The saga of dyssynchrony imaging: Are we getting to the point

Cardiac resynchronisation therapy (CRT) has an established role in the management of patients with heart failure, reduced left ventricular ejection fraction (LVEF < 35%) and widened QRS (>130 msec). Despite the complex pathophysiology of left ventricular (LV) dyssynchrony and the increasing evidence supporting the identification of specific electromechanical substrates that are associated with a higher probability of CRT response, the assessment of LVEF is the only imaging-derived parameter used for the selection of CRT candidates.This review aims to (1) provide an overview of the evolution of cardiac imaging for the assessment of LV dyssynchrony and its role in the selection of patients undergoing CRT; (2) highlight the main pitfalls and advantages of the application of cardiac imaging for the assessment of LV dyssynchrony; (3) provide some perspectives for clinical application and future research in this field.Conclusionthe road for a more individualized approach to resynchronization therapy delivery is open and imaging might provide important input beyond the assessment of LVEF

A chemical survey of exoplanets with ARIEL

Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio

The 2016 Feb 19 outburst of comet 67P/CG: an ESA Rosetta multi-instrument study

On 2016 Feb 19, nine Rosetta instruments serendipitously observed an outburst of gas and dust from the nucleus of comet 67P/Churyumov-Gerasimenko. Among these instruments were cameras and spectrometers ranging from UV over visible to microwave wavelengths, in situ gas, dust and plasma instruments, and one dust collector. At 09:40 a dust cloud developed at the edge of an image in the shadowed region of the nucleus. Over the next two hours the instruments recorded a signature of the outburst that significantly exceeded the background. The enhancement ranged from 50 per cent of the neutral gas density at Rosetta to factors >100 of the brightness of the coma near the nucleus. Dust related phenomena (dust counts or brightness due to illuminated dust) showed the strongest enhancements (factors >10). However, even the electron density at Rosetta increased by a factor 3 and consequently the spacecraft potential changed from ∼−16 V to −20 V during the outburst. A clear sequence of events was observed at the distance of Rosetta (34 km from the nucleus): within 15 min the Star Tracker camera detected fast particles (∼25 m s−1) while 100 μm radius particles were detected by the GIADA dust instrument ∼1 h later at a speed of 6 m s−1. The slowest were individual mm to cm sized grains observed by the OSIRIS cameras. Although the outburst originated just outside the FOV of the instruments, the source region and the magnitude of the outburst could be determined

The Comet Interceptor Mission

Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA’s F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum ΔV capability of 600 ms−1. Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes – B1, provided by the Japanese space agency, JAXA, and B2 – that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission’s science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule

Optimal Lead Placement Strategy for Cardiac Resynchronization Therapy in Non-Left Bundle Branch Block Patients: Still Looking for a Better Understanding!

International audienc

Que font les écoles accueillant des élèves défavorisés des moyens supplémentaires qui leur sont alloués?

Faire en sorte que la réussite scolaire dépende le moins possible de l’origine socioéconomique des élèves, et donc éviter que l’école ne reproduise ou ne renforce les inégalités sociales, est une préoccupation importante de la plupart des systèmes scolaires modernes. Dans cette étude, nous interrogerons la mise en œuvre du décret encadrement différencié en Belgique francophone. Plus particulièrement, nous essayerons de comprendre l’usage que font, sur une période de quatre ans, cinq établissements secondaires des moyens supplémentaires qui leur sont alloués sur la base du public qu’ils accueillent. Nous tentons d’appréhender – à partir d’enquêtes par questionnaire – l’évolution du climat scolaire perçu par leurs élèves, ainsi que la motivation à apprendre de ces derniers. À partir d’observations qualitatives réalisées dans chacun des établissements, nous tenterons également d’identifier les conditions les plus favorables au changement des pratiques pédagogiques qui, au final, pourraient avoir un impact positif sur la scolarité et la réussite des élèves. Ces monographies d’établissement sont l’occasion d’analyser dans quelle mesure et à quelles conditions des politiques d’éducation prioritaire allouant davantage de moyens à certaines écoles, en leur laissant l’autonomie de décision et de planification de l’usage de ces moyens, affectent l’expérience et la réussite scolaire des élèves. Les évolutions constatées auprès des élèves sont très modestes et les résultats soulignent la grande difficulté à (re)mettre le pédagogique, et donc les apprentissages des élèves, au cœur de la dynamique collective d’établissement. Ces observations interrogent certains postulats et certaines modalités de la politique d’encadrement différencié elle-même

Que font les écoles accueillant des élèves défavorisés des moyens supplémentaires qui leur sont alloués ? Une étude longitudinale de cinq établissements scolaires en encadrement différencié.

Faire en sorte que la réussite scolaire dépende le moins possible de l’origine socio-économique des élèves, et donc éviter que l’école ne reproduise ou ne renforce les inégalités sociales, est une préoccupation importante de la plupart des systèmes scolaires modernes. Dans cette étude, nous interrogerons la mise en œuvre du décret encadrement différencié en Belgique francophone. Plus particulièrement, nous essayerons de comprendre l’usage que font, sur une période de quatre ans, cinq établissements secondaires des moyens supplémentaires qui leur sont alloués sur la base du public qu’ils accueillent. Nous tentons d’appréhender – à partir d’enquêtes par questionnaire – l’évolution du climat scolaire perçu par leurs élèves, ainsi que la motivation à apprendre de ces derniers. À partir d’observations qualitatives réalisées dans chacun des établissements, nous tenterons également d’identifier les conditions les plus favorables au changement des pratiques pédagogiques qui, au final, pourraient avoir un impact positif sur la scolarité et la réussite des élèves. Ces monographies d’établissement sont l’occasion d’analyser dans quelle mesure et à quelles conditions des politiques d’éducation prioritaire allouant davantage de moyens à certaines écoles, en leur laissant l’autonomie de décision et de planification de l’usage de ces moyens, affectent l’expérience et la réussite scolaire des élèves. Les évolutions constatées auprès des élèves sont très modestes et les résultats soulignent la grande difficulté à (re)mettre le pédagogique, et donc les apprentissages des élèves, au cœur de la dynamique collective d’établissement. Ces observations interrogent certains postulats et certaines modalités de la politique d’encadrement différencié elle-même