Effect of the umbrella arch technique modelled as a homogenized area above a cross passage

The stability of tunnel cross passages excavated in soft soil has always been a major challenge. In recent years, new techniques based on the installation of pre-reinforcements before tunnel excavation have been developed to control excavation-induced deformation and surface settlements. In this paper, a finite element numerical simulation was conducted to study the reduction effect of an umbrella vault element modelled as a homogenized area on the deformations induced after the excavation of a cross passage. The results of this study show that the ground deformations can be controlled efficiently by using this type of pre-reinforcement. However, the findings showed that there is no effect of the umbrella arch length on the reduction of the ground deformations. This paper represents a very good demonstration of 3D modelling of tunnel junctions using pre-support techniques; it is the most advanced/appropriate research tool for studying the behaviour of cross passages and is useful as a paradigm for other researchers and practitioners

Metabolomics approaches for early cancer diagnosis: A review

Cancer remains a major burden on global public health with high mortality rates worldwide. Current diagnosis can detect cancer in late stages when therapy options become limited. Early diagnosis is broadly recognized as the key to a better treatment to save lives. The metabolomics approach provides a better understanding of the different types of cancer. They offer promising and potential interventions in biomarkers discovery which eventually will be better suited for individualized medicine. It elucidates endpoint products for other omic processes while significantly improving the understanding of pathogenesis and mechanisms yet to be discovered. Metabolomics offers a less-invasive, cost-effective for predicting, screening, diagnosis, prognosis, and monitoring therapeutic responses of the disease. There are two methods to study the metabolism and metabolites: targeted and untargeted. The workflow of these approaches requires different analytical platforms, such as Nuclear Magnetic Resonance spectroscopy (NMR), Mass Spectrometry (MS), and different bioinformatic tools. This review provides a systematic summary of metabolomics methods in identifying metabolic biomarkers of cancers (colorectal, prostate, breast, bladder, pancreas, lung, and buccal cancers). In addition, the current review will try to shed light on DNA lesions as a potential metabolic biomarker for cancer

BATLAS: Deconvoluting Brown Adipose Tissue

Recruitment and activation of thermogenic adipocytes have received increasing attention as a strategy to improve systemic metabolic control. The analysis of brown and brite adipocytes is complicated by the complexity of adipose tissue biopsies. Here, we provide an in-depth analysis of pure brown, brite, and white adipocyte transcriptomes. By combining mouse and human transcriptome data, we identify a gene signature that can classify brown and white adipocytes in mice and men. Using a machine-learning-based cell deconvolution approach, we develop an algorithm proficient in calculating the brown adipocyte content in complex human and mouse biopsies. Applying this algorithm, we can show in a human weight loss study that brown adipose tissue (BAT) content is associated with energy expenditure and the propensity to lose weight. This online available tool can be used for in-depth characterization of complex adipose tissue samples and may support the development of therapeutic strategies to increase energy expenditure in humans

Metabotropic action of postsynaptic kainate receptors triggers hippocampal long-term potentiation

Long-term potentiation (LTP) in the rat hippocampus is the most extensively studied cellular model for learning and memory. Induction of classical LTP involves an NMDA receptor- and calcium-dependent increase in functional synaptic AMPA receptors mediated by enhanced recycling of internalized AMPA receptors back to the postsynaptic membrane. Here we report a novel, physiologically relevant NMDA receptor-independent mechanism that drives increased AMPA receptor recycling and LTP. This pathway requires the metabotropic action of kainate receptors and activation of G-protein, protein kinase C and phospholipase C. Like classical LTP, kainate receptor-dependent LTP recruits recycling endosomes to spines, enhances synaptic recycling of AMPA receptors to increase their surface expression and elicits structural changes in spines, including increased growth and maturation. These data reveal a new and previously unsuspected role for postsynaptic kainate receptors in the induction of functional and structural plasticity in the hippocampus

