HAL-Paris 13
Not a member yet
33893 research outputs found
Sort by
Quelle place du numérique dans le parcours de soins post-hospitalisation des personnes migrantes originaires d’Afrique subsaharienne hospitalisées pour une tuberculose maladie ou une infection par le VIH ?
No full textDigital technology is increasingly being integrated into public health interventions, particularly to promote adherence to care. Migrants from sub-Saharan Africa (SSA) hospitalized for HIV or tuberculosis are particularly vulnerable to psychosocial challenges. The aim of this thesis is to examine the role of digital technology in the post-hospitalization care pathway (PHCP) of SSA migrants who have been hospitalized for tuberculosis or HIV infection.This work is based on the ZINGA research program, which includes two systematic literature reviews (one on HIV and one on tuberculosis) focusing on the adherence to care processes of migrants in high-income countries. It also includes a qualitative survey using semi-structured interviews to study the determinants of the PHCP of SSA patients hospitalized for tuberculosis or HIV infection, as well as a study based on focus groups examining the use of smartphones in the PHCP among SSA migrants who have been hospitalized for tuberculosis and/or HIV infection.The systematic reviews highlight difficulties among migrants in high-income countries to adhere to care processes for HIV or tuberculosis due to psychosocial vulnerabilities. These migrants are predominantly classified in the literature according to their geographical origin, which does not seem to capture the complexities of migration issues. Furthermore, psychosocial determinants (housing instability, unemployment, difficulties in obtaining residency permits, psychological distress) impact the course of the PHCP. Conversely, religious beliefs, survival instincts, family and community ties, and the human resources of the healthcare system are identified as levers to improve the PHCP. Finally, our results show a strong link between our focus group population and the use of their smartphones, identified as organizational and emotional resources during the PHCPLe numérique se déploie dans les interventions de santé publique visant à améliorer l'adhésion aux soins. Les personnes migrantes originaires d'Afrique subsaharienne (ASS) sont particulièrement exposées à des vulnérabilités psychosociales. L'objectif de cette thèse est d'examiner la place du numérique dans le parcours de soins post-hospitalisation (PPH) des personnes migrantes originaires d'ASS, hospitalisées pour une tuberculose ou une infection par le VIH. Ce travail comprend deux revues systématiques de la littérature (VIH et tuberculose) portant sur l'adhésion au processus de soin des personnes migrantes dans les pays à haut niveau de revenu (PHNR). Il inclut également une enquête qualitative par entretiens semi-directifs visant à étudier les déterminants du PPH des personnes migrantes originaires d'ASS, hospitalisées pour tuberculose ou infection par le VIH, ainsi qu'une étude basée sur des focus groupe, s'intéressant aux usages du smartphone dans le PPH, dans cette même population.Les revues systématiques mettent en évidence des difficultés d'adhésion au processus de soin pour le VIH ou la tuberculose chez les personnes migrantes dans les PHNR, en raison de vulnérabilités psychosociales. La classification des personnes migrantes dans la littérature se fait principalement selon leur origine géographique, ce qui ne semble pas capturer la complexité de la question migratoire. Par ailleurs, les déterminants psychosociaux (instabilité liée au logement, absence d'emploi, difficultés à l'obtention d'un titre de séjour, souffrance psychique) impactent le déroulement du PPH. En revanche, la croyance religieuse, l'instinct de survie, les liens familiaux et communautaires, ainsi que les ressources humaines du système de soin sont identifiés comme des leviers pour améliorer le PPH. Enfin, nos résultats montrent un lien fort entre la population des focus groupes et leur smartphone, utilisé comme un soutien organisationnel et émotionnel au cours du PPH
Predicting neonatal infection in PPROM with vaginal microbiology and metagenomics: a prospective cohort study
