DEMON: a Proposal for a Satellite-Borne Experiment to study Dark Matter and Dark Energy

We outline a novel satellite mission concept, DEMON, aimed at advancing our comprehension of both dark matter and dark energy, taking full advantage of two complementary methods: weak lensing and the statistics of galaxy clusters. We intend to carry out a 5000 sqdeg combined IR, optical and X-ray survey with galaxies up to a redshift of z~2 in order to determine the shear correlation function. We will also find ~100000 galaxy clusters, making it the largest survey of this type to date. The DEMON spacecraft will comprise one IR/optical and eight X-ray telescopes, coupled to multiple cameras operating at different frequency bands. To a great extent, the technology employed has already been partially tested on ongoing missions, therefore ensuring improved reliability.Comment: 12 pages, 3 figures, accepted for publication in the SPIE conference proceeding

Strong gravitational lensing in the radio domain

In het Universum kunnen zware objecten, zoals melkwegstelsels en clusters van melkwegstelsels, zich als gigantische vergrootglazen gedragen die verscheidene vergrootte en vervormde afbeeldingen van een bron kunnen produceren. Als dit effect optreed, worden deze objecten sterke zwaartekrachtlenzen genoemd en kunnen ze, in extreme gevallen, heldere uitgerekte afbeeldingen veroorzaken die "reuzebogen" worden genoemd. In dit proefschrift illustreren we drie verschillende toepassingen van dit fenomeen in de radiosterrenkunde: (i) de studie van een melkwegstelsel dat als zwaartekrachtlens fungeert, (ii) de studie van de interne structuur van een bron die verscheidene afbeeldingen heeft door het effect van zwaartekrachtlenzen en (iii) een statistische studie van "reuzebogen" veroorzaakt door clusters van melkwegstelsels. De eerste studie richt zich op het systeem B1600+434, waar een melkwegstelsel twee afbeeldingen produceert van het compacte centrale gebied van een achterliggend stelsel. Onze radiowaarnemingen hebben bevestigd dat de helderheid van een van de afbeeldingen varieert gedurende vier jaar als gevolg van de structuur van de zwaartekrachtlens. Het tweede bestudeerde opject is een uitgebreide bron die waargenomen is bij sub-mm golflengtes en die lijkt te zijn uitvergroot door zwaartekrachtlenzen. Radiowaarnemingen van dit systeem ondersteunen de hypothese dat een deel van de sub-mm straling wordt veroorzaakt door de botsing tussen 3 ver weg gelegen melkwegstelsels. Als laatste presenteren we de eerste voorspellingen voor het verwachtte aantal "reuzebogen" dat waarneembaar is bij radio en sub-mm golflengtes, door de structuur en evolutie van clusters van melkwegstelsels in detail te modelleren. De toekomst van de studie van meervoudige afbeeldingen als gevolg van zwaartekrachtlenzen wordt ook besproken. ... Zie: Samenvatting

Constraining the excitation conditions of the molecular gas in the most distant submillimetre galaxy at z=4.76

We propose to use ATCA to measure CO(5-4) emission in the currently highest redshift submm-selected galaxy (SMG) known: LESS J033229 at z=4.755. Combined with our previous successful ATCA observations of the CO(2-1) transition in this SMG, we will be able to start building up the CO SED excitation ladder and so gain new insight on the excitation conditions of the molecular gas which is fuelling a massive burst of star formation at a time when the Universe was only 1 Gyr old. ATCA is currently the only available facility that can provide these data, giving us a sneak-preview of the capabilities of ALMA for studying the youngest galaxies in the very distant Universe

High IGKC-Expressing Intratumoral Plasma Cells Predict Response to Immune Checkpoint Blockade

Resistance to Immune Checkpoint Blockade (ICB) constitutes the current limiting factor for the optimal implementation of this novel therapy, which otherwise demonstrates durable responses with acceptable toxicity scores. This limitation is exacerbated by a lack of robust biomarkers. In this study, we have dissected the basal TME composition at the gene expression and cellular levels that predict response to Nivolumab and prognosis. BCR, TCR and HLA profiling were employed for further characterization of the molecular variables associated with response. The findings were validated using a single-cell RNA-seq data of metastatic melanoma patients treated with ICB, and by multispectral immunofluorescence. Finally, machine learning was employed to construct a prediction algorithm that was validated across eight metastatic melanoma cohorts treated with ICB. Using this strategy, we have unmasked a major role played by basal intratumoral Plasma cells expressing high levels of IGKC in efficacy. IGKC, differentially expressed in good responders, was also identified within the Top response-related BCR clonotypes, together with IGK variants. These results were validated at gene, cellular and protein levels; CD138+ Plasma-like and Plasma cells were more abundant in good responders and correlated with the same RNA-seq-defined fraction. Finally, we generated a 15-gene prediction model that outperformed the current reference score in eight ICB-treated metastatic melanoma cohorts. The evidenced major contribution of basal intratumoral IGKC and Plasma cells in good response and outcome in ICB in metastatic melanoma is a groundbreaking finding in the field beyond the role of T lymphocytes

UVSQ-SAT, a Pathfinder CubeSat Mission for Observing Essential Climate Variables

International audienceThe UltraViolet and infrared Sensors at high Quantum efficiency onboard a small SATellite (UVSQ-SAT) mission aims to demonstrate pioneering technologies for broadband measurement of the Earth’s radiation budget (ERB) and solar spectral irradiance (SSI) in the Herzberg continuum (200–242 nm) using high quantum efficiency ultraviolet and infrared sensors. This research and innovation mission has been initiated by the University of Versailles Saint-Quentin-en-Yvelines (UVSQ) with the support of the International Satellite Program in Research and Education (INSPIRE). The motivation of the UVSQ-SAT mission is to experiment miniaturized remote sensing sensors that could be used in the multi-point observation of Essential Climate Variables (ECV) by a small satellite constellation. UVSQ-SAT represents the first step in this ambitious satellite constellation project which is currently under development under the responsibility of the Laboratory Atmospheres, Environments, Space Observations (LATMOS), with the UVSQ-SAT CubeSat launch planned for 2020/2021. The UVSQ-SAT scientific payload consists of twelve miniaturized thermopile-based radiation sensors for monitoring incoming solar radiation and outgoing terrestrial radiation, four photodiodes that benefit from the intrinsic advantages of Ga 2 O 3 alloy-based sensors made by pulsed laser deposition for measuring solar UV spectral irradiance, and a new three-axis accelerometer/gyroscope/compass for satellite attitude estimation. We present here the scientific objectives of the UVSQ-SAT mission along the concepts and properties of the CubeSat platform and its payload. We also present the results of a numerical simulation study on the spatial reconstruction of the Earth’s radiation budget, on a geographical grid of 1 ° × 1 ° degree latitude-longitude, that could be achieved with UVSQ-SAT for different observation periods