Time-delay interferometry noise transfer functions for LISA

International audienceThe Laser Interferometry Space Antenna (LISA) mission is the future space-based gravitational-wave (GW) observatory of the European Space Agency. It is formed by three spacecraft exchanging laser beams in order to form multiple interferometers. The data streams to be used in order to extract the large number and variety of GW sources are time-delay interferometry (TDI) data. One important processing step to produce these data is the TDI on-ground processing, which recombines multiple interferometric on-board measurements to remove certain noise sources from the data, such as laser frequency noise or spacecraft jitter noise. The LISA noise budget is therefore expressed at the TDI level in order to account for the different TDI transfer functions applied for each noise source and thus estimate their real weight on mission performance. In this study, we present an update model for the beams, measurements and TDI, with several approximations to derive the noise transfer functions. The laser locking and noise correlation are taken into account to see their impact in the transfer functions. A methodology for such a derivation has been established in detail, as well as verification procedures against simulated data. It results in a set of transfer functions, which are now used by the LISA project, in particular in its performance model. Using these transfer functions, realistic noise curves for various instrumental configurations are provided to data analysis algorithms and used for instrument design

Time-delay interferometry noise transfer functions for LISA

The Laser Interferometry Space Antenna (LISA) mission is the future space-based gravitational-wave (GW) observatory of the European Space Agency. It is formed by 3 spacecraft exchanging laser beams in order to form multiple interferometers. The data streams to be used in order to extract the large number and variety of GW sources are time-delay interferometry (TDI) data. One important processing step to produce these data is the TDI on-ground processing, which recombines multiple interferometric on-board measurements to remove certain noise sources from the data, such as laser frequency noise or spacecraft jitter noise. The LISA noise budget is therefore expressed at the TDI level in order to account for the different TDI transfer functions applied for each noise source and thus estimate their real weight on mission performance. In this study, we present an update model for the beams, measurements and TDI, with several approximations to derive the noise transfer functions. The laser locking and noise correlation are taken into account to see their impact in the transfer functions. A methodology for such a derivation has been established in details, as well as verification procedures against simulated data. It results in a set of transfer functions, which are now used by the LISA project, in particular in its performance model. Using these transfer functions, realistic noise curves for various instrumental configurations are provided to data analysis algorithms and used for instrument design

Aspects de la construction en bois en Normandie. Du Ier siècle au XIVe siècle

Halbout Patrick, Le Maho Jacques, Blaszkiewicz Patrick, Flambard Jean Marc, Halbout-Bertin Dominique, Jigan Claude, Lemaître Claude, Marin Jean-Yves, Pilet-Lemière Jacqueline, Pilet Christian, Pitte Dominique, Verlut Romain. Aspects de la construction en bois en Normandie. Du Ier siècle au XIVe siècle. In: Cahier des Annales de Normandie n°16, 1984. Aspects de la construction en bois en Normandie. Du Ier siècle au XIVe siècle. pp. 3-107

Altered spinogenesis in iPSC-derived cortical neurons from patients with autism carrying de novo SHANK3 mutations

The synaptic protein SHANK3 encodes a multidomain scafold protein expressed at the postsynaptic density of neuronal excitatory synapses. We previously identifed de novo SHANK3 mutations in patients with autism spectrum disorders (ASD) and showed that SHANK3 represents one of the major genes for ASD. Here, we analyzed the pyramidal cortical neurons derived from induced pluripotent stem cells from four patients with ASD carrying SHANK3 de novo truncating mutations. At 40–45 days after the diferentiation of neural stem cells, dendritic spines from pyramidal neurons presented variable morphologies: flopodia, thin, stubby and muschroom, as measured in 3D using GFP labeling and immunofuorescence. As compared to three controls, we observed a signifcant decrease in SHANK3 mRNA levels (less than 50% of controls) in correlation with a signifcant reduction in dendritic spine densities and whole spine and spine head volumes. These results, obtained through the analysis of de novo SHANK3 mutations in the patients’ genomic background, provide further support for the presence of synaptic abnormalities in a subset of patients with ASD

Altered spinogenesis in iPSC-derived cortical neurons from patients with autism carrying de novo SHANK3 mutations

Abstract The synaptic protein SHANK3 encodes a multidomain scaffold protein expressed at the postsynaptic density of neuronal excitatory synapses. We previously identified de novo SHANK3 mutations in patients with autism spectrum disorders (ASD) and showed that SHANK3 represents one of the major genes for ASD. Here, we analyzed the pyramidal cortical neurons derived from induced pluripotent stem cells from four patients with ASD carrying SHANK3 de novo truncating mutations. At 40–45 days after the differentiation of neural stem cells, dendritic spines from pyramidal neurons presented variable morphologies: filopodia, thin, stubby and muschroom, as measured in 3D using GFP labeling and immunofluorescence. As compared to three controls, we observed a significant decrease in SHANK3 mRNA levels (less than 50% of controls) in correlation with a significant reduction in dendritic spine densities and whole spine and spine head volumes. These results, obtained through the analysis of de novo SHANK3 mutations in the patients’ genomic background, provide further support for the presence of synaptic abnormalities in a subset of patients with ASD

Synthesis and Enzymatic Conversion of Amino Acids Equipped with the Silanetriol Functionality: A Prelude to Silicon Biodiversification

Abstract Synthetic routes are reported for the three analogues of the simplest L‐2‐amino‐dicarboxylic acids, aspartate, glutamate, and aminoadipate, in which the silanetriol group (Si(OH)3) replaces the distal carboxyl group (CO2H). Direct access to the silanetriol amino acids relied either on catalytic hydrosilylation of a terminal alkene using triethoxysilane, or on alkylation of a glycine equivalent anion by triallyl(iodomethyl)silane. In both cases, acid hydrolysis afforded the silanetriol amino acids. These were shown to self‐assemble into siloxane Si‐O clusters as their concentration in water increased in the pH range of 1–12. Such reversible cross‐linking did not prevent silanetriol amino acids from serving as substrates of an aminotransferase enzyme, boding well for their utilization as microbial nutrients to encompass silicon in future stages of metabolism and polypeptide edifices

Erratum to: Data blinding for the nEDM experiment at PSI

ISSN:1434-6001ISSN:1434-601

GammapyVersion 0.19

Gammapy is a community-developed, open-source Python package for gamma-ray astronomy built on Numpy, Scipy and Astropy. It is the core library for the CTA science tools and can also be used to analyse data from existing imaging atmospheric Cherenkov telescopes (IACTs), such as H.E.S.S., MAGIC and VERITAS. It also provides some support for Fermi-LAT and HAWC data analysis