La qualité des interactions enseignante-enfants au regard de l’éveil scientifique à l’éducation préscolaire

L’objectif de cet article vise à examiner si l’environnement éducatif scientifique influence la qualité des interactions entre les enseignantes et les enfants. Pour ce faire, 26 enseignantes à l’éducation préscolaire ont été observées dans deux environnements éducatifs différents : (1) alors que la classe est engagée dans une activité scientifique et (2) dans un contexte éducatif autre. Les observations ont porté plus spécifiquement sur la qualité des interactions, évaluées à l’aide du Classroom Assessment Scoring System (CLASS Pre-k), selon trois domaines : le soutien émotionnel, l’organisation de la classe et le soutien à l’apprentissage. Les données indiquent que le niveau de qualité du soutien à l’apprentissage est plus élevé lorsque l’environnement éducatif est dit scientifique. Les résultats sont discutés selon les résultats de recherches antérieures

Characterization of 3D PET systems for accurate quantification of myocardial blood flow

Three-dimensional (3D) mode imaging is the current standard for positron emission tomography-computed tomography (PET-CT) systems. Dynamic imaging for quantification of myocardial blood flow (MBF) with short-lived tracers, such as Rb-82- chloride (Rb-82), requires accuracy to be maintained over a wide range of isotope activities and scanner count-rates. We propose new performance standard measurements to characterize the dynamic range of PET systems for accurate quantitative imaging. Methods: 1100-3000 MBq of Rb-82 or N-13-ammonia was injected into the heart wall insert of an anthropomorphic torso phantom. A decaying isotope scan was performed over 5 half-lives on 9 different 3D PET-CT systems and 1 3D/twodimensional (2D) PET-only system. Dynamic images (28x15s) were reconstructed using iterative algorithms with all corrections enabled. Dynamic range was defined as the maximum activity in the myocardial wall with <10% bias, from which corresponding dead-time, count-rates and/or injected activity limits were established for each scanner. Scatter correction residual bias was estimated as the maximum cavity blood-tomyocardium activity ratio. Image quality was assessed via the coefficient of variation measuring non-uniformity of the left ventricle (LV) myocardium activity distribution. Results: Maximum recommended injected activity/body-weight, peak dead-time correction factor, count-rates and residual scatter bias for accurate cardiac MBF imaging were: 3-14 MBq/kg, 1.5-4.0, 22-64 Mcps singles and 4-14 Mcps prompt coincidence count-rates, and 2-10% on the investigated scanners. Non-uniformity of the myocardial activity distribution varied from 3-16%. Conclusion: Accurate dynamic imaging is possible on the 10 3D-PET systems if the maximum injected MBq/kg values are respected to limit peak dead-time losses during the bolus first-pass transit

Upregulated IL-32 expression and reduced gut short chain fatty acid caproic acid in people living with HIV with subclinical atherosclerosis

Despite the success of antiretroviral therapy (ART), people living with HIV (PLWH) are still at higher risk for cardiovascular diseases (CVDs) that are mediated by chronic inflammation. Identification of novel inflammatory mediators with the inherent potential to be used as CVD biomarkers and also as therapeutic targets is critically needed for better risk stratification and disease management in PLWH. Here, we investigated the expression and potential role of the multi-isoform proinflammatory cytokine IL-32 in subclinical atherosclerosis in PLWH (n=49 with subclinical atherosclerosis and n=30 without) and HIV- controls (n=25 with subclinical atherosclerosis and n=24 without). While expression of all tested IL-32 isoforms (α, β, γ, D, ϵ, and θ) was significantly higher in peripheral blood from PLWH compared to HIV- controls, IL-32D and IL-32θ isoforms were further upregulated in HIV+ individuals with coronary artery atherosclerosis compared to their counterparts without. Upregulation of these two isoforms was associated with increased plasma levels of IL-18 and IL-1β and downregulation of the atheroprotective protein TRAIL, which together composed a unique atherosclerotic inflammatory signature specific for PLWH compared to HIV- controls. Logistic regression analysis demonstrated that modulation of these inflammatory variables was independent of age, smoking, and statin treatment. Furthermore, our in vitro functional data linked IL-32 to macrophage activation and production of IL-18 and downregulation of TRAIL, a mechanism previously shown to be associated with impaired cholesterol metabolism and atherosclerosis. Finally, increased expression of IL-32 isoforms in PLWH with subclinical atherosclerosis was associated with altered gut microbiome (increased pathogenic bacteria; Rothia and Eggerthella species) and lower abundance of the gut metabolite short-chain fatty acid (SCFA) caproic acid, measured in fecal samples from the study participants. Importantly, caproic acid diminished the production of IL-32, IL-18, and IL-1β in human PBMCs in response to bacterial LPS stimulation. In conclusion, our studies identified an HIV-specific atherosclerotic inflammatory signature including specific IL-32 isoforms, which is regulated by the SCFA caproic acid and that may lead to new potential therapies to prevent CVD in ART-treated PLWH

