A case for variational geomagnetic data assimilation: insights from a one-dimensional, nonlinear, and sparsely observed MHD system

Secular variations of the geomagnetic field have been measured with a continuously improving accuracy during the last few hundred years, culminating nowadays with satellite data. It is however well known that the dynamics of the magnetic field is linked to that of the velocity field in the core and any attempt to model secular variations will involve a coupled dynamical system for magnetic field and core velocity. Unfortunately, there is no direct observation of the velocity. Independently of the exact nature of the above-mentioned coupled system -- some version being currently under construction -- the question is debated in this paper whether good knowledge of the magnetic field can be translated into good knowledge of core dynamics. Furthermore, what will be the impact of the most recent and precise geomagnetic data on our knowledge of the geomagnetic field of the past and future? These questions are cast into the language of variational data assimilation, while the dynamical system considered in this paper consists in a set of two oversimplified one-dimensional equations for magnetic and velocity fields. This toy model retains important features inherited from the induction and Navier-Stokes equations: non-linear magnetic and momentum terms are present and its linear response to small disturbances contains Alfvén waves. It is concluded that variational data assimilation is indeed appropriate in principle, even though the velocity field remains hidden at all times; it allows us to recover the entire evolution of both fields from partial and irregularly distributed information on the magnetic field. This work constitutes a first step on the way toward the reassimilation of historical geomagnetic data and geomagnetic forecast

The ARF ru mor suppressor: structure, functions ans status in cancer

International audienc

Gestión del Talento Humano : Impacto del proceso de administración de personal en el desarrollo en la organización

Esta investigación aborda como tema general Gestión de talento humano y subtema impacto del proceso de admisión de personal en el desarrollo en la organización, el cual lleva a cabo toda empresa para incorporar nuevos integrantes a la fuerza laboral, desarrolla y retiene a un recurso humano existente. Se tiene como objetivo especificar el impacto del proceso de admisión de personal en el desarrollo de la organización, debido a lo fundamental que es para crear un equipo competitivo y aportar valor a la empresa, por ello, debe ser un pilar importante dentro de cualquier estrategia empresarial. Se trata de predecir qué candidatos serán los adecuados para desempeñar con éxito las tareas de la vacante por la que han sido contratados. Varios factores han contribuido a este fenómeno: económicos, tecnológicos, sociales, culturales, jurídicos, políticos, demográficos y ecológicos que actúan de manera conjunta y sistémica en un campo dinámico de fuerzas para producir resultados inimaginables, que originan imprevisibilidad e incertidumbre en las organizaciones. Cuando las organizaciones son exitosas, tienden a crecer o, como mínimo a sobrevivir, el crecimiento exige mayor complejidad en los recursos necesarios para ejecutar las operaciones, ya que aumenta el capital, se incrementa la tecnología, las actividades de apoyo, además provoca el aumento del número de personas y genera la necesidad de intensificar la aplicación de conocimientos habilidades y destrezas indispensables para mantener la competitividad de la organización Para la realización de este trabajo se desarrolló una metodología de trabajo que permitió establecer objetivos específicos para el tema seleccionado, desarrollarlos cada uno mediante la búsqueda, lectura, análisis y selección planteadas por especialistas del área de recursos humanos, entre ellos Idalberto Chiavenato, Michael Hitt, J. Stewart Black, Lyman W. Porter, Harold Koontz y otros, así mismo se implementaron las Normas APA para las referencias bibliograficas

P14 ARF inhibits the growth of lung adenocarcinoma cells harboring an EGFR L858R mutation by activating a STAT3-dependent pro-apoptotic signalling pathway

International audienc

A dedicated microarray for in-depth analysis of pre-mRNA splicing events: application to the study of genes involved in the response to targeted anticancer therapies.

