23 research outputs found
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Maucourant C. Préparation des élèves-maîtresses aux écoles maternelles et aux classes enfantines. (Expérience tentée à l'École normale d'institutrices de Charleville). In: La revue pédagogique, tome 67, Juillet-Décembre 1915. pp. 281-288
Khinchin theorem for integral points on quadratic varieties
We prove an analogue the Khinchin theorem for the Diophantine approximation
by integer vectors lying on a quadratic variety. The proof is based on the
study of a dynamical system on a homogeneous space of the orthogonal group. We
show that in this system, generic trajectories visit a family of shrinking
subsets infinitely often.Comment: 19 page
Applying Unique Molecular Identifiers in Next Generation Sequencing Reveals a Constrained Viral Quasispecies Evolution under Cross-Reactive Antibody Pressure Targeting Long Alpha Helix of Hemagglutinin.
To overcome yearly efforts and costs for the production of seasonal influenza vaccines, new approaches for the induction of broadly protective and long-lasting immune responses have been developed in the past decade. To warrant safety and efficacy of the emerging crossreactive vaccine candidates, it is critical to understand the evolution of influenza viruses in response to these new immune pressures. Here we applied unique molecular identifiers in next generation sequencing to analyze the evolution of influenza quasispecies under in vivo antibody pressure targeting the hemagglutinin (HA) long alpha helix (LAH). Our vaccine targeting LAH of hemagglutinin elicited significant seroconversion and protection against homologous and heterologous influenza virus strains in mice. The vaccine not only significantly reduced lung viral titers, but also induced a well-known bottleneck effect by decreasing virus diversity. In contrast to the classical bottleneck effect, here we showed a significant increase in the frequency of viruses with amino acid sequences identical to that of vaccine targeting LAH domain. No escape mutant emerged after vaccination. These results not only support the potential of a universal influenza vaccine targeting the conserved LAH domains, but also clearly demonstrate that the well-established bottleneck effect on viral quasispecies evolution does not necessarily generate escape mutants
Geophysical and geochemical methods applied to investigate fissure-related hydrothermal systems on the summit area of Mt. Etna volcano (Italy)
A multidisciplinary approach integrating self-potential, soil temperature, heat flux, CO2 efflux and gravity
gradiometry signals was used to investigate a relatively small fissure-related hydrothermal systemnear the summit
of Mt. Etna volcano (Italy). Measurements were performed through two different surveys carried out at the
beginning and at the end of July 2009, right after the end of the long-lived 2008–2009 flank eruption and in coincidencewith
an increase in diffuse flank degassing related to a reactivation of the volcano, leading to the opening
of a new summit vent (NSEC). The main goal was to use a multidisciplinary approach to the detection of
hidden fractures in an area of evident near-surface hydrothermal activity. Despite the different methodologies
used and the different geometry of the sampling grid between the surveys, all parameters concurred in
confirming that the study area is crossed by faults related with the main fracture systems of the south flank of
the volcano,where a continuous hydrothermal circulation is established. Results also highlighted that hydrothermal
activity in this area changed both in space and in time. These changes were a clear response to variations in
themagmatic system, notably tomigration of magma at various depth within the main feeder systemof the volcano.
The results suggest that this specific area, initially chosen as the optimal test-site for the proposed approach,
can be useful in order to get information on the potential reactivation of the summit craters of Mt. Etna
Applying Unique Molecular Identifiers in Next Generation Sequencing Reveals a Constrained Viral Quasispecies Evolution under Cross-Reactive Antibody Pressure Targeting Long Alpha Helix of Hemagglutinin
To overcome yearly efforts and costs for the production of seasonal influenza vaccines, new approaches for the induction of broadly protective and long-lasting immune responses have been developed in the past decade. To warrant safety and efficacy of the emerging crossreactive vaccine candidates, it is critical to understand the evolution of influenza viruses in response to these new immune pressures. Here we applied unique molecular identifiers in next generation sequencing to analyze the evolution of influenza quasispecies under in vivo antibody pressure targeting the hemagglutinin (HA) long alpha helix (LAH). Our vaccine targeting LAH of hemagglutinin elicited significant seroconversion and protection against homologous and heterologous influenza virus strains in mice. The vaccine not only significantly reduced lung viral titers, but also induced a well-known bottleneck effect by decreasing virus diversity. In contrast to the classical bottleneck effect, here we showed a significant increase in the frequency of viruses with amino acid sequences identical to that of vaccine targeting LAH domain. No escape mutant emerged after vaccination. These results not only support the potential of a universal influenza vaccine targeting the conserved LAH domains, but also clearly demonstrate that the well-established bottleneck effect on viral quasispecies evolution does not necessarily generate escape mutants