La "sortie de guerre" des enfants français : le cas des lettres envoyées au président Woodrow Wilson (1918‐1919)

L’application aux civils du concept de « sortie de guerre » offre aux historiens de nouvelles pistes de recherche. Bien que la mobilisation culturelle de l’enfance dans la Grande Guerre ait fait l’objet de plusieurs études depuis les dernières années, le processus de démobilisation reste, quant à lui, peu exploré. Ce mémoire s’intéressera donc à la « sortie de guerre » chez les enfants français, à travers des sources inédites : des lettres adressées au président des États-Unis, Woodrow Wilson, à la fin de 1918. L’analyse met en lumière la perception des enfants sur la paix, la guerre, les Américains, et les changements de leur quotidien depuis l’armistice. Après une première partie historiographique, le deuxième chapitre portera sur la représentation de Wilson, des Américains et de la paix. Dans le dernier chapitre seront analysés le quotidien des enfants dans les mois suivant l’armistice, les représentations de la guerre et le processus de démobilisation. Fin 1918, la guerre tient encore beaucoup de place dans les propos des enfants et peu de signes de démobilisation émergent de leurs lettres. Ainsi, le président américain est représenté comme le sauveur de la France et le grand vainqueur de la guerre plutôt qu’en apôtre de la paix. Le sujet principal des lettres porte ainsi sur la reconnaissance et la gratitude des enfants envers le président et les États-Unis pour leur participation à la guerre et pour l’aide à la victoire. Les valeurs et le passé communs entre les deux pays alliés, exploités par la propagande de guerre, sont soulignés par les enfants. La fin de la guerre commence à peine à se faire ressentir dans le quotidien des enfants. La période est marquée par les célébrations de la victoire. De plus, la peur tend à s’atténuer avec la fin des violences de guerre et des nouveaux deuils. Les perturbations de la guerre demeurent cependant chez plusieurs enfants, particulièrement chez les réfugiés et les orphelins de guerre : la pauvreté, les séparations familiales et les privations alimentaires en affectent ainsi plusieurs. La perpétuation de ce climat de guerre influence la démobilisation des enfants, qui manifestent leur patriotisme et leur haine de l’ennemi. Les représentations de l’ennemi et des combattants du temps de la guerre prévalent donc encore, mais les enfants expriment néanmoins leur lassitude du conflit et leur désir d’un rapide retour à la normale.Applied to civilians, the study of how French got out of the war (“sortie de guerre”) offers new perspectives to historians. The cultural mobilization of children during the Great War has led to several studies but demobilization is yet overlooked. This master thesis will examine the “coming out of the war” of French children through previously unexamined sources : letters to the American president Woodrow Wilson in late 1918. This analysis highlights the perception of children regarding peace, war, the American people, and the changes in their daily life since the armistice. The first chapter of this dissertation will address historiographical issues. The second will examine the representations of Wilson and the American people in the letters as well as the children perception of peace. The last chapter will focus on the children’s depictions of their daily life in the months following the armistice, their representations of the war and the youth demobilization process. At the end of 1918, the war still takes plenty of room in the children letters and only few signs of cultural demobilization emerges in them. The president is portrayed as the savior of France but, more interestingly as a great man of the war, rather than as an apostle of peace. The main purpose of the children’s letters is to show gratitude to the president for the participation of his country in the victorious war. The common values and shared history between the two allied countries, drawn from the war propaganda, are often highlighted by the children. The end of the war is just beginning to be felt in the lives of children. This period is marked by celebrations of victory, as fear disappears with the end of war violence and of new grieves. However, for several children, the disruption of war remains, particularly among refugees and war orphans. Poverty, food deprivation and family separations affect many children. This outgoing situation influences the demobilization of children, who show their patriotism and their hatred of the Germans through their letters. Although if wartime representations of the enemy and soldiers still prevail, children continue to express their weariness of the conflict and their desire for a rapid return to normalcy

A Novel Variational Approach for Multiphoton Microscopy Image Restoration: from PSF Estimation to 3D Deconvolution

