during adulthood. In the mouse, Topaz1 is a germ cell-specific gene. TOPAZ1 protein is highly conserved in vertebrates and specifically expressed in mouse and sheep gonads. It is localized in the cytoplasm of germ cells from the sheep fetal ovary and mouse adult testis. CONCLUSIONS: We have identified a novel PAZ-domain protein that is abundantly expressed in the gonads during germ cell meiosis. The expression pattern of TOPAZ1, and its high degree of conservation, suggests that it may play an important role in germ cell development. Further characterization of TOPAZ1 may elucidate the mechanisms involved in gametogenesis, and particularly in the RNA silencing process in the germ lin

The ARIA-MASK-air® approach

Funding Information: The authors thank Ms Véronique Pretschner for submitting the paper. MASK‐air has been supported by Charité Universitätsmedizin Berlin, EU grants (EU Structural and Development Funds Languedoc Roussillon and Region PACA; POLLAR: EIT Health; Twinning: EIP on AHA; Twinning DHE: H2020; Catalyse: Horizon Europe) and educational grants from Mylan‐Viatris, ALK, GSK, Novartis, Stallergènes‐Greer and Uriach. None for the study. ® Publisher Copyright: © 2023 The Authors. Clinical and Translational Allergy published by John Wiley & Sons Ltd on behalf of European Academy of Allergy and Clinical Immunology.MASK-air®, a validated mHealth app (Medical Device regulation Class IIa) has enabled large observational implementation studies in over 58,000 people with allergic rhinitis and/or asthma. It can help to address unmet patient needs in rhinitis and asthma care. MASK-air® is a Good Practice of DG Santé on digitally-enabled, patient-centred care. It is also a candidate Good Practice of OECD (Organisation for Economic Co-operation and Development). MASK-air® data has enabled novel phenotype discovery and characterisation, as well as novel insights into the management of allergic rhinitis. MASK-air® data show that most rhinitis patients (i) are not adherent and do not follow guidelines, (ii) use as-needed treatment, (iii) do not take medication when they are well, (iv) increase their treatment based on symptoms and (v) do not use the recommended treatment. The data also show that control (symptoms, work productivity, educational performance) is not always improved by medications. A combined symptom-medication score (ARIA-EAACI-CSMS) has been validated for clinical practice and trials. The implications of the novel MASK-air® results should lead to change management in rhinitis and asthma.publishersversionpublishe