An optimal control problem for the continuity equation arising in smart charging

This paper is focused on the mathematical modeling and solution of the optimal charging of a large population of identical plug-in electric vehicles (PEVs) with mixed state variables (continuous and discrete). A mean field assumption is formulated to describe the evolution interaction of the PEVs population. The optimal control of the resulting continuity equation of the mixed system under state constraints is investigated. We prove the existence of a minimizer. We then characterize the solution as the weak solution of a system of two coupled PDEs: a continuity equation and of a Hamilton-Jacobi equation. We provide regularity results of the optimal feedback control

DISSOLUTION OF AEROSOL IRON IN SEA WATER USING FLOW-INJECTION WITH CHEMILUMINESCENCE DETECTION

Iron is an essential micronutrient for the metabolism of marine organisms and impacts on primary productivity and hence indirectly on climate change. The dominant source of iron to the sea surface in open ocean regions is from the atmosphere by aeolian dust transport but the solubility of iron from dust is poorly constrained. In this thesis, chemical and physical factors impacting on the process of dust dissolution and iron release in seawater were investigated using FI-CL detection. A manual FI manifold was automated and optimised for the determination of iron, at nanomolar concentrations, released from aerosols in seawater. The limit of detection was 0.04 ± 0.03 nM and the precision (rsd) ranged from 0.2 to 10.8%. Protocols, maintenance find troubleshooting sections were documented for effective utilisation o f the technique. A seawater treatment system to produce low DOC (dissolved organic carbon) and dFe (dissolved iron) seawater was adapted and optimised. This UV photo-oxidation system was poorly efficient in removing DOC (-40%), complexing ligands (~60%) and dFe (apparent removal 90%). An autosampler was designed, validated, and integrated with an incubation system for sub-sampling during dissolution experiments of aerosol iron in seawater. Fast release of iron f r om the aerosol particles occurred within the first 2 h, followed by a decrease over 1 day. Preliminary experiments w i t h UV-irradiated seawater exhibited lower solubilities compared w i t h non UV-irradiated seawater. High dust concentrations gave lower final solubilities compared with low dust concentrations. A 24 h kinetic study was carried out using NIST 1648 under contrasting light and dark regimes. Dissolution of the endmember under dark conditions released 0.36% of the iron whilst the addition of 20 nM to 200 nM Desferrioxamine B (DFOB) stimulated a release of 0.90 to 1.6%. In light, the release of iron was 0.50% with aerosol, whilst the addition of DFOB (20 nM) induced an adsorption (-1.18%). Iron release from aerosol samples from three sites around the Eastern Mediterranean: Erdemli, Tel-Shikmona and Heraklion was determined in a NATO funded project. The solubility of contrasting aerosol populations from crustal and anthropogenic sources was investigated. Crustally derived aerosol samples exhibited a variable kinetic profile of iron release with an average of maximum solubility of 0.39 ± 0.52%. The anthropogenically influenced aerosol samples exhibited consistent kinetic profiles (fast release < 2 h) with an average of maximum solubility of 10.6 ± 8.9%. From these results, an approximation of the atmospheric dry inputs of soluble iron in seawater to the Levantine Basin was calculated for the first time, ranging from 804 ± 910 t for the Northern Levantine Basin to 2,670 ± 3,050 t for the Southern Levantine Basin

Mammography-based screening program: preliminary results from a first 2-year round in a Brazilian region using mobile and fixed units

RLH, TBS and ALF made substantial contributions to the conception and design of the article, the acquisition, analysis and interpretation of the data, and drafting of the article. ECM, JSCM and NB made substantial contributions to the conception and design of the study.Background: Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer deaths among women worldwide. The use of mobile mammography units to offer screening to women living in remote areas is a rational strategy to increase the number of women examined. This study aimed to evaluate results from the first 2 years of a government-organized mammography screening program implemented with a mobile unit (MU) and a fixed unit (FU) in a rural county in Brazil. The program offered breast cancer screening to women living in Barretos and the surrounding area. Methods: Based on epidemiologic data, 54 238 women, aged 40 to 69 years, were eligible for breast cancer screening. The study included women examined from April 1, 2003 to March 31, 2005. The chi-square test and Bonferroni correction analyses were used to evaluate the frequencies of tumors and the importance of clinical parameters and tumor characteristics. Significance was set at p < 0.05. Results: Overall, 17 964 women underwent mammography. This represented 33.1% of eligible women in the area. A mean of 18.6 and 26.3 women per day were examined in the FU and MU, respectively. Seventy six patients were diagnosed with breast cancer (41 (54%) in the MU). This represented 4.2 cases of breast cancer per 1000 examinations. The number of cancers detected was significantly higher in women aged 60 to 69 years than in those aged 50 to 59 years (p < 0.001) or 40 to 49 years (p < 0.001). No difference was observed between women aged 40 to 49 years and those aged 50 to 59 years (p = 0.164). The proportion of tumors in the early (EC 0 and EC I) and advanced (CS III and CS IV) stages of development were 43.4% and 15.8%, respectively. Conclusions: Preliminary results indicate that this mammography screening program is feasible for implementation in a rural Brazilian territory and favor program continuation

