642 research outputs found
Hardy varieties in competition with weeds for sustainable agriculture and especially organic farming
A three-year programme was begun in 2007 to develop a method for assessing the competitive potential of wheat varieties with respect to weeds and to encourage the adoption of this criterion in selection programmes. The first year of experiments made it possible to identify the most explanatory characteristics of the competitive potential of wheat (using Italian ryegrass to simulate weeds): height first, followed by ground cover and leaf habit. These factors are nevertheless not adequate for totally predicting the competitive potential of wheat varieties and, in particular, intermediate varieties for which wide variations were observed from one situation to another in our experiments. We are now waiting for the results of two additional years of experiments
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
N\'eron models of Jacobians over bases of arbitrary dimension
We work with a smooth relative curve with nodal reduction over an
excellent and locally factorial scheme . We show that blowing up a nodal
model of 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 , and describe it locally on 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
Whole CMV proteome pattern recognition analysis after HSCT identifies unique epitope targets associated with the CMV status
Cytomegalovirus (CMV) infection represents a vital complication after Hematopoietic Stem Cell Transplantation (HSCT). We screened the entire CMV proteome to visualize the humoral target epitope-focus profile in serum after HSCT. IgG profiling from four patient groups (donor and/or recipient +/- for CMV) was performed at 6, 12 and 24 months after HSCT using microarray slides containing 17174 of 15mer-peptides overlapping by 4 aa covering 214 proteins from CMV. Data were analyzed using maSigPro, PAM and the 'exclusive recognition analysis (ERA)' to identify unique CMV epitope responses for each patient group. The 'exclusive recognition analysis' of serum epitope patterns segregated best 12 months after HSCT for the D+/R+ group (versus D-/R-). Epitopes were derived from UL123 (IE1), UL99 (pp28), UL32 (pp150), this changed at 24 months to 2 strongly recognized peptides provided from UL123 and UL100. Strongly (IgG) recognized CMV targets elicited also robust cytokine production in T-cells from patients after HSCT defined by intracellular cytokine staining (IL-2, TNF, IFN and IL-17). High-content peptide microarrays allow epitope profiling of entire viral proteomes; this approach can be useful to map relevant targets for diagnostics and therapy in patients with well defined clinical endpoints. Peptide microarray analysis visualizes the breadth of B-cell immune reconstitution after HSCT and provides a useful tool to gauge immune reconstitution.The work has been funded by ALF (Arbetslivfonden) to M.M. and P.L. funds from Karolinska Institutet and Vinnova, Sweden to M.M
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
, 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 . 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 .Comment: 88 page
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
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