Inverse problem regularization with hierarchical variational autoencoders

In this paper, we propose to regularize ill-posed inverse problems using a deep hierarchical variational autoencoder (HVAE) as an image prior. The proposed method synthesizes the advantages of i) denoiser-based Plug \& Play approaches and ii) generative model based approaches to inverse problems. First, we exploit VAE properties to design an efficient algorithm that benefits from convergence guarantees of Plug-and-Play (PnP) methods. Second, our approach is not restricted to specialized datasets and the proposed PnP-HVAE model is able to solve image restoration problems on natural images of any size. Our experiments show that the proposed PnP-HVAE method is competitive with both SOTA denoiser-based PnP approaches, and other SOTA restoration methods based on generative models

Diverse super-resolution with pretrained deep hiererarchical VAEs

Image super-resolution is a one-to-many problem, but most deep-learning based methods only provide one single solution to this problem. In this work, we tackle the problem of diverse super-resolution by reusing VD-VAE, a state-of-the art variational autoencoder (VAE). We find that the hierarchical latent representation learned by VD-VAE naturally separates the image low-frequency information, encoded in the latent groups at the top of the hierarchy, from the image high-frequency details, determined by the latent groups at the bottom of the latent hierarchy. Starting from this observation, we design a super-resolution model exploiting the specific structure of VD-VAE latent space. Specifically, we train an encoder to encode low-resolution images in the subset of VD-VAE latent space encoding the low-frequency information, and we combine this encoder with VD-VAE generative model to sample diverse super-resolved version of a low-resolution input. We demonstrate the ability of our method to generate diverse solutions to the super-resolution problem on face super-resolution with upsampling factors x4, x8, and x16.Comment: 21 pages , 5 figure

Transmission et appropriation des savoirs fromagers : un siècle de relations entre industriels de Roquefort et transformateurs corses

À travers la chronique d'un siècle de relations entre les industriels aveyronnais du Roquefort et les producteurs corses, cet article se propose d'analyser les transmissions, les échanges ou les appropriations successives qui ont pu s'opérer entre les deux cultures laitières et fromagères. Cette chronique peut être analysée en trois temps. Celui de la rencontre à la fin du siècle dernier. Celui de l'hégémonie des industriels de Roquefort en Corse, période où la culture fromagère traditionnelle corse est bouleversée alors que celle de l'industrie du Roquefort est à son apogée. Celui, enfin, courant des années 1970 à nos jours, qui serait le temps du repli de la fabrication du roquefort et de la redécouverte du patrimoine régional corse, tant par les Corses que par les industriels de Roquefort.Handing down and appropriation of cheese knowledge : one century of relationship between Roquefort industrials and Corsican transformers Throughout the century chronicle of relationship between "Roquefort aveyronnais" industrials and Corsican producers, this contribution intend to analyse transmissions, exchanges or successive appropriations witch could bring down between the two dairy and cheese cultures. This chronicle can be analysed in three steps. Firstly, the meeting in the end of the century. Secondly, the Corsican Roquefort industrials hegemony. This period correspond to a overthrow of Corsican traditional cheese culture even though the Roquefort industry is at the height. Thirsty, from 70's till today, which correspond to a roquefort manufactory crease and the re-discovery of Corsican regional patrimony, as much for Corsicans as Roquefort industrials

Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

O império dos mil anos e a arte do "tempo barroco": a águia bicéfala como emblema da Cristandade

