Supernovae, CMB, and Gravitational Leakage into Extra Dimensions

We discuss observational constraints coming from CMB and type Ia supernovae, for the model of accelerated universe produced by gravitational leakage into extra dimensions. Our fits indicate that the model is currently in agreement with the data. We also give the equations governing the evolution of cosmological perturbations. Future observations will be able to severely constrain the model.Comment: 20 pages, 6 figures, typos corrected and minor changes before publicatio

High Fat/High Glucose Diet Induces Metabolic Syndrome in an Experimental Rat Model.

Metabolic syndrome (MetS) is defined as a constellation of many metabolic disorders such as hypertension, impaired glucose tolerance, dyslipidemia and obesity, being this last disorder a key factor in the etiology of the syndrome. The widespread of MetS in actual society, mainly in developed countries, is becoming an important health problem and is increasing the need to develop new treatments against this pathology is increasing fast. The main objective of the present study was to evaluate the MetS-associated alterations developed in a new glucose diet-induced-obesity (DIO) rodent model. These alterations were also compared to those alterations developed in a fructose-DIO rodent model. Wistar rats were divided into four groups: Control (C), High-fat (HF), High-fat/high-fructose (HFF) and High-fat/high-glucose (HFG). The animals were fed ad libitum for 20 weeks. At the end of the study, HFG animals showed lower expression of energy expenditure genes when compared to the other DIO groups. Oxidative stress biomarkers such as MDA and mitochondrial RT-qPCR analyses showed an increase of oxidative damage together with mitochondrial dysfunction in HFG group. This group also showed increased insulin and glucose plasma levels, though HFF animals showed the greatest increase on these parameters. All DIO groups showed increased plasma levels of triglycerides. Altogether, our results indicated a better impact of glucose than fructose, when combined with a high-fat diet, to induce most of the alterations associated with MetS in rats. In addition, our research facilitates a new animal model to evaluate future treatments for MetS.post-print2242 K

Value of large scale expansion of tumor infiltrating lymphocytes in a compartmentalised gas-permeable bag: interests for adoptive immunotherapy

<p>Abstract</p> <p>Background</p> <p>Adoptive cell therapy (ACT) has emerged as an effective treatment for patients with metastatic melanoma. However, there are several logistical and safety concerns associated with large-scale <it>ex vivo </it>expansion of tumour-specific T lymphocytes for widespread availability of ACT for cancer patients. To address these problems we developed a specific compartmentalised bag allowing efficient expansion of tumour-specific T lymphocytes in an easy handling, closed system.</p> <p>Methods</p> <p>Starting from lymph nodes from eight melanoma patients, we performed a side-by-side comparison of Tumour-Infiltrating Lymphocytes (TIL) produced after expansion in the compartmentalised bag versus TIL produced using the standard process in plates. Proliferation yield, viability, phenotype and IFNγ secretion were comparatively studied.</p> <p>Results</p> <p>We found no differences in proliferation yield and cell viability between both TIL production systems. Moreover, each of the cell products complied with our defined release criteria before being administered to the patient. The phenotype analysis indicated that the compartmentalised bag favours the expansion of CD8+ cells. Finally, we found that TIL stimulated in bags were enriched in reactive CD8+ T cells when co-cultured with the autologous melanoma cell line.</p> <p>Conclusions</p> <p>The stimulation of TIL with feeder cells in the specifically designed compartmentalised bag can advantageously replace the conventional protocol using plates. In particular, the higher expansion rate of reactive CD8+ T cells could have a significant impact for ACT.</p

The type Ia supernova SNLS-03D3bb from a super-Chandrasekhar-mass white dwarf star

