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Démolitions ordinaires dans l'Est lyonnais: Vaulx-en-Velin Sud, un espace vulnérable ?
No full textInternational audienceÀ rebours des travaux sur les grandes opérations de démolition-reconstruction, notamment faites dans le cadre de la rénovation urbaine et des grands projets, l'intervention se propose d'aborder la démolition sous sa modalité la plus discrète : celle du « grignotage » ordinaire du bâti ancien. Elle vise à visibiliser ce phénomène de démolition ordinaire qui, s'il a toujours plus ou moins existé, s'est accéléré ces vingt-cinq dernières années avec les injonctions à la sobriété foncière dans les grands agglomérations. L'intervention se fonde sur une recension cartographique des édifices disparus dans plusieurs communes de l'Est lyonnais et reviendra sur les aspects méthodologiques de la démarche. Enfin, elle abordera le cas d'un espace en proie à ce phénomène, le quartier de Vaulx-en-Velin Sud, voisin de la ZAC du Carré de Soie
Relevance of trigonometric method to achieve the angular correction during pedicule subtraction osteotomy
No full textInternational audienceIntroductionPedicle subtraction osteotomy (PSO) represents an efficient technique to correct severe and rigid spinal deformities. One of the challenges, in addition to stabilize adequately the spinal segment, is to reach the desired angular correction that was defined preoperatively. The objective of this work is to describe and evaluate a simple, reproducible and relevant method based on trigonometrical concepts, guiding the surgeon to achieve the targeted correction. Study design Comparative retrospective CT-scan based consecutive series of PSO.Material and Method The concept of the trigonometric method is based on the geometrical relation between the angular correction obtained at the site of the PS0 (angle α) and the height of bony resection achieved at the posterior wall of theosteotomized vertebra (h). The proposed formula is: h = 2.L.tan(α/2) with L corresponding to the antero-posterior length of the vertebral body. Therefore, according to the corrected angle planned, the height of bony resection can be established helping the surgeon intra-operatively. Adult patients included in the study were operated for a grade 3 or 4PSO between January 2012 and October 2020. For these patients, we compared the correction obtained on the post-operative CT-scan versus the correction predicted by the formula.Results A total of 55 patients were included with 34 women and 21 men. Mean age was 65.2 ± 9.9 years. 75% of PSO wereperformed on L4. Degenerative changes were the most frequent cause of the deformity (45%). The mean difference (defined as the delta Δm) between the correction effectively achieved surgically and the correction angle predicted by the trigonometric formula was 1.4 ± 1.5° [0-5.6]. Mean angular correction achieved at the level of the PSO was 22.8°±6.5, with a minimum and maximum correction of 7.5° and 36.6°, respectively.When thebone resection was limited strictly to the pedicle height, mean correction was found to be 24°, while resection 2/3 mm less than pedicle height resulted into a mean correction of 16°, and for resection 2/3 mm more than pedicle height, a mean correction of 27°can be expected. Finally, the correction could reach 32° if the bone resection was 5 mm superior to pedicle height.Conclusion The mathematical formula seems to be enough accurate and reliable to guide the spine surgeons and to be utilized intra-operatively and during preoperative planning in order to define the amount of vertebral bony resection required at the PSO level according to the desired angular correction
Purified and biocompatible magnetoliposomes highly loaded with superparamagnetic iron oxide nanoparticles (SPIONs)
No full textInternational audienc
Break-down of the relationship between α-relaxation and equilibration in hydrostatically compressed metallic glasses
No full textInternational audienceGlasses encode the memory of any thermo-mechanical treatment applied to them. This ability is associated to the existence of a myriad of metastable amorphous states which can be probed through different experimental pathways. It is usually assumed that this memory can be erased in the supercooled liquid, and that this process occurs on a time scale controlled by the α-relaxation. We find that this assumption does not apply for hydrostatically compressed glasses. Annealing under pressure a prototypical metallic glass can irreversibly modify its dynamics, thermodynamics and structure, reduce the atomic mobility and lead to structural modifications of the first coordination shells which reduce the thermal stability with respect to a glass annealed in absence of pressure. When heated above their glass transition temperature, these compressed glasses do not convert into the pristine supercooled liquid, implying the existence of an additional process, beyond the α-relaxation, contributing to the equilibrium recovery of the material. These results establish pressure as a powerful tool for engineering non-equilibrium glassy materials with tailored properties, while deepening our understanding of relaxation dynamics in disordered systems under extreme conditions
Which theories have a measurement problem?