The article reveals that between the mid-17th century and the mid-18th century, in the ecclesiastical world of the religious orders (Jesuits, franciscans, Carmelites, Cistercians, Augustinian, etc.) and the episcopate, there was the progressive adoption of the imperial symbol, the double-headed eagle, attribute of the Christian Empire, the germanic Holy Roman Empire emblem. However, in the religious field, this imperial eagle of the baroque time appears without the political insignia (sword, scepter and the imperial orb), adorning altars, monstrances, trumphal archs, facades of temples, doors, walls, domes, pulpits, sacred washbasins, sculptures and paintings of the Virgin and Child, liturgical robes, etc.; therefore related to the cult and the dogmas of the Catholic faith - in artistic works, the association between the double eagle and the flesh-spirit or human-divine unity, axial principle of the Catholic faith, represented by Virgin-Mother and Christ, is often indicated directly. The research has located and identified numerous remnants of the double eagle emblem in religious field in Portugal and Spain and in their conquests and dominions in America, Asia and Africa, and also in Italy, and the historiography on painful birth of the modern era in the West has never realized this phenomenon. Symbolizing absolute power, universal power, these works with sacred significance, as the ecclesiastical discourse of the time, demonstrate movement occurred in religious plane. With the aim to assert not only spiritual but also temporal power of Christ and his mystical body, the Church was impelled by the idea of restoring the "Republica Christiana" or Christendon - disrupted by conflicts of power and faith - and of introducing a Universal Apostolic Monarchy extended to all mankind: the Empire of the Last Days, the Empire of Christ in the world, the fifth Empire

L'enseignement, lieu de rencontre entre historiens et sociologues

JEAN-CLAUDE PASSERON AND ANTOINE PROST For Antoine Prost, history in France enjoys a specific status : it is a central element in the making of the national identity. French society grasps and analyses itself through its history, and this induces a specific type of knowledge.In Raymond Aron's opposition between explanation and understanding, history is on the side of understanding. Sociology deals more with explanation, i.e. looking for causes. Durkheim, in the Suicide, is the best representative of that trend. Jean-Claude Passeron argues that the two disciplines are in fact on the same ground, and that there is no epistemological reason to differentiate them. They are sociologically different because of the way each of the academic communities plays its own game moving back and forth between experimental reasoning and setting up the plot of historical narration. Sociologists prefer the moments of experimental reasoning but cannot develop them to their end. Historians, particularly when dealing with past times for which present words do not mean much, can do little more than suggest. The two disciplines are therefore in such a situation that they cannot avoid dialogue on the same terrain, and should thus enrich each other.Résumé : Pour Antoine Prost, l'histoire en France jouit d'un statut particulier : elle centrale dans la constitution de l'identité nationale. La société française se saisit s'analyse elle-même à travers son histoire et ceci induit un certain type de connaissance. Dans l'opposition que fait Raymond Aron entre explication compréhension, l'histoire est du côté de la compréhension. La sociologie vise plus expliquer, c'est-à-dire à rechercher des causes. C'est le Durkheim du Suicide qui représente le mieux. Jean-Claude Passeron pense que les deux disciplines sont en fait sur le terrain et qu'elles sont épistémologiquement indiscernables. Elles se sociologiquement par la façon dont chacune des deux communauté joue du va vient entre raisonnement expérimental et mise en intrigue dans le récit historique. Les sociologues préfèrent les moments de raisonnement expérimental qu'ils peuvent pas toutefois pousser à leur terme, les historiens tout particulièrement ils traitent de périodes très anciennes pour lesquelles les mots d'aujourd'hui n'ont de sens, en sont réduits à suggérer. Les deux disciplines sont sans doute destinées à dialoguer sur le même terrain à se féconder mutuellement.Passeron Jean-Claude, Prost Antoine. L'enseignement, lieu de rencontre entre historiens et sociologues. In: Sociétés contemporaines N°1, Mars 1990. Histoire et sociologie. pp. 7-45

Diverse super-resolution with pretrained deep hiererarchical VAEs

International audienceImage super-resolution is a one-to-many problem, but most deep-learning based methods only provide one single solution to this problem. In this work, we tackle the problem of diverse super-resolution by reusing VD-VAE, a state-of-the art variational autoencoder (VAE). We find that the hierarchical latent representation learned by VD-VAE naturally separates the image low-frequency information, encoded in the latent groups at the top of the hierarchy, from the image high-frequency details, determined by the latent groups at the bottom of the latent hierarchy. Starting from this observation, we design a super-resolution model exploiting the specific structure of VD-VAE latent space. Specifically, we train an encoder to encode low-resolution images in the subset of VD-VAE latent space encoding the low-frequency information, and we combine this encoder with VD-VAE generative model to sample diverse super-resolved version of a low-resolution input. We demonstrate the ability of our method to generate diverse solutions to the super-resolution problem on face super-resolution with upsampling factors x4, x8, and x16