A SMART decade: outcomes of an integrated, inclusive, first-year college-level STEM curricular innovation

In the early 2000s, our primarily undergraduate, white institution (PUI/PWI), began recruiting and enrolling higher numbers of students of color and first-generation college students. However, like many of our peer institutions, our established pedagogies and mindsets did not provide these students an educational experience to enable them to persist and thrive in STEM. Realizing the need to systematically address our lack of inclusivity in science majors, in 2012 faculty from multiple disciplines developed the Science, Math, and Research Training (SMART) program. Here, we describe an educational innovation, originally funded by a grant from the Howard Hughes Medical Institute, designed to support and retain students of color, first generation college students, and other students with marginalized identities in the sciences through a cohort-based, integrated, and inclusive first-year experience focused on community and sense of belonging. The SMART program engages first-year students with semester-long themed courses around “real world” problems of antibiotic resistance and viral infections while integrating the fields of Biology, Chemistry, Mathematics, and an optional Computer Science component. In the decade since its inception, 97% of SMART students have graduated or are on track to graduate, with 80.9% of these students earning a major in a STEM discipline. Here, we present additional student outcomes since the initiation of this program, results of the student self-evaluative surveys SALG and CURE, and lessons we have learned from a decade of this educational experience

Mangafodipir Protects against Hepatic Ischemia-Reperfusion Injury in Mice

Mangafodipir is a contrast agent used in magnetic resonance imaging that concentrates in the liver and displays pleiotropic antioxidant properties. Since reactive oxygen species are involved in ischemia-reperfusion damages, we hypothesized that the use of mangafodipir could prevent liver lesions in a mouse model of hepatic ischemia reperfusion injury. Mangafodipir (MnDPDP) was compared to ischemic preconditioning and intermittent inflow occlusion for the prevention of hepatic ischemia-reperfusion injury in the mouse.Mice were subjected to 70% hepatic ischemia (continuous ischemia) for 90 min. Thirty minutes before the ischemic period, either mangafodipir (10 mg/kg) or saline was injected intraperitoneally. Those experimental groups were compared with one group of mice preconditioned by 10 minutes' ischemia followed by 15 minutes' reperfusion, and one group with intermittent inflow occlusion. Hepatic ischemia-reperfusion injury was evaluated by measurement of serum levels of aspartate aminotransferase (ASAT) activity, histologic analysis of the livers, and determination of hepatocyte apoptosis (cytochrome c release, caspase 3 activity). The effect of mangafodipir on the survival rate of mice was studied in a model of total hepatic ischemia.<0.01), and by higher rates of survival in treated than in untreated animals (P<0.001). The level of protection by mangafodipir was similar to that observed following intermittent inflow occlusion and higher than after ischemic preconditioning.Mangafodipir is a potential new preventive treatment for hepatic ischemia-reperfusion injury

A broadband thermal emission spectrum of the ultra-hot Jupiter WASP-18b

Close-in giant exoplanets with temperatures greater than 2,000 K (''ultra-hot Jupiters'') have been the subject of extensive efforts to determine their atmospheric properties using thermal emission measurements from the Hubble and Spitzer Space Telescopes. However, previous studies have yielded inconsistent results because the small sizes of the spectral features and the limited information content of the data resulted in high sensitivity to the varying assumptions made in the treatment of instrument systematics and the atmospheric retrieval analysis. Here we present a dayside thermal emission spectrum of the ultra-hot Jupiter WASP-18b obtained with the NIRISS instrument on JWST. The data span 0.85 to 2.85 $\mu$m in wavelength at an average resolving power of 400 and exhibit minimal systematics. The spectrum shows three water emission features (at $>$6$\sigma$ confidence) and evidence for optical opacity, possibly due to H$^-$, TiO, and VO (combined significance of 3.8$\sigma$). Models that fit the data require a thermal inversion, molecular dissociation as predicted by chemical equilibrium, a solar heavy element abundance (''metallicity'', M/H = 1.03$_{-0.51}^{+1.11}$ $\times$ solar), and a carbon-to-oxygen (C/O) ratio less than unity. The data also yield a dayside brightness temperature map, which shows a peak in temperature near the sub-stellar point that decreases steeply and symmetrically with longitude toward the terminators.Comment: JWST ERS bright star observations. Uploaded to inform JWST Cycle 2 proposals. Manuscript under review. 50 pages, 14 figures, 2 table

