N\'eron models of Jacobians over bases of arbitrary dimension

We work with a smooth relative curve $X_U/U$ with nodal reduction over an excellent and locally factorial scheme $S$. We show that blowing up a nodal model of $X_U$ in the ideal sheaf of a section yields a new nodal model, and describe how these models relate to each other. We construct a N\'eron model for the Jacobian of $X_U$, and describe it locally on $S$ as a quotient of the Picard space of a well-chosen nodal model. We provide a combinatorial criterion for the N\'eron model to be separated.Comment: 37 pages including bibliography. Comments are welcom

Diversity and focus of CMV specific T-cell responses in patients post-HSCT and with solid tumor

Human Cytomegalovirus (CMV) is a beta-herpesvirus that commonly infects humans. Most symptoms in healthy individuals are very mild. The virus is never eliminated and remains in the individual life-long. Thus, CMV and the immune response stay in coexistence until the protective response remains. CMV disease occurs when the immune system is either immature or immunocompromised, such as in hematopoietic stem cell transplant recipients. Over the last decades, CMV has been reported in diverse cancer including glioblastoma (GBM) that could suggest a potential link between CMV infection and cancer initiation or development. The papers in this thesis investigated the CMV-specific immune response of individuals in different clinical settings: patients after hematopoietic stem cell transplantation (HSCT) and patients with brain tumor or pancreatic cancer. The thesis consists of the following studies: In Paper I, we investigated the CMV-specific interferon-gamma (IFNγ) production in a cohort of 277 patients over time post-HSCT. Impairment of the CMV-specific immune response post-HSCT is associated with CMV infection. We monitored the IFNγ production in response to CMV-pp65 over a period of 2 years post-HSCT and observed a higher IFNγ production at the first month post-HSCT. Moreover, we identified that several clinical parameters such acute graft-versus-host disease (GVHD) and CMV infection affect the IFNγ production in response to CMV-pp65. In Paper II, we aimed to characterize the CMV-specific CD8+ cytotoxic T-cells (CTL) with high affinity T-cell receptor (TCR) in patients post-HSCT using three different CMV-pp65 tetramers. High affinity CMV-CTL presented an effector memory phenotype and a stronger PD-1 expression as compared to CMV-CTL with lower affinity. Additionally, the high affinity CMV-CTLs were found at higher proportion in patients with chronic GVHD over time post-HSCT. Therefore, Paper I and II together may better characterize the CMV-specific immune response post-HSCT and potentially the bidirectional relationship between virus and GVHD. In Paper III, we investigated the plasma interleukin 7 (IL-7) and the soluble IL-7 receptor (sIL-7R) levels post-HSCT. IL-7, through its receptor, is essential for T-cell proliferation, thus, to the response to infection. Patients presenting CMV infection exhibited a lower plasma level of sIL-7R and higher level of IL-7 in the early months post-HSCT. Furthermore, the plasma level of IL-7R was reduced in patients with acute GVHD. Together these observations suggest that sIL-7R may be associated with increased risk of GVHD and potential CMV infection. In Paper IV, the clinical setting is different. We focused on the CMV-specific IFNγ production in a large cohort of patients with brain tumor and pancreatic cancer. Patients with brain tumor and more specifically those with GBM presented an impaired immune response towards viral and mitogen antigens. While survival was correlated with the CMV- specific humoral response, no correlation between survival and CMV-specific IFNγ production could be observed. Contrarily, patients with high Epstein-Barr virus (EBV)- and PHA-specific IFNγ production showed an improved survival post-operation suggesting this immune response as potential marker of general immunocompetence

Bilinear Strichartz estimates and almost sure global solutions for the nonlinear Schr{\"o}dinger equation

The purpose of this article is to construct global solutions, in a probabilistic sense, for the nonlinear Schr{\"o}dinger equation posed on $\mathbb{R}^d$, in a supercritical regime. Firstly, we establish Bourgain type bilinear estimates for the harmonic oscillator which yields a gain of half a derivative in space for the local theory with randomised initial conditions, for the cubic equation in $\mathbb{R}^3$. Then, thanks to the lens transform, we are able to obtain global in time solutions for the nonlinear Schr{\"o}dinger equation without harmonic potential. Secondly, we prove a Kato type smoothing estimate for the linear Schr{\"o}dinger equation with harmonic potential. This allows us to consider the Schr{\"o}dinger equation with a nonlinearity of odd degree in a supercritical regime, in any dimension $d\geq 2$.Comment: 88 page

Néron models in high dimension: Nodal curves, Jacobians and tame base change

We describe certain birational modifications of nodal relative curves over a regular base of arbitrary dimension. Using these modifications, we provide criteria for the existence of Néron models of nodal curves and their Jacobians over a regular base of arbitrary dimension, and describe the Néron models explicitly when they exist. Then, we study the descent behavior of Néron models of abelian varieties under tamely ramified and surjective maps between regular schemes.Number theory, Algebra and Geometr