No full textInternational audienceIt is shown that any theory that has certain properties has a measurement problem, in the sense that it makes predictions that are incompatible with measurement outcomes being absolute (that is, unique and non-relational). These properties are Bell Nonlocality, Information Preservation, and Local Dynamics. The result is extended by deriving Local Dynamics from No Superluminal Influences, Separable Dynamics, and Consistent Embeddings. These results are achieved using a framework of \textit{perspectival theories} that generalizes the notion of a Heisenberg cut beyond quantum theory. As well as explaining why the existing Wigner's-friend-inspired no-go theorems hold for quantum theory, the results also shed light on whether a future theory of physics might overcome the measurement problem. In particular, they suggest the possibility of a theory in which absoluteness is maintained, but without rejecting relativity theory (as in Bohm theory) or embracing objective collapses (as in GRW theory)
Agressivité des soins en fin de vie en oncologie : où en sont nos pratiques ? Revue de pertinence dans un centre de lutte contre le cancer français
No full textInternational audienceAggressiveness of end-of-life care refers to intensive medical interventions at an advanced disease stage, including the late initiation of chemotherapy. This study assesses its incidence among patients hospitalized at the Léon-Bérard Center
Impact of Congenital Substrate 3D Imaging Reconstruction to Guide VT Catheter Ablation: The CORECA Study
No full textInternational audienceBACKGROUND: In the presence of sustained monomorphic ventricular tachycardia (VT), catheter ablation may be an option in congenital heart disease. However, the heterogeneity of underlying congenital heart disease and previous cardiac surgeries is associated with a unique and particularly complex substrate. The aim of the study was to investigate whether preprocedural 3-dimensional anatomic and substrate reconstruction based on cardiac computed tomography scan or magnetic resonance imaging could reliably identify VT substrate and ablation targets. METHODS: Consecutive patients with cardiac computed tomography or magnetic resonance imaging referred for VT ablation in 5 congenital electrophysiology centers were included. Three observers, electrophysiologists, blinded to the ablation procedure and each other, annotated potential ablation targets on 3-dimensional imaging reconstructions with a dedicated software (InHeart). Once completed, the annotations were compared between observers and with the ablation target(s) on the electroanatomical mapping generated during the procedures. RESULTS: Forty patients (mean age, 38±12 years; 67.5% male) underwent VT ablation, including 28 with a history of spontaneous sustained VT. VT was inducible in 97.5% of cases, with an acute success rate of ablation of 92.5%. Preprocedural imaging identified VT substrate in concordance with electroanatomical mapping in 87.5% of cases. There was a high degree of agreement between the observers. Positive interobserver agreement was complete in 65.0% of cases, moderate in 22.5%, and poor in 5.0%. Considering the total number of isthmuses identified by imaging in comparison with electroanatomical mapping, the sensitivity of imaging was 87.0%, and its positive predictive value was 77.0%. CONCLUSIONS: In our series, 3-dimensional anatomic reconstruction enabled identification of the critical VT substrate in most patients with complex congenital heart disease, particularly those with anatomically based reentrant circuits. Substrate target can be identified by operators with good interobserver reproducibility. This approach may guide VT ablation in these challenging cases
A local Lorentzian Ferrand-Obata theorem for conformal vector fields
No full textFor a conformal vector field on a closed, real-analytic, Lorentzian manifold we prove that the flow is locally isometric -- that it preserves a metric in the conformal class on a neighborhood of any point -- or the metric is everywhere conformally flat. The main theorem can be viewed as a local version of the Lorentzian Lichnerowicz conjecture in the real-analytic setting. The key result is an optimal improvement of the local normal forms for conformal vector fields of [FM13], which focused on non-linearizable singularities. This article is primarily concerned with essential linearizable singularities, and the proofs include global arguments which rely on the compactness assumption