Early Release Science of the Exoplanet WASP-39b with JWST NIRSpec G395H

Measuring the abundances of carbon and oxygen in exoplanet atmospheres is considered a crucial avenue for unlocking the formation and evolution of exoplanetary systems. Access to an exoplanet's chemical inventory requires high-precision observations, often inferred from individual molecular detections with low-resolution space-based and high-resolution ground-based facilities. Here we report the medium-resolution (R$\sim$600) transmission spectrum of an exoplanet atmosphere between 3-5 $\mu$m covering multiple absorption features for the Saturn-mass exoplanet WASP-39b, obtained with JWST NIRSpec G395H. Our observations achieve 1.46x photon precision, providing an average transit depth uncertainty of 221 ppm per spectroscopic bin, and present minimal impacts from systematic effects. We detect significant absorption from CO$_2$ (28.5$\sigma$) and H$_2$O (21.5$\sigma$), and identify SO$_2$ as the source of absorption at 4.1 $\mu$m (4.8$\sigma$). Best-fit atmospheric models range between 3 and 10x solar metallicity, with sub-solar to solar C/O ratios. These results, including the detection of SO$_2$, underscore the importance of characterising the chemistry in exoplanet atmospheres, and showcase NIRSpec G395H as an excellent mode for time series observations over this critical wavelength range.Comment: 44 pages, 11 figures, 3 tables. Resubmitted after revision to Natur

Early Release Science of the exoplanet WASP-39b with JWST NIRCam

Measuring the metallicity and carbon-to-oxygen (C/O) ratio in exoplanet atmospheres is a fundamental step towards constraining the dominant chemical processes at work and, if in equilibrium, revealing planet formation histories. Transmission spectroscopy provides the necessary means by constraining the abundances of oxygen- and carbon-bearing species; however, this requires broad wavelength coverage, moderate spectral resolution, and high precision that, together, are not achievable with previous observatories. Now that JWST has commenced science operations, we are able to observe exoplanets at previously uncharted wavelengths and spectral resolutions. Here we report time-series observations of the transiting exoplanet WASP-39b using JWST's Near InfraRed Camera (NIRCam). The long-wavelength spectroscopic and short-wavelength photometric light curves span 2.0 - 4.0 $\mu$m, exhibit minimal systematics, and reveal well-defined molecular absorption features in the planet's spectrum. Specifically, we detect gaseous H$_2$O in the atmosphere and place an upper limit on the abundance of CH$_4$. The otherwise prominent CO$_2$ feature at 2.8 $\mu$m is largely masked by H$_2$O. The best-fit chemical equilibrium models favour an atmospheric metallicity of 1-100$\times$ solar (i.e., an enrichment of elements heavier than helium relative to the Sun) and a sub-stellar carbon-to-oxygen (C/O) ratio. The inferred high metallicity and low C/O ratio may indicate significant accretion of solid materials during planet formation or disequilibrium processes in the upper atmosphere.Comment: 35 pages, 13 figures, 3 tables, Nature, accepte

Identification of carbon dioxide in an exoplanet atmosphere

Carbon dioxide (CO2) is a key chemical species that is found in a wide range of planetary atmospheres. In the context of exoplanets, CO2 is an indicator of the metal enrichment (that is, elements heavier than helium, also called ‘metallicity’), and thus the formation processes of the primary atmospheres of hot gas giants. It is also one of the most promising species to detect in the secondary atmospheres of terrestrial exoplanets. Previous photometric measurements of transiting planets with the Spitzer Space Telescope have given hints of the presence of CO2, but have not yielded definitive detections owing to the lack of unambiguous spectroscopic identification. Here we present the detection of CO2 in the atmosphere of the gas giant exoplanet WASP-39b from transmission spectroscopy observations obtained with JWST as part of the Early Release Science programme. The data used in this study span 3.0–5.5 micrometres in wavelength and show a prominent CO2 absorption feature at 4.3 micrometres (26-sigma significance). The overall spectrum is well matched by one-dimensional, ten-times solar metallicity models that assume radiative–convective–thermochemical equilibrium and have moderate cloud opacity. These models predict that the atmosphere should have water, carbon monoxide and hydrogen sulfide in addition to CO2, but little methane. Furthermore, we also tentatively detect a small absorption feature near 4.0 micrometres that is not reproduced by these models

Localisation spatiotemporelle appliquée à la microscopie de localisation ultrasonore