Exergy analysis and dynamic optimization of petroleum production systems to reduce CO2 emissions

Ce projet de recherche s’inscrit dans une démarche d’amélioration de l’efficacité énergétique et de la réduction des émissions de gaz à effet de serre des systèmes de production de pétrole et de gaz au sein du groupe Total.L’analyse exergétique a été développée et appliquée pour la première fois à la partie subsurface (réservoir-puits) et élargie pour l’ensemble du système de production de pétrole et de gaz, permettant de quantifier les différentes pertes et destructions d’exergie, l’exergie naturelle fournie par le réservoir et l’exergie générée artificiellement (activation), pour des exemples théoriques et réels. Nous avons aussi proposé une représentation avec des diagrammes de Grassmann adaptés pour afficher les résultats de l’analyse exergétique sur l’ensemble du système de production. Enfin, les résultats de l’analyse exergétique nous ont permis de proposer des solutions technologiques pour améliorer la productivité et réduire les émissions de CO2.Dans la deuxième partie de ce projet nous avons développé une nouvelle méthodologie pour l’optimisation dynamique des systèmes de production d’hydrocarbures dans l’environnement contraint des logiciels dédiés à la production pétrolière (en l’occurrence dans cette thèse la suite IPM (Integrated Production Modeling) développée par PETEX). L’objectif est de proposer une optimisation simultanée de la structure et des paramètres opératoires du système de production (écoulement naturel ou assisté? quel type d’activation: gas-lift, pompes? quel type de pompe?) tout le long de la vie du champ. Deux fonctions objectif sont proposées pour évaluer la performance des systèmes de production d’hydrocarbures pendant tous leurs cycles de vie : i) l’exergie nette cumulée (CNE) et ii) profit cumulé (CNP). Le problème énoncé est ensuite résolu à l'aide de la suite IPM de PETEX, couplée au calculateur thermodynamique Simulis® Thermodynamics (PROSIM) pour les calculs exergétiques. L’approche est une approche séquentielle et les pas horaires sont de l’ordre de l’année, chaque pas horaire étant simulé en quasi-statique. L'algorithme génétique inclus dans la suite IPM est utilisé pour résoudre le problème d’optimisation dynamique en variables mixtes moyennant quelques adaptations. Les résultats montrent qu’il est possible de trouver un compromis entre la rentabilité et les émissions de gaz à effet de serre (GES).This research project is part of an initiative to improve the energy efficiency and reduce greenhouse gas emissions of oil and gas production systems within the Total Group. Exergy analysis has been developed and applied for the first time to the subsurface part (reservoir-well) and extended to the entire oil and gas production system, making it possible to quantify the different losses and destruction of exergy, the natural exergy provided by the reservoir ,and the artificially generated exergy (artificial lift and boosting), for theoretical and real examples. We have also proposed a representation with adapted Grassmann diagrams to display the results of the exergy analysis on the whole production system. Finally, the results of the exergy analysis allowed us to propose technological solutions to improve hydrocarbon production and reduce greenhouse gas (GHG) emissions.In the second part of this project we developed a new methodology for the dynamic optimization of hydrocarbon production systems in a constrained software environment dedicated to petroleum production (in this case the IPM (Integrated Production Modeling) solution developed by PETEX). The objective is to propose a simultaneous optimization of the structure and operating parameters of the production system (natural or artificial ? what type of artificial lift and/or boosting system : gas-lift, pumps? Which type of pumps?) throughout its life cycle. Two objective functions are proposed to evaluate the performance of hydrocarbon production systems: (i) cumulative net exergy (CNE) and (ii) cumulative net profit (CNP). The stated problem is then solved using PETEX's IPM suite, coupled with the Simulis® Thermodynamics Calculator (PROSIM) for exergy calculations. The approach is sequential and the time-steps are in the order of a year, each time-step being simulated in quasi-static. The genetic algorithm included in the IPM suite is used to solve the mixed variables dynamic optimization problem with some adaptations. The results show that it is possible to find a compromise between profitability and greenhouse gas (GHG) emissions