Articuler les rapports de sexe, de classe et interethniques

La combinaison des rapports de sexe, de classe et interethniques dans la production des inégalités n’a été que très partiellement étudiée en France, et surtout de manière très générale et fort peu opératoire. En s’appuyant sur les travaux des Black Feminists, cet article propose une introduction au riche débat sur le thème de l’intersection de ces différents rapports sociaux qui s’est développé en Amérique du Nord, de manière conjointe dans les champs académiques et militants, depuis une trentaine d’années. Il aborde ses conditions d’émergence et de développement, sous l’impulsion d’Afro-américaines voulant faire reconnaître la spécificité de leur expérience du monde social ; les enjeux épistémologiques et méthodologiques ainsi que les efforts d’application empirique de ce cadre d’analyse ; enfin ses prolongements juridiques et politiques, marqués par une tendance à la réification des catégories de l’altérité (la « race », le genre, la classe) au détriment des processus qui les produisent.À l’heure où la France s’apprête à se doter d’une autorité indépendante de lutte contre les discriminations, cette vigoureuse discussion offre nombre d’enseignements tant pour leur analyse que pour leur traitement.Articulating Gender, Class and Interethnic Relations :The North American DebateThe intersection of gender, class and interethnic relations in the production of inequalities has as yet only been partially examined in France, and, only in a very general and non-operant way. Drawing on the work of Black Feminists in the USA, this article proposes an introduction to the rich debate on the theme of the intersection of these different forms of social relations, as this developed over thirty years in North America, both in academic and militant spheres. The article addresses the conditions of emergence and of development of this intersectionality, under the impetus of Afro-Americans wanting to make known the specificity of their experience of the social world ; the epistemological and methodological issues at stake as well as the efforts to empirically apply this analytic framework ; lastly, the legal and political implications, marked by the tendency to reify categories of otherness (“race”, gender and class) to the detriment of the processes that generate them.At a time when France is about to set up an independent authority to fight against discrimination, this vigorous discussion offers a number of interesting teachings, regarding both analysis and treatment of discriminations.Articular las relaciones de sexo, de clase e interétnicas : varias enseñanzas del debate norteamericanoEl estudio de la combinación de las relaciones de sexo, de clase e interétnicas en la producción de desigualdades ha sido parcialmente abordado en Francia y de manera muy general y poco operacional. Apoyándose en los trabajos de las Black Feminists, este artículo propone una introducción al rico debate que desde hace treinta años, y de manera concomitante entre el mundo académico y militante, aborda el tema de la intersección entre las diferentes relaciones sociales que se ha desarrollado en América del Norte. Este debate analiza : las condiciones de su emergencia y desarrollo bajo la impulsión de Afro-Americanas deseosas del reconocimiento de la especifidad de su experiencia del mundo social ; las cuestiones epistemológicas y metodológicas así como los esfuerzos de aplicación empírica del marco de análisis ; y, por último, las prolongaciones jurídicas y políticas marcadas por la tendencia a la reificación de las categorías de la alteridad (la « raza », el género, la clase) en detrimento de los procesos que las producen.En un momento en que Francia se dispone a dotarse de una autoridad independiente de lucha contra las discriminaciones, esta vigurosa discusión ofrece numerosas enseñanzas tanto por su análisis como por su tratamiento

«Le fjord glacé d’Ilulissat: la mise en tourisme d’un paysage naturel patrimonialisé»

Tourism started slowly in Ilulissat (Greenland) in the 1980s-1990s, before expanding further in the 21st century since the UNESCO classification of the Sermeq Kujalleq Glacier Fjord and the fact that the Arctic has become a symbol of climate change. These journeys are both imaginary, described as «cryotropism», «borealism» or «nordicity», and very real: the impact of tourism is visible in the environment. A new international airport is planned for 2023. What type of tourist and therefore travel will this attract? We asked ourselves to what extent the Ilulissat natural site could be managed in a sustainable way. In order to answer this question, we adopted the participant observation from an immersion in the Ilulissat Fjord Office and conducted about twenty semistructured interviews

Models of Jacobians of curves

We show that the Jacobians of prestable curves over toroidal varieties always admit N\'eron models. These models are rarely quasi-compact or separated, but we also give a complete classification of quasi-compact separated group-models of such Jacobians. In particular we show the existence of a maximal quasi-compact separated group model, which we call the saturated model, which has the extension property for all torsion sections. The N\'eron model and the saturated model coincide over a Dedekind base, so the saturated model gives an alternative generalisation of the classical notion of N\'eron models to higher-dimensional bases; in the general case we give necessary and sufficient conditions for the N\'eron model and saturated model to coincide. The key result, from which most others descend, is that the logarithmic Jacobian of \cite{Molcho2018The-logarithmic} is a log Neron model of the Jacobian