No full textInternational audienceObjectiveEarly-onset neonatal sepsis (EONS) due to ascending infection is a potentially preventable complication of preterm premature rupture of membranes (PPROM). Our objective was to determine whether the analysis of bacteria from vaginal swab samples is predictive of the risk of EONS in PPROM.Study DesignIn a prospective 3-center observational cohort, patients with PPROM were enrolled between 22 and 36 weeks’ gestation (WG) + 6 days. Vaginal swab samples at delivery were analyzed using two different approaches, classical bacterial cultures and shotgun metagenomic sequencing analysis. A metagenomics score was constructed combining the characterization of the vaginal microbiome and the presence of pathogens and the optimal cut-off to predict EONS was tested on a receiver operating curve.Results563 PPROM cases were enrolled, with 646 liveborn neonates. PPROM occurred < 32 WG in 41.9% and deliveries were < 34 WG in 41.0%. The incidence of EONS was 29/646 (4.5%). When considering all central and peripheral microbiological samples available for 26 neonates, the main pathogens isolated were Escherichia coli in 14 cases (53.8 %), other gram-negatives in 5 (19.2%), strict anaerobes in 3 (11.5%); there was a single case (3.8%) each with Group B Streptococcus (GBS), Streptococcus anginosus, Staphylococcus aureus and Ureaplasma urealyticum.We studied the prediction of EONS among 272 mothers and their 310 neonates (20 EONS, 6.4%) with both culture and metagenomic data available. A culture positive for a major or intermediate pathogen in the vaginal sample at delivery had a sensitivity of 80.0 % (95% CI=56.3-94.3) and a specificity of 37.9% (95% CI=32.3-43.8), adjusted odds ratio (aOR) of 1.6 (95 % CI [0.5-5.0]) to predict EONS. The presence of E. coli was associated with an EONS risk of 10.6% vs 4.9%, in the absence of E. coli (p=0.07).The metagenomics score was highly associated with EONS, with an area under the receiver operating curve of 0.75 (95% CI, 0.61–0.90). At the optimal cutoff value, sensitivity was 70% (95% CI, 64–95%), specificity was 85% (95% CI, 81–89%). A metagenomics score greater than 40 was associated with a significantly increased risk of EONS with an aOR of 8.9 (95 % CI [3.5; 22.3]) in multivariate analysis adjusted for latency period and gestational age, p<0.001.ConclusionIn PPROM, conventional microbial culture of maternal vaginal samples was associated with EONS, but its predictive values remain insufficient to guide perinatal care. Metagenomic microbial signatures improved predictive values. This opens the perspective for a rapid point-of-care test
Discours mémoriels minoritaires aux lendemains du massacre des bananeraies (1928-1938) : des usages du passé à contre-courant du discours libéral dominant
No full textInternational audienceDans la nuit du 5 au 6 décembre 1928, l’armée colombienne fit feu sur des travailleurs en grève qui s’étaient rassemblés dans la ville caribéenne de Ciénaga. L’événement de répression étatique, d’emblée minoré par le gouvernement conservateur en place, donna à lieu à des lectures discordantes et le passé traumatique fit rapidement l’objet d’instrumentalisation, notamment à l’initiative du Parti libéral colombien. Quelle place occupe l’expérience des secteurs minoritaires dans les usages politiques du passé mis en œuvre durant la décennie postérieure au massacre ? La réflexion s’appuiera notamment sur les discours dissonants retranscrits dans la presse locale de deux entrepreneur∙euses de mémoire : Santander Alemán, cheminot afro-descendant et témoin du massacre, et María Eufemia, autochtone de la Sierra Nevada, dont le contre-récit révèle les failles du prétendu « monopole sur le passé légitime » des libéraux
Méthode de décomposition de domaine espace-temps et parallèle en temps pour les écoulements incompressibles et nouvelle analyse de la méthode de relaxation d’onde de Schwarz optimisée
No full textThe aim of this thesis is to study algorithms for solving partial differential equations using parallel algorithms in time and space-time. The manuscript is divided into two independent parts. The first concerns the solution of fluid mechanics equations (Oseen and Navier-Stokes) using the Parareal and Optimized Schwarz Waveform Relaxation (OSWR) algorithms. The second part proposes a new ana- lysis of OSWR algorithm for the heat equation, based on a discrete-time analysis.In the first part, we begin by rewriting the weak Oseen problem equivalently to the monodomain problem, on a partition of the study domain, and then we introduce the OSWR algorithm for solving this coupled problem. We then prove the convergence of the velocities obtained by the algorithm towards the family