Conséquences d'une carence en donneurs de méthyles sur la différenciation cellulaire, la survie et la neuroplasticité : approches mécanistiques in vitro sur des lignées neuronales

Folate (vitamin B9) and vitamin B12 act as cofactors in the one-carbon metabolism that regulates transmethylation reactions involved in epigenetic mechanisms. A deficiency in folate and/or B12 decreases the generation of methionine from homocysteine, a toxic amino acid that has been associated with pathologies of the central nervous system at all ages (spina bifida, Alzheimer's disease...). In order to depict the cellular and molecular mechanisms implicated in the response to the deficiency in these micronutrients, two new cell models have been developed. Thus, we have analyzed the effects of folate deficiency on proliferation, differentiation and neuroplasticity of neuronal progenitors obtained from the hippocampus of rat embryos, i.e. the H19-7 cell line. Regarding the second model, we designed an original approach by stable transfection of NIE-115 murine neuroblastoma cells to impose the anchorage of a chimeric B12 binding protein, transcobalaminoleosin (TO) to intracellular membrane in order to produce intracellular sequestration of B12. Taken together, our results have shown that deficiency-associated alterations of the one-carbon metabolism lead to reduced neurogenesis and to dramatic impairment of neuron differentiation. This suggests the existence of specific mechanisms through which vitamin B9/B12 deficiency and/or homocysteine may affect brain functioning and plasticity.Les folates (vitamine B9) et la vitamine B12 interviennent comme cofacteurs dans le métabolisme des monocarbones qui régule les réactions de transméthylation impliquées dans les mécanismes épigénétiques. Un déficit en folates et/ou B12 réduit la production de méthionine à partir de l'homocystéine, un acide aminé toxique dont l'accumulation a été associée à la survenue de pathologies du système nerveux central aux différents stades de la vie (spina bifida, maladie d'Alzheimer...). Afin d'explorer les mécanismes cellulaires et moléculaires impliqués dans la réponse à la carence en ces micronutriments, nous avons développé deux nouveaux modèles cellulaires. Ainsi, nous avons étudié les effets d'une déficience en folate sur la prolifération, la différenciation et la plasticité neuronale de progéniteurs neuronaux issus de l'hippocampe d'embryons de rat, la lignée H19-7. Le second modèle correspond à un projet innovant visant à obtenir une déplétion cellulaire en B12 par séquestration membranaire. Il a été obtenu par transfection stable de la lignée de neuroblastome murin NIE-115 dans le but d'induire l'expression d'une protéine chimère contenant le transporteur plasmatique de la vitamine B12, la transcobalamine II, et une protéine d'ancrage membranaire. L'ensemble de ces travaux montre que les altérations du métabolisme des monocarbones associées aux carences répriment la neurogenèse et induisent des troubles de la différentiation neuronale. Ceci suggère l'existence de mécanismes précis par lesquels le déficit en folates, en vitamine B12 et/ou l'homocystéine peuvent affecter le fonctionnement du cerveau et sa plasticité

Factoring multi power RSA moduli with a class of secret exponents

In this paper, we consider the RSA variant based on the key equation ed ≡ 1 (mod φ(N)) where N = prq, r ≥ 2. We show that if the secret exponent d is close to any multiple of the prime factor p or its powers, then it is possible to factor N in polynomial time in log N

Conséquences d'une carence en donneurs de méthyles sur la différenciation cellulaire, la survie et la neuroplasticité (approches mécanistiques in vitro sur des lignées neuronales)

