28 research outputs found
The Supercam Instrument Suite on the Mars 2020 Rover: Science Objectives and Mast-Unit Description
On the NASA 2020 rover mission to Jezero crater, the remote determination of the texture, mineralogy and chemistry of rocks is essential to quickly and thoroughly characterize an area and to optimize the selection of samples for return to Earth. As part of the Perseverance payload, SuperCam is a suite of five techniques that provide critical and complementary observations via Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), visible and near-infrared spectroscopy (VISIR), high-resolution color imaging (RMI), and acoustic recording (MIC). SuperCam operates at remote distances, primarily 2–7 m, while providing data at sub-mm to mm scales. We report on SuperCam’s science objectives in the context of the Mars 2020 mission goals and ways the different techniques can address these questions. The instrument is made up of three separate subsystems: the Mast Unit is designed and built in France; the Body Unit is provided by the United States; the calibration target holder is contributed by Spain, and the targets themselves by the entire science team. This publication focuses on the design, development, and tests of the Mast Unit; companion papers describe the other units. The goal of this work is to provide an understanding of the technical choices made, the constraints that were imposed, and ultimately the validated performance of the flight model as it leaves Earth, and it will serve as the foundation for Mars operations and future processing of the data
The SuperCam Instrument Suite on the Mars 2020 Rover: Science Objectives and Mast-Unit Description
On the NASA 2020 rover mission to Jezero crater, the remote determination of the texture, mineralogy and chemistry of rocks is essential to quickly and thoroughly characterize an area and to optimize the selection of samples for return to Earth. As part of the Perseverance payload, SuperCam is a suite of five techniques that provide critical and complementary observations via Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), visible and near-infrared spectroscopy (VISIR), high-resolution color imaging (RMI), and acoustic recording (MIC). SuperCam operates at remote distances, primarily 2-7 m, while providing data at sub-mm to mm scales. We report on SuperCam's science objectives in the context of the Mars 2020 mission goals and ways the different techniques can address these questions. The instrument is made up of three separate subsystems: the Mast Unit is designed and built in France; the Body Unit is provided by the United States; the calibration target holder is contributed by Spain, and the targets themselves by the entire science team. This publication focuses on the design, development, and tests of the Mast Unit; companion papers describe the other units. The goal of this work is to provide an understanding of the technical choices made, the constraints that were imposed, and ultimately the validated performance of the flight model as it leaves Earth, and it will serve as the foundation for Mars operations and future processing of the data.In France was provided by the Centre National d'Etudes Spatiales (CNES). Human resources were provided in part by the Centre National de la Recherche Scientifique (CNRS) and universities. Funding was provided in the US by NASA's Mars Exploration Program. Some funding of data analyses at Los Alamos National Laboratory (LANL) was provided by laboratory-directed research and development funds
Etude de l'évolution des propriétés de transport des membranes d'électrodialyse lors de leur encrassement par des polyphénols de moûts de raisins
Lors de toute électrodialyse de solutions de substances naturelles les performances des membranes semi-perméables aux ions varient par suite de l'encrassement.L'évolution au cours du temps des propriétés de transport des membranes d'un électrodialyseur a été étudiée avec quatre méthodes dans le cas où les modifications sont provoquées en déminéralisant des moûts très colorés de raisin.Les trois premières méthodes ne nécessitent pas de démonter le module d'électrodialyse et concernent le couple de membranes semi-perméables aux anions et aux cations.