RÉSUMÉ: L’âge est le facteur de risque principal des maladies cardiovasculaires. En effet, avec l’âge, les vaisseaux sanguins perdent de leur élasticité, ce qui entraîne une pulsatilité élevée en aval des artérioles et mène selon des études à la génération de microlésions dans les capillaires. Cependant, actuellement, aucune technique d’imagerie clinique n’est capable d’imager la microcirculation dans tout le cerveau. La microscopie de localisation ultrasonore (ULM) pourrait relever ce défi. En effet, cette technique repose classiquement sur la localisation puis le suivi de centaines de milliers de microbulles injectées dans le système vasculaire, grâce à des acquisitions ultrasonores de plusieurs minutes. L’intérêt de cette technique est qu’elle offre la possibilité de dépasser la limite de résolution spatiale due à la diffraction, en localisant des microbulles parcimonieuses. Cette technique permet ainsi d’imager les capillaires en profondeur. Notre équipe a introduit l’ULM Dynamique, se révélant être capable de mesurer la vitesse du sang au cours du rythme cardiaque et par conséquent la pulsatilité. Cependant, pour pouvoir être utilisé en clinique, les temps d’acquisitions doivent être réduits. L’augmentation de la concentration des microbulles est donc un levier identifié pour réduire ce temps. Toutefois, les algorithmes classiques peinent lorsqu’on augmente la concentration, ce qui introduit des erreurs dans les estimations de vitesses dérivées du suivi des microbulles. Ce mémoire introduit une nouvelle méthode qui renverse l’ordre des étapes conventionnelles en effectuant d’abord le suivi des microbulles puis dans un second temps la localisation. Ce renversement est motivé par l’hypothèse que considérer l’acquisition dans son entièreté apporte plus d’informations que la considérer image après image. Nous avons démontré que la méthode proposée fournissait de meilleurs résultats pour la reconstruction de l’anatomie vasculaire ou l’estimation des vitesses, que ce soit en simulation ou in vivo. La méthode que nous proposons ouvre la voie à de nouvelles techniques de localisation et de suivi des microbulles. Dans le but d’atteindre une meilleure compréhension des dérèglements des flux à l’intérieur des capillaires, qui touchent les personnes atteintes par des maladies cardiovasculaires, liées au vieillissement notamment. ABSTRACT: Cardiovascular diseases present a significant health concern, with age being the primary risk factor. When people get older, their blood vessels gradually lose elasticity, resulting in in-creased pulsatility downstream in the microvascular system. This phenomenon, as evidenced by research, leads to the formation of microlesions in the capillaries. Unfortunately, there is no current clinical imaging technique that can image the hemodynamic in the brain. The Ultrasound Localization Microscopy (ULM) presents the potential to address this chal-lenge. Indeed, ULM bypasses the limit of spatial resolution caused by diffraction via the localization and the tracking of sparse microbubbles populations across ultrasound images. Our research team has introduced Dynamic ULM, a novel approach capable of measuring the pulsatility. Nevertheless, to apply this technique in clinical, it is essential to reduce acquisition times. An identified strategy to achieve this is by increasing microbubble concentration. However, conventional algorithms break down with higher concentrations, leading to errors in the vascular maps and in the velocity estimations derived from microbubble tracking. To address this limitation, we propose a new paradigm that reverses the conventional steps, by doing tracking in the first place and then the localization. This method is based on the hypothesis that considering the acquisition as a whole yields richer information compared to frame-by-frame analysis. Our findings demonstrate that the proposed method obtains better results in reconstructing vascular anatomy and estimating velocities, both in simulation and in vivo. This advancement paves the way for improved microcirculation imaging and better understanding of hemodynamic in aging-related cardiovascular diseases

Cycle more with virtual reality: a proof of concept study in an institutionalised able-bodied geriatric population

International audienceBackground/Objectives: Physical activity (PA) has significant benefits for older adults. However, the recommended PA is rarely achieved in nursing homes. In this proof of concept study, we assessed whether virtual reality (VR) could help to increase spontaneous PA during a stationary cycling session. Design: Prospective crossover proof of concept study. Setting: Nursing home. Participants: Twelve participants (10 men) aged 63-88, able-bodied but with moderate cognitive impairment. Intervention: TWO stationary cycling sessions with and without VR. Measurements: Cycling distance, pedalling duration, average speed, mean pedalling cadence and the modified Borg rating of perceived exertion scale. Results: Cycling distance and duration were significantly higher in the VR condition. Most participants would rather repeat cycling sessions with VR than without. Conclusion: The use of VR seems feasible to help achieve PA recommendations for able-bodied people living in nursing homes, even with moderate cognitive impairments