Les folates (vitamine B9) et la vitamine B12 interviennent comme cofacteurs dans le métabolisme des monocarbones qui régule les réactions de transméthylation impliquées dans les mécanismes épigénétiques. Un déficit en folates et/ou B12 réduit la production de méthionine à partir de l'homocystéine, un acide aminé toxique dont l'accumulation a été associée à la survenue de pathologies du système nerveux central aux différents stades de la vie (spina bifida, maladie d'Alzheimer ). Afin d'explorer les mécanismes cellulaires et moléculaires impliqués dans la réponse à la carence en ces micronutriments, nous avons développé deux nouveaux modèles cellulaires. Ainsi, nous avons étudié les effets d'une déficience en folate sur la prolifération, la différenciation et la plasticité neuronale de progéniteurs neuronaux issus de l'hippocampe d'embryons de rat, la lignée H19-7. Le second modèle correspond à un projet innovant visant à obtenir une déplétion cellulaire en B12 par séquestration membranaire. Il a été obtenu par transfection stable de la lignée de neuroblastome murin NIE-115 dans le but d'induire l'expression d'une protéine chimère contenant le transporteur plasmatique de la vitamine B12, la transcobalamine II, et une protéine d'ancrage membranaire. L'ensemble de ces travaux montre que les altérations du métabolisme des monocarbones associées aux carences répriment la neurogenèse et induisent des troubles de la différentiation neuronale. Ceci suggère l'existence de mécanismes précis par lesquels le déficit en folates, en vitamine B12 et/ou l'homocystéine peuvent affecter le fonctionnement du cerveau et sa plasticité.Folate (vitamin B9) and vitamin B12 act as cofactors in the one-carbon metabolism that regulates transmethylation reactions involved in epigenetic mechanisms. A deficiency in folate and/or B12 decreases the generation of methionine from homocysteine, a toxic amino acid that has been associated with pathologies of the central nervous system at all ages (spina bifida, Alzheimer's disease ). In order to depict the cellular and molecular mechanisms implicated in the response to the deficiency in these micronutrients, two new cell models have been developed. Thus, we have analyzed the effects of folate deficiency on proliferation, differentiation and neuroplasticity of neuronal progenitors obtained from the hippocampus of rat embryos, i.e. the H19-7 cell line. Regarding the second model, we designed an original approach by stable transfection of NIE-115 murine neuroblastoma cells to impose the anchorage of a chimeric B12 binding protein, transcobalaminoleosin (TO) to intracellular membrane in order to produce intracellular sequestration of B12. Taken together, our results have shown that deficiency-associated alterations of the one-carbon metabolism lead to reduced neurogenesis and to dramatic impairment of neuron differentiation. This suggests the existence of specific mechanisms through which vitamin B9/B12 deficiency and/or homocysteine may affect brain functioning and plasticity.NANCY1-Bib. numérique (543959902) / SudocSudocFranceF

Numerical modeling to predict the spread of landslide of schist’s area under climatic event of Ain El Hammam (Algeria)

International audienceThe several reactivations of the landslide of Ain El Hammam (AEH) after each important weather event compel us to look closely at its triggering factors and predict its mechanisms and its evolution at the longer term. In this sense, the prediction of the slope behavior becomes necessary. This paper presents a numerical model of the AEH landslide using Plaxis® software. This model considers hydraulic effects such as precipitation and pore pressure even in the unsaturated parts. Soil and rock behaviors are described with proper elasto-plastic models named Hardening Soils and Jointed Rocks. The first model takes into account hardening on isotropic and deviatoric mechanism as well as a non-associated flow rule. The second model considers a non-isotropic elasticity with perfect plasticity along with given sliding directions. The hydraulic and mechanical models are coupled with an effective stress concept. To detect unstable areas in the landslide, we developed a Matlab® program to take into account the Hill’s bifurcation criterion, which is based on sign of the second-order work. It has been proved that this criterion allows detecting all failure modes that can appear in rate-independent materials and especially the ones that develop before the plasticity limit criterion. From such computations, we can predict the shape and position of slip surface responsible of the actual ground movement of the slope. To validate the numerical results, analysis of field measurement is included. We use high resolution of electrical tomography to delineate the geometry and position of failure surface and approve our results