In multi-photon microscopy (MPM), a recent in-vivo fluorescence microscopy system, the task of image restoration can be decomposed into two interlinked inverse problems: firstly, the characterization of the Point Spread Function (PSF) and subsequently, the deconvolution (i.e., deblurring) to remove the PSF effect, and reduce noise. The acquired MPM image quality is critically affected by PSF blurring and intense noise. The PSF in MPM is highly spread in 3D and is not well characterized, presenting high variability with respect to the observed objects. This makes the restoration of MPM images challenging. Common PSF estimation methods in fluorescence microscopy, including MPM, involve capturing images of sub-resolution beads, followed by quantifying the resulting ellipsoidal 3D spot. In this work, we revisit this approach, coping with its inherent limitations in terms of accuracy and practicality. We estimate the PSF from the observation of relatively large beads (approximately 1$\mu$m in diameter). This goes through the formulation and resolution of an original non-convex minimization problem, for which we propose a proximal alternating method along with convergence guarantees. Following the PSF estimation step, we then introduce an innovative strategy to deal with the high level multiplicative noise degrading the acquisitions. We rely on a heteroscedastic noise model for which we estimate the parameters. We then solve a constrained optimization problem to restore the image, accounting for the estimated PSF and noise, while allowing a minimal hyper-parameter tuning. Theoretical guarantees are given for the restoration algorithm. These algorithmic contributions lead to an end-to-end pipeline for 3D image restoration in MPM, that we share as a publicly available Python software. We demonstrate its effectiveness through several experiments on both simulated and real data

The multiple maternal legacy of the Late Iron Age group of Urville-Nacqueville (France, Normandy) documents a long-standing genetic contact zone in northwestern France

The compilation of archaeological and genetic data for ancient European human groups has provided persuasive evidence for a complex series of migrations, population replacements and admixture until the Bronze Age. If the Bronze-to-Iron Age transition has been well documented archaeologically, ancient DNA (aDNA) remains rare for the latter period and does not precisely reflect the genetic diversity of European Celtic groups. In order to document the evolution of European communities, we analysed 45 individuals from the Late Iron Age (La Tène) Urville-Nacqueville necropolis in northwestern France, a region recognized as a major cultural contact zone between groups from both sides of the Channel. The characterization of 37 HVS-I mitochondrial sequences and 40 haplogroups provided the largest maternal gene pool yet recovered for the European Iron Age. First, descriptive analyses allowed us to demonstrate the presence of substantial amounts of steppe-related mitochondrial ancestry in the community, which is consistent with the expansion of Bell Beaker groups bearing an important steppe legacy in northwestern Europe at approximately 2500 BC. Second, maternal genetic affinities highlighted with Bronze Age groups from Great Britain and the Iberian Peninsula regions tends to support the idea that the continuous cultural exchanges documented archaeologically across the Channel and along the Atlantic coast (during and after the Bronze Age period) were accompanied by significant gene flow. Lastly, our results suggest a maternal genetic continuity between Bronze Age and Iron Age groups that would argue in favour of a cultural transition linked to progressive local economic changes rather than to a massive influx of allochthone groups. The palaeogenetic data gathered for the Urville-Nacqueville group constitute an important step in the biological characterization of European Iron age groups. Clearly, more numerous and diachronic aDNA data are needed to fully understand the complex relationship between the cultural and biological evolution of groups from the period

Origin and mobility of Iron Age Gaulish groups in present-day France revealed through archaeogenomics

The Iron Age period occupies an important place in French history, as the Gauls are regularly presented as the direct ancestors of the extant French population. We documented here the genomic diversity of Iron Age communities originating from six French regions. The 49 acquired genomes permitted us to highlight an absence of discontinuity between Bronze Age and Iron Age groups in France, lending support to a cultural transition linked to progressive local economic changes rather than to a massive influx of allochthone groups. Genomic analyses revealed strong genetic homogeneity among the regional groups associated with distinct archaeological cultures. This genomic homogenisation appears to be linked to individuals’ mobility between regions as well as gene flow with neighbouring groups from England and Spain. Thus, the results globally support a common genomic legacy for the Iron Age population of modern-day France that could be linked to recurrent gene flow between culturally differentiated communities