Demonstration of a Hybrid Space Architecture During RIMPAC 2020

The Micro-Satellite Military Utility (MSMU) Project Arrangement (PA) is an agreement under the Responsive Space Capabilities (RSC) Memorandum of Understanding (MOU) that involves the Departments and Ministries of Defence of Australia, Canada, Germany, Italy, the Netherlands, New Zealand, Norway, United Kingdom and United States. MSMU’s charter is to inform a space enterprise that provides military users with reliable access to a broad spectrum of information in an opportunistic environment. Research and Development teams from MSMU partner nations supported Exercise Rim of the Pacific (RIMPAC) 2020 which took place 17 to 31 August 2020 in the Hawaiian region. RIMPAC 2020 provided an opportunity to explore the military utility of a Hybrid Space Architecture (HSA) of satellites including traditional government and commercial satellites, as well as micro-satellites and nanosatellites, by leveraging contributions across the MSMU partner nations. The objective was to continue testing the hypothesis that an HSA, mostly composed of small satellites, can bring significant value to the operational theatre. The MSMU PA partner nations have leveraged several multi-national exercises, with the first being the Exercise RIMPAC 2018. Previous exercises enabled multinational technology advancements, interoperability testing, process refinement, and capability developments to make advancements towards MSMU’s goal to address the warfighter’s need for diverse ISR capabilities. The most recent accomplishment was a major integration effort across mission planning tools, space-based Intelligence, Surveillance and Reconnaissance (ISR) data providers, and exploitation tools. The MSMU team accessed ~256 space-based sensors (EO – Electro Optical, SAR – Synthetic Aperture Radar, AIS – Automatic Identification System) to collect maritime domain and ISR data over a harbor, airfields and open sea. Data was exploited via international channels in order to determine the success rate of capturing pertinent data to be later exploited and disseminated. This paper describes results from the experiment and offers insights into the HSA military utility

In-situ estimation of ice crystal properties at the South Pole using LED calibration data from the IceCube Neutrino Observatory

The IceCube Neutrino Observatory instruments about 1 km3 of deep, glacial ice at the geographic South Pole using 5160 photomultipliers to detect Cherenkov light emitted by charged relativistic particles. A unexpected light propagation effect observed by the experiment is an anisotropic attenuation, which is aligned with the local flow direction of the ice. Birefringent light propagation has been examined as a possible explanation for this effect. The predictions of a first-principles birefringence model developed for this purpose, in particular curved light trajectories resulting from asymmetric diffusion, provide a qualitatively good match to the main features of the data. This in turn allows us to deduce ice crystal properties. Since the wavelength of the detected light is short compared to the crystal size, these crystal properties do not only include the crystal orientation fabric, but also the average crystal size and shape, as a function of depth. By adding small empirical corrections to this first-principles model, a quantitatively accurate description of the optical properties of the IceCube glacial ice is obtained. In this paper, we present the experimental signature of ice optical anisotropy observed in IceCube LED calibration data, the theory and parametrization of the birefringence effect, the fitting procedures of these parameterizations to experimental data as well as the inferred crystal properties.</p

Galactic Core-Collapse Supernovae at IceCube: “Fire Drill” Data Challenges and follow-up

The next Galactic core-collapse supernova (CCSN) presents a once-in-a-lifetime opportunity to make astrophysical measurements using neutrinos, gravitational waves, and electromagnetic radiation. CCSNe local to the Milky Way are extremely rare, so it is paramount that detectors are prepared to observe the signal when it arrives. The IceCube Neutrino Observatory, a gigaton water Cherenkov detector below the South Pole, is sensitive to the burst of neutrinos released by a Galactic CCSN at a level >10σ. This burst of neutrinos precedes optical emission by hours to days, enabling neutrinos to serve as an early warning for follow-up observation. IceCube\u27s detection capabilities make it a cornerstone of the global network of neutrino detectors monitoring for Galactic CCSNe, the SuperNova Early Warning System (SNEWS 2.0). In this contribution, we describe IceCube\u27s sensitivity to Galactic CCSNe and strategies for operational readiness, including "fire drill" data challenges. We also discuss coordination with SNEWS 2.0

All-Energy Search for Solar Atmospheric Neutrinos with IceCube

The interaction of cosmic rays with the solar atmosphere generates a secondary flux of mesons that decay into photons and neutrinos – the so-called solar atmospheric flux. Although the gamma-ray component of this flux has been observed in Fermi-LAT and HAWC Observatory data, the neutrino component remains undetected. The energy distribution of those neutrinos follows a soft spectrum that extends from the GeV to the multi-TeV range, making large Cherenkov neutrino telescopes a suitable for probing this flux. In this contribution, we will discuss current progress of a search for the solar neutrino flux by the IceCube Neutrino Observatory using all available data since 2011. Compared to the previous analysis which considered only high-energy muon neutrino tracks, we will additionally consider events produced by all flavors of neutrinos down to GeV-scale energies. These new events should improve our analysis sensitivity since the flux falls quickly with energy. Determining the magnitude of the neutrino flux is essential, since it is an irreducible background to indirect solar dark matter searches