Cosmon dark matter?

We investigate if the fluctuations of the scalar field mediating quintessence -- the cosmon -- can play an important role in cosmology. Small fluctuations with short wavelength behave similar to a relativistic gas. In contrast, the contribution to the energy density from horizon size fluctuations may decrease less rapidly than radiation. We discuss the possibility that the cosmon fluctuations grow nonlinearly, form lumps and constitute the clustering dark matter of the universe. Cosmon dark matter would lead to interesting consequences for the equation of state and the coupling between quintessence and dark matter.Comment: Published version,correction in appendix A, 43 pages, LaTe

Renormalization Group Approach to Generalized Cosmological models

We revisit here the problem of generalized cosmology using renormalization group approach. A complete analysis of these cosmologies, where specific models appear as asymptotic fixed-points, is given here along with their linearized stability analysis.Comment: 10 pages, to appear in the International Journal of Theoretical Physic

Quantum gravity from the point of view of locally covariant quantum field theory

We construct perturbative quantum gravity in a generally covariant way. In particular our construction is background independent. It is based on the locally covariant approach to quantum field theory and the renormalized Batalin-Vilkovisky formalism. We do not touch the problem of nonrenormalizability and interpret the theory as an effective theory at large length scales

Quintessence-the Dark Energy in the Universe?

Quintessence - the energy density of a slowly evolving scalar field - may constitute a dynamical form of the homogeneous dark energy in the universe. We review the basic idea and indicate observational tests which may distinguish quintessence from a cosmological constant.Comment: 13 pages, 3 figures, LaTe

Interacting new agegraphic viscous dark energy with varying GG

We consider the new agegraphic model of dark energy with a varying gravitational constant, $G$, in a non-flat universe. We obtain the equation of state and the deceleration parameters for both interacting and noninteracting new agegraphic dark energy. We also present the equation of motion determining the evolution behavior of the dark energy density with a time variable gravitational constant. Finally, we generalize our study to the case of viscous new agegraphic dark energy in the presence of an interaction term between both dark components.Comment: 12 pages, accepted for publication in IJTP (2010

Somatic Mutational Landscape of Splicing Factor Genes and Their Functional Consequences across 33 Cancer Types

Hotspot mutations in splicing factor genes have been recently reported at high frequency in hematological malignancies, suggesting the importance of RNA splicing in cancer. We analyzed whole-exome sequencing data across 33 tumor types in The Cancer Genome Atlas (TCGA), and we identified 119 splicing factor genes with significant non-silent mutation patterns, including mutation over-representation, recurrent loss of function (tumor suppressor-like), or hotspot mutation profile (oncogene-like). Furthermore, RNA sequencing analysis revealed altered splicing events associated with selected splicing factor mutations. In addition, we were able to identify common gene pathway profiles associated with the presence of these mutations. Our analysis suggests that somatic alteration of genes involved in the RNA-splicing process is common in cancer and may represent an underappreciated hallmark of tumorigenesis

L’utilisation des défibrillateurs semi-automatiques par le grand public améliore la survie immédiate des arrêts cardiaques survenant dans les aéroports internationaux [Impact of onsite or dispatched automated external defibrillator use on early survival after sudden cardiac arrest occurring in international airports]

Out-of-hospital cardiac arrest (OHCA) is a major public health challenge. Use of automated external defibrillators (AED) by laypersons improves survival of patient's victim of OHCA. The aim of our study was to compare onsite AED vs. dispatched AED management of cardiac arrest occurring in international airports. We conducted a retrospective, observational, comparative, study on data collected from three international airports: Paris-Charles-de-Gaulle (CDG), Chicago and Madrid-Barajas. We included patients with OHCA occurring inside the airport between 2009 and 2013. Group public access (PUB) included airports where AED were available to laypersons and group dispatched (SEC) was represented by Paris-CDG airport where AED was provided by paramedic teams. The primary endpoint was successful resuscitation defined as survival at time of hospital admission. We included 150 consecutive patients victim of OHCA in the three airports. The time between collapse and AED setting was significantly shorter in the PUB vs. SEC group (4±3minutes vs. 11±11, P=0.0006). The total duration of resuscitation was shorter in the PUB group (10±10minutes vs. 36±25minutes, P<0.0001). Survival at time of hospital admission was higher in the PUB group (62% vs. 38%, P=0.01). The availability of public access AEDs in international airports seems to allow a quicker defibrillation and an increased success rate of resuscitation