A review of biomedical multiphoton microscopy and its laser sources

International audienceInteractions between agents and clients at the street-level of welfare bureaucracies have been made more strategic than ever by the shift towards workfare, responsibilization and individualization. Based on this premise, this paper addresses the theoretical question of the relationship between the interaction order and the social order raised in Goffman's sociology. It supports the idea that a third order, the institutional order, constitutes the link between interactions and social structures. To do so, it focuses on the bureaucratic organization of people-processing in welfare, and shows how macrosocial characteristics are involved in individual interactions which, in turn, contribute to reproducing the social structure of positions and power relations

Transport d'impulsions femtosecondes par fibres optiques pour des applications à la biophotonique

National audienceCe travail concerne le transport d'impulsions femtosecondes par fibre optique pour des applications à la biophotonique. Le 1er chapitre est consacré à un état de l'art du sujet, mettant en évidence la problématique liée aux effets dispersifs et non linéaires qui déforment les impulsions lors de leur propagation dans une fibre. Deux solutions sont proposées : utiliser des fibres non conventionnelles ou des fibres standard. Le 2ème chapitre est consacré aux systèmes de compensation de la dispersion. Un état de l'art introduit le sujet et présente l'étireur à grisms de façon générale. Cet étireur est modélisé numériquement puis étudié expérimentalement. Le chapitre 3 est consacré à l'acheminement d'impulsions femtosecondes par une fibre non standard avec une source ultralarge bande. La dispersion est compensée par un étireur grisms. Le système est modélisé puis validé expérimentalement. L'étireur à grisms, complété par un modulateur spatial de lumière permet de réaliser du façonnage d'impulsions en amplitude et en phase en sortie de cette fibre. Dans le chapitre 4, l'acheminement d'impulsions femtosecondes est adapté pour une fibre standard avec un oscillateur standard. Dans le chapitre 5, toutes ces notions sont articulées pour être appliquées à la spectroscopie et à la microscopie multiphotonique par fibre optique. Une analyse spectrale de réponses multiphotoniques endogènes de tissus biologiques en position proximale est effectuée. Des images d'échantillons biologiques par microscopie multiphotonique fibrée sont présentées et l'évolution vers l'endomicroscopie est abordée

Multiphoton microscopy

International audienceEndoscopic examination is a well-established medical practice and helps hospital practitioners to orientate diagnostic and treatments with a painless protocol which also contributes to improve the care of patients. But the endoscopic images generated are restrained to a surface imaging and image quality is limited to a millimetric resolution. The precision of the diagnostic can be impacted by these restrictions and some significant alteration of the structure, metabolism or physiology of organs can be missed. Today, many technical developments are in progress for the development of endomicroscopes. That imposes for example to resort to the intermediary of an optical waveguide whose internal structure imposes many technical and computational constraints, discussed in the present article. The miniaturization of distal optics or scanning devices are still in progress of elaboration simultaneously with an optimal computational strategy for erasing image defaults linked to the necessity of extremal miniaturization

Confocal and multiphoton endomicroscopy

International audienceEndoscopic examination is a well-established medical practice and helps hospital practitioners to orientate diagnostic and treatments with a painless protocol which also contributes to improve the care of patients. But the endoscopic images generated are restrained to a surface imaging and image quality is limited to a millimetric resolution. The precision of the diagnostic can be impacted by these restrictions and some significant alteration of the structure, metabolism or physiology of organs can be missed. Today, many technical developments are in progress for the development of endomicroscopes. That imposes for example to resort to the intermediary of an optical waveguide whose internal structure imposes many technical and computational constraints, discussed in the present article. The miniaturization of distal optics or scanning devices are still in progress of elaboration simultaneously with an optimal computational strategy for erasing image defaults linked to the necessity of extremal miniaturization

Utiliser la santé pour promouvoir la paix : entre illusions et politisation

International audienc