The acceleration of the expansion of the universe, and the need for Dark Energy, were inferred from the observations of Type Ia supernovae (SNe Ia). There is consensus that SNe Ia are thermonuclear explosions that destroy carbon-oxygen white dwarf stars that accrete matter from a companion star, although the nature of this companion remains uncertain. SNe Ia are thought to be reliable distance indicators because they have a standard amount of fuel and a uniform trigger -- they are predicted to explode when the mass of the white dwarf nears the Chandrasekhar mass -- 1.4 solar masses. Here we show that the high redshift supernova SNLS-03D3bb has an exceptionally high luminosity and low kinetic energy that both imply a super-Chandrasekhar mass progenitor. Super-Chandrasekhar mass SNe Ia should preferentially occur in a young stellar population, so this may provide an explanation for the observed trend that overluminous SNe Ia only occur in young environments. Since this supernova does not obey the relations that allow them to be calibrated as standard candles, and since no counterparts have been found at low redshift, future cosmology studies will have to consider contamination from such events.Comment: 9 pages, 4 figures. To appear in Nature Sept. 21. Accompanying News & Views in same issue. Supplementary information available at www.nature.com/natur

Erratum: The solar orbiter radio and plasma waves (RPW) instrument (Astronomy and Astrophysics (2020) 642 (A12) DOI: 10.1051/0004-6361/201936214)

The erratum concerns Fig. 9 entitled "Antenna radio-electrical properties" for which some of the parameters are not correct. The new figure with new parameters is provided in Fig. 1 of this corrigendum. Fig. 1. Corrected Antenna radio-electrical properties. (Figure Presented)

Rapidly Rising Transients in the Supernova - Superluminous Supernova Gap

The American Astronomical Society. All rights reserved..We present observations of four rapidly rising (trise ≈ 10 days) transients with peak luminosities between those of supernovae (SNe) and superluminous SNe (Mpeak ap; -20) - one discovered and followed by the Palomar Transient Factory (PTF) and three by the Supernova Legacy Survey. The light curves resemble those of SN 2011kl, recently shown to be associated with an ultra-long-duration gamma-ray burst (GRB), though no GRB was seen to accompany our SNe. The rapid rise to a luminous peak places these events in a unique part of SN phase space, challenging standard SN emission mechanisms. Spectra of the PTF event formally classify it as an SN II due to broad Hα emission, but an unusual absorption feature, which can be interpreted as either high velocity Hα (though deeper than in previously known cases) or Si ii (as seen in SNe Ia), is also observed. We find that existing models of white dwarf detonations, CSM interaction, shock breakout in a wind (or steeper CSM), and magnetar spin down cannot readily explain the observations. We consider the possibility that a "Type 1.5 SN" scenario could be the origin of our events. More detailed models for these kinds of transients and more constraining observations of future such events should help to better determine their nature. © 2016

Photométrie différentielle de supernovae de type Ia lointaines (0.5 inf. à z inf. à 1.2) mesurées avec le télescope spatial Hubble et estimation des paramètres cosmologiques