Stem Cell Reports

Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) offer great potential for drug screening and disease modeling. However, hiPSC-CMs remain immature compared to the adult cardiac cells. Cardiomyocytes isolated from adult human hearts have a typical rod-shaped morphology. Here, we sought to develop a simple method to improve the architectural maturity of hiPSC-CMs by using a rod-shaped cell micropatterned substrate consisting of repeated rectangles (120 μm long × 30 μm wide) surrounded by a chemical cell repellent. The generated hiPSC-CMs exhibit numerous characteristics similar to adult human cardiomyocytes, including elongated cell shape, well-organized sarcomeres, and increased myofibril density. The improvement in structural properties correlates with the enrichment of late ventricular action potentials characterized by a more hyperpolarized resting membrane potential and an enhanced depolarization consistent with an increased sodium current density. The more mature hiPSC-CMs generated by this method may serve as a useful in vitro platform for characterizing cardiovascular disease.Édition génomique par CRISPR/Cas9 pour traiter les cardiomyopathies liées aux mutations du gène LMN

Novel Fat Depot–Specific Mechanisms Underlie Resistance to Visceral Obesity and Inflammation in 11β-Hydroxysteroid Dehydrogenase Type 1–Deficient Mice

OBJECTIVE-The study objective was to determine the key early mechanisms underlying the beneficial redistribution, function, and inflammatory profile of adipose tissue in 11 beta-hydroxysteroid dehydrogenase type 1 knockout (11 beta-HSD1(-/-)) mice fed a high-fat (HF) diet. RESEARCH DESIGN AND METHODS-By focusing on the earliest divergence in visceral adiposity, subcutaneous and visceral fat depots from 11 beta-HSD1(-/-) and C57B1/6J control mice fed an HF diet for 4 weeks were used for comparative microarray analysis of gene expression, and differences were validated with real-time PCR. Key changes in metabolic signaling pathways were confirmed using Western blotting/immunoprecipitation, and fat cell size was compared with the respective chow-fed control groups. Altered adipose inflammatory cell content and function after 4 weeks (early) and 18 weeks (chronic) of HF feeding was investigated using fluorescence (and magnetic)-activated cell sorting analysis, immunohistochemistry, and in situ hybridization. RESULTS-In subcutaneous fat, HF-fed 11 beta-HSD1(-/-) mice showed evidence of enhanced insulin and p-adrenergic signaling associated with accretion of smaller metabolically active adipocytes. In contrast, reduced 11 beta-HSD1(-/-) visceral fat accumulation was characterized by maintained AMP kinase activation, not insulin sensitization, and higher adipocyte interleukin-6 release. Intracellular glucocorticoid deficiency was unexpectedly associated with suppressed inflammatory signaling and lower adipocyte monocyte chemoattractant protein-1 secretion with strikingly reduced cytotoxic T-cell and macrophage infiltration, predominantly in visceral fat. CONCLUSIONS-Our data define for the first time the novel and distinct depot-specific mechanisms driving healthier fat patterning and function as a result of reduced intra-adipose glucocorticoid levels.</p

Collective movements and social structure of the zebrafish in a fragmented environment

