Two transiting hot Jupiters from the WASP survey : WASP-150b and WASP-176b

Funding: The research leading to these results has received funding from the European Research Council under the FP/2007-2013 ERC grant Agreement No. 336480 and from the ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation. A.C.C. acknowledges support from the UK Science and Technology Facilities Council (STFC)consolidated grant No. ST/R000824/1.We report the discovery of two transiting exoplanets from the WASP survey, WASP-150b and WASP-176b. WASP-150b is an eccentric (e = 0.38) hot Jupiter on a 5.6 day orbit around a V = 12.03, F8 main-sequence host. The host star has a mass and radius of 1.4 M⊙ and 1.7 R⊙ respectively. WASP-150b has a mass and radius of 8.5 MJ and 1.1 RJ, leading to a large planetary bulk density of 6.4 ρJ. WASP-150b is found to be ~3 Gyr old, well below its circularization timescale, supporting the eccentric nature of the planet. WASP-176b is a hot Jupiter planet on a 3.9 day orbit around a V = 12.01, F9 sub-giant host. The host star has a mass and radius of 1.3 M⊙ and 1.9 R⊙. WASP-176b has a mass and radius of 0.86 MJ and 1.5 RJ, respectively, leading to a planetary bulk density of 0.23 ρJ.Publisher PDFPeer reviewe

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Lumière sur la diversité des petits mondes en transit d'étoiles solaires

Small exoplanets, with sizes from Earth-like to Neptune-like, exhibit a surprising diversity in terms of composition. Their bulk density, derived by combining space-based transit photometry and high-precision Doppler spectroscopy, is ranging from low-density mini-Neptunes to massive super-Earths. So far, the transition between rocky and gaseous planets appears to be continuous. These objects are challenging all planet-formation theories and no example of them is known in the solar system. The exploration of these small exoplanets is currently limited by the precision achieved on their fundamental properties. While about a hundred super-Earths have been characterized so far, it is possible to determine unambiguously whether they are rocky or gaseous only for a dozen of them. The objective of this PhD is to contribute to the study of the diversity of these small worlds around solar stars by combining the most powerful exoplanet-hunter instruments: the NASA Kepler space telescope within the K2 mission and the HARPS spectrograph at the European Southern Observatory. The first goal is to exploit and interpret the data from a 2-year large programme on HARPS within a European consortium, in order to increase the number of well characterised small planets, and make the link between the observations and the formation paths of these bodies. This PhD also contributes to the ground follow-up of the K2 mission using the SOPHIE spectrograph at the Haute-Provence observatory, as well as the TESS mission using HARPS. Beyond the instrumental precision, the main limitation to identify low-amplitude planetary signatures is the magnetic activity of stars. Stellar noises can be dominant and the existing correction methods are far to be perfect. This work also focuses on this primordial aspect and probe the additional constraints which can be brought by various observing techniques, particularly spectropolarimetry as it allows to probe the evolution of the large scale magnetic field which is reponsible for the rotational modulation observed in radial-velocity.Les petites planètes, entre la taille de la Terre et celle de Neptune, présentent une grande diversité de compositions. Leur densité moyenne, obtenue en combinant la photométrie des transits avec la spectroscopie Doppler à haute précision, s'étend de mini-Neptunes peu denses aux super-Terres massives. À l'heure actuelle, on observe une transition continue entre les planètes rocheuses et gazeuses, et ces objets inconnus dans le système solaire défient les théories de formation planétaire. L'exploration de ces petites planètes est limitée actuellement par la précision atteinte sur leurs paramètres fondamentaux. Alors que plus d'une centaine de ces planètes ont été caractérisées à l'heure actuelle, il n'est possible de déterminer précisément la composition que d'une douzaine d'entre-elles. L'objectif de cette thèse est de contribuer à l'étude de la diversité des petits mondes autour d'étoiles solaires en combinant deux des plus puissants instruments pour la détection d'exoplanètes : le télescope spatial Kepler de la NASA dans le cadre de la mission K2 et le spectrographe HARPS de l'observatoire européen austral. Le premier objectif est l'exploitation et l'interprétation des données issues d'un large programme de deux ans sur HARPS, au sein d'un consortium européen, pour enrichir le nombre de petites planètes bien caractérisées, et faire le lien avec les scénarios de formation et d'évolution des corps planétaires. Cette thèse contribue aussi au suivi sol de la mission K2 avec le spectrographe SOPHIE à l'observatoire de Haute-Provence, et de la mission TESS avec HARPS. Au-delà de la précision des instruments, la limitation majeure dans l'identification des petits signaux planétaires est l'activité magnétique des étoiles. L'impact de ces bruits stellaires peut dans certains cas être dominant et il n'existe pour l'instant aucune méthode de correction parfaitement adaptée. Cette thèse s'intéresse modestement à ces aspects incontournables. En particulier, l'intérêt de contraintes additionnelles issues d'observations avec des techniques variées est explorée. C'est le cas notamment de la spectropolarimétrie qui permet un suivi de l'évolution du champ magnétique, responsable des modulations observées en vitesse radiale