of velocities solving the coupled multi-domain problem. Although the algorithm is able to determine a pressure in all the subdomains at each iteration, these do not converge to the pressures solution of the monodomain problem. We propose a pressure reconstruction methodology to remedy this. We then follow the same path to introduce an algorithm obtained from the coupling of the Parareel and OSWR algorithms, which defines a methodology for solving the Oseen problem in parallel in time and space. In order to extend the OSWR algorithm to the Navier-Stokes problem, we need to solve this problem on subdomains with Robin boundary conditions. We therefore begin by establishing the existence and uniqueness of the solution to this problem. We can then introduce the algorithm and check that it is well-posed, then show its convergence for velocity and pressure, after correction. Numerical simulations for academic problems and a more realistic problem are presented to illustrate the efficiency of these techniques.The second part provides a new analysis of the OSWR algorithm for solving the one-dimensional heat equation. After establishing an analysis based on the introduction of a numerical time scheme, we provide a new analysis of convergence, and two new results : convergence depends only on the Robin parameter and the number of time steps, and convergence can be achieved in a finite number of iterations if the Robin parameter is chosen astutely. Most of all, we show that the choice of an optimal parameter must depend on the number of domain decomposition iterations performed. We then propose such a parameter and we show numerically its efficiency. We also provide an analysis for choosing an optimised Robin parameter in the case where the Robin data is initialised from the initial condition, which is a common case in practice in order to accelerate convergence. Finally, the analysis is extended to the heat equation in two spatial dimensions.Cette thèse a pour objectif l'étude d'algorithmes de résolution d'équations aux dérivées partielles par des algorithmes parallèles en temps et espace-temps. Le manuscrit est divisé en deux parties indépendantes. La première concerne la résolution des équations de la mécanique des fluides (Oseen et Navier-Stokes) avec les algorithmes Pararéel et Optimized Schwarz Waveform Relaxation (OSWR). La seconde partie propose une nouvelle analyse de l'algorithme OSWR pour l'équation de la chaleur, reposant sur une analyse discrète en temps.Dans la première partie, nous commençons par réécrire le problème d'Oseen faible de manière équivalente au problème monodomaine, sur une partition du domaine d'étude, puis nous introduisons l'algorithme OSWR pour la résolution de ce problème couplé. Nous montrons alors la convergence des vitesses obtenues par l'algorithme vers la famille de vitesses solution du problème couplé multi- domaines. Bien que l'algorithme permette de déterminer une pression dans tous les sous-domaines à chaque itération, celles-ci ne convergent pas vers les pressions solutions du problème monodomaine. Nous proposons alors une méthodologie de reconstruction de pression pour remédier à cela. Nous reprenons alors le même cheminement pour introduire un algorithme issu du couplage des algorithmes Pararéel et OSWR, ce qui définit une méthodologie de résolution du problème d'Oseen parallèle en temps et en espace. Pour pouvoir étendre l'algorithme OSWR au problème de Navier-Stokes, nous devons résoudre ce problème sur des sous-domaines avec des conditions limites de Robin. Nous commençons donc par établir l'existence et l'unicité de la solution à ce problème. Nous pouvons alors introduire l'algorithme et vérifier qu'il est bien posé, puis montrer sa convergence pour la vitesse et la pression, après correction. Des simulations numériques pour des problèmes académiques ainsi qu'un problème plus réaliste sont présentées pour illustrer l'efficacité de ces techniques.La seconde partie apporte une analyse nouvelle de l'algorithme OSWR pour la résolution de l'équation de la chaleur unidimensionnelle. Après avoir établi une analyse reposant sur l'introduction d'un schéma numérique en temps, nous apportons une nouvelle analyse de la convergence, et deux résultats nouveaux : la convergence ne dépend que du paramètre de Robin et du nombre de pas de temps, et la convergence peut être atteinte en un nombre fini d'itérations si le paramètre de Robin est choisi astucieusement. Surtout, nous mettons en évidence que le choix d'un paramètre optimal doit être dépendant du nombre d'itérations de décomposition de domaine réalisées, et proposons un tel paramètre, dont nous montrons numériquement l'efficacité. Nous apportons aussi une analyse permettant de choisir un paramètre de Robin optimisé dans le cas où la donnée de Robin est initialisée à partir de la condition initiale, ce qui est un cas usuel en pratique afin d'accélérer la convergence Enfin, l'analyse est étendue à l'équation de la chaleur en deux dimensions d'espace
