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

Prognostic value of preoperative border-zone (Watershed) infarcts on the early postoperative outcomes of carotid endarterectomy after acute ischemic stroke

Objectives: To evaluate the prognostic value of cerebral border-zone infarctions (watershed infarctions) on the early postoperative outcomes of patients undergoing carotid endarterectomy (CEA) after acute ischemic stroke (AIS). Methods: Sixty-six (66) patients with symptomatic carotid stenosis (SCS) that underwent ipsilateral CEA after AIS from January 2007 to March 2012 were included in this study. They were divided into two groups according to the topographic patterns of the stroke: group 1, Territorial Cerebral Ischemic Strokes (TCIS) caused by emboli of carotid origin; group 2, cerebral border-zone infarctions (CBZI) related to an SCS associated with hemodynamic impairment. All data was collected in a prospective database and analyzed. Outcome measures included postoperative neurological morbidity and 30-day mortality. Results: Forty-three (43) patients (65.15%) experienced TCIS and were included in group 1, 23 patients (34.85%) had a CBZI and were included in group 2. There were no postoperative deaths. The postoperative neurologic morbidity rate was significantly higher in the CBZI group (22% vs. 2%, p = 0.02). Multivariate analysis demonstrates that CBZI was the only independent predictive factor of neurologic morbidity after CEA for AIS related to an SCS. Furthermore, the risk of postoperative neurologic morbidity remained significantly higher for patients with CBZI after adjustement for age, sex, initial NHISS scores, and associated contralateral carotid occlusion (HR: 0.059, 95% CI 0.004-0.85; p = 0.03). Conclusion: CBZIs, compared to TCIS, were associated with a higher neurological complication rate during the postoperative period after CEA for SCS in cases of AIS. Further studies are required to better define the timing and the best treatment modality for patients with CBZI related to an SCS in order to reduce associated procedural complications.\uc2\ua9 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved

Surgical management of isolated superficial femoral artery degenerative aneurysms

Objective To investigate the mode of presentation, diagnosis, association with other aneurysms, operative management, and outcomes of superficial femoral artery (SFA) aneurysms. Methods Records of all patients who underwent surgery for isolated, true SFA aneurysms (not due to infection, vasculitis, or tissue disorders) from 2002 to 2012 in two European centers were retrospectively analyzed. Demographic (sex, age), clinical (cardiovascular risk factors, location of the aneurysm, symptoms, presentation, emergency setting), surgical and radiological data (diameter, surgical technique, runoff vessels patency, presence of aneurysms elsewhere) were obtained for analysis. Follow-up was undertaken with clinical and ultrasound examinations at 1 month, 3 months, 6 months, 12 months, and yearly thereafter. The patency of the graft and the status of the anastomoses and inflow and outflow vessels were assessed. Main end points were represented by 30 days and long-term mortality and amputation-free survival. Results A total of 27 cases of SFA aneurysm were analyzed. Mean age at operation was 78 years \uc2\ub1 8.5. At presentation, SFA aneurysms were often symptomatic (rupture was present in 7/27 cases and acute distal ischemia in 6/27 cases), large (mean diameter, 54 mm \uc2\ub1 33.1 mm), bilateral (38% of the cases), and associated with aneurysms elsewhere (84%). Sixteen patients underwent resection of the aneurysm and polytetrafluoroethylene interposition graft, seven patients exclusion of the aneurysm with a femoropopliteal bypass (autogenous bypass in five cases, prosthetic in two), three patients simple ligation, and one patient underwent primary amputation. Mean follow-up was 41.47 months (range, 0.43-128.67 months). Early (<30 days) mortality and amputation rate were 4% and 7%, respectively. Estimated 5-year survival, limb salvage, and graft patency rates were 62%, 88%, and 85%, respectively. Conclusions Degenerative aneurysms of the SFA display peculiar characteristics (in terms of clinical onset, diagnostic timing, and clinical behavior) so that they differ from other peripheral aneurysms. In fact, they often grow to reach a considerable diameter before medical attention is sought, presenting with rupture or ischemia at diagnosis. SFA aneurysms preferentially affect elderly men and are often associated with aneurysms elsewhere. However, despite their rarity, the treatment is usually feasible, and long-term outcomes are good. Copyright \uc2\ua9 2014 by the Society for Vascular Surgery