Variations électriques dans La Vie moderne à l'époque de Georges Charpentier (1879-1883)
No full textInternational audienceFirst issued in April 1879, La Vie moderne, faithful to its mission to popularise science, initially appeared to be particularly welcoming to electricity, an energy that was then in full expansion: scientific columns were dedicated to it and fruitful interactions with the arts and literature were emerging. However, the rapid turnover in the magazine's staff (the departure of columnists Pierre Giffard and Henry Vivarez; the ousting of Émile Bergerat; the sale of the title by Georges Charpentier) was accompanied by a significant change in its editorial policy: the popularising dimension disappeared in favour of a preoccupation with chic and fashion that left little room for the many earlier manifestations of electricity.Si l’on en croit les mémoires publiés par Bergerat, c’est à la présence d’un « transparent lumineux » à la gloire du champagne Mercier d’Épernay que le journaliste doit d’avoir obtenu l’occupation à titre gratuit du vaste local nécessaire au lancement de La Vie moderne. Au début de l’année 1879, cette enseigne était sûrement éclairée au gaz. Mais ce « brasier d’enfer » qui avait le pouvoir de transformer brusquement le sombre entresol en « une grotte de stalactites, illuminée par cent torches » préfigure avec bonheur les rapports intimes et privilégiés que le journal illustré et l’électricité allaient par la suite nouer. Il faut dire que la fondation de l’organe de presse coïncide avec les prémices de la large diffusion de l’énergie révolutionnaire. L’un naît donc à la lumière de l’autre et la seconde va largement irriguer les colonnes du premier. En effet, si l’art est la préoccupation première de La Vie moderne, son empire s’étend bien au-delà et fait la part belle à tout ce qui relève du progrès et de la modernité : au premier rang des nouveautés qui la passionnent se trouve donc évidemment l’électricité. Celle-ci s’invite partout, dans les chroniques scientifiques, mais aussi dans les descriptions de réceptions mondaines. Surtout, elle se présente dans un surprenant rapport alchimique avec les arts et la littérature : elle magnifie les peintures tout autant qu’elle nourrit les œuvres de fiction qui lui avaient quant à elles préalablement fourni un cadre de pensée.Cependant, alors que l’électricité s’affirme toujours davantage comme l’énergie du futur, elle semble perdre rapidement du terrain dans La Vie moderne au profit d’un intérêt grandissant pour le chic et la mode. L’attention portée à la science en général et à l’électricité en particulier semble s’être trouvée sacrifiée sur l’autel de ces deux vanités. Or cette évolution est concomitante avec la disparition progressive de ceux qui avaient donné son identité originale à la revue. Il s’agit au premier chef d’Émile Bergerat qui se voit évincé dès la fin de l’année 1880, et en second lieu de Georges Charpentier qui cède définitivement le titre en 1883, confirmant en cela le sensible infléchissement de plusieurs options éditoriales. La période qui va de la création de La Vie moderne en avril 1879 jusqu’à sa cession en juin 1883 offre donc un observatoire idéal pour suivre les mutations médiatiques que le fil d’Ariane électrique aura mises en lumière
Pascal, le défi de l’honnêteté
No full textInternational audiencePascal est à la fois un théoricien original de l’honnêteté et un adversaire déterminé de cet idéal du siècle classique, qu’il a vu à l’œuvre chez ses amis Méré et Miton. L’honnêteté réunit pour lui trois composantes : un idéal digne d’admiration, fondé sur une anthropologie étonnamment lucide ; une présomption inquiétante de régler le malheur de l’humanité par des mesures purement techniques, contente d’une simple caricature de charité ; un échec inhérent, dont les enseignements sont précieux