Pruning processes of minima on a graph that are Abelian
No full textWe introduce two processes on graphs equipped with a total ordering of the vertices, that at each step remove a local minimum, and its smallest neighbour, and modify the graph according to some rule. We find two rules that make the process abelian, that is, the order by which local minima are removed does not affect the outcome of the procedure (in this case, the list of vertices removed as minima).Running these processes on regular lattices produces interesting structures: while the number of vertices decreases monotonically, the number of edges peaks up after a phase transition of percolation type, when the local clusters of removed minima glue together into a giant component. Despite having been generated by a deterministic greedy procedure, the final set of minima has properties similar to those of a critical system in the Statistical Mechanics of Phase Transitions and Critical Phenomena, a feature that reminds of Self-Organised Criticality.</div
Transcriptomic classification of prolactinomas and somatotropinomas identifies subtypes with variable resistance to treatment
No full textInternational audienceAbstract Objective Dopamine agonists and somatostatin analogs are commonly used in prolactinomas and somatotropinomas. Response to these therapies is heterogeneous. Whether resistance is linked to specific tumor subtypes or to shared mechanisms of resistance is not known. The aim was to explore distinct molecular subtypes of prolactinomas and somatotropinomas and their association with response to treatment. Methods The transcriptome of 46 prolactinomas and 58 somatotropinomas was analyzed. Unsupervised classifications were generated and tested for association with histological and clinical data, including response to treatment. Results Four subtypes of prolactinomas were identified, with variable sensitivity to dopamine agonists (P < 10−4). Sensitive tumors accumulated in the subgroup with the highest DRD2 expression, while resistant tumors accumulated in the 3 remaining ones, enriched in genes related to cAMP metabolism, to mitochondrial and ribosomal activity, and to immunity, respectively. Sparsely granulated somatotropinomas (N = 16) presented a separated molecular entity, mixing tumors resistant and sensitive to somatostatin analogs. The remaining somatotropinomas were classified into 5 subtypes, with variable sensitivity to somatostatin analogs (P < 10−4). Sensitive tumors accumulated in 3 subgroups, characterized by GNAS somatic mutation, PIT1 and SF1 coexpression, and the stem-cell marker SOX2 expression, respectively. Resistant tumors accumulated in the 2 remaining ones, enriched in genes related to cell cycle and to mesenchymal differentiation, respectively. Somatostatin receptor 2 (SSTR2) expression was associated with response to somatostatin analogs in sparsely granulated somatotropinomas (P = .022), but not in other somatotropinomas (P = .923). Conclusions Prolactinomas and somatotropinomas were classified into distinct transcriptomic groups. Resistance to medical therapies was linked to distinct tumor subtypes, suggesting distinct mechanisms of resistance
Verifying Timed Properties of Programs in IoT nodes using Parametric Time Petri Nets
No full textInternational audienceThe analysis of timed properties of programs is a complex task, as it is highly dependent on both the software and the hardware. In this work, we propose a framework for modeling with timed formal models the execution of programs, taking into account the micro-architecture of the machine on which it executes.We model both the program, at the instruction set architecture level, and the hardware, including the processor micro-architecture, using time Petri nets.Our implementation uses the ARM Cortex-M instruction set architecture and a hardware architecture representative of microcontrollers used in IoT nodes.The whole translation is fully automated and allows, starting from binary code, to automatically produce the models usable by the state-of-the-art time Petri net model checker Roméo.In addition, and as a proof of concept, we show how we can check, and enforce to some extent, opacity properties on programs, leveraging the ability of Roméo to verify a parametric timed extension of the classical computation tree logic.</div