La prise de décision collective est un des mécanismes usités par les espèces sociales lors d’événements de collectes de nourriture, d’optimisation de chemins, de mouvements collectifs, de fuites face à un prédateur ou bien même de sélections d’habitat. Les zebrafish (Danio rerio), animaux grégaires de référence en biologie, n’ont jamais été étudiés dans des contextes de choix collectifs binaires et ils nous semblait légitime d’analyser leurs comportements décisionnels. L’objectif de cette thèse est de répondre aux attentes du projet ASSISI|bf de création d’un système expérimental modulable capable d’accueillir robots comme poissons, de mise au point d’une société mixte adaptative auto-organisée, et de caractérisation des comportements individuels et collectifs des zebrafish implémentables dans les robots. Nos observations montrent que la prise collective de décision et la cohésion des groupes en environnement ouvert, et présentant deux points de repère identiques, sont des processus dynamiques qui varient selon la souche de Danio rerio (AB ou TL) et sont liées à la densité des populations. Constamment en mouvement, les poissons oscillent entre les deux points de repère identiques installés dans leur environnement. La souche AB est toujours plus attirée par ces hétérogénéités et est beaucoup moins cohésive que la souche TL. En environnement contraint, de type deux chambres reliées par un couloir, nous réitérons le même type d’expérience chez la souche la plus à même de prendre des décisions collectivement (AB) et en faisant varier la densité des groupes de 1 à 20 individus. Il ressort que les Danio rerio de type AB restent essentiellement en groupe mais que l’augmentation de leur densité tend à les diviser. Nous remarquons aussi que la densité influe partiellement sur la topologie du groupe : il existe, lors des sorties collectives, une corrélation entre l’ordre de sortie des zebrafish (les suiveurs) et l’ordre de distance de chaque individu par rapport à l’initiateur desdites sorties. Cette corrélation est d’autant plus forte quand les suiveurs sont soit très proches, soit les plus éloignés de l’initiateur. Le dispositif expérimental précédent nous permet d’autre part de nous concentrer sur la notion de leadership chez des groupes de 2 à 10 Danio rerio AB. Nous mettons en évidence que chaque poisson initie au moins une fois un départ collectif, le nombre d’initiations effectives est proportionnel au nombre de tentatives d’initiations, que tous les poissons présentent le même taux de succès d’initiation après une tentative et qu’il existe une corrélation positive entre initiations et vitesse moyenne de nage.Une analyse poussée des mouvements collectifs nous fait constater que les zebrafish se déplacent essentiellement en groupe et transitent sans interruption ni périodicité entre les chambres. Nous sommes actuellement en train d’améliorer cette étude en apportant de nouveaux points de comparaison afin de vérifier si la non-périodicité des transitions entre les chambres est liée à la densité des groupes testés. Enfin, nous nous inspirons du précédent système expérimental – les deux chambres reliées par un couloir – pour créer une version actualisée d’un labyrinthe en Y. Ce labyrinthe en Y est dit perpétuel car il combine tout le savoir faire que nous avons développé dans l’élaboration des précédents systèmes expérimentaux : une faible habituation des zebrafish pour leur milieu, une réduction des interactions entre l’expérimentateur et les animaux et la possibilité pour les poissons de circuler dans un labyrinthe à symétrie centrale, sans zone de départ ni zone de fin formalisées (typiques des labyrinthes en Y)The collective decision-making is one of the mecanisms used by social species during foraging, path optimisation, collective movements, predator avoidance or habitat selection. Zebrafish (Danio rerio), gregarious animal models in biology, have never been studied in the context of collective binary choices. We found logical to analyse their decision behaviours. The goal of this thesis is to meet the expectations of the ASSISI|bf project of creation of an andjustable experimental setup able to sustain robots and fish, of development of an adaptive and self-organised mixed society and of the caracterisation of individual and collective behaviours of the zebrafish, implementable in the robots. We show that the collective decision making and the cohesion of groups of zebrafish in an open environment, composed of two identical landmarks, are dynamical processes that vary in function of the strain of Danio rerio (AB or TL) and are related to the density of the populations. Always on the move, the fish oscillate between the two landmarks. The AB zebrafish are more attracted by the landmarks and are less cohesive than the TL zebrafish. In a contrained environment, two rooms connected by a corridor, we do the same type of experiments with only AB zebrafish and vary the density of the groups from 1 to 20 individuals. AB zebrafish swim together. The increase of the density of the groups make them split. We noticed that the density of the groups has an effect on the topology of the groups : during collective departures from a room to the other one, there is a correlation between the rank of exit of the zebrafish (followers) and the rank of the distances of each individual from the initiator of the exits. This correlation is higher when the followers are either the closest or the farest from the initiator.Using the previous experimental setup, we focused also on the topics related to leadership for groups of 2 to 10 individuals. We show that each fish intiate at least once a collective departure and that the number of initiations is proportional to the number of initiation attempts. Also, we found that all the fish have the same success rate in the initiations after an initiation attempt and that there is a positive correlation between the intiations and the average speed. A deeper analysis of the collective movements shows that the zebrafish swim in group and transit without any interruption or even without periodicity between the rooms. We are currently improving this study and will bring new points of comparison to check if the non-periodicity of the transitions could be related to the density of the groups. Finally, we developed a new version of the Y-maze based on the previous observations.This perpetual Y-maze shows many usefull features for the study of the behaviour : a low habituation rate, a reduction of the interactions between the animals and the experimentators, and allows the fish to move in a Y-maze without starting nor ending zones as in typical Y-maz

La fonction logistique, un outil performant d'analyse et de prévision à moyen terme. Application à la production de pétrole et de gaz aux Etats-Unis, en URSS et dans d'autres pays

A partir de la similitude observée entre l'évolution de la production pétrolière d'un pays et celle de la pénétration d'un produit dans un marché (fonction logistique), l'auteur expose le principe d'une méthode originale qui permet, sous certaines conditions, de prévoir quelle sera la production annuelle probable d'un pays producteur à un horizon de 10 à 15 ans. La validité de cette méthode est d'abord démontrée sur l'exemple de la production pétrolière aux Etats-Unis. Elle est ensuite illustrée par les résultats obtenus pour un certain nombre de pays : production future de gaz aux Etats-Unis, production pétrolière future du Canada, de l'URSS, du Venezuela et de l'ensemble du monde hors Moyen-Orient