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Outcome of patients admitted with oxygen mismatch and myocardial injury or infarction in emergency departments
International audienceAIMS: To describe the outcomes and associated factors in a population of patients admitted to emergency departments with at least one condition of oxygen supply/demand imbalance, regardless of the troponin result or restrictive criteria for type 2 myocardial infarction. METHODS: We constituted a retrospective cohort of 824 patients. Medical records of patients having undergone a troponin assay were reviewed for selection and classification, and data including in-hospital stay and readmissions were collected. The reported outcomes are in-hospital mortality, 3-year mortality, and major adverse cardiovascular events. RESULTS: Patients with myocardial infarction or injury, either chronic or acute, were older, with more history of hypertension and chronic heart or renal failure but not for other cardiovascular risk factors and medical history. Acute myocardial injury and type 2 myocardial infarction were significantly associated with in-hospital mortality [odds ratio (OR) 3.71 95% confidence interval (CI) 1.90-7.33 and OR 3.15 95% CI 1.59-6.28, respectively]. However, the long-term mortality does not differ in comparison with patients presenting chronic myocardial injury or nonelevated troponin, ranging from 26.9 to 34.3%. Patients with chronic myocardial injury and type 2 myocardial infarction had more long-term major cardiovascular events (39.3 and 38.8%), but only for acute heart failure, and none was associated with this outcome after adjustment. CONCLUSION: Among patients admitted to emergency departments with an oxygen supply/demand imbalance, acute myocardial injury and type 2 myocardial infarction are strongly associated with in-hospital mortality. However, they are not associated with higher long-term mortality or major cardiovascular events after discharge, which tend to occur in elderly people with comorbidities
Correlation Between Microstructure and Ageing of Iron Manganite Thermistors
Negative Temperature Coefficient (NTC) thermistors made of spinel structure transition metal manganites usually display ageing phenomena under thermal stress. Their resistance drift depends on their composition, crystal structure (cubic or tetragonal) and heat treatments. We have previously shown in iron manganite thermistors, MnFeO (with ), that the ageing is due to the migration of Fe and Mn ions between tetrahedral and octahedral sites of the spinel structure. Iron manganites were investigated by Transmission Electron Microscopy (TEM) in order to relate microstructure to electrical stability. For iron manganites with iron content , two dimensional defects result in a domain microstructure (microtwins). As increases and exceeds 0.78, the domain structure gradually vanishes and transforms into a tweed microstructure () and, for , no bidimensional defects are observed. Thus it is suggested that the microstructural disturbance plays an important role in the kinetics of the ion migration during the ageing of the studied ceramics.
Les thermistances à Coefficient de Température Négatif (CTN) élaborées à partir de manganites de métaux de transition à structure spinelle présentent, sous contrainte thermique, le phénomène de vieillissement. La dérive de leur résistance dépend de la composition chimique, de la structure cristallographique (cubique ou quadratique) et des traitements thermiques. Précédemment, nous avons montré, pour les thermistances à base de manganites de fer de composition MnFeO (avec ), que le vieillissement est dû à une migration des ions Fe et Mn entre les sites tétraédriques et octaédriques de la structure spinelle. Une étude des manganites de fer a été réalisée par Microscopie Électronique à Transmission (MET) afin de relier la microstructure à la stabilité électrique. Pour les manganites de fer ayant une teneur en fer , la microstructure en forme de domaines (micromaclages) résulte de la présence de deux types de défauts bidimensionnels. Pour des teneurs supérieures, jusqu'à 0,78, cette microstructure disparaît graduellement et se transforme en une microstructure tweed
() et, pour , aucun défaut bidimensionnel n'est observé. Ces observations nous ont conduits à suggérer que ces différences dans la microstructure influencent grandement la cinétique de migration des ions durant le vieillissement des céramiques étudiées
Sucralose and acesulfame K modulate human and rodent vascular smooth muscle contractility independently of the presence of the sweet taste receptor. A study of the SOSweet project
International audienc
Sucralose and acesulfame K modulate human and rodent vascular smooth muscle contractility independently of the presence of the sweet taste receptor. A study of the SOSweet project
International audienc
Expanded phenotypic spectrum of neurodevelopmental and neurodegenerative disorder Bryant-Li-Bhoj syndrome with 38 additional individuals.
Bryant-Li-Bhoj syndrome (BLBS), which became OMIM-classified in 2022 (OMIM: 619720, 619721), is caused by germline variants in the two genes that encode histone H3.3 (H3-3A/H3F3A and H3-3B/H3F3B) [1-4]. This syndrome is characterized by developmental delay/intellectual disability, craniofacial anomalies, hyper/hypotonia, and abnormal neuroimaging [1, 5]. BLBS was initially categorized as a progressive neurodegenerative syndrome caused by de novo heterozygous variants in either H3-3A or H3-3B [1-4]. Here, we analyze the data of the 58 previously published individuals along 38 unpublished, unrelated individuals. In this larger cohort of 96 people, we identify causative missense, synonymous, and stop-loss variants. We also expand upon the phenotypic characterization by elaborating on the neurodevelopmental component of BLBS. Notably, phenotypic heterogeneity was present even amongst individuals harboring the same variant. To explore the complex phenotypic variation in this expanded cohort, the relationships between syndromic phenotypes with three variables of interest were interrogated: sex, gene containing the causative variant, and variant location in the H3.3 protein. While specific genotype-phenotype correlations have not been conclusively delineated, the results presented here suggest that the location of the variants within the H3.3 protein and the affected gene (H3-3A or H3-3B) contribute more to the severity of distinct phenotypes than sex. Since these variables do not account for all BLBS phenotypic variability, these findings suggest that additional factors may play a role in modifying the phenotypes of affected individuals. Histones are poised at the interface of genetics and epigenetics, highlighting the potential role for gene-environment interactions and the importance of future research