Association of early doses of diuretics and nitrates in acute heart failure with 30 days outcomes: ancillary analysis of ELISABETH study
No full textInternational audienceAims The optimal dose of diuretics and nitrates for acute heart failure treatment remains uncertain. This study aimed to assess the association between intravenous nitrates and loop diuretics doses within the initial 4 h of emergency department presentation and the number of days alive and out of hospital (NDAOH) through 30 days. Methods This was an ancillary study of the ELISABETH stepped-wedge cluster randomized trial that included 502 acute heart failure patients 75 years or older in 15 French emergency departments. The primary endpoint was the NDAOH at 30 days. The total dose of intravenous nitrates and loop diuretics administered in the initial 4 h were each categorized into three classes: ‘no nitrate’, ‘> 0–16’, and ‘> 16 mg’ for nitrates and ‘< 60’, ‘60’, and ‘> 60 mg’ for diuretics. Secondary endpoints included 30-day mortality, 30-day hospital readmission, and hospital length of stay in patients alive at 30 days. Generalized linear mixed models were used to examine associations with the endpoints. Results Of 502 patients, the median age was 87 years, with 59% women. The median administered dose within the initial 4 h was 16 mg (5.0; 40.0) for nitrates and 40 mg (40.0; 80.0) for diuretics. The median NDAOH at 30 days was 19 (0.0–24.0). The adjusted ratios of the NDAOH were 0.88 [95% confidence interval (CI): 0.63–1.23] and 0.76 (95% CI: 0.58–1.00) for patients that received 60 and > 60 mg, respectively, compared with patients that received 40 mg or less of diuretics. Compared with patients who did not receive nitrates, the adjusted ratios of the NDAOH were 1.17 (95% CI: 0.82–1.67) and 1.45 (95% CI: 0.90–2.33) for patients who received 1–16 and > 16 mg, respectively. There was no significant association with any of the secondary endpoints. Conclusion In this ancillary analysis, there was no significant association between different doses of diuretics and nitrates with the NDAOH at 30 days. Point estimates and CIs may suggest that the optimal doses are less than 60 mg of diuretics, and more than 16 mg of nitrates in the first 4 h
Residence-colonization trade-off and niche differentiation enable coexistence of Escherichia coli phylogroups in healthy humans
No full textInternational audienceDespite abundant literature on pathogenicity and virulence of the opportunistic pathogen Escherichia coli, much less is known about its ecological and evolutionary dynamics as a commensal. Based on two detailed longitudinal datasets on the gut microbiota of healthy adults followed for months to years in France and the USA, we identified a robust trade-off between the ability to establish in a new host (colonization) and to remain in the host (residence). Major E. coli lineages (phylogroups or subgroups) exhibited similar fitness but diverse strategies, from strong colonisers residing few days in the gut to poor colonisers residing for years. Strains with the largest number of extra-intestinal virulence associated genes and highest pathogenicity also resided for longest in hosts. Furthermore, the residence of a strain was more strongly reduced when it competed with other strains from the same phylogroup than from another phylogroup, suggesting niche differentiation between phylogroups. Based on a discrete-state Markov model developed to describe E. coli dynamics in a host population, we found that the trade-off and niche differentiation acted together as equalizing and stabilizing mechanisms allowing phylogroups to coexist over long periods of time. Our model also predicted that external disturbances may disproportionately affect resident strains, such as the extraintestinal pathogenic ones of subgroup B2.3. Our results call for further studies outside high-income countries, where the prevalence of this phylogroup is much lower. More generally, the trade-off between colonization and persistence could play a role in the diversification of other bacterial species of the microbiome