International audience: Alternative pre-mRNA splicing (AS) widely expands proteome diversity through the combinatorial assembly of exons. The analysis of AS on a large scale, by using splice-sensitive microarrays, is a highly efficient method to detect the majority of known and predicted alternative transcripts for a given gene. The response to targeted anticancer therapies cannot easily be anticipated without prior knowledge of the expression, by the tumor, of target proteins or genes. To analyze, in depth, transcript structure and levels for genes involved in these responses, including AKT1-3, HER1-4, HIF1A, PIK3CA, PIK3R1-2, VEGFA-D and PIR, we engineered a dedicated gene chip with coverage of an average 185 probes per gene and, especially, exon-exon junction probes. As a proof of concept, we demonstrated the ability of such a chip to detect the effects of over-expressed SRSF2 RNA binding protein on the structure and abundance of mRNA products in H538 lung cancer cells conditionally over-expressing SRSF2. Major splicing changes were observed, including in HER1/EGFR pre-mRNA, which were also seen in human lung cancer samples over-expressing the SRSF2 protein. In addition, we showed that variations in HER1/EGFR pre-mRNA splicing triggered by SRSF2 overexpression in H358 cells resulted in a drop in HER1/EGFR protein level, which correlated with increased sensitivity to gefitinib, an EGFR tyrosine kinase inhibitor. We propose, therefore, that this novel tool could be especially relevant for clinical applications, with the aim to predict the response before treatment

Magnetostrophic MRI in the Earth's Outer Core

We show that a simple, modified version of the Magnetorotational Instability (MRI) can develop in the outer liquid core of the Earth, in the presence of a background shear. It requires either thermal wind, or a primary instability, such as convection, to drive a weak differential rotation within the core. The force balance in the Earth's core is very unlike classical astrophysical applications of the MRI (such as gaseous disks around stars). Here, the weak differential rotation in the Earth core yields an instability by its constructive interaction with the planet's much larger rotation rate. The resulting destabilising mechanism is just strong enough to counteract stabilizing resistive effects, and produce growth on geophysically interesting timescales. We give a simple physical explanation of the instability, and show that it relies on a force balance appropriate to the Earth's core, known as magnetostrophic balance

Nuclear trafficking of EGFR by Vps34 represses Arf expression to promote lung tumor cell survival

International audienc

p14 ARF activates a Tip60-dependent ATM/ATR/CHK pathway in response to genotoxic stresses 2 Running title: ARF activates a Tip60-dependent DNA damage checkpoint 3

International audienc

Immunogenicity and safety of a quadrivalent inactivated influenza vaccine in pregnant women: a randomized, observer-blind trial

ABSTRACTVaccination against influenza during pregnancy provides direct protection to pregnant women and indirect protection to their infants. Trivalent inactivated influenza vaccines (IIV3s) are safe and effective during pregnancy, but quadrivalent inactivated influenza vaccines (IIV4s) have not been evaluated in pregnant women and their infants. Here, we report the results of a randomized phase IV study to evaluate the immunogenicity and safety of IIV4 vs. IIV3 in pregnant women. Participants aged ≥18 years at weeks 20 to 32 of gestation were randomly assigned in a 2:1 ratio to receive a single dose of IIV4 (n = 230) or IIV3 (n = 116). Between baseline and 21 days after vaccination, hemagglutination inhibition (HAI) antibody titers increased in both groups by similar magnitudes for the two influenza A strains and single B strain common to IIV4 and IIV3. For the additional B strain in IIV4, HAI titers were higher in IIV4 recipients than IIV3 recipients (post-/pre-vaccination geometric mean titer ratio, 6.3 [95% CI: 5.1 ? 7.7] vs. 3.4 [95% CI: 2.7 ? 4.3]). At delivery, in both groups, HAI antibody titers for all strains were 1.5 ? 1.9-fold higher in umbilical cord blood than in maternal blood, confirming active transplacental antibody transfer. Rates of solicited and unsolicited vaccine-related adverse events in mothers were similar between the two groups. Live births were reported for all participants and there were no vaccine-related adverse events in newborns. These results suggest IIV4 is as safe and immunogenic as IIV3 in pregnant women, and that maternal immunization with IIV4 should protect newborns against influenza via passively acquired antibodies.Peer reviewe