Après avoir rappelé le contexte théorique et observationnel de la cosmologie dans le modèle "standard", cette thèse présente comment, à partir de la comparaison des luminosités apparentes de supernovae de type la (SNIa) proches et lointaines, il est possible de préciser la géométrie de l'univers et de faire des mesures des principaux paramètres cosmologiques. Nous décrivons, ensuite, comment à partir d'observations à l'aide de l'imageur à large champ de vue CFH12K monté sur le CFHT (Canada France Hawaii Telescope, 3.6m, Hawaii) et d'outil logiciel développé au sein de notre groupe, nous avons pu découvrir durant la campagne de recherche du Supernova Cosmology Project du printemps 2001 un lot de 4 SNIa lointaines. Une recherche similaire effectuée auprès du CTIO (Cerro Tololo Interamerican Telescope, 4m, Chili) par nos collaborateurs a permis la découverte d'une dizaine de supernovae supplémentaires. Nous présentons dans cette thèse l'analyse des 6 supernovae les plus lointaines (avec des décalages vers le rouge compris entre 0.5 et 1.2) qui ont été suivies par l'instrument WFPC2 du télescope spatial Hubble. A partir de ces observations, nous avons construit leur courbe de lumière en utilisant des outils de photométrie différentielle spécifique à l'instrument WFPC2 développés lors de ce travail. La simulation du flux de ces supernovae dans les instruments d'observation a permis de construire des modèles de courbe de lumière et ainsi d'ajustement leurs caractéristiques: luminosité apparente au maximum et taux de décroissance. Enfin, la comparaison de ce lot à un lot d'une centaine de SNIa proches issues de la littérature, nous a permis de faire une mesure des paramètres cosmologiques. Nous trouvons en considérant un univers plat des valeurs respectives pour la densité réduite de matière de 0.35 (0.15 stat) et 0.22 (0.25 stat) pour les supernovae avec un décalage vers le rouge autour de 0.5 et autour de 1.After an introduction of the general context of the "standard" cosmological model, this thesis presents, how, using comparison of the apparent luminosity of nearby and distant type Ia supernovae (SNIa), it is possible to specify the geometry of the universe and perform a measurement of the principal cosmological parameters. We describe, next, how, from observations using the imageur to wide view field CFH12K mounted on the CFHT (Canada France Hawaii Telescope, 3.6m, Hawaii) and softwares developed within our group, we were able to discover during the research of the spring 2001 within the Supernova Cosmology Project a batch of 4 distant SNIa. A similar research carried out with the CTIO (Cerro Tololo Interamerican Telescope, 4M, Chile) by our collaborators allowed the discovery of about tell additional supernovae. We present in this thesis the analyze of the 6 farthest supernovae (with redshift between 0.5 and 1.2) that were followed by the instrument WFPC2 of the Hubble Space Telescope. From these observations, we constructed their lightcurves using photometric differential analysis specific to the instrument WFPC2 developed during this work. The simulation of the flux of those supernovae within the observationnal instruments enabled us to construct lightcurve models and then the fit of their characteristics : apparent luminosity at the time of maximum and decline rate. Finally, using the comparison of this batch to a batch of about one hundred nearby SNIa coming from the literature, we performed a measure of the parameters cosmologiques. We find considering a flat universe a reduced density of matter of 0.35 (0.15 stat) and 0.22 (0.25 stat) respectively for the supernovae with a redshift around 0.5 and around 1.AIX-MARSEILLE1.OAMP.Le Verrier (130552205) / SudocORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

Pré-requis à la mise en place d'une collection de sérums associés aux maladies auto-immunes au laboratoire d'auto-immunité du Centre Hospitalier Lyon-Sud

LYON1-BU Santé (693882101) / SudocSudocFranceF

Design and development of a portable beta spectrometer for 90Sr measurement in contaminated matrices

International audienceDetermining the nature and activity of radionuclides is an important task in the nuclear industry. Pure β- emitters are hard to characterize because the mean free path of electrons in dense matter is very short. Most measurement techniques are therefore based on destructive laboratory analyses. This article presents a non-destructive approach based on a portable β- spectrometer, designed to provide qualitative and quantitative information on pure β- emitters, notably 90Sr. Building on existing methods focused on the measurement of 90Sr activity in natural soil contaminated by the Chernobyl accident, the aim of this project is to develop a detector for the radiological characterization of different types of contaminated matrices, in particular the contaminated concrete structures typically found in nuclear facilities. A measurement device equipped with an EJ200 plastic scintillator was designed using Monte Carlo simulations with the MCNP6 and PENELOPE calculation codes. The energy calibration and the response of the detector were determined using experimental measurements and MCNP simulations of laboratory configurations of standard β- sources. These data were used to validate the model of the detector, as well as to determine calibration factors by numerical simulation for various on-site measurement configurations. The device was then used to characterize samples of sand from a decommissioning site in France (Fontenay-aux-Roses). The resulting 90Sr activities are within experimental uncertainties of those obtained using destructive measurements. These results are promising for wider applications on nuclear decommissioning sites