Degradable Glycopolyester-Like Nanoparticles by Radical Ring-Opening Polymerization

A small library of degradable polyester-like glycopolymers was successfully prepared by the combination of radical ring-opening copolymerization (rROP) of 2-methylene-1,3-dioxepane (MDO) with vinyl ether (VE) derivatives, and a Pd-catalyzed thioglycoconjugation. The resulting thioglycopolymers were formulated into self-stabilized thioglyconanoparticles which were stable up to 4 months and were enzymatically degraded. Nanoparticles and their degradation products exhibited a good cytocompatibility on two healthy cell lines. Interactions between thioglyconanoparticles and lectins were investigated and highlighted the presence of both specific carbohydrate/lectin interactions and non-specific hydrophobic interactions. Fluorescent thioglyconanoparticles were also prepared either by encapsulation of Nile Red, or by the functionalization of the polymer backbone with Rhodamine B. Such nanoparticles were used to prove the cell internalization of the thioglyconanoparticles by lung adenocarcinoma (A549) cells which underlined the great potential of P(CKA-co-VE) copolymers for biomedical application

Comparative Study of Percussion Drilling in Glasses with a Femtosecond Laser in Single Pulse, MHz-Burst, and GHz-Burst Regimes and Optimization of the Hole Aspect Ratio

In this contribution, we present a comparative study on top-down drilling in sodalime glass, with a femtosecond laser operating in single-pulse, MHz-burst and GHz-burst modes, respectively. We investigate the hole depth, drilling rate, and hole morphology for these three regimes while keeping the same experimental conditions. We demonstrate that, for both burst regimes, the burst length has to be adapted for optimizing the hole depth. In the GHz-burst regime, the lower the ablation rate the longer the holes. The three drilling regimes lead to different hole morphologies, where the GHz-burst mode results in the best hole quality featuring glossy inner walls and an almost cylindrical morphology. Furthermore, we obtain crack-free holes, the deepest measuring 3.7 mm in length and 25 µm in entrance diameter corresponding to an aspect ratio of 150, which is the highest aspect ratio reported thus far with femtosecond GHz-burst drilling to the best of our knowledge

Degradable Glycopolyester-Like Nanoparticles by Radical Ring-Opening Polymerization

International audienceA small library of degradable polyester-like glycopolymers was successfully prepared by the combination of radical ring-opening copolymerization of 2-methylene-1,3-dioxepane as a cyclic ketene acetal (CKA) with vinyl ether (VE) derivatives and a Pd-catalyzed thioglycoconjugation. The resulting thioglycopolymers were formulated into self-stabilized thioglyconanoparticles, which were stable up to 4 months and were enzymatically degraded. Nanoparticles and their degradation products exhibited a good cytocompatibility on two healthy cell lines. Interactions between thioglyconanoparticles and lectins were investigated and highlighted the presence of both specific carbohydrate/lectin interactions and nonspecific hydrophobic interactions. Fluorescent thioglyconanoparticles were also prepared either by encapsulation of Nile red or by the functionalization of the polymer backbone with rhodamine B. Such nanoparticles were used to prove the cell internalization of the thioglyconanoparticles by lung adenocarcinoma (A549) cells, which underlined the great potential of P(CKA-co-VE) copolymers for biomedical applications

Bessel Beam Dielectrics Cutting with Femtosecond Laser in GHz-Burst Mode

We report, for the first time to the best of our knowledge, Bessel beam dielectrics cutting with a femtosecond laser in GHz-burst mode. The non-diffractive beam shaping is based on the use of an axicon and allows for cutting glasses up to 1 mm thickness with an excellent cutting quality. Moreover, we present a comparison of the cutting results with the state-of-the-art method, consisting of short MHz-bursts of femtosecond pulses. We further illustrate the influence of the laser beam parameters such as the burst energy and the pitch between consecutive Bessel beams on the machining quality of the cutting plane and provide process windows for both regimes

Maintenance of Chronological Aging Features in Culture of Normal Human Dermal Fibroblasts from Old Donors

Chronological aging is defined as a time-dependent decline of tissue homeostasis which severely impacts skin. Understanding the mechanisms of skin aging is an active research area limited by the lack of relevant in vitro models. Being a component of aging, replicative or stress-induced senescence is repeatedly used to mimic skin aging in vitro, thus presenting only a partial view of the complexity of aging. Herein, we aimed to clarify whether primary normal human dermal fibroblasts retained age-related characteristics when cultured in 2D monolayer, and could be used as a relevant model for aging research. We compared three groups of fibroblasts isolated from different aged donors. We observed strongly decreased population doubling capacities, a reduced clonogenic ability, an impairment in extracellular matrix production together with modifications of respiratory metabolism with an increase in age. These disruptions were particularly marked when comparing fibroblasts isolated from old individuals (over 70 years old) to those isolated from young individuals (18–37 years old), while cells from middle-aged donors exhibited an intermediate profile. These alterations of cell features can be related to the signs of dermis aging, thus showing that cultured primary cells indeed retain some characteristics of the original tissue from which they were extracted